• Asian-Australasian Journal of Animal Sciences
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• 제17권9호
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• pp.1260-1265
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• 2004

This research was conducted to compare the effects of vitamin E (VE) when supplemented in either feed or water on the performance and meat quality of broilers. For a six-week feeding trial, a total of 330 broiler chicks were allotted to five treatments. The treatments were 1) 0 ppm VE, 2) 10 ppm VE in feed, 3) 20 ppm VE in feed, 4) 5 ppm VE in water and 5) 10 ppm VE in water. During the starter phase (0-3 weeks) chicks on non-supplemented groups grew slower (p<0.05) than the supplemented ones and the same trend was followed during the finisher (4-6 weeks) and overall period (0-6 weeks). The feed intake was significantly higher in feed supplemented groups as compared with water-supplemented groups and at higher levels as compared with lower levels of supplementation. The nutrient digestibility studies conducted after 15 and 35 days on the feeding trial showed that the digestibility of all nutrients was significantly (p<0.05) higher in supplemented groups than the non-supplemented one. The dressing percentage was higher in supplemented groups, when fed in feed and at higher levels when compared with their respective counterparts. Similar trends were noticed with respect to bone resistance. The calcium and phosphorus contents in tibia were also significantly (p<0.05) higher in supplemented, feed fed groups at higher levels than other groups. The TBARS values measured after 5 and 10 days of storage, which reflect the degree of oxidation, showed significantly lower levels in supplemented diets. The plasma and muscle vitamin E levels also showed a positive linear correlation with the levels supplemented both in feed and water. Overall it can be inferred that supplementation of VE was beneficial and there was not much difference observed when fed either in feed or water at the levels measured in the present study.

• Preventive Nutrition and Food Science
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• 제14권4호
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• pp.283-289
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• 2009

We evaluated total phenolics and antioxidative activities of water extracts from different parts of Cudrania tricuspidata (specifically, the leaves, stems, roots, and fruits). The antioxidative activities of these samples were determined using five methods, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging, reducing power, ferric reducing ability of plasma (FRAP), and $\beta$-carotene/linoleic acid system. The water extract of leaves exhibited the higher DPPH, ABTS radical scavenging activities, reducing power, and FRAP than water extract of stem, roots, and fruits. Inhibition values on linoleic oxidation of water extracts from leaves, stems, roots, and fruits were calculated as 45.98%, 33.03%, 39.73%, and 25.48% at 10 mg/mL, respectively. The water extract of C. tricuspidata leaves had the highest amount of toal phenolics (73.60$\pm$0.28 mg/g). High-performance liquid chromatography (HPLC) analysis showed that quercetin is the predominant phenolic compound in water extract of leaves. Thus, our study verified that the water extract of leaves has strong antioxidant activities which are correlated with its high level of phenolic compounds, particularly quercetin. This water extract of C. tricuspidata leaves can be used as an effective and safe source of antioxidants.

• 한국재료학회지
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• 제22권4호
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• pp.190-194
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• 2012

The formation of high-quality polycrystalline silicon (poly-Si) on relatively low cost substrate has been an important issue in the development of thin film solar cells. Poly-Si seed layers were fabricated by an inverse aluminum-induced crystallization (I-AIC) process and the properties of the resulting layer were characterized. The I-AIC process has an advantage of being able to continue the epitaxial growth without an Al layer removing process. An amorphous Si precursor layer was deposited on Corning glass substrates by RF magnetron sputtering system with Ar plasma. Then, Al thin film was deposited by thermal evaporation. An $SiO_2$ diffusion barrier layer was formed between Si and Al layers to control the surface orientation of seed layer. The crystallinity of the poly-Si seed layer was analyzed by Raman spectroscopy and x-ray diffraction (XRD). The grain size and orientation of the poly-Si seed layer were determined by electron back scattering diffraction (EBSD) method. The prepared poly-Si seed layer showed high volume fraction of crystalline Si and <100> orientation. The diffusion barrier layer and processing temperature significantly affected the grain size and orientation of the poly Si seed layer. The shorter oxidation time and lower processing temperature led to a better orientation of the poly-Si seed layer. This study presents the formation mechanism of a poly seed layer by inverse aluminum-induced crystallization.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권2호
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• pp.179-184
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• 2016

