• Title/Summary/Keyword: RAD

Search Result 714, Processing Time 0.03 seconds

Construction of RHEED Apparatus and Study on K, Cs/Si)(111) System (RHEED 장치의 제작과 K, Cs/Si(111)계에 관한 연구)

  • 이경원;안기석;강건아;박종윤;이순보
    • Journal of the Korean Vacuum Society
    • /
    • v.1 no.1
    • /
    • pp.43-49
    • /
    • 1992
  • RHEED apparatus which is one of the systems of surface structure analysis has been constructed.Electron beam is focused by means of magnetic lens, and the beam divergence is about $1{\times}10^{-3}$ rad. The Acceleration voltage of this RHEED apparatus is continuously variable from 0 to 20 kV. K and Cs-adsorbed structureson Si(111)$7{\times}7$ surface at room and high temperatures($200{\times}700^{\circ}C$) have been investigated by RHEED. It is observed that the K and Cs-adsorbed Si(111)surface structures at saturation coverage are Si(111)$7{\tiems}7-K$ and Si(111)$1{\tiems}1-Cs$ at room temperature, respectively. When the specimen temperature was elevated during evaporation,the $3{\times}1$ structure appears in the range of temperature between $300^{\circ}C$ and $550^{\circ}C$, and the $1{\tiems}1$ structure appears above $550^{\circ}C$ in K/Si(111)system. Also, in Cs/Si(111) system the $\sqrt{3}{\times}\sqrt{3}$ structure appears at $300^{\circ}C$, and the $\sqrt{3}{\times}\sqrt{3}+3{\times}1$ structure appears between $350^{\circ}C$ and $400^{\circ}C$.

  • PDF

Measurement of the Radiolysis Gases Generated in Several Waste Forms by External Irradiation (${\gamma}$-조사에 의한 방사성폐기물의 방사분해가스 발생량 평가)

  • Kwak, Kyung-Kil;Ryue, Young-Gerl;Kim, Ki-Hong;Je, Whan-Gyeong;Kim, Dong-Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.4 no.4
    • /
    • pp.345-352
    • /
    • 2006
  • The cemented and paraffin wastes form which are incorporated the concentrated wastes, the cemented waste form which is incorporated the spent ion-exchange resins, and the miscellaneous waste(decontamination paper) were irradiated up to $10^{+8}$ rads at $5.43{\times}10^{+5}$ rads/hr with Co-60(72,023.9 Ci) as an external irradiation source. As a result, the radiolysis gases such as $H_2,\;CH_4,\;N_2,\;C_2H_6,\;O_2,\;CO\;and\;CO_2$, were measured in all the wastes. The major gas which was generated in all the wastes was hydrogen($H_2$). The volume of the generated gases showed a difference from $0.029{\sim}0.788\;cm^3.atm/1.1g$ according to the type of wastes, and more was generated in the cemented waste form incorporated a spent ion-exchange resin than in the other wastes. More hydrogen($H_2$) gas was generated in the decontamination paper waste than in the other wastes, and the G($H_2$) value was 0.12.

  • PDF

Comparative Analysis of Muscle Proteome from Porcine White and Red Muscles by Two-dimensional Electrophoresis (이차원전기영동법을 이용한 white muscle과 red muscle간의 단백질 발현양상의 비교분석)

  • Kim, N.K.;Joh, J.H.;Chu, K.S.;Park, H.R.;Park, B.Y.;Kim, O.H.;Lee, C.S.
    • Journal of Animal Science and Technology
    • /
    • v.45 no.5
    • /
    • pp.731-738
    • /
    • 2003
  • The technique known as proteomics is useful for characterizing the protein expression pattern of a particular tissue or cell type as well as quantitatively identifying differences in the levels of individual proteins. In present study, we carried out the comparative expression patterns of white and red muscles. We used the two-dimensional electrophoresis(2-DE) for analyzing the protein expression. Proteins isolated from porcine white and red muscles were separated by 12% poly-acrylamide gel and then were detected by coomassie blue and silver staining. More than 600 protein spots were detected on each 2-DE gel. By visual analysis of the stained gel, five proteins were identified to be differentially expressed in the white vs red muscle. By database searching based on the molecular weights and pI(isoelectric point) of the five proteins, three of them were found to be most close to troponin I, T and myoglobin. However, further researche is needed for identification and functional analysis of the unidentified proteins. In conclusion, we found five proteins, which are differentially expressed in the white vs red muscle. The functional analysis of the differentially expressed proteins will provide valuable information on biochemical characteristics of the muscle type.

