• Child Health Nursing Research
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• v.19 no.1
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• pp.29-38
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• 2013

Purpose: This study was done to develop a cell phone addiction scale for Korean parents of young children, and to evaluate the reliability and validity of the developed scale. Methods: The scale was developed through construction of a conceptual framework, generation of initial items, verification of content validity, selection of secondary items, preliminary study, and extraction of final items. Participants were 465 parents and 178 children. Data were analyzed using item analysis, factor analysis, criterion related validity, internal consistency, and split-half reliability. Results: Twenty items were categorized into three factors explaining 60.3% of total variance. Factors were named as withdrawal - 4 items, loss of control - 9 items, and persistence - 7 items. Scores for the scale were significantly correlated with self-control, impulsiveness, cell phone use, and cell phone addiction of children as measured by a scale for Korean children. Cronbach's alpha coefficient for the 20 items was .94, and Guttman coefficient was .87. Scale scores identified children as high risk users, at risk users, or average users by standard scores. Conclusion: The results suggest that the cell phone addiction scale for Korean parents is a reliable and valid instrument to measure cell phone addiction in young children.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.356-362
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• 2010

When pine (Pinus densiflora) needles were fractionated into cold water (PD-CW), hot water (PD-HW) and methanol extract (PD-M), PD-M showed potent simulating activity (1.19-fold of the saline control) for proliferation of bone marrow cells mediated by Peyer's patch cells in vitro. MeOH extracts were prepared by homogenization, stirring or reflux to identify the method of methanol extraction, and MeOH extract by reflux method showed significantly highest intestinal immune system modulating activity (1.30-fold) in vitro. The intestinal immune system modulating effect of orally administered PD-M fractionated from pine needles also were studied in mice. Analyzing intestinal immune system modulating activity mediated Peyer's patch cells from C3H/He mice which had been fed with PD-M at different doses for 7 days, 1.0 g/kg of BW/day indicated that the bone marrow cells had proliferated (3.65-fold of 3% EtOH administered group). In addition, the amounts of IL-6 in the culture supernatant of Peyer's patch cells at 1.0 g/kg of BW/day were increased (1.13-fold) whereas the production of GM-CSF was not dose dependent. These results indicate that oral administration of PD-M enhances the secretion of hematopoietic growth factors such as GM-CSF and IL-6 from Peyer's patch cells, and these cytokines also act on modulator of bone marrow cell proliferation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.7.1-7.9
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• 2017

Background: This study was to investigate the effect of biomechanical stimulation on osteoblast differentiation of human periosteal-derived stem cell using the newly developed bioreactor. Methods: Human periosteal-derived stem cells were harvested from the mandible during the extraction of an impacted third molar. Using the new bioreactor, 4% cyclic equibiaxial tension force (0.5 Hz) was applied for 2 and 8 h on the stem cells and cultured for 3, 7, and 14 days on the osteogenic medium. Biochemical changes of the osteoblasts after the biomechanical stimulation were investigated. No treatment group was referred to as control group. Results: Alkaline phosphatase (ALP) activity and ALP messenger RNA (mRNA) expression level were higher in the strain group than those in the control group. The osteocalcin and osteonectin mRNA expressions were higher in the strain group compared to those in the control group on days 7 and 14. The vascular endothelial growth factor (VEGF) mRNA expression was higher in the strain group in comparison to that in the control group. Concentration of alizarin red S corresponding to calcium content was higher in the strain group than in the control group. Conclusions: The study suggests that cyclic tension force could influence the osteoblast differentiation of periosteal-derived stem cells under optimal stimulation condition and the force could be applicable for tissue engineering.

