Rapid analytical method of Sr in urine sample: Rapid separation of Sr by phosphate co-precipitation and extraction chromatography, followed by determination by triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS).

A rapid analytical method for determining Sr in urine samples (1-2 L) was developed to assess the internal exposure of workers in a radiological emergency. Strontium in a urine sample was rapidly separated by phosphate co-precipitation, followed by extraction chromatography, and the Sr activity was determined by triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS). Measurement in the MS/MS mode with an O reaction gas flow rate 1 mL min showed no tailing of Sr at m/z = 90 up to 50 mg L Sr.

Effect of Co60 irradiation on the degradation and mineralization of sulfonated aromatic compounds in aqueous solutions.

As sulfonated aromatic compounds are widely used in industry, they have frequently been detected in aquatic environments. This study evaluated the degradation and mineralization of 2,6-naphthalenedisulfonic acid disodium salt (2,6-NS), sodium 2-naphthalenesulfonate (2-NS), benzenesulfonic acid sodium salt (BS), and 4-vinylbenzene sulfonate sodium (4-VBS) by exposing aqueous solutions of these compounds to Co60 irradiation. The radiolytic degradation of these pollutants was found to follow pseudo-first-order kinetics.

Attenuation of radiation toxicity by the phosphine resistance factor dihydrolipoamide dehydrogenase (DLD).

Phosphine gas is an excellent fumigant for disinfesting stored grain of insect pests, but heavy reliance on phosphine has led to resistance in grain pests that threatens its efficacy. Phosphine-resistance was previously reported to be mediated by the enzyme DLD. Here we explore the relationship between phosphine toxicity and genotoxic treatments with the goal of understanding how phosphine works.

Detailed study of water radiolysis-based degradation of chloroorganic pollutants in aqueous solutions.

Water radiolysis-induced destruction, dechlorination and mineralization of harmful chlorophenols, i.e., 2,4,6-trichlorophenol (2,4,6-tCPH), 4-chlorophenol (4-CPH) and 4-chlorocatechol (4-CC), using radioactive Co-60 have been investigated as individual and combination methods (2,4,6-tCPH+4-CPH+4-CC) with an initial concentration of 100 μM of each pollutant.

Gamma radiation and indoor radon concentrations in the western and southwestern regions of Saudi Arabia.

The exposure of the population to natural gamma radiation in air and to indoor radon gas was investigated in Makkah, AlBaha, Assir, Jazan and Najran regions in the western and southwestern of Saudi Arabia. The survey was performed by using LiF:Mg,Cu,P thermoluminescence dosimeters (TLDs) for indoor and outdoor absorbed dose rates in air measurements in 885 locations, and a passive integrating ionizing system, equipped with an E-Perm Electret ion chamber, for radon concentration measurements in a total of 1119 dwellings. The ambient indoor rates vary from 54 to 191 nSv h, while it is in the range of 42-112 nSv h for the outdoor.

Gallic acid degradation by electron beam irradiation under various conditions.

In this study, aqueous solutions of gallic acid (GA) were irradiated in an electron beam (EB) accelerator under different experimental conditions (various initial GA concentrations, presence or absence of oxidant and oxygen). For an initial GA concentration of 50 μM, complete GA degradation was achieved with an absorbed dose of 850 Gy in the presence of dissolved oxygen. Both GA removal and mineralization are favored when oxygen is present.

Oxygen and Arsenite Synergize Phosphine Toxicity by Distinct Mechanisms.

Phosphine is the only fumigant approved globally for general use to control insect pests in stored grain. Due to the emergence of resistance among insect pests and the lack of suitable alternative fumigants, we are investigating ways to synergistically enhance phosphine toxicity, by studying the mechanism of action of known synergists, such as oxygen, temperature, and arsenite. Under normoxia, exposure of the model organism Caenorhabditis elegans for 24 h at 20°C to 70 ppm phosphine resulted in 10% mortality, but nearly 100% mortality if the oxygen concentration was increased to 80%.

Colorimetric Aptasensor of Vitamin D3: A Novel Approach to Eliminate Residual Adhesion between Aptamers and Gold Nanoparticles.

