全文获取类型
收费全文 | 36302篇 |
免费 | 2282篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 325篇 |
儿科学 | 1165篇 |
妇产科学 | 1015篇 |
基础医学 | 4964篇 |
口腔科学 | 617篇 |
临床医学 | 5926篇 |
内科学 | 6586篇 |
皮肤病学 | 636篇 |
神经病学 | 3522篇 |
特种医学 | 607篇 |
外科学 | 3133篇 |
综合类 | 404篇 |
一般理论 | 55篇 |
预防医学 | 4524篇 |
眼科学 | 468篇 |
药学 | 2122篇 |
中国医学 | 68篇 |
肿瘤学 | 2556篇 |
出版年
2023年 | 183篇 |
2022年 | 374篇 |
2021年 | 784篇 |
2020年 | 465篇 |
2019年 | 784篇 |
2018年 | 907篇 |
2017年 | 622篇 |
2016年 | 650篇 |
2015年 | 839篇 |
2014年 | 1179篇 |
2013年 | 1793篇 |
2012年 | 2660篇 |
2011年 | 2821篇 |
2010年 | 1535篇 |
2009年 | 1295篇 |
2008年 | 2547篇 |
2007年 | 2562篇 |
2006年 | 2576篇 |
2005年 | 2395篇 |
2004年 | 2314篇 |
2003年 | 2189篇 |
2002年 | 2054篇 |
2001年 | 223篇 |
2000年 | 154篇 |
1999年 | 304篇 |
1998年 | 413篇 |
1997年 | 367篇 |
1996年 | 326篇 |
1995年 | 279篇 |
1994年 | 271篇 |
1993年 | 253篇 |
1992年 | 167篇 |
1991年 | 138篇 |
1990年 | 134篇 |
1989年 | 128篇 |
1988年 | 107篇 |
1987年 | 113篇 |
1986年 | 90篇 |
1985年 | 108篇 |
1984年 | 155篇 |
1983年 | 157篇 |
1982年 | 194篇 |
1981年 | 168篇 |
1980年 | 159篇 |
1979年 | 93篇 |
1978年 | 74篇 |
1977年 | 81篇 |
1976年 | 60篇 |
1975年 | 53篇 |
1974年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Sílvia H. De Carvalho Sales‐Peres André De Carvalho Sales‐Peres Juliane A. Marsicano Patricia G. De Moura‐Grec Cristiane A. P. De Carvalho Adriana R. De Freitas Arsenio Sales‐Peres 《International dental journal》2013,63(3):154-160
Background: The prevalence and severity of tooth wear and dental erosion is rising in children and there is no consensus about an index to be employed. Aim: To assess the reliability of an epidemiological scoring system dental wear index (DWI) to measure tooth wear and dental erosive wear. Design: An epidemiological cross‐sectional survey was conducted to evaluate and compare tooth wear and dental erosion using the dental wear index and erosion wear index (EWI). The study was conducted with randomised samples of 2,371 children aged between 4 years and 12 years selected from the State of São Paulo, Brazil. Records were used for calculating tooth wear and dental erosion; the incisal edge and canine cusp were excluded. Results: As the schoolchildren's ages increased the severity of primary tooth wear increased in canines (P = 0.0001, OR = 0.34) and molars (P = 0.0001, OR = 2.47) and erosion wear increased in incisal/occlusal (P = 0.0001, OR = 5.18) and molars (P = 0.0001, OR = 2.47). There was an increased prevalence of wear in the permanent teeth of older schoolchildren, particularly on the incisal/occlusal surfaces (P = 0.0001, OR = 7.03). Conclusion: The prevalence of tooth wear and dental erosion increased as age increased in children. The epidemiological scoring system Dental Wear Index is able to measure both tooth wear and dental erosive wear. This index should be used to monitor the progression of non‐carious lesions and to evaluate the levels of disease in the population. 相似文献
972.
973.
974.
