23 results on '"Eun Sun Yu"'
Search Results
2. Risk factors of the progression to hypertension and characteristics of natural history during progression: A national cohort study.
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Kwan Hong, Eun Sun Yu, and Byung Chul Chun
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Medicine ,Science - Abstract
BACKGROUND:Although the high disease burden that results from cardiovascular complications of hypertension, factors related to the progression to hypertension in the normotensive population are not actively reported. The purpose of this study was to estimate the rate of the progression to hypertension and to reveal the associated risk factors. METHODS:The study included normotensive participants from the National Health Insurance Service-National Health Screening Cohort, and contained a 10% sample of all adults who received a national health screening test in either 2002 or 2003. At the end of the study in 2015, the patients were divided into two groups based on whether or not they progressed to hypertension. Cox proportional hazard modeling was performed to identify risk factors for progression. Subgroup analysis using logistic regression was employed to reveal factors influencing the different natural history of the progression. RESULTS:Among the 75,335 included participants, the progression rate to hypertension was 66.39% (50,013), with an adjusted incidence rate of 8.62 per 100 person-year in the aged 40-64 group and 12.68 in the aged 65 or above group. Age, BMI, hemoglobin, and family history of hypertension and other diseases were related to the progression. Among the progression group, 78.21% (39,116) participants skipped a pre-hypertensive status; this group consisted of older females with lower pulse pressure and more alcohol consumption compared to people who had pre-hypertensive status before the progression. CONCLUSION:Substantial risk factors for the progression to hypertension should be carefully managed even in normotensive participants who receive health screening tests.
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- 2020
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3. Incidence and risk factors for progression from prehypertension to hypertension: a 12-year Korean Cohort Study
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Eun Sun Yu, Byung Chul Chun, and Kwan Hong
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Male ,medicine.medical_specialty ,Physiology ,030204 cardiovascular system & hematology ,Prehypertension ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Diabetes mellitus ,Internal medicine ,Republic of Korea ,Internal Medicine ,medicine ,Humans ,030212 general & internal medicine ,Family history ,business.industry ,Proportional hazards model ,Incidence ,Incidence (epidemiology) ,Middle Aged ,medicine.disease ,National health insurance ,Hypertension ,Cohort ,Disease Progression ,Female ,Cardiology and Cardiovascular Medicine ,business ,Cohort study - Abstract
Objectives This study evaluated the incidence and risk factors for progression from prehypertension to hypertension among middle-aged and elderly Korean adults. Methods A total of 115 456 participants with prehypertension in 2003-2004 were selected from the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) Program. All participants were followed until 2015. Potential risk factors for progression to hypertension were evaluated using the chi-squared test or t-test. A Cox proportional hazards model was used to predict the risk of progression to hypertension according to sex. The incidence of hypertension in the prehypertension group was evaluated by calculating the incidence density during the entire follow-up period. Results During the follow-up period, 48 919 participants experienced progression to hypertension, which corresponded to incidence densities of 45.82/1000 person-years among men and 53.57/1000 person-years among women. Among both men and women, progression to hypertension was predicted by an elevated BMI, family history of hypertension, history of diabetes mellitus, and older age. Among men, progression to hypertension was associated with frequent drinking and high alanine aminotransferase levels. Among women, progression to hypertension was associated with high hemoglobin levels and low household income. Conclusion This study identified various risk factors for progression from prehypertension to hypertension among middle-aged and elderly Korean adults. This information may help researchers develop comprehensive and effective strategies for managing prehypertension.
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- 2020
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4. 1003Modifiable risk factors and incidence of diabetes mellitus progressing in the prediabetic Population
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Eun Sun Yu, Kwan Hong, and Byung Chul Chun
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education.field_of_study ,Pediatrics ,medicine.medical_specialty ,Epidemiology ,business.industry ,Incidence (epidemiology) ,Diabetes mellitus ,Population ,medicine ,General Medicine ,education ,medicine.disease ,business - Abstract
Background Although the prevention of diabetes mellitus is important, factors related to its progression in the prediabetic population are rarely revealed. This study aimed to estimate the rate of progression and uncover the modifiable risk factors leading to progression. Methods We constructed a group from the National Health Screening Cohort, consisting of adults who received national health screening tests in 2002. After selecting a prediabetic population, we classified them into two groups based on their diabetes progression after a 13-year follow up. The adjusted incidence rate was estimated, and the Cox proportional hazard modelling was performed to identify risk factors for progression. Results The progression rate of diabetes in the prediabetic population (88,330) was 22.85% (20,184), with an adjusted incidence rate of 25.18 (95% confidence interval, CI: 24.44 – 26.02) per 1,000 person-year, ages 40-64 and 25.69 (95% CI: 24.46 – 26.95) in those 65 or older. Among modifiable risk factors, smoking showed the highest hazard ratio, 1.21 (95% CI: 1.16 – 1.25), followed by BMI and alcohol consumption with hazard ratios of 1.06 (95% CI: 1.06 – 1.07) and 1.06 (95% CI: 1.02 – 1.09), respectively. Conclusions Considering the high progression rate of the prediabetic population, modifiable risk factors, such as smoking, should be managed. Key messages The progression rate of the prediabetic population was 25–26% per 1,000 person-year. At the 13-year follow up, modifiable risk factors, such as smoking, BMI, and alcohol consumption, affected the prediabetic population.
