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Strong interlayer coupling and stable topological flat bands in twisted bilayer photonic Moiré superlattices

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Light(Science & Applications) 2022年第10期11卷 2523-2529页

作者： Chang-Hwan Yi hee chul park Moon Jip park Center for Theoretical Physics of Complex Systems Institute for Basic Science(IBS)Daejeon 34126Republic of Korea

The moiré superlattice of misaligned atomic bilayers paves the way for designing a new class of materials with wide *** this work,we propose a photonic analog of the moiré superlattice based on dielectric resonator *** sharp contrast to van der Waals materials with weak interlayer coupling,we realize the strong coupling regime in a moiré superlattice,characterized by cascades of robust flat bands at large ***,we find that these flat bands are characterized by a non-trivial band topology,the origin of which is the moiré pattern of the resonator *** physical manifestation of the flat band topology is a robust one-dimensional conducting channel on edge,protected by the reflection symmetry of the moiré *** explicitly breaking the underlying reflection symmetry on the boundary terminations,we show that the first-order topological edge modes naturally deform into higher-order topological corner *** work pioneers the physics of topological phases in the designable platform of photonic moiré superlattices beyond the weakly coupled regime.

关键词： topological bands coupling

Research on Cavitation Characteristics and Influencing Factors of Herringbone Gear Pump

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2917-2946页

作者： Jinlong Yang Kwang-hee Lee chul-hee Lee Department of Mechanical Engineering of Inha University Incheon22212South Korea

Cavitation is a common issue in pumps,causing a decrease in pump head,a fall in volumetric efficiency,and an intensification of outlet flow *** is one of the main hazards that affect the regular operation of the *** on pump cavitation mainly focuses on mixed flow pumps,jet pumps,external spur gear pumps,***,there are few cavitation studies on external herringbone gear *** addition,pumps with different working principles significantly differ in the flow and complexity of the internal flow ***,it is urgent to study the cavitation characteristics of external herringbone gear *** with experimentalmethods,visual research and cavitation area identification are achieved through computation fluid dynamic(CFD),and changing the boundary conditions and shape of the gear rotor is *** simulation yields a head error of only 0.003%under different grid numbers,and the deviation between experimental and simulation results is less than 5%.The study revealed that cavitation causes flow pulsation at the outlet,and the cavitation serious area is mainly distributed in the meshing gap and meshing *** can be inhibited by reducing the speed,increasing the inlet pressure,and changing the helix angle can be *** example,when the inlet pressure is 5 bar,the maximumgas volume fraction in themeshing area is less than 50%.These results provide a reference for optimizing the design and finding the optimal design parameters to reduce or eliminate cavitation.

关键词： Herringbone gear pump cavitation rotating speed inlet pressure helix angle TwinMesh

Preconditioning process for dermal tissue decellularization using electroporation with sonication

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Regenerative Biomaterials 2022年第1期9卷 22-29页

作者： Mi hee Leeand Jong-chul park Min-Ah Koo HaKyeong Jeong Seung hee Hong Gyeung Mi Seon Mi hee Lee Jong-chul park Cellbiocontrol Laboratory Yonsei University College of Medicine50-1 Yonsei-roSeodaemun-guSeoul 03722Republic of Korea Department of Medical Engineering Graduate School of Medical ScienceBrain Korea 21 ProjectYonsei University College of Medicine50-1 Yonsei-roSeodaemun-guSeoul 03722Republic of Korea

Decellularization to produce bioscaffolds composed of the extracellular matrix(ECM)uses enzymatic,chemical and physical methods to remove antigens and cellular components from *** decellularization methods depend on the characteristics of tissues,and in particular,tissues with dense,complex structure and abundant lipid content are difficult to completely *** study enables future research on the development of methods and treatments for fabricating bioscaffolds via decellularization of complex and rigid skin tissues,which are not commonly considered for decellularization to date as their structural and functional characteristics could not be preserved after severe *** this study,decellularization of human dermal tissue was done by a combination of both chemical(0.05%trypsin-EDTA,2%SDS and 1%Triton X-100)and physical methods(electroporation and sonication).After decellularization,the content of DNA remaining in the tissue was quantitatively confirmed,and the structural change of the tissue and the retention and distribution of ECM components were evaluated through histological and histochemical analysis,*** of the chemical pretreatment that increase the efficiency of physical stimulation as well as decellularization,and conditions for electroporation and sonication without the use of detergents,unlike the methods performed in previous studies,were established to enable the complete decellularization of the skin *** combinatorial decellularization treatment formed micropores in the lipid bilayers of the skin tissues while removing all cell and cellular residues without affecting the ECM ***,this procedure can be widely used to fabricate bioscaffolds by decellularizing biological tissues with dense and complex structures.

