ESTIMATION OF THE ORGAN AND EFFECTIVE DOSE TO PATIENTS UNDERGOING MEDICAL DIAGNOSTIC X-RAY EXAMINATIONS IN SAUDI ARABIA.

Quantifying the radiological risk from diagnostic radiography is essential for patients' safety. Effective dose is considered the best quantity to determine the stochastic risk associated with the radiological examinations. Therefore, the present work investigated organ and effective dose for adult patients in the most common type of X-ray examinations, such as the chest (PA/LAT), abdomen (AP) and lumbar spine (AP/LAT) projections.

MEASUREMENT OF THE ACTIVITY CONCENTRATIONS OF GAMMA EMITTING RADIONUCLIDES IN TOOTHPASTE SAMPLES AND ASSESSMENT OF THE CORRESPONDING ANNUAL EFFECTIVE DOSES.

It is inevitable that we are exposed to radiation daily from various sources and products that we consume on daily basis. The use of toothpaste for oral hygiene is one of the most common daily practices by humans and yet very little data are available regarding its radiation content. In this work, we investigated the concentrations of gamma emitting radionuclides in toothpaste samples consumed in Jordan.

ASSESSMENT OF THE RADIOACTIVITY OF GAMMA EMITTERS IN BABY FORMULA FOR DIFFERENT AGE GROUPS AND BABY CEREAL CONSUMED IN JORDAN.

In the present work, different brands of baby formula and cereal consumed in Jordan were analyzed for their radioactivity content. The activity concentrations of 40K varied with the designated age group in formula with the average concentrations being (in Bq/kg): 160.2 ± 33.

Assessment of Patient Radiation Dose during Conventional Diagnostic X-ray Examinations in Three Public Hospitals in Northern Jordan using TLDs.

This study aims to measure entrance surface doses during routine chest and abdomen x-ray examinations of adult and child patients. Radiation dose measurements were performed using thermoluminescent dosimeters TLD-100s in three major public hospitals in northern Jordan on a total of 100 patients. Wide variations in entrance surface doses were observed within and between hospitals, which might be attributed to significant variations of the selected exposure parameters.

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.

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.

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.

Activity Concentrations and Dose Assessment of Gamma Emitting Radionuclides in Canned Tuna and Sardines Produced after the Fukushima Nuclear Accident.

The aim of the present work was to investigate the radioactivity concentrations of gamma emitting radionuclides in canned tuna and sardines that were produced after the Fukushima nuclear accident and to assess the resulting radiation doses to the public. Fifty-eight brands of canned tuna and sardines consumed in the Middle East and produced from different parts of the world were analyzed using a germanium detector. Cesium-137 (137Cs) was not detected above the minimum detectable activity in any of the samples.

The radioactivity of seasonal dust storms in the Middle East: the May 2012 case study in Jordan.

Dust storms in the Middle East are common during spring. Some of these storms are massive and carry a large amount of dust from faraway regions, which pose health and pollution risks. The huge dust storm event occurred in early May, 2012 was investigated for its radioactive content using gamma ray spectroscopy.

Distribution of natural and anthropogenic radionuclides in heavy rainfall areas in Jordan.

Soil is the main reservoir of both natural and artificial radionuclides, which are transported to the human body through the food chain. Thus, assessment of the level of radioactivity in soil is of crucial importance. Artificial radionuclide concentrations in soil depend heavily on rainfall and weather conditions.

Assessment of gamma-emitting radionuclides in sediment cores from the Gulf of Aqaba, Red Sea.

The Gulf of Aqaba is the only seaport in Jordan which currently has intense activities such as industrial development, phosphate ore exportation, oil importation, shipping, commercial and sport fishing. Most of these activities, especially the phosphate ore exportation, could cause serious radiological effects to the marine environment. Thus, it is essential to investigate the level of the radioactivity concentrations to establish a baseline database, which is not available yet in the Gulf of Aqaba.

Measurement of natural and artificial radioactivity in powdered milk consumed in Jordan and estimates of the corresponding annual effective dose.

The activity concentrations of (40)K, (226)Ra, (228)Ra and (137)Cs were measured for 14 brands of the powdered milk consumed in Jordan, which are imported from various regions around the world. The activity concentrations of (40)K were found not to vary greatly from one brand to the other with an average of 348 +/- 26 Bq kg(-1). However, the activity concentrations of (137)Cs revealed a geographical distribution being: (i) undetected in any of the samples from Argentina, (ii) uniformly distributed in samples from Europe with an average of 0.

