• 한국축산식품학회지
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• 제34권2호
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• pp.257-261
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• 2014

The objective of this study was to evaluate the effects of NaCl on the biofilm formations of the isolate from Staphylococcus aureus outbreaks linked to ham. The S. aureus ATCC13565 isolated from ham was exposed to NaCl concentrations of 0%, 2%, 4%, and 6% supplemented in tryptic soy broth (TSB) for 24 h at $35^{\circ}C$, followed by plating 0.1 mL of the culture on tryptic soy agar containing 0%, 2%, 4%, and 6% NaCl, respectively. After incubating at $35^{\circ}C$ for 24 h, the colonies on the plates were collected and diluted to $OD_{600}$ = 0.1. The diluents of S. aureus were incubated on a 96-well flat bottom plate containing TSB plus the appropriate NaCl concentrations, and the biofilm formation was quantified by crystal violet staining after being incubated at $35^{\circ}C$ for 9 h. Confocal laser scanning microscope (CLSM) was also used for visualizing the biofilm formation of S. aureus at NaCl concentrations of 0%, 2%, 4%, and 6%. The transcriptional analysis of biofilm-related genes, such as icaA, atl, clfA, fnbA, sarA, and rbf, was conducted by quantitative real-time PCR. Crystal violet staining and CLSM showed that the biofilm formations of S. aureus increased (p<0.05) along with the NaCl concentrations. Moreover, the expression of the icaA genes was higher at the NaCl concentrations of 4% and 6% as compared with 0% of NaCl by approximately 9-folds and 20-folds, respectively. These results indicated that the NaCl formulated in processed food may increase the biofilm formations of S. aureus by increasing the icaA gene expressions.

• Asian-Australasian Journal of Animal Sciences
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• 제17권11호
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• pp.1501-1508
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• 2004

In this study the effect of extenders and temperatures on sperm viability and fertilizing capacity of boar sperm during long-term storage was investigated. Acrosomal integrity, membrane integrity, motility and hypo-osmotic resistance were evaluated by fluorescence and light microscopy. An in vitro fertilization test was performed to assess the fertilizing capacity of stored spermatozoa. The five diluents tested were ranked according to their ability to maintain sperm functional parameters and Zorlesco (ZO) extender with BSA or with PVA instead of BSA produced the best results. Zorlesco extender substituted with PVA (ZO+PVA) was found to maintain motility both at 15 and 20$^{\circ}C$. within 5 days of storage, but the quality of semen stored at 15$^{\circ}C$ decreased thereafter as compared to semen stored at 20$^{\circ}C$ Semen stored at 5$^{\circ}C$ demonstrated rapid loss of motility already within 24 h. Both fertilization and cleavage of semen stored at 20$^{\circ}C$ in ZO substituted with PVA instead of BSA did not change significantly until day 8 of storage. It is therefore concluded that PVA can be used to substitute for BSA and 20$^{\circ}C$ was more suitable than 15$^{\circ}C$ for boar semen storage, and in vitro fertilizing capacity of spermatozoa was maintained for at least 8 days in ZO+PVA at 20$^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• 제24권2호
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• pp.181-189
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• 2011

Cryopreservation protocols induce partially irreversible damage to mammalian sperm plasma membranes. Previous studies have indicated that adding cholesterol to the plasma membrane, as cholesterol-loaded-cyclodextrins, improves cryosurvival of sperm. Therefore, the purpose of this study was to determine if treating sperm of Markhoz bucks with cholesterol-loaded-cyclodextrins (CLC) (0, 0.75, 1.5, 2.25 and 3 mg/ml diluted $240{\times}10^6$ sperm/ml) in Tris-citric acid-glucose diluents with and without egg yolk (containing 5% glycerol) would improve the post-thaw sperm quality. The motion characteristics were evaluated with a Computer Assisted System Analyzer (CASA); acrosome integrity and vitality were measured with the triple-stain technique. Samples were recovered before and after freezing by means of putting straws into $37^{\circ}C$ water for 30 sec and then parameters were assessed. The results showed that the treatments significantly affected motility, progressive motility, recovery rate, curvilinear velocity, beat cross frequency, live sperm with reacted acrosome, live sperm with unreacted acrosome, dead sperm with reacted acrosorne, and dead sperm with unreacted acrosome during freezing (p<0.05). However; no significant differences were found for average path velocity, straight line velocity, amplitude of lateral head displacement, straightness and linearity (p>0.05). The best results were observed for extender containing 2.25 mg/ml ($240{\times}10^6$ sperm/ml) CLC supplemented with 2.6% egg yolk. In conclusion, the findings of this study indicate improved Markhoz sperm viability and motility following treatment in the presence of egg yolk.