关键词： decellularization electroporation sonication extracellular matrix

Methane Emission from Rice Fields:Necessity for Molecular Approach for Mitigation

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Rice science 2024年第2期31卷 159-178页

作者： Sujeevan RAJENDRAN Hyeonseo park Jiyoung KIM Soon Ju park Dongjin SHIN Jong-hee LEE Young Hun SONG Nam-Chon PAEK chul Min KIM Department of Horticulture Industry Wonkwang UniversityIksan 54538Korea Plant Molecular Biology and Biotechnology Research Center Gyeongsang National UniversityJinju 52828Korea Department of Southern Area Crop Science National Institute of Crop ScienceMiryang 50424Korea Department of Agricultural Biotechnology Seoul National UniversitySeoul 08826Korea Department of Plant Science Plant Genomics and Breeding InstituteResearch Institute of Agriculture and Life SciencesSeoul National UniversitySeoul 08826Korea

Anthropogenic methane emissions are a leading cause of the increase in global averagetemperatures,often referred to as global *** soils play a significant role in methaneproduction,where the anaerobic conditions promote the production of methane by *** fields contribute a considerable portion of agricultural methane emissions,as riceplants provide both factors that enhance and limit methane *** plants harbor both methaneproducingand methane-oxidizing *** from rice roots provide source for methaneproduction,while oxygen delivered from the root aerenchyma enhances methane *** haveshown that the diversity of these microorganisms depends on rice cultivars with some genes characterizedas harboring specific groups of microorganisms related to methane ***,there is still aneed for research to determine the balance between methane production and oxidation,as rice plantspossess the ability to regulate net methane *** agronomical practices,such as fertilizerand water management,have been employed to mitigate methane ***,studiescorrelating agronomic and chemical management of methane with productivity are ***,evidences for breeding low-methane-emitting rice varieties are scattered largely due to the absence ofcoordinated breeding *** has indicated that phenotypic characteristics,such as rootbiomass,shoot architecture,and aerenchyma,are highly correlated with methane *** reviewdiscusses available studies that involve the correlation between plant characteristics and *** emphasizes the necessity and importance of breeding low-methane-emitting rice varieties inaddition to existing agronomic,biological,and chemical *** review also delves into the idealphenotypic and physiological characteristics of low-methane-emitting rice and potential breeding techniques,drawing from studies conducted

关键词： methane emission rice breeding aerenchyma greenhouse gas radial oxygen loss

Proton therapy for hepatocellular carcinoma:Current knowledges and future perspectives

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World Journal of Gastroenterology 2018年第28期24卷 3090-3100页

作者： Gyu Sang Yoo Jeong Il Yu hee chul park Department of Radiation Oncology Samsung Medical Center Sungkyunkwan University School of Medicine Department of Medical Device Management and Research Samsung Advanced Institute for Health Sciences and Technology Sungkyunkwan University

Hepatocellular carcinoma(HCC) is the second leading cause of cancer-related death, as few patients can be treated with currently available curative local modalities. In patients with HCC where curative modalities are not feasible, radiation therapy(RT) has emerged as an alternative or combination therapy. With the development of various technologies, RT has been increasingly used for the management of HCC. Among these advances, proton beam therapy(PBT) has several unique physical properties that give it a finite range in a distal direction, and thus no exit dose along the beam path. Therefore, PBT has dosimetric advantages compared with X-ray therapy for the treatment of HCC. Indeed, various reports in the literature have described the favorable clinical outcomes and improved safety of PBT for HCC patients compared with X-ray therapy. However, there are some technical issues regarding the use of PBT in HCC, including uncertainty of organ motion and inaccuracy during calculation of tissue density and beam range, all of which may reduce the robustness of a PBT treatment plan. In this review, we discuss the physical properties, current clinical data, technical issues, and future perspectives on PBT for the treatment of HCC.

关键词： radiation therapy hepatocellular carcinoma proton beam therapy X-ray therapy

Optimizing radiotherapy with immune checkpoint blockade in hepatocellular carcinoma

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World Journal of Gastroenterology 2019年第20期25卷 2416-2429页

作者： Changhoon Choi Gyu Sang Yoo Won Kyung Cho hee chul park Department of Radiation Oncology Samsung Medical CenterSeoul 06351South Korea Department of Radiation Oncology Samsung Medical CenterSungkyunkwan University School of MedicineSeoul 06351South Korea

Hepatocellular carcinoma (HCC) is the fifth most common cancer, and its incidence is rapidly increasing in North America and Western Europe as well as South-East Asia. Patients with advanced stage HCC have very poor outcomes;therefore, the discovery of new innovative approaches is urgently needed. Cancer immunotherapy has become a game-changer and revolutionized cancer treatment. A comprehensive understanding of tumor-immune interactions led to the development of immune checkpoint inhibitors (ICIs) as new therapeutic tools, which have been used with great success. Targeting immune checkpoint molecules such as programmed cell death-1 (PD-1) and cytotoxic T lymphocyteassociated protein-4 (CTLA-4) reinvigorates anti-tumor immunity by restoring exhausted T cells. Despite their effectiveness in several types of cancer, of the many immune suppressive mechanisms limit the efficacy of ICI monotherapy. Radiation therapy (RT) is an essential local treatment modality for a broad range of malignancies, and it is currently gaining extensive attention as a promising combination partner with ICIs because of its ability to trigger immunogenic cell death. The efficacy of combination approaches using RT and ICIs has been well documented in numerous preclinical and clinical studies on various types of cancers but not HCC. The application of ICIs has now expanded to HCC, and RT is recognized as a promising modality in HCC. This review will highlight the current roles of PD-1 and CTLA-4 therapies and their combination with RT in the treatment of cancers, including HCC. In addition, this review will discuss the future perspectives of the combination of ICIs and RT in HCC treatment.

