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Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina hromada Patrick heimel Markus Kerbl lászlóGál Sylvia Nürnberger Barbara Schaedl James Ferguson Nicole Swiadek Xavier Monforte Johannes C.heinzel Antal Nógrádi Andreas h.Teuschl-Woller David hercher Department life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria ludwig Boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). however, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

Geometrically exact nonlinear analysis of pre-twisted composite rotor blades

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Chinese Journal of Aeronautics 2018年第2期31卷 300-309页

作者： li'na shang Pinqi XIA Dewey h.hODGES College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Guggenheim School of Aerospace Engineering Georgia Institute of Technology

Modeling of pre-twisted composite rotor blades is very complicated not only because of the geometric non-linearity, but also because of the cross-sectional warping and the transverse shear deformation caused by the anisotropic material properties. In this paper, the geometrically exact nonlinear modeling of a generalized Timoshenko beam with arbitrary cross-sectional shape,generally anisotropic material behavior and large deflections has been presented based on hodges＇ method. The concept of decomposition of rotation tensor was used to express the strain in the beam. The variational asymptotic method was used to determine the arbitrary warping of the beam cross section. The generalized Timoshenko strain energy was derived from the equilibrium equations and the second-order asymptotically correct strain energy. The geometrically exact nonlinear equations of motion were established by hamilton＇s principle. The established modeling was used for the static and dynamic analysis of pre-twisted composite rotor blades, and the analytical results were validated based on experimental data. The influences of the transverse shear deformation on the pre-twisted composite rotor blade were investigated. The results indicate that the influences of the transverse shear deformation on the static deformation and the natural frequencies of the pre-twisted composite rotor blade are related to the length to chord ratio of the blade.

关键词： Geometrically exact Nonlinear Pre-twisted composite blade Transverse shear deformation Variational asymptotic Warping

Tensile properties of functionalized carbon nanothreads

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Nano Materials Science 2022年第3期4卷 220-226页

作者： haifei Zhan Jing shang Chaofeng lü Yuantong Gu Department of Civil Engineering Zhejiang UniversityHangzhou310058PR China School of Mechanical Medical and Process EngineeringQueensland University of Technology(QUT)BrisbaneQLD4001Australia Center for Materials Science Queensland University of Technology(QUT)BrisbaneQLD4001Australia

low dimensional sp~3 carbon nanostructures have attracted increasing attention recently, due to their unique properties and appealing applications. Based on in silico studies, this work exploits the impacts from functional groups on the tensile properties of carbon nanothreads(NTh)– a new sp~3 carbon nanostructure. It is found that functional groups will alter the local bond configuration and induce initial stress concentration, which significantly reduces the fracture strain/strength of NTh. Different functional types lead to different local bond reconfigurations, and introduce different impacts on NTh. Further studies reveal that the tensile properties decreases generally when the content of functional groups increases. however, some NThs with higher content of functional groups exhibit higher fracture strain/strength than their counterparts with lower percentage. Such observations are attributed to the synergetic effects from the sample length, self-oscillation, and distribution of functional groups. Simulations show that the tensile behaviour of NTh with the same functional percentage differs when the distribution pattern varies. Overall, ethyl groups are found to induce larger degradation on the tensile properties of NTh than methyl and phenyl groups. This study provides a comprehensive understanding of the influence from functional groups, which should be beneficial to the engineering applications of NTh.

关键词： Carbon nanothread Functional group Tensile deformation Stress concentration Molecular dynamics simulation

Spraying Arginine at 5 Days before harvest Delays Postharvest Broccoli Senescence via Nutrient Accumulation

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食品科学 2025年第1期46卷 131-141页

作者： SUN Yupeng ChEN Ying shang Qingwen GUO Yanyin ZhANG Yuxiao WANG Yunqiao XUE Qingyue College of Agricultural Engineering and Food Science Shandong University of TechnologyZibo 255049China Zichuan District Agricultural and Rural Affairs Service Center Zibo 255049China

To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/l)was conducted at 0,1,3,and 5 days before *** appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of *** results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli ***,during the growth stage,total sugar accumulation was higher in the 5-ARG *** addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest *** conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of ***,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.

关键词： arginine broccoli preharvest spraying nutrient accumulation storage quality postharvest senescence

Probabilistic assessment of tunnel convergence considering spatial variability in rock mass properties using interpolated autocorrelation and response surface method

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Geoscience Frontiers 2018年第6期9卷 1619-1629页

作者： Qing lü Zhipeng Xiao Jun Zheng Yuequan shang College of Civil Engineering and Architecture Zhejiang University

This study aims at the probabilistic assessment of tunnel convergence considering the spatial variability in rock mass properties. The method of interpolated autocorrelation combined with finite difference analysis is adopted to model the spatial variability of rock mass properties. An iterative procedure using the first-order reliability method(FORM) and response surface method(RSM) is employed to compute the reliability index and its corresponding design point. The results indicate that the spatial variability considerably affects the computed reliability index. The probability of failure could be noticeably overestimated in the case where the spatial variability is neglected. The vertical scale of fluctuation has a much higher effect on the probabilistic result with respect to the tunnel convergence than the horizontal scale of fluctuation. And the influence of different spacing of control points on the computational accuracy is investigated.

