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51.
Although explosive isometric contraction provides little work toward the outside, force-time parameters of the rising phase of the force-time curve may be able to predict muscle power. The purpose of this study was to examine the relationship between muscle power with work (power grip) and force-time parameters during the rising phase in explosive isometric grip. Fifteen healthy young adult males participated in this study. Power grip was measured using loads of 20%–50% of maximal voluntary contraction (MVC) (peak isometric force). Subjects pulled explosively on a grip bar held with the second digital joints without the thumb. Peak power was calculated from peak velocity and load. Explosive isometric grip was measured using a hand dynamometer. Time-series data of both tests were sampled by an analog-to-digital interface. Both tests were performed with the subjects seated with a sagittal and horizontal position of the arm supported by an armrest. Peak power in the power grip test tended to be larger with an increase of the load, but there was no significant difference between 40% and 50% MVC. Only the peak power in 50% MVC significantly correlated with peak grip force (r=0.52, p<0.05). The force-time parameters related to the peak rate of the rising force phase in explosive isometric grip significantly correlated with the peak powers (30%–50% MVC, r=|0.58−0.78|). Peak rate of the rising force phase in explosive isometric grip may be useful for predicting muscle power with loads between 30%–50% MVC.  相似文献   
52.
目的:探讨河南中医学院设置健康保险专业的论证。方法:从我国健康保险业的发展实际出发,集中分析河南中医学院设置健康保险专业的必要性,论证了河南中医学院在师资、设施、生源与就业等方面的可行性,以培养目标、课程设置和实习基地建设为轴线,提出了设置健康保险专业的建议。结果与结论:河南中医学院设置健康保险专业有必要、有可行性、有优势。  相似文献   
53.
Health policy, epidemiology and power: the interest web   总被引:4,自引:4,他引:0  
The relation between epidemiological research results and policy-making is reviewed. Apparently, traditional models of policy-making(incrementalism, mixed scanning synoptic planning) do not explainwhy research findings are hardly used in policy-making procedures. It is suggested that this phenomenon is related to three determinantsof policy-making: (i) a bias stemming from sets of causal, finaland normative assumptions and presuppositions; (ii) interestwebs of groups in certain domains; and (iii) the power of organizationsto monitor and communicate. The conclusion is that epidemiologistsshould engage in the policy-making process more consciouslyand conscientiously.  相似文献   
54.
 Intracellular pH (pHi) is known to modulate contraction. Neonatal tissues can differ from adult tissue in contractile response to stimuli known to alter pHi e.g. hypoxia. Changes of pH are attenuated by buffering, thus any difference in buffering power (β) between tissues could affect their functional response to pHi perturbation. Similarly the extent to which any extracellular pH (pHo) alteration is transmitted into a pHi change will also influence function. We have therefore determined the intrinsic β and effect of pHo change on pHi in neonatal and adult ureteric, uterine and gastric smooth muscles using the pH-sensitive fluorophore carboxy-SNARF. β was found to be similar in the three adult tissues, but there were significant differences between neonatal tissues. In contrast, we found little difference in the amount of pHi change produced by pHo change between neonatal and adult tissues from the same smooth muscle, but a difference between smooth muscles. These data highlight significant differences between smooth muscles and their developmental state, which may contribute to different degrees of protection when pH is perturbed. Received: 17 October 1997 / Received after revision: 27 November 1997 / Accepted: 28 November 1997  相似文献   
55.
血流频谱分析在乳腺肿块鉴别诊断中的价值   总被引:3,自引:0,他引:3  
韩增辉  王全华 《医学争鸣》1997,18(6):536-538
目的:检验血流频谱分析在鉴别乳腺原发性肿块良恶性方面的价值并确立最佳的数值标准。方法:使用彩色多普勒血流显像和能量多普勒显像分别引导脉冲多普勒频谱分析,检查了104例乳腺原发性包块(良性55例63个病灶,恶性49例64个病灶),测量指标包括肿块周边与内部血流收缩期峰速、搏动指数及阻力指数,并分别绘制受试者工作曲线确定各自的最佳阈值。结果,以CDFI状态取频谱,乳癌病灶周边及内部血流的平均PSV,P  相似文献   
56.
