• 제목/요약/키워드: C2 Model

검색결과 6,646건 처리시간 0.039초

흰 쥐 적출 심장에서 비작업성 관류 회로를 이용한 인삼 성분 Ginsenoside Rg1 Mixtures의 심근 보호 효과에 관한 실험적 연구 (Experimental Studies on the Effect of Ginsenoside Rg1 Mixtures in an Isolated Rat Heart after Ischemic Arrest and Reperfusion)

  • 김동원;신원선;이재영;김범식;조규석;유세영
    • Journal of Chest Surgery
    • /
    • 제31권6호
    • /
    • pp.567-575
    • /
    • 1998
  • 최근 심장 분야 수술의 발달로 여러 가지 고난도의 심장 수술과 심장 이식술의 시행이 증가하고 있으며, 술 후 예후에 크게 영향을 주는 심장의 심근 손상 방지에 대한 다각적인 연구가 행해지고 있는데, 수술 및 이식 전후의 허혈기와 재관류시 발생할 수 있는 심근 손상을 최소화하고, 술 후 심근 기능의 조속한 회복을 위한 목적으로 여러 약제 및 방법을 제시하고 있다. 한편 한국에서는 오래 전 부터 만병 통치의 영약으로 전해져 오고 있는 인삼을 이용한 동물 실험 및 임상 경험을 통해 성분 효과에 대한 여러 결과가 보고되고 있고, 심장 기능에 대한 효과도 약리학적 측면에서 많은 결과가 발표되었다. 그런데 여러 분획 추출물 중 ginsenoside Rg1 mixtures에 대해서는 그 결과가 다소 미비한 상태이고 ginsenoside Rb1과의 이원 작용에 대한 결과가 흥미로울 것으로 판단되었으며 여러 저자들의 결과에 차이가 있어 ginsenoside Rg1을 이용하여 심근의 허혈 후 재관류 시행 10분 및 지속적 관류 상태에서의 심근 손상에 대한 심근 보호 정도를 혈역학적 지표 및 관상 혈류를 통한 관류액의 효소치를 측정하여 실험한 결과 심근 허혈 및 재관류 후 심근 손상 방지와 심근 기능 회복에 효과가 있다고 판단되며 향후 약제의 투여 용량에 따른 심근 보호 정도에 관한 실험이 필요할 것으로 사료되고, 인삼 성분 각 분획의 복합 투여에 의한 결과도 재차 확인하여야 할 것으로 생각된다.

  • PDF

Determination of human breast cancer cells viability by near infrared spectroscopy

  • Isoda, Hiroko;Emura, Koji;Tsenkova, Roumiana;Maekawa, Takaaki
    • 한국근적외분광분석학회:학술대회논문집
    • /
    • 한국근적외분광분석학회 2001년도 NIR-2001
    • /
    • pp.4105-4105
    • /
    • 2001
  • Near infrared spectroscopy (NIRS) was employed to qualify and quantify on survival, the injury rate and apoptosis of the human breast cancer cell line MCF-7 cells. MCF-7 cells were cultured in RPMI medium supplemented with 10% FCS in a 95% air and 5% CO2 atmosphere at 37$^{\circ}C$. For the viable cells preparation, cells were de-touched by 0.1% of trypsin treatment and washed with RPMI supplemented with 10% FCS medium by centrifugation at 1000 rpm for 3min. For the dead cells preparation, cells were de-touched by a cell scraper. The cells were counted by a hemacytometer, and the viability was estimated by the exclusion method with frypan blue dye. Each viable and dead cells were suspended in PBS (phosphate bufferred saline) or milk at the cell density desired. For the quantitative determination of cell death by measuring the LDH (lactate dehydrogenase) activity liberated from cells with cell membrane injuries, LDH-Cytotoxic Test Wako (Wako, Pure Pharmaceutical Co. Ltd., Japan) was used. We found that NIRS measurement of MCF-7 cells at the density range could evaluate and monitor the different characteristics of living cells and dead cells. The spectral analysis was performed in two wavelength ranges and with 1,4, 10 mm pathlength. Different spectral data pretreatment and chemometrics methods were used. We applied SIMCA classificator on spectral data of living and dead cells and obtained good accuracy when identifying each class. Bigger variation in the spectra of living cells with different concentrations was observed when compared to the same concentrations of dead cells. PLS was used to measure the number of cells in PBS. The best model for measurement of dead cells, as well as living cells, was developed when raw spectra in the 600-1098 nm region and 4 mm pathlength were used. Smoothing and second derivative spectral data pretreatment gave worst results. The analysis of PLS loading explained this result with the scatter effect found in the raw spectra and increased with the number of cells. Calibration for cell count in the 1100-2500 nm region showed to be very inaccurate.

