413 results on '"Jong-In Shim"'
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2. GaAs-based red micro-light-emitting diodes with an oxide perimeter region for improved external quantum efficiency
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Sangjin Min, Won-Jin Choi, Dong Hwan Kim, Keuk Kim, Jaehyeok Park, Han-Youl Ryu, Jong-In Shim, and Dong-Soo Shin
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Physics ,QC1-999 - Abstract
Red micro-light-emitting diodes (μ-LEDs) with AlGaInP/GaInP multiple quantum wells are fabricated with an oxide perimeter region to control the current injection path. When the values of the external quantum efficiency (EQE) of the 30 μm-size μ-LED with the oxide perimeter region are compared with those of the device without the oxide perimeter region, an improvement as high as 40% is observed at current densities
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- 2024
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3. Investigation into charge carrier dynamics in organic light-emitting diodes
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Dong-Guang Zheng, Hyeon-Dong Lee, Gyeong Won Lee, Dong-Soo Shin, Jeongwon Kim, Jong-In Shim, Zhiqun Lin, Tae-Woo Lee, and Dong Ha Kim
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organic light-emitting diodes ,ideality factor ,carrier transport processes ,degradation mechanism ,Chemistry ,QD1-999 ,Physics ,QC1-999 - Abstract
Organic light-emitting diodes (OLEDs) have demonstrated remarkable advancements in both device lifetime and luminous efficiency. However, insufficient operation lifetime due to device degradation remains a major hurdle, especially for brighter devices. Understanding the degradation mechanisms of OLEDs due to the degradation of functional materials and the formation of defects in device architectures continues to be a significant challenge. Herein, we evaluate the degradation characteristics by scrutinizing the electrical and optical properties, as well as analyzing the charge carrier dynamics in pristine and aged states of phosphorescent OLEDs (PhOLEDs). We show that degradation mechanisms in PhOLEDs can be elucidated in terms of the ideality factors of current and luminance in pristine and aged device states. The consistent shifts in distinct ideality factors across various states points out that the device degradation is attributed to the deterioration of the guest material, i.e. green-light-emitting phosphorescent material. Conversely, the incongruity in ideality factor changes between the two states indicates that the degradation results from the deterioration of non-light-emitting material. Subsequent characterization experiments provide further evidence that this degradation is primarily attributed to the deterioration of CBP-host material. The thorough understanding of degradation mechanisms established in this study can contribute to realizing the highly reliable PhOLEDs with a long lifetime.
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- 2024
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4. A next-generation light-emitting device: ZOGAN LED with a heterogeneous p-layer composed of oxide and nitride semiconductors
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Yung Ryel Ryu, Sung Ki Hong, E. Fred Schubert, Dong-Min Jeon, Dong-Soo Shin, Jong-In Shim, Sang-Mook Kim, and Jong Hyeob Baek
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Physics ,QC1-999 - Abstract
We have developed a light-emitting device, called the ZOGAN light-emitting diode (LED). The ZOGAN LED is formed with the p-layer composed of both ZnO-based oxide and GaN-based nitride semiconductors. The ZOGAN LED shows the characteristics of light-emitting devices required for ultra-high-resolution displays.
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- 2024
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5. Extracting the inherent ideality factor of a diode from electrical current–voltage characteristics
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Jaehyeok Park, Chaeyoon Yu, Sangjin Min, Jong‐In Shim, and Dong‐Soo Shin
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diodes ,light‐emitting diodes ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Abstract The ideality factor of a diode gives the information on the current conduction or recombination processes occurring inside the device. The ideality factor obtained from the electrical current–voltage (I–V) characteristics by the conventional method is typically masked by the effect of the series resistance at high currents. In this study, from a careful analysis of the I–V characteristics, a new formula that can extract the inherent ideality factor without the effect of the series resistance is presented and experimentally tested with a blue light‐emitting diode. The new ideality factor thus obtained is compared with the one by the photovoltaic measurement.
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- 2023
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6. Enhanced Light Emission from Type-II Red InGaN/GaNSb/GaN Quantum-Well Structures
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Seoung-Hwan Park, Jong-In Shim, and Dong-Soo Shin
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Physics ,QC1-999 - Abstract
Electronic and optical properties of type-II InGaN/GaNSb/GaN quantum-well (QW) structures are investigated by using the multiband effective mass theory for potential applications in red light-emitting diodes. The heavy-hole effective mass around the topmost valence band is not affected much by the insertion of the GaNSb layer, and the optical matrix elements are greatly increased by the inclusion of the GaNSb layer in the InGaN/GaN QW structure. As a result, the type-II InGaN/GaNSb/GaN QW structure shows a much larger emission peak than the conventional type-I QW structure owing to the decrease in spatial separation between electron and hole wavefunctions, in addition to the reduction of the effective well width. It is also observed that the In content in InGaN well can be significantly reduced for the type-II QW structure with a large Sb content, compared to that for the type-I QW structure.
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- 2022
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7. Analysis of Transient Degradation Behaviors of Organic Light-Emitting Diodes under Electrical Stress
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Gyeong Won Lee, Yoonsuk Choi, Heejin Kim, Jongwoo Park, Jong-In Shim, and Dong-Soo Shin
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organic light-emitting diodes ,degradation ,transient ,charge recombination and transport ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Despite the wide application of organic light-emitting diodes (OLEDs), the performance of OLED devices is sometimes limited by their reliabilities. In this paper, we report the transient degradation behaviors of fluorescent blue OLEDs, where both the current and luminance initially increase under electrical stress within a short stress time. We analyze the degradation mechanism in terms of the carrier recombination and transport. From the comprehensive analyses of electrical and optical characteristics, it is suggested that the electron transport is responsible for the initial transient behavior of the device.
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- 2021
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8. Recycling cathode materials for lithium-ion batteries via Hydro-to-Cathode® method
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Jong Hyun Shim
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recycling ,lithium-ion battery ,Hydro-to-Cathode® ,cathode material ,closed-loop system ,Industrial electrochemistry ,TP250-261 - Abstract
Due to the rising price and limited resource supply chain of Li [NixMnyCoz]O2 (x + y + z = 1) (NMC) cathode material, lithium-ion battery (LIB) recycling technologies have been emerging as the best solution to address the price issue. Mainly, conventional hydrometallurgy processes have been applied to the LIB recycling field in recognition of its value. One remarkable advantage of the hydrometallurgy method is that it serves as a bridge to enable the Hydro-to-Cathode® method. However, using recycled raw materials in the production of precursor cathode materials needs to be studied in parallel with the impurity (dopant) effect. The insufficient selective impurity removal technology leads to unexpected electrochemical properties in the final NMC cathode active material, which can be doped by several different impurities. Consequently, scrutinizing dopant elements (inorganic and organic) is critical if we want to consider the Hydro-to-Cathode® method as a major recycling process of NMC cathode material.
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- 2025
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9. Enhanced Radiative Recombination Rate by Local Potential Fluctuation in InGaN/AlGaN Near-Ultraviolet Light-Emitting Diodes
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Abu Bashar Mohammad Hamidul Islam, Dong-Soo Shim, and Jong-In Shim
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light-emitting diodes ,indium composition ,defects ,piezoelectric field ,potential fluctuation ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
We investigate the differences in optoelectronic performances of InGaN/AlGaN multiple-quantum-well (MQW) near-ultraviolet light-emitting diodes by using samples with different indium compositions. Various macroscopic characterizations have been performed to show that the strain-induced piezoelectric field (FPZ), the crystal quality, and the internal quantum efficiency increase with the sample’s indium composition. This improved performance is owing to the carrier recombination at relatively defect-free indium-rich localized sites, caused by the local in-plane potential-energy fluctuation in MQWs. The potential-energy fluctuation in MQWs are considered to be originating from the combined effects of the inhomogeneous distribution of point defects, FPZ, and indium compositions.
