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Assessment of the Effective Dose to the Human Body and Estimation of Lifetime Attributable Risk by CT Examination (CT 검사별 노출되는 유효선량과 생애 암 귀속 위험도 평가)

  • Cho, Yong In;Kim, Jung Hoon
    • Journal of the Korean Society of Radiology
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    • v.14 no.2
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    • pp.169-178
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    • 2020
  • The number of CT scans is increasing every year due to the improvement of the medical standards of the public, and thus the annual dose of medical radiation is also increasing. In this study, we evaluated the effective dose of the human body exposed to CT scans and estimated LAR. First, five region were selected from the CT diagnostic reference level guideline, and the effective dose of human body exposed to each examination was evaluated by clinical CT device. Second, the human organs and effective dose were calculated using the ALARA-CT program under the same conditions. Third, lifetime attributable risk (LAR) estimated by the effective dose exposed through the previous CT scan was estimated. As a result, the most effective dose was 21.18 mSv during the abdomen 4 phase scan, and the dose level was below DRL for all other tests except for the abdominal examination. As a result of evaluating effective dose using a dose calculation program under the same conditions, the results showed about 1.1 to 1.9 times higher results for each examination. In the case of organ dose, the closer the organ to the scan site, the higher the scattering ray. The lifetime attributable risk to CT radiation dose in adults was gradually decreased with age, and the results were somewhat different according to gender.

Calpain Protease-dependent Post-translational Regulation of Cyclin D3 (Calpain protease에 의한 cyclin D3의 post-translation조절)

  • Hwang, Won Deok;Choi, Yung Hyun
    • Journal of Life Science
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    • v.25 no.1
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    • pp.1-7
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    • 2015
  • Cyclin D is a member of the cyclin protein family, which plays a critical role as a core member of the mammalian cell cycle machinery. D-type cyclins (D1, D2, and D3) bind to and activate the cyclin-dependent kinases 4 and 6, which can then phosphorylate the retinoblastoma tumor suppressor gene products. This phosphorylation in turn leads to release or derepression of E2F transcription factors that promote progression from the G1 to S phase of the cell cycle. Among the D-type cyclins, cyclin D3 encoded by the CCND3 gene is one of the least well studied. In the present study, we have investigated the biochemistry of the proteolytic mechanism that leads to loss of cyclin D3 protein. Treatment of human prostate carcinoma PC-3-M cells with lovastatin and actinomycin D resulted in a loss of cyclin D3 protein that was completely reversible by the peptide aldehyde calpain inhibitor, LLnL. Additionally, using inhibitors for various proteolytic systems, we show that degradation of cyclin D3 protein involves the Ca2+-activated neutral protease calpain. Moreover, the half-life of cyclin D3 protein half-life increased by at least 10-fold in PC-3M cells in response to the calpain inhibitor. We have also demonstrated that the transient expression of the calpain inhibitor calpastatin increased cyclin D3 protein in serum-starved NIH 3T3 cells. These data suggested that the function of cyclin D3 is regulated by Ca2+-dependent protease calpain.

Factors affecting Pig Farmers' Adoption of the HACCP System

  • Jung, Gu-Hyun;Ahn, Kyeong Ah;Kim, Han-Eul;Jo, Hye Bin;Choe, Young-Chan
    • Agribusiness and Information Management
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    • v.3 no.2
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    • pp.43-62
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    • 2011
  • The goal of this study is to determine, based on survey results, the underlying factors that affect the intention of the farmers who have not adopted the Hazard Analysis and Critical Control Points (HACCP) system for the rearing phase of pig production to adopt this system in the future. The research model for this study was con structed based on strategic contingency theory, the theory of the diffusion of innovation, and the technology acceptance model (TAM). Using structural equation modeling with partial least squares (PLS), this study analyzes the effects of the intensity of competition, the environmental uncertainty, the innovativeness and self-efficacy of the individual farmers, and the impact of the credibility of the Agricultural Technology Service Center (ATSC), which acts as the principal agent of technology dissemination and as a leader of change, on the perceived usefulness of technology and the farmers' intention to adopt the system. The results of the analysis are as follows. First, with regard to the underlying factors affecting the intention to adopt the new system, the intensity of competition within the industry and the institutional credibility of the ATSC were inferred to underlie the perceived usefulness. Second, institutional credibility has a positive impact on the perceived usefulness of the system, and the perceived usefulness, in turn, has a positive impact on the intention to adopt. The perceived ease of use also has a positive impact on the intention to adopt. Because the factor that has the biggest impact on the intention of a farm to adopt is the credibility of the ATSC, it is crucial for extension organizations, such as the ATSC, to make greater efforts to promote the expansion of the HACCP system. Because farmers feel that the implementation of the HACCP system is an instrumental strategy for coping with the high intensity of competition within the industry, they attempt to gain a competitive edge through the production of safe livestock products.

