Microstructure and Mechanical Properties of Cold Drawn Ti–Nb–Ta–Zr–O Wires for Orthodontic Applications

Wei‑dong Zhang,Junye Ren,Bin Liu,Yong Liu,Zhenggang Wu,Jingwen Qiu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.7

Ti–36Nb–2Ta–3Zr–0.35O (TNTZO) alloy is an excellent candidate for biomedical applications. In this study, a new methodcombining cold-swaging and cold-drawing was used to fabricate the TNTZO alloy wires with 0.3 mm diameter for orthodonticapplications. The microstructure and mechanical properties of cold-drawn and annealed TNTZO wires (referred toas TNTZO0.3and TNTZO0.3(HT), respectively) were investigated. The results show that the microstructure of cold drawnTNTZO0.3consists of main-sized elongated grains with 70 nm width. After annealing at 700 °C for 5 min, the microstructureof TNTZO0.3(HT) wires becomes equiaxial with a grain size of ~ 5 μm. The cold drawn TNTZO0.3wires exhibit improvedmechanical properties, higher tensile strength (about 1000 MPa) and similar elastic modulus (69 GPa), compared to annealedTNTZO0.3(HT) wires. Besides, TNTZO0.3has higher creep resistance and lower stress exponent (around 2), compared to Tiwires and TC4 wires with the same diameter. These results prove that TNTZO0.3wires have most of the ideal characteristicsof orthodontic wires.

Down-regulation of SENP1 Expression Increases Apoptosis of Burkitt Lymphoma Cells

Huang, Bin-Bin,Gao, Qing-Mei,Liang, Wei,Xiu, Bing,Zhang, Wen-Jun,Liang, Ai-Bin Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objective: To investigate the effect of down-regulation of Sentrin/SUMO-specific protease 1 (SENP1) expression on the apoptosis of human Burkitt lymphoma cells (Daudi cells) and potential mechanisms. Methods: Short hairpin RNA (shRNA) targeting SENP1 was designed and synthesized and then cloned into a lentiviral vector. A lentiviral packaging plasmid was used to transfect Daudi cells (sh-SENP1-Daudi group). Daudi cells without transfection (Daudi group) and Daudi cells transfected with blank plasmid (sh-NC-Daudi group) served as control groups. Flow cytometry was performed to screen GFP positive cells and semiquantitative PCR and Western blot assays were employed to detect the inference efficiency. The morphology of cells was observed under a microscope before and after transfection. Fluorescence quantitative PCR and Western blot assays were conducted to measure the mRNA and protein expression of apoptosis related molecules (caspase-3, 8 and 9). After treatment with $COCl_2$ for 24 h, the mRNA and protein expression of hypoxia inducible factor -$1{\alpha}$ (HIF-$1{\alpha}$) was determined. Results: Sequencing showed the expression vectors of shRNA targeting SENP1 to be successfully constructed. Following screening of GFP positive cells by FCM, semiqualitative PCR showed the interference efficiency was $79.2{\pm}0.026%$. At 48 h after transfection, the Daudi cells became shrunken, had irregular edges and presented apoptotic bodies. Western blot assay revealed increase in expression of caspase-3, 8 and 9 with prolongation of transfection (P<0.05). Following hypoxia treatment, mRNA expression of HIF-$1{\alpha}$ remained unchanged in three groups (P>0.05) but the protein expression of HIF-$1{\alpha}$ markedly increased (P<0.05). However, in the sh-SENP1-Daudi group, the protein expression of HIF-$1{\alpha}$ remained unchanged Conclusion: SENP1-shRNA can efficiently inhibit SENP1 expression in Daudi cells. SENP1 inhibition may promote cell apoptosis. These findings suggest that SENP1 may serve as an important target in the gene therapy of Burkitts lymphoma.

