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Inhibition of BET selectively eliminates undifferentiated pluripotent stem cells

Science Bulletin 2018年第8期63卷 477-487页

作者： Jung Hyun Im Seon In Hwang Jong-Wan Kim soon-Jung Park Kyu-ree Kang Jueng Soo You Kee Pyo Kim Sung-Hwan Moon hyuk-jin cha Hyung-Min Chung Hans R. Scholer Jung Keun Hyun DongWook Han Department of Stem Cell Biology School of Medicine Konkuk University Seoul 05029 Republic of Korea Department of Nanobiomedical Science Dankook University Graduate School Cheonan 330714 Republic of Korea Department of Biochemistry School of Medicine Konkuk University Seoul 05029 Republic of Korea Department of Cell and Developmental Biology Max Planck Institute for Molecular Biomedicine 48149 Munster Germany Department of Life Sciences College of Natural Sciences Sogang University Seoul 04107 Republic of Korea KU Open-lnnovation Center. Institute of Biomedical Science & Technology Konkuk University Seoul 05029 Republic of Korea Department of Advanced Translational Medicine School of Medicine Konkuk University Seoul 05029 Republic of Korea

Embryonic stem cells （ESCs） maintain their cellular identity through the systematic regulation of master transcription factors and chromatin remodeling complexes. Recent work has shown that the unusually large-scale enhancers-namely super-enhancers （SEs）, on which BRD4, a member of the bromodomain and extraterminal domain （BET） family is highly enriched-could regulate pluripotency-related transcrip- tion factors. Moreover, inhibition of BRD4 binding on SEs has been shown to induce the differentiation of ESCs. However, the underlying mechanism of BRD4 inhibition-mediated stern cell differentiation remains elusive. Here we show that both mouse and human ESCs lose their capacity for self-renewal upon treat- ment with JQ1, a selective inhibitor of BET family including BRD4, with rapid suppression of pluripotency-associated genes. Notably, a high concentration of JQI could selectively eliminate ESCs via apoptosis, without affecting the functionality of differentiated somatic cells from ESCs, suggesting that inhibition of BET may have a beneficial effect on the development of pluripotent stem cell-based cell therapy.

关键词： Bromodomain and extraterminal domain (BET) JQ1 Pluripotent stem cells

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Effects of homogenization temperature on microstructure and mechanical properties of high-speed-extruded Mg–5Bi–3Al alloy

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Journal of Magnesium and Alloys 2022年第10期10卷 2833-2846页

作者： Jae Won cha Sang-Cheol jin Jae-Gil Jung Sung hyuk Park School of Materials Science and Engineering Kyungpook National University80 DaehakroDaegu 41566Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

This study investigates the effects of billet homogenization temperature on the dynamic recrystallization behavior during high-speed extrusion and resultant microstructure and tensile properties of the Mg–5Bi–3Al(BA53,wt%)*** billets homogenized at 350 and450℃(350H and 450H billets)are extruded at a high speed of 69 m/*** 350H billet has a relatively smaller grain size and a higher abundance of fine Mg3Bi2particles compared to the 450H *** extrusion of the 350H billet,enhanced dynamic recrystallization occurs as a result of its finer grains and abundance of particles,while the growth of recrystallized grains is suppressed by the grain-boundary pinning effect of ***,the extruded 350H material is characterized by smaller grains,relatively greater number of Mg3Bi2particles,and a higher internal strain energy than the extruded 450H *** tensile strength of the extruded 350H material is higher than that of the extruded 450H material owing to stronger grain-boundary hardening,particle hardening,and strain hardening *** extruded 350H material also exhibits a higher tensile elongation as its smaller grains inhibit the formation of crack-inducing undesirable twins during *** results from this study demonstrate that a decrease in the homogenization temperature from 450 to 350℃leads to improved strength and ductility in the high-speed-extruded BA53 material.

