Surface premelting of ice far below the triple point.

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.

X-ray nanodiffraction imaging reveals distinct nanoscopic dynamics of an ultrafast phase transition.

SignificancePhase transitions, the changes between states of matter with distinct electronic, magnetic, or structural properties, are at the center of condensed matter physics and underlie valuable technologies. First-order phase transitions are intrinsically heterogeneous. When driven by ultrashort excitation, nanoscale phase regions evolve rapidly, which has posed a significant experimental challenge to characterize. The newly developed laser-pumped X-ray nanodiffraction imaging technique reported here has simultaneous 100-ps temporal and 25-nm spatial resolutions. This approach reveals pathways of the nanoscale structural rearrangement upon ultrafast optical excitation, different from those transitions under slowly varying parameters. The spatiotemporally resolved structural characterization provides crucial nanoscopic insights into ultrafast phase transitions and opens opportunities for controlling nanoscale phases on ultrafast time scales.

Acceptability of doxycycline prophylaxis, prior antibiotic use, and knowledge of antimicrobial resistance among Australian gay and bisexual men and non-binary people.

BACKGROUND: There is growing interest in novel sexually transmissible infection (STI) prevention strategies, including doxycycline post-exposure prophylaxis (doxy-PEP). We assessed interest in doxy-PEP and other STI prevention strategies among gay and bisexual men and non-binary people in Australia, as well as prior antibiotic use for STI prevention, and knowledge of antimicrobial resistance (AMR). METHODS: We conducted a national, online survey in June-July 2023. Multivariable logistic regression was used to identify factors associated with the acceptability of doxy-PEP. RESULTS: Of 2,046 participants, 26.9% had been diagnosed with an STI in the previous year. Condoms were rated as an acceptable STI prevention strategy by 45.1% of the sample, STI pre-exposure prophylaxis by 54.0%, and doxy-PEP by 75.8%. Previous antibiotic use for STI prevention was reported by 7.5% of the sample, and 2.6% were currently using antibiotics for STI prevention. Over half the sample (62.1%) had some knowledge of AMR. Of those who knew something about AMR,76.2% were concerned about it. Interest in using doxy-PEP was independently associated with previous use of antibiotics for STI prevention (adjusted odds ratio 3.09, 95%CI = 1.78-5.35, p < 0.001), while those who were concerned about AMR were less interested in it (AOR 0.51, 95%CI = 0.36-0.72, p < 0.001). CONCLUSIONS: Doxy-PEP was highly acceptable to gay and bisexual men and non-binary people in Australia, and few factors distinguished between interest in using it or not. We recommend community and professional discussion and education about the effective use of doxy-PEP, AMR, and who would most benefit from doxy-PEP.

The Implications of PrEP Use, Condom Use, and Partner Viral Load Status for Openness to Serodifferent Partnering Among US Sexual Minority Men (SMM).

PrEP has been reported to facilitate openness to serodifferent sexual partnerships among sexual minority men (SMM). However, other aspects of a sexual scenario likely come into play, including whether or not condoms are used and whether or not the partner living with HIV has an undetectable viral load. This online survey study evaluated the association between PrEP status and openness to serodifferent partnering, as well as the effects of various sexual scenario variables (condom use and partner's viral load) among 268 HIV-negative SMM in the US. Each participant reported their PrEP status and rated their openness to serodifferent partnering in four sexual scenarios, which varied by condom use (with/without) and partner viral load status (detectable/undetectable). Analyses of covariance (ANCOVAs) were conducted to assess differences in openness to serodifferent partnering by PrEP status in each scenario, adjusting for background characteristics. A two-way repeated measures ANCOVA and a three-way mixed factorial ANCOVA, including PrEP status as a between-subjects variable, were also performed to assess the effects of condom use and partner viral load status on openness. Across all scenarios, current PrEP users expressed significantly greater openness to serodifferent partnering compared to participants who had never used PrEP. Current PrEP users were also more likely than former PrEP users to consider partnering with someone with an undetectable viral load without using condoms. Both PrEP users and PrEP-inexperienced individuals had greater openness to serodifferent partnering with a partner having an undetectable (vs. detectable) viral load, which was magnified by condom use among the latter.

