263 results on '"Hwang KY"'
Search Results
2. Upconverting nanoparticle-containing erythrocyte-sized hemoglobin microgels that generate heat, oxygen and reactive oxygen species for suppressing hypoxic tumors
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Hanju Kim, Johyun Yoon, Hwang Kyung Kim, Woo Tak Lee, Nguyen Thi Nguyen, Xuan Thien Le, Eun-Hee Lee, Eun Seong Lee, Kyung Taek Oh, Han-Gon Choi, and Yu Seok Youn
- Subjects
Hemoglobin microgel ,Upconversion ,Photothermal therapy ,Photodynamic therapy ,Hypoxic tumors ,Oxygen-generation ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Biology (General) ,QH301-705.5 - Abstract
Inspired by erythrocytes that contain oxygen-carrying hemoglobin (Hb) and that exhibit photo-driven activity, we introduce homogenous-sized erythrocyte-like Hb microgel (μGel) systems (5–6 μm) that can (i) emit heat, (ii) supply oxygen, and (iii) generate reactive oxygen species (ROS; 1O2) in response to near-infrared (NIR) laser irradiation. Hb μGels consist of Hb, bovine serum albumin (BSA), chlorin e6 (Ce6) and erbium@lutetium upconverting nanoparticles (UCNPs; ∼35 nm) that effectively convert 808 nm NIR light to 660 nm visible light. These Hb μGels are capable of releasing oxygen to help generate sufficient reactive oxygen species (1O2) from UCNPs/Ce6 under severely hypoxic condition upon NIR stimulation for efficient photodynamic activity. Moreover, the Hb μGels emit heat and increase surface temperature due to NIR light absorption by heme (iron protoporphyrin IX) and display photothermal activity. By changing the Hb/UCNP/Ce6 ratio and controlling the amount of NIR laser irradiation, it is possible to formulate bespoke Hb μGels with either photothermal or photodynamic activity or both in the context of combined therapeutic effect. These Hb μGels effectively suppress highly hypoxic 4T1 cell spheroid growth and xenograft mice tumors in vivo.
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- 2023
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3. Correlation of CD47 Expression with Adverse Clinicopathologic Features and an Unfavorable Prognosis in Colorectal Adenocarcinoma
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Hyunsung Kim, Seungyun Jee, Yeseul Kim, Jongmin Sim, Seongsik Bang, Hwang Kyu Son, Hosub Park, Jaekyung Myung, Young Hyeh Ko, and Seung Sam Paik
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colorectal adenocarcinoma ,CD47 ,immunohistochemistry ,immune checkpoints ,prognosis ,Medicine (General) ,R5-920 - Abstract
CD47, a transmembrane protein, is widely overexpressed on the tumor cell surface. However, the prognostic significance of CD47 expression in colorectal adenocarcinoma (CRA) has not yet been clarified. Here, we investigated the clinicopathologic significance of CD47 expression in CRA. CD47 expression was evaluated via immunohistochemical analysis of microarray sections of 328 CRA tissues. CD47 expression was observed in 53 (16.2%) of the 328 CRA tissues, and positive expression was associated with lymphatic invasion (p = 0.018), perineural invasion (p = 0.024), tumor budding (p = 0.009), the pathologic N stage (p = 0.022), and the American Joint Committee on Cancer (AJCC) stage (p = 0.027). In survival analyses of 329 patients, a positive CD47 expression was associated with a poor recurrence-free survival (RFS) (p = 0.032). In multivariate analysis, however, it was not an independent prognostic factor. In patients who underwent surgical resection without adjuvant treatment, a positive CD47 expression was associated with a shorter RFS (p = 0.001) but not with cancer-specific survival (CSS). In patients who received postoperative adjuvant treatment, no significant differences were found in both RFS and CSS. In conclusion, we investigated CD47 expression in 328 CRA tissues. A positive CD47 expression was observed in a minority (16.2%) of the tissues and was significantly associated with adverse clinicopathologic features and a poor patient outcome.
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- 2021
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4. Highly Red Light-Emitting Erbium- and Lutetium-Doped Core-Shell Upconverting Nanoparticles Surface-Modified with PEG-Folic Acid/TCPP for Suppressing Cervical Cancer HeLa Cells
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Kyungseop Lim, Hwang Kyung Kim, Xuan Thien Le, Nguyen Thi Nguyen, Eun Seong Lee, Kyung Taek Oh, Han-Gon Choi, and Yu Seok Youn
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upconverting nanoparticles ,photodynamic therapy ,tetrakis(4-carboxy-phenyl)porphyrin ,near infrared ,cancer ,hypoxia ,Pharmacy and materia medica ,RS1-441 - Abstract
Photodynamic therapy (PDT) combined with upconverting nanoparticles (UCNPs) are viewed together as an effective method of ablating tumors. After absorbing highly tissue-penetrating near-infrared (NIR) light, UCNPs emit a shorter wavelength light (~660 nm) suitable for PDT. In this study, we designed and prepared highly red fluorescence-emitting silica-coated core-shell upconverting nanoparticles modified with polyethylene glycol (PEG5k)-folic acid and tetrakis(4-carboxyphenyl)porphyrin (TCPP) (UCNPs@SiO2-NH2@FA/PEG/TCPP) as an efficient photodynamic agent for killing tumor cells. The UCNPs consisted of two simple lanthanides, erbium and lutetium, as the core and shell, respectively. The unique core-shell combination enabled the UCNPs to emit red light without green light. TCPP, folic acid, and PEG were conjugated to the outer silica layer of UCNPs as a photosensitizing agent, a ligand for tumor attachment, and a dispersing stabilizer, respectively. The prepared UCNPs of ~50 nm diameter and −34.5 mV surface potential absorbed 808 nm light and emitted ~660 nm red light. Most notably, these UCNPs were physically well dispersed and stable in the aqueous phase due to PEG attachment and were able to generate singlet oxygen (1O2) with a high efficacy. The HeLa cells were treated with each UCNP sample (0, 1, 5, 10, 20, 30 μg/mL as a free TCPP). The results showed that the combination of UCNPs@SiO2-NH2@FA/PEG/TCPP and the 808 nm laser was significantly cytotoxic to HeLa cells, almost to the same degree as naïve TCPP plus the 660 nm laser based on MTT and Live/Dead assays. Furthermore, the UCNPs@SiO2-NH2@FA/PEG/TCPP was well internalized into HeLa cells and three-dimensional HeLa spheroids, presumably due to the surface folic acid and small size in conjunction with endocytosis and the nonspecific uptake. We believe that our UCNPs@SiO2-NH2@FA/PEG/TCPP will serve as a new platform for highly efficient and deep-penetrating photodynamic agents suitable for various tumor treatments.
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- 2020
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5. Preliminary Evaluation of the Earthquake Hazard for Underground Electric Facility Lines in Pohang City based on ArcGIS
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Kim Young S., Tran Thien Q., Do Tan M., Park Inn J., and Hwang Kyeong M.
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Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Pohang, a big city of Gyeongbuk province, South Korea, is developing rapidly in every aspect, containing many important infrastructures such as seaports, industrial factories, commercial centers, and underground electric facility systems that play an integral part in the contribution of electricity stemming from nuclear power plants. The main purpose of this research is a preliminary assessment of the earthquake hazard for underground electric facility lines (UEFL) located beneath Pohang city by using ArcGIS program. About 1000 drilling boreholes were collected as a database. All of the data were processed by filtering with respect to the depths, then the SPT-N values of unknown points were estimated by interpolation. Four interpolation methods (e.g., Inverse Distance Weighting (IDW), Kriging, Natural Neighbor, and Spline) were evaluated to find the method which gives the best representation of the SPT-N value for unknown points. The IDW method was finally selected. Afterwards, the border surface between soft- and hard-soil layers, the ground rock zonation map, the dramatic change of soil condition, and the depth of structure were determined as important scales to evaluate primarily whether the structures might be in danger or not when an earthquake occurs. In this way, proposed method can be applied to whole South Korea with over 100,000 available borehole data.
