• Radiation Oncology Journal
• /
• v.29 no.2
• /
• pp.83-90
• /
• 2011

Purpose: Flavopiridol enhanced radiation-induced apoptosis of cancer cells in our previous in vitro study. The purpose of this study was to assess if flavopiridol could enhance the radioresponse of mouse mammary tumors in vivo. Materials and Methods: Balb/c mice bearing EMT-6 murine mammary carcinoma were treated with flavopiridol only, radiation only, or both for 7 days. Flavopiridol was administered 2.5 mg/kg twice a day intraperitoneally (IP). Radiation was delivered at a 4 Gy/fraction at 24-h intervals for a total dose of 28 Gy. Tumor volume was measured and compared among the different treatment groups to evaluate the in vivo radiosensitizing effect of flavopiridol. Tumors were removed from the mice 20 days after treatment, and TUNEL and Immunohistochemical stainings were performed. Results: Significant tumor growth delay was observed in the radiation only and combined treatment groups, when compared with the control group. However, there was no significant difference between the tumor growth curves of the control and flavopiridol only group or between the radiation only and combination treatment group. Apoptotic cells of different treatment groups were detected by terminal deoxynucleotidyl transferase-medicated nick end labeling (TUNEL) staining. The expressions of Ku70 in tumor tissues from the different groups were analyzed by immunohistochemistry. Similarly, no significant difference was found between the apoptotic rate or Ku70 expression among the different treatment groups. Conclusion: Flavopiridol did not show evidence of enhancing the radioresponse of mouse mammary tumors in this study.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.9
• /
• pp.3176-3183
• /
• 2010

A multi-scale fatigue life prediction methodology of composite pressure vessels subjected to multi-axial loading has been proposed in this paper. The multi-scale approach starts from the constituents, fiber, matrix and interface, leading to predict behavior of ply, laminates and eventually the composite structures. The multi-scale fatigue life prediction methodology is composed of two steps: macro stress analysis and micro mechanics of failure based on fatigue analysis. In the macro stress analysis, multi-axial fatigue loading acting at laminate is determined from finite element analysis of composite pressure vessel, and ply stresses are computed using a classical laminate theory. The micro stresses are calculated in each constituent from ply stresses using a micromechanical model. Three methods are employed in predicting fatigue life of each constituent, i.e. a maximum stress method for fiber, an equivalent stress method for multi-axially loaded matrix, and a critical plane method for the interface. A modified Goodman diagram is used to take into account the generic mean stresses. Damages from each loading cycle are accumulated using Miner's rule. Monte Carlo simulation has been performed to predict the overall fatigue life of a composite pressure vessel considering statistical distribution of material properties of each constituent, fiber volume fraction and manufacturing winding angle.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.5 no.1
• /
• pp.21-28
• /
• 2017

The steel-plate concrete(SC) is used in a form of module assembly construction in the outer wall of nuclear-power plant and LNG containment. Since the steel-plate concrete modules are generally manufactured from the plant, the weight of SC has significantly effect on the total construction cost in the aspect of shipment. Therefore, the use of lightweight aggregates concrete(LWAC), which fill the inside of SC module can be a solution. However, the amount of used lightweight aggregates(LWA) is limited in the use of current concrete mixing process due to the concrete quality problems and it also determines the allowable minimum density of LWAC. In this research, the preplaced casting method is applied because of increasing the volume fraction of LWA significantly, which results from the producing process of pre-packing the LWA in the formwork and filling the interstitial voids between LWA using cement paste grout. The density and compressive strength of selected preplaced LWAC were $1,600kg/m^3$ and 30MPa and it was applied for the mock-up specimens of SC panel. It was used for the 3-point bending test for evaluating its structural performance. The results show that the preplaced LWAC can reduce the density of concrete with the adequate mechanical and structural performance.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.5 no.3
• /
• pp.290-297
• /
• 2017

The flexural behavior tests of UHPC segmental U-girder and composite U-girder which has 160MPa compressive strength and 15.4m length were carried out. The test variables are volume fraction of steel fibers and slab over the U-girder. Each U-girder has longitudinal re-bars in web and lower flange. PS tendons which has 2 of 15.2mm diameter in upper flange and PS tendons which has 7 of 15.2mm diameter in lower flange were arranged and prestressed at onetime in U-girder connection stage. Enough strong prestressing force which applied to U-girder due to ultra high performance concrete strength can withstand the self weight and dead load in U-girder stage. By comparison with the brittle behavior of U-girder, composite U-girder showed the stable and ductile behavior. After the construction of slab over U-girder, flexural load capacity of composite U-girder can bear the design load in final construction stage with only one time prestressing operation which already carried out in U-girder stage. This simple prestressing method due to the ultra high strength concrete have the advantage in construction step and cost. The shear key which has narrow space has the strong composite connection between ultra high strength concrete U-girder and high strength concrete slab didn't show any slip and opening right before failure load.