• 멤브레인
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• 제27권2호
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• pp.189-198
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• 2017

본 연구는 수처리 분리막에 제조하기 위하여 열유도 상분리법(thermally induced phase separation, TIPS)을 이용하였고, 기계적 물성과 내화학성이 우수한 폴리플루오르화비닐리덴(poly(vinylidene fluoride)(PVDF)) 고분자와 실리카를 이용하여 특성평가를 진행하였다. 특성평가에 사용된 희석제는 dioctyl phthalate (DOP), dibutyl phthalate (DBP)를 사용하였으며, PVDF와 실리카의 비율에 따른 분리막 제조 조건을 알아보기 위하여 결정화 온도, 흐림점, SEM 이미지 등을 관찰하였다. 실리카의 함량이 증가할수록 결정화 온도와 흐림점이 증가하였음을 확인하였고, 상평형도 작도를 통하여 분리막 제조 조건을 확인하였다.

• 폴리머
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• 제35권2호
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• pp.183-188
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• 2011

수산기를 함유한 3관능 아크릴레이트(PETA; pentaerytritol triacrylate)를 pentaerytritol과 acrylic acid의 축합반응으로 합성하였다. 최적반응 조건이 용매로 heptane이 사용되고 pentaerytritol과 acrylic acid의 몰비가 1:4일때, 최고수율의 3관능 아크릴레이트를 얻을 수 있었다. 그 후, 다양한 디이소시아네이트와 PETA간 축합반응을 통해 여러가지 6관능 우레탄 아크릴레이트(UA)를 합성하였다. 합성된 우레탄 아크릴레이트는 반응형 희석제를 광개시제와 함께 자외선 광경화한 후, 형성된 경화필름의 물성을 측정하였다. 방향족 벤젠고리를 포함하고 있는 우레탄 아크릴레이트는 지방족 분자를 포함하고 있는 우레탄 아크릴레이트에 비해 내후성이 취약하였으며, UA-2의 경우 연필경도 및 내스크레치성이 가장 우수하였고 경화도가 가장 우수하였던 UA-l의 경우 내약품성이 가장 우수하였다. 밀착성의 경우 모든 조성에서 우수한 결과를 얻었으며, 경화도가 가장 낮은 UA-3의 경우 물리적 특성이 가장 낮았다.

• 청정기술
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• 제23권2호
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• pp.148-157
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• 2017

To prepare UV-curable polyurethane-acrylate oligomer, NCO-terminated urethane prepolymers with trimethylolpropane, [TMP; 0 (0), 0.1 (0.021) and 0.2 (0.043) mole (mole fraction)] as crosslinkable tri-functional chain extender were end-capped with pentaerythritol triacrylate [PETA; 2.0 (0.400), 1.7 (0.354) and 1.4 (0.304) mole (mole fraction)] with one hydroxyl group/three vinyl functionalities. The stable as-formulated UV-curable polyurethane-acrylates [stable mixtures of PETA-capped oligomer/reactive acrylic monomer diluents without/with heptadecafluorodecyl methacrylate (PFA; 0, 6 and 9 wt%)] were formed up to 0.2 (0.043) mole (mole fraction) of TMP content in the prepolymer, while homogeneous-mixing failed at 0.3 (0.068) mole (mole fraction), in which the crosslink density in NCO-terminated urethane prepolymer was too high to enable the formation of stable mixture. This study examined the effect of TMP/PETA molar ratio and heptadecafluorodecyl methacrylate (PFA) content (wt%) on the properties of UV-cured polyurethane-acrylates as marine antifouling coating materials. The properties of UV-cured polyurethane-acrylate were found to be significantly dependent on the crosslinkable TMP/PETA ratio and PFA content. With the increasing of the TMP and PFA contents, the contact angles increased, and consequently the surface tension decreased. The adhesion of algae/barnacles to PFA contained film samples were found to be sufficiently weak to allow their easy removal. These results suggest that the UV-cured samples containing PFA have strong potential as coating materials for antifouling applications.

• 한국광물학회지
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• 제21권4호
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• pp.415-423
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• 2008

외핵은 대부분 철로 이루어져 있으나 외핵의 밀도를 10% 정도 줄일 수 있는 희석 원소가 존재해야 한다. 외핵에서 존재할 가능성이 있는 가벼운 희석원소가 수소와 산소라는 가정 하에, 고압 하에서 수소의 열역학적 안정성을 적철석($Fe_2O_3$) + 수소($H_2$) $\to$ 괴타이트(FeOOH) + 철(Fe) 반응관계식을 이용하여 계산하였다. 열역학적 해석 결과, 상온 및 상압에서 이러한 화학반응의 깁스자유에너지는 12.62 kJ/mol로 계산되었다. 상온에서 압력이 증가함에 따라 깁스자유에너지 값은 감소하여 0.068 GPa에서 '0 kJ/mol'을 나타내었다. 압력이 증가함에 따라 깁스자유에너지 값은 일정한 비율로 점차적으로 감소하여 200 GPa에서는 -208.26 kJ/mol을 나타내었다. 이러한 열역학적 분석 결과로 볼 때 고압 하에서 수소와 철산화물이 반응하여 철원소와 철 수산화물을 생성하는 환원반응이 선호되며, 수소와 산소가 철수산화물의 형태로 원시지구 핵 내에 존재하게 되었을 가능성을 배제할 수 없다.

