249 results on '"Ji-Hyun, Jang"'
Search Results
2. Utilizing a Siloxane-Modified Organic Semiconductor for Photoelectrochemical Water Splitting
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Hyo-Jin Ahn, Ki-Yong Yoon, Mingi Sung, Hyeonjin Yoo, Hyungju Ahn, Byoung Hoon Lee, Junghoon Lee, and Ji-Hyun Jang
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Fuel Technology ,Renewable Energy, Sustainability and the Environment ,Chemistry (miscellaneous) ,Materials Chemistry ,Energy Engineering and Power Technology - Published
- 2023
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3. Data Mining for Classificational Prediction of Poly-victim Children by School Adaptation Factors and Local Spatial Factors
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Ji Hyun Jang, Hyun Ok Kim, and Soo Young Kim
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General Earth and Planetary Sciences ,General Environmental Science - Published
- 2023
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4. The Effect of In-flight Hygiene Factors on Affective Image and Customer's Hygiene-related Citizenship Behavior
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Ji-Hyun Jang, Yoonho Roh, and Yeong-Hyeon Hwang
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- 2023
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5. Boosting Charge Transfer Efficiency by Nanofragment MXene for Efficient Photoelectrochemical Water Splitting of NiFe(OH)x Co-Catalyzed Hematite
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Juhyung Park, Ki-Yong Yoon, Myung-Jun Kwak, Jihun Kang, Suhee Kim, Sourav Chaule, Seong-Ji Ha, and Ji-Hyun Jang
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General Materials Science - Published
- 2023
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6. A Social Network Analysis among Regional Lifelong Education Institutions : Focusing on lifelong education institutions in Ulsan Metropolitan City
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Gi-Wang Shin and Ji-Hyun Jang
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General Engineering ,Energy Engineering and Power Technology - Published
- 2022
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7. A Study on Independent Living Program for Borderline Intellectual Functioning Children from Out-of-Home Care
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Hyun-ju Kim, Kyung-im Han, and Ji-hyun Jang
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Psychiatry and Mental health - Published
- 2022
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8. Comparison of outcomes between abdominal, minimally invasive and combined vaginal-laparoscopic hysterectomy in patients with stage IAI/IA2 cervical cancer: 4C (Canadian Cervical Cancer Collaborative) study
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Sabrina Piedimonte, Gregory R. Pond, Marie Plante, Gregg Nelson, Janice Kwon, Alon Altman, Tomer Feigenberg, Laurie Elit, Susie Lau, Jeanelle Sabourin, Karla Willows, Christa Aubrey, Ji-Hyun Jang, Ly-Ann Teo-Fortin, Norah Cockburn, Nora-Beth Saunders, Sarah Shamiya, Limor Helpman, and Danielle Vicus
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Adult ,Aged, 80 and over ,Canada ,Uterine Cervical Neoplasms ,Obstetrics and Gynecology ,Middle Aged ,Hysterectomy ,Disease-Free Survival ,Young Adult ,Oncology ,Humans ,Minimally Invasive Surgical Procedures ,Female ,Laparoscopy ,Aged ,Neoplasm Staging ,Retrospective Studies - Abstract
Although minimally invasive hysterectomy (MIS-H) has been associated with worse survival compared to abdominal hysterectomy (AH) for cervical cancer, only 8% of patients in the LACC trial had microinvasive disease (Stage IA1/IA2). We sought to determine differences in outcome among patients undergoing MIS-H, AH or combined vaginal-laparoscopic hysterectomy (CVLH) for microinvasive cervical cancer.A retrospective cohort study of all patients undergoing hysterectomy (radical and non radical) for FIGO 2018, microinvasive cervical cancer across 10 Canadian centers between 2007 and 2019 was performed. Recurrence free survival (RFS) was estimated using Kaplan Meier Survival analysis. Chi-square and log-rank tests were used to compare outcomes.423 patients with microinvasive cervical cancer were included; 259 (61.2%) Stage IA1 (22/8.5% with LVSI) and 164(38.8%) IA2. The median age was 44 years (range 24-81). The most frequent histology was squamous (59.4%). Surgical approach was: 50.1% MIS-H (robotic or laparoscopic), 35.0% AH and 14.9% CVLH. Overall, 70.9% underwent radical hysterectomy and 76.5% had pelvic lymph node assessment. There were 16 recurrences (MIS-H:4, AH:9, CVLH: 3). No significant difference in 5-year RFS was found (96.7% MIS-H, 93.7% AH, 90.0% CVLH, p = 0.34). In a sub-analysis of patients with IA1 LVSI+/IA2(n = 186), survival results were similar. Further, there was no significant difference in peri-operative complications (p = 0.19). Patients undergoing MIS-H had a shorter median length of stay(0 days vs 3 (AH) vs. 1.5 (CVLH), p0.001), but had more ER visits (16.0% vs 3.6% (AH), 3.5% (CVLH), p = 0.036).In this cohort, including only patients with microinvasive cervical cancer, no difference in recurrence was found by surgical approach. This may be due to the low rate of recurrence making differences hard to detect or due to a true lack of difference. Hence, this patient population may benefit from MIS without compromising oncologic outcomes.
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- 2022
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9. Bi-functional 3D-NiCu-Double Hydroxide@Partially Etched 3D-NiCu Catalysts for Non-Enzymatic Glucose Detection and the Hydrogen Evolution Reaction
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Kyeong-Nam Kang, Sun-I Kim, Jong-Chul Yoon, Jinho Kim, Collin Cahoon, and Ji-Hyun Jang
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General Materials Science - Abstract
Hydrogen production, which is in the spotlight as a promising eco-friendly fuel, and the need for inexpensive and accurate electronic devices in the biochemistry field are important emerging technologies. However, the use of electrocatalytic devices based on expensive noble metal catalysts limits commercial applications. In recent years, to improve performance and reduce cost, electrocatalysts based on cheaper copper or nickel materials have been investigated for the non-enzymatic glucose oxidation reaction (GOR) and hydrogen evolution reaction (HER). In this study, we demonstrate a facile and easy electrochemical method of forming a cheap nickel copper double hydroxide (NiCu-DH) electrocatalyst deposited onto a three-dimensional (3D) CuNi current collector, which can effectively handle two different reactions due to its high activity for both the GOR and the HER. The as-prepared electrode has a structure comprising abundant 3D-interconnected porous dendritic walls for easy access of the electrolyte ions and highly conductive networks for fast electron transfer; additionally, it provides numerous electroactive sites. The synergistic combination of the dendritic 3D-CuNi with its abundant active sites and the self-made NiCu-DH with its excellent electrocatalytic activity toward the oxidation of glucose and HER enables use of the catalyst for both reactions. The as-prepared electrode as a glucose sensor exhibits an outstanding glucose detection limit value (0.4 μM) and a wide detection range (from 0.4 μM to 1.4 mM) with an excellent sensitivity of 1452.5 μA/cm
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- 2022
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10. Graphene‐Encapsulated Bifunctional Catalysts with High Activity and Durability for Zn–Air Battery
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Seong‐Ji Ha, Jongha Hwang, Myung‐Jun Kwak, Jong‐Chul Yoon, and Ji‐Hyun Jang
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Biomaterials ,General Materials Science ,General Chemistry ,Biotechnology - Published
- 2023
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11. A Study on the Differences and Decision Tree of Children’s Emotional Behavior according to the Mixed Spatial Types
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Hyun Ok Kim, Ji Hyun Jang, and Sooyoung Kim
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- 2022
