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   1296篇
  免费   92篇
  国内免费   22篇
耳鼻咽喉   4篇
儿科学   48篇
妇产科学   17篇
基础医学   83篇
口腔科学   19篇
临床医学   153篇
内科学   384篇
皮肤病学   228篇
神经病学   39篇
特种医学   101篇
外科学   98篇
综合类   16篇
预防医学   137篇
药学   56篇
肿瘤学   27篇
  2018年   8篇
  2017年   12篇
  2016年   30篇
  2015年   35篇
  2014年   35篇
  2013年   64篇
  2012年   12篇
  2011年   17篇
  2010年   34篇
  2009年   53篇
  2008年   15篇
  2007年   18篇
  2006年   25篇
  2005年   11篇
  2004年   12篇
  2003年   12篇
  2002年   14篇
  2001年   11篇
  2000年   22篇
  1999年   39篇
  1998年   68篇
  1997年   55篇
  1996年   60篇
  1995年   51篇
  1994年   56篇
  1993年   38篇
  1992年   57篇
  1991年   15篇
  1990年   42篇
  1989年   43篇
  1988年   55篇
  1987年   35篇
  1986年   28篇
  1985年   13篇
  1984年   35篇
  1983年   17篇
  1982年   20篇
  1981年   22篇
  1980年   17篇
  1978年   11篇
  1977年   8篇
  1976年   13篇
  1975年   8篇
  1973年   9篇
  1972年   7篇
  1971年   9篇
  1966年   9篇
  1964年   14篇
  1960年   6篇
  1941年   6篇
排序方式: 共有1410条查询结果,搜索用时 14 毫秒
71.
Measuring clinicians' shared decision‐making (SDM) performance is a key requirement given the intensity of policy interest in many developed countries – yet it remains one of the most difficult methodological challenges, which is a concern for many stakeholders. In this Viewpoint Article, we investigate the development of existing patient‐reported measures (PRMs) of SDM identified in a recent review. We find that patients were involved in the development of only four of the 13 measures. This lack of patient involvement in PRM development is associated with two major threats to content validity, common to all 13 PRMs of SDM: (i) an assumption of patient awareness of ‘decision points’ and (ii) an assumption that there is only one decision point in each healthcare consultation. We provide detailed examples of these threats and their impact on accurate assessment of SDM processes and outcomes, which may hamper efforts to introduce incentives for SDM implementation. We propose cognitive interviewing as a recommended method of involving patients in the design of PRMs in the field of SDM and provide a practical example of this approach.  相似文献   
72.
As the use of marijuana among adolescents remains high, more effective interventions are needed. We conducted this cross‐sectional survey at an outpatient, university‐based, adolescent clinic to determine the prevalence of marijuana use in an inner‐city adolescent population and to examine the relationship of stress and coping methods to marijuana user status (never user, experimenter, and frequent user). The subjects were 918 adolescents aged 12–21 years. Lifetime use in this population was 59% (n = 611) with 18.4% (n = 191) reporting frequent weekly use. Almost all (97%) marijuana users acknowledged marijuana use by friends. Stepwise logistic regression analysis showed that negative life events, greater use of the negative coping method of anger and less frequent use of the positive coping method of parental support were significantly and independently related to marijuana user status. In the presence of high peer use, exploring parent‐child relationships and use of anger coping and intervening accordingly may decrease marijuana use.  相似文献   
73.

Background

Lipid metabolism is altered in subjects with liver steatosis. FAS is a key enzyme in de novo lipogenesis and both FAS gene expression and enzymatic activity are primarily regulated by metabolic signals in the liver. Lipoprotein lipase (LPL), the rate-limiting enzyme for the hydrolysis of core triglycerides, plays a pivotal role in lipid metabolism. This study aims to investigate if circulating levels of FAS and LPL could be clinically associated with liver steatosis.

Methods

In this work, we present data obtained from a subsample of 94 subjects with liver steatosis enrolled by NUTRIEPA study, a nutritional trial in subjects with liver steatosis. Serum levels of FAS protein and LPL activity were evaluated by ELISA test and by a fluorescent method, respectively. The diagnosis and the degree of liver steatosis were based on laboratory and ecographic measurements. Statistical methods included Kruskal-Wallis analysis of variance and Wilcoxon signed-rank test, where appropriate. The ?? 2 test has been performed to analyse categorical variables.

Results

The subjects with severe steatosis had significantly higher serum levels of FAS protein and LPL activity compared to subjects with mild and moderate liver steatosis. Moreover, a positive trend in serum levels of FAS expression from lower to higher degree of steatosis was also detected.

Conclusions

We describe a relationship between human liver steatosis and elevated levels of circulating lipogenic enzymes. Increased serum levels of FAS expression and LPL activity could be considered a marker of severe liver steatosis.  相似文献   
74.
Percutaneous nephrostolithotomy, which can require a double puncture, is presently the method of choice in our institution for the removal of renal stones. Patients that underwent this procedure were evaluated to identify the possible reasons for the double puncture. Of 200 patients evaluated, 14 needed a second tract. The three variables that determined whether a second puncture was needed, in order of importance, were number and size of the stones, with second tracts needed in patients with multiple stones and staghorn calculi; anatomical variations of the renal collecting system itself, with bifid systems the most significant anatomic variation; and the dexterity of the radiologist in performing the puncture and the ability of the urologist to extract the stone. Second tracts were needed more frequently in patients who presented with stones in both the lower and middle poles of the collecting systems.  相似文献   
75.
76.
Letters to the Editor are welcomed for publication (subject to editing). Letters must be signed by all authors, typewritten double spaced, and must not exceed two pages of text including references. Two copies of all letters should be submitted along with one copy on disk. Letters should not duplicate material submitted or published in other journals. Prepublication proofs will not be provided.  相似文献   
77.
Abstract:   Traditionally, the duplicated digit in an infant with polydactyly is managed by suture ligation and the digit is allowed to auto-amputate. However, painful neuromas may result from this commonly used technique and sharp excision has been suggested as a superior alternative. We present a case of a 16-year-old male who requested revascularization after a traumatic partial amputation of a supernumerary digit on his left hand. He requested revascularization because suture ligation of a duplicated digit on his right hand as an infant had resulted in a neuroma and considerable pain.  相似文献   
78.
79.
80.
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