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Fulltext Preparation, Optimisation, and In Vitro Evaluation of [18F]AlF-NOTA-Pamidronic Acid for Bone Imaging PET

Hassan H, Othman MF, Abdul Razak HR, Zakaria ZA, Ahmad Saad FF, Osman MA, et al.

Molecules, 2022 Nov 17;27(22).
PMID: 36432069 DOI: 10.3390/molecules27227969

[18F]sodium fluoride ([18F]NaF) is recognised to be superior to [99mTc]-methyl diphosphate ([99mTc]Tc-MDP) and 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) in bone imaging. However, there is concern that [18F]NaF uptake is not cancer-specific, leading to a higher number of false-positive interpretations. Therefore, in this work, [18F]AlF-NOTA-pamidronic acid was prepared, optimised, and tested for its in vitro uptake. NOTA-pamidronic acid was prepared by an N-Hydroxysuccinimide (NHS) ester strategy and validated by liquid chromatography-mass spectrometry analysis (LC-MS/MS). Radiolabeling of [18F]AlF-NOTA-pamidronic acid was optimised, and it was ensured that all quality control analysis requirements for the radiopharmaceuticals were met prior to the in vitro cell uptake studies. NOTA-pamidronic acid was successfully prepared and radiolabeled with 18F. The radiolabel was prepared in a 1:1 molar ratio of aluminium chloride (AlCl3) to NOTA-pamidronic acid and heated at 100 °C for 15 min in the presence of 50% ethanol (v/v), which proved to be optimal. The preliminary in vitro results of the binding of the hydroxyapatite showed that [18F]AlF-NOTA-pamidronic acid was as sensitive as [18F]sodium fluoride ([18F]NaF). Normal human osteoblast cell lines (hFOB 1.19) and human osteosarcoma cell lines (Saos-2) were used for the in vitro cellular uptake studies. It was found that [18F]NaF was higher in both cell lines, but [18F]AlF-NOTA-pamidronic acid showed promising cellular uptake in Saos-2. The preliminary results suggest that further preclinical studies of [18F]AlF-NOTA-pamidronic acid are needed before it is transferred to clinical research.

Matched MeSH terms: Fluorine Radioisotopes*
2021 Asia-Pacific Graves' Disease Consortium Survey of Clinical Practice Patterns in the Management of Graves' Disease

Parameswaran R, de Jong MC, Kit JLW, Sek K, Nam TQ, Thang TV, et al.

Endocrine, 2023 Jan;79(1):135-142.
PMID: 36129592 DOI: 10.1007/s12020-022-03193-7

AIM: Although Graves' disease (GD) is common in endocrine practices worldwide, global differences in diagnosis and management remain. We sought to assess the current practices for GD in countries across Asia and the Pacific (APAC), and to compare these with previously published surveys from North America and Europe.
METHODS: A web-based survey on GD management was conducted on practicing clinicians. Responses from 542 clinicians were received and subsequently analysed and compared to outcomes from similar surveys from other regions.
RESULTS: A total of 542 respondents participated in the survey, 515 (95%) of whom completed all sections. Of these, 86% were medical specialists, 11% surgeons, and 3% nuclear medicine physicians. In addition to serum thyroid-stimulating hormone (TSH) and free thyroxine assays, most respondents would request TSH-receptor autoantibody (TRAb) measurement (68%) during initial work-up. Thyroid ultrasound is requested by about half of respondents (53%), while the use of nuclear medicine scans is limited. The preferred first-line treatment is anti-thyroid drug (ATD) therapy (79%) with methimazole (MMI) or carbimazole (CBZ), followed by radioiodine (RAI; 19%) and surgery (2%). In case of surgery, one-third of respondents would opt for a subtotal rather than a total thyroidectomy. In case of mild Graves orbitopathy (GO), ATDs (67%) remains the preferred treatment, but a larger proportion of clinicians prefer surgery (20%). For a patient with intention to conceive, the preferred treatment pattern remained unchanged, although propylthiouracil (PTU) became the preferred ATD-agent during the first trimester. In comparison to European and American practices, marked differences were noted in the relatively infrequent usage of nuclear medicine scans and the overall higher use of a ATDs and β-blockers and adjunctive ATD-treatment during RAI in the APAC-group.
CONCLUSION: Although regional differences regarding the diagnosis and management of GD are apparent in this first pan-Asia-Pacific survey, this study reveals the overall approach to the management of this disease in Asia-Pacific generally tends to fall between the trends appreciated in the American and European cohorts.

