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  • Development of environmental friendly electrocatalysts for sustainable green hydrogen production

    Chemical Engineering Prof. KIM, JUNG KYU

    Development of environmental friendly electrocatalysts for sustainable green hydrogen production

    Prof. Jung Kyu Kim (School of Chemical Engineering, SKKU) reported his collaboration research achievements with Prof. Uk Sim (Department of Materials Science & Engineering, Chonnam National University) and NILL Inc. : development of environmental friendly electrocatalysts for sustainable green hydrogen production. First, bimetallic oxides with spinel structures, M2GeO4 (M = Fe, Co), were synthesized via a facile one-pot hydrothermal method and were used as electrocatalysts for urea-assisted water electrolysis to enhance the efficiency of hydrogen production. In alkaline electrolyte with urea, Fe2GeO4, which was used as the anode in the electrolysis cell, reduced the overall input potential to produce H2. The superior performance of Fe2GeO4 in the urea-added water electrolysis was attributed to the higher oxidation state of its metal cations, larger electrochemical active surface area, and lower charge transfer resistance than those of Co2GeO4. Hence, Fe2GeO4 showed 5.49 times higher H2 peak intensity than Co2GeO4, indicating higher efficiency of H2 production. Second, single-phase metal-rich nickel phosphide (Ni12P5)-incorporated carbon composites were designed for a highly efficient water-splitting system. The distinct Ni12P5 is anchored in nitrogen (N)- and phosphorus (P)-rich carbon matrices (Ni12P5@N,P-C); the creation of the matrices entails a facile hydrothermal-followed pyrolysis treatment to explore their bifunctional activities in the water-splitting system. The Ni12P5@N,P-C composite-based two-electrode water-splitting system shows a low operating potential of 1.57 V at 10 mA cm–2 and achieves the commercially required high current density of 500 mA cm–2 at a stable potential of 2 V. The functionalization of composite electrocatalysts based on strategical engineering and the intrusion of multiple active sites can help develop enhanced electrochemical energy systems. These two research achievements were selected as the front cover art of journals ‘Environmental Science: Nano (DOI: 10.1039/D1EN00529D)’ and ‘ACS Sustainable Chemistry & Engineering (DOI: 10.1021/acssuschemeng.1c06514)’, respectively. *Paper 1: Boosting eco-friendly hydrogen generation by urea-assisted water electrolysis using M2GeO4 (M = Fe, Co) as an active electrocatalyst (저널: Environmental Science: Nano, DOI: 10.1039/D1EN00529D) *Paper 2: Anchoring of Ni12P5 Microbricks in Nitrogen- and Phosphorus-Enriched Carbon Frameworks: Engineering Bifunctional Active Sites for Efficient Water-Splitting Systems (저널: ACS Sustainable Chemistry & Engineering, DOI: 10.1021/acssuschemeng.1c06514)

  • Unveiling the impact of Fe incorporation on intrinsic performance of reconstructed water oxidation electrocatalyst

    Chemical Engineering Prof. YOO, PILJIN

    Unveiling the impact of Fe incorporation on intrinsic performance of reconstructed water oxidation electrocatalyst

    Professor Pil Jin Yoo’s group (with Drs. Clament Sagaya Selvam and Gwan Hyun Choi) at school of chemical engineering announced that highly efficient and extremely stable oxygen evolution reaction (OER) electrocatalysts have been developed for the next generation water electrolysis technology. With a successful co-working with profs. ‪Won-Sub Yoon (Department of Energy Science) and ‪Won Bo Lee (Seoul National University) groups, in this work, they investigated the fundamental mechanism of dynamic interactions between electrolyte and electrocatalyst surface through experimental and theoretical way. This work was published in ACS Energy Letters (Impact Factor: 23.101) featured as a cover paper. Thanks to its environmental benignity, the water electrolysis technology has received great interest both from academy and industry as a promising solution for producing clean hydrogen energy. During the electrolysis of water into hydrogen and oxygen gases, while the reaction side for the hydrogen evolution reaction proceeds in a relatively smooth and stable way, the concurrently occurring OER reaction generally suffers from high overpotential and degradation of electrocatalysts, hindering the practical and commercial utilization of the water electrolysis to the market. To challenge this issue, the SKKU research team first proposed the nanostructured cobalt-sulfur hybrids (Co9S8) as a basic electro-conductive platform for high performance OER and subsequently electro-deposited a thin layer of nickel oxyhydroxide (NiOOH) over the surface of Co9S8 to simultaneously impart the erosion stability and electrochemical activity. In addition, for the first time, they elucidated that the enhanced electrocatalytic performance was originated from the self-Fe-doping of the catalyst surface as a result of dynamic interactions with the electrolyte. With regard to this technological advance, prof. Yoo commented that “This approach would offer a new design toolkit for high performance OER electrocatalysts and it is greatly anticipated for being extensively utilized for materials in eco-friendly energy technology”. Prof. Yoo group has also reported leading-edge research result on novel electrocatalysts in Energy & Environmental Science (Impact Factor: 38.532) in May. This work was published on December 10th in ACS Energy Letters (Impact Factor: 23.101) as a cover paper with the governmental funding support of NRF 2018M3D1A1058624, 2020R1A2B5B02002483, and 2021R1A4A1024129. ※ Paper 1 : “Unveiling the Impact of Fe Incorporation on Intrinsic Performance of Reconstructed Water Oxidation Electrocatalyst”, ACS Energy Letters, 6, 4345−4354 (2021). * Paper 2 : “Modularly aromatic-knit graphitizable phenolic network as a tailored platform for electrochemical applications”, Energy & Environmental Science, 14, 3203–3215 (2021).

