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In this article, we highlight the epitaxial growth of non-polar a-plane ZnO and aluminium-doped ZnO using the low-cost, non-vacuum and highly up-scalable intermittent spray pyrolysis technique. We successfully deposited epitaxial ZnO and Al: ZnO thin films over r-sapphire using our optimized homemade Spray Pyrolysis setup. The epitaxial relationships are those usually found in the samples grown by the conventional well established epitaxial growth methods, that is, with a ZnO(112¯0)∥Al2O3(011¯2) out-of-plane direction. We investigated the effect of growth temperature on the growth of ZnO over r-sapphire substrate in the temperature range 300 °C to 600 °C and found that under the growth conditions that were used, there was an optimum growth temperature range of 450 °C-500 °C in which we could grow very compact uniform epitaxial ZnO thin films. At both, lower and higher growth temperatures, due to the instability induced in growth conditions (Ehrlich-Schwoebel effect and stress-induced instability, respectively), there was surface roughening. The effect of aluminium doping on ZnO was also investigated for the optimum growth temperatures 450 °C and 500 °C using morphological, structural and electrical (Hall measurements) characterisation. The Al:ZnO sample with a nominal aluminium concentration of 1 % without any post-deposition treatments had a carrier concentration of 5.03 × 1019 cm-3 and mobility of 10 cm2/V·s.

Objectives: Stimulants are a class of drugs approved for the treatment of attention-deficit hyperactivity disorder (ADHD) and narcolepsy. However, they are also often used “off-label” as adjunct therapies for the treatment of obesity and depression. The objective of this study is to summarize how stimulant use is globally measured in the literature and to explore rates of stimulant use in Alberta, Canada. Methods: A traditional narrative literature review was conducted to summarize global methods of stimulant assessment. Then using definitions guided by the literature and current regulatory bodies in Alberta, we conducted a series of descriptive analyses to assess how frequent stimulant use was in Alberta patients from 2019 to 2021: 1) number of dispenses by year; 2) average days of drug supply; 3) proportion of days covered (PDC); and 4) defined daily dose (DDDs). Results: In the literature review, the most frequently used measures of stimulant drug use were trends over time (prevalence), types of drug use, and dispensations of prescriptions. In all, there is a global trend of increased use of stimulants among both adults and children. In Alberta, 173,789 patients were prescribed stimulant medication in 2019–2021, representing approximately 4 % of the entire Alberta population. Overall, 61.1 % were between the ages of 10–34 and 46.8 % were female. The number of dispensations rose from 713,896 in 2019 to 973,930 in 2021 – with up to 43 % being lisdexamfetamine stimulant dispenses. Conclusions: Although stimulant use in AB was measured using similar trend estimates as the literature, there is a lack of research to support whether these measures are accurate and effective at the population-level. Future steps to standardize both medical and nonmedical use of prescription stimulants are warranted in efforts to fully quantify both benefits and risks associated with stimulant use.