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   1240篇
  免费   92篇
  国内免费   8篇
耳鼻咽喉   9篇
儿科学   49篇
妇产科学   35篇
基础医学   173篇
口腔科学   18篇
临床医学   113篇
内科学   346篇
皮肤病学   26篇
神经病学   96篇
特种医学   15篇
外科学   89篇
综合类   10篇
预防医学   141篇
眼科学   22篇
药学   118篇
中国医学   8篇
肿瘤学   72篇
  2024年   3篇
  2023年   24篇
  2022年   78篇
  2021年   159篇
  2020年   54篇
  2019年   66篇
  2018年   71篇
  2017年   44篇
  2016年   52篇
  2015年   61篇
  2014年   47篇
  2013年   72篇
  2012年   103篇
  2011年   117篇
  2010年   43篇
  2009年   30篇
  2008年   51篇
  2007年   62篇
  2006年   38篇
  2005年   40篇
  2004年   39篇
  2003年   29篇
  2002年   30篇
  2001年   1篇
  1999年   2篇
  1998年   3篇
  1997年   4篇
  1996年   1篇
  1993年   2篇
  1992年   1篇
  1989年   1篇
  1988年   1篇
  1985年   1篇
  1984年   2篇
  1981年   2篇
  1980年   1篇
  1978年   2篇
  1977年   1篇
  1975年   2篇
排序方式: 共有1340条查询结果,搜索用时 15 毫秒
21.
The polycystic ovary syndrome (PCOS) is characterized by insulin resistance with compensatory hyperinsulinemia. Insulin resistance also plays a role in the metabolic syndrome (MBS). We hypothesized that the MBS is prevalent in PCOS and that women with both conditions would present with more hyperandrogenism and menstrual cycle irregularity than women with PCOS only. We conducted a retrospective chart review of all women with PCOS seen over a 3-yr period at an endocrinology clinic. Of the 161 PCOS cases reviewed, 106 met the inclusion criteria. The women were divided into two groups: 1) women with PCOS and the MBS (n = 46); and 2) women with PCOS lacking the MBS (n = 60). Prevalence of the MBS was 43%, nearly 2-fold higher than that reported for age-matched women in the general population. Women with PCOS had persistently higher prevalence rates of the MBS than women in the general population, regardless of matched age and body mass index ranges. Acanthosis nigricans was more frequent in women with PCOS and the MBS. Women with PCOS and the MBS had significantly higher levels of serum free testosterone (P = 0.002) and lower levels of serum SHBG (P = 0.001) than women with PCOS without the MBS. No differences in total testosterone were observed between the groups. We conclude that the MBS and its components are common in women with PCOS, placing them at increased risk for cardiovascular disease. Women with PCOS and the MBS differ from their counterparts lacking the MBS in terms of increased hyperandrogenemia, lower serum SHBG, and higher prevalence of acanthosis nigricans, all features that may reflect more severe insulin resistance.  相似文献   
22.
23.
24.
25.
Over 260,000 (2013) new oral squamous cell carcinoma (OSCC) cases are reported annually worldwide. Despite development in OSCC management, the outcome is still unsatisfactory. Identification of new molecular markers may be of use in prevention, prognosis, and choice of an appropriate therapy. The intracellular molecular signalling pathway of phosphatidyl-inositol-3-kinase is involved in the process of cell growth, differentiation, migration, and survival. The main components of this pathway: PIK3CA (phosphatidylinositol-4,5-bisphosphate-3-kinase catalytic subunit α), PTEN (phosphatase and tensin homologue deleted on chromosome 10), and AKT (serine-threonine kinase) are potential objects of research when introducing new therapeutic agents. The aim of this paper is to evaluate the PIK3CA, PTEN, and AKT gene mutations as prognostic factors in OSCC and to describe their role in aggressive disease progression. This is crucial for oral cancer biology understanding and for indicating which direction new clinical treatments should take.  相似文献   
26.
BackgroundFamilial hypercholesterolemia (FH) is an inherited disorder mainly caused by mutations in the LDL receptor (LDL-R) and characterized by elevation of low-density lipoprotein cholesterol (LDL-C) levels and premature cardiovascular disease.ObjectiveIn this study, we evaluated the clinical phenotype of the p.Asp47Asn, described as an uncertain pathogenic variant, and its effect on the structure of LDL-R and ligand interactions with apolipoproteins.Methods27 children and adolescents with suspected FH diagnosis were recruited from a pediatric endocrinology outpatient clinic. Blood samples were collected after 12 h fasting for lipid profile analysis. DNA sequencing was performed for six FH-related genes by Ion Torrent PGM platform and copy number variation by MLPA. For index cases, a familial cascade screening was done restricted to the same mutation found in the index case. In silico analysis were developed to evaluate the binding capacity of LDL-R to apolipoproteins B100 and E.ResultsLipid profile in children and adolescents demonstrated higher LDL-C levels in p.Asp47Asn carriers compared to the wild type genotype. In silico analysis predicted a reduction in the binding capacity of the ligand-binding modules LA1-2 of p.Asp47Asn LDL-R for ApoB100 and ApoE, which was not produced by local structural changes or folding defects but as a consequence of a decreased apparent affinity for both apolipoproteins.ConclusionThe clinical phenotype and the structural effects of p.Asp47Asn LDL-R mutation suggest that this variant associates to FH.  相似文献   
27.
28.
29.
Mast cells and fibroblasts are two key players involved in many fibrotic and degenerative disorders. In the present study we examined the nature of binding interactions between human mast cells and tendon fibroblasts (tenocytes). In the mast cell‐fibroblast co‐culture model, mast cells were shown to spontaneously bind to tenocytes, in a process that was partially mediated by α5β1 integrin receptors. The same receptors on mast cells significantly mediated binding of these cells to tissue culture plates in the presence of tenocyte‐conditioned media; the tenocyte‐derived fibronectin in the media was shown to also play a major role in these binding activities. Upon binding to tenocytes or tissue culture plates, mast cells acquired an elongated phenotype, which was dependent on α5β1 integrin and tenocyte fibronectin. Additionally, tenocyte‐derived fibronectin significantly enhanced mRNA expression of the adhesion molecule, THY1, by mast cells. Our data suggests that α5β1 integrin mediates binding of mast cells to human tenocyte and to tenocyte‐derived ECM proteins, in particular fibronectin. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:9–16, 2015.
  相似文献   
30.
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