Studying the photothermal activation of polydopamine-shelled, phase-change emulsion droplets into microbubbles using small- and ultra-small-angle neutron scattering.

Polydopamine-shelled perfluorocarbon (PDA/PFC) emulsion droplets are promising candidates for medical imaging and drug delivery applications. This study investigates their phase transition into microbubbles under near-infrared (NIR) illumination in situ using small- and ultra-small-angle neutron scattering (SANS and USANS) and contrast variation techniques. Supported by optical microscopy, thermogravimetric analysis, and ultrasound imaging, SANS and USANS results reveal rapid phase transition rates upon NIR illumination, dependent on PFC content and droplet size distribution. Specifically, perfluoropentane droplets rapidly transform into bubbles upon NIR irradiation, whereas perfluorohexane droplets exhibit greater resistance to phase change (bulk boiling points = 30 °C and 60 °C, respectively). Furthermore, smaller emulsion droplets with unimodal distribution resist NIR-triggered phase changes better than their bimodal counterparts. This observation is attributable to the lower boiling points of large emulsion droplets (lower Laplace pressure than smaller droplets) and the faster photothermal heating rates due to their thicker polydopamine shells. The insights gained from these techniques are crucial for designing phase-change emulsions activated by NIR for photothermal therapies and controlled drug delivery.

A Pilot Randomised Controlled Trial to Increase the Sustainment of an Indoor-Outdoor-Free-Play Program in Early Childhood Education and Care Services: A Study Protocol for the Sustaining Play, Sustaining Health (SPSH) Trial.

Early Childhood Education and Care (ECEC) settings are important environments to support children's physical activity (PA). In 2021, COVID-19 regulations recommended the provision of indoor-outdoor free-play programs in ECEC settings to reduce the transmission of COVID-19, resulting in an increased uptake of this practice. As the context has since changed, research suggests that ECEC services could cease the implementation of these practices. Therefore, this pilot randomised controlled trial (RCT) aims to examine the feasibility, acceptability, and impact of a sustainment strategy to ensure the ongoing implementation (sustainment) of ECEC-delivered indoor-outdoor free-play programs. Twenty ECEC services located in New South Wales, Australia that have implemented indoor-outdoor free-play programs since the release of COVID-19 guidelines will be recruited. The services will be randomly allocated either the sustainment strategy or usual care. The "Sustaining Play, Sustaining Health" program consists of eight strategies, developed to address key barriers against and facilitators of sustainment informed by the Integrated Sustainability Framework. The outcomes will be assessed via internal project records, staff surveys, and a self-reported measure of free play. This study will provide important data to support the performance of a fully powered trial within Australian ECEC settings and to inform the development of future sustainment strategies.

Copper-Binding Properties of Polyethylenimine-Silica Nanocomposite Particles.

Increasing demand for copper resources, accompanied by increasing pollution, has resulted in an urgent need for effective materials for copper binding and extraction. Polyethylenimine (PEI) is one of the strongest copper-chelating agents but is not suitable directly (as is) for most applications due to its high solubility in water. PEI-based composite materials show potential as efficient and practical alternatives. In the present work, the interaction of copper ions with PEI-silica nanocomposite particles and precursor PEI microgels (as a reference) is investigated. It is hypothesized that the main driving force of the reaction is chelation of copper ions by amino groups in the PEI network. The presence of silica in the PEI-silica composites was shown to increase the copper-binding capacity in comparison with the parent microgel. The copper-binding behavior of etched (PEI-free "ghost") composite particles in comparison with the original composites and microgel particles shows that silica nanoparticles in the composite structure increase the number of copper-binding sites in the PEI network rather than adsorbing copper themselves. PEI-silica composites can be easily recycled after copper adsorption by simply washing in 1 M nitric acid, which results in complete copper extraction. Employing this recovery method, PEI-silica composite particles can be used for multiple, efficient cycles of copper removal and extraction.

Structure-Performance Relationships for Tail Substituted Zwitterionic Betaine-Azobenzene Surfactants.

