• 생명과학회지
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• 제25권9호
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• pp.1021-1026
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• 2015

Invertase (β-D-fructosfuranosidase, EC 3.2.1.26)는 설탕을 포도당과 과당으로 가수분해하는 반응을 촉매한다. 3종류의 invertases [액포(수용성 산), 세포질(수용성 알칼리) 및 세포벽 결합]가 식물에서 연구되어 왔다. 우리는 순차적인 ammonium sulfate 침전, 이온교환크로마토그래피, 흡수크로마토그래피, Green-19 친화크로마토그래피 과정을 통해 완두콩(Pisum sativum L.) 발아체로부터 중성 invertase의 세포막 연결 isoform을 430배 순수 분리하였다. 분리된 세포막과 결합 된insoluble invertase (IN-INV)는 최적 pH는 중성에서 알칼리 사이(pH 6.8-7.5)로 나타났다. 이 효소는 Tris 뿐만 아니라 Hg²⁺ and Cu²⁺와 같은 중금속에 의해 저해되었다. IN-INV 의 K_m과 V_max 값은 각각 12.95 mM과 2.98 U/min으로 측정되었다. IN-INV는 기질로써 과당뿐만 아니라 라피노오스와 반응하기 때문에 진정한 β-fructofuranosidase로 판명되었다. IN-INV의 분자량 20 kDa이었다. 위 결과로 볼 때 GA 영향으로 급속히 자라는 발아체에서 단백질이 분리되었는데 특징적으로 invertase였다.

• 대한소아치과학회지
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• 제26권2호
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• pp.262-274
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• 1999

구강내의 불소농도를 증가시키는 여러 방법에는 불화된 상수도를 섭취하거나 불소보조제를 복용하는 전신적 투여방법과 불소치약, 불소양치액, 불소젤의 도포와 같은 국소적 투여방법이 있다. 그동안 다양한 delivery system을 통한 국소도포용 불소제제가 임상적으로 우식증을 예방하는데 도움이 된다는 사실이 확인되었다. 최근의 연구에서 불소의 항우식효과는 치아주위의 oral fluid environment속에서 불소의 중요성을 지적하고 있다. 비자극성 전타액내 불소농도는 주어진 시간동안 치면과 상호작용이 가능한 aqueous phase의 불소를 나타낸다고 한다. 따라서 타액내의 불소 농도를 조사함으로써 간접적으로 우식예방효과에 대한 정보를 얻을 수 있다. 우식증예방을 위해 환자에게 여러 가지 국소도포방법 중 한 가지를 추천하기에 앞서 이들 각 방법이 타액내 불소농도를 증가시키는데 얼마나 효과적인지 알 필요가 있다. 이에 저자는 국소적 불소도포후 구강내 불소의 잔류량과 시간별 농도를 비교하고자 현재 국내에서 많이 쓰이고 있는 서로다른 네가지 불소제제를 사용하고 난 뒤 시간변화에 따른 타액내 불소농도를 HMDS를 이용한 확산법과 불소이온전극을 사용하여 측정하고 다음과 같은 결과를 얻었다. 1. 비자극성 혼합타액내 평균 불소농도는 $0.0152ppm{\pm}0.0091ppm$이었으며, 비자극성 타액분비율은 0.34-0.36ml/min으로 각군간에 통계적 유의차는 없었다. 2. 불소제제 사용직후를 제외하고는 모든 구간에서 타액내 불소 농도는 APF gel군>neutral gel군>불소양치액군>불소치약군의 순이었고, 불소처치 120분 경과후 불소치약군의 타액내 불소농도가, 180분 경과후 불소양치액군의 불소농도가 대조군과 통계적 유의차를 보이지 않은 반면, 6시간 경과후까지 APF gel군과 neutral gel군의 타액내 불소농도가 대조군에 비해 유의성있게 높게 유지되었다(p<0.05). 3. 불소제제 사용직후부터 120분 경과후까지 타액내 잔류불소량($AUC_{0-120min}$)은 neutral gel군>APF gel군>불소양치액군>불소치약군의 순이었고, neutral gel군과 APF gel군이 대조군과 나머지 두 군에 비해 유의하게 높은 값을 보였다(p<0.05).

