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High Frequency Sporophytes Regeneration from the Spore Culture of the Endangered Aquatic Fern <i>Isoetes coreana</i>

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American Journal of Plant Sciences 2013年第6期4卷 14-20页

作者： Myung Jin Oh Changkyun kim Hye Ryun Na Hyunchur Shin Jang R. Liu Hong-Keun Choi suk weon kim Biological Resources Center Korea Research Institute of Bioscience and Biotechnology (KRIBB) Daejeon South Korea Department of Biological Science Ajou University Suwon South Korea Department of Life Science Soonchunhyang University Asan South Korea Green Bio Research Center Korea Research Institute of Bioscience and Biotechnology (KRIBB) Daejeon South Korea.

Using a mixed culture of megaspores and microspores from I. coreana, we established high frequency sporophyte regeneration system. After 20 days of culturing in MS basal medium, microscopic examination showed significant morphological changes and the microspore released numerous small vesicles into the culture medium. Megaspores also showed dramatic morphological changes during its incubation time in culture. The spore wall was cracked by the expansion of the megaspore (about 2 times increase in diameter). Simultaneously, brown spots were observed on the surface of the megaspores. The frequency of female gametophytes developing from immature megaspores cultured in MS basal liquid medium (pH 7) supplemented with 1 mgl-1 GA3 was 46%. However, these female gametophytes derived from megaspore only culture could not differentiate into sporophytes. The mixed culture of microspores and megaspores resulted in successful sporophyte regeneration. The highest frequency (12.3%) of green sporophyte regeneration from mixed spore culture occurred when the cultures were maintained at 25℃ under cool-white fluorescent light (40 μmol·m-2·s-1) with a 16 h photoperiod. Regenerated sporophytes were transferred to a test tube containing vermiculite and a sand mixture and left there until they had three leaves. After root growth and the fifth leaf had emerged, more than 95% of the regenerated sporophytes were successfully transferred to the soil and grown to mature plants. The sporophyte regeneration system established in this study could be successfully used for the restoration of the endangered aquatic species, I. coreana.

关键词： Aquatic Fern Isoetes coreana Spore Culture Sporophyte Regeneration

Regulation of sleep by astrocytes in the hypothalamic ventrolateral preoptic nucleus

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Neural Regeneration Research 2025年第4期20卷 1098-1100页

作者： Jae-Hong kim Ruqayya Afridi Il-Sung Jang Maan Gee Lee Kyoungho suk Brain Korea 21 four KNU Convergence Educational Program of Biomedical Sciences for Creative Future Talents School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of DentistryKyungpook National UniversityDaeguRepublic of Korea Brain Science&Engineering Institute Kyungpook National UniversityDaeguRepublic of Korea

Astrocytes are functionally dynamic cells that support neurons in multiple ways throughout an organism’s *** astrocytic regulation of neuronal activity has been increasingly recognized in recent *** are now recognized as playing a more complex role than mere bystanders in the central nervous ***,their role in regulating the sleep neurocircuitry is not well *** this perspective,we highlight the role of astrocytes in sleep modulation,with a particular focus on regulatory mechanisms related to the ventrolateral preoptic nucleus(VLPO)of the *** briefly discuss recent literature reporting the role of VLPO astrocytes in regulating sleep-associated behaviors.

关键词： sleep ventrolateral astrocytes

MICROMECHANICS OF ROUGH SURFACE ADHESION:A HOMOGENIZED PROJECTION METHOD

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Acta Mechanica Solida Sinica 2009年第5期22卷 377-390页

作者： Kyung-suk kim Division of Engineering Brown UniversityProvidenceRI 02912USA

A quasistatic homogenized projection is made to characterize the effective cohesive zone behavior for rough-surface adhesion. In the context of the homogenized projection, the traction versus separation relation for the homogenized cohesive zone （HCZ） of a rough interface can be highly oscillatory due to instabilities during microscopic adhesion and decohesion processes. The instabilities are found to occur not only individually but also collectively among the adhesive micro-asperity contacts, leading to extensive energy dissipation. Based on the behaviors of the HCZ relations, a framework for describing instability-induced energy dissipation in rough-surface adhesion is proposed to elucidate the effect of roughness on apparent interface adhesion. Two non- dimensional parameters, α related to roughness morphology and n related to flaw distribution, are identified to be most crucial for controlling the energy dissipation. For an interface with a shallow roughness and a strong intrinsic adhesive strength, the interface adhesion can be stronger if we make it rougher （reducing α） or lower its flaw density （increasing n）. The HCZ projection method can be potentially extended and employed to bridge the apparent adhesion from intrinsic adhesion properties for engineering surfaces with multi-scale shallow roughness.