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12. Unveiling the Role of the Ti Dopant and Viable Si Doping of Hematite for Practically Efficient Solar Water Splitting
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Ki-Yong Yoon, Juhyung Park, Hosik Lee, Ji Hui Seo, Myung-Jun Kwak, Jun Hee Lee, and Ji-Hyun Jang
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General Chemistry ,Catalysis - Published
- 2022
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13. Awareness of the Operation Status and Activation Plans of Lifelong Learning City for the Disabled by the Persons Concerned: Focusing on Busan Metropolitan City
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Yoo-Kyung Seo, Jae-Kook Park, and Ji-Hyun Jang
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General Medicine - Published
- 2022
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14. Factors influencing the intention to use VR for travel information search: A study of VR users in China
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Lu Wang, Ji-Hyun Jang, and Yeong-Hyeon Hwang
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- 2022
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15. A randomized clinical trial for comparing the efficacy of desensitizing toothpastes on the relief of dentin hypersensitivity
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Ji-Hyun Jang, Soram Oh, Hyun-Jung Kim, and Duck-Su Kim
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Multidisciplinary - Abstract
The 4-week double-blind clinical trial to manage dentin hypersensitivity (DH) using different desensitizing toothpastes was conducted. 53 participants with DH were enrolled in this trial. The participants were randomized into 3 groups: Group N; no active ingredient-containing toothpaste (Pleasia fluoride-free), Group SC; a toothpaste containing strontium chloride (Sensodyne Original), and Group TP; a toothpaste containing tricalcium phosphate (Vussen S). They were instructed to brush their teeth manually for 3 min, 3 times per day for 4 weeks with the allocated toothpastes, and were assessed at baseline (0), 2, and 4 weeks, respectively. Schiff sensitivity score was recorded to 3 different stimuli (air-blast, cold, and acid) at each assessment. Overall DH was also assessed using a visual analog scale (VAS). The longer participants used the toothpastes, the greater reduction in DH in all groups to the three stimuli. Group TP demonstrated significant reduction of DH compared to group N for air-blast and cold stimuli. Group TP showed significantly lower VAS than group N and SC. Tricalcium phosphate containing toothpaste used in this trial was most useful to reduce DH. It can be one of the treatment options that alleviate DH.
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- 2023
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16. Oncologic Outcomes of Surgically Treated Cervical Cancer with No Residual Disease on Hysterectomy Specimen: A 4C (Canadian Cervical Cancer Collaborative) Working Group Study
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Christa Aubrey, Gregory R. Pond, Limor Helpman, Danielle Vicus, Laurie Elit, Marie Plante, Susie Lau, Janice S. Kwon, Alon D. Altman, Karla Willows, Tomer Feigenberg, Jeanelle Sabourin, Vanessa Samouelian, Laurence Bernard, Norah Cockburn, Nora-Beth Saunders, Sabrina Piedimonte, Ly-Ann Teo-Fortin, Soyoun Rachel Kim, Noor Sadeq, Ji-Hyun Jang, Sarah Shamiya, and Gregg Nelson
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cervical cancer ,minimally invasive surgery - Abstract
Minimally invasive surgery for the treatment of macroscopic cervical cancer leads to worse oncologic outcomes than with open surgery. Preoperative conization may mitigate the risk of surgical approach. Our objective was to describe the oncologic outcomes in cases of cervical cancer initially treated with conization, and subsequently found to have no residual cervical cancer after hysterectomy performed via open and minimally invasive approaches. This was a retrospective cohort study of surgically treated cervical cancer at 11 Canadian institutions from 2007 to 2017. Cases initially treated with cervical conization and subsequent hysterectomy, with no residual disease on hysterectomy specimen were included. They were subdivided according to minimally invasive (laparoscopic/robotic (MIS) or laparoscopically assisted vaginal/vaginal hysterectomy (LVH)), or abdominal (AH). Recurrence free survival (RFS) and overall survival (OS) were estimated using Kaplan–Meier analysis. Chi-square and log-rank tests were used to compare between cohorts. Within the total cohort, 238/1696 (14%) had no residual disease on hysterectomy specimen (122 MIS, 103 AH, and 13 VLH). The majority of cases in the cohort were FIGO 2018 stage IB1 (43.7%) and underwent a radical hysterectomy (81.9%). There was no statistical difference between stage, histology, and radical vs simple hysterectomy between the abdominal and minimally invasive groups. There were no significant differences in RFS (5-year: MIS/LVH 97.7%, AH 95.8%, p = 0.23) or OS (5-year: MIS/VLH 98.9%, AH 97.4%, p = 0.10), although event-rates were low. There were only two recurrences. In this large study including only patients with no residual cervical cancer on hysterectomy specimen, no significant differences in survival were seen by surgical approach. This may be due to the small number of events or due to no actual difference between the groups. Further studies are warranted.
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- 2023
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17. Critical Void Dimension of Carbon Frameworks to Accommodate Insoluble Products of Lithium–Oxygen Batteries
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Chihyun Hwang, Myung-Jun Kwak, Jinhyeon Jeong, Kyungeun Baek, Ki-Yong Yoon, Cheolwon An, Jin-Wook Min, Jonghak Kim, Jeongin Lee, Seok Ju Kang, Ji-Hyun Jang, and Hyun-Kon Song
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General Materials Science - Abstract
High-energy density lithium-oxygen batteries (LOBs) seriously suffer from poor rate capability and cyclability due to the slow oxygen-related electrochemistry and uncontrollable formation of lithium peroxide (Li
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- 2021
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18. Triboelectric nanogenerator-integrated structural supercapacitor with in situ MXene-dispersed N-doped Zn–Cu selenide nanostructured woven carbon fiber for energy harvesting and storage
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Hae Gu Lee, Ankita Hazarika, Dong Chan Kim, Anand Prakash Jaiswal, Young-Bin Park, Myung-Jun Kwak, Ji-Hyun Jang, Jaewoo Seo, Hyung Wook Park, Changyoon Jeong, and Biplab K. Deka
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Supercapacitor ,Materials science ,Renewable Energy, Sustainability and the Environment ,Nanoporous ,Energy conversion efficiency ,Nanogenerator ,Energy Engineering and Power Technology ,Nanotechnology ,engineering.material ,Coating ,engineering ,General Materials Science ,Energy harvesting ,Faraday efficiency ,Triboelectric effect - Abstract
A woven carbon fiber (WCF)-based triboelectric nanogenerator (TENG)-cum-structural supercapacitor is an excellent multifunctional device for clean energy harvesting and storage. This type of device has high load-bearing capacity and functions smoothly under severe outdoor conditions. Herein, WCF-based multifunctional TENG is reported that generated 8.9 W m−2 power with 84% energy conversion efficiency. The energy generated by the TENG was simultaneously stored in a connected supercapacitor that provide 1.93 Wh kg−1 of energy density and delivers 39.23 W kg−1 of power density. The specific surface area of the WCF was enhanced several hundred-fold by coating with an N-doped Zn–Cu selenide nanoporous material, thereby enabling higher energy generation and elevated storage capacity of the device. The TENG use a polyester-based solid polymer electrolyte as the negative electrode and polydimethylsiloxane-coated WCF as the positive electrode. The device has a very high coulombic efficiency with high mechanical strength and ability to resist massive impact. An application of the multifunctional device was demonstrated. These types of multifunctional devices have great potential in the self-charging automobile, aerospace, sensor, and electronics sectors.
