@article{TackeKropfgansTafeletal.1994,
  author    = {Tacke, Reinhold and Kropfgans, Martin and Tafel, Andrea and Wiesenberger, Frank and Sheldrick, William S. and Mutschler, Ernst and Egerer, Hansj{\"o}rg and Rettenmayr, Nikola and Gross, Jan and Waelbroeck, Magali and Lambrecht, G{\"u}nter},
  title     = {(Hydroxymethyl)diphenyl(piperidinoalkyl)silane des Typs (HOCH2)(C6H5)2Si(CH2)nNC5H10 (n = 2,3) und deren Methoiodide: Synthese, Struktur und antimuscarinische Eigenschaften},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86904},
  year      = {1994},
  abstract  = {No abstract available.},
  language  = {de}
}
@article{SuterPlessErnzerhofetal.1994,
  author    = {Suter, H. U. and Pleß, V. and Ernzerhof, M. and Engels, Bernd},
  title     = {Difficulties in the Calculation of Electron Spin Resonance Parameters using Density Functional Methods},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59113},
  year      = {1994},
  abstract  = {Density functional theory is applied to the calculation ofthe isotropic byperfine coupJing constants in some small molecules. Various functionals are tested. The agreement of the calculated values to experimental data and values obtained from sophisticated ab initio methods depends on the functionals used and the system under consideration. With respect to spin density calculations the functional of Lee, Yang and Parr with Becke's excbange functional (BLYP) is found to give good results for tbe heavier center of the CH and the NH molecule, while the spin densities of other molecules such as OH, H\(_2\)CN, H\(_2\)CO\(^+\), NO and O\(_2\) deviate considerably from experimental and/or other theoretical results (30\%-60\%). In cases where the singly occupied orbital can contribute to the isotropic hyperfine coupling constants, accurate results are obtained. The reason fortbis is analyzed.},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{SuterHuangEngels1994,
  author    = {Suter, H. U. and Huang, M.-B. and Engels, Bernd},
  title     = {A Multireference Configuration Interaction Study of the Hyperfine Structure of the Molecules CCO, CNN and NCN in their triplet ground states},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59108},
  year      = {1994},
  abstract  = {The hyperfine structures of the isoelectronic molecules CCO. CNN, and NCN in their triplet ground states (X\(^3 \sum ^-\)) are investigated by means of ab initio methods. The infrared frequencies and geometries are detennined and compared with experiment. Configuration selected multireference configuration interaction calculations in combination with perturbation theory to correct the wave function (MRD-CI/B\(_K\)) employing extended atomic orbital (AO) basis sets yielded very accurate hyperfine properties. The theoretical values for CCO are in excellent agreement with the experimental values determined by Smith and Weltner [J. Chem. Phys. 62,4592 (1975)]. For CNN, the first assignment of Smith and Weltner for the two nitrogen atoms has to be changed. A qualitative discussion of the electronic structure discloses no simple relation between the structure of the singly occupied orbitals and the measured hyperfine coupling constants. Vibrational effects were found to be of little importance.},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{SuterEngels1994,
  author    = {Suter, H. U. and Engels, Bernd},
  title     = {Theoretical investigation of ESR parameters: H\(_2\)CN and H\(_2\)CO\(^+\)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59029},
  year      = {1994},
  abstract  = {The hyperfine structure of the two isoelectronic molecules H\(_2\)CN and H\(_2\)CO\(^+\) in their electronic ground state (X\(^2\)B\(_2\)) is studied. The influence of the atomic orbital (AO), basis sets, of the correlation treatment, and of the. equilibrium geometry on the obtained hyperfine propertles 1s - investigated. It is found that the multireference double excitation-configuration interaction (MRD-CI)/ BK treatment in which an MRD-CI wave function is corrected by a modified B\(_K\) method yields equivalent results to quadratic CI [QCISD(T)], coupled cluster single doubles [CCSD(T)), or Brueckner doubled [BD(T)]. Uncertainties in the equilibrium geometries are found to be the major source for discrepancies between theoretically and experimentally determined isotropic hyperfine coupling constants (hfccs). For the heavier centers, the calculated values of the isotropic hfccs agrees nearly perfectly with experimental values (\(\approx\) 1\%-2\%). The calculated values for the hydrogens are too low, but using the equilibrium structure suggested by Yamamoto and Sato [J. Chem. Phys. 96, 4157 ( 1992)], the best estimate deviates by less than 3\%.},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{Stoeber1994,