Discovery of novel glycoside hydrolases from C-glycoside-degrading bacteria using sequence similarity network analysis

Wei Bin,Wang Ya-Kun,Yu Jin-Biao,Wang Si-Jia,Yu Yan-Lei,Xu Xue-Wei,Wang Hong 한국미생물학회 2021 The journal of microbiology Vol.59 No.10

C-Glycosides are an important type of natural product with significant bioactivities, and the C-glycosidic bonds of C-glycosides can be cleaved by several intestinal bacteria, as exemplified by the human faeces-derived puerarin-degrading bacterium Dorea strain PUE. However, glycoside hydrolases in these bacteria, which may be involved in the C-glycosidic bond cleavage of C-glycosides, remain largely unknown. In this study, the genomes of the closest phylogenetic neighbours of five puerarin-degrading intestinal bacteria (including Dorea strain PUE) were retrieved, and the protein-coding genes in the genomes were subjected to sequence similarity network (SSN) analysis. Only four clusters of genes were annotated as glycoside hydrolases and observed in the genome of D. longicatena DSM 13814T (the closest phylogenetic neighbour of Dorea strain PUE); therefore, genes from D. longicatena DSM 13814T belonging to these clusters were selected to overexpress recombinant proteins (CG1, CG2, CG3, and CG4) in Escherichia coli BL21(DE3). In vitro assays indicated that CG4 efficiently cleaved the O-glycosidic bond of daidzin and showed moderate β-D-glucosidase and β-D-xylosidase activity. CG2 showed weak activity in hydrolyzing daidzin and pNP- β-D-fucopyranoside, while CG3 was identified as a highly selective and efficient α-glycosidase. Interestingly, CG3 and CG4 could be selectively inhibited by daidzein, explaining their different performance in kinetic studies. Molecular docking studies predicted the molecular determinants of CG2, CG3, and CG4 in substrate selectivity and inhibition propensity. The present study identified three novel and distinctive glycoside hydrolases, highlighting the potential of SSN in the discovery of novel enzymes from genomic data.

Capital and Unemployment in a Two-Class Growth Model

Wei-Bin Zhang 서울대학교 경제연구소 1993 Seoul journal of economics Vol.6 No.4

The paper proposes a simple dynamic one-sector and two-class growth model with endogenous unemployment and government intervention. The model explains dynamics of capital owned by the two classes and the market structure with labor unemployment. The dynamic properties of the model and effects of changes in some parameters are investigated.

Deflection of Castellated Beams Subjected to Uniformly Distributed Transverse Loading

Wei-bin Yuan,Nan-ting Yu,Zhao-shui Bao,Li-ping Wu 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.3

This paper presents an analytical solution for determining the deflection of castellated/cellular beams with hexagonal/circular web openings, subjected to a uniformly distributed transverse load. The solution is derived using the principle of minimum potential energy. To validate the derived analytical solution, three-dimensional linear finite element analysis is performed using four-node shell elements built-in ANSYS software. Good agreement between the finite element result and the present analytical solution is demonstrated.

Technical Note : The FasT-Fix Repair Technique for Ramp Lesion of the Medial Meniscus

( Wei Ping Li ),( Zhong Chen ),( Bin Song ),( Rui Yang ),( Wei Quan Tan ) 대한슬관절학회 2015 대한슬관절학회지 Vol.27 No.1

Introduction: This technical note describes a new arthroscopic technique to repair the peripheral attachment lesion of the posterior horn of the medial meniscus. The operation was performed under arthroscopy using a standard anterior portal. Surgical Technique: A FasT-Fix needle was inserted obliquely close to the tibial plateau and the first implant was inserted into the joint capsule depending on its bending angle underneath the meniscus. The second implant was inserted through 1/3 periphery of the meniscus into the meniscocapsular area. The pre-tied self-sliding knot was tensioned to achieve secure fixation of the posterior meniscal peripheral attachment at the original attachment point. Materials and Methods: From August 2011 to February 2014, 23 knees were diagnosed as ramp lesion, underwent meniscal repair using FasT-Fix technique. Results: All patients were followed up for average 14 months. The Lysholm score improved from preoperative 64.4±4.52 to postoperative 91.2±4.60. Conclusions: We believe that the FasT-Fix technique via the standard anterior portal can be a more convenient and less traumatic alternative for repair of the peripheral attachment lesion of the posterior horn of the medial meniscus in the anterior cruciate ligament deficient knee.

