Dong Wook Shin

Seoul National University Hospital, Sŏul, Seoul, South Korea

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Publications (140)419.27 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The fabrication of interlayer dielectrics (ILDs) in flexible organic light-emitting diodes (OLEDs) not only requires flexible materials with a low dielectric constant, but also ones that possess the electrical, thermal, chemical, and mechanical properties required for optimal device performance. Porous polymer-silica hybrid materials were prepared to satisfy these requirements. Hollow SiO2 spheres were synthesized using atomic layer deposition (ALD) and a thermal calcination process. The hybrid film, which consists of hollow SiO2 spheres and polyimide, shows a low dielectric constant of 1.98 and excellent thermal stability up to 500 °C. After the bending test for 50 000 cycles, the porous hybrid film exhibits no degradation in its dielectric constant or leakage current. These results indicate that the hybrid film made up of hollow SiO2 spheres and polyimide (PI) is useful as a flexible insulator with a low dielectric constant and high thermal stability for flexible OLEDs.
    Physical chemistry chemical physics : PCCP. 12/2014;
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    ABSTRACT: Screening for hepatocellular carcinoma (HCC) is clinically important as its early detection has remarkable survival benefits. We investigated the possible role of FIB-4, a recently developed noninvasive marker for liver fibrosis based on routine laboratory tests, as a clinical indicator for predicting future HCC among hepatitis B surface antigen (HBsAg) carriers. Our retrospective cohort study involved 986 Korean HBsAg carriers aged 40 or older who visited Seoul National University Hospital for health check-up. National medical service claims data was used to determine HCC incidence. Median follow-up time was 5.4 years (interquartile range 4.4 years). Adjusted for age, sex, body mass index, smoking, alcohol, and anti-viral medication for hepatitis B, compared to subjects with FIB-4 <1.25, subjects with 1.7≤ FIB-4 <2.4 showed aHR 4.57 (95% CI 1.50-13.92) and subjects with FIB-4 ≥2.4 showed aHR 21.34 (95% CI 7.73-58.92) for HCC incidence. FIB-4 was shown to have incremental predictive value to ultrasonographic liver cirrhosis for HCC incidence (C-index 0.701 vs. 0.831; P=0.001). FIB-4 was also better predictive of HCC incidence compared to that of ultrasonographic liver cirrhosis (C-index 0.775 vs. 0.701; P=0.040). Conclusion: High FIB-4 is a highly predictive risk factor for HCC incidence among Korean HBsAg carriers. FIB-4 is a promising, easily applicable, and cost-effective clinical tool in identifying a subpopulation of HBsAg carriers who are at heightened risk. Our study needs to be replicated in larger future studies on various ethnic groups; nonetheless, our study suggests FIB-4 may play a valuable role in HCC screening among HBsAg carriers. This article is protected by copyright. All rights reserved.
    Hepatology 12/2014; · 12.00 Impact Factor
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    ABSTRACT: The fabrication of interlayer dielectrics (ILDs) in flexible organic light-emitting diodes (OLEDs) not only requires flexible materials with a low dielectric constant, but also ones that possess the electrical, thermal, chemical, and mechanical properties required for optimal device performance. Porous polymer-silica hybrid materials were prepared to satisfy these requirements. Hollow SiO2 spheres were synthesized using Atomic Layer Deposition (ALD) and a thermal calcination process. The hybrid film which consists of hollow SiO2 spheres and polyimide shows a low dielectric constant of 2.35 and excellent thermal stability up to 530oC. After the bending test for 50,000 cycles, the porous hybrid film exhibits no degradation in its dielectric constant or leakage current. These results indicate that the hybrid film made of hollow SiO2 spheres and polyimide (PI) is useful as a flexible insulator with a low dielectric constant and high thermal stability for flexible OLEDs.
