• 제목/요약/키워드: engineering

Search Result 346,363, Processing Time 0.321 seconds

Development of Dose Planning System for Brachytherapy with High Dose Rate Using Ir-192 Source (고선량률 강내조사선원을 이용한 근접조사선량계획전산화 개발)

  • Choi Tae Jin;Yei Ji Won;Kim Jin Hee;Kim OK;Lee Ho Joon;Han Hyun Soo
    • Radiation Oncology Journal
    • /
    • v.20 no.3
    • /
    • pp.283-293
    • /
    • 2002
  • Purpose : A PC based brachytherapy planning system was developed to display dose distributions on simulation images by 2D isodose curve including the dose profiles, dose-volume histogram and 30 dose distributions. Materials and Methods : Brachytherapy dose planning software was developed especially for the Ir-192 source, which had been developed by KAERI as a substitute for the Co-60 source. The dose computation was achieved by searching for a pre-computed dose matrix which was tabulated as a function of radial and axial distance from a source. In the computation process, the effects of the tissue scattering correction factor and anisotropic dose distributions were included. The computed dose distributions were displayed in 2D film image including the profile dose, 3D isodose curves with wire frame forms and dosevolume histogram. Results : The brachytherapy dose plan was initiated by obtaining source positions on the principal plane of the source axis. The dose distributions in tissue were computed on a $200\times200\;(mm^2)$ plane on which the source axis was located at the center of the plane. The point doses along the longitudinal axis of the source were $4.5\~9.0\%$ smaller than those on the radial axis of the plane, due to the anisotropy created by the cylindrical shape of the source. When compared to manual calculation, the point doses showed $1\~5\%$ discrepancies from the benchmarking plan. The 2D dose distributions of different planes were matched to the same administered isodose level in order to analyze the shape of the optimized dose level. The accumulated dose-volume histogram, displayed as a function of the percentage volume of administered minimum dose level, was used to guide the volume analysis. Conclusion : This study evaluated the developed computerized dose planning system of brachytherapy. The dose distribution was displayed on the coronal, sagittal and axial planes with the dose histogram. The accumulated DVH and 3D dose distributions provided by the developed system may be useful tools for dose analysis in comparison with orthogonal dose planning.

Understanding the Response Characteristics of X-ray Verification Film (X-선 Verification 필름의 반응 특성에 관한 연구)

  • Yeo Inhwan;Seong Jinsil;Chu Sung Sil;Kim Gwi Eon;Suh Chang Ok;Burch Sandra E.;Wang Chris K.
    • Radiation Oncology Journal
    • /
    • v.16 no.4
    • /
    • pp.505-515
    • /
    • 1998
  • Purpose : This study is intended to understand the sensitometric characteristics and the emulsion properties of the commercially available CEA TVS film in comparison with the Kodak X-Omat V film. Materials and Methods : For this purpose, we have formulated an analytic expression of the characteristic curves for x-ray film exposed to mixed radiation of electrons, photons, and visible light. This mathematical expression was developed based on reaction-rate and target-hit theories. Unlike previous expressions. it relates optical density to emulsion properties such as grain size and silver bromide content We have also developed a quantity which characterizes the film response to visible light relative to that to photons and electrons. This quantity could be expressed as a function of grain area. Thus, we have developed mathematical expressions and quantities with which the emulsion properties of the films can be revealed based on the sensitometric characteristics. Demonstrating the use of this analytical study, we exposed CEA and Kodak verification films to the mixed radiation of electrons, photons, and visible light, and interpreted the experimental results accordingly. Results : We have demonstrated that: (1) the saturation density increases as the silver bromide content increases, (2) the time required to reach the threshold dose (to which the film begins to respond) when films are exposed to visible light decreases as the grain size increases, and (3) the CEA film contains more silver bromide. whereas the Kodak film contains larger grains. These findings were supported by the data provided by the manufacturers afterward. Conclusion : This study presented an analytical and experimental basis for understanding the response of X-ray film with respect to the emulsion properties.