关键词： Mg–Bi–Al alloy High-speed extrusion Homogenization Dynamic recrystallization Tensile properties

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Performance Study of a Hybrid Heat Pump Dryer based on Numerical Analysis and Experimental Set-up

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Journal of Thermal Science 2021年第1期30卷 111-122页

作者： SHAMSUDDEEN Mohamed Murshid cha Dong-An KIM Seon-chang KANEMOTO Toshiaki KIM jin-hyuk Industrial Technology Korea University of Science&TechnologyDaejeon 34113Republic of Korea Thermal&Fluid System R&D Group Korea Institute of Industrial TechnologyCheonan 31056Republic of Korea Institute of Ocean Energy Saga UniversityHonjo 1Saga 840-8502Japan

Seafood,especially sea cucumbers and oysters are an expensive delicacy in several Asian *** sun-drying of these products takes 3 to 4 days and fetches a lower market *** industrial drying machines used for seafood drying are unable to dry sea cucumbers and oysters without texture and color degradation as they are delicate,temperature-sensitive and have longer drying *** economical drying system that does not cause texture or color degradation is the heat pump drying system and is commonly applied for agriculture and fabric *** this study,the heat pump technology is applied to develop two hybrid dryer models(bottom discharge and front discharge)to dry shellfish and sea cucumbers in large scale for storage and *** model is tested in a laboratory-scale with wet sponges as input material for its dehumidification capacity and the power consumed to attain the target *** front discharge model is found to have rapid drying capability and *** fluid dynamic tools are used to study the hot air flow behavior and flow uniformity inside the drying *** front discharge model showed smooth uniform flow over the trays with fewer losses in the flow *** front discharge model with higher drying rate,lower power consumption and uniform airflow distribution over the trays is chosen for the industrial-scale design.

关键词： heat pump hybrid dryer CFD drying rate sea cucumber oyster

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Variations in dynamic recrystallization behavior and mechanical properties of AZ31 alloy with extrusion temperature

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Journal of Magnesium and Alloys 2023年第7期11卷 2351-2365页

作者： Jae Won cha Sung hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea

This study investigates the effects of extrusion temperature on the dynamic recrystallization(DRX)behavior of a Mg-3Al-1Zn-0.3Mn(AZ31,wt%)alloy during hot extrusion and on the microstructural characteristics and mechanical properties of materials extruded at 350 and 450℃.An increase in the extrusion temperature causes a decrease in the amount of strain energy accumulated in the material during extrusion,because of promoted activation of pyramidalslip and dynamic *** reduced strain energy weakens the DRX behavior during extrusion,which eventually results in a decrease in the area fraction of recrystallized grains of the extruded *** material extruded at 450℃has coarser grains and a stronger basal fiber texture than that extruded at 350℃.As the extrusion temperature increases from 350 to 450℃,the tensile yield strength(TYS)of the extruded material increases from 191.8 to 201.5 MPa,whereas its compressive yield strength(CYS)decreases from 122.5 to 111.0 MPa;consequently,its tension-compression yield stress ratio(CYS/TYS)decreases from 0.64 to *** increase in the TYS is attributed mainly to the stronger texture hardening and strain hardening effects of the extruded material,and the decrease in the CYS is attributed to the reduced twinning stress resulting from grain coarsening and texture *** microstructural and textural evolutions of the materials during extrusion and the deformation and hardening mechanisms of the extruded materials are discussed in detail.

关键词： Mg-Al-Zn alloy Extrusion Dynamic recrystallization Microstructure Yield asymmetry

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Effects of Al addition on microstructure and mechanical properties of extruded Mg-3Bi alloy

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Journal of Magnesium and Alloys 2022年第7期10卷 1887-1898页

作者： Sang-Cheol jin Jae Won cha Jun Ho Bae Hui Yu Sung hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Implementation Research Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea School of Materials Science and Engineering Hebei University of TechnologyTianjin 300130China