    Physical Chemistry Chemical Physics 11/2014; · 4.20 Impact Factor
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    ABSTRACT: To determine whether a cardiovascular disease (CVD) health screening program is associated with CVD-related health conditions, incidence of cardiovascular events, mortality, healthcare utilization, and costs. Cohort study of a 3% random sample of all Korea National Health Insurance members 40years of age or older and free of CVD or CVD-related health conditions was conducted. A total 443,337 study participants were followed-up from January 1, 2005 through December 31, 2010. In primary analysis, the hazard ratios for CVD mortality, all-cause mortality, incident composite CVD events, myocardial infarction, cerebral infarction, and cerebral hemorrhage comparing participants who attended a screening exam during 2003-2004 compared to those who did not were 0.58 (95% CI: 0.53-0.63), 0.62 (95% CI: 0.60-0.64), 0.82 (95% CI: 0.78-0.85), 0.84 (95% CI: 0.75-0.93), 0.84 (95% CI: 0.79-0.89), and 0.73 (95% CI: 0.67-0.80), respectively. Screening attenders had higher rates of newly diagnosed hypertension, diabetes mellitus, and dyslipidemia, lower inpatient days of stay and cost, and lower outpatient cost compared to non-attenders. Participation in CVD health screening was associated with lower rates of CVD, all-cause mortality, and CVD events, higher detection of CVD-related health conditions, and lower healthcare utilization and costs. Copyright © 2014. Published by Elsevier Inc.
    Preventive medicine. 11/2014; 70C:19-25.
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    ABSTRACT: Continuity of care is considered a core element of high-quality primary care, but its impact on mortality and health care costs is unclear. We aimed to determine the impact of continuity of care on mortality, costs, and health outcomes in patients with newly diagnosed cardiovascular risk factors.
    The Annals of Family Medicine 11/2014; 12(6):534-41. · 4.61 Impact Factor
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    ABSTRACT: Background Previous studies on the association of alcohol consumption with lower urinary tract symptoms (LUTS) have been inconsistent, and none took into account the dynamic nature of LUTS, fluctuating over time. The purpose of the study was to determine the longitudinal association of alcohol consumption with LUTS.Methods We used generalized estimating equations to analyze the longitudinal association of alcohol consumption with LUTS in a longitudinal study of 9,712 healthy men 30 years or older who visited our institution multiple times for routine comprehensive health evaluations, with an average follow-up period of 27.9 months.ResultsLight–moderate alcohol consumption (0.1 to 29 g/d) was associated with decreased likelihood of moderate–severe LUTS, whereas heavy alcohol consumption (≥30 g/d) was associated with increased likelihood of moderate–severe LUTS in a dose-dependent manner. Compared to those with 0 g/d alcohol intake, subjects who drank 0.1 to 9.9, 10 to 19.9, 20 to 29.9, 30 to 39.9, or ≥40 g/d of alcohol were in general significantly associated with moderate–severe LUTS with adjusted odds ratio (95% confidence interval) as follows respectively: 0.94 (0.87 to 1.02), 1.00 (0.91 to 1.09), 0.85 (0.77 to 0.93), 1.08 (0.98 to 1.19), and 1.31 (1.19 to 1.44). However, the protective association of light–moderate alcohol consumption with LUTS was greatly attenuated when serum high-density lipoprotein (HDL) was added to the analysis, specifically for voiding symptoms.Conclusions We show strong evidence there is longitudinal association of alcohol consumption with LUTS. The protective effect of light–moderate alcohol consumption on LUTS is in part modulated by HDL as a confounder, similar to its effect on coronary heart disease.
