首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1221篇
  免费   72篇
  国内免费   5篇
耳鼻咽喉   14篇
儿科学   61篇
妇产科学   15篇
基础医学   135篇
口腔科学   12篇
临床医学   122篇
内科学   210篇
皮肤病学   9篇
神经病学   60篇
特种医学   84篇
外科学   203篇
综合类   10篇
预防医学   201篇
眼科学   14篇
药学   61篇
中国医学   1篇
肿瘤学   86篇
  2023年   8篇
  2022年   56篇
  2021年   81篇
  2020年   25篇
  2019年   39篇
  2018年   40篇
  2017年   18篇
  2016年   20篇
  2015年   43篇
  2014年   32篇
  2013年   45篇
  2012年   52篇
  2011年   53篇
  2010年   27篇
  2009年   26篇
  2008年   59篇
  2007年   47篇
  2006年   52篇
  2005年   64篇
  2004年   46篇
  2003年   45篇
  2002年   30篇
  2001年   28篇
  2000年   28篇
  1999年   33篇
  1998年   8篇
  1997年   13篇
  1996年   6篇
  1995年   11篇
  1994年   15篇
  1993年   8篇
  1992年   16篇
  1991年   14篇
  1990年   15篇
  1989年   21篇
  1988年   20篇
  1987年   21篇
  1986年   12篇
  1985年   16篇
  1984年   19篇
  1983年   7篇
  1981年   6篇
  1979年   10篇
  1978年   7篇
  1976年   8篇
  1975年   8篇
  1973年   5篇
  1972年   6篇
  1971年   4篇
  1967年   6篇
排序方式: 共有1298条查询结果,搜索用时 0 毫秒
71.
72.
73.
Synaptosomal associated protein of 25 kDa (SNAP-25) has been implicated in the membrane fusion machinery of neurotransmitter release and axonal growth. Using immunocytochemistry, we have analyzed the distribution and ultrastructural localization of SNAP-25 in selected areas of the central and peripheral nervous systems of adult rats. We show that the protein is specifically expressed in the trans face of the Golgi apparatus and in the axonal compartment. In axons and nerve endings, SNAP-25 is localized to discrete areas of the membranes of most organelles such as the axoplasmic reticulum, the axolemma, the outer membrane of mitochondria and synaptic vesicles. This wide distribution of SNAP-25 suggests that the protein is involved in the fusion of membranes in the whole axonal compartment of neurons. © 1995 Wiley-Liss, Inc.  相似文献   
74.
Thirteen cases of heel flap injuries following motorcycle spoke accidents have been analysed. The injuries have been graded into three Grades (I, II and III) depending upon the severity and extent of the injury to the foot. The different forms of management are outlined. Most of the injuries have been confined to the right side because of poor assembly of the rear wheel of the motorcycle. Inadequate footwear is a contributory factor. It is urged that protective footwear be made compulsory for both the driver and the pillion passenger. Changes should also be made in the design of the rear wheels of motorcycles.  相似文献   
75.
76.
Ultrastructural studies were performed on portions of the operatively resected right atrium from six patients with a ventricular septal defect and six patients with an endocardial cushion defect. The six patients with a ventricular septal defect had normal right atrial mean pressure and no evidence of right atrial volume overload. Ultrastructurally, the atrial muscle cells in these patients appeared normal and measured 6 to 12 μ in diameter. The six patients with an endocardial cushion defect had elevated right atrial mean pressure and evidence of right atrial volume overload. Ultrastructurally, the atrial muscle cells in these patients were generally larger than 12 μ in diameter. The cells were irregular and had multiple and occasionally widened intercalated discs. In addition, there were degenerative changes in two patients with markedly increased atrial pressure. These changes included extensive loss of contractile elements, aggregation of small irregular mitochondria and proliferation of tubules of the sarcoplasmic reticulum. The structural changes suggest that hypertrophy of the right atrium may be secondary to volume overload of the atrium, whereas degenerative changes may be secondary to increased right atrial pressure.  相似文献   
77.