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- 2018
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6. Crystal structure of thermostable alpha-amylase from Bacillus licheniformis refined at 1.7 angstrom resolution
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Hwang, Ky, Hyun Kyu Song, Chang, C., Lee, J., Lee, Sy, Kim, Kk, Choe, S., Sweet, Rm, and Suh, Sw
7. A study on recent tendency of anti-tumor herbal acupuncture
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Yoo Hwa-Seung, Lee Yong-Yeon, Cho Jung-Hyo, Lee Yeon-Weol, Son Chang-Gue, Cho Chong-Kwan, and Hwang Kyu-Jeong
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anti-tumor herbal acupuncture ,point injection ,herbal intravenous injection ,cancer patient ,QOL ,Medicine ,Miscellaneous systems and treatments ,RZ409.7-999 ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Objectives: The purpose of this study is to develop and activate anti-tumor herbal acupuncture for cancer patients in South Korea. Methods: We investigated some literatures on anti-tumor herbal acupuncture which is used in South Korea and China, and made diagrams. Results: The results are summarized as follows. Anti-tumor herbal acupuncture is one of the traditional oriental medical method which is effective for cancer patients. In domestic studies, most of herb materials are belong to action of cooling&detoxification(25.0%) and strengthening body resistance(46.4%) which are proved to have effects of anti-tumor, immune activation and preventing tumor. In China, point injection therapy are used for improving symptoms of cancer patients and healing tumor. Also herbal intravenous injection is used for combination of chinese traditional and western cancer therapy and treating cancer patients variously. Conclusions: From the above results, it is expected that anti-tumor herbal acupuncture is useful to improve clinical symptoms and quality of life(QOL) of cancer patients. Also we must develop new progressive methods of point injection and herbal intravenous injection for treating cancer patients, and advance clinical studies and trials.
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- 2001
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8. The 'Harmonizing Optimal Strategy for Treatment of coronary artery stenosis - sAfety & effectiveneSS of drug-elUting stents & antiplatelet REgimen' (HOST-ASSURE) trial: study protocol for a randomized controlled trial
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Park Kyung, Park Byoung-Eun, Kang Si-Hyuck, Park Jin-Joo, Lee Seung-Pyo, Cha Kwang, Rhew Jay, Jeon Hui-Kyoung, Shin Eun, Oh Ju, Jeong Myung-Ho, Kim Sanghyun, Hwang Kyung-Kuk, Yoon Jung-Han, Lee Sung, Park Tae-Ho, Moon Keon, Kwon Hyuck-Moon, Chae In-Ho, and Kim Hyo-Soo
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Cilostazol ,cobalt chromium ,coronary heart disease ,everolimus-eluting stent ,platinum chromium ,zotarolimus-eluting stent ,Medicine (General) ,R5-920 - Abstract
Abstract Background Second-generation drug-eluting stents (DES) have raised the bar of clinical performance. These stents are mostly made from cobalt chromium alloy. A newer generation DES has been developed from platinum chromium alloy, but clinical data regarding the efficacy and safety of the platinum chromium-based everolimus-eluting stent (PtCr-EES) is limited, with no comparison data against the cobalt chromium-based zotarolimus-eluting stent (CoCr-ZES). In addition, an antiplatelet regimen is an integral component of medical therapy after percutaneous coronary intervention (PCI). A 1-week duration of doubling the dose of clopidogrel (double-dose antiplatelet therapy (DDAT)) was shown to improve outcome at 1 month compared with conventional dose in acute coronary syndrome (ACS) patients undergoing PCI. However in Asia, including Korea, the addition of cilostazol (triplet antiplatelet therapy (TAT)) is used more commonly than doubling the dose of clopidogrel in high-risk patients. Methods In the 'Harmonizing Optimal Strategy for Treatment of coronary artery stenosis - sAfety & effectiveneSS of drug-elUting stents & antiplatelet REgimen' (HOST-ASSURE) trial, approximately 3,750 patients are being prospectively and randomly assigned in a 2 × 2 factorial design according to the type of stent (PtCr-EES vs CoCr-ZES) and antiplatelet regimen (TAT vs DDAT). The first primary endpoint is target lesion failure at 1 year for the stent comparison, and the second primary endpoint is net clinical outcome at 1 month for comparison of antiplatelet therapy regimen. Discussion The HOST-ASSURE trial is the largest study yet performed to directly compare the efficacy and safety of the PtCr-EES versus CoCr-ZES in an 'all-comers' population. In addition, this study will also compare the clinical outcome of TAT versus DDAT for 1-month post PCI. Trial registration ClincalTrials.gov number NCT01267734.
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- 2012
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9. Black rice (Oryza sativa L.) extract attenuates hepatic steatosis in C57BL/6 J mice fed a high-fat diet via fatty acid oxidation
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Jang Hwan-Hee, Park Mi-Young, Kim Heon-Woong, Lee Young-Min, Hwang Kyung-A, Park Jae-Hak, Park Dong-Sik, and Kwon Oran
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Black rice ,Cyanidin-3-glucoside ,Hepatic steatosis ,High-fat diet ,Fatty acid oxidation ,Nutrition. Foods and food supply ,TX341-641 ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
Abstract Background Two major risk factors for the onset of fatty liver disease are excessive alcohol intake and obesity, the latter being associated with non-alcoholic fatty liver disease (NAFLD). The aim of this study was to examine the effects of black rice extract (BRE) on hepatic steatosis and insulin resistance in high-fat diet-fed mice, providing a model of NAFLD. Methods Twenty-four mice were randomly divided into three groups (n = 8 in each group): normal fat diet (ND), high fat diet (HF), and high fat diet supplemented with 1% (w/w) BRE (HF +1% BRE). The experimental diets were fed for seven weeks. Results A HF induced hepatic steatosis with significant increases in the serum levels of free fatty acids (FFAs), triglyceride (TG), total cholesterol (TC), and insulin. By contrast, supplementary BRE (10 g/kg of diet) included in the HF alleviated hepatic steatosis and significantly decreased serum TG and TC levels (p < 0.01 for both). Dietary BRE also increased expression of fatty acid metabolism-related genes, including carnitine palmitoyltransferase (CPT1A), acyl-CoA oxidase (ACO), cytochrome P450 (CYP4A10), and peroxisome proliferator activated receptor (PPAR)-α (p < 0.05 for all). Conclusions Dietary BRE supplementation improved serum lipid profiles and significantly enhanced mRNA expression levels of fatty acid metabolism-related genes, primarily via β-oxidation and ω-oxidation in the liver. Taken together, these findings suggest that a BRE-supplemented diet could be useful in reducing the risks of hepatic steatosis and related disorders, including hyperlipidemia and hyperglycemia.
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- 2012
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10. The Microscopic Origin of Residual Stress for Flat Self-Actuating Piezoelectric Cantilevers
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Hwang Kyo, Kim Tae, and Lee Jeong
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Nanomechanics ,Residual stress ,Piezoelectric ,Cantilever ,Biosensor ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Abstract In this study, flat piezoelectric microcantilevers were fabricated under low-stress Pb(Zr0.52Ti0.48)O3 (PZT) film conditions. They were analyzed using the Raman spectrum and wafer curvature methods. Based on the residual stress analysis, we found that a thickness of 1 μm was critical, since stress relaxation starts to occur at greater thicknesses, due to surface roughening. The (111) preferred orientation started to decrease when the film thickness was greater than 1 μm. The d33 value was closely related to the stress relaxation associated with the preferred orientation changes. We examined the harmonic response at different PZT cantilever lengths and obtained a 9.4-μm tip displacement at 3 Vp-p at 1 kHz. These analyses can provide a platform for the reliable operation of piezoelectric microdevices, potentially nanodevice when one needs to have simultaneous control of the residual stress and the piezoelectric properties.
