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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Ground water 37 (1999), S. 0 
    ISSN: 1745-6584
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geosciences
    Notes: One of the challenges of monitoring network design in a fractured rock setting is the heterogeneity of the rocks. This paper summarizes the activities and problems associated with the monitoring of contaminated groundwater in porous, low-permeability fractured chalk in the Negev Desert, Israel. Preferential flow documented in the study area required siting the monitoring boreholes in the predominant fracture systems. Lineaments traced from aerial photographs were examined in the field to sort out the large-extension, through-going, multilayer fracture systems crossing the study area. At each proposed drilling site, these fractures were exposed below the sediment cover using trenches. Slanted boreholes were drilled at a distance from the fracture systems so that each borehole would intersect the targeted fracture plane below the water table. Based on their short recovery period and contaminated ground water, these newly drilled, fracture-oriented boreholes appeared to be better connected to preferential flowpaths crossing the industrial site than the old boreholes existing on site. Other considerations concerning the drilling and logging of monitoring boreholes in a fractured media were: (1) coring provides better documentation of the vertical fracture distribution, but dry augering is less costly and enables immediate ground water sampling and the sampling of vadose rock for contaminant analysis; (2) caliper and TV camera logs appear to provide only partial information regarding the vertical fracture distribution; and (3) the information gained by deepening the monitoring boreholes and testing fractures crossing their uncased walls has to be carefully weighed against the risk of potential cross-contamination through the monitoring boreholes, which is enhanced in fractured media.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1433-0563
    Keywords: Key words Renal cell cancer • Biological prognostic factors • Risk stratification ; Schlüsselwörter Nierenparenchymkarzinome • Prognosefaktoren • Risikostratifizierung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Beobachtung sehr unterschiedlicher klinischer Verläufe für Patienten mit Nierenzellkarzinomen, die ein identisches pathologisches Stadium, eine vergleichbare histologische Differenzierung sowie ein ähnliches Wachstumsmuster aufweisen, scheint die Existenz von Tumoren mit unterschiedlichem biologischen Potential zu belegen. Letzteres wird durch gegenwärtig zur Verfügung stehende Klassifikationssysteme nicht in so ausreichendem Maße determiniert, daß eine ihnen entsprechende Charakterisierung einzelner Tumoren die Basis für eine validierte bzw. individualisierte Therapieentscheidung darstellen könnte. Die Notwendigkeit hierzu ergibt sich aber aus der Einführung modifizierter operativer Strategien im Sinne einer sich zunehmend etablierenden organerhaltenden Chirurgie, sowie aus der jüngst beschriebenen Applikation einer sich am biologisch sicher noch besser charakterisierbaren Progressionsrisiko bestimmter Subgruppen von Patienten mit Nierenzellkarzinom ausrichtenden adjuvant-systemischen Therapie (Immun-Chemotherapie). Hieraus ergibt sich für den klinisch orientierten Grundlagenforscher bzw. den grundlagenwissenschaftlich orientierten Kliniker das Bedürfnis, prognostisch bedeutsame Variablen in Ergänzung zu „klassischen“ Prognosefaktoren (T-Stadium, histologischer Differenzierungsgrad, Wachstumsmuster) zu identifizieren, die das biologische Aggressivitätspotential des einzelnen Tumors so valide abzuschätzen erlauben, daß sich hieraus die Möglichkeit eines an den einzelnen Patienten individuell adaptierten therapeutischen Vorgehens ergibt. Diesbezüglich wurden in der jüngeren Vergangenheit verschiedenste biologische Parameter unter Einschluß des Nachweises von Alterationen auf chromosomaler/DNA-Ebene, aber auch der Veränderung physiologischer Proteinexpression, als potentielle Progressionsmarker bzw. biologische Prognosefaktoren diskutiert. Ziel der vorliegenden Abhandlung ist eine Bestandsaufnahme bezüglich der gegenwärtigen Verfügbarkeit solcher biologischer Variablen, denen künftig eine klinische Bedeutung in Verbindung mit dem Ziel einer individualisierten Therapie des Nierenzellkarzinomes zukommen könnte.
