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Plasma Heating Induced by Tadpole-like Downflows in the Flaring Solar Corona

The Innovation 2021年第1期2卷 137-143页

作者： Tanmoy Samanta Hui Tian Bin Chen Katharine KReeves Mark C.M.Cheung angelos Vourlidas Dipankar Banerjee Department of Physics and Astronomy George Mason UniversityFairfaxVA 22030USA Johns Hopkins University Applied Physics Laboratory LaurelMD 20723USA School of Earth and Space Sciences Peking UniversityBeijing 100871Peopleʼs Republic of China Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012Peopleʼs Republic of China New Jersey Institute of Technology NewarkNJ 07102USA Harvard-Smithsonian Center for Astrophysics CambridgeMA 02138USA Lockheed Martin Solar and Astrophysics Laboratory Palo AltoCA 94304USA Aryabhatta Research Institute of Observational Sciences BeluwakhanUttarakhand 263001India Part of this work was done during the postdoc appointment of T.S.at Peking University BeijingPeopleʼs Republic of China

As one of the most spectacular energy release events in the solar system,solar flares are generally powered by magnetic reconnection in the solar *** a result of the re-arrangement of magnetic field topology after the reconnection process,a series of new looplike magnetic structures are often formed and are known as flare loops.A hot diffuse region,consisting of around 5–10 MK plasma,is also observed above the loops and is called a supra-arcade ***,dark,tadpole-like structures are seen to descend through the bright supra-arcade *** remains unclear what role these so-called supra-arcade downflows(SADs)play in heating the flaring coronal *** we show a unique flare observation,where many SADs collide with the flare loops and strongly heat the loops to a temperature of 10–20 *** of these interactions generate clear signatures of quasi-periodic enhancement in the full-Sun-integrated soft X-ray emission,providing an alternative interpretation for quasi-periodic pulsations that are commonly observed during solar and stellar flares.

关键词： Sun:corona Sun:solar flare Sun:magnetic reconnection Sun:plasma heating

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Deconstructing athletes’sleep:A systematic review of the influence of age,sex,athletic expertise,sport type,and season on sleep characteristics

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Journal of Sport and Health Science 2021年第4期10卷 387-402页

作者： angelos Vlahoyiannis George Aphamis Gregory C.Bogdanis Giorgos K.Sakkas Eleni Andreou Christoforos D.Giannaki Department of Life and Health Sciences University of NicosiaNicosia 1700Cyprus School of Physical Education and Sport Science National and Kapodistrian University of AthensAthens 17237Greece Department of Physical Education and Sport Science University of ThessalyTrikala 42100Greece School of Sport and Health Sciences Cardiff Metropolitan UniversityCardiff CF52YBUK

Purpose:This systematic review aimed to describe objective sleep parameters for athletes under different conditions and address potential sleep issues in this specific ***:PubMed and Scopus were searched from inception to April *** studies measured sleep only via objective evaluation tools such as polysomnography or *** modified version of the Newcastle-Ottawa Scale was used for the quality assessment of the ***:Eighty-one studies were included,of which 56 were classified as medium quality,5 studies as low quality,and 20 studies as high quality.A total of 1830 athletes were monitored over 18,958 *** values for sleep-related parameters were calculated for all athletes according to sex,age,athletic expertise level,training season,and type of *** slept on average 7.2±1.1 h/night(mean±SD),with 86.3%±6.8%sleep efficiency(SE).In all datasets,the athletes’mean total sleep time was<8 *** was low for young athletes(80.3%±8.8%).Reduced SE was attributed to high wake after sleep onset rather than sleep onset *** heavy training periods,sleep duration and SE were on average 36 min and 0.8%less compared to pre-season and 42 min and 3.0%less compared to in-season training periods,***:Athletes’sleep duration was found to be short with low SE,in comparison to the general consensus for non-athlete healthy *** sleep issues were revealed in young *** quality and architecture tend to change across different training periods.

