A qualitative study of the feasibility and acceptability of a smoking cessation program for people living with HIV and emotional dysregulation.

Despite high rates of co-occurring tobacco use and anxiety among persons living with HIV, evidence-based interventions for these individuals are limited. An existing cognitive-behavioral treatment protocol for smoking cessation and anxiety (Norton, P. J., & Barrera, T. L. (2012). Transdiagnostic versus diagnosis-specific CBT for anxiety disorders: A preliminary randomized controlled noninferiority trial. Depression and Anxiety, 29(10), 874-882. https://doi.org/10.1002/da.21974) was modified to address transdiagnostic constructs, such as anxiety sensitivity, distress tolerance, and depressive symptomatology (Labbe, A. K., Wilner, J. G., Kosiba, J. D., Gonzalez, A., Smits, J. A., Zvolensky, M. J., … O'Cleirigh, C. (2017). Demonstration of an Integrated Treatment for Smoking Cessation and Anxiety Symptoms in People with HIV: A Clinical Case Study. Cognitive and Behavioral Practice, 24(2), 200-214. https://doi.org/10.1016/j.cbpra.2016.03.009). This study examines the feasibility and acceptability of the intervention as determined from qualitative data from structured exit interviews from 10 participants who completed treatment. Results demonstrated that participants were very motivated to quit smoking and enrolled in the program for health-related reasons and to be able to quit. Participants found nearly all the treatment components to be useful for reaching their smoking cessation goal and in managing emotional dysregulation. Last, all participants stated that they would strongly recommend the treatment program. This qualitative study provides initial evidence for the feasibility and acceptability of a modified smoking cessation treatment protocol for HIV+ individuals with anxiety and emotional dysregulation. Future research will focus on evaluating the efficacy of the protocol in a full-scale randomized controlled trial, as well as working to collect qualitative data from participants who discontinue treatment to better understand reasons for treatment attrition.

Biological recognition of graphene nanoflakes.

The systematic study of nanoparticle-biological interactions requires particles to be reproducibly dispersed in relevant fluids along with further development in the identification of biologically relevant structural details at the materials-biology interface. Here, we develop a biocompatible long-term colloidally stable water dispersion of few-layered graphene nanoflakes in the biological exposure medium in which it will be studied. We also report the study of the orientation and functionality of key proteins of interest in the biolayer (corona) that are believed to mediate most of the early biological interactions. The evidence accumulated shows that graphene nanoflakes are rich in effective apolipoprotein A-I presentation, and we are able to map specific functional epitopes located in the C-terminal portion that are known to mediate the binding of high-density lipoprotein to binding sites in receptors that are abundant in the liver. This could suggest a way of connecting the materials' properties to the biological outcomes.

Light scattering and random lasing in aqueous suspensions of hexagonal boron nitride nanoflakes.

Liquid phase exfoliation allows large scale production of 2D materials in solution. The particles are highly anisotropic and strongly scatter light. While spherical particles can be accurately and precisely described by a single parameter-the radius, 2D nanoflakes, however, cannot be so easily described. We investigate light scattering in aqueous solutions of 2D hexagonal boron nitride nanoflakes in the single and multiple scattering regimes. In the single scattering regime, the anisotropic 2D materials show a much stronger depolarization of light when compared to spherical particles of similar size. In the multiple scattering regime, the scattering as a function of optical path for hexagonal boron nitride nanoflakes of a given lateral length was found to be qualitatively equivalent to scattering from spheres with the same diameter. We also report the presence of random lasing in high concentration suspensions of aqueous h-BN mixed with Rhodamine B dye. The h-BN works as a scattering agent and Rhodamine B as a gain medium for the process. We observed random lasing at 587 nm with a threshold energy of 0.8 mJ.

Cobalt hydroxide nanoflakes and their application as supercapacitors and oxygen evolution catalysts.

Finding alternative routes to access and store energy has become a major issue recently. Transition metal oxides have shown promising behaviour as catalysts and supercapacitors. Recently, liquid exfoliation of bulk metal oxides appears to be an effective route which provides access to two-dimensional (2D) nano-flakes, the size of which can be easily selected. These 2D materials exhibit excellent electrochemical charge storage and catalytic activity for the oxygen evolution reaction. In this study, various sized selected cobalt hydroxide nano-flake materials are fabricated by this time efficient and highly reproducible process. Subsquently, the electrochemical properties of the standard size Co(OH)2 nanoflakes were investigated. The oxide modified electrodes were prepared by spraying the metal oxide flake suspension onto a porous conductive support electrode foam, either glassy carbon or nickel. The cobalt hydroxide/nickel foam system was found to have an overpotential value at 10 mA cm-2 in 1 M NaOH as low as 280 mV and an associated redox capacitance exhibiting numerical values up to 1500 F g-1, thereby making it a viable dual use electrode.

Revealing the nature of excitons in liquid exfoliated monolayer tungsten disulphide.

Transition metal dichalcogenides (TMD) hold promise for applications in novel optoelectronic devices. There is therefore a need for materials that can be obtained in large quantities and with well understood optical properties. In this report, we present thorough photoluminescence (PL) investigations of monolayer tungsten disulphide obtained via liquid phase exfoliation. As shown by microscopy studies, the exfoliated nanosheets have dimensions of tens of nanometers and thickness of 2.5 monolayers on average. The monolayer content is about 20%. Our studies show that at low temperature the PL is dominated by excitons localized on nanosheet edges. As a consequence, the PL is strongly sensitive to the environment and exhibits an enhanced splitting in magnetic field. As the temperature is increased, the excitons are thermally excited out of the defect states and the dominant transition is that of the negatively charged exciton. Furthermore, upon excitation with a circularly polarized light, the PL retains a degree of polarization reaching 50% and inherited from the valley polarized photoexcited excitons. The studies of PL dynamics reveal that the PL lifetime is on the order of 10 ps, which is probably limited by non-radiative processes. Our results underline the potential of liquid exfoliated TMD monolayers in large scale optoelectronic devices.

Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes.

We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.

Helium ion microscopy of graphene: beam damage, image quality and edge contrast.

A study to analyse beam damage, image quality and edge contrast in the helium ion microscope (HIM) has been undertaken. The sample investigated was graphene. Raman spectroscopy was used to quantify the disorder that can be introduced into the graphene as a function of helium ion dose. The effects of the dose on both freestanding and supported graphene were compared. These doses were then correlated directly to image quality by imaging graphene flakes at high magnification. It was found that a high magnification image with a good signal to noise ratio will introduce very significant sample damage. A safe imaging dose of the order of 10(13) He(+) cm(-2) was established, with both graphene samples becoming highly defective at doses over 5 × 10(14) He(+) cm(-2).The edge contrast of a freestanding graphene flake imaged in the HIM was then compared with the contrast of the same flake observed in a scanning electron microscope and a transmission electron microscope. Very strong edge sensitivity was observed in the HIM. This enhanced edge sensitivity over the other techniques investigated makes the HIM a powerful nanoscale dimensional metrology tool, with the capability of both fabricating and imaging features with sub-nanometre resolution.