Azobenzene-containing surfactants (azo-surfactants) have garnered significant attention for their use in generating photoresponsive foams, interfaces, and colloidal systems. The photoresponsive behavior of azo-surfactants is driven by the conformational and electronic changes that occur when the azobenzene chromophore undergoes light-induced trans ⇌ cis isomerization. Effective design of surfactants and targeting of their properties requires a robust understanding of how the azobenzene functionality interacts with surfactant structure and influences overall surfactant behavior. Herein, a library of tail substituted azo-surfactants were synthesized and studied to better understand how surfactant structure can be tailored to exploit the azobenzene photoswitch. This work shows that tail group structure (length and branching) has a profound influence on the critical micelle concentration of azo-surfactants and their properties once adsorbed to an air-water interface. Neutron scattering studies revealed the unique role that intermolecular π-π azobenzene interactions have on the self-assembly of azo-surfactants, and how the influence of these interactions can be tuned using tail group structure to target specific aqueous aggregate morphologies.

A randomised controlled trial of an implementation strategy delivered at scale to increase outdoor free play opportunities in early childhood education and care (ECEC) services: a study protocol for the get outside get active (GOGA) trial.

BACKGROUND: Increased outdoor play time in young children is associated with many health and developmental benefits. This study aims to evaluate the impact of a multi-strategy implementation strategy delivered at scale, to increase opportunities for outdoor free play in Early Childhood Education and Care (ECEC) services. METHODS: The study will employ a parallel-group randomised controlled trial design. One hundred ECEC services in the Hunter New England region of New South Wales, Australia, will be recruited and randomised to receive either a 6-month implementation strategy or usual care. The trial will seek to increase the implementation of an indoor-outdoor routine (whereby children are allowed to move freely between indoor and outdoor spaces during periods of free play), to increase their opportunity to engage in outdoor free play. Development of the strategy was informed by the Behaviour Change Wheel to address determinants identified in the Theoretical Domains Framework. ECEC services allocated to the control group will receive 'usual' implementation support delivered as part of state-wide obesity prevention programs. The primary trial outcome is the mean minutes/day (calculated across 5 consecutive days) of outdoor free play opportunities provided in ECEC services measured at baseline, 6-months (primary end point) and 18-months post baseline. Analyses will be performed using an intention-to-treat approach with ECEC services as the unit of analysis, using a linear mixed effects regression model to assess between-group differences. A sensitivity analysis will be undertaken, adjusting for service characteristics that appear imbalanced between groups at baseline, and a subgroup analysis examining potential intervention effect among services with the lowest baseline outdoor free play opportunities. DISCUSSION: Identifying effective strategies to support the implementation of indoor-outdoor routines in the ECEC setting at scale is essential to improve child population health. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ( ACTRN12621000987864 ). Prospectively registered 27th July 2021, ANZCTR - Registration.

Tracking the heat-triggered phase change of polydopamine-shelled, perfluorocarbon emulsion droplets into microbubbles using neutron scattering.

Perfluorocarbon emulsion droplets are hybrid colloidal materials with vast applications, ranging from imaging to drug delivery, due to their controllable phase transition into microbubbles via heat application or acoustic droplet vapourisation. The current work highlights the application of small- and ultra-small-angle neutron scattering (SANS and USANS), in combination with contrast variation techniques, in observing the in situ phase transition of polydopamine-shelled, perfluorocarbon (PDA/PFC) emulsion droplets with controlled polydispersity into microbubbles upon heating. We correlate these measurements with optical and transmission electron microscopy imaging, dynamic light scattering, and thermogravimetric analysis to characterise these emulsions, and observe their phase transition into microbubbles. Results show that the phase transition of PDA/PFC droplets with perfluorohexane (PFH), perfluoropentane (PFP), and PFH-PFP mixtures occur at temperatures that are around 30-40 °C higher than the boiling points of pure liquid PFCs, and this is influenced by the specific PFC compositions (perfluorohexane, perfluoropentane, and mixtures of these PFCs). Analysis and model fitting of neutron scattering data allowed us to monitor droplet size distributions at different temperatures, giving valuable insights into the transformation of these polydisperse, emulsion droplet systems.

Assessing the responses of smokers to requests to stop smoking on hospital grounds.