Effects of Al addition to a Mg±Bi binary alloy on its microstructural characteristics and tensile properties after extrusion are investigated via extrusion of Mg-3Bi±x Al(x=0,1,and 2 wt%)billets and analysis of the extruded *** Al addition negligibly affects the second-phase particles of the extruded alloy;however,an increase in the Al content causes significant decreases in the average grain size and maximum texture intensity of the extruded material owing to an increase in the area fraction of dynamically recrystallized(DRXed)*** Al addition improves the strength of the extruded alloy;this improvement is attributed to the enhanced grain-boundary hardening and solid-solution hardening effects induced by grain refinement and Al solute atoms,*** the Al content increases from 0 wt%to 1 wt%and 2 wt%,the tensile elongation increases substantially from 2.8%to 9.4%and 16.9%,*** reduction in the number and size of un DRXed grains with increasing Al content suppresses the formation and coalescence of cracks in the un DRXed grains during tension,which results in a significant improvement in the tensile ductility of the extruded *** tensile deformation,large undesirable twins that act as crack initiation sites are locally formed in the un DRXed grains of the Mg-3Bi alloy,whereas relatively smaller twins are uniformly formed in both the DRXed and the un DRXed grains of the Mg-3Bi-2Al ***,the extruded Mg-3Bi-2Al alloy has a substantially higher tensile yield strength±elongation product(2924 MPa%)than the extruded Al-free B3 alloy(381 MPa%).

关键词： Mg-Bi-Al alloy Extrusion Microstructure Strength Ductility

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Comparative study of extrudability, microstructure, and mechanical properties of AZ80 and BA53 alloys

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Journal of Magnesium and Alloys 2023年第1期11卷 249-258页

作者： Sang-Cheol jin Jae Won cha Jongbin Go Jun Ho Bae Sung hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Department of Materials Science and Engineering Kyoto UniversityKyoto 606-8501Japan Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

The extrudability,microstructural characteristics,and tensile properties of the Mg–5Bi–3Al(BA53)alloy are investigated herein by comparing them with those of a commercial Mg–8Al–0.5 Zn(AZ80)*** AZ80 is extruded at 400℃,severe hot cracking occurs at exit speeds of 4.5 m/min or *** contrast,BA53 is successfully extruded without any surface cracking at 400℃ and at high exit speeds of 21–40 m/*** extruded at 3 m/min(AZ80–3)and 40 m/min(BA53–40),both AZ80 and BA53 exhibited completely recrystallized microstructures with abasal ***,BA53–40 has a coarser grain structure owing to grain growth promoted by the high temperature in the deformation ***80–3 contains a continuous network of Mg_(17)Al_(12) particles along the grain boundaries,which form via static precipitation during natural air-cooling after the material exits the extrusion ***53–40 contains coarse Mg_(3)Bi_(2) particles aligned parallel to the extrusion direction along with numerous uniformly distributed fine Mg_(3)Bi_(2) ***80–3 has higher tensile strength than BA53–40 because the relatively finer grains and larger number of solute atoms in AZ80–3 result in stronger grain-boundary and solid-solution hardening effects,*** BA53 is extruded at a high temperature and extrusion speed of 400℃ and 40 m/min,respectively,the extruded material has a high tensile yield strength of 188 *** can be primarily attributed to the large particle hardening effect resulting from the numerous fine Mg_(3)Bi_(2) particles.

关键词： Mg-Bi-Al alloy Extrusion Hot cracking Second phase Tensile properties

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Improvement in tensile strength of extruded Mg-5Bi alloy through addition of Sn and its underlying strengthening mechanisms

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Journal of Magnesium and Alloys 2022年第11期10卷 3100-3112页

作者： Sang-Cheol jin Jae Won cha Jeong Hun Lee Taekyung Lee Sang-Ho Han Sung hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Ulsan Regional Division Korea Institute of Industrial TechnologyUlsan 44413Republic of Korea School of Mechanical Engineering Pusan National UniversityBusan 46241Republic of Korea Department of Materials Analysis Korea Institute of Materials ScienceChangwon 51508Republic of Korea

