• Journal of the Semiconductor & Display Technology
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• v.17 no.4
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• pp.66-69
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• 2018

This study was researched the electrical properties of semiconductor devices such as ITO, $SiO_2$, $V_2O_5$ thin films. The films of ITO, $SiO_2$, $V_2O_5$ were deposited by the rf magnetron sputtering system with mixed gases of oxygen and argon to generate the plasma. All samples were cleaned before deposition and prepared the metal electrodes to research the current-voltage properties. The electrical characteristics of semiconductors depends on the interface's properties at the junction. There are two kinds of junctions such as ohmic and schottky contacts in the semiconductors. In this study, the ITO thin film was shown the ohmic contact properties as the linear current-voltage curves, and the electrical characteristics of $SiO_2$ and $V_2O_5$ films were shown the non-linear current-voltage curves as the schottky contacts. It was confirmed that the electronic system with schottky contacts enhanced the electronic flow owing to the increment of efficiency and increased the conductivity. The schottky contact was only defined special characteristics at the semiconductor and the interface depletion layer at the junction made the schottky contact which has the effect of leakage current cutoff. Consequently the semiconductor device with shottky contact increased the electronic current flow, in spite of depletion of carriers.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.357-366
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• 2019

$G{\alpha}_q$-coupled receptor stimulation was implied in the activation process of transient receptor potential canonical (TRPC)1/4 and TRPC1/5 heterotetrameric channels. The inactivation occurs due to phosphatidylinositol 4,5-biphosphate ($PI(4,5)P_2$) depletion. When $PI(4,5)P_2$ depletion was induced by muscarinic stimulation or inositol polyphosphate 5-phosphatase (Inp54p), however, the inactivation by muscarinic stimulation was greater compared to that by Inp54p. The aim of this study was to investigate the complete inactivation mechanism of the heteromeric channels upon $G{\alpha}_q$-phospholipase $C{\beta}$ ($G{\alpha}_q-PLC{\beta}$) activation. We evaluated the activity of heteromeric channels with electrophysiological recording in HEK293 cells expressing TRPC channels. TRPC1/4 and TRPC1/5 heteromers undergo further inhibition in $PLC{\beta}$ activation and calcium/protein kinase C (PKC) signaling. Nevertheless, the key factors differ. For TRPC1/4, the inactivation process was facilitated by $Ca^{2+}$ release from the endoplasmic reticulum, and for TRPC1/5, activation of PKC was concerned mostly. We conclude that the subsequent increase in cytoplasmic $Ca^{2+}$ due to $Ca^{2+}$ release from the endoplasmic reticulum and activation of PKC resulted in a second phase of channel inhibition following $PI(4,5)P_2$ depletion.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.707-716
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• 1997

Recent reports revealed that the $Na^+-Ca^{2+}$ exchangers and feet structures of sarcoplasmic reticulum(SR) are located in close vicinity in the specific compartment. Therefore, we investigated the possibility that the $Na^+-Ca^{2+}$ exchanger may decrease the tension development by transporting the $Ca^{2+}$ out of the cell right after it released from SR, on the basis of this anatomical proximity. We exammined the negative force-frequency relationship of the developed tension in the electrically field stimulated left atria of postnatal developing rat(1, 3 day, 1 week and 4 week old after birth). Cyclopiazonic $acid(3{\times}10^{-5}\;M)$ treatment decreased the developed tension further according to postnatal age. $Monensin(3{\times}10^{-6}\;M)$ treatment did not increase the maximal tension in 4 week-old rat, preserving negative staircase, while the negative staircase in the younger rat were flattened. $Ca^{2+}$ depletion in the buffer elicited more suppression of the maximal tension according to the frequency in all groups except the 4 week-old group. The % decrease of the maximal developed tension of 4 week-old group at 1 Hz to that of 0.1 Hz after $Na^+$ and $Ca^{2+}$ depletion was only a half of those of the yonger groups. Taken together, it is concluded that the $Na^+-Ca^{2+}$ exchange transports more $Ca^{2+}$ released from SR out of the cell in proportion to the frequency, and this is responsible for the negative staircase effect of the rat heart.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.2
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• pp.109-115
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• 2017

Using the computational fluid dynamics (CFD) technique, we performed a numerical simulation in anodesupported solid oxide fuel cell (SOFC). The effect of gas channel/rib width on the cell performance and temperature uniformity was investigated in planar type SOFC. The open source CFD toolbox, OpenFOAM, was used as a numerical analysis tool. As a result, the effect of gas channel/rib width on the cell performance and temperature uniformity was not significant if the oxygen depletion is not occurring. On the other hand, the usage of a wide rib and operation at high current density may lead to performance degradation due to oxygen depletion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1173-1180
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• 1997

