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   9117篇
  免费   746篇
  国内免费   78篇
耳鼻咽喉   63篇
儿科学   338篇
妇产科学   312篇
基础医学   1190篇
口腔科学   281篇
临床医学   881篇
内科学   1876篇
皮肤病学   84篇
神经病学   546篇
特种医学   404篇
外科学   1503篇
综合类   178篇
一般理论   10篇
预防医学   436篇
眼科学   348篇
药学   486篇
中国医学   33篇
肿瘤学   972篇
  2023年   55篇
  2022年   59篇
  2021年   215篇
  2020年   149篇
  2019年   193篇
  2018年   260篇
  2017年   137篇
  2016年   195篇
  2015年   248篇
  2014年   341篇
  2013年   360篇
  2012年   550篇
  2011年   633篇
  2010年   398篇
  2009年   379篇
  2008年   555篇
  2007年   608篇
  2006年   567篇
  2005年   514篇
  2004年   459篇
  2003年   410篇
  2002年   316篇
  2001年   309篇
  2000年   259篇
  1999年   217篇
  1998年   101篇
  1997年   105篇
  1996年   83篇
  1995年   59篇
  1994年   66篇
  1993年   58篇
  1992年   112篇
  1991年   104篇
  1990年   110篇
  1989年   115篇
  1988年   79篇
  1987年   78篇
  1986年   69篇
  1985年   65篇
  1984年   45篇
  1983年   46篇
  1982年   33篇
  1981年   32篇
  1980年   34篇
  1979年   24篇
  1978年   18篇
  1977年   30篇
  1976年   22篇
  1975年   18篇
  1973年   8篇
排序方式: 共有9941条查询结果,搜索用时 930 毫秒
1.
The human visual system is amenable to a number of adaptive processes; one such process, or collection of processes, is the adaptation to blur. Blur adaptation can be observed as an improvement in vision under degraded conditions, and these changes occur relatively rapidly following exposure to blur. The potential important future directions of this research area and the clinical implications of blur adaptation are discussed.  相似文献   
2.
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   
3.
4.
5.
6.
7.
8.
9.
We carried out a nonrandomized, unblinded study to compare the efficacy of rifampin alone with that of rifampin in combination with trimethoprim in the eradication of the Haemophilus influenzae type b (HIB) carrier state among contacts of patients with invasive HIB infection. The study population comprised 17 index patients admitted to hospital with severe HIB infections and 233 contacts, 43 of whom had nasopharyngeal colonization with HIB of the same biotype as that of the index patient. Rifampin in a daily dose of 20 mg/kg (maximum 600 mg) for 4 days eradicated the carrier state in 86% of cases, as did the combination of rifampin at the same dosage and trimethoprim in a daily dose of 5 mg/kg (maximum 160 mg) for 4 days.  相似文献   
10.
Objective: The study goal was to compare the laser spot size created using reflective and refractive micromanipulators with a CO2 laser and to determine the sensitivity of spot size to laser power. Study Design and Setting: A CO2 laser and operating microscope (400-mm focal length) was coupled to either a reflective (Cassegrain-like) or refractive micromanipulator. Laser spot size was determined by measuring the region of ablation created by laser irradiation of wood (dry tongue depressors), exposed photographic film, and agar gel using optical micrometry. Laser power varied from 0.5 to 20 W with pulse durations of 0.1 and 0.5 second. Results: The reflective micromanipulator demonstrated overall smaller spot sizes for a given laser power and lower incremental change in spot size with increasing power. The reflective design demonstrated less sensitivity to increases in laser power. Conclusions: Micromanipulator optical design can result in significant differences in laser spot size. The reflective device used in this study demonstrated less sensitivity to increasing laser power. (Otolaryngol Head Neck Surg 2002;126:593-597.)  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