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- 2021
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19. Uterine Sarcoma With FGFR1-TACC1 Gene Fusion: A Case Report and Review of the Literature
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Roman E. Zyla, Emily A. Goebel, Ji-Hyun Jang, and Gulisa Turashvili
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Obstetrics and Gynecology ,Pathology and Forensic Medicine - Published
- 2021
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20. Evaluation of design, mechanical properties, and torque/force generation of heat-treated NiTi glide path instruments
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Soram, Oh, Ji-Yeon, Seo, Ji-Eun, Lee, Hyun-Jung, Kim, Ji-Hyun, Jang, and Seok Woo, Chang
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Titanium ,Hot Temperature ,Torque ,Nickel ,Humans ,General Dentistry - Abstract
Background Recently, various kinds of heat-treated nickel-titanium (NiTi) glide path instruments have been manufactured. This study aimed to investigate design, phase transformation behavior, mechanical properties of TruNatomy Glider (#17/02), V Taper 2H (#14/03), and HyFlex EDM (#15/03) and compare torque/force generated during simulated glide path preparation with them. Methods The designs and phase-transformation behaviors of the instruments were examined via scanning electron microscopy (n = 3) and differential scanning calorimetry (n = 2). Their bending (n = 15), torsional (n = 15), and cyclic fatigue resistances (n = 15) were tested. The ultimate strength and distortion angle were obtained from torsional resistance test. The number of cycles to failure (NCF) was calculated from cyclic fatigue resistance test. The preparation of the glide path was simulated using a double-curved artificial canal (n = 15), and the maximum torque and screw-in forces were measured. Data except NCF was compared between brands with one-way ANOVA with Tukey’s honestly significant difference test. NCF was analyzed via Kruskal–Wallis and Mann–Whitney U tests. Results TruNatomy Glider had the greatest number of threads. TruNatomy Glider showed progressive taper, while V Taper 2H and HyFlex EDM had constant taper. The austenitic transformation-finish temperatures of all the instruments were above body temperature. V Taper 2H demonstrated significantly lower ultimate strength, higher distortion angle, and a higher number of cycles to failure compared with HyFlex EDM and TruNatomy Glider (p p Conclusions V Taper 2H #14/03 showed superior cyclic fatigue resistance and lower ultimate strength. TruNatomy Glider generated greater clockwise torque and screw-in force during apical preparation. The mechanical properties, torque, and screw-force was affected by design of heat-treated glide path instruments. Cervical pre-flaring prior to glide path instrument is recommended.
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- 2022
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21. Stress-Relief Network in Silicon Microparticles and Composite Anodes for Durable High-Energy-Density Batteries
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Suhee Kim, Ji-Hyun Jang, Soojin Park, Sangyeop Lee, Cheolwon An, Chihyun Hwang, Hyun-Kon Song, Sungho Choi, Gyujin Song, and Myung-Jun Kwak
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Materials science ,Silicon ,Composite number ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Anode ,Stress relief ,chemistry ,Materials Chemistry ,Electrochemistry ,Energy density ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering ,Composite material ,Faraday efficiency - Abstract
Silicon microparticles (SiMPs), which have a high capacity, a high initial Coulombic efficiency, and a low volume-to-surface ratio compared with nanosized materials, are promising anode materials f...
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- 2021
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22. NiFeOx decorated Ge-hematite/perovskite for an efficient water splitting system
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Juhyung Park, Jun Hee Lee, Minsu Jung, Myung-Jun Kwak, Ki-Yong Yoon, Sang-Geun Ji, Ji-Hyun Jang, Sang Il Seok, Ji Hui Seo, and Hosik Lee
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Materials science ,Science ,General Physics and Astronomy ,Perovskite solar cell ,chemistry.chemical_element ,Germanium ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Photocatalysis ,Artificial photosynthesis ,Perovskite (structure) ,Nanoscale materials ,Multidisciplinary ,Dopant ,business.industry ,General Chemistry ,Hematite ,021001 nanoscience & nanotechnology ,Tin oxide ,0104 chemical sciences ,chemistry ,visual_art ,visual_art.visual_art_medium ,Optoelectronics ,Water splitting ,0210 nano-technology ,business ,Tin - Abstract
To boost the photoelectrochemical water oxidation performance of hematite photoanodes, high temperature annealing has been widely applied to enhance crystallinity, to improve the interface between the hematite-substrate interface, and to introduce tin-dopants from the substrate. However, when using additional dopants, the interaction between the unintentional tin and intentional dopant is poorly understood. Here, using germanium, we investigate how tin diffusion affects overall photoelectrochemical performance in germanium:tin co-doped systems. After revealing that germanium is a better dopant than tin, we develop a facile germanium-doping method which suppresses tin diffusion from the fluorine doped tin oxide substrate, significantly improving hematite performance. The NiFeOx@Ge-PH photoanode shows a photocurrent density of 4.6 mA cm−2 at 1.23 VRHE with a low turn-on voltage. After combining with a perovskite solar cell, our tandem system achieves 4.8% solar-to-hydrogen conversion efficiency (3.9 mA cm−2 in NiFeOx@Ge-PH/perovskite solar water splitting system). Our work provides important insights on a promising diagnostic tool for future co-doping system design., Germanium (Ge) has potential as a dopant suitable for the hematite-based photoelectrochemical water splitting system. Here, the authors report the fabrication of Ge doped porous hematite and demonstrate an efficient tandem system of Ge doped porous hematite and the perovskite solar cell.
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- 2021
23. DeepOption: A novel option pricing framework based on deep learning with fused distilled data from multiple parametric methods
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Ji Hyun Jang, Jinmo Gu, Hayoung Kim, Jisang Yoon, and Jung-Eun Kim
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Index (economics) ,Computer science ,business.industry ,Deep learning ,Big data ,020206 networking & telecommunications ,02 engineering and technology ,Machine learning ,computer.software_genre ,Data type ,Hang ,Mean absolute percentage error ,Hardware and Architecture ,Valuation of options ,Signal Processing ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Artificial intelligence ,business ,Transfer of learning ,computer ,Software ,Information Systems - Abstract
The remarkable performance of deep learning is based on its ability to learn high-level features by processing large amounts of data. This exceptionally superior performance has attracted the attention of researchers studying option pricing. However, option data are more expensive and less accessible than other types of data and are imbalanced because of the liquidity of options. This motivated us to propose a new option pricing and delta-hedging framework called DeepOption. This framework, which is based on deep learning, can improve the performance even when applying imbalanced real option data. In particular, the framework fuses simulated big data, known as distilled data, obtained using various traditional parametric methods. The proposed model employs the following three-stage training approach: Our model is pre-trained using big distilled data after it is fine-tuned using real option data through transfer learning. Finally, a delta branch is added to the model and trained. We experimentally evaluated the proposed method using three sets of real option data, namely S&P 500 European call options, EuroStoxx50 call options, and Hang Seng Index put options. Our experimental results on option pricing demonstrate that our proposed model outperforms parametric methods and other machine learning methods. Specifically, our model, which uses pre-training with distilled data, reduces the overall mean absolute percentage error (MAPE) by more than 50%, compared with that of a deep learning model using only real option data without pre-training.
