112 results on '"Lee, Jun Young"'
Search Results
2. Evolution of Microcracks in Epitaxial CeO2 Thin Films on YSZ-Buffered Si.
- Author
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Jung, Soo Young, Choi, Hyung-Jin, Lee, Jun Young, Kim, Min-Seok, Ning, Ruiguang, Han, Dong-Hun, Kim, Seong Keun, Won, Sung Ok, Lee, June Hyuk, Jang, Ji-Soo, Jang, Ho Won, and Baek, Seung-Hyub
- Abstract
Epitaxial buffer layers such as ceria (CeO
2 )/yttria-stabilized zirconia (YSZ) allow the direct integration of functional oxide single crystal thin films on silicon (Si). Microcracks in the buffer layer, often evolving from the large thermal tensile stress, are detrimental to the integration of high-quality complex oxide thin films on Si. In this study, we investigated the evolution of microcracks in sputter-grown epitaxial CeO2 layers by systematically varying the sputtering power and thickness of CeO2 thin films on YSZ single crystal (low thermal mismatch) and YSZ-buffered Si (high thermal mismatch) substrates. Using a plane stress model, we revealed that as the sputtering power increased, the epitaxial CeO2 thin films tended to be more compressively strained at the growth temperature. This could accommodate the tensile strain arising during cooling to room temperature, thereby suppressing the evolution of microcracks. Our result provides not only a method to suppress microcracks in the oxide heterostructure on Si, but also a tool to control their strain state, by controlling their growth parameters. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
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3. Urinary albumin creatinine ratio is associated with lipid profile.
- Author
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Hwang, Sang Won, Lee, Taesic, Uh, Young, and Lee, Jun Young
- Subjects
KOREANS ,ALBUMINURIA ,DISEASE risk factors - Abstract
Moderately elevated albuminuria (30–300 mg/g) is a marker of renal dysfunction and a risk factor of cardiovascular disease. Additionally, several recent studies have reported a relationship between moderately elevated albuminuria and triglyceride (TG) levels. Therefore, we aimed to evaluate the relationship between the urine albumin-to-creatinine ratio (UACR) and total cholesterol (TC), TG, and high-density lipoprotein C (HDL-C) levels. We analyzed data from 19,340 patients from the 2011–2014 and 2019–2020 from the Korea National Health and Nutrition Examination Surveys. Multivariate linear regression analysis showed that the UACR was positively associated with TC and TG levels and negatively associated with HDL-C levels in both Korean women and men. These results were reanalyzed according to the degree of proteinuria (normal, moderately elevated albuminuria, and severely elevated albuminuria (≥ 300 mg/g)). We found a positive relationship between UACR and TC and TG levels, but a negative association with HDL-C levels, except for TC (moderately elevated albuminuria) and HDL-C (moderately elevated albuminuria) in Korean men and TC (severely elevated albuminuria), TG (severely elevated albuminuria), and HDL-C (normal range albuminuria) in Korean women. The correlation between albuminuria and lipid profiles became more evident as albuminuria shift from normal to the severely elevated albuminuria. Thus our multivariate linear regression analysis showed that lipid profiles (TG, TC, and HDL-C levels) were associated with the UACR. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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4. Gender Differences in Lower Limb Biomechanics During Stair Ascent in Young Subjects.
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Hong, Junghwa, Lee, Jun-Young, Shin, Hyeon-Soo, Kim, Min-Jae, Kim, Ju-Hee, Lee, Sean Min, Lee, Kikwang, and Eom, Gwang-Moon
- Abstract
The aim of this study was to investigate gender differences in the biomechanics of lower limb joints during stair ascent, focusing on the distribution of joint loads. Thirty-six young subjects (18 males and 18 females) ascended instrumented stairs while kinematic and kinetic data were measured. Mechanical variables of the lower limb joints and body posture on the sagittal plane were compared between genders, and their associations were also investigated. Female subjects exerted more mechanical work, power, and joint moment than male subjects at the knee joint, while males exerted more at the hip joint. Females and males showed a longer moment arm of ground reaction force at the knee and hip joints, respectively. The moment arm, but not the magnitude, of ground reaction force was strongly associated with the joint moment (r = 0.80–0.97). Females exhibited a more crouched stance limb (lower heel lift, greater ankle dorsiflexion, and knee flexion) than males. A more crouched and extended lower limb posture was found to be correlated with a longer moment arm at the knee and hip joints, respectively. Half of the variance in moment arm could be explained by the heel lift angle. The results indicate that females allocate greater work to the knee joint but less to the hip joint than males do in order to elevate body mass to a higher step during stair ascent. The work distribution strategy appears to be influenced significantly by posture, particularly the choice of foot contact method: heel-toe standing in females and toe standing in males. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
5. Loss and efficiency comparisons of single-phase full-bridge inverters according to switch structures.
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Kong, So-Jeong, Kim, Young-Joo, Kim, Jin-Su, Choi, Jae-Hyuck, and Lee, Jun-Young
- Published
- 2024
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6. Production of cobalt-57 for industrial and medical applications in RFT-30 cyclotron facility.
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Lee, Jun Young, Chae, JungHo, Lee, Jongchul, Hwang, Injoo, Hur, Min Goo, and Park, Jeong Hoon
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CYCLOTRONS , *NUCLEAR reactions , *PROTON beams , *SOLID phase extraction , *INDUSTRIAL applications , *QUALITY control - Abstract
Cobalt-57 (57Co) has emerged as a promising radionuclide and as an isotope for diagnostic and calibration sources. Herein, we report the production, chemical separation, and quality control of 57Co in an RFT-30 cyclotron facility. 57Co is produced via (p, 2p) nuclear reaction using an enriched 58Ni target material. Electrodeposits of 58Ni on Ag backing were obtained and irradiated using an incident proton beam energy of 17.4 MeV. The chemical separation of 57Co and recovery of the enriched 58Ni target material were simplified via a solid-phase extraction method. The radionuclide purity (> 99.9%) and metallic impurities (< 25 ppb) of purified 57Co were confirmed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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7. Mechanism of Knee Adduction Moment Reduction Through Contralateral Cane Use in Healthy Subjects.
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Shin, Hyeon-Soo, Lee, Jun-Young, Cho, Yeong-Jun, Kim, Min-Jae, and Eom, Gwang-Moon
- Abstract
The use of a contralateral cane has demonstrated a reduction in the external knee adduction moment (KAM) in patients with knee osteoarthritis. However, the underlying mechanism remains unclear. This study aimed to investigate the specific mechanism in healthy young subjects. Sixteen healthy young participants were included in this study. They walked on a floor under three loading conditions: no cane and with cane loads equivalent to 5% and 10% of body weight. Change in posture and kinetic features of ipsilateral leg were examined at two instants of ground reaction force (GRF) peaks. The results revealed a substantial decrease (40–55%) in both KAM and moment arm, whereas only 12% decrease was observed in GRF with 10% cane loading. Furthermore, KAM was strongly correlated with moment arm (r = 0.97, p < 0.01), but not with GRF (p > 0.05). The reduction in moment arm could be attributed to a medial shift of knee joint and/or a lateral shift of GRF. At the maximum cane loading, medial shift in the knee joint center was significant (p < 0.001), while any shift in GRF was insignificant (p > 0.80). The results suggest that the primary factor contributing to the reduction in KAM is the decrease in moment arm among healthy young subjects. Importantly, the reduction in moment arm was primarily induced by a medial shift of the knee joint center, emphasizing the significance of postural changes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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8. Design of a welding power supply with wide input voltage range.