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- 2019
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10. Hemi-Percutaneous Epiphysiodesis Using Transphyseal Screws at Lateral Proximal Tibias After Epiphyseal Fusion of Distal Phalanges in the Hand Results in Undercorrection of Genu Varum
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Kyung Rae Ko, Jae Woo Shim, Jong Sup Shim, Dong Suk Kim, and Soonchul Lee
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coronal plane alignment ,genu varum ,tibia vara ,epiphysiodesis ,hemiepiphysiodesis ,transphyseal screw ,Medicine (General) ,R5-920 - Abstract
Background and Objectives: To investigate postoperative courses after hemi-percutaneous epiphysiodesis using transphyseal screws (PETS) for genu varum. We especially focused on the degree of skeletal maturation that results in undercorrection. Materials and Methods: We identified patients with idiopathic genu varum treated with hemi-PETS at the proximal tibia and followed-up to the completion of skeletal maturation. The acceptable correction was defined as the (1) final deformity < varus 1.0° or (2) final correction angle obtained by surgery (f-CA) > mean value of preoperative deformity. Results: In our cohort of 29 patients and their 29 lower limbs (one side was randomly selected in bilateral cases), the mean hip–knee–ankle (HKA) alignment was varus 6.5 ± 1.3° at the time of hemi-PETS. The mean f-CA was 5.8 ± 2.0° with a rebound of 0.3 ± 1.0°. Ten patients showed the finding of partial or complete fusion of the epiphysis of distal phalanges in the hand at the time of hemi-PETS (the fusion group, FG). Their f-CA was 4.0 ± 1.9° (with preoperative deformity of 6.9 ± 1.4°), which was significantly smaller than that (6.7 ± 1.3°, p = 0.001) of remaining 19 patients (the open group, OG). The acceptable correction was obtained in all 19 patients of the OG. Otherwise, it was obtained in two patients in the FG (p < 0.001). The other two patients in the FG preoperatively showed a complete epiphyseal fusion of the distal phalanges in the hand, and their f-CA was 0.7 and 1.1°, respectively. Conclusions: The degree of skeletal maturation corresponding to epiphyseal fusion of distal phalanges in the hand results in undercorrection after the hemi-PETS performed at the proximal tibia for genu varum.
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- 2024
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11. EAM-integrated DBR-LD with 16-channel and 100-Gbps/λ PAM-4 modulation.
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Su Ik Park, Oh Kee Kwon, Chul Wook Lee, Ki Soo Kim, Kyung Su Park, Jae Hyun Jin, Jung Hoon Kim, and Jong In Shim
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- 2023
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12. Single-cell RNA sequencing of human nail unit defines RSPO4 onychofibroblasts and SPINK6 nail epithelium
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Hyun Je Kim, Joon Ho Shim, Ji-Hye Park, Hyun Tae Shin, Jong Sup Shim, Kee-Taek Jang, Woong-Yang Park, Kyung-Hoon Lee, Eun Ji Kwon, Hyung-Suk Jang, Hanseul Yang, Jong Hee Lee, Jun-Mo Yang, and Dongyoun Lee
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Biology (General) ,QH301-705.5 - Abstract
Kim et al. conducted single-cell RNA sequencing to determine the transcriptome profiles of human nail units using polydactyly specimens to demonstrate mesenchymal and epithelial cell populations, characterized by RSPO4 and SPINK6 respectively. RSPO4 + onychofibroblasts localized with LGR6 + nail matrix, leading to WNT/ β-catenin activation and suggesting a role for onychofibroblasts in onychomatricoma pathogenesis.
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- 2021
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13. A Comprehensive Review of Percutaneous Nephrostomy and Suprapubic Cystostomy
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Sa Hong Jo, Sang Min Lee, Jong Joon Shim, Ho Cheol Choi, Jae Boem Na, Hwa Seon Shin, Mi Jung Park, Soo Buem Cho, Sung Eun Park, and Jung Ho Jang
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kidney ,nephrostomy ,percutaneous ,urinary bladder ,cystostomy ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Percutaneous nephrostomy is widely used for the diagnosis and treatment of various urinary tract diseases, such as ureteral fistula, stenosis, and percutaneous nephrolithotomy, and the relief of urinary obstruction. Suprapubic cystostomy is also known as a good method for bladder drainage in patients with lower urinary tract obstruction or injury and neurogenic bladder. Despite the frequent use of these procedures, reports in the literature are insufficient for an interventional radiologist to understand the procedures easily and thoroughly. In this article, the indication, anatomy, placement, and postoperative management of percutaneous nephrostomy and suprapubic cystostomy have been described, explaining that the procedures are safe and effective.
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- 2019
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14. Analysis of the Effect of Tillage Depth on the Working Performance of Tractor-Moldboard Plow System under Various Field Environments.
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Yeon-Soo Kim, Sang-Dae Lee, Seung-Min Baek, Seung-Yun Baek, Hyeon-Ho Jeon, Jun-Ho Lee, Wan-Soo Kim 0002, Jong-Yeal Shim, and Yong-Joo Kim
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- 2022
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15. Understanding and evaluating the mean photon energy and the external quantum efficiency of light‐emitting diodes
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Ilgyu Choi, Sangjin Min, Jong‐In Shim, and Dong‐Soo Shin
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Electrical and Electronic Engineering ,Atomic and Molecular Physics, and Optics - Published
- 2022
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16. Theoretical studies on in-plane polarization characteristics of (11$$\bar{2}$$0) nonpolar InGaN/GaN quantum-well structures grown on InGaN substrates
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Seoung-Hwan Park, Jong-In Shim, and Dong-Soo Shin
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General Physics and Astronomy - Published
- 2022
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17. Factors Affecting Rebound Phenomenon After Temporary Hemiepiphysiodesis and Implant Removal for Idiopathic Genu Valgum in Adolescent Patients
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Kyung Rae Ko, Jong Sup Shim, Tae Soo Shin, and Min Chang Jang
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Genu Valgum ,Treatment Outcome ,Adolescent ,Genu Varum ,Pediatrics, Perinatology and Child Health ,Humans ,Orthopedics and Sports Medicine ,General Medicine ,Bone Plates ,Retrospective Studies - Abstract
The aim of this study was to investigate factors determining postoperative courses, especially focusing on the rebound phenomenon, in adolescent patients with idiopathic genu valgum who underwent temporary hemiepiphysiodesis and implant removal.We identified and reviewed patients with idiopathic genu valgum treated with temporary hemiepiphysiodesis [using tension-band plates (plate group, PG) or transphyseal screws (screw group, SG)] and followed-up to skeletal maturity.In our cohort [68 patients and their 68 limbs (randomly selected in bilateral cases)], the mean hip-knee-ankle alignment was -5.4±1.8 degrees at the time of temporary hemiepiphysiodesis (negative means valgus), 2.6±2.1 degrees at the time of implant removal, and 0.7±2.6 degrees at the last follow-up, respectively. Regarding the implants, the correction speed was not significantly different (P=0.192-0.315) between the PG (total 1.29±0.37 degrees/mo, 0.71±0.23 degrees/mo at distal femur, 0.59±0.16 degrees/mo at proximal tibia, n=19) and the SG (total 1.22±0.49 degrees/mo, 0.65±0.25 degrees/mo at distal femur, 0.57±0.23 degrees/mo at proximal tibia, n=49). The magnitude of rebound phenomenon in the PG (4.1±1.9 degrees) was greater (P0.001) than that in the SG (1.1±3.1 degrees). The use of plates and faster correction speed, rather than more severe preoperative deformity or greater correction angle, were positively associated with the rebound phenomenon in regression analyses. Among the 68 knees, 1 showed valgus alignment ≥5 degrees and 5 showed varus alignment ≥5 degrees at the last follow-up. All the 6 cases were observed in the SG. Surgical wound dehiscence was observed in 1 patient in the PG.The use of plates and faster correction speed were positively associated with the rebound phenomenon. Careful attention will be needed with the corresponding conditions for optimal results. Progressive genu varum after transphyseal screw removal, which was observed in this study, should be explored in future research.Level III-retrospective comparative series.
