• Archives of Pharmacal Research
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• v.29 no.11
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• pp.998-1005
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• 2006

The effects of imipramine on A-type delayed rectifier $K^{+}$ currents and ATP-sensitive $K^{+}\;(K_{ATP)$ currents were studied in isolated murine proximal colonic myocytes using the whole-cell patch-clamp technique. Depolarizing test pulses between-80 mV and +30 mV with 10 mV increments from the holding potential of-80 mV activated voltage-dependent outward $K^{+}$ currents that peaked within 50 ms followed by slow decreasing sustained currents. Early peak currents were inhibited by the application of 4-aminopyridine, whereas sustained currents were inhibited by the application of TEA. The peak amplitude of A-type delayed rectifier $K^{+}$ currents was reduced by external application of imipramine. The half-inactivation potential and the half-recovery time of A-type delayed rectifier $K^{+}$ currents were not changed by imipramine. With 0.1 mM ATP and 140 mM $K^{+}$ in the pipette and 90 mM $K^{+}$ in the bath solution and a holding potential of -80 mV, pinacidil activated inward currents; this effect was blocked by glibenclamide. Imipramine also inhibited $K_{ATP}$ currents. The inhibitory effects of imipramine in A-type delayed rectifier $K^{+}$ currents and $K_{ATP}$ currents were not changed by guanosine 5-O-(2-thiodiphosphate) ($GDP{\beta}S$) and chelerythrine, a protein kinase C inhibitor. These results suggest that imipramine inhibits A-type delayed rectifier $K^{+}$ currents and $K_{ATP}$ currents in a manner independent of G-protein and protein kinase C.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.178-182
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• 1996

Using superoxide dismutase (SOD)-deficient mutants of Saccharomyces cerevisiae, the oxidative stresses induced by 0.1 mM of copper ion $(Cu^{++})$ was studied. In aerobic culture condition, yeasts lacking MnSOD (mitochondrial SOD) showed more significant growth retardation than CuZnSOD (cytoplasmic SOD)-deficient yeasts. However, not so big differences in growth pattern of those mutants compared withwild type were observed under anaerobic condition. It was found that, under aerobic condition, the supplementation of 0.1 mM copper ioh:(Cu") into culture medium caused the remarkable increase of CuZnSOD but not so significant change in MnSOD. It was also observed that catalase activities appeared to be relatively high in the presence of copper ion in spite of the remarkable reduction of glutathion peroxidase in CuZnSOD-deficient yeasts, but the slight increments of catalase and glutathion peroxidase were detected in MnSOD-deficient strains. It implies that the lack of cytoplasmic SOD could be compensated mainly by catalase. However, these phenomena resulted in the significantincrease of cellular lipid peroxides content in CuZnSOD-deficient yeasts and the slight increment of lipid peroxides in MNSOD-deficient cells. In anaerobic cultivation supplementing copper ion, the cellular enzyme activities of catalase and glutathion peroxidase in SOD-deficient yeasts were slightly increased without any significant changes of lipid peroxides in cell membrane. It suggests that a little amount of free radicals generated by copper ion under anaerobic condition could be sufficiently overcome by catalase as well as glutathion peroxidase.dase.

• Korean Journal of Health Education and Promotion
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• v.25 no.1
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• pp.71-81
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• 2008

Objectives: The purpose of this study was to evaluate the long term effects of school-based oral health program on the decrease of dental caries among elementary school children. Methods: The subjects of this study were total 283 students of one elementary school in Deagu, Korea. They had received school-based oral health programs more than one year since 2004. This school-based oral health program included regular oral examination, fluoride mouthrinsing, pit-and-fissure sealing, APF gel application, tooth brushing instruction and chewing the xylitol tablets. The subjects' oral health status were examined and calibrated by a dentist every year from 2004 to 2007. Results: The change of DMFT index were as follows: (1)The subjects who entered the school at 2004 - 0.32(2004), 0.25(2005), 0.25(2006) and 0.38(2007), (2)the subjects who entered the school at 2005 - 0.18(2005), 0.31(2006) and 0.32(2007), and (3)the subjects who entered the school at 2006 - 0.19(2006) and 0.27(2007). Conclusions: This study partially showed the effects of school-based oral health programs on the increments of dental caries. This programs should be expanded widely among elementary schools in Korea.

