检索结果-南通市图书馆

Epigenetics: An emerging player in gastric cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第21期20卷 6433-6447页

作者： changwon kang Ji-Joon Song Jaeok Lee Mi Young Kim Department of Biological Sciences Korea Advanced Institute of Science and TechnologyDaejeon 305-701South Korea

Cancers,like other diseases,arise from gene mutations and/or altered gene expression,which eventually cause dysregulation of numerous proteins and noncoding RNAs.Changes in gene expression,i.e.,upregulation of oncogenes and/or downregulation of tumor suppressor genes,can be generated not only by genetic and environmental factors but also by epigenetic factors,which are inheritable but nongenetic modifications of cellular chromosome components.Identification of the factors that contribute to individual cancers is a prerequisite to a full understanding of cancer mechanisms and the development of customized cancer therapies.The search for genetic and environmental factors has a long history in cancer research,but epigenetic factors only recently began to be associated with cancer formation,progression,and metastasis.Epigenetic alterations of chromatin include DNA methylation and histone modifications,which can affect gene-expression profiles.Recent studies have revealed diverse mechanisms by which chromatin modifiers,including writers,erasers and readers of the aforementioned modifications,contribute to the formation and progression of cancer.Furthermore,functional RNAs,such as microRNAs and long noncoding RNAs,have also been identified as key players in these processes.This review highlights recent findings concerning the epigenetic alterations associated with cancers,especially gastric cancer.

关键词： Gastric cancer Epigenetics DNA methylation Histone

Structural and electrochemical stabilization enabling high-energy P3-type Cr-based layered oxide cathode for K-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第5期6卷 81-93页

作者： Wonseok Ko Seokjin Lee Hyunyoung Park Jungmin kang Jinho Ahn Yongseok Lee Gwangeon Oh Jung-Keun Yoo Jang-Yeon Hwang Jongsoon Kim Department of Energy Science Sungkyunkwan UniversitySuwonRepublic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwonRepublic of Korea Department of Energy Engineering Hanyang UniversitySeoulRepublic of Korea Carbon Composites Department Korea Institute of Materials Science(KIMS)ChangwonRepublic of Korea Department of Battery Engineering Hanyang UniversitySeoulRepublic of Korea

Layered-type transition metal(TM)oxides are considered as one of the most promising cathodes for K-ion batteries because of the large theoretical gravimetric capacity by low molar mass.However,they suffer from severe structural change by de/intercalation and diffusion of K^(+)ions with large ionic size,which results in not only much lower reversible capacity than the theoretical capacity but also poor power capability.Thus,it is important to enhance the structural stability of the layered-type TM oxides for outstanding electrochemical behaviors under the K-ion battery system.Herein,it is investigated that the substitution of the appropriate Ti^(4+)contents enables a highly enlarged reversible capacity of P3-type KxCrO_(2) using combined studies of first-principles calculation and various experiments.Whereas the pristine P3-type KxCrO_(2) just exhibits the reversible capacity of∼120 mAh g^(−1) in the voltage range of 1.5-4.0 V(vs.K^(+)/K),the∼0.61 mol K^(+)corresponding to∼150 mAh g^(−1) can be reversible de/intercalated at the structure of P3-type K0.71[Cr_(0.75)Ti_(0.25)]O_(2) under the same conditions.Furthermore,even at the high current density of 788 mA g^(−1),the specific capacity of P3-type K0.71[Cr_(0.75)Ti_(0.25)]O_(2) is∼120 mAh g^(−1),which is∼81 times larger than that of the pristine P3-type KxCrO_(2).It is believed that this research can provide an effective strategy to improve the electrochemical performances of the cathode materials suffered by severe structural change that occurred during charge/discharge under not only K-ion battery system but also other rechargeable battery systems.

