Se Hyun Kim

Seoul National University Bundang Hospital, Sŏul, Seoul, South Korea

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Publications (147)642.38 Total impact

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    ABSTRACT: The aim of this study was to evaluate the outcomes and patterns of recurrence in the different subtypes of breast cancer. We analyzed 1432 stage I-III breast cancer patients who had undergone surgery at Seoul National University Bundang Hospital between June 2003 and August 2011. Five subtypes were defined according to estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (HER2), and Ki-67. Overall survival (OS) and breast cancer-free interval (BCFI) rates were estimated using the Kaplan-Meier method. Site-specific recurrence was estimated using Gray's test. The median follow-up period was 53 months. There were 22 local recurrences, 18 cases of contralateral breast cancer, 19 regional nodal recurrences, and 70 distant metastases. The 5-year BCFIs by subtype were luminal B-HER2 (+), 94.2 %; luminal A, 93.9 %; luminal B-HER2 (-), 91.4 %; HER2, 83.1 %; and triple-negative, 81.9 % (p < 0.001). Cases with the luminal A had a 5-year OS rate of 98.3 % that was the longest compared to those of cases with luminal B-HER2 (-), 95.8 %; luminal B-HER2 (+), 98.0 %; HER2, 90.8 %; and triple-negative, 89.9 % (p < 0.001). The triple-negative had a higher rate of local recurrence at the first site than others (p = 0.013). HER2 and triple-negative had higher rates of nodal recurrence at the first site than others (p < 0.001). The outcomes and patterns of site-specific recurrence in Korean breast cancer patients were different for each subtype. Defining recurrence patterns by breast cancer subtypes can help determine the appropriate method of surveillance and treatment.
    Breast Cancer Research and Treatment 04/2015; DOI:10.1007/s10549-015-3390-7 · 4.20 Impact Factor
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    ABSTRACT: To measure the prognostic significance of absolute monocyte count/absolute lymphocyte count prognostic score (AMLPS) in patients with gastric cancer. We retrospectively examined the combination of absolute monocyte count (AMC) and absolute lymphocyte count (ALC) as prognostic variables in a cohort of 299 gastric cancer patients who underwent surgical resection between 2006 and 2013 and were followed at a single institution. Both AMC and ALC were dichotomized into two groups using cut-off points determined by receiving operator characteristic curve analysis. An AMLPS was generated, which stratified patients into three risk groups: low risk (both low AMC and high ALC), intermediate risk (either high AMC or low ALC), and high risk (both high AMC and low ALC). The primary objective of the study was to validate the impact of AMLPS on both disease-free survival (DFS) and overall survival (OS), and the second objective was to assess the AMLPS as an independent prognostic factor for survival in comparison with known prognostic factors. Using data from the entire cohort, the most discriminative cut-off values of AMC and ALC selected on the receiver operating characteristic curve were 672.4/μL and 1734/μL for DFS and OS. AMLPS risk groups included 158 (52.8%) patients in the low-risk, 128 (42.8%) in the intermediate-risk, and 13 (4.3%) in the high-risk group. With a median follow-up of 37.2 mo (range: 1.7-91.4 mo), five-year DFS rates in the low-, intermediate-, and high-risk groups were 83.4%, 78.7%, and 19.8%, respectively. And five-year OS rates in the low-, intermediate-, and high-risk groups were 89.3%, 81.1%, and 14.4%, respectively. On multivariate analysis performed with patient- and tumor-related factors, we identified AMLPS, age, and pathologic tumor-node-metastasis stage as the most valuable prognostic factors impacting DFS and OS. AMLPS identified patients with a poor DFS and OS, and it was independent of age, pathologic stage, and various inflammatory markers.
