• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.12-17
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• 2019

Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in fresh-cut salads available from the market were determined by gas chromatography-mass spectrometry (GC-MS). The target compounds in 3 g of acidified homogenates were extracted with 20 mL of methyl t-butyl ether (MTBE). The extract was concentrated to 1 mL and heated for 1 h at $55^{\circ}C$. The analytes were separated using a DB-1701 column and detected with a mass spectrometer. The method detection limit was approximately $6{\mu}g/kg$, and both analytical accuracy and precision were found to be satisfactory. The linearity of the calibration curves expressed as the coefficients of determination was >0.996. The analysis of seven samples using the established method showed that the four samples contained considerable amounts of analytes ($25.4-31.2{\mu}g/kg$ of DCAA and $18.8-46.1{\mu}g/kg$ of TCAA). These results raised a concern about the impact of fresh-cut salad consumption on human health.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.4
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• pp.217-226
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• 2019

Background: We aimed to assess the dose needed to achieve the propofol effect-site concentration using target-controlled infusion in intellectually disabled patients and to detail the most effective method for achieving a safe level of consciousness without hemodynamic changes as well as detail any resulting adverse effects. Methods: We performed a retrospective review of sedation service records of 138 intellectually disabled patients (51, mental retardation; 36, autism; 30, brain lesion, 12 genetic diseases, 9 dementia) aged over 15 years and weighing over 30 kg. These patients had received propofol via target-controlled infusion in the special care dental clinic of Seoul National University Dental Hospital from May 2008 to September 2018 for restorative treatment (112), minor surgery (13), prosthodontics (7), periodontics treatment (5), and implant (1). Results: For all groups, the duration of dental treatments was $43{\pm}18$ minutes, total sedation time was $73{\pm}23$ minutes, and total BIS values was $57{\pm}12$. The propofol maintenance dosage values for each group were: mental retardation, $3{\pm}0.5(2-4){\mu}g/ml$; autism, $3.1{\pm}0.7(2-5){\mu}g/ml;$; brain lesion, $2.8{\pm}0.7(1.5-5){\mu}g/ml;$; genetic disease, $2.9{\pm}0.9(1-4){\mu}g/ml;$ and dementia $2.3{\pm}0.7(1-3.4){\mu}g/ml;$. Conclusions: The dementia group needed a lower dosage to reach a safe, effective propofol effect-site concentration than the other groups. Since there were no complications, deep sedation is a great alternative to general anesthesia for dental treatment of intellectually disabled patients.

• Journal of Korean Society on Water Environment
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• v.35 no.2
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• pp.123-130
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• 2019

Ethylenediaminetetraacetic acid-modified bentonite (EMB) was used for adsorption of zinc ion (Zn) from aqueous solution, compared with unmodified bentonite (UB). Parameters such as dose (0.750 ~ 3.125 g/L), mixing intensity (10 ~ 150 rpm), contact time (0.17 ~ 30 min), pH (2 ~ 7), and temperature (298 ~ 338 K), were studied. Zn removal efficiency for EMB was 20 ~ 30 % higher, than that for UB, in all experiments. Thermodynamic studies demonstrated that adsorption process was spontaneous with Gibb's free energy (${\Delta}G$) values, ranging between -5.211 and -7.175 kJ/mol for EMB, and -0.984 and -2.059 kJ/mol for UB, and endothermic with enthalpy (${\Delta}H$) value of 9.418 kJ/mol for EMB and 7.022 kJ/mol for UB. Adsorption kinetics was found to follow the pseudo-second order kinetics model, and its rate constant was 3.41 for EMB and $2.00g/mg{\cdot}min$ for UB. Adsorption equilibrium data for EMB were best represented by the Langmuir adsorption isotherm, and calculated maximum adsorption capacity was 2.768 mg/g. It was found that the best conditions for Zn removal of EMB within the range of operation used, were 3.125 g/L dose, 90 rpm intensity, 10 min contact time, pH 4, and 338 K. Therefore, EMB has good potential for adsorption of Zn.

