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Biphasic Nano-Domains of Planar Lipid Bilayer Complexed with Fluorogenic Polymer Reporter Tailored for Antimicrobial Detection

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CCS Chemistry 2022年第11期4卷 3637-3647页

作者： Jimin Hwang Woo Hyuk Jung Yeol Kyo choi Dong june Ahn Department of Chemical and Biological Engineering Korea UniversitySeoul 02841 Department of Biological Sciences Lehigh UniversityBethlehemPennsylvania 18015 KU-KIST Graduate School of Converging Science and Technology Korea UniversitySeoul 02841

We have fabricated an unexpected type of supported planar bilayer composed of receptor phospholipids and single-chained diacetylenes as fluorogenic reporters using protruded anchor moieties with a positive terminal *** topographical and surface thermodynamic analyses,as well as molecular dynamics simulations,revealed the coexistence of well-dispersed liquid-condensed(L_(c))domains forming nano-islands and liquid-expanded(L_(e))region in the planar bilayer,enhancing sensitivity against a prototype of ubiquitous membrane-associated antimicrobial peptides,*** L_(e)regions,acting as target receptors,enabled sensitive detection as the melittin adsorbed and inserted into these regions due to strong hydrophobic interactions between phospholipids and *** L_(c)domains,serving as signal reporters,enabled diacetylenes to assemble,polymerize,and fluoresce in response to the insertion of melittin into the L_(e)***,biphasic nanodomains of the planar lipid bilayer finally endowed this sensor system with a detection range of 100μMto 50 nM and a limit of detection(LOD)of∼37 nM for *** exceeded the operational performance of the colorimetric polydiacetylene vesicle solution 45 times,which reportedly ranged from 100 to 4μM with an LOD of∼1.7μM.

关键词： biphasic nano-domain supported lipid bilayer fluorogenic polymer reporter liquid-expanded region liquid-condensed domain

Structural considerations in friction welding of hybrid Al_2O_3-reinforced aluminum composites

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Transactions of Nonferrous Metals Society of China 2011年第A01期21卷 42-46页

作者： In-Duck PARK Choon-Tae LEE hyun-Soo KIM Woo-Jin choi Myung-Chang KANG Busan Metropolitan City Hall Fundamental Industries Division 2001 Jungang-ro Yeonje-gu Busan 611-735 Korea Department of Automotive & Mechanical Engineering Silla University Research & Development Center Sam-Ho precision 1256-1 Daejeo2-dong Gangseo-gu Busan 618-807 Korea National Core Research Center for Hybrid Materials Solution Pusan National University

Comparative studies on the relationship between the welding parameters and joining efficiency in the friction welding of hybrid Al203-reinforced aluminum composites were conducted. Metal matrix composites （MMCs） with 37% （volume fraction） aluminum particle were joined by friction welding. The results show that the effects of the rotation speed on the reduction rate of particle size are greater than those of the upset pressure, and the area of the MMC weld zone decreases as the joining efficiency increases, while it is considered that the joining efficiency does not increase as the reduction rate of particle size decreases. During the macro-examination of the bonding interlace, a gray discolored region was observed on the bonding interface, and the center of the region was dark gray. After the micro-examination of the bonding interface, base metal made some second particulate formed by condensed alumina particulate but discoloration part distributed minute alumina particulate without second particulate. Consequently, it was also observed that rotational speed of 3 000 r/min and upset pressure of 63.6 MPa showed a very ***.

关键词： friction welding hybrid aluminum composite bonding interface joining efficiency metal matrix composite

Bioinspired Multi-material Polyjet-printed Frog Robot for Synchronous and Asynchronous Swimming

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Journal of Bionic Engineering 2023年第3期20卷 923-933页

作者： Afaque Manzoor Soomro Jae-Wook Lee Fida Hussain Memon Faheem Ahmed Kashif Hussain Kyung hyun choi Department of Mechatronics Engineering Jeju National UniversityJeju63243South Korea Department of Electrical Engineering Sukkur IBA UniversitySukkur65200Pakistan

This paper proposes the bioinspired soft frog robot. All printing technology was used for the fabrication of the robot. Polyjet printing was used to print the front and back limbs, while ultrathin filament was used to print the body of the robot, which makes it a complete soft swimming robot. Dual thrust generation approach has been proposed by embedding the main muscle and antagonistic muscle in all the limbs, which enables it to attain high speed (18 mm/s), significant control to swim in dual mode (synchronous and asynchronous modes). To achieve the swimming motion of frog, four SMA (BMF 300) muscle wires were used. The frog robot is named as (FROBOT). The hind limbs are 60 mm long and 10 mm thick on average, while the front limbs are 35 mm long and 7 mm thick. Model-based design and rigorous analysis of the dynamics of real frogs have allowed FROBOT to be developed to swim at a level that is remarkably consistent with real frogs. Electrical and mechanical characteristics have been performed. In addition, the test data were further processed using TRACKER to analyze angle, displacement and velocity. FROBOT (weighs 65 g) can swim at different controllable frequencies (0.5–2 Hz), can rotate in any direction on command from custom built LabVIEW software allowing it to swim with speed up to 18 mm/s on deep water surface (100 cm) with excellent weight balance.

