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   1458080篇
  免费   113436篇
  国内免费   2569篇
耳鼻咽喉   20355篇
儿科学   49184篇
妇产科学   38640篇
基础医学   205834篇
口腔科学   37715篇
临床医学   128736篇
内科学   296088篇
皮肤病学   30359篇
神经病学   118287篇
特种医学   57156篇
外国民族医学   673篇
外科学   224350篇
综合类   30055篇
现状与发展   3篇
一般理论   656篇
预防医学   112701篇
眼科学   31759篇
药学   107347篇
  3篇
中国医学   2756篇
肿瘤学   81428篇
  2019年   11951篇
  2018年   16522篇
  2017年   12712篇
  2016年   13783篇
  2015年   15854篇
  2014年   22399篇
  2013年   33870篇
  2012年   47166篇
  2011年   50329篇
  2010年   29878篇
  2009年   28109篇
  2008年   48333篇
  2007年   51694篇
  2006年   51521篇
  2005年   50845篇
  2004年   49678篇
  2003年   47693篇
  2002年   46688篇
  2001年   65655篇
  2000年   67768篇
  1999年   58198篇
  1998年   17590篇
  1997年   15846篇
  1996年   16079篇
  1995年   15153篇
  1994年   14318篇
  1993年   13275篇
  1992年   45609篇
  1991年   44477篇
  1990年   43153篇
  1989年   40969篇
  1988年   37798篇
  1987年   37136篇
  1986年   34505篇
  1985年   33247篇
  1984年   25458篇
  1983年   21594篇
  1982年   13356篇
  1981年   12160篇
  1980年   10928篇
  1979年   22079篇
  1978年   15697篇
  1977年   13388篇
  1976年   12454篇
  1975年   13256篇
  1974年   15246篇
  1973年   14644篇
  1972年   13328篇
  1971年   12055篇
  1970年   11353篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
In the 6th Basic Plan for Long-Term Electricity Supply and Demand (6th BPE) for Korea, for the first time, the environmental costs of air pollution caused by oxides of sulfur (SOx), oxides of nitrogen (NOx), and particulate matters (PM) from power plants were estimated and included. However, several deficiencies in evaluating the environmental costs were found. In this study, (1) the validity of the environmental costs used in the 6th BPE was assessed, (2) a systematic approach was suggested and used to improve the environmental costs estimation, and (3) the sensitivity of the cost of generating electricity to the environmental costs by fuel type with the proposed approach was discussed. We found that the applied environmental costs used in the 6th BPE did not fully include the demographic characteristics of Korea. By applying more realistic parameter values, it was found that the newly estimated environmental cost was about 23 times higher than the cost estimated in the original 6th BPE for coal-fired power plants and about 1.5 times higher for liquefied natural gas (LNG)-fired power plants, suggesting that LNG-fired power plants are more economical if using more realistic environmental costs. Thus, it is critical to check the validity of parameter values when calculating environmental costs.  相似文献   
73.
74.
75.
76.
77.
78.
This study used the National Survey of Ambulatory Surgery (NSAS) database to measure the incidence of and risk factors for symptoms in the ambulatory surgery center and problems within 24 h after isolated carpal tunnel release (CTR). The NSAS contained records on 400,000 adult patients with carpal tunnel syndrome who were treated with CTR in 2006, based on ICD-9 codes. The type of anesthesia used and factors associated with symptoms and problems were sought in bivariate and multivariable statistical analyses. The mean duration of the procedure was 16 ± 8.8 min. Only 5 % were performed under local anesthesia without sedation, 45 % with IV sedation, 28 % regional anesthesia, and 19 % general anesthesia. Symptoms in the ambulatory surgery center or a problem within 24 h after discharge were recorded in 10 % of patients, all of them minor and transient, including difficulties with pain and its treatment. The strongest risk factors were male sex, age of 45 years and older, and participation of an anesthesiologist. Local anesthesia and regional anesthesia were associated with more perioperative symptoms and postoperative problems. Most CTR are performed with some sedation in the United States. CTR is a safe procedure: one in 10 patients will experience a minor issue in the perioperative or immediate postoperative period.  相似文献   
79.
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   
80.
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