• 제목/요약/키워드: dose intensity

검색결과 604건 처리시간 0.024초

$Mg_2SiO_4$ : Tb 소자의 기본 특성에 관한 연구 (A Study of Fundamental Characteristics for $Mg_2SiO_4$ : Tb Phosphor)

  • 박명환;박종삼;권덕문;이준일
    • 대한방사선기술학회지:방사선기술과학
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    • 제19권2호
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    • pp.79-83
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    • 1996
  • The thermoluminescence(TL) response in changing annealing condition, triboluminescence, and darkroom temperature for $Mg_2SiO_4$:Tb phosphor are examined. The experimental results are summerized as follows : 1. The uniformity of TL intensity is better In the disinfected $Mg_2SiO_4$ : Tb than in contaminated one. 2. The triboluminescence of $Mg_2SiO_4$ : Tb is almost not detected even if numbers of $Mg_2SiO_4$ : Tb falling are increased. 3. The fading effect of $Mg_2SiO_4$ : Tb is scarcely affected by freezing room. The followings are resulted from the study. The disinfected $Mg_2SiO_4$ : Tb phosphor should be used in the dose measurement and the immediate reading for $Mg_2SiO_4$ : Tb after exposure is better. And if the reading is not immediately taken, a law darkroom temperature for $Mg_2SiO_4$ : Tb storage is recommended.

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Membrane strip을 이용한 지질단백질 Cholesterol 측정시스템의 개발 (Development of Membrane Strip Assay System for Lipoprotein Cholesterol)

  • 신인수;백세환
    • KSBB Journal
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    • 제11권2호
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    • pp.140-150
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    • 1996
  • 가정용 혈중 cholesterol 측정시스템을 개발하고자, 그 성능을 조절할 수 었는 벤수들의 최적화가 수 행되었다. 시스템의 주요 구성성분은 분석에 요구되는 효소들 (cholesterol esterase, cholesterol oxidase, 그리고 horseradish peroxidase) 이 부동화된 nitrocellulose membrane strip과 비 이온세척제 (Tri­t ton X-1OO) 및 발색물질 (3,3'-diaminobenzidine) 이 포함된 시료운반용액이다. 시료와 운반용액이 훈 합된 수용액을 membrane의 하단으로부터 흡수시키 면 모세관현상에 의해 시료는 부통화된 효소층으로 전달되어 연속효소반응이 일어난다. 마지막 효소반 응에서 발색물질은 산화되고 그에 따라 cholesterol 농도에 비례한 특정색이 신호로써 발생된다. 그 신호세기에 대해 효소들의 부동화조건과 운반용액의 화학조성이 최적화되었다. 최적조건 하에서 구성된 측정시스템의 농도응탑곡선은 혈중 cholesterol 농도를 측정하기에 충분히 높은 민감도를 나타내었다.

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요통환자에서 중성어혈 약침 사용 용량에 따른 효과 (Dose dependent effects of Jungsongouhyul Pharmacopuncture on Low Back Pain)

  • 정만진;권오곤;우창훈;안희덕
    • 대한약침학회지
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    • 제14권2호
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    • pp.45-52
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    • 2011
  • Objectives : The object of this study is to analyse about Low Back Pain's intensity according to dosage of Jungsongouhyul pharmacopuncture. Method : Three groups were made with 15 patients in Po-Hang Oriental Hospital, which is affiliates to Daegu Haany University. They were observed August 1st, 2010 to September 30th. 2010. Each group was treated by based on acupuncture, herb and other therapy and differential dosage of Jungsongouhyul pharmacopuncture 0,4, 0.8, and 1.2cc. We had measured pain threshold and Visual Analog Scale during first week of their admission. The statistical analysis was performed by using the oneway ANOVA and Tukey's test. Result : Change of VAS was not statistically significant. Change of pain threshold was statistically significant. Multiple comparisons of pain threshold between the group1,2 was not statistically significant. Multiple comparisons of pain threshold between the group1,3 and group2,3 was statistically significant. Conclusions : Jungsongouhyul Pharmacopuncture 1.2cc was more effective than 0.4 and 0.8cc.