- Published
- 2011
11. Round-robin test on thermal conductivity measurement of ZnO nanofluids and comparison of experimental results with theoretical bounds
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Jang Seok Pil, Hwang Kyo Sik, Kim Hyun Jin, Ha Hyo Jun, Lee Seung-Hyun, Rhee Chang-Kyu, Lee Gyoung-Ja, Kim Chang-Kyu, Lee Jaekeun, Kwon Younghwan, Kim Doohyun, Kim Soo Hyung, Koo Junemo, Hong Sung Wook, Choi Stephen, Choi Chul Jin, Lee Ji-Hwan, Lee Wook-Hyun, Lee Ki-Woong, and Bae Hwa-Young
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Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Abstract Ethylene glycol (EG)-based zinc oxide (ZnO) nanofluids containing no surfactant have been manufactured by one-step pulsed wire evaporation (PWE) method. Round-robin tests on thermal conductivity measurements of three samples of EG-based ZnO nanofluids have been conducted by five participating labs, four using accurate measurement apparatuses developed in house and one using a commercial device. The results have been compared with several theoretical bounds on the effective thermal conductivity of heterogeneous systems. This study convincingly demonstrates that the large enhancements in the thermal conductivities of EG-based ZnO nanofluids tested are beyond the lower and upper bounds calculated using the models of the Maxwell and Nan et al. with and without the interfacial thermal resistance.
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- 2011
12. A Note on -Genocchi Polynomials and Numbers of Higher Order
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Hwang Kyung-Won, Kim Young-Hee, and Jang Lee-Chae
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Mathematics ,QA1-939 - Abstract
We investigate several arithmetic properties of -Genocchi polynomials and numbers of higher order.
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- 2010
13. Comparative proteomic analysis of malformed umbilical cords from somatic cell nuclear transfer-derived piglets: implications for early postnatal death
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Seo Han, Lee Hoon, Park ChanKyu, Kim Teoan, Paik Seung-Sam, Park Ho-Hyun, Cho Seong-Keun, Hwang Kyu-Chan, Choi Yun-Jung, Kim Jae-Hwan, Park Jong-Yi, Park Soo-Bong, Hwang Seongsoo, and Kim Jin-Hoi
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Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background Somatic cell nuclear transfer (scNT)-derived piglets have high rates of mortality, including stillbirth and postnatal death. Here, we examined severe malformed umbilical cords (MUC), as well as other organs, from nine scNT-derived term piglets. Results Microscopic analysis revealed complete occlusive thrombi and the absence of columnar epithelial layers in MUC (scNT-MUC) derived from scNT piglets. scNT-MUC had significantly lower expression levels of platelet endothelial cell adhesion molecule-1 (PECAM-1) and angiogenesis-related genes than umbilical cords of normal scNT piglets (scNT-N) that survived into adulthood. Endothelial cells derived from scNT-MUC migrated and formed tubules more slowly than endothelial cells from control umbilical cords or scNT-N. Proteomic analysis of scNT-MUC revealed significant down-regulation of proteins involved in the prevention of oxidative stress and the regulation of glycolysis and cell motility, while molecules involved in apoptosis were significantly up-regulated. Histomorphometric analysis revealed severe calcification in the kidneys and placenta, peliosis in the liver sinusoidal space, abnormal stromal cell proliferation in the lungs, and tubular degeneration in the kidneys in scNT piglets with MUC. Increased levels of apoptosis were also detected in organs derived from all scNT piglets with MUC. Conclusion These results suggest that MUC contribute to fetal malformations, preterm birth and low birth weight due to underlying molecular defects that result in hypoplastic umbilical arteries and/or placental insufficiency. The results of the current study demonstrate the effects of MUC on fetal growth and organ development in scNT-derived pigs, and provide important insight into the molecular mechanisms underlying angiogenesis during umbilical cord development.
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- 2009
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14. Sums of Products of -Euler Polynomials and Numbers
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Hwang Kyung-Won, Kim Young-Hee, and Kim Taekyun
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Mathematics ,QA1-939 - Abstract
We derive formulae for the sums of products of the -Euler polynomials and numbers using the multivariate fermionic -adic -Volkenborn integral on .
- Published
- 2009
15. Symmetry Properties of Higher-Order Bernoulli Polynomials
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Hwang Kyung-Won, Kim Taekyun, and Kim Young-Hee
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Mathematics ,QA1-939 - Abstract
We investigate properties of identities and some interesting identities of symmetry for the Bernoulli polynomials of higher order using the multivariate -adic invariant integral on .
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- 2009
16. On the Identities of Symmetry for the -Euler Polynomials of Higher Order
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Park KyoungHo, Hwang Kyung-won, and Kim Taekyun
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Mathematics ,QA1-939 - Abstract
The main purpose of this paper is to investigate several further interesting properties of symmetry for the multivariate -adic fermionic integral on . From these symmetries, we can derive some recurrence identities for the -Euler polynomials of higher order, which are closely related to the Frobenius-Euler polynomials of higher order. By using our identities of symmetry for the -Euler polynomials of higher order, we can obtain many identities related to the Frobenius-Euler polynomials of higher order.
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- 2009
17. A Note on the -Euler Measures
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Hwang Kyung-Won, Lee Byungje, and Kim Taekyun
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Mathematics ,QA1-939 - Abstract
Properties of -extensions of Euler numbers and polynomials which generalize those satisfied by and are used to construct -extensions of -adic Euler measures and define -adic --series which interpolate -Euler numbers at negative integers. Finally, we give Kummer Congruence for the -extension of ordinary Euler numbers.
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- 2009
18. On the Identities of Symmetry for the Generalized Bernoulli Polynomials Attached to of Higher Order
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Jang Lee-Chae, Hwang Kyung-Won, Kim Taekyun, and Kim Young-Hee
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Mathematics ,QA1-939 - Abstract
We give some interesting relationships between the power sums and the generalized Bernoulli numbers attached to of higher order using multivariate -adic invariant integral on .
- Published
- 2009
19. Note on the -Extension of Barnes' Type Multiple Euler Polynomials
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Kim Taekyun, Kim Young-Hee, Hwang Kyung-Won, and Jang Leechae
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Mathematics ,QA1-939 - Abstract
We construct the -Euler numbers and polynomials of higher order, which are related to Barnes' type multiple Euler polynomials. We also derive many properties and formulae for our -Euler polynomials of higher order by using the multiple integral equations on .
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- 2009
20. Interpolation Functions of -Extensions of Apostol's Type Euler Polynomials
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Kim Young-Hee, Kim Taekyun, and Hwang Kyung-Won
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Mathematics ,QA1-939 - Abstract
The main purpose of this paper is to present new -extensions of Apostol's type Euler polynomials using the fermionic -adic integral on . We define the - -Euler polynomials and obtain the interpolation functions and the Hurwitz type zeta functions of these polynomials. We define -extensions of Apostol type's Euler polynomials of higher order using the multivariate fermionic -adic integral on . We have the interpolation functions of these - -Euler polynomials. We also give -extensions of Apostol's type Euler polynomials of higher order and have the multiple Hurwitz type zeta functions of these - -Euler polynomials.
- Published
- 2009
21. Adenovirus-mediated interleukin-12 gene transfer combined with cytosine deaminase followed by 5-fluorocytosine treatment exerts potent antitumor activity in Renca tumor-bearing mice
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Kim Samyong, Yun Hwan-Jung, Yoo Jinsang, Cho Won-Kyung, Hwang Kyung-Sun, and Im Dong-Soo
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Therapeutic gene transfer affords a clinically feasible and safe approach to cancer treatment but a more effective modality is needed to improve clinical outcomes. Combined transfer of therapeutic genes with different modes of actions may be a means to this end. Interleukin-12 (IL-12), a heterodimeric immunoregulatory cytokine composed of covalently linked p35 and p40 subunits, has antitumor activity in animal models. The enzyme/prodrug strategy using cytosine deaminase (CD) and 5-fluorocytosine (5-FC) has been used for cancer gene therapy. We have evaluated the antitumor effect of combining IL-12 with CD gene transfer in mice bearing renal cell carcinoma (Renca) tumors. Methods Adenoviral vectors were constructed encoding one or both subunits of murine IL-12 (Ad.p35, Ad.p40 and Ad.IL-12) or cytosine deaminase (Ad.CD). The functionality of the IL-12 or CD gene products expressed from these vectors was validated by splenic interferon (IFN)-γ production or viability assays in cultured cells. Ad.p35 plus Ad.p40, or Ad.IL-12, with or without Ad.CD, were administered (single-dose) intratumorally to Renca tumor-bearing mice. The animals injected with Ad.CD also received 5-FC intraperitoneally. The antitumor effects were then evaluated by measuring tumor regression, mean animal survival time, splenic natural killer (NK) cell activity and IFN-γ production. Results The inhibition of tumor growth in mice treated with Ad.p35 plus Ad.p40 and Ad.CD, followed by injection of 5-FC, was significantly greater than that in mice treated with Ad.CD/5-FC, a mixture of Ad.p35 plus Ad.p40, or Ad.GFP (control). The combined gene transfer increased splenic NK cell activity and IFN-γ production by splenocytes. Ad.CD/5-FC treatment significantly increased the antitumor effect of Ad.IL-12 in terms of tumor growth inhibition and mean animal survival time. Conclusion The results suggest that adenovirus-mediated IL-12 gene transfer combined with Ad.CD followed by 5-FC treatment may be useful for treating cancers.
