• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.3
• /
• pp.387-395
• /
• 1994

The effect of vitamin C on th egramoxone toxicity in the duodenal globlet cells of rats were investigated suing histochemical methods. Rats in control, gramoxone and gramoxone+vitmain C (Vt.C) group, aged 6 to 7 weeks, were fed 18% casein diet. In th egramoxone group, neutral and acid mucins of the globlet cells in villi and crypts of duodenum tended to decrease as compared with the control group. And the globle cells secreting nonsuphated mucins tended to increase in number, being usually accompanied by a decrease of the globlet cells secreting suphated mucins which are prominent in the duodenal mucosa of control group. However, the goblet cells secreting nonsuphated mucins tended to increase in the gramoxone + Vt.C group. Morphological changes of the globlet cells in the gramoxone group were noted vacuolation and demolition of globlet cells, while those changes were not significant in the gramoxone +Vt. C group. It seems to be that Vt. C has alleviating effects on the gramoxone toxicity in secretion and production of the duodenal goblet cells.

• Microbiology and Biotechnology Letters
• /
• v.50 no.3
• /
• pp.387-394
• /
• 2022

Verotoxin-1 (VT-1) or Shiga-like toxin 1 (Stx-1) is produced by enterohemorrhagic Escherichia coli (EHEC) and is an AB5 holotoxin with a strong inhibitor of protein synthesis. VT-1 is a type 2 ribosome-inactivating protein (RIP) that has been shown to have cytotoxic and anticancer potential by inducing necrosis, apoptosis, and cell cycle arrest, making it a promising antitumor candidate. Here, we tested the cytotoxicity of VT-1 on CaCo2 and NCM425 cell lines and the results showed that VT-1 was more potent on CaCo2. Morphological changes were also evaluated on the cellular level and the results showed that VT-1 caused a decrease in viable cell count, altered cell membrane permeability, and an increase in total nuclear intensity. On the other hand, VT-1 displayed a lesser impact on mitochondrial membrane potential (MMP) and cytochrome c release. On the expression of caspases 3 and 9, VT-1 exhibited an insignificant effect on both which alongside the mitochondrial membrane potential (MMP) and cytochrome c results, might indicate that CaCo2 suffered from the necrosis process as a mechanism of cell death after exposure to VT-1.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.6
• /
• pp.274-278
• /
• 2005

Voltage transformer(VT) comparison measurement system is usually used for measurements of ratio error and phase angle error of VT made in industry. Both ratio error and phase angle error in VT are critically influenced by values of burden of VT used. External burden effects on both ratio error and phase angle error in VT are theoretically calculated. From the theoretical calculation, a method of evaluation for linearity of ratio error and phase angle error in VT measurement system have been developed using the standard capacitive burdens, with negligible dissipation factor less than 10$^{-4}$. These burden consists of five standard capacitors, with nominal capacitance of 1.1 $\mu$F, 1 $\mu$F, 0.1 $\mu$F, 0.01 $\mu$F, 0.001 $\mu$F. The developed method has been applied in VT measurement system of industry, showing in good consistency and linearity within 0.001 $\%$ between theoretical and measured values.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.50 no.4
• /
• pp.197-203
• /
• 2001

Recently, the construction of gas insulated substation(GIS)s has been increased in Korea. But, the whole quantity of the VTs which were used in GIS has been imported. Under the circumstance that $SF_6$ gas power apparatus are being developed up to 800kV rating in Korea, the development of EＨＶ　$SF_6$ gas VT is essential for localizing the power apparatus. As for EHV VT, destructive ferroresonance can be generated due to the combination of capacitiances between poles of circuit breaker, ground capacitance of bus and nonlinear excitation property of VT core. But the theoretical analysis about ferroresonance has not been fully achieved in Korea. Therefore, in this paper the authors would like to contribute for localizing EHV $SF_6$ gas VT by developing the diagram of ferroresonance zone according to the parameters of the circuit and the saturable reactor.

• Journal of the East Asian Society of Dietary Life
• /
• v.16 no.2
• /
• pp.145-155
• /
• 2006

This study investigated the correlation of the nutritional status of antioxidant vitamins and serum lipids and MDA levels in postmenopausal women. Data about general characteristics, dietary intakes and biochemical parameters, including serum lipids, MDA and antioxidant vitamins levels, were collected from 85 postmenopausal women. The subjects were classified into three groups according to their serum total cholesterol level: normocholesterolemia group (NC, < 200 mg/dL), moderate hypercholesterolemia group (MC, $200{\sim}239mg/dL$) and hypercholesterolemia group(HC, ${\geq}240mg/dL$). The results are as follows. 1) General characteristics and serum MDA levels were not significantly different among the three groups. 2) Daily nutrients intakes adjusted to energy intake were not significantly different among the three groups, and were compatible with dietary reference intakes (DRIs) for Koreans. 3) Dietary Vt. A, ${\beta}-carotene$, Vt. C and Vt. E intake were not significantly different among the groups, while Vt. E intake was positively related with serum TC (r=0.288, p<0.05) and triglyceride (r=0.341, p<0.001) levels. 4) Serum Vt. A level standardized by serum TC level was significantly low and serum Vt. E level was significantly high in the HC group. Serum Vt. E level was positively related with serum TC level (r=0.389, p<0.001). 5) Dietary Vt. E intake was negatively correlated to serum MDA level (r=-0.242 p<0.05). Serum Vt. C and Vt. E levels were also negatively correlated to serum MDA level (r=-0.312, p<0.001 and r=-0.299, p<0.05). When the correlation was analyzed only in the group with hypercholesterolemia, correlation coefficients between the antioxidant vitamin and serum MDA level were higher. We concluded that intakes of antioxidant vitamins can contribute to decreasing the risk of cardiovascular disease by decreasing the oxidative stress of body rather than by controlling serum lipid levels.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.53 no.9
• /
• pp.470-474
• /
• 2004

