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   12937篇
  免费   764篇
  国内免费   42篇
耳鼻咽喉   121篇
儿科学   362篇
妇产科学   251篇
基础医学   1727篇
口腔科学   312篇
临床医学   1107篇
内科学   3247篇
皮肤病学   140篇
神经病学   1191篇
特种医学   364篇
外国民族医学   1篇
外科学   1898篇
综合类   122篇
一般理论   3篇
预防医学   986篇
眼科学   234篇
药学   687篇
中国医学   33篇
肿瘤学   957篇
  2023年   119篇
  2022年   245篇
  2021年   502篇
  2020年   269篇
  2019年   389篇
  2018年   455篇
  2017年   316篇
  2016年   299篇
  2015年   334篇
  2014年   494篇
  2013年   653篇
  2012年   1025篇
  2011年   962篇
  2010年   609篇
  2009年   452篇
  2008年   758篇
  2007年   774篇
  2006年   660篇
  2005年   712篇
  2004年   630篇
  2003年   520篇
  2002年   545篇
  2001年   176篇
  2000年   136篇
  1999年   167篇
  1998年   88篇
  1997年   83篇
  1996年   78篇
  1995年   75篇
  1994年   60篇
  1993年   48篇
  1992年   78篇
  1991年   56篇
  1990年   71篇
  1989年   50篇
  1988年   57篇
  1987年   47篇
  1986年   60篇
  1985年   45篇
  1984年   42篇
  1983年   61篇
  1982年   38篇
  1981年   35篇
  1980年   36篇
  1979年   36篇
  1978年   24篇
  1977年   27篇
  1976年   27篇
  1975年   24篇
  1974年   32篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
Lepidapedon sereti n. sp. is described from the macrourid Coelorinchus sereti from the deep water off Vanuatu. It is placed in the Elongatum group and Elongatum subgroup. It differs from the other species described in this subgroup by the distinctly dorsally subterminal excretory pore. It also differs from other species in combinations of size, excretory vesicle length, proportions of forebody, post-testicular region and other metric features. This constitutes the first record of a Lepidapedon (sensu stricto) from the Central Western Pacific Ocean.  相似文献   
172.
173.
Immunologic Research - Results of the anti-nuclear antibodies-indirect immunofluorescence assay (anti-cell antibodies test) on HEp-2 cell substrates should be communicated to clinicians in a...  相似文献   
174.
175.
IntroductionThe incidence of immediate postobturation pain associated with 2 sealer techniques was compared and potential prognostic factors identified.MethodsPatients referred for endodontic treatment were recruited with informed consent. Root canals were debrided and teeth rendered asymptomatic before random allocation to receive TotalFill BC (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) or AH Plus sealer (Dentsply Maillefer, Ballaigues, Switzerland). Patients blinded to the sealer reported their postobturation pain experience 1, 3, and 7 days after treatment. Blinded and calibrated assessors independently reviewed treatment quality, sealer extrusion, and radiographic data under standardized conditions.ResultsOne hundred sixty eligible patients (163 teeth, 95.3%) returned their pain diary. No postobturation pain difference was found between the 2 sealers (P > .05), although the AH Plus sealer technique was significantly associated with extrusion beyond the apex (P < .05; odds ratio [OR] = 3.02; 95% confidence interval [CI], 1.39–6.57). Thirty-three (20.6%) patients reported pain on day 1 (median 1 = very mild pain), 16 (10.0%) on day 3 (median 1 = very mild pain), and 9 (5.6%) on day 7 (median 2 = mild pain). The prognostic factors were as follows:(1) moderate/severe preoperative pain (OR = 4.41; 95% CI, 1.42–13.76 on day 3 and OR = 5.16; 95% CI, 1.17–22.78 on day 7),(2) provoked preoperative pain (OR = 4.24; 95% CI, 1.40–12.78 on day 3 and OR = 5.35; 95% CI, 1.27–22.51 on day 7),(3) pulpless tooth (OR = 0.11; 95% CI, 0.02–0.57 on day 3), and(4) sonic activation during treatment (OR = 3.02; 95% CI, 1.39–6.57 on day 1 and OR = 3.01; 95% CI, 1.05–8.59 on day 3).ConclusionsThere was no significant difference in pain experience between teeth filled using AH Plus or TotalFill BC Sealer 1, 3, and 7 days after obturation. Patient- and treatment-related factors could influence postobturation pain.  相似文献   
176.
177.
178.
179.
180.
Mood disorders are characterized by impaired emotion regulation abilities, reflected in alterations in frontolimbic brain functioning during regulation. However, little is known about differences in brain function when comparing regulatory strategies. Reappraisal and emotional acceptance are effective in downregulating negative affect, and are components of effective depression psychotherapies. Investigating neural mechanisms of reappraisal vs emotional acceptance in remitted major depressive disorder (rMDD) may yield novel mechanistic insights into depression risk and prevention. Thirty-seven individuals (18 rMDD, 19 controls) were assessed during a functional magnetic resonance imaging task requiring reappraisal, emotional acceptance or no explicit regulation while viewing sad images. Lower negative affect was reported following reappraisal than acceptance, and was lower following acceptance than no explicit regulation. In controls, the acceptance > reappraisal contrast revealed greater activation in left insular cortex and right prefrontal gyrus, and less activation in several other prefrontal regions. Compared with controls, the rMDD group had greater paracingulate and right midfrontal gyrus (BA 8) activation during reappraisal relative to acceptance. Compared with reappraisal, acceptance is associated with activation in regions linked to somatic and emotion awareness, although this activation is associated with less reduction in negative affect. Additionally, a history of MDD moderated these effects.  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