Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1995-1999  (3,901)
  • 1985-1989  (4,065)
  • Chemical Engineering  (5,177)
  • Theoretical, Physical and Computational Chemistry  (1,576)
  • Genetics  (1,213)
Source
Material
Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Mitochondrial DNA mutation at np 3243 in a family with maternally inherited diabetes mellitus (1999)
    Springer
    Acta diabetologica 36 (1999), S. 163-167 
    Details
    ISSN: 1432-5233
    Keywords: Key words Mitochondrial DNA ; Genetics ; Maternally inherited diabetes mellitus ; Deafness ; np 3243 mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Mitochondrial DNA (mtDNA) gene defects may play a role in the development of maternally inherited diabetes mellitus and deafness (MIDD). A family from Southern Italy who showed maternal transmission of type 2 diabetes mellitus with three individuals affected is described. A 10.4 kb deletion and mutations at nucleotide positions (np) 3243, 7445 and 11778 in the mtDNA of six relatives were sought. The mitochondrial np 3243 mutation of the tRNA Leu (UUR) gene was identified in a boy affected by optic atrophy and mental retardation, as well as in his diabetic mother. No other mutations or deletions were found. Our study points out the variable phenotypic expression of the np 3243 mtDNA mutation. This may suggest the presence of other mitochondrial or nuclear mutations required to modulate the phenotype. A clinical and metabolic follow-up of all family members was necessary to understand the role of the np 3243 mutation, especially in one child affected by optic atrophy and mental retardation. Further studies will be aimed at investigating the prevalence of mutations and deletions of mtDNA in type 2 diabetes mellitus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005920050161
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    AC/GT and AG/CT microsatellite repeats in peach [Prunus persica (L) Batsch]: isolation, characterisation and cross-species amplification in Prunus (1999)
    Springer
    Theoretical and applied genetics 99 (1999), S. 65-72 
    Details
    ISSN: 1432-2242
    Keywords: Key words Simple sequence repeat (SSR) ; Microsatellites ; Molecular markers ; Genetics ; Fingerprinting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We report the sequences of 17 primer pairs of microsatellite loci, which we have cloned and sequenced from two genomic libraries of peach [Prunus persica (L) Batsch] ‘Redhaven’, enriched for AC/GT and AG/CT repeats respectively. For ten of these microsatellite loci we were able to demonstrate Mendelian inheritance in a segregating back-cross population; the remainder did not segregate. The polymorphism of the microsatellites was evaluated in a panel of ten peach genotypes, including true-to-type peaches, nectarines and one canning-peach. Fifteen microsatellites (88%) were polymorphic showing 2–4 alleles each. The mean heterozygosity, averaged over all loci, was 0.32 and significantly higher than that reported in the literature for isozymes and molecular markers, such as RFLPs and RAPDs. We have also assayed the cross-species transportability and found that ten microsatellite (59%) gave apparently correct amplification in all Prunus species surveyed, namely P. domestica (European plum), P. salicina (Japanese plum), P. armeniaca (apricot), P. dulcis (almond), P. persica var. vulgaris (peach), P. persica var. laevis (nectarine), P. avium (sweet cherry) and P. cerasus (sour cherry), with three of them also being amplified in Malus (apple). The remaining microsatellites gave less-extensive amplification. Because of their appreciable polymorphism and wide cross-species transportability, most of these new markers can be integrated into the linkage maps which are currently being constructed in peach, as well as in other stone fruit crops, such as almond, apricot, cherry and plum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Pathologie der Rhabdo- myosarkome des Kindes- und Adoleszentenalters Ein Bericht des Kindertumorregisters bei der Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH) (1999)
    Springer
    Der Pathologe 20 (1999), S. 87-97 
    Details
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Rhadomyosarkom ; Klassifizierung ; Immunhistochemie ; Genetik ; Prognose ; Key words Rhabdomyosarcoma ; Classification ; Immunohistochemistry ; Genetics ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Rhabdomyosarcoma (RMS) is the most important and a very heterogeneous group of malignant soft tissue tumors of childhood and adolescence.The two major subtypes (embryonal and alveolar) share a common myogenic differentiation, but seem to be histogenetically not related. The so-called ’International Classification of Rhabdomyosarcoma’ includes, besides the two major subtypes, the botryoid and leiomyomatous subtypes of embryonal RMS which are associated with a better prognosis and are treated less aggressively according to current protocols. In addition, the solid variant of alveolar RMS is included in the alveolar group of RMS. The identification of the various subtypes is necessary and important because the treatment with the current protocols is also related to histology. Using conventional stains and immunohistochemistry, these subtypes are distinguishable. Genetic analysis can be helpful in the demonstration of t(2;13) or t(1;13) translocations in alveolar RMS. The identification of alveolar RMS with t(1;13) translocation might become important in the future, because this type of translocation seems to be related to a better prognosis as compared to tumors with a t(2;13) translocation.
    Notes: Zusammenfassung Rhabdomyosarkome stellen eine heterogene Gruppe von ganz verschiedenartigen, histogenetisch wohl nicht zusammengehörenden Tumoren dar. Nach der heute verwendeten „Internationalen Klassifikation” der Rhabdomyosarkome werden neben der Unterteilung in embryonalen und alveoläre Rhabdomyossarkome auch Subtypen des embryonalen RMS identifiziert (botryoider und leiomyomatöser Subtyp), die durch eine günstigere Prognose und durch die Notwendigkeit einer weniger aggressive Therapie gekennzeichnet sind. Durch Einsatz von verschiedenen histologischen und immunhistochemischen Färbungen ist die Identifizierung der verschiedenen Typen der RMS heute möglich und auch zwingend notwendig, da die einzelnen Entitäten nach ganz unterschiedlichen Therapieprotokollen behandelt werden. Der Nachweis typischer molekulargenetischer Veränderungen kann in der Unterscheidung insbesondere von embryonalen und alveolären RMS hilfreich sein. In der Regel ist die Abgrenzung zwischen diesen beiden Entitäten auch an konventionell gefärbten Schnittpräparaten möglich. Die Identifizierung von alveolären RMS mit einer t(1;13)-Translokation könnte in Zukunft eine große Bedeutung haben, da diese genetische Veränderung möglicherweise mit einer günstigeren Prognose assoziert sein könnte als die t(2;13)-Translokation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002920050326
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Etiology of the inflammatory bowel diseases (1999)
    Springer
    International journal of colorectal disease 14 (1999), S. 2-9 
    Details
    ISSN: 1432-1262
    Keywords: Key words Inflammatory bowel disease ; Crohn's disease ; Ulcerative colitis ; Epidemiology ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Inflammatory bowel diseases (IBD) are complex disorders. While the exact etiology of these diseases remains unknown, recent progress in the epidemiology and genetics of IBD has clearly demonstrated both environmental and genetic factors to play a role in the development of the disease, and it is expected that some risk factors are common for both Crohn's disease (CD) and ulcerative colitis (UC). The environmental factor(s) are associated with the Western way of life in the second half of the twentieth century. Cigarette smoking is presently the best known environmental factor. However, the effect of tobacco is opposite in CD and UC. A familial history of IBD is the most important risk factor for developing the disease, suggesting a genetic predisposition to IBD. This hypothesis has recently been confirmed by the localization of at least two susceptibility loci on chromosomes 12 and 16. These genes seem to play a role in both CD and UC. They must now to be identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003840050175
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Genetik schizophrener Störungen Neuere Konzepte und Befunde (1999)
    Springer
    Der Nervenarzt 70 (1999), S. 955-969 
    Details
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Schizophrenie ; Genetik ; Schizophrenes Spektrum ; Kopplungsuntersuchungen ; Assoziationsuntersuchungen ; Key words Schizophrenia ; Genetics ; Schizophrenia spectrum ; Linkage studies ; Association studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Schizophrenia is a genetic complex disease as it does not follow monogenic transmission while non-familial environmental factors have a strong additional impact. A heterogenous, continuous phenotype is transmitted in families which can now be more precisely characterized. Genes coding for proteins with presumed pathophysiological relevance are apparently not playing a major causal role. However, in the last three years several (currently seven) candidate regions have been identified in a replicable manner by linkage studies. These regions are likely to host susceptibility genes for schizophrenia, but none of them has been identified up to now. Given these findings, polygenic transmission has now become very likely. The candidate regions are currently being narrowed down by various promising techniques.
    Notes: Zusammenfassung Die Schizophrenie gehört zu den genetisch komplexen Erkrankungen, die keinem monogenen Erbgang folgen und bei denen auch nichtfamiliäre Umgebungsfaktoren eine wichtige Rolle spielen. Dabei wird intrafamiliär ein heterogener, quantitativ variierender Phänotyp übertragen, der zunehmend genauer charakterisiert werden kann. Keines der bekannten Gene mit vermuteter pathophysiologischer Relevanz spielt nach den bisherigen Erkenntnissen eine substantielle Rolle. In den vergangenen drei Jahren ist es aber erstmals durch Kopplungsuntersuchungen gelungen, mehrere replizierbare Kandidatenregionen (derzeit sieben) auf dem Genom zu identifizieren, in denen vermutlich Suszeptibilitätsgene für Schizophrenie liegen. Keines dieser Gene wurde jedoch bislang identifiziert. Mit diesen Befunden ist eine polygene Übertragung der Schizophrenie sehr wahrscheinlich geworden. Verschiedene Techniken zur Eingrenzung der Kandidatenregionen werden derzeit erfolgreich angewandt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001150050524
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A mutation at codon 279 (N279K) in exon 10 of the Tau gene causes a tauopathy with dementia and supranuclear palsy (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 62-77 
    Details
    ISSN: 1432-0533
    Keywords: Key words Frontotemporal dementia ; Genetics ; Progressive supranuclear palsy ; Tauopathy ; Exon ; amplifcation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Recently intronic and exonic mutations in the Tau gene have been found to be associated with familial neurodegenerative syndromes characterized not only by a predominantly frontotemporal dementia but also by the presence of neurological signs consistent with the dysfunction of multiple subcortical neuronal circuitries. Among families, the symptomatology appears to vary in quality and severity in relation to the specific Tau gene mutation and often may include parkinsonism, supranuclear palsies, and/or myoclonus, in addition to dementia. We carried out molecular genetic and neuropathological studies on two patients from a French family presenting, early in their fifth decade, a cognitive impairment and supranuclear palsy followed by an akinetic rigid syndrome and dementia. The proband died severely demented 7 years after the onset of the symptoms; currently, his brother is still alive although his disease is progressing. In both patients, we found a Tau gene mutation in exon 10 at codon 279, resulting in an asparagine to lysine substitution (N279K). Neuropathologically, widespread neuronal and glial tau accumulation in the cortex, basal ganglia, brain stem nuclei as well as in the white matter were the hallmark of the disease. These deposits were shown by immunohistochemistry and immunoelectron microscopy, using a battery of antibodies to phosphorylation-dependent and phosphorylation-independent epitopes present in multiple tau regions. In the neocortex, tau-immunopositive glial cells were more numerous than immunopositive neurons; the deeper cortical layers as well as the white matter adjacent to the cortex contained the largest amount of immunolabeled glial cells. In contrast, some brain stem nuclei contained more neurons with tau deposits than immunolabeled glial cells. The correlation of clinical, neuropathological and molecular genetic findings emphasize the phenotypic heterogeneitiy of diseases caused by Tau gene mutations. Furthermore, to test the effect of the N279K mutation and compare it with the effect of the P301L exon 10 mutation on alternative splicing of Tau exon 10, we used an exon amplification assay. Our results suggest that the N279K mutation affects splicing similar to the intronic mutations, allowing exon 10 to be incorporated more frequently in the Tau transcript.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010051052
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Analysis of potential phosphorylation sites in human T cell leukemia virus type 1 Tax (1999)
    Springer
    Journal of biomedical science 6 (1999), S. 206-212 
    Details
    ISSN: 1423-0127
    Keywords: Tax ; HTLV-1 ; Trans-activation ; Phosphorylation ; Mutagenesis ; Transcription ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The human T cell leukemia virus type 1 (HTLV-1) Tax is a phosphoprotein, however, the contribution of phosphorylation to Tax activity is unknown. Previous studies have shown that phosphorylation of Tax occurs on serine residue(s), within one tryptic fragment, in response to 4β-phorbol-12β-myristate-13α-acetate, in both mouse and human cells. Studies were conducted in multiple cell lines to identify the specific phosphorylated serines as a prelude to functional analysis. The phosphorylation pattern of Tax was found to be different in 293T and COS-7 cells in comparison with MT-4 and Px-1 cells. However, one tryptic fragment remained consistent in comigration analyses among all cell lines. Using selected Tax serine mutants a tryptic fragment containing a serine at residue 113 believed to be the site of phosphorylation of Tax did not comigrate with the common phosphorylated tryptic fragment. Analysis of selected Tax mutants for ability totrans-activate the cytomegalovirus promoter demonstrated mutation of serine 77 to alanine reducedtrans-activation by 90% compared to wild-type Tax. However, examination of the phosphorylation pattern of the serine 77 mutant demonstrated that it is not the site of phosphorylation. These studies demonstrate the importance of using relevant cell lines to characterize the role of phosphorylation in protein function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02255904
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Controlling septation in fission yeast: finding the middle, and timing it right (1999)
    Springer
    Current genetics 35 (1999), S. 571-584 
    Details
    ISSN: 1432-0983
    Keywords: Key words Cytokinesis ; Kinase ; Mitosis ; Schizosaccharomyces pombe ; Cell division ; Phosphatase ; Mutant ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fission yeast Schizosaccharomyces pombe provides a simple eukaryotic model for the study of cytokinesis. S. pombe cells are rod-shaped, grow mainly by elongation at their tips, and divide by binary fission after forming a centrally placed division septum. Analysis of mutants has begun to shed light upon how septum formation and cytokinesis are regulated both spatially and temporally. Some of the proteins involved in these events have been functionally conserved throughout eukaryotic evolution, suggesting that aspects of this control will be common to all eukaryotic cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002940050455
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Clinical relevance of monosomy 22q11.2 in children with pulmonary atresia and ventricular septal defect (1999)
    Springer
    European journal of pediatrics 158 (1999), S. 302-307 
    Details
    ISSN: 1432-1076
    Keywords: Key words Congenital heart disease ; Pulmonary atresia and ventricular septal defect ; Genetics ; Monosomy 22q11.2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of our study was to describe the prevalence and the clinical spectrum of monosomy 22q11.2 in a population of patients with pulmonary atresia and ventricular septal defect. We examined all 44 patients with this conotruncal cardiac malformation who presented to our institution from January 1994 until December 1997. The type of collateral lung perfusion was recorded including anomalies of the pulmonary arteries as well as facial and immunological abnormalities. Molecular-cytogenetic testing for a 22q11.2 microdeletion was performed using the probes D22S75 and cHKAD26. Statistical differences were evaluated with the Fisher's Exact Test. Monosomy 22q11.2 was present in ten children (23%) with major aortopulmonary collateral arteries (group 1). The remaining 13 children (29%) with major aortopulmonary collateral arteries (group 2) and all 21 children (48%) with ductus arteriosus (group 3) were negative for this microdeletion. All children in group 1 had facial anomalies, six had mild immunological abnormalities including decreased CD 4+ or CD 8+ cells. Anomalies of the pulmonary vascular bed were significantly more frequent in children of group 1 (9/10) than in children of group 2 (4/13) or group 3 (0/21). Due to these pulmonary vascular anomalies, corrective surgery had been accomplished in fewer children with monosomy 22q11.2 (none in group 1) as compared to 7/13 children in group 2 and 14/21 children in group 3. Conclusion In children with pulmonary atresia and ventricular septal defect, monosomy 22q11.2 is preferentially associated with major aortopulmonary collateral arteries. Due to the higher incidence of pulmonary arterial abnormalities, successful surgical repair will require a different therapeutic approach in most patients with this microdeletion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004310051077