  • PDF

Characteristics of Phosphorus Accumulation in Rotation System of Plastic Film House and Paddy Soils (시설재배지에서 윤답전환체계가 인산분포에 미치는 영향)

  • Lee, Yong-Bok;Lee, In-Bog;Hwang, Jun-Young;Lee, Kyung-Dong;Kim, Pil-Joo
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.35 no.1
    • /
    • pp.47-58
    • /
    • 2002
  • Much of the plastic film house soils in the southern part of the Korean peninsula are managed using a upland-paddy rotation culture system (hereafter, RS) to prevent salt accumulation in soil. However, information on the effects of RS on soil properties and environmental conservation is limited. In order to determine the effects of RS on soil properties, 22 fields under RS and 20 fields under a non-rotation system (hereafter, NRS) in plastic film houses were selected in Chinju, in southern Korea, and the P distribution characteristics were investigated, including the chemical properties. The RS contributed to the removal of water-soluble salts in the surface layer and to the redistribution of organic matter evenly in the soil profile. In the AP horizon, available phosphorus levels were $1,611mg\;kg^{-1}$ in RS and $1,789mg\;kg^{-1}$ in NRS, which markedly exceeds the optimum range for plant cultivation. Total P was lower in RS (average $4,593mg\;kg^{-1}$) than in NRS (average $5,440mg\;kg^{-1}$) and this decrease was taken to be an effect of RS. Inorganic P was the predominant form of P in both systems, followed by organic P and residual P. A soil profile showed that total and inorganic P concentrations decreased with depth in both systems. However, organic P increased withdepth in RS, which was in contrast to that noted in NRS. The increase in organic P with depth in RS implied that organically rather than inorganically derived phosphate moved through the soil. The concentrations of water-soluble P, Ca-P and Al-P were higher in NRS than in RS soil profiles, but the Fe-P concentration was higher in RS than in NRS, which might be affected by the anaerobic conditions found in paddy soils. In both systems, the Al-P form of extractable P predominated in the surface layer, followed by Ca-P, Fe-P and water-soluble P. With increasing depth, the composition rate of Ca-P to extractable P decreased to less than 10% in the 60-70cm depth, as Fe-P dominated at this level. The content of water-soluble P, potentially the main source of eutrophication, was higher in NRS than in RS. These results indicated that the RS used in plastic film houses contributed to the removal of water-soluble salts but only slightly decreased the phosphate concentration.

Inhibitory effects of extracts from Smilacina japonica on lipopolysaccharide induced nitric oxide and prostaglandin E2 production in RAW264.7 macrophages (RAW264.7 대식세포에서 풀솜대 추출물의 nitric oxide 및 prostaglandin E2생성 저해효과)

  • Nam, Jung-Hwan;Seo, Jong-Taek;Kim, Yul-Ho;Kim, Ki-Deog;Yoo, Dong-Lim;Lee, Jong-Nam;Hong, Su-Young;Kim, Su-Jeong;Sohn, Hwang-Bae;Kim, Hyun-Sam;Kim, Bo-Sung;Lee, Kyung-Tea;Park, Hee-Jhun
    • Journal of Plant Biotechnology
    • /
    • v.41 no.4
    • /
    • pp.201-205
    • /
    • 2014
  • Smilacina japonica is a localized common rhizomatous flowering plant, This plant is often used in Korean traditional systems of medicine as a remedy for migrain, diplegia, physical impurity, blood circulation, abscess and contusion. Generally drugs that are used for arthritis have antinociceptive and anti-inflammatory properties. However, validity of the anti-inflammatory activity has not been scientifically investigated so far. Therefore, the aim of this study was to investigate the anti-inflammatory potential of S. japonica using the ethanolic extract and its subfractions. To evaluate the anti-inflammatory effects, we examined the inflammatory mediators such as nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) on RAW 264.7 macrophages. Our results indicated that hexane fraction significantly inhibited the LPS induced NO and $PGE_2$ production in the cells. The hexane fractions inhibitory activity for NO tests with $IC_{50}$ values showed in $53.3{\mu}g/ml$ and $PGE_2$ tests with $IC_{50}$ values showed at $32.5{\mu}g/ml$. Theseis result suggest a potential role of hexane fraction from S. japonica as source of anti-inflammatory agent.

