• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.207-216
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• 2013

This study was conducted to establish the method for preserving PGCs that enables long-term storage in liquid nitrogen for developmental engineering or preservation of species. The purpose of this study is to clarify the effects of freeze-thaw treatment on viability of PGCs in chickens. PGCs were collected separately from a germinal gonad of an early embryo of 5.5~6 day (stage 28) of Isa brown, Korean Oge (KO), White Leghorn and Commercial breeds. PGCs separated from a germinal gonad of an early embryo of 5.5~6 day (stage 28) are suspended in a freezing medium containing a freezing and protecting agents (e.g. dimethyl sulfoxide (DMSO), ethylene glycol (EG) and glycerol). The PGCs were then purified using magnetic activated cell sorting (MACS) method. The viability of PGCs after thawing was $87.4{\pm}0.4%$ and $89.4{\pm}0.2%$ with the 10% EG treatments with no significant difference between the Isa brown and Commercial breeds. The viability of PGCs after freeze- thawing was significantly higher for Isa brown ($87.4{\pm}0.4%$) and Commercial breeds ($89.4{\pm}0.2%$) than Korean Oge (KO) ($77.6{\pm}1.1%$) and White Leghorn ($76.2{\pm}0.9%$)(p<0.05) using 10% EG cryoprotectant. This study established a method for pre- serving chicken PGCs that enables systematic storage and labeling of cryopreserved PGCs in liquid ($LN_2$) at agermplasm repository and ease of entry into a data base. In the future, the importance for this new technology is that poultry lines can be conserved while work is being conducted on improving the production of germline chimeras.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.448-454
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• 2000

This study was to examine the physicochemical characteristics of coagulation reaction between ignited oyster shell powder (IOSP) and red tide organisms (RTO), and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea,IOSP was made from oyster shell and its physicochemical characteristics were examined for particle size distribution, surface characteristic by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various c(Incentrations of IOSP, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number, IOSP showed positive zeta potentials of $11.1{\~}50.1\;mV\;at\;pH\;6.2{\~}12.7$, A positive zeta potential of IOSP slowly decreased with decreasing pNa 4,0 to 2,0. When pNa reached zero, the zeta potential approached zero, When a pMg value was decreased, the positive zeta potential of IOSP increased until pMg 3.0 and decreased below pMg 3.0. IOSP showed 4.8 mV of positive zeta potential while RTO showed -9.2 mV of negative zeta potential in sea water. A positive-negative EDL (electrical double-layer) interaction occurred between $Mg(OH)_2$ adsorption layer of IOSP and RTO in sea water so that EDL attractive force always worked between them. Hence, their coagulation reaction occurred at primary minimum on which an extreme attractive force acted because of charge neutralization by $Mg(OH)_2$ adsorption layer of IOSP. As a result, the coagulation reaction was rapidly processed and was irreversible according to DLVO (Deriaguin-Landau-Verwey-Overbeek) theory. Removal rates of RTO were exponentially increased with increasing both IOSP concentration and G-value. The removal rates were steeply increased until 50 mg/l of IOSP and reached $100{\%}\;at\;400\;mg/l$ of IOSP. Removal rates of RTO were $70.5,\;70.5,\;81.7,\;85.3{\%}$ for G-values of $1,\;6,\;29,\;139\;sec^(-1)$at IOSP 100 mg/l, respectively. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.378-382
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• 2000

The effects of bisphenol A (BPA), known as one of the endocrine disrupting chemicals (EDCs), on the hatching of fertilized eggs (FE) and the spawning of adult fish in songsari, Oryzias latipes were investigated. In condition of the experimental groups, incubated water temperature was $25.0{\pm}0.5^{\circ}C$ and photoperiod was 16 h (light) : 8 h (dark). fE were exposed to aqueous solutions of BPA at nominal concentration of 50, 100 and $200 {\mu}g/l$. The time required in hatching of FE was long in the BPA $50 and 100 {\mu}g/l$ treatment groups when compared to the controls, and in the BPA $200 {\mu}g/l$ treatment group, FE failed to hatch. And also hatching rate was decreased in the BPA treatment groups in comparison to the controls, Adult fishes were reared to oral administration via a diet of 50, 100 and $200 {\mu}g/g$ body weight BPA concentration for 3 weeks, Number of total eggs spawned in the adult fish were fewer in the BPA 100 and 200 treatment groups than in the controls and BPA 50 treatment group. Frequency of abnormal eggs in the total eggs spawned was 11.8 and $16.2{\%}$ in the control and acetone carrier control lower than 36.8, 46,8 and $74.1{\%}$ in the BPA 50, 100 and 200 treatment groups, respectively. And hatching rate of FE decreased in the BPA treatment groups in comparison to the controls. In these results, inhibition of the hatching of FE and the quantity and quality of spawned eggs in adult fish were observed from BPA treatment groups when compared to the controls.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.45-47
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• 2002