关键词： Hepatocellular carcinoma Radiation therapy Immune checkpoint inhibitors Abscopal effect

Oxygen vacancy engineering for tuning the catalytic activity of LaCoO_(3) perovskite

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Journal of Rare Earths 2024年第3期42卷 506-514,I0003页

作者： Jeong Hyun Cho Minjae Kim Inchan Yang Kyung Tae park Chang Houn Rhee Hai Woong park Ji chul Jung Department of Chemical Engineering Myongji UniversityYongin 17058Republic of Korea Institute of Advanced Composite Materials Korea Institute of Science and TechnologyWanju-gunJeollabuk-do 55324Republic of Korea Iron&Steel Process Engineering Research Group POSCOPohang 37859Republic of Korea Hydrogen Research Center Research Institute of Industrial Science&Technology(RIST)Pohang 37673Republic of Korea

Herein, we attempted to engineer oxygen vacancies on the surface of LaCoO_(3) perovskite through simple post-treatments(acid or reductive thermal treatments). Acid treatment induces oxygen vacancies through the selective etching of the La cations, whereas thermal treatment in a reducing atmosphere generates oxygen vacancies by directly removing lattice oxygen. The characterization results confirm that the number of surface oxygen vacancies, which are crucial in various catalytic oxidation reactions,considerably increases in the LaCoO_(3) catalysts treated with acid or reducing gas. Acid treatment enriches the oxygen vacancies while maintaining the structure of the LaCoO_(3) catalysts, which can not be achieved through reductive thermal treatment. Therefore, the acid treatment is considered a promising technique for oxygen vacancy engineering of perovskite catalysts for tuning their catalytic activities. Furthermore,the catalytic activities of the posttreated LaCoO_(3) catalysts for CO oxidation were evaluated and are noted to be considerably better than those of the pristine LaCoO_(3) catalyst due to their abundant oxygen vacancies. Consequently, we conclude that the oxygen vacancies of perovskite catalysts can be effectively engineered via two simple methods and play a significant role in CO oxidation.

关键词： LaCoO_(3)perovskite Acid treatment Reductive thermal treatment Oxygen vacancy CO oxidation Rare earths

Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of parkinson's disease:a systematic review and meta-analysis

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Neural Regeneration Research 2024年第7期19卷 1584-1592页

作者： Jong Mi park Masoud Rahmati Sang chul Lee Jae Il Shin Yong Wook Kim Department and Research Institute of Rehabilitation Medicine Yonsei University College of MedicineSeoulSouth Korea Department of Physical Education and Sport Sciences Faculty of Literature and Human SciencesLorestan UniversityKhoramabadIran Department of Pediatrics Yonsei University College of MedicineSeoulSouth Korea

parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease *** cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of parkinson’s *** stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of *** performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a parkinson’s disease animal *** searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,*** study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control *** use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 parkinson’s disease model animals were included in the *** with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational *** the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a

关键词： animal animal experimentation mesenchymal stem cells models parkinson’s disease stem cell transplantation

Efficient Electromagnetic Wave Absorption and Thermal Infrared Stealth in PVTMS@MWCNT Nano‑Aerogel via Abundant Nano‑Sized Cavities and Attenuation Interfaces

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Nano-Micro Letters 2024年第1期16卷 370-383页

作者： Haoyu Ma Maryam Fashandi Zeineb Ben Rejeb Xin Ming Yingjun Liu Pengjian Gong Guangxian Li chul B.park College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan University24 Yihuan RoadNanyiduanChengdu 610065SichuanPeople’s Republic of China Microcellular Plastics Manufacturing Laboratory Department of Mechanical and Industrial EngineeringUniversity of Toronto5 King’s College RoadTorontoON M5S 3G8Canada Jiangsu JITRI Advanced Polymer Materials Research Institute Tengfei Building88 Jiangmiao RoadJiangbei New DistrictNanjing 211800JiangsuPeople’s Republic of China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringInternational Research Center for X PolymersZhejiang University38 Zheda RoadHangzhou 310027People’s Republic of China

Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)*** fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.

关键词： Nano-pore size Heterogeneous interface Electromagnetic wave absorption Thermal infrared stealth Nano-aerogel