• Journal of Pharmaceutical Investigation
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• 제32권1호
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• pp.7-11
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• 2002

The purpose of this study was to develop a new $^{l3}C-urea-containing$ capsule for diagnosis of H. pylori. The urea-containing capsules were prepared with various diluents such as polyethylene glycol (PEG), microcrystalline cellulose, sodium lauryl sulfate and citric acid. The dissolution test, $^{l3}C-urea$ breath test and stability test were then performed on the capsules. Microcrystalline cellulose and sodium lauryl sulfate retarded the initial dissolution rates of urea. However, PEG increased the initial dissolution rates of urea. Furthermore, two formulae composed of PEG, [$^{l3}C-urea/PEG$ (38/1.9 mg/cap)] and [$^{l3}C-urea/PEG/citric$ acid (38/1.9/1.9 mg/cap)] had the maximum DOB value, about 16 at 20 mim, while the formula composed of only 38 mg $^{l3}C-urea$ had the maximum DOB value at 30 min. The results indicated that PEG improved the, sensitivity of $^{l3}C-urea$ in the human volunteers. The capsule [$^{l3}C-urea/PEG$ (38/1.9 mg/cap)] was stable for at least six months in 25 and $37^{\circ}C$. Thus, a PEG-containing capsule, [$^{l3}C-urea/PEG$ (38/1.9 mg/cap)] would be a more economical, sensitive and stable preparation for diagnosis of H. pylori.

• 한국표면공학회지
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• 제49권2호
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• pp.211-217
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• 2016

Boride coating applied on steam turbine parts of power plants has provided good particle erosion resistance under temperature of $550^{\circ}C$, but it isn't able to protect the parts effectively any more in ultra super critical (USC) steam turbine which is being operated up to temperature of $650^{\circ}C$. To ensure stable durability for USC steam turbine parts, an alternative coating replacing boride coating should be developed. In this study, multi-component boride coatings containing elements such as chromium (Cr) and vanadium (V) were formed on base metal (B50A365B) using thermochemical treatment method called by pack cementation. The thermochemical treatments involve consecutive diffusion of boron(B) and Cr or/and V using pack powders containing diffusion element sources, activators and diluents. The top layer of Cr-boride coating is primarily consisted of $Cr_2B_3$ and $Cr_5B_3$, while that of V-boride coating is mostly consisted of $VB_2$ and $V_2B_3$. The (Cr,V)-boride coating is consisted of $Cr_2B_3$, $Cr_5B_3$ and $V_2B_3$ mostly. The top surfaces of 3 multi-component boride coatings show hardness of $3200-3400H_v$, which is much higher than that of boride, about $1600-2000H_v$. In 5 wt.% NaCl solution immersion tests, the multi-component boride coatings show much better corrosion resistance than boride coating.

• 한국임상약학회지
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• 제9권1호
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• pp.71-76
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• 1999

The stability of penicillin G potassium injection after reconstitution was evaluated in two different diluents of sodium chloride $0.9\%$ and dextrose $5\%$ in water stored at room temperature or refrigerated condition. The concentrations of penicillin G, stored for 24 hours at room temperature or for 10 days at refrigerated condition, were determined by HPLC. Also the pHs of the reconstituted solutions were monitored. The concentrations and pHs of penicillin G potassium 500,000 U/ml injection after reconstitution gradually decreased in all conditions. Stored at room temperature after reconstitution, a new peak which suspected as degradation products of penicillin G was detected in 5 hours in sodium chloride $0.9\%$, 4 hours in dextrose $5\%$ in water. At refrigerated condition, the new peak was detected in 4 days in both sodium chloride $0.9\%$ and dextrose $5\%$ in water. The degradation products of penicillin G allergy have been thought to be one of the substances responsible for evoking allergic reactions. In conclusion, the penicillin G potassium 500,000 U/ml injection after reconstitution was stable for 4 hours in sodium chloride $0.9\%$ 3 hours in dextrose $5\%$ in water solution at room temperature. At refrigerated condition, both solutions were stable for 3 days after reconstitution.