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A search for metal-poor stars pre-enriched by pair-instability supernovae I. A pilot study for target selection from Sloan Digital Sky Survey

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Research in Astronomy and Astrophysics 2012年第12期12卷 1637-1648页

作者： Jing Ren Norbert Christlieb Gang Zhao School of Space Science and Physics Shandong University at Weihai Weihai 264209 China zentrum ftir astronomie der universitat heidelberg Landessternwarte Konigstuhl 12 D-69117Heidelberg Germany Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

We report on a pilot study on identifying metal-poor stars pre-enriched by Pair-Instability Supernovae（PISNe）.Very massive,first generation（Population Ⅲ） stars（140 M⊙≤M≤260 M⊙）end their lives as PISNe,which have been predicted by theories,but no relics of PISNe have been observed *** the distinct characteristics of the yields of PISNe,as predicted by theoretical calculations,are a strong odd-even effect,and a strong overabundance of Ca with respect to iron and the solar *** use the latter characteristic to identify metal-poor stars in the Galactic halo that have been pre-enriched by PISNe,by comparing metallicites derived from strong, co-added Fe lines detected in low-resolution（i.e.,R=λ/△λ～2000）spectra of the Sloan Digital Sky Survey（SDSS）,with metallicities determined by the SDSS Stellar Parameters Pipeline（SSPP）.The latter are based on the strength of the CaⅡ K line and assumptions on the Ca/Fe abundance *** are selected as candidates if their metallicity derived from Fe lines is significantly lower than the SSPP *** a sample of 12 300 stars for which SDSS spectroscopy is available,we have identified 18 candidate *** resolution and signal-to-noise ratio spectra of these candidates are being obtained with the Very Large Telescope of the European Southern Observatory and the XSHOOTER spectrograph,to determine their abundance patterns,and to verify our selection *** plan to apply our method to the database of several million stellar spectra to be acquired with the Guo Shou Jing Telescope （LAMOST）in the next five years.

关键词： stars:PopulationⅡ PopulationⅢ-stars:supernovae(PISNe)-stars: abundance-stars:chemically peculiar-method:data analysis-techniques:spec- troscopic-instrumentation:spectrographs

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Test observations that search for metal-poor stars with the Guoshoujing Telescope (LAMOST)

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Research in Astronomy and Astrophysics 2010年第8期10卷 753-760页

作者： Hai-Ning Li Gang Zhao Norbert Christlieb A-Li Luo Jing-Kun Zhao Yong-Heng Zhao Jian-Jun Chen Zhong-Rui Bai Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China zentrum fur astronomie der universitat heidelberg Landessternwarte Konigstuhl 12 69117 Heidelberg Germany

Metal-deficient stars are regarded as fossils of the early generation of stars and therefore make crucial observational targets related to stellar astrophysics. They provide fundamental information and insights on properties of the very early stage of the chemical history of the Galaxy and have been investigated for decades. The unique design of the Guoshoujing Telescope （LAMOST）, such as its large field and multi-object observational capability, enables it to be an excellent tool for searching for these metal-poor stars in the Milky Way. This work reports the result of test observations which search for metal-poor stars with LAMOST, during which nine candidate metal-poor stars with [Fe/H] ≤ - 1.0 were newly detected based on the low-resolution spectroscopic observations of the LAMOST commissioning data. The sample of stars demonstrates the efficiency of selecting from the input catalog, as well as the ability of LAMOST to enlarge the sample of metal-poor stars in the Milky Way. Furthermore, the sample of stars could be used for future calibrations of the LAMOST stellar pa- rameter pipeline.

关键词： Galaxy stellar content -- surveys -- stars Population Ⅱ

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Deciphering fluid inclusions in high-grade rocks

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Geoscience Frontiers 2014年第5期5卷 683-695页

作者： Alfons van den Kerkhof Andreas Kronz Klaus Simon Geowissenschaftliches zentrum der universitat Gottingen Goldschmidtstr.1-3 D 37073 GottingenGermany

