Pt-and $TiO_2-doped\; Nb_2O_5$ Thin Film by Ion-Beam-Enhanced Deposition

Zhu, Jianzhong,Ren, Congxin The Korean Vacuum Society 1998 Applied Science and Convergence Technology Vol.7 No.1

This paper describes the preparation of Pt-and $TiO_2$-doped <T$Nb_2O_5$ thin film by Ion-Beam-Enhanced Deposition. Platinum and titanium doping, and Nb2O5 deposition were carried out in situ. The dependence of oxygen sensing properties on the amounts of Pt and Ti dopant in the <T$Nb_2O_5$ film was investigated. There were the highist sensitivity, the lowest temperature coefficient and the shortest responce time at doping of 5 mol% $TiO_2$ and 0.3 mol%Pt

Adsorption of copper on iminodisuccinic acid modified attapulgite: characterization and mechanism

Qiuzi Zhu,Jianzhong Zhu,Meng Su,Liang Liu,Cunshi Wang,Dongliang Ji,Wangjun Bai,Wentao Shen 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.4

Heavy-metal ions are common pollutants in wastewater and are thus attracting considerable attention. Herein, an eco-friendly biodegradable adsorbent, iminodisuccinic acid (IDS) modified attapulgite (ATP) is prepared by graft-polymerization to reduce Cu(II) in water, referred as IDS-ATP. The equilibrium adsorption capacity of IDS-ATP for Cu(II) is increased by 329.5% and 272% compared with raw ATP and non-degradable chelator ethylenediaminetetraacetic acid-modified ATP (EDTA-ATP), respectively. Moreover, the adsorption capacities for Cu(II) in combined system increased by 186% compared with in single system. The structure and surface properties of IDS-ATP are characterized, demonstrating that the IDS moieties are anchored on the surface of ATP without structural damage. In the aqueous Cu(II) (64 mg /L), the best adsorption pH is 5.0, the best dosage is 800 mg/L, and the adsorption equilibrium time is 4 h. The adsorption of IDS-ATP is chemical adsorption and regenerated adsorbent still exhibits high adsorption capacity. The adsorption mechanism includes the coordination of amino groups with Cu(II), the chelation of -COOH on heavy metals (HMs), and the ion exchange. Taking Cu(II) as an example to study the process of IDS-ATP in water, it is beneficial to apply this degradable material to reduce the other HMs.

Multi‑objective optimization algorithm for optimizing NVH performance of electric vehicle permanent agnet synchronous motors

Yidi Zhu,Fengxian Bai,Jianzhong Sun 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

The NVH (noise, vibration, harshness) performance of a motor is one of the main problems affecting the comfort, safety, and reliability of electric vehicles. Electromagnetic force is the main cause of motor noise. Most of the existing research focuses on the overall noise level, and does not consider the impact of specific orders of electromagnetic force on noise, which results in a lack of applicability of noise reduction techniques. In this paper, a rotor with an auxiliary slot was used to weaken the electromagnetic force. A multi-objective optimization algorithm combining finite-element simulation with a response surface method was proposed. To determine the relationship between specific orders of electromagnetic force and the auxiliary slot parameters, simulation experiments were carried out with a large range and a large step size in finiteelement analysis software. Then, the parameter range with a low value of electromagnetic force was selected. In this new range, the response surface method was used to establish the parameter and electromagnetic force expressions. Then, the linear weighting method in the multi-objective optimization algorithm was selected to determine the objective function of the multi-order electromagnetic force optimization. The weight of each order of electromagnetic force was set according to its contribution to the noise. Finally, the effectiveness of the proposed method was verified by simulations. Simulation results show that this method can quickly and effectively determine the optimal size of the auxiliary slot. In addition, the maximum value of the noise was reduced from 107.6 to 103.2 dB.

Efficient Expression and Purification of Recombinant Alcohol Oxidase in Pichia pastoris

Yunping Liu,Jianfeng Pan,Peilian Wei,Jianzhong Zhu,Lei Huang,Jin Cai,Zhinan Xu 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.4

In order to improve the production of alcohol oxidase (AOX), a recombinant Pichia pastoris (P. pastoris)system was constructed by transformation of the plasmid pPIC9K-AOX into P. pastoris GS115. The effects of different expression conditions on alcohol oxidase activity in the culture supernatant were investigated in the shake flask scale. The results showed that the highest extracellular activity (562 U/L) of alcohol oxidase was obtained after 56h induction with 4% methanol at OD600 1.0 in the medium containing 50 g/L maltose, which is about 4.2 folds higher than previously reported. High-purity functional recombinant AOX (>90%) was purified from the culture with the Ni-NTA affinity column and Sephadex G-100 chromatographical methods, with a total recovery rate of 68.9%. Further studies showed that the purified rAOX had similar enzymatic characteristics as the native enzyme, except that the thermal stability and resistance to H2O2 inhibition of rAOX were significantly greater compared to the previous report. The purified rAOX was well tolerant to various water-miscible organic solvents. This efficient expression and purification process will be promising for large-scale production of rAOX as an important diagnostic enzyme for alcohol detection in many areas.

