Molecular Cloning and Expression of a Cu/Zn-Containing Superoxide Dismutase from Thellungiella halophila

Xu Xiaojing,Zhou Yijun,Wei Shanjun,Ren Dongtao,Yang Min,Bu Huahu,Kang Mingming,Wang Junli,Feng Jinchao 한국분자세포생물학회 2009 Molecules and cells Vol.27 No.4

Superoxide dismutases (SODs) constitute the first line of cellular defense against oxidative stress in plants. SODs generally occur in three different forms with Cu/Zn, Fe, or Mn as prosthetic metals. We cloned the full-length cDNA of the Thellungiella halophila Cu/Zn-SOD gene ThCSD using degenerate RT-PCR and rapid amplification of cDNA ends (RACE). Sequence analysis indicated that the ThCSD gene (GenBank accession number EF405867) had an open reading frame of 456 bp. The deduced 152-amino acid polypeptide had a predicted molecular weight of 15.1 kDa, an estimated pI of 5.4, and a putative Cu/Zn-binding site. Recombinant ThCSD protein was expressed in Escherichia coli and assayed for SOD enzymatic activity in a native polyacrylamide gel. The SOD activity of ThCSD was inactivated by potassium cyanide and hydrogen peroxide but not by sodium azide, confirming that ThCSD is a Cu/Zn-SOD. Northern blotting demonstrated that ThCSD is expressed in roots, stems, and leaves. ThCSD mRNA levels increased by about 30-fold when plants were treated with sodium chloride (NaCl), abscisic acid (ABA), and indole-acetic acid (IAA) and by about 50-fold when treated with UVB light. These results indicate that ThCSD is involved in physiological pathways activated by a variety of environmental conditions.

Mycobacterium tuberculosis PE_PGRS45 (Rv2615c) Promotes Recombinant Mycobacteria Intracellular Survival via Regulation of Innate Immunity, and Inhibition of Cell Apoptosis

Xu Tao,Wang Chutong,Li Minying,Wei Jing,He Zixuan,Qian Zhongqing,Wang Xiaojing,Wang Hongtao 한국미생물학회 2024 The journal of microbiology Vol.62 No.1

Tuberculosis (TB), a bacterial infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis), is a significant global public health problem. Mycobacterium tuberculosis expresses a unique family of PE_PGRS proteins that have been implicated in pathogenesis. Despite numerous studies, the functions of most PE_PGRS proteins in the pathogenesis of mycobacterium infections remain unclear. PE_PGRS45 (Rv2615c) is only found in pathogenic mycobacteria. In this study, we successfully constructed a recombinant Mycobacterium smegmatis (M. smegmatis) strain which heterologously expresses the PE_PGRS45 protein. We found that overexpression of this cell wall-associated protein enhanced bacterial viability under stress in vitro and cell survival in macrophages. MS_PE_PGRS45 decreased the secretion of pro-inflammatory cytokines such as IL-1β, IL-6, IL-12p40, and TNF-α. We also found that MS_PE_PGRS45 increased the expression of the anti-inflammatory cytokine IL-10 and altered macrophage-mediated immune responses. Furthermore, PE_PGRS45 enhanced the survival rate of M. smegmatis in macrophages by inhibiting cell apoptosis. Collectively, our findings show that PE_PGRS45 is a virulent factor actively involved in the interaction with the host macrophage.

Distinct growth phenomenon observed on L-Arg․ CF3COOH crystals

Xiaojing Liu,Zeyan Wang,Guanghui Zhang,Guangwei Yu,Aidong Duan,Xinqiang Wang,Dong Xu 한국물리학회 2009 Current Applied Physics Vol.9 No.1

Atomic force microscopy has been employed to study the growth behaviour on the {101} facets of L-Arg ․ CF3COOH crystals grown at 25℃ at a supersaturation of σ = 0.2. Nucleation on the wider step terraces and a large nucleus composed of two separate 2D nuclei were observed for the first time. For the region where blocking occurs convex pattern are found in the macrosteps, which correspond to the sites of the impurities that act as pinning points hindering step propagation. Finally, liquid inclusions will be generated because of disparate formation mechanisms. Atomic force microscopy has been employed to study the growth behaviour on the {101} facets of L-Arg ․ CF3COOH crystals grown at 25℃ at a supersaturation of σ = 0.2. Nucleation on the wider step terraces and a large nucleus composed of two separate 2D nuclei were observed for the first time. For the region where blocking occurs convex pattern are found in the macrosteps, which correspond to the sites of the impurities that act as pinning points hindering step propagation. Finally, liquid inclusions will be generated because of disparate formation mechanisms.