关键词： homogenized cohesive zone interface adhesion roughness effect instability energy dissipation

Self-motivated,thermally oxidized hematite nanoflake photoanodes:Effects of pre-polishing and ZrO_(2) passivation layer

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Journal of Energy Chemistry 2022年第2期31卷 415-423页

作者： Love Kumar Dhandole Hyun Hwi Lee weon-Sik Chae Jum suk Jang Jae Sung Lee Department of Energy Engineering School of Energy and Chemical EngineeringUlsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea Division of Biotechnology College of Environmental and Bioresource SciencesChonbuk National UniversityIksan 54596Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Daegu Center Korea Basic Science InstituteDaegu 41566Republic of Korea

High-temperature thermal oxidation of an Fe foil produces a high-quality,crystalline hematite nanoflake suitable as a photoanode for the photoelectrochemical(PEC)water *** pre-polishing of the foil surface has a profound effect in the formation of a vertically-aligned nanoflakes of hematite phase with extended(110)planes by removing the loosely-bonded oxide *** the surface of the photoanode is modified with a ZrO_(2) passivation layer and a cobalt phosphate co-catalyst,the charge recombination at the photoanode-electrolyte interface is greatly suppressed to improve its overall PEC *** a result,the photocurrent density at 1.10 VRHE under 1 sun condition is enhanced from 0.22 mA cm^(-2) for an unmodified photoanode to 0.59 mA cm^(-2) for the fully modified photoanode,and the photocurrent onset potential is shifted cathodically by 400 ***,the photoanode demonstrates outstanding stability by showing steady production of H_(2) and O_(2) gases in the stoichiometric ratio of 2:1 in a continuous PEC operation for 10 h.

关键词： Fe foil Thermal oxidation Nanoflakes Photoelectrochemical water splitting Surface modifications

Gradient Si-and Ti-doped Fe_(2)O_(3) hierarchical homojunction photoanode for efficient solar water splitting:Effect of facile microwave-assisted growth of Si-FeOOH on Ti-FeOOH nanocorals

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Journal of Energy Chemistry 2023年第2期77卷 27-37,I0002页

作者： Tae Sik Koh Periyasamy Anushkkaran weon-Sik Chae Hyun Hwi Lee Sun Hee Choi Jum suk Jang Division of Biotechnology College of Environmental and Bioresource SciencesJeonbuk National UniversityIksan 54596Republic of Korea Daegu Center Korea Basic Science InstituteDaegu 41566Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea

The construction of a homojunction is an effective approach for addressing issues such as slow charge separation and charge-transfer kinetics in *** the present work,we designed a gradient Si-and Ti-doped Fe_(2)O_(3) homojunction photoanode to improve the photoelectrochemical(PEC)performance of a Ti-doped Fe_(2)O_(3) ***-FeOOH nanocorals were synthesized using a hydrothermal process,and Si-FeOOH was grown on Ti-FeOOH nanocorals using a rapid and facile microwaveassisted(MW)*** varying the MW irradiation time,the thickness of the Si/Ti:Fe_(2)O_(3) photoanode was adjusted and an optimized 3-Si/Ti:Fe_(2)O_(3) photoelectrode was achieved with a significantly enhanced photocurrent density(1.37 mA cm^(-2) at 1.23 V ***)and a cathodic shift of the onset potential(150 mV)compared with that of bare Ti-Fe_(2)O_(3).This enhanced PEC performance can be ascribed to homojunction formation and Si gradient *** Si dopant increased the donor concentration and the formation of a homojunction improved the intrinsic built-in electric field,thereby promoting charge separation and charge ***,the as-formed homojunction passivated the surfacetrapping states,consequently improving the charge transfer efficiency(60%at 1.23 VRHE)at the photoanode/electrolyte *** findings could pave the way for the microwave-assisted fabrication of diverse efficient homojunction photoanodes for PEC water splitting applications.