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- 2021
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24. Sentinel lymph node biopsy in endometrial cancer: The new norm - A multicentre, international experience
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Melissa Lavecchia, Ji-Hyun Jang, Hwa-Jung Lee, Sophia Pin, Helen Steed, Jung-Yun Lee, Sunita Ghosh, and Janice S. Kwon
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Oncology ,Surgery - Published
- 2023
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25. DFT-study supported synergistic electrochemical supercapacitor performance of Bi2MoS6 nanosheets
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Sandesh H. Narwade, Nanasaheb M. Shinde, Balaji G. Ghule, Ji-Hyun Jang, and Rajaram S. Mane
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Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,Electrical and Electronic Engineering - Published
- 2023
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26. Ultrathin MoS2 flakes embedded in nanoporous graphene films for a multi-functional electrode
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Seong-Ji Ha, Joung-Chul Yoon, Jae-Eun Lee, Ji-Hyun Jang, Jongha Hwang, and Sung-Wook Kim
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Materials science ,Fabrication ,Renewable Energy, Sustainability and the Environment ,business.industry ,Graphene ,Nanoporous ,02 engineering and technology ,General Chemistry ,Substrate (electronics) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Capacitance ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Electrode ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business ,Molybdenum disulfide ,Power density - Abstract
Molybdenum disulfide (MoS2) is considered a promising material in energy storage systems, and is thus drawing considerable attention. However, the relatively low conductivity of bulk MoS2 has been a threat for practical applications. This study developed a simple and scalable fabrication method of few-layer MoS2 sheets embedded in a nanoporous graphene film (NGF) as a high capacitance active material. Transfer of MoS2/NGF onto a flexible substrate followed by plotter cutting produced a highly efficient micro-supercapacitor with superior flexibility, mechanical stability, and great potential for applications in wearable electronics. Notably, MoS2/NGF-based mSC revealed a high volumetric capacitance of 55 F cm−3 and 82.2% of capacitance retention after 20 000 cycles, which are superior to the reported data for solid-state micro-supercapacitors. With these performances, the flexible MoS2/NGF mSC exhibited an ultrahigh energy density of 7.64 mW h cm−3 and power density of 9.96 W cm−3 in a H3PO4 gel polymer electrolyte. The high volumetric capacitance and energy/power densities of MoS2/NGF as micro-supercapacitor electrodes are due to direct growth of ultra-thin MoS2 onto the interconnected 3D nanoporous graphene film with extended active sites and good conductivity. The MoS2/NGF mSC integrated on the skin efficiently powered a light emitting diode and strain sensors. This work suggests a meaningful way to realize film type MoS2 active materials in flexible micro-supercapacitors for wearable applications.
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- 2021
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27. Effect of Dentin Desensitizer Containing Novel Bioactive Glass on the Permeability of Dentin
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Ji-Hyun Jang, Hyun-Jung Kim, Joo-Young Choi, Hae-Won Kim, Samjin Choi, Soogeun Kim, Ayoung Bang, and Duck-Su Kim
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stomatognathic system ,General Materials Science ,bioactive glass ,dentin desensitizer ,dentin hypersensitivity ,real-time dentinal fluid flow ,Raman spectroscopy - Abstract
The objective of this study was to evaluate the effect of novel bioactive glass (BAG)-containing desensitizers on the permeability of dentin. Experimental dentin desensitizers containing 3 wt% BAG with or without acidic functional monomers (10-MDP or 4-META) were prepared. A commercial desensitizer, Seal & Protect (SNP), was used as a control. To evaluate the permeability of dentin, real-time dentinal fluid flow (DFF) rates were measured at four different time points (demineralized, immediately after desensitizer application, after two weeks in simulated body fluid (SBF), and post-ultrasonication). The DFF reduction rate (ΔDFF) was also calculated. The surface changes were analyzed using field emission scanning electron microscopy (FE-SEM). Raman spectroscopy was performed to analyze chemical changes on the dentin surface. The ΔDFF of the desensitizers containing BAG, BAG with 10-MDP, and BAG with 4-META significantly increased after two weeks of SBF storage and post-ultrasonication compared to the SNP at each time point (p < 0.05). Multiple precipitates were observed on the surfaces of the three BAG-containing desensitizers. Raman spectroscopy revealed hydroxyapatite (HAp) peaks on the dentin surfaces treated with the three BAG-containing desensitizers. Novel BAG-containing dentin desensitizers can reduce the DFF rate about 70.84 to 77.09% in the aspect of reduction of DFF through the HAp precipitations after two weeks of SBF storage.
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- 2022
28. Irisin promotes odontogenic differentiation and angiogenic potential in human dental pulp cells
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Sung-Hyeon Choi, Ji-Hyun Jang, Yun-Chan Hwang, J W Son, Jeong-Tae Koh, Won-Mann Oh, and Bin-Na Lee
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MAPK/ERK pathway ,Angiogenesis ,0206 medical engineering ,02 engineering and technology ,03 medical and health sciences ,0302 clinical medicine ,Downregulation and upregulation ,Western blot ,Cell Movement ,Myokine ,medicine ,Humans ,Viability assay ,General Dentistry ,Protein kinase B ,Cells, Cultured ,Dental Pulp ,Cell Proliferation ,medicine.diagnostic_test ,Chemistry ,Cell Differentiation ,Cell migration ,030206 dentistry ,Alkaline Phosphatase ,020601 biomedical engineering ,Cancer research ,Odontogenesis ,Signal Transduction - Abstract
AIM To determine whether irisin, a newly discovered myokine that links exercise-induced and metabolic homeostasis, is able to promote odontogenic differentiation and angiogenesis in human dental pulp cells (HDPCs). METHODOLOGY Cell viability in the presence of irisin was measured. Real-time PCR and Western blot analysis were performed to evaluate the expression levels of irisin, odontogenic and angiogenic markers. The involvement of mitogen-activated protein kinase (MAPK) and the protein kinase B (Akt) signalling pathway was evaluated by Western blot. To evaluate mineralization nodule formation, alkaline phosphatase (ALP) staining and alizarin red S staining were performed. Scratch wound assays were performed to evaluate the effects of irisin on cell migration. The data were analysed using one-way analysis of variance (anova) followed by Tukey post hoc test and Student's t-test. Statistical significance was considered at P
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- 2020
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29. Co3O4 Exsolved Defective Layered Perovskite Oxide for Energy Storage Systems
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Hu Young Jeong, Guntae Kim, Kyeong-Nam Kang, Hansol Lee, Ji-Hyun Jang, Junyoung Kim, and Myung-Jun Kwak
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Materials science ,Renewable Energy, Sustainability and the Environment ,Oxide ,Energy Engineering and Power Technology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Energy storage ,0104 chemical sciences ,Metal ,chemistry.chemical_compound ,Fuel Technology ,Adsorption ,Chemical engineering ,chemistry ,Chemistry (miscellaneous) ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,0210 nano-technology ,Perovskite (structure) - Abstract
We report a Co3O4 exsolved perovskite oxide PrBaMn1.7Co0.3O5+δ (Co3O4–PBMCO) that utilizes the Faradaic transfer of metal oxide and favorable OH– adsorption for an energy storage mechanism, as an a...
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- 2020
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30. Recycling of Particulate Photoabsorbers for Highly Stable Solar Desalination Operation
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Jihun Kang, Kwanghyun Kim, Sun-I Kim, Seung-Tak Ryu, Suhee Kim, and Ji-Hyun Jang
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Coffee grounds ,Waste management ,Materials Chemistry ,Electrochemistry ,Energy Engineering and Power Technology ,Chemical Engineering (miscellaneous) ,Graphitic carbon ,Environmental science ,Electrical and Electronic Engineering ,Particulates ,Solar desalination ,Desalination - Abstract
Porous graphitic carbon produced from waste coffee grounds (WCG), enormous amounts of which are generated and thrown away worldwide every year, is demonstrated as an effective broadband solar photo...
