• Imaging Science in Dentistry
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• v.30 no.4
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• pp.275-279
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• 2000

Purpose: Radiation damage is produced and viable cell number is reduced. We need to know the type of cell death by the ionizing radiation and the amount and duration of cell cycle arrest. In this study, we want to identified the main cause of the cellular damage in the oral cancer cells and normal keratinocytes with clinically useful radiation dosage. Materials and Methods: Human gingival tissue specimens obtained from healthy volunteers were used for primary culture of the normal human oral keratinocytes (NHOK). Primary NHOK were prepared from separated epithelial tissue and maintained in keratinocyte growth medium containing 0.15 mM calcium and a supplementary growth factor bullet kit. Fadu and Hep-2 cell lines were obtained from KCLB. Cells were irradiated in a /sup 137/Cs γ-irradiator at the dose of 10 Gy. The dose rate was 5.38 Gy/min. The necrotic cell death was examined with Lactate Dehydrogenase (LDH) activity in the culture medium. Every 4 day after irradiation, LDH activities were read and compared control group. Cell cycle phase distribution and preG1-incidence after radiation were analyzed by flow cytometry using Propidium Iodine staining. Cell cycle analysis were carried out with a FAC Star plus flowcytometry (FACS, Becton Dickinson, USA) and DNA histograms were processed with CELLFIT software (Becton Dickinson, USA). Results: LDH activity increased in all of the experimental cells by the times. This pattern could be seen in the non-irradiated cells, and there was no difference between the non-irradiated cells and irradiated cells. We detected an induction of apoptosis after irradiation with a single dose of 10 Gy. The maximal rate of apoptosis ranged from 4.0% to 8.0% 4 days after irradiation. In all experimental cells, we detected G2/M arrest after irradiation with a single dose of 10 Gy. Yet there were differences in the number of G2/M arrested cells. The maximal rate of the G2/M ranges from 60.0% to 80.0% 24h after irradiation. There is no significant changes on the rate of the G0/G1 phase. Conclusion: Radiation sensitivity was not related with necrosis but cell cycle arrest and apoptosis. These data suggested that more arrested cell is correlated with more apoptosis.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.3035-3042
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• 2015

Background: Isorhamnetin (Iso), a novel and essential monomer derived from total flavones of Hippophae rhamnoides that has long been used as a traditional Chinese medicine for angina pectoris and acute myocardial infarction, has also shown a spectrum of antitumor activity. However, little is known about the mechanisms of action Iso on cancer cells. Objectives: To investigate the effects of Iso on A549 lung cancer cells and underlying mechanisms. Materials and Methods: A549 cells were treated with $10{\sim}320{\mu}g/ml$ Iso. Their morphological and cellular characteristics were assessed by light and electronic microscopy. Growth inhibition was analyzed by MTT, clonogenic and growth curve assays. Apoptotic characteristics of cells were determined by flow cytometry (FCM), DNA fragmentation, single cell gel electrophoresis (comet) assay, immunocytochemistry and terminal deoxynucleotidyl transferase nick end labeling (TUNEL). Tumor models were setup by transplanting Lewis lung carcinoma cells into C57BL/6 mice, and the weights and sizes of tumors were measured. Results: Iso markedly inhibited the growth of A549 cells with induction of apoptotic changes. Iso at $20{\mu}g/ml$, could induce A549 cell apoptosis, up-regulate the expression of apoptosis genes Bax, Caspase-3 and P53, and down-regulate the expression of Bcl-2, cyclinD1 and PCNA protein. The tumors in tumor-bearing mice treated with Iso were significantly smaller than in the control group. The results of apoptosis-related genes, PCNA, cyclinD1 and other protein expression levels of transplanted Lewis cells were the same as those of A549 cells in vitro. Conclusions: Iso, a natural single compound isolated from total flavones, has antiproliferative activity against lung cancer in vitro and in vivo. Its mechanisms of action may involve apoptosis of cells induced by down-regulation of oncogenes and up-regulation of apoptotic genes.

• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.73-81
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• 1997

Retention ponds have been dug along some of the motorways to control water flow during rainstorms and to minmize environmental pollution. A retention pond located at Les Ardilleres about 20km South of Orleans along the A-71 motorway has been selected to evaluate the effectiveness of such a pond as a trap for heavy metals. Based on the "index of geoaccumulation" and the "enrichment factor" normalized to Fe introduced by Muller in 1979 and by Helz in 1976, respectively, the degree of contamination by heavy metals for the roadside soil and the settling particles was evaluated. As expected, the contamination was very severe in the roadside soil, while it was not so great in the settling particles. Using these methods, cadmium anomaly was traced in the settling particles of the retention pond, their occurrence being attributed partly to natural and partly to anthropogenic pollution. The estimated input of heavy metals associated with settling particles to the pond was 0.9 g/day Pb, 2.1 g/day Zn and 6mg/day Cd. A tentative mass balance of Pb and Zn originated by motor vehicles suggested that only 5 to l1% of heavy metals deposited on the surface of the motorway is carried to the retention pond by runoff water ; suggestions are made to improve their efficiency.ve their efficiency.