  • PDF

3T3L-1 지방전구세포와 고지방식이로 유도된 비만 마우스 모델에서 모과 추출물의 항비만 효과와 억제 기전 (Anti-obese Effects and Signaling Mechanisms of Chaenomeles sinensis extracts in 3T3-L1 Preadipocytes and Obese Mice Fed a High-fat Diet)

  • 김다혜;권보라;김상준;김홍준;정승일;유강열;김선영
    • 대한한의학방제학회지
    • /
    • 제25권4호
    • /
    • pp.457-469
    • /
    • 2017
  • Obesity is one of the most serious health problem because it induced numerous metabolic syndrome and increases the incidence of various disease, including diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. In 3T3-L1 adipocytes, increases in reactive oxygens species (ROS) occur with lipid accumulation. NADPH oxidase, producing superoxide anion, may contribute to the development of obesity-associated insulin resistance and type 2 diabetes. In this study, we elucidated the effect of Chaenomeles sinensis koehne extract (CSE) against the development of obesity and the inhibition mechanisms in 3T3-L1 preadiocytes. CSE decreased triglyceride content and inhibited the expression of adipogenic transcription factors including peroxisome proliferator-activated receptor $(PPAR){\gamma}$, CCAT/enhancer binding protein $(C/EBP){\alpha}$ and sterol regulatory element-binding protein (SREBP-1). In addition, CSE highly increased antioxidant activity in a dose-dependent manner. CSE remarkably reduced intracellular ROS increase and NAD(P)H oxidase activity, NOX1, NOX4, Rac1 protein expression, and phosphorylation of p47phox and p67phox We also studied the effect of CSE on weight gain induced by high-fat diet. The oral treatment of CSE (500 mg/kg, body weight) in diet-induced obese (DIO) mice showed decrease in triglyceride and adipocyte size. Therefore, these results indicate that the effect of CSE on anti-obese effects, adipocyte differentiation and reducing triglyceride contents as well as adipocyte size in obese mice, may be associated with inhibition of NAD(P)H oxidase-induced ROS production and adipose transcription factors. These results showed the potential to inhibit the obesity by CSE treatment through controlling the activation of NAD(P)H oxidase in vitro and in vivo obese model.

다중에너지 영상 획득을 위한 Depth-Encoding 고분해능 단일광자단층촬영 검출기 개발: 몬테칼로 시뮬레이션 연구 (Development of a High Resolution SPECT Detector with Depth-encoding Capability for Multi-energy Imaging: Monte Carlo Simulation)

  • 백철하;황지연;이승재;정용현
    • 한국의학물리학회지:의학물리
    • /
    • 제21권1호
    • /
    • pp.93-98
    • /
    • 2010
  • 본 연구에서는 I-125 (35 keV) 와 Tc-99m (140 keV)에 대해 고해상도를 지닌 SPECT 영상을 동일한 검출기로 획득하는 방법을 제시하였고, 이를 몬테칼로 시뮬레이션 코드인 DETECT2000과 GATE를 이용하여 검증하였다. 제안된 검출기는 두께 3.0 mm의 CsI (Tl) 블록형 섬광체와 하마마츠사의 H8500C PSPMT로 이루어져 있다. 35 keV 감마선을 방출하는 I-125 핵종을 영상화할 때는 두꺼운 섬광체를 사용 할 경우, 일반적인 앵거방법으로는 빛 퍼짐이 많아지기 때문에 내인성 공간분해능이 저하되지만, 최대우도 함수와 색인테이블을 사용하여 감마선 반응 위치를 추적하면 내인성 공간분해능을 향상시킬 수 있다. DETECT2000 시뮬레이션 결과 1.0 mm 이내의 내인성 공간분해능을 획득하였다. 140 keV를 방출하는 Tc-99m를 영상화할 경우에는 I-125 전용인 1.0 mm 두께의 섬광체를 사용하였을 경우보다 3.0 mm 두께의 섬광체를 사용하였을 때 2.3배 이상 향상된 민감도를 보였다. 본 연구에서 제안한 검출기의 장점은 저에너지의 I-125 선원에 대해 상대적으로 두꺼운 섬광체를 사용하더라도 최대우도함수를 사용하기 때문에 분해능의 감소가 없다는 점과 Tc-99m 선원에 대해 민감도의 저하가 적다는 점이다. 본 연구에서 제안한 검출기를 사용하면 고에너지와 저에너지를 가진 핵종을 모두 영상화할 수 있다.