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    ABSTRACT: Organic field-effect transistors (OFETs) were fabricated using polymer blended gate dielectrics in an effort to enhance the electrical stability against a gate bias stress. A poly(melamine-co-formaldehyde) acrylated (PMFA) gate dielectric layer with great insulating properties was blended with polypentafluorostyrene (PFS), a type of hydrophobic fluorinated polymer. Although the overall electrical performance dropped slightly due to the rough and hydrophobic surfaces of the blend films, at the blend ratio (10%), the OFET’s threshold voltage shift under a sustained gate bias stress applied over 3 h decreased remarkably compared with an OFET based on a PMFA dielectric alone. This behavior was attributed to the presence of the hydrophobic and electrically stable PFS polymer, which provided a low interfacial trap density between the gate dielectric and the semiconductor. A stretched exponential function model suggested that the energetic barrier to create trap states was high, and the distribution of energetic barrier heights was narrow in devices prepared with PFS.
    Organic Electronics 03/2015; DOI:10.1016/j.orgel.2015.03.005 · 3.68 Impact Factor
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    ABSTRACT: Evidences suggest an association between leukocytosis and thrombotic or hemorrhagic complication in polycythemia vera (PV) and essential thrombocythemia (ET), but clinical implication is not well known. To evaluate whether leukocyte burden during follow-up is related to thrombotic or hemorrhagic events in PV and ET. We retrospectively analyzed patients with PV or ET treated at Seoul National University Bundang Hospital, Korea. Time-weighted averages of leukocytes during the follow-up period were defined as leukocyte burden and were calculated for each patient and compared between patient subgroups. In each patient with events, leukocyte burden for the 3-month period before the event was compared with that for the entire follow-up period. In 102 patients with PV or ET, 35 events (16 thrombotic, 19 hemorrhagic) occurred in 29 patients (median follow-up, 54months). Leukocyte burden were significantly higher in patients with events than in event-free patients (12,015×10(3) /μL vs. 9,567×10(3)/μL, P=0.003). The difference was more prominent in ET patients than in PV patients, and in patients with hemorrhagic events than in those with thrombotic events. In patients with events, the leukocyte burden in the pre-event period was higher than in the entire follow-up period (16,767×10(3)/μL vs. 12,015×10(3)/μL, P=0.002). In all patients, leukocyte burden during entire follow-up period of 11,000×10(3)/μL or higher was an independent risk factor for vascular events. In PV or ET patients, leukocyte burden during disease course is related to increased incidence of thrombotic or hemorrhagic events. Copyright © 2015. Published by Elsevier Ltd.
    Thrombosis Research 02/2015; DOI:10.1016/j.thromres.2015.02.023 · 2.43 Impact Factor
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    ABSTRACT: Platinum-based doublet chemotherapy is the treatment of choice for patients with non-small cell lung cancer (NSCLC), however, the role of a platinum-based doublet as second-line therapy after failure of an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for NSCLC patients has not yet been elucidated. The purpose of this study was to compare the clinical efficacy of pemetrexed versus a platinum-based doublet as second-line therapy after failure of EGFR TKI used as first-line therapy for NSCLC patients with EGFR mutations. We designed a multicenter retrospective cohort study of 314 NSCLC patients with EGFR mutations who received an EGFR TKI as first-line palliative chemotherapy. Our analysis included 83 patients who failed EGFR TKI therapy and received second-line cytotoxic chemotherapy. Forty-six patients were treated using a platinum-based doublet and 37 patients were treated using singlet pemetrexed. The overall response rates (RRs) of patients receiving a platinum-based doublet and patients receiving pemetrexed were17.4% and 32.4%, respectively (P=0.111). The median progression-free survival (PFS) of patients receiving pemetrexed was significantly longer than that of patients receiving a platinum-based doublet (4.2 months vs. 2.7 months, respectively; P=0.008). The hazard ratio (HR) was 0.54 (95% confidence interval [CI], 0.34-0.86;P=0.009). s Our retrospective analysis found that second-line pemetrexed singlet therapy provided significantly prolonged PFS compared to second-line platinum-based doublet chemotherapy for NSCLC patients with EGFR mutations who failed first-line EGFR TKI. Conduct of prospective studies for confirmation of our results is warranted.
