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   1674513篇
  免费   138384篇
  国内免费   3271篇
耳鼻咽喉   22500篇
儿科学   55248篇
妇产科学   48104篇
基础医学   237828篇
口腔科学   48903篇
临床医学   147099篇
内科学   330837篇
皮肤病学   35753篇
神经病学   137103篇
特种医学   67562篇
外国民族医学   492篇
外科学   254458篇
综合类   41237篇
现状与发展   3篇
一般理论   589篇
预防医学   127308篇
眼科学   37661篇
药学   127359篇
  4篇
中国医学   3426篇
肿瘤学   92694篇
  2018年   16425篇
  2016年   14281篇
  2015年   16658篇
  2014年   22746篇
  2013年   34446篇
  2012年   46594篇
  2011年   49016篇
  2010年   29094篇
  2009年   27746篇
  2008年   46725篇
  2007年   49146篇
  2006年   49732篇
  2005年   48165篇
  2004年   47819篇
  2003年   45843篇
  2002年   44971篇
  2001年   78352篇
  2000年   80834篇
  1999年   68452篇
  1998年   18608篇
  1997年   17018篇
  1996年   16927篇
  1995年   16596篇
  1994年   15594篇
  1993年   14725篇
  1992年   56624篇
  1991年   54989篇
  1990年   53602篇
  1989年   51883篇
  1988年   48109篇
  1987年   47390篇
  1986年   45128篇
  1985年   43598篇
  1984年   32597篇
  1983年   28080篇
  1982年   16499篇
  1981年   14731篇
  1980年   13834篇
  1979年   30886篇
  1978年   21386篇
  1977年   18059篇
  1976年   16971篇
  1975年   17908篇
  1974年   21861篇
  1973年   21035篇
  1972年   19175篇
  1971年   18061篇
  1970年   16569篇
  1969年   15528篇
  1968年   14211篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Background Immune checkpoint blockers (ICBs) activate CD8+ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.Methods Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab—sICB) or combination (nivolumab and ipilimumab—cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8+ T cells was sequenced and differential gene expression according to irAE development assessed.Results 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9–33.4) versus not-reached (P = 2.8 × 10−6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8+ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.Conclusions Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.Subject terms: Immunotherapy, Melanoma  相似文献   
82.
83.
84.
85.
86.
87.
88.
89.
The aim of the present study was to evaluate the antimicrobial activity of two synbiotic combinations, Lactobacillus fermentum with short-chain fructooligosaccharides (FOS-LF) and Bifidobacterium longum with isomaltooligosaccharides (IMO-BL), against enterohaemorrhagic Escherichia coli O157:H7 and enteropathogenic E. coli O86. Antimicrobial activity was determined (1) by co-culturing the synbiotics and pathogens in batch cultures, and (2) with the three-stage continuous culture system (gut model), inoculated with faecal slurry from an elderly donor. In the co-culture experiments, IMO-BL was significantly inhibitory to both E. coli strains, while FOS-LF was slightly inhibitory or not inhibitory. Factors other than acid production appeared to play a role in the inhibition. In the gut models, both synbiotics effectively inhibited E. coli O157 in the first vessel, but not in vessels 2 and 3. E. coli O86 was not significantly inhibited.  相似文献   
90.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
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