The study of fluid inclusions in high-grade rocks is especially challenging as the host minerals have been normally subjected to deformation, recrystallization and fluid-rock interaction so that primary in- clusions, formed at the peak of metamorphism are rare. The larger part of the fluid inclusions found in metamorphic minerals is typically modified during uplift. These late processes may strongly disguise the characteristics of the ＂original＂ peak metamorphic fluid. A detailed microstructural analysis of the host minerals, notably quartz, is therefore indispensable for a proper interpretation of fluid inclusions. Cathodoluminescence （CL） techniques combined with trace element analysis of quartz （EPMA, LA- [CPMS） have shown to be very helpful in deciphering the rock-fluid evolution. Whereas high-grade metamorphic quartz may have relatively high contents of trace elements like Ti and A1, low- temperature re-equilibrated quartz typically shows reduced trace element concentrations. The result- ing microstructures in CL can be basically distinguished in diffusion patterns （along microfractures and grain boundaries）, and secondary quartz formed by dissolution-reprecipitation. Most of these textures are formed during retrograde fluid-controlled processes between ca. 220 and 500 ℃, i.e. the range of semi-brittle deformation （greenschist-facies） and can be correlated with the fluid inclusions. In this way modified and re-trapped fluids can be identified, even when there are no optical features observed under the microscope.

关键词： Fluid inclusionsGranuliteCharnockiteCathodoluminescenceLA-ICPMSQuartz

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Subcellular Localization and In Vivo Interactions of the Arabidopsis thaliana Ethylene Receptor Family Members

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Molecular Plant 2008年第2期1卷 308-320页

作者： Christopher Grefen Katrin Stadele Kamil Ruzicka Petr Obrdlik Klaus Hatter Jakub Horak zentrum fur Molekularbiologie der Pflanzen Pflanzenphysiologie Universitat Tubingen Auf der Morgenstelle 1 72076 Tubingen Germany zentrum for Molekularbiologie der Pflanzen Entwicklungsgenetik Universit&t Tubingen Auf der Morgenstelle 3 72076 Tubingen Germany IonGate Biosciences GmbH Industriepark Hochst D 528 65926 Frankfurt am Main Germany

The gaseous phytohormone ethylene regulates many developmental processes and responses to environmental conditions in higher plants. In Arabidopsis thaliana, ethylene perception and initiation of signaling are mediated by a family of five receptors which are related to prokaryotic two-component sensor histidine kinases. The transient ex- pression of fluorescence-tagged receptors in tobacco （Nicotiana benthamiana） epidermal leaf cells demonstrated that all ethylene receptors are targeted to the ER endomembrane network and do not localize to the plasmalemma. In support of in planta overlay studies, the ethylene receptors form homomeric and heteromeric protein complexes at the ER in living plant cells, as shown by membrane recruitment assays. A comparable in vivo interaction pattern was found in the yeast mating-based split-ubiquitin system. The overlapping but distinct expression pattern of the ethylene receptor genes suggests a differential composition of the ethylene receptor complexes in different plant tissues. Our findings may have crucial functional implications on the ethylene receptor-mediated efficiency of hormone perception, induction of signaling, signal attenuation and output.

关键词： Subcellular Localization Vivo Interactions Arabidopsis thaliana Ethylene Receptor Family Members

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Heat Shock Factors HsfB 1 and HsfB2b Are Involved in the Regulation of Pdf1.2 Expression and Pathogen Resistance in Arabidopsis

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Molecular Plant 2009年第1期2卷 152-165页

作者： Mukesh Kumar Wolfgang Busch Hannah Birke Birgit Kemmerling Thorsten Nurnberger Friedrich Schoffl Present address: Heinrich-Pette-lnstitut Martinistrabe 52 D-20251 Hamburg Germany Max-Planck-lnstitut fur Entwicklungsbiologie Abteilung Molekularbiologie Speemannstrabe 37-39 D-72076 Tubingen Germany universitat Tubingen Zentrum for Molekularbiologie der Pflanzen (ZMBP)--AIIgemeine Genetik Auf der Morgenstelle 28 D-72076 Tubingen Germany universitat Tubingen Zentrum fur Molekularbiologie der Pflanzen (ZMBP)--Biochemie der Pflanzen Auf der Morgenstelle 5 D-72076 Tubingen Germany

