Digital Piracy of Time-sensitive Content and Illegal Gambling: Evidence from Live Sports Broadcasting

Bora Jeong,Gunwoong Lee 한국경영정보학회 2022 한국경영정보학회 학술대회논문집 Vol.2022 No.6

Appraisal of a Model to Estimate Survival in Ambulatory Patients with Hepatocellular Carcinoma Classified as Barcelona Clinic Liver Cancer Stage B

Jeong-Ju Yoo,Su Jong Yu,Bora Lee,Eun Ju Cho,Jeong-Hoon Lee,Sang Gyune Kim,Yoon Jun Kim,Young Seok Kim,Jung-Hwan Yoon 거트앤리버 소화기연관학회협의회 2020 Gut and Liver Vol.14 No.3

Background/Aims: Patients with an intermediate stage of hepatocellular carcinoma (HCC) represent a highly heterogeneous population; therefore, many models have been proposed to predict the survival of these patients. The aim of this study was to evaluate the prognostic performance of a novel subclassification for tumors classified as Barcelona Clinic Liver Cancer (BCLC) stage B using the Model to Estimate Survival in Ambulatory HCC patients (MESIAH). Methods: This analysis was based on 377 patients with HCC treated at Seoul National University Hospital (training cohort) and 189 patients at the Soonchunhyang University Bucheon Hospital (validation cohort). Four subclassification systems were tested: MESIAH; original BCLC B subclassification (B1, B2, B3, and B4); modified model A (B1, B2, and B3+B4); and modified model B (B1, B2+B3, and B4). Results: Median survival progressively decreased from stage B1 through stages B2 to B3 according to the new MESIAH subclassification (p<0.001). Moreover, significantly different survival among contiguous stages was observed. In the multivariable Cox regression, the MESIAH subclassification was an independent predictor of overall survival (p<0.001). In terms of discrimination and calibration, MESIAH performed better than the original BCLC B subclassification, modified model A and modified model B. Conclusions: The MESIAH model would be an effective tool for stratifying heterogeneous BCLC stage B cancer, and the ability of this model to predict survival is better than that of the other previously proposed models.

FOXO1 functions in the regulation of nicotinamide phosphoribosyltransferase (Nampt) expression

Jeong, Bora,Park, Jeong Woo,Kim, Jae Geun,Lee, Byung Ju Elsevier 2019 Biochemical and biophysical research communication Vol.511 No.2

<P><B>Abstract</B></P> <P>Here, we report that Forkhead Box O1 (FOXO1) protein, a tumor suppressor, regulates expression of nicotinamide phosphoribosyltransferase (Nampt) in human breast cancer MCF-7 cells. Nampt plays an important role in the regulation of cell growth, survival, DNA replication and repair, and angiogenesis in tumorigenesis. We revealed that FOXO1 directly inhibits Nampt expression via binding to FOXO1 binding domains in the 5′-flanking region of the <I>nampt</I> gene. Nampt expression was increased by insulin and downstream phosphatidylinositol 3-kinase (PI3K)/Akt signaling, which was inhibited by FOXO1 overexpression. Accordingly, we showed that FOXO1 is also involved in insulin signaling-induced cell survival and proliferation in MCF-7 cells. These results suggest that FOXO1 plays an important role in human breast cancer cells by regulating <I>nampt</I> gene expression.</P> <P><B>Highlights</B></P> <P> <UL> <LI> FOXO1 plays a pivotal role in the expression of Nampt in human breast cancer cells. </LI> <LI> Insulin signaling pathway stimulates Nampt expression via inhibiting FOXO1. </LI> <LI> FOXO1 mediates insulin/PI3K-induced mitogenic effect on breast cancer cells via regulating Nampt expression. </LI> </UL> </P>

Effects of Storage Time on Molecular Weights and Properties of Melamine-Urea-Formaldehyde Resins

( Bora Jeong ),( Byung-dae Park ),( Valerio Causin ) 한국목재공학회 2020 목재공학 Vol.48 No.3

As the properties of the melamine-urea-formaldehyde (MUF) resins were changing during their storage time, this study investigated the impacts of the synthesis method and melamine content of the MUF resins on the pH, apparent viscosity, molecular weights, and crystallinity to estimate these properties over storage times of up to 30 days. Melaminesat three addition levels (5, 10, and 20 wt% based on the resin solids) were simultaneously reacted with urea and formaldehyde (MUF-A resins), while those at the same addition levels were first reacted with formaldehyde and then with urea(MUF-B resins). The pH values of the MUF-A and MUF-B resins decreased linearly as the storage time increased; the apparent viscosity increased linearly for the low melamine contents (5% and 10%) but increased exponentially for 20%. As anticipated, the molecular weights (Mw and Mn) increased linearly with the storage time, with a steeper increase in the Mw of the MUF-B resins compared with that of the MUF-A resins. The crystallinity of the two resin types decreased with storage time at higher melamine content. The relationships between these properties and the storage time made it possible to estimate the property changes in these resins synthesized by the different synthesis methods and melamine contents; this could help predict the properties of such resins in the industry during their storage.