• Restorative Dentistry and Endodontics
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• v.43 no.2
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• pp.22.1-22.9
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• 2018

Objectives: To evaluate and compare light-transmittance in dental tissues and dental composite restorations using the incremental double-layer technique with varying layer thickness. Materials and Methods: B1-colored natural teeth slabs were compared to dental restoration build-ups with A2D and B1E-colored nanofilled, supra-nanofilled, microfilled, and microhybrid composites. The enamel layer varied from 0.3, 0.5, or 1.2 mm thick, and the dentin layer was varied to provide a standardized 3.7 mm overall sample thickness (n = 10). All increments were light-cured to $16J/cm^2$ with a multi-wave LED (Valo, Ultradent). Using a spectrophotometer, the samples were irradiated by an RGB laser beam. A voltmeter recorded the light output signal to calculate the light-transmittance through the specimens. The data were analyzed using 1-way analysis of variance followed by the post hoc Tukey's test (p = 0.05). Results: Mean light-transmittance observed at thicker final layers of enamel were significantly lower than those observed at thinner final layers. Within 1.2 mm final enamel resin layer (FERL) thickness, all composites were similar to the dental tissues, with exception of the nanofilled composite. However, within 0.5 mm FERL thickness, only the suprananofilled composite showed no difference from the dental tissues. Within 0.3 mm FERL thickness, none of the composites were similar to the dental tissues. Conclusions: The supra-nanofilled composite had the most similar light-transmittance pattern when compared to the natural teeth. However, for other composites, thicker FERL have a greater chance to match the light-transmittance of natural dental tissues.

• Journal of Biosystems Engineering
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• v.10 no.2
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• pp.1-11
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• 1985

A double pipe grain heater using engine exhaust gas as a heat source was developed. The performance of the grain heater was examined with soybeans as a test material experimentally and numerically using a mathematical model constructed. The following conclusions were drawn: 1. The modified screw conveyor used in the grain heater has a characteristic of decreasing capacity with increasing speed at speeds above 60 rpm. Operation with speeds below 60 rpm is recommended. 2. Heating soybeans by the heater at soybean flow rate up to 100 kg/hr, inlet temperature of the exhaust gas to the heater are recommended as above $400^{\circ}C$, $300^{\circ}C$, and $200^{\circ}C$ roughly for a 2, 5, and 10 kW engine, respectively. 3. Temperature increments of soybean by the heater at soybean flow rates ranged from 25 to 100 kg/hr are in the ranges of $6^{\circ}C-35^{\circ}C$, $15^{\circ}C-88^{\circ}C$, and $15^{\circ}C-140^{\circ}C$ with exhaust gas from a 2, 5, and 10 kW engine, respectively, at an exhaust temperature of $500^{\circ}C$. 4. Thermal efficiency of the heater at soybean flow rates ranged from 25 to 100 kg/hr are in the ranges of 35-37%, 28-34%, and 20-29% with exhaust gas from a 2, 5, and 10 kW engine, respectively. 5. The grain heater can be used to heat the other grain, also, without any bad effect from the exhaust gas used as a heat source.

• Toxicological Research
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• v.25 no.1
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• pp.29-33
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• 2009

Phellinus gilvus (PG) is a widely used mushroom for health promotion. We studied the hepatoprotective effect of the polysaccharide aqueous extract of PG (PGP) against carbon tetrachloride ($CCl_4$)-induced liver injury in rats. Sprague Dawley rats were divided into 5 groups: Normal control, $CCl_4$ control, PGP 50, 100, and 200 mg/kg + $CCl_4$. The levels of serum biochemical parameters, liver lipid peroxide and antioxidant enzymes, and histological appearances were evaluated. The $CCl_4$-induced increments of alanine aminotransferase, asparate aminotransferase, and alkaline phosphatase levels in serum were significantly decreased by PGP-pretreatments. The PGP dose-dependently decreased hepatic malondialdehyde formations in $CCl_4$-treatment groups. Hepatic antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) were elevated by PGP in $CCl_4$-treatment groups. Histopathological evaluation of liver showed that the loss of hepatocytes, fatty changes, swelling and extensive necrosis of hepatocytes in centrilobular regions of the $CCl_4$-treated rats were ameliorated by PGP pretreatment. The PGP has hepatoprotective and antioxidative effects in $CCl_4$-induced liver injury of rat.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.274-280
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• 2002

