Application of a wet oxidation method for the quantification of ³H and ¹⁴C in low-level radwastes

Ahn, H.J.,Song, B.C.,Sohn, S.C.,Lee, M.H.,Song, K.,Jee, K.Y. Pergamon Press ; Elsevier Science Ltd 2013 Applied radiation and isotopes Vol.81 No.-

Wet oxidation methods are utilized to separate and quantify <SUP>3</SUP>H and <SUP>14</SUP>C radionuclides in inorganic and organic radwastes generated at nuclear facilities. Because <SUP>3</SUP>H and <SUP>14</SUP>C are pure beta emitters with half-lives of 12.3 and 5,730 years, respectively, these radionuclides should be chemically separated from other radionuclides present in radwastes for accurate quantification. In particular, a collection technique for <SUP>14</SUP>C radionuclide in radwastes is needed because it is converted into <SUP>14</SUP>CO<SUB>2</SUB> gas by an oxidation reaction. To confirm the recoveries of <SUP>3</SUP>H and <SUP>14</SUP>C, various standard radioactive sources were used to verify the proposed method. Because the majority of <SUP>3</SUP>H radionuclides are distributed in tritiated water (HTO), only tritiated water was used as a standard for <SUP>3</SUP>H radionuclides. Additionally, <SUP>14</SUP>C-labeled methanol (<SUP>14</SUP>CH<SUB>3</SUB>OH), lauric acid (<SUP>14</SUP>CH<SUB>3</SUB>(CH<SUB>2</SUB>)<SUB>10</SUB>COOH), sodium bicarbonate (NaH<SUP>14</SUP>CO<SUB>3</SUB>), and toluene (C<SUB>6</SUB>H<SUB>5</SUB><SUP>14</SUP>CH<SUB>3</SUB>) were used as <SUP>14</SUP>C standards. The compounds were oxidized with chemical oxidants and then separated. The individual species were mixed with a scintillation cocktail and counted using a liquid scintillation counter. The recoveries of <SUP>14</SUP>C and <SUP>3</SUP>H were 82-97% and 98%, respectively. The wet oxidation method will be applied to RI wastes for clearance.

Intravesical Instillation of c-MYC Inhibitor KSI-3716 Suppresses Orthotopic Bladder Tumor Growth

Jeong, K.C.,Kim, K.T.,Seo, H.H.,Shin, S.P.,Ahn, K.O.,Ji, M.J.,Park, W.S.,Kim, I.H.,Lee, S.J.,Seo, H.K. Williams and Wilkins Co 2014 The Journal of urology Vol.191 No.2

Purpose: c-MYC is a promising target for cancer therapy but its use is restricted by unwanted, devastating side effects. We explored whether intravesical instillation of the c-MYC inhibitor KSI-3716 could suppress tumor growth in murine orthotopic bladder xenografts. Materials and Methods: The small molecule KSI-3716, which blocks c-MYC/MAX binding to target gene promoters, was used as an intravesical chemotherapy agent. KSI-3716 action was assessed by electrophoretic mobility shift assay, chromatin immunoprecipitation, transcription reporter assay and quantitative reverse transcriptase-polymerase chain reaction. Inhibition of cell proliferation and its mechanism was monitored by cell cytotoxicity assay, EdU incorporation assay and flow cytometry. The in vivo efficacy of KSI-3716 was examined by noninvasive luminescence imaging and histological analysis after intravesical instillation of KSI-3716 in murine orthotopic bladder xenografts. Results: KSI-3716 blocked c-MYC/MAX from forming a complex with target gene promoters. c-MYC mediated transcriptional activity was inhibited by KSI-3716 at concentrations as low as 1 μM. The expression of c-MYC target genes, such as cyclin D2, CDK4 and hTERT, was markedly decreased. KSI-3716 exerted cytotoxic effects on bladder cancer cells by inducing cell cycle arrest and apoptosis. Intravesical instillation of KSI-3716 at a dose of 5 mg/kg significantly suppressed tumor growth with minimal systemic toxicity. Conclusions: The c-MYC inhibitor KSI-3716 could be developed as an effective intravesical chemotherapy agent for bladder cancer.