공학계열 대학생의 물리학습동기 측정 (Measurement of Motivation to Learn Physics in Engineering College Students)

  • 문공주;황요한;하민수
    • 과학교육연구지
    • /
    • 제44권1호
    • /
    • pp.74-83
    • /
    • 2020
  • 본 연구는 공학대학 학생들의 물리학에 대한 자발적인 학습이 이뤄지지 않는 이유를 탐색하기 위해 물리학습동기를 측정하였다. 본 연구에서는 Glynn 등이 개발한 Science Motivation Questionnaire II(SMQ II)을 물리학습 상황으로 수정한 Physics Motivation Questionnaire(PMQ)을 이용하여 서울에 위치하는 C대학의 공학계열 1학년 학생 374명을 대상으로 물리학습동기를 측정하였다. PMQ는 intrinsic motivation, career motivation, self-determination, self-efficacy, grade motivation의 5요인으로 구성되며 총 25개 리커트 척도문항의 검사도구이다. PMQ는 탐색적요인분석(EFA)를 통해 5가지 요인이 공학계열 대학생들의 물리학습동기를 측정하는데 있어 구조적으로 타당함을 확인하였다. 또한 라쉬(Rasch)모델 분석을 활용하여 문항적합도(MNSQ)를 확인하였다. 측정결과, 물리학습동기의 요인 중에서는 성적동기가 평균 4.18로 가장 높게 나타났으며, 그 다음으로 직업동기가 평균 3.75으로 높은 수준으로 나타났다. 그리고 내재동기는 평균 3.42, 자기효능감은 평균 3.38, 자기결정력는 평균 3.32로 나타났다. 이와 같은 연구 결과를 통해 공학대학 학생들의 과학학습 동기는, 점수 및 직업과 관련된 외적 동기가 높게 나타나는 특성이 있음을 확인할 수 있었다. 따라서 공학계열 학생들 물리학습에 대한 숙달목표지향을 가지고 내적 동기를 높일 수 이도록 하는 교수-학습 전략의 개발에 노력해야 할 것이다.

Genetic and Phenotypic Parameter Estimates of Body Weight at Different Ages and Yearling Fleece Weight in Markhoz Goats

  • Rashidi, A.;Sheikahmadi, M.;Rostamzadeh, J.;Shrestha, J.N.B.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제21권10호
    • /
    • pp.1395-1403
    • /
    • 2008
  • The objective of the present study was to estimate genetic parameters for economic traits in Markhoz goats. Data collected from 1993 to 2006 by the Markhoz goat Performance Testing Station in Sanandaj, Iran, were analyzed. The traits recorded as body weight performance at birth (BW), weaning (WW), six month (6MW), nine month (9MW), yearling (YW) and yearling fleece weight (YFW) were investigated. Least square analyses were used for estimation of environmental effects. Genetic parameters were estimated with single and multi trait analysis using restricted maximum likelihood (REML) procedures, under animal models. By ignoring or including maternal additive genetic effects and maternal permanent environmental effects, five different models were fitted for each trait. The effects of sex, type of birth, age of dam and year of birth on the all body weights were significant (p<0.01), but had no effects on YFW except year of birth. Age of kids had significant influences on WW and 6MW (p<0.01). A log likelihood ratio test was carried out for choosing the most suitable model for each trait. Total heritability estimates for YFW and growth traits varied from 0.16 for YFW and WW to 0.41 for YW. For all traits, maternal heritability was lower than direct heritability, ranging from 0.06 for BW to 0.01 for 6MW and 9MW. The magnitude of $c^2$ was more substantial for BW than the others, and relative importance was reduced from 0.12 for BW to 0.04 for 9MW. The direct additive genetic correlations estimates were positive and varied from 0.21 between BW-YW to 0.96 between WW-6MW. Direct additive genetic correlations between YFW and body weight traits were positive and ranged from 0.14 between BW-YFW to 0.67 between 6MW-YFW. For all traits, the corresponding estimates for phenotypic correlation were positive and lower than genetic correlations. The maternal additive genetic correlations between various traits were varied and ranged from -0.19 between 9MW-YFW to 0.96 between 6MW-9MW. The estimates of the maternal permanent environmental correlations between various traits were positive and ranged from 0.33 between WW-YFW to 0.93 between WW-6MW. Also, the environmental correlations between various traits ranged from 0.01 between BW-YFW and WW-YFW to 0.70 between 9MW-YW. Estimates of genetic parameters for various traits in this study confirm that selection should be applied on WW for genetic improvement in Markhoz goats.

