Liquid Crystals Based on the -Phenylpyridinium Cation-Mesomorphism and the Effect of the Anion.

Families of symmetric, ionic, tetracatenar mesogens are described based on a rigid, -phenylpyridinium core, prepared as their triflimide, octyl sulfate and dodecyl sulfate salts for a range of terminal chain lengths. The mesomorphism of the individual series is described before a comparison is drawn between the different families and then more broadly with (i) neutral tetracatenar materials and (ii) related bis(3,4-dialkoxystilbazole)silver(I) salts. For the octyl and dodecyl sulfates and the related triflates reported earlier, a SmA phase is seen at shorter chain lengths, giving way to a Col phase as the terminal chain lengthens.

Ionic N-phenylpyridinium tetracatenar mesogens: competing driving forces in mesophase formation and unprecedented difference in phase stabilisation within a homologous series.

Ionic, tetracatenar liquid crystals containing an N-phenylpyridinum core are described; many of these compounds display a SmA phase, something extremely rare in tetracatenar materials. The competing forces driving mesophase formation lead to an unprecedented difference in phase stabilities for SmA and Colh phases.

Retrospective audit of airway management practices in children with craniocervical pathology.

Background: Craniocervical immobilization using halo body orthoses may be required in the management of children with craniocervical junction pathology. To date, the effect of such immobilization on perioperative anesthetic management has not been addressed in large series.

Aims: The aim of this study was to review the airway management of children requiring halo body orthoses undergoing general anesthesia.

The cost-effectiveness of screening for ovarian cancer: results from the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS).

Background: To assess the within-trial cost-effectiveness of an NHS ovarian cancer screening (OCS) programme using data from UKCTOCS and extrapolate results based on average life expectancy.

Methods: Within-trial economic evaluation of no screening (C) vs either (1) an annual OCS programme using transvaginal ultrasound (USS) or (2) an annual ovarian cancer multimodal screening programme with serum CA125 interpreted using a risk algorithm (ROCA) and transvaginal ultrasound as a second-line test (MMS), plus comparison of lifetime extrapolation of the no screening arm and the MMS programme using both a predictive and a Markov model.

Results: Using a CA125-ROCA cost of £20, the within-trial results show USS to be strictly dominated by MMS, with the MMS vs C comparison returning an incremental cost-effectiveness ratio (ICER) of £91 452 per life year gained (LYG).

Reduction of severe visual loss and complications following intra-arterial chemotherapy (IAC) for refractory retinoblastoma.

Background: Intra-arterial chemotherapy (IAC) for retinoblastoma has been documented as causing visual loss and ocular motility problems. A lack of safety data has precluded its acceptance in all centres.

Methods: Retrospective cohort study of patients with retinoblastoma from 2013 to 2015 who had a healthy foveola and relapsed following systemic chemotherapy.