关键词： Bioinspired Soft robotics Frog FROBOT Asynchronous swimming

Comparative molecular docking studies of lupeol and lupenone isolated from Pueraria lobata that inhibits BACE1: Probable remedies for Alzheimer's disease

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Asian Pacific Journal of Tropical Medicine 2017年第12期10卷 1117-1122页

作者： Prashamsa Koirala Su Hui Seong hyun Ah Jung Jae Sue choi Department of Food and Life Science Pukyong National University Department of Food Science and Human Nutrition Chonbuk National University

Objective: To discover lead lupane triterpenoid's potential isolated from Pueraria lobata roots against b-site amyloid precursor protein cleaving enzyme 1(BACE1), which serve as a rate limiting step in amyloid beta(Aβ) production altering the course of Alzheimer's disease. In addition, enzyme kinetics study and molecular docking were conducted to establish the inhibition type and structure activity ***: A systematic study of 70% ethanolic P. lobata root extract was employed to identify its BACE1 inhibitory potential. Further, BACE1 inhibitory potential of two lupane terpenoids, yielded from ethanolic extract, was assessed. In order to determine their inhibition mode, Lineweaver–Burk plots and Michaelis–Menten model for BACE1 was performed. Auto Dock 4.2 program in addition determined the molecular interaction of BACE1 with isolated ***: Considering the inhibitory potential of 70% ethanolic extract of P. lobata against BACE1(IC_(50)= 80.35 mg/mL), lupeol and lupenone were subsequently isolated and exhibited notable or moderate BACE1 inhibitory activity with IC_(50) values of 5.12 and 62.98 mmol/L, respectively, as compared to the positive control quercetin(IC_(50)= 21.28 mmol/L). The enzyme kinetics study enabled us to identify both compounds as competitive inhibitors, where lupeol displayed a very potent inhibition against BACE1 with low inhibition constant(Ki) value of 1.43 mmol/L, signifying greater binding *** order to understand the binding mechanism and structure–activity relationship of two triterpene-based BACE1 inhibitors, we employed computer aided docking studies which evidently revealed that hydroxyl group of lupeol formed two hydrogen bonds with the ASP32(catalytic aspartic residue) and SER35 residues of BACE1 with the binding energy of(-8.2 kcal/mol), while the ketone group of lupenone did not form any hydrogen bonds with BACE1 giving evidence for less binding affinity. These results in turn have predicted the dep

关键词： Pueraria lobata BACE1 Lupeol Lupenone Molecular docking Kinetics

Contact surface fatigue life for roller rack pinion system

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Journal of Central South University 2012年第12期19卷 3454-3459页

作者： KIM Chang-hyun choi Heung-soap KWON Soon-man Department of Mechanical Design and Manufacturing Engineering Changwon National UniversityChangwon 641-773Korea Department of Mechano-Informatics and Design Engineering Hongik UniversitySejong 339-701Korea

A roller rack pinion(RRP)system,which consists of a rack-bar and a cam pinion,transforms a rotation motion into linear *** rack-bar has a series of roller train and meshes with the cam ***,the exact tooth profile of the cam pinion and the non-undercut condition to satisfy the required performance have been proposed with the introduction of the profile shift ***,the load stress factors are investigated under the variation of the shape design parameters to predict the gear surface fatigue limit which is strongly related to the gear noise and vibration at the contact *** results show that the pitting life can be extended significantly with the increase of the profile shift coefficient.

关键词： roller rack pinion profile shift coefficient load stress factor pitting life

Cardiac metastasis from colorectal cancer:A case report

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World Journal of Gastroenterology 2009年第21期15卷 2675-2678页

作者： Pyong Wha choi Chul Nam Kim Sun Hee Chang Woo Ik Chang Chang Young Kim hyun Min choi Department of Surgery Ilsan Paik HospitalInje University College of Medicine Department of Diagnostic Pathology Ilsan Paik HospitalInje University College of Medicine Department of Chest Surgery Ilsan Paik HospitalInje University College of Medicine Department of Internal Medicine Ilsan Paik HospitalInje University College of Medicine

The heart is an unusual site of metastasis from any malignancy. We report a case of cardiac metastasis from colorectal cancer. A 70-year-old woman was referred with a presumptive diagnosis of sigmoid colon cancer with cardiac myxoma. Two-dimensional echocardiography showed a 4 cm x 4.5 cm mobile mass on the lateral right atrial wall, and computed tomography revealed a low attenuated Iobulating mass in the right atrium. The patient underwent anterior resection for sigmoid colon cancer （T4N2）. Thereafter, she experienced progressive shortness of breath. Therefore, a cardiac operation was performed 2 wk after the colorectal operation. Histological examination revealed adenocarcinoma, which was identical to the primary lesion. Although two- dimensional echocardiography has become the diagnostic test of choice for detecting cardiac tumors, in patients with colorectal cancer showing a cardiac mass, further diagnostic evaluation such as a magnetic resonance imaging might be necessary.

