472 results on '"Jun-Hyun Kim"'
Search Results
2. Light-enhanced catalytic activity of stable and large gold nanoparticles in homocoupling reactions
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Jian Hou, Jemima A. Lartey, Chang Yeon Lee, and Jun-Hyun Kim
- Subjects
Medicine ,Science - Abstract
Abstract Validating the direct photocatalytic activity of colloidal plasmonic nanoparticles is challenging due to their limited stability and needed support materials that can often contribute to the chemical reactions. Stable gold nanoparticles (AuNPs) with tunable sizes are prepared across porous polymer particles without any chemical bonds where the resulting composite particles exhibit intense surface plasmon resonances (SPRs) in the visible region. These composite particles are then tested as photocatalysts under a broadband solar-simulated light source to examine the contribution degree of photothermal heating and SPR coming from the incorporated AuNPs in the C–C bond forming homocoupling reaction. Generally, the thermal and photothermal heating are the main driving force to increase the reactivity of relatively smaller AuNPs (~ 44 nm in diameter) with a narrower SPR band. However, the SPR-induced catalytic activity is much greater for the composite particles containing larger AuNPs (~ 87 nm in diameter) with a broader SPR. As the polymer particle matrix does not influence the catalytic activity (e.g., inducing charge delocalization and/or separation), the unique SPR role of the colloidal AuNPs in the catalytic reaction is assessable under light irradiation. This study experimentally demonstrates the possibility of evaluating the direct contribution of SPRs to photocatalytic chemical reactions.
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- 2024
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3. Promoting Thermal Conductivity of Alumina-Based Composite Materials by Systematically Incorporating Modified Graphene Oxide
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Nawon Lee, Jinsol Park, Nayeon Jang, Sehui Lee, Dayeon Kim, Sanggin Yun, Tae Woo Park, Jun-Hyun Kim, and Hyun-Ho Park
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graphene oxide ,alumina particle ,polydimethylsiloxane ,thermal conductivity ,thermal interface material ,Crystallography ,QD901-999 - Abstract
Small amounts of thermally conductive graphene oxide (GO) and modified GO are systematically introduced as a second filler to thermal interface materials (TIMs) consisting of alumina (Al2O3) particles and polydimethylsiloxane (PDMS). The surface of GO is covalently linked with an organic moiety, octadecylamine (ODA), to significantly improve the miscibility and dispersity of GO across the TIM matrix. Subsequently, two series of PDMS-Al2O3 composite TIMs are manufactured as a function of GO and ODA-GO content (0.25 wt%–2.5 wt%) to understand the effect of these second additives. The incorporation of GO into the Al2O3-PDMS composite materials generally increases the thermal conductivity (TC), ranging from 18% to 29%. Conversely, the use of ODA-GO further enhances the overall performance of TIMs (22–54%) by facilitating the dispersion degree of GO across the composite matrix. The great improvement in TC is presumably related to the formation of conductive pathways by uniformly integrating 2D-type GO flakes across spherical Al2O3 particle networks. The ability to simply regulate the polarity of the thermally conductive second filler can provide an idea for designing cost-effective and practical TIM-2-type pads that can be commercially applicable in between an integrated heat spreader and a heat sink.
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- 2024
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4. Oblique Lumbar Interbody Fusion with Selective Biportal Endoscopic Posterior Decompression for Multilevel Lumbar Degenerative Diseases
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Woo-Myung Lee, Ki-Han You, Min-Seok Kang, Jun-Hyun Kim, and Hyun-Jin Park
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multilevel lumbar degenerative disease ,oblique lumbar interbody fusion ,biportal endoscopic spinal surgery ,selective neural decompression ,Medicine - Abstract
Oblique lumbar interbody fusion is a minimally invasive procedure for treating degenerative lumbar disease. Its advantages include correcting coronal and sagittal spinal alignment and indirect neural decompression. However, achieving a successful outcome is limited in some patients who need direct decompression for central canal lesions including hard stenotic lesions (endplate or facet articular osteophytes and ossification of posterior longitudinal ligaments) and sequestration of the disk. Biportal endoscopic spinal surgery is a minimally invasive technique, which directly decompresses the lesion. By taking advantage of two procedures, in a long-level lumbar lesion, alignment correction and direct decompression can be both achieved. Herein, the authors introduce multilevel lumbar fusion through oblique lumbar interbody fusion and selective direct decompression through biportal endoscopic spinal surgery and discuss the surgical indications, surgical pitfalls, and recommendations for application. Consequently, it is regarded as a minimally invasive interbody fusion method for patients with multilevel lumbar degenerative degeneration.
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- 2023
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5. Rapid Antibacterial Activity Assessment of Chimeric Lysins
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Jin-Mi Park, Jun-Hyun Kim, Gun Kim, Hun-Ju Sim, Sun-Min Ahn, Kang-Seuk Choi, and Hyuk-Joon Kwon
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Staphylococcus aureus ,chimeric lysins ,cell-free expression system ,linker optimization ,SH3 shuffling ,antibacterial activity ranking ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Various chimeric lysins have been developed as efficacious antibiotics against multidrug-resistant bacteria, but direct comparisons of their antibacterial activities have been difficult due to the preparation of multiple recombinant chimeric lysins. Previously, we reported an Escherichia coli cell-free expression method to better screen chimeric lysins against Staphylococcus aureus, but we still needed to increase the amounts of expressed proteins enough to be able to detect them non-isotopically for quantity comparisons. In this study, we improved the previous cell-free expression system by adding a previously reported artificial T7 terminator and reversing the different nucleotides between the T7 promoter and start codon to those of the T7 phage. The new method increased the expressed amount of chimeric lysins enough for us to detect them using Western blotting. Therefore, the qualitative comparison of activity between different chimeric lysins has become possible via the adjustment of the number of variables between samples without protein purification. We applied this method to select more active chimeric lysins derived from our previously reported chimeric lysin (ALS2). Finally, we compared the antibacterial activities of our selected chimeric lysins with reported chimeric lysins (ClyC and ClyO) and lysostaphin and determined the rank orders of antibacterial activities on different Staphylococcus aureus strains in our experimental conditions.
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- 2024
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6. Functional outcomes of residual varus alignment versus mechanical alignment in total knee arthroplasty for varus osteoarthritis: A preferred reporting items for systematic reviews and meta-analyses-compliant meta-analysis
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Seung-Beom Han, Ki-Mo Jang, Jun-Hyun Kim, Sang-Bum Kim, and Kyun-Ho Shin
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Orthopedic surgery ,RD701-811 - Abstract
Background One in five patients with mechanical alignment (MA) after total knee arthroplasty (TKA) was reportedly dissatisfied. As constitutional varus knees are common, restoring the patients’ natural residual varus (RV) alignment is as an appealing alternative to neutral MA. This meta-analysis aimed to evaluate the effects of RV alignment on the functional outcomes compared with those of MA in TKA for the knees with varus osteoarthritis. Methods The MEDLINE/PubMed, Cochrane Library, and EMBASE databases were comprehensively searched for papers comparing the effects of RV alignment and MA on the functional outcomes from the time of inception of the databases to July 2020. Studies comparing the functional outcomes in the knees subjected to TKA with RV alignment (case group) and MA (control group) were included. The Knee Society knee and functional scores (KSKS and KSFS, respectively), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Oxford knee score (OKS), and forgotten joint score (FJS) were compared. Results Seven studies were finally included; all studies showed a low risk of selection bias and provided detailed demographic data. The pooled mean difference in the KSKS (0.06, 95% confidence interval [CI]: −0.14 to 0.27; p = 0.55) and KSFS (0.08, 95% CI: −0.08 to 0.35; p = 0.56) between RV alignment and MA did not significantly differ. The pooled mean differences in the WOMAC (−0.25, 95% CI: −0.57 to 0.07; p = 0.12), OKS (0.06, 95% CI: −0.15 to 0.27; p = 0.56), and FJS (0.41, 95% CI: −0.18 to 1.00; p = 0.18) between the groups were not significant. Conclusion The beneficial effects of RV alignment on the functional outcomes are limited compared to those of MA in TKA for varus osteoarthritis to date. Currently, TKA with neutral MA should be considered as the gold standard.
