Dislocation Density-Based Constitutive Model and Processing Map for T2 Copper During Isothermal and Time-Variant Deformation

Gang Chen,Yu Jin,Jing Wang,Cheng Zhang,Qiang Chen,Hongming Zhang,Xingjian Zhao,Zhiyong Li,Changhai Xie,Zhiming Du 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

Isothermal compression tests were carried out to study the hot deformation behavior of T2 copper under various conditions. The deformation parameters, such as temperature and strain rate, have strong influence on flow stress and microstructureevolution of the alloy. A unified dislocation density-based model considering dynamic recovery and recrystallization wasestablished. And material parameters of the developed model were optimized by genetic algorithm. Comparisons betweenthe experimental and model data demonstrates that the developed model can precisely describe the flow behavior at quitewide range of deformation conditions. Meanwhile, the designed iterative procedure allows the model to be applied in timevariantdeformation conditions. Processing map and microstructure examination were constructed to optimize the processingwindow of the studied alloy. According to the processing maps, flow instability mainly appeared at low temperatures of500–650 °C and strain rates higher than 0.1 s−1. The optimum deformation parameters of T2 copper was concluded as thetemperature range of 700–800 °C and the strain rate of 0.1–1 s−1.

Moderate tetrabasic zinc chloride supplementation improves growth performance and reduces diarrhea incidence in weaned pigs

Zhang, Gang,Xia, Tian,Zhao, Jinbiao,Liu, Ling,He, Pingli,Zhang, Shuai,Zhang, Liying Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.2

Objective: Two experiments were conducted to evaluate tetrabasic zinc chloride (TBZC) on the health of weaned pigs, and to determine the optimal supplemental concentrations and whether dietary TBZC could replace the pharmacological concentrations of dietary zinc oxide (ZnO) to improve growth performance and decrease Zn excretion in weaned pigs. Methods: In Exp. 1, 180 weaned pigs (8.92±1.05 kg body weight [BW]) were randomly assigned to 1 of 5 treatments, including the basal diet containing 125 mg/kg zinc sulfate (ZnSO₄), and the basal diet with 1,200, 1,800, 2,400, or 3,000 mg/kg TBZC supplementation. In Exp. 2, 240 weaned pigs (7.66±1.09 kg BW) were randomly assigned to 1 of 5 treatments, including a negative control diet without Zn supplementation, a positive control diet (2,250 mg/kg ZnO), and 3 experimental diets with different concentrations of TBZC supplementation (1,000, 1,250, and 1,500 mg/kg). Results: In Exp. 1, the average daily gain (ADG), feed efficiency (G:F) and diarrhea incidence responded quadratically (p<0.01) as the TBZC supplemental concentrations increased, and pigs fed 1,200 and 1,800 mg/kg TBZC showed the best growth performance. Moreover, 1,800 mg/kg TBZC supplementation showed the greatest (p<0.01) total antioxidant capacity and glutathione peroxidase activities in liver of pigs. Histopathological examination revealed lesions in heart, liver, lung and kidney, and mild or severe histological lesions mainly occurred with the supplementation of 2,400 and 3,000 mg/kg TBZC. In Exp. 2, 1,000 and 1,250 mg/kg TBZC supplementation in diets significantly (p<0.01) increased ADG and G:F of weaned pigs, reduced Zn excretion in feces, and had no effect on diarrhea-reducing compared to 2,250 mg/kg ZnO supplementation. Conclusion: The TBZC is a potential alternative to ZnO. The recommended concentration of TBZC in weaned pig diets is 1,000 to 1,250 mg/kg.

Study on the Wild Ginseng and Cultured Ginseng in Northeast of China

(Zhang Huai Wang),(Chang Hai Li),(Cheng Gang Zhang),(Xiao Dong Wang) 고려인삼학회 1998 Advances in Ginseng Research - Proceedings of the Vol.- No.-

Construction and Application of Effective Path Statistics Network

Gang Zhang,Qing-Kui Chen 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.9

The Internet has dynamic change nature and the resources limitation that cause the loss of some commands, and thus the failure of group command transmission in the course of transmitting. On account of this, the paper presents Effective Path Statistics Network (EPSN), converting the group command transmission based on the Internet into the one based on EPSN. It describes the definition, construction and working principle of EPSN, and further conducts sampling and analyzing of metrics according to it. Based on the result the paper illustrates modeling and calculating of group command transmission. The experiments show that EPSN can effectively relieve the negative effect caused by the Internet dynamic change nature and the resources limitation.