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Linkage analysis of candidate myelin genes in familial multiple sclerosis (1999)
    Springer
    Neurogenetics 2 (1999), S. 155-162 
    Details
    ISSN: 1364-6753
    Keywords: Key words Multiple sclerosis ; Genetics ; Myelin basic protein ; Myelin oligodendrocyte glycoprotein ; Proteolipid protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: ABSTRACT Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system. A complex genetic etiology is thought to underlie susceptibility to this disease. The present study was designed to analyze whether differences in genes that encode myelin proteins influence susceptibility to MS. We performed linkage analysis of MS to markers in chromosomal regions that include the genes encoding myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG), oligodendrocyte myelin glycoprotein (OMGP), and myelin oligodendrocyte glycoprotein (MOG) in a well-characterized population of 65 multiplex MS families consisting of 399 total individuals, 169 affected with MS and 102 affected sibpairs. Physical mapping data permitted placement of MAG and PLP genes on the Genethon genetic map; all other genes were mapped on the Genethon genetic map by linkage analysis. For each gene, at least one marker within the gene and/or two tightly linked flanking markers were analyzed. Marker data analysis employed a combination of genetic trait model-dependent (parametric) and model-independent linkage methods. Results indicate that MAG, MBP, OMGP, and PLP genes do not have a significant genetic effect on susceptibility to MS in this population. As MOG resides within the MHC, a potential role of the MOG gene could not be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100480050076
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Management of mantle cell lymphoma (1999)
    Springer
    Annals of hematology 78 (1999), S. 485-494 
    Details
    ISSN: 1432-0584
    Keywords: Key words Mantle cell lymphoma ; Classification ; Pathology ; Prognosis ; Immunology ; Genetics ; Antineoplastic agents ; Combined ; Therapeutic use ; Radiotherapy ; Hematopoietic stem cell transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002770050545
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Why is acute leukemia more common in males? A possible sex-determined risk linked to the ABO blood group genes (1999)
    Springer
    Annals of hematology 78 (1999), S. 233-236 
    Details
    ISSN: 1432-0584
    Keywords: Key words Acute leukemia ; Genetics ; Sex ; ABO Blood group
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Acute leukemia is more common in males at almost every age, and this fact remains unexplained. A study was carried out in northeast peninsular Malaysia, where the population is predominantly Malay, to examine whether there was a difference in ABO blood group distribution between males and females with acute leukemia (AL). The ABO blood groups of 109 male and 79 female patients with AL (98 ALL, 90 AML) were compared with those of 1019 controls. In the control population, 39.7% were group O. Among males with AL, 39.4% were group O, whereas among females with AL, the proportion was 24.1% (p=0.03). The same trend to a lower proportion of group O among females was seen if the group was divided into adult/pediatric or lymphoblastic/myeloblastic groups, though these differences were not statistically significant. If these findings can be confirmed, they suggest the presence of a "sex-responsive" gene near to the ABO gene locus on chromosome 9, which relatively protects group O women against AL, at least in our population. The existence of such a gene might also partly explain why acute leukemia, and possibly other childhood cancers, are more common in males.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002770050507
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    The neurofibromatoses. An overview (1999)
    Springer
    Italian journal of neurological sciences 20 (1999), S. 89-108 
    Details
    ISSN: 1126-5442
    Keywords: Key words Neurofibromatosis ; Nf1 ; Nf2 ; Mosaic/segmental neurofibromatosis ; Variants ; Classification ; Neurological manifestations ; Genetics ; Childhood ; Adulthood
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The last two decades have seen clinical and molecular delineation of the different forms of neurofibromatosis. Differentiation of these forms is not just an academic exercise: their natural history, management and genetic counselling are quite different. Of the numerical classifications of neurofibromatosis proposed in the past, only neurofibromatosis type 1 (Nf1) and neurofibromatosis type 2 (Nf2) are now well delineated clinically and have been shown to be distinct at the molecular level. For both forms of neurofibromatosis, patients with clinical generalised disease have been demonstrated to be mosaic at the molecular level, and features of segmental or mosaic Nf1 and Nf2 have been delineated. Other reported forms of neurofibromatosis are rarer; they include Watson syndrome, hereditary spinal neurofibromatosis, familial intestinal neurofibromatosis, autosomal dominant café-au-lait spots alone, autosomal dominant neurofibromas alone, and schwannomatosis, the latter believed to be a variant of Nf2. Further delineation is neeeded for individuals having overlapping features of Noonan's syndrome and neurofibromatosis (the so-called Noonan/neurofibromatosis syndrome) and the syndrome of “multiple naevi, multiple schwannomas and multiple vaginal leiomyomas”. In this article we review the forms of neurofibromatosis which we believe are true clinical entities. Particular attention is given to the neurological manifestations of neurofibromatosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100720050017
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Insulin resistance and impaired insulin secretion due to phosphofructo-1-kinase-deficiency in humans (1999)
    Springer
    Journal of molecular medicine 77 (1999), S. 96-103 
    Details
    ISSN: 1432-1440
    Keywords: Key words Diabetes ; Genetics ; Phosphofructokinase ; Glycogenosis ; NIDDM ; PFK
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The etiology of non-insulin-dependent diabetes mellitus (NIDDM) is usually explained as a combination of peripheral insulin resistance and impaired beta-cell function. Phosphofructo-1-kinase (PFK1) is a rate limiting enzyme in glycolysis, and its muscle subtype (PFK1-M) deficiency leads to an autosomal recessively inherited disorder known as glycogenosis type VII or Tarui’s disease. It was evaluated whether PFK1-M deficiency leads to NIDDM in humans. A core family of four was evaluated for PFK1-M deficiency by DNA- and enzyme-activity-analyses. All members underwent oral and intravenous glucose tolerance test (oGTT/ivgtt), as well as an insulin sensitivity test (IST) using octreotide. Results: Father (46 years, BMI 22.4 kg/m2) and older son (19 years, BMI 17.8 kg/m5) showed homozygous PFK1-M deficiency, while mother (47 years, BMI 28.4 kg/m5) and younger son (13 years, BMI 16.5 kg/m5) were shown to be heterozygously PFK1-M-deficient on enzyme activity levels. DNA analysis revealed an exon 5-missense-mutation at one allele of all four members, and an exon 22-frameshift-mutation at the other allele of the two homozygously affected individuals. By oGTT the father showed impaired glucose tolerance, and the mother clinical diabetes. By ivGTT both parents and the older son had a decreased first phase insulin secretion, and a diminished glucose disappearance rate. The IST showed marked insulin resistance in both parents and the older son, and moderate resistance in the younger son, previously not described. Conclusion: PFK1-M-deficiency leads to a metabolic state typical for early NIDDM in homozygously affected humans, especially concerning insulin resistance and loss of first phase beta-cell insulin secretion, and may contribute to the manifestation of NIDDM in a subgroup of patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001090050311
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Polymorphisms in the glutamate transporter gene EAAT2 in European ALS patients (1999)
    Springer
    Journal of neurology 246 (1999), S. 1140-1144 
    Details
    ISSN: 1432-1459
    Keywords: Key words Amyotrophic lateral sclerosis ; Genetics ; Glutamate transporter gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Amyotrophic lateral sclerosis (ALS) is a progressive neurological disorder characterised by degeneration of upper and lower motor neurons. Whilst the primary pathogenic trigger is unknown in most cases, evidence is mounting to implicate a role for glutamate-mediated neurotoxicity in the disorder. Recent studies have shown reduced levels of the mainly astroglial glutamate transporter EAAT2 in ALS motor cortex and spinal cord and multiple abnormal EAAT2 mRNA species in ALS brain tissue. One cause of the low EAAT2 levels may be that point mutations in the EAAT2 gene, EAAT2, result in an abnormal unstable protein. To test this hypothesis we analysed EAAT2 in 128 sporadic and 23 familial European ALS cases. No variants within the coding sequence of EAAT2 to affect the protein sequence nor in the consensus splice sites of the flanking intronic sequences were found in any cases, similar to findings in other reports. Frequent polymorphisms within the flanking intronic sequences of both exons 2 and 4 were seen but at similar frequencies in controls. Mechanisms other than mutations within the coding region of EAAT2 must therefore be responsible for the low levels of EAAT2 seen in most cases of ALS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150050532
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Early diagnosis and the clinical genetics of Alzheimer’s disease (1999)
    Springer
    Journal of neurology 246 (1999), S. 69-72 
    Details
    ISSN: 1432-1459
    Keywords: Key words Alzheimer’s disease ; Genetics ; Genetic counseling ; Predictive testing ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Alzheimer’s disease (AD) has a significant genetic background manifested as autosomal dominant inheritance in some early-onset families and as familial risk in late-onset cases. Three genes responsible for early-onset autosomal dominant AD have been identified, and one gene, apolipoprotein E, has been confirmed as a susceptibility gene for late-onset forms of the disorder. These findings raise the possibility of genetic testing, either for early diagnosis or prediction. For early-onset autosomal dominant AD genetic testing will have a limited but useful role in confirming diagnosis in established cases and in predictive counselling for relatives; a situation analogous to that for Huntington’s disease. For late-onset AD significant problems remain to be overcome before the advances in molecular genetics have a direct clinical application
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150050310
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Self-incompatibility in passion fruit: evidence of two locus genetic control (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 564-568 
    Details
    ISSN: 1432-2242
    Keywords: Key words Passiflora ; Self-incompatibility ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The self-incompatibility in yellow passion fruit was previously described as homomorphic sporophytic with monofactorial inheritance. Five progenies were obtained by bud-selfing. The plants of these progenies were selfed, reciprocally crossed within each progeny and crossed with known incompatible phenotypes to identify their phenotypic group. Fruit set was evaluated at the 7th day after pollination. Two progenies consisted of two self-incompatible groups, the other three formed three suck groups. The groups were identified as S1, S2, S3, S4, S5 and S6. The results provide evidence that the self-incompatibility of passion fruit is controlled by two loci, the S-gene and another, whose expression needs to be investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    A stylar ribonuclease assay to detect self-compatible seedlings in almond progenies (1999)
    Springer
    Theoretical and applied genetics 99 (1999), S. 800-810 
    Details
    ISSN: 1432-2242
    Keywords: Key words Almond ; Compatibility ; Genetics ; Prunus dulcis ; Ribonucleases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Six almond progenies, each the product of a cross between a self-compatible and a self-incompatible parent, were analysed for stylar ribonucleases. Proteins were extracted and separated using non-equilibrium pH gradient electrofocusing (NEPHGE), and the gels were stained for ribonuclease activity. Most seedlings showed either two principal bands, interpreted as corresponding to two incompatibility alleles, or a single band. The seedlings were also bagged in the field at flowering time to determine fruit set after selfing, and some were also examined for the growth of pollen-tubes in selfed styles using UV fluorescence microscopy. With very few exceptions, those seedlings showing single-banded zymograms were found to be self-compatible according to field and microscope studies, and those with two bands were found to be self-incompatible. We conclude that the allele for self-compatibility in almond does not code for ribonuclease activity and that the ribonuclease isoenzyme assay is a convenient technique for predicting self-compatibility in segregating progenies. A novel band in two derivatives of ’Ferrastar’ was ascribed to a new incompatibility allele, S 10 .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051299
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Craniosynostosis: from a clinical description to an understanding of bone formation of the skull (1999)
    Springer
    Child's nervous system 15 (1999), S. 676-680 
    Details
    ISSN: 1433-0350
    Keywords: Key words Craniosynostosis ; Genetics ; FGFR ; Msx2 ; Development ; Skull
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The genetic studies of syndromic craniosynostoses lead to the characterisation of genes that regulate the correct development of the bones of the skull. From these studies, it appears that FGF/FGFR signalling has a crucial role in this problem. Numerous mutations affecting the genes coding for FGFR1, 2 or 3 are responsible for these syndromes. It is interesting to note that some identical mutations produced various different phenotypes, suggesting that other genes modulate the phenotypic expressivity. The other involved genes in these syndromes code for such proteins as Msx2 or Twist that interact in the cellular pathways responsible for FGF action. From these genetic studies, it is now important to establish the role of these proteins during the development of the skull. Msx2 plays a repressive role in osteogenesis, whereas FGFRs act as promoting proteins. In the near future, it will be very important to improve our understanding of these phenomena in order to test specific treatments to prevent the development of such syndromes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003810050457
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Division of labor in a dynamic environment: response by honeybees (Apis mellifera) to graded changes in colony pollen stores (1999)
    Springer
    Behavioral ecology and sociobiology 46 (1999), S. 171-179 
    Details
    ISSN: 1432-0762
    Keywords: Key words Honeybee ; Apis mellifera ; Division of labor ; Genetics ; Pollen foraging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A fundamental requirement of task regulation in social groups is that it must allow colony flexibility. We tested assumptions of three task regulation models for how honeybee colonies respond to graded changes in need for a specific task, pollen foraging. We gradually changed colony pollen stores and measured behavioral and genotypic changes in the foraging population. Colonies did not respond in a graded manner, but in six of seven cases showed a stepwise change in foraging activity as pollen storage levels moved beyond a set point. Changes in colony performance resulted from changes in recruitment of new foragers to pollen collection, rather than from changes in individual foraging effort. Where we were able to track genotypic variation, increases in pollen foraging were accompanied by a corresponding increase in the genotypic diversity of pollen foragers. Our data support previous findings that genotypic variation plays an important role in task regulation. However, the stepwise change in colony behavior suggests that colony foraging flexibility is best explained by an integrated model incorporating genotypic variation in task choice, but in which colony response is amplified by social interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002650050607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Erbliche Ursachen und Risikofaktoren der Alzheimer-Krankheit (1999)
    Springer
    Der Nervenarzt 70 (1999), S. 195-205 
    Details
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Alzheimer-Krankheit ; Genetik ; Risikofaktoren ; Genetische Beratung ; Key words Alzheimer’s disease ; Genetics ; Risk factors ; Genetic counseling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A multifactorial etiology underlies the majority of cases of Alzheimer’s disease (AD). Both ill-defined environmental and genetic factors contribute to the development of the disease. Allele ɛ4 of ApoE is a genetic risk factor. Its presence increases the risk of developing AD. However, presence of e4 is neither necessary nor sufficient for the disease to arise. Apart from the common multifactorial forms of the disease, there are rare variants which are inherited as Mendelian traits. To date three genes are known that can be mutated in these rare forms of AD. Of these, mutations in the gene presenilin 1 on chromosome 14 are most frequent. In addition, mutations in the gene presenilin 2 on chromosome 1 and in the amyloid precursor protein gene (APP on chromosome 21) occur in autosomal dominant AD. This article reviews our present knowledge of the genetics of AD and discusses its relevance for patients with AD and their relatives.
