73 research outputs found
Examining oral pre-exposure prophylaxis (PrEP) literacy among participants in an HIV vaccine trial preparedness cohort study
Background: PrEP literacy is influenced by many factors including the types of information available and how it is interpreted. The level of PrEP literacy may influence acceptability and uptake. Methods: We conducted 25 in-depth interviews in a HIV vaccine trial preparedness cohort study. We explored what participants knew about PrEP, sources of PrEP knowledge and how much they know about PrEP. We used the framework approach to generate themes for analysis guided by the Social Ecological Model and examined levels of PrEP literacy using the individual and interpersonal constructs of the SEM. Results: We found that PrEP awareness is strongly influenced by external factors such as social media and how much participants know about HIV treatment and prevention in the local community. However, while participants highlighted the importance of the internet/social media as a source of information about PrEP they talked of low PrEP literacy in their communities. Participants indicated that their own knowledge came as a result of joining the HIV vaccine trial preparedness study. However, some expressed doubts about the effectiveness of the drug and worried about side effects. Participants commented that at the community level PrEP was associated with being sexually active, because it was used to prevent the sexual transmission of HIV. As a result, some participants commented that one could feel judged by the health workers for asking for PrEP at health facilities in the community. Conclusion: The information collected in this study provided an understanding of the different layers of influence around individuals that are important to address to improve PrEP acceptability and uptake. Our findings can inform strategies to address the barriers to PrEP uptake, particularly at structural and community levels. Trial registration: https://clinicaltrials.gov/ct2/show/NCT04066881
The Wor1-like Protein Fgp1 Regulates Pathogenicity, Toxin Synthesis and Reproduction in the Phytopathogenic Fungus Fusarium graminearum
WOR1 is a gene for a conserved fungal regulatory protein controlling the dimorphic switch and pathogenicity determents in Candida albicans and its ortholog in the plant pathogen Fusarium oxysporum, called SGE1, is required for pathogenicity and expression of key plant effector proteins. F. graminearum, an important pathogen of cereals, is not known to employ switching and no effector proteins from F. graminearum have been found to date that are required for infection. In this study, the potential role of the WOR1-like gene in pathogenesis was tested in this toxigenic fungus. Deletion of the WOR1 ortholog (called FGP1) in F. graminearum results in greatly reduced pathogenicity and loss of trichothecene toxin accumulation in infected wheat plants and in vitro. The loss of toxin accumulation alone may be sufficient to explain the loss of pathogenicity to wheat. Under toxin-inducing conditions, expression of genes for trichothecene biosynthesis and many other genes are not detected or detected at lower levels in Δfgp1 strains. FGP1 is also involved in the developmental processes of conidium formation and sexual reproduction and modulates a morphological change that accompanies mycotoxin production in vitro. The Wor1-like proteins in Fusarium species have highly conserved N-terminal regions and remarkably divergent C-termini. Interchanging the N- and C- terminal portions of proteins from F. oxysporum and F. graminearum resulted in partial to complete loss of function. Wor1-like proteins are conserved but have evolved to regulate pathogenicity in a range of fungi, likely by adaptations to the C-terminal portion of the protein
Examining oral pre-exposure prophylaxis (PrEP) literacy among participants in an HIV vaccine trial preparedness cohort study
Background PrEP literacy is influenced by many factors including the types of information available and how it is interpreted. The level of PrEP literacy may influence acceptability and uptake. Methods We conducted 25 in-depth interviews in a HIV vaccine trial preparedness cohort study. We explored what participants knew about PrEP, sources of PrEP knowledge and how much they know about PrEP. We used the framework approach to generate themes for analysis guided by the Social Ecological Model and examined levels of PrEP literacy using the individual and interpersonal constructs of the SEM. Results We found that PrEP awareness is strongly influenced by external factors such as social media and how much participants know about HIV treatment and prevention in the local community. However, while participants highlighted the importance of the internet/social media as a source of information about PrEP they talked of low PrEP literacy in their communities. Participants indicated that their own knowledge came as a result of joining the HIV vaccine trial preparedness study. However, some expressed doubts about the effectiveness of the drug and worried about side effects. Participants commented that at the community level PrEP was associated with being sexually active, because it was used to prevent the sexual transmission of HIV. As a result, some participants commented that one could feel judged by the health workers for asking for PrEP at health facilities in the community. Conclusion The information collected in this study provided an understanding of the different layers of influence around individuals that are important to address to improve PrEP acceptability and uptake. Our findings can inform strategies to address the barriers to PrEP uptake, particularly at structural and community levels. Trial registration https://clinicaltrials.gov/ct2/show/NCT0406688
Vaccine efficacy of ALVAC-HIV and bivalent subtype C gp120–MF59 in adults
