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Evaluation of 1,4-naphthoquinone derivatives as antibacterial agents:activity and mechanistic studies

Frontiers of Environmental Science & Engineering 2023年第3期17卷 49-61页

作者： Zhizhuo Liu Zhemin Shen Shouyan Xiang yang sun Jiahua Cui Jinping Jia School of Environmental Science&Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The diverse and large-scale application of disinfectants posed potential health risks and caused ecological damage during the 2019-nCoV pandemic,thereby increasing the demands for the development of disinfectants based on natural products,with low health risks and low aquatic *** the present study,a few natural naphthoquinones and their derivatives bearing the 1,4-naphthoquinone skeleton were synthesized,and their antibacterial activity against selected bacterial strains was *** vitro antibacterial activities of the compounds were investigated against Escherichia coli and Staphylococcus *** the minimum inhibitory concentration(MIC)of≤0.125μmol/L for juglone(1a),5,8-dimethoxy-1,4-naphthoquinone(1f),and 7-methyl-5-acetoxy-1,4-naphthoquinone(3),a strong antibacterial activity against *** was *** 1,4-naphthoquinone derivatives exhibited a strong antibacterial activity,with MIC values ranging between 15.625 and 500μmol/Land ECso values rangingbetween10.56 and248.42μmol/*** of the synthesized compounds exhibited strong antibacterial activities against *** these compounds,juglone(la)showed the strongest antibacterial *** results from mechanistic investigations indicated that juglone,a natural naphthoquinone,caused cell death by inducing reactive oxygen species production in bacterial cells,leading to DNA *** addition,juglone could reduce the self-repair ability of bacterial DNA by inhibiting RecA *** addition to having a potent antibacterial activity,juglone exhibited low cytotoxicity in cell-based *** conclusion,juglone is a strong antibacterial agent with low toxicity,indicating that its application as a bactericidal agent may be associated with low health risks and aquatic toxicity.

关键词： 1,4-naphthoquinone derivatives Antibacterial Actionmechanism RecA

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Description of rotational properties of the superheavy nucleus ^(256,258,260)Rf by projected shell model

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Chinese Science Bulletin 2014年第29期59卷 3853-3857页

作者： Zhiyi Zhou Yanxin Liu Yingchun yang Fangqi Chen yang sun Department of Physics and Astronomy Shanghai Jiao Tong University School of Science Huzhou Teachers College Shanghai Jiao Tong University Press China Institute of Atomic Energy

Band structure of the Z=104 nucleus256Rf has been a recent research focus in nuclear *** performed projected shell model calculations for this and some other neighboring Rf ***,we studied rotational properties of these nuclei and showed that variations in dynamic moment of inertia were sensitive to single-particle structures,which may be useful information for locating the anticipated island of *** transition properties were also calculated,and measurable quantities were predicted for further experimental test.

关键词：投影壳模型超重核属性旋转转动性能能带结构粒子结构电磁转换

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Engineered geranyl diphosphate methyltransferase produces 2-methyl-dimethylallyl diphosphate as a noncanonical C_(6) unit for terpenoid biosynthesis

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Synthetic and Systems Biotechnology 2023年第1期8卷 107-113页

作者： Chen-yang Xia Bo-Wen Lu Ji-Yun Cui Bai-yang Wang Yue-yang sun Fei Gan Hubei Key Laboratory of Cell Homeostasis College of Life ScienceWuhan UniversityWuhanChina TaiKang Center for Life and Medical Science Wuhan UniversityWuhanChina Hubei Provincial Cooperative Innovation Center of Industrial Fermentation WuhanChina

Terpenoids constitute the largest class of natural products with complex structures,essential functions,and versatile *** of new building blocks beyond the conventional five-carbon(C_(5))units,dimethylallyl diphosphate(DMAPP)and isopentenyl diphosphate,expands significantly the chemical space of ***-guided engineering of an S-adenosylmethionine-dependent geranyl diphosphate(GPP)C2-methyltransferase from Streptomyces coelicolor yielded variants converting DMAPP to a new C_(6) unit,*** of the Gly residue at the position 202 resulted in a smaller substrate-binding pocket to fit DMAPP instead of its native substrate *** of Phe residue at the position 222 with a Tyr residue contributed to DMAPP binding via hydrogen ***,using Escherichia coli as the chassis,we demonstrated that 2-methyl-DMAPP was accepted as a start unit to generate noncanonical trans-and cis-prenyl diphosphates(C_(5n+1))and *** work provides insights into substrate recognition of prenyl diphosphate methyltransferases,and strategies to diversify terpenoids by expanding the building block portfolio.

