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Reduction of Cancer Risk With an Oral Supplement of Selenium

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Biomedical and Environmental Sciences 1997年第2期10卷 227-234页

作者： G·F·COMBSJR L·C·clark 等 DivisionofNutritionalSciencesandSchoolofOperationsResearch CornellUniversityIthacaNY ArizonaCancerC

The hypothesis that a dietary Supplement of selenium (Se) may reduce cancer risk was tested experimetally in humans. Patients with histories of basal/squarnous cell carcinomas of the skin were assigned randomly in double-blind fashion to dally oral supplements of either Seenriched yeast (200 μg Se/day), or a low-Se yeast placebo. A total of 1312 patients recruited in 1983-1990 were followed with regular dermatologic examinations through 1993 for a total of 8269 person-years of observation. Skin cancer diagnoses were confirmed *** Se concentration was determined at 6-12 months intervals. All deaths and patient-reported illnesses were recorded; reported cancers were confirmed and documented by consultation with the patient medical care providers. The results indicate that Se did not significantly affect the primary endpoints: incidences of recurrent basal/squarnous cell carcinomas of the skin. However, Setreatment was associated with reductions in several secondary endpoints:total mortality, mortality from all cancers combined, as well as the incidence of all cancers combined, lung cancer, colorectal cancer and prostate cancer. The consistencies of these associations over time, between study clinics and for the leading cancer sltes strongly suggests benefits of Se-supplementation for this cohort of patients, supporting the hypopthesis that supplemental Se can reduce cancer risk. Although Se did no shown protective effects against nonmelanoma skin cancers, the suggested reductions in risks to other frequent cancers demand further evaluation in well controlled cliflical intervention trials

关键词： In SCC Reduction of Cancer Risk With an Oral Supplement of Selenium BCC

Free Play and"Loving Care":A Qualitative Inquiry of Chinese Kindergarten Teachers' Professional Ethics

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ECNU Review of Education 2022年第4期5卷 664-682页

作者： Jie Zhang Mollie R.clark Yeh Hsueh Faculty of Education East China Normal University3663 North Zhongshan RoadShanghai 200062China The University of Memphis

Purpose:Chinese kindergarten teachers commonly held"loving and caring for young children"as a core professional ethic,but many reported fatigue and burnout because of this ethical *** study presents a unique account of how children's free play has helped transform teachers'professional ethics and increased their professional ***/Approach/Methods:Followinga purposivesampling,we interviewed eight Chinese teachers who actively promoted children's free *** analysis of the interview transcripts led to an in-depth interpretation of the teachers'experiences through a dialogue with various concepts and ***:A major finding was that children's free play facilitated the change in teachers'understandings of their professional *** observation and support of children's free play brought them the unprecedented joy of teaching,which helped them redefine loving and caring for children andgave risetoa new codeof professional ethics.

关键词： Free play kindergarten teachers'professional development professional ethics the ethic of loving care

Seeing through the magnetite:Reassessing Eoarchean atmosphere composition from Isua(Greenland) ≥3.7 Ga banded iron formations

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Geoscience Frontiers 2017年第6期8卷 1233-1240页

作者： Allen P.Nutman Vickie C.Bennett clark R.L.Friend GeoQuEST Research Centre School of Earth and Environmental SciencesUniversity of WollongongWollongongNSW 2522Australia Research School of Earth Sciences Australian National UniversityCanberraACT 0200Australia Glendale TiddingtonOxonOX9 2LQUK

Estimates of early atmosphere compositions from metamorphosed banded iron formations(BIFs)including the well-studied ≥3.7 BIFs of the Isua supracrustal belt(Greenland)are dependent on knowledge of primary versus secondary Fe-mineralogical *** new observations from locally well preserved domains,we interpret that a previously assumed primary redox indicator mineral,magnetite,is secondary after sedimentary Fe-clays(probably greenalite)±*** ~3.7 Ga Isua BIF,pre-tectonic nodules of quartz+Fe-rich amphibole±calcite reside in a finegrained(≤100 μm)quartz+magnetite *** interpret the Isua nodule amphibole as the metamorphosed equivalent of primary Fe-rich clays,armoured from diagenetic oxidative reactions by early silica ***,in another low strain lacunae,~3.76 Ga BIF layering is not solid magnetite but instead fine-grained magnetite+quartz *** magnetite+quartz aggregates are interpreted as the metamorphosed equivalent of Fe-clay-rich layers that were oxidised during diagenesis,because they were not armoured by early *** almost all Isua BIF exposures,this evidence has been destroyed by strong ductile *** Fe-clays likely formed by abiotic reactions between aqueous Fe^(2+)and *** clays along with silica±carbonate were deposited below an oceanic Fe-chemocline as the sedimentary precursors of *** of the clays on the sea floor may have been by anaerobic oxidation of Fe^(2+),a mechanism compatible with iron isotopic data previously published on these *** new determinations of the primary redoxsensitive Fe-mineralogy of BIF significantly revise estimates of early Earth atmospheric oxygen and CO_2 content,with formation of protolith Fe-rich clays and carbonates compatible with an anoxic Eoarchean atmosphere with much higher CO_2 levels than previously estimated for Isua and in the present-day atmosphere.

