• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.231-237
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• 2014

This research showed that delphinidin, an anthocyanin present in blueberry, induced apoptosis in MDA-MB-231 breast cancer cells as well as mediated anti-cancer effects in vivo. As a result, growth of cancer cells as assessed by MTT assay decreased in a concentration-dependent manner. Chromatin condensation by DAPI staining significantly increased in a concentration-dependent manner, indicating apoptosis. The level of p53-protein increased while those of anti-apoptotic molecules (Bcl-2, p-$GSK3{\beta}$) decreased in the western blot. Tumor size decreased in cells treated with 10 mg/kg of delphinidin compared with the control group in vivo. Cell apoptosis assessed by TUNEL assay significantly increased, and tumor inhibitory effect was confirmed. Therefore, delphinidin can be developed for cancer preventive medicine due to its growth inhibitory effects and induction of apoptosis in human breast cancer cells.

• Journal of Service Research and Studies
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• v.8 no.4
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• pp.77-88
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• 2018

Collaboration works on R&D project have many characteristics in interoranizational relationships. There are many variables on explaining the their relationships. In the previous study, I chose some relevant variables and some hypotheses. Base on service marketing theories and relationship marketing perspective I suggest 5 hypotheses. Independent variables are fairness and quality, and dependent variable is loyalty. And trust are treated as the intervening variable between the independent variables and dependent variable. To test the research model and some hypothesis empirically, I collected the data using the questionnaire. Sample size was 448, it was enough to analyze statistically. Data were analysed using the SPSS and AMOS. In the previous study, H1($fairness{\rightarrow}trust$), H2($quality{\rightarrow}trust$), H5($trust{\rightarrow}loyalty$) were accepted, but H3 and H4 were rejected. The reason H3($fairness{\rightarrow}loyalty$) and H4($quality{\rightarrow}loyalty$) were not accepted might be attributed to the fact that trust was the mediating variable between fairness and loyalty, quality and loyalty. Specific research methodologies and statistical findings from AMOS were referred in the previous study(Jeong 2018). In this study, I suggested some hypotheses on the mediating role trust between fairness and loyalty and service quality and loyalty. Using the PROCESS-macro, I found that trust was the mediating variable between fairness and loyalty as well as service quality and loyalty. This research is the complementary and extended study from previous research.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.457-467
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• 2022

Electron bombardment to silicate glass during electron probe microanalysis (EPMA) causes outward migration of Na from the excitation volume and subsequent decrease in the measured X-ray count rates of Na. To acquire precise Na₂O content of silicate glass, one should use proper analytical technique to avoid or minimize Na migration effect or should correct for decreases in the measured Na X-ray counts. In this study, we analyzed 8 silicate glass standard samples using automated Time Dependent Intensity (TDI) correction method of Probe for EPMA software that can calculate zero-time intercept by extrapolating X-ray count changes over analysis time. We evaluated an accuracy of TDI correction for Na measurements of silicate glasses with EPMA at 15 kV acceleration voltage and 20 nA probe current electron beam, which is commonly utilized analytical condition for geological samples. Results show that Na loss can be avoided with 20 ㎛-sized large beam (<0.1 nA/㎛²), thus silicate glasses can be analyzed without TDI correction. When the beam size is smaller than 10 ㎛, Na loss results in large relative errors up to -55% of Na₂O values without correction. By applying TDI corrections, we can acquire Na₂O values close to the reference values with relative errors of ~ ±10%. Use of weighted linear-fit can reduce relative errors down to ±6%. Thus, quantitative analysis of silicate glasses with EPMA is required for TDI correction for alkali elements such as Na and K.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.301-306
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• 1990

The Physical and chemical properties or dry acorn starch(DS), detannined acorn starch (DTS) and defatted and detannined acorn starch(Drn) were investigated. Ail acorn starch sample, observed by a scanning electron microscope, showed a hemispherical shape ud its size was about $5{\sim}10{\mu}m$ in diameter. It had a little change on the pasting temperature of DS, DTS and DFTS but peak viscosity of DTS was somewhat higher than that of n. Flow behavior of gelatinized starch pastes showed a pseudoplastic behavior and flow behavior index was lower than unit. The consistency coefficient showed concentraion and temperature dependency. The activation energies of DS, DTS and DFTS were $2.09{\sim}3.58Kcal/g\;{\cdot}\;mol and time dependent characteristic of acorn starch samples showed thixotrpic behavior.