Prevalence and Pathogenesis of Barrett's Esophagus in Luoyang, China

Zhang, Ru-Gang,Wang, Chang-Song,Gao, Cun-Fang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Background: Prevalence of Barrett's esophagus (BE) in Luoyang, China, has not been reported, and its pathogenesis is controversial. The aim of this study was therefore to investigate the prevalence of BE and its underlying factors in the city of Luoyang. Method: This was a prospective study in one center. Many patients were analyzed using endoscopy who showed upper gastrointestinal symptoms between August 2006 and June 2007. In addition, the effect of apoptosis-related proteins and heat shock proteins upon BE's pathogenesis were also investigated by an immunohistochemical protocol. Results: Prevalence of BE was at 4.55% and the mean age of those affected was about 10 years older than for esophagitis. Typical reflux symptoms were significantly lower than with esophagitis, whereas signs of caspase-3 and HSP105 elevation were significantly higher. Expression of TERT, HSP70 and $HSP90{\alpha}$ in BE cases was significantly lower than in esophagitis. However, there was no statistical difference between the two groups in expression of HSP27. Conclusions: The prevalence of BE is high in Luoyang, which could result from esophagitis despite typical reflux symptoms being relatively uncommon. Initiation and development of BE might be the result of accelerated proliferation, apoptosis and differentiation of original cells to intestinal epithelium.

Lnc Tmem235 promotes repair of early steroid-induced osteonecrosis of the femoral head by inhibiting hypoxia-induced apoptosis of BMSCs

Zhang Fei,Peng Wuxun,Wang Tao,Zhang Jian,Dong Wentao,Wang Chuan,Xie Zhihong,Luo Hong,Liu Gang 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Bone marrow mesenchymal stem cells (BMSCs) have been used in the treatment of early steroid-induced osteonecrosis of the femoral head (SONFH). However, the hypoxic microenvironment in the osteonecrotic area leads to hypoxia-induced apoptosis of transplanted BMSCs, which limits their efficacy. Therefore, approaches that inhibit hypoxia-induced apoptosis of BMSCs are promising for augmenting the efficacy of BMSC transplantation. Our present study found that under hypoxia, the expression of the long noncoding RNA (Lnc) transmembrane protein 235 (Tmem235) was downregulated, the expression of Bcl-2-associated X protein was upregulated, the expression of B-cell lymphoma-2 protein was downregulated, and the apoptotic rate of BMSCs was over 70%. However, overexpression of Lnc Tmem235 reversed hypoxia-induced apoptosis of BMSCs and promoted their survival. These results demonstrated that Lnc Tmem235 effectively inhibited hypoxia-induced apoptosis of BMSCs. Mechanistically, we found that Lnc Tmem235 exhibited competitive binding to miR-34a-3p compared with BIRC5 mRNA, which is an inhibitor of apoptosis; this competitive binding relieved the silencing effect of miR-34a-3p on BIRC5 mRNA to ultimately inhibit hypoxia-induced apoptosis of BMSCs by promoting the expression of BIRC5. Furthermore, we cocultured BMSCs overexpressing Lnc Tmem235 with xenogeneic antigen-extracted cancellous bone to construct tissue-engineered bone to repair a model of early SONFH in vivo. The results showed that overexpression of Lnc Tmem235 effectively reduced apoptosis of BMSCs in the hypoxic microenvironment of osteonecrosis and improved the effect of BMSC transplantation. Taken together, our findings show that Lnc Tmem235 inhibited hypoxia-induced apoptosis of BMSCs by regulating the miR-34a-3p/BIRC5 axis, thus improving the transplantation efficacy of BMSCs for treating early SONFH.

