全文获取类型
收费全文 | 599篇 |
免费 | 63篇 |
国内免费 | 23篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 13篇 |
2021年 | 21篇 |
2020年 | 17篇 |
2019年 | 30篇 |
2018年 | 37篇 |
2017年 | 28篇 |
2016年 | 35篇 |
2015年 | 35篇 |
2014年 | 44篇 |
2013年 | 42篇 |
2012年 | 60篇 |
2011年 | 41篇 |
2010年 | 29篇 |
2009年 | 25篇 |
2008年 | 30篇 |
2007年 | 26篇 |
2006年 | 27篇 |
2005年 | 21篇 |
2004年 | 28篇 |
2003年 | 20篇 |
2002年 | 7篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有685条查询结果,搜索用时 31 毫秒
651.
Yong Li Tao Wang Chun-gen Piao Lai-fa Wang Guo-zhong Tian Tian-hui Zhu Min-wei Guo 《Antonie van Leeuwenhoek》2015,107(2):321-328
652.
Fandong Meng Songbai Hong Jiawei Wang Anping Chen Yao Zhang Yichen Zhang Ivan A. Janssens Jiafu Mao Ranga B. Myneni Josep Peñuelas Shilong Piao 《Ecology letters》2023,26(5):816-826
Global greening, characterized by an increase in leaf area index (LAI), implies an increase in foliar carbon (C). Whether this increase in foliar C under climate change is due to higher photosynthesis or to higher allocation of C to leaves remains unknown. Here, we explored the trends in foliar C accumulation and allocation during leaf green-up from 2000 to 2017 using satellite-derived LAI and solar-induced chlorophyll fluorescence (SIF) across the Northern Hemisphere. The accumulation of foliar C accelerated in the early green-up period due to both increased photosynthesis and higher foliar C allocation driven by climate change. In the late stage of green-up, however, we detected decreasing trends in foliar C accumulation and foliar C allocation. Such stage-dependent trends in the accumulation and allocation of foliar C are not represented in current terrestrial biosphere models. Our results highlight that a better representation of C allocation should be incorporated into models. 相似文献
653.
Live H. Hagen Charles G. Brooke Claire A. Shaw Angela D. Norbeck Hailan Piao Magnus
. Arntzen Heather M. Olson Alex Copeland Nancy Isern Anil Shukla Simon Roux Vincent Lombard Bernard Henrissat Michelle A. OMalley Igor V. Grigoriev Susannah G. Tringe Roderick I. Mackie Ljiljana Pasa-Tolic Phillip B. Pope Matthias Hess 《The ISME journal》2021,15(2):421
654.
Xin Wang Zhongze Piao Biye Wang Runqing Yang Zhixiang Luo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(3):609-617
In most quantitative trait loci (QTL) mapping studies, phenotypes are assumed to follow normal distributions. Deviations from
this assumption may affect the accuracy of QTL detection, leading to detection of false positive QTL. To improve the robustness
of QTL mapping methods, we replace the normal distribution assumption for residuals in a multiple QTL model with a Student-t distribution that is able to accommodate residual outliers. A Robust Bayesian mapping strategy is proposed on the basis of
the Bayesian shrinkage analysis for QTL effects. The simulations show that Robust Bayesian mapping approach can substantially
increase the power of QTL detection when the normality assumption does not hold and applying it to data already normally distributed
does not influence the result. The proposed QTL mapping method is applied to mapping QTL for the traits associated with physics–chemical
characters and quality in rice. Similarly to the simulation study in the real data case the robust approach was able to detect
additional QTLs when compared to the traditional approach. The program to implement the method is available on request from
the first or the corresponding author.
Xin Wang and Zhongze Piao contributed equally to this study. 相似文献
655.
Xuefei Han Yuan Zhang Liulin Xiong Yang Xu Piao Zhang Qingjie Xia Tinghua Wang Yingchun Ba 《Molecular neurobiology》2017,54(3):1684-1697
Spinal cord injury (SCI), as a major cause of disability, usually causes serious loss of motor and sensory functions. As a bifunctional axonal guidance cue, netrin-1 can attract axons via the deleted in colorectal cancer (DCC) receptors and repelling others via Unc5 receptors, but its exact role in the recovery of motor and sensory function has not well been studied, and the mechanisms remains elusive. The aim of this experiment is to determine whether lentiviral (LV)-mediated overexpression of netrin-1 or RNA interference (RNAi) can regulate the functional recovery in rats subjected to spinal cord transection (SCT). Firstly, two lentiviral vectors including Lv-exNtn-1 (netrin-1 open reading frame (ORF)) and Lv-shNtn-1 (netrin-1 sh) were constructed and injected into spinal cords rostral and caudal to the transected lesion site. Overexpressing netrin-1 enhanced significantly locomotor function, and reduced thermal and mechanical stimuli in vivo, compared with the control, while silencing netrin-1 did not significantly change the situation. Western blot and immunostaining analysis confirmed that netrin-1 ORF treatment not only effectively increased the expression level of netrin-1, also up-regulated the level of synaptophysin (SYP) in spinal cord rostral to the lesion, but also enhanced growth-associated protein-43 (GAP-43) expression in spinal cord caudal to the lesion site. Comparatively, knockdown of netrin-1 did not give rise to positive findings in our experimental condition. These findings therefore pointed that Lv-mediated netrin-1 overexpression could promote motor and sensory functional recoveries following SCT, and the underlying mechanisms were associated with SYP and GAP-43 expressions. The present study therefore provided a novel strategy for the treatment of SCI and explained the possible mechanisms for the functional improvement. 相似文献
656.
