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Solar wind ion charge state distributions and compound cross sections for solar wind charge exchange X-ray emission 被引量:1
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作者 Dimitra Koutroumpa 《Earth and Planetary Physics》 EI CSCD 2024年第1期105-118,共14页
Solar Wind Charge eXchange X-ray(SWCX) emission in the heliosphere and Ea rth’s exosphere is a hard to avoid signal in soft Xray obse rvations of astrophysical targets.On the other hand,the X-ray imaging possibilitie... Solar Wind Charge eXchange X-ray(SWCX) emission in the heliosphere and Ea rth’s exosphere is a hard to avoid signal in soft Xray obse rvations of astrophysical targets.On the other hand,the X-ray imaging possibilities offered by the SWCX process has led to an increasing number of future dedicated space missions for investigating the solar wind-terrestrial inte ractions and magnetospheric interfaces.In both cases,accurate modelling of the SWCX emission is key to correctly interpret its signal,and remove it from obse rvations,when needed.In this paper,we compile solar wind abundance measurements from ACE for different solar wind types,and atomic data from literature,including charge exchange cross-sections and emission probabilities,used fo r calculating the compound cross-section a for the SWCX X-ray emission.We calculate a values for charge-exchange with H and He,relevant to soft X-ray energy bands(0.1-2.0 keV)for various solar wind types and solar cycle conditions. 展开更多
关键词 solar wind charge exchange X-rays MAGNETOSPHERE HELIOSPHERE
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The magnetosheath at high spectral resolution 被引量:1
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作者 K.D.Küntz D.Koutroumpa +4 位作者 W.R.Dunn A.Foster F.S.Porter D.G.Sibeck B.Walsh 《Earth and Planetary Physics》 EI CSCD 2024年第1期234-246,共13页
While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems... While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look ahead to the abilities of the next generation of astrophysics missions.Of these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing SMILE’s global mapping.LEM’s strength is its spectral resolution.It will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray background using the difference in their relative velocities. 展开更多
关键词 MAGNETOSHEATH charge exchange solar wind abundances
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Deformations at Earth’s dayside magnetopause during quasi-radial IMF conditions:Global kinetic simulations and Soft X-ray Imaging 被引量:1
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作者 ZhongWei Yang RiKu Jarvinen +7 位作者 XiaoCheng Guo TianRan Sun Dimitra Koutroumpa George K.Parks Can Huang BinBin Tang QuanMing Lu Chi Wang 《Earth and Planetary Physics》 EI CSCD 2024年第1期59-69,共11页
The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)is a joint mission of the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS).Primary goals are investigating the dynamic response of the Eart... The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)is a joint mission of the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS).Primary goals are investigating the dynamic response of the Earth's magnetosphere to the solar wind(SW)impact via simultaneous in situ magnetosheath plasma and magnetic field measurements,X-Ray images of the magnetosheath and magnetic cusps,and UV images of global auroral distributions.Magnetopause deformations associated with magnetosheath high speed jets(HSJs)under a quasi-parallel interplanetary magnetic field condition are studied using a threedimensional(3-D)global hybrid simulation.Soft X-ray intensity calculated based on both physical quantities of solar wind proton and oxygen ions is compared.We obtain key findings concerning deformations at the magnetopause:(1)Magnetopause deformations are highly coherent with the magnetosheath HSJs generated at the quasi-parallel region of the bow shock,(2)X-ray intensities estimated using solar wind h+and self-consistentO7+ions are consistent with each other,(3)Visual spacecraft are employed to check the discrimination ability for capturing magnetopause deformations on Lunar and polar orbits,respectively.The SMILE spacecraft on the polar orbit could be expected to provide opportunities for capturing the global geometry of the magnetopause in the equatorial plane.A striking point is that SMILE has the potential to capture small-scale magnetopause deformations and magnetosheath transients,such as HSJs,at medium altitudes on its orbit.Simulation results also demonstrate that a lunar based imager(e.g.,Lunar Environment heliospheric X-ray Imager,LEXI)is expected to observe a localized brightening of the magnetosheath during HSJ events in the meridian plane.These preliminary results might contribute to the pre-studies for the SMILE and LEXI missions by providing qualitative and quantitative soft X-ray estimates of dayside kinetic processes. 展开更多