Matched MeSH terms: Iodine Radioisotopes/therapeutic use
Vertical distributions of radionuclides along the tourist-attractive Marayon Tong Hill in the Bandarban district of Bangladesh

Siraz MMM, Roy D, Dewan MJ, Alam MS, A M J, Rashid MB, et al.

Environ Monit Assess, 2023 Feb 10;195(3):382.
PMID: 36759352 DOI: 10.1007/s10661-023-10921-7

This is the first attempt in the world to depict the vertical distribution of radionuclides in the soil samples along several heights (900 feet, 1550 feet, and 1650 feet) of Marayon Tong hill in the Chittagong Hill Tracts, Bandarban by HPGe gamma-ray spectrometry. The average activity concentrations of 232Th, 226Ra, and 40K were found to be 37.15 ± 3.76 Bqkg-1, 19.69 ± 2.15 Bqkg-1, and 347.82 ± 24.50 Bqkg-1, respectively, where in most cases, 232Th exceeded the world average value of 30 Bqkg-1. According to soil characterization, soils ranged from slightly acidic to moderately acidic, with low soluble salts. The radium equivalent activity, outdoor and indoor absorbed dose rate, external and internal hazard indices, external and internal effective dose rates, gamma level index, and excess lifetime cancer risk were evaluated and found to be below the recommended or world average values; but a measurable activity of 137Cs was found at soils collected from ground level and at an altitude of 1550 feet, which possibly arises from the nuclear fallout. The evaluation of cumulative radiation doses to the inhabitants via periodic measurement is recommended due to the elevated levels of 232Th.This pioneering work in mapping the vertical distribution of naturally occurring radioactive materials (NORMs) can be an essential factual baseline data for the scientific community that may be used to evaluate the variation in NORMs in the future, especially after the commissioning of the Rooppur Nuclear Power Plant in Bangladesh in 2024.

Matched MeSH terms: Potassium Radioisotopes/analysis
Kinetic properties of 137Cs uptake by the cesium-accumulating eustigmatophycean microalga

Khudzari J, Fukuda SY, Shiraiwa Y, Iwamoto K

Environ Sci Pollut Res Int, 2023 Mar;30(12):34460-34467.
PMID: 36509956 DOI: 10.1007/s11356-022-24573-6

Cesium-137 (137Cs) is one of the radioactive substances that was released into the environment as a result of the Fukushima nuclear disaster. Radiocesium exposure is of great concern due to its potential environmental implications. However, research on 137Cs removal using algae is still limited. This is the first report to describe the kinetic properties of 137Cs uptake by Vacuoliviride crystalliferum in the presence and absence of potassium. In this work, we studied the kinetic properties of 137Cs uptake using a freshwater microalga, V. crystalliferum (NIES 2860). We also analyzed the effects of temperature, light, and potassium (K) on the 137Cs uptake. Results showed that V. crystalliferum can remove up to 90% of 157 nM 137Cs within an hour. At 20 °C, the removal increased by up to 96%, compared to less than 10% at 5 °C. However, the removal was inhibited by nearly 90% in the dark compared to the removal in the light, implying that V. crystalliferum cells require energy to accumulate 137Cs. In the inhibition assay, K concentrations ranged from 0 to 500 µM and the inhibitory constant (Ki) for K was determined to be 16.7 µM. While in the uptake assay without potassium (- K), the Michaelis constant (Km) for Cs was 45 nM and increased to 283 nM by the addition of 20 µM potassium (+ K), indicating that V. crystalliferum had a high affinity for 137Cs. In addition, the maximum uptake velocity (Vmax) also increased from 6.75 to 21.10 nmol (mg Chl h)-1, implying the existence of Cs active transport system. In conclusion, V. crystalliferum is capable of removing radioactive 137Cs from the environment and the removal was favorable at both normal temperature and in the light.

