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Myelin histology:a key tool in nervous system research

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Neural Regeneration Research 2024年第2期19卷 277-281页

作者： Óscar Darío García-García Víctor Carriel Jesús Chato-Astrain Department of Histology Tissue Engineering GroupUniversity of Granada&Instituto de Investigación Biosanitaria ibs.GRANADAGranadaSpain

The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve *** to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental ***,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience *** this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining *** the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques.

关键词： fluorescence microscopy histology light microscopy lipid histochemistry metallographic techniques myelin histochemistry myelin immunohistochemistry myelin structure&composition myelin ultrastructural evaluation tissue fixation&processing

Direct-to-indirect mapping for optimal low-thrust trajectories

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Astrodynamics 2024年第1期8卷 27-46页

作者： David ottesen Ryan p.Russell Department of Aerospace Engineering and Engineering Mechanics The University of Texas at AustinAustinTexas78712USA

optimal,many-revolution spacecraft trajectories are challenging to solve.A connection is made for a class of models between optimal direct and indirect *** transfers that minimize thrust-acceleration-squared,primer vector theory maps direct,many-impulsive-maneuver trajectories to the indirect,continuous-thrust-acceleration *** mapping algorithm is independent of how the direct solution is obtained and requires only a solver for a boundary value problem and its partial derivatives.A Lambert solver is used for the two-body problem in this *** mapping is simple because the impulsive maneuvers and co-states share the same linear space around an optimal *** numerical results,the direct coast-impulse solutions are demonstrated to converge to the indirect continuous solutions as the number of impulses and segments *** two-body design space is explored with a set of three many-revolution,many-segment examples changing semimajor axis,eccentricity,and *** first two examples involve a small change to either semimajor axis or eccentricity,and the third example is a transfer to geosynchronous *** a single processor,the optimization runtime is seconds to minutes for revolution counts of 10 to 100,and on the order of one hour for examples with up to 500 *** of these thrust-acceleration-squared solutions are good candidates to start a homotopy to a higher-fidelity minimization problem with practical constraints.

关键词： direct optimization indirect optimization impulsive maneuvers Lambert's problem two-body dynamics primer vectortheory

palladium-catalyzed S_(N)2 glycosylation of phenols

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Science China Chemistry 2024年第4期67卷 1037-1038页

作者： Yu Zhu p.Andrew Evans Department of Chemistry Queen’s University90 Bader LaneKingstonK7L 3N6Canada Xiangya School of pharmaceutical Sciences Central South UniversityChangsha 410013China

Glycosides are essential structural motifs present in an array of important medicines,materials,and natural products[1].Nevertheless,the chemo-and stereoselective construction of the glycosidic linkage is a long-standing challenge because relatively minor variations in the glycosyl donor or acceptor’s structure can impact stereoselectivity,thus influencing the product's functional properties.

关键词： properties palladium catalyzed

Determination of critical state line(CSL)for silty-sandy iron ore tailings subjected to low-high confining pressures

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1684-1695页

作者： Nilo Cesar Consoli João Vítor de Azambuja Carvalho Alexia Cindy Wagner Hugo Carlos Scheuermann Filho Inácio Carvalho pedro pazzoto Cacciari João paulo de Sousa Silva Civil Engineering Universidade Federal do Rio Grande do SulPorto AlegreRS90035-190Brazil Exploration and Mineral projects-Mineral Development Centre VALE S.A.Santa LuziaMG33040-900Brazil Department of Civil Geological and Mining EngineeringPolytechnique MontrealQuebecH3C 3A7Canada