In order to assess the functional roles of heat stress-induced class B-heat shock factors in Arabidopsis, we investigated T-DNA knockout mutants of AtHsfB1 and AtHsfB2b. Micorarray analysis of double knockout hsfB1/hsfB2b plants revealed as strong an up-regulation of the basal mRNA-levels of the defensin genes Pdfl.2a/b in mutant plants. The Pdfexpression was further enhanced by jasmonic acid treatment or infection with the necrotrophic fungus Alternaria brassicicola. The single mutant hsfB2b and the double mutant hsfB 1/B2b were significantly improved in disease resistance after A. brassicicola infection. There was no indication for a direct interaction of Hsf with the promoter of Pdf1.2, which is devoid of perfect HSE consensus Hsf-binding sequences. However, changes in the formation of late HsfA2-dependent HSE binding were detected in hsfB1/B2b plants. This suggests that HsfB1/B2b may interact with class A-Hsf in regulating the shut-off of the heat shock response. The identification of Pdfgenes as targets of Hsf-dependent negative regulation is the first evidence for an interconnection of Hsf in the regulation of biotic and abiotic responses.

关键词： Abiotic/environmental stress transcriptional control and transcription factors transcriptome analysis defense responses disease resistance Arabidopsis.

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GalevNB:a conversion from N-body simulations to observations

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Research in Astronomy and Astrophysics 2016年第3期16卷 1-10页

作者： Xiao-Ying Pang Christoph Olczak Di-Feng Guo Rainer Spurzem Ralf Kotulla National Astronomical Observatories and Key Laboratory of Computational Astrophysics Chinese Academy of SciencesBeijing 100012China Shanghai Institute of Technology Shanghai 201418China Astronomisches Rechen-Institut Zentrum für Astronomie der Universitat HeidelbergMonchhofstr.12-1469120 HeidelbergGermany Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Key Lab for Astrophysics Shanghai Normal UniversityShanghai 200234China Key Laboratory of Frontiers in Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Department of Astronomy University of Wisconsin-Madison475 N Charter StMadison WI 53706USA

We present GalevNB （Galev for N-body simulations）, a utility that converts fundamental stellar properties of N-body simulations into observational properties using the GALEV （GAlaxy EVolutionary synthesis models） package, and allowing direct comparisons between observations and N-body simulations. It works by converting fundamental stellar properties, such as stellar mass, temperature, luminosity and metallicity into observational magnitudes for a variety of filters used by mainstream instruments/telescopes, such as HST, ESO, SDSS, 2MASS, etc., and into spectra that span the range from far-UV （90 A） to near-IR （160 ~tm）. As an application, we use Ga 1 evNB to investigate the secular evolution of the spectral energy distribution （SED） and color magnitude diagram （CMD） of a simulated star cluster over a few hundred million years. With the results given by GalevNB we discover a UV-excess in the SED of the cluster over the whole simulation time. We also identify four candidates that contribute to the FUV peak： core helium burning stars, second asymptotic giant branch （AGB） stars, white dwarfs and naked helium stars.

关键词： stars kinematics and dynamics -- stars C-M diagrams -- stars AGB and post-AGB -- stars white dwarf

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Kr and Xe isotopic compositions of Fe-Mn crusts from the western and central Pacific Ocean and implications for their genesis

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Acta Oceanologica Sinica 2014年第8期33卷 26-33页

作者： BU Wenrui SHI Xuefa LI Li ZHANG Mingjie G.P.Glasby LIU Jihua Key Laboratory of Marine Sedimentology & Environmental Geology First Institute of OceanographyState Oceanic Administration School of Resources and Environment Lanzhou University Department of Geochemistry Geowissenschafliches Zentrum der Universitat G?ttingen (GZG)G?ttingen 37077Germany