SOCIAL STATUS AND INEQUALITY IN AN INTEGRATED WALRASIAN-GENERAL EQUILIBRIUM AND NEOCLASSICAL-GROWTH THEORY

Wei-Bin Zhang 중앙대학교 경제연구소 2017 Journal of Economic Development Vol.42 No.4

This study deals with interactions between social status, economic growth and income and wealth distribution in an economic growth model of heterogeneous households with economic structure. The model emphasizes the role of social status on economic structural change and wealth and income distribution. It is influenced by the ideas related to economic growth and social status in the literature of economic growth and an integrated Walrasian general equilibrium theory and neoclassical growth theory. The economic system consists of one capital goods sector, one consumer goods sector, and any number (of types) of households. The motion is described by a set of differential equations. For illustration, we simulate the motion of the economic system with three groups of households. We identify the existence of a unique stable equilibrium point. We also carry out comparative dynamic analysis. The comparative analyses provide some insights into the complexity of economic growth with social status.

Quantitative study on erosion degree of bone china glaze by common acid reagent at different temperature

Wei Hong,Wen-jie Li,Hui-chao Huang,Xiao-wei Weng,Yi-qin Zhang,Xiao-hui Liu,Yan-hua Guo,Ya-bin Su 한양대학교 청정에너지연구소 2022 Journal of Ceramic Processing Research Vol.23 No.6

In this experiment, we selected "Tangshan bone china" 10.5-inch white porcelain flat plate produced by five differententerprises as experimental samples to study the erosion of bone porcelain enamel by different kinds of acidic reagents atdifferent temperatures. The specific experimental process was as follows: at different temperatures, 20% hydrochloric acid,30% sulfuric acid, 100 g/L citric acid and 10% acetic acid were used to continuously erode the sample glaze for 10h, and thewhiteness and 45º mirror direction gloss were measured every 2h. The results show that different acidic reagents at differenttemperatures have significant differences in the erosion characteristics and strength of bone porcelain glaze, and the corrosionresistance of products from different enterprises also have significant differences.

Growth and Agglomeration of a Small-Open Multi-Regional Economy

( Wei Bin Zhang ) 세종대학교 경제통합연구소 (구 세종대학교 국제경제연구소) 2007 Journal of Economic Integration Vol.22 No.3

We study economic growth of a multi-regional small open economy in a perfectly competitive economy. The national economy consists of multiple regions and each region has one production sector and one housing sector. Following the traditional literature of small open economies, we assume that the rate of interest is fixed in international market. The production side is the same as in the neoclassical growth theory. Households move freely among regions, equalizing utility level among regions by choosing housing, goods and saving. A region`s amenity is endogenous, depending on the region`s output and population. We explicitly solve the dynamics of the multi-regional economy. The system has a unique stable equilibrium point. We simulate the motion of the model and examine effects of changes in the rate of interest, the preference, and amenity parameters. We show, for instance, that a productivity improvement in the region with lowest productivity reduces the GDP and GNP and a rise in the preference for large cities may accelerate agglomeration of the population and economic activities into a region with high productivity.

Agglomeration and Returns to Scale with Capital and Public Goods in a Multi-Regional Economy

Wei-Bin Zhang 한국국제경제학회 2009 International Economic Journal Vol.23 No.1

This paper develops a multi-regional growth model with amenity, capital accumulation and regional public goods. The economy consists of any number of regions and each region consists of the industrial sector and public sector. The industrial sector provides goods in perfectly competitive markets. The public sector, which is financed by the regional government’s tax incomes, supplies regional public goods. The public goods affect both firms and households. We show the existence of a unique equilibrium in the dynamic system. The comparative statics analysis also provides some important insights. For instance, if environmental improvement occurs in the advanced (less advanced) region, the national output rises (falls). If a region has a high rate of technological change and the other region remains technologically stationary, economic activities and labor force tend to be located in the technologically advancing region. If the propensity to save is increased, national output is increased and more people will be located in the technologically advanced region.