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- 2022
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18. Influence of forward-current stress on the generation of deep-level traps in InGaN/GaN blue micro-LEDs
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A. B. M. Hamidul Islam, Tae Kyoung Kim, Yu-Jung Cha, Jae Won Seo, Jiun Oh, Jong-In Shim, Dong-Soo Shin, and Joon Seop Kwak
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- 2023
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19. Detection of Linezolid-Resistant Enterococcus faecalis and Enterococcus faecium Isolates from the Layer Operation System in Korea
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Kwang Won Seo, Jong Bo Shim, Yeong Bin Kim, Eun Bi Noh, Sunghyun Yoon, and Young Ju Lee
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Microbiology (medical) ,Pharmacology ,biology ,Immunology ,biochemical phenomena, metabolism, and nutrition ,Ribosomal RNA ,biology.organism_classification ,Antimicrobial ,computer.software_genre ,Microbiology ,Enterococcus faecalis ,Multiple drug resistance ,chemistry.chemical_compound ,Antibiotic resistance ,chemistry ,23S ribosomal RNA ,Linezolid ,Operating system ,computer ,Enterococcus faecium - Abstract
Linezolid (LNZ) is one of the most important antimicrobial agents against infections caused by gram-positive bacteria, including enterococci. In a layer operation system, antimicrobial resistance can be transferred to commercial layers via the fecal-oral route. This study investigated the presence and distribution of LNZ-resistant Enterococcus faecalis and Enterococcus faecium in a layer operation system. Among 117 E. faecalis and 154 E. faecium, 10 (8.5%) E. faecalis and 5 (3.2%) E. faecium isolates showed resistance to LNZ and chloramphenicol, and they exhibited multidrug resistance against 5 or more classes of antimicrobial agents. Among the resistant isolates, 9 (90.0%) and 2 (20.0%) E. faecalis harbored optrA and cfr genes, respectively. The optrA and fexA genes were not detected in five LNZ-resistant E. faecium. None of the 15 LNZ-resistant isolates harbored the fexA gene, and no mutations were observed in the genes encoding domain V of 23S ribosomal RNA (rRNA) and ribosomal proteins L3 (rplC) and L4 (rplD). Transferability was identified in three of the nine optrA-positive LNZ-resistant isolates. The tetM, tetL, and ermB genes were cotransferred with the optrA gene in all optrA-positive transconjugants. The results indicate that optrA is well-distributed in E. faecalis, implying a greater level of transferability. Thus, enhanced surveillance efforts are needed to monitor the emergence and spread of optrA in enterococci in layer operation system.
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- 2021
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20. The presence of <scp>RSPO4</scp> ‐expressing onychofibroblasts in the onychodermis
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Dongyoun Lee, Joon Ho Shim, Ji‐Hye Park, and Jong Sup Shim
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Mesoderm ,Histology ,Nails ,Humans ,Dermatology ,Thrombospondins ,Pathology and Forensic Medicine - Published
- 2022
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21. Improving Disk I/O Performance by Using Raw Disk for Web Proxy Servers.
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Jong-Ik Shim and Jae-dong Lee
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- 2003
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22. Structural Behavior of Composite Beams having Truss Reinforcement Embedded in Concrete
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Jong-Seok Shim and Yong-Keun Kwon
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Materials science ,business.industry ,Truss ,Structural engineering ,business ,Reinforcement ,Composite beams - Published
- 2021
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23. Change in Portal Pressure and Clinical Outcome in Cirrhotic Patients with Gastric Varices after Plug-Assisted Retrograde Transvenous Obliteration
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Young Seok Kim, Sang Gyune Kim, Jae Woo Park, Sae Hwan Lee, Baek Gyu Jun, Jong Joon Shim, Jeong-Ju Yoo, Gab Jin Cheon, Jae Myung Lee, Jae Young Jang, Soung Won Jeong, Young Don Kim, and Hong Soo Kim
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Liver Cirrhosis ,Male ,medicine.medical_specialty ,Liver, Pancreas and Biliary Tract ,Portal venous pressure ,Esophageal and Gastric Varices ,Severity of Illness Index ,Gastroenterology ,End Stage Liver Disease ,03 medical and health sciences ,Liver disease ,0302 clinical medicine ,Esophageal varices ,Internal medicine ,Ascites ,Humans ,Medicine ,Hepatic encephalopathy ,Aged ,Retrospective Studies ,Gelatin sponge ,Hepatology ,business.industry ,Gastric varices ,Therapeutic embolization ,Balloon Occlusion ,Middle Aged ,medicine.disease ,Portal Pressure ,Treatment Outcome ,030220 oncology & carcinogenesis ,Female ,Original Article ,030211 gastroenterology & hepatology ,Liver function ,Portosystemic shunt ,medicine.symptom ,business - Abstract
Background/Aims: Plug-assisted retrograde transvenous obliteration (PARTO) is widely used to manage gastric varices with a portosystemic shunt. It is not clear whether portal pressure and the incidence of complications increase after PARTO. The aim of this study was to determine the changes in portal pressure and the associated changes in liver function, ascites, hepatic encephalopathy, and especially esophageal varix (EV) after PARTO. Methods: From March 2012 to February 2018, 54 patients who underwent PARTO were analyzed retrospectively. The parameters collected included liver function and episodes of cirrhotic complications before and at 1 and 6 months after PARTO. Results: The analysis of 54 patients showed improvement in liver function during the 6-month follow-up period (Model for End-Stage Liver Disease score: change from 11.46±4.35 to 10.33±2.96, p=0.021). Among these 54 patients, 25 patients were evaluated for their hepatic venous pressure gradient (HVPG) before and after PARTO (change from 12.52±3.83 to 14.68±5.03 mm Hg; p
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- 2020
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24. Native defect clustering-induced carrier localization centers leading to a reduction of performance in Ga0.70In0.30N/GaN quantum wells
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Dong-Pyo Han, Jiwon Kim, Dong-Soo Shin, and Jong-In Shim
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Atomic and Molecular Physics, and Optics - Abstract
In this study, we aimed to better understand the mechanism for creating carrier localization centers (CLCs) in Ga0.70In0.30N/GaN quantum wells (QWs) and examine their impacts on device performance. Particularly, we focused on the incorporation of native defects into the QWs as a main cause of the mechanism behind the CLC creation. For this purpose, we prepared two GaInN-based LED samples with and without pre-trimethylindium (TMIn) flow-treated QWs. Here, the QWs were subjected to a pre-TMIn flow treatment to control the incorporation of defects/impurities in the QWs. In an effort to investigate how the pre-TMIn flow treatment affects the incorporation of native defects into the QWs, we employed steady-state photo-capacitance and photo-assisted capacitance-voltage measurements, and acquired high-resolution micro-charge-coupled device images. The experimental results showed that CLC creation in the QWs during growth is closely related to the native defects, most likely VN-related defects/complexes, since they have a strong affinity to In atoms and the nature of clustering. Moreover, the CLC creation is fatal to the performance of the yellow-red QWs since they simultaneously increase the non-radiative recombination rate, decrease the radiative recombination rate, and increase operating voltage—unlike blue QWs.
