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The DNA concentration effect on DNA radiation damage induced by 7Li ions and γ rays

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Chinese Science Bulletin 2008年第18期53卷 2758-2763页

作者： KONG FuQuan WANG Xiao NI MeiNan SUI Li YANG MingJian ZHAO Kui China institute of Atomic Energy Beijing 102413 China School of Science Hebei University of Technology Tianjin 300130 China Key Laboratory of Beam Technology and Modification of Ministry of education of China Beijing Normal University Beijing 100875China Handan College Handan 056005 China

To evaluate the influence of the DNA concentration in the aqueous solution on DNA radiation damage, the plasmid DNA in the presence or absence of Mannitol (scavenger of free radical OH·) was irradiated by 7Li ions and γ rays at various DNA concentrations. Gel electrophoresis analysis revealed that the DNA damage of single and double strand breaks induced by irradiation became more severe at lower DNA concentration. In the condition of γ-ray irradiation, most of double strand breaks (DSB) damage was neutralized and less associated with DNA concentration in the presence of mannitol. However, under 7Li irradiation, DSB damage could not be cleared by mannitol but was gradually aggravated with decreasing DNA concentrations. These findings imply that under low-LET irradiation, most of the DSB damage is generated by free radical OH? diffusion, and thus may be counteracted by scavengers, while at higher-LET irradiation, quite a fraction of DSB induction is caused by direct ionizing energy deposi- tion of heavy ions, which cannot be eliminated. This work also indicates that the proportion between free radical damage and direct ionizing damage is a constant which is independent of DNA concentra- tion when the DNA concentration is under a certain value (50 ng/μL). Our study sheds light on the un- derlying mechanisms in the DNA radiation damage process.

关键词：重离子质粒 DNA γ射线

Microbial and molecular fossils from the Permian Zoophycos in South China

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Science China Earth Sciences 2007年第8期50卷 1121-1127页

作者： GONG YiMing XU Ran XIE ShuCheng HUANG XianYu HU Bin QI YongAn ZHANG GuoCheng Key Laboratory of Biogeology and Environmental Geology of Ministry of education State Key Laboratory of Geological Processes and Mineral ResourcesChina University of GeosciencesWuhan 430074China institute of Resources and Environment Key Laboratory of Biogenic Traces&Sedimentary Minerals of Henan ProvinceHenan Polytechnic UniversityJiaozuo 454003China

The trace fossil Zoophycos was enriched in the lower part of the Guadalupian Maokou Formation of Permian in Laibin, Guangxi of South China, and characterized by observable lamellae within its spreiten. Associated with these lamellae are the prolific coccus- and spirillum-shaped microbe fossils. These microbes morphologically identified are 0.4―3.0 μm in diameter or length. Molecular fossils, including normal alkanes (dominated by C18, without an odd-over-even predominance), acyclic isoprenoids (such as pristane (Pr) and phytane (Ph)), extended tricyclic terpanes, pentacyclic triterpanes, steranes, al-kylcyclohexanes, dibenzothiophenes, benzonaphthothiophenes, benzobisbenzothiophenes, were in-strumentally identified in the wackestone characterized by the occurrence of abundant Zoophycos (composite ichnofabric indices are 4) and crowded microbial fossils. The value of the Pr/Ph ratio is less than 1, indicative of a dysoxic condition. The identification of abundant sulfur compounds (the thio-phene series) related to the contribution of reductive sulfur favors the occurrence of sulphate-reducing bacteria. The association of abundant microbial colonies with microbial molecular fossils within the spreiten suggests that trace fossils Zoophycos would be a multifunctional garden carefully constructed by the Zoophycos-producer, where different microbial colonies were orderly and carefully planted and cultured in different minor lamellae within spreiten. Hence, it is proposed that the Zoophycos-producer symbiosed with microbial colonies on the mutual basis of food supply and the redox conditions.

