全文获取类型
收费全文 | 9849篇 |
免费 | 606篇 |
国内免费 | 18篇 |
出版年
2023年 | 103篇 |
2022年 | 361篇 |
2021年 | 561篇 |
2020年 | 228篇 |
2019年 | 278篇 |
2018年 | 397篇 |
2017年 | 266篇 |
2016年 | 410篇 |
2015年 | 575篇 |
2014年 | 581篇 |
2013年 | 719篇 |
2012年 | 727篇 |
2011年 | 707篇 |
2010年 | 406篇 |
2009年 | 355篇 |
2008年 | 437篇 |
2007年 | 448篇 |
2006年 | 363篇 |
2005年 | 296篇 |
2004年 | 286篇 |
2003年 | 244篇 |
2002年 | 232篇 |
2001年 | 121篇 |
2000年 | 85篇 |
1999年 | 84篇 |
1998年 | 69篇 |
1997年 | 54篇 |
1996年 | 37篇 |
1995年 | 50篇 |
1994年 | 38篇 |
1993年 | 40篇 |
1992年 | 66篇 |
1991年 | 54篇 |
1990年 | 57篇 |
1989年 | 61篇 |
1988年 | 41篇 |
1987年 | 40篇 |
1986年 | 42篇 |
1985年 | 45篇 |
1984年 | 44篇 |
1983年 | 43篇 |
1982年 | 42篇 |
1981年 | 45篇 |
1980年 | 52篇 |
1979年 | 24篇 |
1978年 | 34篇 |
1977年 | 25篇 |
1975年 | 22篇 |
1974年 | 27篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
11.
O Ahmed 《BMJ (Clinical research ed.)》1980,280(6207):119
12.
Mixed convection peristaltic flow of Jeffrey nanofluid in a channel with compliant walls is addressed here. The present investigation includes the viscous dissipation, thermal radiation and Joule heating. Whole analysis is performed for velocity, thermal and concentration slip conditions. Related problems through long wavelength and low Reynolds number are examined for stream function, temperature and concentration. Impacts of thermal radiation, Hartman number, Brownian motion parameter, thermophoresis, Joule heating and slip parameters are explored in detail. Clearly temperature is a decreasing function of Hartman number and radiation parameter. 相似文献
13.
14.
15.
16.
17.
18.
Theofilos Poutahidis Sean M. Kearney Tatiana Levkovich Peimin Qi Bernard J. Varian Jessica R. Lakritz Yassin M. Ibrahim Antonis Chatzigiagkos Eric J. Alm Susan E. Erdman 《PloS one》2013,8(10)
Wound healing capability is inextricably linked with diverse aspects of physical fitness ranging from recovery after minor injuries and surgery to diabetes and some types of cancer. Impact of the microbiome upon the mammalian wound healing process is poorly understood. We discover that supplementing the gut microbiome with lactic acid microbes in drinking water accelerates the wound-healing process to occur in half the time required for matched control animals. Further, we find that Lactobacillus reuteri enhances wound-healing properties through up-regulation of the neuropeptide hormone oxytocin, a factor integral in social bonding and reproduction, by a vagus nerve-mediated pathway. Bacteria-triggered oxytocin serves to activate host CD4+Foxp3+CD25+ immune T regulatory cells conveying transplantable wound healing capacity to naive Rag2-deficient animals. This study determined oxytocin to be a novel component of a multi-directional gut microbe-brain-immune axis, with wound-healing capability as a previously unrecognized output of this axis. We also provide experimental evidence to support long-standing medical traditions associating diet, social practices, and the immune system with efficient recovery after injury, sustained good health, and longevity. 相似文献
19.
