全文获取类型
收费全文 | 623357篇 |
免费 | 42783篇 |
国内免费 | 3904篇 |
专业分类
耳鼻咽喉 | 7885篇 |
儿科学 | 14581篇 |
妇产科学 | 14564篇 |
基础医学 | 85219篇 |
口腔科学 | 16280篇 |
临床医学 | 54854篇 |
内科学 | 130154篇 |
皮肤病学 | 11857篇 |
神经病学 | 51044篇 |
特种医学 | 22121篇 |
外国民族医学 | 93篇 |
外科学 | 98003篇 |
综合类 | 13360篇 |
现状与发展 | 1篇 |
一般理论 | 381篇 |
预防医学 | 38480篇 |
眼科学 | 15738篇 |
药学 | 47637篇 |
6篇 | |
中国医学 | 2547篇 |
肿瘤学 | 45239篇 |
出版年
2021年 | 7862篇 |
2020年 | 4811篇 |
2019年 | 7875篇 |
2018年 | 10293篇 |
2017年 | 7796篇 |
2016年 | 8332篇 |
2015年 | 9712篇 |
2014年 | 14032篇 |
2013年 | 18896篇 |
2012年 | 27532篇 |
2011年 | 28642篇 |
2010年 | 16521篇 |
2009年 | 15021篇 |
2008年 | 25668篇 |
2007年 | 27361篇 |
2006年 | 27147篇 |
2005年 | 26204篇 |
2004年 | 24663篇 |
2003年 | 23245篇 |
2002年 | 21948篇 |
2001年 | 30326篇 |
2000年 | 30329篇 |
1999年 | 25912篇 |
1998年 | 8162篇 |
1997年 | 6755篇 |
1996年 | 5977篇 |
1995年 | 5534篇 |
1994年 | 4816篇 |
1993年 | 4375篇 |
1992年 | 17267篇 |
1991年 | 15924篇 |
1990年 | 15120篇 |
1989年 | 14911篇 |
1988年 | 13523篇 |
1987年 | 12979篇 |
1986年 | 12034篇 |
1985年 | 11253篇 |
1984年 | 8108篇 |
1983年 | 6703篇 |
1982年 | 4060篇 |
1981年 | 3520篇 |
1980年 | 3159篇 |
1979年 | 6169篇 |
1978年 | 4076篇 |
1977年 | 3599篇 |
1975年 | 3103篇 |
1974年 | 3532篇 |
1973年 | 3262篇 |
1972年 | 3168篇 |
1971年 | 3042篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
21.
Christopher D Hue Frances S Cho Siqi Cao Cameron R ”Dale” Bass David F Meaney Barclay Morrison III 《Journal of cerebral blood flow and metabolism》2015,35(7):1191-1198
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α− isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury. 相似文献
22.
Autoimmune comorbid diseases associated with lichen planus: a nationwide case–control study
下载免费PDF全文
![点击此处可从《Journal of the European Academy of Dermatology and Venereology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
23.
Loss‐of‐function mutations in the gene encoding filaggrin underlie a Japanese family with food‐dependent exercise‐induced anaphylaxis
下载免费PDF全文
![点击此处可从《Journal of the European Academy of Dermatology and Venereology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
24.
25.
Y.R. Song B. Wu Y.T. Yang J. Chen L.J. Zhang Z.W. Zhang H.Y. Shi C.L. Huang J.X. Pan P. Xie 《Brazilian journal of medical and biological research》2015,48(11):973-982
Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2%
of the general population of different European countries. Unfortunately, there is no
objective laboratory-based test to aid BD diagnosis or monitor its progression, and
little is known about the molecular basis of BD. Here, we performed a comparative
proteomic study to identify differentially expressed plasma proteins in various BD
mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A
total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched
healthy control subjects were recruited. Seven high-abundance proteins were
immunodepleted in plasma samples from the 4 experimental groups, which were then
subjected to proteome-wide expression profiling by two-dimensional electrophoresis
and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem
mass spectrometry. Proteomic results were validated by immunoblotting and
bioinformatically analyzed using MetaCore. From a total of 32 proteins identified
with 1.5-fold changes in expression compared with healthy controls, 16 proteins were
perturbed in BD independent of mood state, while 16 proteins were specifically
associated with particular BD mood states. Two mood-independent differential
proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be
associated with early perturbations in lipid metabolism. Moreover, down-regulation of
one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved
in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be
associated with early perturbations in lipid metabolism that are independent of mood
state, while CA-1 may be involved in the pathophysiology of depressive episodes. 相似文献
26.
27.
28.
Danielle E Whittier Elizabeth J Samelson Marian T Hannan Lauren A Burt David A Hanley Emmanuel Biver Pawel Szulc Elisabeth Sornay-Rendu Blandine Merle Roland Chapurlat Eric Lespessailles Andy Kin On Wong David Goltzman Sundeep Khosla Serge Ferrari Mary L Bouxsein Douglas P Kiel Steven K Boyd 《Journal of bone and mineral research》2022,37(3):428-439
Prevalence of osteoporosis is more than 50% in older adults, yet current clinical methods for diagnosis that rely on areal bone mineral density (aBMD) fail to detect most individuals who have a fragility fracture. Bone fragility can manifest in different forms, and a “one-size-fits-all” approach to diagnosis and management of osteoporosis may not be suitable. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides additive information by capturing information about volumetric density and microarchitecture, but interpretation is challenging because of the complex interactions between the numerous properties measured. In this study, we propose that there are common combinations of bone properties, referred to as phenotypes, that are predisposed to different levels of fracture risk. Using HR-pQCT data from a multinational cohort (n = 5873, 71% female) between 40 and 96 years of age, we employed fuzzy c-means clustering, an unsupervised machine-learning method, to identify phenotypes of bone microarchitecture. Three clusters were identified, and using partial correlation analysis of HR-pQCT parameters, we characterized the clusters as low density, low volume, and healthy bone phenotypes. Most males were associated with the healthy bone phenotype, whereas females were more often associated with the low volume or low density bone phenotypes. Each phenotype had a significantly different cumulative hazard of major osteoporotic fracture (MOF) and of any incident osteoporotic fracture (p < 0.05). After adjustment for covariates (cohort, sex, and age), the low density followed by the low volume phenotype had the highest association with MOF (hazard ratio = 2.96 and 2.35, respectively), and significant associations were maintained when additionally adjusted for femoral neck aBMD (hazard ratio = 1.69 and 1.90, respectively). Further, within each phenotype, different imaging biomarkers of fracture were identified. These findings suggest that osteoporotic fracture risk is associated with bone phenotypes that capture key features of bone deterioration that are not distinguishable by aBMD. © 2021 American Society for Bone and Mineral Research (ASBMR). 相似文献
29.