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非经典阻尼动力系统的迭代法

世界地震工程 1994年第3期10卷 67-75,9页

作者： f.e.udwadia R.Kumer 卞启

一、前言近来,确定非经典阻尼结构系统反应的兴趣又重新活跃起来了。

关键词：阻尼结构动力系统迭代法

SYNGR4 and PLeKHB1 deregulation in motor neurons of amyotrophic lateral sclerosis models: potential contributions to pathobiology

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Neural Regeneration Research 2022年第2期17卷 266-270页

作者： Rita f.Marques Kent e.Duncan Institute for Biochemistry and Molecular Biology Department of ChemistryUniversity of HamburgHamburgGermany Neuronal Translational Control Research Group Center for Molecular Neurobiology Hamburg(ZMNH)University Medical Center Hamburg-EppendorfHamburgGermany

Amyotrophic lateral sclerosis is the most common adult-onset neurodegenerative disease affecting motor neurons. Its defining feature is progressive loss of motor neuron function in the cortex, brainstem, and spinal cord, leading to paralysis and death. Despite major advances in identifying genes that can cause disease when mutated and model the disease in animals and cellular models, it still remains unclear why motor symptoms suddenly appear after a long pre-symptomatic phase of apparently normal function. One hypothesis is that age-related deregulation of specific proteins within key cell types, especially motor neurons themselves, initiates disease symptom appearance and may also drive progressive degeneration. Genome-wide in vivo cell-type-specific screening tools are enabling identification of candidates for such proteins. In this minireview, we first briefly discuss the methodology used in a recent study that applied a motor neuron-specific RNASeq screening approach to a standard model of TAR DNA-binding protein-43(TDP-43)-driven amyotrophic lateral sclerosis. A key finding of this study is that synaptogyrin-4 and pleckstrin homology domain-containing family B member 1 are also deregulated at the protein level within motor neurons of two unrelated mouse models of mutant TDP-43 driven amyotrophic lateral sclerosis. Guided by what is known about molecular and cellular functions of these proteins and their orthologs, we outline here specific hypotheses for how changes in their levels might potentially alter cellular physiology of motor neurons and detrimentally affect motor neuron function. Where possible, we also discuss how this information could potentially be used in a translational context to develop new therapeutic strategies for this currently incurable, devastating disease.

关键词： amyotrophic lateral sclerosis glucagon-like peptide-1 receptor motor neuron disease mouse model neurodegeneration phosphatidylserine pleckstrin homology domain synaptogyrin TAR DNA-binding protein-43 vesicle transport

Converting TRex-RGB green-channel data to 557.7 nm auroral intensity:Methodology and initial results

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earth and Planetary Physics 2024年第1期8卷 258-274页

作者： Jun Liang D.M.Gillies e.Spanswick e.f.Donovan University of Calgary CalgaryT2N 1N4Canada

The recently deployed Transition Region explorer(TRex)-RGB(red-green-blue)all-sky imager(ASI)is designed to capture“true color”images of the aurora and airglow.Because the 557.7 nm green line is usually the brightest emission line in visible auroras,the green channel of a TRex-RGB camera is usually dominated by the 557.7 nm emission.Under this rationale,the TRex mission does not include a specific 557.7 nm imager and is designed to use the RGB green-channel data as a proxy for the 557.7 nm aurora.In this study,we present an initial effort to establish the conversion ratio or formula linking the RGB green-channel data to the absolute intensity of 557.7 nm auroras,which is crucial for quantitative uses of the RGB data.We illustrate two approaches:(1)through a comparison with the collocated measurement of green-line auroras from the TRex spectrograph,and(2)through a comparison with the modeled green-line intensity according to realistic electron precipitation flux measurements from low-earth-orbit satellites,with the aid of an auroral transport model.We demonstrate the procedures and provide initial results for the TRex-RGB ASIs at the Rabbit Lake and Lucky Lake stations.The RGB response is found to be nonlinear.empirical conversion ratios or formulas between RGB green-channel data and the green-line auroral intensity are given and can be applied immediately by TRex-RGB data users.The methodology established in this study will also be applicable to the upcoming SMILe ASI mission,which will adopt a similar RGB camera system in its deployment.

关键词： TRex RGB green-line aurora auroral transport model

The Beijing 2022 Winter Olympics:An opportunity to promote physical activity and winter sports in Chinese youth

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Journal of Sport and Health Science 2022年第1期11卷 3-5页

作者： Barbara e.Ainsworth James f.Sallis School of Kinesiology Shanghai University of SportShanghai 200438China College of Health Solutions Arizona State UniversityPhoenixAZ 85004USA Mary MacKillop Institute for Health Research Australian Catholic UniversityMelbourneVIC 3000Australia Herbert Wertheim School of Public Health and Human Longevity Science University of California San DiegoSan DiegoCA 92093USA

TagedPIn february and March 2022,China will host the Beijing 2022 Olympic and Paralympic Winter Games.The vision for this landmark event promises a“joyful rendezvous upon pure ice and snow uniting the passion of hundreds of millions for winter sports”.1 Themes have been developed to create a positive environmental impact with new development for the northern region of the country and to promote winter sports and improve the health and well-being of the Chinese people.The key messages for the winter games include inspiring youth with the Olympic spirit and encouraging millions to embrace winter sports.Notably,the Chinese government aims to mobilize at least 300 million of its citizens to engage in winter sports as an outcome of hosting the Winter Olympic Games.

