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Phylogenetic relationship,biogeography,and conservation genetics of endangered Fraxinus chiisanensis(Oleaceae),endemic to South Korea

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Plant Diversity 2022年第2期44卷 170-180页

作者： Changkyun kim Dong-Kap kim Hang Sun joo-Hwan kim Plant Research Division Honam National Institute of Biological ResourcesMokpo 58762Republic of Korea Forest Biodiversity Division Korea National ArboretumPocheon 11186Republic of Korea CAS Key Laboratory for Plant Biodiversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650204YunnanPR China Department of Life Science Gachon UniversitySeongnam 13120Republic of Korea

Endemic plants are important for understanding phylogenetic relationships,biogeographical history,and genetic variation because of their restricted distribution and their role in conserving ***,we investigated the phylogenetic relationships of the Korean endemic Fraxinus chiisanensis by reconstructing the molecular phylogeny of Fraxinus based on two nuclear DNA(nrITS and phantastica)and two chloroplast DNA(psbA-trnH and rp132-trnL)*** our fossil-calibrated phylogenetic framework,we also inferred the biogeographical history of *** provide a scientific basis for the conservation of ***,we determined the levels of genetic diversity and genetic differentiation in this *** information from nuclear and chloroplast DNA sequence data,our molecular phylogenetic analyses identified *** as a genetically distinct unit from its sister group,Fraxinus platypoda from *** molecular dating analyses using nuclear and chloroplast DNA data sets show *** diverged from its sister *** in the Early or Middle Miocene and differentiated in the Late Miocene on the Korean *** results suggest that the divergence of *** was associated with the submergence of the East China Sea land bridge and enhanced monsoons in East *** compared to ***,*** exhibits low genetic diversity within populations and high genetic differentiation among *** results help us to understand the evolutionary history of *** and to develop a conservation strategy for this species.

关键词： East China Sea land bridge Endemic species Fraxinus chiisanensis Korean Peninsula Genetic diversity Biogeography

Dendritic cell-mimicking scaffolds for ex vivo T cell expansion

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Bioactive Materials 2023年第3期21卷 241-252页

作者： Hye Sung kim Tzu-Chieh Ho Moshe j.Willner Michael W.Becker Hae-Won kim Kam W.Leong Department of Biomedical Engineering Columbia UniversityNew YorkNYUSA Institute of Tissue Regeneration Engineering Dankook UniversityCheonanRepublic of Korea Wilmot Cancer Institute University of Rochester Medical CenterRochesterNYUSA Department of Regenerative Dental Medicine College of DentistryDankook UniversityCheonanRepublic of Korea Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine Dankook UniversityCheonanRepublic of Korea Mechanobiology Dental Medicine Research Center Dankook UniversityCheonanRepublic of Korea Department of Systems Biology Columbia University Irving Medical CenterNew YorkNY10032USA

We propose an ex vivo T cell expansion system that mimics natural antigen-presenting cells(APCs)for adoptive cell therapy(ACT).Microfiber scaffolds coated with dendritic cell(DC)membrane replicate physicochemical properties of dendritic cells specific for T cell activation such as rapid recognition by T cells,long duration of T cell tethering,and DC-specific co-stimulatory *** DC membrane-coated scaffold is first surface-immobilized with T cell stimulatory ligands,anti-CD3(αCD3)and anti-CD28(αCD28)antibodies,followed by adsorption of releasable interleukin-2(IL-2).The scaffolds present both surface and soluble cues to T cells ex vivo in the same way that these cues are presented by natural APCs in *** demonstrate that the DC-mimicking scaffold promotes greater polyclonal expansion of primary human T cells as compared toαCD3/αCD28-func-tionalized *** importantly,major histocompatibility complex molecules derived from the DC membrane of the scaffold allow antigen-specific T cell expansion with target cell-specific killing *** addition,most of the expanded T cells(~97%)can be harvested from the scaffold by density gradient ***,the DC-mimicking scaffold offers a scalable,modular,and customizable platform for rapid expansion of highly functional T cells for ACT.

关键词： Adoptive cell therapy Ex vivo T cell expansion Cytotoxic T cell Dendritic cell membrane Cell membrane coating Scaffold

Experimental and finite element analysis for fracture of coating layer of galvannealed steel sheet

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 111-116页

作者： S.I.kim j.U.HER Y.C.jANG Y.LEE Sheet Products and Process Research Group POSCO Techology Research Laboratory Department of Mechanical Engineering Chung-Ang University

Mechanical properties of galvannealed (GA) steel sheet used for automotive exposed panel and predicted failure phenomenon of its coating layer were evaluated using finite element method. V-bending test was performed to understand better the fracture of coating layer of GA steel sheet during plastic deformation. Yield strength of the coating layer was calculated by using a relative difference between hardness of coating layer measured from the nano-indentation test and that of substrate. To measure shearing strength at the interface between substrate and coating layer, shearing test with two specimens attached by an adhesive was carried out. Using the mechanical properties measured, a series of finite element analyses coupled with a failure model was performed. Results reveal that the fracture of coating layer occurs in an irregular manner at the region where compressive deformation is dominant. Meanwhile, a series of vertical cracks perpendicular to material surface are observed at the tensile stressed-region. It is found that 0.26-0.28 of local equivalent plastic strain exists at the coating and substrate at the beginning of failure. The fracture of coating layer depends on ductility of the coating layer considerably as well.

