• Journal of Nutrition and Health
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• v.29 no.7
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• pp.747-757
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• 1996

In this study, the serum level of 25-hydroxyvitamin D(25-(OH)D) was measured by high pressure liquid chromatography(HPLC), and factors affecting it were investigated in 72 young adults age ranging from 21 years to 39 years with normal bone density. The mean level of serum 25-(OH)D was 20.0$\pm$6.8ng/ml in males and 26.1$\pm$12.3ng/ml in females, which was significantly higher in females (p<0.01). The serum level of parathyroid hormone(PTH) showed a negative correlation with that of 25-(OH)D(p<0.05). Time spent outdoors in a day correlated positively with the serum level of 25-(OH)D(p<0.01). During the day, a specific time between 12:00 a.m. and 2:00 p.m. showed the most significant correlation with the level of 25-(OH)D(p<0.005). Among the nutrients studied, fat and vitamin D intake were positively correlated with the serum 25-(OH)D level. Stepwise multiple regression analysis showed that the serum level of 25-(OH)D could be fit by vitamin D intake(34.7% explained), serum PTH level (27.3% explained) and the time spent outdoors during the specific time(28.4% explained).1996)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.449-452
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• 2009

In order to improve incombustibility of EPDM(Ethylene propylene diene monomer)-based rubber, inorganic materials as $Al(OH)_3$ and $Sb_2O_3$ were added. The mechanical and thermal properties have been measured for vulcanized rubber loaded with different concentrations of $Al(OH)_3$ and $Sb_2O_3$. As inorganic material contents increases from 5phr to 30phr, the specific gravity and hardness increase while elongation at break decreases. This study performed incombustibility test and thermal analysis through TGA(Thermogravimetric Analyzer). As a results, incombustible and thermal properties of EPDM-based rubber were improved as $Al(OH)_3$ and $Sb_2O_3$ contents increase.

• Journal of Environmental Science International
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• v.13 no.1
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• pp.79-87
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• 2004

Esterification of soybean oil with methanol was investigated. First of all, liquid-liquid equilibriums for systems of soybean oil and methanol were measured at temperatures ranging from 40 to 65$^{\circ}C$. Profiles of conversion of soybean oil with time were determined from the glycerine content in reaction mixtures for the different kinds of catalysts, such as NaOH, CaO, Ca(OH)$_2$, MgO, Mg(OH)$_2$, and Ba(OH)$_2$. The effects of dose of catalyst, cosolvent and reaction temperature on final conversion were examined. Esterification of waste vegetable oil with methanol was investigated and compared to the case of soybean oil. Solubility of methanol in soybean oil was substantially greater than that of soybean oil in methanol. When the esterification reaction of soybean oil was catalyzed by solid catalyst, final conversion was strongly dependent on the alkalinity of the solid catalyst, and increased with the alkalinity of the metal. Hydroxides from the alkali metals were more effective than oxides. When Ca(OH)$_2$ was used for the esterification catalyst, maximum value of final conversion was measured at dose of 4％. When CHCl$_3$ as a cosolvent, was added into the reaction mixture of soybean oil which catalyzed by Ba(OH)$_2$, maximum value of final conversion was appeared at dose of 3％. When waste vegetable oil was catalyzed by NaOH and solid catalysts, high final conversion, over 90％, and fast reaction rate were obtained.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.65-70
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• 2001

OH radical and NOx have been measured in a methane-air partially premixed flame using PLIF technique to define preheated air combustion characteristics. The temperature of mixture is determined by 300K, 400K, 600K and 800K below the auto-ignition temperature respectively. Flame height increases as equivalence ratio increased. As initial enthalpy is supplied, the radius of flame was increased and much amount of yellow flame in rich equivalence ratio was observed. This is due to the faster burning velocity. Also initial oxidization begins earlier as the initial temperature of mixture increased. It means that height of premixed flame front decreased. This phenomenon can be observed OH PLIF image. The qualitative analysis of OH concentration in the PLIF image shows that overall OH concentration increases with equivalence ratio and the initial temperature of mixture increased. At the preheating temperature goes up, axial gradient of OH concentration is less steep than that of lower temperature condition. This may identify that combustion reacts continuously, so preheated air combustion can evade the local heating and make high temperature indiscriminately in the overall reaction zone.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.95-104
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• 1997

