检索结果-南通市图书馆

Inhibition of BET selectively eliminates undifferentiated pluripotent stem cells

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Stabilized sub-grain and nano carbides-driven 1.2 GPa grade ultra-strong CrMnFeCoNi high-entropy alloy additively manufactured by laser powder bed fusion

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第22期117卷 8-22页

作者： Young-Kyun kim kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Institute of Materials Science(kimS) Changwon 51508Republic of Korea

High-entropy alloys(HEAs)with interstitial atoms that are produced by additive manufacturing have gained intensive interest in the materials science community because of their suitability for constructing high-strength net-shape ***,a strategy to additionally enhance the strength of selective laser melted carbon-containing HEAs was *** as-built carbon-containing HEAs(C_(x)(Cr_(20)Mn_(20)Fe_(20)Co_(20)Ni_(20))_(100-x)(x=0.5 at.%,1.0 at.%,and 1.5 at.%))contain supersaturated carbon,and the extent of supersaturation increases as the carbon content *** subjected to aging treatment at 650°C for 1 h,the microstructure of the three alloys did not change at the grain ***,the microstructure at the sub-grain scale changed markedly,and these changes influenced the tensile properties and deformation *** particular,the tensile strength of aged 1.5C-HEA at 650°C was∼1.2 GPa at room temperature,which is higher than those reported for CrMnFeCoNi ***,the main deformation mechanism changed from deformation twinning to dislocation-mediated slip,resulting in much higher strain hardening capacity after the aging *** work led to the development of an alternative promising method that involves tailoring the microstructure,to enhance the mechanical properties of additively manufactured metallic materials that contain interstitial atoms.

关键词： Selective laser melting High-entropy alloy Carbon contents Aging Microstructure evolution Tensile property Deformation mechanism

Effect of carrier gas species on the microstructure and compressive deformation behaviors of ultra-strong pure copper manufactured by cold spray additive manufacturing

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第2期97卷 264-271页

作者： Young-Kyun kim kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea

Cold spray(CS)which has recently become a promising additive manufacturing(AM)technology,was used to fabricate ultra-strong pure *** addition,the effects of carrier gas species on the microstructural characteristics,mechanical properties and deformation mechanisms were systemically *** CSAM copper manufactured with N_(2) carrier gas reveals a heterogeneous bimodal microstructure consisting of ultra-fine grains at the particle interface and relatively coarse grains in inner *** He carrier gas,a homogeneous grain structure consisting of ultra-fine grains in most areas was *** tests showed that N_(2) and He carrier gasses enabled ultra-high yield strengths of 340 and415 MPa,*** values are comparable to severely plastic deformed copper,which has extremely low ductility and shape *** the other hand,both samples showed a strain-softening phenomenon that does not commonly occur at room *** deformation microstructures revealed that dynamic recovery(DRV)and dynamic recrystallization(DRX)phenomena were generated despite being deformed at room *** on the above findings,the overall deformation mechanisms according to the carrier gas species in the CSAM copper manufacturing process were ***,the work hardening and softening behaviors of CSAM Cu are predicted by using a constitutive equation.

关键词： Cold spray additive manufacturing Carrier gas Pure Cu Mechanical properties Deformation behavior

1.45 GPa ultrastrong cryogenic strength with superior impact toughness in the in-situ nano oxide reinforced CrMnFeCoNi high-entropy alloy matrix nanocomposite manufactured by laser powder bed fusion

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第2期97卷 10-19页

作者： Young-Kyun kim Min-Chul kim kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Atomic Energy Research Institute(KAERI) Daejeon 34057Republic of Korea

CrMnFeCoNi high-entropy alloys(HEAs)exhibit an excellent combination of tensile strength and ductility at cryogenic *** study led to the introduction of a new method for the development of high-performance CrMnFeCoNi HEAs at cryogenic temperatures by jointly utilizing additive manufacturing(AM)and the addition of interstitial *** interstitial oxygen present in the powder feedstock was transformed into beneficial nano-sized oxides during AM *** HEA nanocomposite fabricated using laser powder bed fusion(L-PBF)not only contains heterogeneous grains and substructures but also a high number density of nano-sized *** tensile results revealed that the L-PBF HEA nanocomposite has superior yield strengths of 0.77 GPa and 1.15 GPa,and tensile strengths of 0.92 GPa and 1.45 GPa at 298 K and 77 K,*** addition,the Charpy impact energies of the samples tested at 298 K and 77 K were measured as 176.2 J and 103.7 J,*** results indicate that the L-PBF HEA nanocomposite successfully overcomes the well-known strength-toughness *** tensile deformation microstructure contained a relatively large number of deformation twins(DTs)at cryogenic temperature,a possible consequence of the decrease in the stacking fault energy with decreasing *** the other hand,cracks were found to propagate along the grain boundaries at room temperature,whereas a transgranular crack was observed at cryogenic temperature in the specimens fractured as a result of the Charpy impact.

