• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.414-418
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• 2008

The role of positron emission tomography (PET) with F-18 fluorodeoxyglucose (F-18 FDG) in the diagnosis of hepatocellulcar carcinoma (HCC) has been limited because of a variable FDG uptake in HCC. However, the usefulness of PET/CT for detecting extrahepatic metastasis and monitoring of the treatment response in HCC has been reported. A 55-year-old man with a hepatitis B surface antigen-positive, was admitted to our hospital due to dyspnea, general weakness and body weight loss for one month. Chest X-ray showed multiple reticulo-nodular densities on both lower lung fields, which implies metastatic lesions. F-18 FDG PET/CT revealed consecutively intense hypermetabolic mass in right hepatic lobe, inferior vena cava and right atrium. We report a case of HCC with IVC and right atrium invasion identified by F-18 FDG PET/CT.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.93-93
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• 2010

Semiconductor nanocrystal quantum dots (NQDs) have recently attracted considerable interest for use in photovoltaics. Band gaps of NQDs can be tuned over a considerable range by varying the particle size thereby allowing enhance absorption of solar spectrum. NQDs, synthesized using colloidal routes, are solution processable and promise for a large-area fabrication. Recent advancements in multiple-exciton generation in NQD solutions have afforded possible efficiency improvements. Various architectures have attempted to utilize the NQDs in photovoltaics, such as NQD-sensitized solar cell, NQD-bulk-heterojuction solar cell and etc. Here we have fabricated CdSe NQDs with the band gap of 1.8 eV to 2.1 eV on thin-layers of p-type organic crystallites (1.61 eV) to realize a donor-acceptor type heterojuction solar cell. Simple structure as it was, we could control the interface of electrode-p-layer, and n-p-layer and monitor the following efficiency changes. Specifically, surface molecules adsorbed on the NQDs were critical to enhance the carrier transfer among the n-layer where we could verify by measuring the photo-response from the NQD layers only. Further modifying the annealing temperature after the deposition of NQDs on p-layers allowed higher conversion efficiencies in the device.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.1
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• pp.3-13
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• 1994

To minimize the time ordinarily spent in mono filter cigarette design, we studied the relationship between major seven independant variables ; filament(X1) and total denier(X2), porosity of the aller plug wrap(X3), filter length(X4), Porosity of the tip paper(X5) and cigarette paper(X6) and net weight of the reference cut tobacco(X7). Ninty trial numbers were obtained as a results of using rotatable central composite design and it is analyzed by the multiple regression analysis with stepwise in SAS/pc under restricted conditions. That is, UPD (Y1) = 82.96 - 3.80X1 + 2.50X2 - 3.29X3 - 3.15X5 - 0.83X22 + 1.88X5X6 - 1.38 X5X7(R2: 0.63), EPD(Y2) : 120.91 - 5.70X1 + 3.60X2 + 4.23X4 - 0.93X6 + 4.06X7 (R2=0.84), TVR(Y3) = 49.70 - 0.78X1 + 3.60X3 + 2.00X4 + 4.20X5 - 0.93X6 + 2.64X7 - 1.07X1X2 + 1.0IX1 X3 + 1.05X2X6 + 0.45X22 - 0.64X42 + 1.29X4X6 - 0.97X4X7 - 1.28X5X6 + 1.53X5X7 + 1.39X6X7(R2=0.65), and EVR(Y4) : 3.24-0.21X3-0.20X4 -0.24X5+0.67X6+0.26X4X7 (R2=0.55), where EPD : encapsulated pressure drop, VPD : unencapsulated pressure drop, TVR ; tip ventilation rate, and En : envelope ventilation rate. All variables in the model are significant at the 0.05 level.

• Journal of dental hygiene science
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• v.24 no.3
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• pp.134-145
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• 2024

