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Showing papers by "University of Duisburg-Essen published in 1997"


Book
01 Jan 1997
TL;DR: In this paper, the Grauert-Mullich Theorem is used to define a moduli space for sheaves on K-3 surfaces, and the restriction of sheaves to curves is discussed.
Abstract: Preface to the second edition Preface to the first edition Introduction Part I. General Theory: 1. Preliminaries 2. Families of sheaves 3. The Grauert-Mullich Theorem 4. Moduli spaces Part II. Sheaves on Surfaces: 5. Construction methods 6. Moduli spaces on K3 surfaces 7. Restriction of sheaves to curves 8. Line bundles on the moduli space 9. Irreducibility and smoothness 10. Symplectic structures 11. Birational properties Glossary of notations References Index.

1,856 citations


Journal ArticleDOI
TL;DR: In this article, stable Pt electrodes with a spacing down to 4 nm have been fabricated and a new deposition technique, electrostatic trapping, which can be used to bridge the electrodes in a controlled way with a single conducting nanoparticle such as a conjugated or metal cluster molecule.
Abstract: For molecular electronics, one needs the ability to electrically address a single conducting molecule. We report on the fabrication of stable Pt electrodes with a spacing down to 4 nm and demonstrate a new deposition technique, i.e., electrostatic trapping, which can be used to bridge the electrodes in a controlled way with a single conducting nanoparticle such as a conjugated or metal–cluster molecule. In electrostatic trapping, nanoparticles are polarized by an applied electric field and are attracted to the gap between the electrodes where the field is maximum. The feasibility of electrostatic trapping is demonstrated for Pd colloids. Transport measurements on a single Pd nanoparticle show single electron tunneling coexisting with tunnel-barrier suppression.

469 citations


Journal ArticleDOI
TL;DR: To assess whether NO can serve as a marker of inflammation in cystic fibrosis (CF) lung disease, exhaled NO was measured in CF patients with a chemiluminescence analyser.
Abstract: Nitric oxide (NO) is produced by various cell types in the human respiratory tract. Endogenously produced nitric oxide is detectable in the exhaled air of healthy individuals. Exhaled NO has been shown to be increased in airway inflammation, most probably due to cytokine-mediated activation of NO synthases. To assess whether NO can serve as a marker of inflammation in cystic fibrosis (CF) lung disease, we measured exhaled NO in CF patients with a chemiluminescence analyser. Single breath measurements were performed in 27 stable CF patients (age range, 6-40 years) and 30 non-smoking controls (age range, 6-37 years). Exhaled NO concentrations were 9.1 +/- 3.6 ppb in the controls and 5.9 +/- 2.6 ppb (P < 0.001) in CF patients. To account for room air NO concentrations on the measurement of exhaled NO, we also calculated the difference between exhaled NO and ambient NO concentrations. Difference values were also significantly lower in CF compared with controls (P < 0.0001). In CF patients there was a positive correlation between exhaled NO and forced vital capacity (r = 0.43, P = 0.033), suggesting that exhaled NO is lower in patients with severe lung disease than in those with mild disease. We conclude that measurements of exhaled NO in CF does not reflect activity of CF airway inflammation. The decreased concentrations of exhaled NO may be due to inhibitory effects of inflammatory cytokines on NO syntheses in the airways and alveolar epithelial cells or to increased retention in airway secretions.

214 citations


Journal ArticleDOI
TL;DR: In this article, the authors showed that the product reverted to 1 upon heating in solution or in the solid state, with an enthalpy change of −29.8 (1.5) kcal mol-1.15) was unaffected by the presence of CCl4.
Abstract: Broad-band irradiation (λmax = 350 nm) of FvRu2(CO)4 (1, Fv = η5:η5-bicyclopentadienyl) resulted in rapid isomerization to colorless (μ2-η1:η5-cyclopentadienyl)2Ru2(CO)4 (2) in a novel process involving a formal dinuclear oxidative addition to a C−C bond. The product reverted to 1 upon heating in solution or in the solid state, under the latter conditions with an enthalpy change of −29.8 (1.5) kcal mol-1. Mechanistic studies with a mixture of 1 and 1-d8 revealed the absence of label scrambling, pointing to intramolecular pathways. The quantum yield (0.15) was unaffected by the presence of CCl4, and no chlorination products were observed under these conditions. Irradiation of solutions of 1 or 2 with 300 nm light provided Fv(μ2-η1:η5-cyclopentadienyl)2Ru4(CO)6 (6) or, in the presence of alkynes, the adducts FvRu2(CO)3(RCCR) (8−10, R = H, C6H5, CO2CH3). Heating 1 and PR3 (R = CH2CH3, CH3, or OCH3) yielded FvRu2(CO)3(PR3) (12−14), in which a fluxional process occurs characterized by intramolecular terminal t...

