White adipose tissue distribution and amount are associated with increased white matter connectivity.

Obesity represents a significant public health concern and is linked to various comorbidities and cognitive impairments. Previous research indicates that elevated body mass index (BMI) is associated with structural changes in white matter (WM). However, a deeper characterization of body composition is required, especially considering the links between abdominal obesity and metabolic dysfunction. This study aims to enhance our understanding of the relationship between obesity and WM connectivity by directly assessing the amount and distribution of fat tissue. Whole-body magnetic resonance imaging (MRI) was employed to evaluate total adipose tissue (TAT), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT), while MR liver spectroscopy measured liver fat content in 63 normal-weight, overweight, and obese males. WM connectivity was quantified using microstructure-informed tractography. Connectome-based predictive modeling was used to predict body composition metrics based on WM connectomes. Our analysis revealed a positive dependency between BMI, TAT, SAT, and WM connectivity in brain regions involved in reward processing and appetite regulation, such as the insula, nucleus accumbens, and orbitofrontal cortex. Increased connectivity was also observed in cognitive control and inhibition networks, including the middle frontal gyrus and anterior cingulate cortex. No significant associations were found between WM connectivity and VAT or liver fat. Our findings suggest that altered neural communication between these brain regions may affect cognitive processes, emotional regulation, and reward perception in individuals with obesity, potentially contributing to weight gain. While our study did not identify a link between WM connectivity and VAT or liver fat, further investigation of the role of various fat depots and metabolic factors in brain networks is required to advance obesity prevention and treatment approaches.

Impact of the COVID-19 Health Crisis on Key Populations at Higher Risk for, or Living With, HIV or Hepatitis C Virus and People Working With These Populations: Multicountry Community-Based Research Study Protocol (EPIC Program).

BACKGROUND: Information concerning the impact of the COVID-19 health crisis on populations most affected by HIV and hepatitis C virus (HCV; or key populations [KP]), and those working with these populations in community settings, is limited. Community-based organizations working in the field of HIV and viral hepatitis are well placed to identify and meet the new needs of KP owing to the health crisis. OBJECTIVE: This study aims to describe the development and implementation of an exploratory and descriptive multicountry, community-based research program, EPIC (Enquêtes Pour évaluer l'Impact de la crise sanitaire covid en milieu Communautaire), within an international network of community-based organizations involved in the response to HIV and viral hepatitis. The EPIC program aimed to study the impact of the COVID-19 health crisis on KP or people living with HIV or HCV and people working with these populations at the community level (community health workers [CHWs]) and to identify the key innovations and adaptations in HIV and HCV services. METHODS: A general protocol and study documents were developed and shared within the Coalition PLUS network. The protocol had a built-in flexibility that allowed participating organizations to adapt the study to local needs in terms of the target population and specific themes of interest. Data were collected using surveys or interviews. RESULTS: From July 2020 to May 2022, a total of 79 organizations participated in the EPIC program. Across 32 countries, 118 studies were conducted: 66 quantitative (n=12,060 among KP or people living with HIV or people living with HCV and n=811 among CHWs) and 52 qualitative (n=766 among KP or people living with HIV or people living with HCV and n=136 among CHWs). CONCLUSIONS: The results of the EPIC program will provide data to describe the impact of the health crisis on KP and CHWs and identify their emerging needs. Documentation of innovative solutions that were put into place in this context may help improve the provision of services after COVID-19 and for future health crises. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/45204.

CACTUS: a computational framework for generating realistic white matter microstructure substrates.

Monte-Carlo diffusion simulations are a powerful tool for validating tissue microstructure models by generating synthetic diffusion-weighted magnetic resonance images (DW-MRI) in controlled environments. This is fundamental for understanding the link between micrometre-scale tissue properties and DW-MRI signals measured at the millimetre-scale, optimizing acquisition protocols to target microstructure properties of interest, and exploring the robustness and accuracy of estimation methods. However, accurate simulations require substrates that reflect the main microstructural features of the studied tissue. To address this challenge, we introduce a novel computational workflow, CACTUS (Computational Axonal Configurator for Tailored and Ultradense Substrates), for generating synthetic white matter substrates. Our approach allows constructing substrates with higher packing density than existing methods, up to 95% intra-axonal volume fraction, and larger voxel sizes of up to 500µm3 with rich fibre complexity. CACTUS generates bundles with angular dispersion, bundle crossings, and variations along the fibres of their inner and outer radii and g-ratio. We achieve this by introducing a novel global cost function and a fibre radial growth approach that allows substrates to match predefined targeted characteristics and mirror those reported in histological studies. CACTUS improves the development of complex synthetic substrates, paving the way for future applications in microstructure imaging.

