全文获取类型
收费全文 | 23770篇 |
免费 | 2294篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 208篇 |
儿科学 | 579篇 |
妇产科学 | 588篇 |
基础医学 | 3274篇 |
口腔科学 | 637篇 |
临床医学 | 2518篇 |
内科学 | 4887篇 |
皮肤病学 | 305篇 |
神经病学 | 2504篇 |
特种医学 | 1027篇 |
外国民族医学 | 1篇 |
外科学 | 3079篇 |
综合类 | 662篇 |
一般理论 | 25篇 |
预防医学 | 2141篇 |
眼科学 | 639篇 |
药学 | 1702篇 |
2篇 | |
中国医学 | 38篇 |
肿瘤学 | 1289篇 |
出版年
2021年 | 242篇 |
2020年 | 181篇 |
2019年 | 289篇 |
2018年 | 370篇 |
2017年 | 294篇 |
2016年 | 289篇 |
2015年 | 342篇 |
2014年 | 481篇 |
2013年 | 868篇 |
2012年 | 1132篇 |
2011年 | 1227篇 |
2010年 | 624篇 |
2009年 | 625篇 |
2008年 | 1130篇 |
2007年 | 1202篇 |
2006年 | 1244篇 |
2005年 | 1267篇 |
2004年 | 1234篇 |
2003年 | 1158篇 |
2002年 | 1169篇 |
2001年 | 531篇 |
2000年 | 501篇 |
1999年 | 469篇 |
1998年 | 259篇 |
1997年 | 202篇 |
1996年 | 208篇 |
1995年 | 254篇 |
1994年 | 228篇 |
1993年 | 213篇 |
1992年 | 398篇 |
1991年 | 461篇 |
1990年 | 420篇 |
1989年 | 348篇 |
1988年 | 397篇 |
1987年 | 346篇 |
1986年 | 336篇 |
1985年 | 354篇 |
1984年 | 328篇 |
1983年 | 253篇 |
1982年 | 205篇 |
1981年 | 225篇 |
1980年 | 207篇 |
1979年 | 278篇 |
1978年 | 223篇 |
1977年 | 214篇 |
1976年 | 189篇 |
1975年 | 193篇 |
1974年 | 217篇 |
1972年 | 185篇 |
1971年 | 167篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
21.
Sergey Kalinin Gordon P. Meares Shao Xia Lin Elizabeth A. Pietruczyk Gesine Saher Lena Spieth Klaus-Armin Nave Anne I. Boullerne Sarah E. Lutz Etty N. Benveniste Douglas L. Feinstein 《Glia》2020,68(3):600-616
Liver kinase B1 (LKB1) is a ubiquitously expressed kinase involved in the regulation of cell metabolism, growth, and inflammatory activation. We previously reported that a single nucleotide polymorphism in the gene encoding LKB1 is a risk factor for multiple sclerosis (MS). Since astrocyte activation and metabolic function have important roles in regulating neuroinflammation and neuropathology, we examined the serine/threonine kinase LKB1 in astrocytes in a chronic experimental autoimmune encephalomyelitis mouse model of MS. To reduce LKB1, a heterozygous astrocyte-selective conditional knockout (het-cKO) model was used. While disease incidence was similar, disease severity was worsened in het-cKO mice. RNAseq analysis identified Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched in het-cKO mice relating to mitochondrial function, confirmed by alterations in mitochondrial complex proteins and reductions in mRNAs related to astrocyte metabolism. Enriched pathways included major histocompatibility class II genes, confirmed by increases in MHCII protein in spinal cord and cerebellum of het-cKO mice. We observed increased numbers of CD4+ Th17 cells and increased neuronal damage in spinal cords of het-cKO mice, associated with reduced expression of choline acetyltransferase, accumulation of immunoglobulin-γ, and reduced expression of factors involved in motor neuron survival. In vitro, LKB1-deficient astrocytes showed reduced metabolic function and increased inflammatory activation. These data suggest that metabolic dysfunction in astrocytes, in this case due to LKB1 deficiency, can exacerbate demyelinating disease by loss of metabolic support and increase in the inflammatory environment. 相似文献
22.
23.
24.
Functional inhibition of PAR2 alleviates allergen‐induced airway hyperresponsiveness and inflammation 下载免费PDF全文
25.
Stephania Herodotou Robert E. Treharne Ken Durose Gordon J. Tatlock Richard J. Potter 《Materials》2015,8(10):7230-7240
Transparent conducting oxides (TCOs), with high optical transparency (≥85%) and low electrical resistivity (10−4 Ω·cm) are used in a wide variety of commercial devices. There is growing interest in replacing conventional TCOs such as indium tin oxide with lower cost, earth abundant materials. In the current study, we dope Zr into thin ZnO films grown by atomic layer deposition (ALD) to target properties of an efficient TCO. The effects of doping (0–10 at.% Zr) were investigated for ~100 nm thick films and the effect of thickness on the properties was investigated for 50–250 nm thick films. The addition of Zr4+ ions acting as electron donors showed reduced resistivity (1.44 × 10−3 Ω·cm), increased carrier density (3.81 × 1020 cm−3), and increased optical gap (3.5 eV) with 4.8 at.% doping. The increase of film thickness to 250 nm reduced the electron carrier/photon scattering leading to a further reduction of resistivity to 7.5 × 10−4 Ω·cm and an average optical transparency in the visible/near infrared (IR) range up to 91%. The improved n-type properties of ZnO: Zr films are promising for TCO applications after reaching the targets for high carrier density (>1020 cm−3), low resistivity in the order of 10−4 Ω·cm and high optical transparency (≥85%). 相似文献
26.
27.
28.
29.
30.