• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1147-1153
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• 2004

Bladder cancer is a common cancer with high risk of recurrence and mortality. Intravesicle chemotherapy after trans-urethral resection is required to prevent tumor recurrence and progression. It has been known that antioxidants enhance the antitumor effect of bacillus Calmette-Guerin (BCG), the most effective intravesical bladder cancer treatment. Capsaicin, the major pungent ingredient in genus Capsicum, has recently been tried as an intravesical drug for overactive bladder and it has also been shown to induce apoptotic cell death in many cancer cells. In this study, we investigated the apoptosis-inducing effect and alterations in the cellular redox state of capsaicin in MBT-2 murine bladder tumor cells. Capsaicin induced apoptotic MBT-2 cell death in a time- and dose-dependent manner. The capsaicin-induced apoptosis was blocked by the pretreatment with Z-VAD-fmk, a broad-range caspase inhibitor, or Ac-DEVD-CHO, a caspase-3 inhibitor. In addition to the caspase-3 activation, capsaicin also induced cytochrome c release and decrease in Bcl-2 protein expression with no changes in the level of Bax. Furthermore, capsaicin at the concentration of inducing apoptosis also markedly reduced the level of reactive oxygen species and lipid peroxidation, implying that capsaicin may enhance the antitumor effect of BCG in bladder cancer treatment. These results further suggest that capsaicin may be a valuable intravesical chemotherapeutic agent for bladder cancers.

• Korean Journal of Plant Resources
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• v.23 no.6
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• pp.519-525
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• 2010

Chlorogenic acid, formed of an ester of caffeic acid and quinic acid, which is naturally abundant in many plant species, was used as a model O-dihydoxy phenolic compound. In the previous study, we have reported that the isolated constituent from Apocynum venetum leaves has an inhibitory effect on $Cu^{2+}$-induced oxidative modification of low-density lipoprotein (LDL). Among them, chlorogenic acid showed the most potent anti-LDL oxidative activity than other compounds. For the reason, we investigated the inhibitory effect of the chlorogenic acid on $Cu^{2+}$-induced oxidative modification of LDL, monitored a lag time in the conjugated-diene formation and TBARS formation, and measured TNBS free amino acid group, and form cell formation in vitro system. The TBARS- and diene- formation were strongly inhibited by chlorogenic acid ($0{\sim}100\;{\mu}g/ml$) with dose dependent manner. On the other hand, TNBS reactive lysine amino groups on LDL oxidation were protected by chlorogenic acid- treated cell group. Therefore, chlorogenic acid inhibited to cholesterol accumulation in the isolated peritoneal macrophage.

• International Journal of Concrete Structures and Materials
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• v.2 no.2
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• pp.71-81
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• 2008

A macroscopic finite element model is applied to investigate the effect of fire induced spalling on the response of reinforced concrete (RC) beams. Spalling is accounted for in the model through pore pressure calculations in concrete. The principles of mechanics and thermodynamics are applied to compute the temperature induced pore pressure in the concrete structures as a function of fire exposure time. The computed pore pressure is checked against the temperature dependent tensile strength of concrete to determine the extent of spalling. Using the model, case studies are conducted to investigate the influence of concrete permeability, fire scenario and axial restraint on the fire induced spalling and also on the response of RC beams. Results from the analysis indicate that the fire induced spalling, fire scenario, and axial restraint have significant influence on the fire response of RC beams. It is also shown that concrete permeability has substantial effect on the fire induced spalling and thus on the fire response of concrete beams. The fire resistance of high strength concrete beams can be lower that that of normal strength concrete beams due to fire induced spalling resulting from low permeability in high strength concrete.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1759-1772
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• 1994

In this study, we re-examined the Tate's modified Bernoulli equation to study penetration phenomena for long rod projectile into single or multi-layered finite thickness plates. We used the force equlibrium equation at mushroomed nose/target interface instead of conventional pressure equation at the stagnation point. In our penetration model, we considered the velocity dependent $R_t$ value for semi-infinite target and considered only the back face effect for finite target. To compensate for $R_t$ value according to target's thickness and back face effect, we used the spherical cavity expansion theory for semi-infinite plate and used the cylindrical cavity expansion theory for finite plate. Also we developed the experimental technique using make screen to measure the penetration duration time at each layered plate. In 3-layered laminated RHA/mild steel/ A1 7039 plate, we observed that spall had occured around the back face of A1 7039 plate by the stress wave interaction. Through the comparison between theoretical and experimental data including Lambert's results, we conform that our study has good confidences.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.5
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• pp.1562-1572
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• 1996

The rigid-plastic finite element formulation including the inertia force is derived and then the rigid-plastic finite elemnt program considering the inertia effect is developed. In order to consider the strain hardening, strain rate hardening and thermal softening effects which are frequentrly observed in high-velocity deformation phenomena, the Johnson-Cook constitutive odel is applied. The developed program is used to simulate two high-velocity deformation problemss ; rod impact test and hdigh-velocity compression precess. As a result of rod impact test simulation, it is found that the siulated result has a good agreement with the experimental observation. Through the high-velocity compression process simulation. it is also found that the accuracy of the simulated results is dependent upon the time increment size and mesh size.

