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991.
It is known that an increased level of red blood cell 2,3-diphosphoglycerate (DPG) shifts the oxyhemoglobin dissociation curve to the right, thus allowing a greater unloading of oxygen at the tissue level. It has been hypothesized that phosphate might help increase VO2max by increasing 2,3-DPG level. Eight trained cyclists underwent three cycle ergometer tests (control, placebo, and experimental) to determine whether phosphate ingestion had any positive effect on VO2max, time to exhaustion, serum 2,3-DPG, and serum phosphate levels. We found no change between the control, placebo, or experimental conditions in pretest serum phosphate levels, but we did find increases in 2,3-DPG levels in the phosphate condition (p less than .05), which suggests that even a small amount of phosphate could increase levels of 2,3-DPG. We also found significant differences in VO2max between the control (p less than .05) and placebo (p less than .02) conditions and also in time to exhaustion between the three conditions (p less than .05). We suggest that phosphate may have an ergogenic effect, but clearly more work needs to be undertaken to ascertain the amount of phosphate required and the magnitude of the effect.  相似文献   
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Participant perceptions of exercise programs for overweight women   总被引:1,自引:0,他引:1  
Eighteen women participated in a research project involving two phases: (a) an interview regarding weight history and exercise patterns, and (b) a series of exercise sessions followed by discussions of participants' reactions to them. The data were analyzed using inductive analysis techniques, and results of the analysis were discussed with participants for collaborative validation of the interpretation. Profiles of selected participants and themes that emerged are described. The participants varied in age and body size and had diverse backgrounds, interests, and abilities, but their shared experience of social disapproval based on body size was shown to affect their perceptions of exercise programs and their decisions about participation.  相似文献   
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The experiences of medical students, residents, and faculty with a computerized literature searching system were evaluated. Third-year medical students, internal medicine and family practice residents, and full-time and voluntary faculty at one medical school had the opportunity to use a full-text and bibliographic medical literature retrieval system free of charge for an eleven-month period. Subjects conducted nearly nine thousand literature searches over a period of 942 system hours. Questionnaire data showed that participants could learn to use and would use an electronic information system, felt capable of using the system, utilized the system for a variety of purposes and in a number of different ways, and viewed the system as a valuable tool in searching the medical literature. The results are discussed in the context of the educational needs of the four user-groups and medical education planning by institutions.  相似文献   
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This paper examines the problems of searching for literature of a biographic character and the means of indexing such literature in the Universal Decimal Classification. Recommendations are given on the recording and searching of biographic data in the thematic catalogue.  相似文献   
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