  • Single-Atom Dimer Electrocatalyst for Green Hydrogen Production

    Chemistry Prof. LEE, HYOYOUNG ·Dr. Viet Quoc Bui , Ashwani Kumar

    Single-Atom Dimer Electrocatalyst for Green Hydrogen Production

    Green hydrogen generated from the electrolysis of water using renewable electricity is considered a next-generation renewable energy source for the future and a possible alternative to fossils fuels. But in reality, the overwhelming majority of hydrogen fuel is obtained from the refining of fossils fuels due to the high cost of electrolysis. Currently, the efficiency of water electrolysis is limited and often requires high cell voltage due to the lack of efficient electrocatalysts for hydrogen evolution reactions. Noble metals such as platinum (Pt) are used as catalysts to improve hydrogen generation in both acidic/alkaline media. However, these noble metal catalysts are very expensive and show poor stability under long-term operation. Recently, single-atom catalysts have shown excellent activity compared to their nanomaterial-based counterparts. This is because they are able to achieve up to 100% atom utilization, whereas in nanoparticles only the surface atoms are available for reaction. However, due to the simplicity of the single-metal-atom center, carrying out further modification of the catalysts to perform complex multistep reactions is rather difficult. The simplest way to modify the single atoms is by turning them into single-atom dimers sites, which combine two different single atoms together. Tuning the active site of single-atom catalysts with dimers can improve the reaction kinetics thanks to the synergistic effect between two different atoms. However, while the synthesis and identification of the single-atom dimer structure have been known conceptually, its practical realization has been very difficult. This problem was tackled by a research team led by Associate Director LEE Hyoyoung of the Center for Integrated Nanostructure Physics within the Institute for Basic Science (IBS) located at Sungkyunkwan University. The IBS research team successfully developed atomically dispersed Ni-Co dimer structure stabilized on nitrogen-doped carbon support, which was named NiCo-SAD-NC. “We synthesized Ni-Co single atom dimer structure on nitrogen (N)-doped carbon support via in-situ trapping of Ni/Co ions into the polydopamine sphere, followed by pyrolysis with precisely controlled N-coordination. We employed state-of-the-art transmission electron microscopy and x-ray absorption spectroscopy to successfully identify these NiCo-SAD sites with atomic precision,” says Ashwani Kumar, the first author of the study. The researchers found that annealing for two hours at 800°C in an argon atmosphere was the best condition for obtaining the dimer structure. The research team evaluated the catalytic efficiency of this new system in terms of the overpotential required to drive the hydrogen evolution reaction. The NiCo-SAD-NC electrocatalyst had a comparable level of overvoltage as commercial Pt-based catalysts in acidic and alkaline media. NiCo-SAD-NC also exhibited 8 times higher activity than Ni/Co single-atom catalysts and heterogenous NiCo nanoparticles in alkaline media. At the same time, it achieved 17 and 11 times higher activity than Co and Ni single-atom catalysts, respectively, and 13 times higher than conventional Ni/Co nanoparticles in acidic media. In addition, the researchers demonstrated the long-term stability of the new catalyst, which was able to drive reaction for 50 hours without any change of structure. The NiCo-SAD exhibited superior water dissociation and optimal proton adsorption compared to other single-atom dimers and Ni/Co single-atom sites, boosting pH-universal catalyst’s activity based on the density functional theory simulation. ▲ Figure 1. Representation models of a) nickel single-atom, b) cobalt single-atom, c) nickel-cobalt single-atom dimer (NiCO-SAD-NC), and d) nickel-cobalt heterogenous nanoparticle catalysts. ▲ Figure 2. The schematic diagram of the hydrogen evolution reaction (HER) process using NiCo-SAD stabilized on N-doped carbon (left). HER activity in alkaline (top right) and acidic media (bottom right). “We were very excited to discover that the novel NiCo-SAD structure dissociates water molecules with a much lower energy barrier and accelerates hydrogen evolution reaction in both alkaline and acidic media with performances comparable to that of Pt, which addressed the shortcomings of the individual Ni and Co single-atom catalysts. The synthesis of such single atom dimer structure was a long-standing challenge in the field of single-atom catalysts,” notes Associate Director Lee, the corresponding author of the study. He further explains, “This study takes us a step closer to a carbon-free and green hydrogen economy. This highly efficient and inexpensive hydrogen generation electrocatalyst will help us overcome long-term challenges of cost-competitive green hydrogen production: to produce high-purity hydrogen for commercial applications at a low price and in an eco-friendly manner.” The study was published in Nature Communications (IF 14.92), a world-renowned journal in the field of basic science. ※Title of Paper: Moving Beyond Bimetallic-Alloy to Single-Atom Dimer Atomic-Interface for All-pH Hydrogen Evolution