• Biomedical Science Letters
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• v.12 no.3
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• pp.275-279
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• 2006

It is demonstrated that cadmium has cytotoxic effect on glial cells, oxygen radicals are involved in cadmium-induced cytotoxicity. However, the toxic mechanism of cadmium is left unknown so far. The purpose of this study was to examine the cytotoxicity of $CdCl_2$ on $C_6$ glioma cells. The cytotoxicy was measured by cell viability via XTT assay in $C_6$ glioma cells. Colorimetric assay such as XTT assay is regarded as a very sensitive screening method for the determination of the cell viability on a lots of chemicals. In this study, $CdCl_2$ decreased cell viability according to the dose- and time dependent manners after $C_6$ glioma cells were treated with various concentrations of $CdCl_2$ for 48 hours. $IC_{90}\;and\;IC_{50}$ values for XTT assay was determined at $5{\mu}M\;and\;55{\mu}M$ of $CdCl_2$, respectively. These results suggest that $CdCl_2$ has highly cytotoxic effect on $C_6$glioma cells by the decrease of cell viability.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.672-676
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• 2003

To investigate the effect of acupuncture on Zusanli (ST 36) in this study, gastrin level of serum by radioimmunoassay was measured at 1, 3, 6 weeks in rats. In other groups, 1 mg/day omeprazole was administered for 1, 3, 6 weeks. Omeprazole increased significantly gastrin level of serum at 1, 3, 6 weeks in a time dependent manner. Acupuncture applied to the ST 36 acupoint decreased at 1, 3, 6 weeks. Furthermore, acupuncture applied to other acupoint, Yanglinquan (GB 34) did not produced significant effect. When the common peroneal nerve was dissected, acupuncture of ST 36 produced the change of gastrin level. These data suggest that acupuncture decreased gastrin level of serum in point specific way and that effect was not related with surrounding nerve.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.858-867
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• 1995

Characteristics of premixed flames in counter-flow system are numerically studied using a detailed chemical reaction mechanism including gas phase radiation. Without radiation effect accounted, low CO and high NO$_{x}$ emission indices are observed, when strain rate decreases, due to increased residence time and higher flame temperature. Higher NO$_{2}$ production has been also observed when two premixed flames are interacting or cold air stream is mixed with burned gas. The rate of NO$_{x}$ production and destruction is dependent upon the diffusional strength of H and OH radicals, the existence of NO and the concentration of HO$_{2}$. For radiating flames, the peak temperature and NO$_{x}$ production rate decreases as the strain rate decreases. At high strain rate, it is found that the effect of radiation on flame is little due to its negligible radiating volume. It is also found that NO$_{x}$ production from the interacting premixed flame is reduced due to reduced temperature resulting from radiation heat loss. It is concluded that the radiation from gas has significant effect of flame structure and on emission characteristics.ristics.

• Advances in aircraft and spacecraft science
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• v.4 no.4
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• pp.487-501
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• 2017

The main purpose of the paper is to analyze effect of geometrical parameters of the reentry capsules such as radius of the spherical cap, shoulder radius, back shell inclination angle and overall length on the flow field characteristics. The numerical simulation with viscous flow past ARD (Atmospheric Reentry Demonstrator), Soyuz (Russian) and OREX (Orbital Reentry EXperimental) reentry capsules for freestream Mach numbers range of 2.0-5.0 is carried out by solving time-dependent, axisymmetric, compressible laminar Navier-Stokes equations. These reentry capsules appear as bell, head light and saucer in shape. The flow field features around the reentry capsules such as bow shock wave, sonic line, expansion fan and recirculating flow region are well captured by the present numerical simulations. A low pressure is observed immediately downstream of the base region of the capsule which can be attributed to fill-up in the growing space between the shock wave and the reentry module. The back shell angle and the radius of the shoulder over the capsule are having a significant effect on the wall pressure distribution. The effects of geometrical parameters of the reentry capsules will useful input for the calculation of ballistic coefficient of the reentry module.

• Advances in Traditional Medicine
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• v.1 no.1
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• pp.64-70
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• 2000

Effects of Rhizoma gastrodiae on glucose oxidase-induced neurotoxicity was investigated in cultured newborn mouse spinal dorsal root ganglion(DRG) neurons that were treated in the media with or without glucose oxidase. In addition, the protective effect of Rhizoma gastrodiae extract against glucose oxidase-induced neurotoxicity was examined. Cytotoxic values were expressed as a percentage of number of living cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In this paper, exposure of neurons to glucose oxidase resulted in a significant call death in a dose- and time-dependent manners in DRG neuron cultures. The decrease in cell viability induced by the glucose oxidase was blocked by Rhizoma gastrodiae extract. These results indicate that the neuroprotective effect of Rhizoma gastrodiae extract against glucose oxidase-induced neurotoxicity may result from a prevention or attenuation of oxidative damage induced by glucose oxidase.