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- 2021
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5. Incidence and risk factors of vascular complications in people with impaired fasting glucose: a national cohort study in Korea
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Eun Sun Yu, Byung Chul Chun, and Kwan Hong
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Adult ,Blood Glucose ,Male ,medicine.medical_specialty ,Population ,lcsh:Medicine ,030209 endocrinology & metabolism ,Diseases ,030204 cardiovascular system & hematology ,Article ,Body Mass Index ,Cohort Studies ,Prediabetic State ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Internal medicine ,Diabetes mellitus ,Republic of Korea ,medicine ,Diabetes Mellitus ,Humans ,Longitudinal Studies ,Vascular Diseases ,Family history ,lcsh:Science ,education ,Medical History Taking ,Aged ,Proportional Hazards Models ,education.field_of_study ,Multidisciplinary ,business.industry ,Incidence ,lcsh:R ,Hazard ratio ,Fasting ,Middle Aged ,medicine.disease ,Impaired fasting glucose ,Risk factors ,Cohort ,Hypertension ,lcsh:Q ,Female ,business ,Body mass index ,Cohort study - Abstract
This study aimed to evaluate the risk of vascular complications of impaired fasting glucose (IFG). This population-based study included 425,608 participants from the National Health Screening Cohort in Korea in 2003 and 2004 who were followed-up until 2015. The participants were classified into normal, IFG, and diabetes groups based on fasting plasma glucose levels. Incidence rate (per 1000 person-year) was evaluated for the following vascular complications: cardiovascular (ischemic heart disease, cerebrovascular disease, arterial and capillary disease), renal, and retinal diseases. Hazard ratios (HR) of IFG for diabetes were estimated after adjusting for patient characteristics. Among the 88,330 IFG participants, the incidence of cardiovascular, chronic renal and retinal diseases were 11.52, 0.47, and 1.08 per 1000 person-years, respectively. Furthermore, IFG patients with a family history of diabetes, past history of hypertension, and high body mass index had significantly increased risk of vascular complications [adjusted HR, cardiovascular: 1.39 (95% CI 1.33–1.46); renal: 2.17 (95% CI 1.66–2.83); and retinal: 1.14 (95% CI 0.98–1.32)]. IFG patients have a substantial risk of cardiovascular, chronic renal and retinal diseases. Therefore, early preventative interventions are beneficial, especially for those with high-risk factors, in whom should emphasize on maintaining a healthy lifestyle, early screening and continuous follow-up.
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- 2020
6. A longitudinal analysis of the progression from normal blood pressure to stage 2 hypertension: A 12-year Korean cohort
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Kwan Hong, Byung Chul Chun, and Eun Sun Yu
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Adult ,medicine.medical_specialty ,030204 cardiovascular system & hematology ,Gastroenterology ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Epidemiology ,Republic of Korea ,medicine ,Stage 2 hypertension ,Humans ,030212 general & internal medicine ,Stage (cooking) ,business.industry ,Incidence (epidemiology) ,lcsh:Public aspects of medicine ,Incidence ,Public Health, Environmental and Occupational Health ,lcsh:RA1-1270 ,Guideline ,Middle Aged ,Blood pressure ,Cohort ,Hypertension ,business ,Cohort study ,Research Article - Abstract
Background The study aimed to estimate the incidence of and period of progression to stage 2 hypertension from normal blood pressure. Methods We selected a total of 21,172 normotensive individuals between 2003 and 2004 from the National Health Insurance Service-Health Screening and followed them up until 2015. The criteria for blood pressure were based on the American College of Cardiology/American Heart Association 2017 guideline (normal BP: SBP Results During the median 12.23 years of follow-up period, 52.8% (n= 11,168) and 23.6% (n=5004) of the participants had stage 1 and stage 2 hypertension, respectively. In particular, over 60 years old had a 2.8-fold higher incidence of stage 2 hypertension than 40–49 years old. After the follow-up period, 77.5% (n=3879) of participants with stage 2 hypertension were found to be course C (n= 2378) and D (n=1501). After the follow-up period, 77.5% (n=3879) of participants with stage 2 hypertension were found to be course C (n= 2378) and D (n=1501). The mean years of progression from normal blood pressure to stage 2 hypertension were 8.7±2.6 years (course A), 6.1±2.9 years (course B), 7.5±2.8 years (course C) and 3.2±2.0 years, respectively. Conclusions This study found that the incidence of hypertension is associated with the progression at each stage. We suggest that the strategies necessary to prevent progression to stage 2 hypertension need to be set differently for each target course.