    Alcoholism Clinical and Experimental Research 11/2014; · 3.42 Impact Factor
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    ABSTRACT: Female physicians have a more patient-centered communication style than their male counterparts; however, few studies have investigated how the biomedical or psychosocial nature of a patient diagnosis might moderate this relationship. Seventy six 3rd year residents (50 male and 26 females) seeking board certification from the Korean Academy of Family Medicine participated in the 2013 Clinical Practice Examination by conducting two simulated patient (SP) interviews, one presenting a largely psychosocial case and the other largely biomedical. The interview recordings were coded with the Roter Interaction Analysis System (RIAS). Female physicians and their SPs engaged in more dialog than male physicians in both cases. Female physicians were more patient-centered than males for the psychosocial case (t=-3.24, P<0.05), however, their scores did not differ for the biomedical case. In multivariate analysis, a significant interaction between physician gender and case (z=-3.90, P<0.001) similarly demonstrated greater female patient-centeredness only for the predominantly psychosocial case. Case characteristics moderated the association between physician gender and patient-centeredness. Case characteristics need to be considered in future research on the association of physician gender and the patient-centered communication, as well as in the tailoring of physician communication training. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
    Patient Education and Counseling 10/2014; 98(1):55-60. · 2.60 Impact Factor
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    ABSTRACT: Testosterone is an endocrine hormone with functions in the reproductive organs, anabolic events and skin homeostasis. We report here that GPRC6A serves as a sensor and mediator of the rapid action of testosterone in epidermal keratinocytes. The silencing of GPRC6A inhibited testosterone-induced intracellular calcium ([Ca2+]i) mobilization and H2O2 generation. These results indicated that a testosterone-GPRC6A complex is required for the activation of Gq protein, IP3 generation, and [Ca2+]i mobilization, leading to Duox1 activation. H2O2 generation by testosterone stimulated the apoptosis of keratinocytes through the activation of caspase-3. The application of testosterone into 3-D skin equivalents increased the apoptosis of keratinocytes between the granular and stratified corneum layers. These results support an understanding of the molecular mechanism of testosterone-dependent apoptosis in which testosterone stimulates H2O2 generation through the activation of Duox1.
    Journal of Biological Chemistry 08/2014; · 4.65 Impact Factor
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    ABSTRACT: The complexity of end-of-life (EOL) communication in cancer care is often increased by family caregivers, who frequently affect the information and decision-making process. We assessed cancer patient preferences (PP), family caregiver preferences (FCP), and family caregiver predictions of patient preferences (FCPPP) regarding the disclosure of terminal status, family involvement in the disclosure process, and EOL choices, and we evaluated the concordances among them.
    Psycho-Oncology 08/2014; · 3.51 Impact Factor
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    ABSTRACT: Background Communication between cancer patients and caregivers is often suboptimal. The Cancer Communication Assessment Tool for Patient and Families (CCAT-PF) is a unique tool developed to measure congruence in patient–family caregiver communication employing a dyadic approach. We aimed to examine the cross-cultural applicability of the CCAT in the Korean healthcare setting.Methods Linguistic validation of the CCAT-PF was performed through a standard forward–backward translation process. Psychometric validation was performed with 990 patient–caregiver dyads recruited from 10 cancer centers.ResultsMean scores of CCAT-P and CCAT-F were similar at 44.8 for both scales. Mean CCAT-PF score was 23.7 (8.66). Concordance of each items between patients and caregivers was low (weighted kappa values <0.20 for all items and Spearman's rho <0.18 for scale scores). Scale scores did not differ significantly across a variety of cancer types and stages. The CCAT-P or CCAT-F score was weakly associated with mental health and quality of life outcomes. The CCAT-PF was correlated weakly with both patient-perceived and caregiver-perceived family avoidance of cancer care scales.Conclusion The CCAT-PF Korean version showed similar psychometric properties to the original English version in the assessment of communication congruence between cancer patient and family caregivers. Copyright © 2014 John Wiley & Sons, Ltd.
