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   2046篇
  免费   153篇
  国内免费   11篇
耳鼻咽喉   28篇
儿科学   111篇
妇产科学   30篇
基础医学   234篇
口腔科学   12篇
临床医学   286篇
内科学   432篇
皮肤病学   25篇
神经病学   222篇
特种医学   37篇
外科学   187篇
综合类   14篇
一般理论   4篇
预防医学   142篇
眼科学   16篇
药学   152篇
中国医学   3篇
肿瘤学   275篇
  2023年   25篇
  2022年   14篇
  2021年   45篇
  2020年   48篇
  2019年   67篇
  2018年   78篇
  2017年   60篇
  2016年   63篇
  2015年   60篇
  2014年   82篇
  2013年   111篇
  2012年   187篇
  2011年   163篇
  2010年   98篇
  2009年   71篇
  2008年   121篇
  2007年   122篇
  2006年   121篇
  2005年   128篇
  2004年   130篇
  2003年   102篇
  2002年   88篇
  2001年   14篇
  2000年   14篇
  1999年   19篇
  1998年   16篇
  1997年   11篇
  1996年   11篇
  1995年   17篇
  1994年   11篇
  1993年   10篇
  1992年   9篇
  1991年   11篇
  1990年   7篇
  1989年   9篇
  1988年   6篇
  1987年   6篇
  1986年   11篇
  1985年   9篇
  1984年   3篇
  1983年   6篇
  1982年   5篇
  1981年   2篇
  1980年   2篇
  1978年   4篇
  1977年   5篇
  1973年   2篇
  1972年   1篇
  1966年   1篇
  1960年   1篇
排序方式: 共有2210条查询结果,搜索用时 15 毫秒
1.
BackgroundAt ketamine and esketamine doses at which antidepressant doses are achieved, these agents are relatively selective, noncompetitive, N-methyl-D-aspartate receptor antagonists. However, at substantially higher doses, ketamine has shown mu-opioid receptor (MOR–gene symbol: OPRM1) agonist effects. Preliminary clinical studies showed conflicting results on whether naltrexone, a MOR antagonist, blocks the antidepressant action of ketamine. We examined drug-induced or endogenous MOR involvement in the antidepressant and dissociative responses to esketamine by assessing the effects of a functional single nucleotide polymorphism rs1799971 (A118G) of OPRM1, which is known to alter MOR agonist-mediated responses.MethodsParticipants with treatment-resistant depression from 2 phase III, double-blind, controlled trials of esketamine (or placebo) nasal spray plus an oral antidepressant were genotyped for rs1799971. Participants received the experimental agents twice weekly for 4 weeks. Antidepressant responses were rated using the change in Montgomery–Åsberg Depression Rating Scale (MADRS) score on days 2 and 28 post-dose initiation, and dissociative side effects were assessed using the Clinician-Administered Dissociative-States Scale at 40 minutes post-dose on days 1 and 25.ResultsIn the esketamine + antidepressant arm, no significant genotype effect of single nucleotide polymorphism rs1799971 (A118G) on MADRS score reductions was detected on either day 2 or 28. By contrast, in the antidepressant + placebo arm, there was a significant genotype effect on MADRS score reductions on day 2 and a nonsignificant trend on day 28 towards an improvement in depression symptoms in G-allele carriers. No significant genotype effects on dissociative responses were detected.ConclusionsVariation in rs1799971 (A118G) did not affect the antidepressant response to esketamine + antidepressant. Antidepressant response to antidepressant + placebo was increased in G-allele carriers, compatible with previous reports that release of endorphins/enkephalins may play a role in mediating placebo effect.Trial RegistrationNCT02417064 and NCT02418585; www.clinicaltrials.gov  相似文献   
2.
3.
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   
4.
Thrombotic thrombocytopenic purpura (TTP) is a rare but life‐threatening microangiopathic hemolytic anemia characterized by thrombocytopenia, hemolytic anemia, and ischemic organ damage. It is mainly caused by an autoreactive antibody directed at ADAMTS13. Immunotherapy is frequently associated with autoimmune complications in patients with cancer, but only three cases of TTP have been reported, none implicating single treatment with the anti–programmed cell death receptor 1 ligand antibody nivolumab. We present the first identified and reported case of nivolumab‐associated TTP in a 51‐year‐old woman with stage IIIc anal carcinoma who achieved complete response following chemoradiation and received adjuvant nivolumab as part of a randomized clinical trial. Twelve weeks into treatment, she presented with dark urine, progressive fatigue, and headache. TTP diagnosis was based on laboratory evidence of hemolytic anemia, thrombocytopenia, and ADAMTS13 activity of 9% associated with an inhibitor. She was treated with daily plasma exchange and oral prednisone and responded well to treatment, with platelet counts over 100 K/cmm within 4 days. We reviewed and summarized data from all reported cases of TTP associated with cancer immunotherapy. We provide guidance on identification and management of this devastating hematologic complication, focusing on the importance of early recognition, as most patients achieve complete recovery with appropriate treatment.Key Points
  • Thrombotic thrombocytopenic purpura (TTP) was originally excluded from previous reviews of hematologic immune‐related adverse events; however, several cases have been reported in the past 2 years in patients treated with either single agent or combination of cytotoxic T‐lymphocyte–associated antigen 4 and the programmed cell death receptor 1 (PD‐1) or the PD‐1 ligand inhibitors.
  • Although rare, TTP is a life‐threatening condition that could be challenging to diagnose, and early recognition is key as delayed treatment is associated with significant increase in mortality.
  • The pathophysiology of immunotherapy‐induced TTP is likely related to autoimmune inhibition of ADAMTS13; the addition of prednisone and rituximab to urgent plasmapheresis appears to be effective and should be part of the up‐front management for these patients.
  相似文献   
5.
European Child & Adolescent Psychiatry - The objective of this study was to investigate the stability and predictive utility of autistic traits (ATs) in youth with...  相似文献   
6.
7.
Journal of Neurology - Progressive supranuclear palsy (PSP) is characterized by deposition of straight filament tau aggregates in the grey matter (GM) of deep nuclei and cerebellum. We examined the...  相似文献   
8.
9.
Clinical Rheumatology - The publisher regrets that the two sections under the Results omitted inadvertently on the original published version of the above article.  相似文献   
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