혈관내피세포의 산화적 손상에 대한 지황음자의 방어기전 연구 (Protective Effects of Jihwangeumja on Oxidative Stress-induced Injury of Human Umbilical Vein Endothelial Cells)

  • 정용준;장재호;이대용;이민구;전인철;정대영;이인;신선호;문병순
    • 대한한의학회지
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    • 제25권2호
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    • pp.173-183
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    • 2004
  • Objectives : Oxidative stress can induce negative responses such as growth inhibition or cell death by necrosis or apoptosis due to the intensity of the oxidative stress, as well as positive responses such as cellular proliferation or activation. We examined the effect of Jihwangeumja on this process. Methods and Results : We analyzed the influence of oxidative stress and agents that modify its effect in human umbilical vein endothelial cell (HUVEC). Oxidative stress was induced by $B_2O_2$. With induced oxidative stress the results obtained indicate that it has a harmful effect over cell function and viability, and that this effect is dose and time dependent. When oxidative stress increased, Jihwangeumja reduced cell damage and had protective functions. $B_2O_2$, induced the apoptosis of HUVEC through the activation of intrinsic caspases pathway as well as mitochondrial dysfunction. A significant increase in cell survival was observed in culture cells with oxidative stress when they were treated with Jihwangeumja. Conclusions : These results suggest that Jihwangeumja may be potentially useful to treat HUVEC against oxidative damages mediated by modulation of caspase protease and mitochondrial dysfunction.

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블루베리 듀크 추출물의 예쁜꼬마선충 내의 항산화 효과 (Anti-oxidative Effect of Blueberry Duke Extract in Caenorhabditis elegans)

  • 김준형;안창완;김영지;노윤정;김수진;정성엽;정도연;황인현;김대근
    • 생약학회지
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    • 제48권3호
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    • pp.219-225
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    • 2017
  • We investigated the anti-oxidative effect of the blueberry duke (Vaccinium corymbosum L., Ericaceae) ethanol extract in Caenorhabditis elegans model. The ethanol extract of blueberry duke showed relatively significant DPPH radical scavenging and superoxide quenching activities. To prove antioxidant activity of the extract, we checked the activities of superoxide dismutase (SOD), catalase, intracellular ROS, and oxidative stress tolerance in C. elegans. In addition, to verify if the increased stress tolerance of C. elegans by treating with the extract was due to regulation of stress-response genes, we checked SOD-3 expression using a transgenic strain. As a consequence, the blueberry duke ethanol extract increased SOD and catalase activities of C. elegans, and reduced intracellular ROS accumulation in a dose-dependent manner. Besides, blueberry duke ethanol extract-treated CF1553 worms showed higher SOD-3::GFP intensity.

삼백초 Ethyl acetate 분획물의 예쁜꼬마선충 내의 항산화 효과 (Anti-oxidative Effects of Ethyl acetate Fraction of Saururus chinensis in Caenorhabditis elegans)

  • 이은별;김준형;이재광;한순천;박현미;김대근
    • 생약학회지
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    • 제48권1호
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    • pp.63-69
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    • 2017
  • Saururus chinensis (Lour.) Baill. (Saururaceae) has been used as a traditional medicine for the treatment of dysuria, leukorrhea, eczema, jaundice and ascites in Korea, China and Japan. Ethanol extract of S. chinensis was successively partitioned as methylene chloride, ethyl acetate, n-butanol and $H_2O$ soluble fractions. Among those fractions the ethyl acetate soluble fraction showed the most potent DPPH radical scavenging and superoxide quenching activities. To verify antioxidant activities of ethyl acetate fraction, we checked the activities of superoxide dismutase (SOD) and catalase, and intracellular ROS level and oxidative stress tolerance in Caenorhabditis elegans. Furthermore, to see if increased stress tolerance of worms by treating of ethyl acetate fraction was due to regulation of stress-response gene, we quantified SOD-3 expression using transgenic strain. Consequently, ethyl acetate fraction elevated SOD and catalase activities of C. elegans, and reduced intracellular ROS accumulation in a dose-dependent manner. Moreover, ethyl acetate fraction-treated CF1553 worms exhibited significantly higher SOD-3::GFP intensity.

Toxic detection in mine water based on proteomic analysis of lysosomal enzymes in Saccharomyces cerevisiae

  • Nguyen, Ngoc-Tu;Kim, Yang-Hoon;Bang, Seung Hyuck;Hong, Ji Hye;Kwon, Soon Dong;Min, Jiho
    • Environmental Analysis Health and Toxicology
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    • 제29권
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    • pp.19.1-19.10
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    • 2014
  • Objectives Lysosome is the cell-organelle which is commonly used as biomonitoring tool in environmental pollution. In this study, the lysosomal proteomic of the yeast Saccharomyces cerevisiae was analyzed for utilization in the detection of toxic substances in mine water samples. Methods This work informs the expression of lysosomal proteomic in yeast in response with toxic chemicals, such as sodium meta-arsenite and tetracycline, for screening specific biomarkers. After that, a recombinant yeast contained this biomarker were constructed for toxic detection in pure toxic chemicals and mine water samples. Results Each chemical had an optimal dose at which the fluorescent protein intensity reached the peak. In the case of water samples, the yeast showed the response with sample 1, 3, 4, and 5; whereas there is no response with sample 2, 6, and 7. Conclusions The recombinant yeast showed a high ability of toxic detection in response with several chemicals such as heavy metals and pharmaceuticals. In the case of mine water samples, the response varied depending on the sample content.