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- 2022
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7. Integration of Gold Nanoparticles into Crosslinker-Free Polymer Particles and Their Colloidal Catalytic Property
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Jian Hou, Bin Li, Wongi Jang, Jaehan Yun, Faith M. Eyimegwu, and Jun-Hyun Kim
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gold nanoparticle ,poly(N-isopropylacrylamide) ,cross-linker free particle ,homocoupling ,long-term stability ,Chemistry ,QD1-999 - Abstract
This work demonstrates the incorporation of gold nanoparticles (AuNPs) into crosslinker-free poly(N-isopropylacrylamide), PNIPAM, particles in situ and the examination of their structural and catalytic properties. The formation process of the AuNPs across the crosslinker-free PNIPAM particles are compared to that of crosslinked PNIPAM particles. Given the relatively larger free volume across the crosslinker-free polymer network, the AuNPs formed by the in situ reduction of gold ions are detectably larger and more polydisperse, but their overall integration efficiency is slightly inferior. The structural features and stability of these composite particles are also examined in basic and alcoholic solvent environments, where the crosslinker-free PNIPAM particles still offer comparable physicochemical properties to the crosslinked PNIPAM particles. Interestingly, the crosslinker-free composite particles as a colloidal catalyst display a higher reactivity toward the homocoupling of phenylboronic acid and reveal the importance of the polymer network density. As such, the capability to prepare composite particles in a controlled polymer network and reactive metal nanoparticles, as well as understanding the structure-dependent physicochemical properties, can allow for the development of highly practical catalytic systems.
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- 2023
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8. Design and Medical Effects of a Vaginal Cleaning Device Generating Plasma-Activated Water with Antimicrobial Activity on Bacterial Vaginosis
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Yuan Hwang, Hyanghee Jeon, Geon Yeoung Wang, Hyung Kyu Kim, Jun-Hyun Kim, Dong Keun Ahn, Joong Sub Choi, and Yongwoo Jang
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atmospheric pressure plasma ,plasma-activated water ,plasma medicine ,vaginal cleaning device ,Physics ,QC1-999 ,Plasma physics. Ionized gases ,QC717.6-718.8 - Abstract
Bacterial vaginosis is a common female disease caused by a vaginal infection due to an overgrowth of bacteria that naturally live in the vaginal tract. Bacterial vaginosis has frequently been treated with the oral or vaginal administration of antibiotics and topical disinfectants. However, hygienic application of topical treatment deep in the vagina remains difficult. Herein, we introduce a novel vaginal cleaning device using plasma-activated water generated from supplied water. Remarkably, plasma source generation at atmospheric pressure is well known to eradicate bacterial infection through the generation of free radicals and/or chlorine chemicals with antimicrobial activity. The device was designed to alleviate a bacterial infection by spraying plasma-activated water generated from a cleaning solution container with plasma modules. The spray nozzle contains both a clean outlet and a suction outlet to spray and recover the plasma water, respectively, and is connected to a disposable silicone tube. The other nozzle, which has a laser light and air pump, can perform a second sterilization and dry the vagina after washing. Free chlorine chemicals with antibacterial activity were detected in the plasma-activated water by the device. Clinical application in patients with bacterial vaginosis confirmed the stability and effectiveness of our device. Therefore, these results show a novel clinical application of atmospheric pressure plasma to medical field as a plasma medicine.
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- 2020
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9. Process Optimization for Manufacturing Functional Nanosurfaces by Roll-to-Roll Nanoimprint Lithography
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Usama Tahir, Jin Il Kim, Shama Javeed, Amin Khaliq, Jun-Hyun Kim, Doo-In Kim, and Myung Yung Jeong
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nanopillars/pores ,roll-to-roll imprinting ,multiphase flow ,imprinting-speed ,functional surfaces ,sliding mesh method ,Chemistry ,QD1-999 - Abstract
Roll-to-roll nanoimprint lithography (RTR-NIL) is a low-cost and continuous fabrication process for large-area functional films. However, the partial ultraviolet (UV) resin filling obstructs the ongoing production process. This study incorporates UV resin filling process into the nanopillars and nanopores by using RTR-NIL. A multiphase numerical model with a sliding mesh method is proposed in this study to show the actual phenomena of imprint mold rotation and feeding of UV resin on the polyethylene terephthalate (PET) substrate. The implementation of UV resin filling under environmental conditions was performed by utilizing the open-channel (OC) boundary conditions. The numerical model was solved by using the explicit volume of fluid (VOF) scheme to compute the filling on each node of the computational domain. The effects of different processing parameters were investigated through the proposed numerical model such as imprinting speed (IS), contact angles (CAs), viscosity, initial thickness of the PET, and supporting roll diameter. A good agreement was found between numerical simulations and experimental results. The proposed numerical model gives better insights of the filling process for the mass production of functional surfaces with nanopillars and nanopores patterns for different applications on an industrial scale.
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- 2022
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10. Comparative Catalytic Properties of Supported and Encapsulated Gold Nanoparticles in Homocoupling Reactions
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Wongi Jang, Jaehan Yun, Luke Ludwig, Su Guan Jang, Jae Young Bae, Hongsik Byun, and Jun-Hyun Kim
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gold nanoparticle ,deposition precipitation ,mesoporous TiO2 ,poly(N-isopropylacrylamide) ,homocoupling reaction ,Chemistry ,QD1-999 - Abstract
This report describes strategies to increase the reactive surfaces of integrated gold nanoparticles (AuNPs) by employing two different types of host materials that do not possess strong electrostatic and/or covalent interactive forces. These composite particles are then utilized as highly reactive and recyclable quasi-homogeneous catalysts in a C-C bond forming reaction. The use of mesoporous TiO2 and poly(N-isopropylacrylamide), PNIPAM, particles allows for the formation of relatively small and large guest AuNPs and provides the greatly improved stability of the resulting composite particles. As these AuNPs are physically incorporated into the mesoporous TiO2 (i.e., supported AuNPs) and PNIPAM particles (i.e., encapsulated AuNPs), their surfaces are maximized to serve as highly reactive catalytic sites. Given their increased physicochemical properties (e.g., stability, dispersity, and surface area), these composite particles exhibit notably high catalytic activity, selectivity, and recyclability in the homocoupling of phenylboronic acid in water and EtOH. Although the small supported AuNPs display slightly faster reaction rates than the large encapsulated AuNPs, the apparent activation energies (Ea) of both composite particles are comparable, implying no obvious correlation with the size of guest AuNPs under the reaction conditions. Investigating the overall physical properties of various composite particles and their catalytic functions, including the reactivity, selectivity, and Ea, can lead to the development of highly practical quasi-homogeneous catalysts in green reaction conditions.
