• Archives of Pharmacal Research
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• 제20권6호
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• pp.560-565
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• 1997

The physicochemical properties of melatonin (MT) in propylene glycol (PG) and 2-hydroxypropyl-.betha.-cyclodextrin $(2-HP{\beta}CD)$ vehicles were characterized. MT was endothermally decomposed as determined by differential scanning calorimetry (DSC). Melting point and heat of fusion obtained were $116.9{\pm}0.24^{\circ}C $.and $7249{\pm}217 cal/mol$., respectively. MT as received from a manufacture was very pure, at least 99.9%. The solubility of MT in PG solution increased slowly until reaching 40% PG and then steeply increased. Solubility of MT increased linearly as concentration of $2-HP{\beta}CD$ without PG INCREASED$(R^2=0.993)$. MT solubility in the mixtures of pg and $2-HP{\beta}CD$ also increased linearly but was less than the sum of its solubility in $2-HP{\beta}CD$ and PG individually. The MT solubility was low in water, simulated gastric or intestinal fluid but the highest in the mixture of PG(40v/v%) and $2-HP{\beta}CD$ (30w/v%) although efficiency of MT solubilization in $2-HP{\beta}CD$ decreased as the concentration of PG increased. MT was degraded in a fashion of the first order kinetics $(r^2>0.90)$. MT was unstable in strong acidic solution (HCl-NaCl buffer, pH 1.4) but relatively stable in other pH values of 4-10 at $70^{\circ}C$. In HCl-NaCl buffer, MT in 10% PG was more quickly degraded and then slowed dpwm at a higher concentration. However, the degradation rate constant of MT in 2-HP.betha.CD was not changed significantly when compared to the water. The current studies can be applied to the dosage formulations for the purpose of enhancing percutaneous absorption or bioavailability of MT.

• 전기학회논문지
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• 제60권6호
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• pp.1169-1174
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• 2011

CdTe thin-film solar cell technology is well known that it can theoretically improve its conversion efficiency and manufacturing costs compared to the conventional silicon solar cell technology, due to its optical band gap energy (about 1.45eV) for solar energy absorption, high light absorption capability and low cost requirements for producing solar cells. Although the prior studies obtained the high light absorption, CdTe thin film solar cell has not been come up to the sufficient efficiency yet. So, doping method was selected for the improvement of the electrical characteristics in CdTe solar cells. Some elements including Cu, Ag, Cd and Te were generally used for the p-dopant as substitutional acceptors in CdTe thin film. In this study, the sputtering-deposited CdTe thin film was immersed in $AgNO_3$ solution for ion exchange method to dope Ag ions. The effects of immersion temperature and Ag-concentration were investigated on the optical properties and electrical characteristics of CdTe thin film by using Auger electron spectroscopy depth-profile, UV-visible spectrophotometer, and a Hall effect measurement system. The best optical and electrical characteristics were sucessfully obtained by Ag doping at high temperature and concentration. The larger and more uniform diffusion of Ag ions made increase of the Ag ion density in CdTe thin film to decrease the series resistance as well as mede the faster diffusion of light by the metal ions to enhance the light absorption.

• 대한전기학회논문지
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• 제39권2호
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• pp.183-191
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• 1990

Polycrystalline CdS film have been prepared by coating a slurry constiting of CdS, CdCl2, various amount of InCl3 and propylene glycol on glass substrate and by sintering in a nitrogen atmosphere, and their sintering behaviors, electrical properties and optical properties have been investigated. As the amount of InCl3 increases, the enhancing effect of CdCl2 on sistering decreses resulting in a sharp decrease in optical transmittance and an increase in electrical resistivity. The carrier concentration is almost independent of InCl3 added due to the occurrence of chlorine doping and to the compensating effect of indium dopant. Microstructure an optical properties of CdS film, which contain CdCl2 and InCl3 before sintering, can be improved by sintering in a sealed boat.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.195-197
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• 2002

CdTe quantum dots(QDs) were synthesized in aqueous solution by colloidal method. Photoluminescence(PL) spectra of the synthesized CdTe QDs revealed the intensity of PL peaks was stronger as the condensation time was longer. This result was thought because annealing effect by thermal energy transferred during condensation eliminated defects which act as traps and recombination centers in CdTe particle. PL intensity has stron dependence of Te precursor concentration. It confirmed the ratio of Te ion to Cd ion added during synthesis affected the particle size and size distribution of the CdTe QDs. Finally, the synthesized CdTe QDs were identified to be cubic structured CdTe quantum dots by X-ray diffraction(XRD).