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- 2020
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31. Chairside computer-aided design/computer-aided manufacturing (CAD/ CAM)-based restoration of anterior teeth with customized shade and surface characterization: a report of 2 cases
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Ji-Hyun Jang, Kyoung-Kyu Choi, Duck-Su Kim, Gil-Joo Ryu, and Hyun-Jung Kim
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Orthodontics ,Computer science ,Computer-aided manufacturing ,Computer Aided Design ,Anterior dentition ,CAD ,computer.software_genre ,computer ,Anterior teeth - Published
- 2020
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32. Stacking-Free Porous Graphene Network for High Capacitive Performance
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Ki-Yong Yoon, Jongha Hwang, Ji-Hyun Jang, Seong-Ji Ha, and Anantha Kumar Ramadoss
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Supercapacitor ,Materials science ,Graphene ,Porous graphene ,Capacitive sensing ,Stacking ,Oxide ,Energy Engineering and Power Technology ,Nanotechnology ,Energy storage ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Materials Chemistry ,Electrochemistry ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering - Abstract
Reduced graphene oxide (rGO) composites for energy-related applications have attracted increasing attention. However, previous studies on rGOs still showed limitations because of unresolved several...
- Published
- 2020
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33. Determining the Relationships between Factors Affecting Adolescents’ Happiness in OECD Countries
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Young-Chool Choi, Ji-Hye Lee, and Ji-Hyun Jang
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- 2022
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34. Meso-pore generating P doping for efficient photoelectrochemical water splitting
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Jihun Kang, Ki-Yong Yoon, Jae-Eun Lee, Juhyung Park, Sourav Chaule, and Ji-Hyun Jang
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Renewable Energy, Sustainability and the Environment ,General Materials Science ,Electrical and Electronic Engineering - Published
- 2023
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35. Alpha-Mangostin Suppresses LPS-Induced Inflammation in Human Dental Pulp Cells
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Yu-Seon Kim, Ji-Hyun Jang, Jeong-Tae Koh, Yun-Chan Hwang, Won-Mann Oh, and Bin-Na Lee
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Fluid Flow and Transfer Processes ,α-mangostin ,dental pulp ,inflammation ,lipopolysaccharide ,xanthones ,Process Chemistry and Technology ,General Engineering ,General Materials Science ,Instrumentation ,Computer Science Applications - Abstract
Xanthones are secondary metabolites isolated from the peel of mangosteen showing medicinal potencies. Alpha-mangostin (α-MG) is the most plentiful xanthone, which has been reported to possess anti-inflammatory, anti-oxidant, and anti-bacterial activities. We aimed to investigate the anti-inflammatory effects of xanthones on LPS-treated hDPCs. Cell viability was determined using the WST-1 assay. The mRNA and protein expression profiles of inflammatory mediators were evaluated using quantitative real-time polymerase chain reaction (qPCR) and Western blot analysis. Anti-inflammatory effects were assessed using the Western blot analysis to examine underlying mechanisms. A one-way analysis of variance followed by Tukey’s post hoc test was used to determine statistically significant differences (p < 0.05). The study found no significant differences between the cytotoxic effects in the α-MG-treated groups and controls. The mRNA and protein expression levels of inflammatory markers in the α-MG treated groups decreased. α-MG significantly inhibited LPS-induced phosphorylation of proteins associated with the MAPK and NF-κB pathways. This study suggests that α-MG exerts anti-inflammatory effects by suppressing the MAPK and NF-κB signaling pathways in LPS-treated hDPCs.
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- 2023
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36. Highly Stable Germanium Microparticle Anodes with a Hybrid Conductive Shell for High Volumetric and Fast Lithium Storage
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Gyujin Song, June Ho Lee, Sangyeop Lee, Dong-Yeob Han, Sungho Choi, Myung-Jun Kwak, Ji-Hyun Jang, Donghwa Lee, and Soojin Park
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General Materials Science - Abstract
The ability to realize a highly capacitive/conductive electrode is an essential factor in large-scale devices, requiring a high-power/energy density system. Germanium is a feasible candidate as an anode material of lithium-ion batteries to meet the demands. However, the application is constrained due to low charge conductivity and large volume change on cycles. Here, we design a hybrid conductive shell of multi-component titanium oxide on a germanium microstructure. The shell enables facile hybrid ionic/electronic conductivity for swift charge mobility in the germanium anode, revealed through computational calculation and consecutive measurement of electrochemical impedance spectroscopy. Furthermore, a well-constructed electrode features a high initial Coulombic efficiency (90.6%) and stable cycle life for 800 cycles (capacity retention of 90.4%) for a fast-charging system. The stress-resilient properties of dense microparticle facilitate to alleviate structural failure toward high volumetric (up to 1737 W h L
- Published
- 2021
37. Effects of Various Mineral Trioxide Aggregates on Viability and Mineralization Potential of 3-Dimensional Cultured Dental Pulp Stem Cells
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Sun-Young Kim, Ji-Hyun Jang, Bin-Na Lee, Hyo-Seol Lee, Duck-Su Kim, Hyun Jung Kim, Hyun-Jeong Jeong, and Seung-Ho Kwon
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Technology ,QH301-705.5 ,QC1-999 ,ALIZARIN RED ,Mineralization (biology) ,Andrology ,chemistry.chemical_compound ,stomatognathic system ,Dental pulp stem cells ,General Materials Science ,Viability assay ,Biology (General) ,mineral trioxide aggregates ,dental pulp ,restorative dentistry ,culture method ,QD1-999 ,Instrumentation ,Fluid Flow and Transfer Processes ,Physics ,Process Chemistry and Technology ,General Engineering ,Engineering (General). Civil engineering (General) ,Computer Science Applications ,Staining ,Chemistry ,chemistry ,Alkaline phosphatase ,TA1-2040 ,MTA cement ,Trioxide - Abstract
Three-dimensionally (3D) cultured dental pulp stem cells (DPSCs) reportedly exhibit superior multi-lineage differentiation capacities and have a higher expression in regeneration-related gene categories compared to conventionally cultured DPSCs. This study aimed to evaluate the effects of various mineral trioxide aggregates (MTAs) on DPSCs cultured in 3D, assessing their cell viability and tissue mineralization properties. We examined the morphology, cell viability, alkaline phosphate (ALP) activity and qualitative alizarin red S staining assay of the DPSCs that reacted with various MTAs, which included ProRoot (PRM), Biodentine (BIO), and Well-Root PT (WRP), in two different culture plates, an ultra-low attachment plate (ULA) and a conventional monolayer plate (2D). As a control, MTA-free and IRM samples were prepared. None of the MTA groups affected the microsphere-forming characteristics of DPSCs that had been cultured in ULA. The DPSCs that were cultured in ULA showed high cell viability in all MTA groups compared to IRM. The mineralization potential was favorable in all MTA groups, with a significantly higher ALP activity among the DPSCs that were cultured in ULA. Among MTAs, the PRM group showed substantially higher ALP activity than the other MTA groups. In conclusion, our results indicate that 3D-cultured DPSCs with various MTAs showed comparable viability and mineralization capacity similar to those cultured without reacting with MTA cement.