关键词： trace fossils Zoophycos microbes molecular fossils Permian South China

Characterizing a lubricant additive for 1,3,4-tri-(2-octyldodecyl) cyclopentane: Computational study and experimental verification

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Friction 2016年第3期4卷 257-265页

作者： Jingyan NIAN Yifan SI Zhiguang GUO Ping GAO Weimin LIU State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 ChinaHubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials Hubei University Wuhan 430062 China

In order to increase the life of spacecraft, it is important to improve the comprehensive lubrication performance. Multiple alkylated cyclopentane (MAC) lubricants are presently gaining wide acceptance for actual space applications; adding extreme pressure additive is a strategy to improve lubrication performance. In this study, taking 1,3,4-tri-(2-octyldodecyl) cyclopentane as base oil, tricresol phosphate (traditional additive) and tri-(2-octyldodecyl) phosphate (developmental additive) have been screened computationally for compatibility, shear film forming and energy dissipation. Theoretical results indicate that (a) tricresol phosphate additive is not suited for addition to 1,3,4-tri-(2-octyldodecyl) cyclopentane lubricant due to limited compatibility; (b) tri-(2-octyldodecyl) phosphate is an excellent lubricant additive due to its perfect compatibility, ease of forming a shear film on the surface of friction pairs, higher strength, and low energy dissipation; and (c) lubrication occurs through the solid-liquid composite lubrication mechanism. These theoretical results were confirmed experimentally.

关键词： 1,3,4-tri-(2-octyldodecyl) cyclopentane lubricant additive computational screening lubrication mechanism experimental verification

The effects of pre-equilibrium emission and secondary decay on the determination of freeze-out volume at intermediate energies

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Chinese Physics C 2021年第5期45卷 173-178页

作者： Hui-Xiao Duan Dong-Hai Zhang Fan Zhang Hai-Shun Wu Key Laboratory of Magnetic Molecules and Magnetic Information Materials Ministry of education School of Chemistry and Material ScienceShanxi Normal UniversityLinfen 041004China institute of Modern Physics Shanxi Normal UniversityLinfen 041004China Department of Electronic Information and Physics.Changzhi University Changzhi 046011China

The effects of pre-equilibrium emission and secondary decay on the determination of the freeze-out volume are investigated using the isospin-dependent quantum molecular dynamics model accompanied by the statistical decay model ***-mass projectiles and large-mass targets with central collisions are studied at intermediate *** is revealed that the proton yields of pre-equilibrium emission are smaller than those of secondary ***,the determination of the freeze-out volume from the proton yields is more easily affected by pre-equilibrium ***,the percentage of proton yields in the freezeout stage is found to be approxim-ately 50%.

关键词： freeze-out volume nuclear temperature quadrupole momentum

Isolation and Identification of Pseudo Seven-Coordinate Ru(Ⅲ)Intermediate Completing the Catalytic Cycle of Ru-bda Type of Water Oxidation Catalysts

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CCS Chemistry 2022年第7期4卷 2481-2490页

作者： Tianqi Liu Ge Li Nannan Shen Linqin Wang Brian J.J.Timmer Shengyang Zhou Biaobiao Zhang Alexander Kravchenko Bo Xu Marten S.G.Ahlquist Licheng Sun Department of Chemistry School of Engineering Sciences in ChemistryBiotechnologyand HealthKTH Royal Institute of TechnologyStockholm 10044 Department of Theoretical Chemistry and Biology School of Engineering Sciences in ChemistryBiotechnologyand HealthKTH Royal Institute of TechnologyStockholm 10691 State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou 215123 Center of Artificial Photosynthesis for Solar Fuels School of ScienceWestlake UniversityHangzhou 310024 Nanotechnology and Functional Materials Department of Materials Sciences and EngineeringThe Angstrom LaboratoryUppsala UniversityUppsala 75103 institute of Artificial Photosynthesis(IAP) State Key Laboratory of Fine ChemicalsDalian University of Technology(DUT)Dalian 116024

Isolation of RuⅢ-bda(17-electron specie)complex with an aqua ligand(2-electron donor)is challenging due to violation of the 18-electron *** considerable efforts have been dedicated to mechanistic studies of water oxidation by the Ru-bda family,the structure and initial formation of the Ru^(Ⅲ)-bda aqua complex are still ***,we challenge this often overlooked step by designing a pocketshape Ru-based complex *** computational studies showed that 1 possesses the crucial hydrophobicity at the Ru^(V)(O)state as well as similar probability of access of terminal O to solvent water molecules when compared with classic Ru-bda *** characterization of single-crystal structures at the Ru^(Ⅱ) and Ru^(Ⅲ) states,a pseudo seven-coordinate“ready-togo”aqua ligand with Ru^(Ⅲ)…O distance of 3.62A was *** aqua ligand was also found to be part of a formed hydrogen-bonding network,providing a good indication of how the Ru^(Ⅲ)-OH_(2)complex is formed.

