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Injectable Hyaluronic Acid/Poly(y-glutamic acid)Hydrogel with Step-by-step Tunable Properties for Soft Tissue Engineering

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chinese Journal of Polymer Science 2021年第8期39卷 957-965,I0005页

作者： Xue-Bin ma Rong Yang Kanaparedu P.c.Sekhar Bo chi Key Laboratory of colloid and Interface chemistry of the Ministry of Education School of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China State Key Laboratory of materials-Oriented chemical Engineering College of Food Science and Light IndustryNanjing Tech UniversityNanjing 211816China

Injectable hydrogels as an important class of biomaterials have gained much attention in tissue ***,their crosslinking degree is difficult to be controlled after being injected into *** we all know,the crosslinking degree strongly influences the physicochemical properties of ***,developing an injectable hydrogel with tunable crosslinking degree in vivo is important for tissue ***,we present a dual crosslinking strategy to prepare injectable hydrogels with step-by-step tunable crosslinking degree using Schiff base reaction and *** developed hyaluronic acid/poly(y-glutamic acid)(HA/y-PGA)hydrogels exhibit step-by-step tunable swelling behavior,enzymatic degradation behavior and mechanical *** performance tests show that the storage moduli of HA/y-PGA hydrogels are all less than 2000 Pa and the compressive moduli are in kilopascal,which have a good match with soft *** addition,NIH 3T3 cells encapsulated in HA/y-PGA hydrogel exhibit a high cell viability,indicating a good cytocompatibility of HA/y-PGA ***,the developed HA/y-PGA hydrogel as an injectable biomaterial has a good potential in soft tissue engineering.

关键词： Hyaluronic acid Poly(y-glutamic acid) Injectable hydrogel Tissue engineering

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

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Neural Regeneration Research 2025年第2期20卷 394-401页

作者： Josep Tomàs Víctor cilleros-mañé Laia Just-Borràs marta Balanyà-Segura Aleksandra Polishchuk Laura Nadal marta Tomàs carolina Silvera-Simón manel M.Santafé maria A.Lanuza Unitat d’Histologia i Neurobiologia(UHNeurob) Facultat de Medicina i Ciències de la SalutUniversitat Rovira i VirgiliReusSpain

During the development of the nervous system,there is an overproduction of neurons and *** competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or *** have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse *** purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this *** particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and c(PKA and PKc)and voltage-gated calcium channels,at different nerve endings in developmental *** dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific *** describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon *** downstream displacement of the PKA/PKc activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary ***,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to red

关键词： acetylcholine release adenosine receptors axonal competition brain-derived neurotrophic factor calcium channels motor end-plate muscarinic acetylcholine receptors postnatal synapse elimination serine kinases tropomyosin-related kinase receptorB

AN ANALYSIS FOR DIFFRAcTION OF FLEXURAL WAVES AND DYNAMIc STRESS cONcENTRATIONS IN THIcK PLATES WITH A cAVITY

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Acta Mechanica Solida Sinica 1997年第2期10卷 167-178页

作者： Hu, c ma, XR Huang, WH Liu, DK HARBIN INST TEcHNOL HARBIN 150001PEOPLES R CHINA HARBIN ENGN UNIV HARBIN 150001PEOPLES R CHINA

By using the complex variable method and conformal mapping, the diffraction of flexural waves and dynamic stress concentrations in thick plates with a cavity have been studied. A general solution of the stress problem of the thick plate satisfying the boundary conditions on the contour of an arbitrary cavity is obtained. By employing the orthogonal function expansion technique, the dynamic stress problem can be reduced to the solution of an infinite algebraic equation series. As an example, the numerical results for the dynamic stress concentration factor in thick plates with a circular, elliptic cavity are graphically presented. The numerical results are discussed.

关键词： thick plate diffraction of flexural waves dynamic stress concentration complex variable method conformal mapping

An Inverse Approach for Extracting Elastic-plastic Properties of Thin Films from Small Scale Sharp Indentation

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Journal of materials Science & Technology 2012年第7期28卷 626-635页

作者： Z.S. ma Y.c. Zhou S.G. Long c.S. Lu Key Laboratory of Low Dimensional materials ~ Application Technology of Ministry of Education Xiangtan Uni-versity Xiangtan 411105 China Faculty of materials Optoelectronics and Physics Xiangtan University Xiangtan 411105 China Department of Mechanical Engineering Curtin University of Technology Perth WA 6845 Australia

An inverse method for extracting the elastic-plastic properties of metallic thin films from instrumented sharp indentation has been proposed in terms of dimensional analysis and finite element modeling. A wide range of materials with different elastic modulus, yield strength, and strain-hardening exponent were *** to the Nix-Gao model for the depth dependence of hardness H,the relationship between elastic modulus E and indentation depth h can be expressed as By combiningthese two formulas, we find that there is a relationship between yield stress and indentation depth h：where σyO is the yield strength associated with the strain-hardening exponent n, the true hardness Ho and the true elastic modulus *** constant, whichis only related to n, and hH and hE are characteristic lengths for hardness and elastic modulus. The results obtained from inverse analysis show that the elastic-plastic properties of thin films can be uniquely extracted from the solution of this relationship when the indentation size effect has to be taken into account.

