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Redox evolution of western Tianshan subduction zone and its effect on deep carbon cycle 被引量:3
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作者 Renbiao Tao Lijuan Zhang Lifei Zhang 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第3期915-924,共10页
Knowing the phase relations of carbon-bearing phases at high-pressure(HP) and high-temperature(HT) condition is essential for understanding the deep carbon cycle in the subduction zones.In particular,the phase relatio... Knowing the phase relations of carbon-bearing phases at high-pressure(HP) and high-temperature(HT) condition is essential for understanding the deep carbon cycle in the subduction zones.In particular,the phase relation of carbon-bearing phases is also strongly influenced by redox condition of subduction zones,which is poorly explored.Here we summarized the phase relations of carbon-bearing phases(calcite,aragonite,dolomite,magnesite,graphite,hydrocarbon) in HP metamorphic rocks(marble,metapelite,eclogite) from the Western Tianshan subduction zone and high-pressure experiments.During prograde progress of subduction,carbonates in altered oceanic crust change from Ca-carbonate(calcite) to Ca,Mg-carbonate(dolomite),then finally to Mgcarbonate(magnesite) via Mg-Ca cation exchange reaction between silicate and carbonate,while calcite in sedimentary calcareous ooze on oceanic crust directly transfers to high-pressure aragonite in marble or amorphous CaCO3 in subduction zones.Redox evolution also plays a significant effect on the carbon speciation in the Western Tianshan subduction zone.The prograde oxygen fugacity of the Western Tianshan subduction zone was constrained by mineral assemblage of garnet-omphacite from FMQ-1.9 to FMQ-2.5 at its metamorphic peak(maximum P-T) conditions.In comparison with redox conditions of other subduction zones,Western Tianshan has the lowest oxygen fugacity.Graphite and light hydrocarbon inclusions were ubiqutously identified in Western Tianshan HP metamorphic rocks and speculated to be formed from reduction of Fe-carbonate at low redox condition,which is also confirmed by high-pressure experimental simulation.Based on petrological observation and high-pressure simulation,a polarized redox model of reducing slab but oxidizing mantle wedge in subduction zone is proposed,and its effect on deep carbon cycle in subduction zones is further discussed. 展开更多
关键词 Oxygen FUGACITY Western TIANSHAN SUBDUCTION zone DEEP carbon CYCLE POLARIZED redox model
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Decline of semen quality among 10 932 males consulting for couple infertility over a 20-year period in Marseille, France 被引量:6
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作者 Cendrine Geoffroy-Siraudin Anderson Dieudone Loundou +5 位作者 Fanny Romain Vincent Achard Blandine Courbibre Marie-He1ene Perrard Philippe Durand Marie-Roberte Guichaoua 《Asian Journal of Andrology》 SCIE CAS CSCD 2012年第4期584-590,共7页
Semen from 10 932 male partners of infertile couples was analysed and sperm parameter trends were evaluated at the Reproduction Biology Laboratory of the University Hospital of Marseille (France) between 1988 and 20... Semen from 10 932 male partners of infertile couples was analysed and sperm parameter trends were evaluated at the Reproduction Biology Laboratory of the University Hospital of Marseille (France) between 1988 and 2007. After 3-6 days of abstinence, semen samples were collected. Measurements of seminal fluid volume, pH, sperm concentration, total sperm count, motility and detailed morphology of spermatozoa were performed. Sperm parameters were analysed on the entire population and in men with normal total numeration ( 〉~ 40 million per ejaculate). The whole population demonstrated declining trends in sperm concentration (1.5% per year), total sperm count (1.6% per year), total motility (0.4% per year), rapid motility (5.5% per year) and normal morphology (2.2% per year). In the group of selected samples with total normal sperm count, the same trends of sperm quality deterioration with time were observed. Our results clearly indicate that the auality of semen decreased in this population over the study period. 展开更多
关键词 environment male infertility regional differences semen quality sperm parameters
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Dorsal root ganglion progenitors differentiate to gamma-aminobutyric acid-and choline acetyltransferase-positive neurons 被引量:1
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作者 Lingli Yu Yindi Ding +4 位作者 Ambre Spencer Ji Ma Ruisheng Lu Brian B.Rudkin Chonggang Yuan 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第7期485-491,共7页
