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Arsenic methylation by an arsenite S-adenosylmethionine methyltransferase from Spirulina platensis

Journal of Environmental Sciences 2016年第11期28卷 162-168页

作者： Yuqing Guo ximei xue Yu Yan Yongguan Zhu Guidi Yang Jun Ye Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring College of Life Sciences Fujian Agriculture and Forestry University Key Laboratory of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences

Arsenic-contaminated water is a serious hazard for human health. Plankton plays a critical role in the fate and toxicity of arsenic in water by accumulation and *** platensis（S. platensis）, a typical plankton, is often used as a supplement or feed for pharmacy and aquiculture, and may introduce arsenic into the food chain, resulting in a risk to human health. However, there are few studies about how S. platensis biotransforms arsenic. In this study, we investigated arsenic biotransformation by S. platensis. When exposed to arsenite（As（Ⅲ））, S. platensis accumulated arsenic up to 4.1 mg/kg dry *** exposure to As（Ⅲ）, arsenate（As（Ⅴ）） was the predominant species making up 64% to86% of the total arsenic. Monomethylarsenate（MMA（Ⅴ）） and dimethylarsenate（DMA（Ⅴ））were also detected. An arsenite S-adenosylmethionine methyltransferase from S. platensis（Sp Ars M） was identified and characterized. Sp Ars M showed low identity with other reported Ars M enzymes. The Escherichia coli AW3110 bearing Spars M gene resulted in As（Ⅲ） methylation and conferring resistance to As（Ⅲ）. The in vitro assay showed that Sp Ars M exhibited As（Ⅲ） methylation activity. DMA（Ⅴ） and a small amount of MMA（Ⅴ） were detected in the reaction system within 0.5 hr. A truncated Sp Ars M derivative lacking the last 34 residues still had the ability to methylate As（Ⅲ）. The three single mutants of Sp Ars M（C59S, C186 S, and C238S） abolished the capability of As（Ⅲ） methylation, suggesting the three cysteine residues are involved in catalysis. We propose that Sp Ars M is responsible for As methylation and detoxification of As（Ⅲ） and may contribute to As biogeochemistry.

关键词： Spirulina platensis Arsenic Methylation Methyltransferase

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土壤中砷的生物转化及砷与抗生素抗性的关联

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土壤学报 2019年第4期56卷 763-772页

作者：薛喜枚朱永官中国科学院城市环境研究所中国科学院城市环境与健康重点实验室福建厦门361021 中国科学院生态环境研究所中心城市与区域生态国家重点实验室北京100085

砷是一种广泛存在于自然环境中毒性较强的类金属元素,农田生态系统中的植物(尤其水稻)很容易吸收积累土壤环境中的砷。植物中的砷沿食物链向高等动物传递,威胁人类健康。除土壤本身的理化性质外,土壤中砷的生物转化也强烈影响砷的生物... 详细信息

砷是一种广泛存在于自然环境中毒性较强的类金属元素,农田生态系统中的植物(尤其水稻)很容易吸收积累土壤环境中的砷。植物中的砷沿食物链向高等动物传递,威胁人类健康。除土壤本身的理化性质外,土壤中砷的生物转化也强烈影响砷的生物有效性。目前研究发现异化砷酸盐(As(Ⅴ))呼吸性还原、细胞质As(Ⅴ)还原、亚砷酸盐(As(Ⅲ))氧化、As(Ⅲ)甲基化和有机砷的去甲基化在土壤砷的生物地球化学过程中起重要作用。随着分析化学和分子生物学技术的进步,最新研究发现土壤生物也参与了砷糖、砷糖磷脂、砷甜菜碱、砷代草丁膦、硫代砷等有机砷的合成,其中三价一甲基砷和砷代草丁膦可作为新型抗生素,但其合成机制及生态学功能有待进一步研究。本文还详细介绍了为适应复合污染环境微生物通过自身的进化对抗生素和重金属形成的四种共选择抗性机制:共抗性,交叉抗性、共调控和生物膜感应,特别提出了土壤中砷污染与抗生素抗性相关联这一新的研究方向。最后对砷生物转化和砷与抗生素共抗机制的未来研究方向做了展望。

