A titanium dioxide/nitrogen-doped graphene quantum dot nanocomposite to mitigate cytotoxicity: synthesis, characterisation, and cell viability evaluation

Titanium dioxide nanoparticles (TiO2 NPs) have attracted tremendous interest owing to their unique physicochemical properties. However, the cytotoxic effect of TiO2 NPs remains an obstacle for their wide-scale applications, particularly in drug delivery systems and cancer therapies. In this study, the more biocompatible nitrogen-doped graphene quantum dots (N-GQDs) were successfully incorporated onto the surface of the TiO2 NPs resulting in a N-GQDs/TiO2 nanocomposites (NCs). The effects of the nanocomposite on the viability of the breast cancer cell line (MDA-MB-231) was evaluated. The N-GQDs and N-GQDs/TiO2 NCs were synthesised using a one- and two-pot hydrothermal method, respectively while the TiO2 NPs were fabricated using microwave-assisted synthesis in the aqueous phase. The synthesised compounds were characterised using Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometry. The cell viability of the MDA-MB-231 cell line was determined using a CellTiter 96® AQueous One Solution Cell Proliferation (MTS) assay. The obtained results indicated that a monodispersed solution of N-GQDs with particle size 4.40 ± 1.5 nm emitted intense blue luminescence in aqueous media. The HRTEM images clearly showed that the TiO2 particles (11.46 ± 2.8 nm) are square shaped. Meanwhile, TiO2 particles were located on the 2D graphene nanosheet surface in N-GQDs/TiO2 NCs (9.16 ± 2.4 nm). N-GQDs and N-GQDs/TiO2 NCs were not toxic to the breast cancer cells at 0.1 mg mL−1 and below. At higher concentrations (0.5 and 1 mg mL−1), the nanocomposite was significantly less cytotoxic compared to the pristine TiO2. In conclusion, this nanocomposite with reduced cytotoxicity warrants further exploration as a new TiO2-based nanomaterial for biomedical applications, especially as an anti-cancer strategy

Preventing Advanced Persistent Threats in Complex Control Networks

An Advanced Persistent Threat (APT) is an emerging attack against Industrial Control and Automation Systems, that is executed over a long period of time and is difficult to detect. In this context, graph theory can be applied to model the interaction among nodes and the complex attacks affecting them, as well as to design recovery techniques that ensure the survivability of the network. Accordingly, we leverage a decision model to study how a set of hierarchically selected nodes can collaborate to detect an APT within the network, concerning the presence of changes in its topology. Moreover, we implement a response service based on redundant links that dynamically uses a secret sharing scheme and applies a flexible routing protocol depending on the severity of the attack. The ultimate goal is twofold: ensuring the reachability between nodes despite the changes and preventing the path followed by messages from being discovered.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A pharmacist-led intervention for increasing the uptake of Home Medicines Review (HMR) among residents of retirement villages (PHARMER): protocol for a cluster randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>The majority of retirement village residents are at risk of medication misadventure. In a recent survey of retirement village residents in Victoria, two-thirds had at least one medication-related risk factor, and hence were eligible to receive a government-subsidised Home Medicines Review (HMR). However, only 6% of eligible residents had received a HMR in the previous 12 months. Reasons for the poor uptake of HMR, and interventions for improving HMR uptake, have been identified and developed with input from stakeholders. The trial will test the effect of <b>P</b>harmacist-conducted <b>H</b>MR to <b>A</b>ddress the <b>R</b>isk of <b>M</b>edication-related <b>E</b>vents in <b>R</b>etirement Villages (PHARMER) in improving the uptake of HMRs among retirement village residents.</p> <p>Methods/Design</p> <p>This is a multicentre prospective cluster randomised controlled trial. Ten retirement villages in Victoria, Australia will be recruited for this trial. Retirement villages will be selected in consultation with the Residents of Retirement Villages Victoria Inc. (RRVV), based on geographical locations (e.g. northeast or southwest), size and other factors. Residents from selected villages will be recruited with the help of RRVV Resident Liaison Officers using a range of strategies. Randomisation will be by geographical location to minimise contamination. Participating villages and residents will be allocated to either Pharmacist Intervention Group (PIG) or Usual Care Group (UCG). Each group will include five retirement villages and will have at least 77 residents in total. The intervention (PHARMER) comprises educating residents regarding HMR, and using a risk assessment checklist by residents to notify their General Practitioners of their medication risk. Uptake of HMR and medication adherence will be assessed in both PIG and UCG at three and six months using telephone interviews and questionnaires.</p> <p>Discussion</p> <p>This study is the first to develop and test an intervention to improve the uptake of HMR among Australian residents in retirement villages, with a view to decreasing medication risk. A multi-faceted interventional approach will be used as suggested by stakeholders. The trial is expected to be complete by late 2011 and results will be available in 2012.</p> <p>Trial Registration</p> <p>Australian New Zealand Clinical Trials Registry (<a href="http://www.anzctr.org.au/ACTRN12611000109909.aspx">ACTRN12611000109909</a>)</p

Burkholderia pseudomallei in soil samples from an oceanarium in Hong Kong detected using a sensitive PCR assay

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N17 Modifies mutant Huntingtin nuclear pathogenesis and severity of disease in HD BAC transgenic mice.