关键词： Indentation Elastic-plastic properties Metal thin films Inverse analysis

X-ray Multiple Diffraction Topographic Imaging Technique For Growth History Study of Habit Modifying Impurity Doped crystals

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chemical Research in chinese Universities 2004年第4期20卷 411-416页

作者： LAI X. ma c. K. J. Robert M. c. Miller Institute of Particle Science and Engineering Department of Chemical Engineering University of LeedsInstitute of Particle Science and Engineering Department of Chemical Engineering University of LeedsInstitute of Particle Science and Engineering Department of Chemical Engineering University of LeedsCCLRC Daresbury Laboratory Daresbury Leeds LS2 9JT UKLeeds LS2 9JT UKLeeds LS2 9JT UKWarrington Cheshire WA4 4AD UK

A novel crystal characterization instrument has been built up in which a combination of X-ray multiple diffraction and X-ray topography is applied to enabling the cross-correlation between micro-crystallographic symmetry and its spatial dependence in relation to lattice defects. This facility is used to examine, in a self-consistent manner, growth sector-dependant changes to both the crystallographic structure and the lattice defects associated with the action of habit-modifying additives in a number of representative crystal growth systems. In addition, the new instrument can be used to probe micro-crystallographic aspects(such as distortion to crystal symmetry) and relate these in a spatially resolved manner to the crystal defect structure in crystals doped with known habit modifiers.

关键词： X-ray diffraction X-ray multiple diffraction X-ray topography Habit modification crystal growth Growth defects

Simultaneous removal of chromium and arsenate from contaminated groundwater by ferrous sulfate:Batch uptake behavior

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Journal of Environmental Sciences 2011年第3期23卷 372-380页

作者： Xiaohong Guan Haoran Dong Jun ma Irene M. c. Lo State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China Department of civil and Environmental Engineering The Hong Kong University of Science and Technology Hong Kong 999077 China

chromium and/or arsenate removal by Fe（Ⅱ） as a function of pH, Fe（Ⅱ） dosage and initial cr（Ⅵ）/As（Ⅴ） ratio were examined in batch tests. The presence of arsenate reduced the removal efficiency of chromium by Fe（Ⅱ）, while the presence of chromate significantly increased the removal efficiency of arsenate by Fe（Ⅱ） at pH 6-8, In the absence of arsenate, chromium removal by Fe（Ⅱ） increased to a maximum with increasing pH from 4 to 7 and then decreased with a further increase in pH. The increment in Fe（Ⅱ） dosage resulted in an improvement in chromium removal and the improvement was more remarkable under alkaline conditions than that under acidic conditions. chromium removal by Fe（Ⅱ） was reduced to a larger extent under neutral and alkaline conditions than that under acidic conditions due to the presence of 10 μtmol/L arsenate. The presence of 20 μmol/L arsenate slightly improved chromium removal by Fe（Ⅱ） at pH 3.9-5,8, but had detrimental effects at pH 6.7-9.8. Arsenate removal was improved significantly at pH 4-9 due to the presence of 10μmol/L chromate at Fe（Ⅱ） dosages of 20-60 μmol/L. Elevating the chromate concentration from 10 to 20μmol/L resulted in a further improvement in arsenate removal at pH 4.0-4.6 when Fe（Ⅱ） was dosed at 30-60 μmol/L.

关键词： chromium removal arsenate removal ferrous iron groundwater treatment

Exploring high thermal conductivity polymers via interpretable machine learning with physical descriptors

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npj computational materials 2023年第1期9卷 386-399页

作者： Xiang Huang Shengluo ma c.Y.Zhao Hong Wang Shenghong Ju china-UK Low carbon college Shanghai Jiao Tong UniversityShanghaiChina materials Genome Initiative center School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghaiChina

