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111.
Psychiatric workers facing redeployment completed questionnaire measures of stressors, resources (locus of control and perceived social support), coping, well-being, and negative affectivity, at baseline (N = 109) and 1 year later (loss of 7 participants). Regression analyses of the baseline data suggested that as stressors increased, so did avoidance coping, but less so for those high in internality or perceived social support. Problem-focused coping was bolstered by internality and emotion-focused coping by perceived social support. Other regression analyses, with a longitudinal aspect, suggested that stressors had a deleterious effect on well-being. Problem- and emotion-focused coping had beneficial effects, whereas avoidance coping had a (delayed) deleterious effect. These effects of coping were predominantly main and not buffering effects.  相似文献   
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Mechanism of suppression of cell-mediated immunity by measles virus   总被引:2,自引:0,他引:2  
The mechanisms underlying the profound suppression of cell-mediated immunity (CMI) accompanying measles are unclear. Interleukin-12 (IL-12), derived principally from monocytes and macrophages, is critical for the generation of CMI. Measles virus (MV) infection of primary human monocytes specifically down-regulated IL-12 production. Cross-linking of CD46, a complement regulatory protein that is the cellular receptor for MV, with antibody or with the complement activation product C3b similarly inhibited monocyte IL-12 production, providing a plausible mechanism for MV-induced immunosuppression. CD46 provides a regulatory link between the complement system and cellular immune responses.  相似文献   
114.
OBJECTIVES: This study was performed to determine the efficacy of new encircling overlapping multipulse, multipathway waveforms for transthoracic defibrillation. BACKGROUND: Alternative waveforms for transthoracic defibrillation may improve shock success. METHODS: First, we determined the shock success achieved by three different waveforms at varying energies (18-150 J) in 21 mongrel dogs after short-duration ventricular fibrillation. The waveforms tested included the traditional damped sinusoidal waveform, a single pathway biphasic waveform, and a new encircling overlapping multipulse waveform delivered from six electrode pads oriented circumferentially. Second, in 11 swine we compared the efficacy of encircling overlapping multipulse shocks given from six electrode pads and three capacitors versus encircling overlapping shocks given from a device utilizing three electrodes and one capacitor. RESULTS: In the first experiment, the encircling overlapping waveform performed significantly better than biphasic and damped sinusoidal waveforms at lower energies. The shock success rate of the overlapping waveform (six pads) ranged from 67+/-4% (at 18-49 J energy) to 99+/-3% at > or = 150 J; at comparable energies biphasic waveform shock success ranged from 26+/-5% (p < 0.01 vs. encircling overlapping waveforms) to 99+/-5% (p = NS). Damped sinusoidal waveform shock success ranged from 4+/-1% (p < 0.01 vs. encircling overlapping waveform) to 73+/-9% (p = NS). In the second experiment the three electrode pads, one capacitor encircling waveform achieved shock success rates comparable with the six-pad, three-capacitor waveform; at 18-49 J, success rates were 45+/-15% versus 57+/-12%, respectively (p = NS). At 100 J, success rates for both were 100%. CONCLUSIONS: We conclude that encircling overlapping multipulse multipathway waveforms facilitate transthoracic defibrillation at low energies. These waveforms can be generated from a device that requires only three electrodes and one capacitor.  相似文献   
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STUDY DESIGN: The biomechanical influence of in situ setting hydroxyapatite cement was examined for use in pedicle screw revision surgery. Pull-out testing of control and pedicle screws augmented with hydroxyapatite cement was performed in human cadaver vertebrae. OBJECTIVES: To determine the immediate effect of using hydroxyapatite cement to augment revision pedicle screws after failure of the primary pedicle screw fixation. SUMMARY OF BACKGROUND DATA: The potential problems associated with using polymethylmethacrylate to augment revision pedicular instrumentation have prompted the search for other solutions. The introduction of resorbable hydroxyapatite pastes may have provided new biocompatible solutions for pedicle screw revision. METHODS: Ten human cadaver vertebrae were instrumented with 6.0-mm pedicle screws in each pedicle. The screws were loaded to failure in axial tension (pull-out). The failed pedicles then were instrumented with 7.0-mm pedicle screws, either augmented with hydroxyapatite cement or nonaugmented, which also were loaded to failure. Finally, the nonaugmented 7.0-mm screw hole was reinstrumented with a hydroxyapatite cement-augmented, 7.0-mm pedicle screw and loaded to failure. RESULTS: The pull-out strength of the 7.0-mm, hydroxyapatite cement-augmented screws was 325% (P = 2.9 x 10(-5)) of that of the 6.0-mm control screws, whereas the strength of the 7.0-mm nonaugmented screws was only 73% (P = 2.0 x 10(-2)) of that of the 6.0-mm control screws. The 7.0-mm screws augmented with hydroxyapatite cement also were able to salvage 7.0-mm pull-out sites to 384% (P = 6.9E-5) of the pull-out strength of the 7.0-mm nonaugmented screws. CONCLUSIONS: Hydroxyapatite cement may be a mechanically viable alternative to polymethyl methacrylate for augmenting revision pedicular instrumentation and should be considered for future experimental, animal, and clinical testing.  相似文献   
117.
An encoded 13,020-member combinatorial library was synthesized containing a statine core. Evaluation of this library with plasmepsin II, an aspartyl protease required for hemoglobin metabolism in the malaria parasite, led to the identification of potent and selective inhibitors as well as novel structure-activity relationships.  相似文献   
118.

A possible interpretation of the so-called Poley absorption in polar liquids is that it is due to overlapping contributions from liquid- lattice bands together with a contribution from an inertially “rolled-off” Debye absorption. We propose a test involving the inertially similar but electrically very different molecules methyl chloroform and carbon tetrachloride. This test gives results which offer plausible support for the two-component interpretation.

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119.
Birch  J.R. 《Electronics letters》1980,16(21):799-800
The harmonic content of a commercial c.w. 20 mW 100 GHz IMPATT oscillator operating at ambient temperature has been determined at 200 and 300 GHz using free space techniques. The highest power levels observed at these frequencies were 16.6 and 37.5 dB below the fundamental, respectively, corresponding to power levels of 0.5 mW at 200 GHz and 4.5 ?W at 300 GHz at the oscillator.  相似文献   
120.
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