Matched MeSH terms: Cesium Radioisotopes/analysis
Evaluation of radioactivity in soil and rock samples from an undiscovered sea beach in the southeastern coastline of Bangladesh and associated health risk

Siraz MMM, Kamal MH, Khan ZH, Alam MS, Al Mahmud J, Rashid MB, et al.

Environ Monit Assess, 2023 Aug 10;195(9):1028.
PMID: 37558890 DOI: 10.1007/s10661-023-11636-5

This study marks the first-ever assessment of radiological hazards linked to the sands and rocks of Patuartek Sea Beach, situated along one of the world's longest sea beaches in Cox' Bazar of Bangladesh. Through the utilization of an HPGe detector, a comprehensive analysis of the activity concentrations of 226Ra, 232Th, and 40 K was conducted, and their activity ranged from 7 to 23 Bq/kg, 9-58 Bq/kg, and 172-340 Bq/kg, respectively, in soils, and 19-24 Bq/kg, 27-39 Bq/kg, and 340-410 Bq/kg, respectively, in rocks. Some sand samples exhibited elevated levels of 232Th, while the rock samples displayed higher levels of 40 K compared to the global average. The radiological hazard parameters were assessed, and no values surpassed the recommended limits set by several international organizations. Hence, the sands and rocks of Patuartek sea beach pose no significant radiological risk to the residents or tourists. The findings of this study provide crucial insights for the development of a radiological baseline map in the country, which is important due to the commissioning of the country's first nuclear power plant Rooppur Nuclear Power Plant. The data may also stimulate interest in the rare-earth minerals present in the area, which is important for the electronics industry, thorium-based nuclear fuel cycles.

Matched MeSH terms: Potassium Radioisotopes/analysis
Functional expression, purification, biochemical and biophysical characterizations, and molecular dynamics simulation of a histidine acid phosphatase from Saccharomyces cerevisiae

Nezhad NG, Jamaludin SZB, Rahman RNZRA, Yahaya NM, Oslan SN, Shariff FM, et al.

World J Microbiol Biotechnol, 2024 Apr 17;40(6):171.
PMID: 38630327 DOI: 10.1007/s11274-024-03970-8

A histidine acid phosphatase (HAP) (PhySc) with 99.50% protein sequence similarity with PHO5 from Saccharomyces cerevisiae was expressed functionally with the molecular mass of ∼110 kDa through co-expression along with the set of molecular chaperones dnaK, dnaJ, GroESL. The purified HAP illustrated the optimum activity of 28.75 ± 0.39 U/mg at pH 5.5 and 40 ˚C. The Km and Kcat values towards calcium phytate were 0.608 ± 0.09 mM and 650.89 ± 3.6 s- 1. The half-lives (T1/2) at 55 and 60 ˚C were 2.75 min and 55 s, respectively. The circular dichroism (CD) demonstrated that PhySc includes 30.5, 28.1, 21.3, and 20.1% of random coils, α-Helix, β-Turns, and β-Sheet, respectively. The Tm recorded by CD for PhySc was 56.5 ± 0.34˚C. The molecular docking illustrated that His59 and Asp322 act as catalytic residues in the PhySc. MD simulation showed that PhySc at 40 ˚C has higher structural stability over those of the temperatures 60 and 80 ˚C that support the thermodynamic in vitro investigations. Secondary structure content results obtained from MD simulation indicated that PhySc consists of 34.03, 33.09, 17.5, 12.31, and 3.05% of coil, helix, turn, sheet, and helix310, respectively, which is almost consistent with the experimental results.