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Kim, Jin-Su, Kim, Young-Joo, Nam, Seung-Min, Hong, Dae-Young, Kong, So-Jeong, and Lee, Jun-Young
- Published
- 2023
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9. 2-kW plasma power supply design with small frequency fluctuations.
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Hong, Dae-Young, Kong, So-Jeong, Jeong, Chang-Gyeo, Kwon, Jae-Hyun, Lee, Jun-Young, and Kim, Min-Jae
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- 2023
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10. Quantitative ultrasound for non-invasive evaluation of subclinical rejection in renal transplantation.
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Kim, Deok-Gie, Lee, Jun Young, Ahn, Jhii-Hyun, Lee, Taesic, Eom, Minseob, Cho, Hyun Seok, and Ku, Jihye
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KIDNEY transplantation , *MICROCIRCULATION disorders , *ELASTOGRAPHY , *DIAGNOSTIC ultrasonic imaging , *BIOPSY - Abstract
Objectives: This study aimed to investigate the predictive efficacy of shear-wave elastography, superb microvascular imaging (SMI), and CEUS for allograft rejection in kidney transplants without graft dysfunction. Methods: From January 2021 to November 2021, 72 consecutive patients who underwent both allograft biopsy and ultrasound were evaluated. Blood test results were obtained within a week of the ultrasound examinations, which were performed before the protocol biopsy. Resistive index (RI), tissue viscoelasticity, vascular index, and quantitative CEUS parameters were measured. Patients were divided based on biopsy results into the rejection and non-rejection groups. Results: Among the 72 patients, 21 patients had pathological characteristics of acute rejection. RI of allograft was significantly higher in the rejection group (p = 0.007), compared to the non-rejection group. There were no significant between-group differences in vascular indices of SMI, mean elasticity, and mean viscosity. Meanwhile, among the parameters obtained by the time-intensity curve on CEUS, the cortical and medullary ratios of average contrast signal intensity, peak enhancement, wash-in area AUC, wash-in perfusion index, wash-out AUC, and wash-in and wash-out AUC were significantly different between the two groups (p < 0.05). In the receiver operating characteristic curve analysis for predicting allograft rejection, the AUC was 0.853 for the combination of six CEUS parameters, RI, and blood urea nitrogen. Conclusions: Among non-invasive quantitative ultrasound measurements, CEUS parameters are the most useful for diagnosing subclinical allograft rejection. Furthermore, the combination of CEUS parameters, RI, and blood urea nitrogen may be helpful for the early detection of renal allograft rejection. Key Points: • Among non-invasive quantitative ultrasound measurements, CEUS parameters are the most useful for the diagnosis of subclinical allograft rejection. • On CEUS, the C/M ratios of MeanLin, PE, WiAUC, WiPI, WoAUC, and WiWoAUC are significantly lower in the rejection group; the combination of these showed reliable predictive performance for rejection. • The combination of CEUS parameters, RI, and BUN has a high predictive capability for subclinical allograft rejection. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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11. Design of a 6.6 kW charger based on an SRT converter applying a parallel structure of IGBT and Si-MOSFET.
- Author
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Choi, Jae-Hyuck, Kim, Young-Joo, Kim, Jin-Su, Kwon, Hyeok-Min, and Lee, Jun-Young
- Published
- 2023
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12. 3.3 kW bidirectional charger design based on active-clamp flyback circuits.
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Kwon, Hyeok-Min, Nam, Seung-Min, Choi, Jae-Hyuck, Jung, Chang-Gyeo, Lee, Jun-Young, and Kim, Young-Joo
- Published
- 2023
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13. Selective Area Epitaxy of Complex Oxide Heterostructures on Si by Oxide Hard Mask Lift-Off.
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Ning, Ruiguang, Jung, Soo Young, Choi, Haneul, Lee, Byeong-hyeon, Kim, Min-Seok, Choi, Hyung-Jin, Lee, Jun Young, Park, Jin Soo, Jung, Sung-Jin, Jang, Ho Won, Won, Sung Ok, Chang, Hye Jung, Jang, Ji-Soo, Lee, Kyu Hyoung, Lee, Byung Chul, and Baek, Seung-Hyub
- Abstract
Epitaxial complex oxide heterostructures on Si are an excellent platform for the realization of multifunctional electronic devices to exploit the unique functionalities of the oxides that Si does not possess. It is often necessary to make patterns of epitaxial films on selected areas of Si. Here, a path towards the selective area epitaxial growth of complex oxide heterostructures on Si using a hard mask lift-off technique is reported. A water-soluble oxide (Sr
3 Al2 O6 ) is used as a lift-off hard mask that can survive the high temperature (~ 750 °C) and oxidizing environments for epitaxial oxide growth and be selectively etched away subsequently using deionized water. It is found that the epitaxial growth of yttria-stabilized zirconia (YSZ) buffer layers on Si is very sensitive to organic residues formed during photolithography. Island patterns of epitaxial (La, Sr)MnO3 /CeO2 /YSZ heterostructures are successfully fabricated on Si through the use of oxygen plasma treatment to remove residues. A simple and low-cost method to pattern complex oxide single crystals integrated on Si for the realization of multifunctional oxide-integrated electronics is provided in this study. [ABSTRACT FROM AUTHOR]- Published
- 2023
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14. Perovskite multifunctional logic gates via bipolar photoresponse of single photodetector.
- Author
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Kim, Woochul, Kim, Hyeonghun, Yoo, Tae Jin, Lee, Jun Young, Jo, Ji Young, Lee, Byoung Hun, Sasikala, Assa Aravindh, Jung, Gun Young, and Pak, Yusin
- Subjects
LOGIC circuits ,PHOTODETECTORS ,PEROVSKITE ,DATA transmission systems ,PHOTODIODES ,ELECTRONIC data processing - Abstract
The explosive demand for a wide range of data processing has sparked interest towards a new logic gate platform as the existing electronic logic gates face limitations in accurate and fast computing. Accordingly, optoelectronic logic gates (OELGs) using photodiodes are of significant interest due to their broad bandwidth and fast data transmission, but complex configuration, power consumption, and low reliability issues are still inherent in these systems. Herein, we present a novel all-in-one OELG based on the bipolar spectral photoresponse characteristics of a self-powered perovskite photodetector (SPPD) having a back-to-back p
+ -i-n-p-p+ diode structure. Five representative logic gates ("AND", "OR", "NAND", "NOR", and "NOT") are demonstrated with only a single SPPD via the photocurrent polarity control. For practical applications, we propose a universal OELG platform of integrated 8 × 8 SPPD pixels, demonstrating the 100% accuracy in five logic gate operations irrelevant to current variation between pixels. The authors present a novel all-in-one optoelectronic logic gates based on the bipolar spectral photo-response characteristics of self-powered perovskite photodetector. Five representative logic gates are demonstrated with only a single detector via photocurrent polarity control. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
15. Three-phase 11 kW on-board charger with single-phase reverse function.
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Mun, Seung-Hwan, Choi, Seung-Won, Hong, Dae-Young, Kong, So-Jeong, and Lee, Jun-Young
- Published
- 2022
- Full Text
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16. Hydrophobic films for optical detection of dry carbon dioxide based on ion pairing and an amine polymer.