반도체 소자의 고집적화 및 고속화가 요구됨에 따라 MOSFET 구조의 게이트 절연막으로 사용되고 있는 SiO₂ 박막의 두께를 감소시키려는 노력이 이루어지고 있다. 0.1㎛ 이하의 소자를 위해서는 15Å 이하의 두께를 갖는 SiO₂가 요구된다. 하지만 두께감소는 절연체의 두께와 지수적인 관계가 있는 누설전류를 증가시킨다[1-3]. 따라서 같은 게이트 개패시턴스를 유지하면서 누설전류를 감소시키기 위해서는 높은 유전상수를 갖는 두꺼운 박막이 요구되는 것이다. 그러므로 약 25정도의 높은 유전상수를 갖고 5.2～7.8 eV 정도의 비교적 높은 bandgap을 갖으며, 실리콘과 열역학적으로 안정한 물질로 알려진 HfO2[4-5]가 최근 큰 관심을 끌고 있다. 본 연구에서는 HfO₂ 박막을 실제 소자에 적용하기 위하여 전극 및 열처리에 따른 HfO₂ 박막의 미세구조 및 전기적 특성에 관한 연구를 수행하였다. 이를 위해, HfO₂ 박막을 reactive DC magnetron sputtering 방법으로 증착하고, XRD, TEM, XPS를 사용하여 ZrO₂ 박막의 미세구조를 관찰하였으며, MOS 캐패시터 구조의 C-V 및 I-V 특성을 측정하여 HfO₂ 박막의 전기적 특성을 관찰하였다. HfO₂ 타겟을 스퍼터링하면 Ar 스퍼터링에 의해 에너지를 가진 산소가 기판에 스퍼터링되어 Si 기판과 반응하기 때문에 HfO₂ 박막 형성과 더불어 Si 기판이 산화된다[6]. 그래서 HfO₂같은 금속 산화물 타겟 대신에 순수 금속인 Hf 타겟을 사용하고 반응성 기체로 O₂를 유입시켜 타겟이나 시편위에서 high-k 산화물을 만들면 SiO/sub X/ 계면층을 제어할 수 있다. 이때 저유전율을 갖는 계면층은 증착과 열처리 과정에서 형성되고 특히 500℃ 이상에서 high-k/Si를 열처리하면 계면 SiO₂층은 증가하는 데, 이것은 산소가 HfO₂의 high-k 박막층을 뚫고 확산하여 Si 기판을 급속히 산화시키기 때문이다. 본 방법은 증착에 앞서 Si 표면을 희석된 HF를 이용해 자연 산화막과 오염원을 제거한 후 Hf 금속층과 HfO₂ 박막을 직류 스퍼터링으로 증착하였다. 우선 Hf 긍속층이 Ar 가스 만의 분위기에서 증착되고 난 후 공기중에 노출되지 않고 연속으로 Ar/O₂ 가스 혼합 분위기에서 반응 스퍼터링 방법으로 HfO₂를 형성하였다. 일반적으로 Si 기판의 표면 위에 자연적으로 생기는 비정질 자연 산화막의 두께는 10～15Å이다. 그러나 Hf을 증착한 후 단면 TEM으로 HfO₂/Si 계면을 관찰하면 자연 산화막이 Hf 환원으로 제거되기 때문에 비정질 SiO₂ 층은 관찰되지 않았다. 본 실험에서는 HfO2의 두께를 고정하고 Hf층의 두께를 변수로 한 게이트 stack의 물리적 특성을 살펴보았다. 선증착되는 Hf 금속층을 0, 10, 25Å의 두께 (TEM 기준으로 한 실제 물리적 두께) 로 증착시키고 미세구조를 관찰하였다. Fig. 1(a)에서 볼 수 있듯이 Hf 금속층의 두께가 0Å일때 13Å의 HfO₂를 반응성 스퍼터링 방법으로 증착하면 HfO₂와 Si 기판 사이에는 25Å의 계면층이 생기며, 이것은 Ar/O₂의 혼합 분위기에서의 스퍼터링으로 인한 Si-rich 산화막 또는 SiO₂ 박막일 것이다. Hf 금속층의 두께를 증가시키면 계면층의 성장은 억제되는데 25Å의 Hf 금속을 증착시키면 HfO₂ 계면층은 10Å미만으로 관찰된다. 그러므로 Hf 금속층이 충분히 얇으면 플라즈마내 산소 라디칼, 이온, 그리고 분자가 HfO₂ 층을 뚫고 Si 기판으로 확산되어 SiO₂의 계면층을 성장시키고 Hf 금속층이 두꺼우면 SiO/sub X/ 계면층을 환원시키면서 Si 기판으로의 산소의 확산은 막기 때문에 계면층의 성장은 억제된다. 따라서 HfO₂/Hf(Variable)/Si 계에서 HfO₂ 박막이 Si 기판위에 직접 증착되면, 순수 HfO₂ 박막의 두께보다 높은 CET값을 보이고 Hf 금속층의 두께를 증가시키면 CET는 급격하게 감소한다. 그러므로 HfO₂/Hf 박막의 유효 유전율은 단순 반응성 스퍼터링에 의해 형성된 HfO₂ 박막의 유전율보다 크다. Fig. 2에서 볼 수 있듯이 Hf 금속층이 너무 얇으면 계면층의 두께가 두꺼워 지고 Hf 금속층이 두꺼우면 HfO₂층의 물리적 두께가 두꺼워지므로 CET나 EOT 곡선은 U자 형태를 그린다. Fig. 3에서 Hf 10초 (THf=25Å) 에서 정전 용량이 최대가 되고 CET가 20Å 이상일 때는 high-k 두께를 제어해야 하지만 20Å 미만의 두께를 유지하려면 계면층의 두께를 제어해야 한다.

