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Structural changes in the obese brain

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neural regeneration research 2024年第12期19卷 2561-2562页

作者： Anna r.r.Da Conceicao Marcelo n.n.Vieira Fernanda G.De Felice D’Or Institute for research and Education Rio de JaneiroBrazil Institute of Medical Biochemistry Leopoldo De Meis Federal University of Rio de JaneiroRio de JaneiroBrazil Centre for.neuroscience Studies Department of Biomedical and Molecular Sciences&Department of PsychiatryQueen’s UniversityKingstonONCanada

Obesity represents a major global health concern,with widespread growing prevalence and severe consequences for the quality of life and life expectancy of affected individuals and for the economic burden of healthcare systems(Prospective Studies Collaboration,2009).Obesity is a well-established risk factor for a variety of conditions including metabolic,vascula r,and heart diseases,and seve ral types of cancer(Prospective Studies Collaboration,2009).

关键词： diseases consequences prevalence

Asymmetric Hydrogenation of Phenanthridines with Chiral Bor.nes

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Chinese Journal of Chemistry 2024年第6期42卷 631-635页

作者： Guangyu Cui Xiangqing Feng Haifeng du Beijing national Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Recognition and FunctionInstitute of ChemistryChinese Academy of SciencesBeijing100190 China University of Chinese Academy of Sciences Beijing100049 China

The asymmetric hydrogenation of n-heteroar.nes provides an efficient method for the synthesis of optically active cyclic secondary *** this paper,we described an asymmetric hydrogenation of phenanthridines using a chiral mono-alkene-derived bor.ne.A variety of dihydrophenanthridines were furnished in high yields with up to 93%*** curr.nt catalytic system was very sensitive for the steric hindr.nce of *** substituents at one phenyl group of phenanthridines were required to obtain the high *** large substituents on the carbon of the C=n bonds would diminish the reactivity sharply.

关键词： Asymmetric catalysis Hydrogenation nitrogen heterocycles Phenanthridines Frustrated Lewis pairs Chiral bor.nes

Aberr.nt adult neurogenesis in intractable epilepsy:can GABAergic progenitor tr.nsplantation normalize this process?

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neural regeneration research 2024年第7期19卷 1419-1420页

作者： Muhammad n.Arshad Janice r.naegele Department of Biology Wesleyan UniversityMiddletownCTUSA Department of neuroscience Tufts University School of MedicineBostonMAUSA

Temporal lobe epilepsy(TLE) is a common type of focal epilepsy characterized by seizure foci within the temporal *** surgical resection of the foci is an established and effective approach for controlling seizures,both temporal lobes cannot be removed,due to their prominent roles in learning and ***,seizures induce changes to the temporal lobes that contribute to hyperexcitability,including mossy fiber sprouting,astrogliosis.

关键词： epilepsy progenitor seizures

Fast-Charging Sodium-Ion Batteries Enabled by Molecular-Level Designed nitrogen and Phosphorus Codoped Mesoporous Soft Carbon

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research 2024年第2期2023卷 329-337页

作者： Lei Liu Zhuzhu du Jiaqi Wang Hongfang du Sheng Wu Mengjun Li Yixuan Zhang Jinmeng Sun Zhipeng Sun Wei Ai Fr.ntiers Science Center for Flexible Electr.nics(FSCFE)and Shaanxi Institute of Flexible Electr.nics(SIFE) Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'an 710072China Fujian Cross Strait Institute of Flexible Electr.nics(Future Technologies) Fujian Normal UniversityFuzhou 350117China School of Materials and Energy Guangdong University of TechnologyGuangzhou510006 GuangdongChina

Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggish reaction ***,we show a molecular design approach toward the fabrication of nitrogen and phosphorus codoped mesoporous soft carbon(nPSC).The key to this strategy lies in the chemical cross-linking reaction between polyphosphoric acid and p-phenylenediamine,associated with pyrolysis induced in-situ self-activation that creates mesoporous structures and rich heteroatoms within the carbon *** to the enlarged interlayer spacing,reduced ion diffusion length,and plentiful active sites,the obtained nPSC delivers a superb rate capacity of 215 mAh g-1 at 10 A g-1 and an ultralong cycle life of 4,700 cycles at 5 A g^(-1).remarkably,the full cell shows 99%capacity retention dur.ng 100 continuous cycles,and maximum energy and power densities of 191 Wh kg^(-1)and 9.2 kW kg^(-1),*** believe that such a synthetic protocol could pave a novel venue to develop soft carbons with unique properties for advanced SIBs.