Sebastian Korff Patricia Loughran Chanchun Cai Yi Shan Lee Melanie Scott Timothy R. Billiar 《The Journal of surgical research》2013
Background
Severe injury and associated hemorrhagic shock lead to an inflammatory response and subsequent increased tissue damage. Numerous reports have shown that injury-induced inflammation and the associated end-organ damage is driven by Toll-like receptor 4 (TLR4) activation via damage-associated molecular patterns. We examined the effectiveness of Eritoran tetrasodium (E5564), an inhibitor of TLR4 function, in reducing inflammation induced during hemorrhagic shock with resuscitation (HS/R) or after peripheral tissue injury (bilateral femur fracture, BFF).Material and methods
Mice underwent HS/R or BFF with or without injection of Eritoran (5 mg/kg body weight) or vehicle control given before, both before and after, or only after HS/R or BFF. Mice were sacrificed after 6 h and plasma and tissue cytokines, liver damage (histology; aspartate aminotransferase/alanine aminotransferase), and inflammation (NF-κB) and gut permeability were assessed.Results
In HS/R Eritoran significantly reduced liver damage (values ± SEM: alanine aminotransferase 9910 ± 3680 U/L versus 1239 ± 327 U/L and aspartate aminotransferase 5863 ± 2000 U/L versus 1246 ± 243 U/L, P < 0.01) at 6 h compared with control when given just before HS and again just prior to resuscitation. Eritoran administration also led to lower IL-6 levels in plasma and liver and less NF-κB activation in liver. Increases in gut barrier permeability induced by HS/R were also prevented with Eritoran. Eritoran similarly diminished BFF-mediated systemic inflammatory responses.Conclusion
These data suggest Eritoran can inhibit tissue damage and inflammation induced via TLR4/myeloid differentiation factor 2 signaling from damage-associated molecular patterns released during HS/R or BFF. Eritoran may represent a promising therapeutic for trauma patients to prevent multiple organ failure. 相似文献975.
976.
977.
978.
Kapadia F Frye V Bonner S Emmanuel PJ Samples CL Latka MH 《AIDS education and prevention》2012,24(1):27-40
We investigated the association between perceived peer norms and safer sexual behaviors among substance using Latino youth. Between 2005 and 2006, cross-sectional data were collected from 92 Latino adolescents recruited from clinic- and community-based settings in two U.S. cities. Separate multivariate logistic regression models were used to assess the relationship between perceived peer norms around safer sex and two different outcomes: consistent condom use and multiple sexual partnerships. Among these participants, perceived peer norms encouraging safer sex were associated with consistent condom use even after controlling for individual- and partner-related factors. Perceived peer norms supporting safer sex were inversely associated with recently having two or more sexual partners after controlling for demographic characteristics. Perceived peer norms around safer sexual behavior contribute to a lower likelihood of engaging in two HIV/STI risk behaviors: inconsistent condom use and multiple partnering. These findings suggest that further development of peer-based interventions for Latino youth is warranted. 相似文献
979.
980.
Marroquí L Gonzalez A Ñeco P Caballero-Garrido E Vieira E Ripoll C Nadal A Quesada I 《Journal of molecular endocrinology》2012,49(1):R9-17
Leptin plays an important role in the control of food intake, energy expenditure, metabolism, and body weight. This hormone also has a key function in the regulation of glucose homeostasis. Although leptin acts through central and peripheral mechanisms to modulate glucose metabolism, the pancreatic β-cell of the endocrine pancreas is a critical target of leptin actions. Leptin receptors are present in the β-cell, and their activation directly inhibits insulin secretion from these endocrine cells. The effects of leptin on insulin occur also in the long term, since this hormone inhibits insulin gene expression as well. Additionally, β-cell mass can be affected by leptin through changes in proliferation, apoptosis, or cell size. All these different functions in the β-cell are triggered by leptin as a result of the large diversity of signaling pathways that this hormone is able to activate in the endocrine pancreas. Therefore, leptin can participate in glucose homeostasis owing to different levels of modulation of the pancreatic β-cell population. Furthermore, it has been proposed that alterations in this level of regulation could contribute to the impairment of β-cell function in obesity states. In the present review, we will discuss all these issues with special emphasis on the effects and pathways of leptin signaling in the pancreatic β-cell. 相似文献