  • Presents an approach to a control by steering dipole densities at the interface of III-V–II-VI h-NCs

    SKKU Advanced Institute of Nano Technology Prof. BAE, WANKI ·Prof. Euyheon Hwang

    Presents an approach to a control by steering dipole densities at the interface of III-V–II-VI h-NCs

    Heterostructured nanocrystals (h-NCs), in which multiple nanoscale semiconductor domains are interconnected via bonding interfaces, are new classes of luminophores that stand at the forefront of nearly all light-emitting applications. The success of h-NCs is attributed to the controllability and the tunability of the electronic structure and the spatial distribution of charge carriers in h-NCs. Such changes are emergent collective responses to the dimension and the composition of h-NCs, which define the potential profile at the interface of h-NCs and consequently the photophysical and photochemical characteristics of h-NCs. Everyday light-emitting applications call for the research to understand and manipulate heavy metal-free h-NCs, which are formulated with the combinations of III-V and II-VI compounds (e.g., InP/ZnSe or ZnS h-NCs). However, the limited material choice for III-V/II-VI h-NCs deters the access to one of the external knobs for the control of the potential landscape of h-NCs. The quantum confinement effect allows marginal success in controlling the optical bandgap of III-V/II-VI h-NCs, but the customized potential profile has considered to be unavailable. This constrains the envelopment of materials functions including the recombination dynamics and transport characteristics of charge carriers that are keys to the success of optical and optoelectronic applications implementing h-NCs. In the present study, the team of Prof. Wan Ki Bae and Prof. Euyheon Hwang of SKKU advanced institute for Nanotechnology (SAINT) provide an unprecedented approach to tailor the potential landscape of heavy metal-free III-V/II-VI h-NCs on demand. The present research stems from our discovery that the heterovalent bonding at the interface, which exists inevitably in the formation of III-V/II-VI interfaces, is an additional knob that changes the potential profile of III-V/II-VI h-NCs. Spectroscopic analysis in chorus with quantum mechanical calculation and density functional theory calculation show that the interfacial polarization by the heterovalency at the interface is responsible for the vacuum level shift that alters the potential profile across III-V/II-VI h-NCs. In addition to the findings, the team devise an effective chemical means to control the stoichiometry at the III-V/II-VI interfaces with atomic precision. The interfacial dipole intensity enables to adjust the band positions of III-V cores on demand by an extent of ca. 400 meV at the given geometry of InP/ZnSe h-NCs, which accompanies the changes in their electronic energy levels, the spatial distribution of charge carriers and their recombination dynamics, and the transport characteristics of charge carriers across h-NCs. A comprehensive study on III-V/II-VI h-NCs of varying compositional combinations (i.e., InP/ZnSe, InP/ZnS, InAs/ZnSe, In0.5Ga0.5P/ZnSe, In0.3Ga0.7P/ZnS, and InP/CdS h-NCs) is conducted to comprehend the structural-property relationship quantitatively and to validate the impact experimentally. Furthermore, the team capitalize on the atomic precision with which to synthesize h-NCs by correlating interfacial dipole moments to photochemical stability and optoelectronic performance of resulting h-NCs. The customized potential profile in h-NCs promises to engineer the transport characteristics of charge carriers across h-NCs to environments, enabling us to enhance the photochemical stability of h-NCs against the external stress and the optoelectronic performance of h-NCs in light-emitting diodes close to the theoretical limit (EQE ~ 18.5 %). The present study implies that, together with the quantum confinement effect, the capability of engineering the structural characteristics of the heterovalent interface allows one to customize the potential profile of heavy metal-free III-V/II-VI h-NCs that overcome the limitation of materials choice, and hence fosters the practical use of h-NCs in a variety of light-emitting applications. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Science, ICT, and Future Planning (2020R1A2C2011478, 2021M3H4A3A01062964, 2020M3D1A2101319, and 2021M3H4A1A01004332), and Electronics and Telecommunications Research Institute (ETRI) grant funded by the Korean government (No. 20ZB1200, Development of ICT Materials, Components and Equipment Technologies). This research was also supported by Samsung Display. ※Title: Interface polarization in heterovalent core/shell nanocrystals

