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Cellular & Molecular Immunology 2014年第1期11卷 1-4页

作者： Chang h kim Laboratory of Immunology and hematopoiesis Department of Comparative Pathobiology Weldon School of Biomedical Engineering Purdue Center for Cancer Research PurdueUniversity West Lafayette IN 47907 USA

tcells are one of the most migratory cells in the body. the development and function of t cells depend on their interaction with other cells, which is, in turn, dependent on optimal cell migra- tion. t cells migrate largely in three dif- ferent ways： rapid distribution via blood vessels through hemodynamic move- ment, transendothelial migration and interstitial movement. transendothelial migration involves sequential activation of selectins, chemokine receptors and integrin molecules expressed by migrat- ing t cells, leading to extravasation from blood vessel into local tissue environ- ments.

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Review of Cellulose Smart Material: Biomass Conversion Process and Progress on Cellulose-Based Electroactive Paper

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Journal of Renewable Materials 2018年第1期6卷 1-25页

作者： S.h.hassan Lee hwei Voon t.S.Velayutham Lindong Zhai hyun Chan kim Jaehwan kim Nanotechnology and Catalysis Research Center(NanoCat) Institute of Postgraduate StudiesUniversity of Malaya50603 Kuala LumpurMalaysia Low Dimensional Materials Research Center Department of PhysicsFaculty of ScienceUniversity of Malaya50603 Kuala LumpurMalaysia Department of Mechanical Engineering Inha UniversityIncheon 22212South Korea

Cellulose is a renewable biomass material and natural polymer which is abundantly available on Earth,and includes agricultural wastes,forestry residues,and woody *** excellent and smart characteristics of cellulose materials,such as lightweight,biocompatibility,biodegradability,high mechanical strength/stiffness and low thermal expansibility,have made cellulose a highpotential material for various industry *** has recently been discovered as a smart material in the electroactive polymers family which carries the name of cellulose-based electroactive paper(EAPap).the shear piezoelectricity in cellulose polymers is able to induce large displacement output,low actuation voltage,and low power consumption in the application of biomimetic sensors/actuators and electromechanical *** present study provides an overview of biomass pretreatment from various lignocellulosic cellulose(LC)resources and nanocellulose production via tEMPO-mediated oxidation reaction,followed by the production of different types of EAPap versus its performance,and lastly the applications of EAPap in different areas and ***,LC biomass consists mainly of cellulose having a small content of hemicelluloses and lignins which form a defensive inner structure against the degradation of plant cell ***,selective approaches are discussed to ensure proper extraction of cellulosic fibers from complex biomass for further minimization to *** addition,a comprehensive review of the development of cellulose-based EAPap as well as fabrication,characterization,performance enhancement and applications of EAPap devices are discussed herein.

关键词： Biomass pretreatment nanocellulose renewable materials smart materials actuators

Measuring nanoscale friction at graphene step edges

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Friction 2020年第4期8卷 802-811页

作者： Zhe ChEN Seong h.kim Department of Chemical Engineering and Materials Research Institute Pennsylvania State UniversityUniversity ParkPA 16802USA

Although graphene is well known for super-lubricity on its basal plane, friction at its step edge is not well understood and contradictory friction behaviors have been reported. In this study, friction of mono-layer thick graphene step edges was studied using atomic force microscopy (AFM) with a Si tip in dry nitrogen atmosphere. It is found that, when the tip slides over a'buried' graphene step edge, there is a resistive force during the step-up motion and an assistive force during the step-down motion due to the topographic height change. the magnitude of these two forces is small and the same in both step-up and step-down motions. As for the'exposed' graphene step edge, friction increases in magnitude and exhibits more complicated behaviors. During the step-down motion of the tip over the exposed step edge, both resistive and assistive components can be detected in the lateral force signal of AFM if the scan resolution is sufficiently high. the resistive component is attributed to chemical interactions between the functional groups at the tip and step-edge surfaces, and the assistive component is due to the topographic effect, same as the case of buried step edge. If a blunt tip is used, the distinct effects of these two components become more prominent. In the step-up scan direction, the blunt tip appears to have two separate topographic effects–elastic deformation of the contact region at the bottom of the tip due to the substrate height change at the step edge and tilting of the tip while the vertical position of the cantilever (the end of the tip) ascends from the lower terrace to the upper terrace. the high-resolution measurement of friction behaviors at graphene step edges will further enrich understanding of interfacial friction behaviors on graphene-covered surfaces.

