全文获取类型
收费全文 | 142837篇 |
免费 | 10324篇 |
国内免费 | 635篇 |
专业分类
耳鼻咽喉 | 1726篇 |
儿科学 | 3681篇 |
妇产科学 | 2568篇 |
基础医学 | 18541篇 |
口腔科学 | 3031篇 |
临床医学 | 14105篇 |
内科学 | 29304篇 |
皮肤病学 | 1812篇 |
神经病学 | 12553篇 |
特种医学 | 5671篇 |
外科学 | 22771篇 |
综合类 | 2079篇 |
现状与发展 | 1篇 |
一般理论 | 177篇 |
预防医学 | 13149篇 |
眼科学 | 3033篇 |
药学 | 10036篇 |
2篇 | |
中国医学 | 197篇 |
肿瘤学 | 9359篇 |
出版年
2023年 | 719篇 |
2022年 | 1078篇 |
2021年 | 2678篇 |
2020年 | 1544篇 |
2019年 | 2496篇 |
2018年 | 3070篇 |
2017年 | 2191篇 |
2016年 | 2359篇 |
2015年 | 2833篇 |
2014年 | 4159篇 |
2013年 | 6289篇 |
2012年 | 9177篇 |
2011年 | 9786篇 |
2010年 | 5439篇 |
2009年 | 4977篇 |
2008年 | 8629篇 |
2007年 | 9318篇 |
2006年 | 8901篇 |
2005年 | 8984篇 |
2004年 | 8631篇 |
2003年 | 8108篇 |
2002年 | 7917篇 |
2001年 | 1523篇 |
2000年 | 1304篇 |
1999年 | 1569篇 |
1998年 | 1705篇 |
1997年 | 1362篇 |
1996年 | 1318篇 |
1995年 | 1273篇 |
1994年 | 1093篇 |
1993年 | 1073篇 |
1992年 | 987篇 |
1991年 | 1016篇 |
1990年 | 899篇 |
1989年 | 887篇 |
1988年 | 901篇 |
1987年 | 927篇 |
1986年 | 900篇 |
1985年 | 976篇 |
1984年 | 1024篇 |
1983年 | 969篇 |
1982年 | 1181篇 |
1981年 | 1210篇 |
1980年 | 1020篇 |
1979年 | 704篇 |
1978年 | 740篇 |
1977年 | 654篇 |
1976年 | 580篇 |
1974年 | 543篇 |
1973年 | 518篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Sourajit M.Mustafi Jaroslaw Harezlak Chandana Kodiweera Jennifer S.Randolph James C.Ford Heather A.Wishart Yu-Chien Wu 《中国神经再生研究》2019,(1)
Multiple sclerosis is a neurodegenerative and inflammatory disease, a hallmark of which is demyelinating lesions in the white matter. We hypothesized that alterations in white matter microstructures can be non-invasively characterized by advanced diffusion magnetic resonance imaging. Seven diffusion metrics were extracted from hybrid diffusion imaging acquisitions via classic diffusion tensor imaging, neurite orientation dispersion and density imaging, and q-space imaging. We investigated the sensitivity of the diffusion metrics in 36 sets of regions of interest in the brain white matter of six female patients(age 52.8 ± 4.3 years) with multiple sclerosis. Each region of interest set included a conventional T2-defined lesion, a matched perilesion area, and normal-appearing white matter. Six patients with multiple sclerosis(n = 5) or clinically isolated syndrome(n = 1) at a mild to moderate disability level were recruited. The patients exhibited microstructural alterations from normal-appearing white matter transitioning to perilesion areas and lesions, consistent with decreased tissue restriction, decreased axonal density, and increased classic diffusion tensor imaging diffusivity. The findings suggest that diffusion compartment modeling and q-spa ce analysis appeared to be sensitive for detecting subtle microstructural alterations between perilesion areas and normal-appearing white matter. 相似文献
43.
James L. Dorling Alice E. Thackray James A. King Andrea Pucci Fernanda R. Goltz Rachel L. Batterham David J. Stensel 《Nutrients》2020,12(12)
The fat mass and obesity-associated gene (FTO) rs9939609 A-allele is linked to obesity and dyslipidemia, yet the independent influence of this polymorphism on blood lipids remains equivocal. We examined the influence of the FTO rs9939609 polymorphism on fasting and postprandial blood lipids in individuals homozygous for the risk A-allele or T-allele with similar anthropometric and demographic characteristics. 12 AA and 12 TT males consumed a standardized meal after fasting overnight. Blood samples were collected at baseline (−1.5 h), before the meal (0 h), and for five hours postprandially to measure lipid, glucose, and insulin concentrations. Time-averaged total area under the curve (TAUC) values (0–5 h) were calculated and compared between genotypes. Fasting triacylglycerol (TG), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, non-esterified fatty acid (NEFA), glucose, and insulin concentrations were similar between groups (p ≥ 0.293). TAUC for TG was similar in AAs and TTs (95% confidence interval (CI) −0.52 to 0.31 mmol/L/h; p = 0.606). Likewise, TAUC values were similar for NEFA (95% CI −0.04 to 0.03 mmol/L/h; p = 0.734), glucose (95% CI −0.41 to 0.44 mmol/L/h; p = 0.951), and insulin (95% CI −6.87 to 2.83 pmol/L/h; p = 0.395). Blood lipids are not influenced by the FTO rs9939609 polymorphism, suggesting the FTO-dyslipidemia link is mediated by adiposity and weight management is important in preventing FTO-related lipid variations. 相似文献
44.
45.
46.
Emmi Helle Aldo Córdova-Palomera Tiina Ojala Priyanka Saha Praneetha Potiny Stefan Gustafsson Erik Ingelsson Michael Bamshad Deborah Nickerson Jessica X. Chong University of Washington Center for Mendelian Genomics Euan Ashley James R. Priest 《Genetic epidemiology》2019,43(2):215-226
Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes. 相似文献
47.
48.
James I. Geller MD Joseph G. Pressey MD Malcolm A. Smith MD Rachel A. Kudgus PhD Mariana Cajaiba MD Joel M. Reid PhD David Hall PhD Donald A. Barkauskas PhD Stephen D. Voss MD Steve Y. Cho MD Stacey L. Berg MD Jeffrey S. Dome MD PhD Elizabeth Fox MD Brenda J. Weigel MD 《Cancer》2020,126(24):5303-5310
49.
Dermatophyte infections are exceedingly rare in neonates, possibly due to the thin stratum corneum and high sebum content of neonatal skin. Only a handful of cases of tinea faciei have been reported in neonates, with the majority of reports occuring in India. Here, we report what to our knowledge is the earliest reported presentation of tinea faciei in the United States. We also provide a brief literature review of other reported cases of tinea faciei in neonates less than 30 days of age. 相似文献
50.
James E. Davison 《Paediatrics & Child Health》2019,29(3):142-145
Basic biochemical tests are frequently obtained in acutely unwell neonates and children, as well as in some elective situations. Correct interpretation can be invaluable in identifying rare inherited primary metabolic disorders, but secondary causes of hyperammonaemia, elevated blood lactate or blood gas derangement are more common and require appropriate treatment of the underlying cause. This Personal Practice guide provides an overview of these tests and their interpretation. 相似文献