    Psycho-Oncology 07/2014; · 3.51 Impact Factor
  • Dong Wook Shin, Jong Hyock Park
    Cancer 07/2014; · 5.20 Impact Factor
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    ABSTRACT: Abstract Purpose: To investigate the health behaviors of people with retinitis pigmentosa (RP) in the Republic of Korea. Methods: An online questionnaire was used to survey members of the Korean Retinitis Pigmentosa Society (KRPS), over 3 months from December 2010 to February 2011. Controls were selected from participants of the 4th Korean National Health and Nutrition Examination Survey and were matched with people with RP using the propensity score method to optimize comparative analysis. A semi-structured interview was also conducted with five members of the KRPS to identify potential reasons for physical inactivity and unhealthy diet and to develop effective interventions. Results: A total of 194 eligible people with RP responded to the online survey, and 187 individuals were matched with the control population by propensity score matching. RP subjects reported a lower rate of current smoking and greater use of preventive healthcare services. However, people with RP were more physically inactive (50.8% vs 27.3%, p < 0.001) and consumed more fast food (69.5% vs 58.3%, p = 0.024) than the control population. Conclusion: Physical inactivity and fast food consumption were more frequently reported in people with RP than the general population. Efforts to understand the possible reasons and develop interventions to improve these health behaviors are warranted.
    Ophthalmic epidemiology. 06/2014;
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    ABSTRACT: Human epidermal γδ T cells are known to play crucial roles in the defense and homeostasis of the skin. However, their precise mechanism of action in skin inflammation remains less clear.
    Annals of Dermatology 06/2014; 26(3):308-13. · 0.61 Impact Factor
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    ABSTRACT: We demonstrate a simple electrospinning for preparing Si-carbon composite Nanofiber (NF) in which aciniform aggregates of Si particles are well encased by amorphous carbon. The Si-carbon composite NF exhibit a significantly improved electrochemical performance with a high specific capacity of 1250 mAh·g−1 and a superior cycling performance during 50 cycles at a rate of 0.2 C. More importantly, Si-carbon composite NF maintain about 70% of initial capacity at 0.2 C and an excellent cycling stability even at 25 times higher current density compared to the initial condition, proving that it has superb kinetics compared to ever reported Si or SiOx materials. The electrochemical superiority of Si-carbon composite NF can be attributed to amorphous carbon framework accommodating the inherent volume expansion of Si during lithiation as well as the enlarged contact area between active materials and conducting agent attributed to the morphological characteristics of its one dimensional (1D) nanostructure.
    Electrochimica Acta 02/2014; 118:100–105. · 4.09 Impact Factor
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    ABSTRACT: Decisions for cancer susceptibility genetic testing (CSGT) uptake and dissemination of results occur within the family context. A national survey was performed with 990 patient-family member dyads (participation rate:76.2%), with paired questionnaires examining attitudes toward CSGT uptake and disclosure of results in response to a hypothetical scenario in which a reliable cancer susceptibility genetic test was available for the specific cancer a patient was being treated. While most patients and family members responded they would uptake or recommend CSGT if available, concordance between the dyads was poor for both patient's testing (agreement rate 77.5%, weighted κ =0.09) and first-degree relatives' testing(agreement rate 78.0%, weighted κ =0.09). Most patients (93.2%) and family members (92.9 %) indicated that patients should disclose positive CSGT results to family members, with dyadic agreement of 89.1% (κ = 0.15). However, there were substantial disagreement regarding when disclosure should take place, who should make the disclosure (the patient or the health care professionals), and to whom the results should be disclosed. Patients and family members may hold different attitudes toward CSGT uptake of and disclosure of results within the family. Our findings reinforce the need for a family system approach to incorporate perspectives of patients as well as their family members.
