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Effect of HIV-1 Tat on Secretion of TNF-α and IL-1β by U87 Cells in AIDS Patients with or without AIDS Dementia Complex

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Biomedical and Environmental Sciences 2014年第2期27卷 111-117页

作者： ZHAO Li PU Shuang Shuang GAO Wen Hua chi yuan yuan WEN Hong Ling WANG Zhi Yu SONG Yan Yan YU Xue Jie Department of Laboratory Microbiology School of Public Health Shandong University Clinical Laboratory Affiliated Hospital of Shandong Traditional Chinese Medicine University Hospital of Shandong University Department of Pathology University of Texas Medical Branch

Objective To explore the role of HIV-1 tat gene variations in AIDS dementia complex （ADC） pathogenesis. Methods HIV-1 tat genes derived from peripheral spleen and central basal ganglia of an AIDS patient with ADC and an AIDS patient without ADC were cloned for sequence analysis. HIV-1 tat gene sequence alignment was performed by using CLUSTAL W and the phylogentic analysis was conducted by using Neighbor-joining with MEGA4 software. All tat genes were used to construct recombinant retroviral expressing vector MSCV-IRES-GFP/tat. The MSCV-IRES-GFP/tat was cotransfected into 293T cells with pCMV-VSV-G and pUMVC vectors to assemble the recombinant retrovirus. After infection of gliomas U87 cells with equal amount of the recombinant retrovirus, TNF-α, and IL-1β concentrations in the supernatant of U87 cells were determined with ELISA. Results HIV-1 tat genes derived from peripheral spleen and central basal ganglia of the AIDS patient with ADC and the other one without ADC exhibited genetic variations. Tat variations and amino acid mutation sites existed mainly at Tat protein core functional area （38-47aa）. All Tat proteins could induce ug7 cells to produce TNF-α and IL-1β, but the level of IL-1β production was different among Tat proteins derived from the ADC patient＇s spleen, basal ganglia, and the non-ADC patient＇s spleen. The level of Tat proteins derived from the ADC patient＇s spleen, basal ganglia, and the non-ADC patient＇s spleen were obviously higher than that from the non-ADC patient＇s basal ganglia. Conclusion Tat protein core functional area （38-47aa） may serve as the key area of enhancing the secretion of IL-1β. This may be related with the neurotoxicity of HIV-1 Tat.

关键词： Key words: HIV-1 tat gene AIDS dementia complex Cytokines TNF-α IL-1β Neurotoxicity

Impact of Carbon Chain Structures in the Backbone on the Flexibility of Modified Polyarylene Sulfide Resins: Molecular Dynamics Simulations and Mesoscopic Analysis

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chinese Journal of Polymer Science 2024年第4期42卷 544-557页

作者： chi Zhang Rong Liu Jing-yuan Liu Wen-Wei Jiang Key Laboratory of Fine Chemical Engineering and Functional Materials School of Chemical EngineeringSichuan UniversityChengdu610065China

In the domain of high-performance engineering polymers, the enhancement of mechanical flexibility in poly(phenylene sulfide) (PPS) resins has long posed a significant challenge. A novel molecular structure, designated as PP-He-IS, wherein imide rings and an aliphatic hexylene chain are covalently incorporated into the PPS backbone to enhance its flexibility, is introduced in this study. Molecular dynamics (MD) simulations are employed to systematically explore the effects of diversifying the backbone chain structures by substituting phenyl units with alkyl chains of varying lengths, referred to as PP-A-IS where “A” signifies the distinct intermediary alkyl chain configurations. Computational analyses reveal a discernable decrement in the glass transition temperature (Tg) and elastic modulus, counterbalanced by an increment in yield strength as the alkyl chain length is extended. Notably, the PP-He-IS variant is shown to exhibit superior yield strength while simultaneously maintaining reduced elastic modulus and Tg values, positioning it as an advantageous candidate for flexible PPS applications. Mesoscopic analyses further indicate that structures such as PP-He-IS, PP-Pe-IS, and PP-Bu-IS manifest remarkable flexibility, attributable to the presence of freely rotatable carbon-carbon single bonds. Experimental validation confirms that a melting temperature of 504 K which is lower than that of conventional PPS, and lower crystallinity are exhibited by PP-He-IS, thereby affording enhanced processability without compromising inherent thermal stability. Novel insights into the strategic modification of PPS for mechanical flexibility are thus furnished by this study, which also accentuates the pivotal role played by molecular dynamics simulations in spearheading high-throughput investigations in polymer material modifications.