    Notes: Zusammenfassung Der Großteil der Fälle von Alzheimer-Krankheit (AK) hat eine multifaktorielle Ätiologie. Das bedeutet, bisher nicht genauer bekannte Umwelteinflüsse und genetische Faktoren spielen bei der Entwicklung der Krankheit eine wesentliche Rolle. Von seiten der Genetik unterscheidet man bei der AK gegenwärtig genetische Risikofaktroren und Mutationen. Der einzige bisher gesicherte genetische Risikofaktor ist das Allel ɛ4 des Gens für Apolipoprotein E auf Chromosom 19. Dieses Allel erhöht die Wahrscheinlichkeit, an der AK zu erkranken, ist jedoch weder eine notwendige noch eine hinreichende Bedingung. Neben den häufigen Formen mit multifaktorieller Ätiologie kommen seltene Varianten der Krankheit vor, die nach Mendelschen Regeln vererbt werden. Bisher sind 3 Gene bekannt, die bei diesen seltenen, in der Regel früh auftretenden und autosomal dominant vererbten Formen mutiert sein können. Am häufigsten findet sich bei den autosomal-dominanten Fällen eine Mutation im Gen präsenilin 1 auf Chromosom 14, seltener liegen Mutationen im Gen präsenilin 2 auf Chromosom 1 und im Gen des Amyloid- Vorläuferproteins auf Chromosom 21 vor. In diesem Beitrag geben wir eine Übersicht über gegenwärtige Befunde zur Genetik der AK und diskutieren die Bedeutung dieses Wissens für Patienten und deren Verwandte.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001150050423
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Crosses between diabetic BB/OK and wild rats confirm that a third gene is essential for diabetes development (1998)
    Springer
    Acta diabetologica 35 (1998), S. 109-111 
    Details
    ISSN: 1432-5233
    Keywords: Key words BB rat ; Diabetes ; Genetics ; Crossing study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Several crossing studies with diabetic BB rats have shown that in addition to the lymphopenia (Iddm1) and the MHC class II genes of the RT1u haplotype (Iddm2) there are further non-MHC genes essential for diabetes development. Because diabetes-resistant inbred rat strains may be homozygous for one of the diabetogenic non-MHC genes, masking the expression of diabetogenic genes and leading to an underestimation of the number of diabetogenic genes, we crossed wild and diabetic BB/OK rats. The F1 hybrids were backcrossed onto diabetic female (BC1W-F, n=97) and male BB/OK rats (BC1W-M, n=98) transferred to a specified-pathogen-free environment and studied for the frequency and age at onset of diabetes up to an age of 30 weeks. Comparing the results of these BC1 W hybrids with similarly derived hybrids using diabetes-resistant DA rats (BC1DA-F, n=113; BC1DA-M, n=216), the diabetes frequency in total was comparable indicating the action of three recessive genes. The percentage of diabetics in Iddm1 and Iddm2 homozygotes confirmed the existence of the third gene, Iddm3, but there were some sex differences; significantly more male than female BC1W-F and significantly more BC1DA-M than BC1DA-F males were diabetic. Regarding the age at onset, the BC1W-F hybrids manifested not only significantly earlier, but also more uniformly than BC1DA-F and BC1-M hybrids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005920050114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Hepatocyte nuclear factor-1a gene and non-insulin-dependent diabetes mellitus in the Japanese population (1998)
    Springer
    Acta diabetologica 35 (1998), S. 150-153 
    Details
    ISSN: 1432-5233
    Keywords: Key words Non-insulin-dependent diabetes mellitus ; MODY ; Hepatocyte nuclear factor-1α ; Genetics ; Microsatellite polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Recently, hepatocyte nuclear factor-1α (HNF-1α, which is encoded by the TCF1 gene) mutations were reported in a subset of patients with maturity onset diabetes of the young (MODY3). We studied the contribution of TCF1 to genetic susceptibility to common non-insulin-dependent diabetes mellitus (type 2) in Japanese subjects by investigating allelic association with type 2 diabetes use of three markers. We also studied the frequency of the G191D mutation, the only mutation of TCF1 reported so far in late-onset type 2 diabetes. A total of 356 subjects were studied. There were no significant differences in allele frequency of the three markers between patients with type 2 diabetes and control subjects. A G191D mutation was not found in the subjects studied, giving a frequency of less than 0.4% in common type 2 diabetes. The lack of association of type 2 diabetes with three markers in and near TCF1 suggests that mutations in TCF1 derived from a limited number of founders are not a major cause of common type 2 diabetes even in the genetically homogeneous Japanese population. The data also indicate that the G191D mutation in TCF1 plays little, if any, role in susceptibility to common type 2 diabetes in the Japanese.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005920050120
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    The effect of genotype on response thresholds to sucrose and foraging behavior of honey bees (Apis mellifera L.) (1998)
    Springer
    Journal of comparative physiology 182 (1998), S. 489-500 
    Details
    ISSN: 1432-1351
    Keywords: Key words Honey bee ; Behavior ; Genetics ; Neurobiology ; Foraging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Honey bee foragers were tested for their proboscis extension response (PER) to water and varying solutions of sucrose. Returning pollen and nectar foragers were collected at the entrance of a colony and were assayed in the laboratory. Pollen foragers had a significantly higher probability of responding to water and to lower concentrations of sucrose. Bees derived from artificially selected high- and low-pollen-hoarding strains were also tested using the proboscis extension assay. Returning foragers were captured and tested for PERs to 30% sucrose. Results demonstrated a genotypic effect on PERs of returning foragers. The PERs of departing high- and low-strain foragers were consistent with those of returning foragers. The PERs were related to nectar and water reward perception of foragers. High strain bees were more likely to return with loads of water and lower concentrations of sucrose than foragers from the low pollen strain. Low-strain bees were more likely to return empty. We identified a previously mapped genomic region that contains a variable quantitative trait locus that appears to influence sucrose response thresholds. These studies demonstrate a gene-brain-behavior pathway that can be altered as a consequence of colony-level selection for quantities of stored food.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050196
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Genetics of psoriasis (1998)
    Springer
    Archives of dermatological research 290 (1998), S. 463-476 
    Details
    ISSN: 1432-069X
    Keywords: Key words Psoriasis ; Genetics ; HLA ; Linkage ; Epidemiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Non-pustular psoriasis consists of two disease subtypes, type I and type II, which demonstrate distinct characteristics. Firstly the disease presents in different decades of life, in type I before the age of 40 years and later in type II. Secondly, contrasting frequencies of HLA alleles are found: type I patients express predominantly HLA-Cw6, -B57, and -DR7, whereas in type II patients HLA-Cw2 is overrepresented. Finally, familial inheritance is found in type I but not in type II psoriasis. The study of concomitant diseases in psoriasis contributes to deciphering the distinct patterns of the disease. Defence against invading microorganisms seems better developed in psoriatics than in controls. This evolutionary benefit may have caused the overall high incidence of psoriasis of 2%. Psoriasis is a multifactorial and heterogenetically inherited disease. The heterogeneity is evident by the diversity of genetically linked markers. The multifactorial component results from the observation of external trigger mechanisms, such as the Koebner phenomenon, stress and the intake of certain drugs. Twin studies have shown that environmental factors contribute to the onset of the disease. In type I psoriasis, special extended haplotypes such as EH57.1 (HLA-Cw6-B57-DRB1*0701-DQA1*0201-DQBl*0303) and EH65.1 (HLA-Cw8-B65-DRB1*0102-DQB1*0501) have been found to be increased. The application of microsatellite techniques has identified distinct positions on several chromosomes at which putative psoriasis genes may be located. Disease susceptibility genes are thought to be present on chromosomes 4q, 6p, 16q, 17q and 20p. Moreover, on chromosome 1q, genes regulating epidermal differentiation have been identified. Linkage to this area has been proposed. Furthermore, psoriasis gene loci on chromosomes 2, 8 and 20 have been suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004030050338
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Recent advances in genetic research on schizophrenia (1998)
    Springer
    Journal of biomedical science 5 (1998), S. 28-30 
    Details
    ISSN: 1423-0127
    Keywords: Genetics ; Schizophrenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Evidence for genetic factors in schizophrenia is reviewed with regard to family, twin and adoption studies, and recent advances in molecular genetic technology are applied to explore possible gene loci susceptible to schizophrenia. Application of neuropsychological and neuroimaging methodologies are also reviewed with an aim to develop criteria for defining phenotypes for genetic studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02253353
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Prediction of febrile seizures in siblings: a practical approach (1998)
    Springer
    European journal of pediatrics 157 (1998), S. 340-344 
    Details
    ISSN: 1432-1076
    Keywords: Key words Febrile seizures ; Genetics ; Family ; Risk factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To quantify the risk of febrile seizures (FS) in relatives of children with FS and to predict the risk of FS in siblings, we calculated cumulative risks of FS in first degree relatives of 129 children with FS. The study was conducted as a prospective follow up study of FS recurrences at the outpatient clinic of the Sophia Children's Hospital in Rotterdam. Thirteen parents and 12 siblings had experienced FS, accounting for a 6-year cumulative risk of 7%. The risk of FS was increased in relatives of children with recurrent FS (12%). The risk of FS in siblings (10%) in our study was more than twice the average risk in a similar population (4%). A positive FS history in a parent, young age at onset in the proband, and recurrences in the proband were selected in a multivariable prediction model. If two or more of these risk factors were present, the risk of West European siblings to develop FS was 46% (hazard ratio 5.4). Conclusion The cumulative risk of FS in siblings of children with FS is increased. The age attained risk of FS can be estimated using a practical model incorporating three readily available risk factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004310050824
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Paternal age is a risk factor for Alzheimer disease in the absence of a major gene (1998)
    Springer
    Neurogenetics 1 (1998), S. 277-280 
    Details
    ISSN: 1364-6753
    Keywords: Key words Alzheimer disease ; Risk factors ; Parental age ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: ABSTRACT We compared the parental age at birth of patients with Alzheimer disease (AD) with that of cognitively healthy control subjects. Within 206 carefully diagnosed AD patients, two groups were distinguished according to the likelihood of carrying a major gene for AD (MGAD). This likelihood was calculated by applying a Bayesian approach which incorporates data on aggregation of the disease, age at onset, and "censoring" ages within the family. All AD patients were ranked by MGAD probability. According to the sample's quartiles, two subgroups were defined representing the 52 individuals with the lowest and the 52 with the highest MGAD probability. Age at onset of dementia, education, and apolipoprotein E ε  4 allele frequencies were not statistically different between the two groups. Fathers of patients with a low MGAD probability were significantly older (35.7±8.1 years) than fathers of both other groups (high MGAD probability 31.3±6.9 years, P =0.004; controls 32.6±6.8 years, P =0.04, n=50). The differences for mothers were less pronounced and not statistically significant. These findings suggest that increased paternal age is a risk factor for AD in the absence of a major gene, whereas increased maternal age and AD are associated only weakly and independently of genetic disposition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100480050041
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Recent progress in the genetics of human epilepsies (1998)
    Springer
    Neurogenetics 1 (1998), S. 153-163 
    Details
    ISSN: 1364-6753
    Keywords: Key words Epilepsy ; Genetics ; Linkage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: ABSTRACT Despite several lines of evidence indicating a strong genetic influence in the etiology of idiopathic epilepsies, progress in the mapping and identification of human epilepsy genes has been limited until recently. In addition to the localisation and/or isolation of several genes causing progressive epilepsies associated with cerebral degeneration, at least seven human genomic regions (6p, 8q, 10q, 15q, 16p, 19q, 20q) are now known to harbour genes implicated in idiopathic epilepsies. In the case of nocturnal frontal lobe epilepsy, mutations in a nicotinic acetylcholine receptor subunit gene have been identified. Systematic studies of rare epileptic disorders inherited as monogenic Mendelian traits, as well as studies on more complex polygenic idiopathic epilepsies, are still needed in order to identify all the epilepsy genes. This will allow better diagnosis and genetic counseling in families of affected individuals, a better understanding of both the pathophysiology of epilepsies and normal brain functioning, and the design of new pharmacological and genetic therapies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100480050024
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Microsatellite DNA in Actinidia chinensis: isolation, characterisation, and homology in related species (1998)
    Springer
    Theoretical and applied genetics 97 (1998), S. 1269-1278 
    Details
    ISSN: 1432-2242
    Keywords: Key words Simple sequence repeat (SSR) ; Microsatellites ; Molecular markers ; Genetics ; Kiwifruit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We have isolated and sequenced 263 microsatellite-containing clones from two small insert libraries of Actinidia chinensis enriched for (AC/GT) and (AG/CT) repeats, respectively. Primer pairs were designed for 203 microsatellite loci and successfully amplified from both plasmid and A. chinensis genomic DNA. In this paper we report the sequences of 40 primer pairs for which we have demonstrated Mendelian segregation in the progeny from controlled crosses. The polymorphism of ten microsatellites of each type was evaluated in four diploid and six tetraploid genotypes of A. chinensis. All microsatellites proved to be polymorphic, the number of alleles per locus detected in polyacrylamide sequencing gels ranging from 9 to 17. The high degree of polymorphism in Actinidia renders these markers useful either for mapping in A. chinensis or for fingerprinting cultivars of both domesticated kiwifruit species (A. chinensis and A. deliciosa). While most primer pairs produced single amplification products, about 20% generated banding patterns consistent with the amplification of two different loci. This supports the hypothesis that diploid species of Actinidia (2n=2x=58) are polyploid in origin with a basic chromosome number x=14/15 and that chromosome duplication may have occurred during the evolution of the genus. Finally, we have assayed the cross-species transportability of primer pairs designed from A. chinensis sequences and have found extensive cross-species amplification within the genus Actinidia; 75% of primer pairs gave successful amplification in the eight species assayed (A. arguta, A. rufa, A. polygama, A. chrysantha, A. callosa, A. hemsleyana, A. eriantha, and A. deliciosa), which are representative of the four sections into which the genus is currently split.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051019
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Fruit tree genetics at a turning point: the almond example (1998)
    Springer
    Theoretical and applied genetics 96 (1998), S. 588-601 
    Details
    ISSN: 1432-2242
    Keywords: Key words Fruit trees ; Genetics ; Almond ; Prunus amygdalus ; Breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The large size and the long generation time of fruit trees generally reduce the possibilities of obtaining genetic information on the transmission and heritability of useful agronomic traits in these species. However, from breeding work carried out with fruit trees, an important amount of data is now available, although large differences are apparent among the different species. There is not much information known about almond compared to what is available on other Prunus fruit species, but more data have been accumulated on it than on most of the other nut trees, thus making almond special among all the temperate fruit and nut species. Only five qualitative traits have been described in almond, with an additional two also possibly qualitative. Heritabilities have been estimated for an important number of quantitative traits, mainly phenological times and fruit characters. Important information is available on molecular markers, including enzymes, RFLPs, RAPDs and other recently developed markers. Linkages, however, have only been established among molecular markers, allowing accurate genetic maps to be built but not yet enabling agronomical characters to be located in these maps, probably because the latter have not been sufficiently studied. The effectiveness of the application of genetic maps in plant breeding will depend on the accuracy of the study of different agronomic traits and their expression, implying more field work and recognition of this work. Ultimately, any new fruit cultivar has to be grown in the field and has to allow the grower to make a profit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050777
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Cytological basis for a tetraspory in Cupressus sempervirens L. megagametogenesis and its implications in genetic studies (1998)
    Springer
    Theoretical and applied genetics 96 (1998), S. 776-779 
    Details
    ISSN: 1432-2242