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- 2020
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11. Systematic Incorporation of Gold Nanoparticles onto Mesoporous Titanium Oxide Particles for Green Catalysts
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Jian Hou, Wongi Jang, Jaehan Yun, Franklin O. Egemole, Dianguo Geng, Hongsik Byun, Dong-Woo Kang, and Jun-Hyun Kim
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mesoporous TiO2 ,gold nanoparticle ,homocoupling reaction ,recyclable catalyst ,deposition precipitation ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
This report describes the systematic incorporation of gold nanoparticles (AuNPs) onto mesoporous TiO2 (MPT) particles without strong attractive forces to efficiently serve as reactive and recyclable catalysts in the homocoupling of arylboronic acid in green reaction conditions. Unlike using nonporous TiO2 particles and conventional SiO2 particles as supporting materials, the employment of MPT particles significantly improves the loading efficiency of AuNPs. The incorporated AuNPs are less than 10 nm in diameter, regardless of the amount of applied gold ions, and their surfaces, free from any modifiers, act as highly reactive catalytic sites to notably improve the yields in the homocoupling reaction. The overall physical properties of the AuNPs integrated onto the MPT particles are thoroughly examined as functions of the gold content, and their catalytic functions, including the rate of reaction, activation energy, and recyclability, are also evaluated. While the rate of reaction slightly increases with the improved loading efficiency of AuNPs, the apparent activation energies do not clearly show any correlation with the size or distribution of the AuNPs under our reaction conditions. Understanding the formation of these types of composite particles and their catalytic functions could lead to the development of highly practical, quasi-homogeneous catalysts in environmentally friendly reaction conditions.
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- 2021
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12. Surface Texturing of Si with Periodically Arrayed Oblique Nanopillars to Achieve Antireflection
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Jun-Hyun Kim, Sanghyun You, and Chang-Koo Kim
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surface texturing ,oblique nanopillars ,slanted plasma etching ,light reflection ,antireflection ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Si surfaces were texturized with periodically arrayed oblique nanopillars using slanted plasma etching, and their optical reflectance was measured. The weighted mean reflectance (Rw) of the nanopillar-arrayed Si substrate decreased monotonically with increasing angles of the nanopillars. This may have resulted from the increase in the aspect ratio of the trenches between the nanopillars at oblique angles due to the shadowing effect. When the aspect ratios of the trenches between the nanopillars at 0° (vertical) and 40° (oblique) were equal, the Rw of the Si substrates arrayed with nanopillars at 40° was lower than that at 0°. This study suggests that surface texturing of Si with oblique nanopillars reduces light reflection compared to using a conventional array of vertical nanopillars.
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- 2021
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13. Mixed Dye Removal Efficiency of Electrospun Polyacrylonitrile–Graphene Oxide Composite Membranes
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Wongi Jang, Jaehan Yun, Younggee Seo, Hongsik Byun, Jian Hou, and Jun-Hyun Kim
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graphene oxide ,reduced graphene oxide ,polyacrylonitrile ,nanofiber membrane ,water purification ,Organic chemistry ,QD241-441 - Abstract
Exfoliated graphene oxide (GO) was reliably modified with a cetyltrimethylammonium chloride (CTAC) surfactant to greatly improve the dispersity of the GO in a polyacrylonitrile (PAN) polymer precursor solution. Subsequent electrospinning of the mixture readily resulted in the formation of GO–PAN composite nanofibers containing up to 30 wt % of GO as a filler without notable defects. The absence of common electrospinning problems associated with clogging and phase separation indicated the systematic and uniform integration of the GO within the PAN nanofibers beyond the typical limits. After thoroughly examining the formation and maximum loading efficiency of the modified GO in the PAN nanofibers, the resulting composite nanofibers were thermally treated to form membrane-type sheets. The wettability and pore properties of the composite membranes were notably improved with respect to the pristine PAN nanofiber membrane, possibly due to the reinforcing filler effect. In addition, the more GO loaded into the PAN nanofiber membranes, the higher the removal ability of the methylene blue (MB) and methyl red (MR) dyes in the aqueous system. The adsorption kinetics of a mixed dye solution were also monitored to understand how these MB and MR dyes interact differently with the composite nanofiber membranes. The simple surface modification of the fillers greatly facilitated the integration efficiency and improved the ability to control the overall physical properties of the nanofiber-based membranes, which highly impacted the removal performance of various dyes from water.
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- 2020
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14. Preparation of Polybenzimidazole-Based Membranes and Their Potential Applications in the Fuel Cell System
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Kyungho Hwang, Jun-Hyun Kim, Sung-Yul Kim, and Hongsik Byun
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polybenzimidazole (PBI) ,flexible PBI ,cross-linked PBI ,proton exchange membrane fuel cell (PEMFC) ,Technology - Abstract
Various polybenzimidazole (PBI)-based ion-exchange films were prepared and thoroughly characterized by Fourier transform infrared (FT-IR) spectroscopy, proton conductivity, and water uptake for possible use as fuel cell membranes. Upon the increase in the flexibility of the PBI-based polymer films (e.g., poly(oxyphenylene benzimidazole) (OPBI) and sulfonated OPBI (s-OPBI)), the membranes exhibited slightly improved proton conductivity, but significantly increased dimensional changes. To reduce the dimensional changes (i.e., increase the stability), the cross-linking of the polymer films (e.g., cross-linked OPBI (c-OPBI) and sulfonated c-OPBI (sc-OPBI)) was accomplished using phosphoric acid. Interestingly, the sc-OPBI membrane possessed a greatly increased proton conductivity (0.082 S/cm), which is comparable to that of the commercially available Nafion membrane (0.09 S/cm), while still maintaining slightly better properties regarding the dimensional change and water uptake than those of the Nafion membrane.
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- 2014
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15. Fabrication of Slanted Cu Nanopillars with Uniform Arrays
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Sung-Woon Cho, Hae-Min Lee, Jun-Hyun Kim, Jeong Geun Bak, and Chang-Koo Kim
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Slanted Nanopillars ,Slanted Plasma Etching ,Faraday Cage ,Uniform Array ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Technology - Abstract
Slanted Cu nanopillars with uniform arrays were fabricat‐ ed using slanted Si channel structures as templates. A slanted plasma etching technique was employed, utilizing a Faraday cage system for the formation of these slanted channel structures. The angle of the slanted channel structures was accurately controlled because ions entering the Faraday cage maintained their direction. After the slanted channel structures were formed, they were filled with Cu by electroless deposition. Chemical mechanical polishing was then used to remove the excess Cu film and the SiO2 masks. Finally, the remaining poly Si of the channel structures was removed by wet chemical etching. This work offers a novel method for the fabrication of slanted metal nanostructures with uniform arrays covering a large area.
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- 2016
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16. Antibody-Driven Assembly of Plasmonic Core-Satellites to Increase the Sensitivity of a SERS Vertical Flow Immunoassay.
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Ebbah, Eunice, Amissah, Anthony, Jun-Hyun Kim, and Driskell, Jeremy D.
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- 2024
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17. Prediction of Permanent Enophthalmos Using 3-Dimensional Integral Model in Blowout Fractures.