• Journal of Life Science
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• v.20 no.3
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• pp.365-373
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• 2010

To monitor newly emerged influenza virus variants and to investigate the prevalence pattern, our laboratory performed isolation of the viruses from surveillance sentinel hospitals. In the present study, we analysed influenza A/H1N1, A/H3N2, B viruses isolated in Busan during the 2006/07 and 2007/08 seasons by sequence analysis of the hemagglutinin (HA1 subunit) and neuraminidase (NA) genes. The isolates studied here were selected by the stratified random sample method from a total of 277 isolates, in which 15 were A/H1N1, 16 were A/H3N2 and 29 were B. Based on the phylogenetic tree, the HA1 gene showed that A/H1N1 isolates had a 96.7% to 97.7% homology with the A/Brisbane/59/2007, A/H3N2 isolates had a 98.4% to 99.7% homology with the A/Brisbane/10/2007, and B isolates had a 96.5% to 99.7% homology with the B/Florida/4/2006(Yamagata lineage), which are all the vaccine strains for the Northern Hemisphere in 2008~2009 season. In the case of the NA gene, A/H1N1 isolates had 97.8% to 98.5% homologies, A/H3N2 isolates had 98.9% to 99.4% homologies, and B isolates had 98.9% to 100% homologies with each vaccine strain in the 2008~2009 season, respectively. Characterization of the hemagglutinin gene revealed that amino acids at the receptor-binding site and N-linked glycosylation site were highly conserved. These results provide useful information for the control of influenza viruses in Busan and for a better understanding of vaccine strain selection.

• 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.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.236-249
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• 2003

To investigate the effects of dietary conjugated linoleic acid 011 changes of physicochemical properties of pork. Twenty pigs were divided into 5 treatment groups and subjected to each experimental diet(0, 1.25% and 2.5% CLA for 2 weeks, 1.25% and 2.5% CLA for 4 weeks, as total fed diet before slaughtering(about 110 kg). Pork loin samples were aerobically packed and stored for 14 days at 4$^{\circ}C$. Samples were then analyzed for general compositions, physicochemical characteristics and sensory evaluation. pH value of CLA fed group pork was significantly increased than that of control group(p<0.05). Crude fat content of CLA treated group pork was significantly higher than the control pork(p<0.05), but there were no significant differences in crude protein, crude ash and total moisture contents between control and CLA treated groups. AU CLA fed group pork showed higher WHC value than control pork. Drip loss was significantly lower compared to those of control porks. No significant differences in lean meat and fat color(CIE L*, a*, b*) were observed between control and the CLA treated group porks. Meanwhile, CLA pork tended to be lower in content of total heme pigment compared to control pork. No remarkable differences were found in sensory properties(color and drip loss) among control and CLA diet-fed group porks. Marbling score and acceptability were significantly increased in CLA diet-fed pork compared to the control pork.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1038-1044
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• 1996

