全文获取类型
收费全文 | 3709篇 |
免费 | 371篇 |
国内免费 | 586篇 |
专业分类
4666篇 |
出版年
2024年 | 21篇 |
2023年 | 62篇 |
2022年 | 134篇 |
2021年 | 232篇 |
2020年 | 163篇 |
2019年 | 188篇 |
2018年 | 166篇 |
2017年 | 117篇 |
2016年 | 161篇 |
2015年 | 202篇 |
2014年 | 284篇 |
2013年 | 266篇 |
2012年 | 351篇 |
2011年 | 323篇 |
2010年 | 216篇 |
2009年 | 192篇 |
2008年 | 230篇 |
2007年 | 187篇 |
2006年 | 168篇 |
2005年 | 161篇 |
2004年 | 136篇 |
2003年 | 124篇 |
2002年 | 108篇 |
2001年 | 101篇 |
2000年 | 78篇 |
1999年 | 78篇 |
1998年 | 40篇 |
1997年 | 26篇 |
1996年 | 24篇 |
1995年 | 28篇 |
1994年 | 19篇 |
1993年 | 19篇 |
1992年 | 6篇 |
1991年 | 13篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1965年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
1955年 | 1篇 |
1951年 | 2篇 |
排序方式: 共有4666条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
Downregulation of microRNA‐15a‐3p is correlated with clinical outcome and negatively regulates cancer proliferation and migration in human osteosarcoma 下载免费PDF全文
Jiyuan Shi Qiang Fu Pei Yang Huitong Liu Le Ji Kunzheng Wang 《Journal of cellular biochemistry》2018,119(1):1215-1222
In this study, we investigated the expression, correlation to clinical outcomes and biological functions of microRNA‐15a‐3p (miR‐15a‐3p) in human osteosarcoma. MiR‐15a‐3p expressions in osteosarcoma cell lines and clinical tissues of osteosarcoma patients were measured by qPCR. Relevance of endogenous miR‐15a‐3p to osteosarcoma patients' clinicopathological factors or overall survival was statistically analyzed. In addition, the independence of miR‐15a‐3p predicting cancer patients' overall survival was analyzed by Cox regression method. Furthermore, in osteosarcoma cell lines, Saos‐2 and HOS cells, miR‐15a‐3p was overexpressed through stable lentiviral transduction. The functional regulations of miR‐15a‐3p overexpression on cancer ell proliferation and migration were then analyzed. MiR‐15a‐3p was significantly downregulated in osteosarcoma cell lines and human osteosarcoma tumors. Downregulation of endogenous miR‐15a‐3p in osteosarcoma tumors was significantly associated with cancer patient's poor clinical outcomes and low survival rate. Also, endogenous miR‐15a‐3p was confirmed to be an independent biomarker for predicating cancer patients' survival. In Saos‐2 and HOS cells, lentivirus‐induced miR‐15a‐3p overexpression had significantly tumor suppressing functions, by inhibiting both proliferation and migration. Significant downregulation of miR‐15a‐3p in osteosarcoma may be an independent biomarker to predicting cancer patients' poor prognosis. Overexpression miR‐15a‐3p may be an efficient functional meaning to suppress osteosarcoma development. 相似文献
95.
Zhang Z Qun J Cao C Wang J Li W Wu Y Du L Zhao P Gong K 《Molecular biology reports》2012,39(4):4445-4454
Circulating endothelial progenitor cells (EPCs) have a critical role in endothelial maintenance and repair. Apolipoprotein
A-I mimetic peptide D-4F has been shown to posses anti-atherogenic properties via sequestration of oxidized phospholipids,
induction of remodeling of high density lipoprotein and promotion of cholesterol efflux from macrophage-derived foam cells.
In this study, we test the effects of D-4F on EPC biology. EPCs were isolated from the peripheral venous blood of healthy
male volunteers and characterized by 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine-labeled acetylated LDL uptake
and ulex europaeus agglutinin binding and flow cytometry. Cell proliferation, migration, adhesion, nitric oxide production
and endothelial nitric oxide synthase (eNOS) expression in the absence and presence of D-4F or simvastatin (as a positive
control), were assayed. We demonstrated that D-4F significantly enhanced EPC proliferation, migration and adhesion in a dose-dependent
manner compared with vehicle. However, all of the favorable effects of D-4F on EPCs were dramatically attenuated by preincubation
with NOS inhibitor L-NAME. Further, D-4F also increased nitric oxide production in culture supernatant and the levels of eNOS
expression and phosphorylation. The stimulatory effects of D-4F (10 μg/ml) on EPC biology were comparable to 0.5 μM simvastatin.
These results suggest that eNOS/NO pathway mediates the functional modulation of EPC biology in response to D-4F treatment
and support the notion that the beneficial role of D-4F on EPCs may be one of the important components of its anti-atherogenic
potential. 相似文献
96.
97.
Song Huijia Jespersen Emil Guo Xiao Du Ning Xie Liujuan Pei Lixin Ye Siyuan Wang Renqing Brix Hans Eller Franziska Guo Weihua 《Hydrobiologia》2021,848(14):3353-3369
Hydrobiologia - Soil salinity diminishes the dominance of species and affects their distribution. Phragmites australis is a dominant ecosystem engineer with broad distribution, high intraspecific... 相似文献
98.
Chemical protein modifications facilitate the investigation of natural posttranslational protein modifications and allow the design of proteins with new functions. Proteins can be modified at a late stage on amino acid side chains by chemical methods. The indole moiety of tryptophan residues is an emerging target of such chemical modification strategies because of its unique reactivity and low abundance. This review provides an overview of the recently developed methods of tryptophan modification at the peptide and protein levels. 相似文献
99.