A Preliminary Investigation of Radon Concentration for Some Agricultural Greenhouses in Jeju Island (제주지역 일부 농업 시설 내 라돈 농도 예비 조사)

  • Kang, Tae-Woo;Song, Myeong-Han;Kim, Tae-Hyoung;Chang, Byung-Uck;Kim, Young-Jae;Kim, Geun-Ho;Park, Jae-Woo
    • Korean Journal of Environmental Agriculture
    • /
    • v.31 no.1
    • /
    • pp.9-15
    • /
    • 2012
  • BACKGROUND: A preliminary investigation of the radon ($^{222}Rn$) concentration has been conducted, employing solid-state nuclear-track detectors (SSNTD) and a continuous radon monitor (CRM), for fourteen randomly selected agricultural greenhouses in Jeju Island, where the underground-air was used for air conditioning and $CO_2$ supplement. METHODS AND RESULTS: The SSNTD was used to measure the average radon concentration for three months and the CRM was used for an instantaneous measurement. In order to obtain the radon concentration of a greenhouse, the SSNTDs were placed at a number of evenly distributed points inside the greenhouse and the mean of the measured values was taken. In addition, in order to assess the radon concentration of the underground-air itself, measurement was also made at the borehole of the underground-air in each agricultural facility, employing both the SSNTD and CRM. It is found that the radon concentration of the greenhouses ranges higher than those not using the underground-air and the average of Korean dwellings. While the radon concentration of most agricultural facilities is still lower than the reference level (1,000 Bq/$m^3$) recommended by the International Radiation Protection Committee (ICRP), three facilities at one site show higher concentrations than the reference level. The three-month-averaged radon concentration and the instantaneous radon concentration of the underground-air itself ranges 1,228- 5,259 and 3,322-17,900 Bq/$m^3$, respectively, and regional variation is more significant. CONCLUSION: From this results, radon concentration of the underground-air is assumed that it is associated with the geological characteristics and the boring depth of the region located of their.

Transcriptional Regulation of Genes by Enhancer RNAs (인핸서 RNA에 의한 유전자 전사 조절)

  • Kim, Yea Woon;Kim, AeRi
    • Journal of Life Science
    • /
    • v.26 no.1
    • /
    • pp.140-145
    • /
    • 2016
  • Genes in multicellular organisms are transcribed in development, differentiation, or tissue-specific manners. The transcription of genes is activated by enhancers, which are transcription regulatory elements located at long distances from the genes. Recent studies have reported that noncoding RNAs are transcribed from active enhancers by RNA polymerase II (RNA Pol II); these are called enhancer RNAs (eRNAs). eRNAs are transcribed bi-directionally from the enhancer core, and are capped on the 5’ end but not spliced or polyadenylated on the 3’ end. The transcription of eRNAs requires the binding of transcription activators on the enhancer and associates positively with the transcription of the target gene. The transcriptional inhibition of eRNAs or the removal of eRNA transcripts results in the transcriptional repression of the coding gene. The transcriptional procedure of eRNAs causes enhancer- specific histone modifications, such as histone H3K4me1/2. eRNA transcripts directly interact with Mediator and Rad21, a cohesin subunit, generating a chromatin loop structure between the enhancer and the promoter of the target gene. The recruitment of RNA Pol II into the promoter and its elongation through the coding region are facilitated by eRNAs. Here, we will review the features of eRNAs, and discuss the mechanism of eRNA transcription and the roles of eRNAs in the transcriptional activation of target genes.