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- 2023
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25. The Encapsulation of Natural Organic Dyes on TiO2 for Photochromism Control
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Hye Ju Lee, Jong Won Shim, Jung Jin Lee, and Won Jun Lee
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Inorganic Chemistry ,Organic Chemistry ,General Medicine ,Physical and Theoretical Chemistry ,titanium dioxide ,photochromism ,natural organic dye ,encapsulation ,Molecular Biology ,Spectroscopy ,Catalysis ,Computer Science Applications - Abstract
Titanium dioxide (TiO2) plays a pivotal role in photocatalytic reactions and holds great promise for the cosmetic and paint industries due to its white color and high refractive index. However, the original color of TiO2 changes gradually to blue or yellow with UV irradiation, which affects its color realization. We encapsulated TiO2 with several natural organic dye compounds, including purpurin, curcumin, and safflower, to control its photochromism and realize a range of different colors. The chemical reaction between TiO2 and dyes based on their functional group was investigated, and the light absorption was tested via FTIR and UV–Vis spectroscopy. The changes in morphology and size distribution additionally supported their successful encapsulation. The discoloration after UV irradiation was evaluated by measuring the color difference (ΔE) of control TiO2 and dye encapsulated TiO2. The unique structure utilized natural dyes to preserve photochromism based on the physical barrier and automatically controlled the electronic transition of core TiO2. In particular, the color difference values of purpurin and curcumin were 4.05 and 3.76, which is lower than the 5.36 of the control TiO2. Dye encapsulated TiO2 was manipulated into lipstick to verify its color realization and retention.
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- 2023
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26. Size-dependent variation of efficiency in InGaN-based flip-chip near ultraviolet and blue micro light-emitting diodes
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A. B. M. Hamidul Islam, Tae Kyoung Kim, Yu-Jung Cha, Jae Won Seo, Dong-Soo Shin, Jong-In Shim, and Joon Seop Kwak
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- 2022
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27. Hybrid LED and applications
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Yungryel Ryu, Sungki Hong, Sung J. Son, and Jong In Shim
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- 2022
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28. Comparative Spatial Transcriptomic and Single-Cell Analyses of Human Nail Units and Hair Follicles Show Transcriptional Similarities between the Onychodermis and Follicular Dermal Papilla
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Joonho Shim, Jihye Park, Gulimila Abudureyimu, Min-Hee Kim, Jong Sup Shim, Kee-Taek Jang, Eun Ji Kwon, Hyung-Suk Jang, Eunhye Yeo, Jong Hee Lee, and Dongyoun Lee
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Nails ,Humans ,Keratins ,Cell Biology ,Dermatology ,Single-Cell Analysis ,Transcriptome ,Molecular Biology ,Biochemistry ,Hair Follicle - Abstract
The nail unit and hair follicle are both hard keratin-producing organs that share various biological features. In this study, we used digital spatial profiling and single-cell RNA sequencing to define a spatially resolved expression profile of the human nail unit and hair follicle. Our approach showed the presence of a nail-specific mesenchymal population called onychofibroblasts within the onychodermis. Onychodermis and follicular dermal papilla both expressed Wnt and bone morphogenetic protein signaling molecules. In addition, nail matrix epithelium and hair matrix showed very similar expressions profile, including the expression of hard keratins and HOXC13, a transcriptional regulator of the hair shaft. Integration of single-cell RNA sequencing and digital spatial profiling data through computational deconvolution methods estimated epithelial and mesenchymal cell abundance in the nail- and hair-specific regions of interest and revealed close transcriptional similarity between these major skin appendages. To analyze the function of bone morphogenetic proteins in nail differentiation, we treated cultured human nail matrix keratinocytes with BMP5, which are highly expressed by onychofibroblasts. We observed increased expressions of hard keratin and its regulator genes such as HOXC13. Collectively, our data suggest that onychodermis is the counterpart of dermal papilla and that BMP5 in onychofibroblasts plays a key role in the differentiation of nail matrix keratinocytes.
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- 2022
29. Effect of Interface State Density of the AlGaN Electron Blocking Layer/GaN Barrier Layer in InGaN Blue Light-Emitting Diodes
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Jong-In Shim and Kyu-Sang Kim
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010302 applied physics ,Materials science ,Photoluminescence ,business.industry ,General Physics and Astronomy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Capacitance ,law.invention ,Barrier layer ,law ,0103 physical sciences ,Dispersion (optics) ,Sapphire ,Optoelectronics ,0210 nano-technology ,business ,Quantum well ,Diode ,Light-emitting diode - Abstract
Herein, two kinds of blue InGaN light-emitting diodes (LEDs) were compared in order to understand the effect of the strain originating from two different sapphire substrates. One of the LED types was grown on a patterned sapphire substrate (PSS), and the other was grown on a conventional sapphire substrate (CSS). The internal strains biased on InGaN quantum wells were compared by studying the time-resolved photoluminescence and the electroreflectance. Through analysis of the dynamic capacitance dispersion measurements, the relation between the trap states and trap density of the AlGaN electron blocking layer/GaN barrier interface above the InGaN quantum wells can be understood in great detail. The trapped charges of the CSSs have faster response times than those of the PSSs; this is attributed to the stronger piezo-field, which induces the AlGaN EBL/GaN barrier interface trap states to be effectively located at shallower levels from the conduction band.
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- 2020
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30. Measurement of the Piezoelectric Field in InGaN/AlGaN Multiple-Quantum-Well Near-Ultraviolet Light-Emitting Diodes by Electroreflectance Spectroscopy
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Jong-In Shim, Dong-Soo Shin, and Abu Bashar Mohammad Hamidul Islam
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Photocurrent ,Materials science ,business.industry ,Superlattice ,chemistry.chemical_element ,Condensed Matter Physics ,Piezoelectricity ,Atomic and Molecular Physics, and Optics ,law.invention ,Erbium ,chemistry ,law ,Optoelectronics ,Electrical and Electronic Engineering ,Spectroscopy ,business ,Indium ,Diode ,Light-emitting diode - Abstract
The piezoelectric field in InGaN/AlGaN-based multiple-quantum-well (MQW) near-ultraviolet light-emitting diodes (LEDs) was measured by electroreflectance and photocurrent spectroscopies. At forward and reverse biases, both electroreflectance and photocurrent spectra were studied by utilizing similar-structure samples with indium contents of ~4.5%, ~5.5%, ~6.5%, and ~7.5%. The influence of MQW and superlattice structures on the electroreflectance spectra was interactively identified. The relation between the defects and the diffusion of Mg acceptors through the defects into the MQWs was also observed and systematically confirmed through the capacitance-voltage characteristics. The effects of diffused Mg acceptors on electroreflectance spectra, depletion width, and the piezoelectric field were found. The strain relaxation caused by the defects was also systematically investigated. The calculated piezoelectric fields of these samples were in good agreement with the theoretically calculated values.