• Korean Journal of Materials Research
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• v.21 no.2
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• pp.78-82
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• 2011

Mono- and few-layer graphenes were grown on Ni thin films by rapid-thermal pulse chemical vapor deposition technique. In the growth steps, the exposure step for 60 s in $H_2$ (a flow rate of 10 sccm (standard cubic centimeters per minute)) atmosphere after graphene growth was specially established to improve the quality of the graphenes. The graphene films grown by exposure alone without $H_2$ showed an intensity ratio of $I_G/I_{2D}$ = 0.47, compared with a value of 0.38 in the films grown by exposure in H2 ambient. The quality of the graphenes can be improved by exposure for 60 s in $H_2$ ambient after the growth of the graphene films. The physical properties of the graphene films were investigated for the graphene films grown on various Ni film thicknesses and on 260-nm thick Ni films annealed at 500 and $700^{\circ}C$. The graphene films grown on 260-nm thick Ni films at $900^{\circ}C$ showed the lowest $I_G/I_{2D}$ ratio, resulting in the fewest layers. The graphene films grown on Ni films annealed at $700^{\circ}C$ for 2 h showed a decrease of the number of layers. The graphene films were dependent on the thickness and the grain size of the Ni films.

• Journal of Pharmaceutical Investigation
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• v.41 no.4
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• pp.205-210
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• 2011

Genistein (GT), a major isoflavone found in soybeans, has a potent antioxidant effect that protects the skin from UV-induced damages and malignant melanoma. In order to enhance the cellular uptake of GT, liposome/Tat complexes were prepared by an electrostatic interaction of anionic liposome (DMPC/DCP, 9:1 in molar ratio) with Tat peptide (0.02 to 0.08 mole), one of the well-known cell penetrating peptide (CPP). As the amount of Tat increased, the size increased but the zeta potential decreased. In vitro release study with dialysis membrane elicited GT release from liposomal preparations in a controlled manner. The addition of Tat increased GT release, especially for the initial period. In the cellular uptake study by incubating B16 melanoma cells with various liposomal preparations containing GT, B16 melanoma cells demonstrated a time-dependent increase of drug accumulation. Compared to the aqueous GT suspension, intracellular uptake was substantially enhanced by anionic liposomal formulation and further increased by the complex formulation. Therefore, liposome/ Tat complex might be a good candidate for facilitating intracellular drug delivery.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.118-119
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• 2013

High power, short wavelength red laser diodes (LDs) have attracted significant interests in a variety of fields due to their advantages in terms of reliability, compactness and cost. The higher brightness for human eyes is required, the shorter wavelength like 630 nm is necessary with higher output power. In this respect, LDs are promising as alternative candidates of gas or dye lasers for such applications due to their small size, high optical/electrical power conversion efficiency, robustness and so on. The crystalline quality of GaInP-AlGaInP multiple quantum wells (MQWs) and AlInP cladding layers is a crucial part in the device performance of GaInP red LDs. Here, we first investigated the effect of Si diffusion on the optical properties of GaInP-AlGaInP MQWs grown with different growth temperatures. Secondary ion mass spectroscopy (SIMS) measurements revealed that both the Mg and Si diffusion into MQW active region was significant. To reduce such diffusion, we employed undoped Mg and Si diffusion barrier and could improve the properties.Without both Mg and Si diffusion barriers, no lasing emission was observed. However, lasing emission was observed clearly for the red LDs with both Mg and Si diffusion barriers. We then investigated the temperature dependent optical properties of MQW layers grown with different well thicknesses (6, 8 and 10 nm). When the well thickness was 10 nm, the better crystalline quality was obtained. However, the observed LD performances were similar, probably due to the defects and impurities in the AlGaInP layer. Further investigation with the detailed analyses will be presented later.