Background: Dental hygienists are crucial in managing infection control within dental clinical settings. This study focused on examining the pre-treatment infection control practices (PT-PRF_IC) of Korean dental hygienists in the context of coronavirus disease (COVID-19) and identifying factors influencing their implementation levels. Methods: An online, self-administered survey was conducted with 263 dental hygienists working in dental hospitals or clinics. The survey explored various aspects such as the experience with infection control education (Edu_IC), PT-PRF_IC, and the types of surface disinfectants used. Additionally, data from previous studies on the knowledge level of COVID-19 (KNW_CO), infection control awareness level (AWR_IC), infection control performance level (PRF_IC), and infection control organizational factor (OFW_IC) were utilized. Statistical analyses included t-tests, one-way ANOVA, chi-square tests, Pearson correlation, and multiple linear regression. Results: The study identified variations in PT-PRF_IC based on the number of dental hygienists within an organization. Differences in Edu_IC were observed concerning age, number of years worked, and monthly pay. The OFW_IC had the most substantial impact on PT-PRF_IC, followed by PRF_IC, and AWR_IC. Conclusion: To improve compliance with PT-PRF_IC, it is essential to consider a combination of factors including OFW_IC, PRF_IC, and AWR_IC. Strengthening organizational factors and awareness can enhance infection control practices and prevent COVID-19 transmission during dental care.

• Clean Technology
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• v.28 no.1
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• pp.79-93
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• 2022

In this study, an electronics industrial wastewater activated sludge model (e-ASM) to be used as a Water Digital Twin was calibrated based on real high-tech electronics industrial wastewater treatment measurements from lab-scale and pilot-scale reactors, and examined for its treatment performance, effluent quality prediction, and optimal process selection. For specialized modeling of a high-tech electronics industrial wastewater treatment system, the kinetic parameters of the e-ASM were identified by a sensitivity analysis and calibrated by the multiple response surface method (MRS). The calibrated e-ASM showed a high compatibility of more than 90% with the experimental data from the lab-scale and pilot-scale processes. Four electronics industrial wastewater treatment processes-MLE, A2/O, 4-stage MLE-MBR, and Bardenpo-MBR-were implemented with the proposed Water Digital Twin to compare their removal efficiencies according to various electronics industrial wastewater characteristics. Bardenpo-MBR stably removed more than 90% of the chemical oxygen demand (COD) and showed the highest nitrogen removal efficiency. Furthermore, a high concentration of 1,800 mg L^-1 T MAH influent could be 98% removed when the HRT of the Bardenpho-MBR process was more than 3 days. Hence, it is expected that the e-ASM in this study can be used as a Water Digital Twin platform with high compatibility in a variety of situations, including plant optimization, Water AI, and the selection of best available technology (BAT) for a sustainable high-tech electronics industry.

• Journal of Life Science
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• v.34 no.6
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• pp.418-425
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• 2024

Solid tumors are heterogeneous populations of multiple cell types. While the majority of the cells that comprise cancer are unable to divide, cancer stem cells have self-renewal and differentiation properties. Normal stem cell pathways that control self-renewal are overactivated in cancer stem cells, making cancer stem cells important for cancer cell expansion and progression. Dick first proposed the definition of cancer stem cells in acute myeloid leukemia, according to which cancer stem cells can be classified based on the expression of cell surface markers. Cancer stem cells maintain their potential in the tumor microenvironment. Multiple cell types in the tumor microenvironment maintain quiescent cancer stem cells and serve as regulators of cancer growth. Since current cancer treatments target proliferative cells, quiescent state cancer stem cells that are resistant to treatment increase the risk of recurrence or metastasis. Various signals of the tumor microenvironment induce changes to become a tumor-supportive environment by remodeling the vasculature and extracellular matrix. To effectively treat cancer, cancer stem cells and the tumor microenvironment must be targeted. Therefore, it is important to understand how the tumor microenvironment induces reprogramming of the immune response to promote cancer growth, immune resistance, and metastasis. In this review, we discuss the cellular and molecular mechanisms that can enhance immunosuppression in the tumor microenvironment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.301-309
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• 2016

To facilitate the effective use of butter clam shell as a natural calcium resource, we determined the optimal conditions for calcium lactate (BCCL) preparation with high solubility using response surface methodology (RSM). The polynomial models developed by RSM for pH, solubility and yield were highly effective in describing the relationships between factors (P<0.05). Increased molar ratios of calcined powder (BCCP) from butter clam shell led to reduced solubility, yield, color values and overall quality. The critical values of multiple response optimization to independent variables were 1.75 M and 0.94 M for lactic acid and BCCP, respectively. The actual values (pH 7.23, 97.42% for solubility and 423.22% for yield) under optimization conditions were similar to the predicted values. White indices of BCCLs were in the range of 86.70–90.86. Therefore, organic acid treatment improved color value. The buffering capacity of BCCLs was strong, at pH 2.82 to 3.80, upon the addition of less than 2 mL of 1 N HCl. The calcium content and solubility of BCCLs were 6.2–16.7 g/100 g and 93.6-98.5%, respectively. Fourier transform analysis of infrared spectroscopy data identified BCCL as calcium lactate pentahydrate, and the analysis of microstructure by field emission scanning electron microscopy revealed an irregular form.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.321-327
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• 2015