关键词： Laser powder bed fusion High-entropy alloy matrix nanocomposite Nano-oxide:cryogenic Tensile Impact toughness

Numerical Analysis of Secondary Cooling in Continuous Slab Casting

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第3期24卷 389-390页

作者： kee-Hyeon Cho Byung-Moon kim Research Institute of Industrial Science & Technology GyeongBuk Regional Stragetic Agency for Innovation

In the present study, a numerical optimization program has been developed for predicting the optimal secondary cooling patterns in a continuous slab caster. Optimization strategy using Broydon-Fletcher-Goldfarb-Shanno （13FGS） method is carried out by determining the constant heat transfer coefficients in each spray zone, which could satisfy the casting conditions and metallurgical criteria specified by the engineer. From the present results, it is found that even a slight variation in the pouring temperature, allowable surface temperature, and casting speed could give rise to the changes in the cooling pattern throughout the spray zones.

关键词： Continuous casting Secondary cooling Optimization

Effect of post heat-treatment on the microstructure and high-temperature oxidation behavior of precipitation hardened IN738LC superalloy fabricated by selective laser melting

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第17期76卷 95-103页

作者： Kyu-Sik kim Sangsun Yang Myeong-Se kim kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Institute of Materials Science Changwon51508Republic of Korea Auratech Co. Ltd.Seongnam13449Republic of Korea

The present study investigated the effect of as-built and post heat-treated microstructures of IN738LC alloy fabricated via selective laser melting process on high temperature oxidation *** as-built microstructure showed fine cell and columnar structure due to high cooling *** element segregation was observed in inter-cell/inter-columnar *** post heat-treatment,the initially-observed cell structure disappeared,instead bimodal Ni_3(Al,Ti)particles *** temperature(1273 K and 1373 K)oxidation test results showed parabolic oxidation curves regardless of temperature and initial *** as-built IN738LC fabricated via the selective laser melting process displayed oxidation resistance similar to or slightly better than that of IN738LC fabricated via wrought or cast ***-treated SLM IN738LC,although had similar oxidation weight-gain values to those of the SLM asbuilt material at 1273K,showed relatively better oxidation resistance at 1373 *** Ni_3(Al,Ti)precipitate formed in the post heat treatment changed the local chemical composition,thereby led to changes in alumina former/chromia former location and fraction on the alloy *** was concluded that in heat-treated IN738LC increased alumina former fraction was found,and this resulted in excellent oxidation resistance and relatively low weight-gain.

关键词： IN738LC Selective laser melting High temperature oxidation Post heat-treatment Oxidation mechanism

Recent Advances in Patterning Strategies for Full‑Color Perovskite Light‑Emitting Diodes

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第3期16卷 99-137页

作者： Gwang Heon Lee Kiwook kim Yunho kim Jiwoong Yang Moon kee Choi Graduate School of Semiconductor Materials and Devices Engineering Center for Future Semiconductor Technology(FUST)Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea Department of Energy Science and Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu 42988Republic of Korea Energy Science and Engineering Research Center Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu 42988Republic of Korea Department of Materials Science and Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea Center for Nanoparticle Research Institute for Basic Science(IBS)Seoul 08826Republic of Korea

Metal halide perovskites have emerged as promising light-emitting materials for next-generation displays owing to their remarkable material characteristics including broad color tunability,pure color emission with remarkably narrow bandwidths,high quantum yield,and solution *** recent advances have pushed the luminance efficiency of monochromic perovskite light-emitting diodes(PeLEDs)to their theoretical limits,their current fabrication using the spincoating process poses limitations for fabrication of full-color *** integrate PeLEDs into full-color display panels,it is crucial to pattern red–green–blue(RGB)perovskite pixels,while mitigating issues such as cross-contamination and reductions in luminous ***,we present state-of-the-art patterning technologies for the development of full-color ***,we highlight recent advances in the development of efficient ***,we discuss various patterning techniques of MPHs(i.e.,photolithography,inkjet printing,electron beam lithography and laserassisted lithography,electrohydrodynamic jet printing,thermal evaporation,and transfer printing)for fabrication of RGB pixelated *** patterning techniques can be classified into two distinct approaches:in situ crystallization patterning using perovskite precursors and patterning of colloidal perovskite *** review highlights advancements and limitations in patterning techniques for PeLEDs,paving the way for integrating PeLEDs into full-color panels.

