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Premelting of ice, a quasi-liquid layer (QLL) at the surface below the melting temperature, was first postulated by Michael Faraday 160 y ago. Since then, it has been extensively studied theoretically and experimentally through many techniques. Existing work has been performed predominantly on hexagonal ice, at conditions close to the triple point. Whether the same phenomenon can persist at much lower pressure and temperature, where stacking disordered ice sublimates directly into water vapor, remains unclear. Herein, we report direct observations of surface premelting on ice nanocrystals below the sublimation temperature using transmission electron microscopy (TEM). Similar to what has been reported on hexagonal ice, a QLL is found at the solid-vapor interface. It preferentially decorates certain facets, and its thickness increases as the phase transition temperature is approached. In situ TEM reveals strong diffusion of the QLL, while electron energy loss spectroscopy confirms its amorphous nature. More significantly, the premelting observed in this work is thought to be related to the metastable low-density ultraviscous water, instead of ambient liquid water as in the case of hexagonal ice. This opens a route to understand premelting and grassy liquid state, far away from the normal water triple point. [ABSTRACT FROM AUTHOR]

Background: In mid-2022, a global mpox (formerly 'monkeypox') outbreak affecting predominantly gay and bisexual men emerged in non-endemic countries. Australia had never previously recorded mpox cases and there was no prior research on knowledge or attitudes to mpox among gay and bisexual men across Australia. Methods: We conducted a national, online cross-sectional survey between August 2022 and September 2022. Participants were recruited through community organisation promotions, online advertising, and direct email invitations. Eligible participants were gay, bisexual or queer; identified as male (cisgender or transgender) or non-binary; aged 16 years or older; and lived in Australia. The main outcome measures were: knowledge and concern about mpox; recognition of mpox symptoms and transmission routes; vaccination history; acceptability of behavioural changes to reduce mpox risk, and willingness to be vaccinated. Results: Of 2287 participants, most participants were male (2189/2287; 95.7%) and gay (1894/2287; 82.8%). Nearly all had heard about mpox (2255/2287; 98.6%), and the majority were concerned about acquiring it (1461/2287; 64.4%). Most of the 2268 participants not previously diagnosed with mpox correctly identified skin lesions (2087; 92%), rash (1977; 87.2%), and fever (1647; 72.6%) as potential symptoms, and prolonged and brief skin-to-skin contact as potential ways to acquire mpox (2124, 93.7%; and 1860, 82%, respectively). The most acceptable behavioural changes were reducing or avoiding attendance at sex parties (1494; 65.9%) and sex-on-premises venues (1503; 66.4%), and having fewer sexual partners (1466; 64.6%). Most unvaccinated and undiagnosed participants were willing to be vaccinated (1457/1733; 84.1%). Conclusions: People at risk of mpox should be supported to adopt acceptable risk reduction strategies during outbreaks and to seek vaccination. Mid-2022 saw a global mpox outbreak among primarily gay and bisexual men. During August–September 2022, we surveyed 2287 gay, bisexual and queer men and non-binary people about their knowledge of mpox, willingness to make behavioural changes, and be vaccinated. Nearly all participants had heard of mpox and most were familiar with common symptoms and transmission routes. We found very high willingness to be vaccinated against mpox but we identified some groups who may benefit from targeted information about vaccination. [ABSTRACT FROM AUTHOR]

Introduction: The HIV Strategy in New South Wales (NSW) Australia aims to virtually eliminate HIV transmission by 2020. We estimated the 2016 HIV diagnosis and care cascade for the state of NSW, with a focus on introducing population-based data to improve data quality and assess progress towards the UNAIDS 90-90-90 targets. Methods: To estimate the number of people living with diagnosed HIV (PLDHIV) we used NSW data from the Australian National HIV Registry, enhanced by surveillance among people recently diagnosed with HIV to improve migration estimates. The number of undiagnosed PLHIV was estimated using back-projection modelling by CD4 count at diagnosis. De-duplicated prescription claims data were obtained from the Australian Pharmaceutical Benefits Scheme (PBS), and were combined with an estimate for those ineligible, to determine the number of PLDHIV on antiretroviral therapy (ART). Data from a clinic network with 87% coverage of PLDHIV in NSW enabled the estimation of the number on ART who had HIV suppression. Results and discussion: We estimated that 10,110 PLHIV resided in NSW in 2016 (range 8400 to 11,720), among whom 9230 (91.3%) were diagnosed, and 8490 (92.0% of those diagnosed) were receiving ART. Among PLDHIV receiving ART, 8020 (94.5%) had suppressed viral load ( Conclusion: NSW has met each of the UNAIDS 90-90-90 targets. The enhanced surveillance methods and data collection systems improved data quality. Measuring and meeting the 90-90-90 targets is feasible and could be achieved in comparable parts of the world. Keywords: 90-90-90; antiretroviral treatment; continuum of care; HIV; treatment cascade, 1 | INTRODUCTION In 2014, the Joint United Nations Programme on HIV and AIDS (UNAIDS) launched the 90-90-90 targets that by 2020, 90% of people living with HIV (PLHIV) will [...]

