全文获取类型
收费全文 | 3545篇 |
免费 | 203篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 103篇 |
妇产科学 | 93篇 |
基础医学 | 405篇 |
口腔科学 | 49篇 |
临床医学 | 477篇 |
内科学 | 498篇 |
皮肤病学 | 72篇 |
神经病学 | 391篇 |
特种医学 | 89篇 |
外科学 | 409篇 |
综合类 | 24篇 |
一般理论 | 1篇 |
预防医学 | 575篇 |
眼科学 | 29篇 |
药学 | 203篇 |
中国医学 | 6篇 |
肿瘤学 | 305篇 |
出版年
2024年 | 4篇 |
2023年 | 36篇 |
2022年 | 51篇 |
2021年 | 111篇 |
2020年 | 68篇 |
2019年 | 91篇 |
2018年 | 108篇 |
2017年 | 85篇 |
2016年 | 109篇 |
2015年 | 89篇 |
2014年 | 116篇 |
2013年 | 200篇 |
2012年 | 260篇 |
2011年 | 312篇 |
2010年 | 137篇 |
2009年 | 130篇 |
2008年 | 226篇 |
2007年 | 266篇 |
2006年 | 225篇 |
2005年 | 244篇 |
2004年 | 233篇 |
2003年 | 226篇 |
2002年 | 211篇 |
2001年 | 34篇 |
2000年 | 23篇 |
1999年 | 14篇 |
1998年 | 27篇 |
1997年 | 22篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有3756条查询结果,搜索用时 15 毫秒
21.
Perceptual speed does not cause intelligence, and intelligence does not cause perceptual speed 总被引:2,自引:0,他引:2
Luciano M Posthuma D Wright MJ de Geus EJ Smith GA Geffen GM Boomsma DI Martin NG 《Biological psychology》2005,70(1):1-8
There is ongoing debate whether the efficiency of local cognitive processes leads to global cognitive ability or whether global ability feeds the efficiency of basic processes. A prominent example is the well-replicated association between inspection time (IT), a measure of perceptual discrimination speed, and intelligence (IQ), where it is not known whether increased speed is a cause or consequence of high IQ. We investigated the direction of causation between IT and IQ in 2012 genetically related subjects from Australia and The Netherlands. Models in which the reliable variance of each observed variable was specified as a latent trait showed IT correlations of -0.44 and -0.33 with respective Performance and Verbal IQ; heritabilities were 57% (IT), 83% (PIQ) and 77% (VIQ). Directional causation models provided poor fits to the data, with covariation best explained by pleiotropic genes (influencing variation in both IT and IQ). This finding of a common genetic factor provides a better target for identifying genes involved in cognition than genes which are unique to specific traits. 相似文献
22.
23.
24.
Marine Baillat Vanessa Pauly Gina Dagau Julie Berbis Farid Boubred Laurence Fayol 《Nutrients》2021,13(1)
The purpose of this study was to determine the influence of first-week nutrition intake on neonatal growth in moderate preterm (MP) infants. Data on neonatal morbidity and nutrition intake on day of life 7 (DoL7) were prospectively collected from 735 MP infants (320/7–346/7 weeks gestational age (GA)). Multivariable regression was used to assess the factors associated with extrauterine growth restriction (EUGR) defined as a decrease of more than 1 standard deviation (SD) in the weight z-score during hospitalization. Mean (SD) gestational age and birth weight were 33.2 (0.8) weeks and 2005 (369) g. The mean change in the weight z-score during hospitalization was −0.64 SD. A total of 138 infants (18.8%) had EUGR. Compared to adequate growth infants, EUGR infants received 15% and 35% lower total energy and protein intake respectively (p < 0.001) at DoL7. At DoL7, each increase of 10 kcal/kg/d and 1 g/kg/d of protein was associated with reduced odds of EUGR with an odds ratio of 0.73 (95% CI, 0.66–0.82; p < 0.001) and 0.54 (0.44–0.67; p < 0.001), respectively. Insufficient energy and protein intakes on DoL7 negatively affected neonatal growth of MP infants. Nutritional support should be optimized from birth onwards to improve neonatal weight growth. 相似文献
25.
Robison Valerie Bauman Brenda D’Angelo Denise V. Espinoza Lorena Thornton-Evans Gina Lin Mei 《Maternal and child health journal》2021,25(5):832-840
Maternal and Child Health Journal - To measure the association between dental and medical insurance with the receipt of dental cleaning during pregnancy. We analyzed Pregnancy Risk Assessment... 相似文献
26.