Hepatotoxicity of caffeine and acetaminophen was investigated in this study. Special attention was paid to the effect of vitamins on the reduction of hepatotoxicity caused by the chemicals. Rat hepaocytes isolated by two-step perfusion method were cultured in two differents methods-suspension, monolayer cultures-, and exposed to caffeine and/or acetaminophen for 24hrs. Caffeine or acetaminophen exhibited no significant hepatotoxicity in terms of intracellular glutathione(GSH) level and lipid peroxidation(MDA), but GSH level was significantly decreased after administrated acetaminophen, and the toxicity caused by the chemicals showed a dose-dependent manner. The synergistic effect of caffeine and acetaminophen was observed when both caffeine and acetaminophen were supplemented to culture medium. At the concentration 1mM, caffeine enhanced the intracellular GSH depletion and MDA formation by 63% and 64%, respectively, compared to single supplementation of 10mM acetaminophen in culture medium. This hepatotoxicity induced membrane integrity loss was observed by lightmicroscope on the simultaneous administration of caffeine and acetaminophen in monolayer cultured hepatocytes. Co-supplementation of vitamins with caffeine/acetaminophen to culture medium results in the protection of hepatocytes from hepatotoxic attach by caffeine/acetaminophen. Especially, vitamin E was superior to vitamin C and $\beta$-carotene from the standpoints of GSH depletion and MDA formation. From this results, it has been speculated that vitamin E may play a role of antioxidant scavenging radicals produced from acetaminophen. Taken all together, in vitro culture system like monolayer culture of hepatocytes may be a useful tool for the evaluation of hepatotoxicity or protection ability of food ingredients.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.4
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• pp.233-240
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• 1982

This study was conducted to elucidate the translocation pattern of photosynthate labelled by $^{14}C$ in rice cultivars and the effects of nutrient composition on the translocation in rice plant during ripening, Showing coincidence between the grain filling rate and the translocation of $^{14}C$ into the grain during ripening period, the translocation patterns of cultivars tested were grouped by three; 1) the late dominance type (Akibare), 2) the early dominance type (Taebaegbyeo, Chupungbyeo), and 3) the semi-late dominance type (Milyang #23, Milyang #42, and Yushin). The negative relation ship existed between the translocation ratio of $^{14}C$ into the grain and the nitrogen content in plants, but not significant, The nutrient depletion of P, K, Ca, Mg, and Si in water medium from the panicle initiation to the heading stage resulted in the decrease of grain weight by 4 to 12 percent and the increase of translocation of $^{14}C$ into grain assimilated at heading. The effect of resupply of these nutrients after heading was recognized by the order of P>Mg>K and Ca. But the effect of Si resupply was hardly recognized in increasing grain weight. The photosynthetic rate was greatly affected by the nitrogen status and the depletion of P, K, and Ca decreased the photosynthetic rate in single leaf at heading, while the depletion of Si enhanced the rate.

• Journal of Chest Surgery
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• v.37 no.5
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• pp.391-400
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• 2004

Xenotransplantation in discordant species results in immediate and irreversible hyperacute rejection due to natural antibodies, IgM. With this, antibody depletion is one option to reduce hyperacute rejection, we investigated the effect of PCPP (postcentrifugal plasmapheresis) on the depletion of natural antibodies and the effect of antibody titer on xenograft survival. Material and Method: Outbred swines (n=4) weighing 10∼20 kg were used as donors and mongrel dogs (n=4) weighing 25∼30 kg were used as recipients. Recipient canines underwent plasmapheresis (COBE TPE Laboratories, Lakewood. CO, USA). Pre-transplantation PCPP was peformed on day －2 and day 0. There were three groups (Group 0: no PCPP, Group 1: 1 pla sma-volume (PV) at day －2 and 2 PV at day 0, Group 2: 2 PV at day －2 and 2 PV at day 0). A swine heart was heterotopically transplanted into a recipient's abdominal infrarenal aorta and inferior vena cava. Mean percent depletion of total IgM and IgG in plasma of the recipients was calculated. Serum albumin, electrolyte, complement activity and coagulation factors were measured. Histopathologic examination of heart specimens was performed. Result: Mean percent depletion of IgM and IgG were 95.7$\pm$1.2%, 80.5$\pm$2.4% in the group 2 at the end of PCPP. The percent depletion of serum albumin concentration was decreased from 2.8 to 1.4 g/㎗ in the group 1 and 3.0 to 1.5 g/㎗ in the group 2. Complement hemolytic activity was decreased in group 1 and 2, but returned to normal level within 24 hours. Complement hemolytic activity was reduced to 10% of pre-PCPP level in group 2. Serum fibrinogen decreased to 20% or less and was recovered within 24 hours in group 2. Antithrombin III decreased but less than fibrinogen. PT and aPTT were sometimes but not always prolonged during plasmapheresis. After plasmapheresis, PT and aPTT were prolonged beyond the measurable level. D-dimer was not found during PCPP, but appeared and maintained from 10 minutes after trasplantation. Graft Survival time was 5 min in group 0, and it was 90$\pm$0 min in the group 2. Histopathologic changes were more typically characterized by edema, hemorrhages, thrombosis in all groups at the end of experiment. Conclusion: PCPP effectively removed immuoglobulins and reduced the titer of natural antibodies, as a result, significantly prololonged swine heart xenograft survival.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.750-756
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• 1994