Colorimetric aptasensors based on gold nanoparticles (AuNPs) commonly feature ssDNA probes nonspecifically adsorbed to surface gold particles. A major limitation of this versatile method is the incomplete dissociation of the adsorbed nontarget binding segments of the aptamer sequence upon target binding. This results in weak or nonexistent sensor performance by preventing the particles from aggregating when the optimized salt concentration is added.

Biocidal effect of thymol and carvacrol on aquatic organisms: Possible application in ballast water management systems.

Ballast water is essential for maintaining the balance and integrity of a ship. However, exchanging ballast water resulted in discharging water of different origins in vessel recipient ports, and this may have caused ecosystem disturbance or aquatic pollution. The ballast water management (BWM) system is essential for the purification and disinfection of the ballast water that is taken up.

Assessment of the committed effective dose due to the Po intake from fish consumption for the Arabian Gulf population.

This study aims to assess the committed effective dose due to the intake of Po from the consumption of fish in Arabian Gulf countries. Twenty different kinds of fish, which represent the most common fish species consumed in the Arabian Gulf countries, were analyzed using alpha spectrometer technique. Po activity concentrations in fish samples were found to vary over a wide range from 0.

Removal of antibiotics from water and waste milk by ozonation: kinetics, byproducts, and antimicrobial activity.

The use of antibiotics in the dairy farming for curing and growth promotion results in the production of massive quantities of non-recyclable wastewater by the conventional purification techniques. Additionally, waste milk is produced during the drug withholding periods, which is not suitable for human or animal consumption and cause huge economic loss as well as present serious environmental waste. This study was designed to investigate the decomposition of various antibiotic compounds in un-buffered aqueous solutions and milk samples by ozonation process.

Stress pre-conditioning with temperature, UV and gamma radiation induces tolerance against phosphine toxicity.

Phosphine is the only general use fumigant for the protection of stored grain, though its long-term utility is threatened by the emergence of highly phosphine-resistant pests. Given this precarious situation, it is essential to identify factors, such as stress preconditioning, that interfere with the efficacy of phosphine fumigation. We used Caenorhabditis elegans as a model organism to test the effect of pre-exposure to heat and cold shock, UV and gamma irradiation on phosphine potency.

A STUDY OF THE RADIOACTIVITY IN THE DUST STORM EVENT OF APRIL 2015 IN ARABIAN PENINSULA.

Gulf countries are often affected by dust storms which have a significant influence on the environment and public health. The present work examines the radioactivity content in the intense dust storm occurred over Gulf countries on 1 April 2015. The results showed that the average value of 137Cs in dust samples (±SD) is 14.

CHARACTERIZATION OF AN IN-HOUSE DEVELOPED MULTI-CYLINDRICAL MODERATOR NEUTRON SPECTROMETER.

This article describes the characterization of an in-house developed multi-cylindrical moderator neutron spectrometer, which consists of a cylindrical 3He proportional counter and cylindrical moderator shells of different sizes. The response matrix of the spectrometer was calculated by Monte Carlo simulations for neutron energies from 1 × 10-8 to 10 MeV and verified with measurements in 0.144 MeV, 1.

CORRECTION FACTORS FOR ATTENUATION AND SCATTERING OF THE WALL OF A CYLINDRICAL IONIZATION CHAMBER IN THE 6-7 MeV HIGH-ENERGY PHOTON REFERENCE FIELD.

In high-energy photon reference fields the value of the air kerma rate is determined by using ionization chambers (ICs). From the charge collected inside the IC the dose can be calculated using a set of calibration and correction factors according to ISO 4037-2. A crucial parameter is the correction for the attenuation and scattering of the primary radiation due to the chamber wall.

Decomposition byproducts induced by gamma radiation and their toxicity: the case of 2-nitrophenol.

The induced degradation and detoxification of 2-nitrophenol (2-NP) in aqueous media by gamma irradiation were carefully evaluated in this study. Gamma radiation at absorbed doses as low as 20 kGy was able to degrade 2-NP to reach a removal of at least 85% across the investigated range of concentration (50-150 ppm). 2-NP breaks down to aromatic-based compounds with increasing number of byproducts upon increasing the radiation treatment from the absorbed dose of 50% decomposition (D) to the absorbed dose of 90% decomposition (D), after which no byproducts could be detected, indicating the formation of undetectable aliphatic hydrocarbons, insoluble, or volatile byproducts.