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- 2020
7. Risk factors of the progression to hypertension and characteristics of natural history during progression: A national cohort study
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Eun Sun Yu, Kwan Hong, and Byung Chul Chun
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Male ,Health Screening ,Epidemiology ,Blood Pressure ,030204 cardiovascular system & hematology ,Vascular Medicine ,Biochemistry ,Cohort Studies ,Hemoglobins ,0302 clinical medicine ,Endocrinology ,Risk Factors ,Medicine and Health Sciences ,Medicine ,Public and Occupational Health ,030212 general & internal medicine ,Family history ,education.field_of_study ,Multidisciplinary ,Alcohol Consumption ,Fasting ,Middle Aged ,Cohort ,Hypertension ,Disease Progression ,Female ,Complications of hypertension ,Behavioral and Social Aspects of Health ,Cohort study ,Research Article ,Adult ,medicine.medical_specialty ,Endocrine Disorders ,Science ,Population ,03 medical and health sciences ,Internal medicine ,Diabetes Mellitus ,Humans ,Hemoglobin ,education ,Aged ,Proportional Hazards Models ,Nutrition ,business.industry ,Proportional hazards model ,Biology and Life Sciences ,Proteins ,Diet ,Blood pressure ,Logistic Models ,Medical Risk Factors ,Metabolic Disorders ,business - Abstract
Background Although the high disease burden that results from cardiovascular complications of hypertension, factors related to the progression to hypertension in the normotensive population are not actively reported. The purpose of this study was to estimate the rate of the progression to hypertension and to reveal the associated risk factors. Methods The study included normotensive participants from the National Health Insurance Service-National Health Screening Cohort, and contained a 10% sample of all adults who received a national health screening test in either 2002 or 2003. At the end of the study in 2015, the patients were divided into two groups based on whether or not they progressed to hypertension. Cox proportional hazard modeling was performed to identify risk factors for progression. Subgroup analysis using logistic regression was employed to reveal factors influencing the different natural history of the progression. Results Among the 75,335 included participants, the progression rate to hypertension was 66.39% (50,013), with an adjusted incidence rate of 8.62 per 100 person-year in the aged 40-64 group and 12.68 in the aged 65 or above group. Age, BMI, hemoglobin, and family history of hypertension and other diseases were related to the progression. Among the progression group, 78.21% (39,116) participants skipped a pre-hypertensive status; this group consisted of older females with lower pulse pressure and more alcohol consumption compared to people who had pre-hypertensive status before the progression. Conclusion Substantial risk factors for the progression to hypertension should be carefully managed even in normotensive participants who receive health screening tests.
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- 2020
8. Donor Interlocked Molecular Design for Fluorescence-like Narrow Emission in Deep Blue Thermally Activated Delayed Fluorescent Emitters
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Sang Kyu Jeon, Eun-Sun Yu, Lee Sang-Shin, Yong Joo Cho, and Jun Yeob Lee
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Materials science ,Band gap ,business.industry ,General Chemical Engineering ,Astrophysics::Cosmology and Extragalactic Astrophysics ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Fluorescence ,Full width ,0104 chemical sciences ,Molecular engineering ,Materials Chemistry ,Optoelectronics ,Quantum efficiency ,Emission spectrum ,0210 nano-technology ,business ,Deep blue ,Astrophysics::Galaxy Astrophysics - Abstract
Deep blue thermally activated delayed fluorescent (TADF) emitters with a narrow emission spectrum were developed by managing the molecular structure of the TADF emitters. The deep blue TADF emitters were designed to show large steric hindrance at the central core of the molecule and small singlet–triplet energy gap. The molecular engineering of the deep blue TADF emitters enabled the fabrication of the deep blue TADF device with a full width at half-maximum of only 48 nm and a quantum efficiency of 14.0%. The full width at half-maximum of the deep blue TADF device was similar to that of conventional fluorescent devices, while the quantum efficiency was more than tripled.
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- 2016
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9. Correlation of Molecular Structure with Photophysical Properties and Device Performances of Thermally Activated Delayed Fluorescent Emitters
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Jun Yeob Lee, Lee Sang-Shin, Eun-Sun Yu, Sang Kyu Jeon, Mounggon Kim, and Seok-Ho Hwang
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Materials science ,Dopant ,Carbazole ,Band gap ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Acceptor ,Fluorescence ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,General Energy ,chemistry ,Molecule ,Quantum efficiency ,Physical and Theoretical Chemistry ,0210 nano-technology ,Common emitter - Abstract
Thermally activated delayed fluorescent (TADF) emitters having bicarbazole as a donor unit based on a twin emitting core design were developed by substituting the bicarbazole donor with a diphenyltriazine acceptor. Three bicarbazole derived delayed fluorescent emitters linked via 2,3′-, 3,3′-, and 3,4′-positions of carbazole were synthesized and investigated as blue dopants of the TADF devices. A twin emitting core based TADF emitter derived from a 3,3′-bicarbazole donor exhibited a high quantum efficiency of 25.0% in the greenish blue TADF device. A 3,3′-linkage induced red shift of the emission wavelength, a small singlet–triplet energy gap, and a high quantum efficiency were revealed.
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- 2016
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10. Phosphorescent Blue Organic Light-Emitting Diodes with New Bipolar Host Materials
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Mi-Young Chae, Jung Soo Park, Eun-Sun Yu, Jang Hyuk Kwon, Sung-Hyun Jung, Sik Jeon Woo, and Kulshreshtha Chandramouli
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Materials science ,Phosphorescent oleds ,business.industry ,Biomedical Engineering ,Bioengineering ,General Chemistry ,Condensed Matter Physics ,Luminance ,Narrow band ,OLED ,Optoelectronics ,General Materials Science ,business ,Phosphorescence ,Host (network) ,Electrical efficiency - Abstract
We report narrow band gap bipolar host materials, CbPr-3 (9,9'-[(3,3'-Biphenyl-3.3'-yl-bipyridine)-1,3-biphenyl]bis-9H-carbazole) and Bim-4 (9,9'-[5-(1-phenyl-1H-benzimadazol-2yl)-1,3-phenylene] bis-9H-carbazole), for blue phosphorescent OLEDs application. These two bipolar hosts have high triplet energy of > 2.9 eV, capable of reducing the driving voltages and improving efficiencies. Significant low driving voltages of 7.4 and 6.6 V were obtained for CbPr-3 and Bim-4 hosts, compared with 9.0 V of the commonly used host, mCP (1,3-bis(9-carbazolyl)benzene). At a given constant luminance of 1000 cd/m2, the power efficiency of both the bipolar host devices was enhanced by 2.5 times.