Matched MeSH terms: Radioisotopes*
Fulltext Evidence of Enriched, Hadean Mantle Reservoir from 4.2-4.0 Ga zircon xenocrysts from Paleoarchean TTGs of the Singhbhum Craton, Eastern India

Chaudhuri T, Wan Y, Mazumder R, Ma M, Liu D

Sci Rep, 2018 May 04;8(1):7069.
PMID: 29728630 DOI: 10.1038/s41598-018-25494-6

Sensitive High-Resolution Ion Microprobe (SHRIMP) U-Pb analyses of zircons from Paleoarchean (~3.4 Ga) tonalite-gneiss called the Older Metamorphic Tonalitic Gneiss (OMTG) from the Champua area of the Singhbhum Craton, India, reveal 4.24-4.03 Ga xenocrystic zircons, suggesting that the OMTG records the hitherto unknown oldest precursor of Hadean age reported in India. Hf isotopic analyses of the Hadean xenocrysts yield unradiogenic 176Hf/177Hfinitial compositions (0.27995 ± 0.0009 to 0.28001 ± 0.0007; ɛHf[t] = -2.5 to -5.2) indicating that an enriched reservoir existed during Hadean eon in the Singhbhum cratonic mantle. Time integrated ɛHf[t] compositional array of the Hadean xenocrysts indicates a mafic protolith with 176Lu/177Hf ratio of ∼0.019 that was reworked during ∼4.2-4.0 Ga. This also suggests that separation of such an enriched reservoir from chondritic mantle took place at 4.5 ± 0.19 Ga. However, more radiogenic yet subchondritic compositions of ∼3.67 Ga (average 176Hf/177Hfinitial 0.28024 ± 0.00007) and ~3.4 Ga zircons (average 176Hf/177Hfinitial = 0.28053 ± 0.00003) from the same OMTG samples and two other Paleoarchean TTGs dated at ~3.4 Ga and ~3.3 Ga (average 176Hf/177Hfinitial is 0.28057 ± 0.00008 and 0.28060 ± 0.00003), respectively, corroborate that the enriched Hadean reservoir subsequently underwent mixing with mantle-derived juvenile magma during the Eo-Paleoarchean.

Matched MeSH terms: Gallium Radioisotopes
Fulltext Physical and mechanical properties of thin paper sheets made from onion peels (Allium cepa)

Mohammad Harris M. Yahya, Normala Hassim, Mohd Rozi Ahmad

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2020;8(2):15-21.
MyJurnal

The present work deals with the production of paper materials from onion peels (Allium Cepa) fibers
as an alternative potential non-wood fiber. The onion peels were obtained from a local small and
medium food industry. The onion peels were cooked at 120, 150 and 180 minutes. The peels were
grinded and poured in a set of mould and deckle for the formation of a thin sheet of paper. The
physical, mechanical, morphological characteristics and water rise capillary values (KLEMM
Method) were evaluated to determine its suitability for a paper material. The results show that the
increase in cooking time from 120 to 180 minutes resulted in an increase in the tensile index from
32.28N*m/g to 42.13N*m/g and tear index from 9.80mN*m2
/g to 15.62mN*m2
/g. The bonding
strength increased due to higher number of fibers, finer fiber size, and increase in the fiber contact
area and fiber distribution. The high porosity area affects the performance of water rise capillary
values of the paper sheets. The onion peels fiber gave impressive handsheets characteristics when
compared with other sources of non-wood fibers.

Matched MeSH terms: Nitrogen Radioisotopes
Fulltext A comparison technique of alpha and gamma spectrometry to measure 210Pb activity in marine sediment core

Zal Uyun Wan Mahmood, Yii, Mei-Wo, Che Abd. Rahim Mohamed, Norfaizal Mohamed @ Mohamad, Abdul Kadir Ishak