关键词： friction graphene step edge atomic force microscopy tip bluntness

Complex regulatory effects of gut microbial short-chain fatty acids on immune tolerance and autoimmunity

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Cellular & Molecular Immunology 2023年第4期20卷 341-350页

作者： Chang h.kim Department of Pathology University of Michigan School of MedicineAnn ArborMI48109USA Mary h.Weiser Food Allergy Center Center for Gastrointestinal Researchand Rogel Center for Can

Immune tolerance deletes or suppresses autoreactive lymphocytes and is established at multiple levels during the development,activation and effector phases of t and B *** mechanisms are cell-intrinsically programmed and critical in preventing autoimmune *** have witnessed the existence of another type of immune tolerance mechanism that is shaped by lifestyle choices,such as diet,microbiome and microbial ***-chain fatty acids(SCFAs)are the most abundant microbial metabolites in the colonic lumen and are mainly produced by the microbial fermentation of prebiotics,such as dietary *** review focuses on the preventive and immunomodulatory effects of SCFAs on *** tissue-and disease-specific effects of dietary fiber,SCFAs and SCFA-producing microbes on major types of autoimmune diseases,including type I diabetes,multiple sclerosis,rheumatoid arthritis and lupus,are ***,their key regulatory mechanisms for lymphocyte development,tissue barrier function,host metabolism,immunity,autoantibody production,and inflammatory effector and regulatory lymphocytes are *** shared and differential effects of SCFAs on different types and stages of autoimmune diseases are discussed.

关键词： Short-chain fatty acids Immune tolerance Diabetes mellitus Rheumatoid arthritis Lupus Multiple sclerosis

Control of lymphocyte functions by gut microbiota-derived short-chain fatty acids

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Cellular & Molecular Immunology 2021年第5期18卷 1161-1171页

作者： Chang h.kim Department of Pathology and Mary h.Weiser Food Allergy Center University of Michigan School of MedicineAnn ArborMIUSA

A mounting body of evidence indicates that dietary fiber(DF)metabolites produced by commensal bacteria play essential roles in balancing the immune ***,considered nonessential nutrients in the past,is now considered to be necessary to maintain adequate levels of immunity and suppress inflammatory and allergic ***-chain fatty acids(SCFAs),such as acetate,propionate,and butyrate,are the major DF metabolites and mostly produced by specialized commensal bacteria that are capable of breaking down DF into simpler saccharides and further metabolizing the saccharides into *** act on many cell types to regulate a number of important biological processes,including host metabolism,intestinal functions,and immunity *** review specifically highlights the regulatory functions of DF and SCFAs in the immune system with a focus on major innate and adaptive *** information regarding how SCFAs regulate innate lymphoid cells,t helper cells,cytotoxic t cells,and B cells and how these functions impact immunity,inflammation,and allergic responses are discussed.

关键词： Microbiota Dietary fiber Short-chain fatty acids Innate lymphoid cells B cells th1 th17 tregs CD8 Microbial metabolites

Numerical simulation and experimental study for rheo-forged component using direct and indirect die system

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transactions of Nonferrous Metals Society of China 2010年第9期20卷 1799-1804页

作者： h.h.kim C.G.KANG Precision Manufacturing Systems Division Pusan National University School of Mechanical Engineering Pusan National University

Sand casting and die casting processes have been used widely for complex automotive products such as knuckle, arm, ***, a part fabricated by casting has limited strength due to manufacturing defects such as the dendrite structure, segregation and *** an attempt to offer a solution to these problems, forging has been used as an alternative ***, the forging process provides limited formability for complex shape ***-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming *** order to produce semi-solid materials of the desired microstructure, a stirring process is applied during solidification of molten *** results of an A356 aluminum alloy sample, which are obtained by experiment and by simulation using DEFORM 3D, are present.

关键词： rheo-forging A356 alloy formability forming defects

Anomalously Strong Scattering of Spontaneously Produced Laser Radiation in the First Free-Electron Laser and Study of Free-Electron two-Quantum Stark Lasing in an Electric Wiggler with Quantum-Wiggler Electrodynamics

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Chinese Physics Letters 2006年第6期23卷 1422-1425页

作者： S. h. kim Department of Physics University of Texas at Arlington PO Box 19059 Arlington Texas 76019 USA

We calculate the scattering cross section of an electron with respect to the spontaneously produced laser radiation in the first free-electron laser （FEL） with quantum-wiggler electrodynamics （QWD）. the cross section is 1016 times the thomson cross section, confirming the result obtained by a previous analysis of the experimental data. A QWD calculation show that spontaneous emission in an FEL using only an electric wiggler can be very strong while amplification through net stimulated emission is practically negligible.

