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   894136篇
  免费   63429篇
  国内免费   2321篇
耳鼻咽喉   12467篇
儿科学   28619篇
妇产科学   26150篇
基础医学   125537篇
口腔科学   24662篇
临床医学   74367篇
内科学   181826篇
皮肤病学   18973篇
神经病学   70914篇
特种医学   36458篇
外国民族医学   336篇
外科学   141931篇
综合类   18996篇
一般理论   247篇
预防医学   64098篇
眼科学   20069篇
药学   63647篇
中国医学   1747篇
肿瘤学   48842篇
  2018年   9060篇
  2017年   7180篇
  2016年   7688篇
  2015年   8740篇
  2014年   12385篇
  2013年   19229篇
  2012年   25685篇
  2011年   27286篇
  2010年   16592篇
  2009年   15806篇
  2008年   26157篇
  2007年   27765篇
  2006年   27950篇
  2005年   27480篇
  2004年   26320篇
  2003年   25442篇
  2002年   25011篇
  2001年   41319篇
  2000年   42477篇
  1999年   36056篇
  1998年   9370篇
  1997年   8492篇
  1996年   8436篇
  1995年   8403篇
  1994年   8049篇
  1993年   7556篇
  1992年   28171篇
  1991年   27002篇
  1990年   26424篇
  1989年   25374篇
  1988年   23552篇
  1987年   23174篇
  1986年   22257篇
  1985年   21164篇
  1984年   15794篇
  1983年   13456篇
  1982年   8051篇
  1979年   14577篇
  1978年   10183篇
  1977年   8607篇
  1976年   8125篇
  1975年   8948篇
  1974年   10686篇
  1973年   10178篇
  1972年   9667篇
  1971年   8914篇
  1970年   8580篇
  1969年   8021篇
  1968年   7686篇
  1967年   7082篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
Graefe's Archive for Clinical and Experimental Ophthalmology -  相似文献   
32.
Detailed contemporary knowledge of the characteristics of the surgical population, national anaesthetic workload, anaesthetic techniques and behaviours are essential to monitor productivity, inform policy and direct research themes. Every 3–4 years, the Royal College of Anaesthetists, as part of its National Audit Projects (NAP), performs a snapshot activity survey in all UK hospitals delivering anaesthesia, collecting patient-level encounter data from all cases under the care of an anaesthetist. During November 2021, as part of NAP7, anaesthetists recorded details of all cases undertaken over 4 days at their site through an online survey capturing anonymous patient characteristics and anaesthetic details. Of 416 hospital sites invited to participate, 352 (85%) completed the activity survey. From these, 24,177 reports were returned, of which 24,172 (99%) were included in the final dataset. The work patterns by day of the week, time of day and surgical specialty were similar to previous NAP activity surveys. However, in non-obstetric patients, between NAP5 (2013) and NAP7 (2021) activity surveys, the estimated median age of patients increased by 2.3 years from median (IQR) of 50.5 (28.4–69.1) to 52.8 (32.1–69.2) years. The median (IQR) BMI increased from 24.9 (21.5–29.5) to 26.7 (22.3–31.7) kg.m–2. The proportion of patients who scored as ASA physical status 1 decreased from 37% in NAP5 to 24% in NAP7. The use of total intravenous anaesthesia increased from 8% of general anaesthesia cases to 26% between NAP5 and NAP7. Some changes may reflect the impact of the COVID-19 pandemic on the anaesthetic population, though patients with confirmed COVID-19 accounted for only 149 (1%) cases. These data show a rising burden of age, obesity and comorbidity in patients requiring anaesthesia care, likely to impact UK peri-operative services significantly.  相似文献   
33.
This commentary reviews top advances in hepatobiliary cancer research in 2021–2022, focusing on leveraging immunotherapeutics in combination with other therapies earlier in the disease course and targeted to patient's individualized biomarkers that may predict response or resistance to checkpoint inhibitors.  相似文献   
34.
Myocardial injury due to ischaemia within 30 days of non-cardiac surgery is prognostically relevant. We aimed to determine the discrimination, calibration, accuracy, sensitivity and specificity of single-layer and multiple-layer neural networks for myocardial injury and death within 30 postoperative days. We analysed data from 24,589 participants in the Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation study. Validation was performed on a randomly selected subset of the study population. Discrimination for myocardial injury by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.70 (0.69–0.72) vs. 0.71 (0.70–0.73) with variables available before surgical referral, p < 0.001; 0.73 (0.72–0.75) vs. 0.75 (0.74–0.76) with additional variables available on admission, but before surgery, p < 0.001; and 0.76 (0.75–0.77) vs. 0.77 (0.76–0.78) with the addition of subsequent variables, p < 0.001. Discrimination for death by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.71 (0.66–0.76) vs. 0.74 (0.71–0.77) with variables available before surgical referral, p = 0.04; 0.78 (0.73–0.82) vs. 0.83 (0.79–0.86) with additional variables available on admission but before surgery, p = 0.01; and 0.87 (0.83–0.89) vs. 0.87 (0.85–0.90) with the addition of subsequent variables, p = 0.52. The accuracy of the multiple-layer model for myocardial injury and death with all variables was 70% and 89%, respectively.  相似文献   
35.
Münch  F.  Purbojo  A.  Wenzel  F.  Kohl  M.  Dittrich  S.  Rauh  M.  Zimmermann  R.  Kwapil  N. 《Der Anaesthesist》2022,71(11):882-892
Die Anaesthesiologie - Die Transfusion von Erythrozytenkonzentraten (EK) ist mit verschiedenen Nebenwirkungen assoziiert, die u. a. durch Lagerungsschäden an Erythrozyten hervorgerufen...  相似文献   
36.

A positive relationship between treatment volume and outcome quality has been demonstrated in the literature and is thus evident for a variety of procedures. Consequently, policy makers have tried to translate this so-called volume–outcome relationship into minimum volume regulation (MVR) to increase the quality of care—yet with limited success. Until today, the effect of strict MVR application remains unclear as outcome quality gains cannot be estimated adequately and restrictions to application such as patient travel time and utilization of remaining hospital capacity are not considered sufficiently. Accordingly, when defining MVR, its effectiveness cannot be assessed. Thus, we developed a mixed integer programming model to define minimum volume thresholds balancing utility in terms of outcome quality gain and feasibility in terms of restricted patient travel time and utilization of hospital capacity. We applied our model to the German hospital sector and to four surgical procedures. Results showed that effective MVR needs a minimum volume threshold of 125 treatments for cholecystectomy, of 45 and 25 treatments for colon and rectum resection, respectively, of 32 treatments for radical prostatectomy and of 60 treatments for total knee arthroplasty. Depending on procedure type and incidence as well as the procedure’s complication rate, outcome quality gain ranged between 287 (radical prostatectomy) and 977 (colon resection) avoidable complications (11.7% and 11.9% of all complications). Ultimately, policy makers can use our model to leverage MVR’s intended benefit: concentrating treatment delivery to improve the quality of care.

  相似文献   
37.
38.
39.
40.
Immunologic Research - Hyper immunoglobulin M (HIGM) syndrome is a rare disorder of the immune system with impaired antibody functions. The clinical picture of the patients varies according to the...  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