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- 2019
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31. Fabrication of Less Bowed Light-Emitting Diodes on Sapphire Substrates with a SiO2 Thin Film on Their Back Sides
- Author
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Jong-In Shim, Jong Hak Kim, Chan-Hyoung Oh, Seungmin Lee, Euijoon Yoon, and Yongjo Park
- Subjects
010302 applied physics ,Materials science ,Fabrication ,business.industry ,General Physics and Astronomy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,law ,0103 physical sciences ,Stress relaxation ,Sapphire ,Optoelectronics ,Quantum efficiency ,Wafer ,Thin film ,0210 nano-technology ,business ,Light-emitting diode ,Diode - Abstract
In this study, less bowed light-emitting diodes (LEDs) were fabricated by preparing a LED structure on a sapphire substrate with a SiO2 thin film on its back side. The SiO2 thin film with a low thermal expansion coefficient reduced the bow of the wafer generated by the thermal expansion coefficient difference. As the thickness of SiO2 was increased from 1 µm to 4 µm, the compressive stress in the GaN film was reduced from 16% to 62% with respect to that without SiO2 thin film. The stress reduction in multiple quantum wells also enhanced the internal quantum efficiency of the LED by reducing the piezoelectric field.
- Published
- 2019
- Full Text
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32. Interrelation Between the Internal Quantum Efficiency and Forward Voltage of Blue LEDs
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Jong-In Shim, Dong-Soo Shin, and Chan-Hyoung Oh
- Subjects
Physics ,02 engineering and technology ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Active layer ,law.invention ,020210 optoelectronics & photonics ,law ,0202 electrical engineering, electronic engineering, information engineering ,Radiative transfer ,Quantum efficiency ,Spontaneous emission ,Electrical and Electronic Engineering ,Atomic physics ,Current density ,Saturation (magnetic) ,Light-emitting diode ,Diode - Abstract
In InGaN/GaN multiple-quantum-well (MQW) light-emitting diodes (LEDs), carrier accumulation in MQWs due to the saturation of the radiative recombination rate affects the internal-quantum-efficiency (IQE) and forward-voltage ( ${V} _{\text {F}}$ ) characteristics simultaneously. In this letter, we investigate the interrelation between the IQE and ${V} _{\text {F}}$ at an operating current density, using 31 blue LEDs with MQW active layers grown under slightly different conditions. The general trend observed demonstrates that ${V} _{\text {F}}$ decreases as the IQE increases. We analyze this interrelation between the IQE and ${V} _{\text {F}}$ through separation of radiative and nonradiative current densities, and propose to use the active efficiency (AE) to quantify the performance of the active layer more precisely. We examine the two cases where only the radiative (nonradiative) current density changes and establish that the increase of the radiative current density is more desirable than the decrease of the nonradiative current density in improving the AE of the device.
- Published
- 2019
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33. Modified Shockley Equation for GaInN-Based Light-Emitting Diodes: Origin of the Power- Efficiency Degradation Under High Current Injection
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Tetsuya Takeuchi, Dong-Soo Shin, Motoaki Iwaya, Jong-In Shim, Satoshi Kamiyama, Isamu Akasaki, and Dong-Pyo Han
- Subjects
Materials science ,business.industry ,02 engineering and technology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,law.invention ,020210 optoelectronics & photonics ,law ,0202 electrical engineering, electronic engineering, information engineering ,Radiative transfer ,Optoelectronics ,Spontaneous emission ,Quantum efficiency ,Electrical and Electronic Engineering ,business ,Quantum well ,Voltage drop ,Voltage ,Light-emitting diode ,Diode - Abstract
As an attempt to elucidate the origin of the power-efficiency (PE) degradation at high current injection for GaInN-based light-emitting diodes, the injection current is quantitatively separated to radiative and nonradiative current components as a function of applied voltage. It is found that the conventional Shockley equation for the current-voltage curve of a Si pn diode is not adequate for the LED since the carrier transport and recombination processes are quite different from those of the Si pn diode. Hence, we propose a diode equation for an LED where the radiative and nonradiative currents are separately expressed as a function of applied voltage. By analyzing the proposed diode equation, it is concluded that the PE degradation at high injection currents is due to the increase of the junction voltage and the decrease of the internal quantum efficiency at the same time. The phenomena can be understood by the insufficient recombination rate in the active quantum wells.
- Published
- 2019
- Full Text
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34. A Comprehensive Review of Percutaneous Nephrostomy and Suprapubic Cystostomy
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Jung Ho Jang, Sung Eun Park, Sangmin Lee, Jae Boem Na, Soo Buem Cho, Jong Joon Shim, Mi Jung Park, Ho Cheol Choi, Hwa Seon Shin, and Sa Hong Jo
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lcsh:Medical physics. Medical radiology. Nuclear medicine ,medicine.medical_specialty ,kidney ,Urinary bladder ,Percutaneous ,cystostomy ,business.industry ,Cystostomy ,medicine.medical_treatment ,Urinary system ,lcsh:R895-920 ,urologic and male genital diseases ,Surgery ,medicine.anatomical_structure ,Percutaneous nephrostomy ,percutaneous ,Nephrostomy ,Medicine ,Radiology, Nuclear Medicine and imaging ,business ,Suprapubic cystostomy ,urinary bladder ,nephrostomy - Abstract
Percutaneous nephrostomy is widely used for the diagnosis and treatment of various urinary tract diseases, such as ureteral fistula, stenosis, and percutaneous nephrolithotomy, and the relief of urinary obstruction. Suprapubic cystostomy is also known as a good method for bladder drainage in patients with lower urinary tract obstruction or injury and neurogenic bladder. Despite the frequent use of these procedures, reports in the literature are insufficient for an interventional radiologist to understand the procedures easily and thoroughly. In this article, the indication, anatomy, placement, and postoperative management of percutaneous nephrostomy and suprapubic cystostomy have been described, explaining that the procedures are safe and effective.
- Published
- 2019
35. Analysis of Transient Degradation Behaviors of Organic Light-Emitting Diodes under Electrical Stress
- Author
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Heejin Kim, Dong-Soo Shin, Yoon Suk Choi, Jongwoo Park, Gyeong Won Lee, and Jong-In Shim
- Subjects
Technology ,Materials science ,QH301-705.5 ,QC1-999 ,Luminance ,Stress (mechanics) ,transient ,OLED ,General Materials Science ,Biology (General) ,Instrumentation ,QD1-999 ,Diode ,degradation ,Fluid Flow and Transfer Processes ,business.industry ,Process Chemistry and Technology ,Physics ,General Engineering ,charge recombination and transport ,organic light-emitting diodes ,Engineering (General). Civil engineering (General) ,Electron transport chain ,Fluorescence ,Computer Science Applications ,Chemistry ,Optoelectronics ,Degradation (geology) ,Transient (oscillation) ,TA1-2040 ,business - Abstract
Despite the wide application of organic light-emitting diodes (OLEDs), the performance of OLED devices is sometimes limited by their reliabilities. In this paper, we report the transient degradation behaviors of fluorescent blue OLEDs, where both the current and luminance initially increase under electrical stress within a short stress time. We analyze the degradation mechanism in terms of the carrier recombination and transport. From the comprehensive analyses of electrical and optical characteristics, it is suggested that the electron transport is responsible for the initial transient behavior of the device.