  • Professor Wonyoung Lee’s group develops the world’s best-performing proton conducting fuel cell

    Mechanical Engineering Prof. LEE, WON YOUNG ·Post-doc researcher Mingi Choi

    Professor Wonyoung Lee’s group develops the world’s best-performing proton conducting fuel cell

    Professor Wonyoung Lee’s research team (First author, Mingi Choi, Post-doctoral researcher) at the Department of Mechanical Engineering of Sungkyunkwan University (President Dong-Ryeol Shin) announced that preservation of intrinsic properties of proton conducting electrolytes enables the fuel cell performance to remarkably be improved, resulting in world’s best-performing proton conducting fuel cell. Proton conducting fuel cell has been considered as next-generation ceramic based fuel cell type based on its high ionic conductivity and low activation energy for ion conduction. Although proton conducting fuel cell has been expected to demonstrate the high efficiency and high performance at the low temperature, difficulties in manufacturing still has remained challenge, hindering its wide-spread uses. The research team systematically discovered the underlying mechanism of low performance of proton conducting fuel cell than predicted, and revealed that the volatilization of components in crystal structure of electrolyte during the manufacturing process significantly affect to the grain growth and low chemical stability. The research team proposed the breakthrough for suppressing the undesired volatilization of components, resulting in about 5-fold larger grain size than the previously reported values with prefect chemical composition inside the electrolyte. Based on this perfectly stoichiometric electrolyte, a proton conducting fuel cell system demonstrates the world’s best performance at an operating temperature range of 500-650 °C, which greatly exceeds previously reported values. Professor Wonyoung Lee said, “We overcame the technical challenge for manufacturing the proton conducting fuel cell. Especially, since it demonstrated the world’s best performance using non-complicated method, we believe that this technology can be readily commercialized and can open the possibilities of wide-spread utilization of fuel cell for hydrogen powered stationary power plant, contributing the renewable energy society.” This research is supported by the mid-level research support project of the National Research Foundation (No. 2019R1A2C4070158) and the Sejong Science Fellowship support project (No. 2021R1C1C2006657). It was published online on October 16th in Energy & Environmental Science (IF: 38.53, JCR<1%), an international academic journal in the field of energy. [Figure 1] Correlation between chemical composition and grain growth and chemical stability of the proton conducting electrolyte manufactured by control of volatilization of composition. [Figure 2] Effects of the chemical potential of Ba on the phase separation, grain growth, and proton conductivity as a function of the sintering temperature.

  • Developement of artificial intelligence semiconductor: optoelectronic synaptic device

    Electronic and Electrical Engineering Prof. PARK, JIN HONG ·Dr. Seunghwan Seo & Dr. Je-Jun Lee

    Developement of artificial intelligence semiconductor: optoelectronic synaptic device

    Advanced Materials 5th October (IF: 12.121); An optogenetics-inspired flexible van-der-Waals optoelectronic synapse and its application to convolutional neural network; Seunghwan Seo (1st author) / Je-Jun Lee (1st author) / Prof. Jin-Hong Park (Corresponding author) □ Neuromorphic chips that mimic the learning principle of the human brain are in the spotlight as next-generation processing chips because they can minimize power consumption by processing a large amount of information in parallel and improve their computational functions through learning. In particular, various researches on synaptic semiconductor devices, which are essential for realizing parallel information processing and learning capabilities of neuromorphic chips, have been actively conducted worldwide. □ The research team implemented a flexible optoelectronic synapse on 2D vdW layered rhenium disulfide, which features an inherent photosensitive memory nature derived from the intrinsic persistent photoconductivity effect. Then, the research team successfully demonstrated the applicability of the flexible 2D vdW optoelectronic synapse to optogenetics-inspired intelligent systems via training and inference tasks using a convolutional neural network and the CIFAR-10 dataset. □ These studies were published in the Advanced Materials on October 5th.