Direct Interaction between Ras Homolog Enriched in Brain and FK506 Binding Protein 38 in Cashmere Goat Fetal Fibroblast Cells

Wang, Xiaojing,Wang, Yanfeng,Zheng, Xu,Hao, Xiyan,Liang, Yan,Wu, Manlin,Wang, Xiao,Wang, Zhigang Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.12

Ras homolog enriched in brain (Rheb) and FK506 binding protein 38 (FKBP38) are two important regulatory proteins in the mammalian target of rapamycin (mTOR) pathway. There are contradictory data on the interaction between Rheb and FKBP38 in human cells, but this association has not been examined in cashmere goat cells. To investigate the interaction between Rheb and FKBP38, we overexpressed goat Rheb and FKBP38 in goat fetal fibroblasts, extracted whole proteins, and performed coimmunoprecipitation to detect them by western blot. We found Rheb binds directly to FKBP38. Then, we constructed bait vectors (pGBKT7-Rheb/FKBP38) and prey vectors (pGADT7-Rheb/FKBP38), and examined their interaction by yeast two-hybrid assay. Their direct interaction was observed, regardless of which plasmid served as the prey or bait vector. These results indicate that the 2 proteins interact directly in vivo. Novel evidence is presented on the mTOR signal pathway in Cashmere goat cells.

Study on Positioning Accuracy of Nut/Shaft Air Cooling Ball Screw for High-precision Feed Drive

Zhe-Zhu Xu,류성기,Xiaojing Liu 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.1

Thermal error, which is of the machine tool feed system, is the key factor leading to dimensional error of machined work-piece. This paper presents a new approach in thermal error control instead of thermal error compensation. For the investigation of thermal error control, a novel/well designed high speed/high precision nut/screw air cooling ball screw system was developed to avoid thermal errors which affect the positioning accuracy of ball screw feed drive system. In order to discuss the effectiveness of the developed high speed/high precision nut/screw air cooling ball screw system, a series of tests was done. As the results, it shows that the positioning accuracy will significantly improve with the use of the nut/screw air cooling ball screw feed drive system shown in this paper.

A Study on Improvement of Ball Screw System Positioning Error with Liquid-Cooling

Zhe-Zhu Xu,류성기,Xiaojing Liu,최종훈 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

The demand for higher productivity and tight part tolerances requires machine tools to have faster and more accurate feed drive systems. As tried and tested technology, ball screw drive systems are still used in a majority of machine tools due to their low cost and high degree of stiffness. A high-speed ball screw drive system generates more heat and results in greater positioning error,adversely affecting the accuracy of machined parts. In this paper, we discuss the placement of a liquid-cooling system using water,coolant oil, light oil and cutting oil as coolants in a ball screw shaft to avoid thermal errors and achieve temperature equilibrium faster. In order to estimate the positioning error and thermal distribution of the ball system and effectiveness of the liquid-cooling system, all possible heat gain-loss sources were analyzed and considered calculation factors. The following paper also presents degree of positioning error improvement when a circulation liquid-cooling system and forced liquid-cooling system were employed. When comparing the predictions and the experimental results, we can see very significant cooling performance and a high degree of consistency between prediction and reality.

Application of Biophysical Properties of Meridians in the Visualization of Pericardium Meridian

Xiong Feng,Xu Ruimin,Li Tongju,Wang Jinyu,Hu Qingchuan,Song Xiaojing,Wang Guangjun,Su Huanhuan,Jia Shuyong,Wang Shuyou,Zhu Zongxiang,Zhang Weibo 사단법인약침학회 2023 Journal of Acupuncture & Meridian Studies Vol.16 No.3