  author    = {St{\"o}ber, Gerald},
  title     = {Schwangerschaftsinfektionen bei M{\"u}ttern von chronisch Schizophrenen: die Bedeutung einer differenzierten Nosologie},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78438},
  year      = {1994},
  abstract  = {In einer retrospektiven Untersuchung erinnerten 16 von 80 M{\"u}ttern von chronisch Schizophrenen eine schwere Infektionserkrankung in der Schwangerschaft. Im zweiten Trimenon waren geh{\"a}uft Infektionen aufgetreten. Zehn von 80 M{\"u}ttern von Kontrollpersonen erinnerten ebenfalls eine Infektion. Im Vergleich zu den Kontrollen halfen M{\"u}tter Schizophrener im 5. Schwangerschaftsmonat h{\"a}ufiger Infektionen als in den anderen Gestationsmonaten (p < 0,05). Bei "famili{\"a}ren" und "sporadischen" Schizophrenen gem{\"a}ß DSM III-R kamen im Vergleich zu Kontrollen Infektionen in gleicher H{\"a}ufigkeit vor. Wurden hingegen in der Diagnostik schizophrener Psychosen die Definitionen von Leonhard zugrunde gelegt, ergaben sich signifikante Unterschiede! Bei den systematischen Schizophrenen (denen nach Leonhard keine erbliche Disposition zugrunde liegt) waren Infektionen geh{\"a}uft im 2. Schwangerschaftsdrittel aufgetreten, sowohl im Vergleich zu Kontrollen (p < 0,01) als auch im Vergleich zu den unsystematischen Schizophrenen, die haupts{\"a}chlich genetisch bedingt zu sein scheinen (p < 0,001). Infektionserkrankungen im 5. Schwangerschaftsmonat waren ausschließlich bei den M{\"u}ttern von systematischen Schizophrenen vorgekommen. Bei diesen Krankheitsformen scheinen Infektionen im 2. Schwangerschaftstrimenon und insbesondere im 5. Schwangerschaftsmonat wichtige {\"a}tiologische Faktoren zu sein und k{\"o}nnten miturs{\"a}chlich sein f{\"u}r die beschriebenen zytoarchitektonischen Aberrationen im Zentralnervensystem von chronisch Schizophrenen.},
  subject      = {Medizin},
  language  = {de}
}
@article{StrikDierksFranzeketal.1994,
  author    = {Strik, Werner K. and Dierks, Thomas and Franzek, Ernst and St{\"o}ber, Gerald and Maurer, Konrad},
  title     = {P300 in Schizophrenia: Interactions between Amplitudes and Topography},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63351},
  year      = {1994},
  abstract  = {Low P300 amplitudes and topographical asymmetries have been reponed in schizophrenic patients, but reference-independent amplitude assessment failed to replicate reduced amplitudes. P300 amplitude is conventially assessed at midline electrodes (PZ), anti asymmetric topography as reported in schizophrenics, may conj'ound this measurement. We lnvestigated the possible Interaction between P300 ropography and assessments of amplitudes. ln 41 clinically stable schizophrenics and 31 normal controls, the generalfinding ofreduced amplitudes at the P'l electrode and topographical asymmetrles in the patient group were replicated. ln both groups, a.symmetries of the P300 field (lateralized peaks) reduced the standard amplitude assessment at the midline parletal electrode, but did not Qjfoct the reference-independent, global amplitude assessment. This shows thal asymmetry per se does not imply reduced field strength. in addition, in schizophreraics. but not in controls, there was a significcmt effect oftlae direction of asymmetry on both amplltude measures, amplitudes belng lower with increasing shift ofthe P300 peak to the right side. Considering also the slightly left-lateralized peaks in the normal controls. this suggests rhat only right lateralized P300 peaks upressfunctional deficits in schizophrenics, whereas left lateralized pealcs fall wlthin the physiological variability of the P3OO field. Tht refonnce-independent amplitude assessment is proposed for unambiguous amplitude assessment in order to better define the clinical, psychological and physiopathological mtaning of the P3OO alterations in schizophrenics.},
  subject      = {Schizophrenie},
  language  = {en}
}
@article{StrikDierksFranzeketal.1994,
  author    = {Strik, Werner K. and Dierks, Thomas and Franzek, Ernst and St{\"o}ber, Gerald and Maurer, Konrad},
  title     = {P 300 asymmetries in schizophrenia revisited with reference-independent methods},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63372},
  year      = {1994},
