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Elevated brain temperature under severe heat exposure impairs cortical motor activity and executive function

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Journal of Sport and Health Science 2024年第2期13卷 233-244页

作者： Xiang Ren Tan Mary c.Stephenson Sharifah Badriyah Alhadad Kelvin W.Z.Loh Tuck Wah Soong jason K.W.Lee Ivan c.c.Low Health and Social Sciences Singapore Institute of TechnologySingapore 138683Singapore Human Potential Translational Research Programme Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117597Singapore centre for Translational Magnetic Resonance Research Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117549Singapore Department of Physiology Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117593Singapore Heat Resilience and Performance centre Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117510Singapore N.1 Institute for Health National University of SingaporeSingapore 117456Singapore campus for Research Excellence and Technological Enterprise(cREATE) Singapore 138602Singapore

Background:Excessive heat exposure can lead to hyperthermia in humans,which impairs physical performance and disrupts cognitive *** heat is a known physiological stressor,it is unclear how severe heat stress affects brain physiology and ***:Eleven healthy participants were subjected to heat stress from prolonged exercise or warm water immersion until their rectal temperatures(T_(re))attained 39.5℃,inducing exertional or passive hyperthermia,*** a separate trial,blended ice was ingested before and during exercise as a cooling *** were compared to a control condition with seated rest(normothermic).Brain temperature(T_(br)),cerebral perfusion,and task-based brain activity were assessed using magnetic resonance imaging ***:T_(br)in motor cortex was found to be tightly regulated at rest(37.3℃±0.4℃(mean±SD))despite fluctuations in T_(re).With the development of hyperthermia,T_(br)increases and dovetails with the rising T_(re).Bilateral motor cortical activity was suppressed during high-intensity plantarflexion tasks,implying a reduced central motor drive in hyperthermic participants(T_(re)=38.5℃±0.1℃).Global gray matter perfusion and regional perfusion in sensorimotor cortex were reduced with passive *** function was poorer under a passive hyperthermic state,and this could relate to compromised visual processing as indicated by the reduced activation of left lateral-occipital ***,ingestion of blended ice before and during exercise alleviated the rise in both T_(re)and T_(bc)and mitigated heat-related neural ***:Severe heat exposure elevates T_(br),disrupts motor cortical activity and executive function,and this can lead to impairment of physical and cognitive performance.

关键词： Brain functional activity cognition Heat stress Hyperthermia Motor function

Piezoelectric resonant ice protection systems–Part1/2:Prediction of power requirement for de-icing a NAcA 0024 leading edge

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chinese Journal of Aeronautics 2024年第3期37卷 92-103页

作者： Valerian PALANQUE jason POTHIN Vale′rie POMMIER-BUDINGER Marc BUDINGER Institut clement Ader University of ToulouseINSAISAE-SUPAEROMINES ALBIUPSCNRSToulouse 31055France ISAE-SUPAERO University of Toulouse10 Avenue Edouard BelinToulouse 31055France

This paper proposes a numerical method to analyze the ice protection capability and predict the power requirements of a piezoelectric resonant de-icing *** method is based on a coupled electro-mechanical finite element analysis which enables the fast computation of the modes of resonance of interest to de-ice curved surfaces and the estimation of the input voltage and current required for a given configuration(defined by its mode,actuator location,ice deposit,etc.).Eventually,the electric power to be supplied can be also *** method is applied to a NAcA 0024 leading edge equipped with piezoelectric ***,two extension modes are analyzed and compared with respect to their efficiency and power ***,tests are carried out in an icing tunnel to verify the effectiveness of the piezoelectric ice protection system and the predictions of the maximal required *** system allows de-icing the leading edge in less than 2 s for a glaze ice deposit.

关键词： Ice protection system Piezoelectric Resonance mode Ice fracture Leading edge de-icing

Degradation and resynthesis of chlorophyll during increased oxidative stress and prolonged darkness differ between annual and perennial flax(Linum L.)