关键词： Molecular dynamics simulations Polyarylene Sulfide Main-chain modifications Flexibility Aliphatic hexylene chain

A stable one-point quadrature rule for three-dimensional numerical manifold method

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Science china(Technological Sciences) 2024年第5期67卷 1401-1416页

作者： ZHANG Ning ZHENG Hong YANG Liang WU WenAn yuan chi School of Civil Engineering Qinghai UniversityQinghai810016China Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing100124China Faculty of Engineering China University of GeoscienceWuhan430074China

We present a numerically stable one-point quadrature rule for the stiffness matrix and mass matrix of the three-dimensional numerical manifold method(3D NMM).The rule simplifies the integration over irregularly shaped manifold elements and overcomes locking issues,and it does not cause spurious modes in modal *** essential idea is to transfer the integral over a manifold element to a few moments to the element center,thereby deriving a one-point integration rule by the moments and making modifications to avoid locking *** the stiffness matrix,after the virtual work is decomposed into moments,higher-order moments are modified to overcome locking issues in nearly incompressible and bending-dominated *** the mass matrix,the consistent and lumped types are derived by *** particular,the lumped type has the clear advantage of *** proposed method is naturally suitable for 3D NMM meshes automatically generated from a regular *** tests justify the accuracy improvements and the stability of the proposed procedure.

关键词： three-dimensional numerical manifold method quadrature rule locking mass lumping

Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels

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Defence Technology（防务技术） 2024年第1期31卷 58-72页

作者： Yong-Pan Duan Run-Qiang chi Bao-Jun Pang yuan Cai Hypervelocity Impact Research Center Harbin Institute of TechnologyHarbin150080China College of Science Heilongjiang University of Science and TechnologyHarbin 150022China

Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris *** analyzed the damage to composite overwrapped pressure vessels(COPVs)in the HVI tests and classified the damage into non-catastrophic damage and catastrophic *** proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal *** fragments of the catastrophically damaged COPVs were collected after the *** crack distribution and propagation process of the catastrophic ruptures of the COPVs were *** findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs.

关键词： Orbital debris Hypervelocity impact Composite overwrapped pressure vessels Damage mechanisms

Cobalt-nitrogen co-doped porous carbon sphere as highly efficient catalyst for liquid-phase cyclohexane oxidation with molecular oxygen and the active sites investigation

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Frontiers of Chemical Science and Engineering 2024年第3期18卷 101-112页

作者： Lei Chen yuan Sun Jinshan chi Wei Xiong Pingle Liu Fang Hao College of Chemical Engineering National&Local United Engineering Research Centre for Chemical Process Simulation and IntensificationXiangtan UniversityXiangtan411105China

The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol(KA oil)is a challenging issue in the chemical *** present the industrial conversion of cyclohexane to cyclohexanone and cyclohexanol is normally controlled at less than 5%***,the development of highly active and stable catalysts for the aerobic oxidation of cyclohexane is necessary to overcome this low-efficiency ***,we have developed a cobalt-nitrogen co-doped porous sphere catalyst,Co-NC-x(x is the Zn/Co molar ratio,where x=0,0.5,1,2,and 4)by pyrolyzing resorcinol-formaldehyde resin *** achieved 88.28%cyclohexanone and cyclohexanol selectivity and a cyclohexane conversion of 8.88%under *** results showed that the introduction of zinc effectively alleviated the aggregation of Co nanoparticles and optimized the structural properties of the *** addition,Co0 and pyridinic-N are proposed to be the possible active species,and their proportion efficiently increased in the presence of Zn^(2+)*** this study,we developed a novel strategy to design highly active catalysts for cyclohexane oxidation.