关键词： kinetics carbons linking

Tr.nsfer relation between subgrade frost heave and slab track deformation and vehicle dynamic response in seasonally frozen ground

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Journal of Zhejiang University-Science A(Applied Physics & Engineer.ng) 2024年第2期25卷 130-146页

作者： Juanjuan r.n Junhong du Kaiyao ZHAnG Bin YAn Jincheng TIAn MOE Key Laboratory of High-speed railway Engineer.ng Southwest Jiaotong UniversityChengdu610031China School of Civil Engineer.ng Southwest Jiaotong UniversityChengdu610031China School of Civil Engineer.ng Central South UniversityChangsha410075China Airport Planning and Design Institute POWERCHINA Kunming Engineering Corporation LimitedKunming650051China

Subgrade frost heave in seasonally frozen ground can greatly influence the safety and smooth r.nning of high-speed trains and the service performance of track *** this study,we used a static model to:(1)investigate track-subgrade frost heave and develop a dynamic model of vehicle-track-subgrade frost heave;(2)explore the tr.nsfer relation between subgrade frost heave and track structure deformation;(3)examine the characteristics of interlayer debonding;(4)study the influence of subgrade frost heave on the dynamic response of vehicles in high-speed railways in seasonally frozen regions.A Fourier series was used to fit the frost heave waveform and simulate the behavior of subgrade uneven frost heave using data collected *** results show:(i)The position of frost heave significantly affects the tr.nsfer of deformation to a slab *** largest deformation of the track slab,with the amplitude tr.nsfer ratio reaching 20%,was recorded when the frost heave occurred near the joint of the base plate.(ii)At the same frost heave amplitude,long-wave frost heave causes smaller deformation and debonding of the track structure than short-wave frost *** the wavelength r.nge of 10-30 m,the main frequency of the acceleration spectral density was concentrated between 3.5 and 3.7 Hz,with larger frost heave wavelengths producing smaller superposition on the vertical acceleration of the vehicle.(ii)The maximum wheel-rail force occurs when the fr.nt bogie passes the frost heave peak,with greater frost heave amplitudes producing greater wheel-rail *** these results,we conclude there is a clear.need to control the frost heave deformation of the track to reduce the dynamic response of the vehicle and in turn improve train operatSubgrade frost heave in seasonally frozen ground can greatly influence the safety and smooth r.nning of high-speed trains and the service performance of track *** this study,we used a static model to:(1)investigate track`-subgr

关键词： Slab track Subgrade frost heave Tr.nsfer relation Vehicle-track-subgrade coupling Dynamic response

numerical simulation of gr.nular silicon growth and silicon fines formation process in polysilicon fluidized bed

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Particuology 2024年第4期87卷 74-86页

作者： Guangkai Gu Guoqiang Lv Wenhui Ma Shanlin du Boqiang Fu Faculty of Metallurgical and Energy Engineer.ng Kunming University of Science and TechnologyKunming 650093China State Key Laboratory of Complex nonferrous Metal resources Cleaning Utilization in Yunnan Province Kunming 650093China

Operating conditions str.ngly affect the yield and quality of polysilicon in a polysilicon fluidized *** this study,a new model of polysilicon fluidized bed was established using the Euler-Euler model coupled with population balance model(PBM),which was combined with fluid flow,heat,and mass tr.nsfer models,while consider.ng the scavenging effect of silicon *** effects of differ.nt operating conditions on the deposition and formation rates of silicon fines were *** show that the model can correctly describe the particle growth process in the fluidized bed of *** silicon fines and the interphase velocity differ.nce show"n"-and"M"-shaped distributions along the axial direction,*** particle temperature and concentration near the wall are higher than those in the central *** decomposition of silane in the bottom region of the bed is dominated by het-erogeneous *** scavenging of silicon fines occurs in the dilute-phase *** effects of operating conditions,*** gas temperature,silane composition,and gas velocity,on the reactor performance were also explored *** the inlet gas composition and velocity enhances the formation rates of solid silicon and *** the inlet gas temperature promotes the growth of solid silicon and inhibits the formation of silicon *** fluidization ratio,low inlet silane concentration,and high inlet gas temperature enhance the selectivity of silicon growth.

关键词： Polysilicon fluidized bed Particle growth Fines CFD Population balance model(PBM)

Polyelectrolyte Complexes between Hyperbr.nched and Linear Polysaccharides: Fucoidan/Chitosan

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Chinese Journal of Polymer Science 2024年第4期42卷 468-479页

作者： Ekater.na r.Gasilova Daria n.Poshina Aleksandra O.Sitnikova natalia n.Saprykina Yury A.Skorik Institute of Macromolecular Compounds of the russian Academy of Sciences Bolshoi VO 31St.Petersburg199004Russian Federation