关键词： CLASSICAL ELECtRODYNAMICS RELAtIVIStIC ELECtRONS thERMODYNAMICS EXPLANAtION EMISSION

A cost driven predictive maintenance policy for structural airframe maintenance

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Chinese Journal of Aeronautics 2017年第3期30卷 1242-1257页

作者： Yiwei WANG Christian GOGU Nicolas BINAUD Christian BES Raphael t.hAFtKA Nam h.kim Universite de toulouse INSA/UPS/ISAE/Mines Albi ICA UMR CNRS 5312 Toulouse 31400 Frallce Department of Mechanical & Aerospace Engineering University of Florida Gainesville 32611 USA

Airframe maintenance is traditionally performed at scheduled maintenance *** decision to repair a fuselage panel is based on a fixed crack size threshold,which allows to ensure the aircraft safety until the next scheduled maintenance *** progress in sensor technology and data processing techniques,structural health monitoring（ShM） systems are increasingly being considered in the aviation *** systems track the aircraft health state continuously,leading to the possibility of planning maintenance based on an actual state of aircraft rather than on a fixed *** paper builds upon a model-based prognostics framework that the authors developed in their previous work,which couples the Extended Kalman filter（EKF） with a firstorder perturbation（FOP） *** using the information given by this prognostics method,a novel cost driven predictive maintenance（CDPM） policy is proposed,which ensures the aircraft safety while minimizing the maintenance *** proposed policy is formally derived based on the trade-off between probabilities of occurrence of scheduled and unscheduled maintenance.A numerical case study simulating the maintenance process of an entire fleet of aircrafts is *** the condition of assuring the same safety level,the CDPM is compared in terms of cost with two other maintenance policies：scheduled maintenance and threshold based ShM *** comparison results show CDPM could lead to significant cost savings.

关键词： Extended Kalman filter First-order perturbation method Model-based prognostic Predictive maintenance Structural airframe maintenance

Electric-Wiggler-Enhanced three-Quantum Scattering and the Output Power Affected by this Scattering in a Free-Electron Laser

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Chinese Physics Letters 2009年第1期26卷 58-61页

作者： S. h. kim 6300 Roundrock trail #4203 Piano Texas 75023 USA

We derive the cross section of scattering through the three-quantum interaction of an electron with the incident laser field, the emitted photon, and an axial electrostatic field produced by the magnetic wiggler in the magnetic wiggler acting as the sole zeroth-order perturbing classical field in the first free-electron laser （FEL）. In the derivation, we apply quantum-wiggler electrodynamics （QWD）. We find that this scattering predominates the usual two-quantum scattering. the output power of spontaneous free-electron two-quantum Stark emission driven by the above electrostatic field attenuated by the three-quantum scattering agrees within a factor of 10 with the measured power in the case of the first FEL.

关键词： field emission molybdenum dioxide enhancement factor

多功能胃肠线圈导管在结直肠支架置入病人中的应用研究

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国际医学放射学杂志 2009年第1期32卷 88-88页

作者： t.h. kim h.Y. Song J.h. Shin I.K. Park J.h. kim J.O. Lim 周丽娜 Asan Medical Center Radiology and Research Institute of Radiology Seoul South Korea

本研究主要评估多功能胃肠线圈导管在98例结直肠狭窄支架置入术病人中的应用价值。共有98例结直肠狭窄需支架置入的病人使用该导管进行内支架置入术．其中直肠狭窄者24例，直肠-乙状结肠交界狭窄者13例．乙状结肠狭窄者38例，降结肠狭窄... 详细信息

本研究主要评估多功能胃肠线圈导管在98例结直肠狭窄支架置入术病人中的应用价值。共有98例结直肠狭窄需支架置入的病人使用该导管进行内支架置入术．其中直肠狭窄者24例，直肠-乙状结肠交界狭窄者13例．乙状结肠狭窄者38例，降结肠狭窄者6例，横结肠狭窄者11例，脾曲狭窄者3例，肝曲狭窄者2例，升结肠狭窄者1例。

关键词：结肠介入操作胃肠道