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  • 1
    Electronic Resource
    Electronic Resource
    Optical absorption and ESR spectroscopy of the monomerization and redimerization reaction of 9-cyanoanthracene-dimer crystals (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 87 (1987), S. 3392-3400 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The thermally and photochemically induced dissociation of 9-cyanoanthracene-dimer molecules (9-CNAD) into two monomer molecules is examined using optical spectroscopy and ESR. Optical spectroscopy gives an activation energy of 1.67(5) eV for the thermally induced formation of monomer pairs within the dimer crystal. The photoinduced reactions are examined by ESR spectroscopy of the monomer pairs. The presence of only one Δms=±1 ESR triplet line pair indicates the existence of only one photochemically active species. This results from the nondegeneracy of the ground state energies of the four dimer molecules within the unit cell. The fine structure constants D and E and the orientation of the anthracene monomer molecules have been calculated from the angular dependence of the ESR spectra. The orientation of the crystallographic unit cell axes in the crystal has been determined by Laue diffraction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.452983
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  • 2
    Electronic Resource
    Electronic Resource
    Fractionated total body irradiation and high dose cyclophosphamide: a preparative regimen for bone marrow transplantation for patients with hematologic malignancies in first complete remission (1988)
    Springer
    Annals of hematology 57 (1988), S. 7-13 
    Details
    ISSN: 1432-0584
    Keywords: Bone marrow transplantation ; Acute lymphoblastic leukemia ; Acute non-lymphoblastic leukemia ; Chronic myelogenous leukemia ; Non-Hodgkin's lymphoma ; High grade
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We treated 73 patients with hematologic malignancies in first complete remission (acute lymphoblastic leukemia = 23 patients; acute nonlymphoblastic leukemia = 25 patients; chronic myelogenous leukemia in first chronic phase = 20 patients, and high grade lymphoma = five patients) with a uniform preparative regimen consisting of fractionated total body irradiation (1 320 cGy) and high dose cyclophosphamide (100 mg/kg), followed by allogeneic bone marrow transplantation. By radiation dosimetry we demonstrated that the calculated doses were delivered accurately and reproducibly. Actuarial survival rates (± SEM) in complete remission were as follows: Acute lymphoblastic leukemia = 74±9%; acute nonlymphoblastic leukemia = 50±11%; and chronic myelogenous leukemia = 55±11%. Actuarial relapse rates for these three diagnoses were 19±9%, 17±11%, and 0% respectively. Three of the five lymphoma patients are alive in complete remission at 22+, 28+, and 54+ months. Overall probability of survival for the 73 patients was 59±7%. Interstitial pneumonia, usually associated with cytomegalovirus infection and graft-versus-host disease, and relapse of the underlying malignancy were the major causes of death.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00320628
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  • 3
    Electronic Resource
    Electronic Resource
    VHF radar observations of cat's-eye-like structures at mesopheric heights (1987)
    [s.l.] : Nature Publishing Group
    Nature 327 (1987), S. 43-45 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The mesosphere-stratosphere-troposphere radar technique has been described in a number of publications8'9. It uses irregularities in refractive index at half the radar wavelength (A/2~3m in our case) to provide backscatter. These irregularities are assumed to move with the background wind, and by ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/327043a0
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  • 4
    Electronic Resource
    Electronic Resource
    Isolation and structural identification of a chromophoric coenzyme F420 fragment from culture fluid of Methanobacterium thermoautotrophicum (1983)
    Springer
    Archives of microbiology 136 (1983), S. 191-193 
    Details
    ISSN: 1432-072X
    Keywords: Methanobacterium thermoautotrophicum ; Coenzyme F420 ; Deazaflavin ; 7,8-didemethyl-8-hydroxy-5-deazariboflavin ; Biosynthesis ; Fragment FO
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A fluorescent pigment was isolated from the culture fluid of Methanobacterium thermoautotrophicum strain ΔH. This pigment was shown to be 7,8-didemethyl-8-hydroxy-5-deazariboflavin by various spectroscopic and chromatographic techniques. This compound was previously described as the “FO” acid hydrolysis fragment of coenzyme F420. On the basis of the time of appearance of the pigment in the course of fermentation, it is suggested that this substance may be an over-produced biosynthetic precursor of F420.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00409842
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  • 5
    Electronic Resource
    Electronic Resource
    Wirkung einer simulierten Dauerbelastung durch HgCl2 auf die Generationsfolge der FeldheuschreckeAcrotylus patruelis (H.-S.) (Orthoptera, Acrididae) (1987)
    Springer
    Journal of pest science 60 (1987), S. 84-90 
    Details
    ISSN: 1612-4766