关键词： Actigraphy Polysomnography Sleep architecture Sleep duration Sleep quality

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A Double Shot Noise Process and Its Application in Insurance

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Journal of Mathematics and System Science 2012年第2期2卷 82-93页

作者： angelos Dassios Jiwook Jang Department of Statistics London School of Economics and Political Science London WC2A 2AE United Kingdom Department of Applied Finance and Actuarial Studies Faculty of Business and Economics Macquarie University Sydney NSW 2109 Australia

The authors consider a compound Cox model of insurance risk with the additional economic assumption of a positive interest rate. As the authors note a duality result relating a compound Cox model of insurance risk with a positive interest rate and a double shot noise process, the authors analyze a double shot noise process systematically for its theoretical distributional properties, based on the piecewise deterministic Markov process theory, and the martingale methodology. The authors also obtain the moments of aggregate accumulated/discounted claims where the claim arrival process follows a Cox process with shot noise intensity. Removing the parameters in a double shot noise process gradually, the authors show that it becomes a compound Cox process with shot noise intensity, a single shot noise process and a compound Poisson process. Numerical comparisons are shown between the moments （i.e. means and variances） of a compound Poisson model and their counterparts of a compound Cox model with/without considering a positive interest rate. For that purpose, the authors assume that claim sizes and primary event sizes follow an exponential distribution, respectively.

关键词： Double shot noise process a Cox process stochastic intensity and time value of claims aggregate accumulated/discounted claims.

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Optoacoustic microscopy at multiple discrete frequencies

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Light(Science & Applications) 2018年第1期7卷 7-18页

作者： Stephan Kellnberger Dominik Soliman George J.Tserevelakis Markus Seeger Hong Yang angelos Karlas Ludwig Prade Murad Omar Vasilis Ntziachristos Institute of Biological and Medical Imaging(IBMI) Helmholtz Zentrum MunchenIngolstadter Landstr.185764 NeuherbergGermany Chair of Biological Imaging(CBI)and Center for Translational Cancer Research(TranslaTUM) Technical University MunichEinsteinstrase 2581675 MunchenGermany Cardiovascular Research Center Cardiology DivisionMassachusetts General HospitalHarvard Medical SchoolBostonMA 02114USA Xidian University South Taibai Road 02710071 Xi’anShaanxiChina

Optoacoustic(photoacoustic)sensing employs illumination of transient energy and is typically implemented in the time domain using nanosecond photon ***,the generation of high-energy short photon pulses requires complex laser technology that imposes a low pulse repetition frequency(PRF)and limits the number of wavelengths that are concurrently available for spectral *** avoid the limitations of working in the time domain,we have developed frequency-domain optoacoustic microscopy(FDOM),in which light intensity is modulated at multiple discrete *** integrated FDOM into a hybrid system with multiphoton microscopy,and we examine the relationship between image formation and modulation frequency,showcase high-fidelity images with increasing numbers of modulation frequencies from phantoms and in vivo,and identify a redundancy in optoacoustic measurements performed at multiple *** demonstrate that due to high repetition rates,FDOM achieves signal-to-noise ratios similar to those obtained by time-domain methods,using commonly available laser ***,we experimentally confirm various advantages of the frequency-domain implementation at discrete modulation frequencies,including concurrent illumination at two wavelengths that are carried out at different modulation frequencies as well as flow measurements in microfluidic chips and in vivo based on the optoacoustic Doppler ***,we discuss how FDOM redefines possibilities for optoacoustic imaging by capitalizing on the advantages of working in the frequency domain.