Effectiveness of a Community Empowerment Intervention to Improve Access to Pre-exposure Prophylaxis in Migrant Women Sex Workers: Protocol for a Mixed Methods Implementation Study.

BACKGROUND: The World Health Organization recommends pre-exposure prophylaxis (PrEP) for all populations at substantial risk of HIV infection. However, at-risk women very rarely use PrEP in France-this represents a critical issue among migrant women sex workers (MWSWs). Previous studies on PrEP use among women sex workers or migrants focused on individual or social determinants of motivation. However, operational studies in real-word settings using a holistic population approach to maximize PrEP adherence among MWSWs are lacking. OBJECTIVE: FASSETS (ie, "Favoriser l'Accès à la Santé Sexuelle des Travailleuses du Sexe"; English: "facilitate the access to Sexual Health in women sex workers") is a participative, multilevel, mixed methods study aiming to improve global knowledge of and access to sexual health care and PrEP among MWSWs through targeted empowerment strategies. METHODS: This study comprises several phases: (1) phase 1: an initial qualitative study combining semistructured interviews, informal interviews, and participative observations will be performed among MWSWs, local community nongovernmental organizations, and institutions providing sexual reproductive health services to identify the determinants of PrEP access among MWSWs and for respondent-driven sampling (RDS); (2) phase 2: the size of the hidden MWSW population is estimated in Marseille through capture-recapture (the RDS survey will serve as "recapture"); (3) phase 3: a longitudinal cohort will be formed through RDS to represent the MWSW population with a goal of 150 inclusions-this cohort will be followed up for 12 months, and sequential questionnaires exploring medical history; knowledge of sexual health, HIV, and sexually transmitted infections; migration route; and current living conditions will be administered at inclusion (month 0) and months 3, 6, and 12 to measure the following interventional phase's outcomes; and (4) phase 4: an interventional study with community empowerment actions about sexual health and PrEP will be conducted with community health workers; standardized questionnaires and semistructured interviews, observations, and focus groups will highlight MWSWs' experiences with empowerment resources, concerns about sexual health, and especially PrEP use or uptake, and we will evaluate whether and how community-adapted empowerment actions conducted by community health workers are effective in increasing access to sexual health, prevention and screening of sexually transmitted infections, and PrEP knowledge and access among MWSWs. RESULTS: Recruitment commenced on March 1, 2022. We estimate the follow-up period to end on September 30, 2023. CONCLUSIONS: This multiphase study will provide robust evidence about the magnitude of the MWSW population in Marseille (the second largest town in France) and their current conditions of living, access to and knowledge of sexual health, and PrEP access. Using a mixed methods analysis, we will investigate whether individual and collective community health empowerment approaches can facilitate access to PrEP and its initiation, use, and adherence in this vulnerable population. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/42844.

Cellular Exchange Imaging (CEXI): Evaluation of a diffusion model including water exchange in cells using numerical phantoms of permeable spheres.

PURPOSE: Biophysical models of diffusion MRI have been developed to characterize microstructure in various tissues, but existing models are not suitable for tissue composed of permeable spherical cells. In this study we introduce Cellular Exchange Imaging (CEXI), a model tailored for permeable spherical cells, and compares its performance to a related Ball & Sphere (BS) model that neglects permeability. METHODS: We generated DW-MRI signals using Monte-Carlo simulations with a PGSE sequence in numerical substrates made of spherical cells and their extracellular space for a range of membrane permeability. From these signals, the properties of the substrates were inferred using both BS and CEXI models. RESULTS: CEXI outperformed the impermeable model by providing more stable estimates cell size and intracellular volume fraction that were diffusion time-independent. Notably, CEXI accurately estimated the exchange time for low to moderate permeability levels previously reported in other studies ( κ < 25 µ m / s $$ \kappa <25\kern0.3em \mu \mathrm{m}/\mathrm{s} $$ ). However, in highly permeable substrates ( κ = 50 µ m / s $$ \kappa =50\kern0.3em \mu \mathrm{m}/\mathrm{s} $$ ), the estimated parameters were less stable, particularly the diffusion coefficients. CONCLUSION: This study highlights the importance of modeling the exchange time to accurately quantify microstructure properties in permeable cellular substrates. Future studies should evaluate CEXI in clinical applications such as lymph nodes, investigate exchange time as a potential biomarker of tumor severity, and develop more appropriate tissue models that account for anisotropic diffusion and highly permeable membranes.

