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1.
BACKGROUND: Although transmission of hepatitis C virus (HCV) through parental exposure is well documented, it is still controversial whether familial clustering of HCV occurs. METHODS: To investigate risk factors for HCV infection, 109 cases and 84 non-infected controls were studied. In addition, 250 family members (104 men, 146 women) of cases and 170 family members of controls (64 men, 106 women) were tested for HCV infection using an anti-HCV antibody, alanine aminotransferase (ALT), and reverse transcribed polymerase chain reaction (RT-PCR). RESULTS: In the case-control analysis, people aged > or =60 were almost three times more likely to be infected by HCV than those aged <40. Risk of HCV infection was most strongly related to a history of blood transfusion (OR = 12.6, 95% CI: 4.3-36.5) followed by a history of jaundice (OR = 4.1, 95% CI: 1.3-12.6). Only one family member of cases and no-one related to the controls had HCV infection. CONCLUSIONS: These results suggest that, in Korea, age and parenteral exposure, such as a blood transfusion, are risk factors for HCV infection and familial clustering of HCV infection, if it occurs, is rare. 相似文献
2.
In addition to the C21 steroid 15α-hydroxypregna-4,6-dien-3,20-dione, four 1- or 2-acylated polyunsaturated monoglycerides, 1- or 2-(cis-5,8,11,14-eicosatetraenoyl)-glycerol and 1- or 2-(cis-5,8,11,14,17-eicosapentaenoyl)glycerol were identified as constituents of the prothoracic defensive gland secretion of the
dytiscid beetle Agabus affinis by gas chromatography-mass spectrometry of trimethylsilylated gland extracts. In a feeding assay with minnows, synthetic
samples of the two 2-acylated monoglycerides showed only a weak activity as a feeding deterrent. For that reason, other possible
functions of the monoglycerides are discussed, such as roles as emulsifiers of cannabimimetics. 相似文献
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Objective: Objective and subjective methods have been used in the past to assess workplace fatigue, but little is known about correlations between them. We examine correlations between subjective and objective measures, including measures collected in a workplace scenario. Methods: 15 young and 17 older participants were assessed before and after work with four types of fatigue measure: objective physical (posturography), objective mental (psychomotor vigilance task), subjective physical and mental (self-assessment), objective and subjective realistic (oculomotor behaviour, observer-rated facial expression, typing performance). Results: Pre- and post-test scores were analysed with an ANOVA, significant differences were submitted to a factor analysis. It yielded three factors: one representing posturography, the second self-rated mental and physical fatigue and the third observer-rated facial expression. Conclusions: Results advocate the existence of three independent fatigue components: Objective physical fatigue, introspective and extrospective fatigue.
Practitioner Summary: This study analyses correlations between different subjective and objective fatigue markers to better understand the complex nature of workplace fatigue. Measurements were conducted directly at the workplace. Results reveal that fatigue comprises three independent fatigue components: Objective physical fatigue, introspective and extrospective fatigue. 相似文献
5.
Relations Between Regularization and Diffusion Filtering 总被引:4,自引:0,他引:4
Regularization may be regarded as diffusion filtering with an implicit time discretization where one single step is used. Thus, iterated regularization with small regularization parameters approximates a diffusion process. The goal of this paper is to analyse relations between noniterated and iterated regularization and diffusion filtering in image processing. In the linear regularization framework, we show that with iterated Tikhonov regularization noise can be better handled than with noniterated. In the nonlinear framework, two filtering strategies are considered: the total variation regularization technique and the diffusion filter technique of Perona and Malik. It is shown that the Perona-Malik equation decreases the total variation during its evolution. While noniterated and iterated total variation regularization is well-posed, one cannot expect to find a minimizing sequence which converges to a minimizer of the corresponding energy functional for the Perona–Malik filter. To overcome this shortcoming, a novel regularization technique of the Perona–Malik process is presented that allows to construct a weakly lower semi-continuous energy functional. In analogy to recently derived results for a well-posed class of regularized Perona–Malik filters, we introduce Lyapunov functionals and convergence results for regularization methods. Experiments on real-world images illustrate that iterated linear regularization performs better than noniterated, while no significant differences between noniterated and iterated total variation regularization have been observed. 相似文献
6.
