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   90030篇
  免费   8184篇
  国内免费   5473篇
耳鼻咽喉   1002篇
儿科学   1116篇
妇产科学   1128篇
基础医学   10614篇
口腔科学   1730篇
临床医学   11042篇
内科学   13514篇
皮肤病学   1401篇
神经病学   4681篇
特种医学   2918篇
外国民族医学   53篇
外科学   9893篇
综合类   14573篇
现状与发展   23篇
一般理论   33篇
预防医学   6225篇
眼科学   2792篇
药学   8830篇
  81篇
中国医学   4536篇
肿瘤学   7502篇
  2024年   243篇
  2023年   1218篇
  2022年   2788篇
  2021年   4458篇
  2020年   3304篇
  2019年   2829篇
  2018年   3095篇
  2017年   2733篇
  2016年   2597篇
  2015年   4019篇
  2014年   4888篇
  2013年   4407篇
  2012年   6513篇
  2011年   7030篇
  2010年   4589篇
  2009年   3755篇
  2008年   4799篇
  2007年   4826篇
  2006年   4781篇
  2005年   4667篇
  2004年   3435篇
  2003年   3101篇
  2002年   2602篇
  2001年   2218篇
  2000年   2122篇
  1999年   2113篇
  1998年   1329篇
  1997年   1211篇
  1996年   904篇
  1995年   946篇
  1994年   785篇
  1993年   492篇
  1992年   666篇
  1991年   617篇
  1990年   559篇
  1989年   495篇
  1988年   419篇
  1987年   391篇
  1986年   330篇
  1985年   262篇
  1984年   168篇
  1983年   108篇
  1982年   71篇
  1981年   80篇
  1979年   95篇
  1978年   51篇
  1977年   53篇
  1974年   65篇
  1973年   60篇
  1972年   63篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
Major ursodeoxycholic acid (UDCA)-based therapies for primary biliary cirrhosis (PBC) include UDCA only, or combined with either methotrexate (MTX), corticosteroids (COT), colchicine (COC), or bezafibrate (BEF). As the optimum treatment regimen is unclear and warrants exploration, we aimed to compare these therapies in terms of patient mortality or liver transplantation (MOLT) and adverse events (AE).PubMed, the Cochrane Library, and Scopus were searched for randomized controlled trials up to August 31, 2014. We estimated the hazard ratios (HRs) for MOLT and odds ratios (ORs) for AE. A sensitivity analysis based on the dose of UDCA was also executed.Thirty-one eligible articles were included. Compared with COT plus UDCA, UDCA (HR 0.38, 95% confidence interval [CI] 0.09–1.39), BEF plus UDCA (HR 0.29, 95% CI 0.02–4.83), COC plus UDCA (HR 0.39, 95% CI 0.07–2.25), MTX plus UDCA (HR 0.28, 95% CI 0.05–1.63), or OBS (HR 0.49, 95% CI 0.11–2.01) all provided an increased risk of MOLT. With respect to drug AE profile, although not differing appreciably, BEF plus UDCA was associated with more AEs compared with UDCA (OR 3.16, 95% CI 0.59–20.67), COT plus UDCA (OR 2.27, 95% CI 0.15–33.36), COC plus UDCA (OR 1.00, 95% CI 0.09–12.16), MTX plus UDCA (OR 2.03, 95% CI 0.23–17.82), or OBS (OR 3.00, 95% CI 0.53–20.75). The results of sensitivity analyses were highly consistent with previous analyses.COT plus UDCA was the optimal UDCA-based regimen for both MOLT and AEs. BEF plus UDCA was most likely to cause AEs, whereas monotherapy with UDCA and coadministriation of COT plus UDCA appeared to be associated with the fewest AEs for PBC treatment.  相似文献   
24.
25.
Lessons Learned
  • The combination of trametinib and sorafenib has an acceptable safety profile, albeit at doses lower than approved for monotherapy.
  • Maximum tolerated dose is trametinib 1.5 mg daily and sorafenib 200 mg twice daily.
  • The limited anticancer activity observed in this unselected patient population does not support further exploration of trametinib plus sorafenib in patients with hepatocellular carcinoma.
BackgroundThe RAS/RAF/MEK/ERK signaling pathway is associated with proliferation and progression of hepatocellular carcinoma (HCC). Preclinical data suggest that paradoxical activation of the MAPK pathway may be one of the resistance mechanisms of sorafenib; therefore, we evaluated trametinib plus sorafenib in HCC.MethodsThis was a phase I study with a 3+3 design in patients with treatment‐naïve advanced HCC. The primary objective was safety and tolerability. The secondary objective was clinical efficacy.ResultsA total of 17 patients were treated with three different doses of trametinib and sorafenib. Two patients experienced dose‐limiting toxicity, including grade 4 hypertension and grade 3 elevation of aspartate aminotransferase (AST)/alanine aminotransferase (ALT)/bilirubin over 7 days. Maximum tolerated dose was trametinib 1.5 mg daily and sorafenib 200 mg twice a day. The most common grade 3/4 treatment‐related adverse events were elevated AST (37%) and hypertension (24%). Among 11 evaluable patients, 7 (63.6%) had stable disease with no objective response. The median progression‐free survival (PFS) and overall survival (OS) were 3.7 and 7.8 months, respectively. Phosphorylated‐ERK was evaluated as a pharmacodynamic marker, and sorafenib plus trametinib inhibited phosphorylated‐ERK up to 98.1% (median: 81.2%) in peripheral blood mononuclear cells.ConclusionTrametinib and sorafenib can be safely administered up to trametinib 1.5 mg daily and sorafenib 200 mg twice a day with limited anticancer activity in advanced HCC.  相似文献   
26.
