• The Korean Journal of Pharmacology
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• v.32 no.1
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• pp.23-29
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• 1996

According to the traditional receptor model, competitive antagonists share with agonists the ability to bind to a common site on receptors, but they are different from agonist in that they cannot trigger the biological response-i.e., they lack intrinsic efficacy. Recent findings extend the model by indicating that not all antagonists display an intrinsic efficacy of zero but that some display 'inverse agonism'. In the present study we studied the inverse agonism at $A_1$ adenosine receptors in membranes prepared from rat cerebral cortex. Eight commercially available $A_1$ adenosine receptor antagonists (CGS-15943, ADPX, CPT, DPCPX, DPX, N-0840, PACPX and 8-PT) were screened for inverse agonism by measuring the extent of $[^{35}S]guanosine-5'-({\gamma}-thio)$ triphosphate $([^{35}S]GTP_{\gamma}S)$ binding to G proteins. The agonist-induced stimulation of $[^{35}S]GTP_{\gamma}S$ bindings was completely blocked in the presence of $A_1$ adenosine receptor antagonists. Under optimal conditions, two types of antagonists could be distinguished. Seven antagonists including DPCPX decreased the basal $[^{35}S]GTP_{\gamma}S$ binding in the absence of agonist, displaying inverse agonist activity. One (CGS-15943) had no effect on the basal bindings. N-ethylmaleimide treatment reduced the basal bindings as well as agonist-mediated stimulation of $[^{35}S]GTP_{\gamma}S$ bindings, indicating that a substantial amount of this binding reflects an activated state of the C proteins. In good agreement with these findings, 0.1 mM GTP decreased the apparent affinity of the receptors for the agonist PIA, increased that for DPCPX, and had no effect on that for CGS-15943.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.659-666
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• 2009

Metabolizable protein (MP) supply and amino acid balance in the intestine were manipulated through selection of highly digestible rumen-undegradable protein (RUP) sources and protected methionine (Met) supplementation. Four ruminallycannulated, multiparous Holstein cows averaging 193${\pm}$13 days in milk were used in a 4${\times}$4 Latin square design to assess N utilization and milk production responses to changes in RUP level, post-ruminal RUP digestibility and protected Met supplementation. Treatments were A) 14.0% crude protein (CP), 8.0% rumen degradable protein (RDP) and 6.0% RUP of low intestinal digestibility (HiRUP-LoDRUP); B) 14.1% CP, 8.1% RDP and 6.0% RUP of high intestinal digestibility (HiRUP-HiDRUP); C) 13.1% CP, 7.9% RDP and 5.2% RUP of high intestinal digestibility (LoRUP-HiDRUP), and D) 13.1% CP, 7.9% RDP and 5.2% RUP of high intestinal digestibility plus rumen escape sources of Met (LoRUP-HiDRUP+Met). Experimental diets were formulated to have similar concentrations of RDP, net energy of lactation ($NE_L$), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium, phosphorus and ether extract using the NRC model (2001). Results showed that dry matter intake (DMI), production of milk fat and protein were similar among treatments. Milk production was similar for diet HiRUP-LoDRUP, HiRUP-HiDRUP and LoRUP-HiDRUP+Met, and significantly higher than diet LoRUP-HiDRUP. Milk fat and protein percentage were higher for cows receiving HiDRUP treatments, with the greatest increases in the diet LoRUP-HiDRUP+Met. There was no significant change in ruminal pH, $NH_3g-N$ and volatile fatty acid (VFA) concentration among all treatments. Apparent digestibility of dry matter (DM), CP, NDF and ADF and estimated bacterial CP synthesis were similar for all treatments. Nitrogen intakes, blood and milk urea-N concentrations were significantly higher for cows receiving HiRUP diets. Urine volume and total urinary N excretion were significantly lowered by LoRUP diets. Lowering dietary RUP level while supplementing the highly digestible RUP source with rumen escape sources of Met resulted in similar milk production, maximal milk fat and protein concentration and maximum N efficiency, indicating that post-ruminal digestibility of RUP and amino acid balance in the small intestine can be more important than total RUP supplementation.

• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.64-69
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• 1999

This study was carried out the removal of Cr(VI) which was known to the toxic pollutant in industry using the process of UV and TiO$_2$ photocatalyst in a circular type reactor. In this experiment, the series of photocatalytic process for the removal of Cr(VI) has been selected as a model reaction in a circular type reactor in order to obtain the basic data on the influence of various experimental parameters such as circulation flow rate, pH of solution, initial Cr(VI) light illumination and TiO$_2$ dosage, and salicylic acid concentration. The results of this study were as follows; 1. With both UV light illumination and TiO$_2$ present, Cr(VI) was more effectively eliminated than with either UV or TiO$_2$ alone. 2. As the circulation flow rate of solution increased, the removal efficiency of Cr(VI) was increased. However, over 2.4 l/min of circulation flow rate, the efficiency wa limited. 3. A increase in the photocatalytic removal of Cr(VI) was noticed with decreasing pH. 4. An increase in the photocatalytic removal of Cr(VI) was noticed with decreasing Initial Cr(VI) concentration and first order kinetics was observed from the result at different initial concentration of Cr(VI). 5. Photocatalytic removal efficiency of Cr(VI) increased with increasing TiO$_2$ dosage. However, over 1.0 g/l of TiO$_2$ dosage, the efficiency reached a plateau. 6. As low concentration of saliculic acid were added, there was an increase in the removal efficiency of Cr(VI). However, over 300 mg/l of salicylic acid, the efficiecy was decreased. It eas found that application of photocatalysis to water treatment that contains both Cr(VI) and salicylic acid was possible.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.5
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• pp.538-555
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• 2012

The purpose of this study was to understand $PM_{2.5}$ chemical characteristics on the Suwon/Yongin area and further to quantitatively estimate $PM_{2.5}$ source contributions. The $PM_{2.5}$ sampling was carried out by a high-volume air sampler at the Kyung Hee University-Global Campus from November, 2010 to October, 2011. The 40 chemical species were then analyzed by using ICP-AES(Ag, Ba, Cr, Cu, Fe, Mn, Ni, Pb, Si, Ti, V and Zn), IC ($Na^+$, $K^+$, $NH_4{^+}$, $Mg^{2+}$, $Ca^{2+}$, $NO_3{^-}$, ${SO_4}^{2-}$ and $Cl^-$), DRI/OGC (OC1, OC2, OC3, OC4, OP, EC1, EC2 and EC3) and GC-FID (acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[a] pyrene, indeno[1,2,3-cd] pyrene, benzo[g,h,i]perylene and dibenzo[a,h,]anthracene). When applying PMF model after performing proper data treatment, a total of 10 sources was identified and their contributions were quantitatively estimated. The average contribution to $PM_{2.5}$ emitted from each source was determined as follows; 26.3% from secondary aerosol source, 15.5% from soil and road dust emission, 15.3% from vehicle emission, 15.3% from illegal biomass burning, 12.2% from incineration, 7.2% from oil combustion source, 4.9% from industrial related source, and finally 3.2% from coal combustion source. In this study we used the ratios of PAHs concentration as markers to double check whether the sources were reasonably classified or not. Finally we provided basic information on the major $PM_{2.5}$ sources in order to improve the air quality in the study area.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.11-22
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• 2018

