• Applied Biological Chemistry
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• v.39 no.3
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• pp.206-211
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• 1996

It was generally known that over-ingestion of dietary orotic acid caused hepatic disorder by the lesion of fatty acid and cholesterol synthesis in rats. The present study was carried out to investigate the effects of dietary orotic acid on the lipid composition of serum, liver and kidney of rats. For the experiments, rats were fed with commercialized chow powder diet in the presence or absence of 1% orotic acid. The prepared diets were fed to male rats (Sprague-Dawley strain, $90{\sim}100$ g of body weight for 21 days. According to the results, orotic acid treated group showed that each concentration of serum cholesterol, triglyceride and phospholipid was significantly decreased (p<0.05). The centration of liver triglyceride was significantly decreased (p<0.05). In the presence of 1% orotic acid, the weight of liver inclosed while that of kidney decreased. The treatment of orotic acid seemed to have no effects on the phospholipid composition in liver and kidney, except the kidney lysophosphatidylcholine. In the comparison of the phospholipid composition between liver and kidney, the levels of sphingomyeline and phosphtidylethanolamine in the kidney were higher than those in the liver. Among the composition of fatty acid in kidney, the concentration of linoleic acid (18 : 2) was increased, and the concentration of arachidonic acid (20 : 4) was decreased with the addition of the orotic acid.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.3
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• pp.363-374
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• 2023

A white-box environment refers to a situation where the internal information of an algorithm is disclosed. The AES white-box encryption was first announced in 2002, and in 2016, a side-channel analysis for white-box encryption called Differential Computation Analysis (DCA) was proposed. DCA analysis is a powerful side-channel attack technique that uses the memory information of white-box encryption as side-channel information to find the key. Although various countermeasure studies against DCA have been published domestically and internationally, there were no evaluated or analyzed results from experiments applying the hiding technique using dummy operations to DCA analysis. Therefore, in this paper, we insert LU T-shaped dummy operations into the WBC-AES algorithm proposed by S. Chow in 2002 and quantitatively evaluate the degree of change in DCA analysis response depending on the size of the dummy. Compared to the DCA analysis proposed in 2016, which recovers a total of 16 bytes of the key, the countermeasure proposed in this paper was unable to recover up to 11 bytes of the key as the size of the dummy decreased, resulting in a maximum decrease in attack performance of about 68.8%, which is about 31.2% lower than the existing attack performance. The countermeasure proposed in this paper confirms that the attack performance significantly decreases as smaller dummy sizes are inserted and can be applied in various fields.

• Korean Journal of Exercise Nutrition
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• v.15 no.4
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• pp.163-171
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• 2011

The effects of a high-fat diet and fasting on resting energy expenditure and energy substrate utilization were examined using the method of measuring whole body energy metabolism and oxygen uptake. Eight 4-week old male Sprague-Dawley rats were used for the high-fat diet experiment. Energy metabolism was measured using acrylic metabolic chambers over 24 hours. After 1-week of preliminary feeding, 4 rats were fed a chow diet, whereas the remaining 4 rats were fed a high-fat diet (HF) ad libitum, which contained 40% (w/w, calorie base 60%) more fat than that in the chow diet. The flow rate to measure energy metabolism inside the chamber was controlled at a mean of 3.5 L/min, and five chambers were subjected to measurement. One of the five chambers was used to correct errors by measuring the atmosphere. As a result of 5 weeks of control diet and high-fat diet feeding, body weight of the high-fat diet group tended to increase more than that in the control diet fed group, but the difference was not significant. Oxygen uptake and carbon dioxide production changed as time went on over the 24 hr. The respiratory exchange ratio also changed during the 24 hr, and the difference between the groups was significant. The control group showed significantly more carbohydrate oxidation than that of the high-fat diet fed group. A fasting experiment was conducted using six 7-week old Sprague-Dawley male rats. Energy metabolism measurements were performed using the same method as that used in the high-fat diet experiment; resting metabolism was measured prior to fasting, and a fasting condition began from 9:00 am the next day for 3 days to calculate energy metabolism. Both body weight and 24-hour oxygen uptake decreased significantly as a result of 3-day fasting. Total oxygen uptake in the first day decreased, and declined significantly on day 3 of fasting. Total 24-hour carbon dioxide production decreased significantly over the 3 days. The mean 24-hour respiratory exchange ratio decreased significantly. Additionally, energy expenditure during the dark period (20:00-08:00), which is the active period for rats, decreased significantly with fasting, whereas energy expenditure during the light period (08:00-20:00) did not increase by fasting.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.917-922
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• 2002

