全文获取类型
收费全文 | 22828篇 |
免费 | 1787篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 173篇 |
儿科学 | 755篇 |
妇产科学 | 659篇 |
基础医学 | 2991篇 |
口腔科学 | 240篇 |
临床医学 | 2934篇 |
内科学 | 4229篇 |
皮肤病学 | 280篇 |
神经病学 | 2272篇 |
特种医学 | 444篇 |
外科学 | 2305篇 |
综合类 | 379篇 |
一般理论 | 82篇 |
预防医学 | 3440篇 |
眼科学 | 244篇 |
药学 | 1302篇 |
中国医学 | 17篇 |
肿瘤学 | 1902篇 |
出版年
2024年 | 41篇 |
2023年 | 300篇 |
2022年 | 467篇 |
2021年 | 975篇 |
2020年 | 608篇 |
2019年 | 928篇 |
2018年 | 933篇 |
2017年 | 699篇 |
2016年 | 747篇 |
2015年 | 767篇 |
2014年 | 996篇 |
2013年 | 1364篇 |
2012年 | 2090篇 |
2011年 | 2014篇 |
2010年 | 1056篇 |
2009年 | 851篇 |
2008年 | 1499篇 |
2007年 | 1421篇 |
2006年 | 1404篇 |
2005年 | 1283篇 |
2004年 | 1108篇 |
2003年 | 912篇 |
2002年 | 801篇 |
2001年 | 114篇 |
2000年 | 109篇 |
1999年 | 126篇 |
1998年 | 174篇 |
1997年 | 103篇 |
1996年 | 77篇 |
1995年 | 65篇 |
1994年 | 43篇 |
1993年 | 54篇 |
1992年 | 39篇 |
1991年 | 37篇 |
1990年 | 38篇 |
1989年 | 21篇 |
1988年 | 28篇 |
1987年 | 22篇 |
1986年 | 19篇 |
1985年 | 38篇 |
1984年 | 31篇 |
1983年 | 25篇 |
1982年 | 32篇 |
1981年 | 41篇 |
1980年 | 19篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1975年 | 9篇 |
1972年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
141.
Matthias G. Pauthner Joseph P. Nkolola Colin Havenar-Daughton Ben Murrell Samantha M. Reiss Raiza Bastidas Jérémie Prévost Rebecca Nedellec Benjamin von Bredow Peter Abbink Christopher A. Cottrell Daniel W. Kulp Talar Tokatlian Bartek Nogal Matteo Bianchi Hui Li Jeong Hyun Lee Salvatore T. Butera Dennis R. Burton 《Immunity》2019,50(1):241-252.e6
142.
Henderson LA Macey PM Macey KE Frysinger RC Woo MA Harper RK Alger JR Yan-Go FL Harper RM 《Journal of neurophysiology》2002,88(6):3477-3486
The Valsalva maneuver, a test frequently used to evaluate autonomic function, recruits discrete neural sites. The time courses of neural recruitment relative to accompanying cardiovascular and breathing patterns are unknown. We examined functional magnetic resonance imaging signal changes within the brain to repeated Valsalva maneuvers and correlated these changes with physiological trends. In 12 healthy subjects (age, 30-58 yr), a series of 25 volumes (20 gradient echo echo-planar image slices per volume) was collected using a 1.5-Tesla scanner during a 60-s baseline and 90-s challenge period consisting of three Valsalva maneuvers. Regions of interest were examined for signal intensity changes over baseline and challenge conditions in cardiorespiratory-related regions. In addition, whole brain correlations between signal intensity and heart rate and airway load pressure were performed on a voxel-by-voxel basis. Significant signal changes, correlated with the time course of load pressure and heart rate, emerged within multiple areas, including the amygdala and hippocampus, insular and lateral frontal cortices, dorsal pons, dorsal medulla, lentiform nucleus, and fastigial and dentate nuclei of the cerebellum. Signal intensities peaked early in the Valsalva maneuver within the hippocampus and amygdala, later within the dorsal medulla, pons and midbrain, and deep cerebellar nuclei, and last within the lentiform nuclei and the lateral prefrontal cortex. The ventral pontine signals increased during the challenge, but not in a fashion correlated to load pressure or heart rate. Sites showing little or no correlation included the vermis and medial prefrontal cortex. These data suggest an initiating component arising in rostral brain areas, a later contribution from cerebellar nuclei, basal ganglia, and lateral prefrontal cortex, and a role for the ventral pons in mediating longer term processes. 相似文献
143.
Mills JL Druschel CM Pangilinan F Pass K Cox C Seltzer RR Conley MR Brody LC 《American journal of medical genetics. Part A》2005,136(1):8-11
Women who take folic acid in the periconceptional period greatly reduce their chances of having a child with a neural tube defect (NTD). Using multivitamins may also reduce the risk of having a child with an omphalocele. In this study, we tested single nucleotide polymorphisms in folate-related enzyme genes for association with omphalocele. Polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methylenetetrahydrofolate dehydrogenase (MTHFD1), the reduced folate carrier (SLC19A1), and transcobalamin II (TCN2) were examined in 25 children with euploid omphalocele and 59 matched controls. Omphalocele cases were significantly more likely to carry the T allele of MTHFR 677C-->T, a known risk factor for NTDs (odds ratio 3.50, 95% confidence interval 1.07-11.47, P=0.035). The MTHFD1 R653Q, SLC19A1 R27H, and TCN2 P259R polymorphisms showed no significant association with omphalocele. In this small study, the thermolabile variant of MTHFR, 677C-->T, was associated with an increased risk for omphalocele. This variant causes reduced enzyme activity, thus suggesting a mechanism by which multivitamins with folic acid might prevent omphalocele. Additional investigation is required. 相似文献
144.