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- 2005
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22. Combining gene expression data from different generations of oligonucleotide arrays
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Kong Sek, Hwang Kyu-Baek, Greenberg Steve A, and Park Peter J
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background One of the important challenges in microarray analysis is to take full advantage of previously accumulated data, both from one's own laboratory and from public repositories. Through a comparative analysis on a variety of datasets, a more comprehensive view of the underlying mechanism or structure can be obtained. However, as we discover in this work, continual changes in genomic sequence annotations and probe design criteria make it difficult to compare gene expression data even from different generations of the same microarray platform. Results We first describe the extent of discordance between the results derived from two generations of Affymetrix oligonucleotide arrays, as revealed in cluster analysis and in identification of differentially expressed genes. We then propose a method for increasing comparability. The dataset we use consists of a set of 14 human muscle biopsy samples from patients with inflammatory myopathies that were hybridized on both HG-U95Av2 and HG-U133A human arrays. We find that the use of the probe set matching table for comparative analysis provided by Affymetrix produces better results than matching by UniGene or LocusLink identifiers but still remains inadequate. Rescaling of expression values for each gene across samples and data filtering by expression values enhance comparability but only for few specific analyses. As a generic method for improving comparability, we select a subset of probes with overlapping sequence segments in the two array types and recalculate expression values based only on the selected probes. We show that this filtering of probes significantly improves the comparability while retaining a sufficient number of probe sets for further analysis. Conclusions Compatibility between high-density oligonucleotide arrays is significantly affected by probe-level sequence information. With a careful filtering of the probes based on their sequence overlaps, data from different generations of microarrays can be combined more effectively.
- Published
- 2004
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23. Structural Insights and Catalytic Mechanism of 3-Hydroxybutyryl-CoA Dehydrogenase from Faecalibacterium Prausnitzii A2-165.
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Yang J, Jeon HJ, Park S, Park J, Jang S, Shin B, Bang K, Hawkes HK, Park S, Kim S, and Hwang KY
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- Crystallography, X-Ray, 3-Hydroxyacyl CoA Dehydrogenases metabolism, 3-Hydroxyacyl CoA Dehydrogenases chemistry, 3-Hydroxyacyl CoA Dehydrogenases genetics, NAD metabolism, Models, Molecular, Acyl Coenzyme A metabolism, Acyl Coenzyme A chemistry, Bacterial Proteins chemistry, Bacterial Proteins metabolism, Bacterial Proteins genetics, Catalytic Domain, Protein Conformation, Faecalibacterium prausnitzii metabolism
- Abstract
Atopic dermatitis (AD) is characterized by a T-helper cell type 2 (Th2) inflammatory response leading to skin damage with erythema and edema. Comparative fecal sample analysis has uncovered a strong correlation between AD and Faecalibacterium prausnitzii strain A2-165, specifically associated with butyrate production. Therefore, understanding the functional mechanisms of crucial enzymes in the butyrate pathway, such as 3-hydroxybutyryl-CoA dehydrogenase of A2-165 (A2HBD), is imperative. Here, we have successfully elucidated the three-dimensional structure of A2HBD in complex with acetoacetyl-CoA and NAD
+ at a resolution of 2.2Å using the PAL-11C beamline (third generation). Additionally, X-ray data of A2HBD in complex with acetoacetyl-CoA at a resolution of 1.9 Å were collected at PAL-XFEL (fourth generation) utilizing Serial Femtosecond Crystallography (SFX). The monomeric structure of A2HBD consists of two domains, N-terminal and C-terminal, with cofactor binding occurring at the N-terminal domain, while the C-terminal domain facilitates dimerization. Our findings elucidate the binding mode of NAD+ to A2HBD. Upon acetoacetyl-CoA binding, the crystal structure revealed a significant conformational change in the Clamp-roof domain (root-mean-square deviation of 2.202 Å). Notably, residue R143 plays a critical role in capturing the adenine phosphate ring, underlining its significance in substrate recognition and catalytic activity. The binding mode of acetoacetyl-CoA was also clarified, indicating its lower stability compared to NAD+ . Furthermore, the conformational change of hydrophobic residues near the catalytic cavity upon substrate binding resulted in cavity shrinkage from an open to closed conformation. This study confirms the conformational changes of catalytic triads involved in the catalytic reaction and presents a proposed mechanism for substrate reduction based on structural observations.- Published
- 2024
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24. Structural Insights into the Rrp4 Subunit from the Crystal Structure of the Thermoplasma acidophilum Exosome.
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Park S, Kim HS, Bang K, Han A, Shin B, Seo M, Kim S, and Hwang KY
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- Crystallography, X-Ray, Models, Molecular, Protein Subunits chemistry, Protein Subunits metabolism, Exosome Multienzyme Ribonuclease Complex metabolism, Exosome Multienzyme Ribonuclease Complex chemistry, RNA Stability, Thermoplasma metabolism, Exosomes metabolism, Exosomes chemistry, Archaeal Proteins chemistry, Archaeal Proteins metabolism, Archaeal Proteins genetics
- Abstract
The exosome multiprotein complex plays a critical role in RNA processing and degradation. This system governs the regulation of mRNA quality, degradation in the cytoplasm, the processing of short noncoding RNA, and the breakdown of RNA fragments. We determined two crystal structures of exosome components from Thermoplasma acidophilum ( Taci ): one with a resolution of 2.3 Å that reveals the central components ( Taci Rrp41 and Taci Rrp42), and another with a resolution of 3.5 Å that displays the whole exosome ( Taci Rrp41, Taci Rrp42, and Taci Rrp4). The fundamental exosome structure revealed the presence of a heterodimeric complex consisting of Taci Rrp41 and Taci Rrp42. The structure comprises nine subunits, with Taci Rrp41 and Taci Rrp42 arranged in a circular configuration, while Taci Rrp4 is located at the apex. The RNA degradation capabilities of the Taci Rrp4:41:42 complex were verified by RNA degradation assays, consistent with prior findings in other archaeal exosomes. The resemblance between archaeal exosomes and bacterial PNPase suggests a common mechanism for RNA degradation. Despite sharing comparable topologies, the surface charge distributions of Taci Rrp4 and other archaea structures are surprisingly distinct. Different RNA breakdown substrates may be responsible for this variation. These newfound structural findings enhance our comprehension of RNA processing and degradation in biological systems.
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- 2024
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25. Polymorphic Self-Assembly with Procedural Flexibility for Monodisperse Quaternary Protein Structures of DegQ Enzymes.
