• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.642-648
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• 2006

Mushroom tyrosinase (MT) structural changes in the presence of $Cu ^{2+}$ and $Ni ^{2+}$ were studied separately. Far-UV CD spectra of the incubated MT with the either of the metal ions indicated reduction of the well-ordered secondary structure of the enzyme. Increasing in the maximum fluorescence emission of anilinonaphthalene-8-sulfonic acid (ANS) was also revealing partial unfolding caused by the conformational changes in the tertiary structure of MT. Thermodynamic studies on the chemical denaturation of MT by dodecyl trimethylammonium bromide (DTAB) showed decrease in the stability of MT in the presence of $Cu ^{2+}$ or $Ni ^{2+}$ using their activation concentrations. Both activities of MT were also assessed in the presence of different concentrations of these ions, separately, with various monophenols and their corresponding diphenols. Kinetic studies revealed that cresolase activity on p-coumaric acid was boosted in the presence of either of the metal ions, but inhibited when phenol, L-tyrosine, or 4-[(4-methylphenyl)azo]-phenol was substrate. Similarly, catecholase activity on caffeic acid was enhanced in the presence of $Cu ^{2+}$ or $Ni ^{2+}$, but inhibited when catechol, L-DOPA, or 4-[(4-methylbenzo)azo]-1,2-benzenediol was substrate. Results of this study suggest that both cations make MT more fragile and less active. However, the effect of the substrate structure on the MT allosteric behavior can not be ignored.

• BMB Reports
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• 제39권5호
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• pp.636-641
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• 2006

Our previous studies indicated that native carbonic anhydrase does not interact with hydrophobic adsorbents and that it acquires this ability upon denaturation. In the present study, an apo form of the enzyme was prepared by removal of zinc and a comparative study was performed on some characteristic features of the apo and native forms by far- and near-UV circular dichroism (CD), intrinsic fluorescent spectroscopy, 1-anilino naphthalene-8-sulfonate (ANS) binding, fluorescence quenching by acrylamide, and Tm measurement. Results indicate that protein flexibility is enhanced and the hydrophobic sites become more exposed upon conversion to the apo form. Accordingly, the apo structure showed a greater affinity for interaction with hydrophobic adsorbents as compared with the native structure. As observed for the native enzyme, heat denaturation of the apo form promoted interaction with alkyl residues present on the adsorbents and, by cooling followed by addition of zinc, catalytically-active immobilized preparations were obtained.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2889-2896
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• 2023

The waste acceptance criteria for heavy metals in mixed waste should be developed by reflecting the leaching behaviors that could highly depend on the repository design and environment surrounding the waste. The current standards widely used to evaluate the leaching characteristics of heavy metals would not be appropriate for the silo-type repository since they are developed for landfills, which are more common than a silo-type repository. This research aimed to explore the leaching behaviors of cementitious waste with Pb, Cd, and Sb metallic and oxide powders in an environment simulating a silo-type radioactive waste repository. The Toxicity Characteristic Leaching Procedure (TCLP) and the ANS 16.1 standard were employed with standard and two modified solutions: concrete-saturated deionized and underground water. The compositions and elemental distribution of leachates and specimens were analyzed using an inductively coupled plasma optical emission spectrometer (ICP-OES) and energy-dispersive X-ray spectroscopy combined with scanning electron microscopy (SEM-EDS). Lead and antimony demonstrated high leaching levels in the modified leaching solutions, while cadmium exhibited minimal leaching behavior and remained mainly within the cement matrix. The results emphasize the significance of understanding heavy metals' leaching behavior in the repository's geochemical environment, which could accelerate or mitigate the reaction.

