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Bird-mimetic Wing System of Flapping-wing Micro Air Vehicle with Autonomous Flight Control Capability

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Journal of Bionic Engineering 2016年第3期13卷 458-467页

作者： Sriyulianti Widhiarini Ji Hwan Park Bum Soo yoon Kwang joon yoon ll-Hyun Paik Jong Heon Kim Chan Yik Park Seung Moon Jun Changho Nam Department of Aerospace Engineering Konkuk University Gwangjin-gu Seoul South Korea Deptartment of PGM Technology Hanwha Corp. R&D Center Daejeon South Korea Agency for Defense Development Daejeon South Korea Department of Engineering Technology Arizona State University Mesa Arizona

A micro air vehicle with a bird-mimetic up-down and twisting wing drive system was developed in this study. The Flap- ping-wing Micro Air Vehicle （FMAV）, with a 50 cm wingspan and a double-crank drive system, performed successful flights of up to 23 min. The performance and capabilities of the FMAV were enhanced by adapting a number of unique features, such as a bird-mimetic wing shape with a span-wise camber and an up-down and twisting wing drive mechanism with double-crank linkages, This lift-enhancing design by mimicking the flapping mechanism of a bird＇s wing enabled the 210 g FMAV to fly autonomously in an outdoor field under wind speeds of less than 5 m.s-1. Autonomous flight was enabled by installing a flight control computer with a micro-electro-mechanical gyroscope and accelerometers, along with a micro video camera and an ultralight wireless communication system inside the fuselage. A comprehensive wind tunnel test shows that the FMAV with a high-camber wing and double-crank mechanism generates more lift and less net thrust than the FMAV with a flat wing and single-crank mechanism, which confirms the improved performance of the developed FMAV, as well as the superior slow flying or hovering capabilities of the FMAV with a high-camber wing and double-crank wing drive system.

关键词： flapping-wing MAV autonomous flight biomimetic wing double crank wing

Calcium-dependent proteasome activation is required for axonal neurofilament degradation

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Neural Regeneration Research 2013年第36期8卷 3401-3409页

作者： Joo Youn Park So Young Jang yoon Kyung Shin Duk joon Suh Hwan Tae Park Department of Physiology Mitochondria Hub Regulation Center College of Medicine Dong-A University

Even though many studies have identified roles of proteasomes in axonal degeneration, the mo- lecular mechanisms by which axonal injury regulates proteasome activity are still unclear. In the present study, we found evidence indicating that extracellular calcium influx is an upstream regulator of proteasome activity during axonal degeneration in injured peripheral nerves. In degenerating axons, the increase in proteasome activity and the degradation of ubiquitinated proteins were sig- nificantly suppressed by extracellular calcium chelation. In addition, electron microscopic findings revealed selective inhibition of neurofilament degradation, but not microtubule depolymerization or mitochondrial swelling, by the inhibition of calpain and proteasomes. Taken together, our findings suggest that calcium increase and subsequent proteasome activation are an essential initiator of neurofilament degradation in Wallerian degeneration.

关键词： neural regeneration peripheral nerve injury neurofilament degradation sciatic nerve calcium calpain mitochondria microtubule depolymerization axon axon degeneration neuroregeneration

ESR2–HDA6 complex negatively regulates auxin biosynthesis to delay callus initiation in Arabidopsis leaf explants during tissue culture

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Plant Communications 2024年第7期5卷 200-214页

作者： Kyounghee Lee Hobin yoon Ok-Sun Park Jongbu Lim Sang-Gyu Kim Pil joon Seo Department of Chemistry Seoul National UniversitySeoul 08826Korea Research Institute of Basic Sciences Seoul National UniversitySeoul 08826Korea Interdisciplinary Program in Agricultural Biotechnology Seoul National UniversitySeoul 08826Korea Plant Genomics and Breeding Institute Seoul National UniversitySeoul 08826Korea Department of Biological Sciences KAISTDaejeon 34141Korea

Plants exhibit an astonishing ability to regulate organ regeneration upon *** of leaf explants promotes the biosynthesis of indole-3-acetic acid(IAA),which is polar-transported to excised regions,where cell fate transition leads to root founder cell specification to induce de novo root *** regeneration capacity of plants has been utilized to develop in vitro tissue culture ***,we report that IAA accumulation near the wounded site of leaf explants is essential for callus formation on 2,4-dichlorophenoxyacetic acid(2,4-D)-rich callus-inducing medium(CIM).Notably,a high concentration of 2,4-D does not compensate for the action of IAA because of its limited efflux;rather,it lowers IAA biosynthesis via a negative feedback mechanism at an early stage of in vitro tissue culture,delaying callus *** auxin negative feedback loop in CIM-cultured leaf explants is mediated by an auxin-inducible APETALA2 transcription factor,ENHANCER OF SHOOT REGENERATION 2(ESR2),along with its interacting partner HISTONE DEACETYLASE 6(HDA6).The ESR2–HDA6 complex binds directly to,and removes the H3ac mark from,the YUCCA1(YUC1),YUC7,and YUC9 loci,consequently repressing auxin biosynthesis and inhibiting cell fate transition on 2,4-D-rich *** findings indicate that negative feedback regulation of auxin biosynthesis by ESR2 and HDA6 interferes with proper cell fate transition and callus initiation.

