MR-based electrical property tomography using a physics-informed network at 3 and 7 T.

Magnetic resonance electrical propert tomography promises to retrieve electrical properties (EPs) quantitatively and non-invasively in vivo, providing valuable information for tissue characterization and pathology diagnosis. However, its clinical implementation has been hindered by, for example, B1 measurement accuracy, reconstruction artifacts resulting from inaccuracies in underlying models, and stringent hardware/software requirements. To address these challenges, we present a novel approach aimed at accurate and high-resolution EPs reconstruction based on water content maps by using a physics-informed network (PIN-wEPT). The proposed method utilizes standard clinical protocols and conventional multi-channel receive arrays that have been routinely equipped in clinical settings, thus eliminating the need for specialized RF sequence/coil configurations. Compared with the original wEPT method, the network generates accurate water content maps that effectively eliminate the influence of B → 1 + and B → 1 - by incorporating data mismatch with electrodynamic constraints derived from the Helmholtz equation. Subsequent regression analysis develops a broad relationship between water content and EPs across various types of brain tissue. A series of numerical simulations was conducted at 7 T to assess the feasibility and performance of the method, which encompassed four normal head models and models with tumorous tissues incorporated, and the results showed normalized mean square error below 1.0% in water content, below 11.7% in conductivity, and below 1.1% in permittivity reconstructions for normal brain tissues. Moreover, in vivo validations conducted over five healthy subjects at both 3 and 7 T showed reasonably good consistency with empirical EPs values across the white matter, gray matter, and cerebrospinal fluid. The PIN-wEPT method, with its demonstrated efficacy, flexibility, and compatibility with current MRI scanners, holds promising potential for future clinical application.

COVID-19 Vaccine Hesitancy Among People Living with HIV: A Systematic Review and Meta-Analysis.

Vaccine hesitancy is one of the top 10 threats to global health, which affects the prevalence and fatality of vaccine-preventable diseases over the world. During the COVID-19 pandemic, people living with HIV (PLWH) may have higher risks of infection, more serious complications, and worse prognosis without the protection of the COVID-19 vaccine. A systematic review and meta-analysis aiming to evaluate the prevalence of COVID-19 vaccine hesitancy among PLWH was conducted using PubMed, Embase, and Web of Science databases for studies published between January 1, 2020, and August 31, 2022. The pooled prevalence with a corresponding 95%CI of COVID-19 vaccine hesitancy among PLWH was reported. Subgroup analysis was conducted to explore variation in prevalence across different categories. 23 studies with a total of 19,922 PLWH were included in this study. The prevalence of COVID-19 vaccine hesitancy among PLWH was 34.0%, and the influencing factors included male, influenza vaccination experience, and a CD4 count of more than 200 cells/mm3. Subgroup analysis did not identify significant causes of heterogeneity but showed that the prevalence of COVID-19 vaccine hesitancy among PLWH varies by study period, region, and race. Although all PLWH are recommended to receive the COVID-19 vaccine, a large proportion of them remain hesitant to be vaccinated. Therefore, governments and relevant institutions should take specific measures to encourage and promote vaccination to improve the coverage of the COVID-19 vaccine among PLWH.

Psychometric properties of the Short-Form Five Facets of Mindfulness Questionnaire among nursing students in China: A confirmatory factor analysis.

AIM: To analyse the factorial structure and psychometric properties of the Chinese Short-Form Five Facets of Mindfulness Questionnaire (FFMQ-SF) among nursing students in the Chinese mainland. DESIGN: A cross-sectional study. METHODS: A total of 240 undergraduate nursing students were recruited from a school of nursing in Beijing, China from 25 to 30 April 2021. FFMQ-SF and Depression-Anxiety-Stress Scale were used to collect information on the mindfulness level and mental health status of the study participants. Descriptive analyses were performed to examine the demographic characteristics. Confirmatory factor analyses (CFAs) were used to test the structural, convergent and discriminant validity of the scale model. Pearson correlation analysis was used to test the correlation between the variables and the criterion validity. RESULTS: The overall fit of the scale model is good (Bollen-Stine χ2 = 177.206, df = 142, GFI = 0.923, AGFI = 0.883, TLI = 0.980, CFI = 0.983, RMSEA = 0.032, SRMR = 0.090). One-factor models using CFA demonstrated the overall best fit for four out of five subscales of the FFMQ-SF. In the five-factor CFA of the FFMQ-SF, the composite reliability values of the five factors were from 0.685 to 0.870 and the values of average variance extracted were from 0.426 to 0.627. PATIENT OR PUBLIC CONTRIBUTION: The students who participated in this study contributed to the advancement of knowledge on mindfulness and mental health among nursing students in China. They voluntarily completed the online questionnaires and provided their honest and valid responses. Their data was used to evaluate the psychometric properties of the FFMQ-SF and to examine the relationship between mindfulness and psychological problems. Their feedback also helped to improve the quality and applicability of the FFMQ-SF instrument for future research and practice.