关键词： Protein engineering Terpenoid biosynthesis Methyltransferase Noncanonical building block

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A Study of the Catalyst and the Practical Significance of the Energy Cooperation Between China and Russia in the New Period

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学术界 2016年第7期 275-280页

作者： sun yang Du Nini Yin Lili School of Foreign Languages Southwest Petroleum University

On 3,September,2015,China signed more than 20 cooperation agreements,six of which were about oil and gas. This is a breakthrough since the 400 billion natural gas supply deal which was signed in May 2014. These great achievements are inseparable from the continuous efforts of the new generation of collective leadership and multi- level and all- dimensional cooperation under the background of "China dream". This paper aims to discuss the stimulative factors of the developments and breakthroughs from the aspects of the internal efforts between the two governments and external influences of international environment. Lastly,the paper explores the great significance of energy cooperation between China and Russia to the realization of "China dream".

关键词：能源合作中国俄罗斯催化剂天然气供应合作协议影响因素国际环境

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A clinical study of the efficacy of topical corticosteroids on dry eye

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第8期7卷 675-678页

作者： yang Chong-qing sun Wen GU yang-shun Zheyi Eye Center the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

Objective: To evaluate the effect of topical corticosteroid for treatment of moderate or severe dry eye. Methods: Sixty eyes of 30 patients with moderate or severe dry eye, who were not sensitive to artificial tears, were treated with 0.1% fluoro- metholone eye drops. Subjective symptom and objective tests were used to evaluate the efficacy of treatment before and after application of 0.1% fluorometholone eye drops for 1 week and 1 month. Side effects were also evaluated. Results: After 1 week of treatment, subjective symptoms were improved in all dry eye patients; objective tests were improved in all dry eye patients 1 month after treatment, and the difference was significant. Conclusion: Topical corticosteroid drops can rapidly and effectively relieve the symptoms and signs of moderate or severe dry eye.

关键词： Dry eye Treatment Corticosteroids

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Hyperbranched polymer-cored star polyfluorenes as blue light-emitting materials

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Chinese Science Bulletin 2008年第18期53卷 2770-2776页

作者： HAN yang sun MingHao FEI ZhuPing BO ZhiShan Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Polymer Physics and Chemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

Hyperbranched polymer-cored star polyfluorenes with high molecular weights and narrow molecular weight distribution were prepared by palladium-catalyzed one-pot Suzuki polycondensation of multi- functional cores and an AB-type monomer. The optical, electrochemical and thermal properties of the hyperbranched polymer-cored star polymers were investigated. These polymers exhibited good ther- mal and color stability in solid state, and there was no significant blue-green emission after the poly- mers had been annealed in air for 2.5 h. Their three-dimensional hyperbranched structures could ef- fectively reduce the aggregation of the peripheral rigid linear conjugated polyfluorene chains.

关键词：发光二极管聚合物星形高聚物缩聚作用

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Molecular Dynamics Study of Effects of Si-Doping Upon Structure and Mechanical Properties of Carbon Nanotube

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Communications in Theoretical Physics 2006年第4期45卷 741-744页

作者： SONG Hai-yang sun He-Ming ZHANG Guo-Xiang Department of Physics Beijing Institute of Technology Beijing 100081 China

In this paper, a Si-doped single-walled carbon nanotube （SWCNT）（7,7） and several perfect armchair SWCNTs are investigated using the classical molecular dynamics simulations method. The inter-atomic short-range interaction is represented by empirical Tersoff bond order potential. The computational results show that the axial Young＇s modulus of the perfect SWCNTs are in the range of 1.099 ± 0.005 TPa, which is in good agreement with the existing experimental results. From our simulation, the Si-doping decreases the Young＇s modulus of SWCNT, and with the increased strain levels, the effect of Si-doped layer in enhancing the local stress level increases. The Young＇s modulus of armchair SWCNTs are weakly affected by tube radius.

