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71.
NS Alekaev 《Canadian Metallurgical Quarterly》1976,16(5):76-79
The study concerns the effect of angiotensin II when infused into the systemic and portal blood flow upon the general and renal haemodynamics in normal dogs and in hypertensive animals, as well as the effect of the operation of porto-caval transposition upon the course of renovascular hypertension. When peptide is infused, at a rate that causes a moderate pressor effect, into the systemic blood flow of normal animals, an antidiuretic and antinatriuretic effect is obtained, in hypertensive animals--an increase of diuresis, natriuresis and a less distinct pressor effect are obtained. When angiotensin II is infused into the portal flow, a less distinct pressor and renal effect is seen in animals with renovascular hypertension. The operation of porto-caval transposition of the vessels results in a hypotensive effect in the animals with renovascular hypertension. 相似文献
72.
This paper examines the view that productive teaching in the operating theatre requires a recognition of the unique set of factors which may influence the process of communication. For tutor-student interaction to occur in a productive manner, the tutor's behaviour will need to be modified to suit the demands of the other tasks in which both tutor and student are involved. The particular value of recognizing the role of nonverbal behaviours during interaction is discussed, with the use of specific examples related to the positioning of the tutor and student, and their use of facial expression, the eyes and voice. 相似文献
73.
Variation of Vickers microhardness of InBi single crystals with temperature has been studied. Loading time dependence of the
microhardness at different temperatures has been used for the creep study in the temperature range 30° – 85°C. The activation
energy for creep has been evaluated and the results are discussed. 相似文献
74.
ML Nochomovitz AF Dimarco JT Mortimer NS Cherniack 《Canadian Metallurgical Quarterly》1983,127(3):325-329
We studied in 10 supine anesthetized dogs diaphragm contraction produced by electrical activation with intramuscular electrodes surgically implanted in the ventral surface of the diaphragm and compared this with activation of the ipsilateral phrenic nerve (C5, 6, and 7) before it entered the thorax. Repetitive 40-Hz pulse trains with supramaximal current stimulus were used after hyperventilation of the animals to apnea. A single intramuscular electrode within 1 to 2 cm of the site of phrenic nerve entry into the diaphragm produced a mean transdiaphragmatic pressure of 12.0 cm H2O +/- 0.97 SE and mean tidal volume of 0.27 L +/- 0.04 SE. Mean values observed with phrenic nerve stimulation were not statistically different, and both electrode systems produced equivalent outward abdominal motion and upper rib cage paradox, as monitored by inductive plethysmography. There was no difference in gas exchange during stimulation with a single hemidiaphragm electrode and mechanical ventilation compared at the same tidal volume and respiratory rate. Blockade of neuromuscular transmission with curare eliminated intramuscular and phrenic nerve stimulation proportionately, suggesting that activation of the diaphragm is dependent in both cases on the phrenic nerve. This technique does not entail manipulation of the phrenic nerve and may have clinical application as an alternative technique for diaphragm pacing. 相似文献
75.
76.
The health effects of recreational gambling are presently unclear, particularly across age groups. Theories of healthy aging suggest that social activities, including gambling, may be beneficial to the health of older adults. Using cross-sectional data from the National Epidemiologic Survey on Alcohol and Related Conditions (N=43,093), the authors examined associations between gambling (categorized as nongambling, recreational gambling, or problem/pathological gambling) and health and functioning measures stratified by age (40-64 years and ≥65). Problem/pathological gambling was uniformly associated with poorer health measures among both younger and older adults. Among younger respondents, poorer health measures were also found among recreational gamblers. However, among older respondents, recreational gambling was associated not only with some negative measures (e.g., obesity) but also with some positive measures (e.g., better physical and mental functioning). Longitudinal studies are needed to clarify the relationship between gambling and health in older adults in the context of healthy aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
77.
Md Mahmudur Rahman Prabir Bhattacharya Bipin C Desai 《IEEE transactions on information technology in biomedicine》2007,11(1):58-69
A content-based image retrieval (CBIR) framework for diverse collection of medical images of different imaging modalities, anatomic regions with different orientations and biological systems is proposed. Organization of images in such a database (DB) is well defined with predefined semantic categories; hence, it can be useful for category-specific searching. The proposed framework consists of machine learning methods for image prefiltering, similarity matching using statistical distance measures, and a relevance feedback (RF) scheme. To narrow down the semantic gap and increase the retrieval efficiency, we investigate both supervised and unsupervised learning techniques to associate low-level global image features (e.g., color, texture, and edge) in the projected PCA-based eigenspace with their high-level semantic and visual categories. Specially, we explore the use of a probabilistic multiclass support vector machine (SVM) and fuzzy c-mean (FCM) clustering for categorization and prefiltering of images to reduce the search space. A category-specific statistical similarity matching is proposed in a finer level on the prefiltered images. To incorporate a better perception subjectivity, an RF mechanism is also added to update the query parameters dynamically and adjust the proposed matching functions. Experiments are based on a ground-truth DB consisting of 5000 diverse medical images of 20 predefined categories. Analysis of results based on cross-validation (CV) accuracy and precision-recall for image categorization and retrieval is reported. It demonstrates the improvement, effectiveness, and efficiency achieved by the proposed framework. 相似文献
78.
79.
Yalcin A. Popat K.C. Aldridge J.C. Desai T.A. Hryniewicz J. Chbouki N. Little B.E. Oliver King Van V. Sai Chu Gill D. Anthes-Washburn M. Unlu M.S. Goldberg B.B. 《IEEE journal of selected topics in quantum electronics》2006,12(1):148-155
A biosensor application of vertically coupled glass microring resonators with Q/spl sim/12 000 is introduced. Using balanced photodetection, very high signal to noise ratios, and thus high sensitivity to refractive index changes (limit of detection of 1.8/spl times/10/sup -5/ refractive index units), are achieved. Ellipsometry and X-ray photoelectron spectroscopy results indicate successful modification of biosensor surfaces. Experimental data obtained separately for a bulk change of refractive index of the medium and for avidin-biotin binding on the ring surface are reported. Excellent repeatability and close-to-complete surface regeneration after binding are experimentally demonstrated. 相似文献
80.
The concept of complementary models for discrete-time linear finite-dimensional systems with correlated observation and process noise is developed. Using this concept, a new algorithm for the fixed interval smoothing problem is obtained. The new algorithm offers great flexibility with respect to changes in the initial state variancePi_{0} . Next, the relationship among the new smoothing algorithm, the two-filter smoother, and the reversed-time Kalman filter is explored. It is shown that a similarity transformation on the Hamiltonian system simultaneously produces the new smoothing algorithm, as well as the reversed-time Kalman filter. 相似文献