• 대한약학회:학술대회논문집
• /
• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
• /
• pp.328.1-328.1
• /
• 2002

A major lipid-signaling pathway in mammalian cells implicated the activation of sphingomyelinase (SMase), which hydrolyses sphingomyeline to generate ceramide and phosphocholine. Sphingomyelinase is divided into many isoform groups dependent on optimal pH, and essential cation especially magnesium in their activation. Such as acidic sphingomyelinase, neutral sphingomyelinase and alkaline sphingomyelinase. Ceramide is known as a crucial second messenger in cell responses like cell proliferation. cell cycle arrest. cellular senescence, and apoptosis. (omitted)

• 대한의생명과학회지
• /
• 제2권1호
• /
• pp.57-69
• /
• 1996

한국산 대륙밭쥐 (Clethrionomys rufocanus regulus) 정자변태 과정을 알아보기 위하여 정소내 세정 관상피의 세포분화에 따른 형태적 특징들을 기초로 하여 전자현미경으로 관찰한 결과는 다음과 같다. 1. 대륙밭쥐의 정자변태 과정은 골지(Golgi), 두모(cap), 첨체(acrosome), 성숙(maturation) 및 이탈기(spermiation phase)로 구분하였고, 다시 각각 전후단계로 세분하여 전과정을 10단계로 나누었다. 2. 염색질 변화는 골지 후기에서 서서히 응축하여 성숙기에서 균질화되고, 이탈기에서 완전한 핵을 형성하였다. 3. 정자두부는 낫꼴모양을 가지며, 정자꼬리는 골지 전기에서 형성되기 시작하여 이탈기에서 완성되었다. 4. 이탈 전 후기의 정자세포의 형태적 특징으로서는, 이탈전기의 정자 세포는 3가지 유형으로 구분 되어졌다. (1).미토콘드리아의 불규칙 배열과 더불어 경부와 중편부에 세포질 소적을 함유한 정자세포(A-type). (2). 미토콘드리아가 축사를 중심으로 완전히 배열되고, 중편부에 세포질 소적을 함유한 정자세포(B-type). (3) 축사를 중심으로 미토콘드리아의 배열 후 경부에만 세포질 소적을 함유한 정자세포(C-type). 그리고 이탈후기의 경우, 정자세포들이 정자두부만 Sertoli cell의 세포질에 싸여져 있거나 또는 Sertoli cell의 세포질로부터 이탈되기 직전의 정자로 구분되었다.

• 전자공학회논문지A
• /
• 제32A권12호
• /
• pp.9-24
• /
• 1995

In this paper, we proposed and analysed two kinds of priority control mechanism to archive the cell loss rate requirement and the delay requirement of each class. The service classes of our concern are the high time priority class(class 1) and the high loss priority class(class 2). Two kinds of priority control mechanism is divided by the method of storing the arriving class 2 cell in buffer on case of buffer full. The first one is the method which discarding the arriving class 2 cell, the second one is the mothod which storing the arriving class 2 cell on behalf of pushing out the class 1 cell in buffer. In the proposed priority schemes, one cell of the class 1 is transmitted whenever the maximum K cells of the class 2 is transmitted on case of transmitting the class 1 cell and the class 2 cell sequentially. In this paper, we analysed the cell loss rate and the mean cell delay for each class of the proposed priority scheme by using the Markov chain. The analytical results show that the characteristic of the mean cell delay becomes better for the class 1 cell and that of the cell loss rate becomes better for the class 2 cell by selecting properly the cell transfer ratio according to the condition of input traffic.