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Jun Hyun Kim, Yean Su Choi, and Ho Seong Shin
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- 2024
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18. The Role of Visual Communication in Community Participation on Developing A Climate Adaptation Plan
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Armin Mouly, Jun-Hyun Kim, and Wayne Beyea
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Background and objective: Community participation or participatory planning are two terms used interchangeably that aim to incorporate community residents' opinions in the planning process to get the maximum benefit. This approach aims to gather stakeholders and engage them in a meaningful conversation to come to a decision representing the stake for everyone involved. This study focuses on the impacts of photorealistic visualization on community participation in the U.S. Great Lakes Region through a 5-year long (2017-2022) climate adaptation planning project conducted in Marquette County, Michigan, USA.Methods: Using the deliberation with analysis method of public participation, supported by visualizations, and followed by post-project surveys, the study explores how visualizations can improve in disseminating knowledge, bridging the gap of understanding among participants, enhancing engagement and delivering consistent approaches in the community decision-making process to come to a mutual ground of trust and common interest.Results: The study reveals that visualizations used at different phases of the community participation process increased participants' interest and engagement during the meeting, provided them with the necessary knowledge regarding climate change and its negative impact on health, and assisted them in decision-making and prioritizing design goals. The study also reveals that the visuals enhanced the project participants' engagement beyond the project's scope in future planning endeavors and increased their inclination towards climate and health adaptation planning.Conclusion: These findings will play a significant role in shaping the adaptive capacity in rural nonagricultural communities and strengthening the decision-making for similar areas dealing with climate change and its consequences.
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- 2023
19. Oblique Lumbar Interbody Fusion with Selective Biportal Endoscopic Posterior Decompression for Multilevel Lumbar Degenerative Diseases
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KIHAN YOU, Hyun Jin Park, Jun Hyun Kim, Woo Myung Lee, and Min Seok Kang
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Orthopedics and Sports Medicine ,Surgery - Abstract
Oblique lumbar interbody fusion is a minimally invasive procedure for treating degenerative lumbar disease. Its advantages include correcting coronal and sagittal spinal alignment and indirect neural decompression. However, achieving a successful outcome is limited in some patients who need direct decompression for central canal lesions including hard stenotic lesions (endplate or facet articular osteophytes and ossification of posterior longitudinal ligaments) and sequestration of the disk. Biportal endoscopic spinal surgery is a minimally invasive technique, which directly decompresses the lesion. By taking advantage of two procedures, in a longlevel lumbar lesion, alignment correction and direct decompression can be both achieved. Herein, the authors introduce multilevel lumbar fusion through oblique lumbar interbody fusion and selective direct decompression through biportal endoscopic spinal surgery and discuss the surgical indications, surgical pitfalls, and recommendations for application. Consequently, it is regarded as a minimally invasive interbody fusion method for patients with multilevel lumbar degenerative degeneration.
- Published
- 2023
20. Application of competency-based education in the Korean anesthesiology residency program and survey analysis
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Kyung Woo Kim, Won Joo Choe, and Jun Hyun Kim
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Anesthesiology and Pain Medicine - Abstract
Background: Although competency-based education (CBE) is becoming a popular form of medical education, it has not been used to train residents. Recently, the Korean Society of Anesthesiologists completed a pilot implementation and evaluation of a CBE program.This study aims to outline the experience.Methods: The chief training faculty from each hospital took a one-hour online course about CBE. Emails on the seven core competencies and their evaluation were sent ahead of a pilot core competency evaluation (CCE) to residents and faculty. The pilot CCE took place in late 2021, followed by a survey.Results: A total of 68 out of 84 hospitals participated in the pilot CCE. The survey response rate was 55.9% (38/68) for chief training faculty, 10.2% (91/888) for training faculty, and 30.2% (206/683) for residents. More than half of the training faculty thought that CCE was necessary for the education of residents. Residents’ and training faculty’s responses about CCE were generally positive, although their understanding of CCE criteria was low. More than 80% of the hospitals had a defibrillator and cardiopulmonary resuscitation manikin while the rarest piece of equipment was an ultrasound vessel model. Only defibrillators were used in more than half of the hospitals. Thoughts about CCE were related to various factors, such as length of employment, location of hospitals, and the number of residents per grade. Conclusions: This study’s results may be helpful in improving resident education quality to meet the expectations of both teaching faculty and residents while establishing CBE.
- Published
- 2023
21. A message from the Editor-in-Chief and Editorial Board, 2023: journal metrics and statistics, and appreciation to reviewers.
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Jun Hyun Kim and Hyun Kang
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ANESTHESIA , *PAIN medicine , *MEDICAL periodicals , *PUBLISHED articles , *MANUSCRIPTS - Published
- 2024
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22. Medieval literature and Utopia : A Study on ‘fabliau Cocagne’ (I)
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Jun-hyun Kim
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General Medicine - Published
- 2023
23. Messages from the new Editor-in-Chief and Editorial Board, journal metrics and statistics, and appreciation to reviewers
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Jun Hyun Kim and Hyun Kang
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General Medicine - Published
- 2023
24. Rapid incorporation of gold nanoparticles onto graphene oxide-polymer nanofiber membranes for photothermally-accelerated water purification
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Jian Hou, Jaehan Yun, Wongi Jang, Bin Li, Adewale Adedayo Adehinmoye, Jun-Hyun Kim, and Hongsik Byun
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Polymers and Plastics ,General Chemical Engineering ,Materials Chemistry - Abstract
This work demonstrates the rapid coating of gold nanoparticles (AuNPs) onto electrospun composite polyacrylonitrile (PAN) nanofibers containing a large amount of graphene oxide (GO) and reduced graphene oxide (rGO) for photothermally-driven applications. A modification of GO with a cationic surfactant greatly improves its loading efficiency into the PAN nanofibers, and the subsequent hydrazine treatment readily converts the integrated GO into rGO. Rapid loading of AuNPs onto these membranes results in measurably higher photothermal heating characteristics than the pristine PAN, GO-PAN, and rGO-PAN membranes under a solar-simulated light source. The light-induced heating properties are then utilized in the removal of organic dyes in an aqueous solution. While the GO-PAN and rGO-PAN membranes remove the dyes via physical adsorption, the AuNP-loaded membranes show an additional catalytic decomposition process, resulting in detectably faster removal rates. The degradation of the organic dyes is accelerated under a solar simulated light source due to the light-enhanced heating and photocatalytic properties of the integrated AuNPs. The ability to maximize the dual properties of these membranes can greatly reduce toxic organic pollutants, which can lead to the development of practical water purification systems under sunlight irradiation.
- Published
- 2022
25. LayerFish: Bimanual Layering with a Fisheye In-Place.
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Andrew M. Webb, Andruid Kerne, Zach Brown, Jun-Hyun Kim, and Elizabeth Kellogg
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- 2016
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26. Severe pulmonary edema occurred during endobronchial ultrasound under monitored anesthesia care - A case report -.