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Oil crop Science 2024年第2期9卷 121-130页

作者： Kenyon J. Nisbett Abida Alokozai Su Hyun Elizabeth Ko G. Adam Mott jason c.L. Browna Department of Biological Sciences University of Toronto ScarboroughTorontoONCanada Department of cell&Systems Biology University of TorontoTorontoONCanada centre for the Analysis of Genome Evolution&Function University of TorontoTorontoONCanada

Among plants,there is considerable variation in lifespan:annuals live less than one year,whereas perennials live for several years,with the longest-living perennial having survived 43,600 *** proposed by the Disposable Soma Theory,this lifespan variation among plants likely reflects differential investment of limited energy and nutrient resources,with perennials investing more energy and nutrients into biomolecular maintenance compared to annuals in order to ensure persistence over multiple *** differential investment may be particularly important during periods of exogenous stress,which are known to accelerate biomolecular *** present study evaluated this hypothesis using annual and perennial flax(Linum L.)subjected to two exogenous stressors—increased oxidative stress(i.e.,foliar H2O2spraying)and complete prolonged *** chlorophyll has been shown to exhibit degradation in response to changes in environmental conditions,we utilized changes in chlorophyll levels during and after periods of exogenous stress to evaluate our *** predicted that i)perennials would exhibit a slower rate of chlorophyll degradation during exposure to exogenous stressors compared to annuals,and ii)perennials would exhibit a faster rate of chlorophyll resynthesis following such exposure compared to *** levels before,during,and after exposure to both exogenous stressors were measured in two separate trails,once using image colour analysis and once using *** chlorophyll degradation rates in response to oxidative stress did not differ between annuals and perennials,contrary to our predictions,chlorophyll resynthesis rates following such exposure were significantly higher in perennials,as *** plants were subjected to complete prolonged darkness,chlorophyll degradation rates were significantly lower in perennials than annuals,as predicted;however,when plants were subsequently reintroduced to natural photoperiod,ch

关键词： Ageing Life history Maximum lifespan Oxidative stress Somatic maintenance

Astrocytic calcium waves:unveiling their roles in sleep and arousal modulation

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Neural Regeneration Research 2024年第5期19卷 984-987页

作者： Erxi Wu Dan Qi Damir Nizamutdinov jason H.Huang Department of Neurosurgery and Neuroscience Institute Baylor Scott&White HealthTempleTXUSA Texas A&M University School of Medicine TempleTXUSA Texas A&M University School of Pharmacy College StationTXUSA LIVESTRONG cancer Institutes and Department of Oncology Dell Medical Schoolthe University of Texas at AustinAustinTXUSA Department of Neurosurgery Baylor College of MedicineTempleTXUSA

Neuron-astrocyte interactions are vital for the brain’s *** astrocyte activities is crucial for comprehending the complex neural network,particularly the population-level functions of neurons in different cortical states and associated behaviors in *** on animal sleep and wakefulness have revealed distinct cortical synchrony patterns between ***,outnumbering neurons by nearly fivefold,support and regulate neuronal and synaptic *** research on astrocyte activation during cortical state transitions has emphasized the influence of norepinephrine as a neurotransmitter and calcium waves as key components of ion channel *** summary focuses on a few recent studies investigating astrocyte-neuron interactions in mouse models during sleep,wakefulness,and arousal levels,exploring the involvement of noradrenaline signaling,ion channels,and glutamatergic signaling in different cortical *** findings highlight the significant impact of astrocytes on large-scale neuronal networks,influencing brain activity and *** astrocytic signaling pathways shows promise for treating sleep disorders and arousal *** research is needed to understand astrocytic calcium signaling in different brain regions and its implications for dysregulated brain states,requiring future human studies to comprehensively investigate neuron-astrocyte interactions and pave the way for therapeutic interventions in sleep-and arousal-related disorders.