• Journal of Hydrogen and New Energy
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• v.11 no.3
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• pp.119-125
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• 2000

To improve the photochemical energy conversion efficiency and the stability of CdS particulate film electrode which is used to produce hydrogen from the aqueous $H_2S$ solution photoelectrochemically, surface treatment of this film was carried out using $TiCl_4$ solution. CdS particles for preparation of the films were synthesized by precipitation reaction of $Cd({NO_3})_2{\cdot}9H_2O$ and $Na_2S{\cdot}4H_2O$. Then, the CdS sol was hydrothermally treated for 12hr in an autoclave with the variation of treatment temperature to control the crystalline phase of particles. CdS film electrode was thus prepared by annealing at $400^{\circ}C$ for 12hr of the wet-film cast at room temperature, and subsequently surface treated with $TiCl_4$ solution. The electrodes were characterized using XRD, SEM, and the photocurrent meter. The photocurrents of Cds film electrodes prepared with surface treatment were up to two times higher than the electrodes without surface treatment, indicating about $4.0mA/cm^2$. Hydrogen production rate in a continuous flow system using photoelectrochemical or photochemical cells prepared with surface treatment also increased in proportion to the increase of photocurrents.

• Journal of the Korea Concrete Institute
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• v.29 no.3
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• pp.315-322
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• 2017

The purpose of this study is to investigate experimentally the construction performances and economical evaluation of the self-compacting concrete in actual site work after selecting the optimum mix proportions according to cementitious materials. Slag cement type of 46.5% slag powder and belite cement of 51.4% $C_2S$ content, lime stone powder as binders are selected for site experiment including water cement ratio. Also, test items for optimum mix proportion are as followings ; (1) Slump flow, 500 mm reaching time, V-type flowing time and U-box height (2) Setting time, bleeding, shortening depth and adiabatic temperature rising (3) Mixing time in plant (4) Concrete quantity and cost, quality control in actual concrete work. As test results, (4) Optimum water-cement ratio ; Slag cement type 41.0% and belite cement 51.0% (2) Setting time and bleeding finishing time of slag cement are faster, bleeding content of slag cement is higher, shortening depth and adiabatic temperature rising of belite cement type are lower (3) Optimum mixing time in batcher plant is 75 seconds and concrete productive capacity is about $100{\sim}110m^3/hr$. (4) Belite cement type is lower than slag cement type in material cost 14.0%, and concrete quantity in actual concreting work save 3.3% in case of belite cement type. Therefore, self-compacting concrete of belite cement type is definitely superior to that of slag cement type in various test items without compressive strength development.

• Journal of the Korean GEO-environmental Society
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• v.19 no.10
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• pp.21-26
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• 2018

Soil-water characteristic curve, which is called soil retention curve, is required to explore water flows in unsaturated soils, relative permeability of water in multi-phase fluids flow, and change to stiffness and volume of soils. Thus, the understanding of soil-water characteristic curves of soils help us explore the behavior of soils inclduing fluids. Biopolymers are environmental-friendly materials, which can be completely degraded by microbes and have been believed not to affect the nature. Thus, various biopolymers such as deacetylated power, polyethylene oxide, xanthan gum, alginic acid sodium salt, and polyacrylic acid have been studies for the application to soil remediation, soil improvement, and enhanced oil recovery. PAA (polyacrylic acid) is one of biopolymers, which have shown a great effect in enhanced oil recovery as well as soil remediation because of the improvement of water-flood performance by mobility control. The study on soil-water characteristic curves of sandy soils containing PAA (polyacrylic acid) has been conducted through experimentations and theoretical models. The results show that both capillary entry pressure and residual water saturation dramatically increase according to the increased concentration of PAA (polyacrylic acid). Also, soil-water characteristic curves by theoretical models are quite well consistent with the results by experimental studies. Thus, soil-water characteristic curves of sandy soils containing biopolymers such as PAA (polyacrylic acid) can be estimated using fitting parameters for the theoretical model.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.363-363
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• 2008

The development of dry etching process for sapphire wafer with plasma has been key issues for the opto-electric devices. The challenges are increasing control and obtaining low plasma induced-damage because an unwanted scattering of radiation is caused by the spatial disorder of pattern and variation of surface roughness. The plasma-induced damages during plasma etching process can be classified as impurity contamination of residual etch products or bonding disruption in lattice due to charged particle bombardment. Therefor, fine pattern technology with low damaged etching process and high etch rate are urgently needed. Until now, there are a lot of reports on the etching of sapphire wafer with using $Cl_2$/Ar, $BCl_3$/Ar, HBr/Ar and so on [1]. However, the etch behavior of sapphire wafer have investigated with variation of only one parameter while other parameters are fixed. In this study, we investigated the effect of pressure and other parameters on the etch rate and the selectivity. We selected $BCl_3$ as an etch ant because $BCl_3$ plasmas are widely used in etching process of oxide materials. In plasma, the $BCl_3$ molecule can be dissociated into B radical, $B^+$ ion, Cl radical and $Cl^+$ ion. However, the $BCl_3$ molecule can be dissociated into B radical or $B^+$ ion easier than Cl radical or $Cl^+$ ion. First, we evaluated the etch behaviors of sapphire wafer in $BCl_3$/additive gases (Ar, $N_2,Cl_2$) gases. The behavior of etch rate of sapphire substrate was monitored as a function of additive gas ratio to $BCl_3$ based plasma, total flow rate, r.f. power, d.c. bias under different pressures of 5 mTorr, 10 mTorr, 20 mTorr and 30 mTorr. The etch rates of sapphire wafer, $SiO_2$ and PR were measured with using alpha step surface profiler. In order to understand the changes of radicals, volume density of Cl, B radical and BCl molecule were investigated with optical emission spectroscopy (OES). The chemical states of $Al_2O_3$ thin films were studied with energy dispersive X-ray (EDX) and depth profile anlysis of auger electron spectroscopy (AES). The enhancement of sapphire substrate can be explained by the reactive ion etching mechanism with the competition of the formation of volatile $AlCl_3$, $Al_2Cl_6$ or $BOCl_3$ and the sputter effect by energetic ions.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.37-44
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• 2008