    Keywords: Key words Cupressus sempervirens ; Cytology ; Megasporogenesis ; Megagametogenesis ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The processes of megasporogenesis and early megagametogenesis were cytologically investigated in Cupressus sempervirens L. in order to elucidate, at the cellular level, the origin of the megagametophyte. After pollination, sporogenous tissue developed in the chalazal region of the nucellus, but only one megaspore mother cell differentiated and divided meiotically without cell-wall formation. This led to the development of a cell with four nuclei which directly functioned as a megaspore. The C. sempervirens megagametophyte is thus tetrasporic, in contrast to the majority of conifers where the megagametophyte is monosporic. The consequenses of this observation are discussed from a genetics point of view.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050801
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Patient regrets after bilateral prophylactic mastectomy (1998)
    Springer
    Annals of surgical oncology 5 (1998), S. 603-606 
    Details
    ISSN: 1534-4681
    Keywords: Breast cancer ; Genetics ; Prophylactic mastectomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: The discovery of a cadre of breast cancer susceptibility genes has resulted in an increase in the number of women seeking information about prophylactic breast surgery, but virtually no large-scale prospective databases exist to assist women considering prophylactic mastectomy. Methods: The authors constructed a National Prophylactic Mastectomy Registry comprised of a volunteer population of 817 women from 43 states who have undergone prophylactic mastectomy. Results: In the registry, 370 women had undergone bilateral prophylactic mastectomy. Twenty-one (5%) women expressed regrets about the procedure. The median follow-up was 14.6 years (mean 14.8 years; range 0.2–51 years). Those with regrets were subsetted into those with major (n=10) or minor (n=7) regrets. Regrets were more common in those women with whom discussion about prophylactic mastectomy was initiated by a physician (19/255), compared with patients who initiated the discussion themselves (2/108;P〈.05). Conclusions: The overall satisfaction rate of 95% reported here may be explained by the voluntary nature of this registry. The most important factor that predicts an unfavorable outcome following bilateral prophylactic mastectomy is a physician-initiated discussion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02303829
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Autosomal recessive polycystic kidney disease (1998)
    Springer
    Journal of molecular medicine 76 (1998), S. 303-309 
    Details
    ISSN: 1432-1440
    Keywords: Key words Autosomal recessive polycystic kidney disease ; Linkage study ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Autosomal recessive polycystic kidney disease (ARPKD) is a rare inherited disorder which usually becomes clinically manifest in early childhood, although the spectrum of ARPKD is much more variable than generally known. Presentation of ARPKD at later ages and survival into adulthood have been observed in many cases. The responsible gene has been mapped to chromosome 6p. Thus there is no evidence of genetic heterogeneity. The most important indication for DNA diagnosis is the prenatal diagnosis in families with at least one affected child. The critical region has been narrowed with the use of recombinant families of about 4 cM. Several possible candidate genes have been excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001090050221
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    The possibilities of modeling neural networks in the framework of the thermodynamics of genetically disordered systems (glasses) (1998)
    Springer
    Journal of biological physics 24 (1998), S. 41-58 
    Details
    ISSN: 1573-0689
    Keywords: Neural networks ; Associative memory ; Brain functions ; Disordered systems ; Genetics ; Synergetics ; Self-organization ; Vitreous state
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Non-spin glasses possess a number of specific features which, in structural and dynamic aspects, are close to conditions necessary for neural networks to function. In a disordered network there exists a plurality of structural parameters and a number of two-level states defined by double-well potentials. Their characteristics are specified by the conditions of glass formation, i.e. by genesis. The thermodynamic description of glass as a self-organizing system (that does not require introducing an interacting potential model) leads to an unambiguous conclusion that its frequency spectrum is predetermined by the structure, which is characterized by zero-point entropy. Glass is a natural system of oscillators which form a disordered network. In this sense, glass conforms to a known model of a disordered neural network formed by interconnected oscillators. If one assumes that in living organisms the structure of a neural network (the brain) is inherited according to a genetic mechanism, the quickness of learning and recognition of patterns, the stability of associative memory and other capabilities have to be inherited genetically. The more ordered a neural network formed by distinguishable neurons, the better its capabilities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005071706864
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Genetic and Shared Environmental Influences on Adolescent BMI: Interactions with Race and Sex (1998)
    Springer
    Behavior genetics 28 (1998), S. 265-278 
    Details
    ISSN: 1573-3297
    Keywords: Genetics ; body mass index ; adolescents ; race ; sex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract The present study uses a behavioral genetic design to investigate the genetic and environmental influences on variation in adolescent body mass index (BMI) and to determine whether the relative influences of genetic and environmental factors on variation in BMI are similar across racial groups and sexes. Data for the present study come from the National Longitudinal Study on Adolescent Health (Add Health), a large, nationally representative study of adolescent health and health-related behaviors. The Add Health sample contains a subset of sibling pairs that differs in levels of genetic relatedness, making it well suited for behavioral genetics analyses. The present study examines whether genetic and environmental influences on adolescent BMI are the same for males and females and for Black and White adolescents. Results indicate that genetic factors contribute substantially to individual differences in adolescent BMI, explaining between 45 and 85% of the variance in BMI. Furthermore, based on an analysis of opposite-sex sibling pairs, the genes that influence variation in adolescent BMI are similar for males and females. However, the relative importance of genetic and environmental influences on variation in BMI differs for males and females and for Blacks and Whites. Although parameter estimates could be constrained to be equal for Black and White males, they could not be constrained to be equal for Black and White females. Moreover, the best-fitting model for Black females was an ADE model, for White females it was an ACE model, and for males it was an AE model. Thus, shared environmental influences are significant for White female adolescents, but not for Black females or males. Likewise, nonadditive genetic influences are indicated for Black females, but not for White females or males. Implications of these results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021619329904
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Neuronal ceroid lipofuscinoses: a review (1998)
    Springer
    Neurological sciences 19 (1998), S. 271-276 
    Details
    ISSN: 1590-3478
    Keywords: Neuronal ceroid lipofuscinosis ; Clinical features ; Classification ; Diagnosis ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Sommario Le ceroido lipofuscinosi neuronali (NCL) sono tra le encefalopatie progressive più freguenti nell'infanzia ed interessano, seppure più raramente, l'adulto. Clinicamente sono caratterizzate da demenza, deficit visivo, epilessia e disturbi motori. Gli aspetti patologici specifici sono rappresentati da degenerazione neuronale ed accumulo lisosomiale di lipopigmento in differenti tipi cellulari. Il difetto biochimico della malattia non e noto. La classificazione delle NCL, basata su criteri clinici, distingue sei forme classiche ed altre forme atipiche. L'elettrofisiologia e la neuroradiologia sono di importante ausilio diagnostico, ma la diagnosi si fonda sull'identificazione dell'accumulo di lipopigmento the presenta pattern ultrastrutturali specifici. Differenti difetti genetici sono stati dimostrati in diverse forme cliniche, ma il meccanismo patogenetico molecolare rimane ancora da chiarire.
    Notes: Abstract Neuronal ceroid lipofuscinoses (NCLs) are among the most common neurodegenerative diseases in childhood but rarely present in adulthood. The main symptoms are psychomotor deterioration, visual failure, epilepsy and motor disturbances. The NCLs are morphologically characterized by the accumulation of lipopigments within numerous cell types and loss of neurons. Pathogenesis is unknown. The current clinical classification recognizes six classic types of NCL and several atypical forms. Electrophysiological and neuroradiological findings may be of diagnostic significance, but disease recognition rests on the demonstration of a typical ultrastructural pattern. Genetic studies have demonstrated that several different genetic loci are involved in the pathogenesis of NCL, but the molecular mechanisms underlying neuronal death and lipopigment accumulation are not understood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00713852
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Unexpected rate enhancement in the intramolecular carboxylic acid-catalyzed cleavage of o-carboxybenzohydroxamic acid (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 216-222 
    Details
    ISSN: 0894-3230
    Keywords: o-carboxybenzohydroxamic acid ; phthalic anhydride ; phthalic acid ; hydrolysis ; intramolecular acid catalysis ; kinetics ; activation parameters ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Phthalic anhydride was detected spectrophotometrically in the hydrolysis of o-carboxybenzohydroxamic acid (OCBA) in CH3CN-H2O solvent containing 0.03 mol dm-3 HCl. Pseudo-first-order rate constants (k1) for hydrolysis of OCBA are almost independent of the change in CH3CN content from 10 to 80% (v/v) in mixed aqueous solvents. The rate constants k1 are more than 10-fold larger than the corresponding rate constants for hydrolysis of phthalamic acid. These observations are explained in terms of a mechanism slightly different from the mechanism for hydrolysis of phthalamic acid. The activation parameters, ΔH* and ΔS*, are not affected appreciably by an increase in CH3CN content from 10 to 80% in mixed aqueous solvents. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 39
    Electronic Resource
    Electronic Resource
    Solute-solvent and solvent-solvent interactions in binary solvent mixtures. Part 7. Comparison of the enhancement of the water structure in alcohol-water mixtures measured by solvatochromic indicators (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 185-192 
    Details
    ISSN: 0894-3230
    Keywords: solute-solvent interactions ; solvent-solvent interactions ; binary solvents ; alcohol-water mixtures ; water structure ; solvatochromic indicators ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A preferential solvation model that takes into account the enhancement of the structure of water when small amounts of alcohol are added was applied to solvatochromic data for binary mixtures of water with 2-methylpropan-2-ol, propan-2-ol, ethanol and methanol. Application of the model allows the calculation of the effect of the enhancement of the water structure on solvatochromic solvent properties. It is demonstrated that the enhancement of water structure increases the solvent dipolarity/polarizability and hydrogen-bond donor acidity and decreases the solvent hydrogen-bond acceptor basicity. The effect decreases in the order 2-methylpropan-2-ol-water, propan-2-ol-water, ethanol-water and methanol-water. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 40
    Electronic Resource
    Electronic Resource
    Structural dependence of heterolytic bond dissociation energy of carbon-carbon σ bonds in hydrocarbons (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 157-170 
    Details
    ISSN: 0894-3230
    Keywords: heterolytic bond dissociation energy ; carbon-carbon σ bonds ; hydrocarbons ; structural dependence ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The coordination of a resonance-stabilized hydrocarbon cation and anion yielded a series of unprecedented hydrocarbons, which are susceptible to thermal heterolytic cleavage of carbon-carbon σ bonds in polar media, generating the original ions under reversible conditions. When the component ions were sufficiently stabilized, some ion pairs were even isolated as solids, thus providing the first examples of hydrocarbon salts. The direct observation of the heterolysis by means of spectroscopy permitted reliable thermodynamic treatments of the observed degree of ionic dissociation. Correlation of the free energy of heterolysis with solvent dielectric constants and parameters of ion stabilities such as pKHA, pKR+ and redox potentials revealed the importance of the thermodynamic stabilities of ions, the degree of solvation and steric congestion in the starting molecule as major controlling factors in the heterolysis. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 41
    Electronic Resource
    Electronic Resource
    Correlation of the rates of solvolysis of the N,N-diphenylcarbamoylpyridinium ion (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 273-276 
    Details
    ISSN: 0894-3230
    Keywords: N,N-diphenylcarbamoylpyridinium ion ; solvolysis ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Solvolyses of the N,N-diphenylcarbamoylpyridinium ion are subject to specific and/or general base catalysis, which can be eliminated by addition of perchloric acid or increased, especially in fluoroalcohol-containing solvents, by addition of pyridine. The uncatalyzed solvolyses in aqueous methanol and aqueous ethanol involve a weakly nucleophilically assisted (l  =  0.22) heterolysis and the solvolyses in the pure alcohols are anomalously slow. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 42
    Electronic Resource
    Electronic Resource
    Effects of ionic and non-ionic micelles on rate of hydroxide ion-catalyzed hydrolysis of securinine (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 209-215 
    Details
    ISSN: 0894-3230
    Keywords: securinine ; cationic micelles ; anionic micelle ; non-ionic micelle ; alkaline hydrolysis ; kinetics ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effects of micelles of cetyltrimethylammonium bromide (CTABr), tetradecyltrimethylammonium bromide (TTABr), sodium dodecyl sulfate (SDS) and polyoxyethylene 10 lauryl ether (C12E10) on the rates of alkaline hydrolysis of securinine were studied at a constant [-OH] (0.05 M). An increase in the total concentrations of CTABr, TTABr, SDS and C12E10 from 0.0 to 0.2 M causes a decrease in the observed pseudo-first-order rate constants (kobs) by factors of ca 2.5, 3, 7 and 4, respectively. The observed data are explained in terms of pseudophase and pseudophase ion-exchange (PIE) models of micelle. The binding constants, KS, of securinine with SDS, C12E10, CTABr and TTABr micelles are 32.4, 14.8, 22.1, and 9.1 M-1, respectively. The magnitudes of the second-order rate constants, kM, for the reactions in the micellar pseudophase are negligible compared with the corresponding rate constant, kW, for the reaction occurring in the aqueous pseudophase for CTABr, TTABr, SDS and C12E10. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 43
    Electronic Resource
    Electronic Resource
    Colloidal CdS-induced photocatalytic reaction of 2-methylindole - mechanistic analysis of oxidation of indoles (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 277-282 
    Details
    ISSN: 0894-3230
    Keywords: colloidal CdS-induced photochemical reactions ; photocatalytic reactions ; photooxidation ; 2-methylindole ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 2-Methylindole (2-MI) is adsorbed on the surface of colloidal CdS particles with an adsorption intensity of 0.6 × 103 dm3 mol-1. A new emission band at 530 nm is produced by forming an exciplex between excited CdS and 2-MI and the red emission due to CdS is simultaneously quenched. The emission maxima of green bands for different indoles increase in the order indole 〈 tryptophan 〈 2-MI 〈 3-MI and are observed at 508, 520, 530 and 540 nm, respectively. The shift in emission maxima is related to the oxidation potential of these substrates. The irradiation of an aerated reaction mixture containing CdS and 2-MI with visible light induces the oxidation of adsorbed 2-MI by photogenerated holes to produce 2-methyl-3-indolinone and 2-acetamidobenzaldehyde. The latter product is formed due to oxidative C - C bond cleavage of the pyrrole ring. The reactivity of trapped holes towards the adsorbed 2-MI is evidenced by a decrease in the lifetime of the red emission of CdS in the presence of 2-MI. In this reaction the possibility of the participation of singlet oxygen is ruled out. A general mechanism of CdS-induced oxidation of indoles is discussed. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 44
    Electronic Resource
    Electronic Resource
    The Menschutkin reaction of benzyl p-toluenesulfonates with N,N-dimethylanilines. Evidence for the duality of SN1 and SN2 mechanisms (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 254-260 
    Details
    ISSN: 0894-3230
    Keywords: Menschutkin reaction ; duality of SN1, SN2 mechanisms ; benzyl tosylates ; Yukawa-Tsuno equation ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The rate data for the Menschutkin reaction between strongly activated Z-substituted benzyl p-toluenesulfonates and Y-substituted N,N-dimethylanilines in acetonitrile at 35 °C fit the equation, kobs  =  k1 + k2 [DMA], which is consistent with concurrent first- and second-order processes. The k1 and k2 values for each substrate were separated based on the above equation. The SN1 rate constant, k1, is unaffected by the nature of the nucleophile, whereas the SN2 rate constant, k2, increased with the electron-donating substituent of the N,N-dimethylaniline. The substituent effect on the k1 values is linearly correlated by the Yukawa-Tsuno equation with ρ  =  -5.2 and r  =  1.3. The unimolecular reaction can be regarded as a classical SN1 mechanism. In contrast, that on the k2 values shows an upward curvature when analyzed by the Brown σ+ treatment. These results are ascribed to the simultaneous and independent occurrence of SN1 and SN2 mechanisms in the present Menschutkin reaction. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 45