关键词： cathodes first-principles calculations layered-type oxide materials potassium-ion batteries structural stabilization

Transparent high-performance piezoceramics through pressureless sintering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第5期13卷 561-567页

作者： Hye-Lim Yu Woo-Seok kang Ju-Hyeon Lee Temesgen Tadeyos Zate Young-Jin Lee Bo-Kun Koo Dong-Jin Shin Min-Soo Kim Soon-Jong Jeong Young Ghyu Ahn Wook Jo Department of Material Science and Engineering Ulsan National Institute of Science and TechnologyUlsan 44919Republic of Korea Energy Conversion Research Center Korea Electrotechnology Research InstituteChangwon 51543Republic of Korea MLCC Development Team Component Biz.UnitSamsung Electro-Mechanics Co.Ltd.Suwon 16674Republic of Korea

Piezoelectricity offers an electromechanical coupling that is widely utilized in transducer applications.There has been a consistent demand for transparent piezoelectric materials for optoelectrical applications.Therefore,despite the inherent tradeoff between the transparency and the piezoelectricity,numerous strategies have been explored to develop the transparent piezoelectric materials.Nonetheless,the most transparent piezoelectric materials developed to date is either a single crystal or materials that achieve transparency via hot-press sintering,limiting its industrial applicability.Therefore,we introduce a novel piezoelectric material that ensures transparency through co-doping and pressureless sintering of polycrystalline ceramics.In this study,we employed a compositional optimization approach to enhance the synergistic effect between the transparency and the piezoelectric properties of 0.71Pb(Mg_(1/3)Nb_(2/3))O_(3)–0.29PbTiO_(3)(PMN–0.29PT)ceramics.By utilizing the tape casting process for mass production and large-area manufacturing,our Pb_(0.913)La_(0.0145)Sm_(0.0145)(Mg_(1/3)Nb_(2/3))_(0.71)Ti_(0.29)O_(3)(TP2.9)ceramics exhibited over 60%transparency and large piezoelectric coefficient(d33)of 1104 pC/N.This material holds considerable promise for a wide range of industrial applications in both the optical and electronic domains.

关键词： piezoelectric ceramics transparency pressureless sintering co-doping tape casting

Evaluation of the k-nearest neighbor method for forecasting the influent characteristics of wastewater treatment plant

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2016年第2期10卷 299-310页

作者： Minsoo KIM Yejin KIM Hyosoo KIM Wenhua PIAO changwon KIM Department of Civil and Environmental Engineering Pusan National University Busan 609-735 Republic of Korea Department of Civil and Environmental Engineering Catholic University of Pusan Busan 609-757 Republic of Korea EnvironSoft Co. Ltd. #511 Industry-University Co.Bld. Pusan Nationai University Busan 609-735 Republic of Korea

The k-nearest neighbor （k-NN） method was evaluated to predict the influent flow rate and four water qualities, namely chemical oxygen demand （COD）, suspended solid （SS）, total nitrogen （T-N） and total phosphorus （T-P） at a wastewater treatment plant （WWTP）. The search range and approach for determining the number of nearest neighbors （NNs） under dry and wet weather conditions were initially optimized based on the root mean square error （RMSE）. The optimum search range for considering data size was one year. The square root-based （SR） approach was superior to the distance factor-based （DF） approach in determining the appropriate number of NNs. However, the results for both approaches varied slightly depending on the water quality and the weather conditions. The influent flow rate was accurately predicted within one standard deviation of measured values. Influent water qualities were well predicted with the mean absolute percentage error （MAPE） under both wet and dry weather conditions. For the seven-day prediction, the difference in predictive accuracy was less than 5% in dry weather conditions and slightly worse in wet weather conditions. Overall, the k-NN method was verified to be useful for predicting WWTP influent characteristics.

关键词： influent wastewater prediction data-drivenmodel k-nearest neighbor method （k-NN）

Fabrication, microstructure and properties of SiCp/Cu heat sink materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2006年第Z2期25卷 232-236页

作者： kang Suk-bong Korea Institute of Machinery and Materials 66 Sangnam-dong Changwon 641-010 Korea

Cu-coated powder was fabricated by electroless plating process, and the composition and morphology of coated powder were studied. Moreover, Cu-30, 40, 50 vol.%SiCp heat sink materials were fabricated by hot pressing using coated and uncoated powder. And the microstructure and thermophysical properties of the heat sink materials were also studied. The results show that SiCp particles distribute uniformly in heat sink materials and the interface between SiCp particles and Cu matrix is clear and well bonded. On the condition of same volume fraction of SiCp, the thermal conductivity of the material using coated powder is larger than that of the material using uncoated powder. Under experiment conditions, the thermal conductivity and coefficient of thermal expansion of Cu-30 vol.%SiCp heat sink material is 236.2 W·m-1·K-1 and 9.9×10-6/K (30-200 ℃) respectively. It provides important reference data for future experiments.