• 원예과학기술지
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• 제29권5호
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• pp.413-419
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• 2011

국내 자생 수생식물인 노랑꽃창포와 창포를 수질 내 카드뮴(Cd) 제거용 식물재료로 이용하고자 Cd 축적과 내성을 조사하였다. Cd 농도에 따른 치사율을 근거로 Cd에 대한 반수치사량($LD_{50}$)을 계산한 결과, 노랑꽃창포는 $78.5{\mu}M$, 창포는 $47.6{\mu}M$로 나타났다. Cd 스트레스에 대해 노랑꽃창포에서는 POD와 SOD, 창포에서는 CAT와 SOD, 폴리페놀이 활성화되었다. 노랑꽃창포에서는 폴리페놀이 측정되지 않았다. 노랑꽃창포와 창포 모두 Cd 처리 농도가 증가하고 기간이 길어질수록 식물체 내 Cd 축적량이 증가하였고, 두 종 모두 지상부보다는 지하부 축적량이 현저하게 많았다. 지상부에 축적된 Cd 함량은 노랑꽃창포 $548.1mg{\cdot}kg^{-1}$(지하부 축적 대비 82.1%) 창포 $121.4mg{\cdot}kg^{-1}$(지하부 축적 대비 13.7%)로 두 종 모두 Cd 고축적식물로 확인되었으며, 특히 노랑꽃 창포가 Cd 축적능력과 내성이 우수하였다.

• Journal of Nutrition and Health
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• 제35권7호
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• pp.713-728
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• 2002

This study was performed to see effects of whole grape, grape pomace or grape juice intakes on lipid metabolism during aging in old Sprague-Dawely male rats. One hundred twenty rats of 13 months old Sprague-Dawely were blocked into eight groups according to body weight and raised for 3, 5 or 7 months with diets containing 2% (w/w) dried powders of three different pars of grape and 0.02% (w/w) CdCl₂. Body weights of Cd groups were lower than Cd free groups. Kidney and spleen weights were incre ased with age, and EEP weights of Cd groups were lower than those of Cd free groups. Total lipid, triglyceride and total cholesterol concentration in plasma increased with age. Whole grape, grape pomace or grape juice intake lowered plasma total lipid triglyceride and total cholesterol concentrations, and especially grape pomace lowered them markedly. Whole grape, grape pomace or grape juice intake decreased liver total lipid, triglyceride and total cholesterol concentrations and increased fecal lipid excretion. Grape diets decreased and Cd administration increased TBARS concentration in LDL fraction. In conclusion, grape diets were effective in decreasing lipid levels of liver and plasma, TBARS in LDL, and in increasing HDL cholesterol. The grape pomace was most effective among three grape parts. It is plausible that grape might be recommended for the treatment or prevention of cardiovascular disease and delaying aging. (Korean J Nutrition 35 (7): 713∼728, 2002)

• 대한화학회지
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• 제15권6호
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• pp.347-352
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• 1971

The variations of the positive and negative electrode potentials, and of internal pressure were measured during the charge of the sealed type Ni-Cd cell. Both polarization characteristics of a paste type Cd-electrode as a gas diffusion electrode in 30% KOH solution and the effects of active carbon electrode as an oxygen consuming auxiliary electrode of the Ni-Cd cell on the charging characteristics of the cell were studied. Peak voltage at the end of charge of the cell is ascribed to the peak at the negative electrode potential, which is due to the concentration polarization by the lack of $Cd^{++}$ ion and oxygen concentration. And the recovery of the negative electrode potential is resulted from depolarization by the increasing diffusion limiting current density with the increasing oxygen pressure. The active carbon electrode was effective as an oxygen consuming auxiliary electrode. The internal pressure of the cell could be maintained below 200mmHg even at one hour rate charge and overcharge by the use of active carbon electrode as an auxiliary electrode.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.803-809
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• 2009