    Cancer Research and Treatment 02/2015; DOI:10.4143/crt.2014.244 · 2.98 Impact Factor
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    ABSTRACT: Solution-processed organic field effect transistors (OFETs), which are amenable to facile large-area processing methods, have generated significant interest as key elements for use in all-organic electronic applications aimed at realizing low-cost, lightweight, and flexible devices. The low performance levels of n-type solution-processed bottom-contact OFETs unfortunately continue to pose a barrier to their commercialization. In this study, we introduced a combination of CVD-grown graphene source/drain (S/D) electrodes and fullerene (C60) in a solution-processable n-type semiconductor toward the fabrication of n-type bottom-contact OFETs. The C60 coating in the channel region was achieved by modifying the surface of the oxide gate dielectric layer with a phenyl group-terminated self-assembled monolayer (SAM). The graphene and phenyl group in the SAMs induced π-π interactions with C60, which facilitated the formation of a C60 coating. We also investigated the effects of thermal annealing on the reorganization properties and field-effect performances of the overlaying solution-processed C60 semiconductors. We found that thermal annealing of the C60 layer on the graphene surface improved the crystallinity of the face-centered cubic (fcc) phase structure, which improved the OFET performance and yielded mobilities of 0.055 cm(2) V(-1) s(-1). This approach enables the realization of solution-processed C60-based FETs using CVD-grown graphene S/D electrodes via inexpensive and solution-process techniques.
    Physical Chemistry Chemical Physics 02/2015; 17(9). DOI:10.1039/c4cp05787b · 4.20 Impact Factor
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    ABSTRACT: Nanocomposite gate insulators consisting of (Ba, Sr)TiO3 (barium strontium titanate; BST) nanoparticles and crosslinked poly(4-vinyl phenol) (PVP) polymers were fabricated. Well-dispersed nanocomposite films were prepared by optimizing the BST nanoparticle size sorting process (ultrasound crushing and centrifuge method). The size-sorted BST nanoparticles (∼30 nm in size) were homogeneously mixed in the PVP host polymer in various BST contents, from 0 to 70 wt%, to tune the dielectric constant (κ) of the resulting nanocomposite films. The composite films exhibit three-fold increase in the κ value from 3.9 to 11.3. The physical properties including leakage current and surface roughness of the composites were also measured as a function of the BST loading content and particle dispersion. The relationship between these properties and the electrical performance of the corresponding organic thin film transistor were explored.
    Organic Electronics 02/2015; 17:144-150. DOI:10.1016/j.orgel.2014.11.026 · 3.68 Impact Factor
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    ABSTRACT: The electrical performance of triethylsilylethynyl anthradithiophene (TES-ADT) organic field-effect transistors (OFETs) was significantly affected by dielectric surface polarity controlled by grafting hexamethyldisilazane and dimethyl chlorosilane-terminated polystyrene (PS-Si(CH3)2Cl) to 300-nm-thick SiO2 dielectrics. On the untreated and treated SiO2 dielectrics, solvent-vapor annealed TES-ADT films contained millimeter-sized crystals with low grain boundaries (GBs). The operation and bias stability of OFETs containing similar crystalline structures of TES-ADT could be significantly increased with a decrease in dielectric surface polarity. Among dielectrics with similar capacitances (10.5-11 nF cm−2) and surface roughnesses (0.40-0.44 nm), the TES-ADT/PS-grafted dielectric interface contained the fewest trap sites and therefore the OFET produced using it had low-voltage operation and a charge-carrier mobility ∼1.32 cm2 V−1 s−1, on-off current ratio >106, threshold voltage ∼0 V, and long-term operation stability under negative bias stress.