• Journal of Periodontal and Implant Science
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• v.37 no.4
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• pp.743-753
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• 2007

Purpose: The purposes of this study were to compare and quantify the expression of MMP-3, $PGE_2$ and IL-6 in the gingival tissues of patients with $type_2$ diabetes mellitus and healthy adults with chronic periodontitis. Material and methods: Gingival tissue samples were obtained during periodontal surgery or tooth extraction. According to the patient's systemic condition & clinical criteria of gingiva, each gingival sample was devided into three groups. Group 1(n=8) is clinically healthy gingiva without bleeding and no evidence of bone resorption or periodontal pockets, obtained from systemically healthy 8 patients. Group 2(n=8) is inflamed gingiva from patients with chronic periodontitis. Group 3(n=8) is inflamed gingiva from patients with chronic periodontitis associated with type 2 DM. Tissue samples were prepared and analyzed by Westernblotting. The quantification of MMP-3, $PGE_2$ and IL-6 were performed using a densitometer and statistically analyzed by one-way ANOVA followed by Tukey test. Results: 1. The expression levels of MMP-3 were shown highest in group 3 compared to group 1 and 2, and It showed increasing tendency in group 2 and 3. 2. The expressions of $PGE_2$ and IL-6 were shown increasing tendency in group 2 and 3, and It was highest in group 3. 3. As expressions of MMP-3 were increased, $PGE_2$ and IL-6 expressions showed increasing tendency in group 3 than group1 and 2, although there were no proportional relationship. Conclusion: This study demonstrated that the expression levels of MMP-3, $PGE_2$ and IL-6 will be inflammatory markers of periodonta linflamed tissue and DM. It can be assumed that MMP-3 affect to expressions of $PGE_2$ and IL-6 in progression of periodontal inflammation with alveolar bone resorption to type 2 DM.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.61-65
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• 1987

The milk protein portion contains sialic acid which may be used as an index for k-casein. In comparison with non fat dry milk (NFDM) and calcium caseinate, the solubility of NFDM protein isolates at the various pH was inferior. Another consideration for the low solubility relates to the possibility that k-casein may have been extracted or possibly modified by the action of alcohol. The k-casein is the principal stabilizing fraction for casein micelle and any changes which result in its destruction or removal would be expected to have potent results. During solvent treatment, 16.5% of sialic acid was extracted in the first extraction solvent, whereas the second treatment caused only a 4.0% loss, based on sialic acid analysis. A study was conducted on the effect of concentration of methanol on loss of sialic acid. The loss of sialic acid decreased as the concentration of methanol increased to above 62% in both the first and second extracted solvent. It appears that loss of sialic acid is attributed to the water fraction rather than the methanol fraction. The effect of addition of the dried extracted solids on solubility was investigated. Protein solubility of NFDM protein isolates was sharply increased by 10% addition of the extracted solids and, thereafter, decreased. Efforts to restore solubility by feeding-back the extracted material supported the concept that removal of surface k-casein may have been a possible factor.

• Journal of Biomedical Engineering Research
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• v.18 no.3
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• pp.301-306
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• 1997

Surgical removal of hepatic cancerous tissues have been widely performed due to its early detection. However, a patient can not survive if excessive hepatic tissues were removed. Therefore, quantitative evaluation of remaining hepatic function after surgery is a really important factor for surgeon. the currently used ICG Rmax and Lidocaine clearance tests have disadvantages such as tedium, complexity, and inability to estimate remaining hepatic function after surgery. While HEF has advantages such as simplicity, quickness, nonivasiveness, and quantification, its reliability has been doubtful. Thus, the program for calculation of HEF has been developed from serial gamma camera image data. And we compared the reliability of HEF with ICG Rmax and Lidocaine clearance test using 6normal and 18 abnormal rabbits with damaged livers. The correlation coefficient of HEF to ICG Rmax and MEGX was 0.91, 0.94, respectively. I was also found that the HEFs of normal and abnormal hepatic tissues was higher than 100% and lower than 80%, respectively. Thus we confirmed that HEF can be a good indicator distinguishing between abnormal tissues and normal ones. Finally, we could conclude that patients would survive if both the pre-and the post-operative HEF were greater than 60%.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.982-990
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• 2019