- Author
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Jeon H, Han AR, Oh S, Park JG, Namkoong M, Bang KM, Kim HM, Kim NK, Hwang KY, Hur K, Lee BJ, Heo J, Kim S, Song HK, Cho H, and Lee IG
- Subjects
- Cryoelectron Microscopy, Models, Molecular, Molecular Chaperones chemistry, Molecular Chaperones metabolism, Escherichia coli Proteins chemistry, Escherichia coli Proteins metabolism, Protein Structure, Quaternary, Serine Endopeptidases chemistry, Serine Endopeptidases metabolism
- Abstract
As large molecular tertiary structures, some proteins can act as small robots that find, bind, and chaperone target protein clients, showing the potential to serve as smart building blocks in self-assembly fields. Instead of using such intrinsic functions, most self-assembly methodologies for proteins aim for de novo-designed structures with accurate geometric assemblies, which can limit procedural flexibility. Here, a strategy enabling polymorphic clustering of quaternary proteins, exhibiting simplicity and flexibility of self-assembling paths for proteins in forming monodisperse quaternary cage particles is presented. It is proposed that the enzyme protomer DegQ, previously solved at low resolution, may potentially be usable as a threefold symmetric building block, which can form polyhedral cages incorporated by the chaperone action of DegQ in the presence of protein clients. To obtain highly monodisperse cage particles, soft, and hence, less resistive client proteins, which can program the inherent chaperone activity of DegQ to efficient formations of polymorphic cages, depending on the size of clients are utilized. By reconstructing the atomic resolution cryogenic electron microscopy DegQ structures using obtained 12- and 24-meric clusters, the polymorphic clustering of DegQ enzymes is validated in terms of soft and rigid domains, which will provide effective routes for protein self-assemblies with procedural flexibility., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)
- Published
- 2024
- Full Text
- View/download PDF
26. Cargo specificity, regulation, and therapeutic potential of cytoplasmic dynein.
- Author
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Park JG, Jeon H, Hwang KY, Cha SS, Han RT, Cho H, and Lee IG
- Subjects
- Humans, Animals, Biological Transport, Microtubules metabolism, Dyneins metabolism, Cytoplasmic Dyneins metabolism
- Abstract
Intracellular retrograde transport in eukaryotic cells relies exclusively on the molecular motor cytoplasmic dynein 1. Unlike its counterpart, kinesin, dynein has a single isoform, which raises questions about its cargo specificity and regulatory mechanisms. The precision of dynein-mediated cargo transport is governed by a multitude of factors, including temperature, phosphorylation, the microtubule track, and interactions with a family of activating adaptor proteins. Activating adaptors are of particular importance because they not only activate the unidirectional motility of the motor but also connect a diverse array of cargoes with the dynein motor. Therefore, it is unsurprising that dysregulation of the dynein-activating adaptor transport machinery can lead to diseases such as spinal muscular atrophy, lower extremity, and dominant. Here, we discuss dynein motor motility within cells and in in vitro, and we present several methodologies employed to track the motion of the motor. We highlight several newly identified activating adaptors and their roles in regulating dynein. Finally, we explore the potential therapeutic applications of manipulating dynein transport to address diseases linked to dynein malfunction., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
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27. Adverse Clinical Effects Associated With Non-catecholamine Pharmacologic Agents for Treatment of Vasoplegic Syndrome in Adult Cardiac Surgery.
- Author
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Hwang KY, Phoon PHY, and Hwang NC
- Subjects
- Adult, Humans, Norepinephrine therapeutic use, Treatment Outcome, Iatrogenic Disease, Vasoplegia drug therapy, Vasoplegia etiology, Cardiac Surgical Procedures adverse effects, Drug-Related Side Effects and Adverse Reactions
- Abstract
Vasoplegic syndrome is a relatively common complication that can happen during and after major adult cardiac surgery. It is associated with a higher rate of complications, including postoperative renal failure, longer duration of mechanical ventilation, and intensive care unit stay, as well as increased mortality. The underlying pathophysiology of vasoplegic syndrome is that of profound vascular hyporesponsiveness, and involves a complex interplay among inflammatory cytokines, cellular surface receptors, and nitric oxide (NO) production. The pharmacotherapy approaches for the treatment of vasoplegia include medications that increase vascular smooth muscle contraction via increasing cytosolic calcium in myocytes, reduce the vascular effects of NO and inflammation, and increase the biosynthesis of and vascular response to norepinephrine. Clinical trials have demonstrated the clinical efficacy of non-catecholamine pharmacologic agents in the treatment of vasoplegic syndrome. With an increase in their use today, it is important for clinicians to understand the adverse clinical outcomes and patient risk profiles associated with these agents, which will allow better-tailored medical therapy., Competing Interests: Declaration of competing interest None., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
28. Arabidopsis ecotype Ct-1, with its altered nitrate sensing ability, exhibits enhanced growth under low nitrate conditions in comparison to Col-0.
- Author
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Lee S, Tri Le Q, Yang S, Hwang KY, and Lee H
- Abstract
To address the urgent need for sustainable solutions to the increased use of nitrogen fertilizers in agriculture, it is imperative to acquire an in-depth comprehension of the intricate interplay between plants and nitrogen. In this context, our research aimed to elucidate the molecular mechanism behind NO
3 - sensing/signaling in plants, which can enhance nitrogen utilization efficiency. Previous reports have revealed that the density and quantity of root hairs exhibit responsive behavior to varying levels of NO3 - , while the precise molecular mechanisms governing these changes remain elusive. To further investigate this phenomenon, we specifically selected the Ct-1 ecotype, which manifested a greater abundance of root hairs compared to the Col-0 ecotype under conditions of low NO3 - . Our investigations unveiled that the dissimilarities in the amino acid sequence of NRT1.1, a transceptor responsible for regulating nitrate signaling and transport, accounted for the observed variation in root hair numbers. These results suggest that NRT1.1 represents a promising target for gene editing technology, offering potential applications in enhancing the efficiency of nitrogen utilization in agricultural crops., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2023
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29. Streamlining curriculum delivery within the regulatory framework during the COVID-19 pandemic: a medical school experience.
- Author
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Hwang KY, Ti LK, Hwang NC, and Loh MH
- Abstract
Competing Interests: None
- Published
- 2023
- Full Text
- View/download PDF
30. Control of fibrosis with enhanced safety via asymmetric inhibition of prolyl-tRNA synthetase 1.
- Author
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Yoon I, Kim S, Cho M, You KA, Son J, Lee C, Suh JH, Bae DJ, Kim JM, Oh S, Park S, Kim S, Cho SH, Park S, Bang K, Seo M, Kim JH, Lee B, Park JS, Hwang KY, and Kim S
- Subjects
- Humans, Fibrosis, Proline genetics, Proline metabolism, Protein Biosynthesis, Amino Acyl-tRNA Synthetases chemistry, Amino Acyl-tRNA Synthetases genetics, Amino Acyl-tRNA Synthetases metabolism
- Abstract
Prolyl-tRNA synthetase 1 (PARS1) has attracted much interest in controlling pathologic accumulation of collagen containing high amounts of proline in fibrotic diseases. However, there are concerns about its catalytic inhibition for potential adverse effects on global protein synthesis. We developed a novel compound, DWN12088, whose safety was validated by clinical phase 1 studies, and therapeutic efficacy was shown in idiopathic pulmonary fibrosis model. Structural and kinetic analyses revealed that DWN12088 binds to catalytic site of each protomer of PARS1 dimer in an asymmetric mode with different affinity, resulting in decreased responsiveness at higher doses, thereby expanding safety window. The mutations disrupting PARS1 homodimerization restored the sensitivity to DWN12088, validating negative communication between PARS1 promoters for the DWN12088 binding. Thus, this work suggests that DWN12088, an asymmetric catalytic inhibitor of PARS1 as a novel therapeutic agent against fibrosis with enhanced safety., (© 2023 The Authors. Published under the terms of the CC BY 4.0 license.)
- Published
- 2023
- Full Text
- View/download PDF
31. Fermented Kamut Sprout Extract Decreases Cell Cytotoxicity and Increases the Anti-Oxidant and Anti-Inflammation Effect.