The safety of tunnels is quantified by quantitative risk assessment when planning the disaster prevention facilities of railway tunnels, and it is decided whether they are appropriate. The purpose of this study is to estimate the probability of the train stopping in the tunnels at train fire, which has a significant effect on the results of quantitative risk assessment for tunnel fires. For this purpose, a model was developed to calculate the coasting distance of the train considering the coefficient of train running resistance. The probability of stopping in case of train fire in the tunnel is predicted by the Monte Carlo simulation method with the coasting distance and the emergency braking distance as parameters of the tunnel lengths and slopes, train initial driving speeds. The kinetic equations for predicting the coasting distance were analyzed by reflecting the coefficient train running resistance of KTX II. In the case of KTX II trains, the coasting distance is reduced as the slope increases in a tunnel with an upward slope, but it is possible to continue driving without stopping in a slope downward. The probability of the train stopping in the case of train fire in tunnel decreases as the train speed increases and the slope of the tunnel decreases. If human error is not taken into account, the probability that a high-speed train traveling at a speed of 250 km/h or above will stop in a tunnel due to a fire is 0% when the slope of the tunnel is 0.5% or less, and the probability of stopping increases rapidly as the tunnel slope increases and the tunnel length increases.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1386-1395
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• 2020

High fidelity nuclear reactor fuel assembly simulation using CFD method is an effective way for the structure design and optimization. The validated models and user practice guidelines play critical roles in achieving reliable results in CFD simulations. In this paper, the international benchmark MATiS-H is studied carefully and the best user practice guideline is achieved for the rod bundles simulation. Then a 5 × 5 rod bundles model in the advanced pressurized water reactor (PWR) is established and the detailed three-dimensional thermal-hydraulic characteristics are investigated. The influence of spacer grids and mixing vanes on the flow and hear transfer in rod bundles is revealed. As the coolant flows through the spacer grids and mixing vanes in the rod bundles, the drastic lateral flow would be induced and the pressure drop increases significantly. In addition, the heat transfer is enhanced remarkably due to the strong mixing effects. The calculation results could provide meaningful guidelines for the design of advanced PWR fuel assembly.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.5
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• pp.8-15
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• 2002

We optimally designed the VCO(voltage-controlled oscillator) with spiral inductor using the MOSIS HP 0.5${\mu}{\textrm}{m}$ CMOS process. With the developed SPICE model of spiral inductor, the quality factor of spiral inductor was maximized at the operating frequency by varying the layout parameters, e.g., metal width, number of turns, radius, space of the metal lines. For the operation frequency of 2㎓, the inductance of about 3nH, and the MOSIS HP 0.5 CMOS process with the metal thickness of 0.8${\mu}{\textrm}{m}$, oxide thickness of 3${\mu}{\textrm}{m}$, the optimal width of metal lines is about 20${\mu}{\textrm}{m}$ for the maximum Quality factor. With the optimized spiral inductor, the VCO with LC tuning tank was designed, fabricated and measured. The measurements were peformed on-wafer using the HP8593E spectrum analyzer. The oscillation frequency was about 1.610Hz, the frequency variation of 250MHz(15%) with control voltage of 0V - 2V, and the phase noise of -108.4㏈c(@600KHz) from output spectrum.

• Herbal Formula Science
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• v.14 no.1
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• pp.105-119
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• 2006

Objectives & Methods : This present study was performed to investigate the effect of Hwadamtongrak-Tang extract (HTT) on the regulation of cerebral hemodynamics in terms of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats. Also the effects of HTT on changes in local blood flow, inhibition of LD H activity in neuronal cells, and levels of cytokine production in the serum were determined in the ischemic rat model. The major findings are summarized below. Results : 1. HTT significantly increased rCBF in a dose-dependent manner, but MABP was not changed by HTT treatment. These results suggest that HTT may increase rCBF by dilating cerebral arterial diameter. 2. HTT-induced increase in rCBF was blocked by pretreatment with cyclooxygenase inhibitor indomethacin (IDN, 1 mg/kg, i.p.) and MABP was significantly increased by ID N. 3. Pretreatment of methylene blue $(MTB,\;10\;{\mu}g/kg,\;i.p.)$, an inhibitor of guanylate cyclase, significantly decreased both rCBP and MABP in HTT-treated rats. 4. HTT treatment significantly increased rCBP to a stable level during the period of cerebral reperfusion. 5. HTT significantly inhibited LD H activity in neuronal cells, suggesting a neuroprotection by HTT. 6. Serum interleukin $(IL)-1{\beta}$ and tumor necrosis factor $(TNF)-{\alpha}$ levels were significantly decreased in the femoral artery 1 hr after middle cerebral arterial occlusion in HTT-treated rats. IL-10 levels in the serum were significantly increased by HTT treatment whereas transforming growth factor $(TGF)-{\beta}$ levels were similar between HTT-treated and control groups. 7. Serum interleukin $(IL)-1{\beta}$ and tumor necrosis factor $(TNF)-{\alpha}$ levels were significantly decreased in the femoral artery 1 hr after reperfusion in HTT-treated rats. Serum IL-10 levels were significantly decreased in HTT-treated rats compared with the control group, and no significant changes in $(TGF)-{\beta}$ in the serum were observed by HTT treatment. Conclusions: The present data suggest that HTT may have an anti-ischemic effect via the improvement of cerebral hemodynamics and thus protect the brain from ischemic damage.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.3
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• pp.432-438
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• 2017