关键词： Spatial variability Rock mass Tunnel convergence FORM Random field

Micro-sized and Nano-sized Fe_3O_4 Particles as Anode Materials for lithium-ion Batteries

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Journal of Materials Science & Technology 2011年第1期27卷 41-45页

作者： Y.X.Chen l.h.he P.J.shang Q.l.Tang Z.Q.liu h.B.liu l.P.Zhou College of Materials Science and Engineering Hunan UniversityChangsha 410082China Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Micro-sized（1030.3±178.4 nm） and nano-sized（50.4±8.0 nm） Fe3O4 particles have been fabricated through hydrogen thermal reduction of α-Fe2O3 particles synthesized by means of a hydrothermal *** morphology and microstructure of the micro-sized and the nano-sized Fe3O4 particles were characterized by X-ray diffraction,field-emission gun scanning electron microscopy,transmission electron microscopy and highresolution electron *** micro-sized Fe3O4 particles exhibit porous structure,while the nano-sized Fe3O4 particles are solid *** electrochemical performance was also *** nano-sized solid Fe3O4 particles exhibit gradual capacity fading with initial discharge capacity of 1083.1 mAhg-1 and reversible capacity retention of 32.6% over 50 ***,the micro-sized porous Fe3O4 particles display very stable capacity-cycling behavior,with initial discharge capacity of 887.5 mAhg-1 and charge capacity of 684.4 mAhg-1 at the 50th ***,77.1% of the reversible capacity can be maintained over 50 *** micro-sized porous Fe3O4 particles with facile synthesis,good cycling performance and high capacity retention are promising candidate as anode materials for high energy-density lithium-ion batteries.

关键词： lithium-ion battery Fe3O4 Porous structure Anode materials

Surface deformation-dependent mechanical properties of bending nanowires:an ab initio core-shell model

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Applied Mathematics and Mechanics(English Edition) 2022年第2期43卷 219-232页

作者： Ye XIAO J.shang l.Z.KOU Chun lI School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China MIIT Key laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi’an710072China School of Mechanical Medical and Process EngineeringQueensland University of TechnologyBrisbaneQLD4000Australia

An ab initio core-shell model is proposed to evaluate the surface effect in bending nanowires,in which the elastic modulus depends on the surface relaxation and deformation induced by external *** using first-principles calculations based on the density functional theory(DFT),the surface and bulk properties are calculated for Ag,Pb,and Si *** obtained theoretical predictions of the effective Young’s modulus of nanowires agree well with the experimental data,which shows that the fixed-fixed nanowire is stiffened and the cantilevered nanowire is softened as the characteristic size of the cross section ***,the contrastive analysis on the two kinds of nanowires demonstrates that increasing the nanowire aspect ratio would enhance the surface *** present results could be helpful for understanding the size effect in nanowires and designing nanobeam-based devices in nanoelectromechanical systems(NEMSs).

关键词： surface effect density functional theory(DFT) surface relaxation surface stress nanowire

A Quantitative Analysis of Mn Segregation at Partitioned Ferrite/Austenite Interface in a Fe-C-Mn-Si Alloy

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Journal of Materials Science & Technology 2009年第3期25卷 383-388页

作者： h. Guo S.W. Yang C.J.shang X.M. Wang X.l. he Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China

Mn segregation at austenite/ferrite interface is studied in a Fe-C-Mn-Si alloy held at 656℃. Mn is partitioned during the growth of ferrite and as a result, a Mn pile-up exists in front of interface on the matrix side. An approach to evaluate Mn segregation quantitatively is developed by combining STEM raster window scanning and simulation of the interaction of the electron beam with the sample to subtract the contribution of Mn pile-up and obtain pure Mn segregation value. The evaluated maximum Mn interfacial segregation is in the order of a half-monolayer.

关键词： Interfacial segregation Phase transformation STEM Beam broadening

A new approach to solar flare prediction

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Frontiers of physics 2020年第3期15卷 123-149,F0004页

作者： Michael l.Goodman Chiman Kwan Bulent Ayhan Eric l.shang Jacobs Space Exploration Group Natural Environments Branch-EV44NASA Marshall Space Flight CenterHuntsvilleAL35812USA Applied Research llC 9605 Medical Center Drive-Suite 127 ERockvilleMD20850USA

All three components of the current density are required to compute the heating rate due to free magnetic energy *** we present a first test of a new model developed to determine if the times of increases in the resistive heating rate in active region(AR)photospheres are correlated with the subsequent occurrence of M and X flares in the corona.A data driven,3D,non-force-free magnetohydrodynamic model restricted to the near-photospheric region is used to compute time series of the complete current density and the resistive heating rate per unit volume[Q(t)]in each pixel in neutral line regions(NlRs)of 14 *** model is driven by time series of the magnetic field B measured by the helioseismic&Magnetic Imager on the Solar Dynamics Observatory(SDO)*** Doppler periods due to SDO orbital motion are filtered out of the time series for B in every AR *** each AR,the cumulative distribution function(CDF)of the values of the NlR area integral Qi(t)of Q(t)is found to be a scale invariant power law distribution essentially identical to the observed CDF for the total energy released in coronal *** suggests that coronal flares and the photospheric Qi are correlated,and powered by the same *** model predicts spikes in Qi with values orders of magnitude above background *** spikes are driven by spikes in the non-force free component of the current *** times of these spikes are plausibly correlated with times of subsequent M or X flares a few hours to a few days *** spikes occur on granulation scales,and may be signatures of heating in horizontal current *** is also found that the times of relatively large values of the rate of change of the NlR unsigned magnetic flux are also plausibly correlated with the times of subsequent M and X flares,and spikes in Qi.

关键词： active regions magnetic fields flares forecasting heating photosphere models magnetohydrodynamics