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.

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.

Field enhancement factors and self-focus functions manifesting in field emission resonances in scanning tunneling microscopy

Wei-Bin SU,Chun-Liang LIN,Wen-Yuan CHAN,Shin-Ming LU,Chia-Seng CHANG 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

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.

Seismic Performance of a Full-Scale Precast Concrete L-Shaped Column Frame Structure with a Grouted Connection

Wei-Bin Ni,De-Hao Qiao,Hong-Wei Sun,Xu Zhang,Zhong-Wen Zhang,Shao-Jie Wang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

Precast concrete frame structure with nonrectangular columns are becoming attractive to researchers and engineers owing to advantages such as avoiding column protrusion from walls and saving space. This paper presents the experimental investigation of a full-scale precast concrete frame structure with L-shaped columns (PCFS) subjected to reverse cyclic loading. The precast connection adopted grouted anchor connection. As a comparison and benchmark, one full-scale monolithic sample (RCFS) was also tested. The results indicates that the greater steel ratio in the grouted anchor connection region leads to a high local stiffness of the elements, which contributed to delaying occurrence of the first crack at the grouting holes. The failure mode, lateral load capacity, stiffness degradation, load-carrying capacity degradation, energy-dissipating capacity, ductility and interlayer residual deformation were compared between two specimens. PCFS specimen exhibited comparatively better hysteretic behavior, energy-dissipating capacity, residual deformation-resisting capacity and ductility. For RCFS and PCFS specimens, the peak load difference was within 7%. About 15% increases in ductility were observed for PCFS specimen compared with RCFS specimen. The test results would provide reference for the application of the precast concrete structure with nonrectangular columns in the new residential buildings.

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.

Deep-blue organic light-emitting diodes based on multi-tert-butyl modified naphthylene

Bin Wei,Hanfei Xu,Ning Zhao,Xicun Gao,Yiteng Ye,Yingnan Wang,Dengli Yao,Xiao-Wen Zhang,Xiujuan Liu 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.102 No.-

Six tert-butyls modified naphthyl derivative (2,6-di-tert-butyl-1,5-bis-(3,5-di-tert-butyl-phenyl)-naphthalene (N(dtb)4) was synthesized and tested for host and guest materials in organic light-emittingdiodes (OLEDs). Blue OLED using N(dtb)4 as a host and an emitter DSA-PH as a guest reaches an efficiencyof 11.52 cd A 1 (maximum external quantum efficiency 7.8 % and maximum power efficiency10.33 lm W 1). In addition, for the OLED with N(dtb)4 being a guest, we find that the concentrations ofN(dtb)4 will also affect the performance of the OLED, among which ADN: 5 wt.% N(dtb)4 has higher efficiency,and the maximum current efficiency, external quantum efficiency (EQE) and power efficiency ofthe device reach 3.75 cd A 1, 3.93 % and 3.36 lm W 1, respectively. We also investigated the pure N(dtb)4-based ultraviolet OLED (UV-OLED), and achieved the maximum EQE of the device is 1.12 %. These resultsindicate that N(dtb)4, a novel synthesized fluorescent organic material, has great potential applications inOLEDs and accordingly advancing lightings and displays.

Nonlinear Instability of Angle Section Beams under Uniformly Distributed Loads

Wei-bin Yuan,Wei Zhang,Jie Xu,Nan-ting Yu 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.2

This paper presents a study on the flattening behavior of angle-section beams of finite length subjected to uniformly distributed transverse loads. Analytical solutions for static instabilities of angle-section beams when they are bent about their weak axis are derived using energy methods. The basic assumptions used in the present study are that the total strain energy of an angle-section beam subjected to a uniformly distributed load can be simplified into a two-stage process. One is the bending response of the two legs behaving as the plate; the other is the bending response as a beam with flattened section. The nonlinear instability is derived by applying the minimum potential energy principle and the corresponding static critical moments associated with the section flattening-induced buckling are determined. To validate the analytical solution developed, nonlinear finite element analyses are also conducted. Good agreement between the present solution and the FEA results is demonstrated.

Nonlinear Bending of Box Section Beams of Finite Length Under Uniformly Distributed Loading

Wei-bin Yuan,Zhao-shui Bao,Nan-ting Yu,Shuang-shuang Zhu,Li-ping Wu 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.2

In this paper, the bending response of box-section beams of finite length is investigated by using energy methods. The basic assumptions used in the present study are that the total strain energy of a box-section beam subjected to uniformly distributed loading can be simplified into a two-stage analysis process. One is the local bending response of the webs and flanges behaving as plates; the other is the overall bending response of the beam with a deformed cross-section. Analytical solutions for both static and dynamic instabilities of box section beams of finite length subjected to transverse uniformly distributed loading are derived by applying the minimum potential energy principle. To validate the analytical solutions developed, geometric nonlinear finite element analyses are also conducted. Good agreement between the present solutions and the FEA results is demonstrated. Finally, the effects of beam length on the limit critical uniformly distributed load are also discussed.