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Effect of an extraction solvent on the antioxidant quality of Pinus densiflora needle extract

Journal of Pharmaceutical Analysis 2019年第3期9卷 193-200页

作者： Thamizhiniyan Venkatesan young-Woong Choi young-Kyoon kim Department of Forest Products and Biotechnology College of Science and TechnologyKookmin University

Pinus densiflora needle extract (PDNE) is widely reported to have many pharmacological activities including antioxidant potential. However, the solvent system used for extraction greatly affects its antioxidant quality. Hence, in the present study, we investigated the effect of a different ratio (vol/vol) of ethanol to water (0-100%) in the extraction of PDNE with potent antioxidant capacity. The chemical assays, 2,2-diphenyl-1 picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), were conducted to assess the antioxidant potential of PDNE. Subsequently, the cytoprotective effect of PDNE was determined using tert-butyl hydroperoxide (TBHP)-challenged HepG2 cellular model. The needle extracts from 40% ethanol (PDNE-40) showed greater radical scavenging activity followed by 60%, 20%, 80%, 0% and 100% ethanol extracts. EC50 value of the most active extract, PDNE-40, was 8.56 ± 0.51 μg/mL, relative to 1.34 ± 0.28 μg/mL of the standard trolox (for ABTS radical), and 75.96 ± 11.60 μg/mL, relative to 4.83 ± 0.26 μg/mL of the standard trolox (for DPPH radical). Either PDNE-20 or PDNE-40 pretreatment remarkably decreased the levels of reactive oxygen species (ROS), lipid peroxides and protein carbonyls in TBHP-challenged HepG2 cells. In addition, both PDNE-20 and PDNE-40 significantly reversed the decreased ratio of reduced (GSH) to oxidized (GSSG) glutathione. Moreover, these two extracts showed a significant inhibitory effect on TBHP-induced nuclear damage and loss of cell viability. In summary, the inclusion of 40% ethanol in water for extraction of Pinus densiflora needle greatly increases the antioxidant quality of the extract.

关键词： Pinus densiflora needle extract Oxidative stress Cytoprotective Natural antioxidant

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Three-dimensional endoanal ultrasonographic assessment of an anal fistula with and without H_2O_2 enhancement

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World Journal of Gastroenterology 2009年第38期15卷 4810-4815页

作者： Yung kim young Jin Park Department of Surgery Dongguk University Ilsan HospitalDongguk University School of Medicine

AIM： To evaluate the effectiveness of three-dimensional endoanal ultrasound （3D-EAUS） in the assessment of anal fistulae with and without H202 enhancement. METHODS： Sixty-one patients （37 males, aged 17-74 years） with anal fistulae, which were not simple low types, were evaluated by physical examination and 3D-EAUS with and without enhancement. Fistula classification was determined with each modality and compared to operative findings as the reference standard. RESULTS： The accuracy of 3D-EAUS was significantly higher than that of physical examination in detecting the primary tract （84.4% vs 68.7%, P = 0.037） and secondary extension （81.8% vs 62.1%, P = 0.01） and localizing the internal opening （84.2% vs 59.7%, P = 0.004）. A contrast study with H202 detected several more fistula components including two primary suprasphincteric fistula tracks and one supralevator secondary extension, which were not detected on non-contrast study. However, there was no significant difference in accuracy between 3D-EAUS and H202- enhanced 3D-EAUS with respect to classification of the primary tract （84.4% vs 89.1%, P = 0.435） or secondary extension （81.8% vs 86.4%, P = 0.435） or localization of the internal opening （84.2% vs 89.5%, P = 0.406）. CONCLUSION： 3D-EAUS was highly reliable in the diagnosis of an anal fistula. H2O2 enhancement was helpful at times and selective use in difficult cases may be economical and reliable.

关键词： Anal fistula Endoanal ultrasound H2O2enhancement

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Fatigue-Induced Micro-damage Characterization of Austenitic Stainless Steel 316 Using Innovative Nonlinear Acoustics

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Chinese Physics Letters 2012年第6期29卷 82-85页

作者： Chung-Seok kim Kyung-young JHANG Automotive Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea Mechanical Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea

We present innovative nonlinear acoustics for characterizing fatigue-induced micro-damage of austenitic stainless steel 316 subjected to high-cycle *** fatigue-driven deformations are accumulated at several positions near the middle of hourglass-shaped specimens.A bell-shaped curve of acoustic nonlinearity as a function of position is observed,and the variation in acoustic nonlinearity is attributed to the evolution of a lattice defect (dislocation) and stress-induced martensite based on transmission electron microscopy (TEM) *** oblique incidence technique using a longitudinal waveform is a potentially viable method for characterizing the high-cycle fatigue deformation of austenitic stainless steel 316 alloys.