Performance of Urea-Formaldehyde Resins Synthesized at Two Different Low Molar Ratios with Different Numbers of Urea Addition

( Bora Jeong ),( Byung-Dae Park ) 한국목재공학회 2019 목재공학 Vol.47 No.2

This study reports the performance of urea-formaldehyde (UF) resins prepared at two different low formaldehyde/urea (F/U) mole ratios with different numbers of urea addition during synthesis. The second or third urea was added during the synthesis of UF resins to obtain two different low molar ratios of 0.7 and 1.0, respectively. The molecular weights, cure kinetics, and adhesion performance of these resins were characterized by the gel permeation chromatography, differential scanning calorimetry, and tensile shear strength of plywood, respectively. When the number of urea additions and F/U molar ratio increased, the gelation time decreased, whereas the viscosity and molecular weight increased. Further, the UF resins prepared with the second urea and 1.0 molar ratio resulted in greater activation energy than those with third urea and 0.7 molar ratio. Tensile shear strength and formaldehyde emission (FE) of the plywood that bonded with these resins increased when the number of urea additions and molar ratio increased. These results suggest that the UF resins prepared with 0.7 molar ratio and third urea addition provide lower adhesion performance and FE than those resins with 1.0 mole ratio and the second urea addition.

Influence of Nitrogen Doping and Surface Modification on Photocatalytic Activity of TiO₂ Under Visible Light

Bora Jeong,Eun Ji Park,Myung-Geun Jeong,Hye Soo Yoon,Young Dok Kim 한국진공학회 2013 한국진공학회 학술발표회초록집 Vol.2013 No.8

[< 전시-P-34 >] Characteristics of curing kinetics of urea-formaldehyde resins with different molecular weights

( Bora Jeong ),( Byung-daepark ) 韓國木材工學會 2017 한국목재공학회 학술발표논문집 Vol.2017 No.2

As a part of understanding curing behavior of urea- formaldehyde (UF) resin adhesives with different formaldehyde/urea (F/U) mole ratios, differential scanning calorimetry (DSC) was used in this study. UF resin adhesives with two F/U mole ratios (1.0 and 1.2) were used to prepare low molecular weight (LMW) and high molecular weight (HMW) resins. This study used five resin blending ratios of LMW : HMW, such as 100:0, 75:25, 50:50, 25:75, and 0:100. DSC scanned differential scanning calorimetryd sample at different heating rates, such as 2.5, 5, 10 and 20 ℃/min, and isothemal scans (60, 80, 100 and 120 ℃). Peak temperature (T_p) and activation energies (E_a) in different LMW : HMW blending ratios of UF resins were analyzed with DSC . The results indicated that the curing temperature increased with an increase in the heating rate temperature increasing. Also, on-set and peak temperature increased as heating rate increased . Isothemal scans are still in the process of analysis to understand the impact of curing behavior of UF resins.

< 구두-E-02 > Performance of Melamine-Urea-Formaldehyde Resin Adhesives Synthesized with Different Melamine contents and Methods

