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   17971篇
  免费   1169篇
  国内免费   750篇
耳鼻咽喉   103篇
儿科学   213篇
妇产科学   153篇
基础医学   744篇
口腔科学   143篇
临床医学   1253篇
内科学   1849篇
皮肤病学   72篇
神经病学   314篇
特种医学   306篇
外国民族医学   1篇
外科学   6327篇
综合类   2327篇
预防医学   1059篇
眼科学   93篇
药学   1992篇
  21篇
中国医学   2536篇
肿瘤学   384篇
  2024年   24篇
  2023年   523篇
  2022年   666篇
  2021年   1083篇
  2020年   1080篇
  2019年   909篇
  2018年   1006篇
  2017年   1011篇
  2016年   632篇
  2015年   614篇
  2014年   1423篇
  2013年   1470篇
  2012年   1202篇
  2011年   1281篇
  2010年   855篇
  2009年   750篇
  2008年   763篇
  2007年   774篇
  2006年   577篇
  2005年   472篇
  2004年   349篇
  2003年   307篇
  2002年   253篇
  2001年   209篇
  2000年   185篇
  1999年   197篇
  1998年   139篇
  1997年   112篇
  1996年   110篇
  1995年   113篇
  1994年   90篇
  1993年   73篇
  1992年   64篇
  1991年   56篇
  1990年   53篇
  1989年   43篇
  1988年   42篇
  1987年   38篇
  1986年   28篇
  1985年   41篇
  1984年   41篇
  1983年   34篇
  1982年   37篇
  1981年   31篇
  1980年   27篇
  1979年   20篇
  1978年   17篇
  1977年   16篇
  1976年   18篇
  1974年   8篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Hip fractures are becoming increasingly common in a growing elderly population, and are associated with significant morbidity and mortality. Displaced intracapsular femoral neck fractures are usually treated with either total hip arthroplasty (THA) or hemiarthroplasty, although the indication for each operation remains an area for debate. THA has been associated with longer operative time, increased risk of dislocation and a slight increase in general complications compared with hemiarthroplasty. However, it has also been associated with a modest improvement in functional outcomes and quality of life. Guidelines have been created within the UK to aid the decision-making process based upon current available literature. The principal focus of these has been to identify patients suitable for THA, and include patients who are cognitively intact, mobile outside their home with the use of no more than one stick, and who are medically fit enough for the procedure. However, implant selection must also be taken into consideration in order to achieve the best outcomes for patients. Options for implants include use of dual mobility cups and choice of femoral head size in THA, bipolar versus unipolar hemiarthroplasty, and cemented versus uncemented implants. Further research is required into this area to make additional recommendations.  相似文献   
7.

Background

Volatile propofol can be measured in exhaled air and correlates to plasma concentrations with a time delay. However, the effect of single-lung ventilation on exhaled propofol is unclear. Therefore, our goal was to evaluate exhaled propofol concentrations during single-lung compared to double-lung ventilation using double-lumen tubes.

Methods

In a first step, we quantified adhesion of volatile propofol to the inner surface of double-lumen tubes during double- and single-lumen ventilation in vitro. In a second step, we enrolled 30 patients scheduled for lung surgery in two study centers. Anesthesia was provided with propofol and remifentanil. We utilized left-sided double-lumen tubes to separately ventilate each lung. Exhaled propofol concentrations were measured at 1-min intervals and plasma for propofol analyses was sampled every 20 min. To eliminate the influence of dosing on volatile propofol concentration, exhalation rate was normalized to plasma concentration.

Results

In-vitro ventilation of double-lumen tubes resulted in increasing propofol concentrations at the distal end of the tube over time. In vitro clamping the bronchial lumen led to an even more pronounced increase (Δ AUC +62%) in propofol gas concentration over time. Normalized propofol exhalation during lung surgery was 31% higher during single-lung compared to double-lung ventilation.

Conclusion

During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during single-lung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation.

Registration of Clinical Trial

DRKS-ID DRKS00014788 ( www.drks.de ).  相似文献   
8.
9.
The aims of this paper were to validate a modification of an extended total temporomandibular joint replacement (eTMJR) classification system and develop a classification schematic for ease of reference. High-volume TMJ surgeons were asked to score 20 separate eTMJR devices using the updated classification system, and inter-rater variability was calculated. Using the modified classification system developed, a Conger’s kappa (κ) coefficient of 0.53 was returned, suggesting moderate to good levels of agreement. The final classification system was then developed in a series of standardised graphic illustrations as visual representations of the different subcategories of eTMJR devices.  相似文献   
10.
Introduction and objectivesThis document includes cardiac pacing activity performed in Spain in 2021: figures for implanted devices, demographic and clinical factors, characteristics of the implanted material, and remote monitoring data.MethodsThe European Pacemaker Patient Card, the CardioDispositivos.es online platform, the centers’ own databases and the data provided by the supplier companies are used as sources of information.Results17.360 procedures were registered from 95 hospitals, which represents 43% of the activity. The implantation rates of conventional and resynchronization pacemakers were 822 and 31 units per million population, respectively. 652 leadless pacemakers were implanted. The mean age of implantation is high (78.8 years), and atrioventricular block is the most frequent electrocardiographic abnormality. Dual-chamber pacing mode predominated, nonetheless single-chamber pacing was performed in 19% of patients in sinus rhythm, mainly in the elderly. 28.5% of implanted conventional pacemakers and 56,2% of low-energy resynchronization pacemakers were included in the remote monitoring program.ConclusionsIn 2021 the number of conventional pacemakers increased by 8.3% and resynchronizers by 18.9%, despite the decrease in low-energy resynchronization, probably attributable to the development of physiological pacing. Leadless pacemakers increased by 25%. The expansion of remote monitoring continued, consolidating as a fundamental follow-up method.  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