关键词 collisionless shock SMILE mission FORESHOCK
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Taurine: a promising nutraceutic in the prevention of retinal degeneration
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作者 Diego García-Ayuso Johnny Di Pierdomenico +3 位作者 Ana Martínez-Vacas Manuel Vidal-Sanz Serge Picaud María PVillegas-Pérez 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第3期606-610,共5页
Taurine is considered a non-essential amino acid because it is synthesized by most mammals.However,dietary intake of taurine may be necessary to achieve the physiological levels required for the development,maintenanc... Taurine is considered a non-essential amino acid because it is synthesized by most mammals.However,dietary intake of taurine may be necessary to achieve the physiological levels required for the development,maintenance,and function of certain tissues.Taurine may be especially important for the retina.The concentration of taurine in the retina is higher than that in any other tissue in the body and taurine deficiency causes retinal oxidative stress,apoptosis,and degeneration of photoreceptors and retinal ganglion cells.Low plasma taurine levels may also underlie retinal degeneration in humans and therefore,taurine administration could exert retinal neuroprotective effects.Taurine has antioxidant,anti-apoptotic,immunomodulatory,and calcium homeostasis-regulatory properties.This review summarizes the role of taurine in retinal health and disease,where it appears that taurine may be a promising nutraceutical. 展开更多
关键词 amino acid ANTI-INFLAMMATORY ANTIOXIDANT gamma-aminobutyric acid NUTRACEUTICAL photoreceptor degeneration RETINA retinitis pigmentosa TAURINE
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The dorsal root ganglion as a target for neurorestoration in neuropathic pain
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作者 Guillermo Estivill-Torrús Ana Belen Martínez-Padilla +2 位作者 Lourdes Sánchez-Salido Anne Baron-Van Evercooren Beatriz García-Díaz 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第2期296-301,共6页
Neuropathic pain is a severe and chronic condition widely found in the general population.The reason for this is the extensive variety of damage or diseases that can spark this unpleasant constant feeling in patients.... Neuropathic pain is a severe and chronic condition widely found in the general population.The reason for this is the extensive variety of damage or diseases that can spark this unpleasant constant feeling in patients.During the processing of pain,the dorsal root ganglia constitute an important region where dorsal root ganglion neurons play a crucial role in the transmission and propagation of sensory electrical stimulation.Furthermore,the dorsal root ganglia have recently exhibited a regenerative capacity that should not be neglected in the understanding of the development and resolution of neuropathic pain and in the elucidation of innovative therapies.Here,we will review the complex interplay between cells(satellite glial cells and inflammatory cells)and factors(cytokines,neurotrophic factors and genetic factors)that takes place within the dorsal root ganglia and accounts for the generation of the aberrant excitation of primary sensory neurons occurring in neuropathic pain.More importantly,we will summarize an updated view of the current pharmacologic and nonpharmacologic therapies targeting the dorsal root ganglia for the treatment of neuropathic pain. 展开更多
关键词 CYTOKINES dorsal root ganglia genetic factors neuropathic pain neurotrophic factors pharmacologic and nonpharmacologic therapies satellite glial cells sensory neurons
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2023: Weather and Climate Extremes Hitting the Globe with Emerging Features
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作者 Wenxia ZHANG Robin CLARK +12 位作者 Tianjun ZHOU Laurent LI Chao LI Juan RIVERA Lixia ZHANG Kexin GUI Tingyu ZHANG Lan LI Rongyun PAN Yongjun CHEN Shijie TANG Xin HUANG Shuai HU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第6期1001-1016,共16页
