• 한국분말재료학회지
• /
• 제19권6호
• /
• pp.446-450
• /
• 2012

In order to fabricate the porous Mo with controlled pore characteristics, unique processing by using $MoO_3$ powder as the source and camphene as the sublimable material is introduced. Camphene-based 15 vol% $MoO_3$ slurries, prepared by milling at $50^{\circ}C$ with a small amount of dispersant, were frozen at $-25^{\circ}C$. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $750^{\circ}C$, and sintered at $1000-1100^{\circ}C$ for 1 h. After heat treatment in hydrogen atmosphere, $MoO_3$ powders were completely converted to metallic W without any reaction phases. The sintered samples showed large pores with the size of about $150{\mu}m$ which were aligned parallel to the camphene growth direction. Also, the internal wall of large pores and near bottom part of specimen had relatively small pores due to the difference in the camphene growth rate during freezing process. The size of small pores was decreased with increase in sintering temperature, while that of large pores was unchanged. The results are strongly suggested that the porous metal with required pore characteristics can be successfully fabricated by freeze-drying process using metal oxide powders.

• Journal of Pharmaceutical Investigation
• /
• 제35권4호
• /
• pp.287-293
• /
• 2005

The purpose of the present study was to evaluate the bioequivalence of two glimepiride tablets, Amaryl tablet (Handok & Aventis Korea, reference drug) and Mepiril tablet (Myungmoon Pharm. Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (glibenclamide) to human plasma, plasma samples were extracted using 1mL of methyl tertiary butyl ether. Compounds extracted were analyzed by reverse-phase HPLC with multiple reaction monitoring (MRM) mode analyte detection. This method for determination glimepiride proved accurate and reproducible, with a limit of quantitation of 2 ng/mL in human plasma. Twenty-four healthy male Korean volunteers received each medicine at the glimepiride dose of 2 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of glimepiride were monitored by a LC-MS/MS for over a period of 12 hr after the administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Amaryl/Mepiril were log 0.9583-log 1.1357 and log 1.0570-log 1.2376, respectively. These values were within the acceptable bioequivalence intervals of log 0.80-log 1.25. Taken together, our study demonstrated the bioequivalence of Amaryl and Mepiril with respect to the rate and extent of absorption.

• 방사성폐기물학회지
• /
• 제16권3호
• /
• pp.291-299
• /
• 2018

파이로 공정에서는 사용후핵연료 관리 공정 개발의 일환으로 산화 우라늄을 고온 용융염 전해질계에서 전기화학적 방법으로 환원시키기 위한 전해환원 공정이 개발되고 있다. 이에 따른 전해환원 공정의 반응기 설계를 위해서는 전기화학적 이론에 기초한 모델이 요구되고 있다. 본 연구에서는 상 분리를 설명하는 phase-field 이론에 기초하여 우라늄 산화물의 전해환원 모사를 위한 1차원 모델이 개발되었다. 모델은 우라늄 산화물 내 산소 원소의 확산과 펠렛 표면에서 전기화학 반응 속도를 나타내는 매개변수를 사용하여 외부로부터 내부로 진행되는 전해환원을 잘 모사하고 있으며 계산 결과 전체 전류는 산소원소의 내부 확산에 크게 의존하는 것으로 나타났다. 전해환원 반응에 대한 모델은 대용량 장치 설계에 최적화된 조건 도출에 활용될 것으로 예상되며 장치 설계가 완료되면 공정 연계 모사에 직접 사용될 것으로 기대된다.

• Journal of Pharmaceutical Investigation
• /
• 제41권5호
• /
• pp.309-315
• /
• 2011