RESUMEN: Se ha reportado que hombres de minorías sexuales (HMS) están más dispuestos a tener parejas sexuales serodiferentes cuando usan PrEP. Sin embargo, es probable que existan otros aspectos del contexto sexual, como el uso o no de condones y si la pareja que vive con el VIH tiene o no una carga viral indetectable. Este estudio utilizó una encuesta virtual para evaluar la asociación entre el uso de PrEP y el estar abierto a parejas serodiferentes, así como los efectos de diversas variables del contexto sexual (uso de condón y carga viral de la pareja) entre 268 SMM VIH negativos en los EE. UU. Cada participante reportó su uso de PrEP y estimó su apertura a parejas serodiferentes en cuatro contextos sexuales, que variaron según el uso de condón (con o sin) y el estado de carga viral de la pareja (detectable/indetectable). Para examinar si la apertura a tener parejas sexuales serodiferentes estaba asociada con el uso de PrEP en cada contexto sexual, se realizaron análisis de covarianza (ANCOVA), controlando por características demográficas. También se utilizó ANCOVA de medidas repetidas de dos vías y una ANCOVA de diseño factorial mixto de tres vías, incluyendo el estado de PrEP como una variable entre sujetos, para evaluar los efectos del uso de condón y el estado de carga viral de la pareja en la apertura a tener parejas sexuales serodiferentes. En todos los contextos, las personas usando PrEP en ese momento expresaron una apertura significativamente mayor a las parejas serodiferentes comparados con los participantes que nunca habían usado PrEP. Las personas usando PrEP en ese momento también eran más propensas a considerar asociarse con alguien con una carga viral indetectable sin usar condones que los que habían descontinuado PrEP. Tanto los usuarios de PrEP como las personas sin experiencia en PrEP tuvieron una mayor apertura a tener relaciones serodiferentes con una pareja que tuviera una carga viral indetectable (versus detectable), que se magnificó por el uso de condones entre los sin inexperiencia.

The Potential Role of Undetectable = Untransmittable (U = U) in Reducing HIV Stigma among Sexual Minority Men in the US.

The Undetectable = Untransmittable (U = U) message and its scientific underpinnings have been widely suggested to reduce HIV stigma. However, misunderstanding and skepticism about U = U may prevent this destigmatizing potential from being fully realized. This cross-sectional study examined associations between U = U belief (belief that someone with a sustained undetectable viral load has zero risk of sexually transmitting HIV) and HIV stigma among US sexual minority men. Differences by serostatus and effects of brief informational messaging were also explored. The survey was completed online by 106 men living with HIV and 351 HIV-negative/status-unknown men (2019-2020). Participants were 18-83 years old (M[SD] = 41[13.0]). Most were non-Hispanic White (70.0%) and gay (82.9%). Although nearly all participants (95.6%) were aware of U = U, only 41.1% believed U = U. A greater percentage of participants living with HIV (66.0%) believed U = U compared with HIV-negative/status-unknown participants (33.6%). Among participants living with HIV, U = U belief was not significantly associated with perceived, internalized, or experienced HIV stigma or with viral load prejudice (prejudice against people who have a detectable HIV viral load). Among HIV-negative/status-unknown participants, U = U belief was associated with less frequently enacted HIV discrimination, more positive feelings toward people with an undetectable viral load, and lower personal endorsement of stigmatizing beliefs. Brief informational messaging about U = U did not affect most stigma dimensions and did not favorably affect any. Interventions are needed to correct commonly held, outdated misconceptions about HIV transmission risk. Such initiatives must not only engage people living with HIV but also engage HIV-negative/status-unknown people to maximize the destigmatizing potential of U = U.