关键词：砷氧化还原砷甲基化砷其他有机化抗生素抗性基因

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2023年临沂市奶牛蹄病发病情况与防治效果调查

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中国乳业 2024年第12期 62-68页

作者：薛喜梅沂南县蒲汪兽医站山东临沂276300

[目的]掌握临沂市奶牛蹄病发病情况,为提高防控效果提供理论和实践依据。[方法]调查统计临沂市22家规模化牧场(合作社)2023年1—12月奶牛蹄病发病情况,分析发病原因,调查治疗经过,提出防控建议。[结果]2023年临沂市规模化牧场(合作社)... 详细信息

[目的]掌握临沂市奶牛蹄病发病情况,为提高防控效果提供理论和实践依据。[方法]调查统计临沂市22家规模化牧场(合作社)2023年1—12月奶牛蹄病发病情况,分析发病原因,调查治疗经过,提出防控建议。[结果]2023年临沂市规模化牧场(合作社)奶牛蹄病发病率7.8%。常见蹄病8种,变形蹄发病率最高,占全部蹄病的29.8%,其次是蹄叶炎。从发病年龄和胎龄看,成年奶牛发病率高于青年奶牛,且随胎次增加,蹄病发病率明显上升,症状加重。从发病季节看,奶牛蹄病以3月、6—9月发病率最高。奶牛因病淘汰时,蹄病占比最高,而不定期蹄浴和修蹄是规模化牧场奶牛蹄病发生的重要诱因。从治疗效果看,变形蹄、指(趾)间赘生、蹄底刺伤治愈率较高;腐蹄病、蹄底溃疡、白线病临床治疗效果较差。[结论]受生活环境、兽医卫生状况等饲养管理情况、TMR日粮营养状况影响,临沂市规模化牧场奶牛蹄病发病率较高。应加强饲养管理,逐步改善养殖环境、卫生状况,提高TMR日粮质量,降低蹄病发病率。

关键词：奶牛规模化牧场蹄病调查建议

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Targeting cholesterol trafficking to mitigate axonal degeneration in hereditary spastic paraplegia

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Neural Regeneration Research 2025年第5期20卷 1397-1398页

作者： Zhenyu Chen xue-Jun Li Department of Biomedical Sciences University of Illinois College of Medicine RockfordRockfordILUSA Department of Bioengineering University of Illinois at ChicagoChicagoILUSA

Axonal degeneration underlies many debilitating diseases including hereditary spastic paraplegia(HSP),a genetically and clinically diverse group of disorders characterized by spasticity and weakness of the lower *** is one significant cause of chronic neurodisability due to the lack of effective treatments and a wide range of onset ages from early childhood to 70 years.

关键词： degeneration diseases hereditary

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Turbulent Agglomeration of Microparticles in a Cylinder Wake Flow Using LES-DEM:Focusing on the Effect of the Reynolds Number

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Journal of Thermal Science 2025年第1期34卷 34-49页

作者： WANG Shuang MU Lin LI xue XIE Jun DONG Ming School of Energy and Power Engineering Dalian University of Technology School of Optical Information and Energy Engineering Wuhan Institute of Technology School of Energy and Environment Shenyang Aerospace University

Turbulent agglomeration is viewed as a promising technology for enhancing fine particle removal *** better understand particle transport,agglomeration behaviors,and fluid-particle interactions,we numerically explored these phenomena under cylindrical vortex wake influence using a coupled large eddy simulation and discrete element method（LES-DEM） *** validity of the LES approach was verified by comparison with available direct numerical simulation（DNS） *** adopted the Johnson-Kendall-Roberts（JKR） contact model for particle-particle *** particle dispersion and agglomeration characteristics of particles with different diameters（dp=2-20 μm） in the laminar and transition of shear layer（TrSL） flow regimes were *** particles were concentrated at the vortex centers,while larger particles accumulated around the *** agglomeration efficiency exhibited an M-shaped profile spanwise（y-direction）.With increasing Reynolds number,the agglomeration efficiency and turbulence intensity *** particle agglomeration efficiency peaks at a certain Reynolds ***,at higher Reynolds numbers,reducing the residence time of particles in the flow field decreases the agglomeration efficiency.

