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Lei Zhou,Lin Fu,Na Lv,Jing Liu,Yan Li,Xiaosu Chen,Qingyu Xu,Guofeng Chen,Baoxu Pang,Lili Wang,Yonghui Li,Xiaodong Zhang,Li Yu 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-
The AML1-ETO fusion protein (A/E), which results from the t(8;21) translocation, is considered to be a leukemiainitiating event. Identifying the mechanisms underlying the oncogenic activity of A/E remains a major challenge. In this study, we identified a specific down-regulation of brain acid-soluble protein 1 (BASP1) in t(8;21) acute myeloid leukemia (AML). A/E recognized AML1-binding sites and recruited DNA methyltransferase 3a (DNMT3a) to the BASP1 promoter sequence, which triggered DNA methylation-mediated silencing of BASP1. Ectopic expression of BASP1 inhibited proliferation and the colony-forming ability of A/E-positive AML cell lines and led to apoptosis and cell cycle arrest. The DNMT inhibitor decitabine up-regulated the expression of BASP1 in A/E-positive AML cell lines. In conclusion, our data suggest that BASP1 silencing via promoter methylation may be involved in A/E-mediated leukemogenesis and that BASP1 targeting may be an actionable therapeutic strategy in t(8;21) AML.
Chen, Lei,Yan, Huiying,Xue, Xiangxin,Jiang, Dayu,Cai, Yuxi,Liang, Dongmei,Jung, Young Mee,Han, Xiao Xia,Zhao, Bing SAGE Publications 2017 APPLIED SPECTROSCOPY Vol.71 No.7
<P>In this work, we designed a process to assemble gold nanoparticles onto a three-dimensional (3D) polymer surface, which can then be monitored using surface-enhanced Raman scattering (SERS). This work is the first demonstration of the assembly of gold nanoparticles on a filter film and in situ measurement with Raman spectroscopy. Herein, a polyhexamethylene adipamide (Nylon66) film embedded in the organic filter film was used as a template to fabricate a tunable SERS-active substrate. A 'hotspot''-rich gold-nanoparticle-decorated polymer substrate for SERS was prepared; this substrate exhibited high sensitivity in trace detection of targets. The study was conducted using 4-mercaptobenzoic acid as a probe molecule with the aim of comparing the scattering efficiency and the homogeneity of the Raman signal on selected substrates. In addition, we used the gold-decorated polymer film to detect a biotin-avidin complex. The most powerful advantage of the proposed microanalytical device is the in situ SERS application. The 3D nanoporous structures described in this work hold strong potential for use in various applications such as environmental monitoring and biomolecule detection.</P>
Lei Chen,Haipeng He,Mian Wang,Xiaoxi Li,Henghui Yin 한국조직공학과 재생의학회 2017 조직공학과 재생의학 Vol.14 No.4
Expanded polytetrafluoroethylene (ePTFE) polymers do not support endothelialization because of nonconductive characteristics towards cellular attachment. Inner surface modification of the grafts can improve endothelialization and increase the long-term patency rate of the ePTFE vascular grafts. Here we reported a method of inner-surface modification of ePTFE vascular graft with extracellular matrix (ECM) and CD34 monoclonal antibodies (CD34 mAb) to stimulate the adhesion and proliferation of circulating endothelial progenitor cells on ePTFE graft to enhance graft endothelialization. The inner surface of ECM-coated ePTFE grafts were linked with CD34 mAb in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) solution and the physicochemical properties, surface morphology, biocompatibility, and hemocompatibility of the grafts were studied. The hydrophilicity of CD34 mAb-coated graft inner surface was significantly improved. Fourier transform infrared spectroscopy analysis confirmed ECM and CD34 mAb cross-linking in the ePTFE vascular grafts with our method. Scanning electron microscopy analysis showed protein layer covering uniformly on the inner surface of the modified grafts. The cell-counting kit-8 (CCK-8) assay confirmed that the modified graft has no obvious cytotoxicity. The modified graft showed a low hemolytic rate (0.9%) in the direct contact hemolysis test, suggesting the modification improved hemocompatibility of biopolymers. The modification also decreased adhesion of platelets, while significantly increased the adhesion of endothelial cells on the grafts. We conclude that our method enables ePTFE polymers modification with ECM and CD34 mAb, facilitates endothelialization, and inhibits platelet adhesion on the grafts, thus may increase the long-term patency rate of the prosthetic bypass grafts.
Lei-Chen Lin,Wan-Rou Lin,Yu-Chen Hsu,Hung-Yu Pan 한국원예학회 2020 원예과학기술지 Vol.38 No.5
Rhododendron kanehirae Wilson is an endemic species of Taiwan that is listed as extinct in the wild by the Red List of Vascular Plants of Taiwan. R. kanehirae seedlings can form mycorrhizae with the ericoid mycobiont Oidiodendron maius. A completely randomized experimental design was conducted to investigate the effects of three different O. maius isolates (strains CBS110450, RhYM3, and RooDK1) as well as nitrate and ammonium (inorganic nitrogen) on the growth of R. kanehirae by evaluating height and shoot, root, and total fresh weight. Three isolates of O. maius showed different colony morphology and growth rate, which was further verified by molecular analysis. The results showed that application of ammonium fertilizer improved the height and shoot, root, and total fresh weight of all of the R. kanehirae seedlings. Among them, seedlings inoculated with RhYM3 had the highest fresh weights and heights. By applying an appropriate amount of nitrogen combined with RhYM3 inoculation, the rhizome of R. kanehirae grew well. The information provided here is crucial for the conservation of R. kanehirae, as this species is on the verge of extinction.