    Notes: Summary The observation of extremely variable clinical courses for patients with renal cell carcinomas of an identical pathological stage as well as a comparable histological differentiation resp. growth pattern strongly indicates the existence of tumors harboring different biological aggressiveness. Currently available histopathological classification systems do not predict the biological behaviour of renal cell cancer as sufficiently as the establishment of a therapeutical strategy adjusted to the individual patient would require. The need for a more refined characterization of the biological potential of the indidual tumor results from the introduction of modified operative strategies as organ-preserving surgery, for example, as well as from the recently suggested application of an adjuvant systemic therapy adapted to the individual risk for tumor recurrence resp. the development of progressive disease. Therefore, the clinically orientated basic scientist and the basic scientifically orientated clinician intensively try to determine prognostically important biological variables which would allow to better predict the biological aggressiveness of a single tumor in addition to “classical” prognostic parameters (T-stage, histological grading, growth patterns). In this context, several biological parameters including the identification of alterations on the DNA-, RNA- and protein level have been discussed as possible biological prognostic markers for renal cell cancer. The present review tries to reflect currently available biological characteristics of RCC which might gain clinical importance with regard to an individualized therapy in the near future.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The properties of the recently discovered extrasolar planets were not anticipated by theoretical work on the formation of planetary systems, most models for which were developed to explain our Solar System. Indeed, the observational technique used to detect these planets (measurement of ...
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1971
    Keywords: Key words: Eustachian valve — Iatrogenic closure — Lower cardiac inflow obstruction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. A 5-month-old boy with a VACTERL syndrome underwent cardiac surgery for correction of a common arterial trunk and closure of an atrial septal defect. A prominent Eustachian valve was mistaken for the atrial septum and surgically closed. Thirty months later, after gradual shrinking of the foramen ovale with associated reduction of the right-to-left shunt, the boy presented with acute symptoms of a lower inflow obstruction, characterized by hepatomegaly and engorged abdominal vein pattern (Medusa's head). The boy was reoperated successfully after the condition had been recognized.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-2072
    Keywords: Key words Schizophrenia ; Hippocampus ; Ibotenic acid ; Social behaviour ; Anxiety ; Animal model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract   Rationale: Neonatal ibotenic acid lesion of the ventral hippocampus was proposed as a relevant animal model of schizophrenia reflecting positive as well as negative symptoms of this disease. Before and after reaching maturity, specific alterations in the animals’ social behaviour were found. Objective: In this study, social behaviour of ventral hippocampal lesioned rats was analysed. For comparison, rats lesioned either in the ventral hippocampus or the dorsal hippocampus at the age of 8 weeks were tested. Methods: Rats on day 7 of age were lesioned with ibotenic acid in the ventral hippocampus and social behaviour was tested at the age of 13 weeks. For comparison, adult 8-week-old rats were lesioned either in the ventral or the dorsal hippocampus. Their social behaviour was tested at the age of 18 weeks. Results: It was found that neonatal lesion resulted in significantly decreased time spent in social interaction and an enhanced level of aggressive behaviour. This shift is not due to anxiety because we could not find differences between control rats and lesioned rats in the elevated plus-maze. Lesion in the ventral and dorsal hippocampus, respectively, in 8-week-old rats did not affect social behaviour. Conclusions: The results of our study indicate that ibotenic acid-induced hippocampal damage per se is not related to the shift in social behaviour. We favour the hypothesis that these changes are due to lesion-induced impairments in neurodevelopmental processes at an early stage of ontogenesis.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-2072