RESUMEN: Para reducir el estigma del VIH se ha recomendado difundir extensivamente el mensaje Indetectable = Intransmisible (U = U) y sus fundamentos científicos. Sin embargo, falta de comprensión y escepticismo acerca de U = U pueden impedir que se realice plenamente su potencial desestigmatizante. Este estudio transversal examinó las asociaciones entre la creencia U = U (creencia de que alguien con una carga viral indetectable sostenida tiene cero riesgo de transmitir sexualmente el VIH) y el estigma del VIH entre hombres de minorías sexuales estadounidenses. También se exploró si el efecto de los mensajes informativos breves dependía del estatus serológico. La encuesta fue completada en línea por 106 hombres que viven con el VIH y 351 hombres VIH negativos o de estatus desconocido (2019­2020). Los participantes tenían entre 18 y 83 años (M[DS] = 41[13,0]). La mayoría eran blancos no hispanos (70,0%) y gay (82,9%). Aunque casi todos los participantes (95,6%) sabían sobre U = U, sólo el 41,1% creían en U = U. Un mayor porcentaje de participantes con VIH (66,0%) creían que U = U en comparación con los participantes VIH negativos o de estatus desconocido (33,6%). Entre los participantes con VIH, la creencia U = U no se asoció significativamente con el estigma del VIH percibido, interiorizado o experimentado ni con el prejuicio sobre la carga viral (prejuicio contra las personas que tienen una carga viral de VIH detectable). Entre los participantes VIH negativos/con estatus desconocido, la creencia U = U se asoció con menor frecuencia de discriminación por VIH, sentimientos más positivos hacia las personas con una carga viral indetectable y menor respaldo personal a las creencias estigmatizantes. Los mensajes informativos breves sobre U = U no afectaron la mayoría de las dimensiones del estigma y no afectó favorablemente a ninguno. Se necesitan intervenciones para corregir conceptos frecuentes sobre el riesgo de transmisión del VIH que son erróneos y obsoletos. Para maximizar el potencial desestigmatizador de U = U, estas iniciativas no sólo deben involucrar a las personas que viven con el VIH, sino también a las personas VIH-negativas o de estatus desconocido.

Informed, but uncertain: managing transmission risk and isolation in the 2022 mpox outbreak among gay and bisexual men in Australia.

In 2022, a global outbreak of mpox (formerly 'monkeypox') emerged in non-endemic countries, including Australia, predominantly affecting gay, bisexual and other men who have sex with men. Public health advice on transmission and isolation emerged rapidly from different sources, sometimes conflicting and producing uncertainty. Using the concept of 'counterpublic health', which acknowledges the incorporation of official science and experiences of affected communities into embodied practice, this paper investigates how people affected by mpox in Australia managed risk of transmission and navigated self-isolation. In-depth interviews were conducted with 16 people: 13 people diagnosed with mpox and three close contacts. All participants were cisgender gay and bisexual men living in Australia. Participants thought critically about public health advice, often finding it restrictive and unresponsive to the needs of people with mpox. Participants' decisions about reducing mpox risk and isolating often drew on experiences with other infections (i.e. HIV; COVID-19) and were made collaboratively with the people closest to them (e.g. partners, friends, family) to sustain relationships. Future public health responses to infectious disease outbreaks would benefit from identifying more opportunities to formalise and embed mechanisms to obtain feedback from affected communities so as to inform responses.

Mpox Illness Narratives: Stigmatising Care and Recovery During and After an Emergency Outbreak.

In May 2022, a global outbreak of mpox (formerly monkeypox virus) affected thousands of mainly gay and bisexual men. Mpox is usually a time-limited illness that can involve fever, pain, and skin lesions, but may require hospitalisation. There is scant research into the firsthand experiences of people affected by mpox, including experiences of symptoms, healthcare, and recovery. This study considers the different illness narratives of people who experienced mpox in Australia in 2022. In-depth interviews and 6-month follow-up interviews were conducted with 16 people, including 13 people diagnosed with mpox and three close contacts. All participants were cisgender gay or bisexual men living in Australia. Participants' accounts described minor to severe periods of sickness, negative and stigmatising experiences engaging with healthcare, and some participants experienced long-term effects on their sexual well-being and complications from mpox. The emergency outbreak context meant that mpox was highly distressing, making it difficult to manage and producing varying forms of disruption to everyday life. Mpox was narrated as disruptive in different ways: as a minor interruption to holiday plans, a prolonged period of poor health, or a biographically disruptive event prompting a re-evaluation of sexual values and health. This analysis demonstrates that an unfamiliar emergent disease outbreak related to sexual practices and sociality can reconfigure personal life and sexual well-being, suggesting a need to focus on providing quality patient care in outbreaks of mpox and other infectious diseases.