- Published
- 2021
36. Detection of Linezolid-Resistant
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Yeong Bin, Kim, Sunghyun, Yoon, Kwang Won, Seo, Jong Bo, Shim, Eun Bi, Noh, and Young Ju, Lee
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Genes, Bacterial ,Drug Resistance, Bacterial ,Enterococcus faecium ,Republic of Korea ,Enterococcus faecalis ,Linezolid ,Microbial Sensitivity Tests ,Anti-Bacterial Agents ,Multilocus Sequence Typing - Abstract
Linezolid (LNZ) is one of the most important antimicrobial agents against infections caused by gram-positive bacteria, including enterococci. In a layer operation system, antimicrobial resistance can be transferred to commercial layers via the fecal-oral route. This study investigated the presence and distribution of LNZ-resistant
- Published
- 2021
37. Percutaneous removal of common bile duct stones using a modified balloon technique
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Sung Eun Park, Ho Cheol Choi, Sangmin Lee, Jae Min Cho, Yang Won Kim, Hwa Seon Shin, Ji Eun Kim, Jae Boem Na, Mi Jung Park, Jong Joon Shim, Jung Ho Won, and Dae Seob Choi
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Male ,medicine.medical_specialty ,Percutaneous ,transhepatic ,medicine.medical_treatment ,Observational Study ,Balloon ,03 medical and health sciences ,symbols.namesake ,Sphincterotomy, Endoscopic ,0302 clinical medicine ,calculi ,Medicine ,Humans ,balloon ,030212 general & internal medicine ,Major complication ,Embolization ,Fisher's exact test ,Aged ,Retrospective Studies ,Aged, 80 and over ,Common Bile Duct ,Common bile duct ,business.industry ,sphincteroplasty ,Balloon catheter ,angioplasty ,General Medicine ,Balloon Occlusion ,Middle Aged ,medicine.disease ,Surgery ,medicine.anatomical_structure ,Choledocholithiasis ,030220 oncology & carcinogenesis ,Case-Control Studies ,symbols ,Pancreatitis ,Feasibility Studies ,Female ,business ,Research Article - Abstract
To evaluate the effectiveness of percutaneous removal of common bile duct (CBD) stones using a modified balloon technique (balloon catheter sphincteroplasty and expulsion of the stones using half-captured balloons within the sheath) in patients difficult to treat with endoscopy. Fifty patients underwent a modified balloon technique (balloon group), and 53 patients underwent CBD stone removal by the basket method (stone basket group) between 2016 and 2019. We compared the balloon and stone basket groups to evaluate the effectiveness of the modified balloon technique. Outcome variables such as demographics, technical success rates, procedural details, and complications were analyzed. Statistical analysis was performed using Student t test, Fisher exact test, or the χ2 test. The technical success rate in the balloon group was 66% (33/50) in 1 session, 32% (16/50) in 2 sessions, and 2% (1/50) in 3 sessions. That of the stone basket group was 45% (24/53) in 1 session, 38% (20/53) in 2 sessions, and 17% (9/53) in 3 sessions. The total procedure time was significantly shorter in the balloon group (29.5 ± 15.1 minutes) than in the stone basket group (41.7 ± 20.2 minutes) (P
- Published
- 2021
38. Generation of sidewall defects in InGaN/GaN blue micro-LEDs under forward-current stress
- Author
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Abu Bashar Mohammad Hamidul Islam, Tae Kyoung Kim, Dong-Soo Shin, Jong-In Shim, and Joon Seop Kwak
- Subjects
Physics and Astronomy (miscellaneous) - Abstract
This work investigates the effect of current stress on InGaN/GaN multiple-quantum-well flip-chip blue micro light-emitting diodes ( μ-LEDs) with a mesa size of 30 × 30 μm2 and describes the stress-related mechanisms: defect aggregation and generation, which cause the change in optoelectronic performance of μ-LEDs. A forward-current stress is applied at 75 A/cm2 (0.7 mA) for 200 h. The device performance degrades with increasing stress time except until 25 h. During the initial 25 h of aging, the light output power and the external quantum efficiency (EQE) increase due to the improved crystal quality caused by aggregation of point defects in the active region, which are supported by the ideality factor and the S-parameter. The high-resolution emission-microscope images reveal that the generation of point defects at mesa sidewalls rather than the active region is crucial in performance degradation. We highlight, in particular, that the aging test generates sidewall point defects even though the sidewalls were properly passivated by a thick SiO2 layer. The mechanisms of defect aggregation and generation due to aging are consistently described by the ideality factor, the S-parameter, and the EQE.
- Published
- 2022
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39. Structural parameter dependence of light extraction efficiency in photonic crystal InGaN vertical light-emitting diode structures
- Author
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Han-Youl Ryu and Jong-In Shim
- Subjects
Gallium compounds -- Electric properties ,Gallium compounds -- Optical properties ,Indium -- Electric properties ,Indium -- Optical properties ,Light-emitting diodes -- Structure ,Light-emitting diodes -- Optical properties ,Photonics -- Research ,Business ,Computers ,Electronics ,Electronics and electrical industries - Published
- 2010
40. Fabrication of C doped Mg[B.sub.2] wire using a mixture of in-situ and ex-situ powders
- Author
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Eui Cheol Park, Jong Hyun Shim, Soo Min Hwang, Ki Soo Sung, Jun Hyung Lim, Jinho Joo, Won Nam Kang, and Chan-Joong Kim
- Subjects
Electric currents -- Measurement ,Magnesium compounds -- Electric properties ,Magnesium compounds -- Thermal properties ,Semiconductor doping -- Analysis ,Sintering -- Usage ,Superconductivity -- Analysis ,Business ,Electronics ,Electronics and electrical industries - Published
- 2009
41. Surgical Outcomes and Predictive Factors of Medial Toe Excision for Polysyndactyly of the Fifth Toe
- Author
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Kyung Rae Ko, Jaesung Park, Jiwon Kang, and Jong Sup Shim
- Subjects
Postaxial polydactyly ,030222 orthopedics ,medicine.medical_specialty ,business.industry ,030230 surgery ,Toes ,medicine.disease ,Surgery ,body regions ,03 medical and health sciences ,0302 clinical medicine ,Treatment Outcome ,Polysyndactyly ,medicine ,Humans ,Orthopedics and Sports Medicine ,Syndactyly ,business ,Metatarsal Bones ,Retrospective Studies - Abstract
Background: We aimed to report surgical outcomes and analyze prognostic factors of medial toe excision for polysyndactyly of the fifth toe. Methods: We reviewed the details of 139 consecutive patients who underwent surgery for postaxial polydactyly of the foot from 2009 to 2018. Among these, 83 patients (90 feet) with polysyndactyly of the fifth toe, treated by medial toe excision (between the duplicated toes) and reconstruction of the fourth web space using a dorsal rectangular flap, were included. The toe alignment and stability were restored by chondroplasty and soft tissue balancing without an osteotomy. A full-thickness skin graft was performed in 52 feet. The mean age at surgery was 27.1 ± 17.5 months and the mean duration of follow-up was 42.8 ± 24.9 months. Results: At the last follow-up, a relatively small size of the reconstructed toe was observed in 19 feet (19/90, 21.1%). Proximal duplication level (metatarsal or proximal phalanx type) and preoperative hypoplasia of the remaining toe were related to the small postoperative size. Valgus deformity of the remaining toe was observed in 2 feet (2/90, 2.2%). We observed 17 cases with delayed healing or early postoperative wound infection. Among these, 7 cases (7/90, 7.8%) showed postoperative thickening or advancement of the web, which was not observed in cases without wound problems. No cases had functional disturbance or pain. Conclusion: The overall surgical outcomes were satisfactory without an osteotomy. Patients with a proximal duplication level or preoperative hypoplasia of the remaining toe should be informed of its possible small size postoperatively. Levels of Evidence: Level IV, retrospective case series.
