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Crystal structure of Arabidopsis thaliana HPPK/DHPS,a bifunctional enzyme and target of the herbicide asulam

Plant Communications 2022年第4期3卷 137-149页

作者： Grishma Vadlamani Kirill V.Sukhoverkov joel Haywood karen j.breese Mark F.Fisher Keith A.Stubbs Charles S.Bond joshua S.Mylne School of Molecular Sciences The University of Western Australia35 Stirling HighwayCrawleyWA 6009Australia The ARC Centre of Excellence in Plant Energy Biology The University of Western Australia35 Stirling HighwayCrawleyWA 6009Australia Centre for Crop and Disease Management School of Molecular and Life SciencesCurtin UniversityBentleyWA 6102Australia

Herbicides are vital formodern agriculture,but their utility is threatened by genetic or metabolic resistance in weeds,as well as regulatory *** the known herbicide modes of action,7,8-dihydropterin synthase(DHPS),which is involved in folate biosynthesis,is targeted by just one commercial herbicide,asulam.A mimic of the substrate para-aminobenzoic acid,asulam is chemically similar to sulfonamide antibiotics,and although it is still in widespread use,asulam has faced regulatory *** an entire mode of action represented by just one commercial agrochemical,we sought to improve the understanding of its plant *** we solve a 2.3A°resolution crystal structure for Arabidopsis thaliana DHPS that is conjoined to 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase(HPPK),and we reveal a strong structural conservation with bacterial counterparts at the sulfonamide-bindingpocket of *** demonstrate that asulamand the antibiotic sulfamethoxazole have herbicidal as well as antibacterial activity,andwe explore the structural basis of their potency by modeling these compounds in mitochondrial HPPK/*** findings suggest limited opportunity for the rational design of plant selectivity fromasulamand indicate that pharmacokinetic or delivery differences between plants andmicrobesmight be the bestways to safeguard thismode of action.

关键词： structural biology folate metabolism mode of action

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Role of complex organic arsenicals in food in aggregate exposure to arsenic

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journal of Environmental Sciences 2016年第11期28卷 86-96页

作者： David j.Thomas karen Bradham Pharmacokinetics Branch Integrated Systems Toxicology Division National Health and Environmental Effects Research Laboratory Offilce of Research and Development U.S. Environmental Protection Agency Research Triangle Parle NC 27709 USA Public Health Chemistry Branch Exposure Methods and Measurements Division National Exposure Research Laboratory Offilce of Researchand Development U.S. Environmental Protection Agency Research Triangle Park NC 27709 USA

For much of the world＇s population, food is the major source of exposure to *** to this non-essential metalloid at relatively low levels may be linked to a wide range of adverse health effects. Thus, evaluating foods as sources of exposure to arsenic is important in assessing risk and developing strategies that protect public health. Although most emphasis has been placed on inorganic arsenic as human carcinogen and toxicant, an array of arsenic-containing species are found in plants and animals used as foods. Here,we 2evaluate the contribution of complex organic arsenicals（arsenosugars, arsenolipids,and trimethylarsonium compounds） that are found in foods and consider their origins,metabolism, and potential toxicity. Commonalities in the metabolism of arsenosugars and arsenolipids lead to the production of di-methylated arsenicals which are known to exert many toxic effects. Evaluating foods as sources of exposure to these complex organic arsenicals and understanding the formation of reactive metabolites may be critical in assessing their contribution to aggregate exposure to arsenic.

关键词： Arsenic Arsenobetaine Arsenolipids Arsenosugars

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Dyeing of Polypropylene Fibers with Vat Dyes

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journal of Donghua University(English Edition) 2006年第5期23卷 15-19页

作者：刘航 ETTERS j . Nolan LEONAS karen K Department of Textiles Merchandising & Interiors University of Georgia Athens Georgia 30605 USA

Polypropylene fibers have been extensively used in a variety of/products, including carpets and upholstery, due to their non-absorbency, good weather resistance, good resistance to macroorgamsms and so on. Because of their hydrophobic and highly crystalline nature, those well-established conventionai dyeing processes are difficult to apply to unmodified polypropylene. Colors of polypropylene fibers are primarily obtained by mass coloration which has the disadvantages of limited number of colors available and difficulties in inventory control due to the rapidly changing color needs of the market. In this paper, the use of vat dyes to dye polypropylene fabrics is investigated. Seventeen vat dyes were screened and factors influencing uptake of dyes by polypropylene fabrics were studied.