Apoptotic Effect of Extract from Artemisia annua Linné by Akt/mTOR/GSK-3β Signal Pathway in Hep3B Human Hepatoma Cells (Hep3B 간암세포에서 개똥쑥추출물로부터 Akt-mTOR-GSK3β 신호경로에 의한 apoptosis 효과)

  • Kim, Eun Ji;Kim, Guen Tae;Kim, Bo Min;Lim, Eun Gyeong;Ha, Sung Ho;Kim, Sang-Yong;Kim, Young Min
    • Journal of Life Science
    • /
    • v.26 no.7
    • /
    • pp.764-771
    • /
    • 2016
  • Extracts from Artemisia annua Linné (AAE) have been known to possess various functions, including anti-bacterial, anti-virus, and anti-oxidant effects. However, the mechanism of those effects of AAE is not well-known. The aim of this study was to analyze the inhibitory effects of AAE on cell proliferation of the human hepatoma cell line (Hep3B) and to examine its effects on apoptosis. Activation by phosphorylation of Akt is cell proliferation through the phosphorylation of TSC2, mTOR, and GSK-3β. We suggested that AAE may exert cancer cell apoptosis through Akt/mTOR/GSK-3β signal pathways and mitochondria-mediated apoptotic proteins. For this, we examined the effects of extracts of AAE on cell proliferation according to treatment concentration. Treatment with AAE not only reduced cell viability, but also resulted in the induced release of lactate dehydrogenase (LDH). These results were determined with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) assay. Furthermore, we determined the effects of apoptosis through Hoechst 33342 staining, annexinⅤ-propidium iodide (PI) staining, 5,5′, 6,6′-tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide (JC-1) staining, and Western blotting. Our study showed that the treatment of liver cancer cells with AAE resulted in the inhibition of Akt, TSC2, GSK-3β-phosphorylated, Bcl-2, and pro-caspase 3 and the activation of Bim, Bax, Bak, and cleaved PARP expressions. These results indicate that AAE induced apoptosis by means of a mitochondrial event through the regulate of Akt/mTOR/GSK-3β signaling pathways.

Effects of Makgeolli and Makgeolli precipitate on Hepatotoxicity and Serum Lipid Content in Rats (막걸리와 막걸리 침전물이 간 독성 및 혈청 지질함량에 미치는 영향)

  • Kim, Bo Kyung;Kang, Min Sook;Jeon, Myeong-Jeong;Lee, Sang-Hyeon;Kim, Mihyang
    • Journal of Life Science
    • /
    • v.23 no.2
    • /
    • pp.282-289
    • /
    • 2013
  • This study was conducted to investigate the effect of Makgeolli and Makgeolli precipitate on hepatotoxity and the serum lipid content in rats. First, we investigated the effect of Makgeolli and ethanol on the progress of alcoholic fatty liver. The effect of Makgeolli precipitate on carbon tetrachloride ($CCl_4$)-induced hepatotoxicity in the rats was then studied. Indicators of the health status of the experimental period, the body weight gain in ethanol-treated group tended to be lower than those in the control and the Makgeolli-treated groups. The weight of the liver tissue decreased significantly following the administration of ethanol. However, this was not seen following the administration of Makgeolli. The activities of serum aspartate transaminase (AST) and alanine transaminase (ALT) were decreased in the Makgeolli group compared to the ethanol group. Serum cholesterol concentrations increased in the ethanol group, but decreased in the Makgeolli-treated group to an equal volume of the ethanol-treated group. The serum HDL-cholesterol content was significantly higher in the Makgeolli group than in the ethanol group. Analysis of the impact of the Makgeolli precipitate on toxicity induced by $CCl_4$ in the liver showed that the $CCl_4$ treatment significantly increased the activities of serum ALT and AST. However, the levels of cholesterol and triglyceride in serum were decreased. The $CCl_4$ treatment increased the activities of AST and ALT. However, the raw Makgeolli precipitate decreased their activities. Moreover, raw Makgeolli precipitate significantly reduced the $CCl_4$-induced elevation of serum lipids more than heated Makgeolli precipitate. These results suggest that raw Makgeolli precipitate may exert a protective effect against $CCl_4$-induced liver injury by preventing lipid peroxidation.

