• Journal of the Korean Dietetic Association
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• v.25 no.1
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• pp.30-43
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• 2019

This study compared the predictive models for the growth kinetics of Staphylococcus aureus in ham rice balls. In addition, a semi-quantitative risk assessment of S. aureus on ham rice balls was conducted using FDA-iRISK 4.0. The rice was rounded with chopped ham, which was mixed with mayonnaise (SHM), soy sauce (SHS), or gochujang (SHG), and was contaminated artificially with approximately $2.5{\log}\;CFU{\cdot}g^{-1}$ of S. aureus. The inoculated rice balls were then stored at $7^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$, and the number of viable S. aureus was counted. The lag phases duration (LPD) and maximum specific growth rate (SGR) were calculated using a Baranyi model as a primary model. The growth parameters were analyzed using the polynomial equation as a function of temperature. The LPD values of S. aureus decreased with increasing temperature in SHS and SHG. On the other hand, those in SHM did not show any trend with increasing temperature. The SGR positively correlated with temperature. Equations for LPD and SGR were developed and validated using $R^2$ values, which ranged from 0.9929 to 0.9999. In addition, the total DALYs (disability adjusted life years) per year in the ham rice balls with soy sauce and gochujang was greater than mayonnaise. These results could be used to calculate the expected number of illnesses, and set the hazard management method taking the DALY value for public health into account.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.2
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• pp.171-180
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• 2019

Purpose: Malnutrition may influence neurocognitive development in children by directly affecting the brain structural development, or indirectly by affecting the children's cognition experience. Malnutrition alters the cell numbers, cell migration, synaptogenesis, and neurotransmission due to inadequate availability of necessary micronutrients to support cell growth. We aimed to analyze neurocognitive development in infants with malnutrition and its association with long chain polyunsaturated fatty acids (LC-PUFA), micronutrients levels and magnetic resonance spectroscopy (MRS) findings. Methods: The study included two groups; group 1, infants with malnutrition (n=24), group 2; healthy infants (n=21). Peripheral blood was obtained from the participants for studying micronutrients and LC-PUFA levels. The neurocognitive development was analyzed by the use of an Ankara Developmental Screening Inventory test. MRS were performed on all infants. Results: All parameters of neurocognitive development and serum calcium ($9.6{\pm}0.9mg/dL$ vs. $10.4{\pm}0.3mg/dL$, p<0.05) and magnesium ($2.02{\pm}0.27mg/dL$ vs. $2.2{\pm}0.14mg/dL$, p<0.05) levels were noted as being low in infants with marked malnutrition. No difference was found in LC-PUFA levels between healthy and malnourished infants. Thalamic choline/creatine levels were significantly high in infants with malnutrition ($1.33{\pm}0.22$ vs. $1.18{\pm}0.22$, p<0.05). Total neurocognitive development in infants was positively correlated with serum calcium levels (p<0.05, r=0.381). Conclusion: Calcium supplementation may improve neurocognitive development in malnourished infants.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1294-1304
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• 2018

The aims of this research were to examine the effect of heating temperature (65, 75, and $85^{\circ}C$) and $CaCl_2$ concentration level (3, 4, and 5 mM) on the physicochemical properties of ${\beta}$-lactoglobulin (${\beta}$-lg) nanoemulsions (NEs) and to study how the droplet size of NEs affects the bioaccessibility (BA) of coenzyme $Q_{10}$ ($CoQ_{10}$). The droplet size of NEs and BA of $CoQ_{10}$ was assessed by particle size analyzer and UV-Vis spectrophotometer, respectively. An increase in heating temperature and $CaCl_2$ concentration level resulted in a significant (p<0.05) increase in the droplet size of NEs while there were no significant differences in polydispersity index and zeta-potential of NEs. When NEs containing $CoQ_{10}$ were incubated in simulated small intestinal phases, an increase in the droplet size and polydispersity index of NEs was observed. This indicated that NEs were not stable in small intestine and digestion of NEs occurred. As heating temperature and $CaCl_2$ concentration level were decreased, a significant (p<0.05) increase in BA of $CoQ_{10}$ was observed. There was a significant (p<0.05) increase in BA of $CoQ_{10}$ with a decrease in the droplet size of NEs. In conclusion, heating temperature and $CaCl_2$ concentration level were key-parameters affecting the initial droplet size of NEs and BA of $CoQ_{10}$ was negatively correlated with initial droplet size of NEs.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1144-1154
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• 2018