Davide Danovi Amos Folarin Sabine Gogolok Christine Ender Ahmed M. O. Elbatsh P?r G. Engstr?m Stefan H. Stricker Sladjana Gagrica Ana Georgian Ding Yu Kin Pong U Kevin J. Harvey Patrizia Ferretti Patrick J. Paddison Jane E. Preston N. Joan Abbott Paul Bertone Austin Smith Steven M. Pollard 《PloS one》2013,8(10)
Glioblastoma multiforme (GBM) is the most common primary brain cancer in adults and there are few effective treatments. GBMs contain cells with molecular and cellular characteristics of neural stem cells that drive tumour growth. Here we compare responses of human glioblastoma-derived neural stem (GNS) cells and genetically normal neural stem (NS) cells to a panel of 160 small molecule kinase inhibitors. We used live-cell imaging and high content image analysis tools and identified JNJ-10198409 (J101) as an agent that induces mitotic arrest at prometaphase in GNS cells but not NS cells. Antibody microarrays and kinase profiling suggested that J101 responses are triggered by suppression of the active phosphorylated form of polo-like kinase 1 (Plk1) (phospho T210), with resultant spindle defects and arrest at prometaphase. We found that potent and specific Plk1 inhibitors already in clinical development (BI 2536, BI 6727 and GSK 461364) phenocopied J101 and were selective against GNS cells. Using a porcine brain endothelial cell blood-brain barrier model we also observed that these compounds exhibited greater blood-brain barrier permeability in vitro than J101. Our analysis of mouse mutant NS cells (INK4a/ARF−/−, or p53−/−), as well as the acute genetic deletion of p53 from a conditional p53 floxed NS cell line, suggests that the sensitivity of GNS cells to BI 2536 or J101 may be explained by the lack of a p53-mediated compensatory pathway. Together these data indicate that GBM stem cells are acutely susceptible to proliferative disruption by Plk1 inhibitors and that such agents may have immediate therapeutic value. 相似文献
20.
Radwan H. Ahmed Hasniza Zaman Huri Zaid Al-Hamodi Sameer D. Salem Sekaran Muniandy 《PloS one》2015,10(10)
BackgroundA soluble form of CD26/dipeptidyl peptidase-IV (sCD26/DPP-IV) induces DPP-IV enzymatic activity that degrades incretin. We investigated fasting serum levels of sCD26/DPP-IV and active glucagon-like peptide-1 (GLP-1) in Malaysian patients with type 2 diabetes mellitus (T2DM) with and without metabolic syndrome (MetS), as well as the associations between sCD26/DPP-IV levels, MetS, and antidiabetic therapy.MethodsWe assessed sCD26/DPP-IV levels, active GLP-1 levels, body mass index (BMI), glucose, insulin, A1c, glucose homeostasis indices, and lipid profiles in 549 Malaysian subjects (including 257 T2DM patients with MetS, 57 T2DM patients without MetS, 71 non-diabetics with MetS, and 164 control subjects without diabetes or metabolic syndrome).ResultsFasting serum levels of sCD26/DPP-IV were significantly higher in T2DM patients with and without MetS than in normal subjects. Likewise, sCD26/DPP-IV levels were significantly higher in patients with T2DM and MetS than in non-diabetic patients with MetS. However, active GLP-1 levels were significantly lower in T2DM patients both with and without MetS than in normal subjects. In T2DM subjects, sCD26/DPP-IV levels were associated with significantly higher A1c levels, but were significantly lower in patients using monotherapy with metformin. In addition, no significant differences in sCD26/DPP-IV levels were found between diabetic subjects with and without MetS. Furthermore, sCD26/DPP-IV levels were negatively correlated with active GLP-1 levels in T2DM patients both with and without MetS. In normal subjects, sCD26/DPP-IV levels were associated with increased BMI, cholesterol, and LDL-cholesterol (LDL-c) levels.ConclusionSerum sCD26/DPP-IV levels increased in T2DM subjects with and without MetS. Active GLP-1 levels decreased in T2DM patients both with and without MetS. In addition, sCD26/DPP-IV levels were associated with Alc levels and negatively correlated with active GLP-1 levels. Moreover, metformin monotherapy was associated with reduced sCD26/DPP-IV levels. In normal subjects, sCD26/DPP-IV levels were associated with increased BMI, cholesterol, and LDL-c. 相似文献