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   313698篇
  免费   18076篇
  国内免费   8172篇
耳鼻咽喉   5927篇
儿科学   9250篇
妇产科学   5238篇
基础医学   19928篇
口腔科学   7643篇
临床医学   35632篇
内科学   47938篇
皮肤病学   3911篇
神经病学   13928篇
特种医学   13889篇
外国民族医学   318篇
外科学   59564篇
综合类   34039篇
现状与发展   33篇
一般理论   9篇
预防医学   19664篇
眼科学   8884篇
药学   29278篇
  241篇
中国医学   6931篇
肿瘤学   17701篇
  2024年   510篇
  2023年   3896篇
  2022年   7663篇
  2021年   14350篇
  2020年   9412篇
  2019年   14475篇
  2018年   9292篇
  2017年   7905篇
  2016年   9893篇
  2015年   12773篇
  2014年   27115篇
  2013年   23331篇
  2012年   25110篇
  2011年   21892篇
  2010年   21070篇
  2009年   20138篇
  2008年   16819篇
  2007年   15881篇
  2006年   13453篇
  2005年   9461篇
  2004年   5628篇
  2003年   4770篇
  2002年   3830篇
  2001年   3246篇
  2000年   2888篇
  1999年   2143篇
  1998年   2417篇
  1997年   2228篇
  1996年   1777篇
  1995年   1691篇
  1994年   1583篇
  1993年   1235篇
  1992年   1401篇
  1991年   1282篇
  1990年   1232篇
  1989年   1195篇
  1988年   1123篇
  1987年   1014篇
  1986年   823篇
  1985年   1743篇
  1984年   1881篇
  1983年   1354篇
  1982年   1445篇
  1981年   1418篇
  1980年   1214篇
  1979年   1024篇
  1978年   787篇
  1977年   783篇
  1976年   686篇
  1974年   457篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
31.
32.
33.
目前临床研究已证实腹腔镜胃癌根治术治疗早期胃癌的安全性、可行性和有效性。基于此,第4版日本《胃癌治疗指南》推荐腹腔镜手术治疗临床Ⅰ期远端胃癌。然而,腹腔镜胃癌手术治疗进展期胃癌的有效性和安全性仍存争议。中国腹腔镜胃肠外科研究组(CLASS研究组)发起的CLASS-01研究顺利完成,提供了全球首个局部进展期胃癌腹腔镜手术安全性和疗效的前瞻性多中心证据。胃癌外科的主流方向在从“大切口和扩大化手术切除”逐渐向“微创、精准化手术”转变,以使手术安全性和病人术后生活质量最优化。  相似文献   
34.
35.
36.
37.
目的探讨儿童期创伤与抑郁特质之间的中介和调节机制,为开展相关研究和干预提供参考。方法2017-2018年采用整群抽样的方法,抽取湖南某高校大一年级2 786名学生完成儿童期创伤问卷、状态特质抑郁问卷、自动思维问卷和特质应对方式问卷的调查。结果儿童期创伤、自动思维和消极应对对抑郁特质起正向的预测作用,积极应对对抑郁特质起负向的预测作用(β值分别为0.12,0.43,0.14,-0.33,P值均<0.05)。自动思维中介儿童期创伤与抑郁特质之间的关系(Bootstrapping法的95%CI为0.03~0.06)。消极应对分别调节了儿童期创伤与自动思维和儿童期创伤与抑郁特质之间的关系(P值均<0.05)。结论儿童期创伤影响抑郁特质,其关系受到应对方式和自动思维的影响。  相似文献   
38.
??Objective    To observe the effects of lithium chloride pretreatment on cognitive ability of aged rats after oral and maxillofacial surgery. Methods    A total of 48 aged male SD rats??18 ~ 20 months old??weight 550 ~ 700 g?? were bought from the Experimental Animal Center of China Medical University . These rats were randomly divided into three groups??including the normal control group??group C??n=16????surgery and anesthesia group??group O??n=16????and lithium chloride preconditioning group??group L??n=16??.Rats in each group were randomly divided into two parts??one part was given Morris water maze test three days after the surgery and its characteristics of behavior tested. Another part was decapitated 24 h after the surgery and extracted and the hippocampus brain separated at the same time. Test expression content of IL-1β GSK-3β p-GSK-3β??ser9??in the hippocampus by Elisa and Western blotting detection method respectively. Results    Morris water maze test showed that??the first day after surgery??latencies of group L and O were significantly longer than group C??compared with group C in swimming distance?? latency and swim distances of group L were shorter than group O. With the comparison of multiple analysis of variance??differences were statistically significant??P??0.05??. Groups L and O in the second day were slightly shortened compared to the first day??on the third day after surgery it has also improved over the second day. Space exploration experiments in rats showed that??the dwell time of group C was significantly longer in the platform quadrant and the frequency of crossing the platform also increased compared with groups L and O. In addition??group L and group O were higher in IL-β levels than group C??the difference being statistically significant by analysis of variance??P??0.05????but group L was significantly lower compared with group O??the difference being statistically significant??P??0.05??. The content of GSK-3β of three groups were of no significant difference??P > 0.05????but p-GSK-3β??ser9??content was significantly lower in group L and O than in group C. The content of GSK-3β of group L was higher than in group O??the difference being statistically significant??P??0.05??. Conclusion    Pretreatment with lithium chloride in postoperative aged rats can inhibit the expression of inflammatory cytokines and increase GSK-3β phosphorylation in the hippocampus cells??so p-GSK-3β??ser9??upregulates and inhibites  the apoptosis of brain cells??thereby improved cognitive abilities after the cavity and maxillofacial surgery.  相似文献   
39.
40.
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