122 citations


Journal ArticleDOI
TL;DR: In this article, the preparation and catalytic properties of bimetallic colloids consisting of a ligand-stabilized Pt shell on Au or Pd cores supported by alumina are described.
Abstract: The preparation and catalytic properties of bimetallic colloids consisting of a ligand-stabilized Pt shell on Au or Pd cores supported by alumina are described. The aim of this work is to study the influence of the electronegativity of the colloidal core metals on the activity and selectivity of the surface Pt in hydrosilation reactions. Au is more electronegative and Pd is more electropositive than Pt. Results are compared to controls in which the hydrosilation reaction is catalyzed by colloids made of pure Pt which are also stabilized with the same ligands and supported by alumina. The reaction of HMTS with 1-octene to form bis(trimethylsiloxy)octamethylsilane (BTOMS) was selected to serve as an example of a typical hydrosilation reaction. The synthesis of the bimetallic colloids was accomplished by the seed-growth mechanism. The inner core consisting of Au (diameter = 18 nm) or Pd (diameter = 20 nm) was generated by the reduction of HAuCl4 or H2PdCl4, respectively, by sodium citrate. The Pt outer shell...

96 citations


Journal ArticleDOI
01 Feb 1997-Brain
TL;DR: Results show that although cerebellar patients could predict perturbation amplitudes based on prior experience, they could not use this prediction to modify precisely the gain of responses, and the cerebellum might not be critical for predicting upcoming events or for habituating to repeated postural stimuli.
Abstract: We reported previously that patients with cerebellar deficits were unable to scale the magnitude of their early automatic postural responses to the predicted amplitudes of surface translations based on central set from prior experience. The present study investigated whether this deficit in set-dependent amplitude scaling was based predominantly on the cerebellar patient's disability (i) to predict perturbation amplitudes on the basis of prior experience, (ii) to scale the gain or magnitude of upcoming postural responses or (iii) to habituate postural responses. The increase in size of the early postural response when a larger than actual platform amplitude was expected and decrease when a smaller one was expected was defined as a measure of set-dependent amplitude prediction. The suppression of the postural response when the same platform velocity was repeated was used as a measure of habituation. The correlation between the size of early postural responses and platform amplitudes when presented serially, but not randomly, tested the ability to scale the gain of postural responses based on prior experience. Results show that although cerebellar patients could predict perturbation amplitudes based on prior experience, they could not use this prediction to modify precisely the gain of responses. The ability to habituate the magnitude of postural responses was not affected by cerebellar lesions. Thus, the cerebellum might not be critical for predicting upcoming events or for habituating to repeated postural stimuli, although it is important for accurate tuning of response gain based on prediction.

83 citations


Journal ArticleDOI
TL;DR: The AutoSet recommended pressure varies little with time, and closely predicts the final manual titration pressure; the improvement in respiratory disturbance index was largely maintained, and compliance was good, although probably enhanced by close supervision.
Abstract: We have previously shown that AutoSet satisfactorily improves sleep-disordered breathing and sleep architecture in subjects with obstructive sleep apnoea (OSA) syndrome. The aim of this study was to determine, in subjects treated with long-term conventional fixed pressure continuous positive airway pressure (CPAP) at the AutoSet recommended pressure, whether: the long-term compliance is satisfactory; the improvement persists once initial rebound is over; the titration pressure is stable with time; and the titration pressure is comparable with manual titration pressure using a similar end-point. Twenty males with OSA, previously studied with full polysomnography on their diagnostic night, at manual and AutoSet titration, and at the AutoSet recommended fixed pressure, were re-studied after a mean of 3 and 8 months of treatment at the recommended fixed pressure. Re-study included home respiratory monitoring (Nellcor EdenTrace), and repeated manual and AutoSet titration with polysomnography. Compliance was assessed with hour-meter readings. Mean (+/-SEM) usage was 5.7 +/- 0.1 h.night-1 at 3 and 8 months. The arousal index remained normalized. Diagnostic respiratory disturbance index (RDI) was 60.3 +/- 5.7 events.h-1. On AutoSet at fixed CPAP, RDI was initially 2.6 +/- 0.7 events.h-1, then rose slightly (p < 0.001) to 4.3 +/- 0.6 events.h-1 at 3 months, and was 3.6 +/- 0.5 events.h-1 at 8 months. AutoSet titration pressure was: 9.9 +/- 0.4 cmH2O initially, 10.6 +/- 0.4 cmH2O at 3 months, and 9.7 +/- 0.5 cmH2O at 8 months (NS). Manual titration pressure at 8 months was 10.4 +/- 0.4 cmH2O. The standard deviation of the discrepancy with AutoSet was 0.84 cmH2O. In conclusion, the AutoSet recommended pressure varies little with time, and closely predicts the final manual titration pressure; the improvement in respiratory disturbance index was largely maintained, and compliance was good, although probably enhanced by close supervision.