• Korean Chemical Engineering Research
• /
• 제48권2호
• /
• pp.275-282
• /
• 2010

아염소산나트륨($NaClO_2$)의 무격막 전기분해(un-divided electrolysis)에 의한 이산화염소(chlorine dioxide; $ClO_2$) 제조에서 양전극(anode) 재질에 따른 이산화염소수 발생특성을 조사하였다. 양전극으로는 $IrO_2$-coated Ti, $RuO_2$-coated Ti, DSA(dimensionally stable anode) 전극을 사용하였으며, 음전극으로는 Pt-coated Ti 전극을 사용하였다. 다양한 양전극을 사용한 무격막 전해셀(un-divided electrochemical cell) 시스템에서 이산화염소의 전구체인 아염소산나트륨 ($NaClO_2$) 농도, 전해질로 사용된 염화나트륨(NaCl) 농도 그리고 전구체 용액의 전해셀 체류시간(cell residence time;$t_R$), 전구체 용액의 초기 pH 그리고 무격막 전해셀에 공급된 전류(current; A)와 같은 운전 파라미터가 이산화염소수 발생에 미치는 영향을 조사하고 최적 운전조건을 도출하였다. $IrO_2$-coated Ti, $RuO_2$-coated Ti 그리고 DSA 양전극 시스템에서 최적 전해셀 체류시간은 각각 약 2.27, 1.52, 1.52 s, 전구체 용액의 초기 pH는 약 2.3, 최적 아염소산나트륨 농도는 $IrO_2$-coated Ti와 $RuO_2$-coated Ti 양전극 시스템이 약 0.43 g/L, DSA 양전극 시스템이 약 0.32 g/L 그리고 최적전해질 농도는 약 5.85 g/L로 나타났으며 무격막 전해셀에 공급된 최적 전류는 약 0.6 A로 나타났다. 산출된 최적 무격막 전해셀 조건에서 이산화염소수 발생을 위한 $IrO_2$-coated Ti, $RuO_2$-coated Ti 그리고 DSA 양전극 시스템의 전류효율(current efficiency; C.E.%)과 에너지 소모율(energy consumption; E.C. $W{\cdot}hr/g-ClO_2$)은 각각 약 79.80, 114.70, 70.99% 그리고 1.38, 1.03, $1.61W{\cdot}hr/g-ClO_2$로 나타났다.

• Journal of Nutrition and Health
• /
• 제31권1호
• /
• pp.21-27
• /
• 1998

The objective of this study was to observe the effect of dietary calcium(Ca) level on colonic mucosal levels of cell proliferation, 1, 2-diacylglycerol(DAG), TXB2, PGE2 and phospholipid fatty acid composition which have been known as biomarkers for colon cancer. One hundred male Sprague Dawley rats, at 7 weeks of age, were divided into two fat type groups. Each group of which was further divided into two Ca level groups. Each rt was intramuscularly injected with 1, 2,-dimenthylhydrazine(DMH) for 6 weeks (total dose of 180mg/kg body weight) and simultaneously fed one of four experimental diets containing 15% dietary fat(corn oil or perilla oil )and 0.3% or 1.0% Ca by weight for 20 weeks. Compared to corn oil, perilla oil significantly reduced cell proliferation by decreasing labeling index, proliferating zone, crypt length in colonic mucosa and colonic mucosa and colonic mucosal levels of DAG, TXB2 . PGE2 and phospolipid (PL) arachidonic acid distribution. The effect of Ca on biomarketrs was different depending on the type of dietary fat comsumed . Ca effect of Ca on biomarkers was different depending on the type of dietary fat comsumed. Ca effect was not significantly shown in the PO group, but it was significant in the CO group in which high Ca(1.0%) decreased the levels of levels of PL-C20 : 4(%), DAG and PGE2 . However , high Ca supplementation had shown only the trends of improving cell proliferation. Overall , high dietary Ca significantly reduced cell proliferation by inhibiting the synthesis of eicosanoid and DAG with reduced distribution of PL-C20 : 4 , which may have resulted in lower activation of PKC through reduced signal transduction. Since a high level of dietary Ca was more effective in reducing the risk factor against colon cancer in corn oil fed rats, it could be suggested that a higher amount of dietary Ca be consumed , especially when more vegetable oil rich in linoleic acid is included in the diet.

• 한국정밀공학회지
• /
• 제28권4호
• /
• pp.521-525
• /
• 2011

It is known that the low-intensity sound stimulation really affect to grow the cell. The cellular growth mechanism, however, does not been clearly identified even the effect on the low-intensity sound stimulation. The purpose of this study is to investigate the effect of low-intensity sound stimulation on the alveolar UC-MSC proliferation. Before the low-intensity sound stimulation is applied, the UC-MSC are cultured for 24 hours to facilitate their attachments. The cells are divided into two groups. And each was exposed to a medium with or without the low-intensity ultrasound stimulation at 71dB intensity level. The UC-MSC are again divided into three treatment groups of group 1, 2, and 3 and exposed to a frequency at 50Hz, 100Hz, and 1000Hz, respectively. In the results, it is investigated that the growth rates of UC-MSC for the stimulated groups were higher than those of control groups. In 1000Hz frequency, the number of UC-MSC cell is significantly higher than control groups (p>0.05). We would put the hypothesis that the cell growth could be enhanced by an appropriate low-intensity sound stimulation.