Globally,2023 was the warmest observed year on record since at least 1850 and,according to proxy evidence,possibly of the past 100000 years.As in recent years,the record warmth has again been accompanied with yet more... Globally,2023 was the warmest observed year on record since at least 1850 and,according to proxy evidence,possibly of the past 100000 years.As in recent years,the record warmth has again been accompanied with yet more extreme weather and climate events throughout the world.Here,we provide an overview of those of 2023,with details and key background causes to help build upon our understanding of the roles of internal climate variability and anthropogenic climate change.We also highlight emerging features associated with some of these extreme events.Hot extremes are occurring earlier in the year,and increasingly simultaneously in differing parts of the world(e.g.,the concurrent hot extremes in the Northern Hemisphere in July 2023).Intense cyclones are exacerbating precipitation extremes(e.g.,the North China flooding in July and the Libya flooding in September).Droughts in some regions(e.g.,California and the Horn of Africa)have transitioned into flood conditions.Climate extremes also show increasing interactions with ecosystems via wildfires(e.g.,those in Hawaii in August and in Canada from spring to autumn 2023)and sandstorms(e.g.,those in Mongolia in April 2023).Finally,we also consider the challenges to research that these emerging characteristics present for the strategy and practice of adaptation. 展开更多
关键词 weather and climate extremes temperature extremes extreme precipitation DROUGHT WILDFIRES
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Should we perform decompressive laparotomy during severe acute pancreatitis with intra-abdominal hypertension below 25 mmHg:Only the gut knows
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作者 Thibault Vieille Melissa Crotet +3 位作者 Celia Turco Paul Monasterolo Hadrien Winiszewski Gael Piton 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第5期1470-1473,共4页
We suggest that during severe acute pancreatitis(SAP)with intra-abdominal hypertension,practitioners should consider decompressive laparotomy,even with intra-abdominal pressure(IAP)below 25 mmHg.Indeed,in this setting... We suggest that during severe acute pancreatitis(SAP)with intra-abdominal hypertension,practitioners should consider decompressive laparotomy,even with intra-abdominal pressure(IAP)below 25 mmHg.Indeed,in this setting,non-occlusive mesenteric ischemia(NOMI)may occur even with IAP below this cutoff and lead to transmural necrosis if abdominal perfusion pressure is not promptly restored.We report our experience of 18 critically ill patients with SAP having undergone decompressive laparotomy of which one third had NOMI while IAP was mostly below 25 mmHg. 展开更多
关键词 Acute pancreatitis Abdominal compartment syndrome Decompressive laparotomy Mesenteric ischemia Intra-abdominal pressure Abdominal perfusion pressure
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Collisionless shock acceleration of protons in a plasma slab produced in a gas jet by the collision of two laser-driven hydrodynamic shockwaves
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作者 J.-R.Marquès L.Lancia +11 位作者 P.Loiseau P.Forestier-Colleoni M.Tarisien E.Atukpor V.Bagnoud C.Brabetz F.Consoli J.Domange F.Hannachi P.Nicolaï M.Salvadori B.Zielbauer 《Matter and Radiation at Extremes》 SCIE EI CSCD 2024年第2期12-25,共14页
We have recently proposed a new technique of plasma tailoring by laser-driven hydrodynamic shockwaves generated on both sides of a gas jet[Marquès et al.,Phys.Plasmas 28,023103(2021)].In a continuation of this nu... We have recently proposed a new technique of plasma tailoring by laser-driven hydrodynamic shockwaves generated on both sides of a gas jet[Marquès et al.,Phys.Plasmas 28,023103(2021)].In a continuation of this numerical work,we study experimentally the influence of the tailoring on proton acceleration driven by a high-intensity picosecond laser in three cases:without tailoring,by tailoring only the entrance side of the picosecond laser,and by tailoring both sides of the gas jet.Without tailoring,the acceleration is transverse to the laser axis,with a low-energy exponential spectrum,produced by Coulomb explosion.When the front side of the gas jet is tailored,a forward acceleration appears,which is significantly enhanced when both the front and back sides of the plasma are tailored.This forward acceleration produces higher-energy protons,with a peaked spectrum,and is in good agreement with the mechanism of collisionless shock acceleration(CSA).The spatiotemporal evolution of the plasma profile is characterized by optical shadowgraphy of a probe beam.The refraction and absorption of this beam are simulated by post-processing 3D hydrodynamic simulations of the plasma tailoring.Comparison with the experimental results allows estimation of the thickness and near-critical density of the plasma slab produced by tailoring both sides of the gas jet.These parameters are in good agreement with those required for CSA. 展开更多
