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   2075939篇
  免费   142620篇
  国内免费   4150篇
耳鼻咽喉   26904篇
儿科学   67730篇
妇产科学   55655篇
基础医学   305936篇
口腔科学   58212篇
临床医学   186847篇
内科学   400878篇
皮肤病学   47276篇
神经病学   155929篇
特种医学   78260篇
外国民族医学   293篇
外科学   313442篇
综合类   44521篇
现状与发展   5篇
一般理论   620篇
预防医学   153365篇
眼科学   49212篇
药学   152392篇
  8篇
中国医学   5133篇
肿瘤学   120091篇
  2019年   16118篇
  2018年   23731篇
  2017年   17921篇
  2016年   19852篇
  2015年   22490篇
  2014年   31055篇
  2013年   45211篇
  2012年   63481篇
  2011年   67296篇
  2010年   39640篇
  2009年   36915篇
  2008年   62440篇
  2007年   66981篇
  2006年   67016篇
  2005年   64010篇
  2004年   61886篇
  2003年   59049篇
  2002年   56910篇
  2001年   106219篇
  2000年   108386篇
  1999年   89420篇
  1998年   23370篇
  1997年   20402篇
  1996年   20427篇
  1995年   19614篇
  1994年   17900篇
  1993年   16633篇
  1992年   67264篇
  1991年   66158篇
  1990年   64143篇
  1989年   61697篇
  1988年   56370篇
  1987年   55131篇
  1986年   51798篇
  1985年   49245篇
  1984年   36220篇
  1983年   30773篇
  1982年   17038篇
  1979年   32360篇
  1978年   22497篇
  1977年   18843篇
  1976年   18067篇
  1975年   19696篇
  1974年   23416篇
  1973年   22560篇
  1972年   20879篇
  1971年   19481篇
  1970年   18165篇
  1969年   16935篇
  1968年   15889篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
Platelet α-granules release growth factors (GFs) that promote healing and tissue regeneration. Platelet-rich plasma (PRP) is shown to be beneficial in treating alopecia, and however, clinical response can be inconsistent. Due to several fold enrichment of platelets secreting large quantities of GFs following PRP injections, heterogeneity in amounts of GFs secreted by platelets may contribute to inconsistent clinical responses. Herein, we evaluated factors that could potentially contribute to heterogeneous secretion of GFs by platelets. We measured platelet secretion of transforming growth factor beta1 (TGFβ1), platelet-derived growth factor (PDGF-BB), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF2) in aliquots of de-identified PRP samples from female patients undergoing therapy in the hair disease clinic. Although secretion of GFs by platelets was comparable in PRP samples of patients with non-cicatricial and cicatricial alopecia, a Shapiro-Wilk test for normal distribution indicated significant variability across all patient samples. The amount of GF secreted by platelets was comparable when PRP prepared from two FDA-cleared devices with distinct techniques were compared. We provide evidence of platelets secreting heterogeneous amounts of GFs within each sample as high and low secretion of random factors could be simultaneously detected. These results suggest inherent heterogeneity in secretion of GFs by platelets in patient samples that are not influenced by the device used to prepare PRP. Since some GFs could have antagonistic effects on hair growth, a balance between amounts of growth promoting and inhibiting factors may be crucial in determining clinical response to PRP therapy.  相似文献   
113.
114.
115.

Introduction The focus in clinical pharmacy practice is and has for the last 30–35 years been on changing the role of pharmacy staff into service orientation and patient counselling. One way of doing this is by involving staff in change process and as a researcher to take part in the change process by establishing partnerships with staff. On the background of the authors’ widespread action research (AR)-based experiences, recommendations and comments for how to conduct an AR-study is described, and one of their AR-based studies illustrate the methodology and the research methods used. Methodology AR is defined as an approach to research which is based on a problem-solving relationship between researchers and clients, which aims at both solving a problem and at collaboratively generating new knowledge. Research questions relevant in AR-studies are: what was the working process in this change oriented study? What learning and/or changes took place? What challenges/pitfalls had to be overcome? What were the influence/consequences for the involved parts? When to use If you want to implement new services and want to involve staff and others in the process, an AR methodology is very suitable. The basic advantages of doing AR-based studies are grounded in their participatory and democratic basis and their starting point in problems experienced in practice. Limitations Some of the limitations in AR-studies are that neither of the participants in a project steering group are the only ones to decide. Furthermore, the collective process makes the decision-making procedures relatively complex.

  相似文献   
116.
117.
118.
Women with pre-eclampsia have an increased risk of cardiovascular disease later in life. The aim of the study was to establish the presence and pattern of arterial stiffness in women previously with pre-eclampsia from a semi-rural region of South Africa. This was a prospective longitudinal study which involved 36 previously pre-eclamptic women and 86 non-pregnant controls (NPC) who had a past history of non-complicated pregnancy. Maternal wave reflection (augmentation index) and carotid-femoral pulse wave velocity were assessed noninvasively, using applanation tonometry with the SphygmoCor device. Endothelial function was assessed by EndoPAT 2000 device; pneumatic probes were fitted to the index fingers; induced flow-mediated reactive hyperemia; the ratio of the readings before and after occlusion was then used to calculate the score, the reactive hyperemia index (RHI) as a measure of endothelial function.

Pulse wave velocity remained significantly higher in previously pre-eclamptic women than non-pregnant controls up to three months after delivery (p < 0.05), then it reduced to nonsignificant values. All blood pressure indices (central and brachial pressures), were higher in previously pre-eclamptic women as compared to nonpregnant controls up to one year postpartum.

Regional (aortic) arterial stiffness, though it persists for some time after delivery, is transitory in previously pre-eclamptic women from the rural Africa setting. However, their increase blood pressure is an indication of compromised arterial compliance in women previously with pre-eclampsia.  相似文献   

119.
120.
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