Trends in Testing and Self-Reported Diagnoses of Sexually Transmitted Infections in Gay and Bisexual Men in Australia, 2017 to 2021: Analysis of National Behavioral Surveillance Surveys.

BACKGROUND: Gay, bisexual, and other men who have sex with men (GBM) are overrepresented in diagnoses of sexually transmitted infections (STIs) relative to their population size. This study assessed trends in STI testing and diagnoses among GBM in Australia. METHODS: The Gay Community Periodic Surveys are repeated cross-sectional behavioral surveillance surveys of GBM. Participants reported the number of anal swabs, throat swabs, urine samples, and blood tests for syphilis they undertook in the last year. "Frequent comprehensive testing" was defined as ≥3 of each test in the previous year. Participants reported STI diagnoses of chlamydia, gonorrhea, syphilis, and other STIs in the last year. Trends in testing and diagnoses from 2017 to 2020 and 2020 to 2021 were assessed with logistic regression models. RESULTS: We analyzed 24,488 survey responses from participants reporting casual sex in the last 6 months. Between 2017 and 2020, frequent comprehensive STI testing decreased among HIV-negative GBM on preexposure prophylaxis (PrEP) from 71.7% to 68.9% and declined further to 58.6% in 2021. Frequent comprehensive STI testing was stable during 2017-2020 among HIV-negative/untested GBM not on PrEP (17.4%-14.6%) and HIV-positive GBM (30.4%-35.1%) but declined in 2021 to 7.5% among non-PrEP-users and 25.7% among HIV-positive participants. There were minimal changes in STI diagnoses during 2017-2020, but diagnoses declined in 2021. CONCLUSIONS: Many GBM do not meet Australian STI testing guidelines that recommend quarterly testing. Further evaluation of whether this recommendation is realistic or necessary to reduce STIs among GBM is recommended.

Factors Associated With Willingness to Use Daily Antibiotics as Sexually Transmitted Infection Prophylaxis Among HIV Preexposure Prophylaxis-Experienced Gay and Bisexual Men in Australia.

BACKGROUND: Gay and bisexual men (GBM) who use HIV preexposure prophylaxis (HIV-PrEP) have high rates of bacterial sexually transmitted infections (STIs). The use of daily antibiotics as STI preexposure prophylaxis (STI-PrEP) may be appealing to GBM who are using or have previously used HIV-PrEP (HIV-PrEP-experienced) for the prevention of bacterial STIs. METHODS: We examined willingness to use daily STI-PrEP among a cross-sectional sample of HIV-PrEP-experienced GBM in Australia who participated in an observational online cohort study from August 2018 to March 2020. Factors associated with willingness to use daily STI-PrEP were determined using bivariate and multivariate logistic regression. RESULTS: Of the 1347 participants, half (54.3%) were willing to use daily STI-PrEP. Factors independently associated with greater willingness to use daily STI-PrEP included having >10 sexual partners in the last 6 months, using methamphetamine in the last 6 months, being more conscious about avoiding STIs, having a greater number of STIs since commencing HIV-PrEP, being willing to take HIV-PrEP for as long as they were at risk of acquiring HIV, and only using condoms when a sexual partner requested them. Conversely, factors associated with less willingness to use daily STI-PrEP included being university educated, using nondaily dosing regimens of HIV-PrEP, preferring event-driven HIV-PrEP, and being concerned about long-term HIV-PrEP adverse effects. CONCLUSIONS: Sexually transmitted infection PrEP is likely to be appealing to many HIV-PrEP-experienced GBM, especially those who engage in activities associated with a higher risk of STI transmission. However, they are less likely to be willing to use STI-PrEP unless it aligns with their HIV-PrEP dosing regimen, suggesting that research into the safety and efficacy of alternative STI prophylaxis dosing options should be prioritized.

