64 research outputs found

    Biogenic synthesis of gold nanoparticles from waste watermelon and their antibacterial activity against Escherichia coli and Staphylococcus epidermidis

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    Background: Globally, large quantities (tonnes) of diverse sources of food wastes derived from horticulture are produced and offer a valuable renewable source of biochemical compounds. Developing new recycling and food waste utilisation strategies creates unique opportunities for producing gold (Au) nanoparticles with desirable antibacterial properties. The present study used an eco-friendly procedure for biologically synthesizing gold (Au) nanoparticle shapes from waste Citrullis lanatus var (watermelon).Methods: The green chemistry-based procedure used in this study was straightforward and used both red and green parts of waste watermelon. The generated Au nanoparticles were subsequently evaluated using several advanced characterization techniques. The antibacterial properties of the various extracts and synthesised nanoparticles were evaluated using the Kirby-Bauer sensitivity method.Results: The advanced characterization techniques revealed the Au particles ranged in size from nano (100 nm) up micron (2.5 µm) and had a variety of shapes. The red watermelon extract tended to produce spheres and hexagonal plates, while the green watermelon extract tended to generate triangular shaped nanoparticles. Both red and green watermelon extracts produced nanoparticles with similar antibacterial properties. The most favourable response was achieved using a 5:1 green watermelon-based mixture for Staphylococcus epidermidis, which produced a maximum inhibition zone of 12 mm. While gram-negative bacteria Escherichia coli produced a maximum inhibition zone of 10 mm for the same mixture.Conclusions: The study has shown both red and green parts of waste watermelon can be used to produce Au nanoparticles with antibacterial activity towards both Escherichia coli and Staphylococcus epidermidis. The study has also demonstrated an alternative method for producing high-value Au nanoparticles with potential pharmaceutical applications

    Towards 5G Zero Trusted Air Interface Architecture

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    5G is destined to be supporting large deployment of Industrial IoT (IIoT) with the characteristics of ultra-high densification and low latency. 5G utilizes a more intelligent architecture, with Radio Access Networks (RANs) no longer constrained by base station proximity or proprietary infrastructure. The 3rd Generation Partnership Project (3GPP) covers telecommunication technologies including RAN, core transport networks and service capabilities. Open RAN Alliance (O-RAN) aims to define implementation and deployment architectures, focusing on open-source interfaces and functional units to further reduce the cost and complexity. O-RAN based 5G networks could use components from different hardware and software vendors, promoting vendor diversity, interchangeability and 5G supply chain resiliency. Both 3GPP and O-RAN 5G have to manage the security and privacy challenges that arose from the deployment. Many existing research studies have addressed the threats and vulnerabilities within each system. 5G also has the overwhelming challenges in compliance with privacy regulations and requirements which mandate the user identifiable information need to be protected. In this paper, we look into the 3GPP and O-RAN 5G security and privacy designs and the identified threats and vulnerabilities. We also discuss how to extend the Zero Trust Model to provide advanced protection over 5G air interfaces and network components

    Neurodiverse Knowledge, Skills and Ability Assessment for Cyber Security

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    Cyber attacks have become commonplace and cause harm to IT systems operated by governments, businesses and citizens. As a result, there has been substantial job growth within the cyber security industry to try and meet the need for network defence. However, due to fierce competition for with the relevant skills there is a shortfall in skilled workers able to fill these roles. The goal of this project is to develop, validate and verify a novel solution for the recruitment of highly competent cyber security staff who can defend our nation against capable and well-funded adversaries. The proposed solution involves the development of a training scheme to train neurodiverse individuals for these roles. There is evidence for their interest and aptitude within the sector, but no research has been undertaken to establish how best to train them in the context of their individual differences

    Local structural alignment of RNA with affine gap model

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    BACKGROUND: Predicting new non-coding RNAs (ncRNAs) of a family can be done by aligning the potential candidate with a member of the family with known sequence and secondary structure. Existing tools either only consider the sequence similarity or cannot handle local alignment with gaps. RESULTS: In this paper, we consider the problem of finding the optimal local structural alignment between a query RNA sequence (with known secondary structure) and a target sequence (with unknown secondary structure) with the affine gap penalty model. We provide the algorithm to solve the problem. CONCLUSIONS: Based on an experiment, we show that there are ncRNA families in which considering local structural alignment with gap penalty model can identify real hits more effectively than using global alignment or local alignment without gap penalty model.published_or_final_versio

    Legionella pneumophila Secretes a Mitochondrial Carrier Protein during Infection

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    The Mitochondrial Carrier Family (MCF) is a signature group of integral membrane proteins that transport metabolites across the mitochondrial inner membrane in eukaryotes. MCF proteins are characterized by six transmembrane segments that assemble to form a highly-selective channel for metabolite transport. We discovered a novel MCF member, termed Legionella nucleotide carrier Protein (LncP), encoded in the genome of Legionella pneumophila, the causative agent of Legionnaire's disease. LncP was secreted via the bacterial Dot/Icm type IV secretion system into macrophages and assembled in the mitochondrial inner membrane. In a yeast cellular system, LncP induced a dominant-negative phenotype that was rescued by deleting an endogenous ATP carrier. Substrate transport studies on purified LncP reconstituted in liposomes revealed that it catalyzes unidirectional transport and exchange of ATP transport across membranes, thereby supporting a role for LncP as an ATP transporter. A hidden Markov model revealed further MCF proteins in the intracellular pathogens, Legionella longbeachae and Neorickettsia sennetsu, thereby challenging the notion that MCF proteins exist exclusively in eukaryotic organisms

    Surface Composition of Carbon Nanotubes-Fe-Alumina Nanocomposite Powders: An Integral Low-Energy Electron Mo1ssbauer Spectroscopic Study

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    The surface state of carbon nanotubes-Fe-alumina nanocomposite powders was studied by transmission and integral low-energy electron Mo¨ssbauer spectroscopy. Several samples, prepared under reduction of the R-Al1.8-Fe0.2O3 precursor in a H2-CH4 atmosphere applying the same heating and cooling rate and changing only the maximum temperature (800-1070 °C) were investigated, demonstrating that integral low-energy electron Mo¨ssbauer spectroscopy is a promising tool complementing transmission Mössbauer spectroscopy for the investigation of the location of the metal Fe and iron-carbide particles in the different carbon nanotubenanocomposite systems containing iron. The nature of the iron species (Fe3+, Fe3C, R-Fe, ç-Fe-C) is correlated to their location in the material. In particular, much information was derived for the powders prepared by using a moderate reduction temperature (800, 850, and 910 °C), for which the transmission and integral low-energy electron Mössbauer spectra are markedly different. Indeed, R-Fe and Fe3C were not observed as surface species, while ç-Fe-C is present at the surface and in the bulk in the same proportion independent of the temperature of preparation. This could show that most of the nanoparticles (detected as Fe3C and/or ç-Fe-C) that contribute to the formation of carbon nanotubes are located in the outer porosity of the material, as opposed to the topmost (ca. 5 nm) surface. For the higher reduction temperatures Tr of 990 °C and 1070 °C, all Fe and Fe-carbide particles formed during the reduction are distributed evenly in the bulk and the surface of the matrix grains. The integral low-energy electron Mo¨ssbauer spectroscopic study of a powder oxidized in air at 600 °C suggests that all Fe3C particles oxidize to R-Fe2O3, while the R-Fe and/or ç-Fe-C are partly transformed to Fe1-xO and R-Fe2O3, the latter phase forming a protecting layer that prevents total oxidation
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