• KSBB Journal
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• 제30권6호
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• pp.332-338
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• 2015

The objective of this study was designed to determine the possibility of bioethanol production from wasted medium density fiberboard (wMDF). We were investigated the enzymatic saccharification characteristics using the enzyme (Cellic CTec3) after pretreatment with sodium chlorite. According to the component analysis results, the lignin contents before and after the pretreatment of wMDF (milling using sieve size of $1,000{\mu}m$) was significantly reduced from 31.13% to 4.11%. Therefore, delignification ratio of pretreated wMDF was found to be up to about 87-89% depending on the sieve size. And we were tested to compare the saccharification ratio according to the sieve size of wMDF ($1,000{\mu}m$, $200{\mu}m$), but it was no significance depending on the sieve size. When enzyme dosage was 5% based on the substrate concentration, enzymatic saccharification ratio was obtained up to 70% by maintaining at $50^{\circ}C$ for 72 hours. We could made the substrate concentration of pretreated wMDF ($1,000{\mu}m$) up to 12% and then enzymatic saccharification ratio was 76.8%, also contents of glucose and xylose were analyzed to 77,750 and 14,637 mg/L, respectively.

• 한국재료학회지
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• 제26권3호
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• pp.109-116
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• 2016

To achieve the fabrication of high-quality Ag-coated Cu particles through a wet chemical process, we reported herein pretreatment conditions using an ammonium-based mixed solvent for the removal of a $Cu_2O$ layer on Cu particles that were oxidized in air for 1 hr at $200^{\circ}C$ or for 3 days at room temperature. Furthermore, we discussed the results of post-Ag plating with respect to removal level of the oxide layer. X-ray diffraction results revealed that the removal rate of the oxide layer is directly proportional to the concentration of the pretreatment solvent. With the results of Auger electron spectroscopy using oxidized Cu plates, the concentrations required to completely remove 50-nm-thick and 2-nm-thick oxides within 5 min were determined to be X2.5 and X0.13. However, the optimal concentrations in an actual Ag plating process using Cu powder increased to X0.4 and X0.5, respectively, because the oxidation in powder may be accelerated and the complete removal of oxide should be tuned to the thickest oxide layer among all the particles. Back-scattered electron images showed the formation of pure fine Ag particles instead of a uniform and smooth Ag coating in the Ag plating performed after incomplete removal of the oxide layer, indicating that the remaining oxide layer obstructs heterogeneous nucleation and plating by reduced Ag atoms.

• Journal of Periodontal and Implant Science
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• 제42권3호
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• pp.95-104
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• 2012

Purpose: The purpose of this study was to determine whether increasing the Ti6Al4V surface oxide negative charge through heat ($600^{\circ}C$) or radiofrequency plasma glow discharge (RFGD) pretreatment, with or without a subsequent coating with fibronectin, stimulated osteoblast gene marker expression in the MC3T3 osteoprogenitor cell line. Methods: Quantitative real-time polymerase chain reaction was used to measure changes over time in the mRNA levels for osteoblast gene markers, including alkaline phosphatase, bone sialoprotein, collagen type I (${\alpha}1$), osteocalcin, osteopontin and parathyroid hormone-related peptide (PTH-rP), and the osteoblast precursor genes Runx2 and osterix. Results: Osteoprogenitors began to differentiate earlier on disks that were pretreated with heat or RFGD. The pretreatments increased gene marker expression in the absence of a fibronectin coating. However, pretreatments increased osteoblast gene expression for fibronectin-coated disks more than uncoated disks, suggesting a surface oxide-mediated specific enhancement of fibronectin's bioactivity. Heat pretreatment had greater effects on the mRNA expression of genes for PTH-rP, alkaline phosphatase and osteocalcin while RFGD pretreatment had greater effects on osteopontin and bone sialoprotein gene expression. Conclusions: The results suggest that heat and RFGD pretreatments of the Ti6Al4V surface oxide stimulated osteoblast differentiation through an enhancement of (a) coated fibronectin's bioactivity and (b) the bioactivities of other serum or matrix proteins. The quantitative differences in the effects of the two pretreatments on osteoblast gene marker expression may have arisen from the unique physico-chemical characteristics of each resultant oxide surface. Therefore, engineering the Ti6Al4V surface oxide to become more negatively charged can be used to accelerate osteoblast differentiation through fibronectin-dependent and independent mechanisms.