关键词： Perovskite Light-emitting diode Full-color display High-resolution patterning Electroluminescence

Genome-wide SNP discovery and core marker sets for assessment of genetic variations in cultivated pumpkin(Cucurbita spp.)

在线全文

学校读者我要写书评

暂无评论

Horticulture Research 2020年第1期7卷 1139-1148页

作者： Nam Ngoc Nguyen Minkyung kim Jin-kee Jung Eun-Jo Shim Sang-Min Chung Younghoon Park Gung pyo Lee Sung-Chur Sim Department of Bioresources Engineering Sejong UniversitySeoul 05006South Korea Seed Testing and Research Center Korea Seed&Variety ServiceGimcheon 39660South Korea Department of Life Sciences Dongguk UniversitySeoul 04620South Korea Department of Horticultural Bioscience Pusan National UniversityMiryang 50463South Korea Department of Plant Science and Technology Chung-Ang UniversityAnsung 17546South Korea Plant Engineering Research Institute Sejong UniversitySeoul 05006South Korea

Three pumpkin species Cucurbita maxima,***,and *** are commonly cultivated *** identify genome-wide SNPs in these cultivated pumpkin species,we collected 48 F1 cultivars consisting of 40 intraspecific hybrids(15 ***,18 ***,and 7 ***)and 8 interspecific hybrids(*** x ***).Genotyping by sequencing identified a total of 37,869 confident SNPs in this *** SNPs were filtered to generate a subset of 400 SNPs based on polymorphism and genome *** the 400 SNPs,288 were used to genotype an additional 188 accessions(94 F1 cultivars,50 breeding lines,and 44 landraces)with a SNP array-based *** polymorphisms were observed in 224 SNPs(78.0%)and were used to assess genetic variations between and within the four predefined populations in 223 cultivated pumpkin *** principal component analysis and UPGMA clustering found four major clusters representing three pumpkin species and interspecific *** genetic differentiation was supported by pairwise Fst and Nei’s genetic *** interspecific hybrids showed a higher level of genetic diversity relative to the other three *** the 224 SNPs,five subsets of 192,96,48,24,and 12 markers were evaluated for variety *** 192,96,and 48 marker sets identified 204(91.5%),190(85.2%),and 141(63.2%)of the 223 accessions,respectively,while other subsets showed<25%of variety identification *** SNP markers provide a molecular tool with many applications for genetics and breeding in cultivated pumpkin.

关键词： breeding cultivar Cucurbita

2.47 GPa grade ultra-strong 15Co-12Ni secondary hardening steel with superior ductility and fracture toughness

维普期刊数据库评论

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 2021年第7期66卷 36-45页

作者： Young-Kyun kim Kyu-Sik kim Young-Beum Song Jung Hyo Park kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon22212Republic of Korea Agency for Defense Development(ADD) Yuseong-guDaegeon34186Republic of Korea

This study investigated the effect of multi-step heat treatment on the microstructure, mechanical properties and fracture behavior of thick 15 Co-12 Ni secondary hardening steel. As-quenched sample was found to have elongated prior austenite grain(PAG) and coarse lenticular martensitic structure. On the other hand, heat-treated sample was observed to have fine lenticular martensitic structure due to fine PAG size and a lot of nano-sized carbides. Also, after heat treatment, nano-scale reverted austenite film was formed at the martensite interfaces. The heat-treated sample showed 2.47 GPa superior tensile strength and superior elongation of about 12 %. The high strength was mainly due to fine block size and high number density of nano-sized carbides. The average value of plane strain fracture toughness(KIC) was 29.3 MPa m1/2, which indicated a good fracture toughness even with the high tensile strength. The tensile fracture surface was observed to have ductile fracture mode(cup-and-cone) and the formation of about ~1 μm ultra-fine dimples. In addition to this, nano-sized carbides were observed within the *** findings suggested that the nano-sized carbide had a positive effect not only on the strength but also on the ductility of the alloy. The fractured surface after toughness test, also showed ductile fracture mode with a lot of dimples. Based on the above results, correlation among microstructural evolution,deformation and fracture mechanisms along the heat-treatment was also discussed.

关键词： Ultra-high strength High Co-Ni secondary hardening steel Microstructure Tensile properties Fracture toughness Reverted austenite