27.
目的 通过对公开发表在网络和数据库的有关中医药治疗2019新型冠状病毒肺炎(corona virus disease 2019,COVID-19)的文献进行方、药、证的可视化分析,客观全面的对COVID-19的中医药治疗进行探讨,为现代中医临床诊疗提供参考。方法 本文选用运用文献计量学方法和VOSviewer可视化软件对纳入文献中的用药情况进行数据拆分、整理和分析。结果 本研究高质量数据的主要期刊来源是核心期刊《中医杂志》;新冠临床用方以解表清热剂、开窍补益剂、辟秽祛湿剂为主;临床用药以解表药、清热解毒药、化湿祛痰药以及补益药为主;临床治病思路以六经辨证、三焦辨证和卫气营血辨证理论为指导;临床常见证型为湿、热、寒、毒相关证型;重视新冠前期预防以及后期恢复调养;治疗过程用药考究,注重养阴与祛邪并进。结论 新冠的中医临床诊治考病全面,并注重养阴与祛邪并进,可为官方制定治疗方案提供参考。  相似文献   
28.
目的:探讨miR-26b参与原发性肝细胞肝癌(HCC)侵袭的机制。方法:在细胞培养液中培养人肝细胞系HL-7702和HCC细胞各系Hepb-3、HuH-7、MHCC97-L、MHCC97-H。实时荧光定量PCR法(qRT-PCR)检测miR-26b的表达水平;用miR-26b mimics、miR-26b inhibitors和Notch1-siRNA分别转染HCC细胞;MTT实验检测转染后HCC细胞的活力;采用Western blot检测Notch1受体蛋白表达水平的变化;Transwell小室测定不同处理后的HCC细胞的侵袭能力。结果:人正常肝细胞系HL-7702和HCC细胞系Hepb-3、HuH-7、MHCC97-L、MHCC97-H中的miR-26b相对表达含量随其侵袭和迁移能力的升高而依次下降;抑制miR-26b的表达,Notch1受体蛋白表达明显增高,而此时HCC细胞的侵袭性显著增强;相反,上调miR-26b的表达,Notch1受体蛋白表达明显降低,而HCC细胞侵袭性显著下降;miR-26b可能通过调控Notch1信号通路调节HCC细胞侵袭性。结论:miR-26b通过负调控Notch1信号通路抑制HCC细胞侵袭能力,为HCC侵袭的机制奠定了理论基础,miR-26b可能成为HCC治疗的新靶点。  相似文献   
29.
Programmed death ligand 1(PD-L1) mediated immune escape play important roles in the development of cancer. The gene polymorphism of PD-L1, in particular rs4143815 C?>?G, has been associated with the cancer risks, but with conflicting results. Therefore, this meta-analysis was aimed to assess the association between rs4143815 C?>?G and cancer susceptibility. A systematic literature search was performed to select the studies and the pooled odds ratio (OR) with 95% confidence interval (CI) was used to evaluate the strength of association. Eleven eligible studies containing 3711 cases and 3704 controls were enrolled in the meta-analysis. The results suggested that there is a strong association between rs4143815 C?>?G and the cancer risks (G vs. C: OR?=?1.386, 95% CI: 1.132–1.696, p?=?0.002; GG vs. CG?+?CC: OR?=?1.843 95% CI: 1.300–2.613, p?=?0.002; GG?+?CG vs. CC: OR?=?1.280, 95% CI: 1.040–1.576, p?=?0.020). Subgroup analysis based on cancer type suggested that PD-L1 rs4143815 C?>?G might increase the susceptibility to gastric cancer (G vs. C: OR?=?1.842, 95% CI: 1.403–2.418, p?<?0.001) and bladder cancer (G vs. C: OR?=?2.015, 95% CI: 1.556–2.608, p?<?0.001), and genotype GG carriers of PD-L1 rs4143815 C?>?G might have higher risks of HCC (GG vs. CG?+?CC: OR?=?2.226 95% CI: 1.562–3.172, p?<?0.001). PD-L1 rs4143815 C?>?G might confer an increased cancer risk, indicating this SNP may contribute to the pathogenesis of cancer and might be used as a potential biomarker to predict the susceptibility to cancer.  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