关键词 acceleration HYDRODYNAMIC COLLISION
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Ion emission from warm dense matter produced by irradiation with a soft x-ray free-electron laser
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作者 Josef Krása Tomás Burian +33 位作者 Vera Hájková Jaromír Chalupský Šimon Jelínek Katerina Frantálová Michal Krupka Zuzana Kuglerová Sushil Kumar Singh Vojtech Vozda Ludek Vysín MichalŠmíd Pablo Perez-Martin Marion Kühlman Juan Pintor Jakub Cikhardt Matthias Dreimann Dennis Eckermann Felix Rosenthal Sam M.Vinko Alessandro Forte Thomas Gawne Thomas Campbell Shenyuan Ren YuanFeng Shi Trevor Hutchinson Oliver Humphries Thomas Preston Mikako Makita Motoaki Nakatsutsumi Xiayun Pan Alexander Köhler Marion Harmand Sven Toleikis Katerina Falk Libor Juha 《Matter and Radiation at Extremes》 SCIE EI CSCD 2024年第1期71-84,共14页
We report on an experiment performed at the FLASH2 free-electron laser(FEL)aimed at producing warm dense matter via soft x-ray isochoric heating.In the experiment,we focus on study of the ions emitted during the soft ... We report on an experiment performed at the FLASH2 free-electron laser(FEL)aimed at producing warm dense matter via soft x-ray isochoric heating.In the experiment,we focus on study of the ions emitted during the soft x-ray ablation process using time-of-flight electron multipliers and a shifted Maxwell–Boltzmann velocity distribution model.We find that most emitted ions are thermal,but that some impurities chemisorbed on the target surface,such as protons,are accelerated by the electrostatic field created in the plasma by escaped electrons.The morphology of the complex crater structure indicates the presence of several ion groups with varying temperatures.We find that the ion sound velocity is controlled by the ion temperature and show how the ion yield depends on the FEL radiation attenuation length in different materials. 展开更多
关键词 ELECTROSTATIC emitted chemi
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Influence of Continental Atmospheric Forcing on the Decadal Variability of the West African Monsoon
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作者 Adjoua Moïse Landry Famien Sandrine Djakouré +3 位作者 Bi Tra Jean Claude Youan Serge Janicot Abé Delfin Ochou Arona Diedhiou 《Atmospheric and Climate Sciences》 2024年第1期1-28,共28页
The West African Monsoon (WAM) is characterized by strong decadal and multi-decadal variability and the impacts can be catastrophic for the local populations. One of the factors put forward to explain this variability... The West African Monsoon (WAM) is characterized by strong decadal and multi-decadal variability and the impacts can be catastrophic for the local populations. One of the factors put forward to explain this variability involves the role of atmospheric dynamics, linked in particular to the Saharan Heat Low (SHL). This article addresses this question by comparing the sets of preindustrial control and historical simulation data from climate models carried out in the framework of the CMIP5 project and observations data over the 20<sup>th</sup> century. Through multivariate statistical analyses, it was established that decadal modes of ocean variability and decadal variability of Saharan atmospheric dynamics significantly influence decadal variability of monsoon precipitation. These results also suggest the existence of external anthropogenic forcing, which is superimposed on the decadal natural variability inducing an intensification of the signal in the historical simulations compared to preindustrial control simulations. We have also shown that decadal rainfall variability in the Sahel, once the influence of oceanic modes has been eliminated, appears to be driven mainly by the activity of the Arabian Heat Low (AHL) in the central Sahel, and by the structure of the meridional temperature gradient over the inter-tropical Atlantic in the western Sahel. 展开更多
关键词 Influence of Continental Atmospheric Forcing on the Decadal Variability of the West African Monsoon
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与通信兼容的毫米波室内定位中角功率谱视距传输簇的识别方法
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作者 吕鹏飞 SARRAZIN Julien 黄默 《电子与信息学报》 EI CSCD 北大核心 2023年第7期2467-2475,共9页
