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A New X-Ray Tidal Disruption Event Candidate with Fast Variability

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Research in Astronomy and Astrophysics 2022年第5期22卷 28-35页

作者： j.Hampel S.Komossa j.Greiner T.H.Reiprich M.Freyberg T.Erben Argelander-Institut für Astronomie Aufdem Hugel 71D-53121 BonnGermany Max-planck Institut für Radioastronomie Auf dem Hugel 69D-53121 BonnGermany National Astronomical Observatories Chinese Academy of ScienceBeijing 100101China Max-planck Institute für Extraterrestrische physik GieBenbachstrasse 1D-85748 GarchingGermany

During a close encounter between a star and a supermassive black hole,the star can get disrupted by the black hole’s tidal forces,resulting in a tidal disruption event(TDE).The accretion of the star’s material onto the black hole produces strong emission in different wavelength *** we report the discovery with the Roentgen Satellite(ROSAT)of an X-ray-selected transient source in an optically non-active *** the location R.A.:13h31m57s.66 and decl.:-32°43’19".7 a sudden rise in X-ray luminosity by a factor of 8 within 8 days has been ***,a very soft X-ray spectrum with a blackbody temperature kT=0.1 keV and a peak luminosity of at least 1×10^(43)erg s^(-1)suggests a TDE interpretation,and the observed properties are very similar to previously identified soft X-ray(ROSAT)*** optical spectrum taken of the galaxy at the position of RXj133157.6324319.7 six years after the X-ray outburst does not show any emission lines as would be expected from a persistent active galactic *** redshift of the galaxy is determined to be 0.051 based on absorption *** is therefore likely a member of the galaxy cluster *** rise in X-ray luminosity happens within 8 days and thus appears to be fast for such an *** X-ray emission was detected 170 days before and 165 days after the event,and none was detected 25 yr later with the Neil Gehrels Swift *** change in X-ray luminosity is at least a factor of 40.

关键词： accretion-black holes-galaxies-tidal disruption-X-ray sources

Impact of age on transcatheter aortic valve implantation outcomes：a comparison of patients aged≤ 80 years versus patients ＆gt; 80 years

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journal of Geriatric Cardiology 2016年第1期13卷 31-36页

作者： Frank van der Kley philippe j van Rosendael Spyridon Katsanos Vasileios Kamperidis Nina A Marsan Ioannis Karalis Arend de Weger Meindert palmen jeroen j Bax Martin j Schalij Victoria Delgado Heart Lung Center Leiden University Medical Center Leiden the Netherlands

ObjectiveTo investigate the procedural outcomes and the long-term survival of patients undergoing transcatheter aortic valve implantation （TAVI） and compare study results of patients≤ 80 years and patients ＆gt; 80 years *** total of 240 patients treated with TAVI were divided into two groups according to age≤ 80 years （n = 105; 43.8%） and ＆gt; 80 years （n= 135; 56.2%）. The baseline characteristics and the pro-cedural outcomes were compared between these two groups of *** the exception of peripheral artery disease and hypercho-lesterolemia, which were more frequently observed in the older age group, baseline characteristics were comparable between groups. Complica-tion rates did not differ significantly between patients≤ 80 years and patients ＆gt; 80 years. There were no differences in 30-day mortality rates be-tween patients aged≤ 80 years and patients ＆gt; 80 years old （9.5%vs. 7.4%, respectively;p = 0.557）. After a median follow-up of 28 months （in-terquartile range： 16-42 months）, 50 （47.6%） patients aged≤ 80 years died compared to 57 （42%） deaths in the group of patients ＆gt; 80 years old （p= 0.404）.ConclusionThe results of the present single center study showed that age did not significantly impact the outcomes of TAVI.