( Bora Jeong ),( Byung-dae Park ) 한국목재공학회 2019 한국목재공학회 학술발표논문집 Vol.2019 No.1

As a part of understanding the adhesion in wood, this study investigated impacts of the synthesis method and melamine content of urea-melamine-formaldehyde (UMF) resins to their characteristics in the cohesive features (molecular weight (MW), cure kinetics, and crystallinity), interphase features (resin penetration, bond line thickness and maximum storage modulus (E′_max)), and adhesion performance in plywood and medium density fiberboard (MDF). Melamine at three addition levels (5, 10, 20 wt%) was simultaneously reacted with urea and formaldehyde to obtain MUF resins, while melamine at the same levels was initially reacted with formaldehyde and then with urea to prepare MFU resins. As the melamine content increased for two types of resins, MWs, curing peak temperature (T_p), activation energy (E_a), bond-line thickness, E′_max, and adhesion strength of plywood and MDF increased while the formaldehyde emission (FE) decreased. However, the crystallinity of resins, depth of resin penetration, thickness swelling (TS) and water absorption (WA) of MDF decreased. Compared with the synthesis method, MFU resins had greater MWs, lower E_a, greater crystallinity at 20% melamine, smaller resin penetration, thicker bond-line, greater E￠_max, higher adhesion strength, lower FE, smaller TS and WA of MDF than those of MUF resins, showing better overall performance of MFU resins. These results indicate that melamine content and synthesis method mainly affect the cohesive features of these resins, which consequently determine their adhesion performance in plywood and MDF while the interphase features have a partial contribution to the adhesion.

Prognostic Value of Biochemical Response Models for Primary Biliary Cholangitis and the Additional Role of the Neutrophil-to-Lymphocyte Ratio

( Jeong-ju Yoo ),( Eun Ju Cho ),( Bora Lee ),( Sang Gyune Kim ),( Young Seok Kim ),( Yun Bin Lee ),( Jeong-hoon Lee ),( Su Jong Yu ),( Yoon Jun Kim ),( Jung-hwan Yoon ) 대한소화기학회 2018 Gut and Liver Vol.12 No.6

Background/Aims: Recently reported prognostic models for primary biliary cholangitis (PBC) have been shown to be effective in Western populations but have not been wellvalidated in Asian patients. This study aimed to compare the performance of prognostic models in Korean patients and to investigate whether inflammation-based scores can further help in prognosis prediction. Methods: This study included 271 consecutive patients diagnosed with PBC in Korea. The following prognostic models were evaluated: the Barcelona model, the Paris-I/II model, the Rotterdam criteria, the GLOBE score and the UK-PBC score. The neutrophil-to-lymphocyte ratio (NLR) was analyzed with reference to its association with prognosis. Results: For predicting liver transplant or death at the 5-year and 10-year follow-up examinations, the UK-PBC score (areas under the receiver operating characteristic curve [AUCs], 0.88 and 0.82) and GLOBE score (AUCs, 0.85 and 0.83) were significantly more accurate in predicting prognosis than the other scoring systems (all p< 0.05). There was no significant difference between the performance of the UK-PBC and GLOBE scores. In addition to the prognostic models, a high NLR ( >2.46) at baseline was an independent predictor of reduced transplant-free survival in the multivariate analysis (adjusted hazard ratio, 3.74; p<0.01). When the NLR was applied to the prognostic models, it significantly differentiated the prognosis of patients. Conclusions: The UK-PBC and GLOBE scores showed good prognostic performance in Korean patients with PBC. In addition, a high NLR was associated with a poorer prognosis. Including the NLR in prognostic models may further help to stratify patients with PBC. (Gut Liver 2018;12:714-721)

The Catalytic Reduction Performance of Nitrogen Oxides over the Vanadium based Catalysts : Effect of Colloidal Silica and Glass Fiber

Bora Jeong(정보라),Myeung-jin Lee(이명진),Bora Ye(예보라),Seung-Yeop Chun(전승엽),Taewook Kim(김태욱),Hong-Dae Kim(김홍대) 한국에너지기후변화학회 2021 한국에너지기후변화학회 학술대회 Vol.2021 No.5

Regulation of air pollution (e.g., EURO 6, TIER 3) has been strengthened in many jurisdictions due to the occurrence of problems such as particulate matter (PM). At present, selective catalytic reduction (SCR) is the most effective method to control NOX emissions. Industrial V2O5-WO3/TiO2 catalysts (usually containing 0.5–3wt% V2O5 and 5–10wt% WO3) exhibit high de-NOX efficiency, and excellent resistance to sulfur (SO2) and H2O. Nevertheless, they also have several disadvantages such as high and narrow effective temperature range(300–400°C), and a tendency to oxidize SO2 to SO3. Therefore, SCR catalysts with high de-NOX efficiency at lower operating temperatures are required in order to obtain economic benefits and reduced energy consumption. Typically, silica has a good candidate to improve catalytic properties such as led to generation acid site, specific surface area, thermal stability. In this reason, enhanced the SCR catalyst property by using colloidal silica and glass fiber. The aim of this work, we confirmed the effect of silica on the chemi-physical properties and de-NO_X efficiency of vanadium based catalyst. These synthesized catalysts were analyzed by BET, TPD, FT-IR and catalytic performances using fixed-bed reactor in the range of 200-450°C.