- Author
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Ki H, Baek JS, Hawkes HK, Kim YS, and Hwang KY
- Abstract
Kamut sprouts (KaS) contain several biologically active compounds. In this study, solid-state fermentation using Saccharomyces cerevisiae and Latilactobacillus sakei was used to ferment KaS (fKaS-ex) for 6 days. The fKaS-ex showed a 26.3 mg/g dried weight (dw) and 46.88 mg/g dw of polyphenol and the β-glucan contents, respectively. In the Raw264.7 and HaCaT cell lines, the non-fermented KaS (nfKaS-ex) decreased cell viability from 85.3% to 62.1% at concentrations of 0.63 and 2.5 mg/mL, respectively. Similarly, the fKaS-ex decreased cell viability, but showed more than 100% even at 1.25 and 5.0 mg/mL concentrations, respectively. The anti-inflammatory effect of fKaS-ex also increased. At 600 µg/mL, the fKaS-ex exhibited a significantly higher ability to reduce cytotoxicity by suppressing COX-2 and IL-6 mRNA expressions as well as that for IL-1β mRNA. In summary, fKaS-ex exhibited significantly lower cytotoxicity and increased anti-oxidant and anti-inflammatory properties, indicating that fKaS-ex is beneficial for use in food and other industries.
- Published
- 2023
- Full Text
- View/download PDF
32. Structural basis for CEP192-mediated regulation of centrosomal AURKA.
- Author
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Park JG, Jeon H, Shin S, Song C, Lee H, Kim NK, Kim EE, Hwang KY, Lee BJ, and Lee IG
- Subjects
- Centrosome metabolism, Microtubules metabolism, Mitosis, Aurora Kinase A genetics, Aurora Kinase A metabolism, Spindle Apparatus metabolism
- Abstract
Aurora kinase A (AURKA) performs critical functions in mitosis. Thus, the activity and subcellular localization of AURKA are tightly regulated and depend on diverse factors including interactions with the multiple binding cofactors. How these different cofactors regulate AURKA to elicit different levels of activity at distinct subcellular locations and times is poorly understood. Here, we identified a conserved region of CEP192, the major cofactor of AURKA, that mediates the interaction with AURKA. Quantitative binding studies were performed to map the interactions of a conserved helix (Helix-1) within CEP192. The crystal structure of Helix-1 bound to AURKA revealed a distinct binding site that is different from other cofactor proteins such as TPX2. Inhibiting the interaction between Helix-1 and AURKA in cells led to the mitotic defects, demonstrating the importance of the interaction. Collectively, we revealed a structural basis for the CEP192-mediated AURKA regulation at the centrosome, which is distinct from TPX2-mediated regulation on the spindle microtubule.
- Published
- 2023
- Full Text
- View/download PDF
33. Development of carbon nanoparticles-based soluble solid-phase immune sensor for the quantitative diagnosis of inflammation.
- Author
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Kim S, Koo M, Tak Y, Jang S, Park J, Hwang KY, and Park S
- Subjects
- Animals, Dogs, Reproducibility of Results, Antibodies, Immunoassay methods, Inflammation diagnosis, Carbon, Nanoparticles, Biosensing Techniques
- Abstract
Quantitative immunodiagnosis is one of the most commonly used methods for in vitro diagnostics. Various bioanalytical methods have been developed to quantitatively diagnose immune analytes; however, they require blood dilution pretreatment, reaction mixing, complicated experimental steps, and can cause diagnostic errors due to the hook effect. To address this issue, we introduced a simple immunoassay based on carbon nanoparticles (CNPs). The assay was designed to have high flexibility for use in various in vitro diagnostic devices by constructing a soluble solid-phase immune sensor with high solubility using antibody-conjugated CNPs and polymer materials. Excellent performance was achieved using a free-antibody system with dual calibration. To verify the performance of this method with high reliability, canine C-reactive protein was selected as the immune analyte. Interestingly, our method efficiently mitigated the hook effect with outstanding performance in a one-step reaction without blood dilution or reaction mixing. The detection range of the target can be effectively controlled using free antibodies. Therefore, our CNP-based immunodiagnosis method may advance the commercialization of point-of-care immune biosensors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
34. EPRS1 Controls the TGF- β Signaling Pathway via Interaction with TβRI in Hepatic Stellate Cell.
- Author
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Yoon I, Song JA, Suh JH, Kim S, Son J, Kim JH, Jang SY, Hwang KY, Kim MH, and Kim S
- Subjects
- Humans, Receptor, Transforming Growth Factor-beta Type I metabolism, Transforming Growth Factor beta metabolism, Fibrosis, Signal Transduction physiology, Hepatic Stellate Cells metabolism, Receptors, Transforming Growth Factor beta genetics, Receptors, Transforming Growth Factor beta metabolism
- Abstract
Glutamyl-prolyl-tRNA synthetase 1 (EPRS1) is known to associated with fibrosis through its catalytic activity to produce prolyl-tRNA. Although its catalytic inhibitor halofuginone (HF) has been known to inhibit the TGF-β pathway as well as to reduce prolyl-tRNA production for the control of fibrosis, the underlying mechanism how EPRS1 regulates the TGF-β pathway was not fully understood. Here, we show a noncatalytic function of EPRS1 in controlling the TGF-β pathway and hepatic stellate cell activation via its interaction with TGF-β receptor I (TβRI). Upon stimulation with TGF-β, EPRS1 is phosphorylated by TGF-β-activated kinase 1 (TAK1), leading to its dissociation from the multi-tRNA synthetase complex and subsequent binding with TβRI. This interaction increases the association of TβRI with SMAD2/3 while decreases that of TβRI with SMAD7. Accordingly, EPRS1 stabilizes TβRI by preventing the ubiquitin-mediated degradation of TβRI. HF disrupts the interaction between EPRS1 and TβRI, and reduces TβRI protein levels, leading to inhibition of the TGF-β pathway. In conclusion, this work suggests the novel function of EPRS1 involved in the development of fibrosis by regulating the TGF-β pathway and the antifibrotic effects of HF by controlling both of EPRS1 functions.
- Published
- 2023
- Full Text
- View/download PDF
35. Retraction Note: Apicidin induces endoplasmic reticulum stress- and mitochondrial dysfunction-associated apoptosis via phospholipase Cγ1- and Ca2+-dependent pathway in mouse Neuro-2a neuroblastoma cells.
- Author
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Choi JH, Lee JY, Choi AY, Hwang KY, Choe W, Yoon KS, Ha J, Yeo EJ, and Kang I
- Published
- 2022
- Full Text
- View/download PDF
36. A randomized multicenter evaluation of the efficacy of 0.15% hyaluronic acid versus 0.05% cyclosporine A in dry eye syndrome.
- Author
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Lee JE, Kim S, Lee HK, Chung TY, Kim JY, Choi CY, Chung SH, Kim DH, Kim KW, Chung JK, Hwang KY, Hwang HS, Kim JH, and Hyon JY
- Subjects
- Humans, Hyaluronic Acid adverse effects, Tears, Ophthalmic Solutions therapeutic use, Cyclosporine adverse effects, Dry Eye Syndromes drug therapy, Dry Eye Syndromes chemically induced
- Abstract
Hyaluronic acid (HA) and cyclosporine A (CsA) eyedrops are commonly prescribed in dry eye syndrome (DES). The effectiveness of each preparation in DES is well-known, yet the superiority of one over another has been studied little. We assessed the efficacy and tolerability of 0.15% HA compared to combinations of 0.05% CsA plus 0.5% carboxymethylcellulose (CMC), and 0.15% HA plus 0.05% CsA in patients with moderate to severe DES. Total 438 patients with moderate to severe DES were recruited and randomized for one of the three treatments for 12 weeks. Effectiveness was assessed at baseline, 4- and 12-weeks. The primary endpoint was change in corneal staining score. The secondary endpoints were tear break-up time (TBUT), strip meniscometry (SM) score, ocular surface disease index (OSDI) score, and tolerability questionnaire. The change in corneal staining score for 0.15% HA from the baseline was non-inferior to that of 0.05% CsA. Corneal staining score, TBUT, SM score, and OSDI score improved in all groups without statistically significant intergroup differences. Better tolerability and lower prevalence of adverse drug reactions were seen in 0.15% HA. Our findings suggest that 0.15% HA may be equivalently effective and safer than 0.05% CsA in treating moderate to severe DES., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
37. Enhancing Horizontal Ratio of Transition Dipole Moment in Homoleptic Ir Complexes for High Outcoupling Efficiency of Organic Light-Emitting Diodes.