Variations in HIV Prevention Coverage in Subpopulations of Australian Gay and Bisexual Men, 2017-2021: Implications for Reducing Inequities in the Combination Prevention Era.

Using repeated behavioural surveillance data collected from gay and bisexual men (GBM) across Australia, we assessed trends in HIV prevention coverage (the level of 'safe sex' achieved in the population by the use of effective prevention methods, including condoms, pre-exposure prophylaxis [PrEP] and having an undetectable viral load). We stratified these trends by age, country of birth/recency of arrival, sexual identity, and the proportion of gay residents in the participant's suburb. Among 25,865 participants with casual male partners, HIV prevention coverage increased from 69.8% in 2017 to 75.2% in 2021, lower than the UNAIDS target of 95%. Higher levels of coverage were achieved among older GBM (≥ 45 years), non-recently-arrived migrants, and in suburbs with ≥ 10% gay residents. The lowest levels of prevention coverage (and highest levels of HIV risk) were recorded among younger GBM (< 25 years) and bisexual and other-identified participants. Younger, recently-arrived, and bisexual GBM were the most likely to use condoms, while PrEP use was concentrated among gay men, 25-44-year-olds, and in suburbs with more gay residents. The use of undetectable viral load was most common among participants aged ≥ 45 years. Our analysis shows that high HIV prevention coverage can be achieved through a mixture of condom use, PrEP use, and undetectable viral load, or by emphasising PrEP use. In the Australian context, younger, bisexual and other-identified GBM should be prioritised for enhanced access to effective HIV prevention methods. We encourage other jurisdictions to assess the level of coverage achieved by combination prevention, and variations in uptake.

RESUMEN: Utilizando datos repetidos de vigilancia conductual recopilados de hombres homosexuales y bisexuales (GBM) en toda Australia, evaluamos las tendencias en la cobertura de la prevención del VIH (el nivel de "sexo seguro" logrado en la población mediante el uso de métodos de prevención eficaces, incluyendo condones, Profilaxis de Pre-Exposición al VIH [PrEP] y tener una carga viral indetectable). Estratificamos estas tendencias por edad, país de nacimiento/tiempo desde la llegada al país, identidad sexual y proporción de residentes homosexuales en el suburbio del participante. Entre 25.865 participantes con parejas masculinas ocasionales, la cobertura de prevención del VIH aumentó del 69,8% en 2017 al 75,2% en 2021, cifra inferior al objetivo de ONUSIDA del 95%. Se lograron niveles más altos de cobertura entre GBM de mayor edad (≥45 años), inmigrantes no llegados recientemente y en suburbios con ≥10% de residentes homosexuales. Los niveles más bajos de cobertura de prevención (y los niveles más altos de riesgo de VIH) se registraron entre los GBM más jóvenes (<25 años) y los participantes bisexuales y con otras identidades. Los GBM más jóvenes, recién llegados y bisexuales fueron los más propensos a usar condones, mientras que el uso de PrEP se concentró entre hombres homosexuales, de 25 a 44 años, y en los suburbios con más residentes homosexuales. El uso de carga viral indetectable fue más común entre los participantes de ≥45 años. Nuestro análisis demuestra que se puede lograr una alta cobertura de prevención del VIH mediante una combinación del uso de condón, uso de PrEP y carga viral indetectable, o enfatizando el uso de PrEP. En el contexto australiano, se debe dar prioridad a los GBM más jóvenes, bisexuales y con otras identidades para mejorar el acceso a métodos eficaces de prevención del VIH. Alentamos a otras jurisdicciones a evaluar el nivel de cobertura logrado mediante la prevención combinada y las variaciones en la adopción.

Adjusting Behavioural Surveillance and Assessing Disparities in the Impact of COVID-19 on Gay and Bisexual Men's HIV-Related Behaviour in Australia.