• 원예과학기술지
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• 제17권2호
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• pp.138-140
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• 1999

카네이션의 약배양 기술을 확립하고자 저온 전처리, 암처리, Ficoll처리가 약배양에 미치는 효과를 조사하였다. 약배양에 적합한 화분의 발육단계인 1핵기 소포자 전후 화분의 약을 가지는 카네이션 화뢰의 직경은 4~6mm이었다. 카네이션 약배양 후 캘러스 형성과 배양 후 약의 반응에 가장 효과적인 저온전처리 기간은 7일이었다. 명배양하는 것보다 암배양하는 것이 캘러스 형성과, 형성된 캘러스로부터 root 분화에 효과적이었다. Ficoll처리는 캘러스 형성에 큰 효과는 없었지만, 형성된 캘러스로부터 신초와 root가 분화되었다.

• 한국식품저장유통학회지
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• 제5권4호
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• pp.320-325
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• 1998

본 연구에서는 석량, 미원 2품종의 풋콩을 실험재료로 사용하여 냉동 저장전 전처리 기술의 일환인 blanching 및 염장처리를 행하여 냉동저장 중 어떠한 영향을 미치는지를 조사하였다. 품질평가로는 수분함량, 색도, Vitamin C 함량의 변화, peroxidase와 lipoxygenase 활성 및 경도를 살펴보았다. 수분함량의 변화는 무처리 경우에는 현저한 감소를 보여주었으나, blanching 처리구와 염처리구는 저장기간 중에도 큰 변화를 변화를 보이지 않았다. Vitamin C 함량에서는 blanching 처리한 것이 열에 의한 영향 때문에 무처리한 것보다 함량이 줄어든 반면 염장 처리구에서는 높은 비타민 C 함량을 나타내었다. 또한 콩의 맛에 관여하는 효소인 peroxidase와 lipoxygenase의 경우 전처리 공정으로 blanching이나 염처리만으로는 충분히 불활성화 시키지 못하였으나, -2$0^{\circ}C$의 냉동저장 후 lipoxygenase활성은 90%정도 불활성화 된 것으로 나타났다. 그리고 경도를 살펴본 결과, 미원과 석량 모두 blanching처리구가 다소 높은 경도를 보인 반면, 염처리구에서 미원은 경도가 급격히 감소하는 경향을 볼 수 있었으며, 석량의 경우는 약간 감소하는 경향을 보였다. 이상의 결과, 본 연구에서는 염처리조건으로 2%, 180분 동안 염장 처리한 것이 가장 적당한 것으로 나타났다. 그리고 풋콩을 수출용으로 저장하기 위해서는 저장에 앞서 전처리 공정이 필요하며, blanching이나 염처리를 한다면 풋콩의 품질변화를 최소화하고 저장 기간을 연장시킬 수 있으며, 또한 콩의 조리 시 염의 첨가로 조직을 연화시켜 cooking시간을 단축시킬 수 있으리라 기대된다.

• Food Science and Biotechnology
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• 제17권4호
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• pp.751-754
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• 2008

Texture analysis, sensory evaluation, and scanning electronic microscopic (SEM) observation were conducted to evaluate the effects of different calcium salts (calcium lactate, calcium acetate, and calcium chloride) and vitamin C on the textural properties of kimchi, gamma-irradiated at 25 kGy. Increase of the hardness and sensory score were observed in the kimchi pretreated with calcium salt or vitamin C as compared with the untreated and irradiated kimchi. And the hardness and sensory quality of the co-pretreated sample with 0.01% of calcium lactate and 0.3% of vitamin C were the highest after 30 days at $35^{\circ}C$, which indicates that the co-pretreatment is effective in preventing a decrease of the texture and sensory qualities of kimchi by gamma irradiation. Also, this result was supported by the SEM observation.

• 한국식품과학회지
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• 제48권6호
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• pp.565-568
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• 2016

고온에서 가열 살균한 쇠고기의 복합인산염 전처리 유무에 따른 조직 경화 개선 효과를 고기 보수력 증가 측면에서 고찰한 결과 고기 중량 대비 0.35% (w/w) 복합인산염을 갈비살 및 우둔살에 각각 1시간 혼합, 방치한 후 $100^{\circ}C$에서 5-40분간 가열시 무처리구 대비 보수력의 간접 지표인 중량 기반 수율이 5-10% 내외 향상되는 것으로 나타났다. $115^{\circ}C$에서 30분간 가열 살균한 쇠고기에 대한 0.35% (w/w) 복합인산염 1시간 염지 및 $100^{\circ}C$, 2분 조건의 블렌칭 공정 조합 전처리 효과를 무처리구와 비교한 결과 텍스처 개선 효과가 유의차(p<0.05) 있게 나타났다. 전처리 우둔살 및 갈비살의 기계적 질김 강도가 각각 1.3, $1.4kg_f$로서 무처리구의 2.0, $1.8kg_f$에 비해 36, 19% 텍스처 질김 정도가 개선되었다. 전처리 후 가열 살균한 쇠고기에 대한 저장시 질긴 텍스처 변화를 $10^{\circ}C$, 30일 보관 후 기계적 질김 강도 비교를 통해 고찰한 결과 갈비살 및 사태살에서 무처리구 $1.7kg_f$에 비해 $1.1kg_f$의 값을 보여 평균 35% 내외의 질긴 텍스처 개선 효과가 유의차 있게 나타났다(p<0.05).