该文提出一种在室内无线定位中识别毫米波视距传输(LoS)的方法,在室内毫米波无线通信的波束训练框架下,实现了信道角功率谱(PAS)中视距角度簇的识别。该方法通过分水岭算法,将角功率谱聚类成簇,进而采用最大似然比和人工神经网络分析角... 该文提出一种在室内无线定位中识别毫米波视距传输(LoS)的方法,在室内毫米波无线通信的波束训练框架下,实现了信道角功率谱(PAS)中视距角度簇的识别。该方法通过分水岭算法,将角功率谱聚类成簇,进而采用最大似然比和人工神经网络分析角度簇内5个不同信道指标,即空间对称性、冲激响应和传递函数的信号峰度、平均过度延迟和均方根(RMS)延迟扩展。仿真结果中可观察到视距和非视距(NLOS)角功率谱簇之间差异明显,并以实验验证了该识别方法的有效性。 展开更多
关键词 室内定位 视距传输识别 毫米波 信道角度域聚类 分水岭分割
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Exercise sustains the hallmarks of health 被引量:1
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作者 Yan Qiu Benjamin Fernández-García +4 位作者 H.Immo Lehmann Guoping Li Guido Kroemer Carlos López-Otín Junjie Xiao 《Journal of Sport and Health Science》 SCIE CSCD 2023年第1期8-35,共28页
Exercise has long been known for its active role in improving physical fitness and sustaining health.Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative an... Exercise has long been known for its active role in improving physical fitness and sustaining health.Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative and therapeutic strategy for various diseases.It is well-documented that exercise maintains and restores homeostasis at the organismal,tissue,cellular,and molecular levels to stimulate positive physiological adaptations that consequently protect against various pathological conditions.Here we mainly summarize how moderate-intensity exercise affects the major hallmarks of health,including the integrity of barriers,containment of local perturbations,recycling and turnover,integration of circuitries,rhythmic oscillations,homeostatic resilience,hormetic regulation,as well as repair and regeneration.Furthermore,we summarize the current understanding of the mechanisms responsible for beneficial adaptations in response to exercise.This review aimed at providing a comprehensive summary of the vital biological mechanisms through which moderate-intensity exercise maintains health and opens a window for its application in other health interventions.We hope that continuing investigation in this field will further increase our understanding of the processes involved in the positive role of moderate-intensity exercise and thus get us closer to the identification of new therapeutics that improve quality of life. 展开更多
关键词 Beneficial effects of exercise Exercise-related physiological adaptations Hallmarks of health Moderate-intensity exercise Therapeutic exercise
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Nucleoredoxin-like 2 metabolic signaling impairs its potential contribution to neurodegenerative diseases
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作者 Mariangela Corsi Céline Jaillard Thierry Léveillard 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第3期529-530,共2页
Alzheimer’s disease(AD)threatens the foundations of humanity and our society.AD is a neurological disorder primarily affecting the elderly through memory disorders,cognitive decline,and loss of autonomy.The dramatic ... Alzheimer’s disease(AD)threatens the foundations of humanity and our society.AD is a neurological disorder primarily affecting the elderly through memory disorders,cognitive decline,and loss of autonomy.The dramatic consequences of this late-onset disease were illustrated sensitively in Michael Haneke’s masterpiece,Amour.Researchers and governments have invested colossal efforts to develop a treatment for this terrible disease.Currently and in the past decade the amyloid cascade has dominated the therapeutic research on AD,but the absence of benefit for patients treated with drugs that reduce brain amyloid deposit questions the role ofβ-amyloid as a causative agent(Herrup,2021).The recent approval of aducanumab by the United States Food and Drug Administration,a drug that targetsβ-amyloid,is at the center of a scandal among clinicians and researchers,as it does not provide therapeutic benefits to patients and is listed among the breakdowns of the year 2021 by Science magazine(Voosen et al.,2021).The lack of progress in curing AD and recent therapeutic failures calls for further exploratory research. 展开更多
关键词 APPROVAL consequences LISTED
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Tidal triggering of seismicity in the region of Palu, Central Sulawesi, Indonesia
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作者 Ibnu Nurul Huda Sebastien Lambert Jean Souchay 《Geodesy and Geodynamics》 EI CSCD 2023年第4期377-384,共8页
