Configuration-interaction calculations of positron binding to group-II elements

The configuration-interaction (CI) method is applied to the study of positronic magnesium (e+Mg), positronic calcium (e+Ca), and positronic strontium (e+Sr). The CI expansion was seen to converge slowly with respect to Lmax, the maximum angular momentum of any orbital used to construct the CI basis. Despite doing explicit calculations with Lmax=10, extrapolation corrections to the binding energies for the Lmax→∞ limit were substantial in the case of e+Ca (25%) and e+Sr (50%). The extrapolated binding energies were 0.0162 hartree for e+Mg, 0.0165 hartree for e+Ca, and 0.0101 hartree for e+Sr. The static-dipole polarizabilities for the neutral parent atoms were computed as a by-product, giving 71.7a03, 162a03, and 204a03 for Mg, Ca, and Sr, respectively

A novel mixed-methods platform study protocol for investigating new surgical devices, with embedded shared learning: Ibra-net breast lesion localisation study

Introduction: New medical devices must have adequate research, such that outcomes are known, enabling patients to be consented with knowledge of the safety and efficacy of the device to be implanted. Device trials are challenging due to the learning curve and iterative assessment of best practice. This study is designed to pilot a national collaborative approach to medical device introduction by breast surgeons in the UK, using breast localisation devices as an exemplar. The aim is to develop an effective and transferable surgical device platform protocol design, with embedded shared learning. Methods and analysis: The iBRA-net localisation study is a UK based prospective, multi-centre platform study, comparing the safety and efficacy of novel localisation devices with wire-guided breast lesion localisation for wide local excision, using Magseed® as the pilot intervention group. Centres performing breast lesion localisation for wide local excision or excision biopsy will be eligible to participate if using one of the included devices. Further intervention arms will be added as new devices are CE marked. Outcomes will be collected via an online database. The primary outcome measure will be identification of the index lesion. Participating surgeons will be asked to record shared learning events via online questionnaires and focus group interviews to inform future study arms. Ethics and dissemination: The study will aim to collect data on 950 procedures for each intervention (Magseed® and wire localisation) from UK breast centres over an 18-month period. Shared learning will be prospectively evaluated via thematic analysis to refine breast localisation technique and to promote early identification of potential pitfalls and problems. Results will be presented at national and international conferences and published in peer reviewed journals. Registration: This is a UK national audit registered with Manchester University NHS Foundation Trust

Log D versus HPLC derived hydrophobicity: The development of predictive tools to aid in the rational design of bioactive peptoids

Hydrophobicity has proven to be an extremely useful parameter in small molecule drug discovery programmes given that it can be used as a predictive tool to enable rational design. For larger molecules, including peptoids, where folding is possible, the situation is more complicated and the average hydrophobicity (as determined by RP-HPLC retention time) may not always provide an effective predictive tool for rational design. Herein, we report the first ever application of partitioning experiments to determine the log D values for a series of peptoids. By comparing log D and average hydrophobicities we highlight the potential advantage of employing the former as a predictive tool in the rational design of biologically active peptoids. This article is protected by copyright

Results of shared learning of a new magnetic seed localisation device – A UK iBRA-NET breast cancer localisation study

Introduction Shared learning is imperative in the assessment and safe implementation of new healthcare interventions. Magnetic seeds (Magseed®) potentially offer logistical benefit over wire localisation for non-palpable breast lesions but few data exist on outcomes comparing these techniques. A national registration study (iBRA-NET) was conducted to collate device outcomes. In order to share learning, thematic analysis was conducted to ascertain early clinical experiences of Magseed® and wire guided localisation and explore how learning events may be applied to improve clinical outcomes. Methods A qualitative study of 27 oncoplastic surgeons, radiologists and physicians was conducted in January 2020 to ascertain the feasibility and challenges associated with Magseed® versus wire breast localisation surgery. Four focus groups were asked to discuss experiences, concerns and shared learning outcomes which were tabulated and analysed thematically. Results Three key themes were identified comparing Magseed® and wire localisation of breast lesions relating to preoperative, intraoperative and postoperative learning outcomes. Percutaneous Magseed® detection, instrument interference and potential seed or wire dislodgement were the most common issues identified. Clinician experience suggested Magseed® index lesion identification was non-inferior to wire placement and improved the patient pathway in terms of scheduling and multi-site insertion. Conclusions Prospective shared learning suggested Magseed® offered additional non-clinical benefits over wire localisation, improving the efficiency of the patient pathway. Recommendations for improving breast localisation technique, appropriate patient selection and clinical practice through shared learning are discussed that may aid other surgeons in the adoption of this relatively new technique