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Free Radical Scavenging Activity and Ascorbate Content in Various Plant Cell Lines (다양한 식물배양세포주에서 자유라디칼 포착활성과 Ascorbate 함량)

  • AHN, Young-Ock;CHOI, Yong-Hwa;KWON, Seok-Yoon;LEE, Haeng-Soon;KIM, Suk-Won;PARK, Il-Hyun;KWAK, Sang-Soo
    • Korean Journal of Plant Tissue Culture
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    • v.25 no.5
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    • pp.289-293
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    • 1998
  • We investigated the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in methanol extracts of 64 cultured cell lines, which were derived from various plant species, and the ascorbate content in cell lines, which showed a high radical scavenging activity. Thirteen cell lines revealed the antioxidative activity (IC50) by methanol extracts of less than 50 mg in cell fresh wt. Of them, six cell lines showed the same Rf value as ascorbate on the DPPH sprayed silica gel TLC. The ascorbate content in cell lines of Rosa multiflora, Scutellaria baicalensis, and Achyranthes japonica showed 48.5, 30.3, and 16.8μg per g cell fresh wt by HPLC analysis, respectively. In callus cultures of S. baicalensis, the concentration of ascorbate reached a maximun (39±3.4μg/g cell fresh wt) on 30 days after subculture, which corresponded to the stationary growth phase, and subsequently decreased by successive culturing.

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Structural Evolution on Ag/Si(111) Ag/Si(111)√3X√3 with Adatom Coverage (흡착원자의 덮임율에 따른 Ag/Si(111)√3X√3의 구조 변화)

  • Jeong, Ho-Jin;Jeong, Suk-Min
    • Journal of the Korean Vacuum Society
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    • v.17 no.5
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    • pp.387-393
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    • 2008
  • Using a first-principles total-energy method, we investigate structural and energy changes on Ag/Si(111)3×3(3Ag hereafter) as the number of the additional Ag adatoms increases. The Ag coverage varies from 0.02 to 0.14 ML. Most Ag adatoms occupy the ST site, which is the center of small triangles of the substrate Ag layer that is composed of small and large triangles. One of the interesting adsorption features is that the adatoms immerse below the substrate layer. The total energy calculations show that the clusters become the most stable when the number of Ag atoms is three. This three-Ag cluster becomes the building block of the 21×21 phase that shows a large surface conductivity. The simulated STM images show that the adatoms look dark in filled-state images while bright in empty-state images. This suggests that the adatoms donate their charge to the substrate. The simulated STM images agree well with the experimental images.

Hydrolysis Activity of αGalactosidase from Bacillus licheniformis (Bacillus licheniformis로부터 생산된 αGalactosidase의 가수분해 활성)

  • Kim Hyun Suk;Lee Kyung-Seob;So Jae Ho;Yoon Ki-Hong
    • Korean Journal of Microbiology
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    • v.40 no.4
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    • pp.328-333
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    • 2004
  • The maximum productivity of αgalactosidase, capable of hydrolyzing completely αDl,6galactopyranosyl linkages within oligomeric substrates such as melibiose, raffinose and stachyose to liberate galactose residue, was reached to 718 mU/ml in the culture filtrate of Bacillus licheniformis at death phase. The αgalactosidase was identified to show different efficiencies for hydrolyzing the αgalactooligosaccharides according to analysis of reaction products by both TLC and quantification of the liberated reducing sugars. The enzyme was active on αgalactooligosaccharides in the order of melibiose, raffinose, and stachyose. Though the hydrolyzing activity of enzyme was faintly inhibited by reaction products such as galactose, glucose and sucrose with amounts of five folds more than the added substrates (20 mM), the largest inhibition of enzyme activity was caused by galactose among the end products. Unknown compound, which migrated slower than melibiose on TLC, was detected during hydrolysis reaction of melibiose, suggesting that the αgalactosidase has a glycosyl transferase activity. In addition, the enzyme was able to hydrolyze efficiently raffinose and stachyose existed in the soluble extract of soybean meal.

Magnetism of Amorphous Bulk (Sm1xPrx)Fe2 Alloys in a Low Magnetic Field (저자장에서 비정질 후막(Sm1xPrx)Fe2의 자성)

  • Kim, Jai-Young
    • Korean Journal of Materials Research
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    • v.5 no.8
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    • pp.913-920
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    • 1995
  • RFe2(R=rare earth) Laves Phase intermetallic compounds are one of the promising materials for magnetostrictive applications, due to large magnetostriction coefficients in the order of 103 . However, because RFe2intermetallic compounds have large magnetostriction constants as well as large magnetocrystalline anisotropy constants, a large external magnetic field is necessary to reach saturation magnetostriction. Hence researches on giant magnetostriction have been concentrated on producing materials exhibiting a high value of magnetostriction in a low magentic field. The main research trend of the giant magnetostriction to obtain the large value in the low magnetic filed, fortunately as the signs of magnetocrystalline anisotropy constans in RFe2intermetallic compounds alternate with the rare earth metals, has been to substitute the rare earth metal for others and hence to reduce the magnetocrystalline anisotropy energy. In addition, amorphous RFe2alloys have been researched. In this research, both of the methods which are substitution of the rare earth metal and amorphization in RFe2 intermetallic compounds are simultaneously conducted to obtain the large magnetostriction coefficient in the low external magnetic field. Among them, SmFe2and PrFe2are selected, and amorphized in substrate-free bulk state. Magnetism in amorphous bulk (Sm1x Prx) Fe2alloys is investigated in the low magnetic field.ld.