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Jeong, Semin, Lee, Chanmin, Lee, Jun-young, and Hwang, Ki-Seob
- Abstract
Existing optical carbon dioxide sensors using ion pair materials with pH indicators need moisture to function. To sense dry carbon dioxide gas, hydrophobic films were prepared using an amine polymer (branched-polyethyleneimine) instead of water, along with an ion pair dye and an aromatic polymer. The color of the ion pair formed between cresol red sodium salt and tetra-n-octylammonium bromide was yellow when the pH was below neutral. After adding branched polyethyleneimine, the color changed to violet as the pH became basic. On exposure to carbon dioxide, the amine groups on the branched-polyethyleneimine were converted to alkyl carbamate anions and ammonium cations via reaction with the carbon dioxide. When the ion pair reacted with the resulting ammonium cations, the film changed color from violet to yellow. It was determined that the degree of color change was dependent on the carbon dioxide exposure times and the amount of branched-polyethyleneimine added to the film. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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17. Design of pseudo-single-stage-type isolated/bidirectional converter for battery formation equipment.
- Author
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Kwon, Hyuk-Jin, Choi, Jae-Hyuck, Kwon, Hyeok-Min, Shin, Tae-Woong, Choi, Seung-Won, and Lee, Jun-Young
- Published
- 2022
- Full Text
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18. Design of 20 kW audio power supply for single-phase/three-phase applications.
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Kwon, Jae-Hyun, Kwon, Hyeok-Min, Choi, Seung-Won, Lee, Jun-Young, and Kim, Sung-Ok
- Published
- 2022
- Full Text
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19. Design of a 5.6 kW EV low-voltage DC/DC converter based on full-bridge converter with input series output parallel structure.
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Hong, Dae-Young, Kong, So-Jeong, and Lee, Jun-Young
- Published
- 2022
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- View/download PDF
20. High-efficiency 11 kW bi-directional on-board charger for EVs.
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Lee, Sang-Youn, Lee, Woo-Seok, Lee, Jun-Young, and Lee, Il-Oun
- Published
- 2022
- Full Text
- View/download PDF
21. Implications of the Overlapping Degree Between Proximal Fibula and Tibia for Placing the Optimal Syndesmotic Screw: A Virtual Cadaveric Study.
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Jung, Gu-Hee, Lee, Jun-Young, Lim, Jae-Hwan, Lee, Hyeon-Joon, and Lee, June-Yeon
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TIBIA surgery , *STRUCTURAL models , *BONE screws , *PLASTIC surgery , *TREATMENT effectiveness , *FRACTURE fixation , *FIBULA , *TOTAL ankle replacement , *DEAD - Abstract
Background: To determine the optimal direction of the syndesmotic screw and to introduce a consistent landmark for practical application by analyzing three-dimensional (3D) modeling and virtual implantation. Methods: A total of 105 cadaveric lower legs (50 males and 55 females; average height, 160.6 ± 7.1 cm) were used to reconstruct a 3D model by using the Mimics® software and the joint morphology was evaluated. Syndesmotic cylinders (Ø3.5 mm/Length 100 mm) were transversely placed in the proximal end of the incisura fibularis for simulating screw fixation. The tibial proximal cylinder, which was tangent to the posterior tibial condyles, was traced and the angle between the two cylinders was measured as the tibial torsion angle (TTA). After rotating the syndesmotic cylinder parallel to the ground, the overlapping degree between the proximal fibula and tibia was assessed as a radiologic indicator. Results: Concerning tibial torsion, the TTA was an average of 36.7° (range, 17.2°–54.4°; SD, 8.78) When the syndesmotic cylinder was rotated to be parallel to the ground, the proximal fibula had nonlinear or linear overlap with the lateral border of the tibia, regardless of the joint morphology. In this non-overlapping view, three Weber's indices for normal fibular length could be better visualized than the mortise view. Conclusion: The syndesmotic cylinder in the proximal end of the incisura fibularis could be consistently placed parallel to the ground by internally rotating the tibia until there was a nonlinear or linear overlap between the proximal fibula and the tibia, regardless of the joint morphology. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
22. Medical radioisotope 89Zr production with RFT-30 cyclotron.
- Author
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Lee, Jun Young, Hur, Min Goo, Kong, Young Bae, Lee, Eun Je, Yang, Seung Dae, Choi, Pyeong Seok, and Park, Jeong Hoon
- Subjects
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CYCLOTRONS , *RADIOISOTOPES , *POSITRON emission tomography , *NUCLEAR energy , *NUCLEAR research , *NUCLEAR medicine - Abstract
89Zr is an emerging radionuclide with promising application in nuclear medicine for the non-invasive diagnosis of various cancers with PET imaging. This paper would discuss optimization efforts in the production of 89Zr carried out at Accelerator Radioisotope Development Team, Korea Atomic Energy Research Institute. Optimized conditions reveal high production yields of 89Zr ~ 37 ± 1.4 MBq/µA using 89Y(p,n)89Zr, ~ 12.7 MeV of proton, and 35 µA using yttrium coin target with indigenously constructed 30 MeV Cyclotron (RFT-30). Besides, the production optimization, quality control, and biological behavior of [89Zr]Zr-oxalate, chloride and, DFO demonstrated promising results. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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23. High burden of cerebral white matter lesion in 9 Asian cities.
- Author
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Lam, Bonnie Yin Ka, Yiu, Brian, Ampil, Encarnita, Chen, Christopher Li-Hsian, Dikot, Yustiani, Dominguez, Jacqueline C., Ganeshbhai, Patel Vishal, Hilal, Saima, Kandiah, Nagaendran, Kim, SangYun, Lee, Jun-Young, Ong, Anam Paulus, Senanarong, Vorapun, Leung, Kam Tat, Wang, Huali, Yang, Yuan-Han, Yong, Tingting, Arshad, Faheem, Alladi, Suvarna, and Wong, Samuel
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LEUKOENCEPHALOPATHIES ,DISEASE prevalence ,MILD cognitive impairment ,TRANSIENT ischemic attack ,HYPERLIPIDEMIA - Abstract
Age-related white matter lesion (WML) is considered a manifestation of sporadic cerebral small vessel disease and an important pathological substrate for dementia. Asia is notable for its large population with a looming dementia epidemic. Yet, the burden of WML and its associated risk factors across different Asian societies are unknown. Subjects from 9 Asian cities (Bangkok, Bandung, Beijing, Bengaluru, Hong Kong, Kaohsiung, Manila, Seoul, and Singapore) were recruited (n = 5701) and classified into (i) stroke/transient ischemic attack (TIA), (ii) Alzheimer's disease (AD)/mild cognitive impairment (MCI), or (iii) control groups. Data on vascular risk factors and cognitive performance were collected. The severity of WML was visually rated on MRI or CT. The prevalence of moderate-to-severe WML was the highest in subjects with stroke/TIA (43.3%). Bandung Indonesia showed the highest prevalence of WML, adjusted for age, sex, education, disease groups, and imaging modality. Hypertension and hyperlipidemia were significant risk factors for WML, and WML was negatively associated with MMSE in all groups. WML is highly prevalent in Asia and is associated with increasing age, hypertension, hyperlipidemia, and worse cognitive performance. Concerted efforts to prevent WML will alleviate the huge dementia burden in the rapidly aging Asian societies. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
