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Now showing items 33 - 42 of 42

  • Image classification method rationally utilizing spatial information of the image

    Wu, Chao   Li, Yaqian   Zhao, Zhibiao   Liu, Bin  

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  • Identification of a Novel Fungus, Leptosphaerulina chartarum SJTU59 and Characterization of Its Xylanolytic Enzymes

    Wu, Qiong   Li, Yaqian   Li, Yingying   Gao, Shigang   Wang, Meng   Zhang, Tailong  

    Xylanolytic enzymes are widely used in processing industries, e. g., pulp and paper, food, livestock feeds, and textile. Furthermore, certain xylanotic enzymes have demonstrated the capability to improve the resistance and immunity of plants. Screening of high-yield microbial xylanolytic enzyme producers is significant for improving large-scale cost-effective xylanolytic enzyme production. This study provided new evidence of high-level xylanolytic enzyme production by a novel fungus, designated Leptosphaerulina chartarum SJTU59. Under laboratory conditions, L. chartarum SJTU59 produced xylanolytic enzymes of up to 17.566 U/mL (i.e., 878.307 U/g substrate). The enzyme solution was relatively stable over a wide range of pH (pH 3.0 to pH 9.0) and temperature (40 degrees C to 65 degrees C) while showing high resistance to the majority of metal ions tested. Composition analysis of the hydrolytic products of xylan showed sufficient degradation by xylanolytic enzymes from L. chartarum SJTU59, mainly the monosaccharide xylose, and a small amount of xylobiose were enzymatically produced; whereas in the presence of sufficient xylan substrates, mainly xylooligosaccharides, an emerging prebiotic used in food industry, were produced. In addition, the xylanolytic enzyme preparation from L. chartarum SJTU59 could initiate tissue necrosis and oxidative burst in tobacco leaves, which may be related to enhanced plant defense to adversity and disease. L. chartarum SJTU59 possessed a complex xylanolytic enzyme system, from which two novel endo-beta-1,4-xylanases of the glycoside hydrolase (GH) family 10, one novel endo-beta-1,4-xylanase of the GH family 11, and one novel beta-xylosidase of the GH family 43 were obtained via rapid amplification of complementary DNA ends. Given the high yield and stable properties of xylanolytic enzymes produced by L. chartarum SJTU59, future studies will be conducted to characterize the properties of individual xylanolytic enzymes from L. chartarum SJTU59. xylanolytic enzymes-encoding gene(s) of potential use for industrial and agricultural applications will be screened to construct genetically engineered strains.
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  • A Dual-Response Near-Infrared Fluorescent Probe for Rapid Detecting Thiophenol and Its Application in Water Samples and Bio-imaging

    Li, Yaqian   Su, Wei   Zhou, Zile   Huang, Zhen   Wu, Cuiyan   Yin, Peng   Li, Haitao   Zhang, Youyu  

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  • 15-Hydroxyeicosatetraenoic acid (15-HETE) protects pulmonary artery smooth muscle cells against apoptosis via HSP90

    Zhang, Lei   Ma, Jun   Li, Yaqian   Guo, Lei   Ran, Yajuan   Liu, Shulin   Jiang, Chun  

    Aims: 15-Hydroxyeicosatetraenoic acid (15-HETE), generated by hypoxia, is a product of arachidonic acid and mainly catalyzed by 15-lipoxygenase (15-LO) in pulmonary artery. As HSP90 is known to be involved in apoptosis in other tissues and cells, we aim to test whether anti-apoptotic effect of 15-HETE is regulated by the molecular chaperone in pulmonary artery smooth muscle cells.Main methods: To test this hypothesis, we performed cell viability analysis, mitochondrial potential assay, caspase-3 activity measurement, Western blot, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling with and without HSP90 inhibitor.Key findings: Our results showed that both exogenous and endogenous 15-HETE up-regulated HSP90 expression and prevented PASMC from serum deprivation-induced apoptosis. Serum deprivation lead to mitochondrial membrane depolarization, decreased expression of Bcl-2 and enhanced expression of Bax, and activation of caspase-3 and caspase-9 in PASMCs. 15-HETE reversed all these effects in a HSP90-dependent manner.Significance: This study establishes the factor involved in 15-HETE-protecting PASMC from apoptosis and the regulation of HSP90 by 15-HETE may be an important mechanism underlying the treatment of pulmonary artery hypertension and provide a novel therapeutic target in future. (c) 2010 Elsevier Inc. All rights reserved.
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  • Molecular cloning and functional characterization of duck Janus kinase 1