  • Green hydrogen production: Restructuring highly electron-deficient metal-metal oxides

    Chemistry Prof. LEE, HYOYOUNG ·Dr. Liu, Xinghui

    Green hydrogen production: Restructuring highly electron-deficient metal-metal oxides

    While traditional hydrogen production processes require fossil fuels or CO2, electrolysis produces “green hydrogen” from water molecules. Since water cannot be split into hydrogen and oxygen by itself, the electrochemical hydrogen-water conversion needs highly active electrocatalysts. Conventional water electrolysis, however, faces technological challenges to improve the efficiency of the water-splitting reaction for the sluggish oxygen evolution reaction. Though the alkaline water electrolysis technology is dominating the large-scale production of H2, proton exchange membrane (PEM) water electrolysis has clear advantages such as compact configuration, larger maximum current densities, higher energy efficiency, less H2 impurity, and dynamic flexibility of operation. As a half-reaction of water splitting, oxygen evolution reaction (OER) is a major bottleneck due to its sluggish kinetics, while the current OER catalysts typically degrade rapidly under acidic conditions, are not stable in highly oxidative environments, and are of high cost. Thus, developing low-cost and high-efficiency OER catalysts, especially those stable in acidic media, has been a pressing need but remains a grand challenge. Led by Professor LEE Hyoyoung of Sungkyunkwan University, the research team developed a highly efficient and long-lasting electrocatalyst for OER using iridium and MoO3. “ We introduce electron-deficient metal on semiconducting metal oxides-consisting of Ir-MoO3 embedded by graphitic carbon layers (IMO) using an electrospinning method. To rationally design electron-deficient metal on metal oxides, the electrospinning strategy aid of polyvinylpyrrolidone (PVP) facilitates the different reduction ability of the two metal oxides because their formation energies are -0.862 eV/atom for IrO2 and -1.929 eV/atom for MoO3. PVP was adopted to help reduce the IrO2-only in the air annealing condition (500 °C) to achieve the electron-deficient surface of Ir and to provide graphitic carbon layers from thermal decomposition. The graphitic carbon layer acted as the protective layer to confer high durability and conductivity to facilitate the fast electron transfer during the OER process. IMO nanocomposite can therefore be successfully synthesized via the economical one-pot to create an electron-deficient surface on Ir (Irx+; x > 4) by virtue of two factors: (i) surface oxygen of Ir; (ii) the electron-withdrawing material of MoO3.” says LIU Xinghui the first authors of the study. “We were very excited to discover that highly electron-deficient metal-metal oxides surface for IMO, demonstrated superior OER activity by evidence of ultra-low overpotential and high stability compared to the benchmark materials of Ir and RuO2 since the synergic effect of high surface state of Ir with the help of the Mo5+ can withstand resistance in an oxidation state,” notes Professor Lee, the corresponding author of the study. The researchers found that the electrospinning synthesized method not only works for metal of Ir-MoO3. The metal metal-metal oxides systems for Rh-MoO3, Au-MoO3, Ru-MoO3 were created, which provides the general strategy-electron-deficient surface of metal on metal oxides driven by surface oxygen and electron-withdrawing groups of the substrate for guiding other metal-semiconductor design. The research team evaluated the catalytic efficiency with the overvoltage metrics needed for the oxygen evolution reaction. The advanced noble electrocatalyst required only 156 mV (millivolt) overvoltage to attain a current density of 10 mA (milliampere) per cm2 of catalyst, while ruthenium oxide needed 293 mV and Iridium needed 328 mV. In addition, the IMO showed long-term stability for 48 hours without surface change of surface structure. Furthermore, the proton dissociation pathway is suggested via surface oxygen serving as proton acceptors, based on the density functional theory simulation. ▲ The schemic diagram for the OER process using highly electron-deficient iridium metal on metal oxides of MoO3. Professor explains, “This study suggests high stability with high catalytic performance in these materials by creating electron-deficient surfaces and provides a general, unique strategy for guiding the design of other metal-semiconductor nanocatalysts. This study takes us a step closer to a carbon-free and green hydrogen economy. This highly efficient and inexpensive oxygen generation electrocatalyst will help us overcome long-term challenges of the fossil fuel refining process: to produce high-purity hydrogen for commercial applications at a low price and in an eco-friendly manner.” The study was published online in the journal Nature Communications. Notes for editors - References Xinghui Liu, Shibo Xi, Hyunwoo Kim, Ashwani Kumar, Jinsun Lee, Jian Wang, Ngoc Quang Tran, Taehun Yang, Xiaodong Shao, Mengfang Liang, Min Gyu Kim, Hyoyoung Lee Restructuring highly electron-deficient metal-metal oxides for boosting stability in acidic oxygen evolution reaction. Nature Communications. doi.org/10.1038/s41467-021-26025-0

  • Development of Pri-Actor system via coupling bioprinter with an in situ bioreactor

    Bio-Mechatronic Engineering Prof. KIM, GEUNHYUNG ·Mr. Wonjin Kim, Dr. Hyeongjin Lee, Mr. Hanjun Hwangbo