This study examined the isolation and differentiation of dorsal root ganglion progenitor cells for therapeutic use in neurodegenerative diseases. Rat embryonic dorsal root ganglia progenitors were isolated and purifie... This study examined the isolation and differentiation of dorsal root ganglion progenitor cells for therapeutic use in neurodegenerative diseases. Rat embryonic dorsal root ganglia progenitors were isolated and purified using the differential adhesion method combined with cytosine arabinoside treatment. After culture in serum-free medium supplemented with B27, basic fibroblast growth factor and epidermal growth factor, these cells remained viable and survived for more than 18 months in vitro. Most cells differentiated to neurons that were immunoreactive for gamma-aminobutyric acid and choline acetyltransferase as detected by immunohistochemical staining. In addition, nerve growth factor and neurotrophic tyrosine kinase receptor expression were also observed in dorsal root ganglion progenitors and differentiated cells. K252a, an inhibitor that blocks nerve growth factor-induced signaling, inhibited cell survival, suggesting the possible existence of a nerve growth factor autocrine loop in these proliferating cells. 展开更多
关键词 dorsal root ganglion neural progenitor differentiation characterization nerve growth factor tyrosine kinase receptor type 1
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Identification of host miRNAs that may limit human rhinovirus replication 被引量:1
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作者 Victor Paky Bondanese Ana Francisco-Garcia +2 位作者 Nicole Bedke Donna E Davies Tilman Sanchez-Elsner 《World Journal of Biological Chemistry》 CAS 2014年第4期437-456,共20页
AIM: To test whether the replication of human rhinovirus(HRV) is regulated by micro RNAs in human bronchial epithelial cells.METHODS: For the present study, the human cell line BEAS-2B(derived from normal human bronch... AIM: To test whether the replication of human rhinovirus(HRV) is regulated by micro RNAs in human bronchial epithelial cells.METHODS: For the present study, the human cell line BEAS-2B(derived from normal human bronchial epithelial cells) was adopted. DICER knock-down, by si RNA transfection in BEAS-2B cells, was performed in order to inhibit micro RNA maturation globally. Alternatively, antisense oligonucleotides(anti-mi Rs) were transfectedto inhibit the activity of specific micro RNAs. Cells were infected with HRV-1B. Viral replication was assessed by measuring the genomic viral RNA by reverse transcription quantitative polymerase chain reaction(RT-q PCR). Association between micro RNA-induced-silencing-complex and viral RNA was detected by Ago2 co-immunoprecipitation followed by RT-q PCR. Targetscan v.6 was used to predict micro RNA target sites on several HRV strains.RESULTS: Here, we show that micro RNAs affect replication of HRV-1B. DICER knock-down significantly reduced the expression of mature micro RNAs in a bronchial epithelial cell line(BEAS-2B) and in turn, increased the synthesis of HRV-1B RNA. Additionally, HRV-1B RNA co-immunoprecipitated with argonaute 2 protein, an important effector for micro RNA activity suggesting that micro RNAs bind to viral RNA during infection. In order to identify specific micro RNAs involved in this interaction, we employed bioinformatics analysis, and selected a group of micro RNAs that have been reported to be under-expressed in asthmatic bronchial epithelial cells and were predicted to target different strains of rhinoviruses(HRV-1B,-16,-14,-27). Our results suggest that, out of this group of micro RNAs, mi R-128 and mi R-155 contribute to the innate defense against HRV-1B: transfection of specific anti-mi Rs increased viral replication, as anticipated in-silico.CONCLUSION: Taken together, our results suggest that pathological changes in micro RNA expression, as already reported for asthma or chronic obstructive pulmonary disease have the potential to affect Rhinovirus replication and therefore may play a role in virusinduced exacerbations. 展开更多
关键词 Human RHINOVIRUS Micro RNAS Mi R-155 Si RNA LENTIVIRAL TRANSDUCTION ANTIVIRAL INNATE immunity
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Characterization of meso-scale mechanical properties of Longmaxi shale using grid microindentation experiments 被引量:3
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作者 Jianting Du Andrew J.Whittle +2 位作者 Liming Hu Thibaut Divoux Jay N.Meegoda 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2021年第3期555-567,共13页
