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Nano Research 2015年第5期8卷 1584-1594页

作者： Seung Ho Choi jung-kul lee Yun Chan Kang Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seou1136-713 Republic of Korea Department of Chemical Engineering Konkuk University 1 Hwayang-Dong Gwangjin-Gu Seou1143-701 Republic of Korea

The use of new three-dimensional （3D） porous graphene-metal oxide composite microspheres as an anode material for Li-ion batteries （LIBs） is first introduced here. 3D graphene microspheres are aggregates of individual hollow graphene nanospheres composed of graphene sheets. Metal oxide nanocrystals are uniformly distributed over the graphene surface of the microspheres. The 3D porous graphene-SnO2 microspheres are selected as the first target material for investigation because of their superior electrochemical properties. The 3D porous graphene-SnO2 and graphene microspheres and bare SnO2 powders deliver discharge capacities of 1,009, 196, and 52 mAh·g^-1, respectively, after 500 cycles at a current density of 2 A·g^-1 .The 3D porous graphene-SnO2 microspheres exhibit uniquely low charge transfer resistances and high Li-ion diffusivities before and after cycling.

关键词： graphene metal oxide nanostructures electrode material batteries

Effect of esterification reaction of citric acid and ethylene glycol on the formation of multi-shelled cobalt oxide powders with superior electrochemical properties

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Nano Research 2014年第12期7卷 1738-1748页

作者： Gi Dae Park Jong-Heun lee jung-kul lee Yun Chan Kang Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seou1136-713 Republic of Korea Department of Chemical Engineering Konkuk University 1 Hwayang-dong Gwangjin-gu Seou1143-701 Republic of Korea

In this study, for the first time, polymeric precursors have been used in the preparation of yolk-shell powders using a large-scale spray drying process. An esterification reaction between the carboxyl group of citric acid and the hydroxyl group of ethylene glycol inside the droplet produced organic polymers during the drying process of the droplet. During the spray drying process, the polymeric precursors enabled the formation of multi-shell cobalt oxide yolk- shell powders with superior electrochemical properties. The maximum number of shells of the particles in the yolk-shell powders post-treated at 300, 400, and 500 ℃ were six, five, and four, respectively. The initial discharge capacities of the cobalt oxide yolk-shell powders post-treated at 300, 400, and 500 ℃ were 1,188, 1,331, and 1,110 mAh·g^-1, and their initial charge capacities were 868, 1,005, and 798 mAh·g^-1, respectively. The discharge capacities of the powders post- treated at 300, 400, and 500 ℃ after 100 cycles were 815, 958, and 670 mAh·g^-1, respectively and their corresponding capacity retentions measured after the first cycles were 92%, 93%, and 82%, respectively. The pure phase Co3O4 yolk-shell powders post-treated at 400 ℃ had low charge transfer resistance and high lithium-ion diffusion rate.

关键词： yolk-shell energy storage synthesis design lithium battery spray drying

Adverse effects of early-life stress:focus on the rodent neuroendocrine system

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Neural Regeneration Research 2024年第2期19卷 336-341页

作者： Seung Hyun lee Eui-Man jung Department of Molecular Biology College of Natural SciencesPusan National UniversityBusanRepublic of Korea

Early-life stress is associated with a high prevalence of mental illnesses such as post-traumatic stress disorders,attention-deficit/hyperactivity disorder,schizophrenia,and anxiety or depressive behavior,which constitute major public health *** the early stages of brain development after birth,events such as synaptogenesis,neuron maturation,and glial differentiation occur in a highly orchestrated manner,and external stress can cause adverse long-term effects throughout *** body utilizes multifaceted mechanisms,including neuroendocrine and neurotransmitter signaling pathways,to appropriately process external *** individuals first exposed to early-life stress deploy neurogenesis as a stress-defense mechanism;however,in adulthood,early-life stress induces apoptosis of mature neurons,activation of immune responses,and reduction of neurotrophic factors,leading to anxiety,depression,and cognitive and memory *** process involves the hypothalamus-pituitary-adrenal axis and neurotransmitters secreted by the central nervous system,including norepinephrine,dopamine,and *** rodent early-life stress model is generally used to experimentally assess the effects of stress during *** paper reviews the use of the early-life stress model and stress response mechanisms of the body and discusses the experimental results regarding how early-life stress mediates stress-related pathways at a high vulnerability of psychiatric disorder in adulthood.