关键词： fatigue steel martensite

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Sandwich-type ordered mesoporous carbon/graphene nanocomposites derived from ionic liquid

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Nano Research 2016年第9期9卷 2696-2706页

作者： Ho Seok kim young Hwan kim Kwang Chul Roh Kwang-Bum kim Lab of Energy Storage Materials Department of Material Science & EngineeringYonsei UniversitySeou1120749Republic of Korea Energy & Environmental Division Korea Institute of Ceramic Engineering & TechnologyJinju 52851Republic of Korea

Sandwich-type ordered mesoporous carbon/graphene nanocomposites were successfully synthesized using 2D ordered mesoporous silica/graphene nanocomposites as the hard template and an ionic liquid as a N-rich carbon source. We used an ionic liquid of 1-(3-cyanopropyl)-3-methylimidazolium dicyanamide containing nitrile groups (–CN) in the cation and anion as a carbon precursor for the preparation of the nanocomposites. Nitriles do not decompose under thermal treatment in an inert gas atmosphere, but leave significant amounts of N-rich carbon materials. The nanocomposites had a large surface area (1,316 m2·g–1), an average pore diameter of 5.9 nm, and high electrical conductivity. The nanocomposite electrode showed a high specific capacitance of 190 F·g–1at 0.5 A·g–1in 1 M TEABF4/AN electrolyte and a good rate capability between 0 and 2.7 V for supercapacitor (or ultracapacitor) applications. [Figure not available: see fulltext.] © 2016, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

关键词： ionic liquid-derived carbon ordered mesoporous carbon/graphene nanocomposite 2D graphene nanocomposite supercapacitor

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The Role of Relative Spinal Motion during Feline Galloping for Speed Performance

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Journal of Bionic Engineering 2014年第4期11卷 517-528页

作者： young Kook kim Jongwon Park Byungho Yoon Kyung-Soo kim Soohyun kim Robotics Program Korea Advanced Institute of Science and Technology (KAIST) Daejeon 305-701 Republic of Korea Department of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 305-701 Republic of Korea

Felines use their spinal column to increase their running speed at rapid locomotion performance. However, its motion profile behavior during fast gait locomotion has little attention. The goal of this study is to examine the relative spinal motion profile during two different galloping gait speeds. To understand this dynamic behavior trend, a dynamic motion of the feline animal （Felis catus domestica） was measured and analyzed by motion capture devices. Based on the experiments at two different galloping gaits, we observed a significant increase in speed （from 3.2 m.s-1 to 4.33 m.s-1） during the relative motion profile synchronization between the spinal （range： 118.86~ to 168.00~） and pelvic segments （range： 46.35~ to 91.13~） during the hindlimb stance phase （time interval： 0.495 s to 0.600 s）. Based on this discovery, the relative angular speed profile was applied to understand the possibility that the role of the relative motion match during high speed locomotion generates bigger ground reaction force.

关键词： feline galloping galloping gait pattern relative spinal motion speed performance phase match

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Cryptogenic organizing pneumonia associated with pregnancy:A case report

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World Journal of Clinical Cases 2022年第6期10卷 1946-1951页

作者： young Joo Lee young Sun kim Department of Obstetrics and Gynecology Kyung Hee University Medical CenterSeoul 02447South Korea

BACKGROUND Cryptogenic organizing pneumonia(COP),formerly known as bronchiolitis obliterans organizing pneumonia,is an extremely rare disease in *** this case,we report on COP diagnosed in recurrent pneumonia that does not respond to antibiotics in pregnant *** SUMMARY A 35-year-old woman with no prior lung disease presented with concerns of chest pain with cough,sputum,dyspnea,and mild fever at 11 wk’*** was diagnosed with community-acquired pneumonia and treated with antibiotics;her symptoms improved *** weeks after discharge,she was readmitted with aggravated *** computed tomography demonstrated multifocal patchy airspace consolidation and ground-glass opacities at the basal segments of the right lower lobe,at the lateral basal segment of the lower lobe,and at the lingular segment of the left upper *** lavage revealed an increased lymphocyte count and a decreased CD4/CD8 ***(0.5 mg/kg/d)was administered for 10 d after the second *** improved after 3 d of steroid treatment and other symptoms improved on the 5th day of steroid ***-delivery transbronchial lung biopsy further revealed the presence of granulation tissue with fibroblasts in smallbronchiole *** This case suggests that it is important to differentiate COP from atypical pneumonia in the deteriorated condition despite antibiotic treatment.

