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   8698篇
  免费   468篇
  国内免费   67篇
耳鼻咽喉   104篇
儿科学   119篇
妇产科学   74篇
基础医学   1146篇
口腔科学   214篇
临床医学   474篇
内科学   2193篇
皮肤病学   234篇
神经病学   720篇
特种医学   411篇
外科学   1661篇
综合类   47篇
一般理论   1篇
预防医学   199篇
眼科学   79篇
药学   447篇
中国医学   22篇
肿瘤学   1088篇
  2024年   7篇
  2023年   80篇
  2022年   112篇
  2021年   297篇
  2020年   135篇
  2019年   215篇
  2018年   258篇
  2017年   205篇
  2016年   275篇
  2015年   266篇
  2014年   326篇
  2013年   353篇
  2012年   569篇
  2011年   650篇
  2010年   372篇
  2009年   347篇
  2008年   512篇
  2007年   598篇
  2006年   557篇
  2005年   578篇
  2004年   510篇
  2003年   470篇
  2002年   490篇
  2001年   90篇
  2000年   70篇
  1999年   94篇
  1998年   107篇
  1997年   115篇
  1996年   73篇
  1995年   83篇
  1994年   37篇
  1993年   53篇
  1992年   40篇
  1991年   34篇
  1990年   40篇
  1989年   25篇
  1988年   29篇
  1987年   25篇
  1986年   14篇
  1985年   12篇
  1984年   8篇
  1983年   14篇
  1982年   12篇
  1981年   10篇
  1980年   10篇
  1979年   10篇
  1978年   11篇
  1975年   4篇
  1974年   7篇
  1967年   5篇
排序方式: 共有9233条查询结果,搜索用时 218 毫秒
111.
112.
The purpose of this study was to examine the shear fatigue strengths of a resin composite bonded to dentin. Three adhesive systems – a two‐step self‐etch adhesive (OptiBond XTR; Kerr) and two universal adhesives [Scotchbond Universal (3M ESPE) and G‐Premio Bond (GC)] – were used in self‐etch mode to bond a resin composite to dentin at a physiologic frequency of 2 Hz over 50,000, 100,000, and 1,000,000 cycles. A staircase method of fatigue testing was used. Twenty specimens were used for each test condition. There was no significant difference in shear fatigue strength across the cycling periods for the three individual adhesives. Differences in shear fatigue strength were found among the three adhesives within each cycling period. Regardless of the adhesive used in self‐etch mode for bonding a resin composite to dentin, shear fatigue strength was not influenced by the number of cycles used for testing.  相似文献   
113.
114.
Aim: The aim of this study was to investigate the relationship among the expression of suppressor of cytokine signaling 3 (SOCS 3) in the liver, the SNPs in the IL28B locus, and the outcome of interferon therapy. Methods: Prior to interferon treatment, we immunostained 67 liver specimens from chronic hepatitis C (CHC) patients who were receiving peginterferon alpha‐2b/ribavirin therapy for suppressor of cytokine signaling 3 (SOCS3), and compared the expression of SOCS3, IL28 polymorphisms and other clinical factors between the patients and compared their eventual outcomes. Results: Significant differences between the low SOCS3 group and high SOCS3 group were found in age, as well as in the platelet, transaminase, gamma‐glutamyl transpeptidase levels. The incidence of high SOCS3 was not significantly different between subjects with the TT genotype and the TG genotype (TT : TG = 71%:29%, P = 0.250). In a multivariate analysis, age (≥65 years old) (odds ratio 0.221 [0.120–0.966], P = 0.045), IL28B gene (genotype TT) (odds ratio 5.422 [1.254–23.617], P = 0.024) and SOCS3 (high) (odds ratio 0.308 [0.104–0.948], P = 0.040) were significant predictors of the interferon response. In patients with the TT genotype, those with low SOCS3 immunostaining showed a high sustained virological response (69%), while the sustained virological rate was low (27%) in the patients with high SOCS3 immunostaining. Conclusions: Using a combination of the SOCS3 immunostained area in the liver and the expression of IL28B single nucleotide polymorphisms might be a useful predictor of hepatitis C virus clearance by interferon therapy.  相似文献   
115.