Nano design for macroscopic coatings – new application potentials by PVD coatings up to 100 μm thickness Non-homogeneous coatings still limit the application of thicker layers due to defect growth and irregular layer thickness distribution along the surface of complex shaped components. Therefore, the layer thickness is usually limited to about 10 μm. In order to limit the surface roughness by the growing layer, multilayer coating systems are deposited by highly ionized plasmas. This allows significantly smoother layers to be produced, which until now could only be produced by mechanical finishing. Furthermore, by combining selected material systems and targeted parameter selection, structures can be deposited during coating, especially on edges, which result in a reduction of the cutting edge radius. In future, edge geometries should therefore be able to be specifically adjusted through the coating process. 相似文献
7.
Adhesive metallization of filter media by means of vacuum arc technology Textile filter media made of high‐performance fibres are used for separation of pollutants from industrial exhaust gases with higher temperatures. PVD‐coating is an innovative process for antistatic finishing of high‐temperature resistant textiles. PVD‐metallizations are extremely adherent, conductive and does not affect the throughput of gas. The results are the base for the industrial use in different textile applications. 相似文献
8.
Ralf Bandorf Dr. Wolfgang Diehl Dipl.‐Ing Ulrike Heckmann Dipl.‐Phys. Simone Kondruweit Dr. Andreas Pflug Dr. Harald Holeczek Dipl.‐Ing. Martin Metzner Dr. Udo Klotzbach Dr. Andreas Leson Dr. Otmar Zimmer Dr. 《真空研究与实践》2008,20(5):14-19
Propositions and Trends &#x0096; With Functional Surfaces into the Future Functional surfaces are the key to innovative products. Already today the properties, lifetime, and costs for most industrial and consumer products are determined by functionalised surfaces. Three Fraunhofer Institutes supported by the BMBF investigated the actual state of the art of production technology regarding functional surfaces, their future perspectives and the research and development demand. The results are published in the study “Production technology for the generation of functional surfaces” available at info@ist.‐ fraunhofer.de and the essentials are summarised in this article. 相似文献
9.
Hans‐Jörg Breyholz Dr. Stefan Wagner Dr. Andreas Faust Dr. Burkhard Riemann Prof. Dr. Carsten Höltke Dr. Sven Hermann Dr. Otmar Schober Prof. Dr. Michael Schäfers Prof. Dr. Klaus Kopka Priv.‐Doz. Dr. 《ChemMedChem》2010,5(5):777-789
Matrix metalloproteinases (MMPs) are zinc‐ and calcium‐dependent endopeptidases. Representing a subfamily of the metzincin superfamily, MMPs are involved in the proteolytic degradation of components of the extracellular matrix. Unregulated MMP expression, MMP dysregulation and locally increased MMP activity are common features of various diseases, such as cancer, atherosclerosis, stroke, arthritis, and others. Therefore, activated MMPs are suitable biological targets for the specific visualization of such pathologies, in particular by using radiolabeled MMP inhibitors (MMPIs). The aim of this work was to develop a radiofluorinated molecular probe for noninvasive in vivo imaging for the detection of up‐regulated levels of activated MMPs in the living organism. Fluorinated MMPIs ( 26 , 31 and 38 ) based on the pyrimidine‐2,4,6‐trione lead structure RO 28‐2653 ( 1 ) were synthesized, and their MMP inhibition potency was evaluated in vitro. The radiosynthesis and the in vivo biodistribution of the first 18F‐labeled prototype, MMP‐targeted tracer [18F] 26 , suitable for molecular imaging by means of positron emission tomography (PET) were realized. 相似文献
10.