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The tensile elastic modulus (E), yield stress (σY) and microhardness (MH) of neat and binary and ternary blends of glassy semicrystalline ethylene–vinyl alcohol copolymer (EVOH), a glassy amorphous polyamide and a semicrystalline nylon‐containing ionomer covering a broad range of properties were examined. The tests were carried out on dry and water‐equilibrated samples to produce stiffer and softer materials, respectively. From the results, more accurate linear correlations were found to describe adequately the microhardness, modulus and yield stress of these strongly self‐associated polymers through hydrogen bonding. Copyright © 2003 Society of Chemical Industry 相似文献
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BACKGROUND: The development and implementation of a relational database program for nursing quality management at a university hospital was stimulated by a lack of consistent data management and analysis tools in the existing noncomputerized program. PROGRAM DEVELOPMENT AND IMPLEMENTATION: An initial software prototype implemented in the critical care service included data collection instruments for five areas: medication errors, patient falls, returns to an intensive care unit within 48 hours, hospital-acquired skin breakdown, and unplanned extubations. Access to the database was limited and paper reports only were disseminated on a scheduled basis. In a second phase, the database is being deployed throughout the nursing department using a local area network. Nurse managers will enter and interact with the quality database online and have access to graphics, reports, and action plan development. POSSIBLE ERRORS: A wide range of potential errors influences decisions on how to collect, store, retrieve, and process quality management data. Each type of error affects the nurse manager's ability to identify significant patterns or trends that are amenable to intervention. There is no right way of constructing and implementing a quality improvement database; only an optimum balance between cost, complexity, and efficacy. SUMMARY AND CONCLUSIONS: Initial feedback from end uses has been positive. A three-year experience with a personal computer database suggests that the personal computer-based information technology is appropriate for small to medium applications and can support departmentwide CQI efforts. A case scenario using simulated data is included to illustrate the use of computerized reports in assessing and taking action on an increase in falls. 相似文献
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This study focuses on the perception of large scale application of nuclear energy and coal in the Netherlands and France. The application of these energy-sources and the risks and benefits are judged differently by various group in society. In Europe, France has the highest density of nuclear power plants and the Netherlands has one of the lowest. In both countries scientists and social scientists completed a questionnaire assessing the perception of the large scale application of both energy sources. Furthermore, a number of variables relating to the socio cultural and political circumstances were measured. The results indicate that the French had a higher risk perception and a more negative attitude toward nuclear power than the Dutch. But they also assess the benefits of the use of nuclear power to be higher. Explanations for these differences are discussed. 相似文献
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Doppler sonography of the fetal descending aorta, renal artery, middle cerebral artery and umbilical artery in a population of 74 fetuses with a abdominal circumference below the fifth percentile of the reference limits were done. All fetuses were free from structural and chromosomal abnormalities. The pulsatility- and the resistance indices as well as the ratios between these indices from peripheral and cerebral vessels were calculated and correlated to the fetal distress. The measurement of the pulsatility index of the middle cerebral artery provided the best results in predicting the development of fetal distress. Better results were achieved by the use of ratios of pulsatility-indices of various vessels than by the examination of the vessels alone. Our results suggest the usefulness of the examination of the middle cerebral artery and their ratios compared to the renal artery. 相似文献
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Sheep pulmonary adenomatosis (SPA) is a contagious bronchiolo-alveolar carcinoma of sheep associated with an exogenous type D/B retrovirus known as jaagsiekte sheep retrovirus (JSRV). SPA represents a unique model for lung cancer, and studies on its aetiopathogenesis can provide further insight into the mechanisms of epithelial neoplasms. 相似文献
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JM Derlon 《Canadian Metallurgical Quarterly》1993,39(6):385-405
Brain energy metabolism is essentially oxydative, through the glycolysis and the Krebs cycle. Brain tissue cannot survive more than a few minutes if the substrate (glucose, for which there is no endogenous reserve) or oxygen supply is abolished. Otherwise, there is a precise matching between perfusion (cerebral blood flow-CBF) and oxydative (oxygen consumption-CMRO2) and glycolytic regional metabolism. When intraarterial pressure is decreased (due to a systemic arterial pressure impairment or an arterial obstructive lesion), CBF is maintained constant through an increase of the pial vessels caliber and therefore an enhancement of the cerebral blood volume (CBV); this is cerebral circulatory autoregulation. In physiologic conditions, any increase of the local metabolic demand (during a motor, sensory, or cognitive activation) is supplied through a local enhancement of perfusion, and reversely. Therefore, the measurement of brain perfusion is useful not only to assess the consequences of cerebrovascular or some other diseases, but also to observe the functions involved in the normal working brain. This measurement is most frequently focused on CBF (flow) parameter, but in some clinical circumstances the access to CBV will be also of major importance for a correct understanding of the physiological or pathophysiological situation. We shall describe the different methods available both in clinical and experimental practice, and shall indicate for each one its characteristics, advantages and pitfalls. 相似文献