关键词： repetition illumination multiple

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Opening a window to skin biomarkers for diabetes stage with optoacoustic mesoscopy

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Light(Science & Applications) 2023年第11期12卷 2335-2349页

作者： Hailong He Nikolina-Alexia Fasoula angelos Karlas Murad Omar Juan Aguirre Jessica Lutz Michael Kallmayer Martin Fuchtenbusch Hans-Henning Eckstein Annette Ziegler Vasilis Ntziachristos Institute of Biological and Medical Imaging Helmholtz Zentrum MunchenNeuherbergGermany Chair of Biological Imaging at the Central Institute for Translational Cancer Research(TranslaTUM) School of MedicineTechnical University of MunichMunichGermany Department for Vascular and Endovascular Surgery Klinikum rechts der IsarTechnical University of Munich(TUM)MunichGermany DZHK(German Centre for Cardiovascular Research) partner site Munich Heart AllianceMunichGermany Diabetes Center at Marienplatz MunichGermany Forschergruppe Diabetes e.V. Helmholtz Zentrum MunchenNeuherbergGermany Institute of Diabetes Research Helmholtz Zentrum MunchenNeuherbergGermany

Being the largest and most accessible organ of the human body,the skin could offer a window to diabetes-related complications on the ***,skin microvasculature is typically assessed by histological analysis,which is not suited for applications to large populations or longitudinal *** introduce ultra-wideband rasterscan optoacoustic mesoscopy(RSOM)for precise,non-invasive assessment of diabetes-related changes in the dermal microvasculature and skin micro-anatomy,resolved with unprecedented sensitivity and detail without the need for contrast *** unique imaging contrast,we explored a possible role for RSOM as an investigational tool in diabetes healthcare and offer the first comprehensive study investigating the relationship between different diabetes complications and microvascular features in *** applied RSOM to scan the pretibial area of 95 participants with diabetes mellitus and 48 age-matched volunteers without diabetes,grouped according to disease complications,and extracted six label-free optoacoustic biomarkers of human skin,including dermal microvasculature density and epidermal parameters,based on a novel image-processing *** then correlated these biomarkers to disease severity and found statistically significant effects on microvasculature parameters as a function of diabetes *** discuss how label-free RSOM biomarkers can lead to a quantitative assessment of the systemic effects of diabetes and its complications,complementing the qualitative assessment allowed by current clinical metrics,possibly leading to a precise scoring system that captures the gradual evolution of the disease.

关键词： diabetes anatomy precise

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Molecular dynamics modeling of a single diamond abrasive grain in grinding

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Frontiers of Mechanical Engineering 2015年第2期10卷 168-175页

作者： angelos P. MARKOPOULOS Ioannis K. SAVVOPOULOS Nikolaos E. KARKALOS Dimitrios E. MANOLAKOS Section of Manufacturing Technology School ot Mechanical Engineer-ing National Technical University of Athens Athens 15780 Greece

In this paper the nano-metric simulation of grinding of copper with diamond abrasive grains, using the molecular dynamics （MD） method, is considered. An MD model of nano-scale grinding, where a single diamond abrasive grain performs cutting of a copper workpiece, is presented. The Morse potential function is used to simulate the interactions between the atoms involved in the procedure. In the proposed model, the abrasive grain follows a curved path with decreasing depth of cut within the workpiece to simulate the actual material removal process. Three different initial depths of cut, namely 4 A, 8 A and 12 A, are tested, and the influence of the depth of cut on chip formation, cutting forces and workpiece tempera- tures are thoroughly investigated. The simulation results indicate that with the increase of the initial depth of cut, average cutting forces also increase and therefore the temperatures on the machined surface and within the workpiece increase as well. Furthermore, the effects of the different values of the simulation variables on the chip formation mechanism are studied and discussed. With the appropriate modifications, the proposed model can be used for the simulation of various nano-machining processes and operations, in which continuum mechanics cannot be applied or experimental techniques are subjected to limitations.