The disposal of filtered tailings in high dry stacks can induce particle breakage,changing the material's behaviour during the structure's *** grading changes influence material properties at the critical state,and this is not mature for intermediate artificial soils(tailings)in a broad range of confining *** this paper,it aims to describe the behaviour of iron ore tailings in a spectrum of confining pressures broader than the reported in previous studies.A series of consolidated drained(CD)triaxial tests was carried out with confining pressures ranging from 0.075 Mpa to 120 *** results show that the amount of breakage plays an essential role in the response of iron ore *** existence of curved critical state line(CSL)in both specific volume(ν)-logarithm of mean effective stress(p′)and deviatoric stress(q)-mean effective stress(p′)planes,and different responses in the deviatoric stress-axial strain-volumetric strain curves were *** inverse S-shaped equation was proposed to represent the silty-sandy tailings'behaviour up to high pressures onν-lnp′*** proposed equation provides a basis for enhancing constitutive models and considers the evolution of the grading up to severe loading *** adjustment considered three regions with different responses associated with particle breakage at different pressure levels.

关键词： Tailings Iron ore tailings dry stacking Silty-sandy material Critical state soil mechanics High confining pressures particle breakage

High-repetition-rate source of nanosecond duration kA-current pulses driven by relativistic laser pulses

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High power Laser Science and Engineering 2024年第3期12卷 106-115页

作者： Michael Ehret Jakub Cikhardt philip Wykeham Bradford Iuliana-Mariana Vladisavlevici Tomas Burian Diego de Luis Jose Luis Henares Rubén Hernández Martín Jon Imanol Apiñaniz Roberto Lera JoséAntonio pérez-Hernández João Jorge Santos Giancarlo Gatti Centro de Láseres pulsados(CLpU) VillamayorSpain Czech Technical University in prague Faculty of Electrical EngineeringPragueCzech Republic Univ.Bordeaux-CNRS-CEA Centre Lasers Intenses et Applications(CELIA)UMR 5107TalenceFrance Department of Radiation and Chemical physics FZU-Institute of Physics of the Czech Academy of SciencesPragueCzech Republic

We report the first high-repetition-rate generation and simultaneous characterization of nanosecond-scale return currents of kA-magnitude issued by the polarization of a target irradiated with a pW-class high-repetition-rate titanium:sapphire laser system at relativistic *** present experimental results obtained with the VEGA-3 laser at intensities from5×10^(18)to 1.3×10^(20)W cm^(-2).A non-invasive inductive return-current monitor is adopted to measure the derivative of return currents of the order of kA ns-1and analysis methodology is developed to derive return *** compare the current for copper,aluminium and Kapton targets at different laser *** data show the stable production of current peaks and clear prospects for the tailoring of the pulse shape,which is promising for future applications in highenergy-density science,for example,electromagnetic interference stress tests,high-voltage pulse response measurements and charged particle beam *** compare the target discharge of the order of hundreds of nC with theoretical predictions and a good agreement is found.

关键词： current pulses electromagnetic pulse application high-power laser relativistic laser plasma

3D printing of poly(ethyleneimine)-functionalized Mg-Al mixed metal oxide monoliths for direct air capture of Co_(2)

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Journal of Energy Chemistry 2024年第9期96卷 491-500页

作者： Qingyang Shao Zhuozhen Gan Bingyao Ge Xuyi Liu Chunping Chen Dermot o’Hare Xuancan Zhu Research Center of Solar power&Refrigeration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Chemistry Research Laboratory Department of ChemistryUniversity of OxfordOxford OX13TAUK

Direct air capture(DAC)of Co_(2)plays an indispensable role in achieving carbon-neutral goals as one of the key negative emission *** large air flows are required to capture the ultradilute Co_(2)from the air,lab-synthesized adsorbents in powder form may cause unacceptable gas pressure drops and poor heat and mass transfer efficiencies.A structured adsorbent is essential for the implementation of gas-solid contactors for cost-and energy-efficient DAC *** this study,efficient adsorbent poly(ethyleneimine)(pEI)-functionalized Mg-Al-Co_(3)layered double hydroxide(LDH)-derived mixed metal oxides(MMos)are three-dimensional(3D)printed into monoliths for the first time with more than 90%adsorbent *** printing process has been optimized by initially printing the LDH powder into monoliths followed by calcination into MMo *** structure exhibits a 32.7%higher specific surface area and a 46.1%higher pore volume,as compared to the direct printing of the MMo powder into a *** impregnation of pEI,the monolith demonstrates a large adsorption capacity(1.82 mmol/g)and fast kinetics(0.7 mmol/g/h)using a Co_(2)feed gas at 400 ppm at 25℃,one of the highest values among the shaped DAC *** of the amino-polymers during the post-printing process affects the diffusion of Co_(2),resulting in slower adsorption kinetics of pre-impregnation monoliths compared to post-impregnation *** optimal pEI/MeoH ratio for the post-impregnation solution prevents pores clogging that would affect both adsorption capacity and kinetics.