关键词： Age Survival rate Transcatheter aortic valve implantation

No evidence for a genetic association between female mating preference and male secondary sexual trait in a Lake Victoria cichlid fish

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Current Zoology 2010年第1期56卷 57-64页

作者： Inke van der SLUIjS Ole SEEHAUSEN Tom j.M.Van DOOREN jacques j.M.van ALpHEN Department of Animal Ecology Institute of Biology Leiden University Department of Biology McGill University Institute of Ecology and Evolution University of Bern Department of Fish Ecology & Evolution Centre of Ecology Eawag Swiss Federal Institute for Aquatic Science and TechnologyEvolution & Biogeochemistry

Sexual selection by female mating preference for male nuptial coloration has been suggested as a driving force in the rapid speciation of Lake Victoria cichlid fish. This process could have been facilitated or accelerated by genetic associations between female preference loci and male coloration loci. preferences, as well as coloration, are heritable traits and are probably determined by more than one gene. However, little is known about potential genetic associations between these traits. In turbid water, we found a population that is variable in male nuptial coloration from blue to yellow to red. Males at the extreme ends of the phenotype distribution resemble a reproductively isolated species pair in clear water that has diverged into one species with blue-grey males and one species with bright red males. Females of the turbid water population vary in mating preference coinciding with the male phenotype distribution. For the current study, these females were mated to blue males. We measured the coloration of the sires and male offspring. parents-offspring regression showed that the sires did not affect male offspring coloration, which confirms earlier findings that the blue species breeds true. In contrast, male offspring coloration was determined by the identity of the dams, which suggests that there is heritable variation in male color genes between females. However, we found that mating preferences of the dams were not correlated with male offspring coloration. Thus, there is no evidence for strong genetic linkage between mating preference and the preferred trait in this population [Current Zoology 56 （1）： 57-64 2010].

关键词： Speciation Sexual selection Mate choice Genetic association Cichlid fish Lake Victoria

Magnetic field sensors using arrays of electrospun magnetoelectric janus nanowires

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Microsystems & Nanoengineering 2018年第1期4卷 24-35页

作者： Matthew j.Bauer Xiao Wen prabal Tiwari David p.Arnold jennifer S.Andrew Dept.of Materials Science and Engineering University of FloridaGainesvilleFL 32611-6400USA Dept.of Electrical and Computer Engineering University of FloridaGainesvilleFL 32611-6200USA

The fabrication and characterization of the first magnetoelectric sensors utilizing arrays of janus magnetoelectric composite nanowires composed of barium titanate and cobalt ferrite are *** utilizing magnetoelectric nanowires suspended across electrodes above the substrate,substrate clamping is reduced when compared to layered thin-film architectures;this results in enhanced magnetoelectric *** magnetoelectric nanowires are fabricated by sol–gel electrospinning,and their length is controlled through the electrospinning and calcination *** a directed nanomanufacturing approach,the nanowires are then assembled onto pre-patterned metal electrodes on a silicon substrate using *** this process,functional magnetic field sensors are formed by connecting many nanowires in *** observed magnetic field sensitivity from the parallel array of nanowires is 0.514±.027mV Oe^(−1) at 1 kHz,which translates to a magnetoelectric coefficient of 514±27mV cm^(−1) Oe^(−1).

关键词： nanowires composite utilizing

Murine lung eosinophil activation and chemokine production in allergic airway inflammation

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Cellular & Molecular Immunology 2010年第5期7卷 361-374页

作者： C Edward Rose jr joanne A Lannigan paul Kim james j Lee Shu Man Fu Sun-sang j Sung Division of pulmonary and Critical Care Department of MedicineUniversity of Virginia School of MedicineCharlottesvilleVAUSA Department of Microbiology University of Virginia School of MedicineCharlottesvilleVAUSA Center for Immunity Inflammationand Regenerative Medicine and Division of NephrologyDepartment of MedicineUniversity of Virginia School of MedicineCharlottesvilleVAUSA Division of pulmonary Medicine Department of Biochemistry and Molecular BiologyMayo Clinic ArizonaScottsdaleAZUSA