Changes in Soil Physical Properties of Peatmoss Containing Root Media as Influenced by Container Size and Packing Density (용기 크기와 충전밀도 차이에 따른 피트모스 혼합상토의 물리성 변화)

  • Park, Eun Young;Choi, Jong Myung;Lee, Dong Hoon
    • Horticultural Science & Technology
    • /
    • v.31 no.5
    • /
    • pp.558-564
    • /
    • 2013
  • The objective of this research was to secure the fundamental information in changes of soil physical properties as influenced by the compaction of root media during container filling. Three root media were formulated by blending peatmoss (PM) with expanded rice hull (PM + ERH, 8:2, v/v), carbonized rice hull (PM + CRH, 6:4) and ground and aged pine bark (PM + GAPB, 8:2). Based on the optimum bulk density, the amount of root media filled into 6.0, 7.5, 8.5, 10.5 and 12.5 cm were adjusted to 90, 100, 110, 120, and 130%, then the changes in total porosity (TP), container capacity (CC), and air-filled porosity (AFP) were measured. The TP decreased significantly as the packing amount of three root media were elevated in all sizes of container. The TP did not show significant differences among the root media in small sizes of containers, but showed significant differences when sizes of containers became larger. As packing amount of three root media were elevated, the CCs in all sizes of containers were decreased. The PM + CRH had the lowest CC among three root media in containers smaller than 8.5 cm, but had the highest CC in those larger than 10.5 cm. These results indicated that the decreases in CC were influenced by the sizes of containers as well as kinds of root media. The elevation of packing amount in three root media diminished significantly the AFP. The AFP in PM + GAPB medium was two times as high as those of PM + ERH or PM + CRH when equal packing densities were applied in all sizes of containers. As the container sizes became larger in three root media, the extents in decreasing of CC were distinct than those of AFP. Above results indicate that elevation in packing amount of three root media decreased significantly the TP, CC and AFP, but these were influenced differently by sizes of containers and kinds of root media. The results would be useful for expectation in the changes of physical properties in various sizes of containers filled with peatmoss based root media.

Developmental Abnormality in Agricultural Region and Toxicity of the Fungicide Benomyl on Korea salamander, Hynobius leechii (한국산 도롱뇽(Hynobius leechii)의 농경지에서의 배 발생 이상과 살균제 Benomyl의 독성효과)

  • Choi, Yeoung-Ju;Yoon, Chun-Sik;Park, Joo-Hung;Jin, Jung-Hyo;Cheong, Seon-Woo
    • Korean Journal of Ecology and Environment
    • /
    • v.35 no.3 s.99
    • /
    • pp.198-212
    • /
    • 2002
  • A numerical variation and abnormalities were studied on egg bags and embryos of Korean salamander, Hynobius leechii from agricultural habitat. The teratogenic and toxic effects of fungicide benomyl were also investigated with early embryos from non-agricultural habitat. We collected 144 egg bags from agricultural region, and 3418 of early embryos were contained. The lengths of egg bags were varied from 10 to 23 cm and the most frequent length was 19 cm. The number of embryos was varied from 7 to 43, and the most frequent range was 22 to 26. Spontaneous abnormalities were occurred in 406 embryos among 116 egg bags, and 24 kinds of external abnormalities were found. Individuals showing severe external defect were histologically studied and they showed optic dyspalsia, thyroid carcinoma, somatic muscular dysplasia, partial biaxial structure, decrease of red blood cells in the heart, cephalic degeneration and intestinal dysplasia. 385 embryos from non-agricultural region were exposed to 200 nM${\sim}$ 1 ${\mu}$M of benomyl at blastula or gastrula for 12 days. All embryo were dead in the concentration of 1 ${\mu}$M (LD$_{100}$) and 75% of embryos were dead in 800nM of benomyl. Speciflc effect due to benomyl was acrania or cephalic dysplasia and this restult suggests that the benomyl inhibit stongly to the development of neural tissue. These abnormal developments may be caused by antimitotic action, inhibition of tubulin complex, destruction of microtubule, inhibitions of neurulation and closing of neural fold, and by the inhibition of the movement of neural crest cells.