Radioactivity concentrations in soil and vegetables from the northern Jordan Rift Valley and the corresponding dose estimates.

The Jordan Rift Valley (JRV) is considered the food bowl of Jordan, especially during the winter season. In this study, soil and vegetable samples collected from greenhouses in the northern JRV were analysed for their radioactive content. The activity concentrations of (238)U, (235)U, (232)Th, (226)Ra, (137)Cs and (40)K in soil were found to be (+/-SD) 33 +/- 12, 2.

The role of polarization interactions in the wrapping/unwrapping of nucleosomal DNA around the histone octamer: implications to gene regulation.

The inclusion of polarization interactions in nucleic acids and proteins have been recognized as a major improvement both in our understanding of these systems and in the accuracy of current calculations and simulations. Recently, we have investigated the role of these interactions in DNA A-tracts bending using a Monte Carlo simulation approach developed by Jarque and Buckingham, which allows the explicit calculation of the polarization energy at the microscopic level as a function of the interionic distance for two charges embedded in a polarizable medium. Here, we investigate the role of polarization interactions in providing a framework for understanding the wrapping/unwrapping of nucleosomal DNA.

In vivo lipid diffusion coefficient measurements in rat bone marrow.

The diffusion coefficient of lipids, D(l), within bone marrow, fat deposits and metabolically active intracellular lipids in vivo will depend on several factors including the precise chemical composition of the lipid distribution (chain lengths, degree of unsaturation, etc.) as well as the temperature. As such, D(l) may ultimately prove of value in assessing abnormal fatty acid distributions linked to diseases such as cystic fibrosis, diabetes and coronary heart disease.

On the correlation between T(2) and tissue diffusion coefficients in exercised muscle: quantitative measurements at 3T within the tibialis anterior.

Purpose: To assess the transverse relaxation time T(2) and diffusion coefficient D before and following exercise in the tibialis anterior muscle and determine whether T(2) and D values were correlated.

Methods: Measurements of T(2) and D were performed at 3 T within axial slices through the calf muscles of six healthy volunteers at 95 s intervals before and for 10-12 min after a dorsiflexion exercise to exhaustion.

Results: The mean +/- standard deviation (SD) of T(2) and D before exercise were 32 +/- 1.

DNA A-tracts bending: polarization effects on electrostatic interactions across their minor groove.

Bending by the DNA A-tracts constitutes a contentious issue, suggesting deficiencies in the physics employed so far. Here, we inquire as to the importance in this bending of many-body polarization effects on the electrostatic interactions across their narrow minor groove. We have done this on the basis of the findings of Jarque and Buckingham who developed a procedure based on a Monte Carlo simulation for two charges of the same sign embedded in a polarizable medium.

Maintenance of open DNA base pairs through histone acetylated lysine-purine interaction leading to transcriptional activation: a proposed mechanism.

Post-translational acetylation of lysines of the histone N-terminal tails is known to induce transcriptional activation, and thus plays a major role in gene regulation. A mechanism for this effect is suggested by our recent finding that the initial 'solvation' network, which is formed around the purines of base pairs immediately following their opening, has the tendency to be preserved. The experiments involved studying the solvation of nucleosides in water-alcohol mixtures; these systems model the hydrophobic/hydrophilic effects that participate in the interaction between histone-tail amino acid residues and nucleosomal DNA base pairs following their opening by the action of DNA-binding proteins in conjunction with remodeling complexes.

Solvation of nucleosides in aqueous mixtures of organic solvents: relevance to DNA open basepairs.

Toward the goal of understanding how open basepairs in DNA interact with their heterogeneous environment, we have studied the steady-state intrinsic fluorescence properties of the purine and pyrimidine deoxynucleosides in organic solvents in the presence of small amounts of water. The organic solvents used in the present study were: n-butanol, acetonitrile, methanol, n-propanol, isopropanol, and isobutanol. For n-butanol and acetonitrile, which have a high degree of amphiphilicity and weak hydrogen bonding ability, respectively, the fluorescence spectral properties of the purines are found to depend on the sequence of steps in which the aqueous mixtures were formed.