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Green synthesis of Au-Pd bimetallic nanoparticles using aspalathin and their toxicity study
(MDPI, 2026) Pearce, Keenau M; Benjeddou, Mongi; Seatle, Naledi D
Bimetallic nanoparticles have garnered significant attention in scientific literature due to their diverse applications and unique properties. Concurrently, green synthesis methodologies have emerged as environmentally friendly alternatives, reducing the ecological footprint of nanoparticle production. In this study, the efficient synthesis of Au-Pd bimetallic nanoparticles is presented, utilizing Aspalathus linearis (Burm.f.) R. Dahlgren, commonly known as green rooibos (GR), and its pure bioactive compound, Aspalathin (ASP). Integrating ASP as a pure compound into the green synthesis process offers precise control over nanoparticle characteristics, including size, morphology, and composition. Interestingly, the total extract forms an Au-Pd nanoparticle alloy, while aspalathin forms core–shell nanoparticles. Furthermore, cytotoxicity testing was carried out on selected cell lines to assess their impact on cell viability. The cytotoxicity test on cell lines and cellular uptake analysis demonstrated that none of the tested samples exhibited significant cytotoxic effects. ASP-conjugated bimetallic increased the uptake of the nps by the cells more than the total extract. The results demonstrated that the Au-Pd bimetallic nanoparticles hold promise for biomedical applications, owing to their enhanced biocompatibility and tailored properties
Synergistic Physicochemical Confinement In A Dual-Functional Separator For Long-Life Zn–I2 Batteries
(American Chemical Society, 2026) Iwuoha, Emmanuel Iheanyichukwu; Guan, Chunlong; Feleni, Usisipho
Aqueous zinc–iodine (Zn–I2) batteries have attracted considerable interest as promising energy storage systems, owing to their high safety, low cost, and environmental friendliness. However, the practical development of aqueous zinc–iodine batteries is impeded by polyiodide shuttle and severe self-discharge. Herein, a dual-functional separator is prepared by coating biomass-derived nitrogen-doped carbon nanosheets (NCNS-5) onto glass fiber (NCNS-5/GF). This rational design leverages a synergistic “blocking-adsorption-reconversion” mechanism, integrating a dense nanosheet barrier with chemical adsorption at N-dopants. NCNS-5 layer functions as a physical barrier that restricts polyiodide migration and the nitrogen-rich sites strongly adsorb soluble I3–/I5– species and facilitate their reconversion into active iodine species, suppressing shuttle and alleviating self-discharge at the source. The resulting battery exhibits 85.1% capacity retention after long-term cycles, 87.6% Coulombic efficiency after 120 h rest, while maintaining high capacity retention at 60 °C or under high iodine loading. This work presents an effective interfacial-engineering strategy of integrating a physical barrier with chemical mediation in separator design for effectively managing soluble intermediates in conversion-type battery systems. © 2026 American Chemical Society
McKinsey-Tarski algebras and raney extensions
(Springer Science and Business Media B.V., 2026) Suarez, Anna Laura; Bezhanishvili, G.; Raviprakash R.
We introduce the notion of Raney morphism between MT-algebras and show that the resulting category is equivalent to the category of Raney extensions. This is done by generalizing the construction of the Funayama envelope of a frame. The resulting notion of the T0-hull of a Raney extension generalizes that of the TD-hull of a frame.
