• Korean Journal of Materials Research
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• v.11 no.5
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• pp.427-430
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• 2001

We prepared 10cm-diameter Si(100)/500 $\AA$-Si$_3$N$_4$/Si(100) wafer Pairs adopting 500 $\AA$ -thick Si$_3$N$_4$layer as insulating layer between single crystal Si wafers. Si3N, is superior to conventional SiO$_2$ in insulating. We premated a p-type(100) Si wafer and 500 $\AA$ -thick LPCVD Si$_3$N$_4$∥Si (100) wafer in a class 100 clean room. The cremated wafers are separated in two groups. One group is treated to have hydrophobic surface and the other to have hydrophilic. We employed a FLA(fast linear annealing) bonder to enhance the bond strength of cremated wafers at the scan velocity of 0.1mm/sec with varying the heat input at the range of 400~1125W. We measured bonded area using a infrared camera and bonding strength by the razor blade crack opening method. We used high resolution transmission electron microscopy(HRTEM) to probe cross sectional view of bonded wafers. The bonded area of two groups was about 75%. The bonding strength of samples which have hydrophobic surface increased with heat input up to 1577mJ/$m^2$ However, bonding strength of samples which have hydrophilic surface was above 2000mJ/$m^2$regardless of heat input. The HRTEM results showed that the hydrophilic samples have about 25 $\AA$ -thick SiO layer between Si and Si$_3$N$_4$/Si and that maybe lead to increase of bonding strength.

• Journal of the Korean Magnetics Society
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• v.25 no.3
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• pp.67-73
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• 2015

This is a basic research for improving soft magnetic property of Fe based nano crystalline alloy powder core. The main study is done around characteristics of permeability, core loss, and DC bias depending on amount of insulation coating agent and particle size. First, $Fe_{73.5}Si_{13.5}B_9Nb_3Cu_1$ amorphous alloy ribbon was fabricated by using the planar flow casting (PFC) device. Then, heat treatment and ball milling were done to obtain alloy powder. The amount of polyether imide (PEI) added to it was varied by 0.5, 1.0, 2.0, 2.5 wt% to have compression molding into $16ton/cm^2$. After going through crystalline heat treatment, the made toroidal nano crystalline powder core ($OD12.7mm^*ID7.62mm^*H4.75mm$) had smaller permeability as amount of insulation coating agent decreases. However, it was found out that core loss and DC bias characteristics have been improved. The reason for this results were expected to be because green density of power core decreases as amorphous alloy powder particles become smaller as amount of alloy powder insulation coating agent increases, it was determined that 1 wt% of insulation coating agent is appropriate. Also, for powder core made based on alloy powder size with amount of insulation coating agent fixed at 1 wt%, effective permeability and core loss were outstanding as particle size became bigger. However, characteristics of DC bias became worse as applied DC field increases. This is expected to be due to insulation effect, residual pores, or molding density of powder core resulting from thickness of coating on surface of alloy powder.

• Journal of Life Science
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• v.25 no.7
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• pp.786-794
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• 2015

To identify nutritional and therapeutic properties of the new Korean red waxy sorghum cultivar ‘Hwanggeumchalsusu (HGC)’, we assayed the antioxidative effects and neuraminidase inhibitory activity. A methanol and 70% ethanol extract of HGC exhibited strong antioxidative effects (IC₅₀ values of 83.2±2.7 for DPPH) and 85.6±2.4 μg/ml for ABTS) and neuraminidase (ND) inhibitory activity (IC₅₀ values of 1.8±0.1 from extracted with methanol and 3.4±0.1 μg/ml from extracted with 70% ethanol) compared with that of the control, noncolored sorghum cultivar ‘Huinchalsusu (HC)’ (IC₅₀> 200 μg/ml). We isolated nine polyphenols, Gallic acid (1), Protocatecuic acid (2), p-Hydroxy benzoic acid (3), Vanillic acid (4), Caffeic acid (5), Ferulic acid (6), Luteolinidin (7), Apigeninidin (8), Luteolin (9), from the HGC - methanol extract, to determine whether they were the active components Luteolinidin of one kind of polyphenols from the HGC, exhibited significant antioxidative effects (IC₅₀ values of 10.9±0.5 μM for DPPH and 8.6 0.6 μM for ABTS) and neuraminidase (ND) inhibitory activity (IC₅₀ values of 26.3±0.6) showed noncompetitive inhibition model. The binding affinity of the ND inhibitors in molecular docking experiments correlated with their ND inhibitory activities. These results suggest that HGC may be utilized to serve as a potential effective antioxidant and inhibitor of ND.