We synthesized the following series of 3', 5'hydroxy modified thymidine analogs to check the potential asymmetric catalytic effects. 3'-monomethylammino and dimethylaminothymidine was synthesized from thymidine via 8 step and 7 step in 38%, 20% overall yields respectively. 5'Acetyl-3'-dimethylamino thymidine was prepared from thymidine via 8 step in 40% overall yield. 5‘-TBS-3'-up-t BOC methylamino thymidine was prepared from thymidine via 6 step in 30% overall yield. 3'-acetyl-5'-t BOC amino thymidine was prepared from thymidine via 7 step in 31% overall yield.

• Biomolecules & Therapeutics
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• v.15 no.4
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• pp.235-239
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• 2007

In order to evaluate the improvement effects of head of Panax ginseng on chronic arthritis, we have investigated the activity of butanol fraction (BuOH fraction) in vitro and in vivo system. BuOH fraction showed significant inhibition on the elastase activity. Anti-arthritic activity of BuOH fraction was also examined on type II collagen-induced arthritis in DBA/1J mice. Mice were immunized with injection of type II collagen emulsified in Freund's complete adjuvant, followed by a booster injection 21 days later. BuOH fraction(BHPG) was administered at an oral dose of 500mg/kg for 2 weeks from the 1st day boost. The hind paw edema was significantly decreased in the group of treatment with BuOH fraction compared to control. In collagen-induced DBA/1J mice, BuOH fraction did not affected the collagen antibody titer but significantly inhibited the tumor necrosis factoralpha(TNF-${\alpha}$) activity. These results were confirmed with histological evaluation of joint tissues. This study may raise the possibility that the usage of BuOH fraction of head of Panax ginseng as alternative medicine for the relief and prevention of rheumatoid arthritis symptoms.

• Journal of the Korean Home Economics Association
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• v.25 no.4
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• pp.9-18
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• 1987

This study is conducted to investigate the influence of addition of quarternary ammonium salt(cetyl trimethyl ammonium bromide: CTAB) when polyester(PET) fabric is treated with sodium hydroxide(NaOH), depending on experimental variables such as CTAB concentration, NaOH concentration, time & temperature, and the change in physical & chemical properties of alkaline-hydrolyzed PET fabrics depending on their weight loss. The results are as follows: 1. By adding CTAB in aqueous NaOH, the weight loss of PET fabric is increased remarkably and until the concentration of CTAB is reached at its cmc, and the higher the concentration of CTAB are, the more weight loss on PET fibrics are. 2. The addition of CTAB in aqueous NaOH is most effective at lower NaON concentration(2%) among various NaOH concentration, on increasing the amount of weight loss, while there are almost similar results through various treatment time and temperature. 3. As the amount of weight of weight loss on PET fabric is increased, the increase of void space in the PET yarn, of softness & dyeability of PET fabric and the decrease of tensile strength are found. On the other hand, the moisture regain shows a little increase by alkaline-hydrolysis on PET fabric while vertical absorption test & water retention value are not sufficiently sensitive to distinguish between the hydrophillicity of untreated and treated PET fabric. The shrinkage of PET fabric is induced by swelling in hot aqueous NaOH regardless of NaOH concentration & addition of CTAB.