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Zusammenfassung Die Auswirkung einer kontinuierlichen Belastung der Umwelt durch Quecksilber auf die Fortpflanzung und Generationsfolge der FeldheuschreckeAcrotylus patruelis (H.-S.) wurde unter simulierten Bedingungen im Laboratorium untersucht. Die Insekten erhielten Weizenkeimlinge in Hydrokultur und Haferflocken; beide Futtermittel waren mit Quecksilber behandelt. Die Weibchen legten die Eier in mit feuchtem Sand gefüllte Glasbehälter, die mit verschiedenen, umweltrelevanten Mengen an HgCl2 behandelt waren. Unter verschiedener Belastung des Eiablagesubstrates wurden zwei Generationen aufgezogen. Die Eiproduktion stieg nach Fütterung von mit HgCl2 behandelter Nahrung erheblich an und erreichte in der P-Generation das Dreifache. Von den Weibchen der F1-Generation wurden noch mehr Eier abgelegt. Quecksilber stimulierte die Funktion der Ovarien. So haben die Weibchen die Möglichkeit, eine toxisch wirkende Anreicherung von Quecksilber in ihrem Körper zu verhindern. Die Erhöhung der Eiablage kann als Dekontaminationsmechanismus betrachtet werden. Die Weibchen beider Generationen waren nicht in der Lage, den Hg-Gehalt im Boden zu messen. In allen untersuchten Konzentrationen schlüpften Larven. Jedoch war die Schlüpfrate in Konzentrationen, die höher als 6,05 mg HgCl2/kg lagen, deutlich reduziert. Die Schlüpfrate der Larven der F2-Generation war niedriger als die der F1. Die larvale Entwicklung war stark abhängig von der Hg-Konzentration. Eine Fütterung mit kontaminierten Weizenkeimlingen verlängerte die Larvalzeit um 40%. Bei kontinuierlicher Kontamination des Bodens und der Nahrung wurde die Larvalperiode schließlich auf das Doppelte gegenüber der Kontrolle verlängert. Die Imaginalrate wurde mit zunehmender Bodenbelastung durch das Schwermetall reduziert, so daß schließlich nur noch 30% der eingesetzten Larven das Adultstadium erreichten. Auch die Lebensdauer der Imagines war von der Hg-Menge in der Nahrung und im Boden abhängig, in dem sich die Embryonalentwicklung vollzog. Schließlich lebten die Imagines nur noch 20 Tage (normal 3–4 Monate). Im Körpergewicht unterschieden sich die belasteten Imagines nicht von den Kontrolltieren, obgleich ihre Larvalzeit wesentlich länger dauerte, so daß sie mehr Nahrung aufnehmen konnten. Während der Larvalperiode reicherte sich in ihrem Körper Quecksilber um das Dreifache gegenüber der Kontrolle an. Der Gehalt an Hg im Körper wurde erst mit Beginn der Eiablage reduziert. Am meisten wurde das Schwermetall im Darm und in den Hoden angereichert.
    Notes: Abstract A continuous treatment of the environment was investigated under simulated conditions using mercury and the acridideAcrotylus patruelis (H.-S.) as test animal. The insects were fed by wheat germs in hydroculture and rolled oats, both treated with mercury. The females layed their eggs in glass pots filled with sand treated with various amounts of HgCl2. Two generations were bred under continuous treatment. By feeding treated food the oviposition increased significantly reaching the threefold number of eggs in the P-Generation. In the F1 even more eggs were produced. Mercury stimulated the function of the ovaries. In this way the females have the possibility to prevent a toxic accumulation of Hg in their bodies. The increase of oviposition can be considered as a mechanism of decontamination. The females of both generations were not able to measure the content of mercury in the soil. At all investigated concentrations larvae hatched but in those higher than 6.05 mg HgCl2/kg a significant reduction of hatching could be found. The hatching of the larvae of the F2 generation was much less than that of the F1. Larval development depended highly on the concentration of mercury. The larval period was prolonged up to 40% by feeding of contaminated wheat germs. By continuous contamination of the soil and of the food the larval period was increased up to twofold compared with the control. The imaginal rate was reduced by increasing mercury content in the soil. At least only 30% reached the adult stage. The imaginal life span also depended on the Hg amount of the soil in which the eggs developed and on the contamination of the food. At least only 20 days were reached (normally 3–4 months). The body weight of the treated adults did not differ from that of the control. During the larval period the accumulation of mercury in the body was threefold compared with the control insects. The mercury content was reduced at the beginning of oviposition. The amount of the heavy metal increased mainly in the gut and in the gonads of the males.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01906034
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  • 6
    Electronic Resource
    Electronic Resource
    Einfluß von Quecksilber(II)chlorid im Boden auf die Entwicklung von Feldheuschrecken (Acrididae, Saltatoria) (1984)
    Springer
    Journal of pest science 57 (1984), S. 41-45 
    Details
    ISSN: 1612-4766
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Zusammenfassung Unter Verwendung eines standardisierten Sandsubstrats wurde der Einfluß von Sublimat auf die Entwicklung von drei Feldheuschreckenarten (Acrotylus patruelis [H.-S.],Aiolopus thalassinus [F.] undOedipoda coerulescens [L.]) geprüft. In Konzentrationen von mehr als 0.01 ‰ Hg im Substrat wurde die Embryonalentwicklung bei allen drei Arten gestört, so daß die Schlupfrate der Larven deutlich absank. Bei Arten mit Eidiapause wurde die Postembryonalentwicklung noch stärker beeinflußt. In diesen Fällen reichten bereits, 0,001 ‰ Hg im Trockensand aus, um die Population um 50% zu reduzieren. Als derzeitige Toleranzgrenze für Quecksilber im Boden ist maximal 0,1 mg/kg anzugeben.