24. Automated severity scoring of atopic dermatitis patients by a deep neural network.
- Author
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Bang, Chul Hwan, Yoon, Jae Woong, Ryu, Jae Yeon, Chun, Jae Heon, Han, Ju Hee, Lee, Young Bok, Lee, Jun Young, Park, Young Min, Lee, Suk Jun, and Lee, Ji Hyun
- Subjects
ATOPIC dermatitis ,SEVERITY of illness index ,CONVOLUTIONAL neural networks ,ERYTHEMA ,DERMATOLOGY - Abstract
Scoring atopic dermatitis (AD) severity with the Eczema Area and Severity Index (EASI) in an objective and reproducible manner is challenging. Automated measurement of erythema, papulation, excoriation, and lichenification severity using images has not yet been investigated. Our aim was to determine whether convolutional neural networks (CNNs) could assess erythema, papulation, excoriation, and lichenification severity at a level of competence comparable to dermatologists. We created a standard dataset of 8,000 clinical images showing AD. Each component of the EASI was scored from 0 to 3 by three dermatologists. We trained four CNNs (ResNet V1, ResNet V2, GoogLeNet, and VGG-Net) with the image dataset and determined which CNN was the most suitable for erythema, papulation, excoriation, and lichenification scoring. The brightness of the images in each dataset was adjusted to − 80% to + 80% of the original brightness (i.e., 9 levels by 20%) to investigate if the CNNs accurately measured scores if image brightness levels were changed. Compared to the dermatologists' scoring, accuracy rates of the CNNs were 99.17% for erythema, 93.17% for papulation, 96.00% for excoriation, and 97.17% for lichenification. CNNs trained with brightness-adjusted images achieved a high accuracy without the need to standardize camera settings. These results suggested that CNNs perform at level of competence comparable to dermatologists for scoring erythema, papulation, excoriation, and lichenification severity. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
25. High waist circumference rather than high body mass index may be a predictive risk factor for the longer disease duration of chronic spontaneous urticaria.
- Author
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Kim, Yeong Ho, Do Han, Kyung, Bang, Chul Hwan, Lee, Ji Hyun, Lee, Jun Young, Park, Yong Gyu, and Park, Young Min
- Subjects
WAIST circumference ,BODY mass index ,DISEASE duration ,URTICARIA ,PROPORTIONAL hazards models - Abstract
In a previous study, we found that higher waist circumference (WC) and higher body mass index (BMI) both increase the risk of chronic spontaneous urticaria (CSU). The aim of this study was to determine whether WC and BMI also increase the duration of CSU. We used multivariable Cox proportional hazards models to determine the hazard ratio (HR) for longer disease duration (longer than 3 years) according to WC and BMI. A total of 52,667 subjects were enrolled and their mean age was 54.5. After adjustments for other confounding variables the high WC/high BMI group had 1.062 times higher HR (95% CI, 1.028–1.098) than the normal WC/normal BMI group. Interestingly, the high WC/normal BMI group showed a significantly higher HR (1.053; 95% CI, 1.008–1.101) than the normal WC/normal BMI group, but not the normal WC/high BMI group (0.998; 95% CI, 0.951–1.046). Taken together, our results suggest that high WC rather than high BMI is a predictive risk factor for the longer disease duration of CSU. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
26. Amine Functionalized Wheat Bran Husk as Bio-Based Organic Adsorbent for Low-Density Polyethylene Composite of Carbon Dioxide Capture.
- Author
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Kwon, Hyuk Jun, Lee, Chanmin, Kook, Jun-Won, Kim, Jung Hyun, Hwang, Kiseob, and Lee, Jun-Young
- Abstract
This study aimed to prepare a bio-based organic adsorbent (W-PEI) with amine functionalization via Schiff's reaction without carbonization of biomass. The bio-based organic adsorbent was prepared from wheat bran husk (WH), and amine functionalized to absorb CO
2 gas by conjugating polyethyleneimine (PEI) via Schiff's reaction to the aldehyde groups of periodated WH (p-WH). Then, the bio-based organic adsorbent was compounded with low-density polyethylene (LDPE) using a twin screw extruder. The polymeric composites (LDPE/W-PEI) and W-PEI were studied to characterize chemical structure, thermal properties, and CO2 adsorption ability. The CO2 adsorption capacity was measured by thermogravimetric analysis (TGA), and the analysis was performed through the exchange of N2 and CO2 under isothermal conditions at 75 °C. The amount of CO2 adsorption was 0.425 mmol/g of W-PEI powder, while that of polymeric composite (LDPE/W-PEI_20%) containing 20 wt% W-PEI was 0.034 mmol/g, which corresponds to an adsorption efficiency of 40% compared to that of the powder state. Therefore, polymeric composites with improved CO2 gas adsorption could be successfully applied to food packaging and building materials. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
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27. Silica/Epoxy Hybrid Encapsulation with High Heat-Resistance and Low Coefficient of Thermal Expansion.
- Author
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Lee, Sung Bum, Lee, Ho Sik, Son, Chang Bum, Kim, Sung Hee, and Lee, Jun Young
- Abstract
As a matrix resin of silica/epoxy hybrid encapsulation material with high heat resistance and low coefficient of thermal expansion, a tri-functional triglycidyl p-aminophenol (TGPAP) epoxy was successfully synthesized with the desired chemical structure by reacting epichlorohydrin with p-aminophenol using sodium hydroxide catalyst. In order to produce highly pure TGPAP with lower viscosity, a physical thin film vacuum distillation was carried out after synthesis, resulting in 97% purity with the viscosity of 700 cps at room temperature. Silica/TGPAP hybrid was fabricated using two kinds of ground fumed silica with different sizes of 20 μm and 9 μm. Glass transition temperature of the hybrid was found to be as high as 185 °C. Viscosity of the hybrid was 30,000 cps at room temperature before curing, implying good processability. When two different sizes of silica were used with 1 to 1 weight ratio, very low coefficient of thermal expansion of 22.79 ppm/°C was obtained. From thermal shock test, no cracks were observed even after 1,000 cycles of thermal shock between −40 °C and 125 °C when 67 wt% (45.8 vol%) of silica was involved in the hybrid. In conclusion, silica/TGPAP hybrid with improved processability, superior thermal shock resistance and low thermal expansion coefficient could be fabricated as electronic device encapsulation. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
28. Torch motor control algorithm for low spatter CO2 arc welding of ultra-thin steel sheets.
- Author
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Kang, Dong-Hun, Lee, Woo-Seok, Choi, Seung-Won, Lee, Jun-Young, Lee, Il-Oun, and Park, Jun-Sung
