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   13791篇
  免费   885篇
  国内免费   27篇
耳鼻咽喉   120篇
儿科学   313篇
妇产科学   240篇
基础医学   1915篇
口腔科学   271篇
临床医学   1696篇
内科学   2662篇
皮肤病学   83篇
神经病学   1412篇
特种医学   422篇
外科学   1725篇
综合类   166篇
一般理论   14篇
预防医学   1609篇
眼科学   246篇
药学   1042篇
中国医学   13篇
肿瘤学   754篇
  2023年   69篇
  2022年   101篇
  2021年   263篇
  2020年   193篇
  2019年   252篇
  2018年   325篇
  2017年   247篇
  2016年   251篇
  2015年   320篇
  2014年   417篇
  2013年   621篇
  2012年   994篇
  2011年   1071篇
  2010年   582篇
  2009年   585篇
  2008年   953篇
  2007年   993篇
  2006年   985篇
  2005年   978篇
  2004年   958篇
  2003年   831篇
  2002年   825篇
  2001年   182篇
  2000年   151篇
  1999年   151篇
  1998年   161篇
  1997年   140篇
  1996年   99篇
  1995年   77篇
  1994年   69篇
  1993年   70篇
  1992年   78篇
  1991年   64篇
  1990年   54篇
  1989年   72篇
  1988年   45篇
  1987年   49篇
  1986年   42篇
  1985年   47篇
  1984年   48篇
  1983年   42篇
  1982年   30篇
  1981年   30篇
  1980年   21篇
  1979年   25篇
  1978年   17篇
  1977年   12篇
  1976年   22篇
  1975年   14篇
  1973年   12篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Pulmonary hamartomas are usually an incidental finding and range in size from 1 cm to 8 cm in diameter in various series. We report a case of a massive pulmonary hamartoma (size 25.5 × 17.5 × 6.5 cm and weighing 1134 g) in a 61 year old male who presented with a short history of breathlessness. The tumour was arising from the medial border of the right lung and occupying most of the right chest extending in to the anterior mediastinum. The tumour was compressing the right lung and there was no evidence of infiltration into the surrounding structures. It was successfully treated by surgical resection and final histology was pulmonary hamartoma with predominantly adipose and leiomyomatous differentiation.  相似文献   
6.
7.
OBJECTIVE: Cervical nerve root stimulation (CRS) is a technique of assessing the proximal segments of motor axons destined to upper extremity muscles. Few studies report normal values. The objective was to determine CMAP onset-latencies and CMAP amplitude, area, and duration changes in healthy controls for the abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps, and riceps muscles. In addition, to determine the tolerability of CRS, as measured by the visual analog scale (VAS). METHODS: We studied 21 healthy volunteers prospectively with CRS using four target muscles (APB, ADM, biceps, and triceps) bilaterally. Collision studies were used in all APB recordings. VAS was obtained in all subjects. RESULTS: Mean CMAP onset-latencies were: APB 14 +/- 1.5 ms; ADM 14.2 +/- 1.5 ms; biceps 5.4 +/- 0.6 ms; triceps 5.4 +/- 1.0 ms. Onset-latency significantly correlated with height for all nerves. The mean change in CMAP amplitude and area (%) between most distal stimulation and CRS was: APB reduction of 15.1 +/- 11.6 and 4.9 +/- 3.6%; ADM reduction of 21.1 +/- 10.7 and 17.2 +/- 8.8; biceps reduction of 10 +/- 11.5 and reduction of 8.7 +/- 6.8; triceps increase of 3.3 +/- 5.2 and 11.0 +/- 9.9% respectively. Mean CMAP duration change between most distal stimulation and CRS was: APB, increase of 20.4 +/- 7.4%; ADM, increase of 14.4 +/- 8.5%; biceps, increase of 13.9 +/- 10.8%; triceps, increase of 7.7 +/- 6.7%. The mean VAS score was 3.8 +/- 1.2, and all subjects completed the study. CONCLUSIONS: The present study establishes normative data and indicates that CRS is a well-tolerated technique. SIGNIFICANCE: The normal values may be used as reference data for the needle CRS technique in the assessment of proximal conduction abnormalities.  相似文献   
8.
Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates geared to simplified preparation without biochemical blood handling. In this initial article, we describe the conceptual and technical evolution from fibrin glues to platelet concentrates. This retrospective analysis is necessary for the understanding of fibrin technologies and the evaluation of the biochemical properties of 3 generations of surgical additives, respectively fibrin adhesives, concentrated platelet-rich plasma (cPRP) and PRF. Indeed, the 3-dimensional fibrin architecture is deeply dependent on artificial clinical polymerization processes, such as massive bovine thrombin addition. Currently, the slow polymerization during PRF preparation seems to generate a fibrin network very similar to the natural one. Such a network leads to a more efficient cell migration and proliferation and thus cicatrization.  相似文献   
9.
10.
This study investigates the contribution of body fat stores on the age-associated increase in serum cholesterol and triglyceride levels. Percentage of body fat was measured by hydrostatic weighing, and serum cholesterol, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels were determined in a sample of 472 healthy men and women ages 18-50 years. In both sexes, body fat mass was significantly correlated with serum cholesterol (r = 0.21 in men and r = 0.24 in women, P less than 0.01) and triglyceride (r = 0.33 in men and r = 0.24 in women, P less than 0.01) levels. After adjustment for the association between age and serum cholesterol, no correlation was observed between body fat mass and serum cholesterol (r = 0.01 in men and r = 0.09 in women). After correction for age, serum triglyceride levels remained significantly correlated with body fat mass (r = 0.26 and r = 0.17 in men and women, respectively, P less than 0.05). As body fat also increases with age, the possibility that a partial correlation coefficient procedure eliminated a portion of the age effect mediated by an age-related increase in fat, was addressed by performing further analyses. Within each sex subsample two sets of analyses were performed on (a) three groups of subjects individually paired for age but with different levels of body fat stores, and (b) three groups of subjects paired for the amount of body fat but differing in age.(ABSTRACT TRUNCATED AT 250 WORDS)  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