78 citations


Journal Article
TL;DR: The comet assay can be used to gain information about interindividual variation in the efficiency of different DNA repair processes in small samples of normal cells and their malignant counterparts, suggesting a loss of stringent control of DNA Repair processes in these cells.
Abstract: Recent evidence has linked cellular DNA repair capacity to the chemosensitivity of cancer cells to alkylating agents. Using single-cell gel electrophoresis (“comet assay”), we have analyzed the induction and differential processing of DNA damage in human lymphocytes derived from healthy donors and from patients with chronic lymphatic leukemia (CLL) after exposure to N -ethyl- N -nitrosourea in vitro . The extent of comet formation in lymphocytes after N -ethyl- N -nitrosourea exposure appears to depend predominantly on the processing of DNA repair intermediates, because strand breaks in plasmid DNA were not induced by ethylation before the addition of nuclear proteins. Although the initial level of a specific alkylation product (O 6 -ethylguanine) in nuclear DNA was uniform, different dose-response curves were obtained for the comet size in individual cell samples immediately after exposure, with small intercellular variation. The individual kinetics of DNA repair varied significantly between specimens derived from both healthy individuals and CLL patients; for the DNA repair half-time ( t 1/2 ), large difference was found. Pretreatment of cells with methoxyamine as a DNA repair modifier blocking the base excision repair pathway revealed a quite similar extent of base excision repair-independent DNA incision in almost all normal lymphocyte samples. In contrast, this portion varied relatively and absolutely to a great extent among individual samples of CLL lymphocytes, suggesting a loss of stringent control of DNA repair processes in these cells. The comet assay can thus be used to gain information about inter-individual variation in the efficiency of different DNA repair processes in small samples of normal cells and their malignant counterparts.

76 citations


Journal ArticleDOI
TL;DR: In this paper, a single crystal of NH3 was grown in a thin-walled capillary at 178 K, and high-resoln. x-ray diffraction data were obtained for this compd. at 160 K to obtain information about electron d. distribution.
Abstract: A single-crystal of NH3 was grown in a thin-walled capillary at 178 K, and high-resoln. x-ray diffraction data were obtained for this compd. at 160 K to obtain information about electron d. distribution. Conventional and multipole refinements and deformation electron d. maps indicated small but significant N-H bond bending inside the NH3 tetrahedron that is in agreement with ab initio quantum-chem. calcns. and the VSEPR model. Topol. anal. of the exptl. charge d. distribution in the NH3 mol. was performed, and the data are compared with high-level quantum-chem. calcns. Crystals are cubic, space group P213, with a 5.1305(8) .ANG.; Z = 4, dc = 0.838. Some features of the intermol. H bonds in the crystal are discussed.

62 citations


Journal ArticleDOI
TL;DR: Investigation of a 51-yr-old never-smoker after single lung transplantation for alpha 1-antitrypsin deficiency emphysema who received a donor's lung from a heavy cigarette smoker found smoker's inclusions in AM may be detected for at least 2 yr after smoking has ceased, which is considerably longer than the estimated life span of the AM.
Abstract: Alveolar macrophages (AM) from smokers contain characteristic smoker's inclusion bodies within the cytoplasm as a result of ingestion of substances in the inhaled smoke. How long these smoking-related changes in the AM population can be seen after smoking cessation is largely unknown. We had the unique opportunity to investigate a 51-yr-old never-smoker after single lung transplantation (TX) for α 1-antitrypsin deficiency emphysema who received a donor's lung from a heavy cigarette smoker. Serial bronchoalveolar lavage (BAL) was performed in the donor's lung for transplant surveillance at defined time intervals, and the percentage of AM with characteristic smoker's inclusions was counted on slides stained with May-Grunwald-Giemsa stain. The patient had an uneventful course after TX with no major infectious complications or episodes of rejection. One month after TX the percentage of smoker's AM was 98%. BAL after 2, 5, 7, and 12 mo showed a similar high percentage. After 18 mo a first a decrease was seen, ...