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Hwan Yong Choi, Hyung Koo Kang, Min Hee Heo, Sang Il Lee, Ji Yeon Kim, Kyung-Tae Kim, Jang Su Park, Won Joo Choe, Kyung Woo Kim, and Jun Hyun Kim
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PULMONARY edema ,ANESTHESIA ,BRONCHOSCOPES ,ULTRASONIC imaging ,PREOPERATIVE period - Abstract
Background: Endobronchial ultrasound (EBUS) is widely used to diagnose lung cancer. Monitored anesthesia care (MAC) can enhance patient comfort and procedural conditions during EBUS. EBUS under MAC is usually safe but can lead to various complications. Case: A 34-year-old male who had increased sputum for two months showed an enlarged paratracheal lymph node and planned for lymph node biopsy by EBUS. During EBUS under MAC, an unexpected oxygen saturation decline required intervention. After intubation, copious frothy fluid was suctioned from the bronchi, and oxygenation was recovered. A narrowed trachea and the EBUS bronchoscope might have resulted in upper airway obstruction, and suction performed under these conditions might have caused pulmonary edema. The patient received non-invasive ventilation and high-flow nasal cannula and recovered without complications. Conclusions: When there is an expected risk of upper airway obstruction during EBUS, careful preoperative evaluation and preparation are essential to prevent negative pressure pulmonary edema. [ABSTRACT FROM AUTHOR]
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- 2023
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27. Superoleophobic polyketone nanofiber membranes for efficient separation of oil/water emulsions
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Jian Hou, Jinwon Choi, Jaehan Yun, Wongi Jang, Jun-Hyun Kim, and Hongsik Byun
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Biomaterials ,Renewable Energy, Sustainability and the Environment ,Materials Chemistry ,Energy Engineering and Power Technology - Published
- 2023
28. Utilizing EEG and fNIRS for the detection of sleep-deprivation-induced fatigue and its inhibition using colored light stimulation
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Zeshan Shoaib, Arbab Akbar, Eung Soo Kim, Muhammad Ahmad Kamran, Jun Hyun Kim, and Myung Yung Jeong
- Subjects
Multidisciplinary - Abstract
Drowsy driving is a common, but underestimated phenomenon in terms of associated risks as it often results in crashes causing fatalities and serious injuries. It is a challenging task to alert or reduce the driver’s drowsy state using non-invasive techniques. In this study, a drowsiness reduction strategy has been developed and analyzed using exposure to different light colors and recording the corresponding electrical and biological brain activities. 31 subjects were examined by dividing them into 2 classes, a control group, and a healthy group. Fourteen EEG and 42 fNIRS channels were used to gather neurological data from two brain regions (prefrontal and visual cortices). Experiments shining 3 different colored lights have been carried out on them at certain times when there is a high probability to get drowsy. The results of this study show that there is a significant increase in HbO of a sleep-deprived participant when he is exposed to blue light. Similarly, the beta band of EEG also showed an increased response. However, the study found that there is no considerable increase in HbO and beta band power in the case of red and green light exposures. In addition to that, values of other physiological signals acquired such as heart rate, eye blinking, and self-reported Karolinska Sleepiness Scale scores validated the findings predicted by the electrical and biological signals. The statistical significance of the signals achieved has been tested using repeated measures ANOVA and t-tests. Correlation scores were also calculated to find the association between the changes in the data signals with the corresponding changes in the alertness level.
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- 2023
29. The Role of the Campus Outdoor Environment on University Student Mental Health
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Mallory Koning, Jun-Hyun Kim, Fatemeh Saeidi-Rizi, and Noah Durst
- Abstract
Background and objective The mental health and wellness of university students has been a pressing concern in recent years in the US and is becoming an even larger issue due to the COVID-19 Pandemic. Numerous studies have supported the idea that the natural environment can have a positive impact on mental health, but only a few studies focus on the role of university outdoor campus environments on student’s mental health. The main purpose of this study is to investigate the correlations between university student mental health and their campus’s outdoor environment. Methods An online survey was designed and distributed to students at Michigan State University, USA. Students were asked questions about their overall mental well-being, as well as questions about their environmental perceptions, outdoor activity, views to nature through windows and safety concerns regarding their outdoor campus environment. Results The major findings indicate a significant difference in mental health scores for windows in living quarters, where students with living quarter windows had better mental health scores (MHS) than students without living quarter windows. This study also found a marginally significant difference in MHS for students with classroom windows. Other results of this study include a significant difference in MHS for students’ perception of safety on campus, outdoor work time, and perception of greenspace on campus. Conclusion Future campus planner, landscape architects, university planners, and student counselors will use this study to determine what kinds of outdoor spaces should be created and used to improve the well-being of students.
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- 2022
30. Co‐substrate‐fed microbial fuel cell for enhanced power generation and removal of groundwater contaminants
- Author
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Hyeong Jae Kim, Jun Hyun Kim, Yongwon Jeon, and Sunghyun Kim
- Subjects
General Chemistry - Published
- 2022
31. INTERDISCIPLINARY AND DISCIPLINARY LEARNING IN HIGHER EDUCATION: A DIAGNOSTIC STUDY WITH FOUR ACCREDITED PROGRAMS IN THE SUSTAINABLE BUILT ENVIRONMENT
- Author
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Eva Kassens-Noor, Suk-Kyung Kim, Jun-Hyun Kim, Sinem Mollaoglu, Rabia Faizan, Huiqing Huang, and Travis Decaminada
- Subjects
Environmental Engineering ,Geography, Planning and Development ,Architecture ,Public Health, Environmental and Occupational Health ,Building and Construction ,Management, Monitoring, Policy and Law ,General Environmental Science ,Civil and Structural Engineering ,Nature and Landscape Conservation - Abstract
Interdisciplinarity is a critical component of creating a more sustainable built environment and improving student learning outcomes. Yet, learning interdisciplinarity and measuring it in higher education is challenging. This study implemented a diagnostic tool that allowed educators to measure how both disciplinary and interdisciplinary skills, knowledge, and values would grow in courses related to sustainable built environments. One school containing four different disciplines devoted to the built environment, was selected as the study area to collect emprical data. Pre- and post-semester surveys were conducted. Among 286 students, interdisciplinarity grew most among students within the school’s majors, while among students from outside the school majors interdisciplinary learning decreased. Though disciplinary learning outpaces interdisciplinary learning the closer students are to earning their bachelor’s or higher degrees. The result showed that students’ knowledge, values and skills differ depending on the majors, their affiliational context, and the year of classification. The result suggests that the timing of teaching interdisciplinary contents should be earlier. The diagnostic tool which measured pre- and post- course disciplinary and interdisciplinary knowledge, skills, and values related to sustainable built environment would also be applicable in other courses in higher education.
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- 2022
32. The Reclamation of an Industrial Site and Design Impacts on Environmental, Social, and Economic Resilience
- Author
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Brooke Shevela, Jun-Hyun Kim, Wonmin Sohn, and Noah Durst
- Abstract
Background and objective The industrial crisis in Michigan, USA calls for the redevelopment of abandoned industrial sites into functioning public spaces. Neglected spaces have negative impacts on the surrounding communities, promoting aesthetic, safety, economic, and environmental issues. The purpose of this study was to explore and discuss the possible redevelopment of an underused site, with particular focus on its industrial site elements; quantitative measures were then applied to determine redevelopment's effects on the nearby community. Methods The Michigan Central Station in Detroit, Michigan, USA was selected as a case study. Landscape performance research methods were applied to quantitatively analyze the environmental, social, and economic benefits of reclaiming this abandoned industrial site and its various elements. Results The findings show that implementing the case study redesign would result in positive environmental impacts. These impacts include expanded areas of ecologically valuable land, a reduction in sulfur dioxide, and increases in carbon sequestration, retained stormwater, and the use of recycled contents. The case study redevelopment project would impact the surrounding economic context through savings on water treatment costs obtained from the use of retained stormwater, increased property values, and job creation. Furthermore, the redesign would also impact social aspects by increasing the available gathering spaces and public open areas and enhancing safety by adding sidewalks and bike lanes. Conclusion The findings of this study will help designers and planners recognize the value of reusing existing industrial sites instead of undertaking harmful demolition processes, eventually leading to more sustainable community designs.
