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   16457篇
  免费   746篇
  国内免费   293篇
耳鼻咽喉   136篇
儿科学   606篇
妇产科学   395篇
基础医学   1942篇
口腔科学   481篇
临床医学   1288篇
内科学   3250篇
皮肤病学   235篇
神经病学   803篇
特种医学   386篇
外科学   1926篇
综合类   1029篇
现状与发展   1篇
预防医学   2111篇
眼科学   311篇
药学   1306篇
  2篇
中国医学   574篇
肿瘤学   714篇
  2024年   33篇
  2023年   436篇
  2022年   650篇
  2021年   817篇
  2020年   786篇
  2019年   1630篇
  2018年   1330篇
  2017年   806篇
  2016年   386篇
  2015年   433篇
  2014年   932篇
  2013年   1139篇
  2012年   608篇
  2011年   692篇
  2010年   541篇
  2009年   570篇
  2008年   571篇
  2007年   452篇
  2006年   347篇
  2005年   274篇
  2004年   221篇
  2003年   184篇
  2002年   142篇
  2001年   150篇
  2000年   117篇
  1999年   99篇
  1998年   69篇
  1997年   105篇
  1996年   108篇
  1995年   109篇
  1994年   110篇
  1993年   65篇
  1992年   38篇
  1991年   53篇
  1990年   43篇
  1988年   31篇
  1986年   28篇
  1985年   194篇
  1984年   286篇
  1983年   238篇
  1982年   267篇
  1981年   268篇
  1980年   207篇
  1979年   197篇
  1978年   148篇
  1977年   113篇
  1976年   126篇
  1975年   131篇
  1974年   80篇
  1973年   87篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
31.
Despite a population of nearly 60 million, there is currently not a single interventional radiologist in Tanzania. Based on an Interventional Radiology (IR) Readiness Assessment, the key obstacles to establishing IR in Tanzania are the lack of training opportunities and limited availability of disposable equipment. An IR training program was designed and initiated, which relies on US-based volunteer teams of IR physicians, nurses, and technologists to locally train radiology residents, nurses, and technologists. Preliminary results support this strategy for addressing the lack of training opportunities and provide a model for introducing IR to other resource-limited settings.  相似文献   
32.
33.
ObjectiveProgrammed death ligand 1 (PD-L1) has been reported to be connected to prognosis in individuals with malignant pleural mesothelioma (MPM), although there is no consensus based on data from previous studies. Accordingly, this quantitative meta-analysis investigated prognostic and clinicopathological utility of PD-L1 in patients with MPM.MethodsA comprehensive search of the PubMed, Web of Science, Embase, and Cochrane Library databases for articles published up to October 4, 2019 was performed. Studies using immunohistochemical techniques to detect/quantify the expression of PD-L1 in MPM tissue were enrolled in the analysis. The combined hazard ratio (HR) and corresponding 95% confidence interval (CI) was applied to assess the association between PD-L1 expression and overall survival (OS).ResultsA total of 11 studies comprising 1606 patients was included in the present meta-analysis. For OS, pooled data revealed an HR of 1.50 (95% CI 1.32–1.70; p < 0.001), suggesting that patients with PD-L1 overexpression experience inferior OS. Subgroup analysis revealed that elevated PD-L1 remained a significant prognostic indicator for worse OS, irrespective of sample size, cut-off value, ethnicity, and Newcastle-Ottawa Scale score. Moreover, PD-L1 overexpression was associated with non-epithelioid histology (odds ratio 4.30 [95% CI 1.89–9.74]; p < 0.001).ConclusionsResults of this meta-analysis show that elevated expression of PD-L1 could be a factor predicting poorer survival in patients with MPM.  相似文献   
34.
35.
Approximately 36 400 cardiac and 23 100 thoracic operations are carried out in the United Kingdom between 2006 and 2015. National Health Service (NHS) resolution, as known as the NHS litigation authority, is one of the essential bodies of the Department of Health. Its purpose is to provide NHS expertise to resolve concerns fair and square share learning for improvement. We aim to evaluate and increase awareness of medicolegal cases in cardiothoracic surgery. Total numbers and details of claims coded by NHS resolution in cardiothoracic surgery from 2004 to 2017 were requested under the Freedom of Information Act 2000. The data provided in successful claims is further breakdown into damages paid to the claimant, defence cost, claimant cost paid and the sum of the three. In contrast, unsuccessful claims only include the defence cost. Moreover, data provided also includes further analysis of primary causes and primary injuries for Claims Closed/Settled with damages paid. There were 753 claims recorded from 2004 to 2017, of which 415 (55.11%) were successful. The number of claims has been steadily increasing since 2004, with two significant raises from 2009/10 to 2010/11 (37‐55, 48.64% raise) and 2012/13 to 2013/14 (49‐69, 40.82% raise). The mean successful claim ratio was 69.58% (range, 47.56%‐ 83.33%) There is also a steady increase in the successful ratio from 2004 to 2017. In summary, this is the first study published in relation to litigation claims on cardiothoracic surgery in the United Kingdom. The results have provided insight on claims made against cardiothoracic surgery.  相似文献   
36.
37.
Current major advances in drug discovery can be traced back to pioneering contributions originating from academics over a century ago. Living in a symbiotic yet noninvasive coexistence, the academic community and the pharmaceutical industry have strived, each in their own way, to develop the modern medicines that benefit humankind today. The subject is presented from a historical and personal perspective.  相似文献   
38.
Although psychoanalysis was the first-choice treatment for premature ejaculation (PE) between 1920 and 1960, hardly any reports on its efficacy have been published. Moreover, a scientific debate about its findings has never been fully developed. The recent progress that has been made in the classification of three different PE syndromes creates a new opportunity for psychoanalytic investigations of men with complaints of PE, distinguished by the actual duration of their intravaginal ejaculation latency time (IELT). The term premature-like ejaculatory dysfunction has been introduced to distinguish men with self-perceived PE at normal and long IELT durations from those men with lifelong, acquired and normal variable PE. Psychoanalytic research may contribute to a better understanding of the consequences of objective early ejaculations on the unconscious mental life of men with the four forms of PE. By integrating neurobiological, clinical and epidemiological data of ejaculatory performance, a revival of psychoanalytic research of PE in the four distinct, classified PE groups, will probably contribute to a deeper insight in to the unconscious mental life of men affected by PE.  相似文献   
39.
40.
We present 36 consecutive patients with intrinsic glioma of the pons. Tumors with exophytic expansion were excluded. There were 16 females and 20 males, ranging in age from 2 to 13 years, median 6 years. The most common presenting symptoms were cranial nerve dysfunction. unsteadiness of gait, and hemiparesis. Computed tomography (CT) showed a hypodense (17/21) or isodense (4/21) expansion of the pons. Five tumors had areas of contrast enhancement. Following information about prognosis and possible types of management, parents decided for or against radiation therapy: twentyfour children underwent irradiation and 12 did not. Median survival among children receiving a full course of irradiation was 280 days, compared to 140 days in an equivalent group of non-irradiated children. Hemiparesis presenting without cranial nerve symptoms and contrast enhancement on CT scan were poor prognostic factors, whereas sex, age, and duration of symptoms at diagnosis were unrelated to prognosis.  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