A comparative neutron and gamma-ray radiation shielding investigation of molybdenum and boron filled polymer composites

This work presents a detailed radiation shielding study for polymer composites filled with Boron and Molybdenum additives. The chosen novel polymer composites were produced at different percentages of the additive materials to provide a proper evaluation of their neutron and gamma-ray attenuation abilities. The effect of additive particle size on the shielding characteristics was further investigated. On the gamma-ray side, simulation, theoretical and experimental evaluations were performed in a wide range of photon energies varying from 59.5 keV to 1332.5 keV with help of MC simulations (GEANT4 and FLUKA), WinXCOM code, a High Purity Germanium Detector, respectively. A remarkable consistency was reported between them. On the neutron shielding side, the prepared samples produced with nano and micron particle size additives were additionally examined by providing fast neutron removal cross-section (Σ_R) and the simulated neutron transmissions through the prepared samples. The samples filled with nano sized particles show better shielding capability than the one filled with micron sized particles. In other words, a new polymer shielding material that does not contain toxic content is introduced: the sample codded N-B0Mo50 exhibits superior radiation attenuation.

Pain Relief for Children after Adenotonsillectomy

Effective pain relief following adenotonsillectomy in children remains a challenge. This study evaluated the effects of intramuscular 0.5 mg/kg ketamine, 1 mg/kg tramadol or 1 mg/kg meperidine on post-operative pain and recovery in 45 children aged 1-7 years undergoing adenotonsillectomy. Anaesthesia was induced with thiopental or sevoflurane (with succinylcholine for intubation) and was maintained with sevoflurane in oxygen and nitrous oxide. Post-operative pain was scored blind using a modified Toddler–Preschooler Post-Operative Pain Scale 30, 60, 120 and 240 min after tracheal extubation. Post-operative agitation scores were also recorded. Mean post-operative pain score was significantly higher in the tramadol-treated group compared with the meperidine-treated group 120 min after extubation. At all other time-points after extubation, mean post-operative pain scores were similar for the three treatment groups. Ketamine was associated with a significantly higher mean agitation score compared with tramadol and meperidine. We conclude that the effects of ketamine, meperidine and tramadol on post-operative pain following adenotonsillectomy in children were similar.

Altered isotope charge distribution of acetylcholine neurotransmitter and Myasthenia Gravis

Acetylcholine (ACh) is a central neurotransmitter that is used for signal transmission among neurons. For signal transmission in neurons, a neurotransmitter must bind to its receptor in order to produce an action potential. It is known that in Myasthenia Gravis (MG) cases, autoantibodies could block this binding. In the future, the treatment of MG could be achieved via modulation of molecular interaction between ACh and acetylcholine receptor (AChR). This study suggests that if an atom on a ligand (i.e. a neurotransmitter) is replaced with its isotope, it may cause charge redistribution such as that the binding between ligand and its receptor may be improved. Hence suggesting that with replacement of atoms with their isotopes in any biologically important ligand could alter its affinity towards its corresponding receptor, which would have a wide array of applications in medicine.

Effects of N-acetyl-cysteine and acetylsalicylic acid on the tonsil bacterial biofilm tissues by light and electron microscopy

OBJECTIVE

The present study aimed to investigate the effects of the bacterial biofilm formation on the tonsil surface exposed N-acetyl-cysteine (NAC) and acetylsalicylic acid (ASA) of patients undergoing tonsillectomy by light and electron microscopy. The general process of biofilm formation comprises adhesion of free-living or planktonic bacteria to a surface, which subsequently develop into microcolonies and form a biofilm. Based on studies that have shown the presence of biofilms in common sites of chronic infections, it has become clear that bacteria may persist on mucosal surfaces through formation of biofilms.

PATIENTS AND METHODS

Ten patients between 4 and 39 years of age (mean, 11.9 ± 11.2 years). In all cases, periodic acide Schiff (PAS) staining was found to be an accurate predictor of the presence or absence of biofilm using light microscopy as a control standard. Therapeutic doses of NAC and ASA were identificated as the effective on the tonsil bacterial biofilm using light and electron microscopy.

RESULTS

Biofilm formation was detected on all samples. Tonsils removed from patients with ASA-10 had showed higher-grade inhibitory effect at the biofilm formation than the other group (p ≤ 0.0001). The correlation was found between drug dose and decrease at the biofilm formation.

CONCLUSIONS

In chronic or recurrent tonsillitis patients, decrease on the tonsils surface biofilm formation may be associated with ASA dose. Whether effect on the tonsils surface biofilm formation of other agent have a role is not known. Key Words: Acetylsalicylic acid, Chronic tonsillitis, In vitro, Mucosal biofilm, N-Acetyl-cysteine.

Sacral agenesis with imperforate anus and its late complication: neuropathic bladder

The authors report a rare case of imperforate anus as a congenital anomaly. Early diagnosis and close follow up are emphasized, in order to prevent the development of complications which may last for a lifetime.

Phase studies of ethoxylated surfactants-oil-water-undecylenic acid

Two non-ionic surfactants (Simulsol OL 50 and Simulsol 98) separately or as 1:1 mixtures, together with corn oil-undecylenic acid and water formed various phases. Phase equilibrium studies were made. In all phase equilibrium diagrams investigated, both at 20 and 37 degrees C, lamellar and hexagonal liquid crystalline and oily isotropic phases were found, besides the emulsion system. Emulsions were composed of mixed lamellar and hexagonal liquid crystalline phases which formed at low concentrations of surfactant and oil and correspondingly high water concentrations.