ISSUE ADDRESSED: Fear of aggression is often cited as an issue for health service staff in approaching smokers who are breaching smoke-free policies. This study collected data to quantify the interactions between Health Promotion Service staff and smokers. The aim was to trial de-escalation based protocols for Authorised Inspectors and one for general staff with regards to the aggression risk to staff when approaching smokers within hospital grounds. METHODS: The study design was a non-randomised trial with no control group. A standard protocol was developed, based on de-escalation techniques. The primary outcomes of the study were measures of aggression and smokers' compliance with instructions to extinguish their cigarette. Aggression was recorded using the Modified Overt Aggression Scale (MOAS). Two hundred interactions were conducted with smokers during business hours by Health Promotion Service staff. The first 100 interactions were based on an enforcement methodology typically delivered by Authorised Inspectors, while the second 100 interactions were based on an information and assistance methodology to reflect those that could be delivered by general health service staff. RESULTS: Only four instances of aggression were experienced, representing 2% of all interactions. Each of these was limited to verbal aggression. No self-aggression, aggression against property, or physical aggression was encountered. Smokers were significantly more compliant to instructions to extinguish their cigarette in the enforcement method (64%) than the information and assistance method (45%) (P < .001). Groups of smokers were more compliant than individual smokers in the enforcement method (76.3% compared to 56.5%, P < .05). CONCLUSIONS: This study quantifies the risk of aggression to health service staff conducting smoking compliance interactions using two methodologies. By following de-escalation-based protocols, staff can approach smokers in a low-risk manner and support smoke-free policy implementation and compliance. For general staff, the emphasis of interactions must be on providing information and assistance to smokers, not enforcement, as indicated by the reduced rate of immediate compliance, introducing an increased risk of escalation if enforcement is attempted. SO WHAT?: These protocols could be implemented by other health services or organisations that are seeking to optimise the involvement of staff in supporting smoke-free policies.

Exploring and reorienting psychiatrists' attitudes regarding smoking cessation and its potential to improve mental health outcomes: a pilot study.

OBJECTIVE: The aims of this study were to explore the knowledge, attitudes, confidence and practices of Australian psychiatrists and psychiatry registrars with regard to smoking cessation with their patients and to promote clinical practice reflection and re-framing. METHODS: A mixed-methods questionnaire was developed. Interviews were conducted via telephone or face-to-face utilising participatory action research principles. Qualitative data were de-identified and analysed following a reflexive thematic approach. RESULTS: The questionnaire was completed with 15 participants. The majority worked in the public health sector and agreed that smoking cessation could be used as a clinical tool across mental health services. However, nearly all of the participants reported being unfamiliar with the latest literature. Only one-third of participants reported having had received formal training in smoking cessation. Overwhelmingly, more training was reported as necessary and welcomed by participants. CONCLUSION: Our study has identified gaps in psychiatrists' and psychiatry registrars' knowledge and confidence regarding the promotion, initiation and oversight of smoking cessation strategies for patients. It's important that psychiatrists lead the way in re-framing and engaging with this issue, and consider smoking cessation as a tool that can improve mental health outcomes. A review of existing Australian policies, guidelines and training is recommended.

Norepinephrine derived carbon dots for live-cell imaging and effective hemoglobin determination.

Recently, carbon dots (CDs) have attracted wide attention for their potential use as fluorescence probes in biological and analytical chemistry due to their great stability and high fluorescence quantum yields. In our work, norepinephrine (NE)-derived CDs with green luminescence and an average size of 10 nm were fabricated using a one-step hydrothermal route. As-prepared CDs show a strong emission at a wavelength of 520 nm when excited at 420 nm, and demonstrate pH and concentration dependent fluorescence behaviour. Multiple functional groups on the CDs allow their protonation/deprotonation and thus alter fluorescence intensity and peak position in different pH conditions. Prepared CDs show significant potential to be used as a live-cell imaging agent with long-term photostability. Furthermore, a simple but effective method to determine the concentration of hemoglobin (Hb) in diluted human blood samples was also developed based on the inner filter effect (IFE). The method demonstrates good linearity from 0.01-10 µM, with a limit of determination (LOD) of 52 nM.

Exploring the transition of polydopamine-shelled perfluorohexane emulsion droplets into microbubbles using small- and ultra-small-angle neutron scattering.