- Published
- 2020
- Full Text
- View/download PDF
29. Effectiveness of serum beta-2 microglobulin as a tool for evaluating donor kidney status for transplantation.
- Author
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Cha, Sung Whan, Shin, In Sik, Kim, Deok Gie, Kim, Sung Hoon, Lee, Jun Young, Kim, Jae Seok, Yang, Jae Won, Han, Byoung-Geun, and Choi, Seung Ok
- Subjects
KIDNEY transplantation ,MICROGLOBULINS ,KIDNEY function tests ,CREATININE ,GLOMERULAR filtration rate - Abstract
Kidney transplantations using expanded criteria donors (ECD) are being increasingly adopted, but no consensus tools are available to evaluate donor kidney status. Beta-2 microglobulin (B2MG) is a marker of kidney function, and herein, we evaluate the usefulness of assessing B2MG to evaluate donor kidney status. Fifty-seven kidney transplantations were performed from March 2017 to April 2019. Medical records were retrospectively reviewed, and relationships between clinical and laboratory variables and transplant outcomes were investigated. Thirty-eight patients received a standard criteria donor kidney and 19 patients an ECD kidney. Ten patients experienced delayed graft function (DGF), but no patient experienced primary nonfunction. Of the parameters studied, only donor renal replacement therapy (RRT) [odds ratio (OR) 24.162; p = 0.018] and donor serum B2MG (OR 22.685; p = 0.022) significantly predicted DGF. The presence of either of these two risk factors can better reflect the condition of the donor than previous classification. However, on their last follow-up creatinine and estimated glomerular filtration rate values in those with or without these risk factors were not significantly different. For an ECD with a B2MG level of <7.18 and no history of RRT, kidney transplantation can be undertaken without considering the possibility of kidney discard. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
30. Isolated three-port DC–DC converter employing ESS to obtain voltage balancing capability for bipolar LVDC distribution system.
- Author
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Sim, Juyoung, Lee, Jun-Young, and Jung, Jee-Hoon
- Subjects
- *
ENERGY storage , *ELECTRIC potential , *VOLTAGE-frequency converters , *CASCADE converters , *VOLTAGE regulators - Abstract
A bipolar low-voltage DC (LVDC) distribution system used in residential and building applications requires AC–DC converters and voltage balancers that balance the two DC bus polarities. The bipolar DC bus voltage level only relies on the voltage balancer tied with the AC grid. An isolated DC–DC converter for an energy storage system (ESS) with the voltage balancing capability is proposed to prevent the bipolar voltage level collapse caused by the failure of the grid-tied voltage balancer. The proposed converter topology is an enhanced three-port dual-active-bridge (DAB) converter which can balance the bipolar DC voltage level without complex control. Furthermore, it has less current stress in power switches than that of the conventional three-port DAB converter. The effectiveness of the proposed converter is verified with a 3-kW prototype converter. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
31. Use of raw-state bottom ash for aggregates in construction materials.
- Author
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Yoon, Jin Young, Lee, Jun Young, and Kim, Jae Hong
- Abstract
The recycling of raw-state bottom ash as it is holds an advantage from an economic and environmental standpoint in that it omits pre-processes such as milling and wetting. Its physical and chemical properties are first characterized for the purpose, and then the use of raw-state bottom ash for aggregates in construction materials is proposed. Preplaced aggregate concrete or dry-mixing concrete scheme can be selectively applied according to the particle size requirement of bottom ash aggregate. Preplaced bottom ash aggregate concrete is produced by placing the bottom ash aggregate in formwork and injecting grout to fill the voids. To ensure the injectability of the grout, relatively large-sized particles, greater than 5 mm, are recommended to be used. In the case of dry-mixing concrete, this is originally designed for manufacturing concrete masonry units and concrete blocks with a low water-to-cement ratio and consolidated zero-slump concrete using a mechanized vibrating mold. The experimental results show that bottom ash aggregate concrete has moderate compressive strength with a low density. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
32. Crosslinked Organosilicon-Acrylate Copolymer Moisture Barrier Thin Film Fabricated by Initiated Chemical Vapor Deposition (iCVD).
- Author
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Seok, Ji-Hoo, Kim, Sung Hee, Cho, Sung Min, Yi, Gi-Ra, and Lee, Jun Young
- Abstract
Crosslinked organosilicon-acrylate copolymer thin film with desired chemical composition was successfully fabricated by a simply modified initiated chemical vapor deposition (iCVD) process. Unlike the conventional iCVD copolymerization process, in our novel process, comonomers were injected together as one gas phase into the polymerization chamber from miscible liquid comonomer mixture. 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (V4D4) and cyclohexyl methacrylate (CHMA) were used as the comonomers and tert-butyl peroxide was used as the initiator. From Fourier transform infrared (FTIR) spectra and solvent resistance test, we clearly confirmed that the crosslinked copolymer thin film with desired chemical composition could be obtained by controlling only the mixing ratio of liquid comonomers. It is expected that crosslinkable V4D4 organosilicon moiety provides hydrophobic moisture barrier property and CHMA acrylate moiety provides mechanical flexibility and better adhesion. We observed a certain level of moisture blocking capability of the copolymer thin film, implying potential application of the crosslinked organosilicon-acrylate copolymer thin film as flexible polymer buffer layer in organic/inorganic or metal oxide hybrid moisture barrier for flexible display or electronic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
33. Evaluation of relationships between onychomycosis and vascular diseases using sequential pattern mining.
- Author
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Bang, Chul Hwan, Yoon, Jae Woong, Lee, Hyun Ji, Lee, Jun Young, Park, Young Min, Lee, Suk Jun, and Lee, Ji Hyun
- Published
- 2018
- Full Text
- View/download PDF
34. Effects of Resistance Exercise Training on Cognitive Function and Physical Performance in Cognitive Frailty: A Randomized Controlled Trial.
- Author
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Yoon, D. H., Lee, Jun-Young, and Song, Wook
- Subjects
KNEE physiology ,COGNITION disorders ,POSTURAL balance ,FRAIL elderly ,GRIP strength ,RANGE of motion of joints ,MUSCLE strength ,PRIMARY health care ,SHORT-term memory ,STRETCH (Physiology) ,BODY movement ,RANDOMIZED controlled trials ,TREATMENT effectiveness ,INDEPENDENT living ,PHYSICAL activity ,EXECUTIVE function ,DESCRIPTIVE statistics ,RESISTANCE training ,WALKING speed ,OLD age ,PREVENTION - Abstract
Background: Cognitive frailty is defined as the presence of both physical frailty and cognitive impairment (clinical dementia rating score = 0.5), in the absence of dementia. It is characterized by concurrent physical frailty and potentially reversible cognitive impairment. In this study, we sought to elucidate the effects of high-speed resistance exercise training on cognitive function and physical performance in older adults with cognitive frailty.Methods: We conducted a parallel-group, randomized controlled trial involving community-living older adults with cognitive frailty. The participants’ mean age was 73.9 (± 4.3 SD) years, and 69.8% (n=30) were female. Two different 4-month interventions included high-speed resistance exercise training group (n=22) and a control group (balance and band stretching, n=23). Frailty score, cognitive function (memory, processing speed, cognitive flexibility, working memory, executive function), physical function (SPPB, TUG, gait speed), and muscle strength (grip strength, knee extension strength) were assessed at baseline, 8 weeks, and 16 weeks.Results: Statistical analysis showed that exercise improved performance significantly in the tests for cognitive function (processing speed and executive function, both p < 0.05), physical function (SPPB, TUG, gait speed, both p < 0.05), and muscle strength (grip strength, knee extension strength, both p < 0.05). However, no significant changes in frailty score were observed between intervention and either control group (p < 0.05).Conclusion: In conclusion, our findings indicate that high-speed resistance exercise training approaches are effective in improving cognitive function and physical performance in older adults with cognitive frailty. This study shows that it is feasible to identify older adults with cognitive frailty in the community and primary care setting for effective intervention to reduce their level of frailty and cognitive impairment. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
35. Visual Rating and Computer-Assisted Analysis of FDG PET in the Prediction of Conversion to Alzheimer’s Disease in Mild Cognitive Impairment.