关键词： early-life stress hypothalamic-pituitary-adrenergic axis maternal separation mental illness neurodevelopmental disorder neuroendocrine system neurotransmitter

In situ infrared, Raman and X-ray spectroscopy for the mechanistic understanding of hydrogen evolution reaction

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Journal of Energy Chemistry 2024年第3期90卷 632-651,I0014页

作者： Andi Haryanto Kyounghoon jung Chan Woo lee Dong-Wan Kim Department of Chemistry Kookmin UniversitySeoul 02707Republic of Korea School of Civil Environmental and Architectural EngineeringKorea UniversitySeoul 02841Republic of Korea

Hydrogen production by water reduction reactions has received considerable attention because hydrogen is considered a clean-energy carrier,key for a sustainable energy *** methods have been widely used to study the reaction mechanism of the hydrogen evolution reaction(HER),but the calculation results need to be supported by experimental results and direct evidence to confirm the mechanistic *** this review,we discuss the fundamental principles of the in situ spectroscopic strategy and a theoretical model for a mechanistic understanding of the *** addition,we investigate recent studies by in situ Fourier transform infrared(FTIR),Raman spectroscopy,and X-ray absorption spectroscopy(XAS) and cover new findings that occur at the catalyst-electrolyte interface during *** spectroscopic strategies provide practical ways to elucidate catalyst phase,reaction intermediate,catalyst-electrolyte interface,intermediate binding energy,metal valency state,and coordination environment during HER.

关键词： Hydrogen evolution reaction Infrared spectroscopy Raman spectroscopy X-ray absorption spectroscopy Reaction mechanism

Self-assembly of tau fragments as a key pathologic event in tauopathies

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Neural Regeneration Research 2024年第12期19卷 2565-2566页

作者： Ly Thi Huong Luu Le jung Hoon lee Min Jae lee Department of Biochemistry and Molecular Biology Seoul National University College of MedicineSeoulKorea

Tau protein is encoded by the microtubuleassociated protein tau(MAPT)gene and stabilizes microtubules in the *** has unique biophysical properties that make it both highly water-soluble and positively *** tau is an intrinsically disordered protein lacking defined secondary structures,it can acquire highly organized-sheet structures and stack into a filamentous inclusion such as a paired helical filament(PHF).

关键词： tau pathologic assembly

Disordered Structure and Reversible Phase Transformation from K-Birnessite to Zn-Buserite Enable High-Performance Aqueous Zinc-lon Batteries

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Energy & Environmental Materials 2024年第3期7卷 100-111页

作者： Nibagani Naresh Suyoon Eom Sang Jun lee Su Hwan Jeong Ji-Won jung Young Hwa jung Joo-Hyung Kim Department of Materials Engineering and Convergence Technology Gyeongsang National University(GNU)Jinju 52828South Korea School of Material Science and Engineering(Ceramic Engineering) Gyeongsang National University(GNU)Jinju 52828South Korea School of Materials Science and Engineering University of Ulsan(UOU)Ulsan 44776South Korea PLS-ⅡBeamline Division Pohang Accelerator Laboratory(PAL)Pohang 37673South Korea