In recent years, the on-resistance, power loss and cell density of Si power devices have not exhibited significant improvements, and performance is approaching the material limits. GaN is considered an attractive material for future high-power applications because of the wide band-gap, large breakdown field, high electron mobility, high switching speed and low on-resistance. Here we report on the Ohmic contact resistance and reverse-bias characteristics of AlGaN/GaN Schottky barrier diodes with and without annealing. Annealing in oxygen at $500^{\circ}C$ resulted in an increase in the breakdown voltage from 641 to 1,172 V for devices with an anode-cathode separation of $20{\mu}m$. However, these annealing conditions also resulted in an increase in the contact resistance of $0.183{\Omega}-mm$, which is attributed to oxidation of the metal contacts. Auger electron spectroscopy revealed diffusion of oxygen and Au into the AlGaN and GaN layers following annealing. The improved reverse-bias characteristics following annealing in oxygen are attributed to passivation of dangling bonds and plasma damage due to interactions between oxygen and GaN/AlGaN. Thermal annealing is therefore useful during the fabrication of high-voltage GaN devices, but the effects on the Ohmic contact resistance should be considered.

• 한국식품영양과학회지
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• 제23권3호
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• pp.530-539
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• 1994

최근 지방 섭추의 증가에 따른 혈관계 질병이 증가 추세에 있다. 이러한 동맥경화 및 고지질의 질병은 지질 단백질(lipoprotein)과 관련하여, LDL 및 산화 LDL의 특성을 중심으로 고찰하였다. 인체의 혈장에 함유된 LDL 함량의 증가는, 동맥경화와 직결되는 것을 의미하며, 이러한 LDL은 매우 hydrophobic한 특성을 가진 550Kd의 단일 polypeptide인 Apo B-100라는 단백질이, 지질성분인 triglyceide, phospholipid 및 cholesterol와 결합되어 있다. 최근 이러한 LDL은 산화(oxidation)되는 경우, 정상적인 LDL-receptor pathway를 따르지 않고, macrophang와 결합하므로서, foarn cell을 형성하여 동백경화가 촉진되는 것으로 알려지고 있다.

• 한국세라믹학회지
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• 제45권9호
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• pp.549-555
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• 2008

The thermal barrier coating must withstand erosion when subjected to flowing gas and should also maintain good stability and mechanical properties while it must also protect the turbine component from high temperature, hot corrosion, creep, and oxidation during operation. In this study we investigated the influence of subsurface layer, $Al_2O_3$ or NiCrCoAIY bond coat layer, on the indentation damage behavior of YSZ thermal barrier coating layers deposited by electron beam physical vapor deposition (EB-PVD). The bond coat is deposited using different process such as air plasma spray (APS) or spray of high velocity oxygen fuel (HVOF) and the thickness is varied. Hertzian indentation technique is used to induce micro damages on the coated layer. The stress-strain behaviors are characterized by results of the indentation tests.

• Journal of Nutrition and Health
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• 제40권2호
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• pp.138-146
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• 2007

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades. Harmful contaminants naturally occurred from foods which contain high levels of unsaturated fatty acids that are easily oxidized can affect the human anti-oxidation system through the generation of free radicals. Moreover, previous studies proved that ${\gamma}$-irradiation may cause production of free radicals in food. We investigated the effect of ${\gamma}$-irradiated soybeans in relation to oxidative stress in mice. Oxidative index of mice was evaluated by TBARS, DNA fragmentation in various organs such as blood lymphocytes, liver and kidney. Forty male ICR mice were equally divided into 4 groups and fed control diet or ${\gamma}$-irradiated diet containing 50% soybeans (5, 10, and 20 kGy, respectively) for 8 weeks. Peroxide values of the irradiated diets were higher than that of the non-irradiated one and increased according to the storage period. There was no significant difference in weight gain as well as in TBARS value in plasma and kidney of all groups. Liver TBARS value of the group fed with irradiated diet at 20 kGy increased significantly compared with the control group (p < 0.05). DNA oxidative damage as measured by alkaline comet assay showed that % tail DNA in the blood lymphocytes of 5 kGy and 10 kGy groups increased significantly over the control group (p < 0.05). Also, tail moments of 5 kGy and 10 kGy groups were higher than that of the control group. Ultrastructural examination shows myeline figures and swollen mitochondria in parietal and intestinal epithelial cells of the group fed with irradiated diet. Therefore, considering unsaturated fatty acid content, consumption of soybeans ${\gamma}$-irradiated with over 20 kGy or repeatedly may decrease the body's antioxidant mechanism.