COVID-19 has disrupted sexual behaviour and access to health systems. We adapted regular HIV behavioural surveillance of gay and bisexual men (GBM) in Australia in response to COVID-19, assessed the impact on the profile of the sample, the participants' HIV-related behaviour, and whether COVID-19 may have accentuated existing disparities in the Australian HIV epidemic. Data collected from five states during July 2017-June 2021 were included (N = 31,460). The emphasis on online recruitment after COVID-19 led to smaller sample sizes, greater geographic reach, and a higher proportion of bisexual-identifying participants. Most participants (88.1%) reported physical distancing and 52.1% had fewer sex partners due to COVID-19. In the COVID-19-affected rounds (July 2020-June 2021), the number of male partners, recent HIV testing and pre-exposure prophylaxis (PrEP) use all fell, and HIV risk among the smaller group of participants who reported casual sex increased. COVID-related changes were generally more pronounced among GBM aged under 25 years, participants from suburbs with fewer gay residents, and bisexual men. These groups should be prioritised when encouraging GBM to reengage with HIV testing services and effective prevention methods, like condoms and PrEP.

RESUMEN: COVID-19 ha interrumpido el comportamiento sexual y el acceso a los sistemas de salud. Adaptamos la vigilancia regular del comportamiento de hombres homosexuales y bisexuales (GBM) hacia el VIH en Australia en respuesta a COVID-19, evaluamos el impacto en el perfil de la muestra, el comportamiento relacionado con el VIH de los participantes y si COVID-19 puede haber acentuado las existentes disparidades en la epidemia australiana de VIH. Se incluyeron los datos recopilados de cinco estados entre julio de 2017 y junio de 2021 (N = 31 460). El énfasis en el reclutamiento en línea después de COVID-19 resulto en tamaños de muestra más pequeños, mayor alcance geográfico y una mayor proporción de participantes que se identifican como bisexuales. La mayoría de los participantes (88,1%) describieron participando en el distanciamiento físico y el 52,1% tuvo menos parejas sexuales debido a la COVID-19. En las rondas afectadas por COVID-19 (julio de 2020 a junio de 2021), disminuyó la cantidad de parejas masculinas, el uso reciente de pruebas de VIH y de la profilaxis previa a la exposición (PrEP), y el riesgo de VIH entre el grupo más pequeño de participantes que participaron en sexo casual aumentó. Los cambios relacionados con COVID fueron generalmente más pronunciados entre GBM menores de 25 años, participantes de suburbios con menos residentes homosexuales y hombres bisexuales. Se debe priorizar a estos grupos al alentar a GBM a volver a comprometerse con los servicios de pruebas de VIH y métodos de prevención efectivos, como condones y PrEP.

Attitudes Towards Treatment as Prevention Among PrEP-Experienced Gay and Bisexual Men in Australia.

The introduction of HIV pre-exposure prophylaxis (PrEP) has the potential to impact the attitudes gay and bisexual men (GBM) who consequently choose to take PrEP have towards treatment as prevention (TasP), and the extent to which they are willing to have condomless anal intercourse (CLAI) with an HIV-positive sexual partner who has an undetectable viral load (UVL). Using a cross-sectional sample from an observational cohort study conducted from August 2018 to March 2020, we examined the extent to which PrEP-experienced GBM are willing to have CLAI with a partner who has a UVL. Simple and multiple logistic regression models were used to identify associated variables. Of the 1386 participants included in the analyses, 79.0% believed in the effectiveness of TasP, and 55.3% were willing to have CLAI with a partner who has a UVL. Wiling participants were less worried about getting HIV when taking PrEP and more likely to believe in TasP. Further research is needed to better understand the gap between belief in TasP and willingness to have CLAI with a partner who has a UVL among PrEP-experienced GBM.

National Surveillance of Home-Based HIV Testing Among Australian Gay and Bisexual Men, 2018-2020: Uptake After Commercial Availability of HIV Self-Tests.