The layeredδ-MnO_(2)(dMO)is an excellent cathode material for rechargeable aqueous zinc-ion batteries owing to its large interlayer distance(~0.7 nm),high capacity,and low cost;however,such cathodes suffer from structural degradation during the long-term cycling process,leading to capacity *** this study,a Co-doped dMO composite with reduced graphene oxide(GC-dMO)is developed using a simple cost-effective hydrothermal *** degree of disorderness increases owing to the hetero-atom doping and graphene oxide *** is demonstrated that layered dMO and GC-dMO undergo a structural transition from K-birnessite to the Zn-buserite phase upon the first discharge,which enhances the intercalation of Zn^(2+)ions,H_(2)O molecules in the layered *** GC-dMO cathode exhibits an excellent capacity of 302 mAh g^(-1)at a current density of 100 mAg^(-1)after 100 cycles as compared with the dMO cathode(159 mAhg^(-1)).The excellent electrochemical performance of the GC-dMO cathode owing to Co-doping and graphene oxide sheets enhances the interlayer gap and disorderness,and maintains structural stability,which facilitates the easy reverse intercalation and de-intercalation of Zn^(2+)ions and H_(2)O ***,GC-dMO is a promising cathode material for large-scale aqueous ZIBs.

关键词： aqueous zinc-ion batteries birnessite buserite disordered structure phase transformation

Combined Insights from Leachate Structure and Microstructure Characteristics for Eating Quality of Convenience Rice Processed by Super-Heated and Pressurized Steam Technologies

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Rice science 2024年第4期31卷 475-488,I0035,I0036页

作者： Mingyo HA Hyo-Young JEONG Ju Hun lee Hyun-jung CHUNG Division of Food and Nutrition Chonnam National UniversityGwangju 61186South Korea Department of Biotechnology College of Life Sciences and BiotechnologyKorea UniversitySeoul 02841South Korea Division of Food Science&Culinary Arts Shinhan UniversityGyeonggi 11644South Korea

Convenience rice has become widely popular due to its easy availability for cooking. This study investigated the starch structure and composition of leachate and the microstructure of reheated convenience rice using novel processing technologies: super-heated steaming(SHS), auto-electric cooking(AEC), and pressurized-steam cooking(PSC). Additionally, the effect of two different target water contents(58% and 63%) was also evaluated. The PSC_63% sample had the highest total solids and amylopectin amount in the leachate. The amylopectin amount in the leachate differed significantly based on the targeted water content. Morphological characterization revealed that the swelling of starch and the coated layer on the surface of rice grains were most pronounced in the PSC_63% sample due to the pressure processing. The textural hardness of the AEC_58% sample was much higher than that of the other samples. The PSC_63% sample had the highest textural adhesiveness value, which can be attributed to the highest amylopectin amount in the leachate. Sensory characterization showed that the PSC_63% sample had the highest glossiness, whiteness, moistness, and overall acceptability. The principal component analysis score plots presented substantial differences in the leachate and textural and sensory characteristics of reheated convenience rice among the different processing technologies.

关键词： reheated convenience rice starch structure leachate multi-scale structure eating quality processing technology

Enhancing BiVO_(4)photoanode performance by insertion of an epitaxial BiFeO_(3)ferroelectric layer

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Journal of Energy Chemistry 2024年第2期89卷 71-78,I0003页

作者： Haejin Jang Yejoon Kim Hojoong Choi Jiwoong Yang Yoonsung jung Sungkyun Choi Donghyeon lee Ho Won Jang Sanghan lee School of Materials Science and Engineering Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea

BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical ***,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfactory photoelectrochemical *** address this,various modifications have been attempted,including the use of ferroelectric *** materials can form a permanent polarization within the layer,enhancing the separation and transport of photo-excited electron-hole *** this study,we propose a novel approach by depositing an epitaxial BiFeO_(3)(BFO)thin film underneath the BVO thin film(BVO/BFO)to harness the ferroelectric property of *** self-polarization of the inserted BFO thin film simultaneously functions as a buffer layer to enhance charge transport and a hole-blocking layer to reduce charge *** a result,the BVO/BFO photoanodes showed more than 3.5 times higher photocurrent density(0.65 mA cm^(-2))at 1.23 V_(RHE)under the illumination compared to the bare BVO photoanodes(0.18 m A cm^(-2)),which is consistent with the increase of the applied bias photon-to-current conversion efficiencies(ABPE)and the result of electrochemical impedance spectroscopy(EIS)*** results can be attributed to the self-polarization exhibited by the inserted BFO thin film,which promoted the charge separation and transfer efficiency of the BVO photoanodes.