Objective: The objective of this study was to evaluate the effect of combinations of $NaNO_2$ and NaCl concentrations on Listeria monocytogenes (L. monocytogenes) growth in emulsion-type sausage. Methods: Emulsion-type sausages formulated with different combinations of $NaNO_2$ (0 and 10 ppm) and NaCl (1.00%, 1.25%, and 1.50%) were inoculated with a five-strain L. monocytogenes mixture, and stored at $4^{\circ}C$, $10^{\circ}C$, and $15^{\circ}C$, under aerobic or vacuum conditions. L. monocytogenes cell counts were measured at appropriate intervals, and kinetic parameters such as growth rate and lag phase duration (LPD) were calculated using the modified Gompertz model. Results: Growth rates increased (0.004 to 0.079 Log colony-forming unit [CFU]/g/h) as storage temperature increased, but LPD decreased (445.11 to 8.35 h) as storage temperature and NaCl concentration increased. The effect of combinations of NaCl and low-$NaNO_2$ on L. monocytogenes growth was not observed at $4^{\circ}C$ and $10^{\circ}C$, but it was observed at $15^{\circ}C$, regardless of atmospheric conditions. Conclusion: These results indicate that low concentrations of $NaNO_2$ and NaCl in emulsion-type sausage may not be sufficient to prevent L. monocytogenes growth, regardless of whether they are vacuum-packaged and stored at low temperatures. Therefore, additional techniques are necessary for L. monocytogenes control in the product.

• The Journal of Korean Physical Therapy
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• v.21 no.2
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• pp.117-124
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• 2009

Purpose: This study examined the effects of swimming exercise and Achyranthes Radix extracts on the inflammatory and behavioral responses in type II collagen-induced arthritic rats for 28 days. Methods: Sprague-Dawley rats were allocated randomly to one of the following four groups: only type II collageninduced (group Ⅰ), application of swimming exercise after type II collagen-induced (group II), application of Achyranthes Radix ointment after type II collagen-induced (group III), application of swimming exercise and Achyranthes Radix ointment after type II collagen-induced (group IV). Arthritis was established in SD rats by an intradermal injection of Chick type II collagen plus incomplete Freund's adjuvant at the base of the tail of the animals. The swimming exercise program consisted of a 25 min swimming session/day with a load corresponding to 5.5% of the weight bearing, three days/week for four weeks. The Achyranthes Radix ointment (0.1g) was applied twice a day for five days. The changes in behavior, H & E stain, and cyclooxygenase-2 (COX-2) level in the knee joint were assessed. Results: The gross and histological examination, after RA induction showed reddening, edema and erythema. The H & E stain revealed the destruction of articular cartilage, bony erosion and the infiltration of inflammatory cells after RA induction. The mechanical allodynia test results were significantly higher in group I than in groups II, III and IV (p<0.01). The immunohistochemistrical response of COX-2 in the knee joint showed that groups II, III, IV had a lower response effect than group I. Conclusion: Swimming exercise training and Achyranthes Radix ointment decreased the inflammatory responses and enhanced the behavioral responses in the arthritic rats.