scholarly journals Minimum Detectable Activity of Pb-210 in Skull From In vivo Measurements: Insights From the Literature

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiangpeng Meng ◽  
Yuanyuan Liu ◽  
Bin Wu ◽  
Jianping Cheng ◽  
Li Wang ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Minimum Detectable Activity ◽  
Active Area ◽  
Semiconductor Detectors ◽  
Background Count ◽  
Radon Exposure ◽  
Detectable Activity ◽  
Retrospective Assessment ◽  
History Of

To address the urgent need for the retrospective assessment of the health conditions of people with a history of appreciable radon exposure, a novel technique that directly measures the characteristic γ-rays emitted from Pb-210 in the living skull was developed. Since the first pioneering study in 1968, this technique has experienced continued advancement over more than half a century, where the limit of detection of Pb-210 is a common criterion to assess the performance of the measuring devices. However, researchers have defined the limit of detection in assorted ways, and the measurement conditions often greatly differ from study to study, both of which significantly challenge interstudy comparisons and obscure how various factors make their impacts. In this work, we reanalyze the reported results in the literature according to the minimum detectable activity (MDA) defined by Currie and investigate the effects of key elements therein. Firstly, we focus on the reported background count rates and analyze their dependence on detector’s energy resolution and active area. Secondly, we turn to the reported calibration factors and conduct analysis in the same manner. Thirdly, we calculate MDA for each study and monitor its dependence on the active area of detector and measurement duration. In the limit of the largest achievable active area (∼75000 mm2), it is found that the asymptotic MDA is approximately 6 (4) Bq and 15 (11) Bq under 30 (60) min measurement using NaI-CsI scintillator and HPGe semiconductor detectors, respectively. Finally, we discuss these asymptotic MDA in the context of estimated Pb-210 activity in the skull resulted from a hypothetical history of radon exposure.

scholarly journals Precision Measurements of the Minimum Detectable Activity of Radionuclides by Plastic Scintillators for Radiation Monitoring

2019 ◽  
pp. 3-9
Author(s):  
B. Grynyov ◽  
N. Gurdzhian ◽  
O. Zelenskaya ◽  
V. Lyubynskiy ◽  
N. Molchanova ◽  
...  
Keyword(s):  
Count Rate ◽  
Statistical Processing ◽  
Sensitivity Coefficient ◽  
Minimum Detectable Activity ◽  
National Academy Of Sciences ◽  
Background Count ◽  
Background Count Rate ◽  
Energy Radiation ◽  
Detectable Activity ◽  
Plastic Scintillators

This work is devoted to the precision evaluation of the minimum detectable activity (MDA) measurement of gamma radiation radionuc­lides 137Cs and 60Co using plastic scintillators (PS). Scintillators are part of the detectors, which are sensitive elements of radiation portal moni­tors (PM). PS were produced at the Institute for scintillation materials of the National Academy of Sciences of Ukraine (ISMA NAS of Ukraine). The evaluation was generate in accordance with State standard of Ukraine ISO 5725-2:2005 [1] through statistical processing of experi­mental material. This made it possible to take into account the factors that determine the scattering of results without a model equation. Influence of PS sizes, energy radiation detected and distance from PS to the source of ionizing radiation (SIR) on the value of MDA precision measurement was studied. Precision coefficients of radionuclides MDA measurement evalua­ted when changing PS sizes from 500×300×50 mm (7500 cm3) up to 500×500×50 mm (12500 cm3), changing the energy radiation detected from 662 keV (137Cs) until 1332 keV (60Co), changing the distance from the PS to SIR from 10 to 50 cm. The results are presen­ted in Fig. 6—9 and Table. Found, that the greatest contribution to the increase in MDA precision coefficient measurements makes a change in the irradia­tion geometry. It is shown that when distance from PS to SIR increases from 10 to 50 cm, precision values increase: when registering 137Cs, from 3,9 to 7,0 % (V = 7500 cm3) and from 3,6 to 6,3 % (V = 12500 cm3); when registering 60Co, from 3,1 to 4,3 % (V = 7500 cm3) and from 3,2 to 3,8 % (V = 12500 cm3). It is established, that the obtained results are due to the change in the contribution of background count rate to PS count rate under different measurements conditions. This contribution affects on the value of sensitivity coefficient and consequently on the value of MDA and precision coefficient.

