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   2614篇
  免费   255篇
  国内免费   53篇
耳鼻咽喉   15篇
儿科学   194篇
妇产科学   76篇
基础医学   308篇
口腔科学   54篇
临床医学   191篇
内科学   637篇
皮肤病学   75篇
神经病学   228篇
特种医学   217篇
外科学   271篇
综合类   124篇
预防医学   179篇
眼科学   112篇
药学   132篇
中国医学   5篇
肿瘤学   104篇
  2023年   21篇
  2022年   20篇
  2021年   44篇
  2020年   34篇
  2019年   34篇
  2018年   48篇
  2017年   56篇
  2016年   58篇
  2015年   52篇
  2014年   82篇
  2013年   104篇
  2012年   96篇
  2011年   84篇
  2010年   91篇
  2009年   98篇
  2008年   90篇
  2007年   129篇
  2006年   102篇
  2005年   84篇
  2004年   84篇
  2003年   60篇
  2002年   51篇
  2001年   79篇
  2000年   57篇
  1999年   58篇
  1998年   94篇
  1997年   72篇
  1996年   72篇
  1995年   68篇
  1994年   55篇
  1993年   53篇
  1992年   43篇
  1991年   27篇
  1990年   58篇
  1989年   53篇
  1988年   54篇
  1987年   39篇
  1986年   34篇
  1985年   41篇
  1984年   30篇
  1983年   28篇
  1982年   28篇
  1980年   19篇
  1979年   31篇
  1978年   19篇
  1977年   22篇
  1976年   32篇
  1975年   27篇
  1973年   21篇
  1969年   16篇
排序方式: 共有2922条查询结果,搜索用时 0 毫秒
71.
A substance produced by various types of cells can induce from single hematopoietic cells the formation of colonies of normal macrophages and granulocytes. This inducer has been purified 600-fold from serum-free conditioned medium from a tissue culture line of mouse cells. It is shown that the inducer is a protein, with a molecular weight of 65-70,000, whose inducing activity was about 1 ng per colony. Acrylamide gel electrophoresis of this material gave four bands, only one of which contained inducing activity. The purified protein was inactive. Activity was regained by the addition of a low molecular weight cofactor that is present in conditioned medium. Under certain conditions, activity was also regained by the addition of adenosine 3':5'-cyclic monophosphate (cyclic AMP).  相似文献   
72.
To understand the pattern of utilization of ambulatory care by parents of children with special health care needs (CSHCN) and to explore parental challenges in coping with health maintenance of their infants after discharge from a neonatal intensive care unit (NICU). CSHCN require frequent utilization of outpatient ambulatory clinics especially in their first years of life. Multiple barriers are faced by families in disadvantaged populations which might affect adherence to medical referrals. Our study attempts to go beyond quantitative assessment of adherence rates, and capture the influence of parental agency as a critical factor ensuring optimal utilization of healthcare for CSHCN. A prospective, mixed-methods, cohort study followed 158 Jewish and Bedouin-Arab infants in the first year post discharge from NICU in southern Israel. Rates of utilization of ambulatory clinics were obtained from medical records, and quantitative assessment of factors affecting it was based on structured interviews with parents at baseline. Qualitative analysis was based on home visits or telephone in-depth interviews conducted about 1 year post-discharge, to obtain a rich, multilayered, experiential perspectives and explained perceptions by parents. Adherence to post-discharge referrals was generally good, but environmental, cultural, and financial obstacles to healthcare, magnified by communication barriers, forced parents with limited resources to make difficult choices affecting utilization of healthcare services. Improving concordance between primary caregivers and health care providers is crucial, and further development of supportive healthcare for CSHCN in concordance with parental limitations and preferences is needed.  相似文献   
73.
Chiasmal dysfunction produces a characteristic clinical picture, regardless of the mechanism. In most cases a compressive lesion is the cause. In occasional cases, however, no such extrinsic mass is found and other possible etiologies must be explored. In some of these cases, the pathologic process is identifiable with appropriate neuroimaging. For example, inflammation, infiltrative tumors, and radiation necrosis produce intrinsic chiasmal enhancement. Chiasmal ischemia may require specialized magnetic resonance (MR) sequences for diagnosis. Chiasmal hemorrhage, trauma and chiasmal herniation typically produce distinctive changes on noncontrasted imaging. In cases of metabolic insult, either toxic or hereditary, radiographic changes are typically absent. In each of these, the correct diagnosis can usually be made with a combination of clinical and radiographic features.  相似文献   
74.
75.
To compare sleep quality and sleep–wake patterns in parents of children with type 1 diabetes before routine use of the continuous glucose monitoring system (CGMS) and while using it. Thirteen parents completed the Pittsburg Sleep Quality Index (PSQI), a 7-day sleep diary, and wore an actigraph (a wristwatch-size motion detector) during the night for 1 week before pediatric use of CGMS and 4–8 weeks after initiating routine use of the CGMS. Mean age of parents (ten mothers, three fathers) was 39 (range 32–47) years; mean age of children was 9.3 years (range 5.5–16.5 years); mean disease duration was 3.4 (range 0.6–11.2) years. PSQI total score demonstrated similar quality of sleep with and without use of the CGMS (4.6 and 4.9, respectively, p = 0.45). Six of the 13 parents reported severe sleep problems (PSQI ≥ 5) with and without the CGMS. The sleep diary indicated a greater number of awakening episodes during CGMS use than without the CGMS (1.6 and 1, respectively, p = 0.03), and actigraphy documented an increase in the number of wake bouts (22.9 and 19.7, p = 0.03) as well as in total wake time (48.3 and 42.2 min, p = 0.03) during CGMS use as compared with the period prior to CGMS use. Although self-perception of sleep quality remained unchanged, CGMS use appeared to affect actual parental sleep continuity somewhat negatively. This should be made clear to parents who may hold expectations of improvement in sleep quality following initiation of CGMS use.  相似文献   
76.
77.
We present the 2021 Singapore Paediatric Resuscitation Guidelines. The International Liaison Committee on Resuscitation’s Pediatric Taskforce Consensus Statements on Science and Treatment Recommendations, which was published in October 2020, and the updated resuscitation guidelines from the American Heart Association and European Resuscitation Council, were reviewed and discussed by the committee. These recommendations were derived after deliberation of peer-reviewed evidence updates on paediatric resuscitation and took into consideration the local setting and clinical practice.  相似文献   
78.
79.
80.
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