HIV self-testing allows people to collect samples and test themselves at home, addressing known barriers to facility-based testing. We aimed to measure the uptake of home HIV testing among Australian gay and bisexual men (GBM). Using national cross-sectional data from the Australian Gay Community Periodic Surveys, we assessed trends in home HIV testing among non-HIV positive GBM between 2018 and 2020. Overall, the use of home HIV testing was low, but slightly increased during 2018-2020 (from 0.3 to 0.8%, RR = 1.54, 95%CI = 1.23-1.92, p-trend < 0.001). Testing at home was more likely among non-HIV-positive GBM who were born overseas and recently arrived in Australia, at higher risk of HIV, and infrequent HIV testers. Given the greater use of home testing by men at higher risk of HIV, recent migrants and infrequent testers, all priority groups in Australia's HIV epidemic, we recommend increasing access to HIV self-testing to enhance uptake in these and other groups of GBM.

COVID-19 Testing in a Weekly Cohort Study of Gay and Bisexual Men: The Impact of Health-Seeking Behaviors and Social Connection.

Gay, bisexual, and other men who have sex with men (GBM) have developed community norms for regular HIV/STI testing. We investigated factors associated with self-reported COVID-19 testing in response to reported COVID-19 cases and public health restrictions. Participants responded to weekly cohort surveys between 10th May 2021 and 27th September 2021. We used the Andersen-Gill extensions to the Cox proportional hazards model for multivariable survival data to predict factors influencing COVID-19 testing. Mean age of the 942 study participants was 45.6 years (SD: 13.9). In multivariable analysis, GBM were more likely to report testing during periods of high COVID-19 caseload in their state of residence; if they were younger; university educated; close contact of someone with COVID-19; or reported coping with COVID-19 poorly. COVID-19 testing was higher among men who: were more socially engaged with other GBM; had a higher proportion of friends willing to vaccinate against COVID-19; and were willing to contact sexual partners for contact tracing. Social connection with other gay men was associated with COVID-19 testing, similar to what has been observed throughout the HIV epidemic, making community networks a potential focus for the promotion of COVID-19 safe practices.

Deterministic nanoscale quantum spin-defect implantation and diffraction strain imaging.

Local crystallographic features negatively affect quantum spin defects by changing the local electrostatic environment, often resulting in degraded or varied qubit optical and coherence properties. Few tools exist that enable the deterministic synthesis and study of such intricate systems on the nano-scale, making defect-to-defect strain environment quantification difficult. In this paper, we highlight state-of-the-art capabilities from the U.S. Department of Energy's Nanoscale Science Research Centers that directly address these shortcomings. Specifically, we demonstrate how complementary capabilities of nano-implantation and nano-diffraction can be used to demonstrate the quantum relevant, spatially deterministic creation of neutral divacancy centers in 4H silicon carbide, while investigating and characterizing these systems on the≤25nmscale with strain sensitivities on the order of1×10-6,relevant to defect formation dynamics. This work lays the foundation for ongoing studies into the dynamics and deterministic formation of low strain homogeneous quantum relevant spin defects in the solid state.

Explicit Relationship Agreements and HIV Pre-exposure Prophylaxis Use by Gay and Bisexual Men in Relationships.

Relationship agreements are important for HIV prevention among gay and bisexual men (GBM) in relationships, with research earlier in the HIV epidemic often finding that agreements specified monogamy or condom use with casual partners. There is evidence that HIV pre-exposure prophylaxis (PrEP) has shifted sexual practices among some men in relationships, such as allowing condomless sex with casual partners, but there has been little attention paid to relationship agreements among GBM who use PrEP. In this paper, we analyzed national, Australian, cross-sectional data from an online survey completed by non-HIV-positive GBM in 2021 (N = 1,185). Using logistic regression, we identified demographic characteristics, sexual practices and the types of relationship agreement that were associated with PrEP use among GBM in relationships. Using Pearson's chi-squared tests, we explored whether PrEP users in relationships reported similar sexual practices to PrEP users not in relationships. PrEP use among GBM in relationships was independently associated with older age, identifying as gay, being in a non-monogamous relationship, having a spoken (explicit) relationship agreement, having a primary HIV-negative partner taking PrEP or a primary partner living with HIV, reporting recent condomless casual sex, reporting an STI diagnosis in the past year, and knowing at least one other PrEP user. We found that PrEP users in relationships had similar sexual practices to PrEP users not in relationships. GBM in relationships who have casual sex and who meet PrEP suitability criteria may be good candidates for PrEP. Our findings suggest that explicit relationship agreements remain important for HIV prevention, and they support PrEP use among GBM in relationships.