    Electronic Resource
    Electronic Resource
    Editorial (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 231-231 
    Details
    ISSN: 0894-3230
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: No Abstract
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 46
    Electronic Resource
    Electronic Resource
    Solvent effects on infrared spectroscopic and calorimetric characteristics of aliphatic ketones in binary solvent mixtures (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 283-289 
    Details
    ISSN: 0894-3230
    Keywords: calorimetry ; IR spectra ; ketones ; solvation ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Solution enthalpies of n-hexane, acetone, butan-2-one and octan-2-one in a series of tetrachloromethane-acetonitrile mixtures and the carbonyl stretching absorption frequencies in the IR spectra of these ketones were determined. It was found that over the whole range of concentrations (varying from neat tetrachloromethane up to neat acetonitrile) the solvation enthalpy of these compounds can be obtained additively from the contributions of the alkyl and carbonyl fragments. The solvent effect on the solvation enthalpy of the carbonyl group was found to be satisfactorily correlated with the corresponding IR frequency shifts of the C=O group. It was also found that the sensitivities of the carbonyl IR frequencies to the solvent composition are different for various ketones. From both IR and calorimetric data, the preferential solvation parameters were evaluated. The differences between the IR spectroscopic and calorimetric data are discussed. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 47
    Electronic Resource
    Electronic Resource
    Solvent effects on C=O stretching frequencies of some 1-substituted 2-pyrrolidinones (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 261-272 
    Details
    ISSN: 0894-3230
    Keywords: 1-substituted 2-pyrrolidinones ; C=O stretching frequencies ; solvent effects ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In an effort to model solute-solvent interactions, the C=O stretching frequencies of five 1-substituted 2-pyrrolidinones and four other carbonyl-containing compounds were measured for 30 common solvents. These were then correlated with four empirical parameter sets and one theoretical (computational) parameter set. While an empirical parameter set gave the best correlation equations, the theoretical parameter equations are physically and statistically significant. Solvent volume, polarizability and hydrogen bond donor acidity (capacity) terms are significant in the correlation equations. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 14 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 48
    Electronic Resource
    Electronic Resource
    Molecular orbital calculations on the P - S bond cleavage step in the hydroperoxidolysis of nerve agent VX (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 232-240 
    Details
    ISSN: 0894-3230
    Keywords: P - S bond cleavage ; hydroperoxidolysis ; nerve agent VX ; molecular orbital calculations ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The P - S bond cleavage process in the hydroperoxidolysis of a model system for the nerve agent VX was studied using ab initio and semiempirical molecular orbital methods. Aqueous solvation effects were included through single-point calculations using the semiempirical SM5.2PD/A continuum solvation model and geometries optimized at the HF/MIDI! level of theory. The predominant pathway for P - S bond cleavage involves pseudorotation of a low-energy trigonal bipyramidal intermediate followed by apical ligand ejection. In aqueous solution, the free energy barriers for these processes are found to be 14.3 and 4.6 kcal mol-1, respectively, with electronic energies calculated at the MP2/cc-pVDZ//HF/MIDI! level of theory. By comparison with another continuum model of solvation (PCM), it is concluded that the SM5.2PD/A model performs well even for hypervalent phosphorus species, in spite of not having included any such molecules in the model's parameterization set. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 49
    Electronic Resource
    Electronic Resource
    Conformational analysis of a 12-membered crown dithioether in the solid state and in solution (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 241-253 
    Details
    ISSN: 0894-3230
    Keywords: crown dithioether ; conformational analysis ; multicomponent equilibrium ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The solid-state molecular structure and the conformational behaviour in solution of the 12-membered crown dithioether 8-methyl-1,4-dioxa-7,10-dithiacyclododecane-5,12-dione were studied by x-ray crystallography, 1H and 13C NMR spectroscopy and molecular mechanics. The conformational rigidity of some constituent structural fragments allowed a detailed analysis of the structure and distribution of the conformers. A protocol for studies of multiconformational equilibrium was developed by means of the combined use of structure calculations and dynamic NMR measurements. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 50
    Electronic Resource
    Electronic Resource
    Metal-catalyzed carbenoid reactions with iodonium and sulfonium ylides (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 321-333 
    Details
    ISSN: 0894-3230
    Keywords: metal-catalyzed carbenoid reactions ; iodonium ylides ; sulfonium ylides ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Transition metal-catalyzed decomposition of phenyliodonium and diphenylsulfonium ylides was investigated with regard to application in asymmetric carbenoid reactions. Phenyliodonium ylides react in the presence of Rh(II) catalysts with the same selectivity in inter- and intramolecular cyclopropanations as the corresponding diazo compounds, and intramolecular CH insertions proceed with identical enantioselectivities. With diphenylsulfonium ethoxycarbonylmethylide the Cu(I)-catalyzed cyclopropanation of olefins affords trans/cis ratios and asymmetric inductions identical with those of diazo compounds, but with Rh(II) catalysts some small, although significant, selectivity variations occur, which are ascribed to coordination of diphenyl sulfide to one of the coordination sites of the catalyst. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 51
    Electronic Resource
    Electronic Resource
    In vivo formation of C - S bonds in biotin. An example of radical chemistry under reducing conditions (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 529-535 
    Details
    ISSN: 0894-3230
    Keywords: biotin ; in vivo C - S bond formation ; radical chemistry ; reducing conditions ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The last step in the biosynthesis of biotin involves the formation of carbon-sulfur bonds at non-activated carbons catalyzed by biotin synthase. S-Adenosylmethionine (AdoMet) and an electron source are essential for activity in cell-free systems. This important finding connects biotin synthase to a family of enzymes, namely pyruvate-formate lyase, anaerobic ribonucleotide reductase and lysine 2,3-aminomutase, which use the same cofactors. Additional experimental data led to the proposition of the following general mechanism. The carbons to be functionalized are first activated by homolytic cleavage of the C - H bonds, initiated by the deoxyadenosyl radical produced by a monoelectronic reductive cleavage of AdoMet with NADPH as electron source. The electron transfer system involves flavoproteins and very likely the [Fe - S] center of biotin synthase. NADPH and the flavoproteins can be replaced by photoreduced deazaflavin. By using a deuterated substrate, a deuterium transfer into deoxyadenosine has been observed, indicating that biotin synthase should be closely related to lysine 2,3-aminomutase, which uses AdoMet as a surrogate of vitamin B12. The source of sulfur, the nature of the immediate sulfur donor and hence the mechanism of trapping of the intermediate radicals are still unknown. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 52
    Electronic Resource
    Electronic Resource
    Chemistry of secologanin. Part 5. Graphical analysis of the acidic deglycosylation of vincoside derivatives (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 622-631 
    Details
    ISSN: 0894-3230
    Keywords: secologanin ; vincoside derivatives ; acidic deglycosylation ; graphical analysis ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Acidic hydrolysis and cyclization were studied in vincoside glycosides (‘natural’ series) and their dihydro derivatives (‘dihydro’ series) in which either one or both N atoms were free or blocked by an alkyl group. For interpretation of the results, a graph was constructed in which 25 points (actually circles) represent a maximum of 81 aglycone types and 40 arrows indicate 131 possible cyclizations. The reaction matrix of the graph was under thermodynamic control and in most cases afforded the thermodynamically most stable product aglycones. In addition to the deglycosylation, two types of cyclization were observed. In azacyclizations, the preferred nucleophilic site is N-4 over N-1, and the preferred electrophilic site is C-22 in the glycosides, C-21 over C-19 and C-17 in aglycones. In oxacyclizations, the preferred nucleophilic site is O-17 over C-18 and C-21, and the preferred electrophilic site is C-19 over C-21 and C-17 in the ‘natural’ series, C-21 over C-17 in the ‘dihydro’ series. In one case, the kinetically favoured aglycone types which had been generated in the reaction mixture were trapped in a subsequent reaction (outside the graph) before thermodynamic equilibrium was attained. With the help of graphical analysis it was possible to justify the formation of the most favourable and actually isolated products and pathways out of a large number of possibilities. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 53
    Electronic Resource
    Electronic Resource
    Reactant-solute encounters in aqueous solutions studied by kinetic methods: hydration cosphere overlap and camouflage effects (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 841-846 
    Details
    ISSN: 0894-3230
    Keywords: reactant-solute encounters ; aqueous solutions ; water ; kinetic methods ; hydration cosphere destructive overlap ; camouflage effects ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Rates of chemical reactions in aqueous solutions are often sensitive to low concentrations of added solutes such as ureas, alcohols, α-amino acids and carbohydrates. In this work, several simple chemical reactions were used to probe this sensitivity, which arises from interactions between added solute and the reacting solute. It was found that derived interaction parameters provide a novel insight into interactions between solute molecules in aqueous solution. For example, it was possible to identify two interesting effects, which are termed (i) ‘destructive overlap’ of hydration cospheres and (ii) ‘camouflage effects’ by water-solute interactions. Copyright © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 54
    Electronic Resource
    Electronic Resource
    Absolute proton affinities of some substituted toluenes: the additivity rule of thumb for ipso attack (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 663-669 
    Details
    ISSN: 0894-3230
    Keywords: ipso proton affinities ; additivity ; disubstituted toluenes ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The problem of the ipso protonation of toluene and its predominantly disubstituted derivatives was considered by the MP2(fc)/6-31G**//HF/6-31G*+ZPE(HF/6-31G*) theoretical model. The substituents involved covered a wide range of different donor-acceptor capabilities. It is shown that the calculated MP2 ipso proton affinities of substituted toluenes follow mutatis mutandis the same additivity rule which was found earlier to be operative in polysubstituted benzenes, naphthalenes and biphenylenes. The additivity equation is both intuitively appealing and useful, being able to offer quantitative estimates of the proton affinity by very simple calculation. It is based on the concept of the increment, which in turn describes the influence of a single substituent on the proton affinity. Any substituent behaves as a rule as if the other were non-existent, thus giving rise to the independent substituent approximation (ISA). The performance of the additivity rule of thumb is very good, as evidenced by the average absolute deviation of 1 kcal mol-1. Larger deviations are possible, but they rarely occur, being indicative of a difference in interactions between substituents in the initial neutral base and in the final cationic conjugate acid. Finally, it follows as a corollary of the present analysis that protonation ipso to the CH3 group is never thermodynamically the most favourable site of proton attack in the benzene ring, provided that there is a single unsubstituted carbon atom within the aromatic moiety. The relevance of ipso protonation in persubstituted benzenes is briefly discussed. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 55
    Electronic Resource
    Electronic Resource
    Photoinduced electron transfer and strand cleavage in pyrenyl-DNA complexes and adducts (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 561-565 
    Details
    ISSN: 0894-3230
    Keywords: pyrenyl-DNA complexes and adducts ; photoinduced electron transfer ; strand cleavage ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The fluorescence of pyrenyl residues in complexes with the nucleic acid bases G, C and T, but not A, is strongly quenched by photoinduced electron transfer mechanisms. Site-specifically modified 11-mer oligonucleotide duplexes containing a single modified guanosyl base G* bearing a covalently attached pyrenyl residue were prepared in order to probe for photochemical damage associated with these photoinduced electron transfer reactions. When the pyrenyl residue positioned at G* is photoexcited with 355 nm light, direct strand cleavage is observed at that site with low quantum yield. Frank strand breaks are also observed up to five base pairs away from G*, suggesting that intrastrand migration of a reactive intermediate from base to base is occurring. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 56
    Electronic Resource
    Electronic Resource
    From olefin cyclopropanation to olefin metathesis through catalyst engineering: recent applications of olefin metathesis to fine organic synthesis and to polymer chemistry (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 602-609 
    Details
    ISSN: 0894-3230
    Keywords: olefin metathesis ; olefin cyclopropanation ; catalyst engineering ; fine organic synthesis ; polymer chemistry ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An overview of the recent synthetic breakthroughs brought about by the discovery of new, functional group tolerant late transition metal (Rh and Ru)-based catalysts is proposed. Whereas dirhodium(II)-based complexes promote only carbene transfer reactions to olefins (i.e. olefin cyclopropanation), a few ruthenium-based catalysts can be engineered and fine tuned so as to mediate either carbene-transfer reactions or olefin metathesis. The different outcome of the reactions can be rationalized by the capability of the metal center to coordinate or not both the carbene and the olefin. This quite simple-minded approach indicates that several available coordination sites at the metal center favors metathesis reactions to the prejudice of olefin cyclopropanation. Examples of recent applications in ring opening metathesis polymerizations and copolymerizations include the formation of postpolymers of polydienes, of carbohydrate-substituted polymers and of telechelic oligomers. Application of the same ruthenium-based catalysts in ring-closing metathesis is illustrated by the formation of crown ether analogs, of unsaturated peptides and amino acids, of β-lactams, and of different bicyclic systems.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 57
    Electronic Resource
    Electronic Resource
    Imperatives for enzymatic catalysis of isomerization of sugars and sugar phosphates (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 512-518 
    Details
    ISSN: 0894-3230
    Keywords: sugar isomerization ; sugar phosphate isomerization ; enzymatic catalysis ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The relative yields of the products of isomerization of D,L-glyceraldehyde in D2O with intramolecular transfer of a hydride ([1-1H]DHA) and with proton transfer ([1-2H]DHA) were determined by high-resolution 1H NMR analyses. A study of the catalysis of this isomerization by deuteroxide ion, buffer anions and Zn2+ established the following: (1) isomerization with proton and hydride transfer occurs at approximately equal rates in dilute solutions of sodium deuteroxide; (2) Brønsted bases catalyze isomerization with proton transfer in a bimolecular reaction; (3) Zn2+ catalyzes isomerization with hydride transfer in a bimolecular reaction; and (4) Zn2+ and acetate ion react in concert to catalyze isomerization with proton transfer in a termolecular reaction. These results show that the various pathways for isomerization with proton and hydride transfer proceed via transition states of similar energies, so that there is no strong imperative for enzymatic catalysis by any particular reaction mechanism. The relevance of these results to the mechanism of action of xylose isomerase is discussed briefly. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 58
    Electronic Resource
    Electronic Resource
    Selective arylation of exocyclic N-position of 2-pyrimidylnitrenium ion photolytically generated from tetrazolo-[1,5-a]pyrimidine in the presence of trifluoroacetic acid (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 478-484 
    Details
    ISSN: 0894-3230
    Keywords: Selective arylation ; exocyclic N-position ; 2-pyrimidylnitrenium ion ; tetrazolo[1,5a]pyrimidine ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Photo-reactions of tetrazolo[1,5-a]pyrimidine (1) with benzene (2a) and substituted benzenes (2b-f) in the presence of trifluoroacetic acid (TFA) gave 2-(2-, 3- and 4-substituted anilino)pyrimidines (3-5) together with 2-aminopyridine (6) and biphenyl (7) or diarylmethanes (8b, 8c and 8e). From the effect of heavy-atom solvent on the reactions, it is reasonable to assume that 3-5 are formed via a singlet species, but 6-8 via a triplet species. The intermediacy of 2-pyrimidylnitrenium ion is consistent with the evidence derived by the above effect, by a Hammett plot with ρ = -2.9 and by effects of solvent nucleophilicity and counter-anions. The selective exocyclic N-arylation giving 3-5 is discussed. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 59