关键词： molecular dynamics abrasive process chip formation cutting force temperature

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Is more evidence needed for thrombectomy in basilar artery occlusion? The BASICS and BEST meta- analytical approaches

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Stroke & Vascular Neurology 2021年第4期6卷 671-672,I0094-I0096页

作者： Davi J Fontoura Solla Felipe Coelho Argolo Karol P Budohoski angelos G Kolias JoséGuilherme M P Caldas Jamary Oliveira-Filho Division of Neurosurgery Department of NeurologyUniversity of Sao PauloSao PauloBrazil NIHR Global Health Research Group on Neurotrauma Cambridge UniversityCambridgeUK Machine Learning for Mental Health Lab King's College LondonLondonUK Division of Neurosurgery Department of Clinical NeurosciencesAddenbrooke's HospitalCambridge UniversityCambridgeUK Radiology University of Sao PauloSao PauloBrazil Postgraduate Program in Health Sciences Federal University of BahiaSalvadorBahiaBrazil

INTRODUCTION The benefit of mechanical thrombectomy for stroke associated with anterior circulation large vessel occlusion(LVO)is well established and among the most effective treatments in medicine.1 Stroke associated with basilar artery occlusion(BAO)was not included in the seminal thrombectomy randomised clin-ical trials(RCTs).BAO accounts for 1%of the ischaemic strokes and 5%-10%of the LVO,but 70%-80%of BAO victims evolve to death or full dependence.23 The terminal nature of the brainstem and thalamic circulations may predispose to such dismal *** two RCT designed to assess the efficacy of early(<6-8 hours since symptoms onset)thrombectomy for BAO treatment,the BEST and BASICS trials.24 Given the prior evidence for thrombectomy benefit for anterior circu-lation stroke is well settled;BAO stroke shares a similar physiopathology with very poor prog-nosis.

关键词： throm occlusion basilar

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Integrated Assessment of Natural Hazards, Including Climate Change’s Influences, for Cultural Heritage Sites: The Case of the Historic Centre of Rethymno in Greece

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International Journal of Disaster Risk Science 2019年第3期10卷 343-361页

作者： Mohammad Ravankhah Rosmarie de Wit Athanasios V.Argyriou angelos Chliaoutakis Maria Joao Revez Joern Birkmann Maja Zuvela-Aloise Apostolos Sarris Anastasia Tzigounaki Kostas Giapitsoglou Institute of Spatial and Regional Planning(IREUS-Institut fur Raumordnung und Entwicklungsplanung) University of Stuttgart70174 StuttgartGermany Central Institution for Meteorology and Geodynamics(ZAMG-Zentralanstalt fur Meteorologie und Geodynamik) 1190 ViennaAustria GeoSat ReSeArch Lab IMS-ORTH(Geophysical-SatelliteRemote Sensing and Archaeoenvironment LabInstitute for Mediterranean Studies-Foundation for Research and TechnologyHellas)74100 RethymnoGreece Nova Conservacao S.A.1200-872LisbonPortugal The Archaeological Research Unit Department of Historyand ArchaeologyUniversity of Cyprus1678 NicosiaCyprus Ephorate of Antiquities of Rethymno 74100 RethymnoGreece

Within the framework of disaster risk management, this article proposes an interdisciplinary method for the analysis of multiple natural hazards, including climate change’s influences, in the context of cultural heritage. A taxonomy of natural hazards applicable to cultural heritage was developed based on the existing theoretical and conceptual frameworks. Sudden-onset hazards, such as earthquakes and floods, and slow-onset hazards, such as wetting–drying cycles and biological contamination, were incorporated into the hazard assessment procedure. Future alteration of conditions due to climate change, such as change in heat waves’ duration, was also taken into account. The proposed hazard assessment framework was applied to the case of the Historic Centre of Rethymno, a city on the northern coast of the island of Crete in Greece,to identify, analyze, and prioritize the hazards that have the potential to cause damage to the center’s historic structures. The assessment procedure includes climate model projections, GIS spatial modeling and mapping, and finally a hazard analysis matrix to enable the sharing of a better understanding of multiple hazards with the *** results can facilitate decision making by providing the vulnerability and risk analysis with the nature and spatial distribution of the significant hazards within the study area and its setting.

