• Journal of Nutrition and Health
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• 제31권4호
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• pp.679-686
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• 1998

This study was performed to determine whether the infusion of nucleosides and a nucleotide mixture directly ito intestinal lumen can induce a regenerative effect on impaired intestinal mucosa. The effects of massive small bowel resention and also total parenteral nutrition were induced by surgical creation of Thirty-Vella fistual in male Sprague-Dawley rats. The rats received saline solution (Control group) or nucleosides and a nucleotide mixture(lower concentration group(Nucl) or higher concentration group (Nuc2) every two days into the fistula. Mucosal protein, DNA , ornithine decarboxylase(ODC) activity, and morphometry were evaluated at 9 or 21 days postoperation in the fistual and also in the residual ileal segment. On the 9th day, mucosal protein, DNA content, and villous surface area in the fistula and also in the residual ileum increased in rats that received nucleosides and a nucleotide mixture of lower concentration (Nuc 1). On the 21 th day, there were no significant differences in intestinal mucosa between the control group and the lower level nucleoside nucleotide mixture-treated group. The fistula villous height of the higher nucleosides and a nucleotide mixture group was higher than in the control rats. Fistula mucosal ODC activities were not significantly different between groups although the mucosal ODC activity of the residual ileal segment was increased on the 9th day. Our data suggests that this animal model is suitable for studying the effect of dietary factors on intestinal mucosal growth and regeneration after villous stropy , differentiating direct effects of diet on the intestine from systemic effects. It is also suggested that external nucleosides and nucleotides have supportive effects on intestinal mucosal regeneration.

• 한국컴퓨터정보학회논문지
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• 제12권6호
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• pp.89-96
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• 2007

유한고장수를 가진 비동질적인 포아송 과정에 기초한 모형들에서 잔존 오류 1개당 고장 발생률은 일반적으로 상수, 혹은 단조증가 및 단조 감소 추세를 가지고 있다. 소프트웨어 제품의 정확한 인도시기를 예측하거나 효용성 및 신뢰성을 예측하기 위해서는 소프트웨어 테스팅 과정에서 중요한 요소인 테스트 커버리지를 이용하면 보다 효율적인 테스팅 작업을 할 수 있다. 본 논문에서는 기존의 소프트웨어 신뢰성 모형인 지수 커버리지 모형과 S-커버리지 모형을 적용하고 이 분야에 적용 될 수 있는 변형 커버리지 모형(중첩모형 및 혼합모형) 비교 문제를 제안하였다. 고장 간격시간으로 구성된 자료를 이용한 모수추정 방법은 최우추정법과 수치해석 방법인 이분법을 사용하여 모수 추정을 실시하고 효율적인 모형 선택은 편차자승합(SSE)을 이용하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1076-1080
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• 2003

$CO_2$ uptake of vegetation is one of the important variables in order to estimate photosynthetic activity, plant growth and carbon budget estimations. The objective of this research was to develop a new estimation method of $CO_2$ uptake of vegetation based on airborne hyperspectral remote sensing measurements in combination with a photosynthetic rate curve model. In this study, a compact airborne spectrographic imager (CASI) was used to obtain image over a field that had been set up to study the $CO_2$ uptake of corn on August 7, 2002. Also, a field survey was conducted concurrently with the CASI overpass. As a field survey, chlorophyll a content, photosynthetic rate curve, Leaf area, dry biomass and light condition were measured. The developed estimation method for $CO_2$ uptake consists of three major parts: a linear mixture model, an enhanced big leaf model and a photosynthetic rate curve model. The Accuracy of this scheme indicates that $CO_2$ uptake of vegetation could be estimated by using airborne hyperspectral remote sensing data in combination with a physiological model.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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• pp.1013-1018
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• 2014