• Journal of Powder Materials
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• v.26 no.6
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• pp.493-501
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• 2019

In this work, ultra-fine calcium oxide (CaO) powder derived from eggshells is used as the starting material to synthesize mineral trioxide aggregate (MTA). The prepared CaO powder is confirmed to have an average particle size of 500 nm. MTAs are synthesized with three types of fine CaO-based powders, namely, tricalcium silicate (C3S), dicalcium silicate (C2S), and tricalcium aluminate (C3A). The synthesis behavior of C3S, C2S and C3A with ultra-fine CaO powder and the effects of C₃A content and curing time on the properties of MTA are investigated. The characteristics of the synthesized MTA powders are examined by X-ray diffraction (XRD), field emission-scanning electron microscope (FE-SEM), and a universal testing machine (UTM). The microstructure and compressive strength characteristics of the synthesized MTA powders are strongly dependent on the C3A wt.% and curing time. Furthermore, MTA with 5 wt.% C3A is found to increase the compressive strength and shorten the curing time.

• YAKHAK HOEJI
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• v.49 no.4
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• pp.323-329
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• 2005

Antimicrobial peptides are evolutionary ancient weapons for animal and plant species to depend themselves against infectious microbes. In the present study, we investigated if an antimicrobial peptide was produced from Coptidis Rhizoma. For the determination, protein substance from the medicinal plant was isolated by various preparations. Among the preparations, the protein portion dissolved in phosphate-buffered saline solution (CRP-DS) that contained the most amount of protein $(90\%)$ resulted in maximal inhibition of Candida albicans which causes local and systemic infections. Analyses by gel-electrophoresis and gel-permeation chromatography showed the CRP-DS formed a single band of approximately 11.8 KDa as molecular size. Antifungal activity of the CRP-DS was almost equivalent to antifungal activity by fluconazole, resulting in MIC (minimal inhibitory concentration) of approximately $50{\mu}g/ml$. The antifungal activity was a dose-dependent. The antifungal activity appeared to be inactivated by heat-treatment and ionic strength, respectively. In a murine model, the CRP-DS enhanced resistance of mice against disseminated candidiasis. The HPLC analysis demonstrated maximum $4\%$ of berberine as residual content in the CRP-DS preparation resulted in no influence on the antifungal activity. In addition, protein portion isolated from Phellodendri Cortex producing the alkaloid component like Coptidis Rhizoma had no such anticandidal effect. These results indicate that the protein substance from Coptidis Rhizoma was responsible for the antifungal activity.

• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.179-190
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• 2015

Objective and Background: Due to increase in Musculoskeletal Disorders (MSDs) relating to computer use, a number of ergonomics recommendations have been proposed in order to tackle this problem. However, some of these recommendations have been conflicting. Method: This study was to survey the VDT (Visual Display Terminal) use of office workers. The subjects were 452 workers at 13 places of business and the data were collected by self-administered questionnaire. Results: As a result, prevalence of self-reported MSDs of all VDT workers was 90.2% and shoulder took up 57.0% and neck 38.3% by symptom part of body. The population of computer use of more than 6h/day was 84.5%, and 33.8% also reported using the VDT 2~3h/day without the rest time. Desktop computer users were 95.6%, and a 17-inch monitor accounted for 42.0% among the desktop users. As a result of satisfaction survey on overall computer work, 21.1% of the total respondents said satisfied, desk complaint was about 24.6%, and chair complaint was 33.4%. Despite the importance of computer environment, satisfaction was from fair to uncomfortable. Conclusion and Application: In conclusion, office workers are prone to the MSDs due to their work environment. Additionally, this study found that task was a significant effect for the majority of dependent variables, and therefore, the improvement of computer workstations work environment is urgent, and the improvement of desk height adjustment, chair seat size (length, width), backrest condition, location of keyboard (mouse) and arm rest is required.