Mechanical properties,such as the hardness H,Young’s modulus E,creep modulus C,and fracture toughness Kc,are essential parameters in the design of hydraulic fracturing systems for prospective shale gas formations.In ... Mechanical properties,such as the hardness H,Young’s modulus E,creep modulus C,and fracture toughness Kc,are essential parameters in the design of hydraulic fracturing systems for prospective shale gas formations.In this study,a practical methodology is presented for obtaining these properties through microindentation experiments combined with quantitative observations of the mineralogical phases using X-ray diffraction(XRD),scanning electron microscopy(SEM)with backscattered electron(BSE)imaging,and energy-dispersive X-ray spectroscopy(EDS)analyses.We apply this method in the case of three types of Longmaxi shales with different mineralogies(i.e.carbonate-,clay-,and quartz-rich,respectively),which allows us to determine the characteristic indentation depth,hc?8e10 mm,beyond which the mechanical response of the carbonate-rich shale is homogeneous and independent of its complex heterogeneous microstructure.Moreover,exploiting the results of a large number of indentation tests,we demonstrate that the indentation modulus M of the shale increases as a power-law of hardness H,and its creep modulus C increases linearly with H.We also compute the fracture toughness Kc from the indentation data by assuming a perfectly plastic behavior of the sample.Our results are in good agreement with independent measurements of Kc determined by microscratch tests.Finally,further tests on quartz-and clay-rich samples of the Longmaxi shale suggest further variations in the samples’mechanical properties depending on their burial conditions and the mechanical properties of their dominant mineral phases. 展开更多
关键词 Grid microindentation Mineral identification Hardness MODULUS CREEP Fracture toughness
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Dual antibiotic loaded bone cement in patients at high infection risks in arthroplasty: Rationale of use for prophylaxis and scientific evidence 被引量:1
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作者 Christof Ernst Berberich Jérome Josse +1 位作者 Frédéric Laurent Tristan Ferry 《World Journal of Orthopedics》 2021年第3期119-128,共10页
In view of the demographic changes and projected increase of arthroplasty procedures worldwide,the number of prosthetic joint infection cases will naturally grow.Therefore,in order to counteract this trend more rigid ... In view of the demographic changes and projected increase of arthroplasty procedures worldwide,the number of prosthetic joint infection cases will naturally grow.Therefore,in order to counteract this trend more rigid rules and a stricter implementation of effective preventive strategies is of highest importance.In the absence of a"miracle weapon"priorities should lie in evidence-based measures including preoperative optimization of patients at higher infection risks,the fulfilment of strict hygiene rules in the operating theatre and an effective antibiotic prophylaxis regimen.Instead of a"one size fits all"philosophy,it has been proposed to adjust the antibiotic prophylaxis protocol to major infection risks taking into account important patient-and procedure-related risk factors.A stronger focus on the local application mode via use of high dose dual antibioticloaded bone cement in such risk situations may have its advantages and is easy to apply in the theatre.The more potent antimicrobial growth inhibition in vitro and the strong reduction of the prosthetic joint infection rate in risk for infection patients with aid of dual antibiotic-loaded bone cement in clinical studies align with this hypothesis. 展开更多
关键词 Prosthetic joint infection Antibiotic-loaded bone cement Single low dose antibiotic-loaded bone cement Dual high dose antibiotic-loaded bone cement Antibiotic prophylaxis Risk-for-infection patients
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Turbulent hydrodynamics experiments in high energy density plasmas: scientific case and preliminary results of the TurboHEDP project 被引量:2
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作者 A. Casner G. Rigon +13 位作者 B. Albertazzi Th. Michel T. Pikuz A. Faenov P. Mabey N. Ozaki Y. Sakawa T. Sano J. Ballet P. Tzeferacos D. Lamb E. Falize G. Gregori M. Koenig 《High Power Laser Science and Engineering》 SCIE CAS CSCD 2018年第3期50-64,共15页