    Keywords: Key words Hippocampus ; Lesion ; Glutamate receptor and release ; Dopamine receptor ; Locomotor activity ; Schizophrenia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In 6-week and 8-week-old rats (pre- and postpubertally) with neonatal excitotoxic lesions of the ventral hippocampus with ibotenic acid (IBO), we have studied apomorphine-induced motor activity and glutamate and dopamine D1 and D2 binding sites in the hippocampus, striatum, nc. accumbens and frontal cortex as well as K+-stimulated (3H)-D-aspartate release from hippocampal and frontal cortical slices. Specific glutamate binding was enhanced in the frontal cortex of 8-week-old IBO-treated animals, whereas that in other brain regions remained unchanged. Both D1 and D2 binding sites were downregulated in the striatum without changes in other brain structures. In 6-week-old rats, neither the glutamate nor the dopamine binding sites were altered. The amino acid release from hippocampal and frontal cortical slices of adult IBO treated rats was significantly decreased in comparison to controls, whereas in 6-week-old rats, no significant alterations were detectable. The additionally monitored motor activity was enhanced only in adult IBO-lesioned rats after apomorphine pretreatment. The present data are in agreement with the hypothesis of hyperactive dopamine and hypoactive glutamate systems in schizophrenia and are discussed in the light of schizophrenia-like behavioral changes in rats after postnatal hippocampal IBO lesion.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1084
    Keywords: Key words: CT ; Coronary disease ; Coronary arteriosclerosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. To identify patients with increased risk of having coronary artery disease (CAD), electron-beam computed tomography (EBCT) was used for years for quantifying calcifications of the coronary arteries. The first direct comparison between EBCT and conventional CT was performed to determine the reliability of widely available conventional CT for the assessment of the coronary calcium score. Fifty male patients with suspected CAD were investigated with both modalities, EBCT and conventional 500-ms non-spiral partial scan CT. Scoring of the coronary calcification was performed according to the Agatston method. Forty-two of these patients underwent coronary angiography for the assessment of significant luminal narrowing. The correlation coefficient of the score values of both modalities was highly significant (r = 0.982, p 〈 0.001). The variability between the two modalities was 42 %. Mean calcium score in patients with significant coronary luminal narrowing (n = 37) was 1104 ± 1089 with EBCT and 1229 ± 1327 with conventional CT. In patients without luminal narrowing (n = 5) mean calcium score was 73 ± 57 with EBCT and 26 ± 35 with conventional CT. Although images of the heart from conventional CT may suffer from cardiac motion artifacts, conventional CT has the potential to identify patients with CAD with accuracy similar to EBCT.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1617-4623
    Keywords: Key wordsRhizobium-legume symbiosis ; Rhizobium meliloti ; Succinoglycan degradation ; Repressor ; cAMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mutant T482 of Sinorhizobium meliloti CXM1-105, which carries a Tn5 insertion on megaplasmid 1, exhibits an enhanced symbiotic efficiency phenotype. Three genes, eglC, cya3 and syrB2, were identified in the eff-482 region tagged by the Tn5 insertion in T482. The eglC gene encodes an endoglycanase which contributes to the depolymerization of the exopolysaccharide succinoglycan. The N-terminal region of the predicted cya3 gene product was similar to eukaryotic-type adenylate cyclases from Brevibacterium liquefaciens and Streptomyces coelicolor. Four contiguous tetratricopeptide repeats which are known to mediate protein-protein interactions were identified in the C-terminal portion of Cya3. Complementation analysis demonstrated that cya3 indeed encodes a functional adenylate cyclase. A central helix-turn-helix DNA-binding motif and a putative C-terminal coiled-coil structure implicated in protein oligomerization were found in SyrB2. Extra copies of the syrB2 gene negatively affect transcription of both syrB2 itself and cya3. The Tn5 insertion in T482 was localized between the divergently transcribed genes eglC and syrB2. It eliminated eglC function and slightly stimulated transcription of both syrB2 and cya3, which lies downstream of syrB2. Mutants carrying insertions of the lacZ-Gm interposon in the genes eglC, syrB2 and cya3 exhibit the same phenotype as mutant T482, indicating that these three genes influence symbiotic efficiency.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-739X