55 citations



Journal ArticleDOI
01 Mar 1997-Genomics
TL;DR: In this paper, the EXT1 gene was identified on human chromosome 8 and the DNA sequence analysis revealed the presence of a CpG island containing GC and CAAT boxes, but no TATA box.

Journal ArticleDOI
TL;DR: The physical properties of these nanomaterials lie between those of the bulk phase, which can be explained by classical physics, and those of individual atoms or molecules, which are explained by quantum mechanics.
Abstract: The technology is available today to form unique materials comprising only a few atoms or molecules up to thousands. The physical properties of these ‘nanomaterials’ lie somewhere between those of the bulk phase, which can be explained by classical physics, and those of the respective atoms or molecules, which can be explained by quantum mechanics.

Journal Article
TL;DR: The results suggest that in bladder carcinomas abnormal expression of both E-cadherin and gp78 results in a poor disease outcome, independent of tumor stage and grade.
Abstract: Urothelial carcinomas are heterogeneous diseases with an aggressive clinical potential. To date, the most used prognostic factors for bladder carcinomas are grade and stage, which are based on histopathological parameters that are often not reliable in predicting a clinical outcome. Here, we evaluated the clinical outcome of 100 patients with urothelial carcinomas with follow-up information for more than 2 years after surgery in relation to the expression of two cell surface antigens, ie, E-cadherin and autocrine motility factor receptor (AMF-R, gp78). Frozen bladder tissues were serially cut, stained either with hematoxylin and eosin for grading, with the anti-gp78 antibodies, or with anti-E-cadherin antibodies to determine level of expression. Of 63 patients presented at the time of diagnosis with pathological loss of E-cadherin associated with increased gp78 expression, 39 (62%) succumbed to tumor progression or death. Of 37 patients with normal E-cadherin and gp78 expression positive and negative, respectively, 36 (97%) had favorable disease outcomes (P < 0.0001). The results suggest that in bladder carcinomas abnormal expression of both E-cadherin and gp78 results in a poor disease outcome, independent of tumor stage and grade.

Journal ArticleDOI
TL;DR: A new glycoprotein is presented on the cell surfaces of a glial progenitor cell subset for further studies of cell lineage relationships between radial glia cells, astrocytes, and ependymal cells.
Abstract: Glial progenitor cell differentiation and cell lineage relationships during brain development are complex hierarchical processes depending on genetic programming, cell-cell interactions, and microenvironmental factors. The identification of precursor cell-specific antigens provides a tool for the study of both normal development and deviations from lineage-specific differentiation associated with malignant transformation. Monoclonal antibody (mAb) RB13-6 recognizes a 130-kDa cell surface glycoprotein (gp130RB13-6) expressed by a subset of 9OAcGD3-positive glial precursor cells scattered in the rat neuroepithelium on prenatal day (PRD) 13. During prenatal development the fraction of gp130RB13-6-positive fetal brain cells (FBC) decreased from about 18% (PRD 14) to about 1.5% (PRD 22), coinciding with increasing fractions of more mature cell types, as indicated by the elevated expression of p24RB21-15, another cell surface determinant specified by mAb RB21-15 (Kindler-Rohrborn et al.; Differentiation 30:53-60, 1985) and other neural cell type-specific markers. Accordingly, gp130RB13-6 positive precursor cells were localized in the ventricular zones throughout brain development. Concomitant with their formation and in the adult rat brain, ependymal layers lining the ventricular surface, choroid plexus, and the leptomeninges were intensely labeled by anti-gp130RB13-6 mAb. As visualized by confocal laser scanning microscopy of FBC cultures from PRD 13, gp130RB13-6 was coexpressed with the RC1 antigen by progenitor cells morphologically resembling radial glia cells. In addition, a very small subpopulation of astrocytes coexpressing gp130RB13-6 and glial fibrillary acidic protein (GFAP; < 5%) occurred 3 days after seeding. Primary FBC cultures from PRD 18 contained an increased subset of astrocytes coexpressing gp130RB13-6 and GFAP (approximately 25% of all gp130RB13-6 expressing cells), apparently generated from gp130RB13-6-positive precursors. Corresponding to in vivo conditions, ciliated ependymal cells but also microglial cells/macrophages and leptomeningeal cells showed strong expression of gp130RB13-6 in culture. We thus present a new glycoprotein on the cell surfaces of a glial progenitor cell subset for further studies of cell lineage relationships between radial glia cells, astrocytes, and ependymal cells.