The effect of onion juice on ethanol -induced lipid peroxidation were studied were studied in rats. The contents of thiobarbituric acid (TBA) -reactants increased significantly in liver thanol(4ml/kg/day) administered -rats. The activities of serum alanine aminotransferase and alkaline phosphatase increased by ethanol administration compared with control group, but alterations of antioxidant enzymes activities in liver of ethanol administered rats were not significant vs control group. The glutathione contents in liver decreased by ethanol , whereas the glutathione level increased in ethanol and onion juice group compared with ethanol group. The contents of hepatic TBA-reactants and serum aminotrasnferase activity in ethanol group were reduced by onion juice administration. In these results, increased hepatic TBA-reactants of liver in ethanol group might be due to decreased glutathione contents in liver. Reduced glutathione (GSH) plays an important roles in the liver in several detoxification and the reduction of lipid peroxides. So the protective effects of onion juice on ethanol-induced increment of TBA-reactants may be due to the increament of lgutathions content. The glutathione depletion by ethanol was an important factor of ethanol-induced cell damage, and the prevention of onion juice to the glutathione depletion reduced by ethanol may be an important factor on the protection from ethanol-induced lipid perpxidation in rats.

• Journal of Ginseng Research
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• v.35 no.3
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• pp.261-271
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• 2011

Chemical radiation protection is an important strategy to protect living beings against the deleterious effects of radiation. In the present study, the radioprotective effect of hydro-alcoholic extract of Panax ginseng extract (PGR-HAE) was studied on radiation-induced deleterious alterations in Swiss albino mice. Oral administration of such extract (25 mg/kg b wt/day/animal) for 5 consecutive days, half an h. before whole-body exposure to 6 Gy gamma radiation, enhanced the 30 days survival and also inhibited the radiogenic sickness, weight loss and life shortening. PGR-HAE ameliorated radiation induced depletion in blood constituents at different necropsy intervals between 12 h to 30 d, and significantly increased the number of femoral spleen colony forming units that survived after irradiation. Furthermore, it checked depletion of glutathione and antioxidant enzymes (superoxide dismutase, catalase, and glutathione S-transferase) as well as elevation of lipid peroxidation (LPO) level in blood and liver. The significant reduction in the yield of LPO demonstrates that PGR-HAE protects the membranes against radiation-induced oxidative damage. These findings conclude that such plant extract provides significant radioprotection, and it may be potentially valuable in the prevention of injuries caused during planned and unplanned radiation exposure.

• BMB Reports
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• v.28 no.5
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• pp.392-397
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• 1995

The effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on the intracellular $Ca^{2+}$ level was studied in NIH3T3 fibroblast cells. A reduction of the intracellular $Ca^{2+}$ level was observed after exposure to 300 ${\mu}m$ MNNG. However, the intracellular level of $IP_3$, a well-known regulator of $Ca^{2+}$ release from internal storage, was not changed by MNNG treatment. Instead, a reduction of the intracellular NAD level was observed. NAD as well as $IP_3$ stimulated intracellular $Ca^{2+}$ release from permeabilized cells. The treatment of 3-aminobenzamide, which inhibited the MNNG-induced reduction of the NAD level, also prevented the MNNG-induced decrease of the $Ca^{2+}$ level. Our data suggest that MNNG reduces the intracellular $Ca^{2+}$ level by NAD depletion in NIH3T3 cells.