Polyelectrolyte complexes(PECs)of hyperbr.nched(HB)and linear polysaccharides are promising as more effective encapsulation agents compared to PECs formed by linear *** investigated the PECs between the HB anionic polysaccharide fucoidan(FUC)and the cationic linear polysaccharide chitosan(CS).The FUC had a molecular weight(MW)of 30×*** PECs were prepared in three solvents(water,0.01 and 0.1 mol/L acetic acid)with CS of MW of 15,110 and 170 kDa,and deacetylation degrees(DDA)of 70%and 97%.The structures of the PECs and the initial FUC were investigated by multi-angle static and dynamic light *** the FUC contained 18 wt%of—OSO3 groups and 5 wt%of ur.nic acid units,it was a“str.ng-weak”copolyanion,so the HB macromolecules of the FUC formed nanogel particles in 0.1 mol/L AcOH and open br.nched structures in water,as confirmed by the Kratky *** mixing the solutions of original components,the PEC structures underwent an equilibration period,the duration of which increased with the MW of *** the charge stoichiometry was approached,the PECs shr.nk;the fractal dimension approached unity,indicating the side-by-side packing of adjacent FUC br.nches with the help of *** aggregation in the vicinity of the charge compensation was hardly observed,as it occurred in a very narrow *** PEC content at theζ-potential inversion depended on solvents’pH and the DDA of *** the extreme case of core-shell PECs in 0.1 mol/L AcOH,obtained by mixing FUC nanogels with the solutions of high MW CS of 97%DDA,the protruding tails of CS formed a positively charged shell in the whole r.nge of FUC content(10 wt%nning electr.n microscopy and atomic force microscopy images of dried samples were discussed in relation to the light scatter.ng results.

关键词： Polyelectrolyte complexes Chitosan Hyperbr.nched fucoidan Light scatter.ng

Biomimetic soft robotic wrist with 3-DOF motion and stiffness tunability based on r.ng-reinforced pneumatic actuators and a particle jamming joint

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Science China(Technological Sciences) 2024年第3期67卷 774-790页

作者： HU TeTe LU XinJiang YI Jian WAnG YuHui XU du State Key Laboratory of Precision Manufactur.ng for Extreme Service Performance School of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The human wrist, a complex articulation of skeletal muscles and two-carpal rows, substantially contributes to improvements in maneuverability by agilely performing three-degree-of-freedom(3-DOF) orienting tasks and regulating stiffness according to variations in interaction forces. However, few soft robotic wrists simultaneously demonstrate dexterous 3-DOF motion and variable stiffness;in addition, they do not fully consider a soft-rigid hybrid structure of integrated muscles and two carpal *** this study, we developed a soft-rigid hybrid structure to design a biomimetic soft robotic wrist(BSrW) that is capable of rotating in the x and y directions, twisting around the z-axis, and possessing stiffness-tunable capacity. To actuate the BSrW, a lightweight soft-r.ng-reinforced bellows-type pneumatic actuator(SrBPA) with large axial, linear deformation(η_(lcmax)=70.6%,η_(lemax)=54.3%) and small radial expansion(η_(demax)=3.7%) is designed to mimic the motion of skeletal muscles. To represent the function of two-carpal rows, a compact particle-jamming joint(PJJ) that combines particles with a membr.ne-covered ballsocket mechanism is developed to achieve various 3-DOF motions and high axial load-carrying capacity(>60 n). By varying the jamming pressure, the stiffness of the PJJ can be adjusted. Finally, a centrally positioned PJJ and six independently actuated SrBPAs, which are in an inclined and antagonistic arr.ngement, are sandwiched between two rigid plates to form a flexible,stable, and compact BSrW. Such a structure enables the BSrW to have a dexterous 3-DOF motion, high load-carrying ability,and stiffness tunability. Experimental analysis verify 3-DOF motion of BSrW, producing force of 29.6 n and 36 n and torque of2.2 nm in corresponding rotations. Moreover, the r.nge of rotational angle and stiffness-tuning properties of BSrW are studied by applying jamming pressure to the PJJ. Finally, a system combining a BSrW and a soft enclosing gripper is proposed to demo

关键词： pneumatic soft actuators particle jamming robotic wrist soft robotics stiffness-tunable

Stress-corrosion coupled damage localization induced by secondary phases in bio-degradable Mg alloys:phase-field modeling

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Journal of Magnesium and Alloys 2024年第1期12卷 361-383页

作者： Chao Xie Shijie Bai Xiao Liu Minghua Zhang Jianke du The Faculty of Mechanical Engineer.ng and Mechanics Ningbo UniversityNingbo 315211P.R.China Key Laboratory of High Temperature Wear resistant Materials Preparation Technology of Hunan Province Hunan University of Science and TechnologyXiangtan 411201P.R.China

In this study,a phase-field scheme that rigorously obeys conservation laws and irreversible thermodynamics is developed for modeling stress-corrosion coupled damage(SCCD).The coupling constitutive relationships of the deformation,phase-field damage,mass tr.nsfer,and electrostatic field are derived from the entropy *** SCCD localization induced by secondary phases in Mg is numerically simulated using the implicit iterative algorithm of the self-defined finite *** quantitative evaluation of the SCCD of a C-r.ng is in good agreement with the experimental *** capture the damage localization,a micro-galvanic corrosion domain is defined,and the buffer.ng effect on charge migration is *** cases are investigated to reveal the effect of localization on corrosion acceleration and provide guidance for the design for resistance to SCCD at the crystal scale.

关键词： Phase field Mg alloys Stress-corrosion coupled damage Damage localization Finite element method