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Carbon,Nitrogen,and Sulfur Contents in Marine Phytoplankton Cells and Biomass Conversion

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Journal of Ocean University of China 2023年第3期22卷 851-862页

作者： chen wenqing YANG Shimin SHANG Jie WANG Jinwen College of Marine Life Sciences Ocean University of ChinaQingdao 266100China North China Sea Marine Forecasting Center of SOA Qingdao 266102China

In this study,we isolated and cultured phytoplankton along the coast of China and measured the cellular carbon,nitrogen,and sulfur contents under four *** results showed that the contents of the cellular elements varied widely among different *** found that temperature is one of the important factors affecting the carbon,nitrogen,and sulfur contents in phytoplankton cells;however,the degree of influence of temperature is different for different kinds of *** measuring the nitrogen content in cells,we found that the C:N ratio indirectly measured in the experiment fluctuated in the range of 3.50-8.97,and the average C:N ratio was *** this experiment,we accurately measured the cell elemental contents at different temperatures and transformed the cell count results into carbon,nitrogen,and sulfur contents to express the *** method ensures that the contribution of species that are small in number but with a large cell volume in biomass is ***,this method comprehensively considers the interspecific differences of species and the uneven distribution of elements in phytoplankton cells,which is of significance in the estimation of marine carbon and nitrogen *** distribution of nitrogen content in marine phytoplankton can well indicate the marine eutrophication caused by human *** change can affect the community structure and element composition of marine phytoplankton,meanwhile marine carbon and nitrogen element can regulate the climate to a certain extent.

关键词： phytoplankton temperature gradient carbon element nitrogen element sulfur element element content distribution

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Stabilization of hexavalent chromium with pretreatment and high temperature sintering in highly contaminated soil

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Frontiers of Environmental Science & Engineering 2021年第4期15卷 169-181页

作者： Haiyan Mou Wenchao Liu Lili Zhao wenqing chen Tianqi Ao College of Architecture and Environment Sichuan UniversityChengdu610065China Wuhan Economic&Technological Development Zone(Hannan)Urban Administration Bureau Wuhan430056China Geological Brigade of Sichuan Bureau of Geology&Mineral Resources Geological Chengdu611830China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China

This study explored the effectiveness and mechanisms of high temperature sintering following prereduction with ferric sulfate(FeSO_(4)),sodium sulfide(Na_(2)S),or citric acid(C_(6)H_(8)O_(7))in stabilizing hexavalent chromium(Cr(VI))in highly contaminated *** soil samples had an initial total Cr leaching of 1768.83 mg/L,and Cr(VI)leaching of 1745.13 mg/*** FeSO_(4)or C_(6)H_(8)O_(7)reduction was followed by sintering at 1000℃,the Cr leaching was reduced enough to meet the Safety Landfill Standards regarding general industrial solid *** combined treatment greatly improved the stabilization efficiency of chromium because the reduction of Cr(VI)into Cr(III)decreased the mobility of chromium and made it more easily encapsulated in minerals during ***,XRD,TG-DSC,and speciation analysis indicated that when the sintering temperature reached 1000℃,almost all the chromium in soils that had the pre-reduction treatment was transformed into the residual *** 1000℃,the soil melted and promoted the mineralization of Cr and the formation of new Cr-containing compounds,which significantly decreased subsequent leaching of chromium from the ***,without reduction treatment,chromium continued to leach from the soil even after being sintered at 1000℃,possibly because the soil did not fully fuse and because Cr(VI)does not bind with soil as easily as Cr(III).

关键词： Chromium Heavy contaminated soil Reduction Sintering Stabilization Speciation

Preparation and physicochemical effects of zein nanofiber membrane encapsulated with citral/HP-β-CD inclusion complex and its application on cheese

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Food Bioscience 2022年第6期50卷 107-117页

作者： chen Shen wenqing chen Changzhu Li Yong Ye Haiying Cui Lin Lin School of Food and Biological Engineering Jiangsu UniversityZhenjiang212013China State Key Laboratory of Utilization of Woody Oil Resource Hunan Academy of ForestryChangsha410007China School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou510640China