    Electronic Resource
    Electronic Resource
    Kinetics of the hydrolysis of cyclic N-substituted sulfamides: 4-amino-2-cyclohexyl- and 4-amino-2-phenethyl-2,3-dihydro-3-oxo-1,2,5-thiadiazole 1,1-dioxides (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 489-494 
    Details
    ISSN: 0894-3230
    Keywords: Cyclic N-substituted sulfonamides ; 1,2,5-thiadiazole 1,1-dioxide derivatives ; hydrolysis ; kinetics ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The hydrolysis reactions of 4-amino-2-phenethyl- and 4-amino-2-cyclohexyl-2,3-dihydro-3-oxo-1,2,5-thiadiazole 1,1-dioxide (Ia and Ib) were investigated in the range 24-73 °C in buffered aqueous solutions. The observed rate constants (kobs) are independent of pH in the range ca 1-4 pH, but increase with increase in pH above ca 4. A linear log kobs vs pH profile with unit slope is observed from pH ca 4 up to the highest experimental pH (ca 10). The products are the corresponding new compounds: 2-amino-2-[(N-substituted-sulfamoyl)imino]acetic acid salts. The C=N bond of these compounds hydrolyses further, in a slow reaction, to the sulfamide and oxalic acid derivatives. The substrates decompose to the final products without accumulation of the acetic acid derivatives under these experimental conditions. A mechanism is proposed. Rate constants and activation parameters are given for the first reaction step. Owing to steric effects, the reaction rate is higher for the N-phenethyl-substituted derivative than for the 2-cyclohexyl-substituted derivative. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 60
    Electronic Resource
    Electronic Resource
    Rate enhancement of 1,3-dipolar cycloaddition of N-methylindole: the singular role of Grignard reagents (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 455-466 
    Details
    ISSN: 0894-3230
    Keywords: 1,3-dipolar cycloaddition ; N-methylindole ; Grignard reagents ; rate enhancement ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reactions of 2-N-methylindolyl and 2- and 3-benzo[b]thiophenyl anions with nitrile oxides and nitrilimines were performed in order to investigate whether the use of anionic dipolarophiles modifies a classical 1,3-dipolar cycloaddition. When lithium compounds were used as bases, the heterocyclic anions invariably acted as nucleophilic species; in contrast, when a Grignard reagent was employed, the N-methylindole gave cycloaddition products with an extraordinary rate enhancement. The hypothesis that N-methylindole and ethylmagnesium bromide give an adduct much more reactive than N-methylindole itself was supported by the results of a theoretical investigation. The structure and electron distribution of the adduct were determined by ab initio calculations and compared with those of known Grignard complexes with nitrogen ligands. The performance of different basis sets was tested. The quantum theory of atoms in molecules was used to determine atomic charges and to describe the nature of bonds in terms of the properties of the electron density at the bond critical points. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 61
    Electronic Resource
    Electronic Resource
    The ring inversion of silacycloheptatriene and cycloheptatriene. Comparison of the ‘aromaticity’ of planar and boat conformers estimated by nucleus-independent chemical shift (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 475-477 
    Details
    ISSN: 0894-3230
    Keywords: cycloheptatriene ; silacycloheptatriene ; ring inversion ; aromaticity ; ab initio calculation ; nucleus-independent chemical shift ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Nucleus-independent chemical shifts (NICS) of boat and planar structure of silepins (1) and cycloheptatriene (2) were calculated at the HF/6-31+G* level for the Becke3LYP/6-31G* optimized geometries in order to investigate the correlation between the inversion barrier and aromatic nature in the boat and planar forms of 1 and 2. The NICS of unsubstituted silepin 1a indicated that there is almost no stabilization in the boat form (NICS, -0.5) and that the planar form (NICS, 3.5) is relatively destabilized in comparison with the boat form. On the other hand, the NICS of 2 showed that there is considerable homoconjugative stabilization in the boat form (NICS, -4.2) and destabilization in the planar form (NICS, 8.2). In addition to the geometrical effects resulting from angle strain, these electronic effects are considered to affect the energy barriers for ring inversion, which have been calculated to be 0.9 kcal mol-1 for 1a and 5.2 kcal mol-1 for 2. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 62
    Electronic Resource
    Electronic Resource
    Hydrogen-bonding-based thermochromic phenol-amine complexes (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 737-742 
    Details
    ISSN: 0894-3230
    Keywords: thermochromism ; proton transfer ; hydrogen bond ; phenol ; amine ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Variable-temperature UV-vis, 13C NMR and IR studies showed that proton-transferred complexes were formed between phenols and amines in apolar solvents at low temperature. Upon cooling a solution of p-nitrophenol and diisopropylamine in toluene, the colour of the solution changed from colourless to yellow. This thermochromism was ascribed to the proton transfer in the hydrogen-bonding complex. Under UV-vis conditions, butylamine and imidazole also caused similar thermochromism upon complexation with p-nitrophenol, while triethylamine, quinuclidine and pyridine did not. The thermochromic behaviour was particularly dependent on the stoichiometry of the amine and the phenol: a solution of 3,3′-dibromo-5,5′-dinitro-2,2′-biphenyldiol and diisopropylamine with a molar ratio of 1:1 showed no thermochromism, while solutions with 1:2 or higher ratios showed thermochromism, indicating that excess amine is required to obtain the proton-transferred species. These results revealed that the proton-transferred species forms in apolar solvents at low temperature if an appropriate hydrogen-bonding network between the phenol and the amine can stabilize it. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 63
    Electronic Resource
    Electronic Resource
    Double fragmentation in cation radicals. An example in the NADH analogues series (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 774-780 
    Details
    ISSN: 0894-3230
    Keywords: double fragmentation ; cation radicals ; NADH analogues ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The cation radical of 9-tert-butyl-N-methylacridan, generated electrochemically or photochemically, offers, in the presence of strong bases, a remarkable example of a double fragmentation. Whereas in acidic or weakly basic media the tert-butyl radical is cleaved with concomitant formation of the methylacridinium cation, the presence of a strong base triggers the cleavage of both the methyl group borne by the nitrogen atom and the tert-butyl group on C-9 leading to acridine, formaldehyde and the tert-butyl anion, even though methylacridinium cation is stable under these conditions. The origin of this unprecedented behavior resides in the prior deprotonation of the methyl group borne by the nitrogen atom which outruns the usual deprotonation at the 9-carbon because this is slowed by the steric hindrance due to the presence of the tert-butyl group. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 64
    Electronic Resource
    Electronic Resource
    Effect of sulfuric acid on reactions of peroxymonosulfate ion with sulfides and thiol esters (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 803-808 
    Details
    ISSN: 0894-3230
    Keywords: peroxymonosulfate ion ; oxidation ; sulfuric acid ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Peroxymonosulfate ion, HSO5-, as Oxone in aqueous H2SO4, oxidizes sulfides [MeSC6H4X(p), X = Me, H, NO2] to sulfoxides and converts aryl thiobenzoates [PhCOSC6H4X(p), X = Me, H] and thiol phosphorus(V) esters [Ph2POSPh, (EtO)2POSPh, Ph2POSEt, Ph(EtO)POSEt] into the acids and sulfonate ions. Second-order rate constants increase with increasing concentration of H2SO4 (10-53 wt%), owing to the high polarity of the medium rather than to acid catalysis. The rate increases fit the Grunwald-Winstein equation based on YOTs solvent parameters derived from rate effects on SN1 solvolyses. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 65
    Electronic Resource
    Electronic Resource
    Cation radical cycloaddition polymerization: Diels-Alder copolymerization (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 825-830 
    Details
    ISSN: 0894-3230
    Keywords: cation radical cycloaddition polymerization ; Diels-Alder copolymerization ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Diels-Alder cycloaddition copolymerization of a bis(diene) with ionizable bis(dienophiles) via a cation radical mechanism has been accomplished using tris(4-bromophenyl)aminium hexachloroantimonate as a catalyst in dichloromethane solvent. The reactions occur at 0°C and yield Diels-Alder polymers of MW up to ca. 10,000 and a polydispersity index ca. 2. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 66
    Electronic Resource
    Electronic Resource
    Kinetic study of base-promoted elimination reactions of some 1,1,1-trihalo-2,2-bis(dimethoxyphenyl)ethanes in alcoholic solutions (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 54-58 
    Details
    ISSN: 0894-3230
    Keywords: 1,1,1-trihalo-2,2-bis(dimethoxyphenyl)ethanes ; base-promoted elimination ; reaction mechanism ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The base-promoted elimination reactions of 1,1,1-trichloro-2,2-bis(dimethoxyphenyl)ethanes were investigated. The bis(3,4-dimethoxyphenyl)ethane was found to be more reactive than the bis(2,5-dimethoxyphenyl)ethane and the latter more reactive than the bis(2,4-dimethoxyphenyl)ethane. Kinetic data relative to 1,1,1-trihalo(chloro or bromo)-2,2-bis(3,4-dimethoxyphenyl)ethanes show that the tribromo reacts faster than trichloro derivative and that the reactions are general-base promoted with Brønsted β values of about 0.6. A kinetic isotope effect, with kH/kD ratio ranging from 3.5 to 5.7, for the base-promoted elimination reaction of 1,1,1-trichloro-2,2-bis(3,4-dimethoxyphenyl)ethane was found. Tunneling occurs for methoxide and ethoxide ion-promoted eliminations. Activation parameters for alkoxy-promoted elimination show a similar trend for chloride and bromide derivatives. The data collected seem to confirm that there is contiguity between E1cBirr and E2 mechanisms. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 67
    Electronic Resource
    Electronic Resource
    Kinetic and thermodynamic study of 2-bromo-2-methylbutane, 2-chloro-2-methylbutane and 3-chloro-3-methylpentane in diols (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 36-40 
    Details
    ISSN: 0894-3230
    Keywords: haloalkanes ; diols ; kinetics ; thermodynamics ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Rate constants, k, were determined for the solvolytic reactions of 2-bromo-2-methylbutane, 2-chloro-2-methylbutane and 3-chloro-3-methylpentane in 10 pure diols at 298.15 K. The Gibbs energies of activation were calculated in order to study the influence of the solvent and to provide mechanistic information about the activation process. By combining these values with a set of infinite dilution activity coefficients, γ∞, the transfer Gibbs energies of the reactants (initial state) and of the activated complex (transition state) were obtained, which allowed the solvent effects on both states to be quantitatively analysed. The γ∞ values were calculated using the UNIFAC group contribution method. The modified Flory-Huggins equation was used in the combinatorial term. The interaction parameters were taken from the specific UNIFAC γ∞ interaction parameter table, except for the γ∞ values of 2-chloro-2-methylbutane and 3-chloro-3-methylpentane in diethylene glycol and triethylene glycol, which were obtained using the γ∞ UNIFAC-VLE interaction parameter tables. For comparative purposes all the other infinite dilution activity coefficients of the three solutes in the diols were also calculated using the UNIFAC-VLE parameter tables. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 68
    Electronic Resource
    Electronic Resource
    Inhibitory effect of DNA structure on the efficiency of reaction of guanosine moieties with a nitrenium ion (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 71-76 
    Details
    ISSN: 0894-3230
    Keywords: guanosine ; nitrenium ; DNA structure ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The N-acetyl-N-(2-fluorenyl)nitrenium ion (2a) reacts very efficiently with monomeric 2′-deoxyguanosine (d-G) to form a C-8 adduct, N-(2′-deoxyguanosin-8-yl)-2-acetylaminofluorene (6), in an aqueous environment, with a selectivity ratio, kd-G/ks, of 13.1 × 103 M-1 at 0°C and 4.8 × 103 M-1 at 30°C. The reactivity of the self-complementary oligomer d-ATGCAT with 2a can be separated into components due to the single-stranded (SS) and double-stranded (DS) forms. Within the error limits of the measurements kSS/kd-G ≈ 0.27 and kDS/kd-G ≈ 0. Another measure of the reactivity of d-G moieties in the DNA double helix can be obtained from measurements with the circular super-coiled plasmid pUC19. This plasmid provides an upper limit for kpUC19/kd-G of 0.02, where kpUC19 is the average trapping rate constant per d-G moiety in pUC19. The strong inhibition of the trapping reaction caused by the tertiary structure of the DNA double helix may be responsible for the change in product distribution of 2a-d-G adducts found from reaction with d-G, and denatured DNA (exclusive C-8 adduct, 6) and native DNA [5-20% N-2 adduct,3-(2′-deoxyguanosin-N2-yl)-2-acetylaminofluorene, 7]. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 69
    Electronic Resource
    Electronic Resource
    Effects of urea, Na+ and Li+ ions on the kinetics and mechanism of intramolecular general base-catalyzed glycolysm of ionized phenyl salicylate in ethane-1,2-diol-acetonitrile solvents at a constant water concentration (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 109-114 
    Details
    ISSN: 0894-3230
    Keywords: phenyl salicylate ; ethane-1,2-diol ; urea ; sodium salt ; lithium salt ; transesterification ; kinetics ; intramolecular general base catalysis ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Pseudo-first-order rate constants (k1) for the reaction of ethane-1,2-diol (DOL) with ionized phenyl salicylate (PS-), obtained in mixed DOL-CH3CN solvent at constant [H2O] and [NaOH], obey the relationship k1  =  α[DOL]T/(1 + 2KA[DOL]T), where α is the apparent second-order rate constant, KA is the association constant for the dimerization of DOL and [DOL]T is the total concentration of DOL. The values of KA, in the presence of Na+ ions, decrease with increase in [H2O]. Lithium ions cause almost complete depolymerization of polymeric DOL (i.e. KA ≈ 0) under the experimental conditions imposed. The effect of 0.5 M urea on the structural behavior of the mixed solvent is kinetically insignificant. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 70
    Electronic Resource
    Electronic Resource
    Effects of oligooxyethylene linkage on intramolecular [2 + 2] photocycloaddition of styrene derivatives (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 79-83 
    Details
    ISSN: 0894-3230
    Keywords: [2 + 2] ; photocycloaddition ; quantum yield ; oligooxyehylene linkage ; cyclophane ; styrene derivatives ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: There are two possible explanations for the high yields in the intramolecular [2 + 2] photocycloaddition of compounds 3a-d in which two styrene moieties are bridged by an oligooxyethylene linkage: one is the electronic effects of phenoxy oxygen atoms at the para-position of the vinyl group and the other is the steric effects due to the flexibility of oligooxyethylene linkages. In order to clarify the contributions of the two effects, a study was made of the photoreaction of similar compounds in which oxygen atoms are present only at the ends of the chain, and therefore only the electronic effects are involved. In these compounds, the quantum yields of the photocycloaddition were found to be low. Hence the high yields in the photocycloaddition of 3a-d are concluded to be ascribable to the flexibility of oligooxyethylene linkages. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 71
    Electronic Resource
    Electronic Resource
    Improved method for estimating the ZFS parameter D for delocalized biradicals (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 819-824 
    Details
    ISSN: 0894-3230
    Keywords: zero field splitting parameter, D ; organic biradicals ; triplets ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An ‘average’ approximation for calculating the zero-field splitting parameter, D, gives reasonable results when used to calculate D values for non-disjoint delocalized organic biradicals. When used to calculate disjoint localized organic biradicals the D values are approximately half the experimental values. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 72
    Electronic Resource
    Electronic Resource
    Correlation analysis of UV spectral data of some phenylhydrazones and semicarbazones by the dual-parameter equation. Observation of three types of behaviors of the λmax values induced by the polar effects of substituents (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 809-818 
    Details
    ISSN: 0894-3230
    Keywords: UV spectra ; dual-parameter equation ; correlation analysis ; polar effect ; spin-delocalization effect ; p-Y-substituted benzaldehyde phenylhydrazones ; p-Y-substituted benzaldehyde 2,4-dinitrophenylhydrazones ; p-Y-substituted benzaldehyde 4-nitrophenylhydrazones ; p-Y-substituted benzaldehyde N-phenylsemicarbazones ; p-Y-substituted benzaldehyde semicarbazones ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The K-band λmax values of the UV spectra of five types of p-Y-benzaldehyde derivatives, namely phenylhydrazones (1-Ys), 2,4-dinitrophenylhydrazones (2-Ys), 4-nitrophenylhydrazones (3-Ys), semicarbazones (4-Ys) and N-phenylsemicarbazones (5-Ys), were measured and the corresponding wavenumbers (νmax) calculated. Correlation analyses of the νmax values by the dual-parameter equation show that the νmax values of these compounds are affected, albeit to different degrees, by both spin-delocalization effects (σ·) and polar effects (σx) of the substituents. The spin-delocalization effects of substituents always facilitate bathochromic shifts of the λmax values (ρ· negative). However, polar effects of the substituents on these λmax data depend on the mode of polarization of these hydrazone or semicarbazone molecules, i.e. electron-pair acceptor substituents (Ys) facilitate bathochromic shifts for 1-Ys (ρx negative), but hypsochromic shifts for 2-Ys and 3-Ys (ρx positive), and induce very small shifts for 4-Ys and 5-Ys. As expected, donor Ys facilitate hypsochromic shifts for 1-Ys and bathochromic shifts for 2-Ys and 3-Ys and induce very small shifts for 4-Ys and 5-Ys. Possibly, a higher degree of polarization of the substrate molecule would demand a higher degree of polar assistance from the substituents at the transition states. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 73
