全文获取类型
收费全文 | 37961篇 |
免费 | 2792篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 393篇 |
儿科学 | 1008篇 |
妇产科学 | 1035篇 |
基础医学 | 5111篇 |
口腔科学 | 947篇 |
临床医学 | 4705篇 |
内科学 | 7504篇 |
皮肤病学 | 694篇 |
神经病学 | 3379篇 |
特种医学 | 1540篇 |
外国民族医学 | 5篇 |
外科学 | 5157篇 |
综合类 | 190篇 |
一般理论 | 22篇 |
预防医学 | 3072篇 |
眼科学 | 705篇 |
药学 | 2663篇 |
中国医学 | 60篇 |
肿瘤学 | 2597篇 |
出版年
2023年 | 450篇 |
2022年 | 141篇 |
2021年 | 489篇 |
2020年 | 557篇 |
2019年 | 613篇 |
2018年 | 1276篇 |
2017年 | 1193篇 |
2016年 | 1205篇 |
2015年 | 994篇 |
2014年 | 1088篇 |
2013年 | 1878篇 |
2012年 | 2588篇 |
2011年 | 2695篇 |
2010年 | 1264篇 |
2009年 | 817篇 |
2008年 | 2267篇 |
2007年 | 2298篇 |
2006年 | 2143篇 |
2005年 | 1977篇 |
2004年 | 1830篇 |
2003年 | 1710篇 |
2002年 | 1732篇 |
2001年 | 1154篇 |
2000年 | 1319篇 |
1999年 | 843篇 |
1998年 | 256篇 |
1997年 | 237篇 |
1996年 | 202篇 |
1995年 | 202篇 |
1994年 | 184篇 |
1993年 | 158篇 |
1992年 | 270篇 |
1991年 | 262篇 |
1990年 | 261篇 |
1989年 | 247篇 |
1988年 | 261篇 |
1987年 | 251篇 |
1986年 | 237篇 |
1985年 | 286篇 |
1984年 | 249篇 |
1983年 | 207篇 |
1982年 | 163篇 |
1981年 | 135篇 |
1980年 | 110篇 |
1979年 | 213篇 |
1978年 | 126篇 |
1977年 | 132篇 |
1975年 | 93篇 |
1974年 | 91篇 |
1973年 | 98篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
981.
982.
Johnson E Førland DT Hetland G Sætre L Olstad OK Lyberg T 《Scandinavian journal of gastroenterology》2012,(47):984-992
Abstract Background. Oral intake (60 ml daily) over 12 days in eight healthy volunteers of an immunostimulatory extract based on the medicinal mushroom Agaricus blazei Murill (AbM (AndoSan(?))), reduced the monocyte and granulocyte release of mainly proinflammatory cytokines in vivo, suggesting an anti-inflammatory effect. In this foremost in vivo study, the aim was to examine the effect of such AndoSan(?) consumption on the expression of adhesion molecules CD11b, CD11c and CD62L and production of reactive oxygen species (ROS) in leukocytes. Methodology/Principal findings. As shown by flow cytometry, there was a significant increase of CD62L expression on monocytes and granulocytes from before (day 0) compared with 12 days after daily AndoSan(?) consumption. However, only minor alterations and no clear trend in the expression of CD11b and CD11c were detected. Intracellular ROS (mainly superoxide ion) were significantly reduced in these cells from days 0 to 12. Conclusions/Significance. These results support that oral intake of AndoSan(?) exhibits an anti-inflammatory effect in humans in vivo. 相似文献
983.