We investigated the long term effects of Sopungsungi-won (SP), a Korean traditional formula used for senile constipation and diabetes mellitus, on the development of diabetic nephropathy (DN) in Zucker diabetic fatty (ZDF) rats. ZDF rats were fed regular laboratory chow mixed with SP or rosiglitazone (RSG) for an 8-week period. Kidney hypertrophy was developed with increasing plasma glucose level, and glomerular hypertrophy was improved by 22% and 45% in SP- and RSG-treated rats, respectively. Urinary glucose and albumin excretions were also significantly lower in SP-treated rats than in ZDF control rats. Activation of the mitogen-activated protein kinase (MAPK)-transforming growth factor ${\beta}1$ (TGF ${\beta}1$)-fibronectin pathway in kidney, responsible for glomerular dysfunction, was markedly blunted by SP treatment in a dose dependent manner. Our findings, for the first time, provide strong evidence that long-term administration of SP formula prevents the development and progression of DN in ZDF rats. Human trials are needed to confirm these experimental results.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.233-239
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• 1997

A mammary epithelial cell line (MAC-T) established as a model for lactation was utilized to identify and characterize effects of various hormones upon insulin-like growth factor binding protein secretion. Ligand and immunoblot analyses of conditioned media indicated that insulin-like growth factor binding protein-2 was secreted by MAC-T cells. Insulin-like growth factor-I stimulated insulin-like growth factor binding protein-2 secretion in a dose-dependent manner, but prolactin and bovine somatotropin did not alter insulin-like growth factor binding protein-2 secretion. Insulin increased and cortisol decreased insulin-like growth factor binding protein-2 secretion. Effects of insulin-like growth factor-I on insulin-like growth factor binding protein-2 secretion support previous studies using primary cultures of bovine mammary cells and bovine fibroblasts. Effects of cortisol and insulin on insulin-like growth factor binding protein-2 secretion may be explained by changes in protein synthesis. In addition, supraphysiological doses of insulin can cross-react with the insulin-like growth factor-I receptor and stimulate insulin-like growth factor binding protein-2 secretion. MAC-T cells provide a model system to study mechanisms that regulate local insulin-like growth factor-I bioactivity.

• Journal of Nutrition and Health
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• v.37 no.9
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• pp.780-785
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• 2004

Recently many investigators have initiated searches for immunomodulating substances from natural food sources. Ginger (Zingiber officinale Roscoe) has been used as a raw material in many traditional preparations since the ancient time. This study was performed to investigate the immunomodulative effects of Zingiber officinale Roscoe in mice, using ex vivo experiments. In order to elucidate the immunomodulative effects of Ginger, water extracts of the plant were orally administrated into mice, and isolated splenocytes and macrophages were used as experimental model. In order to identify its ex vivo effect six to seven week old Balb/c mice were fed ad libitum on a chow diet and water extracts of ginger were orally administrated every other day for two weeks at two different concentrations (50 and 500 mg/kg b.w.). After preparing the single cell suspension, the proliferation of splenocytes was determined by MTT assay. The result of ex vivo study showed that the highest proliferation of splenocytes and macrophage activatation was seen in the mice orally administrated at the concentration of 500 mg/kg b. w. of ginger water extracts. In conclusion, this study suggests that ginger extracts nay enhance the immune function by regulating the splenocyte proliferation and cytokine prodution capacity by activated macrophages in mice.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.280-283
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• 2005