As a nutritious cold chain food,cheese is susceptible to Listeria monocytogenes *** order to prevent and control Listeria monocytogenes in cheese safely and efficiently,maintain the sensory quality during sale,this paper developed a novel nanofiber membrane with good mechanical strength,hydrophobicity,thermal stability,release performance and bacteriostatic performance as food active *** this study,zein was introduced and electrospun to form a reliable carrier to embed and deliver citral in the cavity of HP-β-CD(Hydroxypropyl-β-cyclodextrin).We found that the zein-based nanofiber membranes showed preferable tensile properties and hydrophobicity with 4%(w:v)addition of citral/HP-β-CD inclusion ***,the thermal stability and release property of citral were significantly improved by embedding in HP-β-CD and loading into zein-base nanofiber ***,after packaged by Zein nanofiber membrane encapsulated with citral/HP-β-CD inclusion complex under the storage conditions of 4°C and 12°C,the growth of Listeria monocytogenes in four kinds of cheeses was inhibited to a certain *** texture and sensory quality of the four cheeses at the two temperatures and the color quality under the low temperature condition of 4°C did not change *** summary,Zein nanofiber membranes encapsulated with citral/HP-β-CD inclusion complex has potential application prospects in the field of food active packaging.

关键词： Zein Citral Hydroxypropyl-β-cyclodextrin Nanofiber membranes Hybrid electrospinning

An unusual UMP C-5 methylase in nucleoside antibiotic polyoxin biosynthesis

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Protein & Cell 2016年第9期7卷 673-683页

作者： wenqing chen Yan Li Jie Li Lian Wu Renxiao Wang Zixin Deng Jiahai Zhou Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education and School of Pharmaceutical Sciences Wuhan University Wuhan 430071 China State Key Laboratory of Bioorganic and Natural Products Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology Shanghai Jiao Tong University Shanghai 200030 China

Polyoxin is a group of structurally-related peptidyl nucleoside antibiotics bearing C-5 modifications on the nucleoside skeleton. Although the structural diversity and bioactivity preference of polyoxin are, to some extent, affected by such modifications, the biosynthetic logic for their occurence remains obscure. Here we report the identification of PolB in polyoxin pathway as an unusual UMP C-5 methylase with thymidylate syn- thase activity which is responsible for the C-5 methyla- tion of the nucleoside skeleton. To probe its molecular mechanism, we determined the crystal structures of PolB alone and in complexes with 5-Br UMP and 5-Br dUMP at 2.15 A, 1.76 A and 2.28 A resolutions, respec- tively. Loop 1 （residues 117-131）, Loop 2 （residues 192- 201） and the substrate recognition peptide （residues 94- 102） of PolB exhibit considerable conformational flexi-bility and adopt distinct structures upon binding to different substrate analogs. Consistent with the structural findings, a PolB homolog that harbors an identical function from Streptomyces viridochromogenes DSM 40736 was identified. The discovery of UMP C5-methy-lase opens the way to rational pathway engineering for polyoxin component optimization, and will also enrich the toolbox for natural nucleotide chemistry.

关键词： polyoxin nucleoside antibiotics,biosynthesis UMP C5-methylase thymidylate synthase

An Analysis of Government Interventions in Addressing Market Failures Caused by Non- Excludable and Non-Rivalrous Public Goods Based on COVID-19 Vaccination Cases

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Proceedings of Business and Economic Studies 2021年第5期4卷 89-92页

作者： wenqing chen University of Birmingham Birmingham B152TTUnited Kingdom

The non-excludable and non-rivalrous characteristics of public goods distinguish them from private *** existence of these two characteristics leads to the 详细信息

The non-excludable and non-rivalrous characteristics of public goods distinguish them from private *** existence of these two characteristics leads to the

关键词： Public goods Free rider Non-excludable Non-rival

Characterization of the tunicamycin gene cluster unveiling unique steps involved in its biosynthesis

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Protein & Cell 2010年第12期1卷 1093-1105页

作者： wenqing chen Dongjing Qu Lipeng Zhai Meifeng Tao Yemin Wang Shuangjun Lin Neil P.J.Price Zixin Deng Laboratory of Microbial Metabolism and School of Life Sciences&BiotechnologyShanghai Jiao Tong UniversityShanghai 200030China National Center for Agricultural Utilization Research(NCAUR) USDA-ARS1815 North University StreetPeoriaIllinois 61604USA College of Pharmacy Wuhan UniversityWuhan 430072China