Jurnal Sains Nuklear Malaysia, 2013;25(2):61-67.
MyJurnal

The most commonly used techniques of alpha and gamma spectrometry were performed to measure
210Pb activity in marine sediment core as a comparison. Alpha analytical technique measured the
activity of 210Pb from it’s in-grow grand-daughter 210Po after a chemical separation, assuming
radioactive equilibrium between the two radionuclides. Meanwhile, gamma analysis technique
allows direct measurement, non-destructive and no preliminary chemical separation. Through the
comparison, it is found that both alpha and gamma analysis techniques were slightly difference.
Overall, the results from alpha analytical technique were basically higher than those from the
gamma analytical techniques. Some logical argument had been discussed to explain this situation.
In routine analysis, the analytical technique used should be chosen carefully based on advantages
and disadvantages of the each technique and analysis requirements. Therefore, it is recommended to
determine exactly the needs and purpose of analysis and to know the sample history before decide
the appropriate analytical technique

Matched MeSH terms: Radioisotopes
Fulltext Landscape response to progressive tectonic and climatic forcing in NW Borneo: Implications for geological and geomorphic controls on flood hazard

Menier D, Mathew M, Pubellier M, Sapin F, Delcaillau B, Siddiqui N, et al.

Sci Rep, 2017 03 28;7(1):457.
PMID: 28352115 DOI: 10.1038/s41598-017-00620-y

Empirical models have simulated the consequences of uplift and orographic-precipitation on the evolution of orogens whereas the effects of these forcings on ridgelines and consequent topography of natural landscapes remain equivocal. Here we demonstrate the feedback of a terrestrial landscape in NW Borneo subject to uplift and precipitation gradient owing to orographic effect, and leading to less-predictable flooding and irreversible damages to life and property. Disequilibrium in a large catchment recording the lowest rainfall rates in Borneo, and adjacent drainage basins as determined through χ, a proxy for steady-state channel elevation, is shown to result in dynamic migration of water divide from the windward-side of the orogen towards the leeward-side to attain equilibrium. Loss of drainage area in the leeward-side reduces erosion rates with progressive shortening resulting in an unstable landscape with tectonic uplift, gravity faults and debris flows.14C dating of exhumed cut-and-fill terraces reveal a Mid-Pleistocene age, suggesting tectonic events in the trend of exhumation rates (>7 mm a-1) estimated by thermochronology, and confirmed by morphotectonic and sedimentological analyses. Our study suggests that divide migration leads to lowered erosion rates, channel narrowing, and sediment accretion in intermontane basins on the leeward-side ultimately resulting in enhanced flooding.

Matched MeSH terms: Carbon Radioisotopes
Fulltext Measurement of 226ra in iaea soil-6 using gamma spectrometry system: Comparison between manual and software calculation

Mei-Wo, Yii, Kamarozaman Ishak, Nooruzainah Abu Hassan, Maziah Mahmud, Khairul Nizam Razali

Jurnal Sains Nuklear Malaysia, 2012;24(1):102-112.
MyJurnal

IAEA Soil-6 is a reference material with a certified value for 226Ra fall between 69.6 – 93.4 Bq/kg at 95% confidence level. This material has been used as a sample and performed repeat measurement weekly between years 2006 – 2009 using a same gamma spectrometry system. The activity concentration of this material is calculated automatically using the operational commercial software and compared with activity obtained from the manual calculation. Study found that only 76.9%, 64.1%, 56.3%, and 79.3% of the results from the software calculation lie within the confidence level for year 2006, 2007, 2008 and 2009, respectively. However, u-score calculation revealed that 94.9 %, 89.7%, 79.2% and 84.9% data set have no significant bias (u < 2.58) for year 2006, 2007, 2008 and 2009, respectively. On the other hand, all manual calculation data were found to be within the 95 % confidence level. Factors suspected to cause differences between these two approaches were discussed here. Manually peak search, marking and calculation still remains as the preferred option for calculating the gamma radionuclides activity unless limitations of the spectrum analysis software, as described in this paper can be resolved/improved upon.