High-Speed Multilevel nand Flash Memory With Tight <tex> $V_{\rm th}$</tex> Distribution Using an Engineered Potential Well and Forward-Bias Adjusted Programming

Gang Zhang,Zhe Wu,Won Jong Yoo IEEE 2011 IEEE transactions on electron devices Vol.58 No.10

<P>This paper reports a high-speed multilevel-cell nand Flash memory device using a Si- SiO<SUB>2</SUB>-TiN- TiO<SUB>2</SUB>-SiO<SUB>2</SUB>-TaN (SOTTOT) engineered potential well (EW). The SOTTOT EW Flash memory device has very fast cell programming speed and good data retention. A 16-kbit nand memory block using SOTTOT cells was programmed using a forward-bias-adjusted programming scheme, which enables bit adjustability during page programming to suppress the development of fast bits. The SOTTOT memory block shows fast programming speed (~40 μs/page), tight threshold voltage (<I>V</I><SUB>th</SUB>) distribution (~0.22 V/level), and clear <I>V</I><SUB>th</SUB>-level margins (~0.9 V) for the eight-level programming. The SOTTOT memory block also shows good resistance against pass/read disturbances as well as good ten-year data retention at an ambient temperature of 75 °C throughout 10<SUP>5</SUP> programming/erasing cycling.</P>

A numerical method for evaluating fire performance of prestressed concrete T bridge girders

Gang Zhang,Venkatesh Kodur,Chaojie Song,Wei Hou,Shuanhai He 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.25 No.6

This paper presents a numerical method for evaluating fire performance of prestressed concrete (PC) T shaped bridge girders under combined effect of structural loading and hydrocarbon fire exposure conditions. A numerical model, developed using the computer program ANSYS, is employed to investigate fire response of PC T shaped bridge girders by taking into consideration structural inherent parameters, namely; arrangement of prestressing strands with in the girder section, thickness of concrete cover over prestressing strands, effective degree of prestress and content of prestressing strands. Then, a sequential thermo-mechanical analysis is performed to predict cross sectional temperature followed by mechanical response of T shaped bridge girders. The validity of the numerical model is established by comparing temperatures, deflections and failure time generated from fire tests. Through numerical studies, it is shown that thickness of concrete cover and arrangement of prestressing strands in girder section have significant influence on the fire resistance of PC T shaped bridge girders. Increase in effective degree of prestress in strands with triangular shaped layout and content in prestressing strands can slow down the progression of deflections in PC T shaped bridge girder towards the final stages of fire exposure, to thereby preventing sudden collapse of the girder. Rate of deflection based failure criterion governs failure in PC T shaped bridge girders under most hydrocarbon fire exposure conditions. Structural inherent parameters incorporated into sectional configuration can significantly enhance fire resistance of PC bridge girders; thus mitigating fire induced collapse of these bridge girders.

Study on the Wild Ginseng and Cultured Ginseng in Northeast of China

Zhang Huai Wang,Chang Hai Li,Cheng Gang Zhang,Xiao Dong Wang 고려인삼학회 1998 International Symposium on Ginseng Vol.- No.-

Overexpression of NDRG2 Can Inhibit Neuroblastoma Cell Proliferation through Negative Regulation by CYR61

Zhang, Zhi-Guo,Li, Gang,Feng, Da-Yun,Zhang, Jian,Zhang, Jing,Qin, Huai-Zhou,Ma, Lian-Ting,Gao, Guo-Dong,Wu, Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Several recent studies have showed that the n-myc downstream regulated gene 2 (NDRG2) is a new tumor suppressor gene, and that it plays an important role in tumor suppression in several cancers or cancer cell lines. However, few studies focused on its function in neuroblastoma cells. In the present investigation, we demonstrated that NDRG2 overexpression inhibited their proliferation. Using a cDNA microarray, we found that overexpression of NDRG2 inhibited the expression of cysteine-rich protein 61 (CYR61), a proliferation related gene. From our research, CYR61 may partially hinder NDRG2-mediated inhibition of cell proliferation. Overexpression of NDRG2 resulted in accumulation of cells in the G1 phase, which was accompanied by upregulation of p21 and p27 and downregulation of CDK4 and cyclin D1. Taken together, these data indicate that NDRG2 inhibits the proliferation of neuroblastoma cells partially through suppression of CYR61. Our findings offer novel insights into the physiological roles of NDRG2 in neuroblastoma cell proliferation, and NDRG2 may prove to be effective candidate for the treatment of children with neuroblastoma.