This paper investigates the correlation between tidal stress and earthquakes for periods ranging from hours to months in the limited zone of the Palu region(Central Sulawesi,Indonesia).Through Schuster and binomial te... This paper investigates the correlation between tidal stress and earthquakes for periods ranging from hours to months in the limited zone of the Palu region(Central Sulawesi,Indonesia).Through Schuster and binomial tests,we examined the relation between the seismicity(time density of seismic events)and tidal potential arising from the Moon and Sun,using all tidal components simultaneously and focusing on the estimation of specific terms.The results show significant correlations between the seismicity and tidal potential for S2(0.5 d)and O1(1.075 d)tidal components in the case of solely isolated earthquake events,particularly for shallow earthquakes.Meanwhile,there is a strong relationship between aftershocks and tidal components larger than the Mf period(13.661 d).Finally,the analysis of the temporal variation of the earthquake-tide relation reveals an optimal correlation for about six years before the 2018 great Palu earthquake.The correlation becomes insignificant afterwards. 展开更多
关键词 Tidal triggering Earth tides Palu region Statistical test
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Plasma optics:A perspective for high-power coherent light generation and manipulation
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作者 C.Riconda S.Weber 《Matter and Radiation at Extremes》 SCIE EI CAS CSCD 2023年第2期1-5,共5页
Over the last two decades,the importance of fully ionized plasmas for the controlled manipulation of high-power coherent light has increased considerably.Many ideas have been put forward on how to control or change th... Over the last two decades,the importance of fully ionized plasmas for the controlled manipulation of high-power coherent light has increased considerably.Many ideas have been put forward on how to control or change the properties of laser pulses such as their frequency,spectrum,intensity,and polarization.The corresponding interaction with a plasma can take place either in a self-organizing way or by prior tailoring.Considerable work has been done in theoretical studies and in simulations,but at present there is a backlog of demand for experimental veri-fication and the associated detailed characterization of plasma-optical elements.Existing proof-of-principle experiments need to be pushed to higher power levels.There is little doubt that plasmas have huge potential for future use in high-power optics.This introduction to the special issue of Matter and Radiation at Extremes devoted to plasma optics sets the framework,gives a short historical overview,and briefly describes the various articles in this collection. 展开更多
关键词 power OPTICS COHERENT
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Taurine:an essential amino sulfonic acid for retinal health
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作者 Johnny Di Pierdomenico Ana Martínez-Vacas +2 位作者 Serge Picaud María P.Villegas-Pérez Diego García-Ayuso 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第4期807-808,共2页
Taurine(2-amino-ethanesulfonic acid)is a naturally occurring amino sulfonic acid derived from cysteine and methionine metabolism.Its common name derives from the ox,as it was first isolated from the bile of an ox(Frog... Taurine(2-amino-ethanesulfonic acid)is a naturally occurring amino sulfonic acid derived from cysteine and methionine metabolism.Its common name derives from the ox,as it was first isolated from the bile of an ox(Froger et al.,2014).The molecular structure of taurine differs from that of amino acids by the presence of a sulfonic acid,instead of the more common carboxylic acid group in the structure of amino acids. 展开更多
关键词 sulfonic structure ETHANE
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New insights into intergeneric relationships of Hickeliinae(Poaceae:Bambusoideae) revealed by complete plastid genomes
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作者 Rivontsoa A.Rakotonasolo Soejatmi Dransfield +4 位作者 Thomas Haevermans Helene Ralimanana Maria S.Vorontsova Meng-Yuan Zhou De-Zhu Li 《Plant Diversity》 SCIE CAS CSCD 2023年第2期125-132,共8页