关键词： arousal astrocyte calcium waves locus coeruleus neuron-astrocyte interaction norepinephrine sleep wakefulness

Modeling displacement flow inside a full-length casing string for well cementing

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Petroleum Research 2024年第1期9卷 1-16页

作者： Hu Dai Ali Eslami jason Schneider Gefei Liu Fred Schwering Pegasus Vertex Inc.USA Laval University Canada Sanjel Energy Services Canada Athabasca Oil corporation Canada

While computer modeling of annular displacement efficiency is widely applied in cementing engineering,modeling the displacement flow inside a casing or drill string for cementing operations has received less *** predicting displacement efficiency inside a full-length pipe is desired by cementing engineers,the attempt of developing a model with both efficiency and accuracy faces *** to computer simulators for this purpose is *** with annular flow,the displacement flow inside pipe,although within a simpler geometry and without eccentricity effect,is not simpler in physics,modelling strategy and predictability,because a variety of flow patterns and flow instabilities can develop to create complicated fluid *** this paper,we present an integrated numerical model developed to simulate displacement flows inside a full-length pipe,which connects an existing annulus model to enable complete displacement simulations of cementing *** model uses three-dimensional grid to solve fluid concentrations with degrees of mixing,and incorporates flow instability detection and flow regime *** in cementing,the model accounts for effects of pumping rate,well inclination,pipe rotation,fluid densities,rheological parameters and *** computationally efficient model does not rely on high-resolution mesh as often required by conventional computational Fluid Dynamics models,thus it is suitable to be implemented in a cementing software for daily use by well cementing *** methodology of the model is discussed in detail in this *** validate the model,we examine simulation results against experimental results obtained in our laboratory tests and cFD simulations;acceptable agreement is found under different testing *** also presented two case studies of real cementing jobs with cement evaluation logs compared to simulation results,showing that the model can predict consistent displacement efficie

关键词： Inside pipe displacement Displacement efficiency Numerical model Primary cementing Displacement flow

卫星和地基遥感观测资料约束下的核-壳态气溶胶光学特性模拟研究

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光学学报 2024年第6期44卷 329-340页

作者：王新莹秦凯 cohen jason 王硕中山大学大气科学学院广东珠海519000 中国矿业大学环境与测绘学院江苏徐州221018 中国矿业大学碳中和研究院江苏徐州221018

针对结合星地观测与模型定量模拟消光性气溶胶光学特性及黑碳质量空间分布这一热点问题,利用TROPOMI卫星紫外波段观测数据与AERONET地基观测数据,基于“核-壳”假设下的米散射模型提出了一种准确量化黑碳气溶胶质量空间分布的模拟方法,... 详细信息

针对结合星地观测与模型定量模拟消光性气溶胶光学特性及黑碳质量空间分布这一热点问题,利用TROPOMI卫星紫外波段观测数据与AERONET地基观测数据,基于“核-壳”假设下的米散射模型提出了一种准确量化黑碳气溶胶质量空间分布的模拟方法,并对北京、中国香港、首尔三个站点的模拟结果进行分析与验证。多源数据约束后米散射模型模拟得到的结果显示:北京的吸收系数在0.04~0.13之间,中国香港的吸收系数整体小于0.08,首尔的吸收系数介于0.02~0.06之间。计算得到的黑碳气溶胶柱内质量空间分布结果显示:北京站黑碳气溶胶柱内质量在200~600 kg/grid之间,中国香港站黑碳气溶胶柱内质量在180~650 kg/grid之间,首尔站黑碳气溶胶柱内质量在300 kg/grid以下。结合卡尔曼滤波排放清单与一阶箱模型对黑碳气溶胶柱内质量结果进行间接验证,计算得到的黑碳气溶胶生命周期为1~4 d不等,符合其在大气中的真实状态,说明结果具有一定可靠性。通过对比加入TROPOMI紫外波段卫星观测数据前后对模型进行约束得到的粒径分布及吸收系数结果的差异发现:加入紫外波段观测数据对模拟结果具有一定增强作用。所提方法模拟结果良好,方案具有一定应用潜力。

关键词： TROPOMI卫星数据 AERONET 黑碳气溶胶米散射模型

construction of a novel six-gene signature to predict tumour response to induction chemotherapy and overall survival in locoregionally advanced laryngeal and hypopharyngeal carcinoma

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Genes & Diseases 2024年第3期11卷 148-150页