Through an investigation of the microstructure and mechanical properties of extruded Mg–5Bi–x Sn(BT5x, x = 0, 2, 4, and 6 wt%) alloys,this study demonstrates that the addition of Sn to an Mg–5Bi binary alloy significantly improves the tensile strength of the extruded *** the extruded alloys exhibit a typical basal fiber texture and a partially dynamically recrystallized(DRXed) microstructure consisting of fine DRXed grains and coarse un DRXed grains. As the Sn content increases from 0 wt% to 6 wt%, the average size of the DRXed grains decreases from 4.2 to 2.8 μm owing to the increase in the amount of precipitates via their grain-boundary pinning effect. The extruded B5 and BT52 alloys contain numerous Mg_(3)Bi_(2) precipitates, but their size and number density are smaller and higher, respectively, in the latter *** Mg_(2)Sn precipitates as well as Mg_(3)Bi_(2)precipitates are present in the extruded BT54 and BT56 alloys, and the number density of the Mg_(2)Sn precipitates is higher in the latter alloy because of its higher Sn content. The addition of 2 wt% Sn to the B5 alloy significantly improves the yield strength(YS) and ultimate tensile strength(UTS) of the extruded alloy—by 76 and 57 MPa, respectively. This drastic improvement is the combined outcome of enhanced grain-boundary hardening, precipitation hardening, and solid-solution hardening effects induced by the refined DRXed grains, numerous precipitates, and Sn solute atoms, respectively. The further addition of 2 wt% or 4 wt% Sn to the BT52 alloy leads to moderate increments in the YS and UTS of the extruded alloy. Specifically, each addition of 2 wt% Sn increases the YS and UTS by ~26 and ~20 MPa, respectively, which is attributed mainly to the additional precipitation hardening effect induced by the Mg_(2)Sn precipitates.

关键词： Mg-Bi-Sn alloy Extrusion Precipitation Microstructure Tensile property

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Human Gait Recognition Based on Sequential Deep Learning and Best Features Selection

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Computers, Materials & Continua 2023年第6期75卷 5123-5140页

作者： Ch Avais Hanif Muhammad Ali Mughal Muhammad Attique Khan Usman Tariq Ye jin Kim Jae-hyuk cha Department of Electrical Engineering HITEC UniversityTaxilaPakistan Department of Computer Science HITEC UniversityTaxilaPakistan College of Computer Engineering and Science Prince Sattam Bin Abdulaziz UniversityAl-Kharaj11942Saudi Arabia Department of Computer Science Hanyang UniversitySeoul04763Korea

Gait recognition is an active research area that uses a walking theme to identify the subject *** Gait Recognition(HGR)is performed without any cooperation from the ***,in practice,it remains a challenging task under diverse walking sequences due to the covariant factors such as normal walking and walking with wearing a ***,over the years,have worked on successfully identifying subjects using different techniques,but there is still room for improvement in accuracy due to these covariant *** paper proposes an automated model-free framework for human gait recognition in this *** are a few critical steps in the proposed ***,optical flow-based motion region esti-mation and dynamic coordinates-based cropping are *** second step involves training a fine-tuned pre-trained MobileNetV2 model on both original and optical flow cropped frames;the training has been conducted using static *** third step proposed a fusion technique known as normal distribution serially *** the fourth step,a better optimization algorithm is applied to select the best features,which are then classified using a Bi-Layered neural *** publicly available datasets,CASIA A,CASIA B,and CASIA C,were used in the experimental process and obtained average accuracies of 99.6%,91.6%,and 95.02%,*** proposed framework has achieved improved accuracy compared to the other methods.