关键词： KA oil production cyclohexane selective oxidation cobalt-nitrogen co-doped porous carbon spheres metal-organic framework

Significant annealing-induced hardening effect in nanolaminate d-nanotwinne d(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)me dium-entropy alloy by severe cold rolling

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Journal of Materials Science & Technology 2024年第3期170卷 156-166页

作者： Shuqing yuan Hui Fu Lei Qian chi Fai Cheung Xu-Sheng Yang State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518060China

Due to the easy coarsening caused by poor thermal stability,the verified annealing-induced hardening in nanograined metals can only maintain at a relatively low-temperature *** this study,a nanolam-inated(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)medium-entropy alloy with an average lamellae thickness of∼20 nm embedded by thinner nanotwins was fabricated by severe cold rolling to achieve superior thermal *** with the conventional nanotwinned CrCoNi with nanotwins inside ultra-fined grains,the hier-archical nanolaminated-nanotwinned(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8) exhibits a significant annealing-induced hard-ening effect,i.e.,hardness increasing from∼250 HV in the original specimen to∼500 HV in the cold-rolled status and finally∼630 HV after annealing at 600℃for 1 *** microstructure characterizations reveal that the reduced dislocation density and formation of L1_(2)ordered domain are mainly responsible for such hardening effect,which is facilitated by the effectively suppressed coarsening with annealing temperature,i.e.,slow detwinning process and well-retained low-angle nanolamellar *** coarsening mechanisms from the cold-rolled nanolamellae to the fully recrystallized micro-equiaxed structures under the annealing temperatures ranging from 400 to 800℃ were also elucidated by atomic observations.

关键词： Annealing-induced hardening Thermal stability Nanolaminated-nanotwinned structure CrCoNi Detwinning Grain boundary migration

Heterogeneous expression of stearoyl-acyl carrier protein desaturase genes SAD1 and SAD2 from Linum usitatissimum enhances seed oleic acid accumulation and seedling cold and drought tolerance in Brassica napus

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Journal of Integrative Agriculture 2024年第6期23卷 1864-1878页

作者： Jianjun Wang Yanan Shao Xin Yang chi Zhang yuan Guo Zijin Liu Mingxun Chen State Key Laboratory of Crop Stress Biology for Arid Areas/National Yangling Agricultural Biotechnology&Breeding Center/Shaanxi Key Laboratory of Crop Heterosis/College of Agronomy Northwest A&F UniversityYangling 712100China

Flax(Linum usitatissimum L.)is a versatile crop and its seeds are a major source of unsaturated fatty ***-acyl carrier protein desaturase(SAD)is a dehydrogenase enzyme that plays a key role in oleic acid biosynthesis as well as responses to biotic and abiotic ***,the function of SAD orthologs from *** has not been ***,we found that two LuSAD genes,LuSAD1 and LuSAD2,are present in the genome of *** cultivar‘Longya 10’.Heterogeneous expression of either LuSAD1 or LuSAD2 in Arabidopsis thaliana resulted in higher contents of total fatty acids and oleic acid in the ***,ectopic expression of LuSAD2 in *** caused altered plant ***,the overexpression of either LuSAD1 or LuSAD2 in Brassica napus also resulted in increased contents of total fatty acids and oleic acid in the ***,we demonstrated that either LuSAD1 or LuSAD2 enhances seedling resistance to cold and drought stresses by improving antioxidant enzyme activity and nonenzymatic antioxidant levels,as well as reducing membrane *** findings not only broaden our knowledge of the LuSAD functions in plants,but also offer promising targets for improving the quantity and quality of oil,and the abiotic stress tolerance of oil-producing crops,through molecular manipulation.