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- 2021
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38. Effect of bioactive glass addition on the physical properties of mineral trioxide aggregate
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Kyoung-Kyu Choi, Seok Woo Chang, Hyun-Jung Kim, Sun-Young Kim, Duck-Su Kim, Soram Oh, Jei Kim, and Ji-Hyun Jang
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Mineral trioxide aggregate ,Simulated body fluid ,Biomedical Engineering ,Medicine (miscellaneous) ,Compressive strength ,law.invention ,X-ray diffraction analysis ,Biomaterials ,chemistry.chemical_compound ,law ,Medical technology ,Dentin ,medicine ,Bioactive glass ,R855-855.5 ,Solubility ,Bond strength ,Chemistry ,Set-ting time ,Pushout bond strength ,medicine.anatomical_structure ,Ceramics and Composites ,Trioxide ,Research Article ,Nuclear chemistry - Abstract
Background The addition of bioactive glass (BG), a highly bioactive material with remineralization potential, might improve the drawback of weakening property of mineral trioxide aggregates (MTA) when it encounters with body fluid. This study aims to evaluate the effect of BG addition on physical properties of MTA. Methods ProRoot (MTA), and MTA with various concentrations of BG (1, 2, 5 and 10% BG/MTA) were prepared. Simulated body fluid (SBF) was used to investigate the effect of the storage solution on dentin remineralization. Prepared specimens were examined as following; the push-out bond strength to dentin, compressive strength, setting time solubility and X-ray diffraction (XRD) analysis. Results The 2% BG/MTA showed higher push-out bond strengths than control group after 7 days of SBF storage. The 2% BG/MTA exhibited the highest compressive strength. Setting times were reduced in the 1 and 2% BG/MTA groups, and solubility of all experimental groups were clinically acceptable. In all groups, precipitates were observed in dentinal tubules via SEM. XRD showed the increased hydroxyapatite peaks in the 2, 5 and 10% BG/MTA groups. Conclusion It was verified that the BG-added MTA increased dentin push-out bond strength and compressive strength under SBF storage. The addition of BG did not negatively affect the MTA maturation reaction; it increased the amount of hydroxyapatite during SBF maturation.
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- 2021
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39. Sn-Controlled Co-Doped Hematite for Efficient Solar-Assisted Chargeable Zn-Air Batteries
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Myung-Jun Kwak, Ki-Yong Yoon, Jae-Eun Lee, Juhyung Park, Jihun Kang, and Ji-Hyun Jang
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Photocurrent ,Materials science ,Chemical engineering ,Annealing (metallurgy) ,visual_art ,Doping ,visual_art.visual_art_medium ,Photocatalysis ,Water splitting ,General Materials Science ,Substrate (electronics) ,Hematite ,Tin oxide - Abstract
The photoelectrochemical performance of a co-doped hematite photoanode might be hindered due to the unintentionally diffused Sn from a fluorine-doped tin oxide (FTO) substrate during the high-temperature annealing process by providing an increased number of recombination centers and structural disorder. We employed a two-step annealing process to manipulate the Sn concentration in co-doped hematite. The Sn content [Sn/(Sn + Fe)] of a two-step annealing sample decreased to 1.8 from 6.9% of a one-step annealing sample. Si and Sn co-doped hematite with the reduced Sn content exhibited less structural disorder and improved charge transport ability to achieve a 3.0 mA cm-2 photocurrent density at 1.23 VRHE, which was 1.3-fold higher than that of the reference Si and Sn co-doped Fe2O3 (2.3 mA cm-2). By decorating with the efficient co-catalyst NiFe(OH)x, a maximum photocurrent density of 3.57 mA cm-2 was achieved. We further confirmed that the high charging potential and poor cyclability of the zinc-air battery could be dramatically improved by assembling the optimized, stable, and low-cost hematite photocatalyst with excellent OER performance as a substitute for expensive Ir/C in the solar-assisted chargeable battery. This study demonstrates the significance of manipulating the unintentionally diffused Sn content diffused from FTO to maximize the OER performance of the co-doped hematite.
- Published
- 2021
40. (Invited) Non-Metal P Doping for Efficient Water Splitting
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Ji-Hyun Jang
- Abstract
Here, we investigate how a simple in-situ phosphorus (P) doping strategy improves the overall PEC performance of hematite. By introducing enriched FePO4 regions on the Ti-doped FeOOH surface and subsequent high-temperature annealing, P,Ti co-doped Fe2O3 (P,Ti-Fe2O3) nanorods were fabricated. P,Ti-Fe2O3 not only increased the conductivity by creating oxygen vacancies but also generated a porous structure inside the hematite. Benefiting from the efficient P doping effects, the resulting P,Ti-Fe2O3 photoanode exhibited 94% improved photocurrent density compared to that of Ti-Fe2O3 (@ 1.23 VRHE) under 1 sun illumination. After applying the co-catalyst, NiFeOx/P,Ti-Fe2O3 showed significantly enhanced photocurrent density (3.54 mA cm-2 at 1.23 VRHE) with a 108 mV cathodic shift. Our study suggests a new approach for achieving porous hematite and a highly efficient PEC system by a simple and cost-effective nonmetal P-doping method.
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- 2022
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41. Bismuth oxide-doped graphene-oxide nanocomposite electrode for energy storage application
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Balaji G. Ghule, Nanasaheb M. Shinde, Yogesh T. Nakate, Ji-Hyun Jang, and Rajaram S. Mane
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Colloid and Surface Chemistry - Published
- 2022
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42. Investigating the Factors Influencing the Sustainability of Social Enterprises in Korea
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Ji-Hyun Jang and Young-Chool Choi
- Subjects
Sustainability ,Business ,Environmental planning - Published
- 2021
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43. Epicardial HDAC3 promotes myocardial growth through a novel microRNA pathway
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Chenleng Cai, Guang Song, Qinshan Li, Xiaosu Song, Ji Hyun Jang, Sunjay Kaushal, and Deqiang Li
- Subjects
Gene knockdown ,FGF9 ,Heart development ,Regeneration (biology) ,Growth factor ,medicine.medical_treatment ,medicine ,Biology ,Fibroblast growth factor ,HDAC3 ,Deacetylase activity ,Cell biology - Abstract
RationalEstablishment of the myocardial wall requires proper growth cues from nonmyocardial tissues. During heart development, the epicardium and epicardium-derived cells (EPDCs) instruct myocardial growth by secreting essential factors including fibroblast growth factor 9 (FGF9) and insulin-like growth factor 2 (IGF2). However, it is poorly understood how the epicardial secreted factors are regulated, in particular by chromatin modifications for myocardial formation.ObjectiveTo understand whether and how histone deacetylase 3 (HDAC3) in the developing epicardium regulates myocardial growth.Methods and ResultsWe deleted Hdac3 in the developing murine epicardium and mutant hearts showed ventricular myocardial wall hypoplasia with reduction of EPDCs. The cultured embryonic cardiomyocytes with supernatants from Hdac3 knockout (KO) mouse epicardial cells (MECs) also showed decreased proliferation. Genome-wide transcriptomic analysis revealed that Fgf9 and Igf2 were significantly down-regulated in Hdac3 KO MECs. We further found that Fgf9 and Igf2 expression is dependent on HDAC3 deacetylase activity. The supplementation of FGF9 or IGF2 can rescue the myocardial proliferation defects treated by Hdac3 KO supernatant. Mechanistically, we identified that microRNA (miR)-322 and miR-503 were upregulated in Hdac3 KO MECs and Hdac3 epicardial KO hearts. Overexpression of miR-322 or miR-503 repressed FGF9 and IGF2 expression, while knockdown of miR-322 or miR-503 restored FGF9 and IGF2 expression in Hdac3 KO MECs.ConclusionsOur findings reveal a critical signaling pathway in which epicardial HDAC3 promotes compact myocardial growth by stimulating FGF9 and IGF2 through repressing miR-322/miR-503, providing novel insights in elucidating etiology of congenital heart defects, and conceptual strategies to promote myocardial regeneration.