关键词： Ru-bda water oxidation pseudo seven-coordinate Ru^(Ⅲ)-OH_(2)intermediate water preorganization

Distribution of P2O5 between solid solution and liquid phase in dephosphorization slag of CaO-SiO2-FeO-P2O5-Na2O system

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Journal of Iron and Steel Research International 2019年第11期26卷 1162-1170页

作者： Chuan-ming Du Ning-ning Lv Chang Su Wei-ming Liu Jin-xing Yang Hai-chuan Wang institute of Multidisciplinary Research for Advanced Materials Tohoku UniversitySendaiMiyagi 980-8577Japan School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243032AnhuiChina Key Laboratory of Metallurgical Emission Reduction and Resources Recycling(Anhui University of Technology) Ministry of Education.Ma'anshan 243002Anhui.China

A multi-phase slag containing Na2O is potential to efficiently dephosphorize high-P hot *** dephosphorization,the generated slag with high P2O5 content is regarded as a P *** P2O5 was mainly concentrated in the 2CaO SiO2-3CaO P2O5 solid solution,the recovery of P from dephosphorization slag primarily depends on the separation of the solid solution from other *** distribution ratios of P2O5 between solid solution and liquid phase in the CaOSiO2-FeO-P2O5-Nslag system were *** results indicated that the addition of Na2O facilitated the enrichment of P2O5 in the solid solution because it increased not only the distribution ratio of P2O5 but also the mass fraction of the solid *** distribution ratio of P2O5 was independent of the P2O5 content in slag.A higher P2O5 content in slag resulted in higher P2O5 and Na2O contents in the solid *** distribution ratio of P2O5 increased with the total Fe content in the liquid phase,regardless of the valence of *** increase in the FeO content in slag brought a higher P2O5 content in the solid *** slag basicity increased,the distribution ratio of P2O5 increased,but the P2O5 content in the solid solution decreased.

关键词： Dephosphorization Steelmaking slag Distribution ratio P2O5 2CaO·SiO2-3CaO·P2O5 solid solution

Coupling ferromagnetic ordering electron transfer channels and surface reconstructed active species for spintronic electrocatalysis of water oxidation

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Journal of Energy Chemistry 2023年第10期85卷 570-580,I0014页

作者： Zexing He Xiaokang Liu Minghui Zhang Lei Guo Muhammad Ajmal Lun Pan Chengxiang Shi Xiangwen Zhang Zhen-Feng Huang Ji-Jun Zou Key Laboratory for Green Chemical Technology of the Ministry of education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Collaborative Innovative Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China Zhejiang institute of Tianjin University Ningbo 315201ZhejiangChina Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Sluggish reaction kinetics of oxygen evolution reaction(OER), resulting from multistep proton-coupled electron transfer and spin constriction, limits overall efficiency for most reported catalysts. Herein, using modeled ZnFe_(2-x)Ni_xO_(4)(0 ≤ x ≤ 0.4) spinel oxides, we aim to develop better OER electrocatalyst through combining the construction of ferromagnetic(FM) ordering channels and generation of highly active reconstructed species. The number of symmetry-breaking Fe–O–Ni structure links to the formation of FM ordering electron transfer channels. Meanwhile, as the number of Ni^(3+)increases, more ligand holes are formed, beneficial for redirecting surface reconstruction. The electro-activated ZnFe_(1.6)Ni_(0.4)O_(4) shows the highest specific activity, which is 13 and 2.5 times higher than that of ZnFe_(2)O_(4) and unactivated ZnFe_(1.6)Ni_(0.4)O_(4), and even superior to the benchmark IrO_(2) under the overpotential of 350 mV. Applying external magnetic field can make electron spin more aligned, and the activity can be further improved to 39 times of ZnFe_(2)O_(4). We propose that intriguing FM exchange-field interaction at FM/paramagnetic interfaces can penetrate FM ordering channels into reconstructed oxyhydroxide layers, thereby activating oxyhydroxide layers as spin-filter to accelerate spin-selective electron transfer. This work provides a new guideline to develop highly efficient spintronic catalysts for water oxidation and other spin-forbidden reactions.