• Composites Research
• /
• v.12 no.3
• /
• pp.8-16
• /
• 1999

Carbon woven fabric/C/SiC composites were fabricated by multiple impregnations of carbon woven fabric/carbon preform with the polymer precursor of SiC, i.e., polycarbosilane. In addition, two kinds of low density carbon/carbon preforms which had different fiber volume fraction and fiber orientation, i.e., a carbon woven fabric(${\thickapprox}$55 vol%)/carbon and a chopped carbon fiber${\thickapprox}$40 vol%)/carbon composites, were reaction-bonded with a silicon melt at 1$700^{\circ}C$ in a vacuum to fabricate dense carbon fiber/Si/SiC composites. The reaction-bonding process increased the density to ~2.1 g/$cm^3$ from 1.6 g/$cm^3$ and 1.15 g/$cm^3$ of a carbon woven and a chopped carbon preforms, respectively. All of the composites fractured with extensive fiber pull-out. The higher the density the higher the stiffness and proportional limit stress. The mechanical properties obtained from a three-point bend and tension tests were compared. The ratios of the peak tensile stresses to the bending strengths of a carbon woven and a chopped carbon composites were about one-third, respectively. The carbon woven fabric/Si/SiC composites with density of 2.06 g/$cm^3$ showed ~120 MPa of ultimate strength and ~80 MPa of proportional limit in bend testing.

• Journal of Preventive Medicine and Public Health
• /
• v.23 no.1 s.29
• /
• pp.43-56
• /
• 1990

To evaluate the difference of concentration and mutagenicity of organic pollutants between residential and traffic area of Seoul, air samples were collected in Bulkwang (residential) and Shinchon (traffic) area. Samples were analyzed to measure the concentration of extractable organic matters (EOM) and their subfractions and mutagenicities were tested using Salmonella typhimurium TA 98. The concentrations of polycyclic aromatic hydrocarbons (PAHs) were also measured by gas-chromatography and compared between two areas. The results were as follows ; 1. While the concentration of total suspended particulate (TSP) in residential area was below the environmental standard in annual average, the concentration in traffic area was above the standard and was up to its maximum $256{\mu}g/m^3$ in November. The difference of TSP concentrations in both areas of each month was statistically significant (P<0.05). 2. The concentration of fine particle in traffic area was significantly higher compare to that in residential area and showed statistically significant monthly difference in both areas (P<0.05). The proportion of concentration of fine particle to TSP was 55-68%. 3. Mean concentrations of EOM in residential and traffic areas were $4.3{\mu}g/m^3\;and\;5.3{\mu}g/m^3$ respectively. The proportion of amount of EOM from fine particle to EOM from TSP was 70-88%. 4. While the percentage of polar neutral organic compounds (POCN) of fine particle in Bulkwang's sample was higher compare to Shinchon's sample, the percentage of aliphatic compounds of fine particle in Shinchon's sample was higher compare to Bulkwang's sample. The percentages of PAH fraction were as low as 6-10% in both areas. 5. The mutagenic activity of nit concentration of organic matters extracted from fine particle was higher compare to that of coarse particle and was increased when metabolically activated with S9. Mutagenicities with metabolic activation calculated by unit air volume were significantly different between residential and traffic area, $17\;revertants/m^3$\;and\;22\;revertants/m^3$ respectively. 6. The concentrations of benzo(a)pyrene in fine particle of traffic and residential areas were $3.10ng/m^3\;and\;2.02ng/m^3$ respectively. Sixteen PAHs were higher in samples of traffic area compare to residential area and also concentrations of PAHs in fine particle were higher compare to coarse particle.

• The Korean Journal of Pesticide Science
• /
• v.4 no.1
• /
• pp.44-50
• /
• 2000

Tolerance mechanism to flupyrazofos was examined with Plutella xylostella (L.) and Spodoptera exigua by investigating the penetration rate of flupyrazofos into larvae body. On determining effective washing of $^{14}C$-flupyrazofos, the washing volume to recover over 98% of $^{14}C$-flupyrazofos was observed at three times (each time: 1 mL). To select a suitable solvent, the recovery rates of each solvent in 3rd instar larvae of DBM were above 98%, but the washing rates of acetone, hexane and ethyl-acetate were 85.1%, 67.2% and 68.4%, respectively. In the BAW larvae, although the recovery rates of each solvent were above 99%, the washing rates of acetone, hexane and ethyl-acetate were 83.5%, 65.9% and 71.7%, respectively. The $PT_{50}$ values of $^{14}C$-flupyrazofos were 0.731 h (44 min) in the DBM larva and 0.504 h (30 min) in the BAW larva. Radiocarbon in acetone washing (external fraction) decreased more quickly in the BAW larva than in the DBM larva, and amount of radiocarbon in larvae body increased more quickly with time in the DBM larva than in the BAW larva. In contrast, amount of radiocarbon in excreta increased more rapidly with time in the BAW larva than in the DBM larva.

