단백 methylase 억제제 5´-Isobutyl-5´-deoxyadenosine과 sinefungin에 의한 BALB/c mouse 비장세포의 증식과 분화의 억제

최의규,홍정희,한유정,백문기 大韓免疫學會 1995 大韓免疫學會誌 Vol.17 No.3

Whether or not protein methylation can be correlated with cell proliferation and differentiation in BALB/c mouse splenocyte cultures has been investigated by using methylase inhibitors, 5'-Isobutyl-5'- deoxyadenosine(SIBA) and sinefungin. 1) Protein methylase I and III activities were found to be elevated in LPS stimulated splenocytes, and the peak of protein methylase I was correlated with that of S phase fraction while changes in protein methylase III activity followed the changes in S phase fraction. 2) SIBA and sinefungin were proved to be potent competitive inhibitors of the protein methylase 'I and III in vitro with apparent Ki for sinefungin of both enzymes being lower than that for SIBA. 3) The protein methylase III were activated by 2-mercaptoethanol and dithiotreitol, and strongly inhibited by Cue+ in vitro; and the inhibition was almost completely released by dithiotreitol and diethyldithiocarbamate. 4) The extent of polyclonal antibody formation, S phase fraction and protein synthesis after induction by LPS were significantly inhibited in a dose response manner by SIBA and sinefungin with higher potency for the former. 5) Inhibition of cell cycle was also observed in the presence of cyloleucine, an inhibitor in SAM synthesis. 6) Of several enzymes investigated, namely protein methylase III, LDH, yglutamyltranspeptidase, and adenosine deaminase, the- protein methylase III was most markedly increased by LPS and decreased by SIBA and sinefungin than other enzymes. From the above results, it is suggested that SIBA and sinefungin suppress the cell proliferation and differentiation through the inhibition of protein methylation.

가물치(Channa asiatica)肝組織의 S-Adenosyl-L-Methionine : Protein Arginine N-Methyltransferase에 關한 硏究 Protein Arginine N - Methyltransferase of Snake Head(Channa asistica) Liver

崔宜奎,金福亮,白汶基 圓光大學校 醫科學硏究所 1986 圓光醫科學 Vol.2 No.2

Protein methylase Ⅰ(S-adenosyl-L-methionine : protein-arginine methyltransferase, EC 2.1.1.23) having an optimal pH at around 7.3 was Purified 117 fold with a 31% recovery from snake head liver. The enzyme showed a optimum temperature at around 3l℃ and was completely inactivated at 43℃. Both histone type Ⅱ-A and histone type Ⅷ-S were verified as good substrates in accepting methyl group from S-adenosyl-L-methionine , whereas histone type Ⅲ-s, egg albumin, r-globulin, bovine serum albumin, and lysozyme were poor. The Km value for S-adenosyl-L-methionine was 6.75×10 exp (-6) M at 37℃ and the maximum velocities were 47.6 and 84.8 pmole/min/㎎ protein at 21℃ and 31℃ respectively so that the activation energy of the enzyme was calculated as 21 .76 kJ/mole. Copper and zinc ions were the potent inhibitor, and the inhibitory effect were 43.5% and 33.8% of total activity at 200uM respectively. Sulfate ion also acted as an inhibitor, showing 50% of this enzyme activity at 160mM. Protein methylase I was not only activated but also stabilized the presence of ammonium ion.

