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   10917篇
  免费   773篇
  国内免费   55篇
耳鼻咽喉   208篇
儿科学   451篇
妇产科学   209篇
基础医学   1467篇
口腔科学   265篇
临床医学   1028篇
内科学   2506篇
皮肤病学   205篇
神经病学   884篇
特种医学   866篇
外国民族医学   1篇
外科学   1506篇
综合类   125篇
一般理论   3篇
预防医学   678篇
眼科学   173篇
药学   660篇
  1篇
中国医学   8篇
肿瘤学   501篇
  2021年   86篇
  2019年   107篇
  2018年   117篇
  2017年   102篇
  2016年   125篇
  2015年   155篇
  2014年   194篇
  2013年   323篇
  2012年   401篇
  2011年   379篇
  2010年   281篇
  2009年   266篇
  2008年   370篇
  2007年   409篇
  2006年   436篇
  2005年   404篇
  2004年   422篇
  2003年   359篇
  2002年   326篇
  2001年   363篇
  2000年   358篇
  1999年   323篇
  1998年   230篇
  1997年   209篇
  1996年   194篇
  1995年   165篇
  1994年   133篇
  1993年   153篇
  1992年   239篇
  1991年   230篇
  1990年   211篇
  1989年   304篇
  1988年   235篇
  1987年   235篇
  1986年   236篇
  1985年   239篇
  1984年   154篇
  1983年   180篇
  1982年   120篇
  1981年   101篇
  1980年   120篇
  1979年   165篇
  1978年   110篇
  1977年   92篇
  1976年   99篇
  1975年   101篇
  1974年   89篇
  1972年   84篇
  1971年   84篇
  1969年   81篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.

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   
5.
6.
The chemical composition of the seeds of the low-alkaloid variety “Inti” of the Andean lupin (Lupinus mutabilis) grown in the south of Chile was examined. The contents of (% of dry weight) total alkaloids, protein, lipids, and oligosaccharides were found to be 0.0075, 51.0, 16.0, and 14.7%, respectively. The low levels of the sulfur amino acids (2.38% of total protein) made them the first amino acids to limit the protein quality of these lupin seeds. The fatty acid pattern was C16:0,13.9%; C18:0, 3.0%; C18:1, 41.8%; C18:2, 38.9%; and C18:3,2.6% of total fatty acids. The α-galactoside amounted to 13.5% of dry weight (raffinose, 2.49%; stachyose, 10.1%, verbascose, 0.85%). It can be stated that “Inti” is highly interesting as a potential protein energy crop for a temperate climate.  相似文献   
7.
8.
9.
For several genetic diseases two biological phenomena have been recognised as important: germline mosaicism; and different new mutation rates in males and females depending on mutation type. Both principles have been investigated separately and their influence on risk estimation in families has been exemplified in the literature. The aim of this paper is to present a general model that includes mosaicism and different new mutation rates. Mosaicism is introduced by defining additional alleles at the disease locus in combination with adapted segregation rules. Taking Duchenne muscular dystrophy as an example, we derive the conditions which have to be fulfilled for a population in mutation selection equilibrium. Our approach describes the model at the population level and not in individual subjects. This has the advantage of being able to use well known algorithms for the calculation of likelihoods in pedigrees, and to include additional diagnostic information such as marker genotypes and carrier deletion test results. We demonstrate the impact of the new model on a typical pedigree. In families where the patient is not available, the distinction between point mutations and deletions is important, since often molecular diagnostic tests for females can only screen for deletions. Negative deletion test results can now be included in the risk calculations.  相似文献   
10.
Exposure of young children to group day-care settings increases the risk of illness and may result in higher use of medical care. These observations raise concerns that the use of such settings for early intervention programs for low-birth-weight infants may increase the already high burden of medical care costs incurred by these children and their families. To address the question of medical care use associated with center-based care, we examined the hospital-based and ambulatory care reported for participants of the Infant Health and Development Program. This project is a multisite randomized trial of an early intervention program for preterm low-birth-weight infants with an intervention including 2 years of center-based care. The Intervention group did not differ in hospital-based care and averaged only two more physicians' visits over the 3-year observation period than the comparison group. We conclude that early intervention programs involving high-quality group care are not accompanied by substantial increases in health care use.  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