Qiu-Ping Lu Miao-Li Wu Hui-Lin Li Yu Zhou Ming-Hua Xian Wei-Zhong Huang Xiu-Hong Piao Yue-Wei Ge 《化学与生物多样性》2023,20(8):e202300646
The abnormal uterine bleeding (AUB) is complex and usually leads to severe anemia. Melastomadodecandrum (MD) is clinically used for the treatment of metrorrhagia bleeding. The MD ellagitannins (MD-ETs) had been evidenced being effective at hemorrhage, and exerts biological activities upon their metabolites including ellagic acid and urolithins. In this study, the blood-permeated metabolites from theMD-ETs were analyzed using LC-MS approach, and 19 metabolites including ellagic acid and urolithin A derivatives were identified. Furthermore, a network pharmacology analysis including the target prediction analysis, AUB target analysis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted to reveal the relationships between “metabolites-targets-pathways”, which was further verified by molecular docking analysis. The results showed that methyl ellagic acid, urolithin A and isourolithin A produced from MD-ETs can be absorbed into the blood, and might act on the core targets of VEGFA, SRC, MTOR, EGFR and CCND1. And the hemostatic effects were exerted through PI3K-Akt, endocrine resistance and Rap 1 signaling pathways. These results implied the potential effective constituents and action mechanism of MD-ETs in the therapy of AUB, which will promote the application of MD-ETs as natural agent for the treatment of gynecological bleeding diseases. 相似文献
657.
Multiple sclerosis (MS) is a multifactorial demyelinating disease characterized by neurodegenerative events and autoimmune response against myelin component. Citrullination or deimination, a post-translational modification of protein-bound arginine into citrulline, catalyzed by Ca2+ dependent peptidylarginine deiminase enzyme (PAD), plays an essential role in physiological processes include gene expression regulation, apoptosis and the plasticity of the central nervous system, while aberrant citrullination can generate new epitopes, thus involving in the initiation and/or progression of autoimmune disorder like MS. Myelin basic protein (MBP) is the major myelin protein and is generally considered to maintain the stability of the myelin sheath. This review describes the MBP citrullination and its consequence, as well as offering further support for the “inside-out” hypothesis that MS is primarily a neurodegenerative disease with secondary inflammatory demyelination. In addition, it discusses the role of MBP citrullination in the immune inflammation and explores the potential of inhibition of PAD enzymes as a therapeutic strategy for the disease. 相似文献
658.
The effects of Con A, WGA, Zymosan A on macrophage cytosolic pH and outflow of lysosomal content through exocytosis were studied with SNAFL-calcein and FITC-Dextran on ACAS570. The results showed all three ligands could induce macrophage cytosolic acidification in about 10 min and kept at the same level hereafter; outflow of lysosomal fluorescent probe through exocytosis appeared in 15-20 min. In resting conditions, macrophage lysosomes mainly distributed in cell center; after stimulated for 15 min by three ligands, the number of lysosomes increased in membrane periphery, in 25-30 min lysosomes moved back toward cell center. We proposed that ligands induced lysosomal pH rises was a basic factor for outflow of lysosomal content through exocytosis, cytosolic acidification inhibited receptor-mediated endocytosis. Cytosolic acidification and outflow of lysosomal content through exocytosis were the results of cellular self-regulation and self-protection during receptor-mediated endocytosis. 相似文献
659.
660.
Na Lin Liu-Lin Xiong Rong-ping Zhang Hong Zheng Lei Wang Zhong-Yi Qian Piao Zhang Zhi-wei Chen Fa-Bao Gao Ting-Hua Wang 《Apoptosis : an international journal on programmed cell death》2016,21(5):621-640
Alzheimer’s disease (AD) can incur significant health care costs to the patient, their families, and society; furthermore, effective treatments are limited, as the mechanisms of AD are not fully understood. This study utilized twelve adult male tree shrews (TS), which were randomly divided into PBS and amyloidbetapeptide1-40 (Aβ1-40) groups. AD model was established via an intracerebroventricular (icv) injection of Aβ1-40 after being incubated for 4 days at 37 °C. Behavioral, pathophysiological and molecular changes were evaluated by hippocampal-dependent tasks, magnetic resonance imaging (MRI), silver staining, hematoxylin–eosin (HE) staining, TUNEL assay and gene sequencing, respectively. At 4 weeks post-injection, as compared with the PBS group, in Aβ1-40 injected animals: cognitive impairments happened, and the hippocampus had atrophied indicated by MRI findings; meanwhile, HE staining showed the cells of the CA3 and DG were significantly thinner and smaller. The average number of cells in the DG, but not the CA3, was also significantly reduced; furthermore, silver staining revealed neurotic plaques and neurofibrillary tangles (NFTs) in the hippocampi; TUNEL assay showed many cells exhibited apoptosis, which was associated with downregulated BCL-2/BCL-XL-associated death promoter (Bad), inhibitor of apoptosis protein (IAP), Cytochrome c (CytC) and upregulated tumor necrosis factor receptor 1 (TNF-R1); lastly, gene sequencing reported a total of 924 mobilized genes, among which 13 of the downregulated and 19 of the upregulated genes were common to the AD pathway. The present study not only established AD models in TS, but also reported on the underlying mechanism involved in neuronal apoptosis associated with multiple gene expression. 相似文献