    Electronic Resource
    Electronic Resource
    Comparison of ΔG°Acid (gas phase) and kinetic acidities measured in methanolic sodium methoxide (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 614-617 
    Details
    ISSN: 0894-3230
    Keywords: ΔG°Acid (gas phase) ; kinetic acidities ; methanolic sodium methoxide ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Hydron exchange rates, kexc (M-1s-1), using methanolic sodium methoxide were compared with ΔG°Acid, (kcal mol-1) (gas phase) for 9-phenylfluorene, C6H5CH(CF3)2, m-CF3C6H4CH(CF3)2, p-CF3C6H4CHClCF3, m-CF3C6H4CHClCF3, 3,5-(CF3)2C6H3CHClCF3, fluorene and C6F5H. There is a good linear correlation for p-CF3C6H4CHClCF3, m-CF3C6H4CHClCF3 and 3,5-(CF3)2C6H3CHClCF3, with the others falling off the line. The fluorinated benzyl compounds and pentafluorobenzene have near-unity isotope effects and therefore differ from the fluorenyl compounds. Although the acidity and the exchange rates for three of the compounds [9-phenylfluorene, C6H5CH(CF3)2 and p-CF3C6H4CHClCF3] are similar, the important proton-transfer step to form a hydrogen-bonded carbanion intermediate and the subsequent breaking of that weak bond to form a free carbanion in methanol differ significantly for the fluoernyl compound compared with the two fluorinated benzylic compounds. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 74
    Electronic Resource
    Electronic Resource
    Intramolecular thermal (4σ + 2π) dyotropy: primary 2H kinetic isotope effects. Experimental limiting barrierparameters for quantum tunnelling in 2H transfer processes and mechanistically significant substituent effects (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 879-886 
    Details
    ISSN: 0894-3230
    Keywords: intramolecular thermal (4σ + 2π) dyotropy ; kinetic isotope effects ; limiting barrier parameters ; quantum tunnelling ; 2H transfer processes ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Primary deuterium kinetic isotope effects (PDKIE) in parazoline-annelated syn-sesquinorbornenes exhibiting irreversible intramolecular (4σ + 2π) thermal dyotropy reveal unambiguous evidence for a tunnelling contribution to the kinetics in one instance but not for a close analogue. For analogous dyotropy of a cyclohexadiene-annelated syn-sesquinorbornene, the tunnelling components of the kinetic behaviour is small by comparison. The H atom traverse between alternative loci for the pyrazolines, deduced from x-ray and neutron diffraction data, is in agreement with approximate barrier parameters obtained by fitting of the PDKIE data to the Bell equation; barrier penetration is 3.22 kcal below the computed barrier corrected for the tunnelling contribution. The relative kinetic effect of systematic variation of the π-donor/acceptor groups on aryl ring substituents at C and N in the pyrazoline ring is consistent with a pericyclic process for dyotropy of these compounds, but not with rearrangement mediated by biradicals resulting from single H atom transfer in the rate-limiting step. Computer modelling of the transition state for dyotropy of these compounds is also consistent with a thermal, orbital symmetry conserved pericyclic reaction. Copyright © 1998 John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 75
    Electronic Resource
    Electronic Resource
    Unusual reactivity of highly strained cyclophanesDedicated to Prof. Dr Maitland Jones, Jr, on the occasion of his 60th birthday (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 362-376 
    Details
    ISSN: 0894-3230
    Keywords: highly strained cyclophanes ; reactivity ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An essential feature of the concept of aromaticity has been the stability and lack of reactivity of aromatics relative to that of other unsaturated compounds. Contrary to this general experience, high and unusual reactivity is encountered when simple, monocyclic benzene rings are bent by short bridges into a boat-shaped conformation, as is the case in small [n] paracyclophanes (n ≤ 8) and [n]metacyclophanes (n ≤ 7). This is illustrated, mostly with examples taken from the authors' own work, for thermal and photochemical behavior and reactions with electrophiles, nucleophiles and dienophiles. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 76
    Electronic Resource
    Electronic Resource
    Heterogeneous catalysis of organic reactions (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 356-361 
    Details
    ISSN: 0894-3230
    Keywords: heterogeneous catalysis ; organic reactions ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A decade's worth of work is reviewed: building on the demonstrated prowess of heterogeneous catalysis in industrial organic chemistry, the author's laboratory devised efficient catalysts for a number of organic reactions, based on aluminosilicates such as clays and zeolites. This review also spells out, at a time when creative research is overshadowed by imitative research, some of the methodological musts that also happen to characterize physical organic chemistry: the devising of experiments so that accurate numerical data can be obtained; the importance of remote, interdisciplinary connections; the need for estrangement from stereotypic preconceptions that may obscure the true explanations for the phenomena; and the over-riding need for concerning oneself only, or at least predominantly, with the important facts that nature tells, if one cares to listen. © 1998 John Wiley & Sons, Ltd.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 77
    Electronic Resource
    Electronic Resource
    Are phosphatetrahedrane and diphosphatetrahedrane phosphorus or carbon bases? (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 678-683 
    Details
    ISSN: 0894-3230
    Keywords: phosphatetrahedrane ; diphosphatetrahedrane ; phosphorus bases ; carbon bases ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The protonation processes of phosphotetrahedrane (PTH) and diphosphatetrahedrane (DPTH) were studied using density functional theory approaches. The geometries of the neutrals and the protonated species were optimized at the B3LYP/6- 31G(d) level and the final energies were obtained using the B3LYP/6- 311+G(3df,2p) level of theory. Both PTH and DPTH are tetrahedral compounds which behave as carbon bases in the gas phase. In contrast with what was found for other phosphorus-containing cage structures such as tetraphosphacubane, the nature of the basic center does not change when the hydrogen atoms are substituted by bulky substituents. This is a consequence of the fact that both phosphorus and carbon protonation processes lead to C - P bond fission, so that the repulsive interactions between the susbtituents are not significantly different in carbon- or phosphorus-protonated structures. Protonation of DPTH at the P - P bond yields a local minimum with a P - H - P linkage similar to that described before for the most stable protonated form of P4. This seems to indicate that the existence of P - P linkages in strained structures clearly favors the formation of non-classical protonated species where the proton bridges the two phosphorus atoms. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 78
    Electronic Resource
    Electronic Resource
    Improved method of calculating group polarization effects: constants σα (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 485-488 
    Details
    ISSN: 0894-3230
    Keywords: group polarization effects ; polarizability countants ; ab initio ; Sadlej's basis set ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An improved model is presented for ab initio calculations of the polarizability constants σα using Sadlej's basis set. A new set of constants was calculated for common groups and these were compared with previous 3-21G and 3-21G* calculations and with some experimental equilibrium constants in the gas phase. For the time being, the calculations seem to be the most general approach for obtaining these constants whereas the experimental possibilities are limited in scope. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 79
    Electronic Resource
    Electronic Resource
    1:1 Crystal complex of 2′,6′-dimethoxyflavone and 2,6-dimethoxybenzoic acid. Relationship of pKa to x-ray hydrogen bond data (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 751-755 
    Details
    ISSN: 0894-3230
    Keywords: 2′,6′-dimethoxyflavone-2,6-dimethoxybenzoic acid complex ; crystal structure ; pKa values ; hydrogen bonds ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The crystal structure of the 2′,6′-dimethoxyflavone-2,6-dimethoxybenzoic acid complex was determined. Owing steric hindrance of the methoxy groups, the two H-bonded molecules are twisted. Earlier results were used to establish a relationship between the pKa values of different acids and their hydrogen bond distances in complexes with 2′,6′-dimethoxyflavone. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 80
    Electronic Resource
    Electronic Resource
    Stability and nitrosation efficiency of substituted N-methyl-N-nitrosobenzenesulfonamides (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 756-760 
    Details
    ISSN: 0894-3230
    Keywords: N-methyl-N-nitrosobenzenesulfonamides ; stability ; nitrosation efficiency ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of substituted N-methyl-N-nitrosobenzenesulfonamides [2,4,6-(CH3)3, 4-CH3O, 4-CH3, 4-Cl and 4-NO2] were synthesized. All of them transfer their nitroso group to N-methylaniline in a quantitative manner, the more reactive being those substituted with electron-withdrawing groups, thus resembling some of the known alkyl nitrites. Studies of their acid denitrosation and base-catalysed hydrolysis demonstrated that the nitrosobenzenesulfonamides are fairly stable in aqueous media between pH 2 and 11. Their relative stability in aqueous media together with their ability to transfer the nitroso group to nucleophiles suggest their use as excellent alternatives to alkyl nitrites in both neutral and basic media. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 81
    Electronic Resource
    Electronic Resource
    Conformational analysis of substituted 5,6,7,8-tetrahydrodibenzo[a,c]cyclo-octene: comparison of 1H NMR, molecular mechanics and semiempirical methods (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 781-786 
    Details
    ISSN: 0894-3230
    Keywords: eight membered rings ; conformational analysis ; molecular mechanics ; semiempirical methods ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The 6-Mono- and trans-6,7-di-substituted derivatives of 5,6,7,8-tetrahydrodibenzo[a,c]cyclo-octene exist in solution in two different conformations. The experimental ΔGo values obtained from 1H NMR spectra are compared with the ΔEsteric and ΔG values calculated by molecular mechanics and semiempirical quantum mechanics methods respectively. The experimental ΔGo values are reproduced better by the ΔEsteric values. The semiempirical methods predict the order of stability of the conformers correctly except for two cases in the PM3 and AM1 methods, but the estimated values are far from the experimental ones. The standard deviation between the experimental ΔGo values and those calculated by semiempirical methods is less for AM1 and MNDO and greater for PM3 and MINDO/3. The conformational space of the flexible side chains in monoacetoxy 1d, monohydroxy 1e, trans-diacid 2d, trans-dimethyl ester 2e and trans-bis-hydroxymethyl 2f searched by molecular mechanics is not reproduced completely by semiempirical methods. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 82
    Electronic Resource
    Electronic Resource
    Effect of solvent composition on the acidity of phenols in dimethyl sulfoxide-water mixtures (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 847-852 
    Details
    ISSN: 0894-3230
    Keywords: phenols ; acidity ; solvent composition ; supersolvent ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of solvent composition on the acidity of substituted phenols in DMSO-H2O systems was examined. It is shown that in DMSO-H2O mixtures with up to 35 mol% DMSO there is a linear relationship between the pKa values of monosubstituted phenols in the binary solvent mixtures of different compositions and the corresponding pKa values in water. This leads to an equation relating the slope and intercept terms, pKa(DMSO-H2O) = slope[pKa(H2O)] + intercept. The basis of this relationship in the Kirkwood-Westheimer equation is examined. The significance of a possible ‘supersolvent’ is discussed. The applicability of the relationships derived herein to other rate-equilibria relationships and solvent mixtures is considered. Copyright © 1998 John Wiley & Sons, Ltd.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 83
    Electronic Resource
    Electronic Resource
    Dipole moments of polyenic oligomeric systems. Part I. A one-dimensional molecular wire model (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 853-856 
    Details
    ISSN: 0894-3230
    Keywords: polyenic oligomerics ; dipole moments ; one-dimensional molecular wire model ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Ground-state dipolar moments of oligomeric compounds, containing electron-donor (D) and electron-acceptor (A) groups as two terminal units of the polyenic bridge (D-wire-A), can well be described by means of a one-dimensional molecular wire model, which considers a scattering process of electrons through the charge-transfer conduction channel. The dipole moment of the oligomers (μn) follows a non-linear dependence of the polyenic bridge length (L) according to μn = μ0 + μ∞(1 - e- γL) where μ0 is the dipole moment of the first compound of the series, without a polyenic unit (n = 0), μ∞ is a limit value for L → ∞ and γ is the one-dimensional conduction constant of the π-molecular orbital channel of the molecular wire. This model can be extended to all those conjugated oligomers of the D-wire-A type where the electronic charge of the donor group can induce a soliton wave as far as through the polyenic bridge towards the acceptor group. Copyright © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 84
    Electronic Resource
    Electronic Resource
    Conformational effects on the mechanism of acid-catalyzed dehydration of hexitols (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 887-894 
    Details
    ISSN: 0894-3230
    Keywords: D-glucitol ; D-mannitol ; conformation ; dehydration reaction ; molecular mechanics ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Monte Carlo search of the low-energy regions of D-mannitol (4) and D-glucitol (5) conformational space was undertaken in order to investigate conformational effects on the stereochemistry of the acid-catalyzed dehydrative cyclization reaction of 4 and 5 to the corresponding 1,4:3,6-dianhydrohexitols. It was found that although dominant conformations in water resemble closely the crystal state conformations of 4 and 5, the same is not true in solvents of low polarity. The magnitudes of the calculated energies of the reactive conformations for the dehydrative cyclization reaction suggest an SN2 mechanism with a late transition state. Copyright © 1998 John Wiley & Sons, Ltd.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 85
    Electronic Resource
    Electronic Resource
    Photochemical removal of the tosyl group from the 5′N position of 5′-aminopyrimidine nucleosides: syntheticapplications (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 618-621 
    Details
    ISSN: 0894-3230
    Keywords: 5′-aminopyrimidines ; p-toluenesulfonyl photoremoval ; 3′-azido-3′-deoxythymidine derivatives ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The p-toluenesulfonyl (tosyl) group, an effective protector of the amine function of thymidine derivatives 2a and b, has proven to be photoremovable. This photoreaction was successfully used in the synthesis of new 5′-amino analogs of 3′-azido-3′-deoxythymidine (AZT), 6a and b. Selective photohydrolysis of 5′N-tosylamides 2a and b was carried out by UV irradiation (〉300 nm) in aqueous acetonitrile in the presence of 1,5-dimethoxynaphthalene as an electron donor. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 86
    Electronic Resource
    Electronic Resource
    Hydrolysis of N-methyl-N-nitroso-p-toluenesulphonamide in micellar media (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 584-588 
    Details
    ISSN: 0894-3230
    Keywords: N-methyl-N-nitroso-p-toluenesulphonamide ; hydrolysis ; micellar media ; pseudophase model ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The acid and basic hydrolysis of N-methyl-N-nitroso-p-toluenesulphonamide (MNTS) was studied in different micellar aggregates (CTACl, CTABr, TTABr, LTABr, and OTACl). The effect of mixed micelles (OTAX-LTAX) was also studied. The kinetic behaviour was explained on the basis of the pseudophase model, from which the binding constants of MNTS to different micelles, the ion exchange constants and the reactivity constants in the micellar pseudophase were obtained. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 87
    Electronic Resource
    Electronic Resource
    Binding of protons and zinc ions to transition states for tautomerization of α-heterocyclic ketones: implications for enzymatic reactions (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 519-528 
    Details
    ISSN: 0894-3230