Both ratio error and phase angle error in voltage transformer(VT) depend on values of burden of VT used. A method of evaluation for linearity of ratio error and phase angle error in VT measurement equipment have been developed using the standard resistance burdens, with negligible AC-DC resistance difference less than $10^-6$. These burden consists of five standard resistors, with nominal resistance of 100 $\Omega$, 1 k$\Omega$, 10 k$\Omega$, 100 k$\Omega$, and 1 M$\Omega$. The developed method has been applied in VT measurement equipment of industry and the validity of the developed method has been verified by showing the consistency of the result of linearity obtained using VT with wide ratio error.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.1
• /
• pp.47-51
• /
• 2009

The purpose of this study was to investigate the effects of vitamin C supplementation and yoga practice on total antioxidant status (TEAC), lipid peroxidation, and blood lipid profiles of middle-aged women. Thirty two women ($53.34{\pm}5.08$ years old) in B city volunteered and the signed consents were received before the study. Experimental groups were normal (n=8), vitamin C intake group (n=8), yoga group (n=8), and vitamin C intake with yoga group (n=8). Total experimental period was 12 weeks. Yoga group practiced yoga 3 times a week for 12 weeks with intensity of RPE $13{\sim}15$. Each practice was 60 minutes. Vt. C group was instructed to take 1 g of Vt. C every day after dinner meal. Changes in TEAC after 12 weeks were 28.23% for the normal group, 30% for Vt. C group, 26.58% for yoga group, and 43.66% for Vt. C with yoga group; the increases in TEAC among groups were not significantly different. Serum malondialehyde (MDA) concentration of the normal group increased by 10% during 12 weeks of experiment while that for the Vt. C, yoga, and Vt. C with yoga group were significantly decreased by 25%, 32.14%, and 33.87%, respectively (p<0.05) compared with the normal group. Neither yoga, Vt. C supplementation nor combined program for 12 weeks were effective enough to change the serum lipid profiles compared with the normal group. In conclusion, Vitamin C supplementation or regular yoga practice seems to have health promoting effects of retarding the oxidative stress by decreasing lipid peroxidation in middle-aged woman.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.22 no.6
• /
• pp.823-832
• /
• 1993

This study was made to determine alleviating effects of vitamin C(Vt C) on the gramoxone toxicity in rats with respect to the growth gain, feed effeciency ratio, total lipid contents, lipid peroxication and protein patterns in rat liver. Growth gain, feed efficiency ratio and liver weight in the gramoxone group were decreased significantly as compared with the control group, while those values obtained in the gramoxone-Vt C group were increased as compared with the gramoxone group. Lipid contents and TBA value of rat liver of the gramoxone group were increased significantly as compared with the control group. However, those values of the gramoxone+Vt C group were decreased as compared with the gramoxone group. No significant differences were observed in the liver protein patterns between the gramoxone and the control group. The contents of liver protein were decreased significantly in the gramoxone group fed for 2 weeks as compared with the control group. The change of the liver protein patterns, such as the decrease of high molecular weight protein and the increase of low molecular weight protein were observed in the gramoxone+Vt C group.

• Aerospace Engineering and Technology
• /
• v.7 no.2
• /
• pp.110-116
• /
• 2008

This paper gives a brief summary of the TVC battery design description, specifications and test results. The TVC battery for KSLV-I upper stage contains 168 Sony l8650VT high power lithium-ion cells. It configured as 2 strings in parallel, with each string containing 84 series connected cells. This allows to meet nominal 270V voltage and capacity requirements specified for the mission of the Thrust Vector Control(TVC) system. The loads profile of the TVC system has short duration, high current pulse. To power such a system with minimal mass, the battery employed l8650VT Cells. This cell is specifically designed for high rate applications and is capable of a 10C continuous discharge.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.11
• /
• pp.503-507
• /
• 2005

Both ratio error and phase angle error in voltage transformer(VT) depend on values of VT burden used. Thus, precise measurement of burden is very important for the evaluation of VT. A method of evaluation for VT burden has been developed by employing the portable decade resistor, with AC-DC resistance difference less than 10-3. The burden value(value and power factor) can be obtained by conductance and susceptance, obtained by measuring the change of ratio error and phase angle error caused by the resistance change of decade resistor. The burden value and power factor obtained by the method are consistent with those obtained using power analyzer within corresponding uncertainties.