OBJECTIVE: To determine the impact of anthropometric characteristics and dietary patterns on Type 2 diabetes mellitus in Vietnam. METHODS: Data from 144 subjects (9m/39f newly diagnosed diabetics; 18m/78f control subjects) were analyzed in this case-control study. Height, weight, waist and hip circumferences and percent body fat were measured. Dietary intakes were assessed by 24-hour recall on three non-consecutive weekdays. Fasting blood samples were collected for the analysis of plasma glucose, fructosamine, protein and lipid concentrations. RESULTS: Although the body mass index (BMI, kg/m(2)) was similar between diabetic and control subjects, diabetic subjects had significantly greater percent body fat (31.1 +/- 5.8% vs. 27.7 +/- 6.2%) and waist-hip ratios (WHR, 0.91 +/- 0.07 vs. 0.86 +/- 0.08). Diabetic subjects had higher intakes of protein (p < 0.01), especially animal protein (p < 0.001), and consumed more meat (p < 0.01) than control subjects. Percent body fat and WHR were positively associated with diabetes (odds ratios [OR] 1.53 [95%CI 1.29-1.79] and 1.09 [95% CI 0.89-1.58], respectively) as were protein intake (OR 1.21 [95% CI 1.12-1.31]) and animal protein intake (OR 1.18 [95% CI 1.10-1.26]). CONCLUSIONS: This study indicates that percent body fat and WHR are risk factors associated with diabetes even when the BMI is normal. Evolving dietary patterns with increasingly more protein and meat consumption may also contribute to the deterioration of glucose metabolism among Vietnamese people.  相似文献   
78.
An assessment of wood workers' exposure to airborne cultivable bacteria, fungi, inhalable endotoxins and inhalable organic dust was performed at 12 sawmills that process mainly coniferous wood species. In each plant, samples were collected at four or five different work sites (debarking, sawing, sorting, planing and sawing cockpit) and the efficiency of sampling devices (impinger or filter) for determining endotoxins levels was evaluated. Results show that fungi are present in very high concentrations (up to 35 000 CFU m(-3)) in all sawmills. We also find that there are more bioaerosols at the sorting work site (mean +/- SD: 7723 +/- 9919 CFU m(-3) for total bacteria, 614 +/- 902 CFU m(-3) for Gram-negative, 19 438 +/- 14 246 CFU m(-3) for fungi, 7.0 +/- 9.0 EU m(-3) for endotoxin and 2.9 +/- 4.8 g m(-3) for dust) than at the sawing station (mean +/- SD: 1938 +/- 2478 CFU m(-3) for total bacteria, 141 +/- 206 CFU m(-3) for Gram-negative, 12 207 +/- 10 008 CFU m(-3) for fungi, 2.1 +/- 1.9 EU m(-3) for endotoxin and 0.75 +/- 0.49 mg m(-3) for dust). At the same time, the species composition and concentration of airborne Gram-negative bacteria were studied. Penicillinium sp. were the predominant fungi, while Bacillus sp. and the Pseudomonadacea family were the predominant Gram-positive and Gram-negative bacteria encountered, respectively.  相似文献   
79.
80.
The purpose of this study was to determine the prevalence of metabolic syndrome (MeS) and its risk factors in urban population of Ho Chi Minh City. A cross-sectional study was conducted in urban areas of Ho Chi Minh City with 611 participants. The demographic, socio-economic details, anthropometric indexes and blood pressure were recorded. A fasting blood sample was collected for the analyses of glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). MeS was defined by presence of three or more of the following components: abdominal obesity, hypertriglyceridemia, low HDL-cholesterolemia, high blood pressure and high fasting plasma glucose. The crude prevalence of MeS was 18.5% (95% CI: 15.5-21.9). After age, sex standardization, this prevalence was 12.0% (95% CI: 10.9-13.2). The prevalence increased with age and sedentary work. Subjects with MeS had significantly higher body fat percentage than that of normal subjects. Metabolic syndrome showed a positive association with age, body fat percentage and sedentary occupation. This first study on MeS showed that 12% adults in urban areas of Ho Chi Minh City had metabolic syndrome. It suggests that MeS is becoming a noteworthy health problem in Vietnam and to the early detection and appropriate intervention as well as healthy lifestyle education programs need to be established.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号