作者： chen Tan Lingwa Wang Yifan Yang Shizhi He George G.chen jason YK.chan Michael cF.Tong c.A.van Hasselt Wenbin Xu Ling Feng Ru Wang Jugao Fang Department of Otolaryngology Head and Neck Surgery Beijing Tongren HospitalCapital Medical UniversityBeijing 100730China Key Laboratory of Otolaryngology Head and Neck Surgery(Ministry of Education of china) Beijing Institute of OtolaryngologyBeijing 100730China Department of Otorhinolaryngology Head and Neck SurgeryThe Chinese University of Hong KongPrince of Wales HospitalHongKong SAR999077China Department of Medical Genetics Institute of Basic Medical ScienceChinese Academy of Medical Science&Peking Union Medical CollageBeijing 100730China

Locoregionally advanced laryngeal and hypopharyngeal cancers(LA-LHcs)are traditionally treated with surgery followed by postoperative radiotherapy,which impairs speech and swallowing functions and reduces the quality of life.^(1,2)The use of induction chemotherapy(Ic)as a larynxpreserving approach for LA-LHcs has been verified and refined.^(3)However,the short-term tumor response to Ic varies,non-responders usually show poor survival and little benefit.

关键词： chemotherapy laryngeal surgery

The Economics of competing Water Uses under a FERc Licensing Agreement: Estimation of Property Value, Recreation, and Hydroelectric Impacts

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Journal of Water Resource and Protection 2024年第6期16卷 414-428页

作者： Matthew Bingham jason Kinnell Veritas Economics Cary USA

Reservoirs provide a variety of services with economic values across multiple sectors. As demands for reservoir services continue to grow and precipitation patterns evolve, it becomes ever more important to consider the integrated suite of values and tradeoffs that attend changes in water uses and availability. Section 316 (b) of the clean Water Act requires that owners of certain water cooled power plants evaluate technologies and operational measures that can reduce their impacts to aquatic organisms. The studies must discuss the social costs and benefits of alternative technologies including cooling towers (79 Fed. Reg. 158, 48300 - 48439). cooling towers achieve their effect through evaporation. This manuscript estimates the property value, recreation, and hydroelectric generation impacts that could result from the evaporative water loss associated with installing cooling towers at the McGuire Nuclear Generating Station (McGuire) located on Lake Norman, North carolina. Although this study specifically evaluates the effects of evaporative water loss from cooling towers, its methods are applicable to estimating the economic benefits and costs of a new water user or reduced water input in any complex reservoir system that supports steam electric generation, hydroelectric generation, residential properties, recreation, irrigation, and municipal water use.

关键词： Property Value FERc Hydroelectric Recreation Water Levels

Systematic Radio Telescope Alignment Using Portable Fringe Projection Profilometry

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Nanomanufacturing and Metrology 2024年第1期7卷 75-85页

作者： Joel Berkson Justin Hyatt Nathan Julicher Byeongjoon Jeong Isaac Pimienta Rachel Ball Wyatt Ellis jason Voris Diego Torres‑Barajas Daewook Kim James c.Wyant college of Optical Sciences University of Arizona1630 E.University Blvd.TucsonAZ 85721USA Department of Astronomy at Steward Observatory University of Arizona933 N Cherry Ave.TucsonAZ 85721USA

In 2019,the Event Horizon Telescope(EHT)released the first-ever image of a black hole event *** are now aiming for higher angular resolutions of distant targets,like black holes,to understand more about the fundamental laws of gravity that govern our *** achieve this higher resolution and increased sensitivity,larger radio telescopes are needed to operate at higher frequencies and in larger *** like the next-generation Very Large Array(ngVLA)and the Square-Kilometer Array(SKA)require building hundreds of telescopes with diameters greater than 10 ms over the next *** has a twofold *** telescope surfaces need to be more accurate to operate at higher frequencies,and the logistics involved in maintaining a radio telescope need to be simplified to support them properly in large *** of these problems can be solved with improved methods for surface metrology that are faster and more accurate with a higher *** leads to faster and more accurate panel alignment and,therefore,a more productive *** this paper,we present the use of binocular fringe projection profilometry as a solution to this problem and demonstrate it by aligning two panels on a 3-m radio telescope *** measurement takes only 10 min and directly delivers feedback on the tip,tilt,and piston of each panel to create the ideal reflector shape.

关键词： Metrology Fringe projection profilometry Off-axis alignment Radio astronomy Radio antenna