The physics of compressible turbulence in high energy density(HED) plasmas is an unchartered experimental area.Simulations of compressible and radiative flows relevant for astrophysics rely mainly on subscale paramete... The physics of compressible turbulence in high energy density(HED) plasmas is an unchartered experimental area.Simulations of compressible and radiative flows relevant for astrophysics rely mainly on subscale parameters. Therefore,we plan to perform turbulent hydrodynamics experiments in HED plasmas(TurboHEDP) in order to improve our understanding of such important phenomena for interest in both communities: laser plasma physics and astrophysics. We will focus on the physics of supernovae remnants which are complex structures subject to fluid instabilities such as the Rayleigh–Taylor and Kelvin–Helmholtz instabilities. The advent of megajoule laser facilities, like the National Ignition Facility and the Laser Megajoule, creates novel opportunities in laboratory astrophysics, as it provides unique platforms to study turbulent mixing flows in HED plasmas. Indeed, the physics requires accelerating targets over larger distances and longer time periods than previously achieved. In a preparatory phase, scaling from experiments at lower laser energies is used to guarantee the performance of future MJ experiments. This subscale experiments allow us to develop experimental skills and numerical tools in this new field of research, and are stepping stones to achieve our objectives on larger laser facilities. We review first in this paper recent advances in high energy density experiments devoted to laboratory astrophysics. Then we describe the necessary steps forward to commission an experimental platform devoted to turbulent hydrodynamics on a megajoule laser facility. Recent novel experimental results acquired on LULI2000, as well as supporting radiative hydrodynamics simulations, are presented. Together with the development of LiF detectors as transformative X-ray diagnostics, these preliminary results are promising on the way to achieve micrometric spatial resolution in turbulent HED physics experiments in the near future. 展开更多
关键词 高能密度 湍流物理 激光技术 发展现状
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Stationary and Transient Simulations for a One-Dimensional Resonant Tunneling Diode
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作者 Xin Hu Shaoqiang Tang Maxime Leroux 《Communications in Computational Physics》 SCIE 2008年第10期1034-1050,共17页
We investigate the validity of stationary simulations for semiconductor quantum charge transport in a one-dimensional resonant tunneling diode via fluid type models.Careful numerical investigations to a quantum hydrod... We investigate the validity of stationary simulations for semiconductor quantum charge transport in a one-dimensional resonant tunneling diode via fluid type models.Careful numerical investigations to a quantum hydrodynamic model reveal that the transient simulations do not always converge to the steady states.In particular,growing oscillations are observed at relatively large applied voltage.A dynamical bifurcation is responsible for the stability interchange of the steady state.Transient and stationary computations are also performed for a unipolar quantum drift-diffusion model. 展开更多
关键词 Quantum effects charge transport DISSIPATION transient/stationary computation
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空间因素与抗战时期上海盗抢犯罪——基于GIS的法租界案例研究(1938-1942) 被引量:4
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作者 蒋杰 《史林》 CSSCI 北大核心 2013年第3期19-27,187,共9页
本研究目的在于讨论空间因素与上海城市犯罪间可能存在的某种关联。以上海档案馆藏法租界警档案为基础,借助GIS软件的展示与分析功能,本文对抗战时期发生在法租界内的盗抢犯罪进行讨论。研究表明,该时生在法租界内的盗抢案件总体分布均... 本研究目的在于讨论空间因素与上海城市犯罪间可能存在的某种关联。以上海档案馆藏法租界警档案为基础,借助GIS软件的展示与分析功能,本文对抗战时期发生在法租界内的盗抢犯罪进行讨论。研究表明,该时生在法租界内的盗抢案件总体分布均衡,但在租界东北部等地区出现集中趋势。借助GIs软件的分析功能,爱多利亚馆马路及霞飞路的部分地段被确定为犯罪热点地区。通过分析这些地区的空间环境,商业功能、地近干道和里弄结构为是可能诱发盗抢犯罪集中的主要因素。 展开更多
关键词 盗抢犯罪 空间因素 法租界
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Signaling in Early Maize Kernel Development 被引量:9
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作者 Nicolas M. Doll Nathalie Depege-Fargei +1 位作者 Peter M. Rogowsky Thomas Widiez 《Molecular Plant》 SCIE CAS CSCD 2017年第3期375-388,共14页