• Advances in environmental research
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• v.5 no.2
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• pp.141-151
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• 2016

Large amounts of aluminum hydroxide ($Al(OH)_3$) exist in water purification sludge (WPS) because of the added aluminum coagulant in water treatment process. Notably, $Al(OH)_3$ is an amphoteric compound, can be dissolved in its basic condition using sodium hydroxide to form aluminate ions ($Al(OH)_4{^-}$). However, in a process in which pH is increasing, the humid acid can be dissolved easily from WPS and will inhibit the recovery and reuse of the dissolved aluminate ions. This study attempts to fix this problem by a novel approach to separate $Al(OH)_4{^-}$ ions using nanofiltration (NF) technology. Sludge impurity in a alkaline solution is retained by the NF membrane, such that the process recovers $Al(OH)_4{^-}$ ions, and significantly decreases the organic matter or heavy metal impurities in the permeate solution. The $Al(OH)_4{^-}$ ion is an alkaline substance. Experimental results confirm that a recovered coagulant of $Al(OH)_4{^-}$ ion can effectively remove kaolin particles from slightly acidic synthetic raw water.

• BMB Reports
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• v.44 no.3
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• pp.170-175
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• 2011

We identified a bovine $B_{12}$ trafficking chaperone bCblC in Bos taurus that showed 88% amino acid sequence identity with a human homologue. The protein bCblC was purified from E. coli by over-expression of the encoding gene. bCblC bound cyanocobalamin (CNCbl), methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl) in the base-off states and eliminated the upper axial ligands forming aquo/hydroxocobalamin ($OH_2$/OHCbl) under aerobic conditions. A transition of $OH_2$/OHCbl was induced upon binding to bCblC. Interestingly, bCblC-bound $OH_2$/OHCbl did not react with reduced glutathione (GSH), while the reaction of free$OH_2$/OHCbl with GSH resulted in the formation of glutathionylcobalamin (GSCbl) and glutathione disulfide (GSSG). Furthermore we found that bCblC eliminates the GSH ligand of GSCbl forming $OH_2$/OHCbl. The results demonstrated that bCblC is a $B_{12}$ trafficking chaperone that binds cobalamins and protects $OH_2$/OHCbl from GSH, which could be oxidized to GSSG by free $OH_2$/OHCbl.

• Journal of Nutrition and Health
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• v.12 no.1
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• pp.9-16
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• 1979

Cholecalciferol은 피하에서 자외선과 체온의 작용을 받아 7-dehydrocholesterol로부터 Previtamin D를 거쳐 합성이 되며 이어서 간에 빨리 축적, 25 hydroxylation을 거치게 되고 신장에서 가장 활성을 띤 형태인 $1.25-(OH)_{2}CC$로 변하게 된다. 한편 신장에서는 체내의 Ca, P이 정상으로 존재하게 되면 1-hydroxylation이 억제되는 대신 24-hydroxylation이 일어나 또 다른 active form인 $24,\;25-(OH)_{2}CC$가 되는데 24-hydroxylation의 역활이 무엇인가에 대해서는 아직 구체적으로 밝혀지지 않았다. $24,\;25-(OH)_{2}CC$나 $1.25-(OH)_{2}CC$는 모두 공통적으로 또 다른 active form인 $1.24,\;25-(OH)_{3}CC$를 형성할 수도 있다. 그중 $1.25-(OH)_{2}CC$는 Steroid H.으로 일컬어지기도 하는 Vit. D metabolite중에서 가장 활성을 가진 형태이며 표적기관으로 크게 소장, 뼈, 신장을 들 수 있다. 소장에서의 역활은 무엇보다도 Ca흡수에 관련되는 것으로 소장에서의 Ca흡수와 Ca BP합성에 관여한다. 골격 형성과 뼈의 mineralization에 관여하는 Vit. D metabolite를의 효과에 관해서는 아직까지 일관성있는 보고가 없다. 한편 $1.25-(OH)_{2}CC$는 side chain oxidation을 거쳐 $CO_{2}$와 미지의 물질을 생성하는데 이 mechanism이 어떤 의미를 갖는지는 분명치 않다. 그밖에 또 다른 표적기관으로서 최근 타액선의 존재가 알려졌으며 Vit. D가 배설되는 경로에 대해서는 새로운 바가 없다. Vit. D가 담즙을 통해서 우선적으로 배설되고 소량이 뇨를 통해 배설되는데 metabolite들의 배설경로는 더욱 규명되어야 할 과제이다.