关键词： Heart Cardiac metastasis Colorectalcancer Atrial myxoma Magnetic resonance imaging

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

Topology optimization of reactive material structures for penetrative projectiles

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Defence Technology（防务技术） 2022年第7期18卷 1205-1218页

作者： Shinyu Kim Saekyeol Kim Taekyun Kim Sangin choi Tae Hee Lee Jung Su Park Sang-hyun Jung Department of Automotive Engineering Hanyang University222 Wangsimni-roSeongdong-guSeoul04763Republic of Korea The 4th R&D Institute Agency for Defense Development35Yuseong P.O.BoxDaejeon34186Republic of Korea

Recently,reactive materials have been developed for penetrative projectiles to improve impact resistance and energy ***,the design of a reactive material structure,involving shape and size,is challenging because of difficulties such as high non-linearity of impact resistance,manufacturing limitations of reactive materials and high expenses of penetration *** this study,a design optimization methodology for the reactive material structure is developed based on the finite element analysis.A finite element model for penetration analysis is introduced to save the expenses of the *** resistance is assessed through the analysis,and result is calibrated by comparing with experimental *** on the model,topology optimization is introduced to determine shape of the *** design variables and constraints of the optimization are proposed considering the manufacturing limitations,and the optimal shape that can be manufactured by cold spraying is *** on the optimal shape,size optimization is introduced to determine the geometric dimensions of the *** a result,optimal design of the reactive material structure and steel case of the penetrative projectile,which maximizes the impact resistance,is *** the design process proposed in this study,reactive material structures can be designed considering not only mechanical performances but also manufacturing limitations,with reasonable time and cost.

关键词： Reactive material Penetrative projectile Topology optimization Manufacturing constraint Cold gas dynamic spray Additive manufacturing

Anti-Alzheimer's disease potential of coumarins from Angelica decursiva and Artemisia capillaris and structure-activity analysis

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Asian Pacific Journal of Tropical Medicine 2016年第2期9卷 101-108页

作者： Md.Yousof Ali Susoma Jannat hyun Ah Jung Ran Joo choi Anupom Roy Jae Sue choi Department of Food and Life Science Pukyong National University Department of Food Science and Human Nutrition Chonbuk National University Angiogenesis& Chinese Medicine Laboratory Department of Pharmacology University of Cambridge

Objective: To use structure-activity analysis to study the anti-Alzheimer's disease(anti-AD) activity of natural coumarins isolated from Angelica decursiva and Artemisia capillaries, along with one purchased coumarin(daphnetin). Methods: Umbelliferone, umbelliferone 6-carboxylic acid, scopoletin, isoscopoletin, 7-methoxy coumarin, scoparone, scopolin, and esculetin have been previously isolated; however 2'-isopropyl psoralene was isolated from Angelica decursiva for the first time to evaluate their inhibitory effects against acetylcholinesterase(ACh E), butyrylcholinesterase(BCh E), and β-site amyloid precursor protein cleaving enzyme 1(BACE1) enzyme activity. We scrutinized the potentials of coumarins as cholinesterase and BACE1 inhibitors via enzyme kinetics and molecular docking simulation. Results: Among the test compounds, umbelliferone 6-carboxylic acid, esculetin and daphnetin exhibited potent inhibitory activity against ACh E, BCh E and BACE1. Both esculetin and daphnetin have a catechol group and exhibit significant anti-AD activity against ACh E and BCh E. In contrast, presence of a sugar moiety and methoxylation markedly reduced the anti-AD activity of the coumarins investigated in this study. With respect to BACE1 inhibition, umbelliferone 6-carboxylic acid, esculetin and daphnetin contained carboxyl or catechol groups, which significantly contributed to their antiAD activities. To further investigate these results, we generated a 3D structure of BACE1 using Autodock 4.2 and simulated binding of umbelliferone 6-carboxylic acid, esculetin and daphnetin. Docking simulations showed that different residues of BACE1 interacted with hydroxyl and carboxylic groups, and the binding energies of umbelliferone 6-carboxylic acid, esculetin and daphnetin were negative(-4.58,-6.25 and-6.37 kcal/mol respectively). Conclusions: Taken together, our results suggest that umbelliferone 6-carboxylic acid, esculetin and daphnetin have anti-AD effects by inhibiting ACh E, BCh

关键词： Umbelliferone 6-carboxylic acid Esculetin Daphnetin Coumarins Cholinesterase BACE1