Eosinophils play important roles in asthma and lung *** models are widely used for assessing the functional significance and mechanistic basis for eosinophil involvements in these ***,little is known about tissue eosinophils in *** addition,little data on eosinophil chemokine production during allergic airway inflammation are *** this study,the properties and functions of homeostatic and activated eosinophils were *** from normal tissues expressed costimulation and adhesion molecules B7-1,B7-2 and ICAM-1 for Ag presentation but little major histocompatibility complex(MHC)class II,and were found to be poor stimulators of T-cell ***,these eosinophils expressed high levels of chemokine mRNA including C10,macrophage inflammatory protein(MIp)-1a,MIp-1c,MIp-2,eotaxin and monocyte chemoattractant protein-5(MCp-5),and produced chemokine *** intracellular chemokines decreased rapidly with concomitant surface marker downregulation upon in vitro culturing consistent with piecemeal *** eosinophils from mice with induced allergic airway inflammation exhibited increased chemokines mRNA expression and chemokines protein production and upregulated MHC class II and CD11c *** were also found to be the predominant producers of the CCR1 ligands CCL6/C10 and CCL9/MIp-1c in inflamed *** production of C10 and MIp-1c correlated with the marked influx of CD11bhigh lung dendritic cells during allergic airway inflammation and the high expression of CCR1 on these dendritic cells(DCs).The study provided baseline information on tissue eosinophils,documented the upregulation of activation markers and chemokine production in activated eosinophils,and indicated that eosinophils were a key chemokine-producing cell type in allergic lung inflammation.

关键词： allergy chemokines eosinophils lung mouse

聚乙烯乙二醇诱导水分亏缺对春小麦分蘖的影响

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国外农学（麦类作物） 1989年第1期 38-40页

作者： D.j.Davidson p.M.Chevalier 肖凯

小麦的分蘖受栽培措施和坏境条件的影响。许多研究表明,干旱可减少小麦的分蘖成穗数。本试验旨在确定在人工控制条件下降低根系周围渗透势对春小麦各级分蘖数的影响。在人工气候室内水培睿小麦品种"Edwall"和"Waverly"。除对照外,用聚... 详细信息

小麦的分蘖受栽培措施和坏境条件的影响。许多研究表明,干旱可减少小麦的分蘖成穗数。本试验旨在确定在人工控制条件下降低根系周围渗透势对春小麦各级分蘖数的影响。在人工气候室内水培睿小麦品种"Edwall"和"Waverly"。除对照外,用聚乙烯乙二醇把培养液的水势维持在—0.1、—0.3和—0.5兆帕三个水平上。在植株营养生长期间测定了它们的分蘖状况、叶面积、植株干物质重量和水分关系。改变根系周围营养液的渗透浓度可推迟分蘖始期,并且使叶面积、干物质、三级和四级分蘖数减少,一级和二级分蘖不受 pEG(聚乙烯乙二醇)处理影响。在播种后40天,pEG 处理植株的水势和渗透势比对照植株负值更大,但二者的压力势则相似。植株通过积累溶质降低渗透势和维持正常的膨压来适应 pEG 诱导的胁迫。适应之后重新开始分蘖,但这时产生的分蘖较小。因此,这种分蘖对渗透胁迫不太敏感,而其后来的营养生长对渗透胁迫则较敏感。

关键词：小麦聚乙烯二醇水分亏缺分蘖

EIS ANALYSIS ON THE ANODIC pROCESS OF ZINC IN AN ALKALINE SOLUTION

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Acta Metallurgica Sinica(English Letters) 2004年第6期17卷 912-922页

作者： Y.Zheng j.M.Wang H.Chen j.Q.Zhang C.N.Cao DepartmentofChemistry ZhejiangUniversityHangzhou310027China DepartmentofChemistry ZhejiangUniversityHangzhou310027China／／ChineseStateKeyLaboratoryforCorrosionandProtectionInstituteofMetalReseachTheChineseAcademyofSciencesShenyang110016China

yThe　EIS　on　theanodic　process　of　pure　Zn　in　an　alkaline　solution　wereperformed　and　fitted　using　the　expression　of　Faradic　admittance,based　on　which　the　mechanism　of　the　process　was　***　results　showed　that　besides　electrode　potential　E　the　electrochemical　reaction　rate　was　affected　by　the　adsorption　of　Zn(OH)ads　on　the　electrode　surface　and　the　diffusion　of　in　the　electrolyte　in　active　region,and　only　by　the　covering　of　passivation　layer　on　the　electrode　surface　in　both　transitive　and　passivation　***　equivalent　circuit　sapplied　in　these　various　circumstances　were　proposed　and　the　variation　of　some　parameters　and　state　variables　was　also　discussed.