Background: The biophysical properties of the meridian system, an important concept of traditional Chinese medicine, include low impedance, resounding voice, and high acoustic conductance, all of which are helpful for elucidating the essence of meridians. Objectives: To visualize the human pericardium meridian (PC) based on the resounding voice property of meridians. Methods: Visualization of the PC was performed by injection of fluorescein sodium at the PC6 acupoint (Neiguan) on the PC. Before injection, percussion active points (PAPs) were identified by the virtue of their resounding voice properties. After injection, the trajectories of fluorescein migration throughout the body surface were recorded and analyzed. The distribution of fluorescein in the tissue was further studied using cross-sections of hind limbs of mini-pigs, in which fluorescein was injected into low impedance points. Results: The identified PAP lines were colocalized with PC. Following intradermal fluorescein injection, 1-3 fluorescent lines, which were unrelated to the arm veins, were observed in 7 of 10 participants; 85.4% of fluorescent signals were coincident with PAPs and their intensity had a negative correlation with the body mass index (r = –0.56, p = 0.045). Cross-sections showed a Y-shaped fluorescence pattern where the two migration lines on the surface were the two vertices of the “Y.” Conclusion: The trajectories of fluorescein in the body are suggestive of the anatomical structure of meridians. The PC is related to the deep horizontal interstitial channels that connect to the body surface through vertical interstitial spaces. These biophysical properties and techniques for meridian visualization are valuable for revealing the anatomical structure of meridians.

Association between Working Hours and Anxiety/Depression of Medical Staff during Large-Scale Epidemic Outbreak of COVID-19: A Cross-Sectional Study

Qin Lang,Xiaojing Liu,Ying He,Qin Lv,Sibo Xu 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.12

Objective This present study aimed to investigate the relationship between working hours and anxiety/depression mood of medical staff in China during COVID-19 epidemic. Methods The cross-sectional interview study was conducted during the period between February 14th and February 29th, 2020. A total of 291 Chinese medical professionals were recruited from 4 cities and participated in the study. Results In 291 participants, 116 (40.0%) medical staff experienced anxiety and 151 (51.8%) underwent depressed mood. In male, the level of GAD-7 and PHQ-9 scores increased with the elevation of working hours per day (WHPD) (β=0.579, p=0.003 and β=0.943; p=0.001) respectively. In female, nonlinear relationship mode was demonstrated. The levels of GAD-7 and PHQ-9 scores increased with the elevation of working hours when it was above 5 hours (β=1.432; p<0.001 and β=1.177; p<0.001), but it did not have a significant association with WHPD when it was less than 5 (p>0.05). Conclusion During the COVID-19 epidemic, we found a strong correlation between the psychological mood and WHPD. The correlation followed different modes in male and female medical workers. Enforcing an upper time limit of WHPD may help decrease the risk of pandemic-related psychological problems in medical workers.

Study on Thermal Behavior Analysis of Nut/Shaft Air Cooling Ball Screw for High-Precision Feed Drive

Zhe-Zhu Xu,류성기,Xiaojing Liu 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.1

In a machine tool, continuous usage causes heat generation at the moving elements and this heat causes expansion of the various structural elements of the machine tool. The main direction of current research about machine tool thermal error is that named thermal error compensation. This paper presents a new approach in thermal error control instead of thermal error compensation and applied on a ball screw feed drive system. Ball screw is the key contributor to the thermal error of a machine tool which leading to dimensional error of machined work-piece. A novel/well designed high speed/high precision nut/screw air cooling ball screw system was developed to control thermal errors on a machine tool feed drive system. In order to discuss the effectiveness of the developed high speed/high precision nut/screw air cooling ball screw system, a series of tests was done. In this paper, experimental thermal behavior of nut/screw air cooling ball screw system for high-precision feed was discussed. As the results, relatively big temperature rising presented through the whole test process in no cooling condition and “Learning curve” phenomenon presented in the cooling cases. And the dominated temperature rising area covered the nut moving range completely.

A Novel High Speed/High Precision Ball Screw

Zhe-Zhu Xu,류성기,Xiaojing Liu,최종훈 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

As a tried and tested technology, ball screw drive systems are still used in a majority of machine tools which can meet the demands of higher productivity and tight part tolerances due to their low cost and high degree of stiffness. High speed ball screw drive system generates more heat and it results in greater positioning error, adversely affecting the accuracy of high precision machined parts. In this paper, a novel/well designed high speed/high precision nut air cooling ball screw system was developed to avoid thermal errors which affect the positioning accuracy and the temperature rise of ball screw. In order to discuss the effectiveness of the developed high speed/high precision nut air cooling ball screw system, a series of tests was done. As the results, it shows that the positioning accuracy will significantly improve with the use of the nut air cooling ball screw drive system shown in this paper.