• Journal of Life Science
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• v.19 no.11
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• pp.1629-1636
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• 2009

Pine trees (Pinus densiflora Sieb. et Zacc.) have been used as a traditional health-promoting medicinal food in Korea. This research was performed to determine the antioxidative and antibacterial activities, tyrosinase, nitric oxide synthesis, angiotensin converting enzyme (ACE), and xanthine oxidase inhibition effects of the pine bud ethanol extract (PBE). Antioxidative activities of PBE were measured by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging activity and superoxide dismutase-like activity (SODA). DPPH radical scavenging and SOD-like activities of PBE were remarkably increased in a dose-dependent manner, and were about 88.9% and 47.9% at 1 mg/ml and 10 mg/ml, respectively. The xanthine oxidase and angiotensin converting enzyme activities were inhibited about 71.9% and 60.8% at 1 mg/ml and $100{\mu}g/ml$ of PBE, respectively. The tyrosinase inhibitory activities of PBE were slightly increased in a dose-dependent manner. The PBE showed strong antimicrobial activities on Escherichia coli (E. coli) and Vibrio paraheamolyticus. Stimulation of the macrophages RAW264.7 cells with lipopolysaccharide (LPS) resulted in increased production of nitric oxide (NO) in the medium. However, NO synthesis was reduced up to 54% by addition of PBE at $200{\mu}g/ml$. These results revealed that pine buds have a strong antioxidative and anti-inflammatory activity, and exhibit angiotensin converting enzyme and xanthine oxidase inhibitory activities. This suggests that pine buds have the greatest property as a source for natural health products.

• Journal of Life Science
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• v.23 no.5
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• pp.629-636
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• 2013

This study was performed to evaluate the anti-inflammatory and antioxidant activities of methanol extract from the leaves of Picrasma quassioides BENNET (PLME). The antioxidant effects of PLME were measured based on polyphenol and flavonoid contents. PLME was found to have $367.52{\mu}g/mg$ and $46.61{\mu}g/mg$ high polyphenol and flavonoid contents. Cell viability was determined by MTT assay. The production of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) was measured by Griess assay and enzyme-linked immunosorbent assay (ELISA). In order to effectively anti-inflammatory agents, we examined the inhibitory effects on the production of lipopolysaccharide (LPS)-induced NO and $PGE_2$ in RAW 264.7 cells. PLME significantly decreased the production of NO and $PGE_2$ in a dose-dependent manner, and also reduced the expression of iNOS, a COX-2 protein. In addition, PLME reduced the NF-${\kappa}B$, $I{\kappa}B$ phosphorylation in RAW 264.7 cells upon stimulation with LPS (100 ng/ml) for 24 h. These results provide evidence for the anti-inflammatory and antioxidant effects of Picrasma quassioides leaves.

• Journal of Life Science
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• v.27 no.4
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• pp.383-389
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• 2017

This study intends to analyze the contents of rutin, procyanidin B3, quercetin, kaempferol, known to have antioxidant, anti-inflammatory and anti-carcinogenic effects, among the polyphenol type contained in the grape pruning stem extracts (GPSE), utilizing grape stems being discarded after harvest, measure the effects on the skin moisture, inhibition of skin cell proliferation, anti-inflammatory on the damaged skin of a HR-1 mice induced with UVB, and verify the applicability as a material for functional food and functional cosmetics. The results of verifying the photoprotection effects through the skin proliferation control through of GPSE showed similar result to suncream was achieved at the GPSE concentration of 2,000 mg/kg on the epidermis (p<0.05). The results showed anti-inflammatory effects on all groups applied with GPSE as compared to the control group irradiated with UVB, but at the GPSE concentration of 1,000 mg/kg, a lower COX-2 protein expression at 8%, lower than the 22% of suncream, was observed to achieve an excellent anti-inflammatory effect (p<0.05). The results of this study confirmed the existence of active polyphenol type, such as rutin, kaempferol, querocetin and procyanidin B3, within the GPSE, and GPSE has improvement effects on moisturizing effects, skin proliferation control effect, inflammatory control effect and improvement effects on the skin barrier function through UV ray damage. GPSE is a functional ingredient with a potential for skin protection effects, and has high utilization as an ingredient for functional food and functional cosmetics.