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- 2012
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11. Anti-inflammatory activity of p-coumaryl alcohol-γ-O-methyl ether is mediated through modulation of interferon-γ production in Th cells
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Jeong Ho Hong, Eun Kyoung Seo, Joo Won Nam, M. S. Lee, Kyunglim Lee, Eun Sun Yu, Eun Sook Hwang, and Hyun Jung Min
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Pharmacology ,food.ingredient ,biology ,Alpinia galanga ,medicine.medical_treatment ,Inflammation ,Molecular biology ,food ,Immune system ,Cytokine ,Interferon ,Immunology ,medicine ,biology.protein ,Cytotoxic T cell ,Interferon gamma ,Antibody ,medicine.symptom ,medicine.drug - Abstract
Background and purpose: p-Coumaryl alcohol-γ-O-methyl ether (CAME) was isolated from Alpinia galanga and shown to contain a phenylpropanoid structure similar to p-coumaryl diacetate (CDA). CDA is known to have antioxidant and anti-inflammatory activity, but the biochemical activities of CAME are unknown. Inflammation is mediated by inflammatory cytokine production, in particular, by CD4+ T helper cells (Th cells), but it is unclear whether phenylpropanoids affect cytokine production in Th cells. In this study, we decided to investigate the functions of CAME and CDA in CD4+ Th cells. Experimental approach: Mouse CD4+ Th cells were isolated from C57BL6 mice and stimulated with an antibody against T cell receptors in the presence of phenylpropanoids. Cytokine production was measured by elisa and intracellular cytokine staining. Gene knockout mice and tetracycline-inducible transgenic mice were used to examine the molecular mechanisms of phenylpropanoids on modulation of cytokine production. Key results: CAME potently reduced intracellular reactive oxygen species in Th cells, as does CDA. However, although CDA was cytotoxic, CAME selectively and potently suppresses interferon-γ (IFNγ) production in CD4+ Th cells, without toxicity. This effect was caused by attenuated expression of the transcription factor, T-box protein expressed in T cells (T-bet), and T-bet was essential for CAME to inhibit IFNγ production in CD4+ Th cells. Conclusions and implications: CAME selectively and substantially suppresses IFNγ production in CD4+ Th cells by decreasing T-bet expression. As increased IFNγ production by CD4+ Th cells can mediate inflammatory immune responses, a selective IFNγ suppressor, such as CAME may be an effective, naturally occurring, compound for modulating inflammatory immune disorders.
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- 2009
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12. Small molecule interlayer for solution processed phosphorescent organic light emitting device
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Tae Jin Park, Woo Sik Jeon, Jung Joo Park, Jang Hyuk Kwon, Eun-Sun Yu, Mi-Young Chae, Ramchandra Pode, and Jin Jang
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Materials science ,business.industry ,General Chemistry ,Condensed Matter Physics ,Luminance ,Small molecule ,Electronic, Optical and Magnetic Materials ,Biomaterials ,Materials Chemistry ,OLED ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Phosphorescence ,Solution process ,Electrical efficiency ,Organic light emitting device ,Voltage - Abstract
Using a 4,4′,4′′-tris( N -carbazolyl)-triphenylamine (TCTA) small molecule interlayer, we have fabricated efficient green phosphorescent organic light emitting devices by solution process. Significantly a low driving voltage of 3.0 V to reach a luminance of 1000 cd/m 2 is reported in this device. The maximum current and power efficiency values of 27.2 cd/A and 17.8 lm/W with TCTA interlayer (thickness 30 nm) and 33.7 cd/A and 19.6 lm/W with 40 nm thick interlayer are demonstrated, respectively. Results reveal a way to fabricate the phosphorescent organic light emitting device using TCTA small molecule interlayer by solution process, promising for efficient and simple manufacturing.
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- 2009
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13. Highly efficient and color tunable thermally activated delayed fluorescent emitters using a 'twin emitter' molecular design
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Jun Yeob Lee, Eun-Sun Yu, Sang Kyu Jeon, Mounggon Kim, Lee Sang-Shin, and Seok-Ho Hwang
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Interconnection ,Materials science ,business.industry ,Metals and Alloys ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Fluorescence ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Materials Chemistry ,Ceramics and Composites ,Physics::Accelerator Physics ,Optoelectronics ,Quantum efficiency ,Emission spectrum ,0210 nano-technology ,business ,Common emitter - Abstract
High efficiency and color tuning of thermally activated delayed fluorescent emitters were achieved at the same time by designing emitters with a twin emitter molecular design. The control of the interconnect position between two emitters could manage the emission spectrum of the thermally activated delayed fluorescent emitters without affecting the quantum efficiency.
