The aim of the present study was to assess the patient-specific equivalent organ dose (HT) and effective dose (ED) delivered to individual patients from cardiovascular interventional radiology (CVIR) ...procedures and to compare these doses to those reported in the literature. The HT and EDs to 113 patients from two CVIR procedures: coronary angiography (CA) and percutaneous coronary interventions (PCI) were acquired from two major hospitals in Tanzania. The HT and EDs were estimated using the knowledge of the patient characteristics, patient related exposure parameters, geometry of examination, measurements of air kerma area product and Monte Carlo-based PCXMC software. The median HT in the present study for the lung, heart and oesophagus for the CA, were 47.1 mSv, 33.8 mSv, and 22.9 mSv, respectively, while for the PCI were 102.6 mSv, 77.5 mSv, and 51.9 mSv, respectively. The median values of ED as recommended by ICRP 103 for the CA and PCI procedures were 11.1 mSv and 24.7 mSv, respectively. The overall variations between individual EDs across the two hospitals differed by factors of up to 63.1 and 25.1, respectively for the CA and PCI procedures. The mean values of HT and EDs in the present study were, for the most part, higher than the reported values for India, Belgium and Italy, while comparable with those reported for Greece. The proposed diagnostic reference levels (DRLs) for the CA and PCI were for KAP 91.4 Gy cm2 and 129.4 Gy cm2, for fluoroscopy time 15.5 min and 28.4 min, for number of cine frames 791.5 and 1213.5, and ED 19.8 and 36.9 mSv, respectively. The observed wide range of exposure parameters and patient doses within and across the hospitals and the observed relatively high patient doses compared to those reported in the literature, call for the need to standardize examination protocols and optimise radiation dose to patients from CVIR procedures.
•Wide range of patient dose (HT and ED) within and across the hospitals were observed.•Mean values of KAP, HT and EDs were higher than the values reported from literature.•Proposed DRLs for CA and PCI were higher than reported DRLs from USA and Europe.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
AMoRE is an international project to search for the neutrinoless double beta decay of
100
Mo
using a detection technology consisting of magnetic microcalorimeters (MMCs) and molybdenum-based ...scintillating crystals. Data collection has begun for the current AMORE-I phase of the project, an upgrade from the previous pilot phase. AMoRE-I employs thirteen
48
depl
.
Ca
100
MoO
4
crystals and five
Li
2
100
MoO
4
crystals for a total crystal mass of 6.2 kg. Each detector module contains a scintillating crystal with two MMC channels for heat and light detection. We report the present status of the experiment and the performance of the detector modules.
Abstract
The second phase of the Advanced Mo-based Rare process
Experiment (AMoRE-II) searches for a neutrino-less double-beta decay
of
100
Mo. A background level in the region of interest of
3034 ± ...10 keV is required to be lower than 10
-4
count/(keV
kg year). Neutrons can generate background signals by gamma-ray
emitting reactions with AMoRE-II detector materials. Thermal neutron
shields will be installed inside and outside the lead shield to
reduce the neutron flux in the shielding system. The background
radioactivity of the inner thermal neutron shield must be low
because AMoRE-II requires a low background level. A thermal neutron
shield with a high shielding efficiency and low radioactivity was
produced by using boric acid powder and silicone rubber. The
shielding efficiency was tested to be
{99.2 ± 0.25(stat)
-0.53
+0.47
(syst)}%, and
the radioactivities of
40
K,
226
Ra,
228
Ac, and
228
Th were measured to be < 9.2 at 90% C.L., 14.2 ± 1.5,
< 1.6 at 90% C.L., and 2.83 ± 0.80 mBq/kg, respectively.
AMoRE-II is the second phase of the Advanced Molybdenum-based Rare process Experiment aiming to search for the neutrino-less double beta decay of 100Mo isotopes using ∼200 kg of molybdenum-containing ...cryogenic detectors. The AMoRE-II needs to keep the background level below 10−5 counts/keV/kg/year with various methods to maximize the sensitivity. One of the methods is to have the experiment be carried out deep underground free from the cosmic ray backgrounds. The AMoRE-II will run at Yemilab with ∼1,000 m depth. However, even in such a deep underground environment, there are still survived cosmic muons, which can affect the measurement and should be excluded as much as possible. A muon veto detector is necessary to reject muon-induced particles coming to the inner detector where the molybdate cryogenic detectors are located. We have studied the possibility of using an extruded plastic scintillator and wavelength shifting fiber together with SiPM as a muon veto system. We found that the best configuration is two layers of plastic scintillators (PSs, 150 cm × 25 cm × 1.2 cm) with two WLS fibers per groove, which could separate radiogenic gammas well with muon detection efficiency above 99.4% along the length of the PS. Based on the expected flux from a prototype measurement at a 700 m deep underground, we found that the dead time of the muon veto system for AMoRE-II at the Yemilab with a 1 ms veto window is 0.6% of whole muon events.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
AMoRE-II is the second phase of the Advanced Molybdenum-based Rare process Experiment aiming to search for the neutrino-less double beta decay of 100Mo isotopes using ~ 200 kg of ...molybdenum-containing cryogenic detectors. The AMoRE-II needs to keep the background level below 10-5 counts/keV/kg/year with various methods to maximize the sensitivity. One of the methods is to have the experiment be carried out deep underground free from the cosmic ray backgrounds. The AMoRE-II will run at Yemilab with ~ 1,000 m depth. However, even in such a deep underground environment, there are still survived cosmic muons, which can affect the measurement and should be excluded as much as possible. A muon veto detector is necessary to reject muon-induced particles coming to the inner detector where the molybdate cryogenic detectors are located. We have studied the possibility of using an extruded plastic scintillator and wavelength shifting fiber together with SiPM as a muon veto system. We found that the best configuration is two layers of plastic scintillators (PSs, 150 cm x 25 cm x 1.2 cm) with two WLS fibers per groove, which could separate radiogenic gammas well with muon detection efficiency above 99.4% along the length of the PS. Based on the expected flux from a prototype measurement at a 700 m deep underground, we found that the dead time of the muon veto system for AMoRE-II at the Yemilab with a 1 ms veto window is 0.6% of whole muon events.