• 수면정신생리
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• 제19권2호
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• pp.68-76
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• 2012

목 적: 수면 장애는 자율신경계의 변화를 유발하여 심혈관계에 영향을 준다. 일차성 불면증(primary insomnia, 이하 PI)은 수면부족 및 각성으로, 폐쇄성 수면무호흡 증후군(obstructive sleep apnea syndrome, 이하 OSAS)은 수면 중 빈번한 각성, 저산소증 등으로 교감신경계 항진을 유발한다. 이에 OSAS와 PI 사이에서 심박동률 변이도(heart rate variability, 이하 HRV) 분석을 통해 자율신경계의 변화 정도를 비교하고자 하였다. 방 법: 임상병력 및 야간수면다원검사(nocturnal polysomnography, 이하 NPSG)로 선택된 PI와 OSAS 전체 315 명의 대상자 중 OSAS는 무호흡-저호흡 지수(apnea-hypopnea index, 이하 AHI)에 따라서 경도, 중등도, 중증도 OSAS로 분류하여 PI를 포함하여 4개의 군으로 분류되었다. 이후 연령, 성별, 군간 개체수를 고려하여 최종적으로 110명의 대상자가 선택되었고, PI군(평균나이 41.50, 표준편차 13.16, AHI <5, n=20), 경도 OSAS군(평균나이 43.67, 표준편차 12.11, AHI 5~15, n=30), 중등도 OSAS군(평균나이 44.93, 표준편차 12.38, AHI 16~30, n=30), 중증도 OSAS군(평균 나이 45.87, 표준편차 12.44, AHI >30, n=30)의 4개 군으로 나누었다. 이후 NPSG를 통해 얻은 각 군의 HRV 지수 비교를 위하여 연령과 체질량지수(body weight index, BMI)를 공변량으로 하여 공분산분석(analysis of covariance, ANCOVA)를 실시한 후 사후분석으로 Sidak test를 실시하였다. 결 과: HRV 지수의 비교 결과 PI군과 경도, 중등도의 OSAS군 간에 유의한 차이는 없었다. 그러나 PI군과 중증도 OSAS군 사이에는 유의한 차이가 있었다. 군간비교에서 통계적으로 가장 현저한 차이를 보인 PI군과 중증도 OSAS군에서 HRV 지수 중 통계적으로 의미 있는 각각의 값은 다음과 같았다. Average RR interval은 $991.1{\pm}27.1$과 $875.8{\pm}22.0$ ms(p=0.016), standard deviation of NN interval(SDNN)은 $85.4{\pm}6.6$과 $112.8{\pm}5.4$ ms(p=0.022), SDNN index는 $57.5{\pm}5.2$과 $87.6{\pm}4.2$(p<0.001), total power는 $11893.5{\pm}1359.9$과 $8097.0{\pm}1107.2ms^2$(p=0.008), very low frequency(VLF)는 $7534.8{\pm}1120.1$과 $11883.8{\pm}912.0ms^2$(p=0.035), low frequency(LF)는 $2724.2{\pm}327.8$과 $4351.6{\pm}266.9ms^2$였다(p=0.003). 결 론: 본 연구에서는 PI군에 비해 중증도의 OSAS군에서 HRV 지수 중 교감신경계의 영향을 많이 받는 VLF, LF 등이 상승하는 양상을 보였고, 이를 통해 PI에 비해 중증도의 OSAS가 교감신경계 활동증가에 보다 더 큰 영향을 끼치는 것을 알 수 있었다.

• 치과방사선
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• 제11권1호
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• pp.33-40
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• 1981

The author studied on the effects of x-irradiation to the development of digital malformation in gestation rats. The time-matings occured between 6 p.m. and 8 a.m. and females with copulation. plugs at 8 a.m. were isolated and properly marked for evidence of copulation. The lower abdomen of mothers were exposed to x-irradiation on the 11½th day of gestation, the critical period developing digital malformation, respectively 100, 150, 200, 250, 300 and 350 rads. At 18½th day of post-conception total 50 pregnant females were dissected and the incidence of digital malformations were obtained. Rat embryos on the 12, 13, 14, 15, 16th day of gestation irradiated by 250 rads were examined for morphogenesis of digital malformation. Digital radiating lines were examined in water and histologically by H-E stain. Supra vital stain samples by Nile-blue sulfate in 37℃ normal saline were prepared for the observation of cell necrosis regions and morphogenesis of digits. The results obtained were as follows; 1. By x-irradiation on 11th day of gestation, digital malformations of Ectrodactylia, Syndactylia Polydactylia and Hematodactylia were developed. Ectrodactylia showed the effective relationship to the amount of irradiation, however Syndactylia ans Polydactylia did not. 2. By x-irradiation, cell necrosis of digital germ was appeared markedly, but in 48 hours after irradiation was depressed to the periphery of digital germ and in 72hours after irradiation was disappeared. Digital radiating line showed marked stage of malformation in 48hours after irradiation and continued to show the same amount of physiological cell necrosis as the compared control group in 72hours. after irradiaion. But in the Syndactylia, physiological cell necrosis was not able to be recognized. 3. Ectrodactylia induced by x-irradiation was considered as the direct resoult of cell necrosis of digital origin, however, Polydactylia and Syndactylia were considered as the resoult of some effect in repair process of x-irradiation damages.