- Author
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Kang, Jae Myeong, Lee, Jun-Young, Kim, Yu Kyeong, Sohn, Bo Kyung, Byun, Min Soo, Choi, Ji Eun, Son, Soo Kyung, Im, Hyung-Jun, Lee, Jae-Hoon, Ryu, Young Hoon, and Lee, Dong Young
- Subjects
- *
ALZHEIMER'S disease diagnosis , *MILD cognitive impairment , *FLUORODEOXYGLUCOSE F18 , *POSITRON emission tomography , *PREDICTION theory - Abstract
Background: Fluorodeoxyglucose (FDG) positron emission tomography (PET) is useful to predict Alzheimer’s disease (AD) conversion in patients with mild cognitive impairment (MCI). However, few studies have examined the extent to which FDG PET alone can predict AD conversion and compared the efficacy between visual and computer-assisted analysis directly.Objective: The current study aimed to evaluate the value of FDG PET in predicting the conversion to AD in patients with MCI and to compare the predictive values of visual reading and computer-assisted analysis.Methods and materials: A total of 54 patients with MCI were evaluated with FDG PET and followed-up for 2 years with final diagnostic evaluation. FDG PET images were evaluated by (1) traditional visual rating, (2) composite score of visual rating of the brain cortices, and (3) composite score of computer-assisted analysis. Receiver operating characteristics (ROC) curves were compared to analyze predictive values.Results: Nineteen patients (35.2%) converted to AD from MCI. The area under the curve (AUC) of the ROC curve of the traditional visual rating, composite score of visual rating, and computer-assisted analysis were 0.67, 0.76, and 0.79, respectively. ROC curves of the composite scores of the visual rating and computer-assisted analysis were comparable (Z = 0.463, p = 0.643).Conclusions: Visual rating and computer-assisted analysis of FDG PET scans were analogously accurate in predicting AD conversion in patients with MCI. Therefore, FDG PET may be a useful tool for screening AD conversion in patients with MCI, when using composite score, regardless of the method of interpretation. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
36. A Framework for Prognostics and Health Management Applications toward Smart Manufacturing Systems.
- Author
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Shin, Insun, Lee, Junmin, Lee, Jun Young, Jung, Kyusung, Kwon, Daeil, Youn, Byeng D., Jang, Hyun Soo, and Choi, Joo-Ho
- Published
- 2018
- Full Text
- View/download PDF
37. Synthesis and evaluation of triphenylphosphonium conjugated 18F-labeled silica nanoparticles for PET imaging.
- Author
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Kim, Gun Gyun, Lee, Jun Young, Choi, Pyeong Seok, Vyas, Chirag K., Yang, Seung Dae, Hur, Min Gu, and Park, Jeong Hoon
- Subjects
- *
CANCER cells , *CELL membranes , *SILICA nanoparticles , *POSITRON emission tomography , *EXTRACELLULAR space - Abstract
Accumulation of triphenylphosphonium (TPP) is normally observed in the mitochondria from the extracellular spaces due to the high difference in plasma membrane potential of the mitochondria. In the cancer cells, the mitochondrial membrane potential gap is higher as compared to that of normal cells resulting in elevated uptake of TPP. Silica nanoparticles (SNPs) being widely developed and used for biomedical applications, in this study, we tried to modify the surface of SNPs with varying amounts of TPP to verify their possible application as a positron emission tomography (PET) agent. The studies confirmed that the high level of TPP loading on the surface of SNPs possess higher positive charge (+ 31.5 mV). Owing to this behavior of plasma membrane potential of cancerous cells the uptake of positively charged SNPs was much higher in tumor cells than that of normal cells which was confirmed by PET imaging. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
38. Fully organic CO2 absorbent obtained by a Schiff base reaction between branched poly(ethyleneimine) and glutaraldehyde.
- Author
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Hwang, Ki-Seob, Park, Hee-Young, Kim, Jung-Hyun, and Lee, Jun-Young
- Abstract
We used a water-in-oil emulsification method to prepare particulate CO
2 absorbents from branched poly(ethyleneimine) (PEI), utilizing13 C nuclear magnetic resonance spectroscopy to determine the amount of free PEI NH2 groups and thus calculate the required cross-linker amount. The functional groups and reactivity of branched PEI particles were characterized by Fourier transform infrared spectroscopy, and their CO2 absorption capacity was determined by thermogravimetric analysis. Dynamic light scattering measurements showed that the synthesized particles exhibited sizes of 0.2-2 μm and high surface areas, which resulted in high CO2 absorption capacities of up to 2.18 mmol CO2 per gram sorbent at 75 °C. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
39. Physicochemical analysis of linear low-density polyethylene composite films containing chemically treated rice husk.
- Author
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Hwang, Ki, Kwon, Hyuk, and Lee, Jun-Young
- Abstract
A study was conducted to determine the appropriate surface treatment for rice husks (RH) in polymer composite film to improve the physical properties relative to those of untreated RH/linear low-density polyethylene (LLDPE) film. Pulverized RH was treated with NaOH (RH-m) and acetic acid (RH-ac) to prepare composite films with LLDPE resin. The treated RH showed typical mercerization and acetylation, as confirmed by spectroscopic and thermal analysis methods. The RH-m sample was mercerized, allowing decomposition of hemicellulose and partially amorphous cellulose. The RH-ac sample was processed via acetylation inducing partial lignin decomposition. Field-emission scanning electron microscopy showed smaller gaps at the RH/LLDPE interface for RH-m and RH-ac compared to that with untreated RH, implying increased composite compatibility. RH-m in particular showed superior tensile strength (15.85 N/mm), elongation (884%), Young's modulus (60.01 N/mm), and tear strength (7.71N/mm) compared to untreated RH and RH-ac. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
40. Water vapor permeability, morphological properties, and optical properties of variably hydrolyzed poly(vinyl alcohol)/linear low-density polyethylene composite films.