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2000년도 추계학술발표논문집
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• pp.83-83
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• 2000

Alkylketene dimer was known as a cellulose reactive or alkaline size because it does not require to fix to the fiber as do the traditional rosin sizes. A proposed sizing mechanism of AKD was the formation of P -ketoester bond between AKD and cellulose which provides the permanent attachment and the orientation of the hydrophobic alkylchains outward. However, some questions about the reaction had arisen and thus, the sizing mechanism of AKD has been a subject of controversy for several decades. The major concern of the controversy is that AKD is really reactive with cellulose or not in the papermaking conditions. In this study, reaction between AKD and pulp fiber was investigated, in order to find out whether AKD forms P-ketoester with pulp fiber during aging under no catalyzed neutral condition with obvious spectroscopic evidence. In addition, effect of aging treatment on the sizing development was studied. It has been disclosed that, in absence of water, AKD reacted with cellulose to form P -ketoester linkage under no catalyzed neutral condition, while, in presence of water, most of AKD was hydrolyzed to a dialkyl ketone or P -ketoacid. In addition, during the aging treatment of AKD-sized paper, its typical IR spectra bands gradually were reduced, completely disappeared after 6hr aging, and formed new absorption bands at 1707cm-' and shoulder peak at 1700cm-' which refer to the typical dialkylketone absorption bands. Therefore, the formation of P -ketoester between AKD and pulp fiber is impossible in the practical papermaking process. It could be suggested that the sizing development of AKD-sized paper is obtained by next two mechanism: 1) formation of a thin-layer of AKD on the fiber surface through melting and spreading of AKD emulsion particles by heat and 2) the hydrolysis of AKD to dialkyl ketone which has higher melting point, during drying and storage of AKD sized papers.

• 생물환경조절학회지
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• 제15권1호
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• pp.91-99
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• 2006

This study was conducted to determine the influence of postharvest dipping treatment with aminoethoxyvinylglycine (AVG) on ethylene production and composition of non-cellulosic neutral sugars in cell walls of 'Tsugaru' apple fruits during storage. Fruits were harvested on August 20, soaked in AVG 50 and 75 $mg L^{-1}$ solution for 5 minutes, and stored in cold storage chamber at $0{\pm}1^{\circ}C$ for 60 days. Fruit quality factor, ethylene productions, and cell wall component changes were investigated at 20 days interval. As a result, the fruit firmness and acid content were much higher in AVG treated fruits than those of untreated one during 60 days of cold storage. Ethylene production of AVG treated fruits was reduced to the level of 1/10 compared with untreated one. As to the change of non-cellulosic neutral sugars in the cell walls of 'Tsu- garu' fruits, the major sugar was arabinose and galactose in water, CDTA and $Na_2CO_3$ soluble fractions. The content of arabinose and galactose in untreated fruits increased as the softening of fruits was in progress, but the fruits treated with AVG showed a little change during storage, so it is predicted that these two cell wall compositional sugars were not solubilized by the treatment of AVG. Accordingly, the marketability of 'Tsu- garu' fruits could remarkably increase when soaking the fruits in AVG solution after harvest.

• Applied Biological Chemistry
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• 제37권5호
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• pp.320-325
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• 1994

볏짚의 사료가치를 증진시키기 위하여 알카리성 과산화수소를 이용하여 볏짚에 대한 처리수준별 화학성분의 변화와 in vitro 소화율을 조사 검토하였다. $H_2O_2(pH 11.5)$의 처리농도를 증가시킬수록 neutral detergent fiber(NDF), acid detergent fiber(ADF), hemicellulose, cellulose 및 lignin이 감소하였으며 $H_2O_2(pH 11.5)$를 처리한 후 수세시는 농도가 증가할수록 NDF, hemicellulose 및 lignin은 감소한 반면 ADF, cellulose, 회분은 증가하였다. 알카리성 과산화수소의 농도를 4%로 조정하여 처리하였을 때 pH는 $11.5{\sim}12.5$에서, 온도는 $55^{\circ}C$에서 세포벽구성물질의 분해에 효과적이었으며, 4% $H_2O_2(pH 11.5)$ 처리시 볏짚의 크기가 작을수록 잔류건물 중, hemicellulose, cellulose 및 lignin이 감소하였다. 알카리성 과산화수소의 처리에 의한 in vitro 소화율은 처리농도 및 pH가 증가할수록 볏짚의 크기가 작을수록 증가하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.231-232
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• 2016