BACKGROUND : A safe, effective vaccine is essential to eradicating human immunodeficiency virus (HIV) infection. A canarypox–protein HIV vaccine regimen (ALVAC-HIV plus AIDSVAX B/E) showed modest efficacy in reducing infection in Thailand. An analogous regimen using HIV-1 subtype C virus showed potent humoral and cellular responses in a phase 1–2a trial in South Africa. Efficacy data and additional safety data were needed for this regimen in a larger population in South Africa. METHODS : In this phase 2b–3 trial, we randomly assigned 5404 adults without HIV-1 infection to receive the vaccine (2704 participants) or placebo (2700 participants). The vaccine regimen consisted of injections of ALVAC-HIV at months 0 and 1, followed by four booster injections of ALVAC-HIV plus bivalent subtype C gp120–MF59 adjuvant at months 3, 6, 12, and 18. The primary efficacy outcome was the occurrence of HIV-1 infection from randomization to 24 months. RESULTS : In January 2020, prespecified criteria for non-efficacy were met at an interim analysis; further vaccinations were subsequently halted. The median age of the trial participants was 24 years; 70% of the participants were women. The incidence of adverse events was similar in the vaccine and placebo groups. During the 24-month followup, HIV-1 infection was diagnosed in 138 participants in the vaccine group and in 133 in the placebo group (hazard ratio, 1.02; 95% confidence interval, 0.81 to 1.30; P = 0.84). CONCLUSIONS : The ALVAC–gp120 regimen did not prevent HIV-1 infection among participants in South Africa despite previous evidence of immunogenicity.Supported by grants (HHSN272201300033C and HHSN272201600012C)
to Novartis Vaccines and Diagnostics (now part of the
GlaxoSmithKline [GSK] Biologicals) by the National Institute of
Allergy and Infectious Diseases (NIAID) of the National Institutes
of Health (NIH) for the selection and process development of the
two gp120 envelope proteins TV1.C and 1086.C; by the Bill and
Melinda Gates Foundation Global Health Grant (OPP1017604)
and NIAID for the manufacture and release of the gp120 clinical
grade material; and by U.S. Public Health Service Grants — UM1
AI068614 to the HIV Vaccine Trials Network (HVTN), UM1
AI068635 to the HVTN Statistical and Data Management Center,
and UM1 AI068618 to the HVTN Laboratory Center — from the
NIAID. GSK Biologicals contributed financially to the provision of
preexposure prophylaxis to trial participants. The South African
Medical Research Council supported its affiliated research sites.http://www.nejm.orgam2022School of Health Systems and Public Health (SHSPH
Lead-acid cells with polyaniline-coated negative plates
Positive- and negative-limited lead-acid cells with conventional and polyaniline (PANI)-coated negative plates were assembled and tested at varying discharge rates. The cells with PANI-coated negative plates exhibit lower impedance in relation to conventional cells and sustain higher discharge-rates with lesser loss in capacity during prolonged charge-discharge cycling as compared to conventional cells. It is suggested that PANI-coated negative plates are beneficial in designing lead-acid batteries operating at partial-state-of-charge
Corrosion Resistant Polypyrrole Coated Lead-Alloy Positive Grids for Advanced Lead-Acid Batteries
We herein report a method for reducing lead-alloy positive grid corrosion in lead acid batteries by developing a polypyrrole (ppy) coating on to the surface of lead-alloy grids through potentiostatic polymerization technique. The experimental results demonstrate that the presence of ppy coating significantly enhances the corrosion resistance and inhibits the oxygen evolution rate as compare to bare grids. C-rate studies of 2 V/2.6 Ah lead-acid cells show ∼15–20% improvement in capacity at low charge-discharge rates (C/20- C/5) and ∼10% at high C rates (C/2 and 3C) for the cells with ppy coating grids in relation to conventional lead-acid cells
Event Triggered Neuroadaptive Controller (ETNAC) Design for Uncertain Linear Systems
In this paper a novel event triggered neural network (NN) based adaptive controller is presented for linear systems with multiple uncertainties. Controller design is primarily based on an observer, called the modified state observer (MSO). MSO is used to approximate uncertainties online, with two tunable gains, which allow fast approximation without inducing high frequency oscillations. On the other hand state information is transmitted to the feedback loop only when required in an aperiodic fashion. This aperiodic update is triggered by a dynamic condition based on errors. Consequently, this event triggered control (ETC) not only reduces the control computations, but also bring down the communication cost. Lyapunov analysis is used to show the stability of the system as well as to develop the event sample triggering condition. Efficacy of the proposed controllers is demonstrated using a numerical example
Titanium dioxide-reduced graphene oxide hybrid as negative electrode additive for high performance lead-acid batteries
Sulfation at the negative electrode is one of the major failure modes of lead-acid batteries. To overcome the issues of sulfation, we herein report solvothermal synthesis of titanium dioxide- reduced graphene oxide hybrid as negative electrode additive in lead acid cell. The presence of titanium dioxide-reduced graphene oxide hybrid additive (0.5 wt. %) provides high interfacial stability, slows down hard sulfation, high active material utilization by occupying pores on the negative plate. 0.5 wt. % of titanium dioxide-reduced graphene oxide hybrid (3:1 wt. ratio) additive to the negative active mass delivers 85% increase in capacity during the first formation cycle, and thereby increases the formation efficiency from 3 cycles to 1 cycle; >20% and ∼200% increase in capacity at low discharge rates of C/20 and high rates of discharge (2C), respectively as compare to conventional lead acid cell. Besides, 3:1 wt. ratio titanium dioxide-reduced graphene oxide hybrid additive cells show ∼200% increase in high rate partial state of charge cycle life in relation to conventional cell. Titanium dioxide-reduced graphene oxide hybrid additives to the negative active mass provides increase in conductivity, controls the crystallization of lead sulphate growth, acts as a capacitor, decreases the hydrogen evolution and hence enhances the electrochemical performance
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