关键词： galvannealed steel sheet fracture simulation coating layer finite element analysis, failure model

Computational Analysis of a Variable Ejector Flow

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journal of Thermal Science 2006年第2期15卷 140-144页

作者： H.D. kim j.H. LEE T. SETOGUCHI S.MATSUO School of Mechanical Engineering Andong National University 388 Songchun-dong Andong 760-749 Korea Department of Mechanical Engineering Saga University 1 Honjo Saga 840-8502 Japan

The present study addresses a variable ejector which can improve the ejector efficiency and control the re-circulation ratio under a fixed operating pressure ratio. The variable ejector is a facility to obtain specific recirculation ratio under a given operating pressure ratio by varying the ejector throat area ratio. The numerical simulations are carried out to provide an understanding of the flow characteristics inside the variable ejector. The sonic and supersonic nozzles are adopted as primary driving nozzles in the ejector system, and a movable cone cylinder, inserted into a conventional ejector-diffuser system, is used to change the ejector throat area ratio. The numerical simulations are based on a fully implicit finite volume scheme of the compressible, Reynolds-Averaged Navier-Stokes equations. The results show that the variable ejector can control the recirculation ratio at a fixed operating pressure ratio.

关键词： variable ejector ejector throat area ratio re-circulation ratio

A Study of the Weak Shock Wave Propagating over a Porous Wall/Cavity System

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journal of Thermal Science 2005年第4期14卷 329-333页

作者： H.D.kim S.j.jUNG T.AOKI T.SETOGUCHI School of Mechanical Engineering.Andong National University Songchun-dongAndong 760-746Korea Department of Energy and Environmental Engineering Kyushu University6-1Kasuga-kouenKasugaFukuoka 816-8580Japan Department of Mechanical Engineering Saga University1HonjoSaga 840-8502Japan

The present computational study addresses the attenuation of the shock wave propagating in a duct, using a porous wall/cavity system. In the present study, a weak shock wave propagating over the porous wall/cavity system is investigated with computational fluid dynamics. A total variation diminishing scheme is employed to solve the unsteady, two-dimensional, compressible, Navier-Stokes equations. The Mach number of an initial shock wave is changed in the range from 1.02 to 1.12. Several different types of porous wall/cavity systems are tested to investigate the passive control effects. The results show that wall pressure strongly fluctuates due to diffraction and reflection processes of the shock waves behind the incident shock wave. From the results, it is understood that for effective alleviation of tunnel impulse waves, the length of the perforated region should be sufficiently long.

关键词： compressible flow perforated wall railway tunnel shock wave.

1.45 GPa ultrastrong cryogenic strength with superior impact toughness in the in-situ nano oxide reinforced CrMnFeCoNi high-entropy alloy matrix nanocomposite manufactured by laser powder bed fusion

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journal of Materials Science & Technology 2022年第2期97卷 10-19页

作者： Young-Kyun kim Min-Chul kim Kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Atomic Energy Research Institute(KAERI) Daejeon 34057Republic of Korea

CrMnFeCoNi high-entropy alloys(HEAs)exhibit an excellent combination of tensile strength and ductility at cryogenic *** study led to the introduction of a new method for the development of high-performance CrMnFeCoNi HEAs at cryogenic temperatures by jointly utilizing additive manufacturing(AM)and the addition of interstitial *** interstitial oxygen present in the powder feedstock was transformed into beneficial nano-sized oxides during AM *** HEA nanocomposite fabricated using laser powder bed fusion(L-PBF)not only contains heterogeneous grains and substructures but also a high number density of nano-sized *** tensile results revealed that the L-PBF HEA nanocomposite has superior yield strengths of 0.77 GPa and 1.15 GPa,and tensile strengths of 0.92 GPa and 1.45 GPa at 298 K and 77 K,*** addition,the Charpy impact energies of the samples tested at 298 K and 77 K were measured as 176.2 j and 103.7 j,*** results indicate that the L-PBF HEA nanocomposite successfully overcomes the well-known strength-toughness *** tensile deformation microstructure contained a relatively large number of deformation twins(DTs)at cryogenic temperature,a possible consequence of the decrease in the stacking fault energy with decreasing *** the other hand,cracks were found to propagate along the grain boundaries at room temperature,whereas a transgranular crack was observed at cryogenic temperature in the specimens fractured as a result of the Charpy impact.

