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   46057篇
  免费   3497篇
  国内免费   148篇
耳鼻咽喉   468篇
儿科学   1243篇
妇产科学   898篇
基础医学   6715篇
口腔科学   797篇
临床医学   4986篇
内科学   9770篇
皮肤病学   971篇
神经病学   4785篇
特种医学   1649篇
外国民族医学   11篇
外科学   6038篇
综合类   503篇
一般理论   31篇
预防医学   3805篇
眼科学   845篇
药学   3191篇
中国医学   133篇
肿瘤学   2863篇
  2023年   381篇
  2022年   584篇
  2021年   1349篇
  2020年   924篇
  2019年   1160篇
  2018年   1366篇
  2017年   1075篇
  2016年   1247篇
  2015年   1336篇
  2014年   1751篇
  2013年   2209篇
  2012年   3416篇
  2011年   3527篇
  2010年   1989篇
  2009年   1674篇
  2008年   2706篇
  2007年   2785篇
  2006年   2666篇
  2005年   2448篇
  2004年   2265篇
  2003年   1913篇
  2002年   1803篇
  2001年   653篇
  2000年   642篇
  1999年   592篇
  1998年   407篇
  1997年   297篇
  1996年   289篇
  1995年   257篇
  1994年   223篇
  1993年   168篇
  1992年   332篇
  1991年   309篇
  1990年   317篇
  1989年   256篇
  1988年   263篇
  1987年   282篇
  1986年   289篇
  1985年   276篇
  1984年   237篇
  1983年   187篇
  1982年   143篇
  1981年   125篇
  1980年   126篇
  1979年   241篇
  1978年   171篇
  1977年   144篇
  1975年   129篇
  1974年   130篇
  1973年   142篇
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
101.
This article focuses on possible psychopharmacological interventions in the immediate post disaster setting. As there is little evidence for the efficacy or effectiveness of such interventions-given the difficulty in performing randomized, double-blind, placebo controlled studies with these populations-the article will delineate the neurobiological basis for pathological sequelae and theoretical drug interventions targeting putative disease mechanisms.  相似文献   
102.
We examined 53 fetuses between 15 and 40 weeks of gestation with transverse and coronal sections of the head in order to evaluate the accuracy and reproducibility of the coronal cerebellar diameter. Intraobserver coefficient of variation was less than or equal to 2.2% and the mean interobserver difference was 2.2% (range, 0 to 6%). A positive linear correlation exists between transverse and coronal measurements (coronal diameter = 1.02 x transverse diameter - 0.48; R2 = 0.99; P less than 0.0001). We conclude that the coronal cerebellar diameter is reproducible and accurate and when indicated clinically can be used instead of the transverse cerebellar diameter when the latter is not obtainable because of fetal position.  相似文献   
103.
104.
Topographic order in the rat retinocollicular projection emerges from an initially diffuse projection during an early postnatal remodeling period that is coincident with the period of naturally occurring ganglion cell death. Here, we examine the relationship between a retinal axon's position along the medial-lateral axis as it enters the superior colliculus (SC) and its ability to form an appropriately positioned arbor and survive the remodeling period. At E18-E19, prior to map remodeling, axons labeled with focal DiI injections in the periphery of temporal, nasal, superior or inferior retina are widespread along the medial-lateral SC axis. At P12, after remodeling, the distributions of axons remain widespread over the medial-lateral SC axis relative to the positioning of their terminal arborizations, and resemble the distributions labeled at E18-E19, with the exception that the small proportion of axons most widely mispositioned along the medial-lateral SC axis are less frequent. These data indicate that the most widely mispositioned retinal axons are preferentially eliminated, but that a high proportion of retinal axons mispositioned along the medial-lateral axis as they enter the SC can correct their position, form topographically appropriate arbors, and survive the remodeling period.  相似文献   
105.
106.
107.
108.
The study was performed to assess the ethiological role of bile in acute pancreatitis provoked by closed duodenal loop in rat. In group I a closed duodenal loop was created by method of Nevalainen. A similar operation was performed in group II, but the common pancreatico-biliary duct was ligated just under the liver. In the control group (group C) only the mobilization of duodenum was performed. After 24 hours the mortality rate was 20% in group I, but 0% in group II and C. The amount of ascitic fluid showed significant elevation in group I versus II and group C, and in group II as compared to group C, too. The serum amylase was significantly higher in group I than group II and group C, and in group II was also higher as compared to group C. Serum total protein differed significantly between all groups, while albumin and total calcium were significantly lower in group I than group II, but group II was only slightly reduced versus group C. Histology showed no differences between groups I and II, but both differed significantly from group C. In conclusion bile seems to be an aggressive factor in pathogenesis of acute pancreatitis induced by closed duodenal loop in rat, but other factors may play more important roles.  相似文献   
109.
The purpose of this study was to investigate the effects of a physical training course in a group of patients (n=74) suffering from chronic tension neck. All participants in the course were employed by a bank corporation in Helsinki, Finland. A comparable control group (n=77) consisted of office workers with tension neck from the same bank corporation who did not attend any training course. The outcome was analysed 6 months after the course. Pain and disability in the neck and shoulder region did not vary significantly between the group which participated in the training course and the control group. The experimental group had increased the amount of physical workout compared to the control group (83.7% vs 69.0%, P = 0.0448). Also, regarding the frequency of relaxation and stretching exercises the two groups differed significantly: the experimental group had continued to perform exercises more often (P= 0.0434). The frequency of sick leave days did not significantly differ between the groups, but the office workers in the experimental group had more periods of extended sick leave (> 10 days) and the controls had more frequent short sick leaves. The experimental group did increase their physical workout significantly compared with the controls, but no differences were detected regarding pain and disability. In order to gain more benefit more attention should be paid to the educational part of the training courses in order to enhance the patients'self-care abilities. Also, strategies to alleviate psychosocial problems and organized relaxation exercises could decrease muscle tension in the neck in office workers.  相似文献   
110.
This study is concerned with the nature and distribution of mineral in the gallbladder of a patient with chronic cholecystitis. Light and electron microscopic imaging revealed the mineral to be in the epithelial cells of the mucosa and fibroblasts of the submucosa. In the epithelial cells at the early stages of deposition, mineral was located in the nuclei and throughout the cytoplasm in association with interdigitating cell processes and apical microvilli but was absent in mitochondria. Elemental and electron diffraction analyses indicated the mineral inclusions to be apatite in nature.  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