The adsorption of a model protein bovine serum albumin (BSA) in expanded bed chromatography was undertaken by exploiting a commercially available expanded bed column (20 mm i.d.) from UpFront Chromatography and Streamline DEAE $(\rho=1.2g/cm^3)$ from Amersham Pharmacia Biotechnology. The influence of whole yeast cells on the adsorption capacity of column was explored by employing yeast cells in a concentration ranged of 0 to $15\%(w/v)$. Equilibrium isotherms for adsorption of BSA on Streamline DEAE were correlated by using Langmuir equation. The presence of yeast cells resulted in decreased of BSA binding capacity in both batch binding and expanded bed chromatography. Results indicated that the yeast cells act as competitor for proteins to bind to the sites on adsorbents.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.824-829
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• 2000

The industries use polymer materials for many purposes because they have many merits. But these materials' costs take up too much proportion in overall cost of products that use these materials as their major material. So it is very economical for polymer industries to reduce these costs. Microcellular foaming process appeared in 1980's to solve this problem and it proved to be quite successful. This process uses inert gases such as CO2, N2. As these gases are dissolved into polymer matrices. many properties are changed. Glass transition temperature is one of these properties. DSC, DMA are devices that measures this temperature, but these are not sufficient to measure the temperature of polymer containing gas. In this paper, we devised a new tester that uses magnetism. We used this device to acquire data of the change of glass transition temperature and made Cha-Yoon model that can predict the change of glass transition temperature. Using this model, the change of this temperature can be estimated as a function of weight gain of gas. Cha-Yoon model proved that Chow's model is inappropriate to predict the change of glass transition temperature of polymer matrices containing gas.

• Journal of Nutrition and Health
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• v.27 no.4
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• pp.323-335
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• 1994

The present study was carried out in normocholesterolemic New Zealand white(NZW) rabbit, to evaluate the effect of dietary supplementation with Korean pinenut oil, on plasma lipids, plasma lipoproteins, liver lipids and platelet aggregation. NZW rabbits were fed for 80 days on a commercial chow diet supplemented with 5% of energy as fats(soybean oil or pinenut oil) or 10% of energy as fats(soybean oil or pinenut oil). A control group was fed a commercial stock diet. There were no significant effects of pinenut oil on plasma free cholesterol, HDL-cholesterol, triglycerides, glucose and lecithin-cholesterol acyltransferase, as compared with those obtained from rabbits fed the soybean oil diet. After 80 days, the concentration of plasma free fatty acid in only the pinenut oil group was significantly decreased by about 50% relative to the control diet. At the end of the dietary treatment, liver triglycerides and phospholipids were significantly decreased in the pinenut oil group, compared to the how diet, whereas the soybean oil-consuming rabbits had only significantly decreased phospholipid levels. Cholesterol contents of liver were unaffected by type of dietary fat. At the end of 80 days, a diet containing pinenut oil resulted in a decrease in apolipoprotein B and the apo B/apo AI ratio as compared with the stock diet or soybean oil diet. Platelet aggregation induced by collagen or arachidonic acid was depressed significantily in pinenut oil diet.

• Journal of computational fluids engineering
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• v.6 no.1
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• pp.1-13
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• 2001

The natural convection heat transfer and solidification in a stratified pool are studied. The flow and heat transfer characteristics in a heat generating pool are compared between single-layered and double-layered pools. And local Nusselt number distributions on outer walls are obtained to consider thermal loads on a vessel wall. The cooling and solidification of Al₂O₃/Fe melt in a hemispherical vessel are simulated to study the mechanism of heat transfer and temperature distribution. A unstructured mesh is chosen for this study because of the non-orthogonality originated from the boundaries of double-layered pool. Interface between the layers is modeled to be fixed. With this assumption mass flux across the interface is neglected, but shear force and heat flux are considered by boundary conditions. The colocated cell-centered finite volume method is used with the Rhie-Chow interpolation to compute cell face velocity. To prevent non-physical solutions near walls in case body force is large the wall pressure is extrapolated by the way to include body force. The numerical solutions calculated by current method show that averaged downward heat flux of the double-layered pool increases compared to single-layered pool and maximum temperature occurs right below the interface of the layers.