关键词： auxin biosynthesis negative feedback loop ESR2 HDA6 YUCCA chromatin modification

Endoscopic management of occluded metal biliary stents:Metal versus 10F plastic stents

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World Journal of Gastroenterology 2010年第42期16卷 5347-5352页

作者： Won Jae yoon Ji Kon Ryu Jung Won Lee Dong-Won Ahn yong-Tae Kim yong Bum yoon Sang Myung Woo Woo Jin Lee Division of Gastroenterology Department of Internal MedicineSeoul National University College of Medicine101 Daehang-roJongno-guSeoul110-744South Korea Center for Liver Cancer National Cancer Center323 Ilsan-roIlsandong-guGoyang-siGyeonggi-do410-769South Korea

AIM:To compare the efficacy of self-expandable metal stents(SEMSs) with 10F plastic stents(PSs) in the endoscopic management of occluded ***:We retrospectively reviewed the medical records of 56 patients who underwent SEMS insertion for palliation of unresectable malignant biliary obstruction between 2000 and 2007 and subsequent endoscopic retrograde biliary drainage(ERBD) with SEMS or PS for initial SEMS occlusion between 2000 and ***:Subsequent ERBD with SEMS was performed in 29 patients and with PS in *** median time to stent occlusion after subsequent ERBD was 186 d in the SEMS group and 101 d in the PS group(P= 0.118).Overall median stent patency was 79 d for the SEMS group and 66 d for the PS group(P = 0.379).The mean number of additional biliary drainage procedures after subsequent ERBD in patients that died(n = 50) during the study period was 2.54 ± 4.12 for the SEMS group and 1.85 ± 1.95 for the PS group(P = 0.457).The mean total cost of additional biliary drainage procedures after the occlusion of subsequent SEMS or PS was $410.04 ± 692.60 for the SEMS group and $630.16 ± 671.63 for the PS group(P = 0.260).Tumor ingrowth as the cause of initial SEMS occlusion was the only factor associated with a shorter time to subsequent stent occlusion(101 d for patients with tumor ingrowth vs 268 d for patients without tumor ingrowth,P = 0.008).CONCLUSION:Subsequent ERBD with PSs offered similar patency and number of additional biliary drainage procedures compared to SEMSs in the management of occluded SEMS.

关键词： Stents Biliary tract neoplasms Obstructive jaundice Endoscopy Endoscopic retrograde cholangiopancreatography

High-performance solid-solution potassium-ion intercalation mechanism of multilayered turbostratic graphene nanosheets

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Journal of Energy Chemistry 2022年第4期31卷 814-823页

作者： Jiae Um Seung Uk yoon Hoseong Kim Beom Sik Youn Hyoung-joon Jin Hyung-Kyu Lim Young Soo Yun Program in Environmental and Polymer Engineering Inha Universityncheon 22212 South Korea Department of Polymer Science and Engineering Inha UniversityIncheon 22212South Korea Division of Chemical Engineering and Bioengineering Kangwon National University Chuncheon Gangwon-do 24341 South Korea KU-KIST Graduate School of Converging Science and Technologyea University 145 Anam-roSeongbuk-guSoul02841 South Korea Department of Integrative Energy Engineering 145 Anam-roSongbuk-guKorea UniversitySeoul 02841 South Korea

The solid-solution reaction between an alkali cation and an active host material is known as a singlephase redox mechanism,and it is typically accompanied by a continuous voltage *** is distinct from the typical alkali cation intercalation reaction at an equivalent site of the active host material,which exhibits a voltage ***,we report an unusual solid-solution potassium-ion intercalation mechanism with a low-voltage plateau capacity on multilayered turbostratic graphene nanosheets(T-GNSs).Despite the disordered graphitic structure with a broad range of d-spacings(3.65–4.18À),the T-GNSs showed a reversible plateau capacity of~200 m A h g^(-1),which is higher than that of a well-ordered graphite nanoplate(~120 m A h g^(-1)).In addition,a sloping capacity of~220 m A h g^(-1)was delivered with the plateau capacity,and higher rate capabilities,better reversibility,and a more stable cycling performance were confirmed on the turbostratic ***-principles calculations suggest that the multitudinous lattice domains of the T-GNSs contain diverse intercalation sites with strong binding energies,which could be the origin of the high-performance solid-solution potassium-ion intercalation behavior when the turbostratic graphene stacks have a d-spacing smaller than that of equilibrium potassium–graphite intercalation compounds(5.35À).