• 한국통신학회논문지
• /
• 제21권12호
• /
• pp.3256-3264
• /
• 1996

This paper presents an efficient VLSI architecture for transposing matris in high speed. In the case of transposing N*N matrix, N$^{2}$ numbers of transposition cells are configured as regular and spuare shaped structure, and pipeline structure for operating each transposition cell in paralle. Transposition cell consists of register and input data selector. The characteristic of this architecture is that the data to be transposed are divided into several bundles of bits, then processed serially. Using the serial transposition of divided input data, hardware complexity of transpositioncell can be reduced, and routing between adjacent transposition cells can be simple. the proposed architecture is designed and implemented with 0.5 .mu.m VLSI library. As a result, it shows stable operation in 200 MHz and less hardware complexity than conventional architectures.

• 전기학회논문지
• /
• 제58권3호
• /
• pp.627-631
• /
• 2009

This paper presents a novel current steering cell matrix DAC(digital-to-analog converter) architecture to reduce decoder area. The current cell matrix of a existing architecture is selected by columns and lows thermometer code decoder of input bits. But The current cell matrix of a proposal architecture is divided 2n by the thermometer code decoder of upper input bits and are selected by the thermometer code decoder of middle and lower input bits. Because of this configuration, decoder numbers have increased. But the gate number that composed of decoder has decreased. In case of the designed 8 bit current steering cell matrix DAC, the gate number of decoder has decreased by about 55% in comparison with a existing architecture.

• Applied Microscopy
• /
• 제13권1호
• /
• pp.63-70
• /
• 1983

The cell division of Bacillus thuringiensis are studed by a electron microscope. It was observed that when the cell division was occurred, the bacterial transverse septeum was centripetally formed, and the bacterial spore was divided into two daughter cells. The fore spore septum was initiated by invagination from either sides of the cell membranes, and was easily distinguished it from the transverse septum of the vegetative cell division. The large vesicular mesosome was. observed at one end of the cell membrane. The nucleoids were of variously irregular shapes and had no a nuclear membrane. The morphology of the bacteria was visualizd by a scanning electron microscope. The surface of the cell was generally rough and had a single polar flagellum, which was appeared to be $0.2{\mu}$ in width and $13{\mu}$ in length.

• 대한지역사회영양학회지
• /
• 제17권2호
• /
• pp.243-257
• /
• 2012

The purpose of this study was to evaluate pancreatic ${\beta}$-cell function of Korean adult and to examine the associations between ${\beta}$-cell function and nutrient intakes. Data were analyzed for 1,917 male and 2,885 female subjects older than 30 years using 'The Forth Korean National Health and Nutrition Survey in 2009'. We calculated HOMA ${\beta}$-cell (The homeostasis model assessment of ${\beta}$-cell function) using fasting glucose and fasting insulin for assessing ${\beta}$-cell function. Subjects were divided into HHG (High HOMA ${\beta}$-cell Group) or LHG (Low HOMA ${\beta}$-cell Group) according to median of HOMA ${\beta}$-cell, and then nutrient intakes were compared between two groups. In the entire study population, HHG showed lower percent of carbohydrate intakes (p < 0.05), and higher fat (p < 0.01), percent of fat (p < 0.05), vitamin A (p < 0.05), carotene (p < 0.05) and riboflavin (p < 0.05) intakes than LHG. In addition, levels of HOMA ${\beta}$-cell were negatively correlated with percent of carbohydrate (${\beta}$ = -0.040, p < 0.05), and positively correlated with percent of fat (${\beta}$ = 0.046, p < 0.01). The subjects were then divided into two subgroups according to body mass index values, either $23kg/m^2$ (under- and normal-weight) or ${\geq}23kg/m^2$ (over-weight and obese). Significant differences of some nutrients intakes and correlations with HOMA ${\beta}$-cell were observed only in under- and normal weight subjects, but not in over-weight and obese subjects. In conclusion, high carbohydrate, lower fat and lower vitamin intakes may be related with pancreatic ${\beta}$-cell dysfunction in under- and normal-weight Korean.