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Comparison of isoButoxycarbonyl derivatives, tert.-butyldimethylsilyl derivatives, with US EPA Method in the sensitivity of Alkylphenols, Chlorophenols, and Bisphenol A Potential field-screening applications of GC/MS-SIM (기체 크로마토그래피/질량분석기를 이용한 field-screening 적용을 위한 알킬페놀류, 클로로페놀류 및 비스페놀 A의 isoBOC 유도체, TBDMS 유도체와 US EPA 방법의 비교)

  • Kim, Hyub;Hong, Jong-Ki;Kim, Yong-Hwa;Kim, Kyoung-Rae
    • Analytical Science and Technology
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    • v.15 no.3
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    • pp.196-213
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    • 2002
  • The alkylphenols, chlorophenols and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring mode followed by three work-up methods for comparison; EPA method, isoBOC derivatization method and TBDMS derivatization method. Eleven phenols in water samples were extracted with dichloromethane. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives or tert.-butyldimethylsilyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The recoveries were 85.1~109.9% (EPA method) and 90.3~126.6% (isoBOC derivatization and TBDMS derivatization), respectively. The method detection limit of bisphenol A for SIM were 0.732 μg/ (EPA method), 0.002 μg/ (isoBOC derivatization) and 0.021 μg/ (TBDMS derivatization). The SIM responses were linear with the correlation coefficient varying 0.9755~0.9981 (isoBOC derivatization), and 0.9908~0.9996 (TBDMS derivatization). When these methods were applied to treated wastewater sample from a polyethylene plant, the concentrations of 11 phenols were below the method detection limit.

Production of δAminolevulinic Acid in Soybean Curd Wastewater by Rhodobacter capsulatus KK-10 (두부공업폐수에서 Rhodobacter capsulatus KK-10을 이용한 δAminolevulinic Acid의 생산)

  • Cheong, Dae-Yeol;Choi, Yang-Mun;Yang, Han-Chul;Cho, Hong-Yon
    • Applied Biological Chemistry
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    • v.40 no.6
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    • pp.556-560
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    • 1997
  • The removal efficiency of COD and the production of δaminolevulinic acid (ALA) were concurrently investigated for both purifying the soybean curd wastewater of high BOD and utilizing the wastewater as a renewable substrate of ALA production using Rhodobacter capsulatus KK-10. Its wastewater was a favorable media for the growth of photosynthetic bacteria in terms of its environmental characteristics having COD/BOD rate of 0.98, ratio of BOD : N : P=100 : 6 : 4, BOD/N ratio of 17.2, lactic acid of 1,080 ppm. Its COD value wastewater was decreased to 94% and dry cell weight was approached to about 1.2 g/l after cultivation of the photosynthetic bacteria for 4 days. By the addition of 15 mM levulinic acid (LA) into the wastewater at the middle log phase of cell growth, the amount of ALA secreted was 55 mg/l. The ALA production was considerably increased to 114 mg/l under the cultural condition of 15 mM supplementations of glycine and succinate with LA at the same period. Furthermore the maximum ALA production of 120 mg/l and COD removal efficiency of 92% were accomplished in the soybean curd wastewater enriched with one addition of 15 mM LA and three serial additions 15 mM ALA precursors.

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Development of Analytical Method for Picoxystrobin in Agricultural Commodities Using GC/ECD and GC/MS (GC/ECD와 GC/MS를 이용한 농산물 중 Picoxystrobin의 분석법 개발)

  • Kwon, Hye-Young;Kim, Chan-Sup;Park, Byung-Jun;Kim, Il-Hwan;Hong, Su-Myeong;Son, Kyung-Ae;Jin, Yong-Duk;Lee, Je-Bong;Im, Geon-Jae;Kim, Doo-Ho
    • Korean Journal of Environmental Agriculture
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    • v.31 no.2
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    • pp.146-151
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    • 2012
  • BACKGROUND: This study was conducted to develop analytical method for picoxystrobin in agricultural commodities using GC/ECD and GC/MS. METHODS AND RESULTS: Each steps of analytical method were optimized for determining picoxystrobin residues in various agricultural commodities. The developed methods include acetone extraction, n-hexane/saline water partition and florisil column chromatography for analysis of all samples (apple, potato, green pepper, hulled rice and soybean), and in addition to these steps, solid phase extraction (SPE) was used for analysis of green pepper and n-hexane/acetonitrile partition was used for analysis of hulled rice and soybean. The instrumental conditions were tested for quantitation in GC/ECD and for confirmation in GC/MS. Recovery was in the range of 86~109% with RSD 10.2% and the quantitation limits (LOQ) of method were 0.025 mg/kg in all agricultural commodities. CONCLUSION: The result showed that the developed method can be used to determine picoxystrobin residue in agricultural commodities.