• 한국축산식품학회지
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• 제38권2호
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• pp.259-272
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• 2018

This study aims to investigate the protective effects of kefir against myocardial infarction induced by isoproterenol (ISO). The rats were randomly divided into 4 groups, each group consisting of 8 rats. The control group, the kefir group (5 mL/kg/d kefir administered to rats as intra-gastric gavage for 60 d), the ISO group (100 mg/kg ISO was administered to rats, s.c. on 61. and 62. d), and kefir+ISO group (5 mL/kg/d kefir was administered to rats intra gastric gavage for 60 days prior to ISO, 100 mg/kg in two doses on day 61 and 62). 12 h after the last ISO dose, all rats were decapitated and their blood samples were collected. Cardiac tissue was reserved for histopathological examination. creatine kinase (CK), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triglycerides, total cholesterol,very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL) and glucose were measured by autoanalyzer, whole blood malondialdehyde (MDA), glutathione (GSH) and plasma advanced oxidation protein products (AOPP) levels were measured spectrophotometrically. It was determined that in the group of kefir+ISO, the levels of AST (p<0.001), CK (p<0.001), LDH (p<0.001), MDA (p<0.001) and AOPP (p<0.001) were decreased, while the GSH (p<0.05) increased, compared to ISO group. There were no significant changes in lipid profile and glucose levels between these two groups. In conclusion, by examining cardiac enzymes and histopathological changes in cardiac tissue, it can be concluded that the administration of kefir in myocardial infarction induced by ISO can protect the heart with its antioxidant characteristic and minimize the toxic damage created by ISO.

• 한국전기전자재료학회논문지
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• 제23권9호
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• pp.681-684
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• 2010

The $TiO_2$/ZnS/Ag/ZnS/$TiO_2$ multilayered structure for the transparent electrodes in plasma display panel was designed by essential macleod program (EMP) and the multilayered film was deposited on a glass substrate by direct-current (DC)/radio-frequency (RF) magnetron sputtering system. During film deposition process, the Ag layer in $TiO_2$/Ag/$TiO_2$ structure became oxidized and the filter characteristic was degraded easily. In this study, ZnS layer was adopted as a diffusion blocking layer between $TiO_2$ and Ag to prevent the oxidation of Ag layer efficiently in $TiO_2$/ZnS/Ag/ZnS/$TiO_2$ structure. Based on the AES depth profiling analysis, the Ag layer was effectively protected by the ZnS layer as compared with the $TiO_2$/Ag/$TiO_2$ multilayered films without ZnS as an antioxidant layer. The 3 times stacked $TiO_2$/ZnS/Ag/ZnS/$TiO_2$ films have low sheet resistance of $1.22{\Omega}/{\square}$ and luminous transmittance was as high as 62% in the visible ranges.

• 분석과학
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• 제14권5호
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• pp.410-415
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• 2001

철강 시료 중의 납 분석을 위하여 수소화물 발생법을 플라스마에 납을 선택적으로 주입하고 유도결합플라스마 질량분석법으로 측정하는 분석법을 개발하였다. 납 수소화물 $PbH_4$의 생성을 위해서는 $NaBH_4$와 반응 전에 먼저 준안정 상태의 Pb(IV)로 만들어주기 위하여 산화제가 필요하다. $1000{\mu}g/mL$ 이상의 철 매질을 함유하는 시료용액으로 납 수소화물을 발생시키기 위한 최적조건을 찾는 연구를 수행하였다. 철 매질이 $10{\mu}g/mL$ 이상 존재할 때는 $K_2Cr_2O_7$이 효과적인 산화제로 작용하였으며 젖산을 가하여 감도를 향상시켰다. 시료용액의 산농도 그리고 산화제와 젖산 농도의 최적값은 철 매질의 농도에 따라 달랐다. 동위원소 희석법을 사용하여 납을 정량하였으며 철강 표준물질 NIST SRM 361, 362 분석결과는 불확도 범위안에서 검정값과 잘 일치하였다.