The salt-fermented anchovy sauce (AS) was packed in round No. 307-1 can, and thermally processed at $121.1^{\circ}C$ to obtain Fo values of 3, 5 and 10. The changes of food components and qualifies by thermal processing of sterilized AS (RAS) were examined. The compositions of AS were as followed; pH 6.81, VBN 394.7 mg/100g, total nitrogen 2,195.5 mg%, amino-nitrogen 1,010.5 mg%, and acidity 10.5 ml. Viable cell counts of AS on 0%, 5%, 20% NaCl-medium were $2.9{\times}10^3,\;9.1{\times}10^3$ and not detected, respectively. And viable cell counts of RAS were not detected. Acidity, total nitrogen and amino nitrogen contents of AS decreased slightly with the severeness of heat treatments, whereas pH and VBN content were increased. Total free amino acid contents of raw AS and RAS were 12,802.5 mg% and $11,212.6{\sim}12,105.4\;mg%$, and major amino acids were alanine, glutamic acid, leucine, isoleucine, valine and lysine. Also contents of IMP, hypoxanthine, TMAO and TMA in AS and RAS were 42.1 mg% and $35.5{\sim}40.9\;mg%$, 103.7 mg% and $103.1{\sim}105.5\;mg%$, 78.8 mg% and $58.2{\sim}71.6\;mg%$, 55.8 mg% and $58.9{\sim}68.5\;mg%$ respectively. And a little changes were observed in whole volatile components of AS with severeness of heat treatments by GC chromatogram patterns. Judging from the chemical and sensory evaluations, the Fo 3 heat treatment sample was not inferior to raw AS, and maintained good quality for 1 year storage.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.406-413
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• 2012

Effect of three additives, chitosan, ferric chloride, and MPE50 on membrane fouling reduction was studied. They were introduced with various dosing rate into activated sludge, and changes in filtration resistance measured by the batch cell filtration test were evaluated. Both the filtration resistance and the specific cake resistance were minimized at 20 mg/g-MLSS with chitosan, 70 mg/g-MLSS with ferric chloride, and 20 mg/g-MLSS with MPE50 addition, respectively. Introduction of the additives into the activated sludge resulted in reduction of not only cake resistance, but also fouling resistance. However, the chitosan addition to three different activated sludge resulted in three different optimal dose of 10, 20, 30 mg/g-MLSS, respectively. This implies that the optimal dose is dependent on sludge characteristics rather than a constant value. Overdose above the optimal dosage always aggravated filterability in all cases. Zeta potential of sludge flocs, relative hydrophobicity, floc size distribution, soluble EPS concentration and supernatant turbidity were measured in order to analyze fouling reduction mechanism. Nearly neutral surface charge along with the largest particle size was observed at the optimal dose. This could be explained by particle destabilization and restabilization mechanism as positively charged additives were injected into sludge flocs of negative surface charge. Both soluble EPS concentration and supernatant turbidity also showed the lowest value at the optimal dose. These foulants are believed to be coagulated and entrapped in sludge flocs during flocculation. Chitosan and MPE50 which are cationic polymeric substances showed higher reduction in both soluble EPS and fine particles comparing with ferric chloride.

• Journal of Korean Society of Forest Science
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• v.35 no.1
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• pp.39-46
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• 1977

In the analysis of variance between population and between individual trees (families), the fluctuation of values of variances due to sample size, (number of family) was analysed by two different designs, i.e. 2-level nested design with equal sample size and randomized complete block design. The variables were seedling heights and root calipers of 1-0 and 1-1 seedlings of Pinus densiflora S. et Z. The details of three natural stands and their progeny characters were presented in previous reports. 1. In nested design analysis. increase of sample size resulted the decrease of F-values among families in general, however, the F-values among populations showen the increasing tendency. The smaller the sample size, the larger the F-values fluctuation was resulted in general. At the point of beyond sample size 10, however, the fluctuation become to be stabilized. The F-value fluctuation seemed to be more in the case of analysis with random sampling method than with sequentially accumulated sampling method. And also such a tendency was more obvious in smaller sample size than in large one. 2. In R.C.B.D. analysis, the sample size to affirm the family variation was smaller than that for population variations.