  abstract  = {Evidence of hemispheric asymmetries in schizophrenia has been reported from different research areas. Asymmetries in evoked potential P300 topography are still controversial because of inconsistent findings. In the present study. previous results of abnormal lateralization of P300 were replicated in stabilized residual Schizophrenie patients. Auditory P300 was recorded during an odd ball task in which subjeets detected rare target stimuli. Schizophrenie patients had the P300 peak shifted to the right hemisphere and differed signifieantly from age- and sex-matched normal control subjects who had left-lateralized P300 peaks. A comparison of different methods of assessment and analysis of the topographical features of the P300 electric fields showed that the extraction of reference-independent descriptors of P300 topography is a reliable and sensitive method for statistical handling of the maps. The results suggest left hemispheric dysfunction during cognitive tasks in a subgroup of Schizophrenie patients. Inconsistencies between previous sturlies are likely to be due to heterogeneous patient groups, which may have included patients in an acute Schizophrenie episode or patients in clinical remission. lnvestigation of the clinical meaning of P300 alterations requires careful psychopathological definition of the patient groups.},
  subject      = {Schizophrenie},
  language  = {en}
}
@article{StopperKuehnelPodschun1994,
  author    = {Stopper, Helga and K{\"u}hnel, A. and Podschun, B.},
  title     = {Combination of the chemotherapeutic agent 5-fluorouracil with an inhibitor of its catabolism results in increased micronucleus induction},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63383},
  year      = {1994},
  abstract  = {The rate limiting step in 5-fluorouracil catabolism is catalyzed by the enzyme dihydropyrimidine dehydrogenase. Since degradation of 5-fluorouracil decreases its efficacy in chemotherapy, the inhibition of its catabolism is a promising tool. We investigated the formation of micronuclei in vitro in mouse L5178Y cells. 5-fluorouracil induced an increase in micronucleus frequency, which could significantly be enhanced by the concurrent application of 2,6-dihydroxypyridine, an inhibitor of dihydropyrimidine dehydrogenase. The 5-fluorouracil concentration necessary to reach maximal genotoxic effects could be reduced to half in the presence of inhibitor. 2,6-Dihydroxypyridine alone and the naturally occuring enzyme substrate uracil did not induce micronucleus formation. Combined application of the chemotherapeutic agent 5-fluorouracil and an inhibitor of its could reduce side-effects by lowering the effective dose of the active drug. With this study we provide further support for the usefulness of this concept.},
  subject      = {Toxikologie},
  language  = {en}
}
@article{StopperKirchnerSchiffmannetal.1994,
  author    = {Stopper, Helga and Kirchner, S. and Schiffmann, D. and Poot, M.},
  title     = {Cell cycle disturbance in relation to micronucleus formation induced by the carcinogenic estrogen diethylstilbestrol},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82250},
  year      = {1994},
  abstract  = {In addition to its tumor-promoting activity in honnone-receptive tissue, the carcinogenic estrogen diethylstilbestrol (DES) has been found to induce cell transformation, aneuploidy and micronucleus formation in mammalian cells. The majority of these micronuclei contained whole chromosomes and were fonned during mitosis. Here a possible relationship between a disturbance in cell cycle progression and micronucleus fonnation is investigated by exposing Syrian hamster embryo (SHE) cells to DES. Continuous bromodeoxyuridine labeling followed by bivariate Hoechst 33258/ethidium bromide flow cytometry was employed for analysis of cell cycle transit and related to the time course of micronucleus formation. Treatment of SHE cells with DES resulted in delayed and impaired cell activation (exit from the GO/G 1 phase), impaired S-phase transit and, mainly, G2-phase traverse. Cells forming micronuclei, on the other hand, were predominantly in G2 phase during DES treatment. These results suggest that impairment of Sand G2 transit may involve a process ultimately leading to micronucleus formation.},
  subject      = {Toxikologie},
  language  = {en}
}
@article{StopperEckertSchiffmannetal.1994,
  author    = {Stopper, Helga and Eckert, I. and Schiffmann, D. and Spencer, D. L. and Caspary, W. J.},
  title     = {Is micronucleus induction by aneugens an early event leading to mutagenesis?},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63390},
  year      = {1994},
  abstract  = {This study was designed to investigate a previously unidentified potential mechanism for mutation induction as well as to clarify a biological comequence of micronucleus formation. We compared the induction of micronuclei with mutation inductioo as measured by trißuorothymidine (TFI') resistance in mouse L5178Y cells using four aneugens: colcemid, diethylstilbestrol, griseofulvin and vioblastine. AU four compounds induced micronuclei which appeared in the first cell cycle after treatment. More than 85\% of the micronuclei induced by each compound stained positive for the presence of kinetochores implying that the micronuclei contained wbole cbromosomes. However, these same compounds were unable to induce TFf resistance under tbree different treatment regimes. We concluded that tbese compounds, under conditions where tbey induce primarily kinetochore positive micronuclel, were not able to induce mutations. Thus, the induction of micronuclei containing wbole chromosomes barborlog a select.able gene is not an early event leadlog to mutations in these cells.},