Developing the next plant generation within the seed requires the coordination of complex programs driving pattern formation, growth, and differentiation of the three main seed compartments: the embryo (future plant... Developing the next plant generation within the seed requires the coordination of complex programs driving pattern formation, growth, and differentiation of the three main seed compartments: the embryo (future plant), the endosperm (storage compartment), representing the two filial tissues, and the surround- ing maternal tissues. This review focuses on the signaling pathways and molecular players involved in early maize kernel development. In the 2 weeks following pollination, functional tissues are shaped from single cells, readying the kernel for filling with storage compounds. Although the overall picture of the signaling pathways regulating embryo and endosperm development remains fragmentary, several types of molecu- lar actors, such as hormones, sugars, or peptides, have been shown to be involved in particular aspects of these developmental processes. These molecular actors are likely to be components of signaling pathways that lead to transcriptional programming mediated by transcriptional factors. Through the integrated action of these components, multiple types of information received by cells or tissues lead to the correct differentiation and patterning of kernel compartments. In this review, recent advances regarding the four types of molecular actors (hormones, sugars, peptides/receptors, and transcription factors) involved in early maize development are presented. 展开更多
关键词 maize kernel seed development EMBRYO ENDOSPERM SIGNALING Zea mays
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Caveolin-1对乳腺癌细胞系MCF-7增殖和存活的影响
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作者 陆瑞盛 马骥 +5 位作者 张燕 于玲莉 Ambre Spencer David Cluet Brian B.Rudkin 袁崇刚 《中国细胞生物学学报》 CAS CSCD 2011年第9期983-987,共5页
该文研究窖蛋白(Caveolin-1)对乳腺癌细胞系MCF-7细胞增殖与存活的影响。运用蛋白质印迹方法(Western blot)检测发现,caveolin-1在5株不同细胞系均只有低表达。运用电穿孔转染方法在乳腺癌细胞系中高表达Caveolin-1,运用Western blot检... 该文研究窖蛋白(Caveolin-1)对乳腺癌细胞系MCF-7细胞增殖与存活的影响。运用蛋白质印迹方法(Western blot)检测发现,caveolin-1在5株不同细胞系均只有低表达。运用电穿孔转染方法在乳腺癌细胞系中高表达Caveolin-1,运用Western blot检测转染后Caveolin-1表达情况发现,转染后细胞内Caveolin-1表达上升,并具有生物活性。运用单核细胞直接细胞毒性测定法(MTT)检测发现,转染后乳腺癌细胞系MCF-7增殖速度降低。运用Western blot方法和免疫荧光(immunofluorescence)方法检测转染后细胞凋亡途径的变化,磷酸化的P38蛋白含量上升,Bax表达量明显上升。据此推测Caveolin-1抑制MCF-7细胞的增殖和存活,并诱导基于Bax途径的细胞凋亡。 展开更多
关键词 CAVEOLIN-1 乳腺癌 增殖和存活
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A longitudinal study of SARS-CoV-2-infected patients reveals a high correlation between neutralizing antibodies and COVID-19 severity 被引量:3
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作者 Vincent Legros Solène Denolly +19 位作者 Manon Vogrig Bertrand Boson Eglantine Siret Josselin Rigaill Sylvie Pillet Florence Grattard Sylvie Gonzalo Paul Verhoeven Omran Allatif Philippe Berthelot Carole Pélissier Guillaume Thiery Elisabeth Botelho-Nevers Guillaume Millet Jérôme Morel Stéphane Paul Thierry Walzer François-Loïc Cosset Thomas Bourlet Bruno Pozzetto 《Cellular & Molecular Immunology》 SCIE CAS CSCD 2021年第2期318-327,共10页
Understanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection against reinfection and,thus,for public health policy and vaccine development for COVID-19.In this study,using eit... Understanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection against reinfection and,thus,for public health policy and vaccine development for COVID-19.In this study,using either live SARS-CoV-2 particles or retroviruses pseudotyped with the SARS-CoV-2 S viral surface protein(Spike),we studied the neutralizing antibody(nAb)response in serum samples from a cohort of 140 SARS-CoV-2 qPCR-confirmed infections,including patients with mild symptoms and also more severe forms,including those that required intensive care.We show that nAb titers correlated strongly with disease severity and with anti-spike IgG levels.Indeed,patients from intensive care units exhibited high nAb titers;conversely,patients with milder disease symptoms had heterogeneous nAb titers,and asymptomatic or exclusive outpatient-care patients had no or low nAbs.We found that nAb activity in SARS-CoV-2-infected patients displayed a relatively rapid decline after recovery compared to individuals infected with other coronaviruses.Moreover,we found an absence of cross-neutralization between endemic coronaviruses and SARS-CoV-2,indicating that previous infection by human coronaviruses may not generate protective nAbs against SARS-CoV-2.Finally,we found that the D614G mutation in the spike protein,which has recently been identified as the current major variant in Europe,does not allow neutralization escape.Altogether,our results contribute to our understanding of the immune correlates of SARS-CoV-2-induced disease,and rapid evaluation of the role of the humoral response in the pathogenesis of SARS-CoV-2 is warranted. 展开更多
关键词 ANTIBODY PATHOGENESIS Humoral response COVID-19 SARS-CoV-2v
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Human Endogenous Retrovirus Type W Envelope from Multiple Sclerosis Demyelinating Lesions Shows Unique Solubility and Antigenic Characteristics 被引量:1