The objective of this study was to evaluate the effect of subacute exposure to inhaled benzo(
a)pyrene (BaP) on fetal survival and luteal maintenance using timed-pregnant Fisher 344 rats. Prior to ...assignment of pregnant rats to treatment and control groups, numbers of implantation sites were determined on gestation day (GD) 8 via midventral laparotomy. Subsequently, animals were assigned randomly to three treatment groups and two control groups. Treatment consisted of subacute exposure of rats via inhalation to BaP 25, 75, and 100
μg/m
3, 4
h daily for 10 days (GD-11–20). Control animals were either sham exposed to carbon black (CB) to control for inert BaP carrier or remained unexposed (UNC). Blood samples were collected on days 15 and 17 of gestation via sinus orbital veini-puncture for plasma. Number of pups per litter was determined postpartum and fetal survival rate was expressed as a percentage of the corresponding implantation sites. Radioimmunoassays were used to determine plasma progesterone, estrogen, and prolactin (indirect measurement of decidual luteotropin) concentrations. Fetal survival among BaP-treated rats declined in a dose-dependent manner (25
μg/m
3, 78.3% per litter; 75
μg/m
3, 38.0% per litter; 100
μg/m
3, 33.8% per litter;
P<0.05) compared with CB (96.7% per litter) and UNC (98.9% per litter). Plasma progesterone, estrogen, and prolactin concentrations also declined as a result of subacute exposure of rats to BaP compared to controls. These data suggest that inhaled BaP compromised fetal survival and consequently luteotropic activity in the exposed animals.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
AMoRE is an international project to search for the neutrinoless double beta decay of \(^{100}\)Mo using a detection technology consisting of magnetic microcalorimeters (MMCs) and molybdenum-based ...scintillating crystals. Data collection has begun for the current AMORE-I phase of the project, an upgrade from the previous pilot phase. AMoRE-I employs thirteen \(^\mathrm{48depl.}\)Ca\(^{100}\)MoO\(_4\) crystals and five Li$_2$$^{100}\(MoO\)_4$ crystals for a total crystal mass of 6.2 kg. Each detector module contains a scintillating crystal with two MMC channels for heat and light detection. We report the present status of the experiment and the performance of the detector modules.
The objective of this study was to evaluate the effect of sub-acute exposure to inhaled benzo(
a)pyrene (BaP) on testicular steroidogenesis and epididymal function in Fisher 344 rats. Animals were ...assigned randomly to two control groups and one experimental group for each exposure regimen. Treatment consisted of sub-acute exposure of rats via inhalation to 25, 75, and 100
μg
BaP/m
3, 4
h daily for 10 days. Control animals were either exposed to carbon black (CB; sham) to control for inert BaP carrier or they remained unexposed (UNC). Blood samples were collected immediately after the cessation of exposures (time 0) and at 24, 48, and 72
h post-cessation of exposure, to assess the effect of bioavailable BaP on systemic testosterone and luteinizing hormone (LH) concentrations by radioimmunoassay (RIA). Progressive sperm motility of stored sperm (cauda epididymal sperm) was determined microscopically, while density of stored sperm was determined by hemocytometric counting. Progressive motility of stored sperm was reduced in rats exposed to 75 and 100
μg
BaP/m
3 compared with their counterparts that were exposed to 25
μg
BaP/m
3 or controls. Plasma testosterone concentrations declined as a result of exposure of rats to 75
μg
BaP/m
3 from 0 to 48
h post-termination of exposure compared with controls (
P<0.05; treatment×time interaction). This decrease was followed subsequently by a compensatory increase in the plasma concentrations of this steroid at 72
h post-cessation of exposures compared with previous time periods and controls (
P<0.05). Increases in the mean plasma LH concentrations were observed in rats exposed to 75
μg
BaP/m
3 compared with controls, throughout the time periods studied (
P<0.05; treatment×time interaction). These data suggest that sub-acute exposure to inhaled BaP contributes to reduced testosterone concentrations and consequently impaired epididymal function of exposed animals.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We report a study on the background of the Advanced Molybdenum-Based Rare process Experiment (AMoRE), a search for neutrinoless double beta decay (0νββ) of 100Mo. The pilot stage of the experiment ...was conducted using ∼1.9 kg of 48deplCa100MoO4 crystals at the Yangyang Underground Laboratory, South Korea, from 2015 to 2018. We compared the measured β/γ energy spectra in three experimental configurations with the results of Monte Carlo simulations and identified the background sources in each configuration. We replaced several detector components and enhanced the neutron shielding to lower the background level between configurations. A limit on the half-life of 0νββ decay of 100Mo was found at T1/20ν≥3.0×1023 years at 90% confidence level, based on the measured background and its modeling. Further reduction of the background rate in the AMoRE-I and AMoRE-II are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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