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   1482篇
  免费   86篇
  国内免费   13篇
耳鼻咽喉   17篇
儿科学   50篇
妇产科学   20篇
基础医学   166篇
口腔科学   36篇
临床医学   109篇
内科学   379篇
皮肤病学   20篇
神经病学   108篇
特种医学   88篇
外科学   209篇
综合类   18篇
预防医学   79篇
眼科学   9篇
药学   120篇
中国医学   3篇
肿瘤学   150篇
  2023年   11篇
  2022年   10篇
  2021年   34篇
  2020年   15篇
  2019年   38篇
  2018年   40篇
  2017年   30篇
  2016年   18篇
  2015年   33篇
  2014年   51篇
  2013年   54篇
  2012年   89篇
  2011年   70篇
  2010年   43篇
  2009年   32篇
  2008年   51篇
  2007年   64篇
  2006年   70篇
  2005年   76篇
  2004年   52篇
  2003年   57篇
  2002年   52篇
  2001年   27篇
  2000年   48篇
  1999年   46篇
  1998年   29篇
  1997年   34篇
  1996年   29篇
  1995年   17篇
  1994年   16篇
  1993年   21篇
  1992年   19篇
  1991年   21篇
  1990年   24篇
  1989年   28篇
  1988年   29篇
  1987年   18篇
  1986年   11篇
  1985年   14篇
  1984年   13篇
  1983年   13篇
  1982年   10篇
  1978年   8篇
  1973年   8篇
  1972年   7篇
  1971年   6篇
  1970年   10篇
  1969年   6篇
  1968年   6篇
  1967年   8篇
排序方式: 共有1581条查询结果,搜索用时 13 毫秒
1.
Oncocytosis and oncocytomas have attracted attention because on the one hand there have been reports of the favourable prognosis and generally benign nature of oncocytic tumours, while on the other hand, Hurthle cell change in thyroid neoplasms have been reported to be correlated with aggressive biological behaviour and a significantly worse clinical course. Presently, there appear to be two schools of thought on the significance of oncocytosis: (i) a process where there is redifferentiation of cells with involvement in the pathogenesis of cancer; and (ii) a compensatory process for ‘functional exhaustion’ of the cell. Many aspects of oncocytosis seem unclear. In this study, transmission electron microscopy is used to demonstrate the presence of thyroid oncocytes in the hemithyroidectomy specimen of a patient with focal lymphocytic thyroiditis. Tissue sections from this specimen did not display preferential uptake of neutral red dye, a distinctive characteristic of M-phase cancer cells which was previously reported. The findings seem to suggest that oncocytes are not cells with distinctive proliferative potentials. If that were the case, then oncogenesis or cancer cell progression and oncocytosis may not be convergent processes.  相似文献   
2.
3.
Development of gene therapies for wound healing will depend on the identification of the genes involved in wound healing and tissue regeneration. Previous quantitative trait loci (QTL) studies in mice using the ear punch model have shown that major QTL exist on chromosome (Chr) 9 for soft tissue regeneration. In this study, we have developed a congenic line that contains the Chr 9 QTL chromosomal region from super healer MRL/MpJ in the genomic background of poor-healing SJL/J. The phenotypic effect of this QTL was confirmed in male mice, where the congenic line has shown significant healing improvement over SJL. Fine mapping of the Chr 9 QTL region with 23 markers at an average distance of 4.2 Mb using a total of 1,564 MRL/MpJ x SJL/J F(2) mice revealed the presence of at least three QTL peaks, implying that three separate loci may contribute to the phenotypic effect of this QTL. Based on the 2-LOD intervals, the total QTL region was confined to a combined length of no more than 28.2 Mb. Application of a Bayesian shrinkage estimation indicated that a major locus was located in a region of just 1.3 Mb.  相似文献   
4.
5.
可逆性胆硷酯酶抑制剂二甲氨基甲酸-5-二氢吲哚酯的合成   总被引:1,自引:0,他引:1  
陈邦华  纪庆娥 《药学学报》1990,25(4):247-252
为了深入研究催醒宁类化合物的结构与抑酶活性的关系,设计合成了-系列1-,3-或5-位不同取代的二氢吲哚类衍生物(中间体和终产物共24个新化合物)。中间体1,3-二甲基-5-烷氧基-2-二氢吲哚酮(A)的C3烷化。采用相转移催化方法进行;反应中还分离到三个副产物(Ⅶ~Ⅸ)。初筛结果表明:这些化合物大多有较强的抑酶活性;1,3-或5-位取代基的改变均明显影响其活性。  相似文献   
6.
7.
The impact of patient education follow-up by telephone on the knowledge of the postmyocardial infarction (MI) patient was investigated in this study. On the basis of Orem's self-care framework, subjects' levels of knowledge in six criterion areas were assessed according to measurement criteria developed by Horn and Swain. Fifty-one subjects from the total population of MI patients admitted to the coronary care unit of the study hospital during the period of research who met study criteria were randomly assigned to experimental and control groups. Statistically significant differences (p less than 0.05) were found in the knowledge level of the experimental group in the areas of the disease, its effects, related self-care measures, recommended exercises, and all teaching areas together. Although significant differences were not found in the teaching areas of therapeutic diet, medications, physical activity restrictions, and recommended rest, a higher mean was produced for the experimental group in all but one area. These findings demonstrate that a telephone teaching program for MI patients 6 to 8 weeks after hospital discharge can be effective in increasing knowledge relative to the disease, self-care, and therapeutic regimen.  相似文献   
8.
9.
Extracellular ATP (7 microM-14 mM) induced monolayer Chang liver cells (ATCC CCL 13) to retract and round up in dose-dependent and time-dependent manners. ATP-induced rounding was concomitant with raised intracellular pH (7.3 to 7.8) and suppressed (a) in sodium-free medium (250 mM sucrose), (b) with the addition of 1 mM quinidine, an inhibitor of Na+/H+ exchanges, and (c) with the addition of 10 nM staurosporine, a potent inhibitor of protein kinase C that is known to activate Na+/H+ exchanges. These findings suggest that ATP-induced cell rounding is due to activation of Na+/H+ antiporters.  相似文献   
10.
E J Bay 《Nursing》1988,18(8):52-53
  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