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作者 Benjamin Charvet Justine Pierquin +6 位作者 Joanna Brunel Rianne Gorter Christophe Que´tard Branka Horvat Sandra Amor Jacques Portoukalian Herve´Perron 《Virologica Sinica》 SCIE CAS CSCD 2021年第5期1006-1026,共21页
In multiple sclerosis(MS),human endogenous retrovirus W family(HERV-W)envelope protein,pHERV-W ENV,limits remyelination and induces microglia-mediated neurodegeneration.To better understand its role,we examined the so... In multiple sclerosis(MS),human endogenous retrovirus W family(HERV-W)envelope protein,pHERV-W ENV,limits remyelination and induces microglia-mediated neurodegeneration.To better understand its role,we examined the soluble pHERV-W antigen from MS brain lesions detected by specific antibodies.Physico-chemical and antigenic characteristics confirmed differences between pHERV-W ENV and syncytin-1.pHERV-W ENV monomers and trimers remained associated with membranes,while hexamers self-assembled from monomers into a soluble macrostructure involving sulfatides in MS brain.Extracellular hexamers are stabilized by internal hydrophobic bonds and external hydrophilic moieties.HERV-W studies in MS also suggest that this diffusible antigen may correspond to a previously described highmolecular-weight neurotoxic factor secreted by MS B-cells and thus represents a major agonist in MS pathogenesis.Adapted methods are now needed to identify encoding HERV provirus(es)in affected cells DNA.The properties and origin of MS brain pHERV-W ENV soluble antigen will allow a better understanding of the role of HERVs in MS pathogenesis.The present results anyhow pave the way to an accurate detection of the different forms of pHERV-W ENV antigen with appropriate conditions that remained unseen until now. 展开更多
关键词 Multiple sclerosis(MS) Brain Antigen HERV-W ENVELOPE Endogenous retrovirus MSRV-ENV SYNCYTIN Demyelination Lipids GLYCOLIPIDS Sulfatides Oligomer HEXAMER
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The LEAFY floral regulator displays pioneer transcription factor properties 被引量:1
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作者 Xuelei Lai Romain Blanc-Mathieu +14 位作者 Loïc GrandVuillemin Ying Huang Arnaud Stigliani Jeremy Lucas Emmanuel Thevenon Jeanne Loue-Manifel Laura Turchi Hussein Daher Eugenia Brun-Hernandez Gilles Vachon David Latrasse Moussa Benhamed Renaud Dumas Chloe Zubieta François Parcy 《Molecular Plant》 SCIE CAS CSCD 2021年第5期829-837,共9页
Pioneer transcription factors(TFs)are a special category of TFs with the capacity to bind to closed chromatin regions in which DNA is wrapped around histones and may be highly methylated.Subsequently,pioneer TFs are a... Pioneer transcription factors(TFs)are a special category of TFs with the capacity to bind to closed chromatin regions in which DNA is wrapped around histones and may be highly methylated.Subsequently,pioneer TFs are able to modify the chromatin state to initiate gene expression.In plants,LEAFY(LFY)is a master floral regulator and has been suggested to act as a pioneer TF in Arabidopsis.Here,we demonstrate that LFY is able to bind both methylated and non-methylated DNA using a combination of in vitro genomewide binding experiments and structural modeling.Comparisons between regions bound by LFY in vivo and chromatin accessibility data suggest that a subset of LFY bound regions is occupied by nucleosomes.We confirm that LFY is able to bind nucleosomal DNA in vitro using reconstituted nucleosomes.Finally,we show that constitutive LFY expression in seedling tissues is sufficient to induce chromatin accessibility in the LFY direct target genes APETALA1 and AGAMOUS.Taken together,our study suggests that LFY possesses key pioneer TF features that contribute to launching the floral gene expression program. 展开更多
关键词 flower development pioneer transcription factor gene regulation chromatin remodeling
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Weyl and Lidskiǐ Inequalities for General Hyperbolic Polynomials
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作者 Denis SERRE 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2009年第6期785-802,共18页
The roots of hyperbolic polynomials satisfy the linear inequalities that were previously established for the eigenvalues of Hermitian matrices,after a conjecture by A.Horn.Among them are the so-called Weyl and Lidski... The roots of hyperbolic polynomials satisfy the linear inequalities that were previously established for the eigenvalues of Hermitian matrices,after a conjecture by A.Horn.Among them are the so-called Weyl and Lidskiǐ inequalities.An elementary proof of the latter for hyperbolic polynomials is given.This proof follows an idea from H.Weinberger and is free from representation theory and Schubert calculus arguments,as well as from hyperbolic partial differential equations theory. 展开更多