Both the calcium and collagen in bone powder are hard to be absorbed by the body. Although enzymatic hydrolysis by protease increased the bio-availability of bone powder, it was a meaningful try to further increase $Ca^{2+}$ release, oligopeptide formation and antioxidant activity of the sheep bone hydrolysate (SBH) by lactic acid bacteria (LAB) fermentation. Lactobacillus helveticus was selected as the starter for its highest protease-producing ability among 5 tested LAB strains. The content of liberated $Ca^{2+}$ was measured as the responsive value in the response surface methodology (RSM) for optimizing the fermenting parameters. When SBH (adjusted to pH 6.1) supplemented with 1.0% glucose was inoculated 3.0% L. helveticus and incubated for 29.4 h at $36^{\circ}C$, $Ca^{2+}$ content in the fermented SBH significantly increased (p<0.01), and so did the degree of hydrolysis and the obtaining rate of oligopeptide. The viable counts of L. helveticus reached to $1.1{\times}10^{10}CFU/mL$. Results of Pearson correlation analysis demonstrated that LAB viable counts, $Ca^{2+}$ levels, obtaining rates of oligopeptide and the yield of polypeptide were positively correlated with each other (p<0.01). The abilities of SBH to scavenge the free radicals of DPPH, OH and ABTS were also markedly enhanced after fermentation. In conclusion, L. helveticus fermentation can further boost the release of free $Ca^{2+}$ and oligopeptide, enhance the antioxidant ability of SBH. The L. helveticus fermented SBH can be developed as a novel functional dietary supplement product.

• Journal of Gastric Cancer
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• v.18 no.4
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• pp.356-367
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• 2018

Purpose: Kallikrein (KLK) proteases are hormone-like signaling molecules with critical functions in different cancers. This study investigated the expression of KLK6 in gastric cancer and its potential role in the growth, migration, and invasion of gastric cancer cells. Materials and Methods: In this study, we compared protein levels of KLK6, vascular endothelial growth factor (VEGF), and matrix metallopeptidase (MMP) 9 in normal gastric epithelial and gastric cancer cell lines by western blot. Fluorescence-activated cell sorting was employed to sort 2 clones of SGC-7901 cells with distinct KLK6 expression, namely, KLK6-high ($KLK6^{high}$) and KLK6-low ($KLK6^{low}$), which were then expanded. Lastly, immunohistochemical analysis was performed to investigate KLK6 expression in gastric cancer patients. Results: The expression levels of KLK6, VEGF, and MMP 9, were significantly higher in the gastric cancer cell lines SGC-7901, BGC-823, MKN-28, and MGC-803 than in the normal gastric epithelial cell line GES-1. Compared to $KLK6^{low}$ cells, $KLK6^{high}$ cells showed enhanced viability, colony-forming ability, migration, and invasion potential in vitro. Importantly, immunohistochemical analysis of a human gastric cancer tissue cohort revealed that the staining for KLK6, VEGF, and MMP9 was markedly stronger in the cancerous tissues than in the adjacent normal tissues. KLK6 expression also correlated with that of VEGF and MMP9 expression, as well as several key clinicopathological parameters. Conclusions: Together, these results suggest an important role for KLK6 in human gastric cancer progression.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.4
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• pp.369-376
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• 2019

Purpose: The aim of this study was to evaluate the clinical significance of inflammatory biomarkers in acute infectious diarrhea among children. Methods: Clinical parameters including fever, bacterial and viral etiology based on stool culture and multiplex polymerase chain reaction, and nine biomarkers including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and leukocytes in blood and calprotectin, lactoferrin, myeloperoxidase, polymorphonuclear elastase, leukocytes, and occult blood in feces were evaluated in children who were hospitalized due to acute diarrhea without underlying disease. Results: A total of 62 patients were included. Among these patients, 33 had fever, 18 showed bacterial infections, and 40 patients were infected with 43 viruses. Of all the biomarkers, CRP was significantly correlated with fever (p<0.001). CRP, ESR, calprotectin, lactoferrin, myeloperoxidase, fecal leukocytes, and occult blood were significantly associated with infection with bacterial pathogens (p<0.001, p=0.04, p=0.03, p=0.003, p=0.02, p=0.03, p=0.002, respectively). The combination of CRP and fecal lactoferrin at their best cut-off values (13.7 mg/L and $22.8{\mu}g/mL$, respectively) yielded a sensitivity of 72.2%, and a specificity of 95.5% for bacterial etiology compared with their individual use. Conclusion: Blood CRP is a useful diagnostic marker for both fever and bacterial etiology in acute pediatric diarrhea. The combination of CRP and fecal lactoferrin yields better diagnostic capability for bacterial etiology than their use alone for acute diarrhea in children without underlying gastrointestinal disease.

• The Korean Journal of Pain
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• v.32 no.4
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• pp.271-279
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• 2019

Background: We utilized diffusion tensor imaging (DTI) to evaluate the cerebral white matter changes that are associated with phantom limb pain in patients with unilateral arm amputation. It was anticipated that this would complement previous research in which we had shown that changes in cerebral blood volume were associated with the cerebral pain network. Methods: Ten patients with phantom limb pain due to unilateral arm amputation and sixteen healthy age-matched controls were enrolled. The intensity of phantom limb pain was measured by the visual analogue scale (VAS) and depressive mood was assessed by the Hamilton depression rating scale. Diffusion tensor-derived parameters, including fractional anisotropy, mean diffusivity, axial diffusivity (AD), and radial diffusivity (RD), were computed from the DTI. Results: Compared with controls, the cases had alterations in the cerebral white matter as a consequence of phantom limb pain, manifesting a higher AD of white matter in both hemispheres symmetrically after adjusting for individual depressive moods. In addition, there were associations between the RD of white matter and VAS scores primarily in the hemispheres related to the missing hand and in the corpus callosum. Conclusions: The phantom limb pain after unilateral arm amputation induced plasticity in the white matter. We conclude that loss of white matter integrity, particularly in the hemisphere connected with the missing hand, is significantly correlated with phantom limb pain.

