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   684篇
  免费   41篇
  国内免费   3篇
耳鼻咽喉   2篇
儿科学   11篇
妇产科学   7篇
基础医学   55篇
口腔科学   24篇
临床医学   62篇
内科学   161篇
皮肤病学   17篇
神经病学   56篇
特种医学   33篇
外科学   116篇
综合类   6篇
预防医学   34篇
眼科学   8篇
药学   43篇
中国医学   1篇
肿瘤学   92篇
  2023年   17篇
  2022年   36篇
  2021年   42篇
  2020年   24篇
  2019年   26篇
  2018年   32篇
  2017年   18篇
  2016年   25篇
  2015年   28篇
  2014年   22篇
  2013年   43篇
  2012年   40篇
  2011年   54篇
  2010年   16篇
  2009年   14篇
  2008年   27篇
  2007年   15篇
  2006年   33篇
  2005年   31篇
  2004年   19篇
  2003年   18篇
  2002年   24篇
  2001年   8篇
  2000年   17篇
  1999年   6篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1994年   1篇
  1992年   3篇
  1991年   8篇
  1990年   9篇
  1989年   6篇
  1988年   6篇
  1987年   12篇
  1986年   6篇
  1985年   5篇
  1984年   8篇
  1983年   2篇
  1980年   1篇
  1977年   2篇
  1976年   2篇
  1975年   4篇
  1974年   4篇
  1973年   1篇
  1972年   1篇
  1969年   1篇
  1968年   1篇
  1967年   3篇
排序方式: 共有728条查询结果,搜索用时 0 毫秒
1.
2.
To investigate the effects of polymorphisms in the ATP-binding cassette transporter A1 (ABCA1) gene on the high-density lipoprotein cholesterol (HDL-C) level and the incidence of myocardial infarction (MI), we performed association studies. Sequence analysis identified 14 polymorphisms in the promoter region of ABCA1. After considering linkage disequilibrium, three polymorphisms in the promoter region and 11 polymorphisms from the JSNP database were determined in 1,880 subjects recruited from the Suita Study, representing the general population in Japan. We evaluated the association between the ABCA1 genotype and HDL-C level adjusted not only for standard factors, but also for genetic factors including ApoA1 and ApoE genotypes. Of the 14 polymorphisms tested, the G(–273)C (P=0.0074), C(–297)T (P=0.0195), and IMS-JST071749 (P=0.0093) polymorphisms were significantly associated with the HDL-C level in the Suita population. We could reconfirm that the G(–273)C genotype was influential in another set of subjects (P=0.0310, n=743). However, the distribution of the ABCA1 G(–273)C genotype in subjects with MI (n=598) was not different from that in the control population (n=801). These results indicate that ABCA1 G(–273)C has a significant effect on the HDL-C level in the general Japanese population, but not on the incidence of MI.  相似文献   
3.
The human ST2 gene can be specifically induced by growth stimulation in fibroblastic cells, and can also be induced by antigen stimulation in Th2 cells. The gene encodes a soluble secreted protein, ST2, and a transmembrane protein, ST2L, which are closely related to the interleukin-1 receptor. To gain insight into the biological roles of the ST2 gene, three monoclonal antibodies (MAbs) against human ST2 gene products were obtained. To obtain these antibodies, immunization was carried out using two different immunogens: purified soluble human ST2 protein (hST2), and COS7 cells, which express the extracellular portion of human ST2L. 2A5 and FB9 MAbs were derived from the immunization with soluble hST2, and HB12 was derived from the COS7 cell immunization. All three antibodies were shown to detect native forms of the human ST2 gene products by immunoprecipitation, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). In the competitive ELISA using biotinylated and nonlabelled MAbs, neither FB9 nor HB12 affected the binding of 2A5 to ST2 gene products. Based on this result, we constructed a sandwich ELISA system using 2A5 and FB9 to measure the concentration of soluble hST2 in sera. The ELISA, combined with the flow cytometry using these antibodies, will be a useful tool for elucidating the functions of human ST2 gene products in individuals.  相似文献   
4.
5.
Assessments have been made of serum IgE and IgA value, specific IgE and IgG4 antibody titers to foods, house dust, mite and percent peripheral++ eosinophil count in 191 infants with and without eczema between 5-7 months of age. Eczema patients were divided into 4 groups according to the degree of eczema involvement and laboratory data were compared between these and not eczematous group. The results were as follows; 1) IgE antibody titers were higher as the degree of eczema involvement increased. 2) RAST positive rates to foods increased with the degree of eczema involvement. Positive rate was highest to egg white followed by milk, soybean, wheat and rice. 3) Only 9 cases were RAST-positive to rice or wheat and all of them had IgE antibodies to other allergens tested. 4) A value of 10 IU/ml, which is the lowest measurable value of IgE in infants was considered to be a little too high to speculate allergy to some foods. 5) Specific IgG4 antibodies were positive only to milk. 6) All the 18 cases with positive milk-specific IgG4 antibody were all negative in milk-specific IgE antibody, and conversely all the 14 cases with positive milk-specific IgE antibody were negative in milk-specific IgG4 antibody. From these results, it was concluded that food allergy is related to the degree of eczema involvement in infants between 5-7 months of age.  相似文献   
6.
Cholinergic neurons in the basal forebrain which project to both the hippocampus and olfactory bulb were identified in the rat by using twin fluorescent retrograde tracers combined with fluorescence immunohistochemistry for choline acetyltransferase (ChAT). The majority of neurons simultaneously labeled with the two tracers were also identified as being ChAT-positive. They were located at the border between the horizontal and vertical limbs of the diagonal band of Broca. Their numbers were very small compared with neurons singly labeled from each of the projection areas.  相似文献   
7.
Summary Silver staining by a modified Bielschowsky's technique and immunostaining for -amyloid protein BAP have revealed the occurrence of diffuse amyloid deposits bilaterally in the presubiculum in each of fourteen Alzheimer's disease cases examined. Observations on serial blocks show these deposits to be localized in the parvopyramidal layer of the presubiculum proper and the transsubiculum. They are also observed in the cellular islands within the molecular layer of the subiculum but not in the parasubiculum. These amyloid deposits are not accompanied by neurofibrillary tangles, neuropil threads, or the aggregated microglial reaction which is characteristically associated with classic senile plaques. Convergence of input from limbic and cortical areas might play a significant role in the formation of these diffuse amyloid deposits.Supported by grants from the MRC of Canada, the Alzheimer's Society of B.C., the American Health Assistance Foundation and the McLean Foundation  相似文献   
8.
The effects of a nonsteroidal aromatase inhibitor, CGS 16949A, on female Sprague-Dawley (SD) rats with 7, 12-dimethylbenz[alpha]anthracene (DMBA)-induced mammary cancers were examined in relation to estrogen receptors (ER). Rat tumor sizes in each treated group were significantly smaller (P less than 0.05) and rat body weights in most treated groups were significantly increased (P less than 0.05) compared to those in the control group (no treatment) at all measurement points during treatment. Rat uterine weights in each treated group decreased significantly compared with those in the control group (P less than 0.05). There was no significant difference between ER-positive and ER-negative groups in tumor size, body weight or uterine weight. At increased doses of CGS 16949A in the experiment, further increases in testosterone levels and further decreases in estradiol levels were shown to occur. The results suggest the mechanisms of CGS 16949A action not to be influenced by the presence or absence of ER, but to be due to its potent aromatase inhibition of the conversion of androgens to estrogens.  相似文献   
9.
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