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   1381篇
  免费   87篇
  国内免费   9篇
耳鼻咽喉   9篇
儿科学   119篇
妇产科学   33篇
基础医学   227篇
口腔科学   36篇
临床医学   78篇
内科学   227篇
皮肤病学   35篇
神经病学   62篇
特种医学   43篇
外科学   112篇
综合类   67篇
预防医学   115篇
眼科学   14篇
药学   158篇
中国医学   22篇
肿瘤学   120篇
  2022年   9篇
  2021年   21篇
  2020年   18篇
  2019年   15篇
  2018年   30篇
  2017年   28篇
  2016年   36篇
  2015年   21篇
  2014年   41篇
  2013年   62篇
  2012年   90篇
  2011年   87篇
  2010年   77篇
  2009年   51篇
  2008年   83篇
  2007年   76篇
  2006年   63篇
  2005年   72篇
  2004年   84篇
  2003年   65篇
  2002年   53篇
  2001年   32篇
  2000年   35篇
  1999年   34篇
  1998年   9篇
  1996年   9篇
  1995年   10篇
  1994年   5篇
  1993年   6篇
  1992年   19篇
  1991年   14篇
  1990年   13篇
  1989年   22篇
  1988年   22篇
  1987年   17篇
  1986年   24篇
  1985年   10篇
  1984年   18篇
  1983年   13篇
  1982年   5篇
  1981年   7篇
  1980年   10篇
  1979年   13篇
  1978年   4篇
  1977年   5篇
  1976年   4篇
  1975年   5篇
  1974年   4篇
  1972年   4篇
  1968年   3篇
排序方式: 共有1477条查询结果,搜索用时 15 毫秒
1.
2.
A case of malignant fibrous histiocytoma of the mediastinum presenting with unusual features of fever and leucocytosis is reported. This is the youngest patient reported in the literature who had this tumour in the mediastinum.  相似文献   
3.
4.
5.
6.
Effects of progesterone on four neurotransmitters (viz, noradrenaline, 5-HT, dopamine and histamine) of brain were seen in rats with intact ovaries. It was found that progesterone lowers the noradrenaline concentration in medulla, pons, midbrain, hypothalamus, thalami and pituitary, uniformly, when the rats were killed within 4 hours of progesterone injection. At longer intervals (48 hrs) effects of progesterone were seen when progesterone in heavy dose was administered to rats pretreated with estrogen. It is likely that one of the modes of action of the oral contraceptives may be the reduction of noradrenaline content in selected areas of brain, by progesterone. It is also suggested, therapeutic usage of progesterone carries the risk of development of depression in the user.  相似文献   
7.
Neurotrophic factors have been demonstrated to prevent the development of peripheral neuropathy in animal models, but the therapeutic use of these factors in human disease has been limited by the short serum half-life and dose-limiting side effects of these potent peptides. We used peripheral subcutaneous inoculation with a replication-incompetent, genomic herpes simplex virus-based vector containing the coding sequence for neurotrophin-3 to transduce sensory neurons of the rat dorsal root ganglion in vivo, and found that expression of neurotrophin-3 from the vector protected peripheral sensory axons from neuropathy induced by intoxication with pyridoxine assessed by electrophysiological (foot sensory response amplitude, and conduction velocity, and H-wave), histological (nerve morphology and morphometry), and behavioral measures of proprioceptive function. In vivo gene transfer using herpes simplex virus vectors provides a unique option for treatment of diseases of the sensory peripheral nervous system.  相似文献   
8.
A truncated recombinant 56-kDa outer membrane protein of the Karp strain of Orientia tsutsugamushi (Kp r56) was evaluated in cynomolgus monkeys (Macaca fascicularis) for immunogenicity and safety as a vaccine candidate for the prevention of scrub typhus. This recombinant antigen induced strong humoral and cellular immune responses in two monkeys and was found to be well tolerated. Antigen-specific immunoglobulin M (IgM) and IgG were produced to almost maximal levels within 1 week of a single immunization. Peripheral blood mononuclear cells from vaccinated animals showed an induction of antigen-specific proliferation and gamma interferon production. The Kp r56 was not as efficient as infection with live organisms in preventing reinfection but was able to reduce the inflammation produced at the site of challenge. This report describes the results of the first systematic study of the immunogenicity of a recombinant scrub typhus vaccine candidate in a nonhuman primate model.  相似文献   
9.
Carrier analysis and prenatal diagnosis of haemophilia A in North India   总被引:4,自引:0,他引:4  
The feasibility of DNA diagnosis for haemophilia A in North India was evaluated using intragenic polymorphic DNA markers in factor VIII gene for linkage analysis as well as direct detection of inversion mutation in intron 22 of the gene. The informativity of RFLP (HindIII, BclI and XbaI) and STR (introns 13 and 22) markers for linkage analysis in factor VIII gene was determined in 100 normal individuals. The observed heterozygosity for RFLP markers HindIII, BclI and XbaI was 0.63, 0.60 and 0.48 while that of STR markers introns 13 and 22 were 0.60 and 0.40 respectively. Six and four alleles were identified for introns 13 and 22 and the most frequent allele was 13(CA)26 and 22(AG)n(GT)26 with an allele frequency of 0.53 and 0.62 respectively. The heterozygosities observed for RFLP markers was higher (>70%) than the STR markers (50%) in the affected families with haemophilia A. Inversion mutation was detected in 37% of severely affected patients. Based on present and previous studies from India, a strategy has been proposed to provide molecular diagnosis to a large number of undiagnosed cases of haemophilia A.  相似文献   
10.
The public health effects of pesticides cannot be denied. However, the undesired effects of chemical pesticides have been recognized as a serious public health concern during the past decades. The present study describes the genotoxic effects of two pesticides, namely cypermethrin and carbosulfan, in a murine test system in vivo. The test parameter used was analysis of sister chromatid exchanges (SCE) in bone marrow cells. Both cypermethrin (5, 10 and 20 mg/kg) and carbosulfan (1.25, 2.5 and 5 mg/kg) induced significant increases in the frequency of SCEs (P < 0.001). However, no significant dose-response correlation could be found for either of the pesticides. Carbosulfan induced a cell cycle delay, as evidenced by an increase in average generation time accompanied by accumulation of cells in the first division cycle, but cypermethrin did not induce any such response. The present study indicates that carbosulfan has a higher potential to cause genetic alterations than cypermethrin in mice and may also pose a mutagenic risk to human beings.  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