    Organic Electronics 02/2015; 17:87-93. DOI:10.1016/j.orgel.2014.11.022 · 3.68 Impact Factor
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    ABSTRACT: We investigated differential patterns of hallucinatory experiences between nonclinical and clinical samples. A total of 223 nonclinical individuals (108 females) and 111 subjects with schizophrenia (54 females) completed the Launay-Slade Hallucination Scale-Revised (LSHS-R) and Perceptual Aberration Scale (PAS). The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) was used for the nonclinical group, and the Positive and Negative Syndrome Scale (PANSS) hallucination item was used for the clinical group. Cronbach׳s alpha values showed good internal consistency for the LSHS-R. In the two groups, significant associations were found between LSHS-R and PAS scores. Two factors were extracted through a principal component analysis (PCA) in the nonclinical group, and three factors were identified in the clinical group. The results of a hierarchical cluster analysis (HCA) revealed that a perception-cognition dimension was clear cluster discriminating element for the nonclinical group, whereas alterations in perception-cognition dimension were characteristic in cluster structure of the clinical group. Our findings suggest that the nature of hallucinatory experiences may differ qualitatively between a nonclinical population and subjects with schizophrenia. Perceptual or cognitive aberrations may add a psychopathologic dimension to hallucinatory experiences. Exploring the internal structure of hallucinatory experiences may provide explanatory insight into these experiences in the general population. Copyright © 2015. Published by Elsevier Ireland Ltd.
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    ABSTRACT: Background: Patients with bipolar disorder are at a high risk for becoming obese. Adipokines are associated with depression and obesity via the inflammatory process. However, few studies have investigated the associations between depression and leptin, adiponectin and resistin levels in patients with bipolar disorder. We explored the associations between serum levels of leptin, adiponectin and resistin and mood and metabolic status in patients with bipolar disorder. Methods: Body mass index (BMI) and serum leptin, adiponectin and resistin levels were assessed in 94 Korean patients with bipolar disorder. The Hamilton Rating Scale for Depression-17 and the Young Mania Rating Scale were used to assess mood state. Results: Leptin (17.19 ± 13.08 vs. 10.47 ± 10.05 ng/ml; p = 0.008) and adiponectin (10.51 ± 8.37 vs. 5.91 ± 2.82 μg/ml; p = 0.001) levels were higher in female than in male patients. After adjusting for mood state, age, smoking, alcohol habit, and BMI in a multivariate analysis of covariance (MANCOVA), leptin (17.86 ± 1.22 vs. 10.05 ± 1.48 ng/ml; p < 0.001) and adiponectin (10.18 ± 0.98 vs. 6.40 ± 1.19 μg/ml; p = 0.027) levels were still higher in female than in male patients. Compared to euthymic patients, depressed patients had higher levels of leptin (17.37 ± 14.69 vs. 11.65 ± 9.04 ng/ml; p = 0.024), but there was no significant difference in adiponectin and resistin levels between the two groups. After adjusting for age, gender and BMI in the MANCOVA, leptin levels were also significantly higher in depressed (16.78 ± 1.34 ng/ml) than in euthymic patients (10.73 ± 1.22 ng/ml; p = 0.001). Conclusion: Leptin is closely associated with the regulation of mood and metabolic homeostasis in patients with bipolar disorder. © 2014 S. Karger AG, Basel.
    Neuropsychobiology 11/2014; 70(4):203-209. DOI:10.1159/000366488 · 2.30 Impact Factor
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    ABSTRACT: There are few data on the clinical implications of immunosuppressive protein expression in tumors and immune cell infiltration within the tumor microenvironment in patients with gastric cancer (GC). In this study, 243 patients with curatively resected GC were included. The levels of immunosuppressive protein expression [programmed cell death 1 ligand 1 (PD-L1), cytotoxic T-lymphocyte antigen 4 (CTLA-4), and indoleamine 2,3-dioxygenase (IDO)] in tumors and the densities of immune cells [CD3(+), CD4(+), CD8(+), or PD-1(+) cells] within the tumor microenvironment were measured using immunohistochemical analysis. Positive PD-L1, CTLA-4, and IDO expression was observed in 43.6, 65.8, and 47.7 % of the patients, respectively. Expression of PD-L1, CTLA-4, and IDO was related to less advanced stage, intestinal type, and well/moderately differentiated adenocarcinoma (P < 0.05). PD-L1 expression was related to better disease-free survival (DFS) and overall survival (OS) in GC [PD-L1(+) vs. PD-L1(-) tumors: 5-year DFS rate, 82.6 vs. 66.9 %; 5-year OS rate, 83.0 vs. 69.1 % (P values <0.05)]. Survival outcomes were also better in patients with a higher density of CD3(+) cells within the tumor microenvironment than in those with a lower density of CD3(+) cells [5-year DFS rate, 80.9 vs. 67.0 %; 5-year OS rate, 82.5 vs. 68.0 % (P values <0.05)]. In multivariate analysis, these two immune markers had a prognostic impact on survival, independent of other clinical variables. GC patients with immunosuppressive protein expression (PD-L1, CTLA-4, or IDO) had distinct clinicopathological characteristics. PD-L1(+) expression and a high-CD3 tumor microenvironment are favorable prognostic markers in GC.