Matched MeSH terms: Radioisotopes
Fulltext Radionuclide concentration of spent resins from puspati triga reactor coolant purification system

Muhamat Omar, Zalina Laili, Julia Abdul Karim, Zarina Masood, Nik Marzukee Nik Ibrahim, Mohd Abd Wahab Yusof

Jurnal Sains Nuklear Malaysia, 2012;24(2):14-18.
MyJurnal

A study to assess the concentration of radionuclides in spent resins of the PUSPATI TRIGA Mark II reactor coolant purification system has been carried out. Fresh spent resins collected and analysed in May 2010, after the changing of leaked heat exchanger in Sept. 2009 was found to contain 24Na, 122Sb, 51Cr, 124Sb, 58Co, 65Zn, 54Mn and 60Co. Old spent resins removed in 2001 and 2002 but analysed in 2010 indicated the presence of 60Co and 152Eu as radionuclides with half-lives of < 1 year might have already been decayed out. These results can be used to establish radionuclide inventory of the spent resins as part of radiation protection programme.

Matched MeSH terms: Radioisotopes
Fulltext Gamma scan technique for detecting coupon inside the mother pipeline

Rasif Mohd Zain, Roslan Yahya, Mohamad Rabaie Shari, Airwan Affandi Mahmood, Mior Ahmad Khusaini Adnan

Jurnal Sains Nuklear Malaysia, 2012;24(2):28-34.
MyJurnal

Many times a year natural gas transmission and distribution companies need to make new connections to pipelines to expand or modify their existing system through hot tapping procedure. This procedure involves the installation of a new pipeline connection while the pipeline remains in service, flowing natural gas under pressure. The hot tap procedure includes attaching a branch connection and valve on the outside of an operating pipeline, and then cutting out the pipe-line wall within the branch and removing the wall section, which is called object of coupon through the valve. During the hot tapping process a critical problems occurred when a coupon fell into the mother pipeline. To overcome this problem, a gamma-ray absorption technique was chosen whereby a mapping technique will be done to detect the coupon position. The technique is non-destructive as it applies Co-60 (5mCi) as a radioisotope sealed source to emit gamma radiation and a NaI(Tl) scintillation as detector. The result provided a visible representation of density profile inside pipeline where the coupon location can be located. This paper provides the detail of the technique used and presents the result obtained.

Matched MeSH terms: Radioisotopes
Fulltext A systematic approach in the gamma spectrometric determination of radionuclides in coolant of puspati triga reactor

Muhamat Omar, Zalina Laili, Abd Khalik Wood, Julia Abdul Karim, Zarina Masood, Mohd Fazli Zakaria, et al.

Jurnal Sains Nuklear Malaysia, 2011;23(2):1-11.
MyJurnal

A systematic study to assess the concentration of radionuclides in primary coolant and associated water samples from the operation of a TRIGA Mark II reactor has been carried out. The samples were transferred into appropriate counting container and were counted by efficiency-calibrated gamma spectrometer systems for several hours to obtain statistically adequate data for qualitative and quantitative evaluation of the radioactive materials presence. The primary coolant was found to contain various gamma emitting radionuclides including 24Na, 41Ar, 42K, 51Cr, , 54Mn, 56Mn, 60Co, 99mTc, 122Sb, 124Sb and 187W. Most of the detected radionuclides were inferred to be originated from activation products of (n,) nuclear reactions of elements of reactor components such as stainless steel and aluminium alloy used in the reactor system. The study confirms the integrity of the reactor system with no apparent release of any fission products radionuclide into the coolant water system.

Matched MeSH terms: Radioisotopes
Fulltext Metal diagenesis and transport in coastal sediments around Penang Island , Malaysia

Khalik Wood, A., Zaharudin Ahmad, Noor Azhar Md. Shazili, Rosnan Yaakob, Carpenter, Roy