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- 2021
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44. Effect of Novel Bioactive Glass-Containing Dentin Adhesive on the Permeability of Demineralized Dentin
- Author
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Hyun-Jung Kim, Jung-Hwan Lee, Kyoung-Kyu Choi, Dongseok Choi, Duck Su Kim, Sun-Young Kim, Ji-Hyun Jang, Jack L. Ferracane, Soogeun Kim, Samjin Choi, Ayoung Bang, and Sang Uk Woo
- Subjects
Technology ,Scanning electron microscope ,Confocal ,dentin remineralization ,Article ,law.invention ,stomatognathic system ,law ,field-emission scanning electron microscopy ,Dentin ,medicine ,dentinal fluid flow ,General Materials Science ,Composite material ,Dentinal Fluid ,skin and connective tissue diseases ,Microscopy ,QC120-168.85 ,Bond strength ,Chemistry ,Raman confocal spectroscopy ,QH201-278.5 ,bioactive glass ,Engineering (General). Civil engineering (General) ,TK1-9971 ,stomatognathic diseases ,dentin permeability ,medicine.anatomical_structure ,Dentinal Tubule ,Descriptive and experimental mechanics ,Bioactive glass ,Adhesive ,Electrical engineering. Electronics. Nuclear engineering ,TA1-2040 - Abstract
This study aimed to evaluate the effect of a novel bioactive glass (BAG)-containing dentin adhesive on the permeability of demineralized dentin. Bioactive glass (85% SiO2, 15% CaO) was fabricated using the sol-gel process, and two experimental dentin adhesives were prepared with 3 wt% silica (silica-containing dentin adhesive, SCA) or BAG (BAG-containing dentin adhesive, BCA). Micro-tensile bond strength (μTBS) test, fracture mode analysis, field-emission scanning electron microscopy (FE-SEM) analysis of adhesive and demineralized dentin, real-time dentinal fluid flow (DFF) rate measurement, and Raman confocal microscopy were performed to compare SCA and BCA. There was no difference in μTBS between the SCA and BCA (p >, 0.05). Multiple precipitates were evident on the surface of the BCA, and partial occlusion of dentinal tubules was observed in FE-SEM of BCA-approximated dentin. The DFF rate was reduced by 50.10% after BCA approximation and increased by 6.54% after SCA approximation. Raman confocal spectroscopy revealed an increased intensity of the hydroxyapatite (HA) peak on the dentin surface after BCA application. The novel BAG-containing dentin adhesive showed the potential of both reducing dentin permeability and dentin remineralization.
- Published
- 2021
45. Study on Structural Relationships among the Factors Affecting Happiness of Adolescent in OECD Countries: Application of QCA Method
- Author
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Ji-Hyun Jang and Young-chool Choi
- Subjects
Variables ,Qualitative comparative analysis ,media_common.quotation_subject ,Happiness ,Economics ,Per capita ,Demographic economics ,Oecd countries ,High ratio ,Affect (psychology) ,Gross domestic product ,media_common - Abstract
The purpose of this study is to investigate the causal relationships among the key educational factors that affect adolescent happiness and to propose policy implications for OECD countries to increase their levels of adolescent happiness. The HSBC score of adolescent happiness in OECD countries was chosen as an indicator, and a number of independent variables such as per capita GDP and per capita educational expenditure amount were included in the subject of analysis. For the analysis, the QCA (Qualitative Comparative Analysis) method was used. The use of QCA has been rarely reported in adolescents’ happiness studies, and are likely to be conceptual and paradigmatic challenges to its adoption in some settings. According to the findings, there are three key factors that contribute to adolescents' high levels of happiness in OECD nations: TEPC*GDP*PUPTEA, tee*GDP*PRIVATEXP, and tee*tepc*gdp*privatexp. In other words, while a number of further steps are required to produce a more parsimonious formulation, the solution in this study suggests six configurations and three prime implicants. The first prime implicant is TEPC(high total per capita expenditure on education)*GDP(high per capita gdp)*PUPTEA(high ratio of students to teaching staff). The second implicant is tee(low total expenditure on education)*GDP(high per capita gdp)*PRIVATEXP(high ratio of private source expenditure on education to gdp). Finally, the third implicant is tee(low total expenditure on education)*tepc(low total per capita expenditure on education)*gdp(low per capita gdp)*privatexp(low ratio of private source expenditure on education to gdp). It is crucial to emphasise that the data reported in this research are simply illustrative and should be examined in a broader context.Alternative causal configurations are acceptable for the complexity of adolescents' happiness, rather than being a limitation of QCA.
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- 2021
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46. Graphitization with Suppressed Carbon Loss for High-Quality Reduced Graphene Oxide
- Author
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Kyeong-Nam Kang, Feng Ding, Ji-Hyun Jang, Xinyue Dai, Jongha Hwang, Myung-Jun Kwak, and Jong-Chul Yoon
- Subjects
Materials science ,Graphene ,General Engineering ,Oxide ,Oxygen evolution ,General Physics and Astronomy ,chemistry.chemical_element ,engineering.material ,Oxygen ,law.invention ,Catalysis ,Delafossite ,chemistry.chemical_compound ,Adsorption ,Chemical engineering ,chemistry ,law ,engineering ,General Materials Science ,Carbon - Abstract
An efficient reduction method to obtain high-quality graphene sheets from mass-producible graphene oxide is highly desirable for practical applications. Here, we report an in situ deoxidation and graphitization mechanism for graphene oxide that allows for high-quality reduced graphene oxide sheets under the low temperature condition (
- Published
- 2021
47. Effect of Leptin on Odontoblastic Differentiation and Angiogenesis: An In Vivo Study
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Won-Mann Oh, Hoon-Sang Chang, Ji-Hyun Jang, Bin-Na Lee, Yun-Chan Hwang, In-Nam Hwang, Jeong-Tae Koh, and Sung-Hyeon Choi
- Subjects
Leptin ,Male ,Vascular Endothelial Growth Factor A ,0301 basic medicine ,medicine.medical_specialty ,Angiogenesis ,Neovascularization, Physiologic ,Adipose tissue ,Dentin, Secondary ,Dental Pulp Capping ,03 medical and health sciences ,0302 clinical medicine ,stomatognathic system ,Dentin sialophosphoprotein ,Internal medicine ,medicine ,Dentin ,Animals ,General Dentistry ,Dental Pulp ,Odontoblasts ,Chemistry ,Cell Differentiation ,030206 dentistry ,Rats ,Pulp capping ,stomatognathic diseases ,030104 developmental biology ,Endocrinology ,medicine.anatomical_structure ,Pulp (tooth) ,Dentin sialoprotein - Abstract
INTRODUCTION Leptin is secreted as a peptide hormone from adipose tissues. The aim of this study was to evaluate the effects of leptin on reparative dentin formation and angiogenesis in the pulp tissue of teeth in vivo. METHODS Twenty-four 7-week-old male rats were anesthetized. Cavities were prepared in maxillary first molars. Pulp cappings were performed with collagen scaffold (Col) with a phosphate-buffered saline (PBS) vehicle (Col + PBS), leptin 1 μmol/L with Col (L1 + Col), or leptin 10 μmol/L with Col (L10 + Col). For the negative control group (no pulp capping), pulp capping was not performed. All cavities were sealed with resin-modified glass ionomer followed by a micro-computed tomographic scan, histologic examination, and immunohistochemical analysis. RESULTS The volume of newly formed mineralized tissue in the leptin group was significantly (P < .01) higher than that in the control group based on micro-computed tomographic analysis. In histologic examination, hard tissue formation was rarely shown in the no pulp capping and Col + PBS groups. However, significantly (P < .01) larger amounts of newly mineralized tissue deposition were observed in the leptin groups. In immunohistochemical analysis, reparative dentin and new vessels formed in the pulp cavity of the leptin groups. Vascular endothelial growth factor, dentin sialoprotein, and dentin sialophosphoprotein were expressed around the newly formed mineralized tissue area. CONCLUSIONS Leptin showed the ability to induce angiogenesis, odontogenic differentiation, and mineralization in exposed rat pulps. Leptin also exhibited favorable inflammatory responses in the pulp tissue. Not only osteodentin but also tubular dentin and new vessels were observed in the pulp cavity.