    Gastric Cancer 11/2014; DOI:10.1007/s10120-014-0440-5 · 4.83 Impact Factor
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    ABSTRACT: Although about one-fourth of patients dying of lung cancer are aged 80 years or older in Korea, the current treatment status and outcome in octogenarians are largely unknown. We aimed to evaluate the proportion of octogenarians with advanced non-small cell lung cancer (NSCLC) who receive systemic chemotherapy and analyze the clinical outcome in these patients. The medical records of 281 octogenarians who were diagnosed with stage IIIB/IV or recurrent NSCLC were retrospectively reviewed. In total, 127 out of 281 patients (45 %) received chemotherapy. Among the patients with ECOG PS 0-2, 119 patients (57 %) received chemotherapy. The first-line treatments were platinum doublets in 61 patients (48 %), single-agent chemotherapy in 34 (27 %), and epidermal growth factor receptor tyrosine kinase inhibitors in 32 (25 %). In patients with ECOG PS 0-2, patients who received chemotherapy lived longer compared with patients who only received best supportive care (16.1 vs. 4.0 months, P < 0.001). Among the 127 patients who received chemotherapy, patients who received EGFR TKIs showed longer survival than patients who only received cytotoxic agents (21.4 vs. 9.8 months, P < 0.001). In a multivariate analysis, ECOG PS 3-4 and smoking history were unfavorable prognostic factors, while recurrent disease and systemic chemotherapy were favorable prognostic factors. Nearly half of octogenarians with advanced NSCLC received systemic chemotherapy. The patients showed prolonged survival compared with the best supportive care group. Further studies are warranted to provide an optimal tailored treatment for octogenarians.
    Journal of Cancer Research and Clinical Oncology 11/2014; DOI:10.1007/s00432-014-1875-0 · 3.01 Impact Factor
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    ABSTRACT: Tuning of the energetic barriers to charge transfer at the semiconductor/dielectric interface in organic field-effect transistors (OLEDs) is achieved by varying dielectric functionalities. Based on this, we demonstrate the correlation between the magnitude of the energy barrier and the gate-bias stress stability of the OFETs, and reveal the origin of the excellent device stability of OFETs employing fluorinated dielectrics.
    Advanced Materials 11/2014; 26(42). DOI:10.1002/adma.201402363 · 15.41 Impact Factor
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    ABSTRACT: Printing electrically functional liquid inks is a promising approach for achieving low-cost, large-area, additive manufacturing of flexible electronic circuits. In order to print thin film transistors, a basic building block of thin film electronics, it is important to have several options for printable electrode materials that exhibit high conductivity, high stability, and low-cost. Here we report completely aerosol-jet printed (AJP) p- and n-type electrolyte gated transistors (EGTs) using a variety of different electrode materials including highly conductive metal nanoparticles (Ag), conducting polymers (polystyrenesulfonate doped poly(3,4-ethylendedioxythiophene, PEDOT:PSS), transparent conducting oxides (indium tin oxide), and carbon based materials (reduced graphene oxide). Using these source-drain electrode materials and a PEDOT:PSS/ion gel gate stack, we demonstrated high performance all-printed p- and n-type EGTs in combination with poly (3-hexythiophene) and ZnO semiconductors. All transistor components (including electrodes, semiconductors, and gate insulators) were printed by AJP. Both kinds of devices showed typical p- and n-type transistor characteristics, and exhibited both low threshold voltages (< 2 V) and high hole and electron mobilities. Our assessment suggests Ag electrodes may be the best option in terms of overall performance for both types of EGTs.