스카른 광석 볼밀 분쇄 산물의 단체분리도 특성

최의규,이성훈,조상호,정수복,김영훈,박재구 한국자원공학회 2011 한국자원공학회지 Vol.48 No.1

A study on correlationship between the size of minerals and the degree of liberation for products from ball mill was carried out. The composition of skarn ore was determined through XRD analysis and a micro-focus X-ray computed tomography. The size of sulfides minerals in skarn ore was measured through digital microscopic. Comminution was carried out through compact a ball mill. Fractional degree of liberation (FDL) at various rotation speed was measured. FDL was derived from fraction of area measured by image analysis method. Furthermore, experimentally determined values for the degree of liberation was compared with those obtained from simulation result based on binary liberation model proposed by Park et al. (1991). The experimentally determined FDL was almost same as simulated values. The FDL was found to rapidly increase at the size of valuable mineral, α=59. The result from this study suggest that the size of valuable mineral is major factor which decide the degree of liberation. 스카른 Zn-Pb-Cu 복합광석에 있어서 유용광물의 입자의 크기와 분쇄산물의 단체분리도와의 상관성에 대한 연구를 실시하였다. XRD분석과 마이크로 포커스 X-ray 단층촬영을 통해 원광의 광물학적 조성을 분석하였으며, 전자 현미경을 통해 유용광물의 입자크기를 측정하였다. 소형 볼밀에 의해 분쇄실험을 진행하였으며 임계 회전속도 분율에 따른 분쇄 산물의 FDL를 측정하였으며, 측정방법은 화상해석법에 의한 유용광물의 2차원 면적비로부터 구하였다. 측정된 단체분리도 결과는 Park et al.(1991)의 2성분계 단체분리 model에 기반을 둔 시뮬레이션 결과와 비교하였다. FDL에 대한 실험결과는 시뮬레이션 결과와 거의 일치하였으며 유용광물의 크기 α=59 ㎛ 부근에서 FDL이 급격히 증가함을 확인하였다. 이것으로부터 원광내의 유용광물의 크기가 단체분리도를 결정하는데 주요인자가 됨을 알 수 있었으며, 시뮬레이션과 화상해석을 통하여 분쇄입도를 결정할 수 있을 것으로 판단된다.

섬유 보강콘크리트의 피로특성 및 내충격성

이봉학,윤경구,홍창우,김동호,최의규 강원대학교 부설 석재복합신소재 제품연구센터 1999 석재연 논문집 Vol.4 No.-

본 연구에서는 강섬유보강콘크리트의 각종 물성 실험 및 휨피로와 충격시험을 통하여 강섬유 보강콘크리트의 우수성을 입증하였다. 각 유형별 휨강도 특성은 Hooked 형이 Crimped 형보다 큰 휨강도를 나타내었으며 또한 형상비가 클수록 큰 강도발현을 보였다. 휨인성 평가에 있어서는 섬유 형상에 관계없이 섬유 혼입량의 증가에 따라 월등한 에너지 흡수능력을 나타내었으며 Hooke형이 Crimped 형보다 뛰어난 에너지 흡수능력을 갖고 있음을 확인하였다. 정적극한강도에 대한 휨피로수명은 보통 콘크리트는 약 53%정도로 나타났으며 강섬유 보강 콘크리트는 약 54∼65%정도를 나타내었다. 또한 충격에 대한 평가는 섬유 혼입량의 증가에 따라 큰 충격저항성능을 발휘하지는 않았으나 초속경시멘트를 사용한 경우가 보통 시멘트를 사용한 경우와 비교하여 매우 우수한 충격저항성을 갖고 있음을 확인하였다. This paper is conducted on the flexural fatigue test and the impact test to find the mechanical properties of steel fiber reinforced concrete. Experimental investigation is examined according to fiber contents(0, 0.4, 0.7, 1.0, 1.5%), fiber aspect ratio(58, 60, 83), fiber type (hooked, crimped fiber), and cement type(normal portland & rapid-set cement). The principal results obtained through this study are as follow; toughness, impact resistance and fatigue resistance tend to considerably increase with fiber contents, fiber aspect ration, and hooked fiber is improved better than crimped fiber. Concrete using rapid set cement is increased strength properties compared with concrete using normal portland cement, but relative strength properties behavior and fatigue resistance show a tendency to decrease a little.

肺吸虫에 依한 肉芽腫性 膵臟炎症의 1例

崔宜奎(Eui Kyu. Choi),李用基(Young Kie. Lee) 대한외과학회 1966 Annals of Surgical Treatment and Research(ASRT) Vol.8 No.9