关键词： Human gait recognition optical flow deep learning features fusion feature selection

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M-IDM: A Multi-Classication Based Intrusion Detection Model in Healthcare IoT

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Computers, Materials & Continua 2021年第5期67卷 1537-1553页

作者： Jae Dong Lee Hyo Soung cha Shailendra Rathore Jong hyuk Park Healthcare AI Team National Cancer CenterGoyang-si10408Korea Department of Computer Science and Engineering Seoul National University of Science and Technology(SeoulTech)Seoul01811Korea

In recent years,the application of a smart city in the healthcare sector via loT systems has continued to grow exponentially and various advanced network intrusions have emerged since these loT devices are being *** studies focused on security threat detection and blocking technologies that rely on testbed data obtained from a single medical IoT device or simulation using a well-known dataset,such as the NSL-KDD ***,such approaches do not reect the features that exist in real medical scenarios,leading to failure in potential threat *** address this problem,we proposed a novel intrusion classication architecture known as a Multi-class Classication based Intrusion Detection Model(M-IDM),which typically relies on data collected by real devices and the use of convolutional neural networks(i.e.,it exhibits better performance compared with conventional machine learning algorithms,such as naïve Bayes,support vector machine(SVM)).Unlike existing studies,the proposed architecture employs the actual healthcare IoT environment of National Cancer Center in South Korea and actual network data from real medical devices,such as a patient’s monitors(i.e.,electrocardiogram and thermometers).The proposed architecture classies the data into multiple classes:Critical,informal,major,and minor,for intrusion ***,we experimentally evaluated and compared its performance with those of other conventional machine learning algorithms,including naïve Bayes,SVM,and logistic regression,using neural networks.

关键词： Smart city healthcare IoT neural network intrusion classication machine learning

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A facile one-step approach to hierarchically assembled core-shell-like MnO2@MnO2 nanoarchitectures on carbon fibers： An efficient and flexible electrode material to enhance energy storage

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Nano Research 2016年第5期9卷 1507-1522页

作者： Goli Nagaraju Yeong Hwan Ko Sung Min cha Sang hyuk Im Jae Su Yu Department of Electronics and Radio Engineering Institute for Wearable Convergence Electronics Kyung Hee University 1732 Deogyeong-daero Giheung-gu Yongin-si Gyeonggi-do 446-701 Republic of Korea Functional Crystallization Center (ERC) Department of Chemical Engineering Kyung Hee University 1732 Deogyeong-daeroGiheuncl-qu Yonqin-si Gyeonqqi-do 446-701 Republic of Korea

Hierarchical core-shell-like MnO2 nanostructures （NSs） were used to anchor MnO2 hexagonal nanoplate arrays （HNPAs） on carbon cloth （CC） fibers. The NSs were prepared by a novel one-step electrochemical deposition method. Under an external cathodic voltage of -2.0 V for 30 min, hierarchical core-shell-like MnO2-NS-decorated MnO2 HNPAs （MnO2 NSs@MnO2 HNPAs） were uniformly grown on CC with reliable adhesion. The phase purity and morphological properties of the samples were characterized by various physicochemical techniques. At a constant external cathodic voltage, growth of MnO2 NSs@MnO2 HNPAs on CC was carried for different time periods. When utilized as a flexible, robust, and binder-free electrode for pseudocapacitors, the hierarchical core-shell-like MnO2 NSs@MnO2 HNPAs on CC showed clearly enhanced electrochemical properties in 1 M Na2SO4 electrolyte solution. The results indicate that the MnO2 NSs@MnO2 HNPAs on CC have a maximum specific capacitance of 244.54 F/g at a current density of 0.5 A/g with excellent cycling stability compared to that of bare MnO2 HNPAs on CC （112.1 F/g at 0.5 A/g current density）. We believe that the superior charge storage performance of the pseudocapacitive electrode can be mainly attributed to the hierarchical MnO2 NSs@MnO2 HNPAs building blocks that have a large specific surface area, offering additional electroactive sites for efficient electrochemical reactions. The facile and single-step approach to growth of hierarchical pseudocapacitive materials on textile based electrodes opens up the possibility for the fabrication of high-performance flexible energy storage devices.

关键词： manganese oxide hierarchical structures carbon cloth electrochemical deposition energy storage properties

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