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51.
This study was designed to evaluate factors that affect blood volumes transferred to skin during simulated needlestick injuries in an in vitro paper prefilter model and an ex vivo porcine tissue model. The effect of needle type and size, penetration depth, and glove use on the volume of radiolabeled blood transferred was determined in each model. Blood volumes ranged from 0.47 +/- 0.26 microL (30-gauge needle, 0.5-cm depth, in vitro model) to 5.88 +/- 1.45 microL (18-gauge needle, 2.0-cm depth, in vitro model). Needle size and penetration depth were significantly associated with transfer volume. Glove material reduced the transferred blood volume by 46%-86% in both models. Transfer volumes were within the same order of magnitude for all conditions. Hence, virus titer in the source blood may be a better predictor of needlestick infectivity than is exposure volume. Regardless, gloves may exert some protective effect and should be worn whenever needles are handled. 相似文献
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The final stage in the production of a radiotherapy treatment plan must always be an independent check that the linear accelerator settings given on the plan do in fact deliver the required dose distribution. A tool is described that enables rapid checking of diaphragm settings in relation to the patient. 相似文献
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A structural model of science achievement and attitude: An extension to high school. 总被引:1,自引:0,他引:1
A previous structural model of Walberg's theory of educational productivity (A. J. Reynolds and H. J. Walberg, 1991) was tested with a national probability sample of 2,535 10th graders for science achievement and attitude. Using data from the Longitudinal Study of American Youth, a 3-wave design incorporated information from students, teachers, and parents. Results indicate that a revised mediated-effects model fit the data best and accounted for substantial variance in Grade 11 science achievement (56%) and attitude (44%). The variables prior achievement, home environment, exposure to mass media through reading, and instructional time had the greatest total effects on science achievement. Prior attitude, home environment, motivation, and prior achievement made the greatest total contributions to science attitude. Although there were different weightings of the factors between the present study and Reynolds and Walberg (1991), both studies support a mediated-effects model of educational productivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Comments on S. Messick's (see record 1996-10004-001) paper on the validity of psychological assessment. The author discusses the indeterminacy of construct validity, the overzealous scuttling of criterion-relevant validity, the drift away from measure-centered validity, and the need for reestablishing multiple forms of validity. The comments are aimed at combating an air of complacency fostered by the introduction and mounting elaboration of the concept of construct validation. The author concludes that the intractability of psychological measurement needs to be confronted more directly. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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H Komuro MB Valentine ST Rowe VJ Kidd S Makino GM Brodeur SL Cohn AT Look 《Canadian Metallurgical Quarterly》1998,33(11):1695-1698
Artificial illumination is an important factor in the management of layers. In this study, a new monochromatic light system was developed for egg layers. Prelaying pullets (Lohmann) were marked and housed in nine light and temperature control rooms (15 battery cages, 3 hens per cage; n = 45), divided into three light treatments: 0.1 and 0.01 W/m2 light intensity using light emitting diode (LED) lamps and 0.1 W/m2 using mini-fluorescent bulbs (PL) (control). In each of the LED rooms, three wavelengths were tested: 560 (n = 9), 660 (n = 9), 880 (n = 6), and 660 intermitted lighting (15 min light 45 min dark, 660IN) (n = 9). Birds were exposed to 12 h light and 12 h of darkness using PL lamps. At 21 wk of age, the light period was increased to 12.75 h by using 5.5 h of LED lamps and 7.25 of PL light source for Groups 1 and 2, the third group received 12.75 h of PL light. Until 28 wk of age, light hours increased by 0.5 h/w using LED light for Groups 1 and 2 and PL source for the third group, reaching 16 h of light at 28 wk of age. Egg production and feed consumption were recorded daily; egg components were recorded weekly for 10 mo. A significant reduction in egg production was observed in all 880nm groups; no differences in egg production and quality were found in the other groups. Feed consumption was significantly lower by 7% in all 0.01 W/m2 groups. We suggest that an important reduction in rearing costs of laying hens may be obtained by using this system. 相似文献
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This is a study on the loss-grief reaction and coping behavior of a mother whose child died of brain tumor. The researcher used field methods to collect data and analyze observations of mother-nurse interaction. The results showed that this mother had self-blame depression, and guilt feelings and affected the whole family. With the help of nurses and various supportive resources the mother was finally able to go through the grieving process smoothly. 相似文献
60.
Herbert W. Franke 《The Visual computer》1988,4(1):35-39
The article points out some new possibilities for using computers as an instrument for visual art, especially stressing the mathematical method of picture synthesis. It is illustrated with results of recent computer art by Herbert W. Franke and Horst Helbig. 相似文献