关键词： Homojunction Microwave-assisted Hematite Gradient doping PEC water splitting

Effect of Plastic Anisotropy on the Formability of Aluminum 6016-T4 Sheet Material

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 625-631页

作者： Young-suk kim Seung-Han YANG kyungpook national university Daegu 41566Republic of Korea

Sheet metal formed of lightweight materials such as aluminum sheeting has received great attention related to the reduction of vehicle emissions. This paper evaluates the anisotropic yield locus using Kuwabara＇s biaxial tensile tester and stretches formability using Hecker＇s hemispheri- cal punch stretching test for aluminum 6016-T4 sheet material. The anisotropic yield locus of the A16016-T4 sheet measured is fitted well by the modified Drucker yield func- tion. Moreover the best fitting to the experimental stress- strain curve from the tensile test was obtained by taking an appropriate hardening model. Analytical study to predict the stretch formability by using Hora＇s Modified Maximum Force Criterion （MMFC） was performed. The predicted forming limit curves （FLC） based on various yield functions were compared with the experiments and discussed.

关键词： Anisotropic yield function AluminumA16016-T4 Biaxial tensile test Forming limit curve

Differential ligand binding/trafficking for distinct CTLA-4 fates: is it an expandable mechanism?

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Cellular & Molecular Immunology 2023年第1期20卷 1-2页

作者： Ji Eon kim Eunmi kim Jung weon Lee Department of Pharmacy Research Institute of Pharmaceutical SciencesCollege of PharmacySeoul National UniversitySeoul08826Republic of Korea

In a recent issue of Nature Immunology,Kennedy et *** that CTLA-4(CD152)differentially targets two distinct ligands,CD80 and CD86,on antigen-presenting cells(APCs)for destruction or recycling following transendocytosis(TE),resulting in separate fates for CTLA-4 on T_(reg) cells and thereby regulating ***,whereas CTLA-4 tightly binds CD80 for TE and causes ubiquitination and trafficking to late endosomes and lysosomes for degradation,CTLA-4 weakly binds CD86 for TE,resulting in dissociation under acidic conditions(pH<6)and recycling of CTLA-4 to the plasma membrane for further CD86 ***,CD86 targeting by CTLA-4 regulates T-cell function in autoimmunity[1]and presumably immune surveillance of cancer cells(Fig.1).

关键词： thereby traffic weakly

Unexpected role of complement component 8 gamma chain in the inflamed brain

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Neural Regeneration Research 2023年第12期18卷 2655-2656页

作者： Jong-Heon kim Kyoungho suk Brain Science and Engineering Institute Kyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of MedicineKyungpook National UniversityDaeguRepublic of Korea

Neuroinflammation,an intricate inflammatory process occurring in the central nervous system(CNS),plays an important role in host *** cells,including astrocytes and microglia,along with cytokines,chemokines,and the complement system are important components of neuroinflammation.A low level of neuroinflammation is associated with and contributes to various homeostatic and neuroprotective processes,such as removing pathogens or cellular debris and promoting tissue repair after brain injury.

关键词： inflammation protective removing

Early prediction of myocardial viability after acute myocardial infarction by two-dimensional speckle tracking imaging

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Journal of Geriatric Cardiology 2015年第5期12卷 474-481页

作者： Jong Shin Woo Tae-Kyung Yu Woo-Shik kim Kwon Sam kim weon kim Division of Cardiology Department of lnternal Medicine Kyung Hee University Hospital Kyung Hee University Seoul South Korea

Background Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction （AMI） is important clinically. The aim of this study was to assess myocardial viability using two-dimensional speckle tracking imaging （2D-STI） in patients with AMI. Methods 2D-STI was performed at initial presentation, three days, and six months after primary percutaneous coronary intervention （PCI） in 30 patients with AMI, who had a left anterior descending coronary artery （LAD） culprit lesion. In addition, 20 patients who had minimal stenotic lesions （〈 30% stenosis） on coronary angiography were also included in the control group. At six months dobutamine echocardiography was performed for viability assessment in seven segments of the LAD territory. According to the recovery of wall motion abnormality, segments were classified as viable or non-viable. Results A total of 131 segments were viable, and 44 were nonviable. Multivariate analysis revealed significant differences between the viable and nonviable segments in the peak systolic strain, the peak systolic strain rate at initial presentation, and peak systolic strain rate three days after primary PCI. Among these, the initial peak systolic strain rate had the highest predictive value for myocardial viability （hazard ratio： 31.22, P 〈 0.01）. Conclusions 2D-STI is feasible for assessing myocardial viability, and the peak systolic strain rate might be the most reliable predictor of myocardial viability in patients with AMI.

关键词： Acute myocardial infarction Two-dimensional speckle tracking imaging Viable myocardium