Association of congenital cytomegalovirus (CMV) infection with autism spectral disorder (ASD) has been suggested since 1980s. Despite the observed association, its role as a risk factor for ASD remains to be defined. In the present review, we systematically evaluated the available evidence associating congenital CMV infection with ASD using PubMed, Web of Science, Cochrane Library, and Embase databases. Any studies on children with CMV infection and ASD were evaluated for eligibility and three observational studies were included in meta-analysis. Although a high prevalence of congenital CMV infection in ASD cases (OR 11.31, 95% CI 3.07–41.66) was indicated, too few events (0–2 events) in all included studies imposed serious limitations. There is urgent need for further studies to clarify this issue.  相似文献   
116.
117.
BackgroundHallux valgus (HV) is an important risk factor for falls (in older people); however, the detailed relationship is less understood. We aimed to evaluate postural stability in bilateral HV patients.MethodsTwo groups of 20 female patients—an HV group and a C (i.e., non-HV) group—participated in this study. Evaluations were made using the Timed Up and Go (TUG) test, the Berg Balance Scale (BBS), the Falls Efficacy Scale (FES), track length (LNG), velocity (VEL), enveloped area (ENV), and root mean square area (RMS).ResultsTUG and FES scores were significantly higher and BBS scores were lower in the HV group than in the C group. LNG was significantly longer, VEL was higher, and ENV and RMS were wider in the HV group than in the C group.ConclusionsThe HV group exhibited impaired walking mobility, balance, and postural stability.  相似文献   
118.
Self‐adhesive resin cements are useful in restorations because they reduce the number of clinical steps involved in the restoration process. This study evaluated, using ultrasonic measurements, the influence of light irradiation and the presence of water on the polymerization behavior and elastic modulus of a self‐adhesive resin cement. A self‐adhesive resin cement (RelyX Unicem 2 Automix) or a resin cement (RelyX ARC) was inserted into a transparent mold on a sample stage, and the presence of water and effect of light‐irradiation were evaluated. The transit time of a sonic wave through the cement disk was divided by the specimen thickness to obtain the sonic velocity, and longitudinal and shear waves were used to determine the elastic modulus. When the resin cements were light‐irradiated, the sonic velocity rapidly increased and plateaued at 2,500–2,700 m s?1. When the cements were not irradiated, the rates of increase in the sonic velocity were reduced. When water was applied to the sample stage, the sonic velocity was reduced. The elastic modulus values of the specimens ranged from 9.9 to 15.9 GPa after 24 h. The polymerization behavior of self‐adhesive resin cements is affected by the polymerization mode and the presence of water.  相似文献   
119.
The present study aimed to determine the effect of the functional monomer, 10‐methacryloxydecyl dihydrogen phosphate (MDP), on the enamel bond durability of single‐step self‐etch adhesives through integrating fatigue testing and long‐term water storage. An MDP‐containing self‐etch adhesive, Clearfil Bond SE ONE (SE), and an experimental adhesive, MDP‐free (MF), which comprised the same ingredients as SE apart from MDP, were used. Shear bond strength (SBS) and shear fatigue strength (SFS) were measured with or without phosphoric acid pre‐etching. The specimens were stored in distilled water for 24 h, 6 months, or 1 yr. Although similar SBS and SFS values were obtained for SE with pre‐etching and for MF after 24 h of storage in distilled water, SE with pre‐etching showed higher SBS and SFS values than MF after storage in water for 6 months or 1 yr. Regardless of the pre‐etching procedure, SE showed higher SBS and SFS values after 6 months of storage in distilled water than after 24 h or 1 yr. To conclude, MDP might play an important role in enhancing not only bond strength but also bond durability with respect to repeated subcritical loading after long‐term water storage.  相似文献   
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