    Notes: Abstract Using a standarized sandy substrate as soil the influence of HgCl2 has been proved on the development of three grasshopper species ((Acrotylus patruelis [H.-S.],Aiolopus thalassinus [F.] andOedipoda coerulescens [L.]). The embryonic development of all the three species was significantly reduced in concentrations of more than 0.01 ‰ Hg in the substrate. In species with egg diapause ten times lower amounts were sufficient to get a reduction of the postembryonic development, only 0.001 ‰ Hg in the soil were necessary to reduce the population to 50%. At present the tolerance limit of mercury in the soil has to pretend with 0.1 mg/kg at maximum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01903594
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  • 7
    Electronic Resource
    Electronic Resource
    Konkurrenz von Endoperoxid- und Hydroperoxid-Bildung bei der Umsetzung von Singulett-Sauerstoff mit cyclischen, konjugierten Dienen. Teil I (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 51-58 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Competition of Endoperoxide and Hydroperoxide Formation in the Reaction of Singlet Oxygen with Cyclic, Conjugated DienesRose-bengal-sensitized photooxygenation of (-)-(R)-α-phellandrene (1) in MeOH at room temperature yielded a complex mixture of products, contrary to previous reports describing cis-(3S, 6R)-epidioxy-p-menthene (2) and trans-(3R, 6S)-epidioxy-p-menthene (3) as the only products. The mixture was separated by prep. HPLC (silica gel, pentane/Et2O 9:1). Besides the known endoperoxides 2 (yield 39%) and 3 (26%), all those hydroper-oxides, which can be deduced from an ene reaction of 1O2 with 1, were isolated, i.e. 4β-p-mentha-2,5-dien-1β-yl hydroperoxide (4) (14%), 4β-p-mentha-2,5-dien-1α-yl hydroperoxide (5) (9%), (2R, 4R)-p-mentha-1(7), 5-dien-2-yl hydroperoxide (6) (2,1%), (2S, 4R)-p-mentha-1(7),5-dien-2-yl hydroperoxide (7) (1,5%) and (1R)-p-mentha-3,6-dien-yl hydroperoxide (8; 1,5%; Scheme 1). Furthermore, the constant cis/trans ratio for all diastereoisomeric pairs (2/2, 4/2, 6/2) was striking. With the help of the two possible conformers 1a and 1b of the starting material a model of a common first step for endoperoxide as well as for hydroperoxide formation is developed. A photooxygenation at -50° supports this model. The absolute value of the cis/trans ratio changes in the same way for the endoperoxides and the hydroperoxides.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720107
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  • 8
    Electronic Resource
    Electronic Resource
    Katalytische Synthese von 5-Benzylidenhydantoinen aus Alkylisocyanaten und Phenylacetylen (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 1451-1453 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Catalytic Synthesis of 5-Benzylidenehydantoins from Alkyl Isocyanates and PhenylacetyleneNew 5-benzylidenehydantions 1-4 have been prepared from alkyl isocyanates and phenylacethylene in the presence of various ruthenium clusters as catalyst precursors. All products have been separated into the expected Z and E isomers.
    Notes: No Abstract
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19871200828
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  • 9
    Electronic Resource
    Electronic Resource
    Ermittlung sicherheitstechnischer Kenngrößen explosionsfähiger GasgemischeVortrag von H. Hofmann auf dem Jahrestreffen der Verfahrens-Ingenieure, 28. bis 30. Sept. 1983 in Nürnberg. (1984)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 56 (1984), S. 180-186 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Determination of safety characteristics for explosive gas mixtures. This paper presents equipment for determining safety characteristics such as explosion limits, flame temperatures, and laminar flame velocities. Contactless methods of measurement such as infrared thermography, interferometry, and Laser-Doppler anemometry are of particular importance. By means of selected gas mixtures it is shown that the composition of the gas mixture, the initial temperature and, as far as explosion limits are concerned, also the type of ignition source are important parameters. Finally, the influence of additives is reported which even in relatively small quantities strongly modify the whole combustion process and are therefore also relevant in safety problems.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330560303
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  • 10
    Electronic Resource
    Electronic Resource
    Konkurrenz von Endoperoxid- und Hydroperoxidbildung bei der Reaktion von Singulettsauerstoff mit cyclischen, konjugierten DienenVortrag bei der Jahrestagung der Deutschen Pharmazeutischen Gesellschaft am 10. September 1987 in Münster. (1988)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 100 (1988), S. 729-730 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19881000525
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