Kr and Xe nuclide abundance and isotopic ratios of the uppermost layer of Fe-Mn Crusts from the western and central Pacific Ocean have been determined. The results indicate that the Kr and Xe isotopic composi-tions, like that of He, Ne and Ar, can be classified into two types： low3He/4He type and high3He/4He type. The low3He/4He type crusts have low84Kr and132Xe abundance, while the high3He/4He type crusts have high84Kr and132Xe abundance. The82Kr/84Kr ratios of the low3He/4He type crusts are lower than that of the air, while the83Kr/84Kr and86Kr/84Kr ratios are higher than those of the air. The Kr isotopic ratios of the high-er3He/4He type crusts are quite similar to those of the air. The128Xe/132Xe,130Xe/132Xe and131Xe/132Xe ratios of the low3He/4He type sample are distinctly lower than those of the air, whereas the129Xe/132Xe,134Xe/132Xe and136Xe/132Xe ratios are higher than those of the air. The low3He/4He type samples have the diagnostic characteristics of the MORB, with excess129, 131, 132, 134, 136Xe relative to130Xe compared with the solar wind. The128Xe/132Xe,130Xe/132Xe and131Xe/132Xe ratios of the high3He/4He type samples are slightly higher than those of the air, and the129Xe/132Xe,134Xe/132Xe and136Xe/132Xe ratios are qiute similar to those of the air. The noble gases in the Fe-Mn crusts are derived from the lower mantle, and they are a mixture of lower mantle primitive component, radiogenic component and subduction recycled component. The helium isotopic ra-tios of the low mantle reservoir are predominantly controlled by primitive He （3He） and U and Th radiogenic decayed He （4He）, but the isotopic ratios of the heavier noble gases, such as Ar, Kr and Xe, are controlled to different extent by recycling of subduction components. The difference of the noble isotopic compositions of the two type crusts is the result of the difference of the noble isotopic composition of the mantle source reservoir underneath the seamounts the crusts occurred, the noble gas

关键词： Fe-Mn crusts Kr and Xe isotopes mantle reservoir Pacific Ocean subduction recycling

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Use of pCONUS HPC for the treatment of unruptured wide- necked bifurcation aneurysms: early clinical experience using single antiplatelet therapy

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Stroke & Vascular Neurology 2021年第1期6卷 57-64页

作者： Marta Aguilar Perez Victoria Hellstern Carmen Serna Candel Christina Wendl Hansjorg Bazner Oliver Gansladt Hans Henkes Neuroradiologische Klinik NeurozentrumKlinikum StuttgartStuttgartGermany Institut fur Rontgendiagnostik Zentrum fur NeuroradiologieFakultat für Medizin der Universitat RegensburgRegensburgGermany Neurologische Klinik NeurozentrumKlinikum StuttgartStuttgartGermany Neurochirurgische NeurozentrumKlinikum StuttgartStuttgartGermany Medizinische Fakultat Universitat Duisburg-EssenEssenGermany

Background In recent years,a growing number of stents and stent-like devices have become available to facilitate the treatment of challenging ***,the need for dual antiplatelet therapy can limit their use,especially in ruptured *** hydrophilic polymer coating(pHPC,phenox)is a novel glycan-based multilayer polymer that reduces platelet *** study aims to report our initial experience using the pCONUS HPC device for the treatment of unruptured wide-necked bifurcation aneurysms(WNBA)using acetylsalicylic acid(ASA)as single antiplatelet therapy(SAPT).Methods We retrospectively identified all patients who were treated with the pCONUS HPC for unruptured WNBA in a multi-staged procedure using ASA as *** were made of periprocedural complications,clinical outcome and angiographic and clinical *** We identified 15 patients with 15 *** average age was 69 years old(range,41-76).Seven aneurysms were located in the middle cerebral artery,five in the anterior communicating artery,two at the basilar tip and one in the posterior communicating *** post-treatment angiography showed five aneurysms with modified Raymond-Roy classification(mRRC)grade Ⅰ and four aneurysms with mRRC grade Ⅱ.There were no haemorrhagic *** patients developed thrombus formation during the second treatment session,all of them completely resolving after administration of glycoprotein Ⅱb/Ⅲa *** follow-up data were available for 10 patients and showed adequate occlusion(mRRC Ⅰ or Ⅱ)in eight aneurysms(80%).In-stent stenosis was observed in one patient whereas two patients showed de novo stenosis in one of the efferent *** This early experience on the use of the pCONUS HPC device suggests that it can be useful for treating unruptured WNBA under ASA as *** investigation with a randomised treatment registry and larger cohort is needed.

