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   9844篇
  免费   702篇
  国内免费   35篇
耳鼻咽喉   209篇
儿科学   355篇
妇产科学   195篇
基础医学   1359篇
口腔科学   229篇
临床医学   944篇
内科学   2277篇
皮肤病学   203篇
神经病学   854篇
特种医学   534篇
外国民族医学   1篇
外科学   1420篇
综合类   106篇
一般理论   3篇
预防医学   641篇
眼科学   164篇
药学   622篇
  1篇
中国医学   5篇
肿瘤学   459篇
  2021年   84篇
  2019年   101篇
  2018年   107篇
  2017年   93篇
  2016年   107篇
  2015年   137篇
  2014年   177篇
  2013年   281篇
  2012年   386篇
  2011年   369篇
  2010年   232篇
  2009年   229篇
  2008年   347篇
  2007年   391篇
  2006年   419篇
  2005年   393篇
  2004年   412篇
  2003年   354篇
  2002年   309篇
  2001年   353篇
  2000年   339篇
  1999年   301篇
  1998年   132篇
  1997年   137篇
  1996年   115篇
  1995年   109篇
  1993年   94篇
  1992年   223篇
  1991年   220篇
  1990年   202篇
  1989年   262篇
  1988年   218篇
  1987年   207篇
  1986年   214篇
  1985年   205篇
  1984年   135篇
  1983年   154篇
  1982年   91篇
  1981年   95篇
  1980年   90篇
  1979年   156篇
  1978年   103篇
  1977年   84篇
  1976年   81篇
  1975年   86篇
  1974年   90篇
  1973年   79篇
  1972年   84篇
  1971年   82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.

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   
4.

Background

Intramedullary nailing is considered a “gold standard” for treatment of tibial shaft fractures. However, some types of fractures are typically considered as “difficult for nailing”. This group includes the periarticular fractures, fractures of both bones at the same level, comminuted and segmental fractures of the tibia. Fixator-assisted nailing (FAN) is an effective method treatment of these types of fractures. The main requirements for the ideal reduction device are an ease of its installation and an ability of multiplanar fracture reduction. Fixator-assisted nailing (FAN) with the use of two perpendicular to each other monolateral tubular frames perfectly meets these requirements. In this study we present this new surgical technique and the analysis of first 30 cases.

Methods

A prospective analysis was conducted for 30 patients with “difficult for nailing” tibial fractures treated with fixator-assisted nailing in our institution between September 1st, 2017, and March 1st, 2018. The duration of surgery and its different stages, the time of fluoroscopy, difficulties encountered during surgery, were analyzed. Clinical and radiological methods were used to evaluated reduction quality.

Results

In all 30 cases the acceptable reduction was achieved. The mean duration of the surgical procedure was 73.7?±?3?min. The mean duration of fluoroscopy 85.9?±?4.8?s. In 7 cases we faced with technical difficulties, which were successfully addressed.

Conclusion

The described technique of FAN is an effective method for the treatment of “difficult for nailing” tibial fractures. Future multi-centered studies with a larger number of patients are needed to validate our results.  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