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排序方式: 共有173条查询结果,搜索用时 15 毫秒
161.
Gill Furze Alun Roebuck Peter Bull Robert JP Lewin David R Thompson 《BMC cardiovascular disorders》2002,2(1):4
Background
What people believe about their illness may affect how they cope with it. It has been suggested that such beliefs stem from those commonly held within society . This study compared the beliefs held by people with angina, regarding causation and coping in angina, with the beliefs of their friends who do not suffer from angina. 相似文献162.
K Grosios J P Leek A F Markham G D Yancopoulos P F Jones 《Cytogenetics and cell genetics》1999,84(1-2):118-120
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Amanda M. Lauer Robert J. Dooling Marjorie R. Leek 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2009,195(2):193-202
Belgian Waterslager canaries (BWC), bred for a distinct low-pitched song, have an inherited high-frequency hearing loss associated
with hair cell abnormalities. Hair cells near the abneural edge of the papilla, which receive primarily efferent innervation
in normal birds, are among the most severely affected. These cells are thought to support nonlinear active processing in the
avian ear, though the mechanisms are poorly understood. Here we present psychophysical evidence that suggests degraded active
processing in BWC compared to normal-hearing non-BWC. Critical ratios, psychophysical masking patterns and phase effects on
masking by harmonic complexes were measured in BWC and non-BWC using operant conditioning procedures. Critical ratios were
much larger in BWC than in non-BWC at high frequencies. Psychophysical tuning curves derived from the masking patterns for
BWC were broadened at high frequencies. BWC also showed severely reduced phase effects on masking by harmonic complexes compared
to non-BWC. As has been hypothesized previously for hearing-impaired humans, these results are consistent with a loss of active
processing mechanisms in BWC. 相似文献
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Eight Polled Dorset lambs were orally inoculated with Sarcocystis ovicanis sporocysts. Two lambs that received 100,000 or 200,000 sporocysts became clinically ill, recovered, and were killed 67 and 88 days after inoculation (DAI). Numerous intramuscular cysts were found in their skeletal and cardiac muscles. Three lambs received 100,000 sporocysts, three lambs received 1 million sporocysts, and three lambs received no sporocysts. After an acute clinical illness characterized by anemia, inappetence, weight loss, fever, and reduced serum protein, all lambs that received 100,000 sporocysts died 27 to 29 DAI and all that received 1 million sporocysts died 24 or 25 DAI. Hemorrhage involving the striated muscle and visceral organs was the most apparent gross lesion. The heart appeared most severely affected. Schizonts were found in vascular endothelial cells of all six inoculated lambs. Uninoculated lambs remained healthy, and neither lesions nor parasites were found in any tissues. Dogs fed tissues containing S. ovicanis cysts produced sporocytes 11 to 37 days after feeding; cats fed similar stages produced no sporocysts. Dogs fed tissues containing schizonts produced no sporocysts. 相似文献
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Guy G.S. Dutton Jose L. Di Fabio Donald M. Leek Edwin H. Merrifield John R. Nunn Alistair M. Stephen 《Carbohydrate research》1981,97(1):127-138
Depolymerization of bacterial, capsular polysaccharides by viral enzymes provides a convenient method for preparing oligosaccharides that correspond to one or more repeating unit(s) of the polysaccharide. Previous methods used for purifying bacteriophage particles, and also the procedures employed in the isolation and purification of the oligomers generated by the bacteriophage action, have been so modified as to provide a more direct route to the degradation products. Improved techniques, both for the propagation of bacteriophage and for the isolation of the oligosaccharides formed, are reported. These simplified methods make possible the use of bacteriophages as convenient “reagents” for the preparation of oligosaccharides on a gram scale. The acid- and base-labile substituents present in certain of the polysaccharides examined were seemingly unaffected by the conditions used for depolymerization. The methods are illustrated by degradation of the capsular polysaccharides from Klebsiella serotypes K17, K36, K46, K60, K63, and K74. 相似文献