- Author
-
Hwang, Ki, Kwon, Hyuk, and Lee, Jun-Young
- Abstract
Poly(vinyl alcohol) (PVA)/ linear low-density polyethylene (LLDPE) composite films were prepared using PVAs of various molecular weights and degrees of hydrolysis. The crystallinity, water permeability, mechanical properties, and optical properties of the composite films were analyzed based on the absorption properties of the different PVAs. The formation of the composite film became increasingly difficult with increase in the molecular weight and the degree of hydrolysis of PVA, because the resulting crystallinity increased the intramolecular hydrogen bonding of the hydroxyl groups on the main chains of PVA. The 4-98/LLDPE composite film absorbed water gradually and continuously for a long time, and its water vapor absorption rate was similar to that of the 4-88/LLDPE film but lower than that of the PVA 205/LLDPE film. The mechanical properties of the 4-98/LLDPE film were slightly better than those of the 4-88/LLDPE film but inferior to those of the PVA 205/LLDPE film. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
41. Development of a transformable wheel actuated by soft pneumatic actuators.
- Author
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Yun, Sung-Sik, Lee, Jun-Young, Jung, Gwang-Pil, and Cho, Kyu-Jin
- Abstract
Small mobile robots with transformable wheels have recently emerged thanks to their increased mobility and maneuverability. When a high payload is applied to these robots, however, wheel transformation becomes difficult because they must directly overcome the payload's weight. In this paper, we propose a wheel that can be transformed from its starting circular shape (radius, 56 mm) to a wheel with three legs (radius, 99 mm) under a high payload with low operating force. The key design principle of this wheel is to kinematically decoupled legs and passive locking. Its legs are kinematically decoupled but operated by a single air pump using a pneumatic channel connected to soft pneumatic actuators installed at each leg. Application of pressure causes the legs to behave like a coupled system through the pneumatic channel. With pressurization, the two legs that are not in contact with the ground easily emerge from body, and the leg in contact with the ground emerges once the wheel rotates. Once emerged, each leg is supported by a rigid pawl instead of by the soft pneumatic actuators. This setup enables the legs to be transformed independently with low air pressure, even under high payloads. It reduces system weight and the energy required to maintain the transformed shape. This legged wheel can overcome obstacles up to 2.9 times the radius of the wheel in its circular form, and wheel transformation can be accomplished with 85 kPa air pressure for payloads up to 1115 g. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
42. Correction: Selective Area Epitaxy of Complex Oxide Heterostructures on Si by Oxide Hard Mask Lift-Off.
- Author
-
Ning, Ruiguang, Jung, Soo Young, Choi, Haneul, Lee, Byeong-hyeon, Kim, Min-Seok, Choi, Hyung-Jin, Lee, Jun Young, Park, Jin Soo, Jung, Sung-Jin, Jang, Ho Won, Won, Sung Ok, Chang, Hye Jung, Jang, Ji-Soo, Lee, Kyu Hyoung, Lee, Byung Chul, and Baek, Seung-Hyub
- Published
- 2023
- Full Text
- View/download PDF
43. Clinical Meaning of Hot Uptake on Bone Scan in Symptomatic Accessory Navicular Bones.
- Author
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Chong, Ari, Ha, Jung-Min, and Lee, Jun-Young
- Abstract
Introduction: We analyzed clinical factors related to uptake on a Tc-99 m HDP bone scan of the accessory navicular (AN). Materials and Methods: We retrospectively reviewed patients who had been examined by an orthopedic surgeon and underwent bone scan due to suspected symptomatic AN. A three-point grading system was used to evaluate uptake on bone scan. Relationships between grade, symptoms, age, gender, symptom duration, and bone size were analyzed. Results: In total, 73 ANs (30 asymptomatic, 43 symptomatic) were enrolled. The majority of asymptomatic ANs had no uptake but some had grade 1 ( n = 8) or 2 ( n = 2) uptake. All asymptomatic ANs with uptake remained asymptomatic during follow-up. For the asymptomatic ANs, larger bones showed a higher grade. With a cut-off value of size ≤6.8 mm, there is no chance of uptake. All symptomatic ANs showed uptake on bone scan. For symptomatic ANs, larger size and shorter pain duration were related to a higher grade. Age, gender, and left-/right-sideness were not related to grade. Multiple regressions revealed that only uptake grade, not size or symptom duration, was the significant risk factor for a symptomatic AN. With a cut-off value of grade <1, a symptomatic AN could be ruled out with a negative predictive value of 100 %. Conclusion: Bone scanning is useful for symptomatic ANs with a high negative predictive value. Higher grade is related to larger size and shorter pain duration. For asymptomatic ANs, grade was related to size but did not predict symptom development. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
44. Lactobacillus curvatus WiKim38 isolated from kimchi induces IL-10 production in dendritic cells and alleviates DSS-induced colitis in mice.
- Author
-
Jo, Sung-Gang, Noh, Eui-Jeong, Lee, Jun-Young, Kim, Green, Choi, Joo-Hee, Lee, Mo-Eun, Song, Jung-Hee, Chang, Ji-Yoon, and Park, Jong-Hwan
- Abstract
Probiotics such as lactobacilli and bifidobacteria have healthpromoting effects by immune modulation. In the present study, we examined the immunomodulatory properties of Lactobacillus curvatus WiKim38, which was newly isolated from baechu (Chinese cabbage) kimchi. The ability of L. curvatus WiKim38 to induce cytokine production in bone marrow-derived dendritic cells (BMDCs) was determined by enzyme-linked immunosorbent assay. To evaluate the molecular mechanisms underlying L. curvatus Wikim38-mediated IL-10 production, Western blot analyses and inhibitor assays were performed. Moreover, the in vivo anti-inflammatory effects of L. curvatus WiKim38 were examined in a dextran sodium sulfate (DSS)-induced colitis mouse model. L. curvatus WiKim38 induced significantly higher levels of IL-10 in BMDCs compared with that induced by LPS. NF-κB and ERK were activated by L. curvatus WiKim38, and an inhibitor assay revealed that these pathways were required for L. curvatus WiKim38-induced production of IL-10 in BMDCs. An in vivo experiment showed that oral administration of L. curvatus WiKim38 increased the survival rate of mice with DSS-induced colitis and improved clinical signs and histopathological severity in colon tissues. Taken together, these results indicate that L. curvatus Wikim38 may have health-promoting effects via immune modulation, and may thus be applicable for therapy of various inflammatory diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
45. Hierarchical Nanoflowers on Nanograss Structure for a Non-wettable Surface and a SERS Substrate.
- Author
-
Lee, Jun-Young, Han, Jaehyun, Lee, Jihye, Ji, Seungmuk, and Yeo, Jong-Souk
- Subjects
NANOSTRUCTURED materials ,WETTING ,SUBSTRATES (Materials science) ,SURFACES (Technology) ,COPPER oxide ,SERS spectroscopy - Abstract
Hierarchical nanostructures of CuO nanoflowers on nanograss were investigated for self-cleaning and surface plasmonic applications. We achieved the hierarchical nanostructures using one-step oxidation process by controlling the formation of flower-like nanoscale residues (nanoflowers) on CuO nanograss. While the nanograss structure of CuO has a sufficient roughness for superhydrophobic characteristics, the additional hierarchy of nanoflowers on nanograss leads to a semi-reentrant structure with a high repellency even for a very small droplet (10 nL) of low surface tension liquid such as 25 % ethanol (~35 mN/m), thus providing non-wettable and self-cleaning properties. Furthermore, the CuO hierarchical nanostructure serves as a substrate for surface-enhanced Raman spectroscopy (SERS). Both of the CuO nanograss and nanoflower provide many nanoscale gaps that act as hot-spots for surface-enhanced Raman signal of 4-mercaptopyridine (4-Mpy), thus enabling a non-destructive detection in a short analysis time with relatively simple preparation of sample. Especially, the CuO nanoflower has larger number of hot-spots at the nanogaps from floral leaf-like structures, thus leading to three times higher Raman intensity than the CuO nanograss. These multifunctional results potentially provide a path toward cost-effective fabrication of a non-wettable surface for self-maintenance applications and a SERS substrate for sensing applications. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