Spatiotemporal Patterns Of Rift Valley Fever Virus In Africa: A Retrospective Genomic Epidemiology And Phylodynamic Modelling Study
(Elsevier Ltd, 2026) Christoffels, Alan; Juma, John; Roesel, Kristina
Background Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen causing outbreaks in humans and ruminants across Africa and the Arabian Peninsula. Originally restricted to the Great Rift Valley, RVFV has expanded geographically, prompting its classification by WHO as a pathogen of pandemic potential. We investigated the evolutionary and spatial dynamics of RVFV across Africa. Methods We used genomic data generated at the International Livestock Research Institute Nairobi genomic laboratory (BioProject PRJNA1106221) and combined with publicly available datasets retrieved from the National Center for Biotechnology (NCBI) GenBank nucleotide database. In retrieving RVFV genome sequences from the NCBI GenBank, we applied the search terms “Rift Valley fever virus segment L AND 6404[SLEN]”, “Rift Valley fever virus segment M AND 3885[SLEN]”, and “Rift Valley fever virus segment S AND 1520:1690[SLEN]” for L (Large), M (Medium), and S (Small) segments, respectively. For sequences without additional spatiotemporal information, we searched PubMed to extract the associated sequence metadata. We performed molecular clock analysis, phylogenetic inference, phylodynamic modelling (continuous phylogeographic reconstruction), and landscape phylogeography on the three RVFV genome segments (L, M, and S). We aimed to assess evolutionary rates, dispersal patterns, and environmental drivers. Focus was placed on lineage C, the most widely distributed variant. Findings The global dataset used in this study consisted of large (n=236), medium (n=237), and small (n=247), which were further filtered to exclude potential reassortants and vaccine strains. Genome sequences retrieved from NCBI GenBank database comprised large (n=180), medium (n=184), and small (n=202). The genome sequences from retrospective human and livestock isolates comprised large (n=56), medium (n=53), and small (n=45) collected in Burundi (2018), Kenya (2007, 2018, 2019, 2021, and 2022), and Rwanda (2018 and 2022). Our dataset revealed that RVFV exhibited low overall genetic diversity. Lineage C, however, showed evidence of active evolution, with substitution rates ranging from 3·58 × 10−4 to 9·76 × 10−4 substitutions per site per year. This lineage probably originated in Zimbabwe in the mid-1970s and has since expanded across eastern and southern Africa. Phylogeographic reconstructions revealed rapid spread, with diffusion coefficients exceeding 50 000 km2 per year. Interpretation Lineage C appears capable of establishing endemic transmission in new regions, with ongoing diversification observed during interepidemic periods. These observations reinforce the value of continuous genomic surveillance, particularly during cryptic transmission phases when adaptive mutations might emerge. Although further evidence is needed, observed trends in climate variability and land-use change point to the potential benefit of targeted surveillance in settings that could be at increased risk, including urban centres and wetlands. Funding This work was supported by the German Federal Ministry for Economic Cooperation and Development, the Rockefeller Foundation, and the Africa Centres for Disease Control and Prevention.
HIV policy implementation challenges: experiences of HIV managers in primary healthcare facilities in the Western Cape
(AOSIS (pty) Ltd, 2026) Akimanimpaye, Furaha; Crowley, Talitha; Titus, Verinia
Background: Implementing HIV policy involves translating policy goals into practical action. In the Western Cape, South Africa, the lack of clear guidelines has challenged the consistent implementation of HIV policies at primary healthcare (PHC) facilities. Objectives: This study aimed to explore HIV managers’ experiences regarding the challenges of HIV policy implementation at PHC facilities within the Northern Tygerberg sub-district, Cape Metropole, Western Cape. Method: An exploratory, descriptive, qualitative design was employed. Purposive sampling was applied to select HIV managers (n = 10) with experience in policy implementation. Data were collected through semi-structured interviews and analysed using thematic analysis. Results: Four themes emerged from the study, reflecting the challenges experienced by HIV managers during the implementation of HIV policies at PHC facilities, including human resource challenges, staff knowledge and attitudes, system readiness, and training. Conclusion: Effective implementation of HIV policy remains essential to the national HIV response. While significant targets have been achieved, ongoing systemic challenges continue to hinder optimal policy execution and the delivery of services. Contribution: The study highlights the critical need for stronger human resource systems, improved training platforms, and enhanced facility infrastructure to ensure effective HIV policy implementation and better health outcomes for individuals living with HIV.