Journal ArticleDOI
TL;DR: The data suggest that metabolic parameters play an important role in the process of late graft loss after kidney transplantation and low levels of serum cholesterol, triglycerides, and glucose, before and after transplantation, were accompanied by a prolonged graft survival.
Abstract: Background At the present time, late graft loss is the major cause of kidney failure after transplantation. However, the influence of metabolic factors on this process is ill-defined. Methods. To identify the impact of lipid metabolism, glucose metabolism, and blood pressure and their prognostic value for graft survival, data for all recipients of a kidney allograft with a potential graft survival of >15 years and a minimum graft survival of 1 month were analyzed retrospectively. Recipients of kidney grafts functioning more than 15 years (n=32) were compared with those with a graft function of less than 10 years (n=152, controls) and evaluated in a multivariate analysis. Results. Low levels of serum cholesterol, triglycerides, and glucose, before and after transplantation, were accompanied by a prolonged graft survival. Prognostic factors for early graft failure included serum triglycerides>300 mg/dl, cholesterol >250 mg/dl before transplantation, serum creatinine >4.0 mg/dl 1 month after transplantation, and donor age above 45 or less than 10 years. Additionally, systolic and, particularly, diastolic blood pressure was lower in the group with a prolonged graft function as compared with controls immediately before and after transplantation. In addition, the incidence of primary graft function was lower and the incidence of acute rejection episodes higher in controls. Cold and warm ischemic time, body mass index, recipient age, and gender did not differ significantly. Conclusions. Our data suggest that metabolic parameters play an important role in the process of late graft loss after kidney transplantation.

Journal ArticleDOI
TL;DR: Administration of LPS during the early quiescent phase of chronic rejection accelerated the chronic process, functionally (proteinuria), morphologically, immunohistologically, and by reverse-transcriptase polymerase chain reaction as compared with untreated controls.
Abstract: The etiology of chronic rejection is unknown, although acute rejection, viral infection, and initial graft ischemia have been implicated. To test the effects of infections on the process of chronic rejection, we simulated bacterial infection by the administration of the endotoxin lipopolysaccharide (LPS), a potent activator of various cell types in an established rat model of chronic rejection. Lewis recipients of Fisher 344 kidneys were treated with a single dose of LPS or vehicle 8 weeks following transplantation and grafts were examined at various time points. In the chronically rejecting controls leukocytic infiltration and the expression of cytokines peaked at 16 weeks. In LPS-treated hosts, leukocyte infiltration and cytokine expression peaked at 12 weeks. By 16 weeks, glomeruli in LPS-treated recipients had become far more sclerotic than those in controls, mimicking the changes observed in controls at 24 weeks. We conclude that infections may play an important role in the development of chronic rejection.

Journal ArticleDOI
01 Nov 1997
TL;DR: In this paper, a mixture of seven and eight shell clusters (Pd7/8(phen)) was directly introduced into the mesoporous structure during the synthesis of MCM 41 as well as by incipient wetness impregnation.
Abstract: MCM 41 was loaded with ligand-stabilized palladium clusters in the size range of 3 -4 nm via different pathways. A mixture of seven- and eight-shell clusters (Pd7/8(phen)) was directly introduced into the mesoporous structure during the synthesis of MCM 41 as well as by incipient wetness impregnation. The samples were characterized by X-ray diffraction, N 2 -sorption, DTA and TEM. The clusters show different thermal stability depending on the synthesis pathway used. In situ incorporation leads to a decomposition of the Pd clusters after calcination at 873 K. However, the clusters that were introduced by incipient wetness impregnation are thermally stable up to 513 K in air. As a first catalytic test the oxidation of CO with synthetic air was used. Compared to catalysts prepared by conventional methods with appropriate palladium salts, the impregnated samples show high activity in the CO oxidation.