    Liu, Dejian   Zheng, Huijun   Li, Yaqian   Zhou, Peng   Jin, Hui   Luo, Rui  

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  • Tissue Composition and Biomechanical Property Changes in the Vaginal Wall of Ovariectomized Young Rats

    Mao, Meng   Li, Yaqian   Zhang, Ye   Kang, Jia   Zhu, Lan  

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  • Optimizing mesoderm progenitor selection and three-dimensional microniche culture allows highly efficient endothelial differentiation and ischemic tissue repair from human pluripotent stem cells

    Zhang, Fengzhi   Wang, Lin   Li, Yaqian   Liu, Wei   Duan, Fuyu   Huang, Rujin   Chen, Xi   Chang, Sophia Chia-Ning   Du, Yanan   Na, Jie  

    Background: Generation of large quantities of endothelial cells is highly desirable for vascular research, for the treatment of ischemia diseases, and for tissue regeneration. To achieve this goal, we developed a simple, chemically defined culture system to efficiently and rapidly differentiate endothelial cells from human pluripotent stem cells by going through an MESP1 mesoderm progenitor stage. Methods: Mesp1 is a key transcription factor that regulates the development of early cardiovascular tissue. Using an MESP1-mTomato knock-in reporter human embryonic stem cell line, we compared the gene expression profiles of MESP1(+) and MESP1(-) cells and identified new signaling pathways that may promote endothelial differentiation. We also used a 3D scaffold to mimic the in vivo microenvironment to further improve the efficiency of endothelial cell generation. Finally, we performed cell transplantation into a critical limb ischemia mouse model to test the repairing potential of endothelial-primed MESP1(+) cells. Results: MESP1(+) mesoderm progenitors, but not MESP1(-) cells, have strong endothelial differentiation potential. Global gene expression analysis revealed that transcription factors essential for early endothelial differentiation were enriched in MESP1(+) cells. Interestingly, MESP1 cells highly expressed Sphingosine-1-phosphate (S1P) receptor and the addition of S1P significantly increased the endothelial differentiation efficiency. Upon seeding in a novel 3D microniche and priming with VEGF and bFGF, MESP1(+) cells markedly upregulated genes related to vessel development and regeneration. 3D microniches also enabled long-term endothelial differentiation and proliferation from MESP1+ cells with minimal medium supplements. Finally, we showed that transplanting a small number of endothelial-primed MESP1(+) cells in 3D microniches was sufficient to mediate rapid repair of a mouse model of critical limb ischemia. Conclusions: Our study demonstrates that combining MESP1(+) mesoderm progenitor cells with tissue-engineered 3D microniche and a chemically defined endothelial induction medium is a promising route to maximizing the production of endothelial cells in vitro and augment their regenerative power in vivo.
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  • DNA origami as an in vivo drug delivery vehicle for cancer therapy.

    Zhang, Qian   Jiang, Qiao   Li, Na   Dai, Luru   Liu, Qing   Song, Linlin   Wang, Jinye   Li, Yaqian   Tian, Jie   Ding, Baoquan   Du, Yang  