    Keywords: proton binding ; zinc ion binding ; transition states ; α-heterocyclic ketones ; tautomerization ; enzymatic reactions ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The description of catalysis in terms of binding of a catalyst to the transition state propoposed by Kurz is applied to tautomerization of the α-heterocyclic ketones phenacylpyridine, phenacylpyrazine, phenacylphenanthroline and phenylacetylpyridine catalysed by protons and zinc ions. Binding constants for protonated and zinc-coordinated transition states, KB≠ are reported and Brønsted coefficients are calculated from comparison of KB≠ with binding constants for the keto reactant and enolate anion intermediate. The formal equivalence of the binding formalism to a conventional Brønsted analysis is emphasized, and the results are compared with those from a ‘generalised’ Brønsted plot of rate constants against equilibrium constants for reactions of uncomplexed, protonated and zinc ion-coordinated ketones. This plot confirms that intrinsic reactivities of metal-coordinated and protonated substrates are similar even where differences exist between substrates. Application of a comparable Kurz-Brønsted treatment to enzymatic reactions depends in principle upon (a) dissecting binding contributions to catalysis from approximation of covalently reacting groups and (b) separating binding at the reaction site of the substrate, to which Kurz's treatment applies, from ‘remote’ binding, which, to a first approximation, is unchanged between Michaelis complex and transition state. The Brønsted relationship highlights stabilization of reactive intermediates as a thermodynamic driving force for binding catalysis at the reaction site. A formal expression which describes this stabilization, and also accommodates stabilization by remote binding of the substrate and intermediate by the enzyme, is proposed. Its relationship to the usual expression for application of the Kurz approach to enzyme catalysis, (kcat/k0)/Km = KB≠, is discussed and the usefulness of the Brønsted and Marcus relationships for interpreting KB≠ is emphasized. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 88
    Electronic Resource
    Electronic Resource
    Mono- and polynuclear ruthenium(II) complexes, photo-probes and reagents for targeted DNA sites (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 566-576 
    Details
    ISSN: 0894-3230
    Keywords: ruthenium (II) complexes ; photoreactivity ; targeted DNA sites ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Several luminescent ruthenium(II) complexes were designed whose main characteristic is their photoreactivity towards mononucleotides and DNA. It was clearly demonstrated that this photoreactivity originates from a photoinduced electron transfer from a guanine to the excited complex. This process leads to the formation of an adduct which was characterized. The structure shows that the complex is anchored to the nucleotidic base via one of its polyazaaromatic ligands, thus marking irreversibly the DNA guanines. Interestingly, this property can be used in order to target, for example, (i) specific DNA sequences and (ii) particular DNA topologies. For each purpose a specific Ru(II) complex was designed. Synthetic oligonucleotides derivatized with mononuclear complexes were prepared to target and damage specific DNA sequences containing G sites. In these systems, it is shown that the DNA damage consists of an irreversible photo-crosslinking of the derivatized oligonucleotide with the complementary strand. In order to target portions of important deformation along double-stranded DNA, the dinuclear complex [Ru(phen)2]2HAT4+ was prepared and studied. This complex is too large to penetrate inside the major or minor grooves of a DNA double helix, so that only single-stranded portions of denatured DNA are accessible to this compound. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 89
    Electronic Resource
    Electronic Resource
    Linear free enthalpy relationships: a powerful tool for the design of organic and organometallic synthesisDedicated to Professor Reinhard W. Hoffmann on the occasion of his 65th birthday. Revised version of a Plenary Lecture presented at ESOR VI, Louvain la Neuve, July 1997. (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 642-654 
    Details
    ISSN: 0894-3230
    Keywords: linear free energy relationships ; organic synthesis ; organometallic synthesis ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Structure-reactivity relationships are usually investigated within relatively narrow classes of compounds, where structural variation can unequivocally be assigned to certain electronic and steric effects. We present a novel, semiquantitative approach to predict possible reactions of cationic electrophiles (carbenium ions, metal π-complexes, diazonium ions) with neutral nucleophiles (alkenes, alkynes, arenes, hydrides, organometallics and n-nucleophiles). It is shown that the rate constants for these reactions are given with a precision better than a factor of 10-100 by the linear free enthalpy relationship log k(20 °C) = s (E + N), where E characterizes the strengths of the electrophiles, N characterizes the strengths of the nucleophiles and s is a nucleophile-dependent slope parameter, usually close to 1. This deviation appears tolerable in view of the reactivity range extending over more than 30 orders of magnitude, the large structural variety of compounds included and the neglect of solvent and steric effects. The simultaneous treatment of aliphatic, aromatic and organometallic compounds, which becomes possible in this way, provides new qualitative insights, and it is shown how the rule of thumb that reactions proceed at 20 °C if E + N 〉 -5 can be used for rationalizing and designing organic reactions. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 90
    Electronic Resource
    Electronic Resource
    A perspective on biological catalysis (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 508-511 
    Details
    ISSN: 0894-3230
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 91
    Electronic Resource
    Electronic Resource
    Radical bromination of 1,1- and 1,2-diphenylethylenes in 1,2-dichloroethaneDedicated to the memory of Professor Giuseppe Bellucci (dièd 3 March 1996). (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 685-692 
    Details
    ISSN: 0894-3230
    Keywords: radical bromination ; diphenylethylenes ; 1,2-dichloroethane ; caged radical intermediates ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The radical bromination of 1,1- and 1,2-diphenylethylenes in 1,2-dichloroethane was investigated on the basis of kinetic and product distribution data. Whereas the ionic process followed a third-order rate law (second order in Br2), the radical bromination was second order in Br2 and zero order in olefin in the reagent concentration range examined. Significant inverse kinetic isotope effects were found for the bromination of 3,4′-bis(trifluoromethyl)-1,1-diphenylethylene and cis-1,2-diphenylethylene under these conditions. At variance with the ionic bromination, which gave mixtures of meso- and d,l-dibromides only the meso-dibromides were obtained both from the cis- and trans-1,2-diphenylethylenes. The kinetic and product distribution data for the radical process are discussed in terms of a mechanism in which caged radical intermediates are formed. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 92
    Electronic Resource
    Electronic Resource
    Kinetic mechanism for dimerization of an α-thioamide substituted benzyl carbocation in aqueous solution (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 701-706 
    Details
    ISSN: 0894-3230
    Keywords: carbocation ; thioamide ; kinetics ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The products of reaction of the α-(N,N-dimethylthiocarbamoyl)-4-methoxybenzyl carbocation (1+) intermediate of solvolysis of α-(N,N-dimethylthiocarbamoyl)-4-methoxybenzyl benzoate esters (1-O2CAr) show a strong dependence on solvent. The only product from reaction in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) is 2-dimethylamino-6-methoxybenzothiophene (2) from intramolecular cyclization of 1+. The reaction of 1+ in 50:50 (v/v) methanol-water (I = 0.50, NaClO4) gives mainly the adducts to solvent. In 50:50 (v/v) trifluoroethanol-water (I = 0.50, NaClO4), 1+ partitions between reaction with solvent (ks, 27% yield), cyclization to form 2 (kc, 3% yield) and nucleophilic addition of 2 to 1+ (kalk, 70% yield) to form dimeric product 3. The yield of 3 in 50:50 (v/v) trifluoroethanol-water (I = 0.50, NaClO4) is independent of the leaving group at 1-O2CAr and remains constant as the concentration of the substrate is increased fourfold. These data show that the rate-determining step for dimerization of 1-O2CAr is ionization of substrate to form 1+ and that the products of the reaction are determined by the rate constant ratio for partitioning of 1+ between addition of solvent and cyclization. The rate constant ratios determined for the partitioning of 1+ in 50:50 (v/v) trifluoroethanol-water (I = 0.50, NaClO4) were ks/kc = 0.8 M-1 and kalk/ks = 540 000 M-1. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 93
    Electronic Resource
    Electronic Resource
    Substituent effects on the electrochemical oxidation of N,N′,N″-triphenyl-1,3,5-triaminobenzenes (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 731-736 
    Details
    ISSN: 0894-3230
    Keywords: substituted 1,3,5-triaminobenzenes ; electrochemistry ; linear free energy correlation ; substituted triphenylamines ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Correlation analysis of the oxidation potentials of a series of N,N′,N″-triphenyl-1,3,5-triaminobenzenes (TPABs) substituted at the para positions of the outer phenyl rings shows a linear free energy relationship with resonance-enhanced substituent parameters (σ+). Reaction parameters (ρ+) for oxidation of TPABs were found to be -1.53, -1.45 and -1.34 (per substituent) in methylene chloride, acetonitrile and propylene carbonate respectively. The resonance enhancement and small magnitude of the ρ+ values are related to a significant but weak delocalization of charge onto the outer phenyl rings in the molecular orbitals of radical cations resulting from the oxidation of TPABs. Data on the oxidation of p-substituted triphenylamines were treated similarly and gave a ρ+ value of -3.27 (per substituent) in acetonitrile, greater than that for TPABs owing to a more significant delocalization of charge onto the phenyl rings in the molecular orbitals of the corresponding radical cations. To demonstrate their predictive value, these linear free energy correlations were used to estimate the oxidation potentials of similarly substituted N,N,N′,N′,N″,N″-hexaphenyl-1,3,5-triaminobenzenes, which are of interest as building blocks for molecular magnetic materials. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 94
    Electronic Resource
    Electronic Resource
    Electrophilic aromatic substitutions: reactions of hydroxy- and methoxy-substituted benzenes with 4,6-dinitrobenzofuroxan: kinetics and mechanism (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 707-714 
    Details
    ISSN: 0894-3230
    Keywords: electrophilic aromatic substitutions ; 4,6-dinitrobenzofuroxan ; σ-complexation ; superelectrophile ; nitrobenzofuroxan ; kinetics of SEAr reaction ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Rate constants have been determined in aqueous Me2SO mixtures for the reaction of super-electrophilic 4,6-dinitrobenzofuroxan (DNBF) with a series of hydroxy- and methoxy-substituted benzenes whose pKa values range between -3 and -9. The study extends the reactivity range of weakly basic aromatics with DNBF, from the family of indoles previously studied with pKa values ranging from -1 to -6. The overall rate constants for the reactions of DNBF as the electrophile are at least one order of magnitude greater than for the reactions of H3O+ with the same series of aromatics. This lends further credence to the notion that DNBF possesses super-electrophilic properties. An LFER is observed between logk50%Me2SODNBF and pKaH2O with slope 0.54. In the case of 1,3,5-trimethoxybenzene a significant kinetic isotope effect (KIE) is observed (kH/kD = 3.71 in 50% Me2SO). This system hence affords one of the few instances in which a KIE has been observed in SEAr reactions. It follows from the observed KIE that the addition of DNBF to the aromatic is not rate-limiting and that reversion to reactants and proton loss from the arenonium intermediate occur at comparable rates. Structures of the products of electrophilic substitution have been confirmed by 1H NMR. In all cases the regiochemistry of the reactions was identical to that observed in protonation studies of the starting aromatics. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 95
    Electronic Resource
    Electronic Resource
    Solvent dependence of pyranine fluorescence and UV-visible absorption spectra (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 743-750 
    Details
    ISSN: 0894-3230
    Keywords: pyranine ; photoacid ; solvent polarity parameters ; solvatochromism ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Fluorescence and UV-visible absorption spectra of HPTS (8-hydroxy-1,3,6-pyrenetrisulphonic acid trisodium salt, pyranine) were measured in a variety of solvents. Fluorescence maxima (in kcal mol-1) can be correlated with the Kosower Z parameter (r = 0.901), the Dimroth-Reichardt ET(30) parameter (r = 0.900) and the Winstein Y parameter (r = 0.916) using one-parameter fits. Good correlations (r = 0.98) were obtained for HPTS fluorescence in ethanol-water mixtures using the Y, YOTs and Z parameters. Fluorescence maxima of HPTS in aqueous sulphuric acid solutions gave an excellent correlation with YOTs (r = 0.991). Multi-parameter correlations, indicating the significance of specific solvent interactions, were also studied. In addition, fluorescence maxima correlate well with maximum/minimum ratios obtained from UV-visible absorption experiments. Results can be applied in the use of HPTS as a molecular probe of solvent environments and for extension of the YOTs scale in acidic solutions. HPTS is a unique molecular probe, not only because of its photoacidic properties and its widespread use as a pH-sensitive biosensor, but also because of its relative stability in acidic environments. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 96
    Electronic Resource
    Electronic Resource
    Ab initio molecular orbital study of the conformational energies (-ΔG° or A values) of 4-alkyltetrahydro-2H-thiopyrans (tetrahydrothiopyrans, thiacyclohexanes, thianes) (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 831-839 
    Details
    ISSN: 0894-3230
    Keywords: conformational energy ; tetrahydrothiopyrans ; ab initio molecular orbital ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Ab initio 6-31G* and MP2/6-31G*//6-31G* methods were used to calculate the relative energies of the rotamers in the chair conformations of 4-alkyltetrahydro-2H-thiopyrans (tetrahydrothiopyrans, thiacyclohexanes, thianes; CH3, C2H5, i-C3H7, t-C4H9, neo-C5H11, SiMe3). The MP2/6-31G*//6-31G* conformational energies (-ΔG° or A values, kcal mol-1) of the 4-alkylthiacyclohexanes (Me = 1.94; Et = 1.72; i-Pr = 1.62; t-Bu = 5.49; neo-Pent = 1.39; SiMe3 = 2.76) are similar to those calculated for the corresponding alkylcyclohexanes. Plots of the calculated conformational energies for the 4-alkylthiacyclohexanes versus the calculated conformational energies for the corresponding alkylcyclohexanes are linear (slope = 1.01 and r = 0.999 for 6-31G* and slope = 1.09 and r = 0.990 for MP2/6-31G*//6-31G*). The conformational energies are strongly influenced by the magnitude and number of repulsive nonbonded hydrogen-hydrogen interactions and the gauche (synclinal) effects in the conformers. The carbon-sulfur bond lengths are mostly in the narrow range of 1.815-1.818 Å. The C - S - C angles vary from 97.1° to 99.4° and the C(3) - C(4) - C(7) angle in the most stable axial conformer is larger that the corresponding angle in its most stable equatorial conformer. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 97
    Electronic Resource
    Electronic Resource
    Non-cross-linked and cross-linked poly(alkylmethyldiallylammonium halides): synthesis and aggregation behavior (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 305-320 
    Details
    ISSN: 0894-3230
    Keywords: poly(alkylmethyldiallylammonium halides) ; aggregation behavior ; polyelectrolytes ; polysoaps ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Hydrophobically modified polyelectrolytes (polysoaps) are a unique class of water-soluble polymers containing distinct hydrophobic and hydrophilic regions. Above a certain concentration, polysoaps form intramolecular and intermolecular aggregates in aqueous solution. They have attracted much attention not only for their ability to mimic some functions demonstrated by biopolymers but also for their important industrial applications. This review highlights some interesting features of novel non-cross-linked and cross-linked poly(alkylmethyldiallylammonium halides) that have been described in recent years. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 98
    Electronic Resource
    Electronic Resource
    Is the brain ready for physical organic chemistry? (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 334-340 
    Details
    ISSN: 0894-3230
    Keywords: brain chemistry ; membrane proteins ; molecular neurobiology ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Efforts to developed detailed insights into the structure and function of the molecules of memory, thought and sensory perception - physical organic chemistry on the brain - are described. By combining more conventional chemical tools with a number of techniques adapted from modern biology, it is now possible to perform systematic structure-function studies on the integral membrane proteins that play a central role in molecular neurobiology. There are substantial challenges associated with such studies, but we believe the potential payoff is considerable. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 99
    Electronic Resource
    Electronic Resource
    Vicarious nucleophilic substitution of hydrogen. Mechanism and orientation (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 341-349 
    Details
    ISSN: 0894-3230
    Keywords: vicarious nucleophilic substitution ; hydrogen ; mechanism ; orientation ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Hydrogens located at activated positions in electrophilic arenes, e.g. ortho and para hydrogens in nitrobenzenes, can be replaced with a nucleophile moiety provided there is at least one nucleofuge X connected to the nucleophilic centre. As the group really leaving in this hydrogen substitution process is not the hydride anion but X, the reaction has been named vicarious nucleophilic substitution of hydrogen (VNS). The concepts on the mechanism of the reaction and their experimental background are presented. Reactivity and orientation - the fundamental questions concerning synthetical applications of VNS - are discussed in light of the supposed mechanistic picture.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 100
    Electronic Resource
    Electronic Resource
    Preface (1998)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 291-291 
    Details
    ISSN: 0894-3230
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: No Abstract
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...