关键词： Photoelectrochemical Photoanode BiVO_(4) Ferroelectric materials BiFeO_(3)

Nanozyme‑Engineered Hydrogels for Anti‑Inflammation and Skin Regeneration

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Nano-Micro Letters 2024年第6期16卷 127-179页

作者： Amal George Kurian Rajendra K.Singh Varsha Sagar jung‑Hwan lee Hae‑Won Kim Institute of Tissue Regeneration Engineering(ITREN) Dankook UniversityCheonan 31116Republic of Korea Department of Nanobiomedical Science&BK21 NBM Global Research Center for Regenerative Medicine Dankook UniversityCheonan 31116Republic of Korea Department of Biomaterials Science School of DentistryDankook UniversityCheonan 31116Republic of Korea UCL Eastman‑Korea Dental Medicine Innovation Centre Dankook UniversityCheonan 31116Republic of Korea Cell and Matter Institute Dankook UniversityCheonan 31116Republic of Korea Mechanobiology Dental Medicine Research Center Dankook UniversityCheonan 31116Republic of Korea

Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare *** therapies,such as corticosteroids and nonsteroidal anti-inflammatory drugs,are limited in efficacy and associated with adverse ***,nanozyme(NZ)-based hydrogels have shown great promise in addressing these ***-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of *** multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and *** review highlights the current state of the art in NZ-engineered hydrogels(NZ@hydrogels)for anti-inflammatory and skin regeneration *** also discusses the underlying chemo-mechano-biological mechanisms behind their ***,the challenges and future directions in this ground,particularly their clinical translation,are *** insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels,offering new possibilities for targeted and personalized skin-care therapies.

关键词： Nanozymes Hydrogels ROS scavenging Anti-inflammation Skin regeneration

Synthesis of crystalline g-C_(3)N_(4) with rock/molten salts for efficient photocatalysis and piezocatalysis

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Green Energy & Environment 2024年第5期9卷 890-898页

作者： Tingting Xu jung Hur Ping Niu Shulan Wang Sangwook lee Sang-Eun Chun Li Li Department of Chemistry College of ScienceNortheastern UniversityShenyang110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China School of Metallurgy Northeastern UniversityShenyang110819China School of Materials Science and Engineering Kyungpook National UniversityDaegu41566Republic of Korea School of Industrial Technology Advances Kyungpook National UniversityDaegu41566Republic of Korea

Graphitic carbon nitride(g-C_(3)N_(4))is emerging as a promising visible-light photocatalyst while the low crystallinity with sluggish charge separation/migration dynamics signiﬁcantly restricts its practical ***,synthesizing highly crystalline g-C_(3)N_(4) with sufﬁcient surface activities still remains ***,different from using alkali molten salts which is commonly reported,we propose an approach for synthesis of highly crystalline g-C_(3)N_(4) with FeCl3/KCl rock/molten mixed *** rock salt can serve as the structure-directing template while molten salt provides the required liquid medium for ***,the synthesized photocatalyst showed further enhanced crystallinity and improved surface area along with high p/p*excitation compared with crystalline C_(3)N_(4) prepared from conventional molten-salt *** catalytically advantageous features lead to its superior photocatalytic and piezocatalytic activities with a high reactivity for overall water splitting that is not commonly reported for C_(3)N_(4).This work provides an effective strategy for structural optimization of organic semiconductor based materials and may inspire new ideas for the design of advanced photocatalysts.

关键词： High crystallinity Carbon nitride Photocatalysis Piezocatalysis Overall water splitting