A novel multi-point optical fibre sensor for ultraviolet detection is presented. The sensor is a single piece of large-core polymer optical fibre which has had sections of its cladding stripped and replaced with phosphor-doped epoxies. These photoluminescent coatings act as the new cladding. Two points on the fibre have been coated with a different phosphor, each providing a different emission spectrum (red and green) when stimulated by ultraviolet radiation. The spectral emission intensity is dependent on the strength of the incident ultraviolet radiation. Part of this emission is coupled to the fibre's core through the evanescent wave of guided modes within the core. The fibre's output is monitored using a low-cost miniature spectrometer. The spectrometer output is used to interpret the different phosphor emission spectra and thus determine localized axial locations on the fibre of increased or decreased ultraviolet intensity. Results are included in the form of spectra (400-900 nm) under different ultraviolet stimulation conditions. An expanded version of this sensor has applications in monitoring ultraviolet water and waste-water sterilization units.

An optical fibre sensor for short pulse duration x-ray dosimetry is presented. The sensor is based on luminescence generated in the cladding of a 1 mm core diameter polymer optical fibre which has been doped with a radioluminescent phosphor. On interaction with x-rays, this phosphor emits visible light, part of which is coupled to the fibre core through a combination of surface roughness at the core-cladding interface and through evanescent wave coupling of these guided waves. From here it is transmitted to an optoelectronic photodetector for monitoring. A 15 cm fibre sensor was used for the experiment which was conducted using a pulsed x-ray source normally employed for the preionization of excimer lasers. The results are calibrated against the emission intensity from a scintillating plastic block and a pen dosimeter. The peak output signal of the fibre sensor increases linearly with the dose produced by the x-ray source. There is also a discussion on the long-term stability of such a sensor, the expansion of this sensor into a multi-point device and methods to improve the efficiency of the luminescence coupling from cladding to core for large core polymer fibres included.

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Background People with classic congenital adrenal hyperplasia (CAH) often require supraphysiologic doses of glucocorticoids (e.g., hydrocortisone, dexamethasone) to treat cortisol deficiency and excess androgen production. Healthcare providers and patients continually try to balance androgen control with side effects from supraphysiologic glucocorticoids. This study aimed to understand the preferences of adults with classic CAH regarding benefits of a potential new adjunctive medication that may provide better androgen control and allow for lower glucocorticoid doses. Methods Discrete choice experiment (DCE) methodology was used to calculate the relative stated preferences for the additional therapy's hypothetical benefits (attributes). Seven attributes were developed for the DCE after review of relevant data and qualitative literature, interviews with eight adults with classic CAH and input from two endocrinologists. The online DCE survey was piloted via interviews with three adults with classic CAH and a soft launch, which confirmed survey content and functioning. Preference data and subgroup differences were analyzed using conditional logit and scale assessment modelling, respectively. Results US adults with classic CAH (N=118, 75% female, age 19–69) valued avoidance of glucocorticoid-induced weight gain by twice the magnitude of other treatment attributes (all coefficients p<0.001 compared to baseline levels of no avoidance/decrease/improvement): complete avoidance of weight gain from glucocorticoids (1.109); moderate decrease in risk of developing health conditions from long-term glucocorticoids: type 2 diabetes (0.540), osteopenia, osteoporosis, fractures (0.521) and cardiovascular disease (0.502); moderate improvement in: fatigue (0.439), fertility (0.437) and excessive body hair (females only) and acne (0.410). Avoidance of glucocorticoid-induced weight gain remained the most preferred attribute across all subgroup analyses. Avoidance of glucocorticoid-induced weight gain was relatively much more important to females (n=89) than males (n=28) and participants with a body mass index ≥30 (n=70) than <30 (n=48). Improvement in fertility was more important to males than females, was valued by participants aged 18–45 (n=82) but was not a significant preference in participants >45 (n=36) and was relatively more important to participants with fertility problems (n=31) than without (n=87). Improvement in hirsutism and acne was highly valued by participants with excessive hair growth (n=38) but had the lowest preference among those without (n=80). Improvement in fatigue was a significant preference for participants with energy problems (n=73) but was not significant for those without (n=45). Conclusions The strong and consistent preference for avoiding glucocorticoid-induced weight gain suggests that patients with classic CAH would most value a novel adjunctive therapy that helps mitigate glucocorticoid-induced weight gain. In relation to other potential adjunctive therapy benefits, reduced risk of glucocorticoid-driven side effects may be valued more than improvement in fatigue or androgen-driven adverse events (fertility and hirsutism/acne). However, subgroup analyses indicated that individuals’ characteristics impact their treatment preferences and priorities, after avoidance of glucocorticoid-induced weight gain. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

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