Gamma irradiation-induced complete degradation and mineralization of phenol in aqueous solution: Effects of reagent.

This study aims to gain new insight into phenol degradation and mineralization in aqueous solution using ionizing radiation to control its radiolytic elimination under various experimental conditions and to present the different radical reactions involved in water radiolysis. The most obvious finding of this study is that the combination of a reagent, i.e.

Comparison of the High-Energy Photon Reference Fields of PTB and JAEA.

A comparison has been conducted between the 6 MeV and 7 MeV (R-F) high-energy photon reference fields of the Physikalisch-Technische Bundesanstalt (PTB) and the Japan Atomic Energy Agency (JAEA). Both fields are set up according to ISO 4037. The results of both participants are in agreement within the combined uncertainties, thus the equivalence of the measurements is demonstrated.

Radiological assessment of water treatment processes in a water treatment plant in Saudi Arabia: Water and sludge radium content, radon air concentrations and dose rates.

There is an increase demand for clean water sources in Saudi Arabia and, yet, renewable water resources are very limited. This has forced the authorities to explore deep groundwater which is known to contain large concentrations of radionuclides, mainly radium isotopes. Lately, there has been an increase in the number of water treatment plants (WTPs) around the country.

New RO TFC Membranes by Interfacial Polymerization in n-Dodecane with Various co-Solvents.

The objective of this research is to prepare and characterize a new and highly efficient polyamide TFC RO membrane by interfacial polymerization in dodecane solvent mixed with co-solvents. Three co-solvents were tested namely; acetone, ethyl acetate, and diethyl ether of concentration of 0.5, 1, 2, 3, and 5 wt %.

Study on the radioactivity and soil-to-plant transfer factor of (226)Ra, (234)U and (238)U radionuclides in irrigated farms from the northwestern Saudi Arabia.

The present study addresses the soil-to-plant transfer factors (TFs) of (226)Ra, (234)U and (238)U for 13 types of vegetables and agricultural crops planted under semi-arid environment in the northwestern part of Saudi Arabia. Crop plants along with plant-growing soils were collected from selected farms, which are irrigated from the non-renewable Saq aquifer, and investigated for their radioactivity content by means of alpha spectrometry after applying a radiochemical separation procedure. Hence, TF data for plant roots, green parts (stem and leaves) and fruits were calculated and contrasted to those reported in the literature.

INFLUENCE OF DIFFERENT TYPES OF PHANTOMS ON THE CALIBRATION OF DOSEMETERS FOR EYE LENS DOSIMETRY.

Both a cylinder and a slab phantom have been recommended to be used as calibration phantoms for eye lens dosimetry in the International Atomic Energy Agency TECDOC. This study describes investigations on the influence of the type of phantom on the calibration of dosemeters. In order to fulfil the purpose, backscatter radiation from practically used water-filled phantoms was evaluated by calculations and experiments.

Plasminogen activator inhibitor-1 enhances radioresistance and aggressiveness of non-small cell lung cancer cells.

Acquired resistance of tumor cells during treatment limits the clinical efficacy of radiotherapy. Recent studies to investigate acquired resistance under treatment have focused on intercellular communication because it promotes survival and aggressiveness of tumor cells, causing therapy failure and tumor relapse. Accordingly, a better understanding of the functional communication between subpopulations of cells within a tumor is essential to development of effective cancer treatment strategies.

Inhibitory effect of traditional oriental medicine-derived monoamine oxidase B inhibitor on radioresistance of non-small cell lung cancer.

Increased survival of cancer cells mediated by high levels of ionizing radiation (IR) reduces the effectiveness of radiation therapy for non-small cell lung cancer (NSCLC). In the present study, danshensu which is a selected component of traditional oriental medicine (TOM) compound was found to reduce the radioresistance of NSCLC by inhibiting the nuclear factor-κB (NF-κB) pathway. Of the various TOM compounds reported to inhibit the IR activation of NF-κB, danshensu was chosen as a final candidate based on the results of structural comparisons with human metabolites and monoamine oxidase B (MAOB) was identified as the putative target enzyme.