Journal ArticleDOI
TL;DR: A strong antileukemic effect was observed after abrupt CsA withdrawal, with 10 of 20 patients achieving a CR, whereas treatment with DLT induced a CR in only two of 14 patients (14%).
Abstract: A retrospective single centre study of the outcome of five different therapy approaches in 48 patients with relapse of chronic myelogenous leukemia after allogeneic bone marrow transplantation

Journal ArticleDOI
TL;DR: In this article, a series of molecular organometallic Sn/chalcogenide complexes, which present valuable complexes for the MOCVD process, are reported, which are obtained from a reaction of the stannylene complex [{{(CH3)3Si}2(CH)}2Sn]2] with elemental O2, S8, Se8 or metallic Te in high yields at RT in an organic solvent.

Book ChapterDOI
15 Oct 1997
TL;DR: A cognitive model of route representation and processes is described, which produces both effects as the outcomes of task-specific retrieval procedures and an experiment whose results support the hypothesis that route structuring, if induced by segmentation, is a special case of feature accumulation.
Abstract: It is well-known that route distance estimates are influenced by the structure of the route. In particular, the number of features along the route (e.g. landmarks) and the structuring of the route into stretches have been shown to influence distance estimates, usually increasing them (feature accumulation, route structuring). However, the two effects have not been related to one another yet. What is the relation between them? We have approached this question from two perspectives. The paper describes a cognitive model of route representation and processes, which produces both effects as the outcomes of task-specific retrieval procedures. It also describes an experiment whose results support the hypothesis that route structuring, if induced by segmentation, is a special case of feature accumulation. We relate the empirical results to the model, show how they support and constrain each other, and outline what further research is needed.

Journal ArticleDOI
TL;DR: The crystal and molecular structures of the title compounds were determined at low temperatures as mentioned in this paper, and the accuracy of the structures allows for a discussion about the bond alternation in the six-membered ring.

Proceedings Article
01 Jan 1997
TL;DR: A context dependent hybrid MMI-connectionist / Hidden Markov Model (HMM) speech recognition system for the Wall Street Journal (WSJ) database is presented with a neural network, which is used as a vector quantizer and an HMM with discrete probablility density functions, which has the advantage of a faster decoding.
Abstract: In this paper we present a context dependent hybrid MMI-connectionist / Hidden Markov Model (HMM) speech recognition system for the Wall Street Journal (WSJ) database. The hybrid system is build with a neural network, which is used as a vector quantizer (VQ) and an HMM with discrete probablility density functions, which has the advantage of a faster decoding. The neural network is trained on an algorithm, that tries to maximize the mutual information between the classes of the input features (e.g. phones, triphones, etc.) and the neural firing sequence of the network. The system has been trained on the 1992 WSJ corpus (si-84). Tests were performed on the fiveand twentythousand word, speaker independent (si_et) tasks. The error rates of a new context dependend neural network are 29% lower (relative) than the error rates of a standard (k-means) discrete system and the error rates are very close to the best continuous/semicontinuous HMM speech recognizers.


Proceedings ArticleDOI
08 Jun 1997
TL;DR: In this article, the design equations for ring hybrids with arbitrary termination impedances and arbitrary power division ratios are derived. But the design equation is not applicable to small ring hybrids, and it cannot be applied to ring hybrid with even and odd symmetries.
Abstract: If a ring hybrid is terminated by arbitrary impedances, design equations can not be derived with conventional methods because symmetry planes for even and/or odd symmetries are not available. Therefore, under these conditions new design equations for ring hybrids have been derived. They can be applied to both ring hybrids with arbitrary termination impedances and arbitrary power division ratios. Also, new design equations for small sized ring hybrids have been developed. They allow that arbitrary power divisions, arbitrary termination impedances and specially small sized ring hybrids can be designed. On the basis of these derived design equations, a simulation of ring hybrids with 4 arc lengths of 75/spl deg/, arbitrary termination impedances and a power split ratio of 4 dB was performed using ideal CPS crossover.

