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   75112篇
  免费   6172篇
  国内免费   451篇
耳鼻咽喉   1140篇
儿科学   1776篇
妇产科学   1496篇
基础医学   11155篇
口腔科学   1118篇
临床医学   7113篇
内科学   15337篇
皮肤病学   2022篇
神经病学   6774篇
特种医学   3864篇
外科学   10528篇
综合类   752篇
一般理论   67篇
预防医学   5039篇
眼科学   1699篇
药学   5532篇
中国医学   458篇
肿瘤学   5865篇
  2023年   497篇
  2022年   367篇
  2021年   2024篇
  2020年   1395篇
  2019年   2079篇
  2018年   2447篇
  2017年   1810篇
  2016年   2242篇
  2015年   2862篇
  2014年   3572篇
  2013年   4242篇
  2012年   6134篇
  2011年   5957篇
  2010年   3482篇
  2009年   2830篇
  2008年   4135篇
  2007年   4190篇
  2006年   3726篇
  2005年   3485篇
  2004年   2964篇
  2003年   2583篇
  2002年   2315篇
  2001年   1136篇
  2000年   1073篇
  1999年   950篇
  1998年   464篇
  1997年   405篇
  1996年   361篇
  1995年   392篇
  1994年   318篇
  1993年   341篇
  1992年   702篇
  1991年   732篇
  1990年   638篇
  1989年   698篇
  1988年   680篇
  1987年   668篇
  1986年   580篇
  1985年   588篇
  1984年   482篇
  1983年   407篇
  1982年   336篇
  1981年   298篇
  1980年   263篇
  1979年   375篇
  1978年   338篇
  1977年   226篇
  1974年   243篇
  1973年   262篇
  1972年   212篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Journal of Immigrant and Minority Health - Little attention has been paid to online health information seeking (OHIS) among immigrants residing in rural areas. This study examines the intensity of...  相似文献   
2.
3.
4.
The aim of this study is to evaluate the prevalence, determinants and prognostic value of pain at diagnosis in patients with desmoid-type fibromatosis (DF). We selected patients from the ALTITUDES cohort (NCT02867033), managed by surgery, active surveillance or systemic treatments, with pain assessment at diagnosis. Patients were invited to fill QLQ-C30 questionnaire and Hospital Anxiety Depression Scale. Determinants were identified using logistic models. Prognostic value on event-free survival (EFS) was evaluated using the Cox model. Overall, 382 patients were included in the current study (median age: 40.2 years; 117 men). The prevalence of pain was 36%, without significant difference according to first-line treatment (P = .18). In the multivariate analysis, pain was significantly associated with tumor size >50 mm (P = .013) and tumor site (P < .001); pain was more frequent in the neck and shoulder locations (odds ratio: 3.05 [1.27-7.29]). Pain at baseline was significantly associated with poor quality of life (P < .001), depression (P = .02), lower performance status (P = .03) and functional impairment (P = .001); we also observed a nonsignificant association with anxiety (P = .10). In the univariate analysis, baseline pain was associated with poor EFS; the 3-year EFS was 54% in patients with pain compared to 72% in those without pain. After adjustment for sex, age, size and line of treatment, pain was still associated with poor EFS (hazard ratio: 1.82 [1.23-2.68], P = .003). One third of recently diagnosed patients with DF experienced pain, especially those with larger tumors and neck/shoulder locations. Pain was associated with unfavorable EFS after adjustment for the confounders.  相似文献   
5.
Amacrine cells of the retina are conspicuously variable in their morphologies, their population demographics, and their ensuing functions. Vesicular glutamate transporter 3 (VGluT3) amacrine cells are a recently characterized type of amacrine cell exhibiting local dendritic autonomy. The present analysis has examined three features of this VGluT3 population, including their density, local distribution, and dendritic spread, to discern the extent to which these are interrelated, using male and female mice. We first demonstrate that Bax-mediated cell death transforms the mosaic of VGluT3 cells from a random distribution into a regular mosaic. We subsequently examine the relationship between cell density and mosaic regularity across recombinant inbred strains of mice, finding that, although both traits vary across the strains, they exhibit minimal covariation. Other genetic determinants must therefore contribute independently to final cell number and to mosaic order. Using a conditional KO approach, we further demonstrate that Bax acts via the bipolar cell population, rather than cell-intrinsically, to control VGluT3 cell number. Finally, we consider the relationship between the dendritic arbors of single VGluT3 cells and the distribution of their homotypic neighbors. Dendritic field area was found to be independent of Voronoi domain area, while dendritic coverage of single cells was not conserved, simply increasing with the size of the dendritic field. Bax-KO retinas exhibited a threefold increase in dendritic coverage. Each cell, however, contributed less dendrites at each depth within the plexus, intermingling their processes with those of neighboring cells to approximate a constant volumetric density, yielding a uniformity in process coverage across the population.SIGNIFICANCE STATEMENT Different types of retinal neuron spread their processes across the surface of the retina to achieve a degree of dendritic coverage that is characteristic of each type. Many of these types achieve a constant coverage by varying their dendritic field area inversely with the local density of like-type neighbors. Here we report a population of retinal amacrine cells that do not develop dendritic arbors in relation to the spatial positioning of such homotypic neighbors; rather, this cell type modulates the extent of its dendritic branching when faced with a variable number of overlapping dendritic fields to approximate a uniformity in dendritic density across the retina.  相似文献   
6.
7.
No national epidemiological investigations have been conducted recently regarding facial lacerations. The study was performed using the data of 3,634,229 people during the 5-year period from 2014 to 2018 archived by the National Health Information Database (NHID) of the Health Insurance Review and Assessment Service. Preschool and children under 10 years old accounted for about one-third of patients. Facial lacerations were concentrated in the “T-shaped” area, which comprised forehead, nose, lips, and the perioral area. The male to female ratio for all study subjects was 2.16:1. Age and gender are significantly related with each other (P < .001). Mean hospital stays decreased, and numbers of outpatient department visits per patient were highest for hospitals and lowest for health agencies. Over the study period, hospital costs per patient in tertiary and general hospitals increased gradually. Preschool and school-aged children are vulnerable to trauma. Male patients outnumbered female patients by a factor of more than 2. The “T-shaped’” area around forehead is vulnerable to injury. Total cost of medical care benefits per patient in tertiary hospitals was about 7 times on average than in health agencies. Regarding functional, behavioral, and aesthetic outcomes, more attention should be paid to epidemiologic data and hospital costs for facial lacerations.  相似文献   
8.
9.
Erythema induratum of Bazin (EIB) is a form of tuberculid resulting from hypersensitivity to tuberculosis antigen. EIB occurs most commonly in middle‐aged women and is not typically seen in children. Here, we present a rare case of EIB, presenting as a chronic nodular panniculitis, in a 10‐year‐old Korean boy.  相似文献   
10.
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