Introduction: We determined the contribution of undiagnosed HIV to new infections among gay and bisexual men (GBM) over a 12-year period in Australia where there has been increasing focus on improving testing and HIV treatment coverage. Methods: We generated annual estimates for each step of the HIV cascade and the number of new HIV infections for GBM in Australia over 2004 to 2015 using relevant national data. Using Bayesian melding we then fitted a quantitative model to the cascade and incidence estimates to infer relative transmission coefficients associated with being undiagnosed, diagnosed and not on ART, on ART with unsuppressed virus, or on ART with suppressed virus. Results: Between 2004 and 2015, we estimated the percentage of GBM with HIV in Australia who were unaware of their status to have decreased from 14.5% to 7.5%. During the same period, there was a substantial increase in the number and proportion of GBM living with HIV on treatment and with suppressed virus, with the number of virally suppressed GBM increasing from around 3900 (30.2% of all GBM living with HIV) in 2004 to around 14,000 (73.7% of all GBM living with HIV) in 2015. Despite the increase in viral suppression, the annual number of new infections rose from around 660 to around 760 over this period. Our results have a wide range due to the uncertainty in the cascade estimates and transmission coefficients. Nevertheless, undiagnosed GBM increasingly appear to contribute to new infections. The proportion of new infections attributable to undiagnosed GBM almost doubled from 33% in 2004 to 59% in 2015. Only a small proportion ( Discussion: Our study suggests that an increase in HIV treatment coverage in Australia has reduced the overall risk of HIV transmission from people living with HIV. However, the proportion of infections and the rate of transmission from undiagnosed GBM has increased substantially. These findings highlight the importance of HIV testing and intensified prevention for Australian GBM at high risk of HIV. Keywords: Australia; gay and bisexual men; mathematical model; transmission dynamics; undiagnosed HIV; HIV cascade, 1 | INTRODUCTION People with undiagnosed HIV contribute disproportionately to HIV transmission because the early stages of infection are the most infectious, and without treatment an individual remains infectious [1-7]. [...]

Although approximately 31,000 Australian gay and bisexual men (GBM) are eligible for HIV pre-exposure prophylaxis (PrEP), only 18,500 people currently use it, indicating a need to investigate why GBM do not use it. This article uses data from a national, online, observational study. It adopts a mixed-methods analysis to responses to survey questions asking about reasons Australian GBM were not using PrEP in 2018, according to their level of HIV risk as delineated by the Australian PrEP prescribing guidelines at the time. Participants responded to check-box questions and had the option to respond to a qualitative free-text question. Results showed that just over one-fifth of men were at higher risk of HIV acquisition. Compared to lower-risk men, higher-risk men were more likely to indicate PrEP was too expensive and more likely to cite embarrassment asking for it. Reasons for not using PrEP included a lack of personal relevance, poor accessibility or knowledge, concerns about PrEP's inability to protect against STIs, potential side effects, and a preference for condoms. We conclude that health promotion more effectively targeting GBM who may benefit the most from PrEP may be valuable. [ABSTRACT FROM AUTHOR]

The discovery of topological Hall effect (THE) has important implications for next‐generation high‐density nonvolatile memories, energy‐efficient nanoelectronics, and spintronic devices. Both real‐space topological spin configurations and two anomalous Hall effects (AHE) with opposite polarity due to two magnetic phases have been proposed for THE‐like feature in SrRuO3 (SRO) films. In this work, SRO thin films with and without THE‐like features are systematically Investigated to decipher the origin of the THE feature. Magnetic measurement reveals the coexistence of two magnetic phases of different coercivity (Hc) in both the films, but the hump feature cannot be explained by the two channel AHE model based on these two magnetic phases. In fact, the AHE is mainly governed by the magnetic phase with higher Hc. A diffusive Berry phase transition model is proposed to explain the THE feature. The coexistence of two Berry phases with opposite signs over a narrow temperature range in the high Hc magnetic phase can explain the THE like feature. Such a coexistence of two Berry phases is due to the strong local structural tilt and microstructure variation in the thinner films. This work provides an insight between structure/micro structure and THE like features in SRO epitaxial thin films. [ABSTRACT FROM AUTHOR]

Although many studies reported on decreases in sexual partner numbers among gay and bisexual-identifying men in the early period of the COVID-19 pandemic, few studies have explored COVID-19 risk-reduction strategies. Drawing on free-text responses in an online survey (from April to July 2020), we describe the ways in which men sought to minimise the risk of COVID-19 in sexual encounters. Partner selection was an important strategy, in particular, restricting sex to men they already knew. Accounts also indicate how participants assessed risk from potential sex partners based on symptoms, residential location, recent travel, work role, and number of other sexual contacts. Less common were in situ practices, such as avoiding kissing. Participants' responses provide insight into creative community-based responses in the early months of the pandemic, some of which have resonances with early responses to HIV. Findings are discussed in relation to the concepts of 'lay epidemiology' and 'counterpublic health'. In particular, we examine how risks and health are experienced and valued in relation to local knowledges, meanings, and practices; and how practices emerge in response to dominant public health discourses that produce an idealised public based on (hetero)normative assumptions. [ABSTRACT FROM AUTHOR]