Perfluorocarbon emulsion droplets are interesting colloidal systems with applications, ranging from diagnostics and theranostics to drug delivery, due to their controllable phase transition into microbubbles via heat application or acoustic droplet vapourisation. This work highlights the application of small- and ultra-small-angle neutron scattering (SANS and USANS, respectively), in combination with contrast variation techniques, in observing the in situ phase transition of polydopamine-stabilised perfluorohexane (PDA/PFH) emulsion droplets into microbubbles during heating. Results show peak USANS intensities at temperatures around 90 °C, which indicates that the phase transition of PDA/PFH emulsion droplets occurs at significantly higher temperatures than the bulk boiling point of pure liquid PFH (56 °C). Analysis and model fitting of the SANS and USANS data allowed us to estimate droplet sizes and interfacial properties at different temperatures (20 °C, 90 °C, and 20 °C after cooling), giving valuable insights about the transformation of these polydisperse emulsion droplet systems.

Design and synthesis of an azobenzene-betaine surfactant for photo-rheological fluids.

HYPOTHESIS: Morphology of surfactant self-assemblies are governed by the intermolecular interactions and packing constraints of the constituent molecules. Therefore, rational design of surfactant structure should allow targeting of the specific self-assembly modes, such as wormlike micelles (WLMs). By inclusion of an appropriate photo-responsive functionality to a surfactant molecule, light-based control of formulation properties without the need for additives can be achieved. EXPERIMENTS: A novel azobenzene-containing surfactant was synthesised with the intention of producing photo-responsive wormlike micelles. Aggregation of the molecule in its cis and trans isomers, and its concomitant flow properties, were characterised using UV-vis spectroscopy, small-angle neutron scattering, and rheological measurements. Finally, the fluids capacity for mediating particle diffusion was assessed using dynamic light scattering. FINDINGS: The trans isomer of the novel azo-surfactant was found to form a viscoelastic WLM network, which transitioned to inviscid ellipsoidal aggregates upon photo-switching to the cis isomer. This was accompanied by changes in zero-shear viscosity up to 16,000×. UV-vis spectroscopic and rheo-SANS analysis revealed π-π interactions of the trans azobenzene chromophore within the micelles, influencing aggregate structure and contributing to micellar rigidity. Particles dispersed in a 1 wt% surfactant solution showed a fivefold increase in apparent diffusion coefficient after UV-irradiation of the mixture.

Supporting visitor compliance with a smoke-free policy at hospital using a nicotine replacement therapy vending machine.

ISSUE ADDRESSED: To support visitors to comply with Central Coast Local Health District's (CCLHD) smoke-free hospital grounds policy, a need was identified for round-the-clock availability of nicotine replacement therapy (NRT). Providing NRT through a vending machine was identified as a possible solution. This initiative complemented other strategies that provide staff and patients who smoke with NRT. METHODS: NRT was originally provided through a snack vending machine; however, there were commercial and regulatory concerns with this method. In 2015, dedicated NRT vending machines were installed at Gosford and Wyong Hospitals, and were operated by the Health Promotion Service. The appropriate regulatory permission was gained to supply a specific brand of NRT. Sales and incident data were recorded, and ongoing smoking counts were performed both before and after installation. RESULTS: In all, 247 sales of NRT gum were made through the vending machines from early 2017 to late 2019. Smoking counts show that there are very low rates of visitor smoking (<1%) in the approximately 4.5 years pre- and post-installation of dedicated vending machines. There was no statistically significant change in the smoking rate of visitors since the vending machine was installed at Wyong Hospital. CONCLUSIONS: While NRT is generally provided to patients and staff within health settings to support compliance with smoke-free policies, alternatives to smoking for visitors are typically overlooked. A NRT vending machine achieves this. However, because there are few purchases made, the vending machines as currently operating are unlikely to make any significant impact on smoke-free policy compliance at these hospitals. SO WHAT?: While vending machines have limited effectiveness on overall smoke-free policy compliance, this strategy may have applicability to all sectors with smoke-free policies, especially those operating 24 hours a day, as a means of providing an alternative to smoking for visitors.

Capture of Perfluorooctanoic Acid Using Oil-Filled Graphene Oxide-Silica Hybrid Capsules.