    ACS Applied Materials & Interfaces 10/2014; 6(21). DOI:10.1021/am504171u · 5.90 Impact Factor
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    ABSTRACT: In the arginylation branch of the N-end rule pathway, unacetylated N-terminal destabilizing residues function as essential determinants of protein degradation signals (N-degron). Here, we show that a neurostimulant, para-chloroamphetamine (PCA), specifically inhibits the Arg/N-end rule pathway, delaying the degradation of its artificial and physiological substrates, including regulators of G protein signaling 4 (RGS4), in vitro and in cultured cells. In silico computational analysis indicated that PCA strongly interacts with both UBR box and ClpS box, which bind to type 1 and type 2 N-degrons, respectively. Moreover, intraperitoneal injection of PCA significantly stabilized endogenous RGS4 proteins in the whole mouse brain and, particularly, in the frontal cortex and hippocampus. Consistent with the role of RGS4 in G protein signaling, treatment with PCA impaired the activations of GPCR downstream effectors in N2A cells, phenocopying ATE1-null mutants. In addition, levels of pathological C-terminal fragments of TDP43 bearing N-degrons (Arg208-TDP25) were significantly elevated in the presence of PCA. Thus, our study identifies PCA as a potential tool to understand and modulate various pathological processes regulated by the Arg/N-end rule pathway, including neurodegenerative processes in FTLD-U and ALS.
    Scientific Reports 09/2014; 4:6344. DOI:10.1038/srep06344 · 5.08 Impact Factor
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    ABSTRACT: Background: Bone metastasis (BM) is reported as a poor prognostic factor in gastric cancer. However, the clinicopathologic characteristics and clinical outcomes of patients with BM compared with patients without BM have not been well described. Patients and methods: The medical records of all metastatic or recurrent gastric cancer (MRGC) patients who visited our institution were reviewed. A total of 137 evaluable patients with BM were analysed together with historical control without BM (N = 111). Results: Of 1342 MRGC patients, 141 (10.5%) had BM. Patients with BM could be divided into initial BM (BM present at initial diagnosis of MRGC; N = 90) and late BM (N = 47) groups. The median survival after the diagnosis of BM in all patients was 4.4 months (95% confidence interval [CI] 3.69-5.11). However, overall survival after the diagnosis of MRGC was significantly shorter in the initial BM group (5.0 versus 12.2 months, p < 0.001). Compared with historical controls, patients with initial BM showed distinct clinicopathologic characteristics. Independent predictors of initial BM were a younger age, signet ring cell histology, primary tumour involving >= two-thirds of the stomach, pleural metastasis, thrombocytopenia and elevated alkaline phosphatase. According to a Cox proportional hazard model including both patients with BM and historical controls, initial BM, poor performance status, peritoneal metastasis, hypercalcemia and high carcinoembryonic antigen (CEA) were identified as poor prognostic factors, whereas chemotherapy was identified as a favourable factor (hazard ratio [HR] 0.33, 95% CI 0.22-0.49). Conclusion: MRGC with initial BM is a distinct group of diseases with specific clinicopathologic characteristics and poor prognosis. Chemotherapy may improve survival in these patients. (c) 2014 Elsevier Ltd. All rights reserved.
    European journal of cancer (Oxford, England: 1990) 09/2014; 50(16). DOI:10.1016/j.ejca.2014.08.003 · 4.82 Impact Factor
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    ABSTRACT: Organic field-effect transistors (OFETs) that operated with good electrical stability were prepared by synthesizing fluorinated polyimide (PI) gate dielectrics based on 6FDA-PDA-PDA PI and 6FDA-CF3Bz-PDA PI. 6FDA-PDA-PDA PI and 6FDA-CF3Bz-PDA PI contain 6 and 18 fluorine atoms per repeat unit, respectively. These fluorinated polymers provided smooth surface topographies and surface energies that decreased as the number of fluorine atoms in the polymer backbone increased. These properties led to a better crystalline morphology in the semiconductor film grown over their surfaces. The number of fluorine atoms in the PI backbone increased, the field-effect mobility improved, and the threshold voltage shifted toward positive values (from -0.38 to +2.21 V) in the OFETs with pentacene and triethylsilylethynyl anthradithiophene. In addition, the highly fluorinated polyimide dielectric showed negligible hysteresis and a notable gate bias stability under both a N2 environment and ambient air.