- Published
- 2020
42. Identifying the cause of thermal droop in GaInN-based LEDs by carrier- and thermo-dynamics analysis
- Author
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Motoaki Iwaya, Dong-Soo Shin, Gyeong Won Lee, Jong-In Shim, Sangjin Min, Satoshi Kamiyama, Dong-Pyo Han, Tetsuya Takeuchi, and Isamu Akasaki
- Subjects
Materials science ,lcsh:Medicine ,02 engineering and technology ,01 natural sciences ,Article ,law.invention ,law ,0103 physical sciences ,Thermal ,Radiative transfer ,Lasers, LEDs and light sources ,Voltage droop ,lcsh:Science ,Electrical impedance ,Diode ,010302 applied physics ,Multidisciplinary ,business.industry ,lcsh:R ,Carrier lifetime ,021001 nanoscience & nanotechnology ,Complex dynamics ,Inorganic LEDs ,Optoelectronics ,lcsh:Q ,0210 nano-technology ,business ,Light-emitting diode - Abstract
This study aims to elucidate the carrier dynamics behind thermal droop in GaInN-based blue light-emitting diodes (LEDs) by separating multiple physical factors. To this end, first, we study the differential carrier lifetimes (DCLs) by measuring the impedance of a sample LED under given driving-current conditions over a very wide operating temperature range of 300 K–500 K. The measured DCLs are decoupled into radiative carrier lifetime (τR) and nonradiative carrier lifetime (τNR), via utilization of the experimental DCL data, and then very carefully investigated as a function of driving current over a wide range of operating temperatures. Next, to understand the measurement results of temperature-dependent τR and τNR characteristics, thermodynamic analysis is conducted, which enables to look deeply into the temperature-dependent behavior of the carriers. On the basis of the results, we reveal that thermal droop is originated by the complex dynamics of multiple closely interrelated physical factors instead of a single physical factor. In particular, we discuss the inherent cause of accelerated thermal droop with elevated temperature.
- Published
- 2020
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43. Predictors of ideal outcomes after reconstructive surgery for chronic Monteggia fracture in children
- Author
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Kyung Rae Ko, Jaesung Park, Jong Sup Shim, and Jae-Yeon Won
- Subjects
Male ,medicine.medical_specialty ,Reconstructive surgery ,Adolescent ,medicine.medical_treatment ,Elbow ,Joint Dislocations ,Ulna ,Monteggia fracture ,Monteggia's Fracture ,Elbow Joint ,medicine ,Humans ,Orthopedics and Sports Medicine ,Range of Motion, Articular ,Child ,Reduction (orthopedic surgery) ,Retrospective Studies ,business.industry ,Infant ,Chronological age ,Plastic Surgery Procedures ,medicine.disease ,Surgery ,medicine.anatomical_structure ,Ulnar shortening osteotomy ,Ligament ,Female ,Level iii ,business ,Elbow Injuries - Abstract
We aimed to analyze surgical outcomes of reconstructive surgery for chronic Monteggia fracture, which is one of the most challenging problems for orthopaedic surgeons.Twenty-eight patients were followed during 55.6 ± 32.0 months after open reduction of the radial head combined with ulnar osteotomy and annular ligament reconstruction. The mean interval from trauma was 15.1 ± 19.6 months, and the mean age at the surgery was 9.1 ± 3.5 years. In addition to the chronological age, elbow maturity was assessed using the Sauvegrain score. Surgical outcomes were primarily evaluated using the Kim's score. In addition, we newly defined more successful criteria for the ideal surgical outcomes, equivalent to preinjury status.There were 19 excellent, 3 good, 4 fair, and 2 poor outcomes based on the Kim's scoring system. Among the 19 patients with excellent outcomes, 14 met our criteria for the ideal outcomes. The age (p 0.001) and the Sauvegrain score (p 0.001) were lower, and the interval (p = 0.004) was shorter in 14 patients with ideal outcomes. There were 9 patients with preoperative deformation of the radial head, and all of them showed non-ideal outcomes. In regression analyses, lower Sauvegrain score (p = 0.004) and shorter interval (p = 0.012) were associated with higher postoperative Kim's score, and lower Sauvegrain score (p = 0.031) was related to the achievement of the ideal outcomes. With the Sauvegrain score of21.5, all patients had postoperative re-dislocation or osteoarthritic changes regardless of the interval. With the Sauvegrain score of21.5 and an interval of ≤7 months, the ideal outcomes were achieved in 85.7%, and no patients had postoperative re-dislocation or osteoarthritic changes.Over the skeletal ages of 14 years in boys and 11.5 years in girls, reconstructive surgery must be cautiously indicated. Under these skeletal ages with an interval of ≤7 months and undeformed radial head, it appears to be ideal.Level III, Retrospective comparative study.
- Published
- 2020
44. Antimicrobial resistance and virulence genes of β-lactamase producing E. coli isolated from commercial layers
- Author
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Lee, Young Ju, Jong Bo Shim, and Kwang Won Seo
- Subjects
Antibiotic resistance ,medicine ,Antimicrobial resistance genes ,Virulence ,Biology ,medicine.disease_cause ,Gene ,Escherichia coli ,Microbiology - Published
- 2019
- Full Text
- View/download PDF
45. Characterization of the Onychomatricodermis Containing Onychofibroblasts of the Nail Unit : Histology, Immunohistochemistry, and Electron Microscopic Study
- Author
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Gulimila Abudureyimu, Ghee Young Kwon, Kee-Taek Jang, Jong Sup Shim, Dong-Youn Lee, and Ji-Hye Park
- Subjects
Pathology ,medicine.medical_specialty ,integumentary system ,business.industry ,Mesenchyme ,Onychomatricodermis ,Histology ,Dermatology ,Staining ,Masson's trichrome stain ,Onychofibroblast ,030207 dermatology & venereal diseases ,03 medical and health sciences ,Onychodermis ,0302 clinical medicine ,medicine.anatomical_structure ,Dermis ,030220 oncology & carcinogenesis ,medicine ,Ultrastructure ,Nail (anatomy) ,Original Article ,Collagen ,business ,Nail matrix - Abstract
Background: We recently discovered the presence of specialized nail mesenchyme below the nail matrix and designated it as onychomatricodermis. Objective: We did further research to characterize the histologic, histochemical, immunohistochemical and ultrastructural features of the onychomatricodermis containing onychofibroblasts in the nail unit. Methods: Ten polydactyly nail unit specimens and 8 nail matrix biopsies were included. H&E-stained slides were reviewed. We did Alcian blue staining and Masson Trichrome staining, as well as immunohistochemical staining for type Ⅰ collagen, CD10, CD13 and CD34. In addition, polydactyly nail units were examined by transmission electron microscopy. Results: In H&E staining, the specialized mesenchyme called onychomatricodermis was observed to be slightly distant from the undersurface of the nail matrix and be less eosinophilic area. Onychomatricodermal ony-chofibroblasts showed light purple abundant cytoplasm. Masson Trichrome staining revealed fewer collagen fibers within the onychomatricodermis. In Alcian blue staining the onychomatricodermis showed mucin deposition within the onychofibroblasts and around them. Immunohistochemically, type Ⅰ collagen was expressed much less in the onychomatricodermis while it was strongly expressed elsewhere in the nail unit. In nail matrix biopsy specimens onychomatricodermal onychofibroblasts expressed CD10 and CD13 strongly, and expressed CD34 as well. Ultrastructurally, collagen fibrils were found sparsely within the onychomatricodermis, whereas collagen fibrils were densely distributed in the dermis of other parts of the nail unit. Conclusion: We demonstrated that there was less collagen expression in the onychomatricodermis containing onychofibroblasts. In addition, we found morphological and immunohistochemical features of onychomatricodermal onychofibroblasts (onychofibroblasts of Dongyoun). These findings support the presence of onychomatricodermis containing onychofibroblasts in the nail unit. (Ann Dermatol 33(2) 108∼115, 2021)
- Published
- 2020
46. Nanoscale Insight into Performance Loss Mechanisms in P3HT:ZnO Nanorod Solar Cells
- Author
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Jong Hyun Shim, Jeffrey M. Mativetsky, Haian Qiu, and Junghyun Cho
- Subjects
Materials science ,business.industry ,Photovoltaic system ,Energy conversion efficiency ,Energy Engineering and Power Technology ,02 engineering and technology ,Hybrid solar cell ,Conductive atomic force microscopy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Active layer ,law ,Solar cell ,Materials Chemistry ,Electrochemistry ,Chemical Engineering (miscellaneous) ,Optoelectronics ,Nanorod ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Current density - Abstract
Hybrid solar cells based on semiconducting polymers and metal oxides offer the possibility of combining the best attributes of both constituents to achieve efficient and low-cost solar energy harvesting. Active layers consisting of ZnO nanorods and semiconducting polymer poly(3-hexylthiophene), P3HT, have been studied extensively over the past decade. This type of solar cell, however, still exhibits a relatively low performance and poor device-to-device reproducibility. For insight into the performance bottlenecks in P3HT:ZnO nanorod solar cells, we employ a point-by-point current–voltage mapping method using conductive atomic force microscopy to probe the local photovoltaic properties of hybrid P3HT:ZnO nanorod active layers with nanoscale spatial resolution. We observe that the short-circuit current density, open-circuit voltage, fill factor, and power conversion efficiency are highly heterogeneous and sensitive to the local thickness of the P3HT hole transport layer that sits atop the active layer, wit...
