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   133篇
  免费   5篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   19篇
妇产科学   3篇
基础医学   18篇
口腔科学   18篇
临床医学   7篇
内科学   20篇
皮肤病学   1篇
神经病学   11篇
特种医学   2篇
外科学   21篇
预防医学   6篇
药学   5篇
肿瘤学   7篇
  2023年   4篇
  2022年   3篇
  2021年   2篇
  2019年   8篇
  2018年   3篇
  2017年   3篇
  2016年   3篇
  2015年   2篇
  2014年   3篇
  2013年   3篇
  2012年   9篇
  2011年   6篇
  2010年   2篇
  2009年   3篇
  2008年   5篇
  2007年   9篇
  2006年   8篇
  2005年   6篇
  2004年   3篇
  2003年   3篇
  2002年   5篇
  2001年   2篇
  2000年   1篇
  1999年   3篇
  1998年   2篇
  1996年   2篇
  1992年   1篇
  1991年   2篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1985年   1篇
  1979年   2篇
  1976年   1篇
  1974年   1篇
  1971年   3篇
  1970年   3篇
  1969年   3篇
  1968年   7篇
  1967年   1篇
  1966年   4篇
排序方式: 共有139条查询结果,搜索用时 590 毫秒
31.
Poultry production in low income countries provides households with nutrient‐rich meat and egg products, as well as cash income. However, traditional production systems present potential health and nutrition risks because poultry scavenging around household compounds may increase children's exposure to livestock‐related pathogens. Data from a cross‐sectional survey were analysed to examine associations between poultry, water, sanitation, and hygiene practices, and anthropometric indicators in children (6–59 months; n = 3,230) in Burkina Faso. Multilevel regression was used to account for the hierarchical nature of the data. The prevalence of stunting and wasting in children 6–24 months was 19% and 17%, respectively, compared with a prevalence of 26% and 6%, respectively, in children 25–60 months. Over 90% of households owned poultry, and chicken faeces were visible in 70% of compounds. Caregivers reported that 3% of children consumed eggs during a 24‐hr recall. The presence of poultry faeces was associated with poultry flock size, poultry‐husbandry and household hygiene practices. Having an improved water source and a child visibly clean was associated with higher height‐for‐age z scores (HAZ). The presence of chicken faeces was associated with lower weight‐for‐height z scores, and no associations were found with HAZ. Low levels of poultry flock size and poultry consumption in Burkina Faso suggest there is scope to expand production and improve diets in children, including increasing chicken and egg consumption. However, to minimize potential child health risks associated with expanding informal poultry production, research is required to understand the mechanisms through which cohabitation with poultry adversely affects child health and design interventions to minimize these risks.  相似文献   
32.
33.
The aim of this study was to evaluate the kinetics of conversion of Scotchbond Multi-purpose Plus (3M ESPE, St Paul, MN) and Prime&Bond NT (Dentsply De Trey, Konstanz, Germany) used in light-cured, self-cured, or dual-cured versions. The adhesive systems were used in the light-cured version (without the use of chemical initiator) or mixed with its respective chemical initiator either with light activation (dual-cured) or not (self-cured). The degree of conversion (DC) was monitored as a function of time during 5 minutes with a Fourier transform infrared spectrometer equipped with an attenuated total reflectance device. Light-cured and dual-cured modes of Scotchbond Multi-purpose Plus presented the highest DC at 5 minutes. The addition of the self-cure activator (dual-cured mode) to Prime&Bond NT reduced the DC. For the self-cured versions, only the Scotchbond Multi-purpose Plus presented any polymerization reaction at 5 minutes. For the two bonding systems tested, it appears that light curing of the adhesive is important in order to reach a high DC in the first moments after the bonding procedure.  相似文献   
34.
35.
36.
37.
Human insulin receptors obtained from normal human placentae were highly purified by affinity chromatography and used to immunize rabbits. The immunological response was evaluated in order to reveal the presence of antibodies blocking the binding of insulin to monocytes of normal subjects. Since no blocking activity was found IgG from rabbits were coupled to agarose in order to evaluate the presence of antibodies directed to determinant(s) other than the insulin binding site. One rabbit was found to produce antibodies binding the insulin receptor on a site different from the insulin binding site.  相似文献   
38.
39.
BACKGROUNDSurgical resection and radiofrequency ablation (RFA) represent two possible strategy in treatment of hepatocellular carcinoma (HCC) in Milan criteria.AIMTo evaluate short- and long-term outcome in elderly patients (> 70 years) with HCC in Milan criteria, which underwent liver resection (LR) or RFA.METHODSThe study included 594 patients with HCC in Milan criteria (429 in LR group and 165 in RFA group) managed in 10 European centers. Statistical analysis was performed using the Kaplan-Meier method before and after propensity score matching (PSM) and Cox regression.RESULTSAfter PSM, we compared 136 patients in the LR group with 136 patients in the RFA group. Overall survival at 1, 3, and 5 years was 91%, 80%, and 76% in the LR group and 97%, 67%, and 41% in the RFA group respectively (P = 0.001). Disease-free survival at 1, 3, and 5 years was 84%, 60% and 44% for the LR group, and 63%, 36%, and 25% for the RFA group (P = 0.001).Postoperative Clavien-Dindo III-IV complications were lower in the RFA group (1% vs 11%, P = 0.001) in association with a shorter length of stay (2 d vs 7 d, P = 0.001).In multivariate analysis, Model for End-stage Liver Disease (MELD) score (> 10) [odds ratio (OR) = 1.89], increased value of international normalized ratio (> 1.3) (OR = 1.60), treatment with radiofrequency (OR = 1.46) ,and multiple nodules (OR = 1.19) were independent predictors of a poor overall survival while a high MELD score (> 10) (OR = 1.51) and radiofrequency (OR = 1.37) were independent factors associated with a higher recurrence rate.CONCLUSIONDespite a longer length of stay and a higher rate of severe postoperative complications, surgery provided better results in long-term oncological outcomes as compared to ablation in elderly patients (> 70 years) with HCC in Milan criteria.  相似文献   
40.
AIM: The aim of this study was to evaluate the microleakage of seven adhesive systems on two substrates (enamel and dentin). METHODS AND MATERIALS: Class V cavities were performed in buccal and lingual surfaces of 56 bovine incisors. The cervical margin was located in dentin and the incisal margin in enamel. The specimens were randomly divided into seven groups (n=16), according to the adhesive system employed: Single Bond; Excite; One Step Plus; Gluma One Bond; Magic Bond; One Up Bond F; and One Coat Bond. The cavities were incrementally filled with a hybrid composite Filtek Z250 and polymerized with a XL 3000 light curing unit. After polishing, the specimens were submitted to thermal cycling followed by dye immersion. Leakage was evaluated under magnification (40X) based on a standard ranking. Data were subjected to statistical analysis (Kruskal-Wallis). RESULTS: Enamel margins exhibited lower leakage than dentin margins (p<0.01). The majority of the specimens were leakage-free and materials performed similarly. Conversely, in dentin most of the specimens exhibited the highest leakage degree and significant differences among materials (p<0.05) were found, with Excite exhibiting the lowest leakage degree. It was concluded enamel provided better sealing and the adhesive system was a significant factor only in dentin.  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