A sensitive and specific liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the analysis of ambroxol (active moiety of acebrophylline). After acetonitrile precipitation of proteins from plasma samples, ambroxol and the domperidone (internal standard, IS) were eluted on a C18 column. The isocratic mobile phase was consisted of 10 mM ammonium acetate and methanol (10 : 90, v/v), with flow rate at 0.2 mL/min. A tandem mass spectrometer, as detector, was used for quantitative analysis in positive mode by a multiple reaction monitoring mode to monitor the m/z 379.2${\rightarrow}$264.0 and the m/z 426.2${\rightarrow}$175.1 transitions for ambroxol and the IS, respectively. Twenty four healthy Korean male subjects received two capsules (100 mg ${\times}$ 2) of either the test or the reference formulation of acebrophylline HCl in a 2 ${\times}$ 2 crossover study, this was followed by a 1week washout period between either formulation. $AUC_{0-t}$ (the area under the plasma concentration-time curve) was calculated by the linear trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. The 90% confidence intervals for the log transformed data were acceptable range of log 0.8 to log 1.25 (e.g., log 0.8964 - log 0.9910 for $AUC_{0-t}$ log 0.8690 - log 1.0750 for $C_{max}$). The major parameters, $AUC_{0-t}$ and $C_{max}$ met the criteria of Korea Food and Drug Administration for bioequivalence indicating that Acephyll$^{(R)}$ capsule (test) is bioequivalent to Surfolase$^{(R)}$ capsule (reference).

• Journal of Microbiology and Biotechnology
• /
• 제26권3호
• /
• pp.503-510
• /
• 2016

The accumulation (internal and superficial distribution) of magnesium ions (Mg²⁺) by the green freshwater microalga Chlorella vulgaris (C. vulgaris) was investigated under autotrophic culture in a stirred photobioreactor. The concentrations of the three forms of Mg²⁺ (dissolved, extracellular, and intracellular) were determined with atomic absorption spectroscopy during the course of C. vulgaris growth. The proportions of adsorbed (extracellular) and absorbed (intracellular) Mg²⁺ were quantified. The concentration of the most important pigment in algal cells, chlorophyll a, increased over time in proportion to the increase in the biomass concentration, indicating a constant chlorophyll/biomass ratio during the linear growth phase. The mean-average rate of Mg²⁺ uptake by C. vulgaris grown in a culture medium starting with 16 mg/l of Mg²⁺ concentration was measured. A clear relationship between the biomass concentration and the proportion of the Mg²⁺ removal from the medium was observed. Of the total Mg²⁺ present in the culture medium, 18% was adsorbed on the cell wall and 51% was absorbed by the biomass by the end of the experiment (765 h). Overall, 69% of the initial Mg²⁺ were found to be removed from the medium. This study supported the kinetic model based on a reversible first-order reaction for Mg²⁺ bioaccumulation in C. vulgaris, which was consistent with the experimental data.

• Molecular & Cellular Toxicology
• /
• 제3권3호
• /
• pp.195-197
• /
• 2007

Currently praziquantel is used for treatment of not only clonorchiasis but also other trematodes and cestodes. But cure rate of praziquantel is just 60-80% for most trematodes. It needs for the treatment-failed patients to have more drugs. The cause of failure of treatment is not studied. We just know that the blood level of praziquantel is severely different among the people. We guess that this factor may influence the results of treatment. In an endemic area of human clonorchiasis in Heilongjiang Providence, China, 78 subjects were selected for the study. Three doses of 25 mg/kg (total 75 mg/kg) of praziquantel were administered to 78 clonorchiasis patients. After three weeks of treatment, stool examination was undertaken once again to confirm the cured and uncured subjects. To analyze SNP (single nucleotide polymorphism) of CYP3A5 PS2-1, CYP3A5 PS2-2, and CYP3A5*6, PCR method was done with specifically designed primers. The mutation rates of all sites were not significant statistically. The number of subjects was too small, so we need more subjects and other delivery proteins of bile ducts (ex. MRP etc.) were also considered for effects of praziquantel. We analyzed, for the first time, the entire CYP3A5 gene in a French population, using a polymerase chain reaction- single strand conformational polymorphism (PCR-SSCP) strategy.