Analysis of Relationship between Spatial Distribution of Land Use and Water Quality in Agricultural Reservoirs (토지이용의 공간적 분포와 농업용저수지 수질 간의 상관분석)

  • Lee, Sae-Bom;Yoon, Chun-Gyeong;Jung, Kwang-Wook;Jang, Jae-Ho;Jeon, Ji-Hong
    • Korean Journal of Ecology and Environment
    • /
    • v.40 no.3
    • /
    • pp.481-488
    • /
    • 2007
  • This study covers the relationship between land use and water quality items. The kinds of land used in this study were almost agricultural areas with paddy fields and mountains. We set up zones at intervals of 200 m along 48 watersheds all over the country. The analysis showed high relationship between the water quality and the land use specially on the areas in the 400 m radius from the stream so that the areas needed to have strict managements. In the cases of residential area and upland, the positive correlation had a tendency to be lower when they were farther away from the stream. It depended on the increase of rainfall during July and August which affected on the water quality of reservoirs. The correlation analysis of paddy fields resulted in negative relationship, which indicated that paddy fields did not have negative effect on the quality of the stream. Through adequate irrigation and Management, paddy fields may be led to have positive effect on the quality of the reservoirs. In the case of forest, it also resulted in negative correlation so it was concerned as a positive factor which helped to improve water quality. Furthermore more than 00% of the land used in this study is comprised of forest so that it would have a positive effect on the reservoir management.

Dust Spatial Distribution and Emission of Tunnel Ventilated Windowless Broiler Building (터널환기 무창육계사의 분진크기별 분포와 배출농도에 관한 연구)

  • Choi, H.C.;Yeon, G.Y.;Spmg, J.I.;Kang, H.S.;Kwon, D.J.;Yoo, Y.H.;Yang, C.B.;Chun, S.S.;Kim, Y.K.
    • Journal of Animal Environmental Science
    • /
    • v.12 no.3
    • /
    • pp.115-122
    • /
    • 2006
  • This study investigated the spatial distribution of dust originating from tunnel-ventilated windowless broiler building measuring 12 m wide, 61 m long, with a side wall height of 3 m and a capacity of 16,982 birds. Dust concentrations in terms of total suspended particles (TSP), and particulate matter of sizes $10\;{\mu}m$(PM10), $2.5\;{\mu}m$(PM2.5), and $1\;{\mu}m(PM1)$ were measured at 30 minutes interval by using GRIMM Aerosol Monitor (GRIMM AEROSOL). The spatial distribution of dust showed the lower dust concentration in the inlet than in the outlet of the tunnel ventilation, and dust concentration decreasing as the dust size decreased, as follows: $317.9\;{\mu}g/m^3$ TSP; $74.7{\mu}m/m^3$ PM10; $9.7\;{\mu}g/m^3$ PM2.5; and $6.2\;{\mu}g/m^3$ PM1 in the inlet; and $2,678.5\;{\mu}g/m^3$ TSP; $555.5\;{\mu}g/m^3$ PM10; $33.3\;{\mu}g/m^3$ PM2.5; and $10.2\;{\mu}g/m^3$ PM1 in the outlet. The dust concentration emitted from the tunnel ventilated fan was $446.6\;{\mu}g/m^3$ TSP; $129.1\;{\mu}g/m^3$ PM10; $15.8\;{\mu}g/m^3$ PM2.5; and $6.1\;{\mu}g/m^3$ PM1 in the 3 meters from the fan and $25.1\;{\mu}g/m^3$ TSP; $8.8\;{\mu}g/m^3$ PM10; $5.6\;{\mu}g/m^3$ PM2.5; and $4.9\;{\mu}g/m^3$ PM1 in the 50 meters from the fan.

  • PDF