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   2039篇
  免费   135篇
  国内免费   9篇
耳鼻咽喉   56篇
儿科学   44篇
妇产科学   50篇
基础医学   363篇
口腔科学   20篇
临床医学   206篇
内科学   475篇
皮肤病学   47篇
神经病学   173篇
特种医学   49篇
外科学   144篇
综合类   17篇
一般理论   1篇
预防医学   166篇
眼科学   35篇
药学   194篇
中国医学   11篇
肿瘤学   132篇
  2023年   36篇
  2022年   129篇
  2021年   184篇
  2020年   72篇
  2019年   82篇
  2018年   98篇
  2017年   65篇
  2016年   87篇
  2015年   88篇
  2014年   82篇
  2013年   113篇
  2012年   157篇
  2011年   158篇
  2010年   70篇
  2009年   56篇
  2008年   89篇
  2007年   87篇
  2006年   84篇
  2005年   64篇
  2004年   40篇
  2003年   40篇
  2002年   26篇
  2001年   11篇
  2000年   13篇
  1999年   13篇
  1997年   8篇
  1992年   15篇
  1991年   18篇
  1990年   14篇
  1989年   16篇
  1988年   15篇
  1987年   5篇
  1986年   18篇
  1985年   5篇
  1984年   5篇
  1983年   7篇
  1982年   7篇
  1981年   8篇
  1979年   7篇
  1977年   7篇
  1976年   5篇
  1975年   11篇
  1974年   4篇
  1973年   6篇
  1972年   5篇
  1971年   8篇
  1970年   6篇
  1969年   9篇
  1968年   3篇
  1966年   3篇
排序方式: 共有2183条查询结果,搜索用时 17 毫秒
1.
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.
Operator's determined (D) and stochastic (S) performance depends on the level of readiness and synchronization of the frontoparietal and parietooccipital cortex areas. The developed feedback algorithm was tested in two series of experiments with volunteered subjects doing computer simulation tasks. The experiments showed feasibility to elaborate feedback adaptive control skills that will sustain for a month period.  相似文献   
4.
5.
6.
The second generation of the scintillation gamma camera gamma KC-2 has been recently produced in lots. Compared to the first Soviet model gamma KC-1 it features advanced spatial resolution, maximum count rate, and image uniformity. A built-in microprocessor controls in real time corrections for distortions thus providing a marked gain in serviceability and expanded diagnostic capacity.  相似文献   
7.
Ovarian cancer is the leading cause of death among patients with gynecological cancers, but the biology of these tumors is still among the least understood of all major human malignancies. In this study, comparative genomic hybridization was used to determine chromosomal alterations in 98 stage III serous papillary adenocarcinomas. The tumors were grouped according to survival and the main prognostic factors stage and surgical outcome. There were chromosomal imbalances that were significantly more common in tumors from patients who died than in tumors from patients who survived: gains of 1q24-qter and losses of 4p, 4q31.1-qter, 5q12-q22, 8p, 16q, and X. Furthermore, we observed that gains of 8q23-8q24.2 and losses of 4p, 4q13-4q26, 4q31.1-qter, 5q12-q22, 8p, and 16q were significantly more common in tumors from patients with macroscopic residual tumor after primary surgery, compared to tumors from those who had undergone radical surgery. Gains of 3q13.3-qter, 6p, 7q21-q31, and 11q13-q23 and losses of 4q31.1-qter and 16q were more common in stage IIIc tumors than in stage IIIa+b tumors. On the basis of our results, we suggest that there are biological differences among the groups mentioned above and that absence of chromosomal aberrations in specific regions predicts a good clinical outcome for individual patients.  相似文献   
8.
The accumulation of macrophage foam cells in atherosclerotic lesions is associated with both initiation and progression of this disease. Scavenger receptors CD36 and SRA are the primary receptors responsible for conversion of macrophages into foam cells. Integrin alphaVbeta3 plays a role in the differentiation of several cell types, but its involvement in the transition of macrophages into foam cells and the potential role of this receptor in atherosclerosis have not been examined. Using an in vitro model of single surface receptor activation by binding with an immobilized monoclonal antibody specific to alphaVbeta3 integrin we show that ligation of alphaVbeta3 integrin prevents differentiation of blood monocytes and macrophages into the foam cell phenotype via coordinate down-regulation of CD36 and SRA. This effect of alphaVbeta3 integrin ligation can be reproduced by contact with endothelial cells, whereas the inhibition of alphaVbeta3 receptor ligation restores the uptake of oxidized low-density lipoprotein. Moreover, we found that alphaVbeta3 integrin is readily detected in situ on macrophages in early and advanced atherosclerotic lesions and that in vitro exposure to oxidized low-density lipoprotein up-regulates alphaVbeta3 integrin expression. We hypothesize that alphaVbeta3 integrin regulates macrophage functional maturation into foam cells in a persistent manner, and therefore, by targeting alphaVbeta3 receptor it could potentially be possible to regulate progression of atherosclerosis in humans.  相似文献   
9.
Hexokinase and glucokinase activity in the supernatant of a rabbit liver homogenate obtained at 18,000g was determined by a spectrophotometric method. Preliminary purification to remove low-molecular-weight components by gel filtration on Molselect G-50 dextran was shown to prevent reduction of NADP unconnected with the hexokinase reaction.Presented by Academician of the Academy of Medical Sciences of the USSR V. S. Il'in.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 7, pp. 891–892, July, 1976.  相似文献   
10.
The purpose of translational research is to test, in humans, novel therapeutic strategies developed through experimentation. Translational research should be regarded as a two-way road: Bench to Bedside and Bedside to Bench. However, Bedside to Bench efforts have regrettably been limited because the scientific aspects are poorly understood by full time clinicians and the difficulty of dealing with humans poorly appreciated by basic scientists. Translational research would be most useful to the scientific community at large if journals would foster specific interest for the publication of ex vivo human observation. The review process for such work should be assigned to clinical scientists competent not only in the intricacies of molecular or cell biology but also intimate with the reality of Internal Review Boards, ethics committees, Governmental Regulatory Agencies and most importantly the humane aspects of dealing with sick individuals and their families. This approach may focus both basic and clinical scientists and those struggling to fill the gap between them on the effective treatment of diseases affecting women, men and children making translational research more than an interesting concept.  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