    Keywords: Albumin ; Clinical practice guidelines ; Daily patient specific decision support ; Drug use evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Chromatographic analysis of bisphosphonates in the past has been based primarily on reversed‐phase liquid chromatography (RPLC) and ion‐exchange chromatography. Gas chromatography (GC) and recently even capillary electrophoresis have also been employed. For bioanalysis, pre‐treatment of the sample is a major part of the analysis; protein precipitation, calcium precipitation, solid‐phase extraction (SPE) and derivatization have demonstrated to play an important role in bisphosphonate assays. For some of these treatments, for example SPE and derivatization, automation may be possible. Derivatization is a prerequisite for GC analysis of bisphosphonates; a volatile derivative has to be formed. For liquid chromatography, two types of derivatization are known for bisphosphonates. First, the bisphosphonate side chain can be modified by a chemical reaction to yield a derivative with advantageous chromatographic and spectroscopic properties. Secondly, by complexation of both phosphonate groups or of phosphate after decomposition of the analyte, a coloured complex can be formed. The most sensitive bioanalytical methods are based on RPLC and fluorescence detection, if necessary after derivatization. If low detection limits are not required, for example for analysis of pharmaceutical preparations, non-specific detection methods can be applied.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1434-808X
    Keywords: Schlüsselwörter Erektile Dysfunktion ; medikamentöse Therapie ; Phosphodiesterase ; Apomorphin ; Yohimbin ; PGE1 ; Key words Erectile dysfunction ; Medical therapy ; Phosphodiesterase ; Apomorphine ; Yohimbine ; PGE1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The medical treatment of erectile dysfunction includes the systemic (oral, epidermal, intramuscular) as well as the local (intracavernosal, intraurethral) application of pharma cological agents. Up to now only yohimbine, a well-known alpha-receptor blocking agent, and sildenafil, a newly introduced phosphodiesterase V inhibitor with predominant peripheral action, have been approved and listed in Germany. Other oral agents under investigation are trazodone and apomorphine (central action) as well as phentolamine (peripheral action). For the small group of patients with an established testosterone deficit, the epidermal or intramuscular substitution of testosterone seems to be a reasonable alternative to other therapeutic options. For the local application of pharmacological agents, intracavernosal injection therapy and intraurethral application (“medicated urethral system for erection”, MUSE) are available. Currently, several promising pharmacological agents with different modes of action and routes of administration are under investigation. The ultimate goal of these basic and clinical research efforts is to develop a specific and “tailored” therapy for each individual patient. While the pharmacological therapy of erectile dysfunction will most likely continue to be the therapeutic standard for most patients, it will certainly be augmented by devices (i. e. vacuum erection devices, “functional electromyostimulation of the corpus cavernosum”, FEMCC) and surgical treatment options (vascular and prosthetic surgery).
    Notes: Zusammenfassung Die medikamentöse Therapie der erektilen Dysfunktion umfaßt die systemische (orale, transkutane, intramuskuläre) sowie die lokale (intrakavernöse, intraurethrale) Applikation von Pharmaka. Die bisher einzigen in Deutschland zugelassenen oralen Substanzen sind das seit vielen Jahren bekannte Yohimbin, ein zentral wirksamer Alpharezeptorenblocker sowie das 1998 eingeführte Sildenafil, ein Phosphodiesterase-Isoenzym V Inhibitor mit überwiegend peripherem Wirkmechanismus. Weitere in der Entwicklung befindliche, orale Substanzen sind Trazodon und Apomorphin (zentraler Angriffspunkt) sowie Phentolamin (peripherer Ansatzpunkt). Für eine eher kleine Gruppe von Patienten mit Testosterondefizit besteht die Möglichkeit einer transkutanen oder intramuskulären Substitutionstherapie. Zur lokalen Applikation stehen sowohl die intrakavernöse (Schwellkörperautoinjektionstherapie-SKAT) als auch die die intraurethrale (MUSE) Anwendungsweise zur Verfügung. Zur Zeit befinden sich mehrere erfolgversprechende Substanzen mit unterschiedlichstem Wirkansatz und verschiedenen Darreichungsformen in der Entwicklung. Ziel dieser intensiven grundlagenwissenschaftlichen und klinischen Forschung ist eine patientenadaptierte, „maßgeschneiderte“ Therapie für den individuellen Patienten. Die pharmakologische Therapie der erektilen Dysfunktion wird auch künftig durch apparative (Vakuumpumpen, „Funktionelle Elektromyostimulation des Corpus cavernosum“-FEMCC) und operative (Gefäßchirurgie, Prothetik) Behandlungsstrategien ergänzt werden.
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