关键词： heat sink material electroless copper plating coefficient of thermal expansion thermal conductivity

Microstructure analyses and phase-field simulation of partially divorced eutectic solidification in hypoeutectic Mg-Al Alloys

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第6期10卷 1672-1679页

作者： Joo-Hee kang Jiwon Park Kyung Song Chang-Seok Oh Oleg Shchyglo Ingo Steinbach Korea Institute of Materials Science Changwon 51508Republic of Korea Interdisciplinary Centre for Advanced Materials Simulation Ruhr-University Bochum44801 BochumGermany

In this study the partially divorced eutectic microstructure ofα-Mg andβ-Mg17Al12was investigated by electron backscatter diffraction,transmission electron microscopy,and phase-field modeling in hypoeutectic Mg-Al alloys.The orientation relationships between the individual eutecticαgrains,eutecticβphase,and primaryαgrains were investigated.While the amount of eutectic morphology is primarily determined by the Al content,the in-depth microstructure analyses and the phase-field simulation suggest non-interactive nucleation and growth of eutecticαphase in theβphase grown on the interdendritic primaryαdendrites.Also,phase-field simulations showed a preferred nucleation sequence where theβphase nucleates first and subsequently triggers the nucleation of eutecticαphase at the movingβphase solidification front,which supports the microstructural analysis results.

关键词： Mg-Al alloy Partially divorced eutectic Solidification Electron backscatter diffraction Phase-Field modeling

Significant enhancement of photoresponsive characteristics and mobility of MoS2-based transistors through hybridization with perovskite CsPbBr3 quantum dots

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nano Research 2019年第2期12卷 405-412页

作者： Taeho Noh Heung Seob Shin changwon Seo Jun Young Kim Jongwon Youn Jeongyong Kim Kwang-Sup Lee Jinsoo Joo Department of Physics Korea University Seoul 02841 Republic of Korea Department of Advanced Materials and Chemical Engineering Hannatn University Daejeon 34430 Republic of Korea Department of Energy Science Sungkyunkwan University Suwon 16419 Republic of Korea

Inorganic perovskite CsPbBr3 quantum dots (QDs) are potential nanoscale photosensitizers;moreover,two-dimensional (2-D) molybdenum disulfide (MoS2) has been intensively studied for application in the active layers of optoelectronic devices.In this study,heterostructures of 2D-monolayered MoS2 with zero-dimensional functionalized CsPbBr3 QDs were prepared,and their nanoscale optical characteristics were investigated.The effect of n-type doping on the MoS2 monolayer after hybridization with perovskite CsPbBr3 QDs was observed using laser confocal microscope photoluminescenca (PL) and Raman spectra.Field-effect transistors (FETs) using MoS2 and the MoS2-CsPbBr3 QDs hybrid were also fabricated,and their electrical and photoresponsive characteristics were investigated in terms of the charge transfer effect.For the MoS2-CsPbBr3 QDs-based FETs,the field effect mobility and photoresponsivity upon light irradiation were enhanced by ~ 4 times and a dramatic ~ 17 times,respectively,compared to the FET prepared without the parovskite QDs and without light irradiation.It is noteworthy that the photoresponsivity of the MoS-2-CsPbBr3 QDs-based FETs significantly increased with increasing light power,which is completely contrary to the behavior observed in previous studies of MoS2-based FETs.The increased mobility and significant enhancement of the photoresponsivity can be attributed to the n-type doping effect and efficient energy transfer from CsPbBr3 QDs to MoS2.The results indicate that the optoelectronic characteristics of MoS2-based FETs can be significantly improved through hybridization with photosensitive parovskite CsPbBr3 QDs.

