• Journal of Oral Medicine and Pain
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• 제32권4호
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• pp.383-396
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• 2007

노화가 미각기능에 미치는 영향에 관해서는 아직도 많은 논란이 계속되고 있다. 노인에게서 보이는 미각기능의 감퇴를 정상적인 노화현상으로 보는 시각과 약물사용이나 타액분비의 감소에 의한 결과로 보는 시각이 교차하고 있으며, 또한 미각 기능을 평가하는 방법에 따라 서로 다른 주장이 제기되기도 하였다. 저자들은 노화가 초역치 미각강도에 미치는 영향을 구명하기 위해서 본 연구를 시행하였으며, 약물사용에 의한 영향을 배제하기 위해서 장기적인 약물사용의 병력이 없는 20대의 여성 30명과 40-50대의 여성 31명을 피검자로 선택하여 염화나트륨, 설탕, 구연산, 염산키니네 수용액에 대한 초역치 미각강도를 소리자극을 이용한 규모짝짓기 방법으로 측정한 다음 그 결과를 서로 비교하였으며, 40-50대 여성에 대해서는 또한 폐경의 여부와 타액분비량의 다과에 따른 차이를 비교하여 다음과 같은 결론을 얻었다. 1. 한국인 40-50대 여성은 20대 여성에 비해 저 농도의 염화나트륨 수용액과 저 농도의 설탕 수용액에 대한 초역치 미각강도가 감소되었으며, 고농도의 염화나트륨 수용액과 고농도의 설탕 수용액, 그리고 모든 농도의 구연산 수용액과 염산키니네 수용액에서는 차이가 없었다. 2. 한국인 40-50대 여성에서 폐경으로 인한 초역치 미각강도의 변화는 나타나지 않았다. 3. 한국인 40-50대 여성에서 타액분비량의 다과에 따른 초역치 미각강도의 변화가 염화나트륨 수용액, 설탕 수용액, 염산키니네 수용액에 대해서는 나타나지 않았다. 4. 한국인 40-50대 여성에서 타액분비량이 적은 군이 많은 군에 비해 저 농도의 구연산 수용액에 대한 초역치 미각강도가 높게 나타났다.

• Journal of Pharmaceutical Investigation
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• 제22권2호
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• pp.97-104
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• 1992

The purpose of this study was (i) to determine whether protease inhibition by medium chain fatty acids such as sodium caprate, sodium caprylate and sodium laurate led to suppression of insulin proteolysis over a range of insulin concentrations and (ii) elucidate preventing effect of the enhancers on molecular self-association of insulin in pH 7.4 phosphate buffer isotonic solution. To this end, the rate of insulin proteolysis in nasal tissue supernatants of the albino rabbits was determined in the presence of $0.1{\sim}2%$ sodium caprylate, sodium caprate and sodium laurate at insulin concentrations ranging from $5\;to\;100\;{\mu}M$. At fatty acid salts concentration lower than 0.5%, insulin proteolysis was accelerated but the enhancers of high concentration (>1%) reduced the rate of insulin proteolysis. These effects were dependent upon insulin concentration and chain length of fatty acid salts. Circular dichroism spectra of insulin solutions were then determined. Monomer fraction of insulin was increased with increasing sodium caprate. Therefore, half-life decrease of insulin at low concentrations of the enhancers was attributed to deaggregation of insulin by the enhancers, increasing the proportion of monomers available for nasal proteolysis. And the increase of half-life at high concentration of the enhancers was attributed to inhibitory effect on protease rather than the effect of monomer fraction.

• Applied Biological Chemistry
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• 제39권1호
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• pp.32-38
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• 1996

대두에 함유된 영양저해인자의 하나인 phytic acid를 감소시키기 위해 일정시간 침지시킨 대두를 microwave로 가열처리하여 phytic acid 및 phosphorus의 함량 변화를 관찰하였다. 단원콩, 만리콩 및 Amsoy의 phytic acid 함량은 각각 탈지대두 1 g중에 19.19 mg, 18.38 mg 및 16.73 mg 함유되어 있었다. 가열시간이 길어짐에 따라 콩에 함유된 phytic acid 및 phytate phosphorus 함량은 감소하는 경향을 보여서, 5분 가열시에 단원콩, 만리콩 및 Amsoy의 phytic acid 감소율은 각각 26.29%, 24.85%, 23.72%이었다. 단원콩을 12에서 30분간 autoclaving 처리하였을때 phytic acid 및 phytate phosphorus의 감소율은 18.62%와 16.95%로 microwave로 5분 처리하였을 때가 훨씬 효과적이었다. 대두의 수분함량과 microwave 가열효과와의 관계는 수분함량이 낮을수록 phytic acid의 감소 효과가 컸다. 몇가지 염용액에 12시간 침지시킨후 4분간 가열처리시 phytic acid의 감소율은 2.5% NaCl에서 24.52%, 2% $NaHCO_3$에서 26.62%, 혼합 염용액(M.S.S.)에서 28.47%로 증류수의 21.53%보다 약간 높게 나타났으며, phytate phosphorus 감소율 또한 위의 세가지 염용액에서 26.17%, 24.64% 및 26.60%로서 증류수의 19.73%보다 약간 더 효과가 있는 것으로 나타났다.