Dosing practices made mundane: Enacting HIV pre-exposure prophylaxis adherence in domestic routines.

Maintaining routines of medication dosing requires effort amidst the variabilities of everyday life. This article offers a sociomaterial analysis of how the oral HIV prevention regimen, pre-exposure prophylaxis (PrEP), is put to use and made to work, including in situations which disrupt or complicate dosing regimes. Other than a daily pill, PrEP can be taken less frequently based on anticipated sexual activity and HIV risk, including 'on-demand' and 'periodic' dosing. Drawing on 40 interviews with PrEP users in Australia in 2022, we explore PrEP and its dosing as features of assemblages in which bodies, routines, desires, material objects and the home environment interact. Dosing emerges as a practice of coordination involving dosette boxes, blister packs, alarms, partners, pets, planning sex, routines and domestic space, and as an effect of experimentations with timing to suit life circumstances and manage side effects. Dosing is materialised in the mundane; a practice that is made to work, as well as domesticated, in its situations. Although there are no 'simple' solutions to adherence, our analysis offers practical insights into how routine, planning and experimentation come together to capacitate PrEP to work in people's lives, in sometimes unexpected ways, including through adaptations of PrEP dosing.

How to have sex in a pandemic: the development of strategies to prevent COVID-19 transmission in sexual encounters among gay and bisexual men in Australia.

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.

The effect of pre-exposure prophylaxis (PrEP) on negotiating casual sex between gay men: disclosure, assumptions, and communication.

BACKGROUND: The disclosure of HIV status and pre-exposure prophylaxis (PrEP) use can be important in the negotiation of safe sex. With the rapid uptake of PrEP in Australia, norms and expectations about discussion and disclosure may have changed. METHODS: We explored the disclosure of PrEP use, HIV status and communication with sex partners by HIV-negative gay men in Sydney, Australia. We conducted semi-structured interviews from October 2017 to May 2018 and analysed data using a codebook thematic analysis approach. RESULTS: Participants had a variety of expectations of what they should tell their partners and what they expected in return. For some participants, PrEP had negated the need for any discussion about HIV. Many participants assumed their partners would find information about their HIV status or PrEP use on their online profiles or that partners would ask, if necessary. CONCLUSIONS: Building a stronger, shared understanding among gay men that disclosure and discussion no longer automatically occur before sexual encounters may be useful.

The impact of social connections and discrimination to HIV risk among Asian gay and bisexual men in Australia.

BACKGROUND: Asian gay, bisexual, and other men who have sex with men (GBMSM) are overrepresented in new HIV diagnoses in Australia. Social engagement with other GBMSM has been associated with HIV testing and pre-exposure prophylaxis (PrEP) uptake. Asian GBMSM may be socially disconnected from LGBTQ+ people, which may increase their HIV risk. This analysis assessed the contribution of social connection on HIV risk among Asian GBMSM. METHODS: Using an online cross-sectional survey of Asian GBMSM in Australia, we measured condomless anal intercourse (CLAI) in the last 6months without PrEP or an undetectable viral load (UVL), i.e. CLAI with a risk of HIV transmission. Bivariable and multivariable logistic regression models were performed to compare demographic characteristics and social engagement of participants who had CLAI without PrEP or UVL to those who had not. Analyses were restricted to participants who reported sex with casual partners in the last 6months. RESULTS: Among 509 participants who had casual partners in the last 6months, 151 (29.7%) reported CLAI without PrEP or UVL. CLAI without PrEP or UVL was negatively associated with full-time employment, and recently being tested for HIV and was positively associated with experiencing discrimination based on sexual orientation. Social engagement with LGBTQ+ people was not associated with CLAI without PrEP or UVL. CONCLUSIONS: CLAI without PrEP or UVL was not related to social connections with LGBTQ+ people but was more likely among Asian men who had experienced sexuality-related discrimination, suggesting that mitigating homophobia and biphobia may assist in improving HIV prevention among Asian GBMSM who live in Australia.