关键词 多项式的根 线性不等式 双曲型 偏微分方程理论 埃尔米特矩阵 初等证明 特征值 温伯格
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Diffraction-limited microfocusing generated by polymer microlines separated by 1.12 μm
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作者 Azeddine Tellal Omar Ziane Patrice L.Baldeck 《Chinese Optics Letters》 SCIE EI CAS CSCD 2019年第8期81-86,共6页
The diffraction of a dielectric microline pair is optimized by numerical simulations to generate an efficient focusing pattern with a micron-scale footprint. Microlines separated by 1.12 μm are fabricated by two-phot... The diffraction of a dielectric microline pair is optimized by numerical simulations to generate an efficient focusing pattern with a micron-scale footprint. Microlines separated by 1.12 μm are fabricated by two-photon polymerization on a glass substrate, and their diffraction pattern is characterized by three-dimensional wide-field transmission microscopy. A line pair, having a width W=0.40 μm and a height H=0.80 μm, leads to diffraction-limited focusing in the visible spectrum. Depending on wavelength, its focal length, lateral resolution,and depth of focus are in the ranges of 0.8–1.3 μm, 0.22–0.44 μm, and 1.7–2.13μm, respectively. Such a microlens based on the diffraction of only two subwavelength scatterers could be used for the design of miniature optical sensors with micron and sub-micron pixels. 展开更多
关键词 optical MICRON its is be
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Capturing Auxin Response Factors Syntax Using DNA Binding Models
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作者 Amaud Stigliani Raquel Martin-Arevalillo +6 位作者 Jeremy Lucas Adrien Bessy Thomas Vinos-Poyo Victoria Mironova Teva Vernoux Renaud Dumas Francois Parcy 《Molecular Plant》 SCIE CAS CSCD 2019年第6期822-832,共11页
Auxin is a key hormone performing a wealth of functions throughout the life cycle of plants. It acts largely by regulating genes at the transcriptional level through a family of transcription factors called auxin resp... Auxin is a key hormone performing a wealth of functions throughout the life cycle of plants. It acts largely by regulating genes at the transcriptional level through a family of transcription factors called auxin response factors (ARFs). Even though all ARF monomers analyzed so far bind a similar DNA sequence, there is evidence that ARFs differ in their target genomic regions and regulated genes. Here, we report the use of position weight matrices (PWMs) to model ARF DNA binding specificity based on published DNA affinity purification sequencing (DAP-seq) data. We found that the genome binding of two ARFs (ARF2 and ARF5/ Monopteros [MP]) differ largely because these two factors have different preferred ARF binding site (ARFbs) arrangements (orientation and spacing). We illustrated why PWMs are more versatile to reliably identify ARFbs than the widely used consensus sequences and demonstrated their power with biochemical experiments in the identification of the regulatory regions o1IAA19, an well-characterized auxin-responsive gene. Finally, we combined gene regulation by auxin with ARF-bound regions and identified specific ARFbs configurations that are over-represented in auxin-upregulated genes, thus deciphering the ARFbs syntax functional for regulation. Our study provides a general method to exploit the potential of genome-wide DNA binding assays and to decode gene regulation. 展开更多
关键词 AUXIN AUXIN Response FACTOR DAP-seq DNA BINDING model
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Zebl represses TCR signaling, promotes the proliferation of T cell progenitors and is essential for NK1.1^(+) T cell development
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作者 Jiang Zhang Melanie Wencker +14 位作者 Quentin Marliac Aurore Berton Uzma Hasan Raphael Schneider Daphne Laubreton Dylan E.Cherrier Anne-Laure Mathieu Amaury Rey Wenzheng Jiang Julie Caramel Laurent Genestier Antoine Margais Jacqueline Marvel Yad Ghavi-Helm Thierry Walzer 《Cellular & Molecular Immunology》 SCIE CAS CSCD 2021年第9期2140-2152,共13页
