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   1392772篇
  免费   89415篇
  国内免费   1784篇
耳鼻咽喉   18819篇
儿科学   39312篇
妇产科学   34503篇
基础医学   211939篇
口腔科学   39209篇
临床医学   122512篇
内科学   265450篇
皮肤病学   29718篇
神经病学   101832篇
特种医学   54238篇
外国民族医学   130篇
外科学   220339篇
综合类   24833篇
现状与发展   2篇
一般理论   332篇
预防医学   95784篇
眼科学   31826篇
药学   108049篇
  4篇
中国医学   3136篇
肿瘤学   82004篇
  2018年   13800篇
  2017年   10451篇
  2016年   11799篇
  2015年   13329篇
  2014年   18117篇
  2013年   26639篇
  2012年   37472篇
  2011年   40077篇
  2010年   23498篇
  2009年   21934篇
  2008年   38213篇
  2007年   40809篇
  2006年   41159篇
  2005年   39444篇
  2004年   38303篇
  2003年   36877篇
  2002年   36006篇
  2001年   73272篇
  2000年   75585篇
  1999年   62774篇
  1998年   15239篇
  1997年   13253篇
  1996年   13332篇
  1995年   12476篇
  1994年   11393篇
  1993年   10678篇
  1992年   47698篇
  1991年   47351篇
  1990年   46321篇
  1989年   45209篇
  1988年   41325篇
  1987年   40535篇
  1986年   37722篇
  1985年   36097篇
  1984年   26040篇
  1983年   22139篇
  1982年   11436篇
  1979年   23690篇
  1978年   16236篇
  1977年   13596篇
  1976年   12768篇
  1975年   14593篇
  1974年   17142篇
  1973年   16271篇
  1972年   15325篇
  1971年   14575篇
  1970年   13798篇
  1969年   12901篇
  1968年   11940篇
  1967年   10723篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
71.
Pharmaceutical Chemistry Journal - Use of formylindolylacetic acid as a reagent at the stage of preparing the glycosides of bis(indolyl)furan-2,5-diones and dioxane as solvent increased yields from...  相似文献   
72.
73.
74.

Background

Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.

Methods

We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).

Results

Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.

Conclusions

Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation.  相似文献   
75.

Objective

The teaching hospital of Nancy, France, implemented a specific multidisciplinary care pathway (French acronym AMDPL) to improve the management of patients presenting with Lyme borreliosis (LB) suspicion. We aimed to assess the first year of activity of this care pathway.

Patients and methods

We included all patients managed in the AMDPL pathway from November 1, 2016 to October 31, 2017. The first step was a dedicated Lyme disease consultation with an infectious disease specialist. Following this consultation, the LB diagnosis was either confirmed and adequate treatment was prescribed, or a differential diagnosis was established and patients received adequate management, or further investigations were required and patients were offered multidisciplinary management as part of a day hospitalization.

Results

A total of 468 patients were included. LB diagnosis was confirmed in 15% of patients (69/468), 49% of patients received a differential diagnosis, and 26% (122/468) of patients had the LB diagnosis ruled out without receiving any other diagnosis.

Conclusions

This is to our knowledge the first multidisciplinary center implemented in France for the management of patients presenting with LB suspicion related to polymorphous signs and symptoms. Several diagnoses could be confirmed or corrected, although some symptoms and complaints could not be explained. This cohort could improve our knowledge of LB and its differential diagnoses.  相似文献   
76.
Objective: To determine serotonin system abnormalities related to major depression or previous suicidal behavior.

Methods: [11C]WAY100635, [18F]altanserin and positron emission tomography were used to compare 5-HT1A and 5-HT2A binding in MDD patients divided into eight past suicide attempters (>4yrs prior to scanning) and eight lifetime non-attempters, and both groups were compared to eight healthy volunteers.

Results: The two receptor types differed in binding pattern across brain regions from each other, but there were no differences in binding between healthy volunteers and the two depressed groups or between depressed suicide attempters and non-attempters. No effects of depression severity or lifetime aggression were observed for either receptor.

Conclusion: Limitations of this study include small sample size and absence of high lethality suicide attempts in the depressed attempter group. No trait-like binding correlations with past suicide attempt or current depression were observed. Given the heterogeneity of nonfatal suicidal behavior, a larger sample study emphasizing higher lethality suicide attempts may find the serotonin biological phenotype seen in suicide decedents.  相似文献   

77.
78.
79.
80.
Abstract

This study was undertaken to compare the concentrations of pro- and anti-angiogenic growth factors, nitric oxide (NO) stable metabolites in maternal serum and embryonic left ventricular (LV) isovolumic relaxation time (IRT, ms) during the first trimester in two groups of women: with pregnancy conceived by assisted reproductive technologies (ART, n?=?39) and normally conceived (control group, n?=?68) pregnancy. The concentration of vasoconstrictor endothelin 1 was 45.5 times more in ART than in control group. On the contrary, the concentrations of NO stable metabolites in ART were 1.9 times less than in control women. The assessment of angiogenic suppressors in ART women demonstrates the decrease in s-endoglin concentration was 1.6 times and in soluble receptor to vascular endothelial growth factor concentration was 2.0 times in comparison with control group. There was a significant increase in LV IRT in ART embryos in comparison to control ones. These data suggest significant changes in pro- anti-angiogenic factors balance and increase in vascular impedance in ART-conceived embryos.  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