Oriental fruit moth, Grapholita molesta, is a serious pest on apples. To control this pest in an environmentally friendly method, mating disruption strategy using sex pheromone has been developed. Area-wide application of mating disruption has been needed to be effective, with little understanding on how much size of apple cultivating area should be treated in one time application of the mating disruption technique. On this matter, we needed to determine a minimal mating active zone of G. molesta that should be applied with mating disrupters to be effective. Molecular markers to discriminate a specific population should be developed to trace population migration for reproductive behaviors. Here we developed two effective molecular markers using random amplified polymorphic DNA (RAPD) technique. Different field populations of G. molesta, based on locations and seasons, were analyzed with these markers. In a specific location, G. molesta populations varied in genetic composition with different seasons. Different local populations showed differential variation according to their relative distances among apple orchards. In overall, genetic variation among different populations became lessen with progression of seasons.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1712-1717
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• 2009

Capsaicin has been shown to affect lipid metabolism. However, it is currently not known whether capsaicin would lower the intestinal absorption of cholesterol. Thus, this study was conducted to investigate the effect of intraduodenally infused capsaicin on the lymphatic absorption of cholesterol and lipids in rats. Male Sprague-Dawley rats weighing 300-350 g were starved for 16 hr and the mesenteric lymph duct was cannulated. Each rat was infused at 3.0 mL/hr for 8 hr via the duodenal catheter with a lipid emulsion, which contained 33.3 kBq [$^{14}C$]-cholesterol, 20.7 μmol cholesterol, 452 μmol triolein, 3.1 μmol $\alpha$-tocopherol, and 396.0 μmol Na-taurocholate without (control) or with 5.0 mg capsaicin in 24 mL PBS buffer (pH 6.4). Simultaneously, lymph was collected hourly for 8 hr. There was no significant difference in lymph flow between the groups. However, the lymphatic absorption of 14C-cholesterol for 8 hr was significantly lower in rats infused with capsaicin than in those infused with no capsaicin. Also, the output of oleic acid for 8 hr was significantly decreased by capsaicin. However, the intestinal absorption of $\alpha$-tocopherol did not differ between the groups. The results indicate that the luminal infusion of capsaicin inhibits the intestinal absorption of cholesterol and lipids in rats.

• Tuberculosis and Respiratory Diseases
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• v.75 no.1
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• pp.9-17
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• 2013

Background: In cancer cells, autophagy is generally induced as a pro-survival mechanism in response to treatment-associated genotoxic and metabolic stress. Thus, concurrent autophagy inhibition can be expected to have a synergistic effect with chemotherapy on cancer cell death. Monensin, a polyether antibiotic, is known as an autophagy inhibitor, which interferes with the fusion of autophagosome and lysosome. There have been a few reports of its effect in combination with anticancer drugs. We performed this study to investigate whether erlotinib, an epidermal growth factor receptor inhibitor, or rapamycin, an mammalian target of rapamycin (mTOR) inhibitor, is effective in combination therapy with monensin in non-small cell lung cancer cells. Methods: NCI-H1299 cells were treated with rapamycin or erlotinib, with or without monensin pretreatment, and then subjected to growth inhibition assay, apoptosis analysis by flow cytometry, and cell cycle analysis on the basis of the DNA contents histogram. Finally, a Western blot analysis was done to examine the changes of proteins related to apoptosis and cell cycle control. Results: Monensin synergistically increases growth inhibition and apoptosis induced by rapamycin or erlotinib. The number of cells in the sub-$G_1$ phase increases noticeably after the combination treatment. Increase of proapoptotic proteins, including bax, cleaved caspase 3, and cleaved poly(ADP-ribose) polymerase, and decrease of anti-apoptotic proteins, bcl-2 and bcl-xL, are augmented by the combination treatment with monensin. The promoters of cell cycle progression, notch3 and skp2, decrease and p21, a cyclin-dependent kinase inhibitor, accumulates within the cell during this process. Conclusion: Our findings suggest that concurrent autophagy inhibition could have a role in lung cancer treatment.