The efficient and economical exploitation of polymers with high thermal conductivity(Tc)is essential to solve the issue of heat dissipation in organic ***,the experimental preparation of functional polymers with high Tc remains a trial-and-error process due to the multi-degrees of freedom during the synthesis and characterization *** informatics equips machine learning(ML)as a powerful engine for the efficient design of polymers with desired ***,available polymer Tc databases are rare,and establishing appropriate polymer representation is still *** this work,we propose a high-throughput screening framework for polymer chains with high Tc via interpretable ML and physical feature *** hierarchical down-selection process stepwise optimizes the 320 initial physical descriptors to the final 20 dimensions and then assists the ML models to achieve a prediction accuracy R2 over 0.80,which is superior to traditional graph ***,we analyze the contribution of the individual descriptors to Tc and derive the explicit equation for Tc prediction using symbolic *** high Tc polymer structures are mostlyπ-conjugated,whose overlapping p-orbitals enable easy maintenance of strong chain stiffness and large group ***,we establish the connections between the individual chains and the amorphous state of *** chains with high Tc have strong intra-chain interactions,and their corresponding amorphous systems are favorable for obtaining a large radius of gyration and causing enhanced thermal *** proposed data-driven framework should facilitate the theoretical and experimental design of polymers with desirable properties.

关键词： properties process chains

Deep Learning Quantum States for Hamiltonian Estimation

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chinese Physics Letters 2021年第11期38卷 1-6页

作者： Xinran ma Z.c.Tu Shi-Ju Ran Department of Physics Beijing Normal UniversityBeijing 100875China Department of Physics Capital Normal UniversityBeijing 100048China

Human experts cannot efficiently access physical information of a quantum many-body states by simply "reading"its coefficients, but have to reply on the previous knowledge such as order parameters and quantum *** demonstrate that convolutional neural network(cNN) can learn from coefficients of many-body states or reduced density matrices to estimate the physical parameters of the interacting Hamiltonians, such as coupling strengths and magnetic fields, provided the states as the ground states. We propose QubismNet that consists of two main parts: the Qubism map that visualizes the ground states(or the purified reduced density matrices) as images, and a cNN that maps the images to the target physical parameters. By assuming certain constraints on the training set for the sake of balance, QubismNet exhibits impressive powers of learning and generalization on several quantum spin models. While the training samples are restricted to the states from certain ranges of the parameters, QubismNet can accurately estimate the parameters of the states beyond such training regions. For instance, our results show that QubismNet can estimate the magnetic fields near the critical point by learning from the states away from the critical vicinity. Our work provides a data-driven way to infer the Hamiltonians that give the designed ground states, and therefore would benefit the existing and future generations of quantum technologies such as Hamiltonian-based quantum simulations and state tomography.

关键词： cNN MSE RDM image Hamiltonian Deep Learning Quantum States for Hamiltonian Estimation Quantum

Ultrafast exciton relaxation dynamics of PbS and core/shell PbS/cdS quantum dots

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Science china chemistry 2011年第12期54卷 2009-2015页

作者： WHEELER Damon A FITZMORRIS Bob c ZHAO HaiGuang ma DongLing ZHANG JinZhong Department of chemistry and Biochemistry University of California Santa Cruz CA 95064 USA Energy Materials and Telecommunications Center- Institui National de la Recherche Scientifique University of Quebec Varennes Qudbec Canada J3X-IS2

Optical properties and ultrafast exciton relaxation dynamics in PbS and core/shell PbS/cdS quantum dots(QDs) have been studied using UV-vis absorption and fluorescence spectroscopy as well as femtosecond(fs) transient absorption *** electronic absorption spectrum of the PbS QDs features broad absorption in the entire near IR-vis-UV region with a monotonic increase in intensity towards shorter *** to PbS,the absorption of the core/shell PbS/cdS QDs shows a slight blue shift in the 600?800 nm region,due to the decrease of the PbS crystal size caused by the synthetic process of the core/shell structure,and increased absorption near 400 nm due to the cdS *** PL of the PbS/cdS QDs was ~2.6 times more intense than that of the PbS QDs,due to surface passivation of PbS by cdS,and blue-shifted,attributable to smaller PbS size and thereby stronger quantum confinement in the core/shell *** transient absorption measurements of both systems showed a strong transient absorption feature from 600 to 750 nm following excitation at 750 *** transient absorption decays can be fit to a biexponential with time constants of 8 and 100 ps for PbS and 6 and 80 ps for PbS/*** amplitude and lifetime of the fast component were excitation intensity dependent,with the amplitude increasing more than linearly with increasing excitation intensity and the lifetime decreasing with increasing *** fast decay is attributed to exciton-exciton annihilation and it occurs more readily for the PbS/cdS than the PbS QDs,which is attributed to a lower density of trap states in the core/shell QDs,as supported by their stronger PL.

关键词： ultrafast femtosecond pump-probe spectroscopy PbS PbS/cdS