Chen, Lei,Kang, Young-Hwa The Plant Resources Society of Korea 2014 한국자원식물학회지 Vol.27 No.6
The antioxidant potentials of the methanol extract and its various fractions from Agrimonia pilosa Ledeb were measured as 1,1-diphenyl-2-picrylhydrazyl (DPPH), and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging abilities as well as the reducing power decreasing NO in vitro. The methanol extract of Agrimonia pilosa Ledeb showed significantly strong scavenging effects on free radicals of DPPH, ABTS, and NO. Hexane fraction (HF), ethyl acetate fraction (EF) and n-butyl alcohol fraction (BF) were prepared by solvent fractionation. By comparison of polyphenol contents among BF and HF, EF with high polyphenol contents showed the highest DPPH, ABTS, and NO scavenging effects with the value of 50.2%, 80.4%, and 65.7%, respectively, at the highest tested dose. HPLC analysis revealed the presence of various phenolic compounds in EF of Agrimonia pilosa Ledeb. These results suggest that EF could be considered as natural antioxidant sources and dietary nutritional supplements to prevent oxidation-related diseases.
Lei Chen,황지은,구강모,김정현,최보람,송경식,박유미,강영화 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.3
Methanol extracts from the placenta, stalk, and pricarp of 5 Korean varieties red pepper (Capsicum annuum L) were obtained and antioxidant constituents including total phenol, total flavonoids, and capsaicin were analyzed. Antioxidant effects were determined by ABTS,DPPH, and nitric oxide (NO) free radicals scavenging activities and superoxide dismutase (SOD)-like activity. All the extracts showed strong antioxidant activities in various bioassays. Chromatic parameters (L*, a*, b*, C*,and Ho) were responsible for the antioxidant capacity of red pepper pericarp extracts. Generally, stalk been considered as disposable part, exhibited not only strong scavenging activities against free radicals, but also high content of total phenols, total flavonoids, and capsaicin. In addition, positive correlations were also observed between antioxidant activities and constituents of phenolics, flavonoids, and capsaicin. It was concluded that red pepper, including stalk,can be functional food materials to enhance human health.
Chen, Lei,Guo, Gang,Yuan, Xianjun,Shimojo, Masataka,Yu, Chengqun,Shao, Tao Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.3
The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality and aerobic stability of total mixed ration (TMR) silages prepared with whole-plant corn in Tibet. TMR (354 g/kg DM) was ensiled with four different treatments: no additive (control), molasses (M), propionic acid (P), and molasses+propionic acid (PM), in laboratory silos (250 mL) and fermented for 45 d. Silos were opened and silages were subjected to an aerobic stability test for 12 days, in which chemical and microbiological parameters of TMR silages were measured to determined the aerobic deterioration. After 45 d of ensiling, the four TMR silages were of good quality with low pH value and ammonia/total N (AN), and high lactic acid (LA) content and V-scores. M silage showed the highest (p<0.05) LA content and higher dry matter (DM) recovery than the control and P silages. P silage had lower (p<0.05) LA content than the control silage. During aerobic exposure, lactic acid contents decreased gradually in the control and M silages, while that of P and PM silages increased, and the peak values were observed after 9 d. M silage had similar yeast counts with the control silage (> $10^5$ cfu/g FM), however, it appeared to be more stable as indicated by a delayed pH value increase. P and PM silages showed fewer yeasts (< $10^5$ cfu/g FM) (p<0.05) and were more stable than the control and M silages during aerobic exposure. It was concluded that M application increased LA content and improved aerobic stability of TMR silage prepared with whole-plant corn in Tibet. P application inhibited lactic acid production during ensiling, and apparently preserved available sugars which stimulated large increases in lactic acid during aerobic exposure stage, which resulted in greater aerobic stability of TMR silage.
P1-Nonconforming shell element and its application to topology optimization
Chen Lei,백태현,장강원 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.1
The P1-nonconforming quadrilateral element developed by Park and Sheen [19] is employed for the formulation of a four-node degeneratedshell element. The numerical stability of the P1-nonconforming quadrilateral element verified in plane elasticity problems andStokes flow problems is investigated for the application of mitigating locking phenomena in shell problems. To facilitate the stiffnessmatrix computation for a non-flat general quadrilateral shell element, a nonparametric reference scheme using both affine transformationand bilinear transformation is adopted. Based on a field-consistency concept, the spurious constraints that cause locking are analyzed andan effective reduced integration scheme is found. The proposed shell element is applied to multi-physics topology optimization problemsinvolving fluid analysis and shell analysis. For fluid analysis, the P1-nonconforming quadrilateral element is also adopted to utilize itsvolumetric locking-free property for incompressible materials. Vein layouts of leaves are designed by topology optimization and comparedwith natural vein layouts to verify the effectiveness of the proposed element.