Biological NMR Spectroscopy

1997 ◽  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
State Of The Art ◽  
Critical Assessment ◽  
Resonance Spectroscopy ◽  
History Of ◽  
Structure Of Proteins

This book presents a critical assessment of progress on the use of nuclear magnetic resonance spectroscopy to determine the structure of proteins, including brief reviews of the history of the field along with coverage of current clinical and in vivo applications. The book, in honor of Oleg Jardetsky, one of the pioneers of the field, is edited by two of the most highly respected investigators using NMR, and features contributions by most of the leading workers in the field. It will be valued as a landmark publication that presents the state-of-the-art perspectives regarding one of today's most important technologies.

scholarly journals Absence of Detectable Radionuclides in Breast Milk in Sendai, Japan in 2012 Even by High-Sensitivity Determination: Estimated Dose among Infants after the Fukushima Nuclear Disaster

2021 ◽  
Vol 18 (11) ◽  
pp. 5825
Author(s):  
Zhaoqing Lyu ◽  
Sani Rachman Soleman ◽  
Tomoko Fujitani ◽  
Yukiko Fujii ◽  
Manal A. M. Mahmoud ◽  
...  
Keyword(s):  
Breast Milk ◽  
High Sensitivity ◽  
Minimum Detectable Activity ◽  
Activity Level ◽  
Internal Exposure ◽  
Dietary Intakes ◽  
Detectable Activity ◽  
Nuclear Disaster ◽  
Exposure Limit ◽  
Fukushima Nuclear Disaster

The aim of this study was to estimate radionuclide levels in breast milk and the transferred dose to their infants in Sendai (100 km from Fukushima), Japan after the 2011 Fukushima nuclear disaster. Radionuclide concentrations were analyzed in 101 specimens of breast milk collected in 2012. Median values for minimum detectable activities were 0.39, 0.34, 1.1, 1.89, and 17.1 Bq/kg for 137Cs, 134Cs, 131I, 110mAg, and 40K, respectively. Only radionuclides from 40K were detected. To estimate potential exposure and radiocesium dose, we assumed that the samples contained each minimum detectable activity level. The mean minimum detectable activity concentrations (standard deviation) of 137Cs and 134Cs were 0.42 (0.15) and 0.37 (0.14) Bq/kg, respectively. Means of estimated dietary intakes of 137Cs and 134Cs among infants were 0.35 (0.12) and 0.31 (0.11) Bq/day, respectively. The committed effective doses of radiocesium in infants aged 3 and 12 months via breastmilk were estimated at 5.6 (2.1) and 3.3 (1.2) μSv/year, respectively. Dietary intakes of 137Cs and 134Cs in breastfeeding mothers were back-calculated at 1.9 (0.71) and 1.7 (0.65) Bq/day, respectively. The study verified no discernible exposure to radionuclides among infants. The most conservative estimates were below the Japanese internal exposure limit of 1 mSv/year.

A Useful Diagnostic Method for Drug-induced Pneumonitis

1994 ◽  
Vol 22 (03n04) ◽  
pp. 329-336 ◽  
Author(s):  
Akira Kawasaki ◽  
Yutaka Mizushima ◽  
Hitoshi Kunitani ◽  
Masanobu Kitagawa ◽  
Masashi Kobayashi
Keyword(s):  
Bronchoalveolar Lavage Fluid ◽  
Challenge Test ◽  
Lavage Fluid ◽  
Peripheral Blood Lymphocytes ◽  
Lymphocyte Stimulation Test ◽  
Drug Induced ◽  
Chief Complaints ◽  
History Of ◽  
Chest X Ray

A 51 year-old male was admitted to our hospital with chief complaints of fever, dry cough and dyspnea. Chest X -ray films and his history of taking Chinese medicine for liver dysfunction were suggestive of drug-induced pneumonitis. Lymphocyte stimulation test (LST) to causative Chinese medical drugs of Sho-saiko-to and Dai-saiko-to was negative with peripheral blood lymphocytes (PBL), but was positive with Iymphocytes from bronchoalveolar lavage fluid (BALF). In vivo challenge test for Sho-saiko-to was positive. The LST with BALF-lymphocytes proved to be very useful in making a diagnosis of drug-induced pneumonitis.