Fluorinated hydrocarbon (FHC) contamination has attracted global attention recently because of persistence within the environment and ecosystems of many types of FHC. The surfactant perfluorooctanoic acid (PFOA) is particularly commonly found in contaminated sites, and thus, urgent action is needed for its removal from the environment. In this study, water dispersible hybrid capsules were successfully prepared from an oil-in-water emulsion stabilized by graphene oxide and including a silicate precursor to grow a strong, mesoporous capsule shell surrounding the droplets. These capsules were decorated with amine groups to present a positively charged outer corona that attracts negative PFOA molecules. The aminated capsules were effectively applied as a novel technology to adsorb and sequester PFOA contamination in water. It was confirmed that PFOA removal by the capsules was pH and PFOA concentration dependent, with adsorption efficiencies of >60 mg g-1 under ideal conditions. PFOA removal kinetics followed using high-performance liquid chromatography and liquid chromatography-mass spectrometry showed that capture of PFOA by the capsules reached a maximum of >99.9% in 2-3 days.

Structural relationships for the design of responsive azobenzene-based lyotropic liquid crystals.

Light-responsive binary (azobenzene + solvent) lyotropic liquid crystals (LCs) were investigated by structural modification of simple azobenzene molecules. Three benzoic acid-containing azobenzene molecules 4-(4-(hydroxyphenyl)diazenyl)benzoic acid (AZO1), 3-(4-(hydroxyphenyl)diazenyl)benzoic acid (AZO2) and 5-(4-(hydroxyphenyl)diazenyl)isophthalic acid (AZO3) were produced with various amide substitutions to produce tectons with a variety of hydrophobicity, size and branching. The LC mesophases formed by binary (azobenzene + solvent) systems with low volatility solvents dimethylsulfoxide (DMSO) and N,N-dimethylformamide (DMF) as well as the protic ionic liquids ethylammonium formate (EAF) and propylammonium formate (PAF), were investigated using a combination of small-angle X-ray and neutron scattering (SAXS and SANS) as well as polarising light microscopy (PLM). Increasing alkyl group length was found to have a strong influence on LC phase spacing, and changes in the position of substitution on the benzene ring influenced the preferred curvature of phases. UV-induced trans to cis isomerization of the samples was shown to influence ordering and optical birefringence, indicating potential applications in optical devices.

Implementing and enforcing a smoke-free policy and by-law on hospital grounds at Central Coast Local Health District.

ISSUE ADDRESSED: Smoking by patients, staff and visitors on the grounds of Central Coast Local Health District (CCLHD). METHODS: NSW Health introduced a smoke-free buildings and vehicles policy in 1988. A smoke-free grounds policy was implemented in 1999, and a smoke-free by-law adopted by CCLHD in 2013, making smoking on CCLHD grounds an offence. Smoking in high-profile areas near hospital entrances was counted regularly since 2000. Several methods for communicating, monitoring and enforcing these smoke-free interventions have been adopted, including signage, Public Address announcements and enforcement patrols to ensure by-law compliance and to issue fines where required. Compliance with the smoke-free interventions has been supported with the availability of Nicotine Replacement Therapy for patients and visitors. RESULTS: When monitoring counts first commenced in 2000, smoking rates in high-profile areas were 8.1% at Gosford Hospital and 11.1% at Wyong Hospital. Counts conducted in 2018 indicated a substantial improvement, with the smoking rate in high-profile areas reducing to 0.25% at Gosford Hospital and 0.5% at Wyong Hospital. Smoking rates in high-profile areas have held steady at approximately 0.3% since 2014, after the by-law was implemented. CONCLUSIONS: The introduction of the smoke-free by-law added extra impetus to efforts to reduce smoking on CCLHD hospital grounds by providing the option to fine people who breach the by-law. Smoking in high-profile areas has declined substantially since 2011, and is minimal since the establishment of the smoke-free by-law. SO WHAT?: The experiences of CCLHD in implementing the smoke-free by-law may provide insights for other health services looking to use a similar intervention at their facilities. There are also methodological lessons for other organisations looking to communicate, monitor and enforce smoke-free policies, without enforcing fines.