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- 2022
33. Two cases of late-onset cardiovascular toxicities after a single injection of local anesthetics during supraclavicular brachial plexus block - A report of two cases
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Ji Yeon Kim, Beom Il Park, Min Hee Heo, Kyoung Woo Kim, Sang-Il Lee, Kyung-Tae Kim, Won Joo Choe, Jang Su Park, and Jun Hyun Kim
- Subjects
General Medicine - Abstract
Background: Local anesthetics systemic toxicity (LAST) is a grave complication of regional anesthesia that usually occurs immediately after local anesthetics injection. Here, we report on rare late-onset toxicity cases after supraclavicular brachial plexus blocks.Case: Two patients underwent surgery for radius fractures. We used lidocaine 100 mg and ropivacaine 150 mg for blocking and infused dexmedetomidine for intraoperative sedation. The 63-year-old male patient’s blood pressure dropped to 87/60 mmHg after 3 h 15 min after blocking. Ventricular fibrillation occurred 10 min later. After five defibrillations, electrocardiography showed ventricular tachycardia that was normalized through one cardioversion. The 54-year-old female patient’s heart rate decreased to 35 beats/min 2 h 30 min after blocking. Her vital signs returned to normal after administering atropine, ephedrine, epinephrine, and lipid emulsion.Conclusions: Physicians should remember that LAST may occur long after local anesthetic injection and be aware of factors that may adversely affect the course of LAST.
- Published
- 2022
34. Controlling the formation of encapsulated gold nanoparticles for highly reactive catalysts in the homocoupling of phenylboronic acid
- Author
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Wongi Jang, Pascal N. Eyimegwu, Jaehan Yun, Jun-Hyun Kim, Jian Hou, and Hongsik Byun
- Subjects
Reaction rate ,chemistry.chemical_compound ,Chemical engineering ,Reducing agent ,Chemistry ,Colloidal gold ,Composite number ,General Chemistry ,Activation energy ,Phenylboronic acid ,Selectivity ,Catalysis - Abstract
The reduction of gold ions using four different types of mild reducing agents was carried out in the presence of poly(n-isopropylacrylamide), PNIPAM, particles under light irradiation at room temperature. Simply controlling the concentration ratios of the gold ions to reductants allowed for the systematic formation of physically encapsulated gold nanoparticles (AuNPs) within the PNIPAM particles due to the presence of weak interactions between the guest AuNPs and host PNIPAM particles. After the examination of the structural and physical properties of the AuNPs and their loading efficiency, the composite particles were extensively utilized in the aerobic homocoupling of phenylboronic acid in EtOH to examine their catalytic properties associated with the rate of reaction, selectivity, and activation energy (Ea). All composite particles showed the highly selective formation of the biphenyl product and comparable Ea values, regardless of the size and distribution of the encapsulated AuNPs as catalysts. However, the way the AuNPs were formed within the PNIPAM particles notably influenced the rate of reaction. As such, developing a simple approach to optimize the encapsulation degree of AuNPs and their structural features in the presence of polymer particles can be applied to designing diverse metal-polymer composite particles for rapid and effective catalytic systems.
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- 2022
35. Catatonia associated with prolonged stupor after general anesthesia in a patient with multiple neuropsychiatric disorders - a case report
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Sungwon Baek, Min Hee Heo, Kyung Woo Kim, Sang Il Lee, Kyung-Tae Kim, Jang Su Park, Won Joo Choe, Jun Hyun Kim, and Ji Yeon Kim
- Subjects
Anesthesiology and Pain Medicine - Published
- 2023
36. Application of k-Means Clustering to Material Research: Measurement of Layer Thickness and Contact Angle
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Dong-Jun Lee, Yong-Min Cho, Jun Hyun Kim, In-Jun Hwang, Yongsug Chung, and Youn-Bae Kang
- Subjects
Mechanics of Materials ,Materials Chemistry ,Metals and Alloys ,Condensed Matter Physics - Published
- 2023
37. Electric field enhancement of coupled plasmonic nanostructures for optical amplification
- Author
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Jun Hyun Kim, Ja Yeon Lee, Eung Soo Kim, and Myung Yung Jeong
- Subjects
Electrical and Electronic Engineering ,Engineering (miscellaneous) ,Atomic and Molecular Physics, and Optics - Abstract
Plasmonic effects that enhance electric fields and amplify optical signals are crucial for improving the resolution of optical imaging systems. In this paper, a metal-based plasmonic nanostructure (MPN) is designed to increase the resolution of an optical imaging system by amplifying a specific signal while producing a plasmonic effect via a dipole nanoantenna (DN) and grating nanostructure (GN), which couple the electric field to be focused at the center of the unit cell. We confirmed that the MPN enhances electric fields 15 times more than the DN and GN, enabling the acquisition of finely resolved optical signals. The experiments confirmed that compared with the initial laser intensity, the MPN, which was fabricated by nanoimprint lithography, enhanced the optical signal of the laser by 2.24 times. Moreover, when the MPN was applied in two optical imaging systems, an indistinguishable signal that was similar to noise in original was distinguished by amplifying the optical signal as 106 times in functional near-infrared spectroscopy(fNIRS), and a specific wavelength was enhanced in fluorescence image. Thus, the incorporation of this nanostructure increased the utility of the collected data and could enhance optical signals in optics, bioimaging, and biology applications.
- Published
- 2023
38. Plasma etching of SiO2 contact hole using perfluoropropyl vinyl ether and perfluoroisopropyl vinyl ether
- Author
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Sanghyun You, Jun-Hyun Kim, and Chang-Koo Kim
- Subjects
General Chemical Engineering ,General Chemistry - Published
- 2022
39. Interstices: Sustained Spatial Relationships between Hands and Surfaces Reveal Anticipated Action.
- Author
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Andrew M. Webb, Hannah Fowler, Andruid Kerne, Galen Newman, Jun-Hyun Kim, and Wendy E. Mackay
- Published
- 2019
- Full Text
- View/download PDF
40. Anesthetic management of an elderly COVID-19 patient with pulmonary thromboembolism for hip surgery - A case report -.