• Journal of Food Hygiene and Safety
• /
• v.13 no.3
• /
• pp.252-257
• /
• 1998

Bamboo salt has been used as a traditional remedy for gastric ulcer and gastro-intestinal disorders. It is produced by baking the salt packed in bamboo cylinder nine times under the fire of pine tree. Three of commercially available bamboo salt products (bamboo salt A, B, and C) were characterized by qualitative and quantitative analyses using inductively coupled plasma (ICP) spectrometer, ion chromatograph (IC), X-ray diffractometer (XRD), and electron microscope (EM). Compared with crude salt, the contents of iron, silicon, potassium, and phosphate in the bamboo salt products were higher whereas the sulfate content was lower. Water-insoluble fraction of bamboo salts contained the following compounds; MgO, $SiO_2,\;Mg_2Si0_4,\;and\;CaMgSi0_4$. The study on the microscopic structures of the bamboo salts were shown to have smooth surface and fused shape compared with crude salt. Among the three bamboo salt products, product A was used to test a possible inhibitory effect on gastric acid secretion. Each test material (bamboo salt A, crude salt, and reagent-grade NaCl) was given orally to Sprague-Dawley rats at doses of 0.2, 1.0, and 2.0 g/kg for 28 days before pyrolus ligation. Twenty four hours after the last administration of the test materials, volume, pH, total acidity, and pepsin activity of gastric juice were measured by the Shay-ligation method. No significant differences were observed in the secretion of gastric acid between treated groups (bamboo salt-, crude salt- and reagent-grade NaCI-treated groups) and control group (distilled water-treated group). This result demonstrated that bamboo salt did not exert anti-ulcer activities in experimental animals used in the present study.

• Korean Journal of Head & Neck Oncology
• /
• v.16 no.2
• /
• pp.167-171
• /
• 2000

Objectives: To compare the outcomes of treatment with a focus on the effectiveness of the two primary techniques of radiation used for treating parotid gland malignancies. Materials and Methods: A retrospective analysis of 70 patients with parotid gland cancer treated between 1981-1997. Radiation was delivered through an ipsilateral field of high energy electron and photon in 37 patients(52.9%). Two wedge paired photon was used to treat in 33 patients(47.1%). The median dose was 60 Gy, typically delivered at 1.8-2.0Gy per fraction. The median follow-up times for surviving patients was 60 months. Results: The overall and disease free 5 year survival rates were 71.6% and 69.5%, respectively. Wedge paired photon and photon-electron treatment disease tree 5 year survival rates were 61.1% and 80.5%, respectively. Overall local failure rate was 18.6%. Local failure rate of wedge paired photon technique was higher than that of mixed beam technique. Late complication rate was 37.1%, but most of them were mild grade. Conclusion: Techniques of radiation were associated with local control. The technique of using an ipsilateral field encompassing the parotid bed and treated with high energy electrons often mixed photons was effective with minimal severe late toxicity. To irradiate deep sited tumors, we consider 3-D conformal treatment plan for well encompassing the target volume.

• Analytical Science and Technology
• /
• v.5 no.4
• /
• pp.389-399
• /
• 1992

Liquid Chromatographic behavior of Pd(II) in Isonitrosoethylacetoacetate lmine, $Pd(IEAA-NR)_2$ (R=H, $CH_3$, $C_2H_5$, $n-C_3H_7$, $C_6H_5-CH_2$, $n-C_4H_9$) chelates were investigated by reversed-phase HPLC on Micropak MCH-5 column using methanol/water as mobile phase. The optimum conditions for the separation of $Pd(IEAA-NR)_2$ chelates were examined with respect to the effect of the flow rate, sample solvent, mobile phase strength and column temperature. It wass found that metal chelates were properly eluted in an acceptable range of capacity factor value($0{\leq}log\;k^{\prime}{\leq}1$). The dependence of the logarithm of capacity factor(k') on the volume fraction of water in the binary mobile phase was examined. Also, the dependence of k' on the liquid-liquid extration distribution ratio($D_c$) in methanol-water/n-alkane extration system was investigated. Both kinds of dependence are linear, which susggests that the retention of the electroneutral metal chelate is largely due to the solvophobic effect. Standard adsorption enthalpy changes (${\Delta}H^{\circ}$) and standard adsorption entropy changes (${\Delta}S^{\circ}$) of Pd(II) Isonitrosoethylacetoacetate imine chelates on Micropak MCH-5 column were calculated by measuring capacity factor with changing temperature of the column.