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   2374篇
  免费   116篇
  国内免费   310篇
耳鼻咽喉   12篇
儿科学   80篇
妇产科学   24篇
基础医学   273篇
口腔科学   13篇
临床医学   133篇
内科学   1109篇
皮肤病学   34篇
神经病学   11篇
特种医学   69篇
外科学   409篇
综合类   281篇
预防医学   74篇
眼科学   18篇
药学   114篇
中国医学   84篇
肿瘤学   62篇
  2024年   1篇
  2023年   55篇
  2022年   82篇
  2021年   115篇
  2020年   103篇
  2019年   144篇
  2018年   136篇
  2017年   88篇
  2016年   96篇
  2015年   107篇
  2014年   190篇
  2013年   179篇
  2012年   143篇
  2011年   153篇
  2010年   124篇
  2009年   158篇
  2008年   141篇
  2007年   124篇
  2006年   112篇
  2005年   107篇
  2004年   70篇
  2003年   57篇
  2002年   47篇
  2001年   42篇
  2000年   32篇
  1999年   35篇
  1998年   25篇
  1997年   20篇
  1996年   21篇
  1995年   19篇
  1994年   11篇
  1993年   9篇
  1992年   7篇
  1991年   6篇
  1990年   3篇
  1989年   7篇
  1988年   4篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   4篇
  1983年   2篇
  1982年   3篇
  1980年   3篇
  1979年   5篇
  1978年   2篇
  1976年   1篇
  1975年   1篇
  1972年   1篇
  1971年   1篇
排序方式: 共有2800条查询结果,搜索用时 31 毫秒
1.
Defects of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein affect the homeostasis of chloride, bicarbonate, sodium, and water in the airway surface liquid, influencing the mucus composition and viscosity, which induces a severe condition of infection and inflammation along the whole life of CF patients. The introduction of CFTR modulators, novel drugs directly intervening to rescue the function of CFTR protein, opens a new era of experimental research. The review summarizes the most recent advancements to understand the characteristics of the infective and inflammatory pathology of CF lungs.  相似文献   
2.
3.
4.
子宫腺肌病(ADS)是子宫内膜腺体及间质侵入子宫肌层导致的以子宫局灶或弥漫性增大为主要改变的良性疾病,其具体发病机制尚不清楚。目前多数研究者认为ADS是基底层内膜细胞增生、侵入到肌层间质的结果。在上皮-间质转化(EMT)过程中,上皮细胞失去细胞极性,细胞间紧密连接和黏附连接减弱,获得了浸润性和游走迁移能力,成为具有间质细胞功能和特性的细胞。EMT在肿瘤形成中赋予细胞迁移、浸润的能力,而ADS发生、发展过程中子宫内膜细胞侵入肌层的生物学行为与之非常相似。已有研究表明EMT在ADS形成中具有重要作用。目前ADS的临床治疗面临较多的挑战,因此阐明ADS的发生机制是寻求临床早期预防、治疗ADS有效方法的关键。  相似文献   
5.
6.
Newborn screening (NBS) for cystic fibrosis (CF) was implemented throughout France since 2002, with a 3-tiered strategy consisting in an immunoreactive trypsinogen (IRT) measurement at day-3, a search for the most common mutations responsible for CF when the IRT value is above the cut-off level, and, if necessary, a safetynet retesting of IRT at day-21. Coordination and follow-up are ensured at the national level and NBS is carried out through a regional organization involving NBS centers, biochemical and molecular genetics laboratories. Sweat testing and comprehensive mutation gene analysis are then performed according to a defined algorithm. Between 2002 and 2014, screening for the 30 most common mutations identified 87% of the alleles and comprehensive mutation gene analysis performed when applicable identified more than 300 additional mutations and resulted in a detection rate of 99.8% of the mutated alleles. Program surveillance ensured at a national level allowed to carry out adaptation of cut-off levels and removal of the p.Arg117His mutation. Thanks to these modifications, the performance of the French NBS program for CF meets the European guideline standards regarding positive predictive values, sensitivity and time to initial visit at the CF center, thus making the strategy effective.© 2020 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.  相似文献   
7.
8.

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.

Methods

Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.

Results

Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).

Conclusions

Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF.  相似文献   
9.
10.
Objective To investigate the roles of microRNA-382 (miR-382) in the pathogenesis of renal tubulointerstitial fibrosis (TIF). Methods Human kidney epithelial cells (HK2)transfected with miR-382 inhibitor (antagomiR-382) were used to examine the effect of miR-382 abundance on cell polarity, as well as to test the complementary relationship between miR-382 and its predicted target gene heat shock protein 60 (HSPD1), which was further verified by 3′-untranslated region luciferase assay and site-directed mutagenesis. The role of miR-382 played in the development of renal interstitial fibrosis and redox regulation was examined in a mouse unilateral ureteral obstruction (UUO) model. Locked nucleic acid (LAN)-modified anti-miR-382 was intravenous delivered via tail vein 30 min prior to UUO, and repeated the dosage 24 h after the surgery. For clinical verification, renal biopsy specimens from 12 IgA nephropathy (IgAN) patients were collected, 6 patients with moderate to severe TIF and 6 patients without TIF. The relative abundance of miR-382 and HSPD1 protein was analyzed by using in situ hybridization and immunohistochemistry. Results HSPD1 was confirmed to be a new, direct target gene of miR-382 by in vitro 3′-untranslated region luciferase assay and site-directed mutagenesis. The development of epithelial transition in HK2 cells was accompanied with up-regulation of miR-382 [(6.54±0.96) vs (1.12±0.26), P<0.05]. Blocking the expression of miR-382 could reversed the progression of epithelial transition partially. In UUO mice the abundance of miR-382 was up-regulated [(6.89±2.47) vs (1.00±0.42), P<0.01] while HSPD1 and Trx were down-regulated compared with the sham group. Down-regulation of miR-382 was associated with significant decrease in TIF, but increase in HSPD1 and thioredoxin protein compared with UUO group [HSPD1: (0.34±0.10) vs (0.14±0.05); Trx: (0.79±0.18) vs (0.36±0.16); all P<0.05]. The expression of miR-382 was up-regulated and HSPD1 was significantly down-regulated in IgAN patients with TIF. Conclusions miR-382 play an important role in renal tubulointerstitial fibrosis in human and mice. HSPD1 is one of the target genes of miR-382. The down-regulation of HSPD1 and the decrease ability of anti-oxidative stress may be the important mechanism of miR-382 involved in renal tubulointerstitial fibrosis.  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