Projections of high resolution climate changes for South Korea using multiple-regional climate models based on four RCP scenarios. Part 1: surface air temperature

Suh, M. S.,Oh, S. G.,Lee, Y. S.,Ahn, J. B.,Cha, D. H.,Lee, D. K.,Hong, S. Y.,Min, S. K.,Park, S. C.,Kang, H. S. SPRINGER SCIENCE AND BUSINESS MEDIA 2016 Asia-Pacific Journal of Atmospheric Sciences Vol.52 No.2

<P>We projected surface air temperature changes over South Korea during the mid (2026-2050) and late (2076-2100) 21st century against the current climate (1981-2005) using the simulation results from five regional climate models (RCMs) driven by Hadley Centre Global Environmental Model, version 2, coupled with the Atmosphere- Ocean (HadGEM2-AO), and two ensemble methods (equal weighted averaging, weighted averaging based on Taylor's skill score) under four Representative Concentration Pathways (RCP) scenarios. In general, the five RCM ensembles captured the spatial and seasonal variations, and probability distribution of temperature over South Korea reasonably compared to observation. They particularly showed a good performance in simulating annual temperature range compared to HadGEM2-AO. In future simulation, the temperature over South Korea will increase significantly for all scenarios and seasons. Stronger warming trends are projected in the late 21st century than in the mid-21st century, in particular under RCP8.5. The five RCM ensembles projected that temperature changes for the mid/late 21st century relative to the current climate are +1.54A degrees C/+1.92A degrees C for RCP2.6, +1.68A degrees C/+2.91A degrees C for RCP4.5, +1.17A degrees C/+3.11A degrees C for RCP6.0, and +1.75A degrees C/+4.73A degrees C for RCP8.5. Compared to the temperature projection of HadGEM2-AO, the five RCM ensembles projected smaller increases in temperature for all RCP scenarios and seasons. The inter-RCM spread is proportional to the simulation period (i.e., larger in the late-21st than mid-21st century) and significantly greater (about four times) in winter than summer for all RCP scenarios. Therefore, the modeled predictions of temperature increases during the late 21st century, particularly for winter temperatures, should be used with caution.</P>

2, 4-Thiazolidindion Induced Plasticity of Myoblast (C2C12) and Satellite Cells (Porcine) - A Comparative Study

Singh, N.K.,Chae, H.S.,Hwang, I.H.,Yoo, Y.M.,Ahn, C.N.,Lee, H.J.,Park, H.J.,Chung, H.Y. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.7

This study was conducted to determine the difference between satellite cells (porcine) and myoblasts (C2C12) in their differentiation under the influence of 2, 4-thiazolidindion. C2C12 myoblast cells and porcine satellite cells (isolated from 10 d old $Landrace{\times}Duroc$ piglets) were grown to absolute confluency. Post confluent cells (day 0) were further exposed to adipogenic induction medium along with 2, 4-thiazolidindion ($8{\mu}M$) for 2 d. Thereafter, cells were exposed to 2, 4-thiazolidindion alone every 2 d till day 10 and analysed. The control was cultured in differentiation medium without any treatment. Increased (p<0.05) expression of transcriptional factors i.e. C/EBP-${\alpha}$ and PPAR-${\gamma}$ and transition of cells to adipocyte morphology was noticed from 2 d and 4 d onwards in satellite cells (Porcine) and myoblasts (C2C12) respectively. Myogenesis was observed to be suppressed completely in case of satellite cells compared to myoblasts in response to 2, 4-thiazolidindion. Pax-7 (transcriptional factor) appeared as a sole entity to satellite cells only, as it was not identified in case of myoblasts. Although both the cells were converting to adipoblasts, the degree of their conversion was different in response to 2, 4-thiazolidindion. Therefore, the hypothesis that satellite cells contribute various domains to the growing myoblasts appeared obscured and found to be dependent on the proliferative energy/or degree of fusion. However, it revealed satellite cells as currency to myoblasts/muscle.