광해오염원 추적을 위한 낙동강 지역 퇴적물 및 하천수의 화학조성 연구

김지윤,최의규,백승한,최혜빈,이정훈 한국지구과학회 2016 한국지구과학회지 Vol.37 No.4

There have been found mine tailings, wastes, and mining drainage scattered in the area of Nakdong River due to the improper maintenance of the abandoned mines. These contaminants can flow into rivers during the heavy rain periods in summer. Along the study area beginning Seokpo-myeon, Bonghwa-gun of Gyeongsangbuk-do untill Dosanmyeon, Andong-si, there are one hundred five mines including sixty metalliferous mines and forty-five nonmetal mines, which can adversely affect the adjacent rivers. To verify the contamination, we collected sediments, seepage water and surface water for a year both in rainy season and dry season. This study found that sediments, containing high concentrations of heavy metals caused by mining activities, are dispersed throughout the entire river basin (68 sample points with pollution index, based on the concentration of trace element, (PI) >10 among the total of 101 samples). The results of river water analysis indicated the increased concentrations of arsenic and cadmium at branches from Seungbu,Sambo, Okbang and Janggun mine, which concerns that the river water may be contaminated by mining drainage and tailing sediments. However, it is difficult to sort out the exact sources of contamination in sediments and waters only by using the chemical compositions. Thus the control of mining pollution is challenging. To prevent water from being contaminated by mining activities, we should be able to divide inflow rates from each origin of the mines. Therefore, there should be a continued study about how to trace the source of contaminants from mining activities by analyzing stable isotopes. 낙동강에는 휴·폐광산의 관리 소홀로 인하여 광미, 광산폐기물, 침출수 등이 산재되어 있으며 여름철 집중 호우기 동안 이 같은 오염물들이 수계에 유입될 수 있다. 경상북도 봉화군 석포면에서 시작해 안동시 안동호 상류에 이르기까지 낙동강에 영향을 미칠 수 있는 광산은 총 105개로 금속광산 60개, 비금속 광산 45개에 달한다. 이를 확인하기 위해서 1년 동안 건기와 우기에 퇴적물, 배출수, 하천수를 채취하였다. 광산의 활동으로 낙동강 주변에 전반적으로 심각한 수준의 중금속 오염을 보이는 퇴적층이 산재해 있음을 확인했다(101개의 시료채취 지점 중 중금속농도를 바탕으로 한 오염지수 10 이상 지점 68개). 하천수 분석 결과에서는 승부, 삼보, 옥방, 장군 광산 등의 지류 시료에서 비소와 카드뮴 농도가 우기 때 증가하는 양상을 보였으며 광산의 배출수와 광미 퇴적층으로 인한 오염이 우려된다. 그러나 광미 퇴적층과 하천수의 화학조성만으로는 오염의 근원이 되는 광산의 유입정도를 분리해 내기 어렵고 이러한 문제는 광해 방지를 어렵게 한다. 광산 활동으로 인한 오염을 효과적으로 방지하기 위해서는 각 오염근원으로부터의 유입비를 분리해 낼 수 있어야 하는데, 그 방법으로써 안정동위원소를 사용하고 이를 통한 오염원 추적 분석 기술 개발에 대한 연구가 필요하다.

카자흐스탄 구리제련소 슬래그 내 구리회수를 위한 선별 특성

박제현,최의규,최홍일,신승한,Park, Jayhyun,Choi, Uikyu,Choe, Hongil,Shin, Shunghan 한국자원리싸이클링학회 2015 資源 리싸이클링 Vol.24 No.4

일반적으로 구리제련 슬래그내 구리함량은 0.5-3.7% 혹은 그 이상의 높은 비율로 포함되어 있며, 슬래그내 구리회수에 대한 대표적인 방법으로는 부유선별, 침출 그리고 배소가 있다. 본 연구에서는 부유선별법에 의한 구리 회수방법을 검토하였으며, 잔세이트포수제를 이용한 황화부선을 수행하였다. 산성과 알칼리 조건에서 부유선별 특성을 관찰하였으며, pH 4 에서 구리회수율 50%, pH 11 에서 구리회수율 67%로 나타났으며, 특히 pH 11에서는 $100{\mu}m$ 이상의 입자가 정광으로 부유되어 회수율이 상대적으로 높게 나타나는 경향을 보였다. 슬래그 입도를 200 mesh 이하로 분쇄하여 단체분리도를 향상시켜 pH조건별 부유선별 실험을 수행한 결과, 회수율이 78 - 83%까지 향상되는 것을 확인할 수 있었다. Almost all copper slags contain a considerable amount of Cu (0.5 - 3.7%) close to or even higher than copper ores. A number of methods for metal recovery from copper slag were reported These methods can be classified into three categories, flotation, leaching and roasting. Sulfide flotation method for the recovery of copper from Kazahstan copper furnace slag is discussed in this investigation. 50% of copper from the slag was recovered by sulfide flotation at pH 4. meanwhile 67% of copper from the slag was recovered at pH 11. Higher copper recovery result at pH 11 rather than that at pH 4 was caused by the fact that copper sulfides were floated in particle size fraction over $100{\mu}m$ in concentrates at pH 11. When the slag were ground below $74{\mu}m$by ball milling, the recovery of copper by floation in slag improved to 78 - 83% because of copper liberation effect.