"The Slums Have To Be Shown": Documenting Drug Injection in Public Spaces Ahead of the Opening of a Drug Consumption Room in Marseille.

EPOSIM is a community-based participatory research study which used the Photovoice method with people who inject drugs (PWID) ahead of a possible opening of a drug consumption room (DCR) in Marseille, France. It aimed to identify the strategies used by PWID when injecting, and the risks they take when they have no safe private space to inject in the area they live in. A total of 7 PWID participated in the full study process. The 189 photographs they took provided us with a good understanding of their injection practices in public places. The main results highlighted the spatiality and materiality of injecting experience in a context where no DCR was available. They also showed the relevance of Photovoice to valorize the voices of PWID when implementing a DCR. Through the showcasing of their photographs at various public exhibitions, the participants seized the opportunity to use Photovoice to make their voices heard beyond the group formed for the study, in order to show the different forms of stigma and insalubrious contexts which they faced on a daily basis. Furthermore, the photographs taken demonstrated that having only health and safety records is not enough to fully understand PWID injection practices. Future studies must take into account PWID perceptions of their relationship with injecting in public spaces and with the management of stigma. The questions of pleasure and comfort must also be explored in evaluation studies of harm reduction measures, for example, DCR.

Santé des personnes LGBTI+ : enjeux scientifiques et perspectives de santé publique.

Despite advances in recent decades, health inequalities faced by sexual, gender and gendered minorities remain poorly recognized. Yet the barriers to accessing prevention and care encountered by these populations are widely documented in international literature. The health of LGBTI+ people is still largely understood and structured as a sexual health issue related to sexually transmitted infections, leaving other crucial issues in the background. Some questions remain hidden, in particular the realities experienced by bisexual, lesbian, intersex people, as well as the diversity of transidentities. This issue is a first on several levels. It is indeed the first time that a scientific journal publishes a collection of this scope in the French-speaking world. Moreover, the issue brings together contributions that reflect the diversity of actors and actresses in this field. Finally, the issue's French-speaking focus allows for diversified geographical insights. This issue is structured around three main parts: 1) Thinking, categorizing: from research to health promotion; 2) Describing health realities: apprehending needs and understanding obstacles; 3) Intervening in the field of sexual, gender and gendered minorities health.

Tractography passes the test: Results from the diffusion-simulated connectivity (disco) challenge.

Estimating structural connectivity from diffusion-weighted magnetic resonance imaging is a challenging task, partly due to the presence of false-positive connections and the misestimation of connection weights. Building on previous efforts, the MICCAI-CDMRI Diffusion-Simulated Connectivity (DiSCo) challenge was carried out to evaluate state-of-the-art connectivity methods using novel large-scale numerical phantoms. The diffusion signal for the phantoms was obtained from Monte Carlo simulations. The results of the challenge suggest that methods selected by the 14 teams participating in the challenge can provide high correlations between estimated and ground-truth connectivity weights, in complex numerical environments. Additionally, the methods used by the participating teams were able to accurately identify the binary connectivity of the numerical dataset. However, specific false positive and false negative connections were consistently estimated across all methods. Although the challenge dataset doesn't capture the complexity of a real brain, it provided unique data with known macrostructure and microstructure ground-truth properties to facilitate the development of connectivity estimation methods.

Hexavalent Ions Insertion in Garnet Li7 La3 Zr2 O12 Toward a Low Temperature Densification Reaction.

Nowadays, solid electrolytes are considered the main alternative to conventional liquid electrolytes in lithium batteries. The fabrication of these materials is however limited by the strict synthesis conditions, requiring high temperatures which can negatively impact the final performances. Here, it is shown that a modification of garnet-based Li7 La3 Zr2 O12 (LLZO) and the incorporation of tellurium can accelerate the synthesis process by lowering the formation temperature of cubic LLZO at temperatures below 700 °C. Optimized synthesis at 750 °C showed a decrease in particle size and cell parameter for samples with higher amounts of Te and the evaluation of electrochemical performances reported for LLZO Te0.25 a value of ionic conductivity of 5,15×10-5  S cm-1 after hot-pressing at 700 °C, two orders of magnitude higher than commercial Al-LLZO undergoing the same working conditions, and the highest value at this densification temperature. Partial segregation of Te-rich phases occurs for high-temperature densification. Our study shows the advantages of Te insertion on the sintering process of LLZO garnet and demonstrates the achievement of highly conductive LLZO with a low-temperature treatment.