• Electronics and Telecommunications Trends
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• v.34 no.5
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• pp.58-70
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• 2019

In this paper, we present the R&D status of ETRI's Trusted Reality (TR) project and its core technologies. ETRI's TR project focuses on the next-generation paradigm of smart phones, ETRI-TR Smart Glasses, which aims to provide the same features as those of smart phones without the involvement of any handheld device. Furthermore, they are characterized by additional features enabled by trustworthy VR/AR/MR/XR, such as privacy masking/unmasking, distributed structure of thin-client computing/networking among TR-Glasses, TR-LocalEdge, and TR-RemoteEdge, with novel see-through eyes-direct communication between IoT real/virtual objects and human eyes. Based on these core technologies of the ETRI's TR project, the human-held ETRI-TR Smart Glasses is expected to aid in the realization of XR vision with particularly more XR's safe_privacy on social life in the near future.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.429-434
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• 2019

A lateral flow immunoassay platform utilizing antibody functionalized water soluble CdSe/ZnS semiconductor quantum dots (QDs) was developed for the analysis of human serum amyloid A-1 (hSAA1) in a buffer solution. hSAA1 was chosen as a target protein because it is regarded as a potential biomarker associated with early diagnosis and prognosis in patients of lung cancer. The immunoassay strip on a nitrocellulose membrane was fabricated by spraying two lines composed of a test line with a monoclonal antibody against hSAA1 (10G1) (anti hSAA1) and a control line of anti-chicken IgY. While the CdSe/ZnS QDs synthesized in an organic phase were transferred to a water phase by ligand exchange using carboxylic acid modified alkane thiol. The QDs was then conjugated to monoclonal antibody against hSAA1 (14F8) [anti hSAA1 (14F8)] and used as a fluorescent detection probe. The sequential lateral flow of hSAA1 in different concentration and QDs-anti hSAA1 (14F8) complex allowed to form the surface sandwich complex of anti hSAA1 (10G1)/hSAA1/QD-anti hSAA1 (14F8), which was then analyzed using fluorescence microscope. A 100 nM concentration of hSAA1 protein can be detected by naked eyes under an optimized lateral flow buffer condition with a sensing time of 5 mins.

• Earthquakes and Structures
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• v.16 no.3
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• pp.279-293
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• 2019

The overall seismic performance of existing pre 1960-70s reinforced concrete (RC) structures is significantly affected by the inadequate length of columns' lap-spliced reinforcement. Due to this crucial structural deficiency, the cyclic response is dominated by premature bond - slip failure, strength and stiffness degradation, poor energy dissipation capacity and low ductility. Recent earthquakes worldwide highlighted the importance of improving the load transfer mechanism between lap-spliced bars, while it was clearly demonstrated that the failure of lap splices may result in a devastating effect on structural integrity. Extensive experimental and analytical research was carried out herein, to evaluate the effectiveness and reliability of strengthening techniques applied to RC columns with lap-spliced reinforcement and also accurately predict the columns' response during an earthquake. Ten large scale cantilever column subassemblages, representative of columns found in existing pre 1970s RC structures, were constructed and strengthened by steel or RC jacketing. The enhanced specimens were imposed to earthquake-type loading and their lateral response was evaluated with respect to the hysteresis of two original and two control subassemblages. The main variables examined were the lap splice length, the steel jacket width and the amount of additional confinement offered by the jackets. Moreover, an analytical formulation proposed by Tsonos (2007a, 2019) was modified appropriately and applied to the lap splice region, to calculate shear stress developed in the concrete and predict if yielding of reinforcement is achieved. The accuracy of the analytical method was checked against experimental results from both the literature and the experimental work included herein.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.563-572
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• 2019

This study was conducted to investigate the effects of school stress and resilience on school children's quality of life. The participants for this study were 266 children of 4, 5, and 6 grades at two elementary schools in G Metropolitan City. Data were collected from September to October, 2019. The participants were assessed for academic stress, resilience, quality of life, and analyzed using descriptive statistics, t-tests, ANOVA, Pearson correlation coefficient, and multiple regression analysis. As a result, factors affecting the quality of life of school-age children were academic stress (β= -.29, p<.001), extracurricular academic stress (β= -.19, p= .004), and resilience (β= .19, p<.001), this variable explained 31.2% of the quality of life of school-age children. The lower the academic stress and the higher the resilience, the higher the quality of life. Therefore, in order to improve the quality of life of school-age children, providers need to develop intervention programs that take these factors into account.