The interest of researchers and governments in exploiting tidal energy resources is increasing. Jangjuk strait is a place with high tidal energy density potential and is therefore appropriate for the constructing of a tidal turbine farm. In this study, a numerical approach is presented to evaluate the current flow and power potential in Jangjuk strait with an ADCIRC model. Then, the tidal field characteristics are utilized as input parameters for tidal resource calculation with an in-house program. The 1 MW scale tidal energy converter devices are employed and arranged in 4 layouts to investigate the annual energy yield as well as flow deficit due to the wake ef ect at the surveyed area. The best-performed array generates an annual energy yield up to 12.96 GWh/year (without considering the wake effect); this value is reduced by 0.16 GWh/year when accounting for the energy loss caused by the flow deficit. Moreover, by altering the turbine yaw angle during the flood and ebb tides, the impacts of this factor on the energy extraction are analyzed. This indicates that the turbine array attains the maximum tidal power when the turbine yaw angle is at 346° and 164° (clockwise, to the North) for the spring and neap tide in turns.

• Analytical Science and Technology
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• v.24 no.1
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• pp.1-9
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• 2011

We described an estimation of measurement uncertainty in quantitative analysis of 11-nor-9-carboxy-${\Delta}^9$-tetrahydrocannabinol (THC-COOH), the metabolite of ${\Delta}^9$-tetrahydrocannabinol, in hair samples by using the bead-assisted liquid-liquid extraction and gas chromatography-tandem mass spectrometric (GC-NCI-MS/MS) detection. Traceability of measurement was established through the use of reference materials, calibrated volumetric tubes, volume measuring devices, and measuring instruments. The analytical results were compared and the different contributions to the uncertainty were evaluated. Inter-day variation was performed by using statistical analysis of several indicative factors. Measurement uncertainty associated with the analyte in real forensic hair samples were estimated using QC data. The major factor of contribution to combined standard uncertainty was inter-day repeatability, while those associated with preparation of analytical standard and also sample of weight were insignificant considering the degree of contribution. Relative uncertainty of relative extended standard uncertainty divided into the measured concentration of the analyte was 17% in a hair sample. The uncertainty of result evaluation will be invaluable to improve quality of the analysis.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.118-123
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• 2018

The objective of this study was to develop a sensitive method for the identification and determination of nitrovin in fishery products by using a solid-phase extraction (SPE), as performed with a liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted with a mixture of acetonitrile and water, and were then defatted with acetonitrile saturated hexane, after which further clean-up was accomplished with SPE on the hydrophilic-lipophilic balance (HLB) cartridges. The analytes were subsequently ionized in the positive mode of an electrospray ionization (ESI), and where thereby detected in a process of multiple reaction monitoring (MRM). The linearity (expressed as correlation coefficients) of the matrix calibration curves was > 0.985. The limit of the quantification for the nitrovin was measured at 0.001 mg/kg. The accuracy (expressed as average recovery) was noted between 72.1 and 122%. The precision (expressed as coefficient variation) was noted from 2.9 to 16.9%. According to the CODEX CAC/GL-71 guideline accuracy, precision, linearity, and limit of detection were determined in three matrices (which were flatfish, eel and shrimp). The proposed method was suitable for analyzing the associated nitrovin residues. This application and result can also be a factor to contribute to the non-detection drugs management in fishery products.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.351-355
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• 2002

Volatile compounds of kimchi-flavored steak sauce were isolated using simultaneous steam distillation and solvent extraction methods and identified by matching mass spectrum and retention index (RI) with the reference data. Twenty-three compounds including five aldehydes, four alcohols, four acids, three sulfur-containing compounds, one ketone, and six others were identified, among which the most abundant compound was eugenol. Sulfides such as dimethyl dis- and trisulfides, and acids such as acetic and dodecanoic acids showed strong effects on the kimchi flavor. Aroma extract dilution analysis with three fold dilution factor shown in over the FD value 34 identified 2-butanal, 2-pentylfuran, methyl-2-propenyl disulfide, and 2-furanmethanol. Strong good aroma was detected in the RI range between 1030 and 1357, bad aroma in RI 1561, sweety aroma in RI 2057, clover aroma of eugenol in RI 2122, and rancid flavor in RI 2251.