T cell development proceeds un der the in fluence of a n etwork of transcription factors(TFs).The precise role of Zeb1,a member of this network,remains unclear.Here,we report that Zeb1 expression is induced early duri... T cell development proceeds un der the in fluence of a n etwork of transcription factors(TFs).The precise role of Zeb1,a member of this network,remains unclear.Here,we report that Zeb1 expression is induced early during T cell development in CD4^(-)CD8^(-)double-negative(DN)stage 2(DN2).Zeb1 expression was further increased in the CD4^(+)CD8^(+)double-positive(DP)stage before decreasing in more mature T cell subsets.We performed an exhaustive characterization of T cells in Cellophane mice that bear Zeb 7 hypomorphic mutations.The Zebl mutation profoundly affected all thymic subsets,especially DN2 and DP cells.Zeb1 promoted the survival and proliferation of both cell populations in a cell-intrinsic manner.In the periphery of Cellophane mice,the number of conventional T cells was near normal,but invariant NKT cells,NK1.1^(+)γδ T cells and Ly49^(+)CD8 T cells were virtually absent.This suggested that Zebl regulates the development of unconventional T cell types from DP progenitors.A transcriptomic analysis of WT and Cellophane DP cells revealed that Zebl regulated the expression of multiple genes involved in the cell cycle and TCR sign aling,which possibly occurred in cooperation with Tcf1 and Heb.In deed,Cellophane DP cells displayed stron ger signaling than WT DP cells upon TCR engagement in terms of the calcium respons巳phosphorylation events,and expression of early genes.Thus,Zebl is a key regulator of the cell cycle and TCR signaling during thymic T cell development.We propose that thymocyte selection is perturbed in Zeb7-mutated mice in a way that does not allow the survival of unconventional T cell subsets. 展开更多
关键词 T cell selection TCR signaling Zebl TRANSCRIPTION development
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Single-chain variable fragment antibody constructs neutralize measles virus infection in vitro and in vivo
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作者 Cyrille Mathieu Marion Ferren +11 位作者 Olivia Harder Francesca TBovier Tara CMarcink Camilla Predella Fabrizio Angius Jennifer Drew-Bear NValerio Dorrello Alex LGreninger Anne Moscona Stefan Niewiesk Branka Horvat Matteo Porotto 《Cellular & Molecular Immunology》 SCIE CAS CSCD 2021年第7期1835-1837,共3页
Despite the availability of an effective measles virus(MeV)vaccine and efforts to increase vaccine coverage by the WHO,UNICEF,and their partners,MeV has not been eradicated,and the estimated global measles death rose ... Despite the availability of an effective measles virus(MeV)vaccine and efforts to increase vaccine coverage by the WHO,UNICEF,and their partners,MeV has not been eradicated,and the estimated global measles death rose from 89,780 in 2016 to 207,500 in 2019.1 Because there is an effective measles vaccine,antiviral development for measles has not been prioritized,but recent outbreaks have highlighted the need for drugs to prevent transmission in unvaccinated populations and to protect and treat immunocompromised individuals.We identified several neutralizing mouse monoclonal antibodies(mAbs)that target the MeV fusion(F)protein in its prefusion state2 and inhibit fusion and viral infection.We engineered a single-chain variable fragment(scFv)from the most potent anti-MeV F mAb.The scFv retains the ability to inhibit fusion and prevents infection in vitro,and intranasal administration of the scFv antibody construct prevents infection in vivo. 展开更多
关键词 NEUTRAL priori UNICEF
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Meristem Biology Flourishes Under Mt. Tai
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作者 Yuling Jiao Olivier Hamant +1 位作者 Zhaojun Ding Xian Sheng Zhang 《Molecular Plant》 SCIE CAS CSCD 2016年第8期1224-1227,共4页
The green and lush Mt. Tai provided an appropriate backdrop for the First International Conference on Plant Meristem Biology held on June 9 and 10, 2016. Proposed and organized by Xian Sheng Zhang (Shandong Agricultu... The green and lush Mt. Tai provided an appropriate backdrop for the First International Conference on Plant Meristem Biology held on June 9 and 10, 2016. Proposed and organized by Xian Sheng Zhang (Shandong Agricultural University, China), Jiayang Li (Insti- tute of Genetics & Developmental Biology, China), Elliot Meyero- witz (California Institute of Technology, USA), and Yuling Jiao (Institute of Genetics & Developmental Biology, China), the con- ference was hosted by Shandong Agricultural University and sponsored by the Department of Education, Shandong Province, China. The first meeting of its kind, it brought about 300 attendees from nine countries together for discussions on molecular mechanisms underlying shoot, root, cambium, 展开更多
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