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- 2015
14. The Impact of Gender on Progression of Renal Disease
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Kyun Il Yoon, Duk Hee Kang, Richard J. Johnson, and Eun Sun Yu
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medicine.medical_specialty ,Kidney ,Vascular smooth muscle ,Endothelium ,Renal cortex ,Glomerulosclerosis ,Biology ,medicine.disease ,Pathology and Forensic Medicine ,Nephropathy ,Vascular endothelial growth factor ,chemistry.chemical_compound ,Vascular endothelial growth factor A ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Internal medicine ,medicine - Abstract
Male gender is associated with a more rapid progression of renal disease independent of blood pressure, dietary protein intake, or serum lipid levels. Recently, we reported a key role for the intrarenal vasculature in progressive renal disease (Kang D-H, Kanellis J, Hugo C, Truong L, Anderson S, Kerjaschki D, Schreiner GF, Johnson RJ: Role of endothelium in progressive renal disease. J Am Soc Nephrol 2002, 13:806–816). We hypothesized that estrogen-mediated preservation of the renal vasculature could account for the better renal outcome in female rats. We analyzed micro- and macrovascular changes in the 5/6 remnant kidney (RK) models both in male (n = 24) and female (n = 24) Sprague-Dawley rats up to 12 weeks after renal mass reduction. At 12 weeks, male and female RK rats had equivalent blood pressure, glomerular tuft area, and RK/body weight, but male rats showed worse renal function, proteinuria, glomerulosclerosis (%), and tubulointerstitial fibrosis. At 12 weeks peritubular capillary (PTC) EC proliferation and PTC density were higher in female RK rats whereas macrovascular changes in preglomerular vessels (smooth muscle cell proliferation, medial wall thickening, and adventitial fibrosis) were less prominent. The expression of vascular endothelial growth factor (VEGF) and VEGF type 2 receptor (flk-1) in renal cortex assessed by immunostaining were higher in female RK rats. To dissect the mechanism of sex hormone-induced vascular remodeling and VEGF regulation, we investigated the in vitro effect of 17β-estradiol (17βE, 10 nmol/L) on proliferation and VEGF expression of renal tubular cells (rat proximal tubular cells), vascular smooth muscle cells (VSMCs), and human umbilical vein endothelial cells (HUVECs). 17βE directly stimulated the proliferation of HUVECs, whereas it inhibited serum-induced proliferation of VSMCs. 17βE stimulated VEGF mRNA expression both in renal tubular cells and VSMCs. However, when cells were pretreated with a nitric oxide donor to simulate the in vivo condition, 17βE inhibited VEGF mRNA expression and protein release in VSMCs. In conclusion, female RK rats developed less glomerulosclerosis and renal failure compared to male RK rats in association with greater preservation of PTC and less preglomerular arteriopathy. Estrogen stimulated basal VEGF expression in renal tubular cells. We propose that estrogen may protect female rats in progressive renal disease by stimulating VEGF expression and maintaining a healthy intrarenal vasculature.
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- 2004
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15. Pilot study of mass screening for Wilson's disease in Korea
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Jin Sung Lee, Han Wook Yoo, Dong Hwan Lee, Hee-Sung Han, Sunyoung Park, Ha Cheol Shin, Soon Nam Kim, Soo Young Lee, Chun Soon Chung, Eun Sun Yu, San Yeon Lee, Young Ju Jang, and Si Houn Hahn
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Male ,medicine.medical_specialty ,Pathology ,Adolescent ,Endocrinology, Diabetes and Metabolism ,Copper metabolism ,Enzyme-Linked Immunosorbent Assay ,Pilot Projects ,Disease ,Biochemistry ,Gastroenterology ,Endocrinology ,Hepatolenticular Degeneration ,Ceruloplasmin measurement ,Internal medicine ,Genetics ,Humans ,Mass Screening ,Medicine ,Child ,Molecular Biology ,Mass screening ,Korea ,biology ,business.industry ,Ceruloplasmin ,Infant ,medicine.disease ,Dried blood spot ,Wilson's disease ,Child, Preschool ,biology.protein ,Female ,Population screening ,business - Abstract
Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism with copper accumulation in the liver as well as in the central nervous system. Treatment of WD includes oral chelating agents and diet and it is effective. However, once irreversible damage has occurred, the effect of treatment is diminished and the patient's quality of life is compromised. It is estimated that at least half of the patients with WD remain undiagnosed and die of untreated disease. Early detection of patients presymptomatically has been hampered by the lack of effective methods for mass screening. Recently, a sandwich ELISA method for ceruloplasmin measurement in blood spots was developed. We have used this method to analyze blood specimens collected on filter paper from 3667 children aged 3 months–15 years. The mean value of ceruloplasmin was 30.5±9.5 mg/dL. Among these children, we identified one WD case, a 32-month-old boy with markedly reduced ceruloplasmin concentration (2.3 mg/dL). Measurement of CP level in dried blood spot sample is proposed as a reliable method for population screening of WD.
