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   2133篇
  免费   228篇
  国内免费   11篇
耳鼻咽喉   41篇
儿科学   51篇
妇产科学   129篇
基础医学   379篇
口腔科学   19篇
临床医学   252篇
内科学   568篇
皮肤病学   13篇
神经病学   87篇
特种医学   53篇
外科学   220篇
综合类   44篇
预防医学   129篇
眼科学   38篇
药学   166篇
中国医学   7篇
肿瘤学   176篇
  2023年   8篇
  2022年   19篇
  2021年   48篇
  2020年   32篇
  2019年   65篇
  2018年   60篇
  2017年   42篇
  2016年   54篇
  2015年   54篇
  2014年   75篇
  2013年   102篇
  2012年   136篇
  2011年   164篇
  2010年   122篇
  2009年   100篇
  2008年   118篇
  2007年   118篇
  2006年   111篇
  2005年   131篇
  2004年   118篇
  2003年   86篇
  2002年   99篇
  2001年   71篇
  2000年   70篇
  1999年   56篇
  1998年   15篇
  1997年   20篇
  1996年   9篇
  1995年   15篇
  1994年   9篇
  1993年   5篇
  1992年   31篇
  1991年   22篇
  1990年   25篇
  1989年   21篇
  1988年   15篇
  1987年   20篇
  1986年   21篇
  1985年   17篇
  1984年   13篇
  1983年   8篇
  1982年   5篇
  1981年   9篇
  1980年   6篇
  1979年   9篇
  1978年   7篇
  1976年   3篇
  1970年   2篇
  1967年   1篇
  1930年   1篇
排序方式: 共有2372条查询结果,搜索用时 15 毫秒
51.
This paper aims to evaluate the effect of splinting during implant impression. A master model with two fixtures at the sites of 45 and 47 was used. 20 impressions were made for all four techniques: (A) indirect; (B) direct, unsplinted; (C) direct, splinted; and (D) direct, splinted, sectioned, and re-splinted. Splinting was undertaken with autopolymerizing acrylic resin (AAR). Horizontal distance between fixtures was compared using a digital caliper. The difference in distance were analysed with one-way ANOVA. Group A showed a significantly lowest accuracy among all techniques (p < or = 0.05). There was no significant difference of accuracy among the groups using direct techniques (p > or = 0.05). Group D was more accurate compared to group B and C. We conclude that splinting of impression copings would be beneficial to obtain an accurate impression.  相似文献   
52.
53.
54.
55.
56.
Plasmapheresis not only removes circulating antibodies but also modulates cellular immunity, including lymphocyte subsets. To investigate the effect of double‐filtration plasmapheresis (DFPP) on the ratio of lymphocyte subsets in patients with myasthenia gravis (MG), we examined the percentages of B‐cells, T‐cells, T helper (Th) cells, T suppressor (Ts) cells, natural killer (NK) cells, NKT cells, and Th/Ts ratio before and after a single DFPP session and after a course of DFPP. A total of 26 patients were recruited; their peripheral blood lymphocyte subsets were assayed using flow cytometry. After a single session of DFPP treatment, the percentages of T‐cells (P = 0.0200), Th cells (P = 0.0178), and the Th/Ts ratio (P = 0.0309) decreased significantly, whereas the percentage of NK cells (P = 0.0007) increased significantly. More importantly, after one course of DFPP treatment, the reduced clinical quantitative MG (QMG) score was correlated with the decrease of the percentage of T‐cells (r = 0.5005, P = 0.0092). Fourteen thymectomized MG patients had decreased percentages of T‐cells (P = 0.0304) and Th cells (P = 0.0444), whereas they had increased NK cells (P = 0.0197) after a single DFPP session. Here, transiently decreased percentages of T‐cells after the full DFPP course could enhance the effectiveness of plasmapheresis for MG patients.  相似文献   
57.
Background.?Necrotizing fasciitis (NF) is a rapidly progressive, life-threatening soft-tissue infection that is traditionally caused by group A Streptococcus (GAS) or mixed aerobic/anaerobic bacteria. Monomicrobial Klebsiella pneumoniae NF (KP-NF) has been reported since 1996 but has not yet been systematically studied. Methods.?We retrospectively studied consecutive NF cases treated at a university hospital in Taiwan during 1997-2010 and investigated the clinical characteristics and outcomes associated with monomicrobial KP-NF, using monomicrobial GAS-NF as a reference. We also analyzed the virulence gene profiles of the isolated K. pneumoniae strains. Results.?Of 134 NF cases, 88 were monomicrobial, of which the most common pathogens were GAS (n?=?16) and K. pneumoniae (n?=?15). Monomicrobial KP-NF entailed a moderate risk of limb loss (20% vs 25%; P?=?1.000) and high mortality (47% vs 19%; P?=?.135), and it was more likely to involve bacteremia (80% vs 31%; P?=?.011), concomitant distant abscesses (27% vs 0%; P?=?.043), and underlying immunocompromising conditions (100% vs 63%; P?=?.018), compared with GAS-NF. The isolated K. pneumoniae strains (n?=?10) were of capsular polysaccharides genotype K1 (n?=?4), K54/K20/K5 (n?=?4), K2 (n?=?1), and K16 (n?=?1). All strains carried rmpA, iucABCDiutA, and iroA. Genotype K1 strains had a significantly higher risk of concomitant distant abscesses, compared with non-K1 strains (75% vs 0%; P?=?.033). Conclusions.?K. pneumoniae has become a common pathogen of monomicrobial NF in Taiwan. Physicians treating patients with monomicrobial KP-NF should be aware of the risk of concomitant distant abscesses, particularly in cases caused by genotype K1.  相似文献   
58.
59.
Heat shock proteins (HSPs), inflammatory cytokines, nitric oxide (NO), and localized hypoxia‐induced apoptosis are thought to be correlated to the degree of cartilage injury. We investigated the effect of hyperbaric oxygen (HBO) on (1) interleukin‐1β (IL‐1β)‐induced NO production and apoptosis of rabbit chondrocytes and (2) healing of articular cartilage defects. For the in vitro study, RT‐PCR and Western blotting were performed to detect mRNA and protein expressions of HSP70, inducible NO synthase (iNOS), and caspase 3 in IL‐1β‐treated chondrocytes. To clarify that the HSP70 was necessary for anti‐iNOS and anti‐apoptotic activity by HBO, we treated the cells with an HSP70 inhibitor, KNK437. For the in vivo study, cartilage defects were created in rabbits. The HBO group was exposed to 100% oxygen at 2.5 ATA for 1.5 h a day for 10 weeks. The control group was exposed to normal air. After sacrifice, specimen sections were sent for examination using a scoring system. Immunohistochemical analyses were performed to detect the expressions of iNOS, HSP70, and caspase 3. Our results suggested that HBO upregulated the mRNA and protein expressions of HSP70 and suppressed those of iNOS and caspase 3 in chondrocytes. KNK437 inhibited the HBO‐induced downregulation of iNOS and casapase 3 activities. The histological scores showed that HBO markedly enhanced cartilage repair. Immunohistostaining showed that HBO enhanced HSP70 expression and suppressed iNOS and caspase 3 expressions in chondrocytes. Accordingly, HBO treatment prevents NO‐induced apoptosis in articular cartilage injury via enhancement of the expression of heat shock protein 70. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 376–384, 2013  相似文献   
60.
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