• Molecules and Cells
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• v.43 no.2
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• pp.182-187
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• 2020

When cells are stimulated by growth factors, they make a critical choice in early G₁ phase: proceed forward to S phase, remain in G₁, or revert to G₀ phase. Once the critical decision is made, cells execute a fixed program independently of extracellular signals. The specific stage at which the critical decision is made is called the restriction point or R-point. The existence of the R-point raises a major question: what is the nature of the molecular machinery that decides whether or not a cell in G₁ will continue to advance through the cell cycle or exit from the cell cycle? The R-point program is perturbed in nearly all cancer cells. Therefore, exploring the nature of the R-point decision-making machinery will provide insight into how cells consult extracellular signals and intracellular status to make an appropriate R-point decision, as well into the development of cancers. Recent studies have shown that expression of a number of immediate early genes is associated with the R-point decision, and that the decision-making program constitutes an oncogene surveillance mechanism. In this review, we briefly summarize recent findings regarding the mechanisms underlying the context-dependent R-point decision.

• Journal of Ceramic Processing Research
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• v.20 no.4
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• pp.411-417
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• 2019

Graphene doped zinc oxide nanoparticles (G-ZnO) were prepared using modified hummer's technique together with the ultrasonic method and characterized by field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), fourier-transform infrared spectroscopy (FTIR) and high-resolution transmission electron microscopy (HRTEM). Different samples of epoxy resin nanocomposites reinforced with G-ZnO nanoparticles were prepared and were marked as F1 (without adding nanoparticles), F2 (1% w/w G-ZnO), and F3 (2% w/w G-ZnO) in combination of ≈ 56:18:18:8w/w% with epoxy resin/hardener, ammonium polyphosphate, boric acid, and Chitosan. The peak heat release rate (PHRR) of the epoxy nanocomposites was observed to decrease dramatically with the increasing G-ZnO nanoparticles. However, the LOI values increased significantly with the increase in wt % of G-ZnO nanoparticles. From the UL-94V data, it was confirmed that the F2 and F3 samples passed the flame test and were rated as V-0. The results obtained in the present work clearly revealed that the synthesized samples can be used as efficient materials in fire-retardant coating technology.

• Nutrition Research and Practice
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• v.13 no.4
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• pp.302-309
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• 2019

BACKGOURND/OBJECTIVES: Vascular inflammation is an important feature in the atherosclerotic process. Recent studies report that leaves and branches of Carpinus turczaninowii (C. turczaninowii) have antioxidant capacity and exert anti-inflammatory effects. However, no study has reported the regulatory effect of C. turczaninowii extract on the arterial inflammatory response. This study therefore investigated modulation of the arterial inflammatory response after exposure to C. turczaninowii extract, using human aortic vascular smooth muscle cells (HAoSMCs). MATERIALS/METHODS: Scavenging activity of free radicals, total phenolic content (TPC), cell viability, mRNA expressions, and secreted levels of cytokines were measured in LPS-stimulated (10 ng/mL) HAoSMCs treated with the C. turczaninowii extract. RESULTS: C. turczaninowii extract contains high amounts of TPC ($225.6{\pm}21.0mg$ of gallic acid equivalents/g of the extract), as well as exerts time-and dose-dependent increases in strongly scavenged free radicals (average $14.8{\pm}1.97{\mu}g/mL$ $IC_{50}$ at 40 min). Cell viabilities after exposure to the extracts (1 and $10{\mu}g/mL$) were similar to the viability of non-treated cells. Cytokine mRNA expressions were significantly suppressed by the extracts (1 and $10{\mu}g/mL$) at 6 hours (h) after exposure. Interleukin-6 secretion was dose-dependently suppressed 2 h after incubation with the extract, at $1-10{\mu}g/mL$ in non-stimulated cells, and at 5 and $10{\mu}g/mL$ in LPS-stimulated cells. Similar patterns were also observed at 24 h after incubation with the extract (at $1-10{\mu}g/mL$ in non-stimulated cells, and at $10{\mu}g/mL$ in the LPS-stimulated cells). Soluble intracellular vascular adhesion molecules (sICAM-1) secreted from non-stimulated cells and LPS-stimulated cells were similarly suppressed in a dose-dependent manner after 24 h exposure to the extracts, but not after 2 h. In addition, sICAM-1 concentration after 24 h treatment was positively related to IL-6 levels after 2 h and 24 h exposure (r = 0.418, P = 0.003, and r = 0.524, P < 0.001, respectively). CONCLUSIONS: This study demonstrates that C. turczaninowii modulates the arterial inflammatory response, and indicates the potential to be applied as a therapeutic use for atherosclerosis.