全文获取类型
收费全文 | 5643篇 |
免费 | 439篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 205篇 |
妇产科学 | 235篇 |
基础医学 | 710篇 |
口腔科学 | 52篇 |
临床医学 | 936篇 |
内科学 | 993篇 |
皮肤病学 | 333篇 |
神经病学 | 502篇 |
特种医学 | 141篇 |
外科学 | 335篇 |
综合类 | 46篇 |
一般理论 | 4篇 |
预防医学 | 864篇 |
眼科学 | 25篇 |
药学 | 362篇 |
中国医学 | 6篇 |
肿瘤学 | 308篇 |
出版年
2023年 | 41篇 |
2022年 | 42篇 |
2021年 | 113篇 |
2020年 | 70篇 |
2019年 | 112篇 |
2018年 | 135篇 |
2017年 | 112篇 |
2016年 | 128篇 |
2015年 | 141篇 |
2014年 | 188篇 |
2013年 | 288篇 |
2012年 | 389篇 |
2011年 | 411篇 |
2010年 | 193篇 |
2009年 | 171篇 |
2008年 | 384篇 |
2007年 | 373篇 |
2006年 | 410篇 |
2005年 | 422篇 |
2004年 | 407篇 |
2003年 | 364篇 |
2002年 | 335篇 |
2001年 | 57篇 |
2000年 | 37篇 |
1999年 | 57篇 |
1998年 | 71篇 |
1997年 | 61篇 |
1996年 | 53篇 |
1995年 | 52篇 |
1994年 | 33篇 |
1993年 | 34篇 |
1992年 | 28篇 |
1991年 | 22篇 |
1990年 | 28篇 |
1989年 | 25篇 |
1988年 | 18篇 |
1987年 | 19篇 |
1986年 | 17篇 |
1985年 | 21篇 |
1984年 | 27篇 |
1983年 | 11篇 |
1982年 | 22篇 |
1981年 | 29篇 |
1980年 | 26篇 |
1979年 | 16篇 |
1978年 | 17篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1974年 | 13篇 |
1973年 | 9篇 |
排序方式: 共有6087条查询结果,搜索用时 31 毫秒
141.
Gerrit A. van Essen Jiri Beran Jeanne‐Marie Devaster Christelle Durand Xavier Duval Meral Esen Ann R. Falsey Gregory Feldman Pierre Gervais Bruce L. Innis Martina Kovac Odile Launay Geert Leroux‐Roels Janet E. McElhaney Shelly McNeil Mohammed Oujaa Jan Hendrik Richardus Guillermo Ruiz‐Palacios Richard H. Osborne Lidia Oostvogels 《Influenza and other respiratory viruses》2014,8(4):452-462
142.
Cheek JD Wirrig EE Alfieri CM James JF Yutzey KE 《Journal of molecular and cellular cardiology》2012,52(3):689-700
Studies of human diseased aortic valves have demonstrated increased expression of genetic markers of valve progenitors and osteogenic differentiation associated with pathogenesis. Three potential mouse models of valve disease were examined for cellular pathology, morphology, and induction of valvulogenic, chondrogenic, and osteogenic markers. Osteogenesis imperfecta murine (Oim) mice, with a mutation in Col1a2, have distal leaflet thickening and increased proteoglycan composition characteristic of myxomatous valve disease. Periostin null mice also exhibit dysregulation of the ECM with thickening in the aortic midvalve region, but do not have an overall increase in valve leaflet surface area. Klotho null mice are a model for premature aging and exhibit calcific nodules in the aortic valve hinge-region, but do not exhibit leaflet thickening, ECM disorganization, or inflammation. Oim/oim mice have increased expression of valve progenitor markers Twist1, Col2a1, Mmp13, Sox9 and Hapln1, in addition to increased Col10a1 and Asporin expression, consistent with increased proteoglycan composition. Periostin null aortic valves exhibit relatively normal gene expression with slightly increased expression of Mmp13 and Hapln1. In contrast, Klotho null aortic valves have increased expression of Runx2, consistent with the calcified phenotype, in addition to increased expression of Sox9, Col10a1, and osteopontin. Together these studies demonstrate that oim/oim mice exhibit histological and molecular characteristics of myxomatous valve disease and Klotho null mice are a new model for calcific aortic valve disease. 相似文献
143.
Buer BC Meagher JL Stuckey JA Marsh EN 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(13):4810-4815
Noncanonical amino acids have proved extremely useful for modifying the properties of proteins. Among them, extensively fluorinated (fluorous) amino acids seem particularly effective in increasing protein stability; however, in the absence of structural data, the basis of this stabilizing effect remains poorly understood. To address this problem, we solved X-ray structures for three small proteins with hydrophobic cores that are packed with either fluorocarbon or hydrocarbon side chains and compared their stabilities. Although larger, the fluorinated residues are accommodated within the protein with minimal structural perturbation, because they closely match the shape of the hydrocarbon side chains that they replace. Thus, stability increases seem to be better explained by increases in buried hydrophobic surface area that accompany fluorination than by specific fluorous interactions between fluorinated side chains. This finding is illustrated by the design of a highly fluorinated protein that, by compensating for the larger volume and surface area of the fluorinated side chains, exhibits similar stability to its nonfluorinated counterpart. These structure-based observations should inform efforts to rationally modulate protein function using noncanonical amino acids. 相似文献
144.