关键词： pol ypropylene vat dye leuco acid vat dye.

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Cichlid fish visual systems: mechanisms of spectral tuning

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Integrative Zoology 2009年第1期4卷 75-86页

作者： karen CARLETON Department of Biology University of MarylandCollege ParkUSA

Hundreds of species of cichlid fishes have evolved in the Great Lakes of *** colorful fishes are known for their ecological ***,we discuss the diversity of their visual *** have seven unique cone opsin genes,which produce visual pigments sensitive from the ultraviolet to the red end of the *** species typically express three visual pigments to produce a trichromatic visual *** species differ in which sets of opsin genes they express,visual sensitivities can differ *** addition to the large visual pigment shifts from changing gene expression,cichlids can also more finely tune visual pigments through altera-tions in opsin amino acid *** of these tuning mechanisms likely play an important role in cichlid ecology and could contribute to the evolution of cichlid diversity through speciation.

关键词： cichlid fish opsin gene vision visual pigments.

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Informal Caregiving and Disaster Risk Reduction:A Scoping Review

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International journal of Disaster Risk Science 2021年第2期12卷 169-187页

作者： Christina j.Pickering Maya Dancey karen Paik Tracey O’Sullivan Interdisciplinary School of Health Sciences University of OttawaOttawa KIN 6N5Canada EnRiCH Research Lab University of OttawaOttawa KIN 6N5Canada Telfer School of Management University of OttawaOttawa KIN 6N5Canada

Informal caregivers are a population currently in the shadows of disaster risk reduction(DRR),and yet essential to the provision of healthcare *** scoping review explored the literature to understand issues related to informal caregiving and promising practices to support resilience for *** guidelines for scoping review as outlined by Tricco et al.(2016),relevant publications were identified from five major databases—Medline,Embase,PubMed,Web of Science,and *** studies referenced informal caregiving and disasters for a variety of population groups including children,people with disabilities or chronic illnesses,and older *** were excluded if they discussed formal caregiving services(for example,nursing),lacked relevance to disasters,or had insufficient discussion of informal ***,21 articles met the inclusion criteria and were fully *** themes were identified:(1)the need for education and training in DRR;(2)stressors around medication and supply issues;(3)factors affecting the decision-making process in a disaster;(4)barriers leading to disaster-related problems;and(5)factors promoting *** areas of strategic action and knowledge gaps are *** informal caregivers do not feel adequately prepared for *** the important role of informal caregivers in healthcare provision,preparedness strategies are essential to support community resilience for those requiring personal care *** understanding and mobilizing assets to support the resilience of informal caregivers,we also support the resilience of the greater healthcare system and the community,in disaster contexts.

关键词： Caregiving Disaster resilience Disaster risk reduction Healthcare Informal caregiving

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Enzymatic and chemo-enzymatic strategies to produce highly valuable chiral amines from biomass with ω-transaminases on 2D zeolites

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National Science Review 2022年第9期9卷 10-18页

作者： j.Miguel Carceller karen S.Arias Maria j.Climent Sara Iborra Avelino Corma Instituto de Tecnologia Química (UPV-CSIC) Universitat Politècnica de València

Amino transaminases(ATAs) have been supported on a 2D ITQ-2 zeolite through electrostatic interactions, resulting in a highly stable active biocatalyst to obtain a variety of valuable chiral amines starting from prochiral ketones derived from biomass. We have extended the biocatalyst applications by designing a chemo-enzymatic process that allows, as the first step, prochiral ketones to be obtained from biomass-derived compounds through an aldol condensation–reduction step using a bifunctional metal/base catalyst. The prochiral ketone is subsequently converted into the chiral amine using the immobilized ATA. We show that it is feasible to couple both steps in a semi-continuous process to produce industrially relevant chiral amines with yields of >95% and ～100% enantiomer excess.