• 한국표면공학회지
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• 제3권1호
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• pp.7-12
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• 1970

Only mannitol or glycerine is generally used for the determination of boric acid in a nickel plating solution in order to make its acidic property so strong that it can be titrated with NaOH. However, these solutions give very amgiguous color change of indicator due to the precipitation of nickel salts . Therefore, only experienced dchemistsorwell trained workimen can accurately confirm the actual end point of the titratiion. For eliminating such interference of nickel salts and easily confirming the end point by any persons , the author attempted to find out a solution which produces no precipitates during the titration in these experiments, and also he tried to funish the reason for ambiguousness in titration. The following results were obtained after many experiments. (1) In any titrations which produce nickel salts such nI(oh)$_2$, the salt is formed umption very approximate to the end point, which shows some error by the consumption of titrant(NaOH) . Then, the pink color of phenolphthalein is absorbed by Ni(OH)$_2$ and the pH jumping at the end pint is also diminished to as little as less than 15% of the total phenophthalein ph range. (2) Known methods by complex salts of citrate,w hich do not produce precipitates of Ni(OH)$_2$, are also not very satisfactory, because, the pH jumping at the end point is only about 35% and the color change of phenolphthalein is form blue-green to purple-blue. (3) New method by complex salts of oxalate were attempted in these experiments. They also did not produce precipitates of Ni(OH)$_2$ and were very satisfactory in color change at the end of point was about 65% and the color change was from blue-green to purpled. In this methods, analytica cost was minimized by the use of less amounts of cheaper chemicals than the conventional citrates complex methods. The mixture of chemicals used was composed methods. The mixture of chemical used was composed of 37g/ι of sodium oxalate(Na$_2$C$_2$O$_4$$.$5H$_2$O), 2g/ι of phenolphthalein, and 400ml /ι of glycerin. The accuracy of analysis was within the error of 0.5%. (4) The procedure of analysis was as follows. One ml of nickel plating solution was taken out and to it were added 20ml of water and 20 ml of the above mixture for the indicator. The solution was titrated with 0.1N NaOH. The quantity of boric acid was calculated by the following equation. Boric acid (g/ι) = 6.184${\times}$F${\times}$ml .

• Mycobiology
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• 제43권4호
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• pp.415-422
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• 2015

The study aimed to evaluate the probiotic properties, antioxidant activity and fermentative capacity of Acremonium charticola and Rhizopus oryzae isolated from the Indonesian fermented dried cassava, with particular application on poultry. A. charticola inhibited the growth of Escherichia coli and Aspergillus flavus. A. charticola and R. oryzae grew in potato dextrose agar (PDA) adjusted to pH 3 and 8 or in PDA supplemented with bile salt up to 0.8%. After soaking for 8 hr, the survival rate of A. charticola in the simulated gastric juice (pH 2) and bile solutions (2% bile salt) was lower than that of R. oryzae. A. charticola and R. oryzae exhibited strong antioxidant activities. Compared to unfermented cassava pulp (control), the fibre content of cassava pulp tended to be lower after fermentation with A. charticola for 14 days. The populations of A. charticola and R. oryzae were significantly higher in fermented cassava pulp than in unfermented one. Coliform was higher in cassava pulp fermented with R. oryzae or A. charticola + R. oryzae compared to control after 7 days of fermentation, however, the bacteria were not different between A. charticola-fermented cassava pulp and control. Lactic acid bacteria (LAB) were higher in A. charticola- and R. oryzae-fermented cassava pulp than those in control, however, no difference of LAB was observed between A. charticola + R. oryzae-fermented cassava pulp and control. In conclusion, A. charticola exhibited antibacterial, antifungal and antioxidant activity, gastrointestinal persistence and fermentative capacity that may be beneficial for poultry industry.

• Biomolecules & Therapeutics
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• 제7권3호
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• pp.263-270
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• 1999

The in vitro permeation of thyrotropin-releasing hormone (TRH) through rabbit nasal, rectal and duodenal mucosae was studied in the absence and presence of an enzyme inhibitor and permeation enhancer. TRH in the donor and receptor solutions was assayed by HPLC. When thimerosal (TM, 0.5 mM) was added to the donor cell as an inhibitor, the permeation rate of TRH (200 $\mu\textrm{g}$/ml) increased linearly as a function of time. Fluxes of TRH through the nasal, rectal and duodenal mucosae were found to be 33.3$\pm$5.9, 11.8$\pm$1.9 and 9.6$\pm$0.7 $\mu\textrm{g}$/$\textrm{Cm}^2$/hr, respectively. The addition of sodium glycocholate, glycyrrhizic acid ammonium salt, sodium taurodihydrofusidate or L-$\alpha$-lysophosphatidylcholine to the donor solution containing TM did not result in the significant increase of permeation flux except for the duodenal mucosa, comparing with that in the presence of TM alone. Consequently, it was suggested that the nasal route was advantageous for systemic delivery of TRH, and the addition of TM and/or an enhancer was necessary to maximize the transmucosal permeation of TRH.