  subject      = {Toxikologie},
  language  = {en}
}
@article{Stein1994,
  author    = {Stein, Roland},
  title     = {Lernbeeintr{\"a}chtigte nach der Schule - Arbeit oder Sozialhilfe? : Erfahrungen aus der Berufsausbildung ehemaliger Sondersch{\"u}ler},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40091},
  year      = {1994},
  abstract  = {Nach der Schulzeit droht Lernbeeintr{\"a}chtigten durch die allgemeine Entwicklung auf dem Arbeits- und Ausbildungsmarkt eine schwierige Berufsfindung, hochgradig unbefriedigende Hilfsarbeiter-T{\"a}tigkeit und - in erheblich zunehmendem Maße - Arbeitslosigkeit und der Verlust von Lebensperspektiven. Der Beitrag zeigt M{\"o}glichkeiten und Grenzen der qualifizierten und zukunfts orientierten Berufsausbildung dieser Gruppe auf, wobei sowohl moderne technologische Entwicklungen als auch die F{\"o}rderung personaler und sozialer Kompetenzen Ber{\"u}cksichtigung finden. Die Fragestellung der Integration Lernbeeintr{\"a}chtigter wird nicht mit der Schulzeit abgeschlossen - sie stellt sich umso st{\"a}rker danach.},
  subject      = {Sonderp{\"a}dagogik / Zeitschrift},
  language  = {de}
}
@article{StaikovaPericEngelsetal.1994,
  author    = {Staikova, M. and Peric, M. and Engels, Bernd and Peyerimhoff, S. D.},
  title     = {Ab initio Investigation of the Structure of the X\(^2\)A', A\(^2\)A'' (1\(^2\)Π) Spectral System of HCO: Investigation of the Magnetic Hyperfine Effects},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59089},
  year      = {1994},
  abstract  = {Results ofan ab initio study ofthe hyperfine structure of the X\(^2\)A', A\(^2\) A" ( 1\(^2 \Pi\)) system ofthe formyl radical are presented. Special attention is paid to the analysis of the interplay between the vibronic and magnetic hyperfine etfects. The results of computations are in very good agreement with the available experimental findings. The values for the hyperfine coupling constants in lower bending Ievels of both electronic species are predicted.},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{StaikovaEngelsPeric1994,
  author    = {Staikova, M. and Engels, Bernd and Peric, M.},
  title     = {Ab initio investigation of the hyperfine structure in the 1\(^2\)Π\(_u\)(X\(^2\)A\(_1\), A\(^2\)B\(_1\) system of BH\(_2\))},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59000},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{Sponholz1994,
  author    = {Sponholz, Barbara},
  title     = {Silicate karst associated with lateritic formations (examples from eastern Niger)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-53852},
  year      = {1994},
  abstract  = {Silicate and iron crust karst pits and sinkholes in eastern Niger are filled with reworked lateritic sediments or with unconsolidated palaeosoils and aeolian deposits. The fillings facies depend on the environmental conditions during deposition. Geomorphological and sedimentological studies on the karst fillings and the interpretation of various karst/filling associations allow an approach to the chronology of landscape development in eastern Niger plateaus.},
  subject      = {Geographie},
  language  = {en}
}
@article{Sponholz1994,
  author    = {Sponholz, Barbara},
  title     = {Ph{\´e}nom{\´e}nes karstiques dans les roches siliceuses au Niger oriental},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86833},
  year      = {1994},
  abstract  = {Dans le Niger oriental, des ph{\´e}nomenes karstiques sont fr{\´e}quents dans les roches siliceuses: gres, silcretes, cro{\^u}tes ferrugineuses, roches cristallines. A partir des {\´e}tudes g{\´e}omorphologiques et micromorphologiques, on peut conclure a une kartsification, au sense de production de formes par dissolution. Les r{\´e}sultats permettent de dater du Tertiaire inf{\´e}rieur la principale p{\´e}riode de karstification. La r{\´e}partition r{\´e}gionale des formes induites par cette karstification indique une d{\´e}pendance probable des conditions pal{\´e}oclimatiques. Actuellement le karst influe encore sur le d{\´e}veloppement des autres formes de relief.},
  language  = {fr}
}
@article{SiwkaSchwinnBaczkoetal.1994,
  author    = {Siwka, Wieslaw and Schwinn, Andreas and Baczko, Knut and Pardowitz, Iancu and Mhalu, Fred and Shao, John and Rethwilm, Axel and ter Meulen, Volker},