    Development of Pri-Actor system via coupling bioprinter with an in situ bioreactor

    The research team led by professor Geun HyungKim in the biomechatronic engineering department developed a “Pri-Actor”bioprinting system named via coupling bioprinter with in situ bioreactorwhich can effectively induce myogenesis to the host cell. The term “Pri-actor”is an amalgamation of printer and bioreactor. Figure 1. Schematical diagram of “Pri-Actor” system. The Pri-Actor system utilizes simultaneous in situ supplementation of physical force (electric field & UV radiation) during the extrusion process of human Adipose Stem Cells (hASCs)-ladened bioink. Subsequentially, a significantly higher degree of cell proliferation and myogenesis was observed with the Pri-Actor printing system. During the short supplementation of electric field (~0.1 s) various printing parameters have been optimized for the optimum degree of myogenic related signaling pathways and activation of ion voltage channels, as well as cellular alignment and effective formation of myotubes. The bio-construct printed via the Pri-Actor system were further analyzed in volumetric muscle defect in the animal model (rat). As result, functional muscle formation with vascular and nervous networks was observed. In addition, the physical analysis revealed that muscle functionality was fully recovered to pre-defect levels. Professor Geun Hyung Kim has stated “Based on the promising results, the Pri-Actor system can effectively mimic the native anatomical structures of muscle, as well as fully restoring the functionality of muscle” Figure 2. schematical diagram of in situ “Pri-Actorsystem” and histological staining of isolated trabecular muscle 8 weeks afterimplantation. Professor Geun Hyung Kim has stated, “Based onthe promising results, the Pri-Actor system can effectively mimic the nativeanatomical structures of muscle, as well as fully restoring the functionalityof muscle”. In addition, he has stated “By controlling the physical stimulationincorporated in the current system can effectively target various oforgans/tissues in the human body. Additionally, further development of the Pri-Actorsystem can expand its potential into a personalized fabrication system forvarious tissues and organs. This study was supported by an NRF grant fundedby the Ministry of Science and ICT for the Bioinspired Innovation TechnologyDevelopment Project. In addition, these studies were published in “AdvancedFunctional Materials” (Impact factor = 18.8) on 2021/08, “Bioactive materials”(Impact factor = 14.6) on 2021/07, and “Chemical Engineering Journal (Impactfactor = 13.3) on 2021/04. Furthermore, these studies were featured in ArirangTV BizTech Korea “Outlook for regenerative medicine” on 2021/08/04 ※Papertitle: A Bioprinting Process Supplemented with In Situ Electrical StimulationDirectly Induces Significant Myotube Formation and Myogenesis. (AdvancedFunctional Materials) ※ Paper title: Bio-printing of aligned GelMa-basedcell-laden structure for muscle tissue regeneration. (Bioactive Materials) ※ Paper title: Bioprinted hASC-laden structures withcell-differentiation niches for muscle regeneration. (Chemical EngineeringJournal) ※Arirang TV: https://www.youtube.com/watch?v=VsgMBgr3EwU

  • Enhanced cancer immunotherapy via controlling immunosuppressive factors with nanotherapeutic platform (AIMS)

    SKKU Advanced Institute of Nano Technology Prof. LIM, YONGTAIK ·Researcher Seung Mo Jin/Sang Nam Lee

    Enhanced cancer immunotherapy via controlling immunosuppressive factors with nanotherapeutic platform (AIMS)