The Hickeliinae(Poaceae:Bambusoideae) is an ecologically and economically significant subtribe of tropical bamboos restricted to Madagascar,Comoros,Reunion Island,and a small part of continental Africa(Tanzania).Becau... The Hickeliinae(Poaceae:Bambusoideae) is an ecologically and economically significant subtribe of tropical bamboos restricted to Madagascar,Comoros,Reunion Island,and a small part of continental Africa(Tanzania).Because these bamboos rarely flower,field identification is challenging,and inferring the evolutionary history of Hickeliinae from herbarium specimens is even more so.Molecular phylogenetic work is critical to understanding this group of bamboos.Here,comparative analysis of 22 newly sequenced plastid genomes showed that members of all genera of Hickeliinae share evolutionarily conserved plastome structures.We also determined that Hickeliinae plastome sequences are informative for phylogenetic reconstructions.Phylogenetic analysis showed that all genera of Hickeliinae are monophyletic,except for Nastus,which is paraphyletic and forms two distant clades.The type species of Nastus(Clade Ⅱ) is endemic to Reunion Island and is not closely related to other sampled species of Nastus endemic to Madagascar(Clade Ⅵ).Clade Ⅵ(Malagasy Nastus) is sister to the Sokinochloa+Hitchcockella clade(Clade Ⅴ),and both clades have a clumping habit with short-necked pachymorph rhizomes.The monotypic Decaryochloa is remarkable in having the longest floret in Bambuseae and forms a distinct Clade Ⅳ.Clade Ⅲ,which has the highest generic diversity,consists of Cathariostachys,Perrierbambus,Sirochloa,and Valiha,which are also morphologically diverse.This work provides significant resources for further genetic and phylogenomic studies of Hickeliinae,an understudied subtribe of bamboo. 展开更多
关键词 BAMBOO Hickeliinae Madagascar Paleotropical PHYLOGENOMICS PLASTOME
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Updated Inventory of Carbon Monoxide in the Taurus Molecular Cloud
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作者 Yan Duan Di Li +4 位作者 Laurent Pagani Paul F.Goldsmith Tao-Chung Ching Chen Wang Jinjin Xie 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第9期56-65,共10页
The most extensive survey of carbon monoxide(CO)gas in the Taurus molecular cloud relied on ^(12)CO and ^(13)CO J=1→0 emission only,distinguishing the region where ^(12)CO is detected without ^(13)CO(named mask 1 reg... The most extensive survey of carbon monoxide(CO)gas in the Taurus molecular cloud relied on ^(12)CO and ^(13)CO J=1→0 emission only,distinguishing the region where ^(12)CO is detected without ^(13)CO(named mask 1 region)from the one where both are detected(mask 2 region)(Goldsmith et al.2008;Pineda et al.2010).We have taken advantage of recent ^(12)CO J=3→2 James Clerk Maxwell Telescope observations,where they include mask 1regions to estimate density,temperature,and N(CO)with a large velocity gradient model.This represents 1395 pixels out of~1.2 million in the mark 1 region.Compared to Pineda et al.(2010)results and assuming a Tkin of 30 K,we find a higher volume density of molecular hydrogen of 3.3×10^(3) cm^(-3),compared to their 250-700 cm^(-3),and a CO column density of 5.7×10^(15)cm^(-2),about a quarter of their value.The differences are important and show the necessity to observe several CO transitions to better describe the intermediate region between the dense cloud and the diffuse atomic medium.Future observations to extend the ^(12)CO J=3→2 mapping further away from the ^(13)COdetected region comprising mask 1 are needed to revisit our understanding of the diffuse portions of dark clouds. 展开更多
关键词 SUBMILLIMETER ISM-ISM clouds-ISM MOLECULES
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Periodicities in Solar Activity, Solar Radiation and Their Links with Terrestrial Environment
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作者 Valentina V. Zharkova Irina Vasilieva +1 位作者 Simon J. Shepherd Elena Popova 《Natural Science》 CAS 2023年第3期111-147,共37页
Solar magnetic activity is expressed via variations of sunspots and active regions varying on different timescales. The most accepted is an 11-year period supposedly induced by the electromagnetic solar dynamo mechani... Solar magnetic activity is expressed via variations of sunspots and active regions varying on different timescales. The most accepted is an 11-year period supposedly induced by the electromagnetic solar dynamo mechanism. There are also some shorter or longer timescales detected: the biennial cycle (2 - 2.7 years), Gleisberg cycle (80 - 100 years), and Hallstatt’s cycle (2100 - 2300 years). Recently, using Principal Component Analysis (PCA) of the observed solar background magnetic field (SBMF), another period of 330 - 380 years, or Grand Solar Cycle (GSC), was derived from the summary curve of two eigenvectors of SBMF. In this paper, a spectral analysis of the averaged sunspot numbers, solar irradiance, and the summary curve of eigenvectors of SBMF was carried out using Morlet wavelet and Fourier transforms. We detect a 10.7-year cycle from the sunspots and modulus summary curve of eigenvectors as well a 22-year-cycle and the grand solar cycle