关键词： Turbostratic graphite Graphene nanosheet Defective carbon Anode Potassium-ion batteries

Lemierre's syndrome caused by Klebsiella pneumoniae:A case report

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World Journal of Nephrology 2021年第5期10卷 101-108页

作者： So Yeon Hwang Seok joon Shin Hye Eun yoon Department of Internal Medicine Incheon St.Mary's HospitalCollege of MedicineThe Catholic University of KoreaIncheon 21431South Korea

BACKGROUND Lemierre's syndrome is a disease that causes anaerobic sepsis,internal jugular vein thrombosis,and septic embolism in the lungs and other organs after acute oropharyngeal *** was named after André-Alfred Lemierre in *** SUMMARY Here,we have reported a case of Lemierre’s syndrome in a 56-year-old female patient who presented with a sore *** patient had septic shock,had not voided,and had severe hyperglycemia at the time of her *** tests revealed bilateral pneumonia,pleural effusion,pulmonary embolism,and renal vein *** patient was admitted to the intensive care unit and placed on mechanical ventilation due to acute respiratory distress *** renal replacement therapy was administered to treat renal failure with *** pneumoniae was cultured from blood and sputum *** reviewing various results,the patient was ultimately diagnosed with Lemierre’s *** patient was treated with appropriate antibiotics and thrombolytic *** was discharged from the hospital after *** Lemierre’s syndrome is associated with a high mortality ***,clinicians should be familiar with the signs and symptoms of this disease as well as the preemptive examinations,procedures,and treatments.

关键词： Lemierre's syndrome Klebsiella pneumoniae Diabetes Mellitus Pulmonary embolism Septic pneumonia Case report

Mimicking a Superhydrophobic Insect Wing by Argon and Oxygen Ion Beam Treatment on Polytetrafluoroethylene Film

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Journal of Bionic Engineering 2009年第4期6卷 365-370页

作者： Youngjong Lee yonghoon Yoo Jihoon Kim Sriyulianti Widhiarini Baeho Park Hoon Cheol Park Kwang joon yoon Doyoung Byun Department of Aerospace Information Engineering Konkuk UniversitySeoul 143-701Republic of Korea Department of Physics Konkuk UniversitySeoul 143-701Republic of Korea Department of Advanced Technology Fusion Konkuk UniversitySeoul 143-701Republic of Korea

Biological tiny structures have been observed on many kinds of surfaces such as lotus leaves and insect wings,which enhance the hydrophobicity of the natural surfaces and play a role of *** presented the fabrication technology of a superhydrophobic surface using high energy ion *** insect wings that mimic the morphology and the superhydrophobocity of cicada's wings were successfully fabricated using argon and oxygen ion beam treatment on a polytetrafluoroethylene (PTFE)*** wing structures were supported by carbon/epoxy fibers as artificial flexible veins that were bonded through an autoclave *** morphology of the fabricated surface bears a strong resemblance to the wing surface of a cicada,with contact angles greater than 160°,which could be sustained for more than two months.

关键词： superhydrophobic insect wing mimicry of the wing ion beam treatment artificial flapper dynamic contact angle

Removal characteristics of CO_2 using aqueous MEA/AMP solutions in the absorption and regeneration process

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Journal of Environmental Sciences 2009年第7期21卷 907-913页

作者： Won-joon Choi Jong-Beom Seo Sang-yong Jang Jong-Hyeon Jung Kwang-joong Oh Greenhouse Gas Research Center Korea Institute of Energy Research Daejeon 305343 Korea Department of Environmental Engineering Pusan National University Busan 609735 Korea Department of Health Administration Sorabol College Gyeongju 780711 Korea

The carbon dioxide （CO2） removal efficiency, reaction rate, and CO2 loading into aqueous blended monoethanolamine （MEA）＋ 2-amino-2-methyl-l-propanol （AMP） solutions to enhance absorption characteristics of MEA and AMP were carried out by the absorption/regeneration process. As a result, compared to aqueous MEA and AMP solutions, aqueous blended MEA ＋ AMP solutions have a higher CO2 loading than MEA and a higher reaction rate than AMP. The CO2 loading of rich amine of aqueous 18 wt.% MEA ＋ 12 wt.% AMP solution was 0.62 mol CO2/mol amine, which is 51.2% more than 30 wt.% MEA （0.41 mol CO2/mol amine）. Consequently, blending MEA and AMP could be an effective way to design considering economical efficiency and used to operate absorber for a long time.

关键词： carbon dioxide monoethanolamine 2-amino-2-methyl-1-propanol absorption regeneration

Growth of BaTiO_3-Ag hybrid composite films at room temperature by aerosol deposition

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中国有色金属学会会刊：英文版 2012年第S3期22卷 735-739页

作者： Young joon yoon Sung Hwan CHO Jihoon KIM Hyo Tae KIM Hong Koo BAIK Jong-Hee KIM Nano-Convergence Intelligence Material Team Korea Institute of Ceramic Engineering and Technology Division of Advanced Materials Engineering Kongju National University Department of Materials Science and Engineering Yonsei University

Barium titanate (BaTiO3) and silver (Ag) composite film with high dielectric constant was grown at room temperature by an aerosol deposition *** dielectric constant increases by 0.5 times after adding Ag to the BaTiO3 matrix,compared with pure *** high dielectric constant can be attributed to the percolation effect of Ag inclusions in the BaTiO3 *** Ag was present in the form of discrete layer in the BaTiO3 *** dielectric properties of BaTiO3 Ag were discussed in detail taking into account the changes in microstructures.

关键词： composites percolation aerosol deposition BaTiO3 Ag