The Use of Collagen Content as Determined by Spectral Domain Polarization-Sensitive Optical Coherence Tomography to Assess Colon Anastomosis Healing in a Rat Model

Son, K.H.,Jeong, H.-W.,Jung, W.-W.,Kim, H.-S.,Lee, S.K.,Kim, K.T.,Ahn, C.B.,Park, K.Y.,Kim, B.-M.,Lee, S.H. S. Karger AG 2014 European surgical research Vol.52 No.1

<P>Abstract</P><P><B><I>Background/Purpose:</I></B> Many studies have been undertaken to prevent anastomosis leakage of the colon, and several methods have been used to assess anastomosis healing, such as measurement of bursting pressure or hydroxyproline (a marker of collagen) content at the anastomosis site. However, these methods are inappropriate for comparing anastomosis healing at two time points in the same animals. In the present study, we measured the collagen level by spectral domain polarization-sensitive optical coherence tomography (SD-PS-OCT) to assess anastomosis healing. <B><I>Methods:</I></B> Sprague-Dawley rats were divided into groups C (saline-administered controls; study group) and M [a 5-fluorouracil (5-FU)-administered experimental group]. Immediately after end-to-end anastomosis of the colon, SD-PS-OCT images of anastomoses were taken (baseline). Animals were administered saline or 5-FU for 7 days. On the 7th postoperative day, SD-PS-OCT images were acquired, a histopathologic exam was performed, and hydroxyproline levels as well as mRNA expressions of collagen-1 and collagen-3 were measured at the anastomosis site. <B><I>Results:</I></B> Fibroblast proliferation and inflammatory cell infiltration were greater in group C than in group M. The mRNA expressions of collagen-1 and collagen-3 were substantially higher in group C. Hydroxyproline levels were higher in group M than in group C. Though collagen levels measured by SD-PS-OCT at 7 days were elevated compared with baseline in group C, no such changes were observed for group M. <B><I>Conclusion:</I></B> Collagen levels at the colon anastomosis site, measured with SD-PS-OCT, were not increased at 7 days postoperatively versus baseline when 5-FU was injected, but were increased in saline-treated controls. The measurement of collagen content by SD-PS-OCT was found to provide a good means of assessing anastomosis healing, because it allows in situ assessment of collagen contents at baseline and during the postoperative period.</P><P>© 2014 S. Karger AG, Basel</P>

약물중독의 치료와 통계적 고찰

안창근,윤승문 中央醫學社 1975 中央醫學 Vol.28 No.1

Drug intoxication with coma patients of I. C. U in N. M. C for 10 years Apr, 1965 to Oct, 1974 were reviewed. It was seen that barbiturate from was the most common one and the poisoning parathion intoxications were not a little. The other causes of acute poisoning was seen such as rodenticide, acid, alkali, meprobamate, etc. Meticulous treatment with respirator and progrostic problems to death rate were discussed. Patients of I. C. U in N. M. C for 10 years Apr, 1965 to Oct, 1974 were reviewed. It was seen that barbiturate from was the most common one and the poisoning parathion intoxications were not a little. The other causes of acute poisoning was seen such as rodenticide, acid, alkali, meprobamate, etc. Meticulous treatment with respirator and progrostic problems to death rate were discussed. Related

MEASUREMENTS OF THE RELATIVE ABUNDANCES OF HIGH-ENERGY COSMIC-RAY NUCLEI IN THE TeV/NUCLEON REGION

Ahn, H. S.,Allison, P. S.,Bagliesi, M. G.,Barbier, L.,Beatty, J. J.,Bigongiari, G.,Brandt, T. J.,Childers, J. T.,Conklin, N. B.,Coutu, S.,DuVernois, M. A.,Ganel, O.,Han, J. H.,Jeon, J. A.,Kim, K. C.,L IOP Publishing 2010 The Astrophysical journal Vol.715 No.2

<P>We present measurements of the relative abundances of cosmic-ray nuclei in the energy range of 500-3980 GeV/nucleon from the second flight of the Cosmic Ray Energetics And Mass balloon-borne experiment. Particle energy was determined using a sampling tungsten/scintillating-fiber calorimeter, while particle charge was identified precisely with a dual-layer silicon charge detector installed for this flight. The resulting element ratios C/O, N/O, Ne/O, Mg/O, Si/O, and Fe/O at the top of atmosphere are 0.919 +/- 0.123(stat) +/- 0.030(syst), 0.076 +/- 0.019(stat) +/- 0.013(syst), 0.115 +/- 0.031(stat) +/- 0.004(syst), 0.153 +/- 0.039(stat) +/- 0.005(syst), 0.180 +/- 0.045(stat) +/- 0.006(syst), and 0.139 +/- 0.043(stat) +/- 0.005(syst), respectively, which agree with measurements at lower energies. The source abundance of N/O is found to be 0.054 +/- 0.013(stat) +/- 0.009(-0.017)(syst+0.010esc). The cosmic-ray source abundances are compared to local Galactic (LG) abundances as a function of first ionization potential and as a function of condensation temperature. At high energies the trend that the cosmic-ray source abundances at large ionization potential or low condensation temperature are suppressed compared to their LG abundances continues. Therefore, the injection mechanism must be the same at TeV/nucleon energies as at the lower energies measured by HEAO-3, CRN, and TRACER. Furthermore, the cosmic-ray source abundances are compared to a mixture of 80% solar system abundances and 20% massive stellar outflow (MSO) as a function of atomic mass. The good agreement with TIGER measurements at lower energies confirms the existence of a substantial fraction of MSO material required in the similar to TeV per nucleon region.</P>

