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   1952篇
  免费   116篇
  国内免费   10篇
耳鼻咽喉   6篇
儿科学   52篇
妇产科学   56篇
基础医学   319篇
口腔科学   38篇
临床医学   150篇
内科学   433篇
皮肤病学   105篇
神经病学   196篇
特种医学   64篇
外科学   162篇
综合类   16篇
预防医学   198篇
眼科学   38篇
药学   112篇
中国医学   7篇
肿瘤学   126篇
  2023年   18篇
  2022年   39篇
  2021年   86篇
  2020年   41篇
  2019年   60篇
  2018年   70篇
  2017年   46篇
  2016年   52篇
  2015年   43篇
  2014年   91篇
  2013年   105篇
  2012年   135篇
  2011年   161篇
  2010年   80篇
  2009年   98篇
  2008年   120篇
  2007年   130篇
  2006年   120篇
  2005年   112篇
  2004年   86篇
  2003年   96篇
  2002年   90篇
  2001年   16篇
  2000年   17篇
  1999年   19篇
  1998年   19篇
  1997年   19篇
  1996年   16篇
  1995年   16篇
  1994年   2篇
  1993年   3篇
  1992年   10篇
  1991年   4篇
  1990年   6篇
  1989年   7篇
  1988年   4篇
  1987年   3篇
  1986年   4篇
  1985年   3篇
  1984年   3篇
  1983年   3篇
  1980年   4篇
  1978年   3篇
  1977年   2篇
  1948年   1篇
  1947年   1篇
  1943年   1篇
  1934年   1篇
  1913年   2篇
  1912年   3篇
排序方式: 共有2078条查询结果,搜索用时 15 毫秒
31.
Previous in vivo and in vitro studies have reported that low-level diode laser therapy induces a biostimulatory effect, such as cell proliferation. The aim of the present study was to evaluate whether the laser irradiation of osteoblast-like cells (MG-63) can modify alkaline phosphatase activity (ALP), antigenic profile, and phagocytic capacity. The MG-63 cell line was exposed to diode laser (ezLase) of 940 nm at 1–1.5 W/cm2 and 3–4 J. ALP was evaluated by a spectrophotometric technique and antigenic expression analysis (CD 54, CD80, CD86, HLA-DR), and phagocytic activity was analyzed by flow cytometry. At 24 h, the treated groups showed an increased ALP, and the highest increase versus controls (P?=?0.002) was at the dose of 1 W/cm2 and 3 J; this modulation of the antigenic profile translated into a reduced expression of CD54, CD86, and HLA-DR and a slightly decreased phagocytic capacity with respect to the nonirradiated control group at the different intensities and fluencies assayed. These results demonstrate that laser therapy can exert a biostimulatory effect on osteoblastic cells at different levels, which may be clinically useful in the regeneration of bone tissue.  相似文献   
32.
33.
Renal dysfunction is closely associated with endothelial damage leading to cardiovascular disease. However, the extent to which endothelial damage induced by uremia is modulated by aging is poorly known. Aging can render endothelial cells more susceptible to apoptosis through an oxidative stress-dependent pathway. We examined whether senescence-associated to oxidative stress determines the injury induced by the uremia in endothelial cells.  相似文献   
34.
35.
36.
Contrary to the English /r/, which has been extensively analysed, there is very little information on the trilled consonants in Spanish. These sounds are in general difficult to produce for young Spanish children and occur later (than other consonant sounds) in normal development. This paper describes acoustic measurements made on the trill productions in Spanish children with varying degrees of speech intelligibility. The spectral (frequency, amplitude, C-V ratio) and temporal characteristics (duration of the trill, number of open and closed periods?apertures and occlusions-and duration of these periods) were studied in 45 children (Granada, Spain) between 3.0 and 9.6 years old, divided into 5 groups. The results reveal differences in spectral and temporal acoustic correlates of trill /r/ among the five speaker groups (e.g., the duration of the first aperture period was longer for the articulatory disordered group than for the normal control group). They seem to indicate, in particular, that children who have trouble learning to make the trill sound do little more than tap the alveolar ridge. Moreover, these children seem to use more of their tongues to make these gestures; also, they do not make many trills or make them very quickly.  相似文献   
37.
38.
BACKGROUND: Aims of the present study were to examine the anthropometrical and metabolic characteristics of the Filipino population migrant to the Southern European city of Rome, Italy. METHODS: A cross-sectional study was carried out in the city of Rome. Three hundred thirty-five Filipinos (95 M/240 F, mean age: 44.0+/-9.8 years, mean residence in Italy: 12.9+/-6.3 years) were studied. Data were collected by standardized questionnaires; anthropometrical parameters, arterial pressure, and fasting capillary blood glucose (FCG) were measured. RESULTS: Abdominal obesity was found in 52.5%, and BMI >or= 25 kg/m(2) in 44.5% of subjects. History of type 2 diabetes mellitus (T2DM) and hypertension were reported by 6.0 and 9.0% of subjects, respectively. Impaired fasting glucose was found in 13.1%, and FCG >or= 110 mg/dl in 18.5% of subjects. Altered systolic and/or diastolic blood pressure was found in 34.3% of subjects. About three-fourths of subjects were unaware of being diabetic and/or hypertensive. Years of Italy residence showed a direct significant correlation with the degree of changes in alimentary behaviours (rho=0.18, p=0.001), and with weight gain (rho=0.27, p<0.001). Multivariate analysis showed only age and waist circumference to be associated with both diabetes and hypertension. CONCLUSIONS: In the present study, the first to examine the metabolic disorders in a migrant Filipino population resident in Rome, a high prevalence of obesity, diabetes, and hypertension was found. The alarming results emerging from this study should be seriously considered by public health practitioners and decision makers, and made known to the Filipinos resident in Europe.  相似文献   
39.
40.
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