• 공업화학
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• 제10권4호
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• pp.576-580
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• 1999

Column에 공기를 분사시켜 수용액으로부터 색을 제거하기 위한 연구를 수행하였다. 착색 용액을 제조하기 위해 Basic Yellow 28 및 Direct Orange 31을 사용하였으며, 모든 색은 8분 이내에 제거되었다. Sodium dodecyl sulfate, oleic acid sodium salt 및 amines와 같은 collector는 색 제거에 효과적이었다. 색 제거는 collector의 첨가량과 수용액 pH의 영향을 받는다고 할 수 있으나, 소량의 collector를 첨가하였을 경우에는 pH에 의존하였으나, 많은 양을 첨가하였을 경우에는 pH에 의존하지 않았음을 알 수 있었다.

• 한국환경보건학회지
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• 제48권3호
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• pp.167-175
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• 2022

Background: Disinfection is essential to provide drinking water from a water source. The disinfection process mainly consists of the use of chlorine and ozone, but when chlorine is used as a disinfectant, the problem of disinfection by-products arises. In order to resolve the issue of disinfection by-products, electro-chlorination technology that produces chlorine-based disinfectants from salt water through electrochemical principles should be applied. Objectives: This study surveys the possibility of optimally producing active chlorine from synthetic NaCl solutions using an electro-chlorination system through RSM. Methods: Response surface methodology (RSM) has been used for modeling and optimizing a variety of water and wastewater treatment processes. This study surveys the possibility of optimally producing active chlorine from synthetic saline solutions using electrolysis through RSM. Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. Results: Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. A central composite design (CCD) was applied to determine the optimal experimental factors for chlorine production. Conclusions: The concentration of the synthetic NaCl solution and the distance between electrodes had the greatest influence on the generation of hypochlorite disinfectant. The closer the distance between the electrodes and the higher the concentration of the synthetic NaCl solution, the more hypochlorous acid disinfectant was produced.

• 콘크리트학회논문집
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• 제14권3호
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• pp.409-419
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• 2002

Nowadays, antiwashout underwater concrete is widely used for constructing underwater concrete structures but they, especially placed in marine environment, can be easily attacked by chemical ions such as SO$\^$2-/$\_$4/ Cl$\^$-/ and Mg$\^$2＋/, so the quality and capability of concrete structures go down. In this paper, to solve and improve those matters, flyash and GGBFS(ground granulated blast furnace slag) were used as partial replacements for ordinary portland cement. As results of experiments for fundamental properties of antiwashout underwater concrete containing 10, 20, 30％ of flyash and 40, 50, 60 ％ of GGBFS respectively, setting time, air contents, suspended solids and pH value were satisfied with the "Standard Specification of Antiwashout Admixtures for Concrete" prescribed by KSCE, and also slump flow, efflux time and elevation of head were more improved than that of control concrete. From the compressive strength test, it was revealed that the antiwashout underwater concrete containing mineral admixtures(flyash and GGBFS) is more effective for long term compressive strength than control concrete. An attempt to know how durable when they are under chemical attack has also been done by immersing in chemical solutions that were x2 artificial seawater, 5 ％ sulphuric acid solution, 10％, sodium sulfate solution and 10％ calcium chloride solution. After immersion test for 91days, XRD analysis was carried out to investigate the reactants between cement hydrates and chemical ions and some crystalline such as gypsum ettringite and Fridel′s salt were confirmed.

• 멤브레인
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• 제29권3호
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• pp.140-146
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• 2019

본 연구에서는 다공성 Polyacrylonitrile (PAN) 중공사막을 지지체막으로 하여 Poly styrene sulfonic acid (PSSA)와 polyethyleneimine (PEI)을 이용하여 layer-by-layer법으로 선택층을 형성시켰다. 코팅용액에 Mg염을 첨가하여 염석법(salting out method)을 이용하였다. 코팅용액의 이온세기, 고분자 농도, 코팅시간 등을 달리하여 나노여과막을 제조하였으며 NaCl, $MgCl_2$, $CaSO_4$ 100 mg/L를 공급액으로 하여 2 atm의 구동 압력에서 투과도와 염 배제율을 평가하였다. PSSA 20,000 ppm, 코팅시간 3분, 이온세기 1.0, PEI 30,000 ppm, 코팅시간 1분, 이온세기 0.1의 조건으로 코팅한 막이 가장 우수한 성능을 보여 주었다. 100 ppm의 NaCl, $MgCl_2$, $CaSO_4$ 공급액에서 각각 20.4, 19.4, 18.7 LMH의 투과도와 67, 90, 66.6%의 염 배제율을 나타내었다.