혼탁매질에서 광분포에 관한 Monte Carlo 시뮬레이션 (Monte Carlo Simulation on Light Distribution in Turbid Material)

  • 김기준;성기천
    • 한국응용과학기술학회지
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    • 제15권4호
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    • pp.11-20
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    • 1998
  • The propagation of light radiation in a turbid medium is an important problem that confronts dosimetry of therapeutic laser delivery and the development of diagnostic spectroscopy. Scattered light is measured as a function of the position(distance r, depth z) between the axis of the incident beam and the detection spot. Turbid sample yields a very forward-directed scattering pattern at short range of position from source to detector, whereas the thicker samples greatly attenuated the on-axis intensity at long range of position. The portions of scattered light reflected from or transmitted throughphantom depend upon internal reflectance and absorption properties of the phantom. Monte Carlo simulation method for modelling light transport in tissue is applied. It uses the photon is moved a distance where it may be scattered, absorbed, propagated, internally reflected, or transmitted out of tissue. The photon is repeatedly moved until it either escape from or is absorbed by the phantom. In order to obtain an optimum therapeutic ratio in phantom material, optimum control the light energy fluence rate is essential. This study is to discuss the physical mechanisms determining the actual light dose in phantom. Permitting a qualitative understanding of the measurements. It may also aid in designing the best model for laser medicine and application of medical engineering.

Role of Regulators of G-Protein Signaling 4 in $Ca^{2+}$ Signaling in Mouse Pancreatic Acinar Cells

  • Park, Soon-Hong;Lee, Syng-Ill;Shin, Dong-Min
    • The Korean Journal of Physiology and Pharmacology
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    • 제15권6호
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    • pp.383-388
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    • 2011
  • Regulators of G-protein signaling (RGS) proteins are regulators of $Ca^{2+}$ signaling that accelerate the GTPase activity of the G-protein ${\alpha}$ -subunit. RGS1, RGS2, RGS4, and RGS16 are expressed in the pancreas, and RGS2 regulates G-protein coupled receptor (GPCR)-induced $Ca^{2+}$ oscillations. However, the role of RGS4 in $Ca^{2+}$ signaling in pancreatic acinar cells is unknown. In this study, we investigated the mechanism of GPCR-induced $Ca^{2+}$ signaling in pancreatic acinar cells derived from $RGS4^{-/-}$ mice. $RGS4^{-/-}$ acinar cells showed an enhanced stimulus intensity response to a muscarinic receptor agonist in pancreatic acinar cells. Moreover, deletion of RGS4 increased the frequency of $Ca^{2+}$ oscillations. $RGS4^{-/-}$ cells also showed increased expression of sarco/endoplasmic reticulum $Ca^{2+}$ ATPase type 2. However, there were no significant alterations, such as $Ca^{2+}$ signaling in treated high dose of agonist and its related amylase secretion activity, in acinar cells from $RGS4^{-/-}$ mice. These results indicate that RGS4 protein regulates $Ca^{2+}$ signaling in mouse pancreatic acinar cells.

The Association Between Occupational Exposure to Hand-Arm Vibration and Hearing Loss: A Systematic Literature Review

  • Weier, Michael H.
    • Safety and Health at Work
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    • 제11권3호
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    • pp.249-261
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    • 2020
  • Background: Hearing loss is one of the most prevalent worker health conditions worldwide. Although the effect of noise exposure on hearing is well researched, other workplace exposures may account for significant hearing loss. The aim of this review was to determine whether occupational hand-arm vibration exposure through use of power or pneumatic tools, independent of noise exposure, is associated with permanent hearing loss. Do workers suffer from hand-arm vibratione-induced hearing loss? Methods: Peer-reviewed articles published in English between 1981 and 2020 were identified through five online databases with five search keywords. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, including online database search methodology, study selection, article exclusion, and assessment of potential study design confounders and biases, were followed. Results: Database searches retrieved 697 articles. Fifteen articles that reported 17 studies met the criteria for review. All but two studies revealed statistically significant associations between occupational exposure to hand-arm vibration and hearing loss. The majority of the study results revealed associations between hand-arm vibration and hearing loss, independent of potential age and noise confounders. Conclusion: Few studies have examined the association between occupational exposure to hand-arm vibration and hearing loss. Dose response data were limited as only one study measured vibration intensity and duration. Although the majority of studies identified statistically significant associations, causal relationships could not be determined. Further research using standardized and uniform measurement protocols is needed to confirm whether the association between occupational exposure to hand-arm vibration and permanent hearing loss is causal and the mechanism(s).