关键词： winter sports hundreds

Unveiling how vitrification affects the porcine blastocyst: clues from a transcriptomic study

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Journal of Animal Science and Biotechnology 2022年第3期13卷 735-755页

作者： C.Almiñana f.Dubuisson S.Bauersachs e.Royer P.Mermillod e.Blesbois f.Guignot UMR PRC INRAE 0085CNRS 7247Universitéde ToursIFCEF–37380 NouzillyFrance functional Genomics Group Institute of Veterinary AnatomyVetSuisse Faculty ZurichUniversity of ZurichZürichSwitzerland UePAO INRAEF–37380 NouzillyFrance

Background:Currently,there is a high demand for efficient pig embryo cryopreservation procedures in the porcine industry as well as for genetic diversity preservation and research purposes.To date,vitrification(VIT)is the most efficient method for pig embryo cryopreservation.Despite a high number of embryos survives in vitro after vitrification/warming procedures,the in vivo embryo survival rates after embryo transfer are variable among laboratories.So far,most studies have focused on cryoprotective agents and devices,while the VIT effects on porcine embryonic gene expression remained unclear.The few studies performed were based on vitrified/warmed embryos that were cultured in vitro(IVC)to allow them to re–expand.Thus,the specific alterations of VIT,IVC,and the cumulative effect of both remained unknown.To unveil the VIT-specific embryonic alterations,gene expression in VIT versus(vs.)IVC embryos was analyzed.Additionally,changes derived from both VIT and IVC vs.control embryos(CO)were analyzed to confirm the VIT embryonic alterations.Three groups of in vivo embryos at the blastocyst stage were analyzed by RNA–sequencing:(1)VIT embryos(vitrified/warmed and cultured in vitro),(2)IVC embryos and(3)CO embryos.Results:RNA–sequencing revealed three clearly different mRNA profiles for VIT,IVC and CO embryos.Comparative analysis of mRNA profiles between VIT and IVC identified 321,differentially expressed genes(DeG)(fDReG were found,respectively,with an overlap of 1045 genes.VIT-specific functional alterations were associated to response to osmotic stress,response to hormones,and developmental growth.While alterations in response to hypoxia and mitophagy were related to the sum of VIT and IVC effects.Conclusions:Our findings revealed new insights into the VIT procedure-specific alterations of embryonic gene expression by first comparing differences in VIT vs.IVC embryos and second by an integrative transcriptome analysis including in vivo control embryos.The identified V

关键词： Blastocyst embryo Gene expression In vitro culture Porcine RNA–sequencing Transcriptomics Vitrification

faddeev calculations on lambda hypertriton with potentials from Gel'fand–Levitan–Marchenko theory

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Communications in Theoretical Physics 2020年第10期72卷 119-124页

作者： e f Meoto M L Lekala Department of Physics University of South AfricaPrivate Bag X61710 JohannesburgSouth Africa

effective lambda-proton and lambda-neutron potentials,restored from theoretical scattering phases through Gel'fand–Levitan–Marchenko theory,are tested on a lambda hypertriton through three-body calculations.The lambda hypertriton is treated as a three-body system consisting of lambda-proton,lambda-neutron and proton–neutron subsystems.Binding energy and root mean square radius are computed for the ground state of lambda hypertriton(Jp=12+).In coordinate space,the dynamics of the system is described using a set of coupled hyperradial equations obtained from the differential faddeev equations.By solving the eigenvalue problem derived from this set of coupled hyperradial equations,the binding energy and root mean square matter radius computed are found to be-2.462 MeV and 7.00 fm,respectively.The potentials are also shown to display a satisfactory convergence behaviour.