关键词： treatment bifurcation HPC

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Cellular and Molecular Requirements for Polar PIN Targeting and Transcytosis in Plants

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Molecular Plant 2008年第6期1卷 1056-1066页

作者： Jurgen Kleine-Vehn tukasz tangowski Justyna Wisniewska Pankaj Dhonukshe Philip B Brewer Jiri Friml Department of Plant Systems Biology VIB and Department of Molecular Genetics Ghent University 9052 Gent Belgium zentrum fur Molekularbiologie der Pflanzen (ZMBP) Universitat Tubingen 72076 Tubingen Germany Present address: Institute of General and Molecular Biology Nicolas Copernicus University 87-100 Torun Poland Present address: Department of Biology Utrecht University 3508 TB Utrecht The Netherlands Present address: Centre for Integrative Legume Research University of Queensland Brisbane Australia

The polar, sub-cellular localization of PIN auxin efflux carriers determines the direction of intercellular auxin flow, thus defining the spatial aspect of auxin signalling. Dynamic, transcytosis-like relocalizations of PIN proteins occur in response to external and internal signals, integrating these signals into changes in auxin distribution. Here, we examine the cellular and molecular mechanisms of polar PIN delivery and transcytosis. The mechanisms of the ARF-GEF-dependent polar targeting and transcytosis are well conserved and show little variations among diverse Arabidopsis ecotypes consistent with their fundamental importance in regulating plant development. At the cellular level, we refine previous findings on the role of the actin cytoskeleton in apical and basal PIN targeting, and identify a previously unknown role for microtubules, specifically in basal targeting. PIN protein delivery to different sides of the cell is mediated by ARFdependent trafficking with a previously unknown complex level of distinct ARF-GEF vesicle trafficking regulators. Our data suggest that alternative recruitment of PIN proteins by these distinct pathways can account for cell type- and cargo-specific aspects of polar targeting, as well as for polarity changes in response to different signals. The resulting dynamic PIN positioning to different sides of cells defines a three-dimensional pattern of auxin fluxes within plant tissues.

关键词： cytoskeleton polarity protein targeting.

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过度通气4小时对控制式脑皮质撞击损伤大鼠的神经认知行为和病损大小的远期影响

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麻醉与镇痛 2012年第1期8卷 16-22页

作者： Eva Eberspacher, DVM, DACVA Manfred Blobner, MD Christian Werner, MD Stefanie Ruf, DVM Barbara Eckel, MD Kristin Engelhard, MD Wolfgang Schmahl, DW Adrian W. Gelb, MBChB, FRCP 邓希锦（译） Klinik ftir Anasthesiologie und perioperative Intensivrnedizin VeterinarmedizinischeUniversitat Wien Vienna Austria Klinik ftir Anaesthesiologie Klinikum rechts der Isar TechnischeUniversitat Munchen Munich Klinik ftir Anasthesiologie Klinikum der JohannesGutenberg-Universitat Mainz Insfitut fiirTierpathologie Tierarztliche Fakultat derLudwig-Maximilians-Universitat Miinchen Munich Germany Department of Anesthesia andPerioperative Care University of California San Francisco California

背景局部创伤性脑损伤大鼠过度通气4小时对其神经认知行为、运动功能、协调能力和病损大小的远期影响。方法对大鼠进行为期14天的神经认知行为学训练，包括孔板实验、木梁行走实验、木梁平衡实验。21只SD大鼠（369±15g），氟烷麻醉后... 详细信息

背景局部创伤性脑损伤大鼠过度通气4小时对其神经认知行为、运动功能、协调能力和病损大小的远期影响。方法对大鼠进行为期14天的神经认知行为学训练，包括孔板实验、木梁行走实验、木梁平衡实验。21只SD大鼠（369±15g），氟烷麻醉后气管插管，机械通气，行控制性皮质撞击损伤（深1．75mm，直径5mm，速度4m／s）。将大鼠随机分入正常通气组（n=10；Paco2=38-42mmHg）和过度通气组（n=11；Paco2=28-32mmHg），机械通气4小时。创伤后持续检测大鼠的行为学和运动能h20天。随后，将大鼠在深麻醉下断头取脑，冰冻脑组织，切片，评估病损大小。结果过度通气组与正常通气组相比外显记忆受损严重。两组大鼠在损伤初期的运动功能和协调能力的测试（木梁行走和木梁平衡实验）中表现均有欠缺，过度通气组更为严重。但是，在实验结束时，两组并无明显差异。创伤后第20天，过度通气组大鼠测得的病损大小（69．7±13．0mm^3）明显大于正常通气组（48．3±15．6mm^3）。结论创伤性脑损伤后过度通气4／1,时（Paco2=28-32mmHg）虽然增加了组织学损伤，但并没有对大鼠远期的神经认知功能造成不良影响。

关键词：神经认知功能过度通气 SD大鼠认知行为撞击损伤脑皮质病损创伤性脑损伤

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