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- 2019
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48. Improvement of the Bonding Properties of Mineral Trioxide Aggregate by Elastin-Like Polypeptide Supplementation
- Author
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Sun-Young Kim, Ji-Hyun Jang, Sahng G. Kim, Hyun-Jung Kim, Dong-Hyun Lee, and Seungryong Cho
- Subjects
Mineral trioxide aggregate ,X-ray microtomography ,Article Subject ,Scanning electron microscope ,02 engineering and technology ,Contact angle ,Dental Materials ,03 medical and health sciences ,0302 clinical medicine ,Dentin ,medicine ,Humans ,Composite material ,Aluminum Compounds ,lcsh:Microscopy ,Porosity ,Instrumentation ,Cement ,lcsh:QH201-278.5 ,Bond strength ,Chemistry ,Silicates ,Dental Bonding ,Oxides ,X-Ray Microtomography ,030206 dentistry ,Calcium Compounds ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,Elastin ,Drug Combinations ,medicine.anatomical_structure ,Microscopy, Electron, Scanning ,Peptides ,0210 nano-technology ,Research Article - Abstract
Introduction. Elastin-like polypeptide (ELP) supplementation was previously reported to enhance the physical properties of mineral trioxide aggregate (MTA). The aim of this study was to investigate the effect of ELP supplementation on the bonding properties of MTA to dentin. Methods. Two types of ELPs were synthesized and mixed with MTA in a 0.3 liquid/powder ratio. The push-out bond strength test and interfacial observation with scanning electron microscopy were performed for ELP-supplemented MTA. The porosity of MTA fillings in the cavity was observed with microcomputed tomography. The stickiness, flow rate, and contact angle were additionally measured for potential increased bonding properties. Results. ELP supplementation improved the bond strength of MTA to dentin. MTA supplemented by a specific ELP exhibited a less porous structure, higher stickiness, and higher flow rate. ELPs also decreased the contact angle to dentin. Conclusions. This research data verifies that ELP improves the bonding properties of MTA to a tooth structure. The sticky and highly flowable characteristics of ELP-supplemented MTA may provide intimate contact with dentin and supply a less porous cement structure, which might improve the bonding properties of MTA.
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- 2019
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49. Effects of newly-developed retrograde filling material on osteoblastic differentiation in vitro
- Author
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Bin-Na Lee, Hoon-Sang Chang, Ji-Hye Yoon, Yun-Chan Hwang, Won-Mann Oh, In-Nam Hwang, Ji-Hyun Jang, and Go-Woon Lee
- Subjects
Mineral trioxide aggregate ,Materials science ,EndoSequence root repair material ,0206 medical engineering ,030206 dentistry ,02 engineering and technology ,020601 biomedical engineering ,Molecular biology ,In vitro ,Staining ,03 medical and health sciences ,0302 clinical medicine ,Ceramics and Composites ,Alkaline phosphatase ,Viability assay ,General Dentistry - Abstract
The aim of this study was to compare chemical properties and bioactivities of with mineral trioxide aggregate (MTA) and EndoSequence Root Repair Material (ERRM). After setting, surfaces of test materials were observed by scanning electron microscope (SEM). The pH and cell viability of materials were tested. Osteoblastic differentiation and alkaline phosphatase (ALP) activity were measured by quantitative real-time PCR and ALP staining. MTA showed spindle-shaped crystals while ERRM showed round-shaped crystals of various sizes. ERRM presented lower pH than MTA. Both materials showed good cell viabilities compared to the control. Expression levels of osteoblastic genes and ALP staining were increased significantly (p
- Published
- 2019
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50. Anti-inflammatory and Osteogenic Effects of Calcium Silicate–based Root Canal Sealers
- Author
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Ji-Hyun Jang, Won-Mann Oh, Bin-Na Lee, In-Nam Hwang, Se-Min Kim, Yun-Chan Hwang, Hoon-Sang Chang, and Ji-Uk Hong
- Subjects
0301 basic medicine ,Biocompatibility ,Lipopolysaccharide ,Cell Survival ,medicine.drug_class ,Root canal ,Anti-Inflammatory Agents ,Gene Expression ,Anti-inflammatory ,Root Canal Filling Materials ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Osteogenesis ,medicine ,Animals ,Viability assay ,General Dentistry ,Cells, Cultured ,Osteoblasts ,Silicates ,Cell Differentiation ,030206 dentistry ,Calcium Compounds ,Alkaline Phosphatase ,Molecular biology ,Stimulation, Chemical ,Staining ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Calcium silicate ,Tumor necrosis factor alpha - Abstract
An ideal root canal sealer creates a bacteria-resistant seal and exhibits antimicrobial activity, biocompatibility, and osteoconductivity. The aim of this study was to assess the effects of 3 root canal sealers on cell viability, inflammatory response, and osteogenic potential in MC3T3-E1 cells.AH Plus (Dentsply Caulk, Milford, DE), MTA Fillapex (Angelus Solucxoes Odontologicas, Londrina, Brazil), and EndoSequence BC (Brasseler, Savannah, GA) were mixed according to the manufacturer's instructions, and samples were prepared as extraction media (final dilution: 1/10). Lipopolysaccharide (LPS) (100 ng/mL) treatment was used to induce an inflammatory response in this study. Cell viability was evaluated using the Water soluble tetrazolium-1 (WST-1) assay. The levels of inflammatory mediators (interleukin 6 and tumor necrosis factor alpha) and osteogenic marker genes (ALP and OCN) were measured by reverse-transcription polymerase chain reaction and real-time polymerase chain reaction. Osteogenic potential was evaluated by alkaline phosphatase staining and alizarin red staining.Calcium silicate-based sealers such as MTA Fillapex and EndoSequence BC showed strong cell viability compared with AH Plus. AH Plus, MTA Fillapex, and EndoSequence BC decreased the levels of LPS-induced inflammatory mediators (P .05). The expression of osteogenic marker genes, alkaline phosphatase activity, and mineralized nodule formation decreased with LPS treatment. However, AH Plus and calcium silicate-based sealers increased the osteogenic potential reduced by LPS treatment (P .05).Calcium silicate-based sealers exhibit anti-inflammatory effects and induce osteogenic differentiation in MC3T3-E1 cells.
- Published
- 2019
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