• 대한한방부인과학회지
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• 제29권3호
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• pp.1-9
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• 2016

Objectives: Cold Hypersensitivity of Hands and Feet (CHHF) has been diagnosed objectively by Digital Infrared Thermal Imaging (DITI) and has been known to be associated with autonomic nervous system (ANS), which can be assessed by Heart Rate Variability (HRV). This study evaluated the correlation between severity of CHHF and HRV variables.Methods: We studied 155 non-menopausal women with CHHF who visited Kyung Hee University Hospital at Gangdong from 01 October 2013 to 30 April 2016. We measured DITI and HRV of each patient. We used DITI to calculate the severity of CHHF with thermal difference between upper arm (L4, 俠白穴) and palm (P8, 勞宮穴) of both hands and anterior thigh (ST32, 伏兎穴) and dorsum of foot (LI3, 太衝穴) of both feet. The correlation between severity of CHHF and HRV variables were analyzed.Results: In time domain analysis, there was significantly positive correlation between the severity of CHHF and both SDNN and RMSSD. In frequency domain analysis, there was significantly positive correlation between the severity of CHHF and TP, HF and HF Norm while there was significantly negative correlation between the severity of CHHF and LF Norm as well as between the severity of cold hypersensitivity of both hands and LF/HF ratio.Conclusions: The more severe CHHF is, the more increased the function of parasympathetic nerve system (PNS) and relatively decreased the function of sympathetic nerve system (SNS) is. Also, it has known that cold hypersensitivity could be caused by deficiency syndrome and qi deficiency has the same ANS tendency as CHHF. Therefore, in practical fields, this result can be helpful in planning treatment and deciding prognosis in respect of deficiency syndrome.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.104-104
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• 2018

Kori Unit 1 is the first permanent shutdown nuclear power plant in Korea and it is on June 18th, 2017. Spent fuel assemblies began to be discharged from the reactor core to the spent fuel pool(SFP) within one week after shutdown of Kori unit 1 and the campaign was completed on June 27th, 2017. The total number of spent nuclear fuel assemblies in SFP of Kori Unit-1 is 485 and their discharging date is different respectively. So, decay heat was evaluated considering the actual enrichment, operation history and cooling time of the spent fuel assemblies stored in SFP of the Kori Unit-1. The code used in the evaluation is the ORIGEN-based CAREPOOL system developed by KHNP. Decay heat calculation of PWR fuel is based on ANSI/ANS 5.1-2005, "Decay heat power in light water reactors" and ISO-10645, "Nuclear energy - Light water reactors - Calculation of the decay heat power in nuclear fuels. Also, we considered the contribution of fission products, actinide nuclides, neutron capture and radioactive material in decay heat calculation. CAREPOOL system calculates the individual and total decay heat of all of the spent fuel assemblies in SFP of Kori Unit-1. As a result, the total decay heat generated in SFP on June 28th, 2017 when the spent fuel assemblies were discharged from the reactor core, is estimated to be about 4,185.8 kw and to be about 609.5 kw on September 1st, 2018. It was also estimated that 119.6 kw is generated in 2050 when it is 32 years after the permanent shutdown. Figure 1 shows the trend of total decay heat in SFP of Kori Unit-1.