关键词： molecular dynamics simulation carbon nanotubes Young's modulus Si-doping

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Development of a novel cycling impact–sliding wear rig to investigate the complex friction motion

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Friction 2019年第1期7卷 32-43页

作者： Zhenbing CAI Zhiqiang CHEN yang sun Jianying JIN Jinfang PENG Minhao ZHU Tribology Research Institute Key Lab of Advanced Technologies of Materials Southwest Jiaotong University

In many industrial devices, impact-sliding wear is caused by a variety of complex vibrations between the contacted interfaces. Under actual conditions, impact and sliding motions do not occur in only one direction, and different complex impact-sliding motions exist on the tribology surfaces. In this study, an impact-sliding wear test rig is developed to investigate the wear effect of different complex motions. Using this rig, multi-type impact-sliding wear effects are realized and measured, such as those derived from unidirectional, reciprocating, and multi-mode combination motions. These three types of impact–sliding wear running behavior are tested and the wear damage mechanism is discussed.

关键词： impact-sliding wear wear test rig complex friction motions wear damage mechanism

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Targeting protein phosphatases for the treatment of inflammation-related diseases:From signaling to therapy

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Signal Transduction and Targeted Therapy 2022年第7期7卷 2157-2180页

作者： Jie Pan Lisha Zhou Chenyang Zhang Qiang Xu yang sun State Key Laboratory of Pharmaceutical Biotechnology Chemistry and Biomedicine Innovation Center(ChemBIC)Department of Biotechnology and Pharmaceutical SciencesSchool of Life ScienceNanjing University163 Xianlin AvenueNanjing 210023China Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Xuzhou Medical University209 Tongshan RoadXuzhou 221004 JiangsuChina

Inflammation is the common pathological basis of autoimmune diseases,metabolic diseases,malignant tumors,and other major chronic *** plays an important role in tissue *** one hand,inflammation can sense changes in the tissue environment,induce imbalance of tissue homeostasis,and cause tissue *** the other hand,inflammation can also initiate tissue damage repair and maintain normal tissue function by resolving injury and restoring *** opposing functions emphasize the significance of accurate regulation of inflammatory homeostasis to ameliorate inflammation-related *** mechanisms involve protein phosphorylation modifications by kinases and phosphatases,which have a crucial role in inflammatory *** mechanisms by which many kinases resolve inflammation have been well reviewed,whereas a systematic summary of the functions of protein phosphatases in regulating inflammatory homeostasis is *** molecular knowledge of protein phosphatases,and especially the unique biochemical traits of each family member,will be of critical importance for developing drugs that target ***,we provide a comprehensive summary of the structure,the“double-edged sword”function,and the extensive signaling pathways of all protein phosphatases in inflammation-related diseases,as well as their potential inhibitors or activators that can be used in therapeutic interventions in preclinical or clinical *** provide an integrated perspective on the current understanding of all the protein phosphatases associated with inflammationrelated diseases,with the aim of facilitating the development of drugs that target protein phosphatases for the treatment of inflammation-related diseases.

关键词： inflammation homeostasis diseases

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Physical-based constitutive model considering the microstructure evolution during hot working of AZ80 magnesium alloy

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Advances in Manufacturing 2019年第1期7卷 30-41页

作者： Ze-Xing Su Chao-yang sun Ming-Wang Fu Ling-Yun Qian School of Mechanical Engineering University of Science and Technology Beijing Beijing 100083 People's Republic of China Beijing Key Laboratory of Lightweight Metal Forming Beijing 100083 People's Republic of China Department of Mechanical Engineering The Hong Kong Polytechnic University Hung Hom Hong Kong People's Republic of China

A physical-based constitutive model was developed to model the viscoplastic flow behavior and microstructure evolution of AZ80 magnesium alloy during the hot working process. The competing deformation mechanisms, including work hardening, dynamic recovery, and dynamic recrystallization, in an isothermal compression environment were considered in the model. The internal state variables, including the normalized dislocation density and recrystallized volume fraction, were incorporated into the model to articulate the microstructure evolution during hot deformation. The kinetic condition critical for dynamic recrystallization, considering the effects of the deformation temperature and strain rate, was obtained by employing both the Poliak-Jonas criterion and Zener-Hollomon parameter. Microstructure observations indicate that the recrystallized volume fraction increases with decreasing Z parameter at constant strain, which is consistent with the predicted kinetics model. Based on the developed model, a good correlation was also obtained between the predicted and experimental flow stress. The results indicate a good predictability of the model in describing the hot deformation behavior and microstructure evolution of AZ80 magnesium alloy.

关键词： AZ80 magnesium alloy Hot deformation Constitutive model Microstructure evolution Dynamic recrystallization (DRX)

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