关键词： Zn alkalinesolution anodicprocess EIS

A Statistical Analysis of point-like Sources in the Chandra Galactic Center Survey

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Chinese journal of Astronomy and Astrophysics 2007年第1期7卷 81-90页

作者： j. E Wu S. N. Zhang F.j. Lu Y. K. jin Department of physics and Center for Astrophysics Tsinghua University Beijing 100084 Key Laboratory of particle Astrophysics Institute of High Energy Physics Chinese Academy ofSciences Beijing 100049 Department of Engineering physics and Center for Astrophysics Tsinghua University Beijing 100084

The Chandra Galactic Center Survey detected -800 X-ray point-like sources in the 2°× 0.8° sky region around the Galactic Center. We study the spatial and luminosity distributions of these sources according to their spectral properties. Fourteen bright sources detected are used to fit jointly an absorbed power-law model, from which the power-law photon index is determined to be -2.5. Assuming that all other sources have the same power-law form, the relation between hardness ratio and HI column density NH is used to estimate the NH values for all sources. Monte Carlo simulations show that these sources are more likely concentrated in the Galactic center region, rather than distributed throughout the Galactic disk. We also find that the luminosities of the sources are positively correlated with their HI column densities, i.e., a more luminous source has a higher HI column density. From this relation, we suggest that the X-ray luminosity comes from the interaction between an isolated old neutron star and interstellar medium （mainly dense molecular clouds）. Using the standard Bondi accretion theory and the statistical information of molecular clouds in the Galactic center, we confirm this positive correlation and calculate the luminosity range in this scenario, which is consistent with the observation （10^32 - 10^35 erg s^-1）.

关键词： methods data analysis-Galaxy center-X-ray stars

Deletion of Glutl in early postnatal cartilage reprograms chondrocytes toward enhanced glutamine oxidation

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Bone Research 2021年第4期9卷 507-520页

作者： Cuicui Wang jun Ying Xiangfeng Niu Xiaofei Li Gary j.patti jie Shen Regis j.O’Keefe Department of Orthopaedic Surgery School of MedicineWashington UniversitySt.LouisMOUSA Institute of Orthopaedics and Traumatology The First Affiliated Hospital of Zhejiang Chinese Medical UniversityHangzhouChina Zhejiang Chinese Medical University HangzhouChina Department of Chemistry Genetics and MedicineWashington UniversitySt.LouisMOUSA

Glucose metabolism is fundamental for the functions of all tissues,including *** the emerging evidence related to glucose metabolism in the regulation of prenatal cartilage development,little is known about the role of glucose metabolism and its biochemical basis in postnatal cartilage growth and *** show here that genetic deletion of the glucose transporter Glutl in postnatal cartilage impairs cell proliferation and matrix production in growth plate(Gps)but paradoxically increases cartilage remnants in the metaphysis,resulting in shortening of long *** the other hand,articular cartilage(AC)with Glutl deficiency presents diminished cellularity and loss of proteoglycans,which ultimately progress to cartilage ***,predisposition to Glutl deficiency severely exacerbates injury-induced *** of the disparities in glucose metabolism between Gp and AC chondrocytes under normal conditions,both types of chondrocytes demonstrate metabolic plasticity to enhance glutamine utilization and oxidation in the absence of glucose ***,uncontrolled glutamine flux causes collagen overmodification,thus affecting extracellular matrix remodeling in both cartilage *** results uncover the pivotal and distinct roles of Glutl-mediated glucose metabolism in two of the postnatal cartilage compartments and link some cartilage abnormalities to altered glucose/glutamine metabolism.

关键词： metabolism cartilage chondrocytes