Investigating health services for sexual and gender minorities in France: a qualitative study protocol.

INTRODUCTION: Discrimination and structural violence experienced by sexual and gender minorities are the source of social inequalities in health. The last decade has been marked by major developments in the provision of sexual health services for these minorities in France. This paper presents the research protocol of the Services for Minorities-Lesbian Gays Bisexuals Transgender Intersex+ (SeSAM-LGBTI+) study, which aims to document the health, social and professional challenges in the organisation of current health services for sexual and gender minorities in France. METHODS AND ANALYSIS: The SeSAM-LGBTI+ study relies on a multidisciplinary qualitative study. It has two objectives: (1) to analyse the history of the development of LGBTI+ health services in France, through interviews with key informants and rights activists and through a study of archives and (2) to study the functioning and challenges of a sample of health services currently offered to LGBTI+ people in France, through a multiple case study, using a multilevel and multisited ethnography. The study will rely on approximately 100 interviews. The analysis will be based on an inductive and iterative approach, combining sociohistorical data and the cross-sectional analysis of the case studies. ETHICS AND DISSEMINATION: The study protocol has undergone a peer review by the Institut de Recherche En santé Publique's scientific committee and has been approved by the research ethical committee of Aix-Marseille University (registration number: 2022-05-12-010). The project has received funding from December 2021 to November 2024. The results of the research will be disseminated from 2023 onwards to researchers, health professionals and community health organisations.

Highly precarious general and sexual health conditions of young domestic servants: results from a qualitative exploratory study and perspectives for community-based research in Bamako, Mali.

Most domestic servants (DS) in Mali are very young female migrants living in precarious conditions. We aimed to understand their living and working conditions in relation to their general and sexual health. Seven focus groups (53 participants) were conducted by the DS community-based organization ADDAD. Narratives were thematically analyzed using an inductive method. The dominant emerging theme was DS' strong dependence on their employers. Employers' attitudes regarding DS workload, the provision of food, water and hygiene products, housing conditions, and healthcare cover, appeared decisive for DS' physical and mental health, and the type of healthcare they used (self-medication, traditional care, healthcare facilities). Psychological, physical and sexual violence in employers' households was frequent. HIV/STI prevention knowledge was poor. These results highlight the serious risks for DS in terms of HIV/STI and unwanted pregnancies. DS were interested in receiving healthcare from ADDAD; this was motivated by the organization's trusting and understanding community-based environment, and DS' fear of discrimination in healthcare facilities. This study highlights the relevance of tackling the defense of rights and sexual health promotion for DS at the community level. Its findings can help identify research questions to evaluate the extent to which DS constitute a key HIV population.

Differential Impact of Brain Network Efficiency on Poststroke Motor and Attentional Deficits.

BACKGROUND: Most studies on stroke have been designed to examine one deficit in isolation; yet, survivors often have multiple deficits in different domains. While the mechanisms underlying multiple-domain deficits remain poorly understood, network-theoretical methods may open new avenues of understanding. METHODS: Fifty subacute stroke patients (7±3days poststroke) underwent diffusion-weighted magnetic resonance imaging and a battery of clinical tests of motor and cognitive functions. We defined indices of impairment in strength, dexterity, and attention. We also computed imaging-based probabilistic tractography and whole-brain connectomes. To efficiently integrate inputs from different sources, brain networks rely on a rich-club of a few hub nodes. Lesions harm efficiency, particularly when they target the rich-club. Overlaying individual lesion masks onto the tractograms enabled us to split the connectomes into their affected and unaffected parts and associate them to impairment. RESULTS: We computed efficiency of the unaffected connectome and found it was more strongly correlated to impairment in strength, dexterity, and attention than efficiency of the total connectome. The magnitude of the correlation between efficiency and impairment followed the order attention>dexterity ≈ strength (strength: |r|=.03, P=0.02, dexterity: |r|=.30, P=0.05, attention: |r|=.55, P<0.001). Network weights associated with the rich-club were more strongly correlated to efficiency than non-rich-club weights. CONCLUSIONS: Attentional impairment is more sensitive to disruption of coordinated networks between brain regions than motor impairment, which is sensitive to disruption of localized networks. Providing more accurate reflections of actually functioning parts of the network enables the incorporation of information about the impact of brain lesions on connectomics contributing to a better understanding of underlying stroke mechanisms.

