Synthesis of Nanometal Oxide–Coated Cotton Composites

Several selected studies dealing with the development of novel antimicrobial metal oxide–coated cotton nanocomposites and their antimicrobial applications have been reviewed in this chapter. Synthesis of metal oxide nanoparticles (NPs) and its deposition onto cotton fibers were conducted using various methods. These include the high energy γ-radiation, thermal treatment-assisted impregnation, “pad-dry-cure” of the impregnated fabric in the colloid formulation of metal oxide soluble, and ultrasonic radiation methods. The coated metal oxide nanoparticles have shown an effective enhancement for antimicrobial activity. They reduce the chance of diseases originating from hospital infections. The antimicrobial properties of cotton fabrics finished with metal oxide NPs against a variety of bacterial strains commonly associated with nosocomial infections, caused by Staphylococcus aureus and Escherichia coli, have been investigated by four different methods. The morphology of the cotton-coated metal oxide nanoparticles and their chemical structure have been analyzed by UV-vis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS). SEM and XRD analyses revealed that the shape and size of the coated nanoparticles are dependent on the nature of the metal oxide and its preparation conditions

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Stabilization of nano-structured ZnO particles onto the surface of cotton fibers using different surfactants and their antimicrobial activity

International audienceZnO NPs were prepared and deposited onto cotton fibers via ultrasound irradiation successfully. Different surfactants (SDS, HY, CTAB,TX-100) have been used to stabilize, homogenize the coated ZnO NPs and control their shape and size as encapsulated species. The use of surfactants has improved the durability of ZnO NPs and decreased its leaching in particular SDS. The small mean crystallite size for ZnO particles due to the use of surfactants is the main reason for decreasing the leached of ZnO particles from cotton substrate. SEM and XRD analysis revealed information about the shape and size of the coated ZnO nanopaticles. The use of SDS and HY surfactants in the synthesis of ZnO NPs coated fabrics showed the highest antibacterial and antifungal activities against different pathogenic bacterial and fungal species with high reduction reached over 90%

The efficacy of surfactants in stabilizing coating of nano-structured CuO particles onto the surface of cotton fibers and their antimicrobial activity

The efficacy of surfactants in stabilizing CuO-NPs onto the surface of the cotton fibers and their ability to produce homogeneous CuO-coated cotton composite was studied using different types of surfactants. The use of surfactants provides better adhesion of the CuO NPs and consequence, enhanced its coating stability during exploitation. The optical structure and morphology of the coated cotton fabrics were examined by several methods include: X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform spectroscopy (FTIR). The CuO-NPs-coated cotton fabrics have resisted the intensive 10 washing cycles in particular, in presence of SDS (25% loss of CuO) in comparison with TX-100 (66.5% loss of CuO). The CuO-NPs coated cotton materials have also showed an excellent inhibition for the growth of the medically relevant staphylococcus aureus

Synthesis, molecular docking and ADMET studies of bis-benzimidazole-based thiadiazole derivatives as potent inhibitors, in vitro α-amylase and α-glucosidase

Different research synthetic methods have been developed recently for the synthesis of bis-benzimidazole analogs to investigate various biological significances. In this present study, an attempt was made to synthesize a new series of bis-benzimidazole analogs in a fast and efficient method. A variety of spectroscopic techniques, including 13C NMR, 1H NMR, and HREI-MS, were used to establish the existence of every synthesized scaffold. Molecular docking profiles were also carried out to ascertain the binding interactions of the compounds. All derivatives (1–18) were evaluated for their biological potential to investigate the inhibitory activity of α-amylase and α-glucosidase through SAR study. Almost all derivatives were found to be engaged in a highly promising activity when compared to referenced drug acarbose (IC50 = 8.24 ± 0.08 µM), in this regard among the tested series analog 9 (IC50 = 0.10 ± 0.50 and 0.20 ± 0.50 µM respectively), showed excellent activity. Moreover, ADME predictions were also studied for potent compounds, exhibited drug like properties