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   2049篇
  免费   67篇
  国内免费   5篇
耳鼻咽喉   27篇
儿科学   61篇
妇产科学   40篇
基础医学   381篇
口腔科学   49篇
临床医学   241篇
内科学   276篇
皮肤病学   33篇
神经病学   38篇
特种医学   192篇
外国民族医学   1篇
外科学   343篇
综合类   51篇
预防医学   141篇
眼科学   10篇
药学   134篇
中国医学   4篇
肿瘤学   99篇
  2021年   24篇
  2018年   20篇
  2016年   21篇
  2015年   22篇
  2014年   30篇
  2013年   46篇
  2012年   48篇
  2011年   43篇
  2010年   59篇
  2009年   55篇
  2008年   46篇
  2007年   47篇
  2006年   41篇
  2005年   50篇
  2004年   47篇
  2003年   42篇
  2002年   51篇
  2001年   41篇
  2000年   50篇
  1999年   37篇
  1998年   44篇
  1997年   42篇
  1996年   45篇
  1995年   46篇
  1994年   30篇
  1993年   34篇
  1992年   34篇
  1991年   78篇
  1990年   72篇
  1989年   80篇
  1988年   70篇
  1987年   66篇
  1986年   60篇
  1985年   53篇
  1984年   42篇
  1983年   38篇
  1982年   20篇
  1981年   24篇
  1980年   24篇
  1979年   33篇
  1978年   31篇
  1976年   22篇
  1975年   28篇
  1974年   33篇
  1973年   26篇
  1972年   25篇
  1971年   23篇
  1970年   21篇
  1969年   24篇
  1968年   21篇
排序方式: 共有2121条查询结果,搜索用时 15 毫秒
1.
Pharmaceutical Chemistry Journal - N-Substituted 4-aryl-2-hydroxy-4-oxobut-2-enoic acid hydrazides and their complexes with Ni(II), Mn(II), Co(II), Cu(II), and Zn(II) were prepared. Their...  相似文献   
2.
Electrocardiographic symptoms were evaluated in 53 patients with an additional left-ventricular chorda (ALVC), detected by two-dimensional echocardiography. Signs of early ventricular repolarization (EVR) were identified in 45 (84.9%) patients. A transverse ALVC was more common in EVR-free patients (87.5%), as compared to patients with ALVC + EVR combinations (51.1%; p less than 0.05).  相似文献   
3.
In this paper a mathematical model describing the growth of a solid tumour in the presence of an immune system response is presented. In particular, attention is focused upon the attack of tumour cells by so-called tumour-infiltrating cytotoxic lymphocytes (TICLs), in a small, multicellular tumour, without necrosis and at some stage prior to (tumour-induced) angiogenesis. At this stage the immune cells and the tumour cells are considered to be in a state of dynamic equilibrium--cancer dormancy--a phenomenon which has been observed in primary tumours, micrometastases and residual disease after ablation of the primary tumour. Nonetheless, the precise biochemical and cellular mechanisms by which TICLs control cancer dormancy are still poorly understood from a biological and immunological point of view. Therefore we focus on the analysis of the spatio-temporal dynamics of tumour cells, immune cells and chemokines in an immunogenic tumour. The lymphocytes are assumed to migrate into the growing solid tumour and interact with the tumour cells in such a way that lymphocyte-tumour cell complexes are formed. These complexes result in either the death of the tumour cells (the normal situation) or the inactivation (sometimes even the death) of the lymphocytes. The migration of the TICLs is determined by a combination of random motility and chemotaxis in response to the presence of chemokines. The resulting system of four nonlinear partial differential equations (TICLs, tumour cells, complexes and chemokines) is analysed and numerical simulations are presented. We consider two different tumour geometries--multi-layered cell growth and multi-cellular spheroid growth. The numerical simulations demonstrate the existence of cell distributions that are quasi-stationary in time and heterogeneous in space. A linear stability analysis of the underlying (spatially homogeneous) ordinary differential equation (ODE) kinetics coupled with a numerical investigation of the ODE system reveals the existence of a stable limit cycle. This is verified further when a subsequent bifurcation analysis is undertaken using a numerical continuation package. These results then explain the complex heterogeneous spatio-temporal dynamics observed in the partial differential equation (PDE) system. Our approach may lead to a deeper understanding of the phenomenon of cancer dormancy and may be helpful in the future development of more effective anti-cancer vaccines.  相似文献   
4.
5.
From study of data on 5- and 10-year survivals of 560 patients who underwent operation for breast cancer in stage T1.2NoMo, the authors determined the most significant prognostic factors. These were the histological form of the tumor and the degree of invasion into the adjoining tissues. The percentage of each studied factor was determined by mathematical analysis, which allowed the individual prognosis for each patient to be made and treatment planned accordingly.  相似文献   
6.
Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 28, No. 7, pp. 3–6, July, 1994.  相似文献   
7.
8.
9.
In the time course of 15-day stress of moderate intensity, rat experiments indicated that following a day there developed a complex of changes typical of acute stressor syndrome. Five days of post-stress , the stress-related cardiac syndrome ceased, bradycardia developed, the contractile function was limited, and the fibrillation threshold returned to the control values, which was shown to be associated with activation of the cholinergic stress-limiting system. Fifteen days later there was normalization of heart rate and cardiac contractility, the fibrillation threshold remained at the baseline level.  相似文献   
10.
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