Does It Bind? A Method to Determine the Affinity of Calcium and Magnesium Ions for Polymers Using H NMR Spectroscopy.

The binding of calcium and magnesium ions (M) by polymers and other macromolecules in aqueous solution is ubiquitous across chemistry and biology. At present, it is difficult to assess the binding affinity of macromolecules for M without recourse to potentiometric titrations and/or isothermal titration calorimetry. Both of these techniques require specialized equipment, and the measurements can be difficult to perform and interpret.

Analysis and results from a UK national dose audit of paediatric CT examinations.

Objective: To present the results following a UK national patient dose audit of paediatric CT examinations, to propose updated UK national diagnostic reference levels (DRLs) and to analyse current practice to see if any recommendations can be made to assist with optimisation.

Methods: A UK national dose audit was undertaken in 2019 focussing on paediatric CT examinations of the head, chest, abdomen/pelvis and cervical spine using the methods proposed by the International Commission on Radiological Protection. The audit pro-forma contained mandatory fields, of which the post-examination dosimetry (volume CT dose index and dose-length product) and the patient weight (for body examinations) were the most important.

Selection of bone dosimetry models for application in Monte Carlo simulations to provide CT scanner-specific organ dose coefficients.

This is the second paper arising from a project concerning the application of Monte Carlo simulations to provide scanner-specific organ dose coefficients for modern CT scanners. The present focus is centred on the bone dosimetry models that have been developed. Simulations have been performed in photon only transport mode, with the assumption of electron equilibrium.

Measurement of scattered and transmitted x-rays from intra-oral and panoramic dental x-ray equipment.

The aim of this study was to quantify the levels of transmitted radiation arising from the use of intra-oral dental x-ray equipment and scattered radiation arising from the use of both intra-oral and panoramic x-ray equipment. Levels of scattered radiation were measured at 1 m from a phantom, using an ion chamber with a volume of 1800 cm. Transmitted radiation was measured using both (i) a phantom and dose-area product (DAP) meter and (ii) a patient and a 1800 cm ion chamber.