Characteristics and influencing factors of anticipated HIV stigma among HIV-negative/unknown MSM in China: A regression mixture model.

BACKGROUND: Anticipated HIV stigma among men who have sex with men's (MSM) has a severe negative effect on their physical and mental health wellbeing and hence requires specific attention. The current study aims to identify the characteristics and the psychosocial influencing factors of anticipated HIV stigma in MSM using regression mixture model (RMM) and to determine the cut-off point of the seven-item Anticipated HIV Stigma Questionnaire (AHSQ) using the receiver operating characteristic (ROC) analysis. METHODS: A cross-sectional study was conducted among HIV-negative/unknown MSM from Blued online platform in China from December 16th, 2020 to March 1st, 2021, enrolling 1394 participants. Data were collected on demographic characteristics, perceived social support, anticipated HIV stigma, depressive symptoms, and HIV knowledge. Latent profile analysis was performed to identify different profiles of anticipated HIV stigma level. Chi-square test, analysis of variance, and RMM analysis were conducted to explore the influencing factors in different profiles. ROC analyses were carried out to identify the cut-off value of anticipated stigma. RESULTS: Among the participants, three profiles of anticipated stigma were identified: "low anticipated HIV stigma" (12.0%), "moderate anticipated HIV stigma" (52.1%), and "severe anticipated HIV stigma" (35.9%). RMM analysis showed that higher income and higher levels of knowledge were positively associated with moderate anticipated HIV stigma, whereas full-time job and social support were negatively associated with moderate anticipated HIV stigma; higher income, depressive symptoms, and knowledge were positively associated with severe anticipated HIV stigma, whereas minor ethnicity and social support were negatively associated with severe anticipated HIV stigma. ROC curve of the AHSQ showed that the optimal cut-off value of ≥16 could indicate positive anticipated HIV stigma. CONCLUSION: The study focuses on the level of anticipated HIV stigma and its psycho-socio influencing factors among HIV-negative/unknown MSM. It provides evidence for implementing relevant psychological interventions to HIV-negative/unknown MSM.

Matrix mechanics regulates muscle regeneration by modulating kinesin-1 activity.

Sarcopenia, a prevalent muscle disease characterized by muscle mass and strength reduction, is associated with impaired skeletal muscle regeneration. However, the influence of the biomechanical properties of sarcopenic skeletal muscle on the efficiency of the myogenic program remains unclear. Herein, we established a mouse model of sarcopenia and observed a reduction in stiffness within the sarcopenic skeletal muscle in vivo. To investigate whether the biomechanical properties of skeletal muscle directly impact the myogenic program, we established an in vitro system to explore the intrinsic mechanism involving matrix stiffness control of myogenic differentiation. Our findings identify the microtubule motor protein, kinesin-1, as a mechano-transduction hub that senses and responds to matrix stiffness, crucial for myogenic differentiation and muscle regeneration. Specifically, kinesin-1 activity is positively regulated by stiff matrices, facilitating its role in transporting mitochondria and enhancing translocation of the glucose transporter GLUT4 to the cell surface for glucose uptake. Conversely, the softer matrices significantly suppress kinesin-1 activity, leading to the accumulation of mitochondria around nuclei and hindering glucose uptake by inhibiting GLUT4 membrane translocation, consequently impairing myogenic differentiation. The insights gained from the in-vitro system highlight the mechano-transduction significance of kinesin-1 motor proteins in myogenic differentiation. Furthermore, our study confirms that enhancing kinesin-1 activity in the sarcopenic mouse model restores satellite cell expansion, myogenic differentiation, and muscle regeneration. Taken together, our findings provide a potential target for improving muscle regeneration in sarcopenia.