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   8328篇
  免费   465篇
  国内免费   102篇
耳鼻咽喉   84篇
儿科学   195篇
妇产科学   193篇
基础医学   1115篇
口腔科学   147篇
临床医学   718篇
内科学   2214篇
皮肤病学   211篇
神经病学   622篇
特种医学   283篇
外科学   1194篇
综合类   61篇
一般理论   5篇
预防医学   615篇
眼科学   95篇
药学   553篇
中国医学   41篇
肿瘤学   549篇
  2023年   45篇
  2022年   87篇
  2021年   212篇
  2020年   91篇
  2019年   139篇
  2018年   176篇
  2017年   133篇
  2016年   122篇
  2015年   162篇
  2014年   240篇
  2013年   304篇
  2012年   558篇
  2011年   628篇
  2010年   313篇
  2009年   325篇
  2008年   618篇
  2007年   651篇
  2006年   613篇
  2005年   589篇
  2004年   521篇
  2003年   460篇
  2002年   418篇
  2001年   75篇
  2000年   73篇
  1999年   91篇
  1998年   107篇
  1997年   102篇
  1996年   79篇
  1995年   63篇
  1994年   54篇
  1993年   56篇
  1992年   56篇
  1991年   51篇
  1990年   59篇
  1989年   78篇
  1988年   63篇
  1987年   49篇
  1986年   47篇
  1985年   58篇
  1984年   30篇
  1983年   31篇
  1982年   23篇
  1981年   22篇
  1980年   24篇
  1978年   16篇
  1977年   22篇
  1976年   18篇
  1975年   19篇
  1974年   17篇
  1973年   14篇
排序方式: 共有8895条查询结果,搜索用时 62 毫秒
101.
102.
Seventeen year old identical twin brothers with no family history of cardiopathy began experiencing palpitations almost simultaneously. In both, examination revealed marked cardiomegaly and hypokinesia of the ventricular walls, and clinical and radiologic signs of progressive cardiac failure developed a few days later. Both boys died suddenly, 49 days and 5 months, respectively, after the initial examination. Electrocardiographic and vectorcardiographic studies revealed a severe intraventricular conduction disturbance that coincided with histologic changes in the myocardial tissue, including profuse interstitial fibrosis, hypertrophy and degeneration of the myocardial fibers, aberrant arrangement of the muscular fibers and considerable alteration of the structure of cardiac tissue. In the absence of hereditary and chromosomal factors, and excluding possible viral intervention during fetal life, it is believed that a teratogenic factor can produce the structural alterations of the tissue and derangement of the fibers observed in these hearts.The irregular contractions of the heart at the level of the net-like meshwork, disarrangement of myocardial fibers, and adaptative mechanisms of the heart inherent in the destruction of the contractile tissue contributed to the functional cardiac disorders that resulted in congestive heart failure and sudden death in these twins.  相似文献   
103.
104.
Methods: Cross sectional analysis of a cohort of patients with RA randomly selected from the clinical databases of 34 centres. Standard definitions and measurements were used, and radiographs read centrally. Estimates and confidence intervals were adjusted to sampling. Results: Data were available for 788 patients. Extra-articular RA was present in 285 (36.2%) patients. Cumulative prevalence and 95% confidence intervals of extra-articular manifestations were estimated: nodules 24.5% (21.5 to 27.5), Sjögren''s syndrome 17.0% (14.4 to 19.6), atlantoaxial subluxation 12.1% (9.8 to 14.4), carpal tunnel syndrome 10.7% (7.8 to 13.6), interstitial lung disease 3.7% (2.4 to 5.0), serositis 2.5% (1.4 to 3.5), eye disease 2.5% (1.1 to 3.9), vasculitis 1.3% (0.5 to 2.1), amyloidosis 0.6% (0.1 to 1.2), and Felty''s syndrome 0.3% (<0.6). Mean (SD) activity/progression indexes were: DAS28-3 3.4 (1.2), HAQ 1.6 (0.4), Larsen score 54.7 (26.4). Less than 5% of the patients were in remission. 205 (72%) patients were receiving disease modifying antirheumatic drugs (DMARDs). Conclusion: Spanish patients with RA ever seen by a rheumatologist have, on average, a moderate degree of activity, despite widespread use of DMARDs. Measures of the degree of progression do not show a benign disease. The proportion of extra-articular manifestations in Spanish patients with RA is similar to that found in other Mediterranean populations, and lower than that reported in Anglo Saxon countries.  相似文献   
105.
106.
107.
Journal of Molecular Medicine - Synchronous endometrial and ovarian carcinomas (SEOCs) that share the same endometrioid histology are generally considered as the result of metastatic spread from...  相似文献   
108.
109.
Over the years, the possibility of using solar radiation in photocatalysis or photodegradation processes has attracted remarkable interest from scientists around the world. In such processes, due to its electronic properties, Ag3PO4 is one of the most important semiconductors. This work delves into the photocatalytic activity, stability, and reactivity of Ag3PO4 surfaces by comparing plane waves with projector augmented wave and localized Gaussian basis set simulations, at the atomic level. The results indicate that the (110) surface, in agreement with previous experimental reports, displays the most suitable characteristics for photocatalytic activity due to its high reactivity, i.e. the presence of a large amount of undercoordinated Ag cations and a high value work function. Beyond the innovative results, this work shows a good synergy between both kinds of DFT approaches.

Over the years, the possibility of using solar radiation in photocatalysis or photodegradation processes has attracted remarkable interest from scientists around the world.  相似文献   
110.
Based on action research as a practitioner‐involving approach, this article communicates the findings of a two‐year study on implementing patient participation as an empowering learning process for both patients and rehabilitation nurses. At a rehabilitation facility for patients who have sustained spinal cord injuries, eight nurses were engaged throughout the process aiming at improving patient participation. The current practice was explored to understand possibilities and obstacles to patient participation. Observations, interviews and logbooks, creative workshops and reflective meetings led to the development and testing of four new rehabilitation initiatives aimed at enhancing patient participation. This study suggests that skills of critical reflection from action research toolbox shed light on both the notion of patient participation and caring in nursing rehabilitation. By actively involving nurses in research, the knowledge development stems from practice and the solutions therefore became practice‐oriented. In addition, the personal and professional development experienced by the involved nurses points to a secondary gain in the form of an analytical and reflective approach to complex issues in relation to patient participation, rehabilitation in general and the individual nurses' sense of professional pride.  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