关键词： Antibiotics Bronchiolitis obliterans organizing pneumonia Corticosteroid Cryptogenic organizing pneumonia Pregnancy Case report

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Grain size dependence of flow stress in ECAPed Ti with constant texture

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中国有色金属学会会刊：英文版 2012年第S3期22卷 673-677页

作者： Chang-young HYUN Ho-Kyung kim Department of Materials Science and Engineering Seoul National University of Science and Technology Department of Automotive Engineering Seoul National University of Science and Technology

The effect of grain size on the flow stress in an ECAPed Ti with a constant texture was investigated,assuming that 2,4,5 and 6 passes microstructures have a similar *** average size of recrystallized grains decreased to 0.5 μm,0.4 μm,and 0.3 μm with respect to the ECAP pass number of 2,4,and 6,*** ultimate tensile strength (UTS) and yield strength (YS) increase with an increase in the number of *** UTS and YS of the 6 passes ECAPed sample were found to be 740.2 MPa and 580.3 MPa,*** equation for the flow stress of an ECAPed Ti with a constant texture as a function of the strain and grain size was derived for the ECAPed *** following equation was finally obtained:σ(ε)=103.9+1825ε-9.6ε1/2·d-1/2+8.3d-1/2.

关键词： Ti mechanical properties grain size flow stress equal channel angular pressing

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Effect of pulse time on surface characteristics and corrosion resistance during pulse electrochemical polishing

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中国有色金属学会会刊：英文版 2012年第S3期22卷 876-880页

作者： young-Bin kim Jeong-Woo PARK Department of Advanced Parts and Materials Engineering Chosun University Department of Mechanical Design Engineering Chosun University

Pulse electrochemical polishing (PECP) was used to improve the mechanical properties,such as surface roughness and corrosion resistance,of conductive metallic *** can provide a smooth,bright,reflective,and deburred surface that exhibits superior corrosion *** this work,stainless steel was used as the anode,and copper was used as the cathode due to their low electrical *** surface roughness of the PECP sample was measured by atomic force microscopy (AFM).A scanning electron microscope (SEM) was used to observe surface characteristics,and an Auger electron spectroscope (AES) was used to analyze the metallurgical composition and thickness of the passive *** aim of this research was to compare the corrosion resistance rates of the unprocessed and PECP-processed stainless steel.

关键词： stainless stell pulse electrochemical polishing corrosion resistance

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Acoustic Nonlinearity of a Laser-Generated Surface Wave in a Plastically Deformed Aluminum Alloy

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Chinese Physics Letters 2012年第12期29卷 39-43页

作者： kim Chung-Seok JHANG Kyung-young Metallurgy and Materials Engineering Chosun UniversitySeosuk-dongGwangju501-759South Korea Mechanical Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea

The acoustic nonlinearity of surface waves is studied to evaluate plastic deformation in aluminum alloys.A narrow-band surface wave is successfully generated by a pulsed Nd-YAG laser system consisting of a beam expander and a slit *** degrees of tensile deformation are induced by interrupting the tensile tests so as to obtain aluminum specimens with different degrees of plastic *** normalized acoustic nonlinearity increases as a function of tensile *** experimental results show that the acoustic nonlinearity of a laser-generated surface wave has a good correlation with the level of tensile deformation and has a potential to evaluate microdamage induced by dislocation microplasticity.

关键词： deformation nonlinearity Deform

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Transparent Supercapacitors: From Optical Theories to Optoelectronics Applications

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Energy & Environmental Materials 2020年第3期3卷 265-285页

作者： Sang-Woo kim Sang-young Lee Department of Energy Engineering School of Energy and Chemical EngineeringUlsan National Institute of Science and Technology(UNIST)Ulsan 689-798Korea

The ever-increasing demand for smart optoelectronics spurs the relentless pursuit of transparent wireless devices as a game-changing technology that can provide unseen visual information behind the *** enable successful operation of the transparent wireless devices,their power sources should be highly transparent in addition to acquiring reliable electrochemical *** various transparent power sources,supercapacitors(SCs)have been extensively investigated as a promising candidate due to their exceptional cyclability,power capability,material diversity,and scalable/low-cost ***,we describe current status and challenges of transparent SCs,with a focus on their core materials,performance advancements,and integration with application devices.A special attention is devoted to transparent conductive electrodes(TCEs)which act as a keyenabling component in the transparent *** on fundamental understanding of optical theories and operating principles of transparent materials,we comprehensively discuss materials chemistry,structural design,and fabrication techniques of *** addition,noteworthy progresses of transparent SCs are briefly overviewed in terms of their architectural design,opto-electrochemical performance,flexibility,form factors,and integration compatibility with transparent flexible/wearable devices of ***,development direction and outlook of transparent SCs are explored along with their viable roles in future application fields.

关键词： energy storage flexibility optoelectronics transparent conductive electrodes transparent supercapacitors

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