Estimation of Weaning Age Effects on Growth Performance in Berkshire Pigs

  • Do, C.H.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제25권2호
    • /
    • pp.151-162
    • /
    • 2012
  • Analysis for back fat thickness (BFAT) and daily body weight gains from birth to the end of a performance test were conducted to find an optimal method for estimation of weaning age effects and to ascertain impacts of weaning age on the growth performance of purebred Berkshire pigs from a closed population in Korea. Individual body weights were measured at birth (B), at weaning (W: mean, 22.9 d), at the beginning of the performance test (P: mean, 72.7 d), and at the end of the performance test (T: mean, 152.4 d). Further, the average daily gains in body weight (ADG) of 3,713 pigs were analyzed for the following periods: B to W (DGBW), W to P (DGWP), P to T (DGPT), B to P (DGBP), B to T (DGBT), and W to T (DGWT). Weaning ages ranged from 17 to 34 d, and were treated as fixed (WF), random with (WC) and random without (WU) consideration of an empirical relationship between weaning ages in the models. WF and WC produced the lowest AIC (Akaike Information Criterion) and least fractions of error variance components in multi-traits analysis, respectively. The fractions of variances due to diverse weaning age and the weaning age correlations among ADGs of different stages (when no overlapping allowed) by WC ranged from 0.09 to 0.35 and from -0.03 to 0.44, respectively. The maximum weaning age effects and optimal back fat thicknesses were attained at weaning ages of 27 to 32 d. With the exception of DGBW, the effects of weaning age on the ADGs increased (ranging from 1.50 g/d to 7.14 g/d) with increased weaning age. In addition, BFAT was reduced by 0.106 mm per increased day in weaning age. In conclusion, WC produced reasonable weaning age correlations, and improved the fitness of the model. Weaning age was one of crucial factors (comparable with heritability) influencing growth performance in Berkshire pigs. Further, these studies suggest that increasing weaning age up to 32 d can be an effective management strategy to improve growth performance. However, additional investigations of the costs and losses related to extension of the suckling period and on the extended range of weaning age are necessary to determine the productivity and safety of this practice in a commercial herd and production system.

Burkholderia tropica as a Potential Microalgal Growth-Promoting Bacterium in the Biosorption of Mercury from Aqueous Solutions

  • Zarate, Ana;Florez, July;Angulo, Edgardo;Varela-Prieto, Lourdes;Infante, Cherlys;Barrios, Fredy;Barraza, Beatriz;Gallardo, D.I;Valdes, Jorge
    • Journal of Microbiology and Biotechnology
    • /
    • 제27권6호
    • /
    • pp.1138-1149
    • /
    • 2017
  • The use of microalgal biomass is an interesting technology for the removal of heavy metals from aqueous solutions owing to its high metal-binding capacity, but the interactions with bacteria as a strategy for the removal of toxic metals have been poorly studied. The goal of the current research was to investigate the potential of Burkholderia tropica co-immobilized with Chlorella sp. in polyurethane discs for the biosorption of Hg(II) from aqueous solutions and to evaluate the influence of different Hg(II) concentrations (0.041, 1.0, and 10 mg/l) and their exposure to different contact times corresponding to intervals of 1, 2, 4, 8, 16, and 32 h. As expected, microalgal bacterial biomass adhered and grew to form a biofilm on the support. The biosorption data followed pseudo-second-order kinetics, and the adsorption equilibrium was well described by either Langmuir or Freundlich adsorption isotherm, reaching equilibrium from 1 h. In both bacterial and microalgal immobilization systems in the co-immobilization of Chlorella sp. and B. tropica to different concentrations of Hg(II), the kinetics of biosorption of Hg(II) was significantly higher before 60 min of contact time. The highest percentage of biosorption of Hg(II) achieved in the co-immobilization system was 95% at pH 6.4, at 3.6 g of biosorbent, $30{\pm}1^{\circ}C$, and a mercury concentration of 1 mg/l before 60 min of contact time. This study showed that co-immobilization with B. tropica has synergistic effects on biosorption of Hg(II) ions and merits consideration in the design of future strategies for the removal of toxic metals.