Toward individualized medicine in stroke-The TiMeS project: Protocol of longitudinal, multi-modal, multi-domain study in stroke.

Despite recent improvements, complete motor recovery occurs in <15% of stroke patients. To improve the therapeutic outcomes, there is a strong need to tailor treatments to each individual patient. However, there is a lack of knowledge concerning the precise neuronal mechanisms underlying the degree and course of motor recovery and its individual differences, especially in the view of brain network properties despite the fact that it became more and more clear that stroke is a network disorder. The TiMeS project is a longitudinal exploratory study aiming at characterizing stroke phenotypes of a large, representative stroke cohort through an extensive, multi-modal and multi-domain evaluation. The ultimate goal of the study is to identify prognostic biomarkers allowing to predict the individual degree and course of motor recovery and its underlying neuronal mechanisms paving the way for novel interventions and treatment stratification for the individual patients. A total of up to 100 patients will be assessed at 4 timepoints over the first year after the stroke: during the first (T1) and third (T2) week, then three (T3) and twelve (T4) months after stroke onset. To assess underlying mechanisms of recovery with a focus on network analyses and brain connectivity, we will apply synergistic state-of-the-art systems neuroscience methods including functional, diffusion, and structural magnetic resonance imaging (MRI), and electrophysiological evaluation based on transcranial magnetic stimulation (TMS) coupled with electroencephalography (EEG) and electromyography (EMG). In addition, an extensive, multi-domain neuropsychological evaluation will be performed at each timepoint, covering all sensorimotor and cognitive domains. This project will significantly add to the understanding of underlying mechanisms of motor recovery with a strong focus on the interactions between the motor and other cognitive domains and multimodal network analyses. The population-based, multi-dimensional dataset will serve as a basis to develop biomarkers to predict outcome and promote personalized stratification toward individually tailored treatment concepts using neuro-technologies, thus paving the way toward personalized precision medicine approaches in stroke rehabilitation.

Evaluating reproducibility and subject-specificity of microstructure-informed connectivity.

Tractography enables identifying and evaluating the healthy and diseased brain's white matter pathways from diffusion-weighted magnetic resonance imaging data. As previous evaluation studies have reported significant false-positive estimation biases, recent microstructure-informed tractography algorithms have been introduced to improve the trade-off between specificity and sensitivity. However, a major limitation for characterizing the performance of these techniques is the lack of ground truth brain data. In this study, we compared the performance of two relevant microstructure-informed tractography methods, SIFT2 and COMMIT, by assessing the subject specificity and reproducibility of their derived white matter pathways. Specifically, twenty healthy young subjects were scanned at eight different time points at two different sites. Subject specificity and reproducibility were evaluated using the whole-brain connectomes and a subset of 29 white matter bundles. Our results indicate that although the raw tractograms are more vulnerable to the presence of false-positive connections, they are highly reproducible, suggesting that the estimation bias is subject-specific. This high reproducibility was preserved when microstructure-informed tractography algorithms were used to filter the raw tractograms. Moreover, the resulting track-density images depicted a more uniform coverage of streamlines throughout the white matter, suggesting that these techniques could increase the biological meaning of the estimated fascicles. Notably, we observed an increased subject specificity by employing connectivity pre-processing techniques to reduce the underlaying noise and the data dimensionality (using principal component analysis), highlighting the importance of these tools for future studies. Finally, no strong bias from the scanner site or time between measurements was found. The largest intraindividual variance originated from the sole repetition of data measurements (inter-run).

Through-Plane Super-Resolution With Autoencoders in Diffusion Magnetic Resonance Imaging of the Developing Human Brain.

Fetal brain diffusion magnetic resonance images (MRI) are often acquired with a lower through-plane than in-plane resolution. This anisotropy is often overcome by classical upsampling methods such as linear or cubic interpolation. In this work, we employ an unsupervised learning algorithm using an autoencoder neural network for single-image through-plane super-resolution by leveraging a large amount of data. Our framework, which can also be used for slice outliers replacement, overperformed conventional interpolations quantitatively and qualitatively on pre-term newborns of the developing Human Connectome Project. The evaluation was performed on both the original diffusion-weighted signal and the estimated diffusion tensor maps. A byproduct of our autoencoder was its ability to act as a denoiser. The network was able to generalize fetal data with different levels of motions and we qualitatively showed its consistency, hence supporting the relevance of pre-term datasets to improve the processing of fetal brain images.

Insights from the IronTract challenge: Optimal methods for mapping brain pathways from multi-shell diffusion MRI.