Mechanical Stimulation and Diameter of Fiber Scaffolds Affect the Differentiation of Rabbit Annulus Fibrous Stem Cells

Zhou Pinghui,Wei Bangguo,Guan Jingjing,Chen Yu,Zhu Yansong,Ye Yuchen,Meng Yue,Guan Jianzhong,Mao Yingji 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.1

BACKGROUND: Degeneration of the annulus fibrosus (AF), an important structure of the intervertebral disc, is one of the main causes of degenerative disc disease. Fabrication of scaffolds replicating the stratified microstructure of the AF is critical for the successful regeneration of AF. METHODS: In this study, we cultured rabbit AF-derived stem cells (AFSCs) using fabricated electrospun fibrous poly-L-lactic acid scaffolds with different diameters. We applied cyclic tensile strain (CTS) on the scaffolds to regulate the differentiation of AFSCs into specific cell types that resided at the inner, middle, and outer zones of the AF. RESULTS: We found that the morphologies of AFSCs on the smaller-fiber-diameter scaffolds were nearly round, whereas spindle-like cells morphologies were observed on large-diameter scaffolds. CTS enhanced these phenomena and made the cells slender. The expression levels of collagen-I in cells increased as a function of the fiber diameter, whereas collagen-II and aggrecan exhibited opposite trends. Moreover, the application of CTS upregulated the gene expressions of collagen-I, collagen-II, and aggrecan. CONCLUSION: Overlaying the scaffolds with different CTS-stimulated cells could eventually lead to engineered AF tissues with hierarchical structures that approximated the native AF tissue. Thus, the proposed methodologies could be potentially applied for AF regeneration. BACKGROUND: Degeneration of the annulus fibrosus (AF), an important structure of the intervertebral disc, is one of the main causes of degenerative disc disease. Fabrication of scaffolds replicating the stratified microstructure of the AF is critical for the successful regeneration of AF. METHODS: In this study, we cultured rabbit AF-derived stem cells (AFSCs) using fabricated electrospun fibrous poly-L-lactic acid scaffolds with different diameters. We applied cyclic tensile strain (CTS) on the scaffolds to regulate the differentiation of AFSCs into specific cell types that resided at the inner, middle, and outer zones of the AF. RESULTS: We found that the morphologies of AFSCs on the smaller-fiber-diameter scaffolds were nearly round, whereas spindle-like cells morphologies were observed on large-diameter scaffolds. CTS enhanced these phenomena and made the cells slender. The expression levels of collagen-I in cells increased as a function of the fiber diameter, whereas collagen-II and aggrecan exhibited opposite trends. Moreover, the application of CTS upregulated the gene expressions of collagen-I, collagen-II, and aggrecan. CONCLUSION: Overlaying the scaffolds with different CTS-stimulated cells could eventually lead to engineered AF tissues with hierarchical structures that approximated the native AF tissue. Thus, the proposed methodologies could be potentially applied for AF regeneration.

Intracellular Localization and Sustained Prodrug Cell Killing Activity of TAT-HSVTK Fusion Protein in Hepatocelullar Carcinoma Cells

Limin Cao,Jin Si,Weiyu Wang,Xiaorong Zhao,Xiaomei Yuan,Huifen Zhu,Xiaolong Wu,Jianzhong Zhu,Guanxin Shen 한국분자세포생물학회 2006 Molecules and cells Vol.21 No.1

Gene therapy with nonviral vectors using the suicide gene/prodrug activating system of herpes simplex virus type-1 thymidine kinase (HSV1-TK)/ganciclovir (GCV) is inefficient in killing malignant tumor cells due to two major factors: (a) an unsatisfactory bystander effect; (b) short-lived expression of the protein. To study the capacity of the protein transduction domain (PTD) of HIV-1 TAT protein to enhance HSV1-TK/GCV cancer gene therapy, we constructed three fusion proteins TAT-TK, TK-TAT and TK. TATTK retained as much enzyme activity as TK, whereas that of TK-TAT was much lower. TAT-TK can enter HepG2 cells and much of it is translocated to the nucleus. The transduced HepG2 cells are killed by exogenously added GCV and have bystander effects on untransduced HepG2 cells. Most importantly, the introduced recombinant protein is stable and remains functional for several days at least, probably because nuclear localization protects it from the cytoplasmic degradation machinery and provides access to the nuclear transcription machinery. Our results indicate that TAT fusion proteins traffic intercellularly and have enhanced stability and prodrug cell killing activity. We conclude that TAT has potential for enhancing enzyme prodrug treatment of liver cancers.

Inactivation of Vibrio parahaemolyticus by Aqueous Ozone

( Lifang Feng ),( Kuo Zhang ),( Mengsha Gao ),( Chunwei Shi ),( Caiyun Ge ),( Daofeng Qu ),( Junli Zhu ),( Yugang Shi ),( Jianzhong Han ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.8

Vibrio parahaemolyticus contamination causes serious foodborne illness and has become a global health problem. As a disinfectant, aqueous ozone can effectively kill a number of bacteria, viruses, parasites, and other microorganisms. In this study, three factors, namely, the aqueous ozone concentration, the exposure time, and the bacterial density, were analyzed by response surface methodology, and the aqueous ozone concentration was the most influential factor in the sterilization ratio. Under low aqueous ozone concentrations (less than 0.125 mg/l), the bacterial cell membranes remained intact, and the ozone was detoxified by intracellular antioxidant enzymes (e.g., superoxide dismutase and catalase). Under high aqueous ozone concentrations (more than 1 mg/l), cell membranes were damaged by the degree of peripheral electronegativity at the cell surface and the concentration of lactate dehydrogenase released into the extracellular space, and the ultrastructures of the cells were confirmed by transmission electron microscopy. Aqueous ozone penetrated the cells through leaking membranes, inactivated the enzymes, inhibited almost all the genes, and degraded the genetic materials of gDNA and total RNA, which eventually led to cell death.