关键词： lambda-nucleon potential lambda-proton potential lambda-neutron potential lambda hypertriton faddeev equations hyperspherical method

Nonlinear Propagation of Positron-Acoustic Periodic Travelling Waves in a Magnetoplasma with Superthermal electrons and Positrons

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Chinese Physics Letters 2017年第6期34卷 70-74页

作者： e.f.eL-Shamy Department of Physics College of ScienceKing Khalid University Department of Physics Faculty of ScienceDamietta University

The nonlinear propagation of positron acoustic periodic （PAP） travelling waves in a magnetoplasma composed of dynamic cold positrons, superthermal kappa distributed hot positrons and electrons, and stationary positive ions is examined. The reductive perturbation technique is employed to derive a nonlinear Zakharov Kuznetsov equation that governs the essential features of nonlinear PAP travelling waves. Moreover, the bifurcation theory is used to investigate the propagation of nonlinear PAP periodic travelling wave solutions. It is found that kappa distributed hot positrons and electrons provide only the possibility of existence of nonlinear compressive PAP travelling waves. It is observed that the superthermality of hot positrons, the concentrations of superthermal electrons and positrons, the positron cyclotron frequency, the direction cosines of wave vector k along the z-axis, and the concentration of ions play pivotal roles in the nonlinear propagation of PAP travelling waves. Tile present investigation may be used to understand the formation of PAP structures in the space and laboratory plasmas with superthermal hot positrons and electrons.

关键词： Nonlinear Propagation of Positron-Acoustic Periodic Travelling Waves in a Magnetoplasma with Superthermal electrons and Positrons

A novel viewpoint in glaucoma therapeutics: enriched environment

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Neural Regeneration Research 2022年第7期17卷 1431-1439页

作者： María f.González fleitas Damián Dorfman Ruth e.Rosenstein Laboratory of Retinal Neurochemistry and experimental Ophthalmology Department of Human BiochemistrySchool of Medicine/CEFyBOUniversity of Buenos Aires/CONICETBuenos AiresArgentina

Glaucoma is one of the world’s most frequent visual impairment causes and leads to selective damage to retinal ganglion cells and their axons.Despite glaucoma’s most accepted risk factor is increased intraocular pressure(IOP),the mechanisms behind the disease have not been fully elucidated.To date,IOP lowering remains the gold standard;however,glaucoma patients may still lose vision regardless of effective IOP management.Therefore,the exclusive IOP control apparently is not enough to stop the disease progression,and developing new resources to protect the retina and optic nerve against glaucoma is a goal of vast clinical importance.Besides pharmacological treatments,environmental conditions have been shown to prevent neurodegeneration in the central nervous system.In this review,we discuss current concepts on key pathogenic mechanisms involved in glaucoma,the effect of enriched environment on these mechanisms in different experimental models,as well as recent evidence supporting the preventive and therapeutic effect of enriched environment exposure against experimental glaucomatous damage.finally,we postulate that stimulating vision may become a non-invasive and rehabilitative therapy that could be eventually translated to the human disease,preventing glaucoma-induced terrible sequelae resulting in permanent visual disability.

关键词： brain-derived neurotrophic factor chondroitin sulfate enriched environment glaucoma optic nerve axons optic nerve glia retinal ganglion cells visual stimulation

focal-shape effects on the efficiency of the tunnelionization probe for extreme laser intensities

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Matter and Radiation at extremes 2020年第4期5卷 53-62页

作者： M.f.Ciappina e.e.Peganov S.V.Popruzhenko Institute of Physics of the ASCR ELI-Beamlines ProjectNa Slovance 218221 PragueCzech Republic ICfO-Institut de Ciencies fotoniques Barcelona Institute of Science and TechnologyAv.Carl Friedrich Gauss 308860 Castelldefels(Barcelona)Spain National Research Nuclear University MePhI Kashirskoe Ave.31115409 MoscowRussia Prokhorov General Physics Institute of the Russian Academy of Sciences Vavilov Str.38119991 MoscowRussia

We examine the effect of laser focusing on the effectiveness of a recently discussed scheme[M.f.Ciappina et al.,Phys.Rev.A 99,043405(2019)and M.f.Ciappina and S.V.Popruzhenko,Laser Phys.Lett.17,025301(2020)]for in situ determination of ultrahigh intensities of electromagnetic radiation delivered by multi-petawatt laser facilities.Using two model intensity distributions in the focus of a laser beam,we show how the resulting yields of highly charged ions generated in the process of multiple sequential tunneling of electrons from atoms depend on the shapes of these distributions.Our findings lead to the conclusion that an accurate extraction of the peak laser intensity can be made either in the near-threshold regime,when the production of the highest charge state happens only in a small part of the laser focus close to the point where the intensity is maximal or through the determination of the points where the ion yields of close charges become equal.We show that for realistic parameters of the gas target,the number of ions generated in the central part of the focus in the threshold regime should be sufficient for a reliable measurement with highly sensitive time-of-flight detectors.Although the positions of the intersection points generally depend on the focal shape,they can be used to localize the peak intensity value in certain intervals.finally,the slope of the intensity-dependent ion yields is shown to be robust with respect to both the focal spot size and the spatial distribution of the laser intensity in the focus.When these slopes can be measured,they will provide the most accurate determination of the peak intensity value within the considered tunnel ionization scheme.In addition to this analysis,we discuss the method in comparison with other recently proposed approaches for direct measurement of extreme laser intensities.

关键词： laser extreme shape