The optimal condition for preparation of powdered calcium acetate (LCCA) which has high solubility, from calcined powder (LCCP) of the littleneck clam shell by response surface methodology (RSM) was examined. Increased molar ratio of LCCP led to reduced solubility, yield, color values, and overall quality. The critical values of multiple response optimization of independent variables were 2.57 M of acetic acid and 1.57 M of LCCP. The actual values (pH 7.0, 96.1% for solubility, and 220.9% for yield) under the optimized condition were similar to the predicted values. LCCA showed strong buffering capacity between pH 4.89 and 4.92 on addition of ~2 mL of 1 N HCl. The calcium content and solubility of LCCA were 21.9-23.0 g/100 g and 96.1-100.1%, respectively. The FT-IR and XRD patterns of LCCA were identified as calcium acetate monohydrate, and FESEM images revealed an irregular and rod-like microstructure.

• Translational and Clinical Pharmacology
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• v.26 no.4
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• pp.160-165
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• 2018

Indobufen ($Ibustrin^{(R)}$), a reversible inhibitor of platelet aggregation, exists in two enantiomeric forms in 1:1 ratio. Here, we characterized the anti-platelet effect of S- and R-indobufen using response surface modeling using $NONMEM^{(R)}$ and predicted the therapeutic doses exerting the maximal efficacy of each enantioselective S- and R-indobufen formulation. S- and R-indobufen were added individually or together to 24 plasma samples from drug-naïve healthy subjects, generating 892 samples containing randomly selected concentrations of the drugs of 0-128 mg/L. Collagen-induced platelet aggregation in platelet-rich plasma was determined using a Chrono-log Lumi-Aggregometer. Inhibitory sigmoid $I_{max}$ model adequately described the anti-platelet effect. The S-form was more potent, whereas the R-form showed less inter-individual variation. No significant interaction was observed between the two enantiomers. The anti-platelet effect of multiple treatments with 200 mg indobufen twice daily doses was predicted in the simulation study, and the effect of S- or R-indobufen alone at various doses was predicted to define optimal dosing regimen for each enantiomer. Simulation study predicted that 200 mg twice daily administration of S-indobufen alone will produce more treatment effect than S-and R-mixture formulation. S-indobufen produced treatment effect at lower concentration than R-indobufen. However, inter-individual variation of the pharmacodynamic response was smaller in R-indobufen. The present study suggests the optimal doses of R-and S-enantioselective indobufen formulations in terms of treatment efficacy for patients with thromboembolic problems. The proposed methodology in this study can be applied to the develop novel enantio-selective drugs more efficiently.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.102-110
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• 2022

This study was conducted to optimize the processing process for the oyster Crassostrea gigas gratin with cream sauce (OG-CS). The optimum concentration of added milk for oyster extract with milk (OE-M) was 35.0% based on the frozen-boiled oyster (F-BO), as suggested by the results of sensory evaluation. Response surface methodology was performed with whipping cream (WC)/[OE-M+mixed powder (garlic powder:onion powder=1:1) (MP)] (X₁) and OE-M/MP (X₂) as independent variables and viscosity (Y₁), amino acid nitrogen (Y₂), and overall acceptance for sensory evaluation (Y₃) as dependent variables. The optimal proportions were 74.55% of WC, 20.25% of OE-M, and 5.2% of MP, and the predicted multiple response optimal values for the dependent variables were 3,735.6 cP of Y₁, 197.0 mg/100 g of Y₂, and 6.2 score of Y₃. Under optimal conditions, the experimental values for Y₁, Y₂, and Y₃ were 3,711.9±30.0 cP, 198.1±1.9 mg/100 g, and 6.3±0.5 score, respectively, which were not significantly different from the predicted values (P>0.05). Further, the results of sensory evaluation suggested that the optimum concentration of macaroni:cheese (1:2) to be 46.2% based on the F-BO. The OG-CS prepared under these optimal conditions was superior to the commercial seafood gratin in overall acceptance.