Jørgensen KK Lindström L Cvancarova M Castedal M Friman S Schrumpf E Foss A Isoniemi H Nordin A Holte K Rasmussen A Bergquist A Vatn MH Boberg KM 《Scandinavian journal of gastroenterology》2012,(47):1021-1029
Abstract Objective. Several studies have implicated primary sclerosing cholangitis (PSC) as an additional risk factor for colorectal neoplasia in inflammatory bowel disease (IBD). Some reports have indicated that the risk is even higher in PSC-IBD patients after liver transplantation (Ltx), but this issue is controversial. We aimed to compare the risk of colorectal neoplasia in PSC-IBD patients before and after Ltx and to identify risk factors for colorectal neoplasia post-transplant. Material and methods. In a multicenter study within the Nordic Liver Transplant Group, we assessed the risk of colorectal neoplasia by using the competing risk regression analysis. Results. Among the 439 PSC patients included, 353 (80%) had IBD at the time of Ltx and 15 (3%) patients developed de novo IBD post-Ltx. The median duration of IBD was 15 (0-50) years at the time of Ltx and follow-up after Ltx was 5 (0-20) years. Ninety-one (25%) PSC-IBD patients developed colorectal neoplasia. The cumulative risk of colorectal neoplasia was higher after than before Ltx (HR: 1.9, 95% CI: 1.3-2.9, p = 0.002). A multivariate analysis demonstrated aminosalicylates and ursodeoxycholic acid as significantly associated with an increased risk of colorectal neoplasia post-Ltx. Duration and activity of IBD did not significantly affect the risk of neoplasia. Conclusion. The even higher risk of colorectal neoplasia in PSC-IBD patients after when compared with that of before Ltx underscores the importance of regular surveillance colonoscopies post-Ltx. The association of aminosalicylates and ursodeoxycholic acid to the development of colorectal neoplasia after Ltx should be further investigated. 相似文献
984.
985.
986.
Bang CN Greve AM Boman K Egstrup K Gohlke-Baerwolf C Køber L Nienaber CA Ray S Rossebø AB Wachtell K 《American heart journal》2012,163(4):690-696
987.
Abstract. We assessed potential effects of local meteorological and environmental conditions, indoor residual spraying with insecticides, insecticide-treated nets (ITNs) use at individual and community levels, and individual factors on Plasmodium falciparum malaria incidence in a village in south Ethiopia. A cohort of 8,121 people was followed for 101 weeks with active and passive surveillance. Among 317 microscopically confirmed P. falciparum malaria episodes, 29.3% occurred among temporary residents. The incidence density was 3.6/10,000 person-weeks of observation. We observed higher malaria incidence among males, children 5-14 years of age, ITNs non-users, the poor, and people who lived closer to vector breeding places. Rainfall increased and indoor residual spraying with Deltamethrin reduced falciparum incidence. Although ITNs prevented falciparum malaria for the users, we did not find that free mass ITNs distribution reduced falciparum malaria on a village level. 相似文献
988.
989.
Collet TH Gussekloo J Bauer DC den Elzen WP Cappola AR Balmer P Iervasi G Åsvold BO Sgarbi JA Völzke H Gencer B Maciel RM Molinaro S Bremner A Luben RN Maisonneuve P Cornuz J Newman AB Khaw KT Westendorp RG Franklyn JA Vittinghoff E Walsh JP Rodondi N;Thyroid Studies Collaboration 《Archives of internal medicine》2012,172(10):799-809
990.
Objectives: The concept of platform switching has been introduced to implant therapy, however long‐term data are sparse. The aim of this study was to biochemically investigate the inflammatory response mediated by MMP‐8 to platform switching after 3 years of loading, in order to understand the long‐term effect of implant/abutment mismatching on peri‐implant health. Methods: A total of 70 implants had been inserted in the posterior maxilla in 26 patients and were randomly assigned to one of the four treatment regimens (implant diameter 3.8 [control group], 4.3 [Test group 1, T1], 4.8 [Test group 2, T2] and 5.5 mm [Test group 3, T3]). All implants were restored using a 3.8 mm abutment. In the test groups, this restoration resulted in a mismatching of 0.25–0.85 mm of implant–abutment diameters. Results: Thirty‐six months after prosthetic rehabilitation, peri‐implant sulcular fluid samples were taken from two aspects of all implants and from periodontally healthy adjacent teeth. Samples were processed in a conventional ELISA using monoclonal antibodies recognizing the active entity of MMP‐8. In the test groups, MMP‐8 mean values were 2.76 ng for T1 (SD: 2.91), 3.30 ng for T2 (SD: 1.94) and 3.18 ng for T3 (SD: 2.46). For the control group, MMP‐8 mean value was 3.6 ng (SD: 2.23), whereas 3.38 ng (SD: 2.2) was recorded at the adjacent teeth. There were no statistically significant differences in MMP‐8 values between the groups (P=0.113, Kruskal–Wallis). Conclusions: The presence of an implant/abutment mismatching specific for this prosthetic concept is compatible with long‐term peri‐implant health as demonstrated by analysis of a sensitive biomarker of the peri‐implant inflammatory response. 相似文献