Effect of graphite reflector on activation of fusion breeding blanket

Lee, C.W.,Lee, Y.O.,Lee, D.W.,Cho, S.,Ahn, M.Y. North-Holland ; Elsevier Science Ltd 2016 Fusion engineering and design Vol.109 No.1

Korea has proposed a Helium-Cooled Ceramic Reflector (HCCR) breeding blanket concept relevant to fusion power plants. Here, graphite is used as a reflector material by reducing the amount of beryllium multiplier. In this paper, activity analysis was performed and the effect of graphite reflector in the view of activation was compared to the beryllium multiplier. As a result, it is expected that using the graphite reflector instead of the beryllium multiplier decreases total activity very effectively. But the graphite reflector produces C-14 about 17.2 times than the beryllium multiplier. Therefore, C-14 produced in the graphite reflector is expected as a significant nuclide in the view of radwaste management.

Enhancement of the Skin-Protective Activities of Centella asiatica L. Urban by a Nano-encapsulation Process

Kwon, M.C.,Choi, W.Y.,Seo, Y.C.,Kim, J.S.,Yoon, C.S.,Lim, H.W.,Kim, H.S.,Ahn, J.h.,Lee, H.Y. Elsevier Science Publishers 2012 Journal of biotechnology Vol.157 No.1

Aqueous extracts of Centella asiatica L. Urban were encapsulated by an edible biopolymer, gelatin, which has no effect on their cosmetic activities. The nanoparticles were w/o-type spherical liposomes that had an average diameter of 115.0nm. The encapsulation efficiency was estimated to be approximately 67%, which was relatively high for these aqueous extracts. The nanoparticles showed lower cytotoxicity (10%) in human skin fibroblast cells than the unencapsulated crude extract (15%) at 1.0mg/ml, this was possibly because a smaller amount of the extract was present in the nanoparticles. The nanoparticles efficiently reduced the expression of matrix metalloproteinase (MMP)-1 in UV-irradiated cells from 136.1% to 77.6% (UV-irradiated control) and inhibited hyaluronidase expression (>60%) at a concentration of 0.5mg/ml, which was higher than the levels produced by the unencapsulated crude extracts. The nanoparticles had a very high flux through mouse skin and also remained at relatively large concentrations in the derma when compared to the unencapsulated crude extracts. These results clearly indicate that the skin-protective activities of C. asiatica were significantly improved through the nano-encapsulation process. These findings also imply that a crude extract can be used and have the same efficacy as purified compounds, which should reduce the purification process and production costs.

A new indazole-based colorimetric chemosensor for sequential detection of Cu²⁺ and GSH in aqueous solution

Kim, M.S.,Jung, J.M.,Kang, J.H.,Ahn, H.M.,Kim, P.G.,Kim, C. Pergamon Press 2017 Tetrahedron Vol.73 No.32

A new selective and sensitive colorimetric chemosensor 1 was developed for the sequential detection of Cu<SUP>2+</SUP> and glutathione (GSH) in aqueous solution. The sensor 1 detected Cu<SUP>2+</SUP> ion by an obvious color change from colorless to pale yellow. Importantly, 1 could be used to detect and quantify Cu<SUP>2+</SUP> ion in water samples, and the detection limit (0.14 μM) of 1 for Cu<SUP>2+</SUP> was much lower than the guideline (31.5 μM) of WHO in drinking water. Also, Cu<SUP>2+</SUP>-2.1 complex can be used as a colorimetric sensor for GSH via naked-eye. The detection limit for GSH was founded to be 2.98 μM. Moreover, the sensing ability of 1 for Cu<SUP>2+</SUP> was supported by theoretical calculations.