A Widely Tunable K-band Voltage-Controlled Oscillator

손현진,신동준,최의규,양종렬 한국과학기술원 반도체설계교육센터 2022 IDEC Journal of Integrated Circuits and Systems Vol.8 No.2

A wideband LC voltage-controlled oscillator (VCO) using a 3-bit switched-capacitor bank is proposed for improving the frequency bandwidth in K-band applications. The capacitor bank is composed of metal-oxide-metal (MOM) capacitors to obtain a high-quality factor of the LC tank. The size of the unit capacitor in the capacitor bank is optimized to achieve a wide tuning range. The fabricated chip area is 400 µm × 610 µm by using the TSMC 65-nm RF CMOS process. The overall tuning range of the proposed VCO is from 18.82 to 23.28 GHz in measurement, and it consumes 46.4 mW, including a buffer stage at a 1 V supply voltage. The measured phase noise is −105.8 dBc/Hz at a 1-MHz offset frequency. A figure-of-merit (FOM) and FOM incorporating the tuning range (FOMT) are −179 dBc/Hz and −185.2 dBc/Hz at a 1-MHz offset from the center frequency, respectively.

Multi-level Waveform Generator with Delay Control for Low Distorted Class D Amplifiers

이문정,이하늘,최의규,양종렬 한국과학기술원 반도체설계교육센터 2021 IDEC Journal of Integrated Circuits and Systems Vol.7 No.2

A multi-level waveform generator with delay control is proposed for improving total-harmonic distortion of class D amplifiers. The voltage-mode class D amplifier is a circuit that amplifies the output voltage at the load to be twice almost the power supply voltage by using an input driving signal. The conventional 3-level class D amplifier generates a lot of harmonics due to the switching operation, and the harmonics can only be removed by the frequency response characteristics of the load. A configuration of the class D amplifier that sets an intermediate voltage level to reduce the harmonics has been presented, but it is required to generate the driving waveform for this. The proposed waveform generator makes driving signals that can change the voltage applied to the amplifier load from three to five levels. The generated step time can be optimally set depending on the driving frequency by controlling the RC delay circuits in the edge detector of the proposed generator. The generator IC fabricated in the area of 840 µm × 640 µm using the TSMC 0.25 µm CMOS process shows 5-level driving waveforms converted the input pulse-width modulation signal of 200 kHz. The measurement results show that the intermediate step time can be adjusted to 0.48 µs by controlling the delay circuit of the proposed waveform generator.

중금속(重金屬) 오염토양(汚染土壤)의 구산(枸酸) 침출(浸出)에 대한 pH의 영향(影響)

정경배,박홍기,류경근,박제현,최의규,Jung, Kyungbae,Park, Hongki,Yoo, Kyoungkeun,Park, Jay Hyun,Choi, Ui Kyu 한국자원리싸이클링학회 2013 資源 리싸이클링 Vol.22 No.5

구리, 아연 및 납 등의 중금속으로 오염된 사격장 토양으로부터 중금속 성분을 제거하기 위한 친환경적인 공정을 개발하기 위해 구연산용액을 이용하여 중금속 침출거동에 대한 pH의 영향을 조사하였다. 구연산 침출실험은 구연산과 구연산나트륨을 혼합하여 pH를 조절한 용액을 이용하여 시료입도 $75{\mu}m$이하, 반응온도 $50^{\circ}C$, 구연산 농도 1 몰, 광액농도 5%, 교반속도 100 rpm, 그리고 침출시간 1 시간의 조건에서 진행하였다. 침출반응 전후의 pH 변화는 미미하여 침출에 미치는 수소이온농도의 직접적인 영향은 크지 않은 것으로 판단되었다. 구리, 아연, 납의 제거율은 pH가 증가함에 따라 감소하였고, 열역학적인 계산결과, 이와 같은 침출거동은 중금속 이온이 구연산염 이온종과 착이온을 형성하는 반응과 중금속이온이 수산화이온과 결합하여 수산화물로 침전하는 반응에 의해 결정되는 것으로 분석되었다. The effect of pH on the citrate leaching behavior of heavy metal ion was investigated to develop an eco-friendly process for removing heavy metals from soil contaminated with copper, zinc, and lead. The leaching tests were performed using citrate solution with pH adjusted by mixing citric acid and sodium citrate under the following leaching conditions: particle size, under $75{\mu}m$; temperature, $50^{\circ}C$; citrate concentration, $1kmol/m^3$; pulp density, 5%; shaking speed, 100 rpm; leaching time, 1 hour. The difference of pH before and after the leaching test was not observed, and this result indicates the direct effect of hydrogen ion concentration on the leaching of metals was insignificant. The removal ratios of copper, zinc, and lead from the contaminated soil decreased with increasing pH. The thermodynamic calculation suggests that the leaching behaviors of metal ions were determined by two reactions; one is the reaction to form complex ions between heavy metal ions and citrate ion species, and the other is the reaction to form metal hydroxide between heavy metal ions and hydroxide ion.