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   1614906篇
  免费   133053篇
  国内免费   2613篇
耳鼻咽喉   21765篇
儿科学   53377篇
妇产科学   46512篇
基础医学   229641篇
口腔科学   47444篇
临床医学   142284篇
内科学   317759篇
皮肤病学   34228篇
神经病学   131215篇
特种医学   65240篇
外国民族医学   474篇
外科学   246081篇
综合类   39951篇
现状与发展   3篇
一般理论   563篇
预防医学   124096篇
眼科学   36796篇
药学   122105篇
  4篇
中国医学   2986篇
肿瘤学   88048篇
  2018年   15105篇
  2016年   13145篇
  2015年   15298篇
  2014年   21071篇
  2013年   31923篇
  2012年   43525篇
  2011年   45699篇
  2010年   26880篇
  2009年   25783篇
  2008年   43853篇
  2007年   46161篇
  2006年   46953篇
  2005年   45538篇
  2004年   44928篇
  2003年   42971篇
  2002年   42036篇
  2001年   75833篇
  2000年   78466篇
  1999年   66545篇
  1998年   17899篇
  1997年   16499篇
  1996年   16444篇
  1995年   16129篇
  1994年   15167篇
  1993年   14328篇
  1992年   55513篇
  1991年   53872篇
  1990年   52628篇
  1989年   50912篇
  1988年   47293篇
  1987年   46629篇
  1986年   44363篇
  1985年   42898篇
  1984年   32103篇
  1983年   27652篇
  1982年   16225篇
  1981年   14520篇
  1980年   13649篇
  1979年   30543篇
  1978年   21136篇
  1977年   17819篇
  1976年   16738篇
  1975年   17635篇
  1974年   21529篇
  1973年   20719篇
  1972年   18891篇
  1971年   17803篇
  1970年   16318篇
  1969年   15290篇
  1968年   13959篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.  相似文献   
13.
14.
Cyclotron-produced copper-64 radioisotope tracers offer the possibility to perform both diagnostic investigation by positron emission tomography (PET) and radiotherapy by a theranostic approach with bifunctional chelators. The versatile chemical properties of copper add to the importance of this isotope in medicinal investigation. [64Cu][Cu (ATSM)] has shown to be a viable candidate for imaging of tumor hypoxia; a critical tumor microenvironment characteristic that typically signifies tumor progression and resistance to chemo-radiotherapy. Various production and radiosynthesis methods of [64Cu][Cu (ATSM)] exist in labs, but usually involved non-standardized equipment with varying production qualities and may not be easily implemented in wider hospital settings. [64Cu][Cu (ATSM)] was synthesized on a modified GE TRACERlab FXN automated synthesis module. End-of-synthesis (EOS) molar activity of [64Cu][Cu (ATSM)] was 2.2–5.5 Ci/μmol (HPLC), 2.2–2.6 Ci/μmol (ATSM-titration), and 3.0–4.4 Ci/μmol (ICP-MS). Radiochemical purity was determined to be >99% based on radio-HPLC. The final product maintained radiochemical purity after 20 h. We demonstrated a simple and feasible process development and quality control protocols for automated cyclotron production and synthesis of [64Cu][Cu (ATSM)] based on commercially distributed standardized synthesis modules suitable for PET imaging and theranostic studies.  相似文献   
15.
16.
17.
18.
19.
20.
Academic output is just one aspect of a successful career as a plastic surgeon. However, for those with a strong interest in academia, the academic output of a department will likely be a key factor when deciding how to rank jobs. The aim of this study was to quantify and rank the academic output of plastic surgery units across the UK and Ireland. The Institute for Scientific Information (ISI) Web of Science Bibliometric analysis tool was used to collate cumulative (1950–2016), 10 year (2006–2016) and 3 years (2013–2015) research output data for plastic surgery units in the UK and Ireland. Sixty-six plastic surgery units were identified. Departments were ranked for each time period according to the number of papers produced, number of citations (Nc) and h-index (a measure of the impact of scientific output). The top 3 departments for number of papers in the last 10 years were The Royal Free Hospital, London (226) Broomfield Hospital, Chelmsford (218), and Morriston Hospital and Swansea (188). The top 3 for h-number were The Royal Free Hospital (21) Wythenshawe Hospital, Manchester (18) and Morriston Hospital (17). Academic output varies across plastic surgery units in the UK and Ireland. A number of departments have consistently maintained high academic outputs across the years and will be of interest to surgeons hoping to pursue a career in academia.  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