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   39897篇
  免费   1986篇
  国内免费   104篇
耳鼻咽喉   611篇
儿科学   962篇
妇产科学   600篇
基础医学   4875篇
口腔科学   537篇
临床医学   4155篇
内科学   8121篇
皮肤病学   554篇
神经病学   3449篇
特种医学   1645篇
外科学   6335篇
综合类   431篇
一般理论   40篇
预防医学   3503篇
眼科学   644篇
药学   2871篇
  12篇
中国医学   35篇
肿瘤学   2607篇
  2024年   121篇
  2023年   289篇
  2022年   514篇
  2021年   1156篇
  2020年   736篇
  2019年   1081篇
  2018年   1259篇
  2017年   854篇
  2016年   900篇
  2015年   1066篇
  2014年   1592篇
  2013年   2102篇
  2012年   3008篇
  2011年   3074篇
  2010年   1620篇
  2009年   1530篇
  2008年   2604篇
  2007年   2564篇
  2006年   2368篇
  2005年   2381篇
  2004年   2233篇
  2003年   2038篇
  2002年   1881篇
  2001年   361篇
  2000年   368篇
  1999年   382篇
  1998年   387篇
  1997年   285篇
  1996年   268篇
  1995年   197篇
  1994年   198篇
  1993年   163篇
  1992年   179篇
  1991年   164篇
  1990年   157篇
  1989年   157篇
  1988年   144篇
  1987年   113篇
  1986年   106篇
  1985年   107篇
  1984年   101篇
  1983年   110篇
  1982年   98篇
  1981年   72篇
  1980年   63篇
  1979年   84篇
  1978年   61篇
  1977年   53篇
  1973年   65篇
  1972年   57篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
The craft of surgery has always relied on the use of instruments. Innovations in surgery have paralleled innovations in instrumentation. Advances in surgical instrumentation continue today and have enabled huge strides in surgical procedures and outcomes during this generation. Computers and related technology are now changing the interface between the surgeon and the patient, and are poised to improve patient outcomes by enhancing the surgeon’s skills and training. The application of computer enhanced telemanipulators, or “robots”, may specifically enhance operations, for example Heller myotomy, that require good visualization and precise careful dissection of delicate structures. This review covers the pathophysiology of achalasia and its history of medical and surgical treatment, leading to modern robotic telesurgical approaches. Improvements in outcome from medical to standard surgical to robotic telesurgical approaches are discussed. Current operative technique for robotic telesurgical treatment of achalasia is described and the authors conclude with a glimpse of where, in the future, current research endeavors will lead us in the treatment of achalasia.  相似文献   
12.
    
  相似文献   
13.
14.
This study examined the use and effectiveness of the Alert assessment form. The form is part of the Alert system, used by one large acute care hospital to identify patients with a propensity for violence. All reported incidents of patient violence from August 1, 2003, through December 31, 2004, were included in patient charts. One hundred seventeen violent patient charts were reviewed and compared with 161 non-violent patient charts, randomly chosen from the same time period. Overall use of the Alert assessment form for violent and non-violent patients was 75.7% and 35.4%, respectively. The assessment form was found to have moderate sensitivity (71%) and high specificity (94%). It is reasonably effective in identifying potentially violent or aggressive patients when it is used according to protocol. Efforts to improve the tool are warranted, as is evaluation of its benefit in settings with low prevalence of violence. Also, greater effort must be taken to prevent violence once an aggressive patient has been identified.  相似文献   
15.
16.
We describe a novel human zinc finger cNDA, C2H2-171. This cDNA represents an mRNA which encodes a protein of 484 amino acids and a calculated molecular weight of 54 kD. Four zinc finger-like domains are found in the C-terminal end of the protein. At the N-terminus, C2H2-171 contains a POZ/tramtrack-like domain similar to that found in the tumor associated zinc finger proteins LAZ-3/BCL-6 and PLZ-F, as well as in non-zinc finger proteins. C2H2-171 RNA is preferentially expressed in the brain, and increases during the course of murine development, with maximal expression in the adult. C2H2-171 RNA is differentially expressed in brain regions, with the highest level of expression in the cerebellum. C2H2-171 RNA was expressed at high levels in primary cerebellar granule cell neurons compared to astrocytes. The gene encoding C2H2-171 is highly conserved in vertebrates, and maps to the terminus of human chromosome 1 (1q44-ter). This chromosomal location is associated with a number of cytogenetic aberrations including those involving brain developmental anomalies and tumorigenesis. These data suggest that C2H2-171 may play an important role in vertebrate brain development and function.  相似文献   
17.
1. Left ventricular (LV) hypertrophy has been implicated in the reduction of baroreflex sensitivity present in hypertension. The aim of the current study was to investigate the mean arterial pressure-heart rate reflex (MAP-HR) in a model which induced left ventricular hypertrophy but no sustained blood pressure elevation. 2. Five mongrel dogs were exposed to transient blood pressure elevation of between 20 and 30 mmHg, through hindlimb compression using a pneumatic pressure suit, for 7 h per day, 6 days per week for 6 weeks. Resting blood pressure was not altered by the 6 week hindlimb compression intervention. 3. Echocardiographically determined LV mass (mean ± s.e.m.) was 116.0 ± 7.4 g prior to hindlimb compression (baseline) and elevated to 125.4 ± 8.1 g (P= 0.003) after 6 weeks of compression. A reduction in the early (E) to late (A) transmitral diastolic flow ratio (E/A) from 1.80 ± 0.06 at baseline to 1.54 ± 0.09 (P = 0.037) after the 6 week intervention suggested that cardiac compliance was reduced. 4. The maximum gain of the MAP-HR reflex, studied using the ‘steady-state’ drug technique, when blood pressure was normal, showed a trend for reduction from 3.85 ± 0.43 beats/min per mmHg at baseline to 3.10 ± 0.45 beats/min per mmHg (P= 0.067) after 6 weeks of compression. This gain reduction became significant after β-adrenoceptor blockade with propranolol (3.13 ± 0.55 vs 2.32 ± 0.25 beats/min per mmHg; P= 0.039). Covariant analysis showed a significant inverse correlation between LV mass and maximum gain (r= 0.96; P<0.001) during the 6 week compression period. 5. The MAP-HR reflex changes in this model mimic those present in hypertension and implicate cardiac hypertrophy as one possible mediator.  相似文献   
18.
Tremper  Kevin K. 《Journal canadien d'anesthésie》1990,37(1):Slxxvii-Slxxxviii
Canadian Journal of Anesthesia/Journal canadien d'anesthésie -  相似文献   
19.
20.
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