关键词： discrete element method large eddy simulation microparticle particle agglomeration

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细菌性食物中毒的病原学情况和微生物检验结果分析

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口岸卫生控制 2020年第5期25卷 43-45页

作者：薛喜梅王永生确山县疾病预防控制中心河南驻马店463200

目的评价细菌性食物中毒的病原学情况和微生物检验结果。方法选取我中心在2016年4月~2019年5月检验科确诊为细菌性食物中毒的患者为重点研究主体,抽取74例患者进行病原菌微生物检验,观察并分析其检验结果以及病毒血清型情况。结果对74... 详细信息

目的评价细菌性食物中毒的病原学情况和微生物检验结果。方法选取我中心在2016年4月~2019年5月检验科确诊为细菌性食物中毒的患者为重点研究主体,抽取74例患者进行病原菌微生物检验,观察并分析其检验结果以及病毒血清型情况。结果对74例患者的病原菌进行检测,分别从粪便、呕吐物、食品、厨具及手拭子等进行检验,检出率最高的是粪便(76.54%);本次共检出菌株1 200株,检出病原菌350株(29.17%),检出率最高的是沙门菌(44.86%),其次是金黄色葡萄球菌、变形杆菌、致泻性大肠埃希菌等;经过血清学鉴定后各病原菌又会细化为多种类型。结论对细菌性食物中毒的患者采取微生物检验的价值高,它能准确判断病原菌的菌株类型、菌株数目以及病毒血清类型等,通过此检验方式可指导临床更好地完成治疗。

关键词：细菌性食物中毒病原学微生物检验

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A Multi-Objective Particle Swarm Optimization Algorithm Based on Decomposition and Multi-Selection Strategy

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Computers, Materials & Continua 2025年第1期82卷 997-1026页

作者： Li Ma Cai Dai Xingsi xue Cheng Peng School of Computer Science Shaanxi Normal UniversityXi’an710119China Fujian Provincial Key Laboratory of Big Data Mining and Applications Fujian University of TechnologyFuzhou350118China Information Construction and Management Center and Institute of Artificial Intelligence and Educational New Productivity Ningxia Normal UniversityGuyuan756099China

The multi-objective particle swarm optimization algorithm(MOPSO)is widely used to solve multi-objective optimization *** the article,amulti-objective particle swarm optimization algorithmbased on decomposition and multi-selection strategy is proposed to improve the search ***,two update strategies based on decomposition are used to update the evolving population and external archive,***,a multiselection strategy is *** first strategy is for the subspace without a non-dominated *** the neighbor particles,the particle with the smallest penalty-based boundary intersection value is selected as the global optimal solution and the particle far away fromthe search particle and the global optimal solution is selected as the personal optimal solution to enhance global *** second strategy is for the subspace with a non-dominated *** the neighbor particles,two particles are randomly selected,one as the global optimal solution and the other as the personal optimal solution,to enhance local *** third strategy is for Pareto optimal front(PF)discontinuity,which is identified by the cumulative number of iterations of the subspace without non-dominated *** the subsequent iteration,a new probability distribution is used to select from the remaining subspaces to ***,an adaptive inertia weight update strategy based on the dominated degree is designed to further improve the search ***,the proposed algorithmis compared with fivemulti-objective particle swarm optimization algorithms and five multi-objective evolutionary algorithms on 22 test *** results show that the proposed algorithm has better performance.

关键词： Multi-objective optimization multi-objective particle swarm optimization decomposition multi-selection strategy

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The complex roles of m^(6)A modifications in neural stem cell proliferation, differentiation, and self-renewal and implications for memory and neurodegenerative diseases

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Neural Regeneration Research 2025年第6期20卷 1582-1598页

作者： Yanxi Li Jing xue Yuejia Ma Ke Ye xue Zhao Fangliang Ge Feifei Zheng Lulu Liu Xu Gao Dayong Wang Qing Xia Department of Biochemistry and Molecular Biology College of Basic Medical SciencesHarbin Medical UniversityHarbinHeilongjiang ProvinceChina College of Basic Medical Sciences Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Basic Medical Institute Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Key Laboratory of Heilongjiang Province for Genetically Modified Animals Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Translational Medicine Research and Cooperation Center of Northern China Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijingChina

N6-methyladenosine(m^(6)A), the most prevalent and conserved RNA modification in eukaryotic cells, profoundly influences virtually all aspects of mRNA metabolism. mRNA plays crucial roles in neural stem cell genesis and neural regeneration, where it is highly concentrated and actively involved in these processes. Changes in m^(6)A modification levels and the expression levels of related enzymatic proteins can lead to neurological dysfunction and contribute to the development of neurological diseases. Furthermore, the proliferation and differentiation of neural stem cells, as well as nerve regeneration, are intimately linked to memory function and neurodegenerative diseases. This paper presents a comprehensive review of the roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, as well as its implications in memory and neurodegenerative diseases. m^(6)A has demonstrated divergent effects on the proliferation and differentiation of neural stem cells. These observed contradictions may arise from the time-specific nature of m^(6)A and its differential impact on neural stem cells across various stages of development. Similarly, the diverse effects of m^(6)A on distinct types of memory could be attributed to the involvement of specific brain regions in memory formation and recall. Inconsistencies in m^(6)A levels across different models of neurodegenerative disease, particularly Alzheimer's disease and Parkinson's disease, suggest that these disparities are linked to variations in the affected brain regions. Notably, the opposing changes in m^(6)A levels observed in Parkinson's disease models exposed to manganese compared to normal Parkinson's disease models further underscore the complexity of m^(6)A's role in neurodegenerative processes. The roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, and its implications in memory and neurodegenerative diseases, appear contradictory. These inconsistencies may be a

关键词： Alzheimer's disease cell self-renewal central nervous system memory microglia nerve regeneration neurodegenerative diseases neurogenesis RNA methylation

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Bearing Fault Diagnosis Based on the Markov Transition Field and SE-IShufflenetV2 Model

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Structural Durability & Health Monitoring 2025年第1期19卷 125-144页

作者： Chaozhi Cai Tiexin Xu Jianhua Ren Yingfang xue School of Mechanical and Equipment Engineering Hebei University of EngineeringHandan056038China

A bearing fault diagnosis method based on the Markov transitionﬁeld(MTF)and SEnet(SE)-IShufﬂenetV2 model is proposed in this paper due to the problems of complex working conditions,low fault diagnosis accuracy,and poor generalization of rolling ***,MTF is used to encode one-dimensional time series vibration sig-nals and convert them into time-dependent and unique two-dimensional feature ***,the generated two-dimensional dataset is fed into the SE-IShufﬂenetV2 model for training to achieve fault feature extraction and classiﬁ*** paper selects the bearing fault datasets from Case Western Reserve University and Paderborn University to experimentally verify the effectiveness and superiority of the proposed *** generalization performance of the proposed method is tested under the variable load condition and different signal-to-noise ratios(SNRs).The experimental results show that the average accuracy of the proposed method under different working conditions is 99.2%without adding *** accuracy under different working conditions from 0 to 1 HP is 100%.When the SNR is 0 dB,the average accuracy of the proposed method can still reach 98.7%under varying working ***,the bearing fault diagnosis method proposed in this paper is characterized by high accuracy,strong anti-noise ability,and ***,the proposed method can also overcome the inﬂuence of variable working conditions on diagnosis accuracy,providing method support for the accurate diagnosis of bearing faults under strong noise and variable working conditions.

关键词： Bearings Markov transitionﬁeld SE-IShufﬂenetV2

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Design and Application of Turbine Cascade Partitioned Endwall Profiling

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Journal of Thermal Science 2025年第1期34卷 110-128页

作者： ZENG Fei JIANG Ruiqi xue Xingxu DU Wei LUO Lei ZHOU Xun AECC Hunan Aviation Powerplant Research Institute School of Energy Science and Technology Harbin Institute of Technology Science and Technology on Diesel Engine Turbocharging Laboratory China North Engine Research Institute

The influence of partitioned profiling design based on a large-pitch highly loaded cascade is studied by numerical *** partitioned profile is mainly composed of a pressure-side convex structure near the leading edge and a suction-side convex structure at the midstream and downstream sides of the *** influence of the change in the vertex axial position and peak value of the B-line on the secondary flow control is *** this paper,air(ideal gas) is selected as the flow *** average static pressure at the outlet and the average total temperature at the inlet are kept *** γ-θ is used as the turbulence *** results show that the pressure-side convex structure suppresses the spanwise and pitchwise migration of the inlet flow by adjusting the static pressure distribution of the flow field,so the development of the pressure-side leg of the horseshoe vortex is effectively *** suction-side convex structure adjusts the static pressure distribution of the flow field and increases the included angle between the cross-flow and suction surface,so the accumulation of low-momentum fluid,the development of a corner vortex and the flow separation at the trailing edge of the suction-side surface are all suppressed near the endwall-suction ***,the energy loss coefficient of the large-pitch highly loaded cascade is decreased from 0.0564 to 0.0485,representing a 25% reduction in secondary flow losses.

关键词： Vortex flow

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