Journal of Nuclear and Related Technologies, 2004;2004(1):1-22.
MyJurnal

Spatial and temporal variations in concentrations of several metals and isotopes in sediment cores from around Penang Island, an area with economically important biological resources off the northwest coast of peninsular Malaysia, are reported. Because of a typical, monazite rich mineralogy in surrounding drainage basins, sedimentary metal enrichment factors relative to global average materials, enrichment factors (EFs) of ˃1.0 do not always indicate significant anthropogenic metal inputs. Because of extensive metal solubilization in the hot, organic carbon rich area, EFs of < 1.0 may be observed for several metals despite significant anthropogenic contributions. Comparison of metal-Al relationships in Penang area surface sediments with those in nearby and presumed uncontaminated Strait of Malacca sediments more accurately correct for atypical regional solubilization and mineralogical effects than comparison to global average materials. Such comparisons show concentrations of Cd, Cu, Pb, Ni, Cr, As, Sb, Zn and V have changed by less than a factor of two by anthropogenic discharges. Sedimentary concentration profiles of Pb, Zn and Cu, ratioed to Sc to normalize for variations in grain size and mineralogy, have subsurface maxima suggestive of modest and recently reduced anthropogenic inputs. Mn, U, As and Sb have Sc-normalized concentration profiles clearly affected by diagenetic processes. Sc-normalized profiles of Cr, Th, Ce and Sm show only small changes with depth, confirming insignificant anthropogenic inputs and undetectable postdepositional diagenetic mobility.
Excess ²¹⁰Pb activities and fluxes in Penang area sediments are limited by supply of this radionuclide, in contrast to sediments of both the northwestern U.S.A. and Amazon continental shelves, where they are limited by particle scavenging reactions.²¹⁰Pb activities in sediments of
the shallow, dynamic Penang area often show erratic or unconvincing changes with depth that
cannot be reliably modeled by assuming steady state, constant deposition rate of particles of
uniform chemistry, mineralogy and initial unsupported ²¹⁰Pb, and that mixing is limited to a
recognizable surface layer and resemble a diffusive process.

Matched MeSH terms: Radioisotopes
Fulltext γ-ray interference and emission probability selection in the determination of natural radionuclide concentration using γ-spectrometry

Omar, M.

Journal of Nuclear and Related Technologies, 2009;2009(2):78-88.
MyJurnal

The interference of 235 U on 226 Ra concentration measured directly using the γ-ray energy of 186 keV and the interference of 228 Ac on the 40 K analysis by gamma-spectrometry system were highlighted and discussed. The interference of 235 U was demonstrated to be very significant, i.e. 45% of the 226 Ra concentration measured directly at 186 keV in natural samples containing uranium series in equilibrium. The interference of 228 Ac on 40 K concentration was particularly significant for samples containing high concentration of 228 Ac ( 228 Ra) such as radioactive minerals. Another important aspect discussed is the assignment of the right emission probability of the 583 keV and 2614 keV of the 208 Tl for the purpose of estimating the concentration of 232 Th or other radionuclides in the thorium series. Extra cautions are required in the interpretation of the measured 208 Tl concentration in samples of various natures. It is suggested that the emission probability used for 208 Tl be reported for comparison and verification.

Matched MeSH terms: Radioisotopes
Fulltext Effect of A13+, Ca2+, Cu2+ and Fe2+ on removal of Radium-226 from Radium-Contaminated soil using humic acid

Esther Phillip, Muhamat Omar, Muhamad Samudi Yasir, Mohd Zaidi Ibrahim, Zalina Laili

Journal of Nuclear and Related Technologies, 2012;2012(2):7-13.
MyJurnal

Effect of AP+, Ca", Cu" and Fe" on the removal of radium-226 from radium-contaminated soil using humic acid extracted from a Malaysian peat soil was investigated using batch washing method. The concentration of Al,+ Ca", Cu" and Fe" ranged from 0 to 100 ppm. The radioactivity concentration of radium-226 was determined by gamma spectrometer. The removal of radium-226 was enhanced in the presence of AP' with concentration between 20 - 60 ppm. Meanwhile, higher concentration of 80 - 100 ppm did not lead to further increase in the removal of radium-226. The removal of radium-226 was decreased in the presence of Ca" and Cu". In the presence of Fe" with concentration between 20 - 60 ppm, decrease in the removal of radium-226 was also observed. Nevertheless, at concentration between 80 - 100 ppm, the presence of Fe" led to increase in the removal of radium-226.