关键词： 3D printing Mixed metal oxides Amine functionalization Structured adsorbent Direct air capture

Could school programs based on social-emotional learning prevent substance abuse among adolescents?

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World Journal of psychiatry 2024年第8期14卷 1143-1147页

作者： João Mauricio Castaldelli-Maia Nicolas Kohatsu Matakas Department of Neuroscience Medical SchoolFMABC University CenterSão Paulo 09060870SPBrazil Department of Substance Use Disorders Perdizes Institute-HCFMUSPSao Paulo 05021001SPBrazil

In this editorial,we comment on the article Adolescent suicide risk factors and the integration of social-emotional skills in school-based prevention programs by Liu et *** the article focused on the issue of suicide and social-emotional learning programs as a possible intervention,we here discuss evidence of other reported outcomes and if it could be an effective way to prevent substance abuse among adolescents.

关键词： Social-emotional learning Substance use Adolescent Student prevention Mental health

The missing hydrogen ion,part-3:Science and the human flaws that compromise it

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Sports Medicine and Health Science 2024年第2期6卷 193-199页

作者： Robert Robergs Bridgette o'Malley Sam Torrens School of Exercise and Nutrition Sciences Queensland University of TechnologyKelvin GroveQueensland4059Australia

The purpose of this research was to use a historical method and core principles from scientific philosophy to explain why mistakes were made in the development of the lactic acidosis *** a broader scope,this research explains what science is,why some scientists despite good intention,often get it wrong,and why it takes so long(decades)to correct these *** is a human behaviour that consists of the identification of a problem based on the correct application of prior knowledge,the development of a method to best resolve or test the problem,completion of these methods to acquire results,and then a correct interpretation of the *** these steps are done correctly there is an increased probability(no guarantee)that the outcome is likely to be *** Kuhn proposed that you can understand what science is from how it has been performed,and from his essays he revealed a very dysfunctional form of science that he called‘normal’(due the preponderance of its presence)***,Karl popper was adamant that the practice of‘normal’science revealed numerous flaws that deviate from fundamental principles that makes science,***,the evidence reveals that within the sports medicine and health sciences,as with all disciplines,errors in science are more frequent than you might *** is an urgent need to improve how we educate and train scientists to prevent the pursuit of‘normal’science and the harm it imparts on humanity.

关键词： Science Scientific philosophy ‘Normal’science Anomaly paradigm

Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

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Forest Ecosystems 2024年第1期11卷 110-119页

作者： J.Touche C.Calvaruso p.De Donato M.-p.Turpault INRAE BEFF-54000NancyFrance UMR 7359 GeoRessourcesFaculte des Sciences-Campus des Aiguillettes54506Vandoeuvre Les NancyFrance EcoSustain Environmental Engineering OfficeResearch and DevelopmentKanfen57330France

The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in *** possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced ***,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly *** experiment in a beech forest in Meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence *** aim was to identify potential nutritional consequences of droughts for *** nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(*** efficiency),thus reducing the K reserve in trees for the next growing *** result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study *** foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(p)were also *** addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree *** calcium(Ca)negative resorption decreased,with no apparent consequence in our study *** results show that nutrient exchanges in the canopy and the partitioning of the green leaf

关键词： Natural drought Beech forest Canopy Resorption Foliar leaching Senesced leaves Nutrition