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   29258篇
  免费   2028篇
  国内免费   203篇
耳鼻咽喉   247篇
儿科学   897篇
妇产科学   945篇
基础医学   4293篇
口腔科学   575篇
临床医学   2198篇
内科学   6264篇
皮肤病学   649篇
神经病学   3359篇
特种医学   906篇
外国民族医学   1篇
外科学   3384篇
综合类   195篇
一般理论   8篇
预防医学   1977篇
眼科学   430篇
药学   2076篇
中国医学   92篇
肿瘤学   2993篇
  2023年   246篇
  2022年   241篇
  2021年   1048篇
  2020年   594篇
  2019年   730篇
  2018年   966篇
  2017年   721篇
  2016年   794篇
  2015年   931篇
  2014年   1131篇
  2013年   1547篇
  2012年   2117篇
  2011年   2153篇
  2010年   1283篇
  2009年   1133篇
  2008年   1825篇
  2007年   1732篇
  2006年   1618篇
  2005年   1458篇
  2004年   1410篇
  2003年   1269篇
  2002年   1150篇
  2001年   600篇
  2000年   533篇
  1999年   517篇
  1998年   287篇
  1997年   206篇
  1996年   178篇
  1995年   173篇
  1994年   141篇
  1993年   115篇
  1992年   271篇
  1991年   250篇
  1990年   240篇
  1989年   242篇
  1988年   179篇
  1987年   152篇
  1986年   169篇
  1985年   137篇
  1984年   107篇
  1983年   90篇
  1982年   61篇
  1981年   54篇
  1979年   61篇
  1975年   40篇
  1974年   42篇
  1970年   39篇
  1969年   47篇
  1968年   50篇
  1967年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Background: Extracellular matrix molecular components, previously linked to multisystem syndromes include collagens, fibrillins and laminins. Recently, we described a novel multisystem syndrome caused by the c.9418G>A p.(V3140M) mutation in the laminin alpha-5 (LAMA5) gene, which affects connective tissues of all organs and apparatus in a three generation family. In the same family, we have also reported a myopic trait, which, however, was linked to the Prolyl 4-hydroxylase subunit alpha-2 (P4HA2) gene. Results of investigation on vitreous changes and their pathogenesis are reported in the present study.Materials and Methods: Nineteen family individuals underwent complete ophthalmic examination including best-corrected visual acuity (BCVA), fundus examination, fundus photography, intraocular pressure measurement, axial length measurement using ocular biometry, Goldmann visual field examination, standard electroretinogram, SD-OCT. Segregation analysis of LAMA5 and P4HA2 mutations was performed in enrolled members.Results: The vitreous alterations fully segregated with LAMA5 mutation in both young and adult family members. Slight reduction of retinal thickness and peripheral retinal degeneration in only two patients were reported.Conclusions: In this work we showed that PVD is a common trait of LAMA5 multisystem syndrome, therefore occurring as an age-unrelated trait. We hypothesize that the p.(V3140M) mutation results in a reduction of retinal inner limiting membrane (ILM) stability, leading to a derangement in the macromolecular structure of the vitreous gel, and PVD. Further investigations will be necessary to elucidate the role of wild type and mutated LAMA5 in the pathogenesis of PVD.  相似文献   
2.
Colorectal cancer (CRC) screening programs help diagnose cancer precursors and early cancers and help reduce CRC mortality. However, currently recommended tests, the fecal immunochemical test (FIT) and colonoscopy, have low uptake. There is therefore a pressing need for screening strategies that are minimally invasive and consequently more acceptable to patients, most likely blood based, to increase early CRC identification. MicroRNAs (miRNAs) released from cancer cells are detectable in plasma in a remarkably stable form, making them ideal cancer biomarkers. Using plasma samples from FIT-positive (FIT+) subjects in an Italian CRC screening program, we aimed to identify plasma circulating miRNAs that detect early CRC. miRNAs were initially investigated by quantitative real-time PCR in plasma from 60 FIT+ subjects undergoing colonoscopy at Fondazione IRCCS Istituto Nazionale dei Tumori, then tested on an internal validation cohort (IVC, 201 cases) and finally in a large multicenter prospective series (external validation cohort [EVC], 1121 cases). For each endoscopic lesion (low-grade adenoma [LgA], high-grade adenoma [HgA], cancer lesion [CL]), specific signatures were identified in the IVC and confirmed on the EVC. A two-miRNA-based signature for CL and six-miRNA signatures for LgA and HgA were selected. In a multivariate analysis including sex and age at blood collection, the areas under the receiver operating characteristic curve (95% confidence interval) of the signatures were 0.644 (0.607–0.682), 0.670 (0.626–0.714) and 0.682 (0.580–0.785) for LgA, HgA and CL, respectively. A miRNA-based test could be introduced into the FIT+ workflow of CRC screening programs so as to schedule colonoscopies only for subjects likely to benefit most.  相似文献   
3.
Archives of Gynecology and Obstetrics - The objective of this study was to determine if high-dose antibiotic prophylaxis with cefazolin decreases the risk of surgical site infection (SSI) after a...  相似文献   
4.
5.
6.
7.
8.
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