Matched MeSH terms: Radioisotopes
Fulltext Determination of radiocaesium composition in East Malaysia seawater

Yii, Mei-Wo, Abdul Kadir Ishak, Zaharudin Ahmad

Journal of Nuclear and Related Technologies, 2006;2006(1):51-58.
MyJurnal

A trial study had been conducted to determine the particulate form of 137 Cs in seawater surrounding East Malaysia. Large volume of seawater was filtered at a flow rate of 15 liters/min through the copper hexacyanoferrates (II) impregnated filters. These filters were ashed and counted using the gamma spectrometry system to determine the dissolved 137 Cs activity. It was found that the particulate form of 137 Cs consists of 20 to 49 % of the total 137 Cs activity concentrations. Some reasonable explanations for higher particulate percentage such as sampling locations, high water flow-rate, and large volume of seawaters were further discussed. It is hope that the result of this study will help to build a better understanding about the usage of impregnated filters to study dissolved 137 Cs activity concentrations.

Matched MeSH terms: Cesium Radioisotopes
Fulltext The presence of 60Co in solid wastes from crude oil production industry

Omar, M., Laili, Z.

Journal of Nuclear and Related Technologies, 2008;2008(1):81-83.
MyJurnal

Thirteen solid waste samples labeled as scales were collected from a storage area of a crude oil production industry and were analysed for radionuclides concentrations. The radium-226 and radium- 228 concentrations were found to be unexpectedly low, i.e. less than 20 Bqkg. However, six samples were found to contain 7 to 2240 Bq/kg 60 Co. Thus, besides naturally occurring radionuclides, there is a possibility to find artificial radionuclides in solid wastes from crude oil production industry.

Matched MeSH terms: Radioisotopes
Fulltext Occupational exposure and radiobiological risk from thyroid radioiodine therapy in Saudi Arabia

Al-Mohammed HI, Sulieman A, Mayhoub FH, Salah H, Lagarde C, Alkhorayef M, et al.

Sci Rep, 2021 Jul 15;11(1):14557.
PMID: 34267237 DOI: 10.1038/s41598-021-93342-1

Worldwide, thyroid cancer accounts for some 10% of total cancer incidence, most markedly for females. Thyroid cancer radiotherapy, typically using 131I (T1/2 8.02 days; β- max energy 606 keV, branching ratio 89.9%), is widely adopted as an adjunct to surgery or to treat inoperable cancer and hyperthyroidism. With staff potentially receiving significant doses during source preparation and administration, radiation protection and safety assessment are required in ensuring practice complies with international guidelines. The present study, concerning a total of 206 patient radioiodine therapies carried out at King Faisal Specialist Hospital and Research Center over a 6-month period, seeks to evaluate patient and occupational exposures during hospitalization, measuring ambient doses and estimating radiation risk. Using calibrated survey meters, patient exposure dose-rate estimates were obtained at a distance of 30-, 100- and 300 cm from the neck region of each patient. Occupational and ambient doses were measured using calibrated thermoluminescent dosimeters. The mean and range of administered activity (AA, in MBq) for the thyroid cancer and hyperthyroidism treatment groups were 4244 ± 2021 (1669-8066), 1507.9 ± 324.1 (977.9-1836.9), respectively. The mean annual occupational doses were 1.2 mSv, that for ambient doses outside of the isolation room corridors were found to be 0.2 mSv, while ambient doses at the nursing station were below the lower limit of detection. Exposures to staff from patients being treated for thyroid cancer were less compared to hyperthyroidism patients. With a well-defined protocol, also complying with international safety requirements, occupational exposures were found to be relatively high, greater than most reported in previous studies.

Matched MeSH terms: Iodine Radioisotopes/administration & dosage; Iodine Radioisotopes/adverse effects*; Iodine Radioisotopes/therapeutic use*

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