- Author
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Min Hee Heo, Hwan Yong Choi, Ji Yeon Kim, Kyung Woo Kim, Sang Il Lee, Kyung-Tae Kim, Jang Su Park, Won Joo Choe, and Jun Hyun Kim
- Subjects
COVID-19 pandemic ,HEPATOCELLULAR carcinoma ,HIP surgery ,EXTRACORPOREAL membrane oxygenation ,ECHOCARDIOGRAPHY - Abstract
Background: COVID-19 and delayed hip surgery are well-known risk factors for thromboembolism in elderly patients. Case: We report the case of an 88-year-old female patient with COVID-19 and pulmonary thromboembolism (PTE) who underwent delayed hip surgery 21 days after the injury. Heparinization and inferior vena cava filters were used to treat and prevent PTE. Transesophageal echocardiography and extracorporeal membrane oxygenation (ECMO) sheaths were inserted as a precaution in case of emergencies during surgery; the procedure was performed without any specific event. Conclusions: COVID-19-infected patients suffering from a hip fracture have a high risk of thromboembolism, and therefore, require utmost attention for appropriate evaluation and prevention. [ABSTRACT FROM AUTHOR]
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- 2023
- Full Text
- View/download PDF
41. Comments in Web Novels and the Subjectivity of the Readers
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Jun-hyun Kim
- Subjects
General Medicine - Published
- 2021
42. Histological and molecular biological analysis on the reaction of absorbable thread; Polydioxanone and polycaprolactone in rat model
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Eun Soo Park, Young In Ha, and Jun Hyun Kim
- Subjects
biology ,Chemistry ,Polyesters ,Rat model ,food and beverages ,Dermatology ,Thread (computing) ,Transforming growth factor beta ,Rats ,Skin Aging ,chemistry.chemical_compound ,Polydioxanone ,medicine.anatomical_structure ,Polycaprolactone ,Rhytidoplasty ,Threading (manufacturing) ,biology.protein ,medicine ,Animals ,Collagen ,Fibroblast ,Myofibroblast ,Biomedical engineering - Abstract
INTRODUCTION One of the most frequently performed anti-aging surgical procedures is thread facelift. Since the 2010s, thread lifts using absorbable polydioxanone (PDO) thread were developed and have become increasingly popular. This research aims to identify the changes in and the mechanisms of absorbable thread-lifting components, namely, PDO (polydioxanone) and PCL (polycaprolactone), with varied absorption periods in the body. METHODS Four different types of threads, namely, single-stranded thread, 4-stranded thread, 12-stranded thread, and barbed Cog thread, were used for each component. Histological changes in the thread and neighboring tissue of rat model were investigated for 2-week interval, and PCR was conducted for genes related to fibroblast proliferation including type 1α1 collagen, type 3α1 collagen, transforming growth factor beta 1 (TGF-β1). RESULTS An increase in the collagen formation in all types of PDO and PCL groups was observed during the first 12 weeks and decreased afterward. Collagen formation decreased later in the PCL thread group significantly than the POD group. PCL thread remained logner in the tissue for over a year regarding POD requiring around 24 weeks of absorption-degradation. A larger surface area between the thread and the tissue induces a greater response in the tissue, resulting in an increase in inflammatory cells, myofibroblasts, and fibroblasts. Results showed a similar pattern of increase in type 1α1 collagen and TGF-β in the PDO thread group. This suggests that TGF-β signal transduction leads to fibroblast proliferation that stimulates collagen formation and tissue re-formation. In contrast, only type 3α1 collagen increased in the PCL thread group. CONCLUSION More collagen formation and tissue responses are induced by PCL thread, remaining longer in the tissue than PDO, leading to more tissue tightening effects that is one of the most important points of face lifting. Morphological comparison of threads shows that not only an increase in surface area between thread and tissue but also multi-strand increase tissue response, which in turn increases tissue maintenance effects.
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- 2021
43. Noninvasive Ventilation for Acute Respiratory Failure in Pediatric Patients: A Systematic Review and Meta-Analysis
- Author
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Daniele Boghi, Kyung Woo Kim, Jun Hyun Kim, Sang-Il Lee, Ji Yeon Kim, Kyung-Tae Kim, Andrea Ambrosoli, Giovanni Guarneri, Giovanni Landoni, and Luca Cabrini
- Subjects
Pediatrics, Perinatology and Child Health ,Critical Care and Intensive Care Medicine - Abstract
To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) on the use of noninvasive ventilation (NIV) for acute respiratory failure (ARF) in pediatric patients.We searched PubMed, EMBASE, the Cochrane Central Register of Clinical Trials, and Clinicaltrials.gov with a last update on July 31, 2022.We included RCTs comparing NIV with any comparator (standard oxygen therapy and high-flow nasal cannula [HFNC]) in pediatric patients with ARF. We excluded studies performed on neonates and on chronic respiratory failure patients.Baseline characteristics, intubation rate, mortality, and hospital and ICU length of stays were extracted by trained investigators.We identified 15 RCTs (2,679 patients) for the final analyses. The intubation rate was 109 of 945 (11.5%) in the NIV group, and 158 of 1,086 (14.5%) in the control group (risk ratio, 0.791; 95% CI, 0.629-0.996; p = 0.046; I2 = 0%; number needed to treat = 31). Findings were strengthened after removing studies with intervention duration shorter than an hour and after excluding studies with cross-over as rescue treatment. There was no difference in mortality, and ICU and hospital length of stays.In pediatric patients, NIV applied for ARF might reduce the intubation rate compared with standard oxygen therapy or HFNC. No difference in mortality was observed.
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- 2022
44. The Cognition of Censorship after the disbandment of KAPF
- Author
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Jun-hyun Kim
- Subjects
Psychoanalysis ,media_common.quotation_subject ,Censorship ,Cognition ,Psychology ,media_common - Published
- 2021
45. Cooling ranges for urban heat mitigation: continuous cooling effects along the edges of small greenspaces
- Author
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Ming-Han Li, Jun-Hyun Kim, Wonmin Sohn, and Jonghoon Park
- Subjects
Ecology ,Temperature sensing ,Air temperature ,Environmental science ,Radius ,Management, Monitoring, Policy and Law ,Urban heat island ,Atmospheric sciences ,Transect ,Cooling down ,Design guide ,Nature and Landscape Conservation ,Degree (temperature) - Abstract
This study assessed the cooling ranges of small greenspaces (SGs) along the edges of surrounding areas and identified the spatial cooling distance threshold. Five SGs in a natural preserved public area located in College Station, Texas, USA, and a reference site (Rf) were selected for this study. Air temperature data collection took six rounds from fall to early summer. In each round air temperature was collected three times during a day (i.e., 10 h, 13 h, and 16 h). Temperature sensing units (TVCs) and loggers recorded air temperature every second via a transect survey. The cooling distance was determined according to each SG’s radius: (1) the centroid of the SG (GC), (2) the edge of the SG (GE), (3) 1.25 times the radius away from the GC (1.25R), and (4) 1.5 times the radius away from the GC (1.5R). Our findings showed the SGs’ cooling effect (∆TRf−i) surpassed their edges in general. The cooling degrees at the GC were higher and dropped continuously from the GE to 1.25R ending with 1.5R showing the lowest. In fall, the SGs’ mean cooling degree exceeded 9.24% at 1.5R compared to Rf. In early summer, the SGs’ mean cooling effects decreased significantly while showing a very small difference between the measurement points. Our findings contribute to uncovering some specific design features with SGs to cooling down cities by applying advanced technology. Our findings will help designers, planners, researchers, and local government officials by providing an optimal landscape planning and design guide for mitigating urban heat.
- Published
- 2021
46. Polyacrylonitrile nanofiber membranes incorporated with large reduced graphene oxide content in situ
- Author
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Jun-Hyun Kim, Wongi Jang, Hongsik Byun, Jaehan Yun, and Jian Hou
- Subjects
chemistry.chemical_classification ,Materials science ,Graphene ,Mechanical Engineering ,Polyacrylonitrile ,Oxide ,Polymer ,Photothermal therapy ,law.invention ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Mechanics of Materials ,law ,Nanofiber ,Surface modification ,General Materials Science - Abstract
This work demonstrates an effective strategy for preparing electrospun composite membranes consisting of polyacrylonitrile (PAN) nanofibers and a large amount of graphene oxide (GO) and reduced graphene oxide (rGO). Simple surface modification of GO with a cationic surfactant reliably results in the preparation of composite nanofibers as a function of GO content up to 30 wt%, which are subsequently transformed into membrane-type sheets via heat and pressure treatments. In addition, an in situ hydrazine treatment readily converts the integrated GO into rGO, which is confirmed by water contact angles, Raman, XRD, and infrared thermography. These series of composite membranes are then employed in the removal of methylene blue dye with and without solar-simulated light irradiation. The PAN–GO composite membranes possessing various oxygen-containing functional groups initially display higher decontamination capability of the dyes than PAN–rGO. Both composite membranes notably improve the removal of the dyes to over 90% in 3 h under the light irradiation where the degree of removal efficiency for the PAN–rGO composite membrane is detectably increased due to its enhanced photothermal heating property. Although integrating GO derivatives into polymer nanofibers is a challenging task due to their limited dispersity and miscibility, our developed approach readily results in the systematic loading of GO and rGO at a high-level content into PAN nanofiber membranes, allowing us to realize their general properties including photothermal heating properties for various applications.