145.
Laura Català Cristina Rius Patricia García de Olalla Jeanne L. Nelson Josep Alvarez Sofía Minguell Neus Camps María Rosa Sala Carlos Arias Irene Barrabeig Mónica Carol Roser Torra Neus Cardeñosa Tomas Pumarola Joan A. Caylà 《Enfermedades infecciosas y microbiología clínica》2012
Introduction
Pandemic A/H1N1 influenza emerged in Mexico at the end of March 2009. Since then, it is still important to provide evidences that contributed to the international spread of the virus and to ascertain the attack rate of this new strain of influenza among the first cases in Spain that led to identify the first transmission in Europe.Methods
Three pandemic A/H1N1 influenza groups related to an overseas flight were studied: 71 student group, 94 remaining passengers, and 68 contacts of confirmed cases. The attack rate with their 95% confidence interval (CI) among the student group and contacts was calculated. On April 26th, when the first cases were notified, strong preventive measures were implemented among the student group and the contacts of the confirmed cases.Results
On 27th April, the first pandemic A/H1N1 influenza cases confirmed in Spain were three students that came back from Mexico by airplane. A student generated the first native case in Spain and one of the first cases in Europe. Similar attack rates were found between the student group (14.1%; CI: 12.1–16.1) and their contacts (13.2%; CI: 4.4–22.0), but no cases among remaining passengers were detected, suggesting low transmission risk during air travel.Conclusion
The first cases of pandemic A/H1N1 influenza in Spain were imported by airplane from Mexico. Preventive efforts to reduce the impact of the influenza influenced that primary and secondary rates were lower than first estimations by WHO. 相似文献146.
Michael L. ALOSCO Andreana BENITEZ John GUNSTAD Mary Beth SPITZNAGEL Jeanne M. MCCAFFERY John E. MCGEARY Athena POPPAS Robert H. PAUL Lawrence H. SWEET Ronald A. COHEN 《Psychogeriatrics》2013,13(1):35-40
Background: Much attention has been paid to the prevalence and predisposition of the fat mass and obesity‐associated (FTO) gene to obesity, although only a few studies have characterized the extent to which this affects cognitive function. This study examined differences between risk allele carriers (i.e. FTO‐AC/AA) and non‐carriers (i.e. FTO‐CC) on indices of attention/executive function/psychomotor speed, memory, language, and visual‐spatial ability in a sample of older patients with cardiovascular disease. Methods: We recruited 120 older adults from an outpatient cardiology clinic who underwent blood draw and completed neuropsychological testing. Participants were classified into two groups: one for those who were homozygous for the non‐risk‐conferring allele (i.e. FTO‐CC) (n= 49) and the other for those who had at least one copy of the obesity risk‐conferring A allele (i.e. FTO‐AC/AA) (n= 71). Results: Mancova analyses adjusting for age and years of education revealed the FTO‐AC/AA group performed significantly worse on indices of memory (λ= 0.94, F(2, 115) = 3.58, P= 0.03, partial η2= 0.06). Follow‐up tests revealed a significant effect for the FTO‐AC/AA group, relative to the non‐carrier group, on encoding (i.e. California Verbal Learning Test Total Learning) and California Verbal Learning Test long‐delay free recall (P < 0.05). No such differences between FTO carriers and non‐carriers emerged on tests of attention/executive function/psychomotor speed, language, or visual‐spatial ability (P > 0.05 for all). Conclusions: These findings suggest that the FTO risk allele is associated with reduced memory performance, particularly on aspects of memory encoding and delayed recall. To elucidate underlying mechanisms, these findings will need to be replicated in larger samples that utilize neuroimaging. 相似文献
147.
Mohamed Khalifa Jennifer Stein Lance Grau Valery Nelson Jeanne Meck Swaroop Aradhya John Duby 《American journal of medical genetics. Part A》2013,161(4):835-840
KBG syndrome (OMIM 148050) is a very rare genetic disorder characterized by macrodontia, distinctive craniofacial abnormalities, short stature, intellectual disability, skeletal, and neurologic involvement. Approximately 60 patients have been reported since it was first described in 1975. Recently mutations in ANKRD11 have been documented in patients with KBG syndrome, and it has been proposed that haploinsufficiency of ANKRD11 is the cause of this syndrome. In addition, copy number variation in the 16q24.3 region that includes ANKRD11 results in a variable phenotype that overlaps with KBG syndrome and also includes autism spectrum disorders and other dysmorphic facial features. In this report we present a 2½‐year‐old African American male with features highly suggestive of KBG syndrome. Genomic microarray identified an intragenic 154 kb deletion at 16q24.3 within ANKRD11. This child's mother was mosaic for the same deletion (present in approximately 38% of cells) and exhibited a milder phenotype including macrodontia, short stature and brachydactyly. This family provides additional evidence that ANKRD11 causes KBG syndrome, and the mild phenotype in the mosaic form suggests that KBG phenotypes might be dose dependent, differentiating it from the more variable 16q24.3 microdeletion syndrome. This family has additional features that might expand the phenotype of KBG syndrome. © 2013 Wiley Periodicals, Inc. 相似文献
148.
149.
150.