    Clinical Genetics 01/2014; · 4.25 Impact Factor
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    ABSTRACT: Many tissues of the human body encounter hyperosmotic stress. The effect of extracellular osmotic changes on melanin production has not yet been elucidated. In this study, we determined that hyperosmotic stress induced by organic osmolytes results in reduced melanin production in human melanoma MNT-1 cells. Under hyperosmotic stress, few pigmented mature melanosomes were detected, but there was an increase in swollen vacuoles. These vacuoles were stained with an anti-M6PR antibody that recognizes late endosomal components and with anti-TA99 and anti-HMB45 antibodies, implying that melanosome formation was affected by hyperosmotic stress. Electron microscopic analysis revealed that the M6PR-positive swollen vacuoles were multi-layered and contained melanized granules, and they produced melanin when L-DOPA was applied, indicating that these vacuoles were still capable of producing melanin, but the inner conditions were not compatible with melanin production. The vacuolation phenomenon induced by hyperosmotic conditions disappeared with treatment with the PI3K activator 740 Y-P, indicating that the PI3K pathway is affected by hyperosmotic conditions and is responsible for the proper formation and maturation of melanosomes. The microarray analysis showed alterations of the vesicle organization and transport under hyperosmotic stress. Our findings suggest that melanogenesis could be regulated by physiological conditions, such as osmotic pressure.
    PLoS ONE 01/2014; 9(8):e105965. · 3.53 Impact Factor
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    ABSTRACT: Objective To investigate the potentially different relationship between family history (FH) of coronary heart disease (CHD) and carotid or coronary atherosclerosis. Methods Asymptomatic healthy Korean adults older than 30 years who received both coronary CTA and carotid USG as part of a self-referred health check-up were retrospectively investigated (N = 662). Multivariable logistic regression analysis was employed to investigate the relationship between FH of CHD and either coronary CTA or carotid USG results. Results Adjusted for major CVD risk factors, FH of CHD was significantly associated with presence of any plaque in coronary arteries (aOR 2.10, 95% CI 1.07–4.16) and significant coronary stenosis (aOR 4.92, 95% CI 1.58–15.4), but was not associated with presence of any plaque in carotid arteries (aOR 1.27, 95% CI 0.61–2.63) and increased carotid IMT (aOR 1.44, 95% CI 0.40–5.22). Addition of FH of CHD had significant incremental predictive value to models for any coronary plaque (AUC 0.781 vs. 0.786, p = 0.0351), and significant coronary stenosis (AUC 0.772 vs. 0.808, p = 0.0129), but not for any carotid plaque (AUC 0.748 vs. 0.748, p = 0.528), and increased carotid IMT (AUC 0.778 vs. 0.783, p = 0.591). Conclusion To our knowledge, our study is the first to show specific comparative evidence that FH of CHD is more strongly associated with coronary than with carotid atherosclerosis. Our results suggest FH of CHD adds predictive value specifically to coronary atherosclerosis, but not carotid atherosclerosis, and suggest the possibility that screening for coronary atherosclerosis (via CAC) among low to intermediate risk asymptomatic adults with FH of CHD may be beneficial, who otherwise would not be screened according to traditional risk algorithms.
    Atherosclerosis 01/2014; 233(2):584–589. · 3.71 Impact Factor
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    ABSTRACT: (-)-Epigallocatechin-3-O-gallate (EGCG) has long been known as a potent inducer of keratinocyte differentiation. Although its molecular mechanisms have been extensively studied, its actions on human skin remain to be elucidated. In this study, we demonstrated that methylated EGCG and EGCG increase the expression of klotho, and that klotho functions as a downstream target of EGCG and methylated EGCG in keratinocyte differentiation. We demonstrated that methylated EGCG3 and EGCG induce morphological changes in normal human epidermal keratinocytes (NHEKs) that are related to up-regulation of klotho expression. We also demonstrated that a klotho-induced keratinocyte differentiation marker in NHEKs is inhibited by H-89, a protein kinase (PKA) inhibitor. These results suggest that methylated EGCG and EGCG may function as inducers of keratinocyte differentiation via transcriptional regulation of the klotho protein.