Helen Pineo Camilla Audia Daniel Black Matthew French Emily Gemmell Gina S. Lovasi James Milner Felipe Montes Yanlin Niu Carolina Prez-Ferrer Jos Siri Ruzka R. Taruc 《Journal of urban health》2021,98(3):442
Anthropogenic environmental change will heavily impact cities, yet associated health risks will depend significantly on decisions made by urban leaders across a wide range of non-health sectors, including transport, energy, housing, basic urban services, and others. A subset of planetary health researchers focus on understanding the urban health impacts of global environmental change, and how these vary globally and within cities. Such researchers increasingly adopt collaborative transdisciplinary approaches to engage policy-makers, private citizens, and other actors in identifying and evaluating potential policy solutions that will reduce environmental impacts in ways that simultaneously promote health, equity, and/or local economies—in other words, maximising ‘co-benefits’. This report presents observations from a participatory workshop focused on challenges and opportunities for urban planetary health research. The workshop, held at the 16th International Conference on Urban Health (ICUH) in Xiamen, China, in November 2019, brought together 49 participants and covered topics related to collaboration, data, and research impact. It featured research projects funded by the Wellcome Trust’s Our Planet Our Health (OPOH) programme. This report aims to concisely summarise and disseminate participants’ collective contributions to current methodological practice in urban planetary health research. 相似文献
27.
28.
Julie Safirstein Jonathan J. Grant Emily Clausen Deepika Savant Rebecca Dezube Gina Hong 《Journal of cystic fibrosis》2021,20(3):506-510
Individuals with cystic fibrosis (CF) have an increased risk for gallbladder abnormalities and biliary tract disease, but the reported incidence of these manifestations of CF varies widely in the literature. With the approval of elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA), increasing numbers of CF patients have been initiated on highly effective cystic fibrosis transmembrane regulator (CFTR) modulator therapy. While elevations in hepatic panel are known potential side effects of CFTR modulators, there have been no published cases of biliary disease or acute cholecystitis attributed to these medications. In this case series, we describe seven patients at two adult CF centers with biliary colic shortly after initiation with ELX/TEZ/IVA, six of whom required cholecystectomy. 相似文献
29.
Gina Martin Drew D. Bowman Megan Graat Andrew F. Clark Alexander J. Wray Zoe Askwith Jamie A. Seabrook Jason A. Gilliland 《Canadian journal of public health. Revue canadienne de santé publique》2021,112(3):440
ObjectivesOn January 1, 2020, the Government of Ontario passed a regulation banning vaping advertisements by retailers, apart from specialty shops. A motivation for this ban was to limit youth exposure to vaping advertisements. The primary goal of this research was to evaluate the impact of this ban on the number and density of vaping advertisements surrounding secondary schools. Additionally, we examined whether the number of vaping advertisements varied by school socio-demographic characteristics.MethodsThis study used a pre-post design. Audits were conducted December 2019 (pre-ban) and again January to February 2020 (post-ban), to identify vaping advertisements within 800 m surrounding secondary schools (n = 18) in London, Ontario.ResultsPrior to the ban, there were 266 vaping advertisements within 800 m of secondary schools. After the ban, this was reduced to 58, a 78.2% reduction. The mean number of vaping advertisements surrounding schools significantly decreased from 18.1 before the ban to 3.6 after the ban (p < 0.001). A significant positive correlation was found, prior to the ban, between the number of vaping advertisements surrounding schools and school-level residential instability (r = 0.42, p = 0.02). After the ban, no significant correlations were found between the number of vaping advertisements and school socio-demographic characteristics.ConclusionThe provincial ban of vaping advertisements in select retail settings significantly reduced the number of vaping advertisements in the areas surrounding secondary schools in London, Ontario. The ban also reduced socio-demographic inequities in youths’ potential exposure to marketing of vaping products. Continued monitoring of the geographic accessibility and promotion of vaping products is warranted. 相似文献
30.
Susan Watt Gina Browne Amiram Gafni Jacqueline Roberts & Carolyn Byrne 《The Milbank quarterly》1999,77(3):363-392
A series of studies conducted in the same region found that programmatic, community-based health and social service interventions have a positive impact on client well-being. These proactive interventions, designed to address the full range of health and social needs, were usually provided at the same–or even lower–costs as uncoordinated, illness-focused care. The results of this series suggest that across-the-board health care reduction, atleast in a system of national health insurance, will produce poorer results, at higher cost, for people with chronic conditions living in the community. Policy planners need more research that concentrates on comparisons of outcomes between and within different models of health and social service delivery. The studies should be designed to help them determine who benefits from different serviceconfigurations carried out within a range of policy environments at various costs. 相似文献