of 342 - 350-years from the summary curve of eigenvectors. The Gleissberg centennial cycle is only detected on the full set of averaged sunspot numbers for 400 years or by adding a quadruple component to the summary curve of eigenvectors. Another period of 2200 - 2300 years is detected in the Holocene data of solar irradiance measured from the abundance of 14C isotope. This period was also confirmed with the period of about 2000 - 2100 years derived from a baseline of the solar background magnetic field, supposedly, caused by the solar inertial motion (SIM) induced by the gravitation of large planets. The implication of these findings for different deposition of solar radiation into the northern and southern hemispheres of the Earth caused by the combined effects of the solar activity and solar inertial motion on the terrestrial atmosphere is also discussed. 展开更多
关键词 Sun: Magnetic Field Sun: Solar Activity Sun: Sunspots Sun: Solar Dynamo
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Phenotypic Characterization of Carbapenemase-Producing Enterobacteriaceae Strains in a Referral Teaching Hospital in Yaoundé, Cameroon
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作者 Cecile Ingrid Djuikoue Paule Dana Djouela Djoulako +10 位作者 Rodrigue Kamga Wouambo Charlène Nkouankou Tomi Christiane Possi Kiyang Murielle Chantale Tchitchoua Vynnie Manuella Nyatchoutou Blondelle Kitio Messeu Herman Koyouo Tagne Cedric Dylan Seugnou Nana Nadjia Benhamed Hortense Gonsu Kamga Benjamin D. Thumamo Pokam 《Open Journal of Medical Microbiology》 CAS 2023年第1期52-67,共16页
Background: Carbapenemase-producing Enterobacteriaceae (CPE) are an important and increasing threat to global health. They are nowadays more encountered routinely in hospitals and cause high morbidity and mortality du... Background: Carbapenemase-producing Enterobacteriaceae (CPE) are an important and increasing threat to global health. They are nowadays more encountered routinely in hospitals and cause high morbidity and mortality due to limited therapeutic alternatives. This study sought to determine the prevalence of CPE in Yaoundé teaching hospital, Cameroon, and the associated risk factors. Materials and Method: To achieve this goal, a descriptive cross-sectional study coupled to an analytical component with consecutive collection of Enterobacteria strains was carried out during a three-month period (from 27<sup>th</sup> July to 24<sup>th</sup> October 2018) in the University Teaching Hospital of Yaoundé, Cameroon. The oxidase and biochemical identification tests using a miniaturized Api 20 E system were performed on colonies grown on Eosin Methylene Blue (EMB) medium and subcultured on nutrient agar. Drug susceptibility testing was carried out according to the Antibiogram Committee of the French Society of Microbiology (CA-SFM 2018.V.2.0). The detection of carbapenemase production was performed by the CA-SFM 2018 algorithm for the screening of carbapenemase-producing enterobacteriaceae and its classification by inhibitory synergy tests. Results: Out of the 104 isolates, Escherichia coli (50%) was the most prevalent species, followed by Klebsiella pneumoniae (37.5%) and Citrobacter frendii (12.5%). Drugs susceptibility patterns showed a high resistance to penicillins group (97.4% to amoxicillin), cephalosporins (68.4% to cefotaxim, 58.1% to cefixim, 60.7% to ceftazidim, 57.1% of cefoxitin) and aztreonam (55.7%). However, 11.9% carbapenems related resistance was noticed: 14.4% to imipenem, 13.8% to ertapenem and 7.5% to meropenem. Numerous co-resistance to quinolones (65.8%), fluoroquinolones (49.6%), aminoglycosides (49.6%) and cotrimoxazole (71.8%) were also observed. From 104 isolates, AmpC production represented 23.08% (25/104) and 36.54% (38/104) were ESBL-isolates. The overall prevalence of CPE was 25% (26/104) with K.pneumoniae predominant (61.53%). Besides, Class A and class B carbapenemase were mainly produced with respectively 20% (21/104) and 5% (5/104). Univariate analysis revealed a significant association of carbapenemase production to Klebsiella pneumoniae (p = 0.01), ESBL and AmpC production ((P = 0.01 and P = 0.001 respectively) while that association was only significant to Klebsiella spp (p = 0.04) and AmpC production (p = 0.02) in multivariate analysis. Conclusion: The multi-resistance of Enterobacteriaceae to antibiotics in Cameroon has considerably increased. More attention should be paid to those bacteria to stall antimicrobial resistance spread. 展开更多
关键词 ENTEROBACTERIACEAE ANTIBIOTICS CARBAPENEMASE RESISTANCE
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