Goodman William Downing Amy Allsop Matthew Munro Julie Taylor Claire Hubbard Gill Beeken Rebecca J. 《Quality of life research》2022,31(8):2435-2444
Quality of Life Research - Quality of life can be negatively impacted by the formation of a stoma and is influenced by a number of factors. Research to date treats people with a stoma as a... 相似文献
145.
Ma Yuan Sajeev Gautam VanderWeele Tyler J. Viswanathan Anand Sigurdsson Sigurdur Eiriksdottir Gudny Aspelund Thor Betensky Rebecca A. Grodstein Francine Hofman Albert Gudnason Vilmundur Launer Lenore Blacker Deborah 《European journal of epidemiology》2022,37(6):591-601
European Journal of Epidemiology - The apolipoprotein E allele 4 (APOE-ε4) is established as a major genetic risk factor for cognitive decline and late-onset Alzheimer’s disease.... 相似文献
146.
Shipkin Rebecca Blackledge Kristin Jacob Jane Bosoy Frederick Schertz Katherine Bachmann Gloria 《Maternal and child health journal》2022,26(5):1005-1014
Maternal and Child Health Journal - This study assessed whether the use of a peer-to-peer educational book, written and illustrated by women who experienced common mental disorders (CMDs) in the... 相似文献
147.
Interpregnancy Interval and Birth Outcomes: A Propensity Matching Study in the California Population
Congdon Jayme L. Baer Rebecca J. Arcara Jennet Feuer Sky K. Gómez Anu Manchikanti Karasek Deborah Oltman Scott P. Pantell Matthew S. Ryckman Kelli Jelliffe-Pawlowski Laura 《Maternal and child health journal》2022,26(5):1115-1125
Maternal and Child Health Journal - Previous studies that used traditional multivariable and sibling matched analyses to investigate interpregnancy interval (IPI) and birth outcomes have reached... 相似文献
148.
Maternal and Child Health Journal - Understand whether and how Black adolescent daughters’ relationships with their single mothers could be strengthened through an intervention to address... 相似文献
149.
Katy Sorensen Abbie L. Cawood Glenn R. Gibson Lisa H. Cooke Rebecca J. Stratton 《Nutrients》2021,13(3)
Cow’s milk protein allergy (CMPA) is associated with dysbiosis of the infant gut microbiome, with allergic and immune development implications. Studies show benefits of combining synbiotics with hypoallergenic formulae, although evidence has never been systematically examined. This review identified seven publications of four randomised controlled trials comparing an amino acid formula (AAF) with an AAF containing synbiotics (AAF-Syn) in infants with CMPA (mean age 8.6 months; 68% male, mean intervention 27.3 weeks, n = 410). AAF and AAF-Syn were equally effective in managing allergic symptoms and promoting normal growth. Compared to AAF, significantly fewer infants fed AAF-Syn had infections (OR 0.35 (95% CI 0.19–0.67), p = 0.001). Overall medication use, including antibacterials and antifectives, was lower among infants fed AAF-Syn. Significantly fewer infants had hospital admissions with AAF-Syn compared to AAF (8.8% vs. 20.2%, p = 0.036; 56% reduction), leading to potential cost savings per infant of £164.05–£338.77. AAF-Syn was associated with increased bifidobacteria (difference in means 31.75, 95% CI 26.04–37.45, p < 0.0001); reduced Eubacterium rectale and Clostridium coccoides (difference in means −19.06, 95% CI −23.15 to −14.97, p < 0.0001); and reduced microbial diversity (p < 0.05), similar to that described in healthy breastfed infants, and may be associated with the improved clinical outcomes described. This review provides evidence that suggests combining synbiotics with AAF produces clinical benefits with potential economic implications. 相似文献
150.
Kim Han Komudi Singh Matthew J. Rodman Shahin Hassanzadeh Yvonne Baumer Rebecca D. Huffstutler Jinguo Chen Julin Candia Foo Cheung Katherine E. R. Stagliano Mehdi Pirooznia Tiffany M. Powell-Wiley Michael N. Sack 《Nutrients》2021,13(5)
Intermittent fasting and fasting mimetic diets ameliorate inflammation. Similarly, serum extracted from fasted healthy and asthmatic subjects’ blunt inflammation in vitro, implicating serum components in this immunomodulation. To identify the proteins orchestrating these effects, SOMAScan technology was employed to evaluate serum protein levels in healthy subjects following an overnight, 24-h fast and 3 h after refeeding. Partial least square discriminant analysis identified several serum proteins as potential candidates to confer feeding status immunomodulation. The characterization of recombinant IGFBP1 (elevated following 24 h of fasting) and PYY (elevated following refeeding) in primary human CD4+ T cells found that they blunted and induced immune activation, respectively. Furthermore, integrated univariate serum protein analysis compared to RNA-seq analysis from peripheral blood mononuclear cells identified the induction of IL1RL1 and MFGE8 levels in refeeding compared to the 24-h fasting in the same study. Subsequent quantitation of these candidate proteins in lean versus obese individuals identified an inverse regulation of serum levels in the fasted subjects compared to the obese subjects. In parallel, IL1RL1 and MFGE8 supplementation promoted increased CD4+ T responsiveness to T cell receptor activation. Together, these data show that caloric load-linked conditions evoke serological protein changes, which in turn confer biological effects on circulating CD4+ T cell immune responsiveness. 相似文献