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- 2002
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16. The design of dual emitting cores for green thermally activated delayed fluorescent materials
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Yong Joo Cho, Eun-Sun Yu, Jun Yeob Lee, Sang Kyu Jeon, and Byung Doo Chin
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Photoluminescence ,Materials science ,Fluorescent materials ,Quantum yield ,Quantum efficiency ,General Medicine ,General Chemistry ,Photochemistry ,Fluorescence ,Catalysis ,Common emitter - Abstract
Dual emitting cores for thermally activated delayed fluorescent (TADF) emitters were developed. Relative to the corresponding TADF emitter with a single emitting core the TADF emitter with a dual emitting core, 3,3′,5,5′-tetra(carbazol-9-yl)-[1,1′-biphenyl]-2,2′,6,6′-tetracarbonitrile, showed enhanced light absorption accompanied by a high photoluminescence quantum yield. The quantum and power efficiencies of the TADF devices were enhanced by the dual emitting cores.
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- 2014
17. Effect of naturally occurring hydroxychavicol acetate on the cytokine production in T helper cells
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Jeong Ho Hong, Eun Kyoung Seo, Joo Won Nam, Eun Sun Yu, Hyun Jung Min, and Eun Sook Hwang
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Interleukin 2 ,food.ingredient ,medicine.medical_treatment ,Alpinia galanga ,Immunology ,Apoptosis ,Pharmacology ,Biology ,Antioxidants ,chemistry.chemical_compound ,Interferon-gamma ,Mice ,Immune system ,food ,medicine ,Immunology and Allergy ,Animals ,Interferon gamma ,Benzyl Alcohols ,Mice, Knockout ,Anti-Inflammatory Agents, Non-Steroidal ,Cell Differentiation ,T helper cell ,T-Lymphocytes, Helper-Inducer ,Mice, Inbred C57BL ,Cytokine ,medicine.anatomical_structure ,Biochemistry ,Chavicol ,chemistry ,Cell culture ,Alpinia ,Cytokines ,Interleukin-2 ,Reactive Oxygen Species ,T-Box Domain Proteins ,medicine.drug - Abstract
Naturally occurring phenolic compounds, such as chavicol analogues, have been shown to have potent antioxidant and anti-inflammatory activities. We have previously isolated two chavicol acetate analogues, acetoxychavicol acetate (ACA) and hydroxychavicol acetate (HCA) from the rhizomes of Alpinia galanga. Although the function of ACA has been studied in many systems, the function of HCA has yet to be systemically examined. In this study, we have comparably examined the functions of ACA and HCA on the cytokine production in Th cells. ACA exhibited potent antioxidant activity and increased cell apoptosis; therefore, cytokine production by Th cells was diminished. Although HCA had neither antioxidant activity nor pro-apoptotic function, it was shown to increase IL-2 production and attenuate IFNgamma expression in Th cells. In addition, we demonstrated that HCA suppressed T-bet expression, which is responsible for IL-2 suppression and IFNgamma induction in Th cells and inhibited T-bet-mediated Th1 cell differentiation. Therefore, we suggest that HCA may be beneficial as therapeutics for treating inflammatory immune disorders caused by extravagant activation of Th1-mediated immune responses.
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- 2008
18. High efficiency green phosphorescent OLEDs with long lifetime by using novel host material
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Eui-Su Kang, Mi-Young Chae, Tu-Won Chang, Nam-Soo Kim, Young-Hoon Kim, and Eun-Sun Yu
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Blocking layer ,Host material ,Phosphorescent oleds ,business.industry ,Chemistry ,Respiratory electron transport ,OLED ,Optoelectronics ,business ,Phosphorescence ,Luminance ,High luminance - Abstract
We developed a novel host material, CheilGH-01 reinforced with electron transporting property to perform high luminance efficiency and low driving voltage with long lifetime in green phosphorescent OLED without HBL (hole blocking layer). The device with a structure of ITO/NPB/TCTA/Host:Ir(ppy) 3 /Balq/Alq 3 /Liq/Al using CheilGH-01 as a host showed better performance than the device with CBP as a host; At luminance of 1000 cd/m 2 , driving voltages, current efficiencies and power efficiencies are 5.4 V, 60 cd/A and 35 lm/W for CheilGH-01 and 7.2 V, 42 cd/A and 18.8 lm/W for CBP. It takes 240 hours for CheilGH-01 and 177 hours for CBP from the initial luminance of 3000 cd/m 2 to the luminance of 1500 cd/m 2 (55% of the initial). In the case of device with a structure of ITO/NPB/TCTA /Host:Ir(ppy) 3 /Alq 3 /Liq/Al, CheilGH-01 showed 300% enhancement in luminance efficiency and more than 800% longer lifetime than CBP; At luminance of 1000 cd/m 2 , driving voltages, current efficiencies and power efficiencies are 6.3 V, 51 cd/A and 26 lm/W for CheilGH-01 and 8.6 V, 21 cd/A and 7.8 lm/W for CBP. It takes 411 hours for CheilGH-01 and 82 hours for CBP from the initial luminance of 3000 cd/m 2 to the luminance of 1500 cd/m 2 . By using our novel host material, we are able to eliminate HBL from the conventional green phosphorescent OLED and still provide OLED with longer lifetime and excellent luminance efficiency.
