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   4149323篇
  免费   346675篇
  国内免费   14799篇
耳鼻咽喉   57940篇
儿科学   131038篇
妇产科学   110713篇
基础医学   637077篇
口腔科学   117625篇
临床医学   372047篇
内科学   745654篇
皮肤病学   102776篇
神经病学   351513篇
特种医学   166605篇
外国民族医学   655篇
外科学   638188篇
综合类   128646篇
现状与发展   24篇
一般理论   2519篇
预防医学   346459篇
眼科学   97080篇
药学   294430篇
  22篇
中国医学   11202篇
肿瘤学   198584篇
  2021年   55383篇
  2019年   58214篇
  2018年   72478篇
  2017年   55380篇
  2016年   61375篇
  2015年   74967篇
  2014年   109334篇
  2013年   174521篇
  2012年   110615篇
  2011年   112975篇
  2010年   121325篇
  2009年   124519篇
  2008年   100130篇
  2007年   105977篇
  2006年   115708篇
  2005年   110781篇
  2004年   113268篇
  2003年   103409篇
  2002年   92923篇
  2001年   141624篇
  2000年   136685篇
  1999年   128920篇
  1998年   69537篇
  1997年   66348篇
  1996年   64400篇
  1995年   59915篇
  1994年   54186篇
  1993年   50491篇
  1992年   97427篇
  1991年   93641篇
  1990年   90084篇
  1989年   88158篇
  1988年   82393篇
  1987年   80712篇
  1986年   76951篇
  1985年   76153篇
  1984年   64809篇
  1983年   58008篇
  1982年   47838篇
  1981年   44548篇
  1980年   41962篇
  1979年   58279篇
  1978年   47141篇
  1977年   41751篇
  1976年   38687篇
  1975年   38266篇
  1974年   42902篇
  1973年   41253篇
  1972年   38542篇
  1971年   35837篇
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
991.
992.
993.
Pharmaceutical Chemistry Journal - N-Substituted 4-aryl-2-hydroxy-4-oxobut-2-enoic acid hydrazides and their complexes with Ni(II), Mn(II), Co(II), Cu(II), and Zn(II) were prepared. Their...  相似文献   
994.
995.
996.
997.
Congenital heart disease is a rare but important finding in adults who experience sudden death. Examination of the congenitally malformed heart has historically been considered esoteric and best left to those with expertise. The Cardiac Risk in the Young cardiovascular pathology laboratory based at St George's University of London has now received over 6,000 cases. Of these, 21 congenitally malformed hearts were retained for research and educational purposes. Hearts were assessed using sequential segmental analysis, and causes of death were adjudicated based on thorough macroscopic examination and histology. Congenital malformations that were encountered included atrial septal defects, ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries in both its regular and congenitally corrected variants. Findings also included hearts with mirror-imaged and isomeric atrial appendages. Direct causes of death included myocardial fibrosis, pulmonary hypertension, and hemorrhage. A small but notable proportion did not reveal a substrate for arrhythmia, raising the question of whether the terminal event was due to the congenital heart disease itself, or an underlying channelopathy. Here, we demonstrate the value of simple sequential segmental analysis in describing and categorizing the cases, with the concept of the “morphological method” serving to identify the distinguishing features of the cardiac components. Clin. Anat. 33:394–404, 2020. © 2019 Wiley Periodicals, Inc.  相似文献   
998.
Parhiala  P.  Ranta  K.  Gergov  V.  Kontunen  J.  Law  R.  La Greca  A. M.  Torppa  M.  Marttunen  M. 《School mental health》2020,12(2):265-283

In order to offer early and accessible treatment for adolescents with depression, brief and effective treatments in adolescents’ everyday surroundings are needed. This randomized controlled trial studied the preliminary effectiveness, feasibility, and acceptability of interpersonal counseling (IPC) and brief psychosocial support (BPS) in school health and welfare services. The study was conducted in the 28 lower secondary schools of a large city in Southern Finland, randomized to provide either IPC or BPS. Help-seeking 12–16-year-old adolescents with mild-to-moderate depression, with and without comorbid anxiety, were included in the study. Fifty-five adolescents received either 6 weekly sessions of IPC or BPS and two follow-up sessions. Outcome measures included self- and clinician-rated measures of depression, global functioning, and psychological distress/well-being. To assess feasibility and acceptability of the treatments, adolescents’ and counselors’ treatment compliance and satisfaction with treatment were assessed. Both treatments were effective in reducing depressive disorders and improving adolescents’ overall functioning and well-being. At post-treatment, in both groups, over 50% of adolescents achieved recovery based on self-report and over 70% based on observer report. Effect sizes for change were medium or large in both groups at post-treatment and increased at 6-month follow-up. A trend indicating greater baseline symptom severity among adolescents treated in the IPC-providing schools was observed. Adolescents and counselors in both groups were satisfied with the treatment, and 89% of the adolescents completed the treatments and follow-ups. This trial suggests that both IPC and BPS are feasible, acceptable, and effective treatments for mild-to-moderate depression in the school setting. In addition, IPC seems effective even if comorbid anxiety exists. Our study shows that brief, structured interventions, such as IPC and BPS, are beneficial in treating mild-to-moderate depression in school settings and can be administered by professionals working at school.

Trial registrationhttp://www.clinicaltrials.gov. Unique identifier: NCT03001245.

  相似文献   
999.
1000.
The endocrine system relies on the vasculature for delivery of hormones throughout the body, and the capillary microvasculature is the site where the hormones cross from the blood into the target tissue. Once considered an inert wall, various studies have now highlighted the functions of the capillary endothelium to regulate transport and therefore affect or maintain the interstitial environment. The role of the capillary may be clear in areas where there is a continuous endothelium, yet there also appears to be a role of endothelial cells in tissues with a sinusoidal structure. Here we focused on the most common endocrine disorder, diabetes, and several of the target organs associated with the disease, including skeletal muscle, liver and pancreas. However, it is important to note that the ability of hormones to cross the endothelium to reach their target tissue is a component of all endocrine functions. It is also a consideration in organs throughout the body and may have greater impact for larger hormones with target tissues containing a continuous endothelium. We noted that the blood levels do not always equal interstitial levels, which is what the cells are exposed to, and discussed how this may change in diseases such as obesity and insulin resistance. The capillary endothelium is, therefore, an essential and understudied aspect of endocrinology and metabolism that can be altered in disease, which may be an appropriate target for treatment.  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