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   7524篇
  免费   417篇
  国内免费   34篇
耳鼻咽喉   41篇
儿科学   114篇
妇产科学   149篇
基础医学   1122篇
口腔科学   228篇
临床医学   616篇
内科学   1474篇
皮肤病学   182篇
神经病学   802篇
特种医学   471篇
外科学   1067篇
综合类   71篇
一般理论   3篇
预防医学   360篇
眼科学   310篇
药学   493篇
中国医学   16篇
肿瘤学   456篇
  2023年   25篇
  2022年   91篇
  2021年   136篇
  2020年   77篇
  2019年   101篇
  2018年   115篇
  2017年   110篇
  2016年   141篇
  2015年   178篇
  2014年   250篇
  2013年   315篇
  2012年   470篇
  2011年   541篇
  2010年   337篇
  2009年   308篇
  2008年   548篇
  2007年   548篇
  2006年   509篇
  2005年   507篇
  2004年   494篇
  2003年   498篇
  2002年   473篇
  2001年   99篇
  2000年   64篇
  1999年   116篇
  1998年   105篇
  1997年   95篇
  1996年   58篇
  1995年   56篇
  1994年   47篇
  1993年   40篇
  1992年   44篇
  1991年   32篇
  1990年   28篇
  1989年   23篇
  1988年   16篇
  1987年   21篇
  1986年   8篇
  1985年   13篇
  1984年   20篇
  1983年   22篇
  1982年   18篇
  1981年   22篇
  1980年   16篇
  1978年   20篇
  1977年   18篇
  1976年   14篇
  1974年   15篇
  1973年   10篇
  1965年   8篇
排序方式: 共有7975条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
56.
57.
In May 2012, the World Health Assembly passed resolution WHA 65.21, calling upon member states to intensify schistosomiasis control and, wherever possible, to attempt transmission interruption and initiate interventions towards local elimination. It is now clear that CONTRAST – a multidisciplinary alliance to optimize schistosomiasis control and transmission surveillance in sub-Saharan Africa – was ahead of the game. Indeed, launched in October 2006, this 4-year project funded by the European Commission made important contributions for sustainable schistosomiasis control in the selected African countries through innovation, validation and application of new tools and locally adapted intervention strategies complementary to preventive chemotherapy. Moreover, CONTRAST articulated a research agenda for schistosomiasis elimination, framed by 10 key questions. Here, we provide a rationale for CONTRAST and discuss its overarching goal, the interrelated objectives, establishment and running of a research node network across Africa, partnership configuration and modus operandi of the project. A collection of 25 articles is presented that are grouped into five main themes: molecular, biological, spatial, social and cross-cutting issues pertaining to the epidemiology and control of schistosomiasis. We summarize key achievements made by CONTRAST, many of which are featured in this special issue of Acta Tropica. Together with an independent view put forth by an eminent schistosomiasis researcher, the current piece provides an umbrella for the 25-article collection, including current gaps and remaining research needs. Finally, post-CONTRAST initiatives are discussed and a speculative viewpoint is given on how schistosomiasis control/elimination will have evolved over the next several years.  相似文献   
58.
We present a case of spinal cord sarcoidosis which resembled a disseminated intramedullary tumour. The case is unusual because the spinal cord is only rarely affected by sarcoidosis and the patient developed a neurological deficit as the first manifestation of the disease. This condition thus has to be considered in the differential diagnosis of primary intramedullary tumours, or metastatic disease with involvement of the spinal cord.  相似文献   
59.
Normal blood flow and velocity in the superior sagittal sinus were measured in 30 patients. A fast two-dimensional ungated phase-contrast (PC) pulse sequence was compared with a peripherally gated cine PC technique for velocity and flow quantitation. The same imaging parameters were used for both methods. Measured values for mean velocity and flow obtained with the two methods were compared by using regression analysis and t testing. For blood flow, the correlation coefficient was 0.976. For velocity measurements, r was 0.950. Mean flow was 285 mL/min ± 19 with the ungated PC method and 281 mL/min ± 19 with the cine PC method. The mean velocities measured with the two methods were 12.94 cm/sec ± 1.1 and 13.59 cm/sec ± 1.1, respectively. There was no significant difference (paired t test) between the methods for mean flow or velocity data. This was true even though flow in the superior sagittal sinus is moderately pulsatile, as shown with the cine PC technique. The ungated PC method provided these data in 13 seconds versus 3.5 minutes for the cine PC method.  相似文献   
60.
The ability to measure skeletal muscle motion with phase-contrast magnetic resonance (MR) imaging was tested with a motion phantom that simulated muscle activity. Quantitative analytic data on unidimensional, bidirectional skeletal muscle motion measured in vivo was obtained in four healthy volunteers. MR images of the subjectss' forearms were obtained during flexion and extension of the fingers and of the anterior and posterior muscle compartments of the lower leg with various resistances to ankle dorsiflexion and plantar flexion. It was necessary to correct the data for the effects of eddy currents. In vitro evaluation of the technique was done by studying through-plane sinusoidal motion of solid objects. The largest error was underestimation of the peak excursion of 11.5 mm by 0.09 mm (the root mean square error for the cycle was 0.04 mm) In vivo experiments demonstrated the contraction of muscles in relation to each other. Data acquisition and analysis techniques must be refined, but measuring skeletal muscle motion with phase-contrast MR imaging should enhance the understanding of bioengineering fundamentals and muscular changes in disease and adaptation.  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