Notable blue shifts of the ν2 $C{\equiv}N$ stretching, $_{v4}$ C-C stretching and $_{v8}$ CCN deformation bands of $CD_3CN$ are observed upon solvation of $InCl_3$, resulting from the donor-acceptor interaction. The Raman spectrum in the $_{v2}$ region shows further details; at least two new bands emerge on the blue side of the $_{v2}$ band of free $CD_3CN$, whose relative intensities vary with concentration, suggesting that there exist at least two different cationic species in the solution. The strong hydrogen bonds formed between the methyl group and ${InCl_4}^-$ result in a large band appearing on the red side of the ν1 $CD_3$ symmetric stretching band. The solvation number of $InCl_3$, determined from the Raman intensities of the $C{\equiv}N$ stretching bands for free and coordinated $CD_3CN$, increases from $\sim$1.5 to $\sim$1.8 with decreasing concentration.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제23권2호
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• pp.132-136
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• 2020

Purpose: To evaluate the effect of gluten-free diet (GFD) on hepatitis B surface antibody (HBsAb) concentrations among previously immunized pediatric celiac disease (CD) subjects. Methods: We retrospectively evaluated pediatric CD subjects in serological remission who were previously immunized for hepatitis B virus as infants. The temporal relationship between HBsAb concentration, the amount of time on a GFD, and age were evaluated. Results: Overall, 373 CD subjects were analyzed: 156 with HBsAb sampled prior to GFD initiation and 217 after initiation of a GFD and in serological remission. Median age at HBsAb concentration measurement for those before and after GFD initiation was 5.3 years (interquartile range [IQR], 3.1-9.2 years) and 7.6 years (IQR, 5.4-10.9 years), respectively (p<0.001). There was no sex difference between the groups. The median time of HBsAb measurement was 2 months (IQR, 0-5.7 months) before and 12.8 months (IQR, 5.3-30.3 months) after initiation of GFD. The HBsAb concentration was low in 79 (50.6%) and 121 (55.7%) subjects before and after GFD initiation, respectively (p=0.350). Age was inversely associated with low HBsAb concentrations. Neither being on a GFD nor sex was associated with low HBsAb concentrations. Conclusion: Adherence to a GFD does not affect HBsAb concentration in children with CD. Age is inversely associated with HBsAb concentration.

• 환경영향평가
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• 제18권4호
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• pp.209-218
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• 2009

The purpose of this study was to accumulation of the heavy metals by riparian vegetation throughout analysis of the heavy metal concentration in riparian vegetation, water, and sediment near mine drainage. According to analyzing concentration of the heavy metals in riparian vegetation, water, and sediment the heavy metal was indicated at the leaf significantly. Compared with the concentration of sediment soil, the maximum concentration of the As, Cd, CN, Pb, Zn was higher 2.6, 2.6, 25, non-detect, and 15 times in leaf. Also those concentration have 9.6, 16.6, 25, 1.6, and 25 times in root. As the results, the author can know the sediment has a very relative to vegetation in mine drainage. because, the increasing of concentration of heavy metal in sediment gives the more accumulative concentration of heavy metal in vegetation. Compared with the concentration of conta minated site and non-contaminated site. As, Cd, CN, Pb, Zn the maximum concentration in sediment soil was higher 5.7, 258.1, 10.9, 370.0, and 298.3 times respectively. In case of vegetation, the maximum concentration of the As, Cd, CN, Pb, Zn was higher 5.6, 62.3, 5.0, non-detect, and 30.6 times in leaf. Also those concentration have 8.5, 63.3, 2.6, 60.7, and 62.1 times in root. In this study, the author can surmise that there indicated a lot of adsorption with the heavy metal concentration in contaminated mine drainage.