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   19606篇
  免费   5716篇
  国内免费   74篇
耳鼻咽喉   533篇
儿科学   582篇
妇产科学   759篇
基础医学   414篇
口腔科学   1147篇
临床医学   3726篇
内科学   6880篇
皮肤病学   415篇
神经病学   842篇
特种医学   497篇
外科学   2302篇
综合类   83篇
现状与发展   2篇
一般理论   1篇
预防医学   3696篇
眼科学   270篇
药学   412篇
中国医学   8篇
肿瘤学   2827篇
  2024年   160篇
  2023年   1075篇
  2022年   415篇
  2021年   781篇
  2020年   1263篇
  2019年   484篇
  2018年   1207篇
  2017年   1288篇
  2016年   1517篇
  2015年   1452篇
  2014年   2052篇
  2013年   2276篇
  2012年   825篇
  2011年   763篇
  2010年   1201篇
  2009年   1580篇
  2008年   714篇
  2007年   535篇
  2006年   833篇
  2005年   450篇
  2004年   362篇
  2003年   271篇
  2002年   250篇
  2001年   308篇
  2000年   280篇
  1999年   289篇
  1998年   351篇
  1997年   262篇
  1996年   252篇
  1995年   210篇
  1994年   161篇
  1993年   122篇
  1992年   149篇
  1991年   142篇
  1990年   144篇
  1989年   111篇
  1988年   107篇
  1987年   84篇
  1986年   89篇
  1985年   79篇
  1984年   69篇
  1983年   57篇
  1982年   33篇
  1980年   29篇
  1979年   27篇
  1978年   32篇
  1977年   31篇
  1975年   25篇
  1974年   27篇
  1972年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Milos Jesenak  MD  PhD    Peter Banovcin  MD  PhD    Zuzana Rennerova  MD  PhD    Lubica Jakusova  MD  PhD    Zuzana Havlicekova  MD  PhD    Vladimir Pohanka  MD  PhD  MPH  FCCP    Maria Pia Villa  MD  PhD    Roberto Ronchetti  MD  PhD 《International journal of dermatology》2009,48(9):941-946
Background  The atopy patch test (APT) is no longer an experimental method; it is increasingly being used as a standard diagnostic tool for the characterization of patients with aeroallergen- and food-triggered disorders. Some technical aspects of this test still remain to be answered. We aimed to study the reproducibility of this test over time in the general child population.
Methods  In a general population of 118 children, we investigated the reproducibility of duplicate APTs with four food allergens in their native form, which were repeated at set intervals from the first test: 7 days (group 1), 14 days (group 2), and 21 days (group 3).
Results  We observed very poor reproducibility on both sides of the back in all three studied subgroups. The reproducibility rates and Cohen's κ values did not improve when we did not consider the side of the back. There were no differences in the prevalence of atopy between the subjects with reproducible and nonreproducible APT results. All three groups studied showed no difference in the prevalence rates of atopy. There was no relationship between APT and skin prick test positivity for the same allergen. Questionnaire-derived data about previous food-related reactions did not help in the evaluation of the doubtful nonreproducible APT results with food allergens.
Conclusions  Our results show that the reproducibility of food APTs is poor and unsatisfactory over time, and there is an urgent need for the development of optimal, stable, and good-quality APT testing substances.  相似文献   
42.
43.
This study evaluated the effects of tobacco Purchase, Use and Possession (PUP) laws on student perceptions of adolescent tobacco use within towns and schools. Twenty‐four towns were randomly assigned into two conditions, the experimental condition (E PUP) involved efforts to increase both PUP law enforcement and reduce minors' access to commercial sources of tobacco, whereas the control condition (C) focused only on efforts to reduce minors' access to commercial sources of tobacco. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The present study found that over time, youth in the experimental PUP condition observed less youth tobacco usage at school and in their town, and perceived lower rates of tobacco among their peers at school and among friends than youth in the control condition. The findings suggest that PUP law enforcement might be used to strengthen community norms against youth tobacco use.  相似文献   
44.
45.
A thirty six week gestation male baby weighing three kilogram was born to a twenty five year old mother by spontaneous vaginal delivery. At four hours of life, the baby developed respiratory distress with cyanosis and was admitted to the neonatal intensive care unit. There was clinical and radiological evidence of bilateral pleural effusion. Thoracentesis revealed a transudate. Repeated thoracentesis was necessary to relieve the respiratory distress. Subsequently, multi resistant Klebsiella aerogenes was isolated from the blood. The baby expired due to gram negative sepsis.  相似文献   
46.
47.
Cancer mortality in the elderly has rarely been analyzed. It is most notably characterized by the level of diagnostic accuracy at ages prone to comorbidities. Trend analysis over the last thirty years and disparities in mortality have underscored the increasing cancer mortality in the over-65 age bracket as well as the relevance of local health context in understanding the significant differences seen throughout France.  相似文献   
48.
49.
Bulimia is a distinct diagnostic eating disorder with its most noted manifestation being the rapid ingestion of large quantities of food followed by its elimination through the mouth. Because of the dental implications of highly acidic stomach contents chronically being regurgitated, the dentist is in a unique position to help identify the patient with bulimia. Dental erosion is not only the most easily noted but also the most destructive of the many oral problems caused by bulimia. This report of case describes a preventive dental prosthesis that can be used by the patient with bulimia to protect those teeth that are most affected by dental erosion. The construction of the prosthesis is easily completed with materials in the dental office and provides a great service to the patient with bulimia.  相似文献   
50.
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