    The research team of Prof. Yong Taik Lim (SKKU Advanced Institute of Nanotechnology, SAINT) developed nanotherapeutic platform(AIMS; Assemblable Immune Modulating Suspension) that can control the immunosuppressive factors in tumor microenvironment (TME) and showed that it can overcome the chemo-immunotherapeutic induced immune tolerance. They focused on the fact that chemo-immunotherapy increases the expression of representative immunosuppressive factor, IDO (Indoleamine-2,3-Dioxygenase) in tumor microenvironment and lymph node, and IDO drawbacks the therapeutic efficacy and induces immune tolerance. To overcome this limitation, researchers included the immunosuppressive reliever to vaccine component (antigen and adjuvant) and developed as a nanotherapeutic platform (AIMS), first in the world. In vivo results indicate that AIMS not only increases the proliferation and polarization of antigen-specific T cells, but also relieves the immunosuppressive cells (MDSC and Treg) and immunosuppressive cytokines(TGF-beta and IL-10) which hamper T cell functionality. Another advantage ofAIMS is that it lowers the systemic toxicity. This is possible because it induces sustain release of loaded drugs (chemotherapeutic agent, adjuvant, and immunosuppressive reliever) and localizes those drugs in the injection site. Byusing AIMS, the kinds and doses of encapsulated drugs can be easily adjustedand can be long-term storage as lyophilized form. This new platform is expected to be developed as a personalized medicine for cancer immunotherapy in the future. Especially, it is notable that the research conducted during the master course of the first authors (Seung Mo Jin and Sang Nam Lee) was published in the world’s leading multidisciplinary science journal ‘Advanced Science’ in August 7th, 2021. First authors of this research (Seung Mo Jin and SangNam Lee) have also published world’s leading chemistry journal ‘Accounts of Chemical Research’ (IF=22.384) in 2020 with Prof. Yong Taik Lim by introducing the materials for cancer immunotherapy. Paper Title: Overcoming Chemoimmunotherapy-Induced Immunosuppression by Assemblable and Depot Forming Immune Modulating Nanosuspension (Advanced Science (IF=16.806), August 7, 2021) Author: Seung Mo Jin (first author, Ph.D. course),Sang Nam Lee (first author, Master/Ph.D. integrated course), Yeon Jeong Yoo(co-author, Master course), Hong Sik Shin (co-author, Master/Ph.D. integratedcourse), Chang Hoon Lee (co-author, Master/Ph.D. integrated course), Soong HoUm (co-author, Professor), Yong Taik Lim (corresponding author, professor)

  • Utilization of social capital in establishing a social safety net for children

    Department of Child Psychology and Education Prof. Yanghee Lee ·Dr. Sangwon Kim

    Utilization of social capital in establishing a social safety net for children

    Social capital refers to potential or actual resources that can be accrued from their embedded relationships, and parents are considered as one of the vital sources from which children can obtain it. Social capital is particularly important in that it can be used to overcome harmful situations faced by children. In the past, social capital had been explored based on the accounts of adults, such as the degree in which parental social capital could be transmitted to children. However, with society's wider acceptance of children as active social agents, children's subjective reports on their social capital have recently gained greater consideration. Professor Yanghee Lee and Dr. Sangwon Kim (the Department of Child Psychology and Education, College of Social Science) stipulated that when parents are the perpetrators of violence, children may lack social capital. Thus, alternatives sources for social capital in children's immediate environment were identified and explored. This study utilized the responses of 4th graders (N= 2,844) from the Korean Youth Panel, and investigated whether social capital from siblings, friends, teachers, neighbors, and online acquaintances mediated the pathway of parental violence leading to aggression or depression. It was found that social capital obtained from siblings, teachers, and neighbors mediated the pathway between parental violence and aggression or depression, and this was consistent in aggression but not in depression. This finding is significant in that other sources of social capital would be crucial in breaking cycle of violence. Social capital obtained from friends did not have a significant mediating effect. It was further confirmed that continuous monitoring should be accompanied because social capital obtained from online acquaintances can lead to increased levels of aggression or depression. Professor Lee explained that this study is noteworthy in that it explored the role of other forms of social capital that can compensate for the lack of parental social capital. She added that it is the responsibility of all of us to protect children from all forms of violence, therefore it is essential to actively seek ways to develop and promote children's social capital. To establish a social safety net for children, Dr. Sangwon Kim said that it is necessary to explore various ways to utilize social capital by considering social capital measured both at the individual and the community level. This study was published in the internationally renowned journal titled Journal of Interpersonal Violence (SSCI, IF=6.144). Professor Lee served as a professor for 30 years and has researched child counseling, play therapy, interventions for children with developmental disabilities, child abuse and neglect, children's rights, and child resilience. She has published more than 100 papers in domestic and international academic journals. She is currently serving as an editorial board member in internationally renowned journals, including Child Abuse & Neglect (SSCI, IF = 3.928), International Journal of Children's Rights (SCOPUS), and others. Also, she served as a Guest editor in Child Abuse & Neglect (2009-2011; 2019-2020) and the International Journal of Children's Rights (2010).

  • Big data analytics for identifying student usage patterns and instructional strategies in an online learning platform

    Education Prof. KIM, DONGHO

    Big data analytics for identifying student usage patterns and instructional strategies in an online learning platform

    A research team led by Dong ho Kim, an assistant professor in the Department of Education, analyzed account information and behavioral log data collected fromabout 100,000 students using an AI-based math learning platform “Algebra Nation,” by leveraging the learning analytics approach and constructed a prediction model to forecast student dropout in the platform. The team carried out a multilevel-Survival Analysis to explore relationships between student dropout and online activities. Their findings shed light on the behavioral characteristics of at-risk online students. They also provided instructional strategies that can be adopted by teachers who want to boost student engagementin online learning platforms. Their work has recently been published in Computers and Education, one of top journals globally recognized as an outlet for research in education. The workhas received a great deal of attention from researchers as we are in face ofthe rapid growth of online learning in all education sectors. Prof. Dongho Kimhas engaged in the area of AI-based online learning platforms. His work focuses on applying a variety of educational technology theories to find out how to support students in technology-enhanced learning environments. “In the non-contact era, growing attention will be paid to online platformsd esigned to help students who are physically separated from their instructor.” JungwonLee, a graduate student in the Prof. Kim’s research team, said. Jungwon Lee is developing an AI chatbot for pre-service teachers to learn how to teach their students.

