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61.
DV Mann MK Robinson JD Rounds E DeRosa DA Niles JS Ingwall DW Wilmore DO Jacobs 《Canadian Metallurgical Quarterly》1997,226(5):653-661
OBJECTIVE: To study the relation between blood and saline administration, postresuscitation hematocrit (Hct) level, and metabolic recovery after hemorrhagic shock. SUMMARY BACKGROUND DATA: It is generally believed that crystalloid can be substituted, in whole or in part, for blood during resuscitation of hemorrhagic shock. This is based on the belief that Hct can be safely reduced but should not fall below a critical level. METHODS: Male rats weighing 200 g were subjected to an isobaric hemorrhagic shock at a mean arterial pressure of 30 mmHg for 14 minutes, after which they were randomized to one of three resuscitation regimens. Control group (n = 36) were resuscitated by return of all shed blood. Mid-Hct (n = 39) and low-Hct (n = 60) groups were depleted of one third and one half of their circulating blood volumes, respectively, and were resuscitated with three times that volume of normal saline. Skeletal muscle intracellular energetics and pH were measured serially using 31P magnetic resonance spectroscopy at baseline, during shock, and after resuscitation. Arterial blood was sampled at the same time points. The number of surviving animals in each group at 24 hours was recorded. RESULTS: After resuscitation, surviving rats in the low-Hct group demonstrated a greater consumption of high-energy phosphocreatine stores than did the other groups (control = 0.479 +/- 0.003, mid-Hct = 0.465 +/- 0.004, low-Hct = 0.457 +/- 0.007, mean +/- standard error of the mean; p < 0.01 low-Hct vs. other groups by analysis of variance). The rats that received saline resuscitation developed a relative intracellular acidosis (control = 7.29 +/- 0.02, mid-Hct = 7.25 +/- 0.02, low-Hct = 7.23 +/- 0.02; p < 0.05 controls vs. other groups by analysis of variance). At 24 hours, the death rates were significantly different among the groups: control = 1 of 36 rats (2.8%), mid-Hct = 6 of 39 (15.4%), and low-Hct = 14 of 60 (23.3%) (p < 0.05 by chi square analysis). CONCLUSION: The oxygen-carrying capacity of resuscitation fluid has an important impact on intracellular metabolism and outcome. 相似文献
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佳能针对家居、商务、旅游、摄影爱好等不同消费群,推出了ZR 60、ZR65MC、ZR 70MC、ELURA 50MC以及OPTURA 10/20等六款全新数码摄像机,让你随时记录生活点滴,回味快乐时光。佳能新一代数码摄像机具有突破性的设计,流线动感的外型,包覆铝镁合金机身,采用了Canon引以为傲的二 相似文献
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DV Leaming 《Canadian Metallurgical Quarterly》1997,23(4):527-535
A survey of the practice styles and preferences of members of the American Society of Cataract and Refractive Surgery with a United States ZIP code was performed in September 1996. Approximately 26% (1440) of the 5520 questionnaires mailed were returned by the November cutoff date. Three main profile questions were used to cross-tabulate data: age of the ophthalmologist, geographic location, and volume of cataract surgery per month. Current data were compared with data in previous annual surveys. 相似文献
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In a long term clinical trial to evaluate a new treatment, quite often each study subject may experience a number of 'failures' that correspond to repeated occurrences of the same type of event or events of entirely different natures during his/her follow-up period. To obtain efficient inference procedures for the therapeutic effect over time, it is desirable to utilize those multiple event times in the analysis. In this article, we review some useful procedures for analysing different kinds of multivariate failure time data. Specifically, we discuss the two-sample problems and the general regression problems with various survival models. We also give some recommendations of appropriate procedures for each type of multiple event data structure for practical usage. 相似文献
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A novel possibility of obtaining a standard voltage of the order of 1 volt with fewer superconducting bridges than Josephson
junctions in existing voltage standards is discussed. It is proposed that a special feature of the current-voltage characteristic
of superconducting bridges be utilized — a group of current steps induced by microwave radiation is observed on it.
Pis’ma Zh. Tekh. Fiz. 23, 62–68 (September 26, 1997) 相似文献
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