    Many chemotherapeutics used for cancer treatments encounter issues during delivery to tumors in vivo and may have high levels of systemic toxicity due to their nonspecific distribution. Various materials have been explored to fabricate nanoparticles as drug carriers to improve delivery efficiency. However, most of these materials suffer from multiple drawbacks, such as limited biocompatibility and inability to engineer spatially addressable surfaces that can be utilized for multifunctional activity. Here, we demonstrate that DNA origami possessed enhanced tumor passive targeting and long-lasting properties at the tumor region. Particularly, the triangle-shaped DNA origami exhibits optimal tumor passive targeting accumulation. The delivery of the known anticancer drug doxorubicin into tumors by self-assembled DNA origami nanostructures was performed, and this approach showed prominent therapeutic efficacy in vivo. The DNA origami carriers were prepared through the self-assembly of M13mp18 phage DNA and hundreds of complementary DNA helper strands; the doxorubicin was subsequently noncovalently intercalated into these nanostructures. After conducting fluorescence imaging and safety evaluation, the doxorubicin-containing DNA origami exhibited remarkable antitumor efficacy without observable systemic toxicity in nude mice bearing orthotopic breast tumors labeled with green fluorescent protein. Our results demonstrated the potential of DNA origami nanostructures as innovative platforms for the efficient and safe drug delivery of cancer therapeutics in vivo. =20
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  • (177)Lu-Labeled Cerasomes Encapsulating Indocyanine Green for Cancer Theranostics.

    Jing, Lijia   Shi, Jiyun   Fan, Di   Li, Yaqian   Liu, Renfa   Dai, Zhifei   Wang, Fan   Tian, Jie  

    This Article reported the fabrication of a robust theranostic cerasome encapsulating indocyanine green (ICG) by incorporating 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(polyethylene glycol)2000]-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid monoamide (DSPE-PEG2000-DOTA), followed by chelating radioisotope of (177)Lu. Its applications in optical and nuclear imaging of tumor uptake and biodistribution, as well as photothermal killing of cancer cells, were investigated. It was found that the obtained cerasome could act efficiently as fluorescence contrast agent as well as nuclear imaging tracer. Encapsulating ICG into cerasome could protect ICG from degradation, aggregation, and fast elimination from body, resulting in remarkable improvement in near-infrared fluorescence imaging, photothermal stability, and in vivo pharmacokinetic profile. Both fluorescence and nuclear imaging showed that such agent could selectively accumulate in tumor site after intravenous injection of the cerasome agent into Lewis lung carcinoma tumor bearing mice, resulting in efficient photothermal ablation of tumor through a one-time NIR laser irradiation at the best time window. The ability to track the uptake of cerasomes on a whole body basis could provide researchers with an excellent tool for developing cerasome-based drug delivery agents, especially the strategy of labeling cerasomes with theranostic radionuclide (177)Lu, enabling the ability of the (177)Lu-labeled cerasomes for radionuclide cancer therapy and even the combined therapy. =20
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  • Effect of Trichoderma harzianum on maize rhizosphere microbiome and biocontrol of Fusarium Stalk rot

    Saravanakumar, Kandasamy   Li, Yaqian   Yu, Chuanjin   Wang, Qiang-qiang   Wang, Meng   Sun, Jianan   Gao, Jin-xin   Chen, Jie  

    Fusarium stalk rot (FSR) caused by Fusarium graminearum (FG) significantly affects the productivity of maize grain crops. Application of agrochemicals to control the disease is harmful to environment. In this regard, use of biocontrol agent (BCA) is an alternative to agrochemicals. Although Trichoderma species are known as BCA, the selection of host-pathogen specific Trichoderma is essential for the successful field application. Hence, we screened a total of 100 Trichoderma isolates against FG, selected Trichoderma harzianum (CCTCC-RW0024) for greenhouse experiments and studied its effect on changes of maize rhizosphere microbiome and biocontrol of FSR. The strain CCTCC-RW0024 displayed high antagonistic activity (96.30%), disease reduction (86.66%), biocontrol-related enzyme and gene expression. The root colonization of the strain was confirmed by eGFP tagging and qRT-PCR analysis. Pyrosequencing revealed that exogenous inoculation of the strain in maize rhizosphere increased the plant growth promoting acidobacteria (18.4%), decreased 66% of FG, and also increased the plant growth. In addition, metabolites of this strain could interact with pathogenicity related transcriptional cofactor FgSWi6, thereby contributing to its inhibition. It is concluded that T. harzianum strain CCTCC-RW0024 is a potential BCA against FSR.
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