• Journal of Korean Neurosurgical Society
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• v.62 no.6
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• pp.712-722
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• 2019

Objective : Although magnetic resonance guided focused ultrasound (MRgFUS) has been used as minimally invasive and effective neurosurgical treatment, it exhibits some limitations, mainly related to acoustic properties of the skull barrier. This study was undertaken to identify skull characteristics that contribute to optimal ultrasonic energy transmission for MRgFUS procedures. Methods : For ex vivo skull experiments, various acoustic fields were measured under different conditions, using five non-embalmed cadaver skulls. For clinical skull analyses, brain computed tomography data of 46 patients who underwent MRgFUS ablations (18 unilateral thalamotomy, nine unilateral pallidotomy, and 19 bilateral capsulotomy) were retrospectively reviewed. Patients' skull factors and sonication parameters were comparatively analyzed with respect to the cadaveric skulls. Results : Skull experiments identified three important factors related skull penetration of ultrasound, including skull density ratio (SDR), skull volume, and incidence angle of the acoustic rays against the skull surface. In clinical results, SDR and skull volume correlated with maximal temperature (Tmax) and energy requirement to achieve Tmax (p<0.05). In addition, considering the incidence angle determined by brain target location, less energy was required to reach Tmax in the central, rather than lateral targets particularly when compared between thalamotomy and capsulotomy (p<0.05). Conclusion : This study reconfirmed previously identified skull factors, including SDR and skull volume, for successful MRgFUS; it identified an additional factor, incidence angle of acoustic rays against the skull surface. To guarantee successful transcranial MRgFUS treatment without suffering these various skull issues, further technical improvements are required.

• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.98-103
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• 2019

Optical filters to control light wavelength of displays or cameras are fabricated by multi-layer stacking process of low and high index thin films. The process of multi-layer stacking of thin films has received much attention as an optimal process for effective manufacturing in the optical filter industry. However, multi-layer processing has disadvantages of complicated thin film process, and difficulty of precise control of film morphology and material selection, all of which are critical for transmittance and coloring effect on filters. In this study, the composite $TiO_2$, which can be used to control of UV absorption, coated on nano hollow silica sol, was synthesized as a coating material for optical filters. Furthermore, systematic analysis of the process parameters during the chemical reaction, and of the structural properties of the coating solutions was performed using SEM, TEM, XRD and photo spectrometry. From the structural analysis, we found that the 85 nm nano hollow silica with 2.5 nm $TiO_2$ shell formation was successfully synthesized at proper pH control and titanium butoxide content. Photo luminescence characteristics, excited by UV irradiation, show that stable absorption of 350 nm-light, correlated with a 3.54 eV band gap, existed for the $TiO_2$ shell-nano hollow silica reacted with 8.8 mole titanium butoxide solution. Transmittance observed on substrate of the $TiO_2$ shell-nano hollow silica showed effective absorption of 200-300 nm UV light without deterioration of visible light transparency.

• Journal of Korean Society on Water Environment
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• v.35 no.1
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• pp.19-27
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• 2019

The purpose of this study is to evaluate the water quality and phytoplankton community in Bukhan River which account for 44.4 % of the total inflow into Lake Paldang, using multivariate statistical techniques (i.e., correlation analysis, principal component analysis (PCA)/factor analysis (FA)). Water samples were collected from March to November 2015 and the following parameters measured; water temperature, pH, DO, EC, SS, BOD, Chl-a, COD, TN, $NO_3-N$, $NH_3-N$, TP, DTP, $PO_4-P$, and phytoplankton community. The water quality of the main stream and the tributaries were not significantly different apart from the relatively high concentration of BOD, COD and nutrients recorded in MH. The highest cell density of Stephanodiscus hantzschii and Merismopedia glauca dominated phytoplankton was observed in PD. Based on the correlation analysis, total phytoplankton and cyanophyceae were highly correlated with BOD, COD and nutrients. PCA/FA resulted in four main factors accounting for 82.240 % of the total variance in the water quality dataset. The group of component 1 (TN, DTN, DO, $NO_3-N$, water temperature) and component 2 ($PO_4-P$, T-P, DTP, SS) were classified as nutrient element factor whereas component 3 (Chl-a, COD, BOD, $NH_3-N$, pH) was related to organic substances. Hence, the identification of the main potential environmental pollution factors in Bukhan River will help policy makers make better and more informed decisions on how to improve the water quality.