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- 2008
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19. Isoeleutherin and eleutherinol, naturally occurring selective modulators of Th cell-mediated immune responses
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Joo Won Nam, Ah Reum Han, Jeong Ho Hong, Eun Kyoung Seo, Eun Sun Yu, and Eun Sook Hwang
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Isoeleutherin ,Transcription, Genetic ,Biophysics ,Receptors, Antigen, T-Cell ,Naphthols ,Biology ,Lymphocyte Activation ,Biochemistry ,Interferon-gamma ,Mice ,Immune system ,medicine ,Moiety ,Animals ,Humans ,Immunologic Factors ,Furans ,Molecular Biology ,Gene ,Pyrans ,Eleutherinol ,Cell Biology ,T helper cell ,T-Lymphocytes, Helper-Inducer ,medicine.anatomical_structure ,Pyrones ,Eleutherin ,CD4 Antigens ,Cytokines ,Interleukin-2 ,Cell activation ,T-Box Domain Proteins ,Naphthoquinones - Abstract
Natural compounds possessing naphthopyran moiety have been attracted by their anti-bacterial, anti-fungal, and anti-viral activities, as well as anti-tumor activities. Although chemical structures were critical for the potential biological activities, the detailed functional mechanisms remained unclear. Here, we have studied the effects of naphthopyran derivatives (eleutherin, isoeleutherin, and eleutherinol) on T helper cell-mediated immune responses to understand the mechanisms of their anti-microbial and anti-tumor activities. The study revealed that isoeleutherin, which has 1,4-naphthoquinone ring with alpha-methyl group, selectively and specifically stimulated IFNgamma production through the activation of T-bet gene transcription, thus enhancing Th1-mediated immune responses. However, a natural naphthopyran-4-one, eleutherinol dramatically inhibited both IFNgamma and IL-2 productions during Th cell activation by suppressing the gene transcriptions of cytokines. Therefore, we suggest that the chemical modification and chirality of naphthopyran moiety in isoeleutherin and eleutherinol may be critical for the selective modulation of T helper cell-mediated immune responses.
- Published
- 2008
20. Regulatory mechanisms of IL-2 and IFNgamma suppression by quercetin in T helper cells
- Author
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Su Yeon An, Eun Sun Yu, Hee Yeon Won, Jeong Ho Hong, Eun Sook Hwang, and Hyun Jung Min
- Subjects
Interleukin 2 ,Transcription, Genetic ,medicine.medical_treatment ,Enzyme-Linked Immunosorbent Assay ,Biology ,Pharmacology ,Lymphocyte Activation ,Biochemistry ,Polymerase Chain Reaction ,chemistry.chemical_compound ,Interferon-gamma ,Mice ,Immune system ,medicine ,Animals ,heterocyclic compounds ,Interferon gamma ,Cells, Cultured ,T-cell receptor ,Experimental autoimmune encephalomyelitis ,T-Lymphocytes, Helper-Inducer ,medicine.disease ,Mice, Inbred C57BL ,Cytokine ,chemistry ,Immunology ,Cytokines ,Interleukin-2 ,Quercetin ,Cell activation ,medicine.drug - Abstract
Quercetin is a popular flavonoid compound that is biosynthesized by plants; it is suggested to modulate a variety of inflammatory responses of macrophages and T lymphocytes. Oral administration of quercetin in arthritic rats dramatically diminishes clinical signs of arthritis. Moreover, quercetin ameliorates experimental autoimmune encephalomyelitis, which is associated with Th1-mediated immune responses. Like quercetin inhibits macrophage-induced cytokine production, it also blocks IL-12-dependent JAK-STAT signaling in Th cells. Despite the anti-inflammatory effects of quercetin acting through Th cells, the regulatory mechanisms remain unclear. Here, we studied the function of quercetin in Th cells and found that quercetin suppressed both IFNgamma and IL-2 production upon T cell receptor stimulation. Furthermore, we uncovered the regulatory mechanisms of quercetin involved in the inhibition of cytokine production during Th cell activation. The fact that quercetin-derived IFNgamma suppression was blocked in T-bet-deficient Th cells demonstrated quercetin act through the modulation of T-bet expression. Whereas IL-2 inhibition by quercetin was independent of T-bet expression, quercetin diminished IL-2R alpha expression, which is critical for positive regulatory loop of IL-2 autoactivation. Taken together, quercetin is suggested to repress both IFNgamma and IL-2 cytokine production by independent mechanisms; T-bet-dependent IFNgamma suppression and IL-2R alpha-dependent IL-2 inhibition.