关键词： Banded iron formation Eoarchean Early atmosphere Greenalite Magnetite

The First Stegosaur (Dinosauria, Ornithischia) from the Upper Jurassic Shishugou Formation of Xinjiang, China

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Acta Geologica Sinica(English Edition) 2007年第3期81卷 351-356页

作者： JIA Chengkai Catherine A. FOSTER XU Xing James M. clark Institute of Vertebrate Paleontology Paleoanthropology Chinese Academy of Sciences Beijing 100044 China Research Institute of Exploration and Development Xinjiang Oilfield Company Karamay Xinjiang 834000 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China Department of Anatomical Sciences Stony Brook University Stony Brook New York 11794 USA Department of Biological Sciences George Washington University Washington DC 20052 USA

A new stegosaur species, Jiangjunosaurusjunggarensis, gen. et sp. nov., is erected based on a specimen collected from the Upper Jurassic upper section of the Shishugou Formation in the Junggar Basin, Xinjiang, China. It represents the first stegosaur from the Jurassic of Xinjiang and increases the diversity of the dinosaur fauna in the Shishugou Formation. The new genus is characterized by symmetrical and proportionally wide tooth crowns, a sub-rectangular axial neural spine seen in lateral view, and large openings on the lateral surfaces of the cervical centra. A preliminary character analysis suggests that this new taxon is more derived than the Middle Jurassic stegosaur Huayangosaurus but more primitive than most other known stegosaur species.

关键词： Dinosauria Stegosauria Upper Jurassic Shishugou Formation Xinjiang

Neurolemma-Injected Xenopus Oocytes: An Innovative Ex Vivo Approach to Study the Effects of Pyrethroids on Ion Channels in Their Native State

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Engineering 2020年第5期6卷 515-521页

作者： John clark Steve Symington University of Massachusetts AmherstMA 01003USA Salve Regina University NewportRI 02840USA

Microtransplantation of rat brain neurolemma into the plasma membrane of Xenopus laevis oocytes is an ex vivo method used to study channels and receptors in their native state using standard electrophysiological *** this review,we show that oocytes injected with adult rat brain neurolemma elicited tetrodotoxin-sensitive inward ion currents upon membrane depolarization,which were increased in a concentration-dependent manner by treatment with the pyrethroid insecticides permethrin and *** our initial protocols,oocyte health was reduced over time and neurolemma incorporation varied between batches of oocytes from different frogs,limiting the usefulness of the assay for regulatory issues.A collection of changes to the assay procedure,data acceptance criteria,and analysis method yield substantially improved precision and,hence,assay *** changes established this ex vivo approach as a toxicologically relevant assay to study the toxicodynamic action of pyrethroids on ion channels in their native state using neurolemma fragments prepared from juvenile and adult rat brains.

关键词： Microtransplantation Pyrethroids Rat brain neurolemma Toxicodynamics Voltage-sensitive sodum channels Xenopus laevis

Quantitative characterization of polyacrylamide–shale interaction under various saline conditions

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Petroleum Science 2017年第3期14卷 586-596页

作者： Samyukta Koteeswaran Jack C.Pashin Josh D.Ramsey Peter E.clark School of Chemical Engineering Oklahoma State UniversityStillwater OK 74078 USA Boone Pickens School of Geology Oklahoma State University Stillwater OK 74078 USA

Interaction of polymer-containing injected fluids with shale is a widely studied phenomenon, but much is still unknown about the interaction of charged polyacrylamides such as anionic and cationic polyacrylamides with shale. The nature of interaction of charged polyacrylamides with shale is not well understood, especially from the perspective of assessing the potential for polyacrylamides to cause formation damage. Zeta potential and rheological measurements were made for Chattanooga and Pride Mountain shales suspended in polyacrylamide solutions with and without inorganic salts and tetramethyl ammonium chloride（TMAC）. The change in zeta potential and viscosity with time was recorded. The magnitude of decrease in the absolute value of zeta potential with time is indicative of adsorption of polymer on the surface of shale and serves as a measure of the extent of polymer interaction with shale. The salts that were used in this study are potassium chloride（KCl）, sodium chloride（Na Cl）. This study quantified the interaction of anionic and cationic polyacrylamide with different North American *** the experimental results, it was determined that the polyacrylamides can interact strongly with shale, particularly the cationic polyacrylamide. The objective of this study was to determine the extent of interaction of anionic and cationic polyacrylamide with each shale sample in the presence of additives such as salts.