Limitations in the accuracy of brain pathways reconstructed by diffusion MRI (dMRI) tractography have received considerable attention. While the technical advances spearheaded by the Human Connectome Project (HCP) led to significant improvements in dMRI data quality, it remains unclear how these data should be analyzed to maximize tractography accuracy. Over a period of two years, we have engaged the dMRI community in the IronTract Challenge, which aims to answer this question by leveraging a unique dataset. Macaque brains that have received both tracer injections and ex vivo dMRI at high spatial and angular resolution allow a comprehensive, quantitative assessment of tractography accuracy on state-of-the-art dMRI acquisition schemes. We find that, when analysis methods are carefully optimized, the HCP scheme can achieve similar accuracy as a more time-consuming, Cartesian-grid scheme. Importantly, we show that simple pre- and post-processing strategies can improve the accuracy and robustness of many tractography methods. Finally, we find that fiber configurations that go beyond crossing (e.g., fanning, branching) are the most challenging for tractography. The IronTract Challenge remains open and we hope that it can serve as a valuable validation tool for both users and developers of dMRI analysis methods.

Influence of TiIV substitution on the properties of a Li1.5Al0.5Ge1.5(PO4)3 nanofiber-based solid electrolyte.

We report the influence of the partial substitution of Ge with Ti on the properties of NASICON Li1.5Al0.5Ge1.5(PO4)3 (LAGP) nanofibers prepared by electrospinning. Replacing a small amount of Ge (up to 20%) with Ti is advantageous for enhancing both the purity and morphology of LAGP fibers, as observed by X-ray diffraction, electron microscopy and nuclear magnetic resonance spectroscopy. When Ti-substituted LAGP (LAGTP) fibers are used as filler to develop composite polymer electrolytes, the ionic conductivity at 20 °C improves by a factor of 1.5 compared to the plain polymer electrolyte. Additionally, above 40 °C the LAGTP fiber-based composite electrolytes were more conductive than the equivalent LAGP fiber-based one. We believe that these findings can make a substantial contribution to optimizing current methods and developing novel synthesis approaches for NASICON based electrolytes.

Impact of COVID-19 Pandemic on Men Who Have Sex With Men That Practice Chemsex in France: Results From the National ERAS Web Survey.

Chemsex-the use of drugs in a sexual context-has been associated with more at-risk sexual practices and substance-related complications in men who have sex with men (MSM). To date, no study has focused on the impact of France's first coronavirus disease 2019 (COVID-19)-related lockdown on the mental health and drug/alcohol use of MSM who practice chemsex. We implemented a web-based survey of 9,488 MSM living in France in June 2020 (after the country's first COVID-19 lockdown). Specifically, we first compared the subpopulation of MSM who self-reported practicing chemsex during their most recent sexual intercourse (defined as "chemsexers") with other MSM, using five outcomes: increased 1/tobacco use, 2/alcohol use, and 3/other psychoactive drug use. 4/using psychotropic medication during the lockdown, and finally 5/psychological distress. We then analyzed the outcomes' associations with the main explanatory variable "chemsexer," after adjusting for all relevant variables. Among 7,195 MSM who had sexual intercourse with a man during the previous 6 months, 359 participants (5%) were identified as "chemsexers." Multivariable analyses showed that during the first lockdown period, chemsexers were significantly more likely than non-chemsexers to have increased their use of tobacco, alcohol, and other psychoactive substances. Chemsexers were also more likely to have used psychotropic medication and to have experienced psychological distress during the previous month. Given the ongoing COVID-19 pandemic in France and worldwide, this finding highlights the need to develop psychosocial interventions and harm reduction services for MSM chemsexers, potentially via mobile health.

Unveiling the Cation Exchange Reaction between the NASICON Li1.5Al0.5Ge1.5(PO4)3 Solid Electrolyte and the pyr13TFSI Ionic Liquid.

Recently, the formation of the ceramic-ionic liquid composite has attracted huge interest in the scientific community. In this work, we investigated the chemical reactions occurring between NASICON LAGP ceramic electrolyte and ionic liquid pyr13TFSI. This study allowed us to identify the cation exchange reaction pyr13-Li occurring on the LAGP surface, forming a LiTFSI salt that was detected by the nuclear magnetic resonance analysis. In addition, using 6Li foils, we succeeded in demonstrating that both LAGP and LiTFSI:pyr13TFSI participate in the diffusion of Li ions by the formation of an ionic bridge between two species.