- Published
- 2018
- Full Text
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47. Measuring the internal quantum efficiency of light-emitting diodes: towards accurate and reliable room-temperature characterization
- Author
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Jong-In Shim and Dong-Soo Shin
- Subjects
010302 applied physics ,Physics ,QC1-999 ,light-emitting diodes ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Engineering physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Characterization (materials science) ,law.invention ,law ,0103 physical sciences ,internal quantum efficiency ,Christian ministry ,Quantum efficiency ,characterization ,Electrical and Electronic Engineering ,0210 nano-technology ,Technology innovation ,Biotechnology ,Light-emitting diode - Abstract
For accurate and reliable measurement of the internal quantum efficiency (IQE) of light-emitting diodes (LEDs), the method should be theoretically solid and experimentally simple to use without any prior assumption of physical parameters or complicated equipment. In this paper, we critically review the conventional characterization techniques for measuring the IQE of LEDs, including the methods based on temperature-dependent electroluminescence and constant AB(C) models. After reviewing the limitations of the existing IQE measurement techniques, we present the recently proposed method based on the improved AB model, called room-temperature reference-point method (RTRM). The RTRM is then applied to various LED devices to show how the IQE measurement techniques can be utilized to analyze their optoelectronic performances quantitatively.
- Published
- 2018
48. Some Considerations on the Necessity and Road map for the Internationalization of Korean Won in Asian Financial market
- Author
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jong-beom Shim
- Subjects
Internationalization ,Market economy ,Financial market ,Business ,Road map ,Foreign exchange market - Published
- 2018
- Full Text
- View/download PDF
49. Postpartum haemorrhage due to genital tract injury after vaginal delivery: safety and efficacy of transcatheter arterial embolisation
- Author
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Sang Min Lee, Jong Woo Kim, Jong Joon Shim, Heung Kyu Ko, Ki Woong Yoon, Young Jong Cho, and Ji Hoon Shin
- Subjects
Adult ,medicine.medical_specialty ,Cervical Artery ,Inferior mesenteric artery ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Pregnancy ,medicine.artery ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Internal pudendal artery ,Uterine artery ,Retrospective Studies ,Vaginal artery ,030219 obstetrics & reproductive medicine ,medicine.diagnostic_test ,Vaginal delivery ,business.industry ,Postpartum Hemorrhage ,Angiography ,Mesenteric Artery, Inferior ,Interventional radiology ,General Medicine ,Enbucrilate ,Delivery, Obstetric ,Embolization, Therapeutic ,Surgery ,Uterine Artery ,Treatment Outcome ,Injections, Intra-Arterial ,Vagina ,Female ,Radiology ,Tomography, X-Ray Computed ,business ,Vascular Surgical Procedures - Abstract
To evaluate the safety and efficacy of transcatheter arterial embolisation (TAE) managing postpartum haemorrhage associated with genital tract injury (PPH-GTI) and to determine the factors associated with clinical outcomes. From 2002 to 2017, a retrospective analysis was performed in 60 patients (mean 31.5 years) undergoing TAE for PPH-GTI. Information regarding clinical data, angiography and embolisation details, and clinical outcomes was obtained. Univariate analyses were performed to determine the factors related to clinical outcomes. Technical and clinical success was achieved in 98% and 88%, respectively. Bleeding foci were observed on angiography in 56 patients (93%). The major bleeding artery was the vaginal artery (32%, 24/74), followed by the uterine artery (cervicovaginal branch) (n = 18), internal pudendal artery (n = 13), cervical artery (n = 9), inferior mesenteric artery (n = 4) and external pudendal artery (n = 3). Embolic agents were gelatin sponge particles (n = 23), gelatin sponge with permanent embolic agents (microcoils, n-butyl cyanoacrylate) (n = 34) and permanent embolic agents only (n = 3). In seven patients, bleeding control failed and was managed by repeat TAE (n = 5) or surgery (n = 2) and with eventual bleeding control in all of these patients. Univariate analysis showed that paravaginal haematoma, massive transfusion and long hospital stay were related to clinical failure. During the mean follow-up period of 33.1 months, regular menstruation resumed in 95.2% (40/42) and 14 of them became pregnant. TAE is safe and effective for treating PPH-GTI. Massive transfusion, paravaginal haematoma and long hospital stay were related to the failure of bleeding control. • PPH-GTI had a high detection rate of active bleeding foci on angiography. • Besides vaginal artery, inferior mesenteric and external pudendal arteries were notable bleeding foci. • Permanent embolic agents were used more than only gelatin sponge particles. • Paravaginal haematoma and massive transfusion were related to clinical failure. • TAE for PPH-GTI was safe and effective with preservation of menstrual cycles.
- Published
- 2018
- Full Text
- View/download PDF
50. Measuring the Internal Quantum Efficiency of Light-Emitting Diodes at an Arbitrary Temperature
- Author
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Chan-Hyoung Oh, Jong-In Shim, Dong-Soo Shin, Dong-Pyo Han, and Hyundon Jung
- Subjects
010302 applied physics ,Physics ,business.industry ,Optical power ,02 engineering and technology ,Electroluminescence ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Temperature measurement ,Atomic and Molecular Physics, and Optics ,law.invention ,Radiative efficiency ,law ,0103 physical sciences ,Optoelectronics ,Quantum efficiency ,Spontaneous emission ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Light-emitting diode ,Diode - Abstract
We present a method of measuring the internal quantum efficiency (IQE) of light-emitting diodes (LEDs) as a function of driving current at an arbitrary temperature only with experimentally measurable quantities of optical power and current. The measurement procedure starts to find an exact value of the IQE at the reference point where the injection efficiency is considered as 100% and the radiative efficiency is calculated from the infinitesimal change of the relative external quantum efficiency (EQE). Once the IQE at the reference point is exactly known, the IQE at any other point is calculated by the relative ratio of the EQE values to the reference one. We show the theoretical formalism of the proposed method and demonstrate its validity using a commercial InGaN blue LED as an example. The comparison with the IQE obtained by the conventional temperature-dependent electroluminescence is also given for various temperatures.
- Published
- 2018
- Full Text
- View/download PDF
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