46. Preparation of hypercrosslinked poly(DVB-VBC) particles with high surface area and structured meso- and micropores.
- Author
-
Hwang, Ki, Choi, Won, Kim, Jung-Hyun, and Lee, Jun-Young
- Abstract
Spherical porous polymer particles with high surface area were synthesized using the water-in-oil-inwater (W/O/W) emulsion polymerization and Friedel-Crafts reaction. After the preparation of W/O emulsions, spherical porous polymer particles were synthesized by suspension polymerization. Spherical porous polymer precursor particles were subjected to Friedel-Crafts reaction using a Lewis acid catalyst. The properties of the final products synthesized with different porogen contents in the water-in-oil (W/O) emulsion were explored. The Friedel-Crafts reaction was used to increase the Brunauer-Emmett-Teller (BET) surface area. In order to identify the effects of the porogen levels and of the Friedel-Crafts reaction, the synthesized porous particles were analyzed by particle size analyzer (PSA), Hg porosimetry, and the BET surface area method. In addition, the morphology of the particles was investigated by FE-SEM. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
47. Ten-year trends in the prevalence and correlates of major depressive disorder in Korean near-elderly adults: a comparison of repeated nationwide cross-sectional studies from 2001 and 2011.
- Author
-
Park, Jee, Lee, Jun-Young, Sohn, Ji, Seong, Su, Cho, Maeng, Park, Jee Eun, Sohn, Ji Hoon, Seong, Su Jeong, and Cho, Maeng Je
- Subjects
- *
DEPRESSION in old age , *CROSS-sectional method , *SOCIAL change , *MENTAL health of older people , *SOCIODEMOGRAPHIC factors , *SELF-evaluation , *LOGISTIC regression analysis , *UNEMPLOYMENT & psychology , *DEMOGRAPHY , *MENTAL depression , *SURVEYS , *UNEMPLOYMENT , *SOCIOECONOMIC factors , *DISEASE prevalence , *MIDDLE age - Abstract
Purpose: Near-elderly adults go through many changes in socioeconomic status, such as retirement, which may affect their mental health differently according to when they live. We aimed to compare the prevalence of major depressive disorder (MDD) and its changes according to sociodemographic factors using nationally representative surveys of Korean near-elderly adults conducted 10 years apart.Methods: Nationwide community samples of individuals aged 55-64 years living in 2001 (n = 1256) and 2011 (n = 1066) were compared. Face-to-face interviews were conducted using the Korean version of the Composite International Diagnostic Interview to diagnose MDD. Sociodemographic data were collected using self-reported questionnaires including questions on employment and economic status. We examined differences in MDD prevalence and its association with sociodemographic factors over time by calculating 2011-to-2001 odds ratios (ORs) using multivariable logistic regression models.Results: Among near-elderly people, MDD tended to be more prevalent in 2011 than in 2001. However, only near-elderly men in 2011 showed a higher risk of MDD compared with those in 2001 (2011-to-2001 OR 4.19), while women did not. The prevalence ratio by gender decreased from 7.04 in 2001 to 2.34 in 2011. Among vulnerable sociodemographic groups, a significant increase in MDD was observed in unemployed men (adjusted OR 8.35), but not in unemployed women or other vulnerable groups.Conclusion: This study provides evidence of a substantial increase in MDD in Korean near-elderly men and suggests that unemployment should be considered as an important correlate of MDD in this group. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
48. Application of cross-linked poly(acrylic acid)-poly(styrene- alt-maleic anhydride) core-shell microcapsule absorbents in cement mortars.
- Author
-
Hwang, Kiseob, Jang, Seoksoo, Jung, Yongwook, Lee, Seunghan, Lee, Jun-Young, and Ha, KiRyong
- Abstract
We synthesized core-shell microcapsule absorbents with crosslinked poly(acrylic acid) (PAA) as the core and poly(styrene- alt-maleic anhydride) (cPAA-PSMA) as the shell by the precipitation polymerization method for delayed absorption of excess water in cement mortar. To control the shell thickness, cPAA-PSMA capsules were synthesized with the core-to-shell monomer mass ratios of 1: 0 (cPAA #1), 1: 0.5 (cPAA-PSMA #2), 1: 1 (cPAA-PSMA #3), and 1: 1.5 (cPAA-PSMA #4). The viscosity of the cement paste with cPAA-PSMA #4 absorbent increased slowly until 90minutes after absorbent addition, beyond which it increased rapidly. This suggests that mortars with cPAA-PSMA #4 absorbents can secure up to 90 minutes of working time. Incorporation of 1.0 wt% cPAA-PSMA #4 into cement mortar increased the compressive and flexural strengths by approximately 35% and 22%, respectively, compared to those of cement mortars without absorbents. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
49. Impact of stigma on use of mental health services by elderly Koreans.
- Author
-
Park, Jee, Cho, Seong-Jin, Lee, Jun-Young, Sohn, Jee, Seong, Su, Suk, Hye, and Cho, Maeng
- Subjects
SOCIAL stigma ,MENTAL health services ,KOREANS ,PSYCHOLOGY of age groups ,MENTAL illness ,PSYCHOLOGY - Abstract
Purpose: This study compared the factors associated with the utilization of mental health services across various age cohorts, with a particular focus on the differential influence of the stigma placed on mental illness on the use of these services. Methods: The present study used data from a Korean national epidemiological survey of mental disorders among community-dwelling adults aged 18-74 years ( n = 3,055). The subjects were categorized into three age groups: young (18-39), middle-aged (40-59), and late adulthood (60-74). The Perceived Devaluation-Discrimination scale was used to assess the stigma placed on mental disorders in each group. The influence of perceived stigma on lifetime utilization of mental health services was examined according to age cohort using multiple logistic regression analyses that were adjusted for various sociodemographic factors ( p < 0.006 with a Bonferroni correction). Results: The late-adulthood cohort was more likely to have perceived stigma of mental illness than were the other two groups, and the utilization of mental health services by the elderly cohort was more strongly affected by this perceived stigma than was such utilization by younger cohorts [adjusted odds ratio (AOR) 4.14, 95 % confidence interval (CI) 1.86-9.22]. In the middle-aged cohort, being female or never being married was a significant determinant of use of mental health services (female, AOR 3.80, 95 % CI 2.17-6.65; unmarried, AOR 3.09, 95 % CI 1.43-6.70). Conclusion: It is important to reduce the perceived stigma placed on mental illness to improve access to mental health care among the current population of elderly people in Korea. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
50. Analysis of the origin of periodic oscillatory flow in the continuous casting mold.
- Author
-
Lee, Jun-young, Kim, Yong-tae, and Yi, Kyung-woo
- Abstract
It is very important to understand flow patterns within the continuous casting mold because they have a significant impact on product quality. Water model experiment and particle image velocimetry were conducted to identify the fluid flow pattern in the steel slab continuous casting mold. The fluid flow pattern in the mold is not steady but instead an oscillatory flow with a specific oscillation frequencies. Many studies have been reported about oscillatory flow within the mold. However, these studies do not provide a clear explanation of physical origin of oscillatory flow. We identified the physical origins of various specific oscillation frequencies, and confirmed through experimentation and simulation that each frequency is related to the cross flow and injection stream oscillation. Moreover, the degree of oscillation at each frequency appears differently depending on the location within the mold, and is shown to have a effect near the mold wall. These results provide a better understanding of complex oscillatory flow patterns within the mold. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
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