关键词： amino transaminase ITQ-2 zeolite chemo-enzymatic process biomass semi-continuous process Pd/MgO

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Potential for natural and enhanced attenuation of sulphanilamide in a contaminated chalk aquifer

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journal of Environmental Sciences 2017年第12期29卷 39-48页

作者： karen A.Bennett Simon D.Kelly Xiangyu Tang Brian j.Reid School of Environmental Sciences University of East AngliaNorwich Research ParkNorwich NR4 7TJUK Food and Environmental Protection Laboratory International Atomic Energy Agency1400 ViennaAustria Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academyof SciencesChengdu 610041China

Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry（IRMS）method was developed to evaluate the extent of biodegradation of the antibiotic,sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ^（13）C of8.44‰ from-26.56（at the contaminant source） to-18.12‰（300 m downfield of the source）.These results confirm reductions in sulphanilamide concentrations（from 650 to 10 mg/L）across the contaminant plume to be attributable to biodegradation（56%） vs. other natural attenuation processes, such as dilution or dispersion（42%）. To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity（~50% mineralisation） to degrade sulphanilamide under high（263 mg/L）, moderate（10 mg/L） and low（0.02 mg/L） substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions.

关键词： Antibiotics Sulphonamide Groundwater contamination Biodegradation Stable isotope fractionation IRMS

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Sexual audience affects male's reproduction investment without consequences on reproductive outputs

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Insect Science 2022年第4期29卷 1170-1180页

作者： Philippe Louâpre karen Muller Soline Bettencourt-Amarante Denis Thiery jérôme Moreau UMR CNRS 6282 Biogeosciences UniversitéBourgogne Franche-ComtéDijonFrance INRA UMR 1065 Santéet Agroecologie du Vignoble Institut des Science de la Vigne et du VinVillenave d'OrnonCedexFrance INRA UMR 1065 SaveUniversitéde BordeauxBordeaux Sciences AgroVillenave d'OrnonCedexFrance

Males evolved plastic strategies to respond to male-male competition and exhibit adaptive traits and behaviors maximizing their access to the females and limiting sperm *** behaviors allow males to express quick responses to current sexual audience,that is,the number of nearby conspecifics prone to *** contrast,physiological responses are frequently delayed because they are constrained by the time and resources having to be mobilized to produce and export sperm and associated *** is especially critical in species for which males produce *** we investigated in what extend moth males(the tortricid moth Lobesia botrana)producing spermatophores exhibit plastic behavioral and physiological responses to different sexual audiences before and during mating and the consequences for their reproductive *** found that males adjusted their mating behaviors and spermatophore size to a potentially elevated risk of sperm competition perceived before *** addition,males responded to the closed presence of females during mating by reducing their mating ***,the various behavioral and physiological responses we highlighted here were not fully reflected in their reproductive performance as we did not reveal any effect on fecundity and fertility of their *** selective pressure exerted on males experiencing male-male competition could thus be sufficient to trigger adjustment in male mating behaviors but constrains physiological responses according to the perception of competition.

关键词： Lobesia borrund male-male compeition mating behavior sexual conflict sexual scletion sperm competition

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Rereading East Germany

Rereading East Germany

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作者： Leeder karen j.

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A critical review of national physical activity policies relating to children and young people in England

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journal of Sport and Health Science 2021年第3期10卷 255-262,F0003页

作者： Anna Chalkley karen Milton School of Sport Exercise and Health SciencesLoughborough UniversityLoughborough LE113TUUK Norwich Medical School University of East AngliaNorwich NR47TJUK

Background:There has been an increasing focus on the importance of national policy to address population levels of physical *** has been suggested that the 4 cornerstones of policy comprise(1)national guidelines on physical activity(PA),(2)setting population goals and targets,(3)surveillance or health-monitoring systems,and(4)public *** current study aimed to review the policy actions that have addressed each of these elements for children and youth in England and to identify areas of progress and remaining ***:A literature search was undertaken to identify past and present documents relevant to PA policy for children and youth in *** document was analyzed to identify content relevant to the 4 cornerstones of ***:Physical activity guidelines(Cornerstone 1)for children and youth have been in place since 1998 and reviewed *** activity targets(Cornerstone 2)have focussed on the provision of opportunities for PA,mainly through physical education in schools rather than in relation to the proportion of children meeting recommended PA *** has been much surveillance(Cornerstone 3)of children’s PA,but this has been undertaken infrequently over time and with varying inclusions of differing domains of *** has been only 1 campaign(Cornerstone 4)that targeted children and their intermediaries,Change4Life,which was an obesity campaign focussing on dietary behavior in combination with *** recently,a government infographic supporting the PA guidelines for children and young people was developed,but details of its dissemination and usage are ***:There have been many developments in national PA policy in England targeted to children and young *** area of most significant progress is national PA *** prevalence targets,streamlining surveillance systems,and investing in public education with supportive policies,environments,and opportunities would st

关键词： Physical activity Policy Public education Recommendations Surveillance

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