Effects of Tumor Microenvironmental Factors on DNA Methylation and Radiation Sensitivity in A549 Human Lung Adenocarcinoma

  • Oh, Jung-Min;Kim, Young-Eun;Hong, Beom-Ju;Bok, Seoyeon;Jeon, Seong-Uk;Lee, Chan-Ju;Park, Dong-Young;Kim, Il Han;Kim, Hak Jae;Ahn, G-One
    • Journal of Radiation Protection and Research
    • /
    • v.43 no.2
    • /
    • pp.66-74
    • /
    • 2018
  • Background: Tumor response to anticancer therapies can much be influenced by microenvironmental factors. In this study, we determined the effect of these microenvironmental factors on DNA methylation using A549 human lung adenocarcinoma cell line. Materials and Methods: We subjected A549 cells to various conditions mimicking tumor microenvironment including hypoxia, acidosis (sodium lactate), oxidative stress ($H_2O_2$), bystander effect (supernatant from doxorubicin (Dox)-treated or irradiated cells), and immune cell infiltration (supernatant from THP-1 or Jurkat T cells). Genomic DNA was isolated from these cells and analyzed for DNA methylation. Clonogenic cell survival, gene expression, and metabolism were analyzed in cells treated with some of these conditions. Results and Discussion: We found that DNA methylation level was significantly decreased in A549 cells treated with conditioned media from Dox-treated cells or Jurkat T cells, or sodium lactate, indicating an active transcription. To determine whether the decreased DNA methylation affects radiation sensitivity, we exposed cells to these conditions followed by 6 Gy irradiation and found that cell survival was significantly increased by sodium lactate while it was decreased by conditioned media from Dox-treated cells. We further observed that cells treated with conditioned media from Dox-treated cells exhibited significant changes in expression of genes including BAX and FAS (involved in apoptosis), NADPH dehydrogenase (mitochondria), EGFR (cellular survival) and RAD51 (DNA damage repair) while sodium lactate increased cellular metabolism rather than changing the gene expression. Conclusion: Our results suggest that various tumor microenvironmental factors can differentially influence DNA methylation and hence radiosensitivity and gene expression in A549 cancer cells.

Radioprotective Effect of Methylene Blue: 2. Electron Microscopy of the Effect of Methylene Blue on the Liver and Heart of Rats following Gamma-Irradiation (Methylene Blue의 방사선방어결과 2. Methylene Blue가 $\gamma$선에 조사한 흰줘의 간 및 심장조직에 미치는 전자현미경적 연구)

  • Sang Yul Nam;Seung Han Chang
    • The Korean Journal of Zoology
    • /
    • v.12 no.4
    • /
    • pp.114-122
    • /
    • 1969
  • Electron microscopic examination of the liver and heart tissues of methylene blue-treated rats before gamma-irradiation was observed in this study. 1. It was observed severe alteration and degeneration of organelles: accumulation of glycogen particles, severe swollen mitochondria, and broken endoplasmic reticulum in liver tissue of saline-treated rat(control) opposed by emthylene blue-treated rat at 64 and 212 hours following gamma-irradiation. 2. Heart muscles of both methylene blue-treated and saline-treated rats showed no significant alterations, but it was observed that slightly elongated mitochondria with broken cristae and some of vacuoles as well as increased glycogen particles in sarcoplasmic reticulum at 212 hours following gamma-irradiation. 3. It may be considered that methylene blue greatly reduces the sensitivities of rats to gamma-irradiation.

  • PDF

Changes in Riboflavin and Ascorbic Acid Content during Ripening of Kimchi (절임조건별(條件別) 배추에 의한 김치의 숙성중(熟成中) Riboflavin과 Ascorbic Acid의 함량변화(含量變化))