- Author
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Kim JM, Hwang KY, Kim S, Lim J, Kang B, Lee KH, Choi B, Kwak SY, and Lee JY
- Abstract
The light-emitting dipole orientation (EDO) of a phosphorescent emitter is a key to improving the external quantum efficiency (EQE) of organic light-emitting diodes (OLEDs) without structural modification of the device. Here, four homoleptic Ir complexes as a phosphorescent emitter are systematically designed based on the molecular structure of tris(2-phenylpyridine)iridium(III) (Ir(ppy)
3 ) to control the EDO. Trimethylsilane, methyl, 2-methylpropyl, and cyclopentylmethyl group substituted to pyridine ring of the ligand contribute to the improvement of the EDO from 76.5% for Ir(ppy)3 to 87.5%. A linear relationship between the EDO and the aspect ratio (geometric anisotropy factor) is founded, implying the importance of the effective area for the nonbonding force between host and dopant molecules. Also, it is investigated that the EDO enhancement mainly originates from the vertical alignment of the C3 axis of molecule in the substrate axis rather than the change in the direction of the transition dipole alignment in the molecular axis. The optical simulation reveals that the outcoupling efficiency of phosphorescent OLEDs adopting new dopants reaches 38.4%. The green OLEDs exhibiting 28.3% of EQE, 103.2 cd A-1 of current efficiency, and 98.2 lm W-1 of power efficiency are demonstrated, which is understood to have little electrical loss., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)- Published
- 2022
- Full Text
- View/download PDF
38. Author Correction: O-GlcNAc modification of leucyl-tRNA synthetase 1 integrates leucine and glucose availability to regulate mTORC1 and the metabolic fate of leucine.
- Author
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Kim K, Yoo HC, Kim BG, Kim S, Sung Y, Yoon I, Yu YC, Park SJ, Kim JH, Myung K, Hwang KY, Kim S, and Han JM
- Published
- 2022
- Full Text
- View/download PDF
39. Magnetoimpedance Biosensors and Real-Time Healthcare Monitors: Progress, Opportunities, and Challenges.
- Author
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Jimenez VO, Hwang KY, Nguyen D, Rahman Y, Albrecht C, Senator B, Thiabgoh O, Devkota J, Bui VDA, Lam DS, Eggers T, and Phan MH
- Subjects
- Delivery of Health Care, Electric Impedance, Humans, Magnetics, Biosensing Techniques, COVID-19 diagnosis
- Abstract
A small DC magnetic field can induce an enormous response in the impedance of a soft magnetic conductor in various forms of wire, ribbon, and thin film. Also known as the giant magnetoimpedance (GMI) effect, this phenomenon forms the basis for the development of high-performance magnetic biosensors with magnetic field sensitivity down to the picoTesla regime at room temperature. Over the past decade, some state-of-the-art prototypes have become available for trial tests due to continuous efforts to improve the sensitivity of GMI biosensors for the ultrasensitive detection of biological entities and biomagnetic field detection of human activities through the use of magnetic nanoparticles as biomarkers. In this review, we highlight recent advances in the development of GMI biosensors and review medical devices for applications in biomedical diagnostics and healthcare monitoring, including real-time monitoring of respiratory motion in COVID-19 patients at various stages. We also discuss exciting research opportunities and existing challenges that will stimulate further study into ultrasensitive magnetic biosensors and healthcare monitors based on the GMI effect.
- Published
- 2022
- Full Text
- View/download PDF
40. Nano-sized drug delivery systems to potentiate the immune checkpoint blockade therapy.
- Author
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Shim MK, Song SK, Jeon SI, Hwang KY, and Kim K
- Subjects
- Humans, Immune Checkpoint Inhibitors pharmacology, Immune Checkpoint Inhibitors therapeutic use, Immunotherapy, Nanoparticle Drug Delivery System, Tumor Microenvironment, Antineoplastic Agents pharmacology, Antineoplastic Agents therapeutic use, Neoplasms therapy
- Abstract
Introduction: Immune checkpoint blockade (ICB) therapy is now FDA-approved for the treatment of various tumor types. By removing inhibitory signals for T-cell activation and disrupting the immune escape mechanism of tumor cells, ICB therapy has shown considerable efficacy with complete tumor regression in patients. However, patients respond poorly to this therapy and show limited response rates owing to the immunosuppressive tumor microenvironment (ITM) in cold tumors., Areas Covered: In this review, recent advances and progress in the use of nano-sized drug delivery system (Nano-DDS) to potentiate the ICB therapy by reversing cold tumors with an ITM into immunogenic hot tumors are discussed. The types of immunogenic cell death (ICD) inducers that initiate or enhance antitumor immune responses are classified, and their extensive combination with immune modulators using Nano-DDS is highlighted., Expert Opinion: Nano-DDS can be efficiently combined with ICD inducers and immune modulators and trigger a potent antitumor immune response based on a comprehensive approach to the cancer-immunity cycle.
- Published
- 2022
- Full Text
- View/download PDF
41. O-GlcNAc modification of leucyl-tRNA synthetase 1 integrates leucine and glucose availability to regulate mTORC1 and the metabolic fate of leucine.
- Author
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Kim K, Yoo HC, Kim BG, Kim S, Sung Y, Yoon I, Yu YC, Park SJ, Kim JH, Myung K, Hwang KY, Kim S, and Han JM
- Subjects
- Autophagy, Humans, Acetylglucosamine metabolism, Glucose metabolism, Leucine metabolism, Leucine-tRNA Ligase metabolism, Mechanistic Target of Rapamycin Complex 1 metabolism
- Abstract
All living organisms have the ability to sense nutrient levels to coordinate cellular metabolism. Despite the importance of nutrient-sensing pathways that detect the levels of amino acids and glucose, how the availability of these two types of nutrients is integrated is unclear. Here, we show that glucose availability regulates the central nutrient effector mTORC1 through intracellular leucine sensor leucyl-tRNA synthetase 1 (LARS1). Glucose starvation results in O-GlcNAcylation of LARS1 on residue S1042. This modification inhibits the interaction of LARS1 with RagD GTPase and reduces the affinity of LARS1 for leucine by promoting phosphorylation of its leucine-binding site by the autophagy-activating kinase ULK1, decreasing mTORC1 activity. The lack of LARS1 O-GlcNAcylation constitutively activates mTORC1, supporting its ability to sense leucine, and deregulates protein synthesis and leucine catabolism under glucose starvation. This work demonstrates that LARS1 integrates leucine and glucose availability to regulate mTORC1 and the metabolic fate of leucine., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
42. Bovine colostrum derived-exosomes prevent dextran sulfate sodium-induced intestinal colitis via suppression of inflammation and oxidative stress.
- Author
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Han G, Cho H, Kim H, Jang Y, Jang H, Kim DE, Kim ES, Kim EH, Hwang KY, Kim K, Yang Y, and Kim SH
- Subjects
- Animals, Colostrum metabolism, Cytokines metabolism, Dextran Sulfate, Disease Models, Animal, Female, Humans, Inflammation metabolism, Mice, Mice, Inbred C57BL, Oxidative Stress, Pregnancy, Colitis chemically induced, Colitis prevention & control, Exosomes metabolism
- Abstract
Despite the rise in the global burden of inflammatory bowel disease, there is a lack of safe and effective therapies that can meet the needs of clinical patients. In this study, we investigated the beneficial effects of bovine milk, especially colostrum-derived exosomes (Col-exo) in a murine model of ulcerative colitis induced by dextran sodium sulfate (DSS). Col-exo activated the proliferation of colonic epithelial cells and macrophages, and created an environment to relieve inflammation by effectively removing reactive oxygen species and regulating the expression of immune cytokines. Besides, Col-exo could pass through the gastrointestinal tract intact and efficiently deliver bioactive cargoes to the stomach, small intestine, and colon. Our results showed that oral gavage of Col-exo can alleviate colitis symptoms including weight loss, gastrointestinal bleeding, and chronic diarrhea by modulating intestinal inflammatory immune responses. Overall, bovine colostrum-derived exosomes with excellent structural and functional stability may offer great potential as natural therapeutics for the recovery of colitis.