Journal Article
TL;DR: The proportion of occupation-related lung cancer for males and females in Northern Germany is estimated to be approximately one quarter of all newly diagnosed male lung cancer cases in the study region, which should prompt to minimise occupational exposure.
Abstract: The aim of the study was to estimate the proportion of occupation-related lung cancer for males and females in Northern Germany. 1004 lung cancer cases (839 males, 165 females) were enrolled into an epidemiological case-control study in the study areas Bremen, the surroundings of Bremen and the Frankfurt/Main area. Population controls were matched for sex and region of residence. All patients born after 1913 of German nationality and with a histologically or cytologically verified carcinoma of the lung, the diagnosis not older than 3 months at the date of interview, were eligible. All individuals were personally interviewed with respect to their smoking and job history. Based on a published list of all jobs and branches of industries with sufficient evidence for lung carcinogenity (based on the reviews by IARC), the so called A-List, all individuals were classified regarding their lifelong occupational history. The same procedure was applied with regard to jobs and branches of industries with a suspected risk of lung cancer (List-B). The statistical analysis used conditional logistic regression, controlled for smoking. Being employed in a job of List-A for at least half a year was associated with a statistically significant odds ratio (OR) of 1.63 (p < 0.0001) and resulting attributable risk (AR) of 16% in males. For the B-List an OR of 1.34 and an AR of 10% resulted in males. The estimates of the attributable risk for jobs and branches of industry with a sufficient evidence of lung cancer risk is comparable to the estimates obtained by Doll and Peto for the US. If additionally jobs and branches of industries with a suspected risk for lung cancer is considered, it must be anticipated that approximately one quarter of all newly diagnosed male lung cancer cases in the study region may be caused by occupational risk factors. This should prompt to minimise occupational exposure.

Journal ArticleDOI
TL;DR: In this paper, the dynamics of quasi-particles in repulsive Bose condensates in a harmonic trap is studied in the classical limit, and it is shown that the dynamics inside the condensate (collective dynamics) is integrable asymptotically for E/chemical potential very small.
Abstract: The dynamics of quasi-particles in repulsive Bose condensates in a harmonic trap is studied in the classical limit. In isotropic traps the classical motion is integrable and separable in spherical coordinates. In anisotropic traps the classical dynamics is found, in general, to be nonintegrable. For quasi-particle energies E much smaller than thechemical potential, besides the conserved quasi-particle energy, we identify two additional nearly conserved phase-space functions. These render the dynamics inside the condensate (collective dynamics) integrable asymptotically for E/chemical potential very small. However, there coexists at the same energy a dynamics confined to the surface of the condensate, which is governed by a classical Hartree-Fock Hamiltonian. We find that also this dynamics becomes integrable for E/chemical potential very small, because of the appearance of an adiabatic invariant. For E/chemical potential of order 1 a large portion of the phase-space supports chaotic motion, both, for the Bogoliubov Hamiltonian and its Hartree-Fock approximant. To exemplify this we exhibit Poincar\'e surface of sections for harmonic traps with the cylindrical symmetry and anisotropy found in TOP traps. For E/chemical potential very large the dynamics is again governed by the Hartree-Fock Hamiltonian. In the case with cylindrical symmetry it becomes quasi-integrable because the remaining small chaotic components in phase space are tightly confined by tori.


Journal ArticleDOI
TL;DR: In this article, the authors introduce two models for the action of impurities in epitaxial growth: barrier-like and trap-like, and they find a symmetry breaking effect that leads to an overall down-hill current.
Abstract: We introduce two models for the action of impurities in epitaxial growth. In the first, the interaction between the diffusing adatoms and the impurities is ``barrier''-like and, in the second, it is ``trap''-like. For the barrier model, we find a symmetry breaking effect that leads to an overall down-hill current. As expected, such a current produces Edwards-Wilkinson scaling. For the trap model, no symmetry breaking occurs and the scaling behavior appears to be of the conserved-KPZ type.

01 Mar 1997
TL;DR: In this article, the authors introduce two models for the action of impurities in epitaxial growth: barrier-like and trap-like, and they find a symmetry breaking effect that leads to an overall down-hill current.
Abstract: We introduce two models for the action of impurities in epitaxial growth. In the first, the interaction between the diffusing adatoms and the impurities is ``barrier''-like and, in the second, it is ``trap''-like. For the barrier model, we find a symmetry breaking effect that leads to an overall down-hill current. As expected, such a current produces Edwards-Wilkinson scaling. For the trap model, no symmetry breaking occurs and the scaling behavior appears to be of the conserved-KPZ type.