全文获取类型
收费全文 | 39778篇 |
免费 | 2648篇 |
国内免费 | 425篇 |
专业分类
耳鼻咽喉 | 456篇 |
儿科学 | 1872篇 |
妇产科学 | 772篇 |
基础医学 | 4493篇 |
口腔科学 | 849篇 |
临床医学 | 3080篇 |
内科学 | 8118篇 |
皮肤病学 | 1020篇 |
神经病学 | 2464篇 |
特种医学 | 1268篇 |
外国民族医学 | 2篇 |
外科学 | 4984篇 |
综合类 | 1979篇 |
现状与发展 | 2篇 |
一般理论 | 20篇 |
预防医学 | 2298篇 |
眼科学 | 1794篇 |
药学 | 4004篇 |
9篇 | |
中国医学 | 721篇 |
肿瘤学 | 2646篇 |
出版年
2023年 | 362篇 |
2022年 | 877篇 |
2021年 | 1580篇 |
2020年 | 872篇 |
2019年 | 1052篇 |
2018年 | 1259篇 |
2017年 | 963篇 |
2016年 | 1062篇 |
2015年 | 1144篇 |
2014年 | 1672篇 |
2013年 | 2028篇 |
2012年 | 2797篇 |
2011年 | 2894篇 |
2010年 | 1698篇 |
2009年 | 1365篇 |
2008年 | 1999篇 |
2007年 | 2027篇 |
2006年 | 1928篇 |
2005年 | 1719篇 |
2004年 | 1531篇 |
2003年 | 1365篇 |
2002年 | 1223篇 |
2001年 | 975篇 |
2000年 | 962篇 |
1999年 | 758篇 |
1998年 | 345篇 |
1997年 | 246篇 |
1996年 | 222篇 |
1995年 | 225篇 |
1994年 | 165篇 |
1993年 | 152篇 |
1992年 | 456篇 |
1991年 | 494篇 |
1990年 | 440篇 |
1989年 | 408篇 |
1988年 | 359篇 |
1987年 | 326篇 |
1986年 | 283篇 |
1985年 | 295篇 |
1984年 | 220篇 |
1983年 | 176篇 |
1982年 | 104篇 |
1981年 | 113篇 |
1979年 | 194篇 |
1978年 | 132篇 |
1977年 | 107篇 |
1975年 | 102篇 |
1974年 | 125篇 |
1973年 | 132篇 |
1972年 | 137篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Qiangsheng He Chongfei Huang Xiwen Qin Yuanyuan Yu Di Tang Junjie Huang Zi Chong Kuo Yuyao Ling Deli Mao Bin Xia Wenjing Li Kuiqing Lu Man Yang Yulong He Wenbo Meng Jinqiu Yuan Yihang Pan 《International journal of cancer. Journal international du cancer》2023,153(5):942-949
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes. 相似文献
4.
5.
Wai Man Mandy Chan Yik Weng Yew Thiam Seng Colin Theng Choon Fong Liew Hazel H Oon 《Singapore medical journal》2020,61(4):194
INTRODUCTIONPsoriasis is a chronic inflammatory condition that affects the skin and joints, and is associated with cardiovascular risk factors, including metabolic syndrome (MetS). We aimed to assess the prevalence of MetS in patients with psoriasis and determine whether there was a correlation between psoriasis severity and MetS in a Singapore population.METHODSThis was a cross-sectional study of patients with psoriasis, aged 18–69 years, who attended a tertiary dermatology referral centre in Singapore from October 2007 to February 2009. Fasting glucose, lipids, blood pressure, Psoriasis Area and Severity Index, and body mass index were measured. MetS was diagnosed in the presence of three or more criteria of the modified National Cholesterol Education Program Adult Treatment Panel III.RESULTSAmong 338 patients with psoriasis, there were 238 (70.4%) men and 100 (29.6%) women, who were Chinese (n = 228; 67.5%), Malay (n = 52; 15.4%) and Indian (n = 58; 17.2%). The prevalence of MetS was 45.1%. MetS was 44% more prevalent in patients older than 50 years (p = 0.02). Malay patients with psoriasis were significantly more likely to have hypertriglyceridaemia, elevated fasting plasma glucose and abdominal obesity. There was no significant correlation between psoriasis severity and risk of MetS.CONCLUSIONThe prevalence of MetS in patients with psoriasis in Singapore was 45.1%, or nearly threefold higher than the Singapore general population. Patients with psoriasis should be screened yearly for MetS and any modifiable cardiovascular risk factors should be actively controlled. 相似文献
6.
目的研究和开发支持中医和现代生物医学本体和术语集的语义标注系统。方法以MedPortal本体库和中医临床术语集等为术语资源库,设计语义标注系统工作流程和功能框架,并开发Web应用系统。结果构建了一个基于Web的中医药文献语义标注系统,支持语料库管理与维护、术语词典管理、语义标注和语义检索等功能,既可以为基于机器学习的信息抽取算法研究提供训练集,又能实现语义层面的多来源数据集成与知识融合。结论该中医药文献语义标注系统设计方案已经过实际项目验证,可为其他同类系统研发提供参考。 相似文献
7.
8.
Vinke Jeroen Kaper Hans J. Vissink Arjan Sharma Prashant K. 《Clinical oral investigations》2020,24(11):4019-4030
Clinical Oral Investigations - The aims of this study are to assess different saliva substitutes for their efficacy to lubricate the oral cavity, and to relate this oral lubrication to the ability... 相似文献
9.
PNPLA3 gene polymorphism and response to lifestyle modification in patients with nonalcoholic fatty liver disease 下载免费PDF全文
10.
Tien‐Yao Tsai Iat‐Lon Leong Ka‐Shun Cheng Lian‐Ru Shiao Tzu‐Hui Su Kar‐Lok Wong Paul Chan Yuk‐Man Leung 《Fundamental & clinical pharmacology》2019,33(1):52-62
A pathological feature in atherosclerosis is the dysfunction and death of vascular endothelial cells (EC). Oxidized low‐density lipoprotein (LDL), known to accumulate in the atherosclerotic arterial walls, impairs endothelium‐dependent relaxation and causes EC apoptosis. A major bioactive ingredient of the oxidized LDL is lysophosphatidylcholine (LPC), which at higher concentrations causes apoptosis and necrosis in various EC. There is hitherto no report on LPC‐induced cytotoxicity in brain EC. In this work, we found that LPC caused cytosolic Ca2+ overload, mitochondrial membrane potential decrease, p38 activation, caspase 3 activation and eventually apoptotic death in mouse cerebral bEND.3 EC. In contrast to reported reactive oxygen species (ROS) generation by LPC in other EC, LPC did not trigger ROS formation in bEND.3 cells. Pharmacological inhibition of p38 alleviated LPC‐inflicted cell death. We examined whether heparin could be cytoprotective: although it could not suppress LPC‐triggered Ca2+ signal, p38 activation and mitochondrial membrane potential drop, it did suppress LPC‐induced caspase 3 activation and alleviate LPC‐inflicted cytotoxicity. Our data suggest LPC apoptotic death mechanisms in bEND.3 might involve mitochondrial membrane potential decrease and p38 activation. Heparin is protective against LPC cytotoxicity and might intervene steps between mitochondrial membrane potential drop/p38 activation and caspase 3 activation. 相似文献