关键词： LuSAD oleic acid cold tolerance drought tolerance Linum usitatissimum Brassica napus

Novel wreck salvaging method using curved rectangular pipe basing method:A case study of"Yangtze River EstuaryⅡ"ancient shipwreck salvage project

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Underground Space 2024年第5期18卷 97-113页

作者： Qianwei Zhuang Guofang Gong Dongrong Zhou chi Zhang Xin Huang Xiaodong Zhu Weihao yuan Deng Li School of Mechanical Engineering Zhejiang UniversityHangzhou 310030China Shanghai Tunnel Engineering Co.Ltd. Shanghai 200137China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China College of Civil Engineering and Architecture Xinjiang UniversityUrumqi 830047China Shanghai Salvage Company Shanghai 200090China

Shipwreck salvage is a risky,time-consuming,and expensive *** there are many sunken ships along coastlines and in the open seas,the salvage process of a sunken ship has rarely been *** integrated salvage of the"Yangtze River EstuaryⅡ"shipwreck used a novel method with 22 closely locked curved rectangular pipes to form a watertight base that wrapped the shipwreck *** basing was lifted out of the water using a powerful crane situated on an engineering *** the first time,the tunneling method was used in a shipwreck salvage project,significantly reducing the disturbance to the shipwreck and its stowage,thereby preserving the original state and integrity of the shipwreck to the greatest *** this study,the basic concepts of the salvage method and process are *** to critical issues in the new salvage method are provided,including jacking force prediction and major considerations for the structural design of the salvage *** design of the salvage system and salvage process of the"Yangtze River EstuaryⅡ"shipwreck are *** monitored jacking force,pipe deformation,and observed water-tightness verified that the proposed method was effective and *** possible application scenarios for the proposed method are presented at the end.

关键词： Pipe jacking Shipwreck salvage Yangtze River EstuaryⅡ Structural design

Evaluation on cutting performance of novel PDC cutter for pipe jacking machine

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Underground Space 2024年第1期14卷 34-52页

作者： Long-Chuan Deng Yi-Xiang yuan Xiao-Zhao Li Qian-Wei Zhuang chi Zhang Yi-Wei Chen School of Earth Sciences and Engineering Nanjing UniversityNanjingJiangsu 210023China Shanghai Tunnel Engineering Co.Ltd. Shanghai 200232China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouJiangsu 221116China School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China

It is inevitable to cut reinforced concrete(RC)appeared in cross passage of city metro by cutting tools when constructing in densely populated *** previous cutters employed to cut RC are insufficient and easily damaged,so a new polycrystalline diamond compact(PDC)cutter is used to solve this *** on the theoretical analysis of cutting mechanism,both circular and tapered PDC cutters with cutting edge angle of 90and negative front rack angle of 10are used to cut *** peeling and breaking patterns of cutting concrete are proposed,the nodular and grainy chips are the preferred modes in cutting steel *** LS-DYNA is employed to investigate the cutting performance in *** simulation results show that the average and peak cutting forces increase with the growth of penetration depth,cutting speed,and roundness,and subsequently the recommended penetration depth less than 1.2 mm is obtained to cut RC due to the existence of steel ***,the linear cutting platform is adopted to investigate the force ability and damage state of PDC *** is concluded that the cutting force increases abruptly and fluctuates heavily when cutting the coarse *** patterns occurred in both numerical and experimental results are generally ***,the steel bar is pulled out and the PDC cutter is damaged at the penetration depth of 0.8 mm,while a good cut occurs at the penetration depth of 0.3 *** tapered PDC cutter with a relatively low cutting force is prone to be broken compared with circular PDC *** is suggested that the circular PDC cutter at the penetration depth of 0.3 mm should be used to cut RC in practical engineering.

关键词： PDC cutter RC Pipe jacking machine Linear cutting tests Damage and wear LS-DYNA