全文获取类型
收费全文 | 3231926篇 |
免费 | 253781篇 |
国内免费 | 30960篇 |
专业分类
耳鼻咽喉 | 41527篇 |
儿科学 | 99624篇 |
妇产科学 | 83868篇 |
基础医学 | 446322篇 |
口腔科学 | 91299篇 |
临床医学 | 309610篇 |
内科学 | 603124篇 |
皮肤病学 | 67418篇 |
神经病学 | 244979篇 |
特种医学 | 124977篇 |
外国民族医学 | 922篇 |
外科学 | 467285篇 |
综合类 | 138914篇 |
现状与发展 | 92篇 |
一般理论 | 1037篇 |
预防医学 | 246380篇 |
眼科学 | 78301篇 |
药学 | 253400篇 |
440篇 | |
中国医学 | 30530篇 |
肿瘤学 | 186618篇 |
出版年
2021年 | 37951篇 |
2020年 | 26732篇 |
2019年 | 32261篇 |
2018年 | 41819篇 |
2017年 | 34574篇 |
2016年 | 35974篇 |
2015年 | 45638篇 |
2014年 | 61012篇 |
2013年 | 79257篇 |
2012年 | 110616篇 |
2011年 | 118560篇 |
2010年 | 72944篇 |
2009年 | 65924篇 |
2008年 | 103159篇 |
2007年 | 107938篇 |
2006年 | 107887篇 |
2005年 | 103872篇 |
2004年 | 95373篇 |
2003年 | 91194篇 |
2002年 | 86751篇 |
2001年 | 147971篇 |
2000年 | 151809篇 |
1999年 | 128501篇 |
1998年 | 37733篇 |
1997年 | 34005篇 |
1996年 | 32907篇 |
1995年 | 31686篇 |
1994年 | 29185篇 |
1993年 | 26269篇 |
1992年 | 97999篇 |
1991年 | 95037篇 |
1990年 | 91936篇 |
1989年 | 88512篇 |
1988年 | 81407篇 |
1987年 | 79751篇 |
1986年 | 75625篇 |
1985年 | 72393篇 |
1984年 | 53526篇 |
1983年 | 45932篇 |
1982年 | 26434篇 |
1979年 | 49456篇 |
1978年 | 34095篇 |
1977年 | 28978篇 |
1976年 | 27183篇 |
1975年 | 28772篇 |
1974年 | 35102篇 |
1973年 | 33739篇 |
1972年 | 31165篇 |
1971年 | 29234篇 |
1970年 | 27027篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Deitelzweig Steve Luo Xuemei Nguyen Jennifer L. Malhotra Deepa Emir Birol Russ Cristina Li Xiaoyan Lee Theodore C. Ferri Mauricio Wiederkehr Danny Reimbaeva Maya Barnes Geoffrey D. Piazza Gregory 《Journal of thrombosis and thrombolysis》2022,54(4):696-696
Journal of Thrombosis and Thrombolysis - 相似文献
22.
Cyclin-Dependent Kinase 4 and 6 Inhibitors as Breast Cancer Therapy: Research Progress and Prospects
Pharmaceutical Chemistry Journal - Cyclin-dependent kinases 4 and 6 (CDK4/6) are the core part of the cell cycle control machinery, which bind to cyclin D to regulate cell G1-S cycle conversion.... 相似文献
23.
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
24.
25.
26.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion. 相似文献
27.
Weina Cheng Yazhi Wang Jingxian Liu Xiaofei Li Ming Yu Cancan Duan Liu Liu Jianyong Zhang 《Journal of applied toxicology : JAT》2022,42(6):970-980
Cantharidin (CTD) is an effective antitumor agent. However, it exhibits significant hepatotoxicity, the mechanism of which remains unclear. In this study, biochemical and histopathological analyses complemented with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS)-based targeted metabolomic analysis of bile acids (BAs) were employed to investigate CTD-induced hepatotoxicity in rats. Sixteen male and female Sprague–Dawley rats were randomly divided into two groups: control and CTD (1.0 mg/kg) groups. Serum and liver samples were collected after 28 days of intervention. Biochemical, histopathological, and BA metabolomic analyses were performed for all samples. Further, the key biomarkers of CTD-induced hepatotoxicity were identified via multivariate and metabolic pathway analyses. In addition, metabolite–gene–enzyme network and Kyoto Encyclopedia of Genes and Genomes pathway analyses were used to identify the signaling pathways related to CTD-induced hepatotoxicity. The results revealed significantly increased levels of biochemical indices (alanine aminotransferase, aspartate aminotransferase, and total bile acid). Histopathological analysis revealed that the hepatocytes were damaged. Further, 20 endogenous BAs were quantitated via UHPLC-MS/MS, and multivariate and metabolic pathway analyses of BAs revealed that hyocholic acid, cholic acid, and chenodeoxycholic acid were the key biomarkers of CTD-induced hepatotoxicity. Meanwhile, primary and secondary BA biosynthesis and taurine and hypotaurine metabolism were found to be associated with the mechanism by which CTD induced hepatotoxicity in rats. This study provides useful insights for research on the mechanism of CTD-induced hepatotoxicity. 相似文献
28.
Feng Song Li Ruipiao Wang Zhiying 《Odontology / the Society of the Nippon Dental University》2022,110(3):508-522
Odontology - To investigate the characterization and function of a novel porous osteogenic material (PLLA / DDM) containing polylactic acid and demineralized dentin matrix. The surface morphology... 相似文献
29.
30.
Clinical & Experimental Metastasis - 相似文献