- Published
- 2022
- Full Text
- View/download PDF
43. Retraction Note to: Licochalcone A induces apoptosis through endoplasmic reticulum stress via a phospholipase Cγ1-, Ca 2+ -, and reactive oxygen species-dependent pathway in HepG2 human hepatocellular carcinoma cells.
- Author
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Choi AY, Choi JH, Hwang KY, Jeong YJ, Choe W, Yoon KS, Ha J, Kim SS, Youn JH, Yeo EJ, and Kang I
- Published
- 2022
- Full Text
- View/download PDF
44. Relapsed Disciform Stromal Herpetic Keratitis Following mRNA COVID-19 Vaccination: A Case Report.
- Author
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Song MY, Koh KM, Hwang KY, Kwon YA, and Kim KY
- Subjects
- COVID-19 Vaccines, Humans, RNA, Messenger, SARS-CoV-2, Vaccination adverse effects, COVID-19, Keratitis, Herpetic diagnosis
- Published
- 2022
- Full Text
- View/download PDF
45. Severe acute respiratory syndrome coronavirus 2 variants-Possibility of universal vaccine design: A review.
- Author
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Yoon E, Kim D, Jeon H, Kwon Y, Jang Y, Kim S, and Hwang KY
- Abstract
Both novel and conventional vaccination strategies have been implemented worldwide since the onset of coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite various medical advances in the treatment and prevention of the spread of this contagious disease, it remains a major public health threat with a high mortality rate. As several lethal SARS-CoV-2 variants continue to emerge, the development of several vaccines and medicines, each with certain advantages and disadvantages, is underway. Additionally, many modalities are at various stages of research and development or clinical trials. Here, we summarize emerging SARS-CoV-2 variants, including delta, omicron, and "stealth omicron," as well as available oral drugs for COVID-19. We also discuss possible antigen candidates other than the receptor-binding domain protein for the development of a universal COVID-19 vaccine. The present review will serve as a helpful resource for future vaccine and drug development to combat COVID-19., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
46. Exploring the Role of Surface States in Emissive Carbon Nanodots: Analysis at Single-Particle Level.
- Author
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Kim D, Calabro RL, Masud AA, Kothalawala NL, Gu M, Kwak SY, Son WJ, Hwang KY, Choi H, Richards CI, Kim DY, and Kim BS
- Abstract
Fluorescent carbon nanodots (CDs) have been highlighted as promising semiconducting materials due to their outstanding chemical and optical properties. However, the intrinsic heterogeneity of CDs has impeded a clear understanding of the mechanisms behind their photophysical properties. In this study, as-prepared CDs are fractionated via chromatography to reduce their structural and chemical heterogeneity and analyzed through ensemble and single-particle spectroscopies. Many single particles reveal fluorescence intensity fluctuations between two or more discrete levels with bi-exponential decays. While the intrinsic τ
1 components are uniform among single particles, the τ2 components from molecule-like emissions spans a wider range of lifetimes, reflecting the inhomogeneity of the surface states. Furthermore, it is concluded that the relative population and chemical states of surface functional groups in CDs have a significant impact on emissive states, brightness, blinking, stability, and lifetime distribution of photoluminescence., (© 2021 Wiley-VCH GmbH.)- Published
- 2021
- Full Text
- View/download PDF
47. Corneal Endothelial Cell Changes After Femtosecond Laser-Assisted Cataract Surgery in Diabetic and Nondiabetic Patients.
- Author
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Kang KH, Song MY, Kim KY, Hwang KY, Kwon YA, and Koh K
- Subjects
- Aged, Endothelial Cells, Endothelium, Corneal, Female, Humans, Lasers, Male, Middle Aged, Prospective Studies, Retrospective Studies, Cataract, Cataract Extraction, Diabetes Mellitus, Laser Therapy, Phacoemulsification
- Abstract
Objective: To compare corneal endothelial cell changes after femtosecond laser-assisted cataract surgery (FLACS) in diabetic and nondiabetic patients., Methods: This retrospective study included patients with cataract who underwent FLACS performed by a single surgeon between August 2018 and November 2020. Changes in corneal endothelial cell density (ECD), hexagonality, coefficient of variation in cell size (CV), and central corneal thickness (CCT) at baseline and at the 1-month and 3-month postoperative follow-ups were investigated by dividing the patients into diabetic and nondiabetic groups., Results: We included 75 patients (60% men, mean age: 57.7±11.4 years, range: 27-80 years) in the analysis: 31 diabetic patients (64% men, mean age: 58.7±11.9 years, range: 27-79 years) and 44 nondiabetic patients (56% men, mean age: 57.1±11.3 years, range: 34-80 years). No differences were observed between the two groups as regards preoperative and intraoperative parameters, the mean postoperative ECD, hexagonality, and CV. At 1 month postoperatively, the CCT was significantly greater in the diabetic group (P=0.034); however, at 3 months, there was no significant difference between the two groups (P=0.927)., Conclusions: Changes in postoperative corneal endothelial cells were comparable between patients with and without diabetes after FLACS. Femtosecond laser-assisted cataract surgery seems to cause less damage to the corneal endothelium in diabetic patients because it uses less phacoemulsification energy., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 Contact Lens Association of Ophthalmologists.)
- Published
- 2021
- Full Text
- View/download PDF
48. Conduct of virtual summative anesthesiology Objective Structured Clinical Examination during the COVID-19 pandemic.
- Author
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Hwang KY, Hwang NC, and Tay KH
- Subjects
- Clinical Competence, Educational Measurement, Humans, Pandemics, SARS-CoV-2, Anesthesiology education, COVID-19
- Published
- 2021
- Full Text
- View/download PDF
49. Recent Advances in Exosome-Based Drug Delivery for Cancer Therapy.
- Author
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Kim H, Jang H, Cho H, Choi J, Hwang KY, Choi Y, Kim SH, and Yang Y
- Abstract
Exosomes are a class of extracellular vesicles, with a size of about 100 nm, secreted by most cells and carrying various bioactive molecules such as nucleic acids, proteins, and lipids, and reflect the biological status of parent cells. Exosomes have natural advantages such as high biocompatibility and low immunogenicity for efficient delivery of therapeutic agents such as chemotherapeutic drugs, nucleic acids, and proteins. In this review, we introduce the latest explorations of exosome-based drug delivery systems for cancer therapy, with particular focus on the targeted delivery of various types of cargoes.
- Published
- 2021
- Full Text
- View/download PDF
50. Ocular surface analysis: A comparison between the LipiView ® II and IDRA ® .
- Author
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Lee JM, Jeon YJ, Kim KY, Hwang KY, Kwon YA, and Koh K
- Subjects
- Adult, Aged, Cross-Sectional Studies, Female, Humans, Lipids, Male, Meibomian Glands, Middle Aged, Dry Eye Syndromes diagnosis, Tears
- Abstract
Purpose: To compare the lipid layer thickness (LLT), meibomian gland (MG) dropouts, and blinking pattern determined by the analysis of images acquired from the LipiView
® II (LVII) and the IDRA® Ocular surface analyzer., Methods: A cross-sectional single-visit observational study was conducted. The LLT (minimum, maximum, and average), percentages of MG dropouts, and partial blink rates (PBR) were taken from both eyes of 47 participants using LVII and IDRA. Both devices were used to image the inferior eyelid of each participant in a random order., Results: Forty-seven participants (mean age 56.77 ± 14.47 (21-79) years, 66% female) completed the study. There was no significant difference in LLT between the two devices. A significant difference in percentages of MG dropouts was obtained between the LVII (36.51 ± 17.53) and the IDRA (45.36 ± 21.87), p = 0.003). There was also a significant difference in PBR between the LVII (0.51 ± 0.37) and the IDRA (0.23 ± 0.27), p < 0.001)., Conclusion: No significant difference in LLT was obtained between LVII and IDRA. IDRA had a significantly lesser percentage of MG dropout and a higher PBR compared to LVII. These results indicate that these devices should not be used interchangeably for the evaluation of MG dropouts and PBR.- Published
- 2021
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