The fluoroquinolones have been reported to cause, although at low frequency, severe phototoxicity which is due to singlet oxygen produced by ultraviolet-A (UVA; 320-400 nm) exposure. The objective of this study was to evaluate the phototoxicity based on plasma and tissue concentrations of commonly prescribed fluoroquinolones; lomefloxacin (LFLX), enoxacin (ENX), ofloxacin (OFLX), and ciprofloxacin (CPFX). The phototoxic potentials were investigated by measuring increments in ear thickness, 24 hrs after these fluoroquinolones were orally administered to Balb/c mice, which they were exposed to UVA 17.5 J/$\textrm{cm}^2$ for 2 hrs following drug administration. The fifty percent ear thickness increment-inducing doses ($ETID_{50}$), determined by single ascending dosing of each fluoroquinolone to mice, were calculated to be 50(LMFX), 250(ENX), 770(OFLX), 1100(CPFX) mg/kg. Post the administration of ETID$_{50}$, drug concentrations in plasma and ear tissue were measured at specified times and phototoxicities were quantified. Both peak plasma ($\mu\textrm{g}$/ml) and ear tissue ($\mu\textrm{g}$/g) concentrations were summarized as follows; 7.3/1.4 for LMFX, 15.0/1.6 for ENX, 90.1/18.4 for OFLX and 87.2/3.7 for CPFX. The degree of photo toxicity was more relevant to plasma concentrations than tissue concentrations. In order to assess the effect of irradiation time after drug administration on phototoxicity, the 2 hr UVA irradiation was given at 0, 1, 2, 3, and 5 hr after administering $ETID_{50}$, respectively and photo toxicities were evaluated. The shorter inteval between dosing and UVA exposure was, the higher risk of phototoxicity was produced.d.

• Osong Public Health and Research Perspectives
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• v.5 no.4
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• pp.187-192
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• 2014

Objectives: Measurement of the incidence of the human immunodeficiency virus (HIV) is very important for epidemiological studies. Here, we determined the recency period with the AxSYM avidity assay and the BED-capture enzyme immunoassay (BED-CEIA) in Korean seroconverters. Methods: Two hundred longitudinal specimens from 81 seroconverters with incident HIV infections that had been collected at the Korea National Institute of Health were subjected to the AxSYM avidity assay (cutoff = 0.8) and BED-CEIA (cutoff = 0.8). The statistical method used to estimate the recency period in recent HIV infections was nonparametric survival analyses. Sensitivity and specificity were calculated for 10-day increments from 120 days to 230 days to determine the recency period. Results: The mean recency period of the avidity assay and BED-CEIA using a survival method was 158 days [95% confidence interval (CI), 135-181 days] and 189 days (95% CI, 170-208 days), respectively. Based on the use of sensitivity and specificity, the mean recency period for the avidity assay and BED-CEIA was 150 days and 200 days, respectively. Conclusion: We determined the recency period to estimate HIV incidence in Korea. These data showed that the nonparametric survival analysis often led to shorter recency periods than analysis of sensitivity and specificity as a new method. These findings suggest that more data from seroconverters and other methodologies are needed to determine the recency period for estimating HIV incidence.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.237-249
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• 2019

The roughness changes on a fracture surface were analyzed via a multi-stage compression test under high temperatures to assess how the cracks in a rock mass affect groundwater movement. The analyzed samples consist of coarse granitic rocks from approximately 40 and 270 m depth, and fine granitic rocks from 500 m depth. The compression test was conducted on $20{\times}40{\times}5mm$ samples using a loading system where the pressure increases in 10 MPa increments to 120 MPa. A high-resolution 3D confocal laser scanning microscope (CLSM) was used to observe the surface changes, including the roughness changes, at each pressure step. The roughness change was calculated based on the roughness factor. The experimental results indicate that the roughness of the fracture surface varies with rock type under the stepwise pressure conditions. These data provide a basis for predicting groundwater flow along rock fractures.

• Wind and Structures
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• v.18 no.4
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• pp.423-441
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• 2014

The high frequency base balance (HFBB) technique is a convenient and relatively fast wind tunnel testing technique for predicting wind-induced forces for tall building design. While modern tall building design has seen a number architecturally remarkable buildings constructed recently, the characteristics of those buildings are significantly different to those that were common when the HFBB technique was originally developed. In particular, the prediction of generalized forces for buildings with 3-dimensional mode shapes has a number of inherent uncertainties and challenges that need to be overcome to accurately predict building loads and responses. As an alternative to the more conventional application of general mode shape correction factors, an analysis methodology, referred to as the linear-mode-shape (LMS) method, has been recently developed to allow better estimates of the generalized forces by establishing a new set of centers at which the translational mode shapes are linear. The LMS method was initially evaluated and compared with the methods using mode shape correction factors for a rectangular building, which was wind tunnel tested in isolation in an open terrain for five incident wind angles at $22.5^{\circ}$ increments from $0^{\circ}$ to $90^{\circ}$. The results demonstrated that the LMS method provides more accurate predictions of the wind-induced loads and building responses than the application of mode shape correction factors. The LMS method was subsequently applied to a tall building project in Hong Kong. The building considered in the current study is located in a heavily developed business district and surrounded by tall buildings and mixed terrain. The HFBB results validated the versatility of the LMS method for the structural design of an actual tall building subjected to the varied wind characteristics caused by the surroundings. In comparison, the application of mode shape correction factors in the HFBB analysis did not directly take into account the influence of the site specific characteristics on the actual wind loads, hence their estimates of the building responses have a higher variability.