A group of 153 children (51 with a history of bronchiolitis and 102 matched controls) were evaluated in a historical cohort study at a mean age of 8 years and again at 13 years to test the primary hypothesis that mild bronchiolitis, far more common than severe (hospitalized) bronchiolitis, predicts wheezing. A secondary hypothesis was that passive smoking also predicts wheezing. Many potentially confounding variables such as family history of asthma were controlled in analyses. Analysis at 13 years produced results that were not anticipated from previous analysis of interviews at age 8. Although mild bronchiolitis was a powerful predictor of wheezing at age 8 years, it was no longer a strong predictor of wheezing at age 13 in either bivariate or multivariate analysis. Although epidemiologic studies, by their nature, cannot prove causality, findings are consistent with the hypothesis that sequelae often follow mild bronchiolitis but diminish during childhood. Maternal smoking was a powerful predictor of wheezing at age 13 in bivariate analysis (Kendall's Tau B = 0.19, P less than 0.01) and in multivariate analysis (odds ratio = 2.67, P less than 0.01). In children at highest risk for wheezing, males with a family history of asthma, multivariate analysis suggested that maternal smoking is associated with an increase in wheezing from 36% to 60%. We conclude that passive smoking, previously identified as a risk factor in this population for both bronchiolitis in infancy and wheezing at age 8, is a risk factor for wheezing-associated morbidity throughout the childhood years.  相似文献   
57.
We investigated non-rapid eye movement (non-REM) sleep in patients with newly diagnosed Parkinson's disease (PD) who had never previously received dopaminergic medication. There were no significant differences in the conventional sleep parameters between de novo patients with PD and a healthy control group, but the length of stage 1 sleep and the number of awakenings increased significantly upon administration of dopaminergic drugs. Analyzing the quantitative electroencephalogram (EEG), we observed a significant reduction in the low-delta frequency range and a nonsignificant increase in the sigma frequency range in de novo patients with PD. The dopaminergic medication also nonsignificantly reduced the low-delta and sigma frequencies, the latter to the level of the controls. Possible mechanisms that may account for the observed differences are discussed. It is suggested that Parkinson's disease as well as the application of dopaminergic drugs exerts a desynchronizing effect on the sleep EEG that is reflected in a disruption of sleep continuity.  相似文献   
58.
Sixty-two cases of breast pathology were randomly selected from the files of the Dunedin Public Hospital for evaluation of mean epithelial nuclear volume. The cases were comprised of both benign and malignant ductal epithelial disease, diagnosed in cytological smears or in histological sections. Nuclear volume in histological preparations was estimated by the stereological technique of point-line intercept measurements to derive volume-weighted mean volumes (vV). An index of the nuclear volume (Vi) of cytology smears was calculated from measurements of nuclear areas by either image analysis Vi(e) or point-line intercepts Vi(p). By all methods of analysis a clear distinction of nuclear volume was found between the benign [means for the cytology were 148 microns 3 (Vi(e)) or 246 microns 3 (Vi(p)), and 203 microns 3 (Vv) for the histology specimens] and malignant diseased cases [means for cytology: 524 microns 3 (Vi(e)) or 886 microns 3 (Vi(p)), and 587 microns 3 (vV) for the histology specimens].  相似文献   
59.
目的 探讨经尿道膀胱肿瘤低功率电切术的适应症、手术方法及其疗效评估. 方法分析65例经尿道膀胱肿瘤切除术.手术时间10~90 min,平均时间41 min;膀胱穿孔1例,术后冲洗时间1~3 d,平均2 d;导尿管留置时间1~5 d,平均4 d.结果 随访0.5~3 a,48例中肿瘤复发15例,其中原位复发2例,异位多位复发13例.结论 经尿道膀胱肿瘤低功率电切可防止并明显减少闭孔神经反射的发生,具有操作简单,损伤小,出血少、恢复快等优点.  相似文献   
60.
核因子kappa B(NF—κB)是许多促炎因子高表达所必需的转录因子。近年来,随着分子生物学技术的发展,NF—κB对免疫、应激和炎症反应以及淋巴细胞分化和生长的调控作用成为研究的热点。作者就NF—κB在缺血-再灌注及体外循环损伤机制中的作用作一综述,并简要介绍阻断NF-κB激活干预治疗的研究进展。  相似文献   
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