Tunicamycin,a potent reversible translocase I inhibitor,is produced by several Actinomycetes *** tunicamycin structure is highly unusual,and contains an 11-carbon dialdose sugar and anα,β-1″,11′-glycosidic *** we report the identification of a gene cluster essential for tunicamycin biosynthesis by high-throughput heterologous expression(HHE)strategy combined with a *** of the genes into heterologous non-producing Streptomyces hosts results in production of tunicamycin by these strains,demonstrating the role of the genes for the biosynthesis of *** disruption experiments coupled with bioinformatic analysis revealed that the tunicamycin gene cluster is minimally composed of 12 genes(tunA–tunL).Amongst these is a putative radical SAM enzyme(Tun B)with a potentially unique role in biosynthetic carbon-carbon bond ***,a seven-step novel pathway is proposed for tunicamycin ***,two gene clusters for the potential biosynthesis of tunicamycin-like antibiotics were also identified in Streptomyces clavuligerus ATCC 27064 and Actinosynnema mirums DSM *** data provide clarification of the novel mechanisms for tunicamycin biosynthesis,and for the generation of new-designer tunicamycin analogs with selective/enhanced bioactivity via combinatorial biosynthesis strategies.

关键词： tunicamycin biosynthetic gene cluster high-throughput heterologous expression bioassay combinatorial biosynthesis

Construction and Application of Interfacial Inorganic Nanostructures

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Chinese Journal of Chemistry 2020年第7期38卷 772-786,I0002页

作者： Rui Wang Yicheng Wei Li An Rui Yang Linchuan Guo Zheng Weng Pengfei Da wenqing chen Jing Jin Jianyi Li Pinxian Xi State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu ProvinceCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhouGansu 730000China

Interfacial nanostructured materials have stimulated extensive interests in the research areas of green energy production and conversion due to their unique structures and *** interfacial crystalline structures with rich intrinsic defects,such as oxygen vacancies,adatoms,grain bounda-ries,and substitutional impurities,have led to unique activities in a variety of catalytic *** rational design and engineering development of the interfaces provide an attractive way to optimize the catalytic performance and finally improve the efficiency of energy conversion and ***,a comprehensive overview of interfacial inorganic nanostructures and their electrocatalytic applications are summarized,and some future challenge and opportunity have also been proposed.

关键词： interfacial attractive summarized

Genesis of the Nuri Cu-W-Mo Deposit,Tibet,China:Constraints from in situ Trace Elements and Sr Isotopic Analysis of Scheelite

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 117-131页

作者： WANG Yiyun WU Zhishan chen wenqing DU Qing’an TANG Liwei SHI Hongzhao MA Guotao ZHANG Zhi LIANG Wei WU Bo MIAO Hengyi chengdu Center China Geological Survey(Geoscience Innovation Center of Southwest China)Chengdu 610081China The Second Geological Institute of China’s Metallurgical Geology Bureau Fuzhou 351111China

The Nuri deposit is the only Cu-W-Mo polymetallic deposit with large-scale WO3 resources in the eastern section of the Gangdese metallogenic belt,Tibet,***,the genetic type of this deposit has been controversial since its *** on a study of the geological characteristics of the deposit,this study presents mineralization stages,focusing on the oxide stage and the quartz-sulfide stage where scheelite is mainly formed,referred to as Sch-A and Sch-B,*** LA-ICP-MS trace element and Sr isotope analyses,the origin,evolutionary process of the oreforming fluid and genesis of the ore deposit are *** Electron Microscope-Cathodoluminescence(SEMCL)observations reveal that Sch-A consists of three generations,with dark gray homogenous Sch-A1 being replaced by relatively lighter and homogeneous Sch-A2 and Sch-A3,with Sch-A2 displaying a gray CL image color with vague and uneven growth bands and Sch-A3 has a light gray CL image color with hardly any growth *** contrast,Sch-B exhibits a‘core-rim’structure,with the core part(Sch-B1)being dark gray and displaying a uniform growth band,while the rim part(Sch-B2)is light gray and *** normalized distribution pattern of rare earth elements in scheelite and Sr isotope data suggest that the early ore-forming fluid in the Nuri deposit originated from granodiorite porphyry and,later on,some country rock material was mixed in,due to strong water-rock *** the O-H isotope data further indicates that the ore-forming fluid in the Nuri deposit originated from magmatic-hydrothermal sources,with contributions from metamorphic water caused by water-rock interaction during the mineralization process,as well as later meteoric *** intense water-rock interaction likely played a crucial role in the precipitation of scheelite,leading to varying Eu anomalies in different generations of scheelite from the oxide stage to the quartz-sulfide stage,while also causing a

关键词： trace elements in situ Sr isotopes tungsten mineralization Gangdese metallogenic belt Tibet

Path Analysis on the Development of Tourism Economy and the Allocation and Management of Resources

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Path Analysis on the Development of Tourism Economy and the ...