In this study, we developed kinetic models to predict the growth of pathogenic Escherichia coli on cheeses during storage at constant and changing temperatures. A five-strain mixture of pathogenic E. coli was inoculated onto natural cheeses (Brie and Camembert) and processed cheeses (sliced Mozzarella and sliced Cheddar) at 3 to 4 log CFU/g. The inoculated cheeses were stored at 4, 10, 15, 25, and $30^{\circ}C$ for 1 to 320 h, with a different storage time being used for each temperature. Total bacteria and E. coli cells were enumerated on tryptic soy agar and MacConkey sorbitol agar, respectively. E. coli growth data were fitted to the Baranyi model to calculate the maximum specific growth rate (${\mu}_{max}$; log CFU/g/h), lag phase duration (LPD; h), lower asymptote (log CFU/g), and upper asymptote (log CFU/g). The kinetic parameters were then analyzed as a function of storage temperature, using the square root model, polynomial equation, and linear equation. A dynamic model was also developed for varying temperature. The model performance was evaluated against observed data, and the root mean square error (RMSE) was calculated. At $4^{\circ}C$, E. coli cell growth was not observed on any cheese. However, E. coli growth was observed at $10{\circ}C$ to $30^{\circ}C$C with a ${\mu}_{max}$ of 0.01 to 1.03 log CFU/g/h, depending on the cheese. The ${\mu}_{max}$ values increased as temperature increased, while LPD values decreased, and ${\mu}_{max}$ and LPD values were different among the four types of cheese. The developed models showed adequate performance (RMSE = 0.176-0.337), indicating that these models should be useful for describing the growth kinetics of E. coli on various cheeses.

• KSBB Journal
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• 제7권4호
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• pp.265-270
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• 1992

자연계에 널리 존재하는 저렴한 기질들은 대부분 여러 종류의 탄소원들을 함유한다. 이러한 혼합기질을 이용하는 효율적인 발효공정을 개발하기 위해서는 이들 기질들이 서로 어떻게 이용되는가를 알아야 하며, 사용되는 미생물의 생육과 생성물 생산을 잘 표현할 수 있는 동력학적 모델이 필요하다. P. stipitis에 의해 혼합기질에서 에탄오릉ㄹ 생산할 때 glucose는 xylose와 cellobiose 이용에 대해 ca-tabilite repression을 일으켰으며, 초기 glucose농도가 높을수록 xylose이용에서 균체의 생육속도는 감소하였으며 xylose이용시간도 길어졌다. 또한 glucose/xylose발효시 xylose이용에서 감소된 생육속도는 glucose가 xylose이용에 permenant repression을 야기시킨다는 것을 알 수 있었다. Cyclic AMP가 중개하는 catabolite repression mechanism에 기초하여 혼합기질에서 생육하는 P. stipitis의 생육모델을 발전시켰다 이 보텔식들을 이용하여 컴퓨터 simulation한 결과는 혼합기질로부터 P. stipitis에 의한 생육 및 에탄올 생성 실험결과와 비교적 잘 일치하였다.

• 대한기계학회논문집B
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• 제26권6호
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• pp.817-822
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• 2002

Sooting characteristics of counterflow ethylene/propane mixture flames have been experimentally studied to investigate the fuel structure effect on PHM and soot formation. Laser-induced incandescene and laser-induced fluorescene techniques were employed to measure soot volume fraction and polycyclic aromatic hydrocarbon (PAH) concentration, respectively. Importance of $C_{3-}$species on PAH growth as well as the H-abstraction-C$_2$ $H_2$addition (HACA) mechanism has been emphasized, considering that PAH growth rate is greater for with mixed fuel than fer pure fuel flames. It was also confirmed that HACA pathways are the dominant soot growth mechanism. A new PAH growth model including both $C_{2-}$ and $C_{3-}$growth mechanisms is proposed based on the experimental results.

• 한국가축번식학회지
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• 제17권1호
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• pp.13-19
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• 1993

We investigated the effects of CP-2 extracted from the mixture of Copis and Croton tiglium L, which showed very high cytotoxic effect to the various tumor cells, on the growth and steroidenesis of primary and transformed cell lines PA-GS6 and PO-GRS1 by cotransfectionwith SV40 and Ha ras oncogenes. CP-2 inhibited the growth of PA-GS6 and PO-GRS1 in a dose dependent manner when the growth of them was measured by cell number and by protein content, while CP-2 did not affect the growth of primary granulose cells. Productions of progesterone ofprimary and transformed granulosa cells were stimulated by forskolin, but this stimulatory effect was blocked by treatment of CP-2. Clinical application of CP-2 asa new anti-cancer drug and utilization of transformed granulosa cells as a model system for the screening of anti-cancer drug were also discussed.