• The Korean Journal of Physiology and Pharmacology
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• 제3권4호
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• pp.383-391
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• 1999

This study was carried out to determine whether the effects of an ${\alpha}_2-adrenoceptor$ agonist, clonidine, on mean arterial pressure (MAP) and heart rate (HR) are influenced by mild hypothermia. Experiments were performed in respiration-controlled and spontaneously breathing pentobarbital-anesthetized rats. Rectal temperature was maintained at $37.5{\pm}0.3^{circ}C$ for normothermic groups or at $35.2{\pm}0.3^{circ}C$ for mild hypothermic groups. Intravenous injection of clonidine (1 and 2 ${\mu}g/kg)$ produced depressor and bradycardic responses in spontaneously breathing rats under both normothermic and mild hypothermic condition: a decrease in MAP was not altered but bradycardic response was significantly augmented in the mild hypothermic group as compared with the normothermic group. Under the respiration-controlled condition, the hypotensive effect of clonidine $(2\;{\mu}g/kg)$ was reduced, whereas the bradycardic effect was increased in mild hypothermic rats as compared with normothermic rats. Both hypotensive and bradycardic effects of clondine $(2\;{\mu}g/kg)$ were blocked by pretreatment with an ${\alpha}_2-adrenoceptor$ antagonist, yohimbine (0.5 mg/kg), in both thermal conditions. Yohimbine (0.5 mg/kg, i.v.) alone produced signifcantly an increase in heart rate in the mild hypothermic group than in the normothermic group. Pretreatment with a muscarinic receptor antagonist, atropine methylnitrate (1 mg/kg, i.v.), attenuated the bradycardic effect of clonidine in the mild hypothermic group but not in the normothermic group. These results suggest that clonidine- induced bradycardia is amplified by mild hypothermia probably through an increased parasympathetic activity.

• 한국식품저장유통학회지
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• 제12권4호
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• pp.305-309
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• 2005

곶감은 상온 유통 시 백분과 곰팡이가 발생하고, 갈변과 조직의 경화가 일어난다. 이러한 문제점을 해결하여 상품성을 유지하고자 계피추출물처리와 포장재에 따른 곶감의 품질변화를 알아보았다. 그 결과 계피추출물에 곶감을 침지한 후 대조구(무포장), LDPE(low density polyethylene)필름포장구과 적층필름포장구(Nylon/LDPE)로 각각 포장하여 상온($15^{\circ}C$)에서 100일간 저장 시 다른 포장구 보다 적층필름포장구(Nylon/LDPE)가 중량변화는 $20.2\%$, 경도는 $87\%$, 갈변도는 $56\%$ 이상 낮게 나타났다. 표면색도 변화 역시 계피추출물 처리시 0.80으로 가장 낮은 변화를 보여, 저장 중 곶감의 품질이 다른 처리구에 비해 높게 유지됨으로써 상품성이 가장 높음을 알 수 있었다.

• Preventive Nutrition and Food Science
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• 제11권4호
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• pp.318-322
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• 2006

The objective of this experiment was to investigate the effect of extrusion of ginseng roots in twin screw extruder on susceptibility of ginseng starch toward hydrolysis by ${\alpha}-amylase$ BAN 480L (Novozyme, Denmark) and cellulase Celluclast 150L and saccharification by amyloglucosidase AMG-E (Novozyme, Denmark). The extrusion was conducted at 22% and 30% moisture contents of feed at screw speed 300 rpm. Barrel temperature at zone 1 was adjusted at $100^{\circ}C$ and $120^{\circ}C$. The results showed that extrusion process improved the ginseng ${\alpha}-amylase$ susceptibility as compared to traditionally dried ginseng (white and red ginseng). Reducing sugar of hydrolyzed extruded samples was 2,500% of its initial concentration, whereas the reducing sugar of hydrolyzed non-extruded sample was only 200% of its initial concentration. However, addition of cellulase during liquefaction lowered the saccharification yield of both non-extruded and extruded samples as well.