- Published
- 2008
21. Characterization of human monoclonal autoantibody Fab fragments against oxidized LDL
- Author
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Young-Eun Jeon, Eun Sun Yu, Sae-Gwang Park, Cheol Joo Lee, Chang-Won Seo, and Young-Ju Jang
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Phage display ,Immunology ,Molecular Sequence Data ,Biology ,Autoantigens ,Epitope ,Immunoglobulin Fab Fragments ,Mice ,Antigen ,Complementary DNA ,Malondialdehyde ,Macrophage ,Animals ,Humans ,Amino Acid Sequence ,Molecular Biology ,Cells, Cultured ,Autoantibodies ,chemistry.chemical_classification ,Mice, Inbred ICR ,Autoantibody ,Antibodies, Monoclonal ,Atherosclerosis ,Amino acid ,Lipoproteins, LDL ,chemistry ,Biochemistry ,Immunoglobulin G ,Monoclonal ,Macrophages, Peritoneal ,lipids (amino acids, peptides, and proteins) ,Female - Abstract
Oxidized low-density lipoprotein (oxLDL) is a key autoantigen in atherosclerosis. The genetic structures and pathogenic roles of autoantibodies against this protein remain to be established. In this study, we cloned several monoclonal IgG autoantibody Fab fragments specific for oxLDL from peripheral blood lymphocytes of atherosclerosis patients, using phage display technology. The sequences of their variable regions were determined at the cDNA level. The closest germline counterparts for the heavy chains belonged to the VH3 or VH1 family. The sequences and lengths of complementarity-determining regions (CDR)3-VH were diverse, and frequent mutations of positively charged amino acids (particularly arginine) over entire VH and VL sequences were observed. It is proposed that anti-oxLDL autoantibody formation is driven by antigens. Among the Fabs, P2-8 and P3-175 bound to both MDA-LDL and Cu-oxLDL, and inhibited the uptake of oxLDL by macrophages, suggesting the epitope(s) recognized by the Fabs is a part of ligands on oxLDL that is involved in uptake by macrophage scavenger receptor. These human autoantibody Fabs require detailed investigation to ascertain their potential as agents for clinical applications.
- Published
- 2006
22. Renoprotective effect of erythropoietin (EPO): Possibly via an amelioration of renal hypoxia with stimulation of angiogenesis in the kidney
- Author
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Kyun-Il Yoon, Duk Hee Kang, Eun Sun Yu, Young-Suk Lee, and Eun Young Park
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medicine.medical_specialty ,Angiogenesis ,Neovascularization, Physiologic ,Stimulation ,Kidney ,law.invention ,Neovascularization ,law ,Internal medicine ,Renal hypoxia ,Animals ,Humans ,Medicine ,Hypoxia ,Erythropoietin ,business.industry ,Anemia ,Recombinant Proteins ,Rats ,Disease Models, Animal ,Endocrinology ,medicine.anatomical_structure ,Nephrology ,Recombinant DNA ,Kidney Failure, Chronic ,medicine.symptom ,business ,medicine.drug - Published
- 2005
- Full Text
- View/download PDF
23. The impact of gender on progression of renal disease: potential role of estrogen-mediated vascular endothelial growth factor regulation and vascular protection
- Author
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Duk-Hee, Kang, Eun Sun, Yu, Kyun-Il, Yoon, and Richard, Johnson
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Male ,Vascular Endothelial Growth Factor A ,Blotting, Western ,Endothelial Cells ,Estrogens ,Kidney ,Immunohistochemistry ,Muscle, Smooth, Vascular ,Rats ,Rats, Sprague-Dawley ,Disease Models, Animal ,Kidney Tubules ,Receptors, Vascular Endothelial Growth Factor ,Sex Factors ,Disease Progression ,Animals ,Female ,Kidney Diseases ,Cell Division ,Cells, Cultured ,Regular Articles - Abstract
Male gender is associated with a more rapid progression of renal disease independent of blood pressure, dietary protein intake, or serum lipid levels. Recently, we reported a key role for the intrarenal vasculature in progressive renal disease (Kang D-H, Kanellis J, Hugo C, Truong L, Anderson S, Kerjaschki D, Schreiner GF, Johnson RJ: Role of endothelium in progressive renal disease. J Am Soc Nephrol 2002, 13:806-816). We hypothesized that estrogen-mediated preservation of the renal vasculature could account for the better renal outcome in female rats. We analyzed micro- and macrovascular changes in the 5/6 remnant kidney (RK) models both in male (n = 24) and female (n = 24) Sprague-Dawley rats up to 12 weeks after renal mass reduction. At 12 weeks, male and female RK rats had equivalent blood pressure, glomerular tuft area, and RK/body weight, but male rats showed worse renal function, proteinuria, glomerulosclerosis (%), and tubulointerstitial fibrosis. At 12 weeks peritubular capillary (PTC) EC proliferation and PTC density were higher in female RK rats whereas macrovascular changes in preglomerular vessels (smooth muscle cell proliferation, medial wall thickening, and adventitial fibrosis) were less prominent. The expression of vascular endothelial growth factor (VEGF) and VEGF type 2 receptor (flk-1) in renal cortex assessed by immunostaining were higher in female RK rats. To dissect the mechanism of sex hormone-induced vascular remodeling and VEGF regulation, we investigated the in vitro effect of 17 beta-estradiol (17 beta E, 10 nmol/L) on proliferation and VEGF expression of renal tubular cells (rat proximal tubular cells), vascular smooth muscle cells (VSMCs), and human umbilical vein endothelial cells (HUVECs). 17 beta E directly stimulated the proliferation of HUVECs, whereas it inhibited serum-induced proliferation of VSMCs. 17 beta E stimulated VEGF mRNA expression both in renal tubular cells and VSMCs. However, when cells were pretreated with a nitric oxide donor to simulate the in vivo condition, 17 beta E inhibited VEGF mRNA expression and protein release in VSMCs. In conclusion, female RK rats developed less glomerulosclerosis and renal failure compared to male RK rats in association with greater preservation of PTC and less preglomerular arteriopathy. Estrogen stimulated basal VEGF expression in renal tubular cells. We propose that estrogen may protect female rats in progressive renal disease by stimulating VEGF expression and maintaining a healthy intrarenal vasculature.
- Published
- 2004
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