关键词： Laser powder bed fusion High-entropy alloy matrix nanocomposite Nano-oxide:cryogenic Tensile Impact toughness

Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

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World journal of Clinical Cases 2013年第8期1卷 242-248页

作者： Seung-jae Hyun Yongjung j kim Seung-Chul Rhim Department of Neurosurgery Spine CenterSeoul National University Bundang HospitalSeoul National University College of MedicineSeongnam 463-707South Korea Department of Orthopaedic Surgery Spine ServiceColumbia University College of Physicians and SurgeonsNew YorkNY 10032United States Department of Neurosurgery Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 138-736South Korea

In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The longterm overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided.

关键词： Sagittal imbalance Pedicle subtraction osteotomy Clinical outcome Proximal junctional kyphosis Complication

Intercomparison of Precipitation Simulated by Regional Climate Models over East Asia in 1997 and 1998

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Advances in Atmospheric Sciences 2007年第4期24卷 539-554页

作者： Dong-Kyou LEE William j.GUTOWSKI Hyun-Suk KANG Chun-ji kim School of Earth and Environmental Sciences Seoul National UniversitySeoulKorea Department of Geological and Atmospheric Sciences Iowa State UniversityAmesUSAJr Department of Atmospheric Sciences Yonsei UniversitySeoulKorea.School of Earth and Environmental SciencesSeoul National UniversitySeoulKorea

Regional climate simulations in Asia from May 1997 to August 1998 were performed using the Seoul National University regional climate model （SNURCM） and Iowa State University regional climate model （***5/LSM）, which were developed by coupling the NCAR/Land Surface Model （LSM） and the Mesoscale Model （MM5）. However, for physical processes of precipitation, the SNURCM used the Grell scheme for the convective parameterization scheme （CPS） and the simple ice scheme for the explicit moisture scheme （EMS）, while the ***5/LSM used the Betts-Miller scheme for CPS and the mixed phase scheme for EMS.The simulated precipitation patterns and amounts over East Asia for the extreme climatic summer in 1997 （relative drought conditions） and 1998 （relative flood conditions） were especially focused upon. The ***5/LSM simulated more precipitation than was observed in 1997 due to more moisture and cloud water in the lower levels, despite weak upward motion. In the SNURCM, strong upward motion resulted in more precipitation than that was observed in 1998, with more moisture and cloud water in the middle levels. In the ***5/LSM, weak upward motion, unchanged moisture in the lower troposphere, and the decrease in latent heat flux at the surface increased convective precipitation only by 3% for the 1998 summer event. In the SNURCM, strong upward motion, the increase in moisture in the lower troposphere, and the increase in latent heat flux at the surface increased convective precipitation by 48% for the summer of 1998. The main differences between both simulations were moisture availability and horizontal momentum transport in the lower troposphere, which were also strongly influenced by large-scale forcing.

关键词： regional climate simulation summer precipitation variability extreme climatic event physical process

Effects of Climate Change and Shifts in Forest Composition on Forest Net Primary Production

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journal of Integrative Plant Biology 2008年第11期50卷 1426-1439页

作者： jyh-Min Chiang Louts R.Iverson Anantha Prasad kim j.Brown Department of Environmental and Plant Biology Ohio University United States Department of Agriculture Forest Service Northern Research Station Department of Life Science Tunghai University

Forests are dynamic in both structure and species composition, and these dynamics are strongly influenced by climate. However, the net effects of future tree species composition on net primary production （NPP） are not well understood. The objective of this work was to model the potential range shifts of tree species （DISTRIB Model） and predict their impacts on NPP （PnET-Ⅱ Model） that will be associated with alterations in species composition. We selected four 200 × 200 km areas in Wisconsin, Maine, Arkansas, and the Ohio-West Virginia area, representing focal areas of potential species range shifts. PnET-Ⅱ model simulations were carried out assuming that all forests achieved steady state, of which the species compositions were predicted by DISTRIB model with no migration limitation. The total NPP under the current climate ranged from 552 to 908 g C/m^2 per year. The effects of potential species redistributions on NPP were moderate （-12% to ＋8%） compared with the influence of future climatic changes （-60% to ＋25%）. The direction and magnitude of climate change effects on NPP were largely dependent on the degree of warming and water balance. Thus, the magnitude of future climate change can affect the feedback system between the atmosphere and biosphere.

关键词： carbon sequestration climate change leaf traits net primary production tree species range shifts.