• 한국자기학회지
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• 제8권1호
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• pp.21-26
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• 1998

온도에 따른 비정질 금속 Co66Fe4Ni1B14Si15의 자기 임피던스의 변화를 저온 장치를 써서 시료의 온도를 10K∼300K까지 변화시키면서 측정하였다. 이때, 시료에 겉어준 교류전류를 10mA로 고정시키고 주파수를 100KHz에서 10MHz 까지 변화시켰다. MIR (Magneto-Impedance Ratio)은 온도가 증가함에 따라 급격히 증가하였으며, MIR(T)≡MIR(0)exp(cT2)의 관계식으로 나타났다. 상온에서 측정한 MIR 값은 측정 주파수내에서 10K에서의 값보다 2∼3배 크게 나타났다. 이 결과는 MI 온도 효과를 이용한 온도 센서로서의 가능성을 제시한다. MIR 곡선의 모양은 온도의 증가에 따라 큰 변화가 없었으며 MIR은 주파수 증가에 따라 커지면서 MIR 곡선의 모양이 퍼지는 전형적인 경향을 나타냈다.

• 대한화장품학회지
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• 제10권1호
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• pp.13-23
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• 1984

The fluorescence intensity rations (F2.F1) of excimer (F2) to monomer (F1) of pyrene were measured as a function of the concentration of sodium dodecyl sulfate (SDS). It was found that there were not gross changes in size and shape of sphere-shape micelles in the first micelle concentration, while at concentrations above the second critical micelle concentration (CMC) the micelles grew in size with increasing concentration. Fluorescence intensities of 8-anilinonaphthalene 1-sulfonate (ANS) were also monitored as a micellar probe with varying concentrations of SDS. Results suggested that a phase transition from sphere-shaped micelles to hemicapped rod-like micelles occurred at the second CMC (17). A general formula for the axial ratio of ellip-soil-shaped micelle in the first micelle concentration was suggested. According to this general formula, the axial ratio of SDS, sodium lauryl ether sulfate and sodium laurate were 1:1, 5:2, and 5:3, respectively. The electrolyte-induced phase transition from spherical to hemicapped rod-like micelles occurred and the size of hemicapped rod-like micelles grew with increasing electrolyte concentrations. The maximum concentrations of solubilzed benzene in sphere-shaped micelles and hemicapped rod-like micelles were measured by differential spectrohpotometry. The hemicapped rod-like micelles in the presence of electrolytes grew in size with increasing amount of benzene solubilized.

• 미생물학회지
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• 제18권1호
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• pp.20-28
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• 1980

1. 꽃에서 분리한 200여 균주에서 30종을 동정하였으며, 그 중 메탄올을 자화할수있는 균주는 23종이었으며, 가장 생장이 좋은 3종을 선별하였다. 그 3종은 Candida incommunis, Cryptococcus aerius, Haηsenula ciferrii였다. 2. 위의 3종은 복합비타민과 yeast extract의 공급이 없이 탄소원으로 메탄올을 자화하여 중식하였으며, 메탄올을 이용하여 증식한 효모의 아미노산 조성을 검사한 결과 필수 아미노산이 모두 포함되어 있었다. 3. 총 아마노산의 함량이 Candida incommunis는 42.5%, Hansenula ciferrii는 39.9%로서 Kloeckera sp. No. 22 (Ogata 둥 1910a)의 39.9%보다 높고, Cryptococcus aeriuS는 36.5%로서 Candida utilis(Ogata 등 1970b)의 31.9%보다 높다. 4.곡류단백질에 흔히 결핍되어 있는 lysine과 threonine의 필수 아미노산이 이들 yeast에서는 소액분의 수준으로 포함되어 있다. 5. 총 질소량 Candida incommunis가 31.4%, Hansenula ciferrii가 28.8%, Cryptococcus aerius가 27.1%로 나타났다. 6. 높은 균체수율을 위한 실험결과 메탄올의 농도 1.3%, 온도 $30^{\circ}C$가 최적 생장조건으로 나타났다.