关键词： Climate change analysis Crete Cultural heritage protection Greece Hazard assessment Historic centre of Rethymno Risk assessment

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Watermarking Images in the Frequency Domain by Exploiting Self-Inverting Permutations

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Journal of Information Security 2013年第2期4卷 80-91页

作者： Maria Chroni angelos Fylakis Stavros D. Nikolopoulos Department of Computer Science University of Ioannina Ioannina Greece

In this work we propose efficient codec algorithms for watermarking images that are intended for uploading on the web under intellectual property protection. Headed to this direction, we recently suggested a way in which an integer number w which being transformed into a self-inverting permutation, can be represented in a two dimensional (2D) object and thus, since images are 2D structures, we have proposed a watermarking algorithm that embeds marks on them using the 2D representation of w in the spatial domain. Based on the idea behind this technique, we now expand the usage of this concept by marking the image in the frequency domain. In particular, we propose a watermarking technique that also uses the 2D representation of self-inverting permutations and utilizes marking at specific areas thanks to partial modifications of the image’s Discrete Fourier Transform (DFT). Those modifications are made on the magnitude of specific frequency bands and they are the least possible additive information ensuring robustness and imperceptiveness. We have experimentally evaluated our algorithms using various images of different characteristics under JPEG compression. The experimental results show an improvement in comparison to the previously obtained results and they also depict the validity of our proposed codec algorithms.

关键词： Watermarking Techniques Image Watermarking Algorithms Self-Inverting Permutations 2D Representations of Permutations Encoding Decoding Frequency Domain Experimental Evaluation

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Cardiac arrest and cardiopulmonary resuscitation in“hostile”environments:Using automated compression devices to minimize the rescuers’danger

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World Journal of Cardiology 2023年第2期15卷 45-55页

作者： George Latsios Marianna Leopoulou Andreas Synetos Antonios Karanasos angelos Papanikolaou Pavlos Bounas Evangelia Stamatopoulou Konstantinos Toutouzas Kostas Tsioufis 1^(st)University Department of Cardiology "Hippokration"University HospitalAthens Medical SchoolAthens 11527Greece 1^(st)Cardiology Clinic 'Hippokration'University HospitalNational and Kapodistrian University of AthensSchool of MedicineAthens 11527Greece Department of Cardiology "Elpis"Athens General HospitalAthens 11522Greece 1^(st)Department of Cardiology Athens Medical SchoolUniversity AthensHippokrat HospitalAthens 11527Greece 1^(st)Cardiology Department Athens Medical School Hippokration General HospitalAthens 11527Greece Department of Cardiology “Thriasio”General HospitalThriasio General HospitalElefsina 19600Greece CathLab 2nd Department of CardiologyMedical SchoolNational and Kapodistrian University of Athens“Attikon”University HospitalAttikon University HospitalAthens 12462Greece The First Department of Cardiology Athens Medical SchoolAthens 11527Greece 1^(st)Department of Cardiology Medical SchoolNational and Kapodistrian University of Athens“Hippokration”General Hospital"Hippokration"University HospitalAthens 11527Greece

Mechanical automated compression devices are being used in cardiopulmonary resuscitation instead of manual,“hands-on”,rescuer-delivered chest ***-theoretical-advantages include high-quality non-stop compressions,thus freeing the rescuer performing the compressions and additionally the ability of the rescuer to stand reasonably away from a potentially“hazardous”victim,or from hazardous and/or difficult resuscitation *** circumstances involve cardiopulmonary resuscitation(CPR)in the Cardiac Catheterization Laboratory,especially directly under the fluoroscopy panel,where radiation is well known to cause detrimental effects to the rescuer,and CPR during/after land or air transportation of cardiac arrest ***,CPR in a coronavirus disease 2019 patient/ward,where the danger of contamination and further serious illness of the health provider is very *** scope of this review is to review and present literature and current guidelines regarding the use of mechanical compressions in these“hostile”and dangerous settings,while comparing them to manual compressions.

关键词： Automated compression devices Cardiopulmonary resuscitation Cathlab Computed tomography Transfer COVID-19

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