  • Rhie, Seung-Gyo;Kim, Hwa-Za
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.13 no.2
    • /
    • pp.131-135
    • /
    • 1984
  • For the convenience of transportation and improvement of the utility of raw chinese cabbage during harvest season, the condition of pretreatment for the raw chinese cabbage with pickle has been examined by preserving for one to ten days. The changes in the content of riboflavin and ascorbic acid in kimchi (pickled-seasoned chinese cabbage), which was manufactured by using the pickled cabbage as a main raw material, along with ginger, garlic, red pepper powder, rad-dish and fermented shrimp as seasonings, during ripening were investigated with specially referred to palatability. The yield of the pickled cabbage compared to the raw cabbage after treating with pickle was 62 to 65% in volume and 15 to 42% in weight. After 10 days of pickling of the chinese cabbage, one-third of total ascorbic acid was diminished but no change in riboflavin content was observed. During ripening of kimchi, riboflavin content in kimchi processed with the pickled cabbage has not been changed compared to the content in convention- ally made kimchi, however, slight decrease in ascorbic acid content in the kimchi processed with the pickled cabbage was as certained. The result of organoleptic test showed that the kimchi processed with the pickled cabbage became inferior to the conventionally made kimchi with the days of ripening.

  • PDF

Physicochemical, Structural, and Rheological Properties of New Domestic Potato Cultivars (국산 신품종 감자의 이화학적, 구조적 및 유변학적 특성)

  • Choi, Moonkyeung;Lee, Jungu;Jin, Yong-Ik;Chang, Dong-Chil;Kim, Misook;Lee, Youngseung;Chang, Yoon Hyuk
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.46 no.5
    • /
    • pp.608-615
    • /
    • 2017
  • The objective of this study was to evaluate the physicochemical, structural, and rheological properties of new domestic potato cultivars ('Goun', 'Sebong', and 'Jinsun') against the foreign potato cultivar 'Atlantic'. Based on the results obtained from scanning electron micrograph, X-ray, and Fourier transform infrared spectrum analyses, the structural properties of all potato flours were not considerably different. Rapid visco analyzer analyses showed that the setback viscosities of 'Goun', 'Sebong', and 'Jinsun' were significantly lower than that of 'Atlantic'. For steady shear rheological properties, potato flour dispersions showed shear-thinning behaviors (n=0.45~0.49) at $25^{\circ}C$. Apparent viscosity and consistency index of 'Atlantic' were similar to those of 'Sebong' and 'Jinsun'. For dynamic shear rheological properties, storage modulus (G′) and loss modulus increased, whereas complex viscosity (${\eta}^*$) was reduced with increasing frequency from 0.63 to 62.8 rad/s. G′ and ${\eta}^*$ values of 'Jinsun' were significantly higher than those of the other potato cultivars.

A Study on the Variation of Rn-222 Concentration in Groundwater at Busan-Geumjeong area (부산 금정구지역의 지하수에 포함된 라돈농도 변화 연구)

  • Cho, Jungg-Sook;Lee, Hyo-Min;Kim, Sun-Woong;Kim, Jin-Seop
    • Journal of Radiation Protection and Research
    • /
    • v.37 no.3
    • /
    • pp.149-158
    • /
    • 2012
  • In this paper, we measured the variations of radon concentrations in groundwater using low-level Liquid Scintillation Counter (LSC), an instrument for analyzing the alpha and beta radionuclides at its 10 sites around the Kumjung-Gu, north-western of Busan. Optimization of Pulse Shape Analyzer (PSA) to determinate the highest value of figure of merit (FM) was decided using Quantulus 1200 LSC with radium-226 source, the optimal PSA level was shown in the range of 100 to 110. The results show that the Minimum Detectable Activity (MDA) of radon concentrations is 0.61 $Bq{\cdot}L^{-1}$ for 20 minutes in PSA level. We find that the average radon concentration in groundwater is high in granitic rock area and low in volcanic rock area. (Biotite granite : 191.39 $Bq{\cdot}L^{-1}$, Micro graphic granite : 141.88 $Bq{\cdot}L^{-1}$, Adamellite : 92.94 $Bq{\cdot}L^{-1}$, Andesite (volcanic) : 35.35 $Bq{\cdot}L^{-1}$). No significant seasonal variation pattern is observed from the long-term variation analysis from 10 selected sites. We have not seen the significant correlation of radon concentration to groundwater temperature, atmospheric temperature, atmospheric pressure and rainfall. The concentration variation is probably caused by more complex factors and processes.