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   16058篇
  免费   859篇
  国内免费   124篇
耳鼻咽喉   151篇
儿科学   319篇
妇产科学   351篇
基础医学   1860篇
口腔科学   393篇
临床医学   1215篇
内科学   5034篇
皮肤病学   412篇
神经病学   1282篇
特种医学   290篇
外科学   2232篇
综合类   96篇
一般理论   8篇
预防医学   1047篇
眼科学   300篇
药学   889篇
中国医学   37篇
肿瘤学   1125篇
  2024年   13篇
  2023年   137篇
  2022年   305篇
  2021年   696篇
  2020年   310篇
  2019年   622篇
  2018年   683篇
  2017年   404篇
  2016年   417篇
  2015年   449篇
  2014年   734篇
  2013年   803篇
  2012年   1468篇
  2011年   1475篇
  2010年   766篇
  2009年   687篇
  2008年   1097篇
  2007年   1101篇
  2006年   950篇
  2005年   908篇
  2004年   833篇
  2003年   670篇
  2002年   680篇
  2001年   69篇
  2000年   56篇
  1999年   80篇
  1998年   101篇
  1997年   96篇
  1996年   66篇
  1995年   44篇
  1994年   46篇
  1993年   38篇
  1992年   24篇
  1991年   19篇
  1990年   17篇
  1989年   14篇
  1988年   13篇
  1987年   10篇
  1986年   9篇
  1985年   6篇
  1984年   14篇
  1983年   9篇
  1982年   11篇
  1981年   12篇
  1980年   11篇
  1979年   8篇
  1975年   11篇
  1971年   9篇
  1970年   5篇
  1967年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
144.
145.
The intervention program for autism known as Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH) is considered an emerging practice for autism. In the present study we used state-of-the-art meta-analytical procedures to examine the pooled clinical effects of TEACCH in a variety of outcomes. A total of 13 studies were selected for meta-analysis totaling 172 individuals with autism exposed to TEACCH. Standardized measures of perceptual, motor, adaptive, verbal and cognitive skills were identified as treatment outcomes. We used inverse-variance weighted random effects meta-analysis supplemented with quality assessment, sensitivity analysis, meta-regression, and heterogeneity and publication bias tests. The results suggested that TEACCH effects on perceptual, motor, verbal and cognitive skills were of small magnitude in the meta-analyzed studies. Effects over adaptive behavioral repertoires including communication, activities of daily living, and motor functioning were within the negligible to small range. There were moderate to large gains in social behavior and maladaptive behavior. The effects of the TEACCH program were not moderated by aspects of the intervention such as duration (total weeks), intensity (hours per week), and setting (home-based vs. center-based). While the present meta-analysis provided limited support for the TEACCH program as a comprehensive intervention, our results should be considered exploratory owing to the limited pool of studies available.  相似文献   
146.
ObjectivesTo determine the impact of energy density on diet quality and anthropometric proxy measures for central body fat in young Spaniards.MethodsData were obtained from a representative national sample of 2513 young Spaniards aged 10 to 24 y. Dietary assessment was performed with a 24-h recall. Adherence to the Mediterranean diet was measured by the KIDMED index. Reduced rank regression analysis was used to identify energy-density dietary patterns. Waist circumferences and height were measured.ResultsPastries and sausages showed the strongest loading for the dietary energy density factor score (DED-FS), with fruits and vegetables at the opposite end of the scale. Multiple linear regression analysis showed a positive association (P < 0.01) of dietary energy density (DED) and the DED-FS with waist circumferences regressed on height and age (WCheight+age) and waist-to-height ratio (WHtR). The adjusted odds ratio for elevated WCheight+age and WHtR increased across quartile distribution of DED (P < 0.001) and DED-FS (P < 0.05). Diet quality characterized by the KIDMED index was negatively associated (P < 0.001) with DED and the DED-FS.ConclusionsHigher DED is a risk for increased central fat distribution and is associated with low adherence to the Mediterranean diet.  相似文献   
147.
148.
149.
The purpose of this study was to characterize mineral trioxide aggregates (MTA) enriched with iron disulfide (FeS2) nanostructures at different concentrations, and to investigate their storage modulus, radiopacity, setting time, pH, cytotoxicity, and antimicrobial activity. Iron disulfide nanostructures [with particle size of 0.357 ± 0.156 μm (mean ± SD)] at weight ratios of 0.2, 0.4, 0.6, 0.8, and 1.0 wt% were added to white MTA (wMTA). The radiopacity, rheological properties, setting time, and pH, as well as the cytotoxicity (assessed using the MTT assay) and antibacterial activity (assessed using the broth microdilution test) were determined for MTA/FeS2 nanostructures. The nanostructures did not modify the radiopacity values of wMTA (~6 mm of aluminium); however, they reduced the setting time from 18.2 ± 3.20 min to 13.7 ± 1.8 min, and the storage modulus was indicative of a good stiffness. Whereas the wMTA/FeS2 nanostructures did not induce cytotoxicity when in contact with human pulp cells (HPCs) and human gingival fibroblasts (HGFs), they showed bacteriostatic activity against Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis. Adding FeS2 nanostructures to MTA might be an option for improving the root canal sealing and antibacterial effects of wMTA in endodontic treatments.  相似文献   
150.
Abstract

Polyurethanes (PU) foams with titanium particles (Ti) were prepared with castor oil (CO) and isophorone diisocyanate (IPDI) as polymeric matrix, and 1, 3 and 5?wt.% of Ti. Composites were physicochemically and mechanically characterized and their biocompatibility assessed using human dental pulp stem cells (HDPSC). PU synthesis was confirmed by FTIR, but the presence of Ti was detected by RAMAN, X-ray diffraction (peak at 2θ?=?40.2°) and by EDX-mapping. Materials showed three decomposition temperatures between 300?°C and 500?°C and their decomposition were not catalyzed by Ti particles. Compressive modulus (164–846?kPa), compressive strength (12.9–116.7?kPa) and density (128–240?kg/m3) tend to increase with Ti concentration but porosity was reduced (87% to 80%). Composites’ foams were fully degraded in acid and oxidative media while remained stable in distilled water. HDPSC viability on all composites was higher than 80% up to 14?days while proliferation dropped up to 60% at 21?days. Overall, these results suggest that these foams can be used as scaffolds for bone tissue regeneration.  相似文献   
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