• Korean Journal of Digital Imaging in Medicine
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• v.5 no.1
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• pp.64-77
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• 2002

DR has had an important fact not only in the department of radiology but also in productivity or work efficiency of a whole hospital. The environment of DR has more various parameter than CR, so it is able to supply high quality of medical services. The current environment of radiology department in each hospital has been changed from Film-Screen system to DR through Full-PACS. This hospital which uses Full-PACS became to study the proper condition of CR and DDR and how the image quality of them is expressed among general photographing systems in the DR environment. From this experiment, the image quality of DDR is better than CR under the same exposure condition. And in the DDR system, the score of image which uses AEC is a little higher than the score which doesn't use it. Especially it can be known that the function of AEC of DDR is useful to improve the image quality in the part of skull and chest. (The function of AEC : It is the tool that detects the ionized current of x-ray which goes through objects with using the ion chamber which is in the detector. Also it controls the examination of X-ray when the proper density is reached.) Because the proper degree of density can be represented by this system, the photographing can be taken much easily without consideration of the exposure condition with the thickness of various objects. From the result of this experiment, it can be known that the selection of proper exposure condition plays an important rule to gain good Image Quality. More researches will be necessary about DDR system which has potential ability in the future.

• Korean journal of food and cookery science
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• v.16 no.5
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• pp.437-444
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• 2000

The purpose of this study were to identify customer expectation, perception and satisfaction of foodservice quality to analyze the influencing factors on foodservice quality and finally to provide basic information for the improvement of foodservice quality. Among expectation scores of food quality attributes, ‘hygiene of food(3.27)’received the highest score. In expectation scores of service quality attributes,‘hygiene of tableware(3.40)’was the most important. Satisfaction of ‘appropriate 1 portion size(-0.11)’was the highest scored, while‘dealing with complaints on meals(-0.70)’was the most dissatisfied one. Satisfaction was highly correlated with‘providing preferred menu(r = -0.62)’of food quality expectation. It was highly correlated with‘dealing with complaints on meals(r = -0.61)’of service quality expectation. Expectation and perception of foodservice as 2.25 and 2.90 out of 5, respectively, which suggests that foodservice needs to be improved. The attributes identified in Quadrant A, which was labelled‘focus here’and supposed to indicate the areas of high expectation but in low perception, was hygiene of carts holding used trays. The results of expectation and perception analysis indicated the areas that the attention of management should be given to improve quality of foodservice. The stepwize regression analysis suggested that foodservice expectation and perception explaints around 56.7% of the variation in general customer satisfaction.

• Korean Journal of Materials Research
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• v.11 no.5
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• pp.367-371
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• 2001

In this paper, theS $r_2$(T $a_{1-x}$ , N $b_{x}$)$_2$ $O_{7}$(STNO) films among ferroelectric materials having a low dielectric constant for metal-ferroelectric-semiconductor field effect transistor(MFS-FET) were discussed. The STNO thin films were deposited on p-type Si(100) at room temperature by co-sputtering with S $r_2$N $b_2$ $O_{7(SNO)}$ ceramic target and T $a_2$ $O_{5}$ ceramic target. The composition of STNO thin films was varied by adjusting the power ratios of SNO target and T $a_2$ $O_{5}$ target. The STNO films were annealed at 8$50^{\circ}C$, 90$0^{\circ}C$ and 9$50^{\circ}C$ temperature in oxygen ambient for 1 hour. The value of x has significantly influenced the structure and electrical properties of the STNO films. In the case of x= 0.4, the crystallinity of the STNO films annealed at 9$50^{\circ}C$ was observed well and the memory windows of the Pt/STNO/Si structure were 0.5-8.3 V at applied voltage of 3-9 V and leakage current density was 7.9$\times$10$_{08}$A/$\textrm{cm}^2$ at applied voltage of -5V.of -5V.V.V.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.60-65
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• 2004

Purpose: The purpose of this study was to evaluate the results of limited vastus lateralis release for treatment of painful bipartite patella. Materials and Methods: From Jan. 1995 to Jun. 2002, we performed limited lateral retinacular release in 14 patients(16 cases) for treatment of painful bipartite patella. All patients were men and mean age was 22.3 years old. The opeative techique was that insertion of the vastus lateralis to the painful patellar fragment is detached subperiosteally. We evaluated the clinical results by degree of pain and level of activity. Also we analyzed the radiologic findings by measuring fragment tilting angle and gap between fragments. The mean follow up period was 14 months. Results: At final follow up, all of the patients showed pain relief and can be returned to more than recreational sports activity after the operation. On radiologic findings, fragment tilting angle and gap between fragments were reduced at statistically significant level. Conclusion: The limited lateral retinacular release for treatment of painful bipartite patella is one of good methods which is less invasive and shows good results in clinical and radiologic findings.