• 한국방재학회 논문집
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• 제10권3호
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• pp.39-43
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• 2010

본 연구의 주목적은 아스팔트 혼합물의 피로균열에 대한 예측모델을 개발하는 것이다. 아스팔트 혼합물의 피로균열 시험을 위하여 응력제어 간접인장피로 시험이 수행되었다. 피로균열에 대한 예측모델 개발을 위하여 내적손상비 증가 개념이 도입되었다. 내적손상비증가 개념에서는 방출에너지 개념을 주로 사용하였으며 기준인장변형율 및 변형율 추이 요소 등이 추가로 사용되었다. 피로시험에서 나타난 방출에너지의 원인은 아스팔트 콘크리트 시료 내부의 손상증가와 재료 자체가 갖고 있는 고유의 점탄성 특성에 기인하는 것으로 판단된다. 방출에너지는 하중재하 횟수가 증가함에 따라 점차 증가함을 보였다.

• 한국축산식품학회지
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• 제35권1호
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• pp.108-113
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• 2015

The purpose of this study was to develop predictive models for the growth of Listeria monocytogenes in pork Bulgogi at various storage temperatures. A two-strain mixture of L. monocytogenes (ATCC 15313 and isolated from pork Bulgogi) was inoculated on pork Bulgogi at 3 Log CFU/g. L. monocytogenes strains were enumerated using general plating method on Listeria selective medium. The inoculated samples were stored at 5, 15, and $25^{\circ}C$ for primary models. Primary models were developed using the Baranyi model equations, and the maximum specific growth rate was shown to be dependent on storage temperature. A secondary model of growth rate as a function of storage temperature was also developed. As the storage temperature increased, the lag time (LT) values decreased dramatically and the specific growth rate of L. monocytogenes increased. The mathematically predicted growth parameters were evaluated based on the modified bias factor ($B_f$), accuracy factor ($A_f$), root mean square error (RMSE), coefficient of determination ($R^2$), and relative errors (RE). These values indicated that the developed models were reliably able to predict the growth of L. monocytogenes in pork Bulgogi. Hence, the predictive models may be used to assess microbiological hygiene in the meat supply chain as a function of storage temperature.

• 대한본초학회지
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• 제33권3호
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• pp.1-9
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• 2018

Objectives : In Korean medicine, a prescription of Sinsun-yukza-hwan (Shenxian-liuzi-wan, SSY) has been used in clinic for treatment of alopecia via oral. This study was performed to determine transdermal effects of the ethanol extract from SSY on hair growth and -related gene expressions in mice. Methods : We analyzed index compound, 5-hydroxy-methyl-2-furaldehyde (HMF), in SSY extract by ultra performance liquid chromatography (UPLC). 6 weeks old C57BL/6 mice with removed hair were used as an alopecia animal model. Mice were divided into 3 experimental groups including normal (3 water: 1 ethanol: 2 polyethylene glycol mixture as a vehicle), SSY extract and 5% minoxidil (as a positive control), treated groups. SSY was applied topically on the hair-shaved skin of C57BL/6 mice every day for 15 days. The color, thickness and density of hair were monitored every $5^{th}$ day by naked eye, photograph and phototrichogram using folliscope. Also hair growth-associated gene expressions were measured by immunoblotting assay. Results : Hair density of minoxidil or SSY-treated group was significantly increased compared to that of vehicle application on the $15^{th}$ day, respectively. And hair thickness of minoxidil and SSY groups was increased compared to that of vehicle treated group on the $15^{th}$ day, respectively. Induction of insulin-like-growth factor 1(IGF-1) and vascular endothelial growth factor (VEGF) were also significantly accelerated by SSY extract compared to those of vehicle-applied group. Conclusions : These results provide scientific evidence to support the potent multi-application of SSY as a cosmeceutical material for promoting hair growth.