关键词： Oxygen evolution reaction Reconstruction mechanism Metal oxyhydroxides Electron transfer channels Ferromagnetic exchange-field penetration

Uncovering Chemical Interactions between Danshen and Danggui Using Liquid Chromatography–Mass Spectrometry and Network Pharmacology-Based Research on Stroke

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World Journal of Traditional Chinese Medicine 2024年第2期10卷 230-243页

作者： Han-Qing Pang Jia-Xiu Guo Xiao-Yu Shang Jian Wang Hui Liu Jing Tian Lu Zhang Jian-Bin Wang Wei Shi Bing-Chun Yan Liang Liu Department of Pharmacy School of MedicineInstitute of Translational MedicineYangzhou UniversityYangzhouChina School of Medicine Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile DiseasesYangzhou UniversityYangzhouChina School of Chemistry and Pharmaceutical Sciences State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(Guangxi Normal University)GuilingChina Yangzhou Food and Drug Inspection and Testing Center YangzhouChina

Objective: The objective of this study was to decipher chemical interactions between Danshen and Danggui using liquid chromatography–mass spectrometry(LC-MS) and explore the mechanisms of Danshen–Danggui against stroke using network pharmacology and molecular docking. Materials and Methods: First, the chemical compounds of Danshen–Danggui were profiled using ultra-high-performance liquid chromatography(HPLC)-quadrupole time-of-flight MS. Accurately characterized compounds in various proportions of Danshen–Danggui were quantified using HPLC combined with triple quadrupole electrospray tandem MS. Network pharmacology was used to uncover the essential mechanisms of action of Danshen–Danggui against stroke. Discovery Studio Software was used for the molecular docking verification of key active chemicals and stroke-related targets. Results: A total of 53 compounds were characterized, and 22 accurately identified constituents(10 phenolic acids, 8 phthalides, and 4 tanshinones) were quantified in 15 proportions of Danshen–Danggui. The quantification results showed that Danggui significantly increased the dissolution of most phenolic acids(compounds from Danshen), whereas Danshen promoted the dissolution of most phthalides(compounds from Danggui). Overall, the combination of Danshen and Danggui at a 1:1 ratio resulted in the maximum total dissolution rate. Further network pharmacology and molecular docking results indicated that Danshen–Danggui exerted anti-stroke effects mainly by regulating inflammation-related(tumor necrosis factor, hypoxia-inducible factor, and toll-like receptor) signaling pathways, which ranked among the top three pathways based on Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis. Conclusion: The chemical compounds in Danshen–Danggui could interact with each other to increase the dissolution of the most active compounds, which could provide a solid basis for uncovering the compatibility mechanisms of Danshen–Danggui and Danshen–Danggu

关键词： Chemical interactions Danggui Danshen liquid chromatography–mass spectrometry network pharmacology

Molecular Cloning and Tissue-specific Expression of Cu/Zn and Mn-superoxide Dismutase in the Three-keeled Pond Turtle, Chinemys reevesii

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Asian Herpetological Research 2013年第2期4卷 79-89页

作者： Xiaojing JIA Cuijuan NIU Ministry of education Key Laboratory of Biodiversity Science and Ecological Engineering College of Life SciencesBeijing Normal University

Both copper/zinc superoxide dismutase （SOD; Cu/Zn-SOD, SOD1） cDNA and manganese SOD （Mn-SOD, SOD2） cDNA were cloned for the first time from the three-keeled pond turtle, Chinemys reevesii, using RT-PCR and RACE methods in this work. The SOD1 cDNA was 749 bp long and consisted of a 32-bp 5＇-untranslated region （UTR）, a 249-bp 3＇-UTR, and a 468-bp open reading frame （ORF） encoding a 155-amino-acid protein with 16.0 kDa predicted molecular mass and 5.95 theoretical isoelectric point （p/）. The SOD2 cDNA was 1687 bp long and comprised 94-bp of 5＇-UTR, 912-bp 3＇-UTR and 681-bp ORF encoding a 226-amino-acid protein with 25.0 kDa predicted molecular mass and 8.83 pI. The deduced amino acid sequence of SOD1 showed relatively high similarity （77.4%-87.1%） and identity （65.4%-74.4%） with the published sequences of SOD1 from other vertebrate species, whereas SOD2 protein shared slightly higher similarity （83.6%-95.6%） and identity （76.1%-88.9%） with other reported vertebrates SOD2s. Phylogenetic analysis revealed that the C. reevesii SOD1 and SOD2 were separately clustered together, and were highly conserved during evolution. Both SOD mRNA expression was detected widely in the brain, liver, muscle, kidney, gut, spleen, lung and heart at variable levels. The highest expression of the two SODs was observed in muscle, and followed in brain, liver, kidney, gut and heart, whereas low transcriptional levels were found in spleen and lung. Meanwhile, high activity of SOD 1 was kept in brain, liver, muscle, kidney and heart, and followed in gut, spleen and lung. The activities of SOD2 in brain, liver, muscle, kidney, gut and heart were significantly higher than those in spleen and lung.

关键词： Chinemys reevesii SOD 1 SOD2 cDNA cloning mRNA expression