대화행위의 연쇄관계와 대화흐름에 대하여 -[일정협의 대화] 중심으로 (On the Sequences of Dialogue Acts and the Dialogue Flows-w.r.t. the appointment scheduling dialogues)

  • 박혜은;이민행
    • 인지과학
    • /
    • 제10권2호
    • /
    • pp.27-34
    • /
    • 1999
  • 이 연구의 목적은 대화행위 개념을 이용하여 독일어 일정협의 대화에서 나타나는 대화의 일반적인 흐름을 밝히는 데에 있다. 이 연구의 기본가정은 대화행위 개념의 도입이 자동번역시스템의 성능향상에 기여한다는 것이다. 그 이유는 통사적인 분석이나 의미적인 분석이 해결하지 못하는 문제들을, 문맥지식을 활용하여 해결하는 데에 있어 대화행위개념이 매우 유용하기 때문이다. 이 대화행위 개념의 하위분류작업은 독일에서 수행되고 있는 VERBMOBIL 프로젝트에서 이루어진 것이다. 본 연구에서는 전문가들에 의해 전사된 실제 대화 자료들을 대화행위의 개념을 활용하여 분석하고, 하나의 대화차례 안에서 발생하는 대화행위들의 연쇄와 각각의 대화차례 사이에서 발생하는 대화행위 연쇄를 조사했다. 여기서 분석대상으로 삼은 전사자료가 다른 연구에서 제시된 전사 자료와는 다소 차이를 보였기 때문에, 본 연구에서는 연쇄 개념을 대화차례사이에 뿐만 아니라 하나의 대화차례 내부까지 적용시켰다. 그리고 대화행위들간의 연쇄관계를 조사함으로써‘일정협의 대화’의 대화 흐름 도를 도출하였다. 이 대화 흐름 도는 통계분석 절차를 통해 가장 빈도수가 높게나온 대화행위 연쇄들을 토대로 만들어진 모형이기 때문에, 일상적인‘일정협의 대화’에 대한 대표성을 갖는다고 볼 수 있다.

  • PDF

패스트푸드 레스토랑의 소비가치가 고객만족, 행동의도에 미치는 영향 (The Effects of Consumption Values on Customer Satisfaction and Behavior Intention in Fast-Food Restaurants)

  • 양승권;심재현
    • 유통과학연구
    • /
    • 제11권2호
    • /
    • pp.35-44
    • /
    • 2013
  • Purpose - Until recently, studies on customer values for restaurants recognized two path structures; the SERVQUAL model, that is, service quality? perceived value? customer satisfaction? behavioral intention, and the customer value? customer satisfaction? behavioral intention path that categorizes customer values into functional value and hedonic value. This study, instead, classifies the consumption values of fast-food restaurants based on the consumption value system provided by Sheth, Newman and Gross (1991) and illustrates the new path structure, consumption value? customer satisfaction? behavioral intention, targeting college students for a generalization of the consumption value system of fast-food restaurants. Research design, data, and methodology - This study establishes five hypotheses based on the relationship between each type of consumption value (functional, emotional, social, and epistemic) and customer satisfaction, and the relationship between customer satisfaction and behavioral intention. For this analysis, data was collected by conducting a pre-test and administering a survey to 213 college students who are regular customers at fast-food restaurants in Seoul, Korea. The data collected was then analyzed using SPSS 15.0 and AMOS 6.0 statistical packages. Results - The study showed that: First, the consumption values of fast-food restaurants are classified into the following four categories: functional value, emotional value, social value, and epistemic value while consumption value can be applied to customer value of fast-food restaurants. Second, the functional and epistemic values had a positive impact on customer satisfaction. The resulting satisfaction is attributed to the intrinsic characteristics of fast-food restaurants like the consistent quality of food, reasonable prices, fast service, and unique or new experiences on every visit. On the other hand, emotional and social values did not affect customer satisfaction. The results on emotional value differed from the general studies on restaurants while the results obtained for social value were not consistent with the studies on high-end restaurants. Third, customer satisfaction had a positive impact on behavioral intention. The survey showed that college students reflected behavioral intention - repurchase intention and word-of-mouth - if they were satisfied with the food quality and employee services provided. Simultaneously, it was seen that the impact of functional value on customer satisfaction of fast food restaurant goers was more than that of epistemic value. Conclusions - The consumption values of fast-food restaurant users could be classified into four categories, functional, emotional, social and epistemic values, based on the consumption value system provided by Sheth, Newman and Gross (1991). It proved that the customer values of restaurant goers can be extended to the path structure of consumption value? customer satisfaction? behavioral intention to confirm its generalization. The study also showed that marketing managers need to focus more on the factors that influence functional value as the fast-food restaurant users consider timely services with the consistent quality of food at a reasonable price and at a convenient place more important than the new experiences or uniqueness.

  • PDF