  title     = {vpu and env sequence variability of HIV-1 isolates from Tanzania},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61355},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Virologie},
  language  = {en}
}
@article{ShephardLutzSchlatter1994,
  author    = {Shephard, S. E. and Lutz, Werner K. and Schlatter, C.},
  title     = {The lacI transgenic mouse mutagenicity assay: quantitative evaluation in comparison to tests for carcinogenicity and cytogenetic damage in vivo},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60638},
  year      = {1994},
  abstract  = {The detection Iimit of the lacl transgenic mouse mutagenicity assay lies, in practice, at approximately a 50-100\% increase in mutant frequency in treated animals over controls. The sensitivity of this assay in detecting genotoxins can be markedly improved by subchronic rather than acute application of the test compound. The lac/ transgenic mouse mutagenicity assay was compared quantitatively to rodent carcinogenicity tests and to presently used in vivo mutagenicity assays. With the genotoxic carcinogens tested thus far, a rough correlation between mutagenic potency and carcinogenic potency was observed: on average, to obtain a doubling in lacl mutant frequency the mice bad to be treated with a total dose equal to 50 times the TD50 daily dose Ievel. This total dose could be administered eilher at a high dose rate within a few days or, preferably, at a low dose rate over several weeks. This analysis also indicated that a lacl experiment using a 250-day exposure period would give a detection Iimit approximately equal to that of a long-term carcinogenicity study. In comparison to the micronucleus test or the chromosome aberration assay, acute sturlies with the presently available lacl system offered no increase in sensitivity. However, subchronic lacl sturlies (3-4-month exposure) resulted in an increase in sensitivity over the established tests by 1-2 orders of magnitude (shown with 2-acetylaminofluorene, N-nitrosomethylamine, N-nitrosomethylurea and urethane). 1t is concluded that a positive result in the lacl test can be highly predictive of carcinogenicity butthat a negative result does not provide a large margin of safety.},
  subject      = {Toxikologie},
  language  = {en}
}
@article{SendtnerThoenen1994,
  author    = {Sendtner, Michael and Thoenen, Hans},
  title     = {Oxidative stress and motorneuron disease},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42684},
  year      = {1994},
  abstract  = {Transgenic mice carrying mutated Cu/Zn superoxide dismutase genes provide insights into the pathogenesis of human motorneuron diseases and may be useful as models in the development and testing of therapies.},
  language  = {en}
}
@article{SendtnerDittrichHughesetal.1994,
  author    = {Sendtner, Michael and Dittrich, F. and Hughes, R. A. and Thoenen, H.},
  title     = {Actions of CNTF and neurotrophins on degenerating motoneurons : preclinical studies and clinical implications},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62939},
  year      = {1994},
  abstract  = {Spinal motoneurons innervating skeletal muscle were amongst the first neurons shown to require the presence of their target cells to develop appropriately. Isolated embryonie chick and rat motoneurons have been used to identify neurotrophic factors and cytokines capable of supporting the survival of developing motoneurons. Such factors include ciliary neurotrophic factor (CNTF), which is present physiologically in high amounts in myelinating Schwann cells of peripheral nerves, and brain-derived neurotrophic factor (BDNF) which is synthesized in skeletal muscle and, after peripheral nerve lesion. in Schwann cells. These factors have been further analyzed for their physiological significance in maintaining motoneuron function in vivo, and for their potential therapeutic usefulness in degenerative motoneuron disease. Both CNTF and BDNF are capable of rescuing injured facial motoneurons in newbom rats. Furthermore, CNTF prolongs survival and improves motor function of pmn mice, an animal model for degenerative motoneuron disease, by preventing degeneration of motoneuron axons and somata. Thus treatment of human motoneuron disease with neurotrophic factors should be possible, provided that rational means for application of these factors can be established considering also the appearance of potential side effects.},
  subject      = {Neurobiologie},
  language  = {en}
}
@article{SendtnerCarrollHoltmannetal.1994,
  author    = {Sendtner, Michael and Carroll, P. and Holtmann, B and Hughes, R. A. and Thoenen, H.},
  title     = {Ciliary Neurotrophic Factor},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42545},
  year      = {1994},
  abstract  = {No abstract available},
  language  = {en}
}