关键词： Anionic and cationic polyacrylamides Chattanooga shale Pride Mountain shale Zeta potentialSlurry rheology

Surface-bound myeloperoxidase is a ligand for recognition of late apoptotic neutrophils by human lung surfactant proteins A and D

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Protein & Cell 2010年第6期1卷 563-572页

作者： Anne Jäkel Howard clark Kenneth B.M.Reid Robert B.Sim Department of Pharmacology University of OxfordMansfield RoadOxford OX13QTUK University of Southampton School of MedicineDivision of Infection Inflammation&ImmunitySouthampton General HospitalSouthampton SO166YDUK MRC Immunochemistry Unit Department of BiochemistryUniversity of OxfordSouth Parks RoadOxford OX13QUUK

Surfactant proteins A(SP-A)and D(SP-D),both members of the collectin family,play a well established role in apoptotic cell recognition and *** in vitro data show that SP-A and SP-D interact with apoptotic neutrophils in a distinct ***-A and SP-D bind in a Ca^(2+)-dependent manner to viable and early apoptotic neutrophils whereas the much greater interaction with late apoptotic neutrophils is Ca^(2+)-*** surface molecules on the apoptotic target cells responsible for these interactions had not been identified and this study was done to find candidate target ***(MPO),a specific intracellular defense molecule of neutrophils that becomes exposed on the outside of the cell upon apoptosis,was identified by affinity purification,mass-spectrometry and western blotting as a novel binding molecule for SP-A and *** confirm its role in recognition,it was shown that purified immobilised MPO binds SP-A and SP-D,and that MPO is surface-exposed on late apoptotic ***-A and SP-D inhibit binding of an anti-MPO monoclonal Ab to late apoptotic *** microscopy confirmed that anti-MPO mAb and SP-A/SP-D colocalise on late apoptotic *** was identified as a further potential ligand for SP-A,and neutrophil defensin as a target for both proteins.

关键词： SP-A SP-D myeloperoxidase neutrophils flow cytometry mass spectrometry

Insights into the efficiency and stability of Cu-based nanowires for electrocatalytic oxygen evolution

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Nano Research 2018年第8期11卷 4323-4332页

作者： Jun Yu Qi Cao Bin Feng Changli Li Jingyuan Liu J. Kenji clark Jean-Jacques Delaunay Department of Mechanical Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan Institute of Engineering Innovation The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan School of Materials Science and Engineering Tsinghua University Beijing 100084 China Department of Chemical System Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan

Copper oxide nanowires with varying oxidation states are prepared and their activity for water oxidation is studied. The nanowires with a CuO phase are found to be the most active, and their degree of crystallinity is important in achieving efficient water oxidation. For the crystalline CuO nanowires in a weakly basic Na2CO3 electrolyte, a Tafel slope of 41 mV/decade, an overpotential of approximately 500 mV at - 10 mA/crn2 （without compensation for the solution resistance）, and a faradaic efficiency of nearly 100% are obtained. This electrode maintains a stable current for over 15 lx The low overpotential of 500 mV at 10 mA/cm2, small Tafel slope, long-term stability, and low cost make CuO one of the most promising catalysts for water oxidation. Moreover, the evolution of the CuO nanowire morphology over time is studied by electron microscop）-revealing that the diffusion of Cu ions from the interior of the nanowires to their surface causes the aggregation of individual nanowires over time. However, despite this aggregation, the current density remains nearly constant, because the total electrochemically active surface area of CuO does not change.

关键词： oxygen evolution reaction crystalline CuO active phase copper ion diffusion

Diverse plant mixtures sustain a greater arbuscular mycorrhizal fungi spore viability than monocultures after 12 years

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Journal of Plant Ecology 2020年第4期13卷 478-488页

作者： Peter Dietrich Christiane Roscher Adam Thomas clark Nico Eisenhauer Bernhard Schmid Cameron Wagg Institute of Ecology and Evolution Friedrich-Schiller-University JenaDornburger Strasse 15907743 JenaGermany Department of Evolutionary Biology and Environmental Studies University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland Department of Physiological Diversity UFZHelmholtz Centre for Environmental ResearchPermoserstrasse 1504318 LeipzigGermany German Centre of Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig Deutscher Platz 5e04103 LeipzigGermany Institute of Biology Leipzig UniversityDeutscher Platz 5e04103 LeipzigGermany Department of Geography University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland Fredericton Research and Development Center Agriculture and Agri-Food Canada850 Lincoln RoadFrederictonNew Brunswick E3B 1P9Canada

Aims Intensive land management practices can compromise soil biodiversity,thus jeopardizing long-term soil *** mycorrhizal fungi(AMF)play a pivotal role in promoting soil productivity through obligate symbiotic associations with ***,it is not clear how properties of plant communities,especially species richness and composition influence the viability of AMF populations in *** Here we test whether monocultures of eight plant species from different plant functional groups,or a diverse mixture of plant species,maintain more viable AMF *** address this question,we extracted AMF spores from 12-year old plant monocultures and mixtures and paired single AMF spores with single plants in a factorial design crossing AMF spore origin with plant species *** Findings AMF spores from diverse plant mixtures were more successful at colonizing multiple plant species and plant individuals than AMF spores from plant ***,we found evidence that AMF spores originating from diverse mixtures more strongly increased biomass than AMF from monocultures in the legume Trifolium repens *** viability and ability to interact with many plant species were greater when AMF spores originated from 12-year old mixtures than *** results show for the first time that diverse plant communities can sustain AMF viability in soils and demonstrate the potential of diverse plant communities to maintain viable AMF propagules that are a key component to soil health and productivity.

关键词： aboveground–belowground interactions biodiversity biomass production mutualism plant–AMF interaction root colonization