We have fabricated the nc-Si, IGZO based nonvolatile memory TFTs using mobile protons, which can be generated by simple hydrogen insertion process via H-NB treatment at room temperature. The TFT devices above exhibited reproducible hysteresis behavior, stable ON/OFF switching, and non-volatile memory characteristics. Also executed hydrogen treatment in order to figure out the difference of mobile proton generation between PECVD and our modified H-NB CVD. The room temperature proton-insertion process can reveal flexible inorganic based all-in-one display panel including driving circuit and memory circuit.

• 한국임상약학회지
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• 제21권2호
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• pp.57-65
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• 2011

Incretin hormones such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide delay gastric emptying, increasing satiety, and enhance insulin secretion. Two new classes of treatments related to incretin hormones for the management of type 2 diabetes mellitus have emerged: GLP-1 receptor agonists (e.g., exenatide, liraglutide) and the dipeptidyl peptidase-4 (DPP-4) inhibitors (e.g., sitagliptin, saxagliptin, vildagliptin, alogliptin), which prevent the degradation of GLP-1. A MEDLINE search was conducted in order to evaluate the efficacy and safety of incretin-based therapies and publications were reviewed. Data from clinical trials indicated incretin-based treatment showed clinically significant reductions in hemoglobin A1c with low risk of hypoglycemia. Weight reductions were observed with GLP-1 receptor agonists where as DPP-4 inhibitors are weight neutral.

• 한국안전학회지
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• 제13권2호
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• pp.96-103
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• 1998

The treatment of the wastewater of Carmine-6B Process was studied using an electrochemical batch reactor with Pt-electrodes. The concentration of azo dye was exponentially decreased unto 6-37% residuum during 50 hr operations. The fractional conversion was not influenced by the initial pH value, but it was increased with increasing the rotating speed and/or temperature of the electrolyte. It was observed by the differential method of rate analysis that the rate of the oxidation reaction at anode was exponentially increased with increasing the cell voltage. The pH of the wastewater was changed from acid or alkali to neutral. The COD of the solution was increased at the beginning of the treatment, but it was decreased soon.

• Environmental Engineering Research
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• 제18권3호
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• pp.157-161
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• 2013

Treatment of textile wastewater by the electrocoagulation (EC) process is being investigated by this experimental study. The objective of this experiment is to observe the efficiency of the EC process in removing chemical oxygen demand (COD) and turbidity. In this experiment an iron electrode is used in the EC process, and different working parameters such as pH, current density and operating time were studied in an attempt to achieve a higher removal capacity. The results show that the maximum COD removal occurred at neutral pH at operating time 30 min. COD and turbidity removal reaches at maximum, with optimum consumption of electrodes, between current density 85-95 $A/m^2$, and only trace amounts of metals were determined in the EC treated effluent.

• Biomolecules & Therapeutics
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• 제1권1호
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• pp.109-120
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• 1993

Mechanisms for the hypocholesterolemic effetcs of $\beta$-glucan remain unclear. Rats were divided into 3 groups; normal control group, atherogenic group(oral administration of cholesterol 40 mg/kg/day and vitamin $D_2$320,000 IU/kg/day),${\beta}$-glucan treatment group(oral administration of atherogenic treatment and ${\beta}$-glucan 0.135 g/kg/day). The ${\beta}$-glucan treatment group showed moderate increases of serum lipids concentration compared with atherogenic group. In histopathological examination, aortas showed no critical lesions. The total fecal neutral sterols and bile acids excreted for 6 days was increased compared with both normal and atherogenic group. These result\ulcorner suggest that mechanisms for the hypocholesterolemic effect of ${\beta}$-glucan on rats were due to the inhibition of cholesterol absorption in the intestinal lumen and acceleration of cholesterol catabolism in the liver.