  • Examining the Complex Relationship Between Adiposity and Various Cardiovascular Diseases

    Samsung Advanced Institute for Health Sciences and Technology, SKKU Prof. WON, HONG HEE ·Researcher Minseo Kim

    Examining the Complex Relationship Between Adiposity and Various Cardiovascular Diseases

    <Graphical Abstract. Association between adiposity and cardiovascular outcomes: an umbrella review and meta-analysis of observational and Mendelian randomization studies. Eur Heart J. 2021> A research team led by Professor Hong-Hee Won (first author: Minseo Kim, and corresponding author: Hong-Hee Won) of the Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, and Samsung Genome Institute (SGI), Samsung Medical Center, conducted a comprehensive analysis on adiposity and cardiovascular disease events and mortality, and published results in one of the most prestigious cardiology journals, European Heart Journal (Impact Factor 29.98)'. This study performed a meta-analysis of more than 500 cohorts to comprehensively analyze the effects of adiposity on the risk of nine cardiovascular diseases and mortality. The study design presented in this study enables a higher-resolution analysis for complex epidemiological topics by examining associations using a cohort study and causality through a genomic study. The relationship between adiposity and cardiovascular disease has been continuously studied for a long time, and it is known that adiposity increases the risk of cardiovascular disease. However, each study showed very heterogeneous results according to obesity metrics, ancestry, and cohort characteristics. In addition, obesity has a unique feature that it has a bidirectional interaction with the disease. That is, although the risk of cardiovascular disease is increased by obesity, conversely, the possibility that obesity is increased due to the occurrence of cardiovascular disease cannot be excluded. In the case of such a complex epidemiologic relationship, there is a limitation in that it is difficult to confirm the exact causality or direction of interaction only through observational studies. In interventional studies such as drug research, causality can be confirmed through a study design called a randomized controlled trial. In the case of obesity and cardiovascular disease, however, research mainly relies on observational studies because it is unethical to induce obesity through intervention. Due to the nature of observational studies, it is difficult to fundamentally exclude confounding variables, and in the case of the bidirectional phenotype such as obesity, it becomes more difficult to identify the relationship. To solve this problem, this research team grafted genome-based research to confirm causality to observational research for the first time. Mendelian randomization study used in this study is based on the fact that genetic variants are randomly assigned during meiosis to form groups with high or low genetic risk of obesity. Comparing the difference in the risk of cardiovascular disease for these two groups can evaluate whether obesity causes the disease without intervention. Mendelian randomization studies have the advantage of being able to obtain independent results from confounding variables and reverse causation caused by the environment because groups are randomly divided at the stage of meiosis. This is in contrast to the weakness of epidemiological studies that they can be often affected by confounding factors or reverse causation. This study presents new high-level evidence for the relationship between obesity and cardiovascular disease, which has been studied for a long time, by utilizing both the strength of large-scale observational studies (association confirmation), and the strength of genome-based research (causality confirmation). A researcher, Minseo Kim (graduated from Korea University College of Medicine and a M.A. student at SAIHST, Sungkyunkwan University), said, “There were weaknesses in clinical research while conducting clinical research. We devised a new research design that could augment clinical research with genomic approaches. This was possible because he learned both clinical research and genomics. It is expected that more sophisticated studies will be possible by using this research methodology for many epidemiological research topics in the future.” Professor Hong-Hee Won said, “This study is meaningful that it systematically presented scientific evidence for causality between obesity and the risk of cardiovascular disease by integrating large-scale epidemiological and genomic studies. As obesity has been shown to be responsible for various cardiovascular diseases and mortality risk, it is important to maintain ideal body weight and to adhere to healthy lifestyles to lower the risk of cardiovascular disease." The results of this study, which was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Science and ICT (Information and Communication Technologies) of the Korea government, were published in one of the most prestigious cardiology journals, 'European Heart Journal (Impact Factor 29.98)'. ▲ Prof. Hong-Hee Won, Ph.D. (corresponding author) ▲ Minseo Kim, M.D. (first author) ▲ A research team led by Professor Hong-Hee Won at SAIHST, Sungkyunkwan University, Samsung Medical Center

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