• 대한기계학회논문집A
• /
• 제39권6호
• /
• pp.639-644
• /
• 2015

원형 리튬 전지는 노트북, 파워툴이나 전기 자동차와 같이 고용량/고율 방전이 필요한 분야에서 널리 사용되는 이차전지 중의 하나로 저장된 화학 에너지를 전기화학적 반응을 통해 전기 에너지로 변환하는 장치이다. 센터 핀은 원형 리튬 전지 내에 가스 분출 채널 확보를 위해 젤리-롤 중심홀이 충/방전 중 좁혀지는 것을 방지하고, 낙하 충격 시 완충 작용으로 분리막 손상을 방지하여 내부 단락을 막아주는 역할을 담당하는 부품이다. 본 연구에서는 센터 핀의 중요한 역할들에 대해 실험적으로 검증하기 위해서 센터 핀 유/무에 따른 2 가지 실험을 진행하였다. 하나는 연속 50 회 충/방전 싸이클 후의 젤리-롤 중심홀의 변화이고, 다른 하나는 UL 표준 기준에 의한 자유 낙하 충격 실험을 통한 젤리-롤 내 분리막 손상에 의한 내부 단락 여부이다. 이러한 실험적 결과를 바탕으로 원형 전지의 센터핀이 안전성 측면에서 반드시 필요한 부품임을 확인할 수 있었다.

• Clinical and Experimental Pediatrics
• /
• 제52권3호
• /
• pp.389-391
• /
• 2009

AHS는 항경련제에 의한 부작용으로 드물게 발생하지만 생명을 위협할 수 있는 지연형 면역반응이다. 보통 항경련제 복용 후 1-8주 사이에 고열, 피부발진, 림프절병증의 임상 증세를 나타내고, 혈액, 간, 신장, 또는 폐 등의 내부 장기를 침범한다. AHS는 항경련제에 의한 부작용으로 증상이 전신적으로 다양하게 나타날 수 있다. 그리고 전염성 단핵구증이나 가와사키병과 같은 전신적 질환들과도 유사한 임상증상들을 보이기 때문에 이런 질환들과 감별하는 것이 중요하고 사망률도 10%에서 보고되고 있어 조기에 발견하고 치료하는 것이 중요하다. 저자들은 임상증상과 초기 검사가 전염성 단핵구증과 비전형적 가와사키병과 매우 유사한 lamotigine에 의한 AHS 1예를 보고하는 바이다.

• 공업화학
• /
• 제10권3호
• /
• pp.432-437
• /
• 1999

폴리에틸렌 열분해실험을 반응기 크기가 $10cm^3$인 스테인레스 스틸 반응기에서 수행하였으며 이때 반응온도는 $390{\sim}450^{\circ}C$이었다. 열분해생성물인 반응생성물과 기체생성물을 분리하여 채취하였고 각 생성물의 분자량분포는 HPLC-GPC와 GC분석을 통해 얻었다. 열분해반응의 개시-종료, 전파-비전파반응, 즉 수소탈취반응, 사슬절단, 고분자물질과 라디칼과의 결합반응 등을 설명할 수 있는 random, specific 생성물의 분자랑분포에 대한 distribution balance식을 제안하였다. 말단절단 과정에 의해 저분자량의 비응축성 기체생성물 (C1~C5)이 생성되었으며 이 기체생성물의 평균분자량은 38이었다. 무작위절단과 말단절단의 속도매개변수 중의 하나인 활성화에너지는 각각 35, 17 kcal/mole 이었다.

• 대한화장품학회지
• /
• 제22권2호
• /
• pp.141-152
• /
• 1996

Many eastern females concern themselves about the condition and the color of their skin. The purpose of the present study is to classify the skin trouble and the change of the facial color due to hormonal cycle in female. We examined the actual cricumstances by questionnaires, and made patch tests of methyl nicotinate, representing rubefacient, to estimate the epidermal penetratin rate, and measured the facial color change during the menstrual cycle period to invest the correlation factors between skin trouble due to cosmetics and facial color change. Fifty-two percent of subjects had skin trouble relating to cosmetics. One second of subjects with skin trouble due to cosmetic complained the change of sysptom by menstrual cycle. The changes of systptom were related on premenstrual period. The skin trouble developed mainly on the first trimester of the pregnancy. In patch test of methyl nicotinate, most cases showed decreased threshold of the reaction on minstruation, and other cases showed increased reactivity of the skin of menstruation. In facial color measurements, it proves in the appearance of red spot, darkness, increasing the value and turning the hue to yellowish, Also it demonstrates that premenstruation hue turn red and value level decrease. During the period, facial color turns pale and hue progress to yellow. This fact coincides with the questionnaire. We have quqntified through questionnaire, which demonstrates it has good correlation with done to the subjects among the internal environment factors hormonal cycle influences the facial color change and the skin trouble due to cosmetics. Through this paper the development of an more fragmented make-up and skin care products is required to increase the interest to females, to make true the creation of beauty.