关键词： MoS2 perovskite quantum dot transistor photoresponsivity mobility charge transfer

Superelastic metastable Ti-Mo-Sn alloys with high elastic admissible strain for potential bio-implant applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第32期163卷 45-58页

作者： Shuanglei Li Jae H.Kim Seung Won kang Jae Ho Kim Tae-Hyun Nam Jong-Taek Yeom Titanium Alloys Department Metal Materials DivisionKorea Institute of Materials Science(KIMS)Changwon 51508Republic of Korea Department of Materials Engineering and Convergence Technology&Research Institute for Green Energy Convergence Technology(RIGET) Gyeongsang National University900 GazwadongJinjuGyeongnam 52828Republic of Korea

The demand for titanium alloys simultaneously having high elastic admissible strain and large recovery strain for bio-implant applications is increasing.Ni-free Ti-based shape memory alloys are promising candidates for obtaining the required multifunctional properties.In this study,a wide content range of(0-15)wt%of low-cost,toxicity-free,and high-biocompatible Sn element was added to the Ti-8Mo(wt%)alloy to study its effect on the superelastic recovery and mechanical properties of biomedical Ti-Mo-Sn alloys.By tailoring Sn content,desired multifunctional properties of high elastic admissible strain and room temperature superelasticity were achieved in the studied Ti-Mo-Sn alloys.It was found that the increase in Sn content stabilized theβphase and a singleβphase was obtained at room temperature in Ti-8Mo-(13,15)Sn alloys.The addition of Sn modified the lattice parameters of theα″martensite andβphase and affected the lattice deformation stain ofβ→α″.The lattice deformation strain along the[011]βdirection was found to be decreased by-0.26%/wt%Sn.The room temperature superelasticity with a recovery strain of 3.1%and an elastic admissible strain of 1%was obtained in the Ti-8Mo-13Sn alloy.As Sn content increased to 15 wt%,a high elastic admissible strain of 1.56%and a recovery strain of 2.0%were obtained.These Ti-Mo-Sn alloys with excellent multifunctional properties are promising candidates for bio-implant applications.

关键词： Ti-Mo-Sn alloy Shape memory alloy Elastic admissible strain Elastic modulus Superelasticity

Understanding secondary phase inclusion and composition variations in the microstructure design of n-type Bi_(2)Te_(3) alloys via selective dissolution of KCl

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2023年第12期12卷 2360-2370页

作者： Gwang Min Park Seunghyeok Lee Jun-Yun kang Seung-Hyub Baek Heesuk Kim Jin-Sang Kim Seong Keun Kim KU-KIST Graduate School of Converging Science and Technology Korea UniversitySeoul 02841Republic of Korea Electronic Materials Research Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea Department of Materials Science and Chemical Engineering Hanyang UniversityAnsan 15588Republic of Korea Ferrous Alloy Department Korea Institute of Materials ScienceChangwon 51508Republic of Korea Soft Hybrid Materials Research Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea Institute of Advanced Composite Materials Korea Institute of Science and TechnologyWanju 55324Republic of Korea

This study investigated the effects of KCl treatment on microstructure and thermoelectric properties of n-type Bi_(2)Te_(2.7)Se_(0.3)(BTS)thermoelectric materials.The innovative KCl treatment was originally intended to introduce nanopores through selective dissolution of KCl from a mixture of thermoelectric materials and KCl.However,it unexpectedly induced substantial variations in material composition and microstructure during the subsequent spark plasma sintering(SPS)process.Hydroxyl groups adsorbed on the powder surface during the dissolution resulted in the emergence of a Bi_(2)TeO_(5) secondary phase within the BTS matrix after the SPS process at 450℃.The concentration of Bi_(2)TeO_(5) increased with an increase in the KCl content.Furthermore,a remarkable grain growth occurred at low KCl concentrations,likely due to the liquid-phase formation in a Te-rich composition during SPS.However,excessive Bi_(2)TeO_(5) at higher KCl concentrations hindered grain growth.These variations in the microstructure had complex effects on electrical properties:The TeBi antisite defects increased the electron concentration,and Bi_(2)TeO_(5) reduced electron mobility.Additionally,the lattice thermal conductivity decreased due to the presence of Bi_(2)TeO_(5),from 0.8 W·m^(−1)·K^(−1) at 298 K for the pristine BTS to 0.6 W·m^(−1)·K^(−1) at 298 K for BTS treated with 1 wt%KCl.These insights allowed precise adjustments of the electrical and thermal conductivities,leading to an enhancement in the maximum value of figure-of-merit(ZT)from 0.76 to 0.96 through the selective dissolution of KCl approach.We believe that our observations potentially enable advances in thermoelectric materials by engineering microstructures.

关键词： thermoelectric materials Bi_(2)Te_(3) Bi_(2)TeO_(5) grain growth n-type KCl