The use of SSNTDS in the retrospective assessment of radon exposure in high radon rural communities in Yugoslavia

1999 ◽  
Vol 31 (1-6) ◽  
pp. 343-346 ◽  
Author(s):  
Z.S. Zunic ◽  
J.P. Mc Laughlin ◽  
C. Walsh ◽  
R. Benderac
Keyword(s):  
Rural Communities ◽  
Radon Exposure ◽  
Retrospective Assessment

Severe Hemolytic Reaction Due to Anti-JK3

1999 ◽  
Vol 123 (10) ◽  
pp. 949-951
Author(s):  
Carol S. Marshall ◽  
Denis Dwyre ◽  
Robin Eckert ◽  
Liisa Russell
Keyword(s):  
The United States ◽  
Cell Phenotype ◽  
Prior History ◽  
Ethnic Variability ◽  
Hemolytic Transfusion Reaction ◽  
History Of ◽  
Rare Phenotype ◽  
Antibody Screen

Abstract A 35-year-old gravida 3, para 3 Filipino woman with a negative antibody screen, no prior history of transfusion, and no hemolytic disease of the newborn in her children suffered a massive postpartum hemorrhage requiring transfusion. A severe hemolytic transfusion reaction occurred 5 days after delivery. Subsequently, a panagglutinin on a routine antibody identification panel was identified as anti-Jk3. The patient's red blood cell phenotype was Jk(a−b−) and all of her children were Jk(a−b+), yet the antibody that formed reacted with equal strength against all Jka- or Jkb-positive cells. The rare Jk(a−b−) phenotype is more common in Polynesians. Anti-Jk3, like other Kidd system antibodies, is difficult to detect because in vivo production may be absent between provocative episodes and because these antibodies often show weak in vitro reactions. The increasing numbers of Pacific Islanders in the United States could result in more frequent encounters with this rare phenotype. Increased awareness of ethnic variability in blood phenotypes and of the capricious nature of Kidd antibodies can help pathologists and technologists deal more effectively with these cases.

Serological biomarkers of zearalenone exposure in beef heifers receiving anti-mycotoxin additive

2020 ◽  
pp. 1-10
Author(s):  
C. Tonini ◽  
M.S. Oliveira ◽  
E.B. Parmeggiani ◽  
D.A.F. Sturza ◽  
A.O. Mallmann ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Biological Fluids ◽  
Basal Diet ◽  
Beef Heifers ◽  
Efficacy Evaluation ◽  
Limit Of Quantification ◽  
In Vivo Measurement ◽  
Significant Difference ◽  
Serological Biomarkers

The inclusion of anti-mycotoxin additives (AMA) in the diet of production animals has been widely used to avoid mycotoxin exposure. In order to confirm the efficacy of such products in vivo, measurement of mycotoxins and/or their metabolites in biological fluids is preconized. This study aimed at determining the serological biomarkers of zearalenone (ZEN), α-zearalenol, β-zearalenol, α-zearalanol, β-zearalanol (β-ZAL) and zearalanone, to evaluate the efficacy of an AMA in beef heifers. The trial lasted 37 days: 11 days of adaptation, 21 days of actual experiment, and 5 days of regression. Twenty-four heifers were randomly assigned to receive one of the following treatments (n=6/group): (T1) basal diet (control); (T2) basal diet + 5 mg/kg of ZEN; (T3) basal diet + 5 mg/kg of ZEN + 2.5 kg/t of AMA; and (T4) basal diet + 5 mg/kg of ZEN + 5.0 kg/t of AMA. Blood sampling was performed on different days after the diet was given. The samples were centrifuged to obtain the blood serum, and then analysed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). β-ZAL was detected above the limit of quantification both in the unconjugated (>0.60 ng/ml) and conjugated (>0.90 ng/ml) forms. The remaining metabolites presented concentrations under the limit of detection. In the efficacy evaluation of the AMA, there was no significant difference (P>0.05) between the treatments with and without additive at the tested levels of inclusion. Thus, β-ZAL may be employed as a biomarker of ZEN exposure via diet to evaluate the efficacy of an AMA through serological parameters. The technique applied in this study proved to be an adequate alternative for in vivo confirmation of the efficacy of products in adsorbing the toxin.

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