    ACS Applied Materials & Interfaces 08/2014; 6(17). DOI:10.1021/am5035076 · 5.90 Impact Factor
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    ABSTRACT: We report herein that a mixed layer of the electron-donating copper phthalocyanine (CuPc) and electron-accepting N,N-ditridecyl perylene diimide (PTCDI-C13) can be an efficient hole injection layer (HIL) for highperformance organic light-emitting diodes (OLEDs). From photophysical, morphological, and structural studies combined with electrical analysis based on the Mott–Schottky model, we conclude that the excellent miscibility between CuPc and PTCDI-C13 enables highly efficient charge transfer, and thus effective p-doping of CuPc, leading to increased hole conductivity of the HIL. As a result, turn-on voltages as low as 2.45 V and greatly improved thermal stabilities as compared to those of OLEDs with conventional CuPc HILs are observed.
    Science of Advanced Materials 08/2014; 6(8). DOI:10.1166/sam.2014.1940 · 2.91 Impact Factor
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    ABSTRACT: We investigated the effects of varying the properties of the interface between a semiconductor P3HT layer and a dielectric Cytop T layer on the performances of the resulting transistor devices by comparing the mobilities of devices prepared with bottom gate/bottom contact or top gate/bottom contact architectures. The reduced channel roughness that arose from the thermal annealing step dramatically enhanced the field-effect mobility, yielding the highest mobility yet obtained for a top-gate transistor: 0.12 cm(2)/V s. High-performance OFETs may be fabricated by controlling the channel roughness and the properties of the interface between the semiconductor and the gate dielectric.
    Organic Electronics 07/2014; 15(7). DOI:10.1016/j.orgel.2014.02.026 · 3.68 Impact Factor
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    ABSTRACT: The evidence of the association between depression and metabolic syndrome is increasing, but the existence of sex differences in this association remains controversial. The aim of this study was to investigate the association between subjective depressive symptoms and metabolic syndrome and each of its components by sex in the Korean population.
    Progress in Neuro-Psychopharmacology and Biological Psychiatry 06/2014; DOI:10.1016/j.pnpbp.2014.06.006 · 4.03 Impact Factor

Publication Stats

1k Citations
642.38 Total Impact Points


  • 2014–2015
    • Seoul National University Bundang Hospital
      Sŏul, Seoul, South Korea
    • Dongguk University
      Sŏul, Seoul, South Korea
  • 2013–2015
    • Yeungnam University
      • Department of Nano, Medical and Polymer Materials
      Gyeongsan, Gyeongsangbuk-do, South Korea
    • University of Minnesota Duluth
      • Department of Chemistry and Biochemistry
      Duluth, Minnesota, United States
  • 2009–2015
    • Kyung Hee University
      • Graduate School of East-West Medical Science
      Sŏul, Seoul, South Korea
  • 2006–2014
    • Seoul National University
      • • Medical Research Center
      • • Department of Biochemistry and Molecular Biology
      Sŏul, Seoul, South Korea
  • 2010–2013
    • Yonsei University
      • • Department of Internal Medicine
      • • Division of Medical Oncology
      Sŏul, Seoul, South Korea
  • 2006–2013
    • Seoul National University Hospital
      • Department of Neuropsychiatry
      Sŏul, Seoul, South Korea
    • Pohang University of Science and Technology
      • Department of Chemical Engineering
      Antō, North Gyeongsang, South Korea
  • 2007–2012
    • Yonsei University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2003
    • CHA University
      • College of Medicine
      Sŏul, Seoul, South Korea