    International Journal of Molecular Sciences 01/2014; 15(4):5749-61. · 2.46 Impact Factor
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    ABSTRACT: We assessed the accuracy of communication between doctors and patients by evaluating the consistency between patient perception of cancer stage and the medical records, and analyzed the most influential factors of incongruence among cancer patients at 10 cancer centers across Korea. Information was gathered from cancer patients at the National Cancer Center and nine regional cancer centers located in every province of Korea between 1 July 2008 and 31 August 2008. Data were analyzed using Pearson's χ2 test and multivariate logistic regression analysis. The stages of cancer reported by the 1,854 patients showed a low degree of congruence with the stages given in medical records (k = 0.35, P<0.001). Only 57.1% of the patients had accurate knowledge of their cancer stage. In total, 18.5% underestimated their stage of disease, and the more advanced the cancer stage, the more likely they were to underestimate it, in order of local (14.2%), regional (23.7%), and distant (51.6%). Logistic regression analysis showed that congruence was lower in patients with cervical cancer (odds ratio [OR] = 0.51, 95% confidence interval [CI] = 0.30-0.87), recurrence (OR = 0.64, 95% CI = 0.50-0.83), and treatment at the National Cancer Center (OR = 0.53, 95% CI = 0.39-0.72). There are knowledge gaps between patients' perceived and actual stage of cancer. Patients with cervical cancer, recurrence, and who received treatment at a regional cancer center showed less understanding of their cancer stage.
    PLoS ONE 01/2014; 9(5):e90483. · 3.53 Impact Factor
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    ABSTRACT: This study aims to assess the current status of shared decision-making on instituting postmenopausal hormone therapy (HT). Two cross-sectional nationwide surveys of postmenopausal women and primary care physicians in the Republic of Korea were conducted in 2012 via face-to-face interviews. A total of 685 women (aged 50-69 y) who with natural menopause and 250 primary care physicians were included. Only 56.8% of primary care physicians reported that they explain the benefits and risks of HT and leave the decision to postmenopausal women. The others usually recommended using or not using HT. Of those postmenopausal women who had discussed such therapy with physicians (147 of 685; 21.5%), not all were aware of breast cancer or cardiovascular risks (only 65.3% and 38.8% were informed, respectively). Although most physicians perceived HT as beneficial for menopausal symptom control (99.6%) and acknowledged the related risk of breast cancer (84.8%), nearly half had the impression that HT was preventive of cardiovascular diseases. The interviewed women were less informed of the benefits and risks of HT than were the physician respondents. The awareness levels of the treated and untreated women did not differ. Participation of postmenopausal women in deciding whether to use HT is not prevalent. Physician-woman information transfer is suboptimal, and treatment decisions often are not based on the best available evidence. The current status of shared decision-making in this setting is clearly in need of improvement.
    Menopause (New York, N.Y.) 12/2013; · 3.08 Impact Factor

Publication Stats

542 Citations
419.27 Total Impact Points

Institutions

  • 2010–2014
    • Seoul National University Hospital
      • Department of Family Medicine
      Sŏul, Seoul, South Korea
  • 2008–2014
    • Amorepacific Corporation
      Sŏul, Seoul, South Korea
  • 2002–2014
    • Hanyang University
      • Division of Materials Science and Engineering (MSE)
      Sŏul, Seoul, South Korea
    • Pohang University of Science and Technology
      • Department of Materials Science and Engineering
      Andong, North Gyeongsang, South Korea
  • 2011–2013
    • University of Texas at Austin
      • Department of Materials Science and Engineering
      Austin, Texas, United States
  • 2009–2013
    • Sungkyunkwan University
      • School of Advanced Materials Science and Engineering (AMSE)
      Sŏul, Seoul, South Korea
    • Korea Advanced Institute of Science and Technology
      • Department of Mechanical Engineering
      Seoul, Seoul, South Korea
  • 2008–2013
    • National Cancer Center Korea
      • Gastric Cancer Branch
      Kōyō, Gyeonggi Province, South Korea
    • Korea Institute of Science and Technology
      • Electronic Materials Research Center
      Sŏul, Seoul, South Korea
  • 2012
    • Yonsei University Hospital
      Sŏul, Seoul, South Korea
    • CHA University
      Sŏul, Seoul, South Korea
  • 2005
    • Yonsei University
      Sŏul, Seoul, South Korea