- Published
- 2021
47. Epidural analgesia versus intravenous analgesia after minimally invasive repair of pectus excavatum in pediatric patients: a systematic review and meta-analysis
- Author
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Kyung Tae Kim, Jun Hyun Kim, Kyung Woo Kim, Min Hee Heo, Jung Hyeon Kim, Sang Il Lee, Ji Yeon Kim, Won Joo Choe, and Jang Su Park
- Subjects
medicine.medical_specialty ,Visual analogue scale ,Epidural analgesia ,Analgesic ,MEDLINE ,law.invention ,Intravenous administration ,Postoperative pain ,Randomized controlled trial ,Pectus excavatum ,Minimally invasive surgical procedures ,Anesthesiology ,law ,Medicine ,Humans ,Pain Management ,RD78.3-87.3 ,Child ,Clinical Research Article ,Pain, Postoperative ,business.industry ,Statistics ,Area under the curve ,medicine.disease ,Analgesia, Epidural ,Thoracic surgery ,Anesthesiology and Pain Medicine ,Cardiothoracic surgery ,Meta-analysis ,Anesthesia ,Funnel Chest ,Systematic review ,business - Abstract
Background Postoperative pain control after the minimally invasive repair of pectus excavatum (MIRPE) is essential, but there is a controversy about a better analgesic method between epidural and intravenous (IV) analgesia. This systematic review and meta-analysis aimed to compare the effect of epidural versus IV analgesia following MIRPE. Methods We searched PubMed, MEDLINE, EMBASE, Cochrane Central Register, and ClinicalTrials.gov for randomized control trials (RCTs) dated up to 31st May 2021. The primary outcome was the area under the curve (AUC) of the weighted mean visual analog scale (VAS) after MIRPE. The secondary outcomes were postoperative nausea, operation time, total operating room time, and postoperative length of hospital stay. Results Four RCTs involving 243 patients were finally included in this meta-analysis. The AUC of the weighted mean VAS was 343.62 in the epidural group and 375.24 in IV group. Epidural group showed lower VAS than IV group at 12 hours (mean difference -0.99 [95% CI: -1.52, -0.47], P = 0.001, I2 = 0%), at 24 hours (mean difference -0.65 [95% CI: -1.15, -0.16], P = 0.009, I2 = 0%), and 48 hours (mean difference -0.81 [95% CI: -1.61, -0.01], P = 0.046, I2 = 46%) after the surgery. Conclusion Epidural analgesia after the MIRPE had a better analgesic effect than IV analgesia from 12 hours to 48 hours after surgery, and AUC of VAS was lower in the epidural group. However, IV analgesia may also be a viable option, and physicians should wisely choose analgesic modalities after MIRPE.
- Published
- 2021
48. Successful anesthetic management of a giant lower lip hemangioma patient using high flow nasal cannula -a case report
- Author
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Won Joo Choe, Hangaram Kim, Sang Il Lee, Jun Hyun Kim, Ji Yeon Kim, Kyung Tae Kim, Kyung Woo Kim, Min Hee Heo, and Jang Su Park
- Subjects
medicine.medical_specialty ,medicine.medical_treatment ,Continuous positive airway pressure ,General anesthesia ,Case Report ,Airway management ,medicine.disease_cause ,Hemangioma ,Anesthesiology ,medicine ,Intubation ,Cannula ,RD78.3-87.3 ,Mouth neoplasm ,business.industry ,Mouth neoplasms ,medicine.disease ,Surgery ,Anesthesiology and Pain Medicine ,business ,Propofol ,Nasal cannula ,medicine.drug - Abstract
Background: Giant lip hemangioma is a rare disease that may cause difficulty in preoxygenation and ventilation when using face masks and intubation during general anesthesia induction.Case: A laparoscopic cholecystectomy was planned for a 77-year-old woman. The patient had a giant lower lip hemangioma that was 12 x 5 x 5 cm, which made preoxygenation and ventilation through a face mask impossible and put her at risk of hemangioma rupture. We preoxygenated her through a high-flow nasal cannula (HFNC). Following propofol and succinylcholine administration, we intubated the patient with a video laryngoscope without desaturation, hemangioma rupture, or CO2 retention. Conclusions: HFNC is a useful tool when difficult intubation is expected in patients who have problems using conventional face masks.
- Published
- 2021
49. A split-face study evaluating the efficacy of a topical antioxidant cream containing tocotrienol after 1064-nm picosecond Nd:YAG laser treatment for environment-induced skin pigmentation
- Author
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Jun Hyun Kim, Seung Min Nam, Eun Soo Park, and Moon Seok Kang
- Subjects
Antioxidant ,RD1-811 ,business.industry ,medicine.medical_treatment ,General Medicine ,Laser ,laser ,law.invention ,chemistry.chemical_compound ,antioxidants ,chemistry ,law ,Picosecond ,Nd:YAG laser ,medicine ,pigmentation ,Surgery ,Tocotrienol ,business ,Biomedical engineering - Abstract
Background This study aimed to evaluate the efficacy and safety of a topical antioxidant cream containing tocotrienol after 1064-nm picosecond neodymium-doped yttrium aluminum garnet (Nd:YAG) laser treatment for environment-induced skin pigmentation.Methods A split-face study was conducted between December 2020 and March 2021 in 26 patients (25 women and one man) who were treated with a 1064-nm picosecond Nd:YAG laser. On the right side of the face, an antioxidant cream containing tocotrienol was applied after picosecond laser treatment, and on the left side, only picosecond laser treatment was performed. We compared the right and left sides of the face at 4 weeks after laser treatment using an automatic skin analysis device to investigate skin pigmentation. The melasma severity scores of the two sides were evaluated before and 4 weeks after picosecond laser treatment.Results The skin pigmentation score showed a significant difference between pretreatment and 4 weeks after picosecond laser treatment on both sides of the face (P0.05).Conclusions Our results show that, for the treatment of environment-induced skin pigmentation, the application of a tocotrienol-containing antioxidant cream after 1064-nm picosecond laser treatment can provide good results without any complications.
- Published
- 2021
50. Electric field enhancement of coupled Plasmonic nanostructure for optical amplification
- Author
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Jun Hyun Kim, Ja Yeon Lee, Eung Soo Kim, and Myung Yung Jeong
- Abstract
In this paper, proposed plasmonic nanostructure is designed to increase the spatial resolution of optical imaging system by amplifying a specific signal while producing a plasmonic effect via a nanoantenna and grating nanostructure. We utilized antenna theory and grating structure to enable the surface plasmon effect and coupling electric field to be focused center of unit cell and enhance the optical signal of 785 nm wavelength. We confirmed that a proposed plasmonic nanostructure can be used to enhance electric fields in specific angle of incident light, 30° and attain a far-field gain of 1137, enabling a more finely resolved optical signal to be obtained. In experiment, the proposed plasmonic nanostructure was confirmed to enhance optical signal of laser by 2.24 times and also confirmed enhancing electric field using AFM. Moreover, when applied in functional near-infrared spectroscopy and fluorescence imaging systems, it was confirmed that an indistinguishable signal can be distinguished by amplifying the optical signal 76 times, and a specific wavelength can also be enhanced. Accordingly, the incorporation of these nanostructures should increase the utility of the collected data and enhance optical signals for applications in optics, bioimaging, and biology.
- Published
- 2022
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