The nucleus is a critical subcellular compartment for the pathogenesis of polyglutamine disorders, including Huntington's disease (HD). Recent studies suggest the first 17-amino-acid domain (N17) of mutant huntingtin (mHTT) mediates its nuclear exclusion in cultured cells. Here, we test whether N17 could be a molecular determinant of nuclear mHTT pathogenesis in vivo. BAC transgenic mice expressing mHTT lacking the N17 domain (BACHD-ΔN17) show dramatically accelerated mHTT pathology exclusively in the nucleus, which is associated with HD-like transcriptionopathy. Interestingly, BACHD-ΔN17 mice manifest more overt disease-like phenotypes than the original BACHD mice, including body weight loss, movement deficits, robust striatal neuron loss, and neuroinflammation. Mechanistically, N17 is necessary for nuclear exclusion of small mHTT fragments that are part of nuclear pathology in HD. Together, our study suggests that N17 modifies nuclear pathogenesis and disease severity in HD mice by regulating subcellular localization of known nuclear pathogenic mHTT species

Genotoxicity evaluation of the insecticide ethion in root of Allium cepa L.

In this study, the genotoxic effects of ethion were investigated in the mitotic cell division of Allium cepa. Primary roots of A. cepa were treated with various concentrations (25, 50, 75, and 100%) of ethion solutions for different duration of time. The result revealed that increase in the concentration and duration of treatment decreases the mitotic indices. 24 h treatment at 100% concentration of ethion induced lowest mitotic index (20.08%) than that of the control (36.37%). The percentage of chromosomal abnormalities in different mitotic stages was significantly generally higher than that of the control in all the treatment period and concentrations. These abnormalities appeared in various degrees depending on the treatment duration and concentrations of ethion. The abnormalities in dividing cell reached a maximum value of 11.30% after 12 h of treatment at 75% concentration. The type of abnormalitiesproduced were scattered prophase, non-synchronized condensation of chromosome, disturbed prophase, equatorial plate shifting, sticky chromosomes, C-metaphase and sticky metaphase. Overall, it can be concluded that ethion has a potential genotoxic effects on mitotic divisions in A. cepa root tip cells. So, it will be necessary to test the mutagenic potential of ethion on a more intensive and extensive basis especially on non-target systems before it is recommended for wider use in agriculturalfield

Metabolomic profiling of Burkholderia pseudomallei using UHPLC-ESI-Q-TOF-MS reveals specific biomarkers including 4-methyl-5-thiazoleethanol and unique thiamine degradation pathway

© 2015 Lau et al.Background: Burkholderia pseudomallei is an emerging pathogen that causes melioidosis, a serious and potentially fatal disease which requires prolonged antibiotics to prevent relapse. However, diagnosis of melioidosis can be difficult, especially in culture-negative cases. While metabolomics represents an uprising tool for studying infectious diseases, there were no reports on its applications to B. pseudomallei. To search for potential specific biomarkers, we compared the metabolomics profiles of culture supernatants of B. pseudomallei (15 strains), B. thailandensis (3 strains), B. cepacia complex (14 strains), P. aeruginosa (4 strains) and E. coli (3 strains), using ultra-high performance liquid chromatography-electrospray ionization-quadruple time-of-flight mass spectrometry (UHPLC-ESI-Q-TOF-MS). Multi- and univariate analyses were used to identify specific metabolites in B. pseudomallei. Results: Principal component and partial-least squares discrimination analysis readily distinguished the metabolomes between B. pseudomallei and other bacterial species. Using multi-variate and univariate analysis, eight metabolites with significantly higher levels in B. pseudomallei were identified. Three of the eight metabolites were identified by MS/MS, while five metabolites were unidentified against database matching, suggesting that they may be potentially novel compounds. One metabolite, m/z 144.048, was identified as 4-methyl-5-thiazoleethanol, a degradation product of thiamine (vitamin B1), with molecular formula C6H9NOS by database searches and confirmed by MS/MS using commercially available authentic chemical standard. Two metabolites, m/z 512.282 and m/z 542.2921, were identified as tetrapeptides, Ile-His-Lys-Asp with molecular formula C22H37N7O7 and Pro-Arg-Arg-Asn with molecular formula C21H39N11O6, respectively. To investigate the high levels of 4-methyl-5-thiazoleethanol in B. pseudomallei, we compared the thiamine degradation pathways encoded in genomes of B. pseudomallei and B. thailandensis. While both B. pseudomallei and B. thailandensis possess thiaminase I which catalyzes degradation of thiamine to 4-methyl-5-thiazoleethanol, thiM, which encodes hydroxyethylthiazole kinase responsible for degradation of 4-methyl-5-thiazoleethanol, is present and expressed in B. thailandensis as detected by PCR/RT-PCR, but absent or not expressed in all B. pseudomallei strains. This suggests that the high 4-methyl-5-thiazoleethanol level in B. pseudomallei is likely due to the absence of hydroxyethylthiazole kinase and hence reduced downstream degradation. Conclusion: Eight novel biomarkers, including 4-methyl-5-thiazoleethanol and two tetrapeptides, were identified in the culture supernatant of B. pseudomallei.published_or_final_versio

The Hydration Structure at Yttria-Stabilized Cubic Zirconia (110)-Water Interface with Sub-Angstrom Resolution

The interfacial hydration structure of yttria-stabilized cubic zirconia (110) surface in contact with water was determined with ~0.5&amp;#8201;&amp;Aring; resolution by high-resolution X-ray reflectivity measurement. The terminal layer shows a reduced electron density compared to the following substrate lattice layers, which indicates there are additional defects generated by metal depletion as well as intrinsic oxygen vacancies, both of which are apparently filled by water species. Above this top surface layer, two additional adsorbed layers are observed forming a characteristic interfacial hydration structure. The first adsorbed layer shows abnormally high density as pure water and likely includes metal species, whereas the second layer consists of pure water. The observed interfacial hydration structure seems responsible for local equilibration of the defective surface in water and eventually regulating the long-term degradation processes. The multitude of water interactions with the zirconia surface results in the complex but highly ordered interfacial structure constituting the reaction front.ope

Microbial fuel cells: a green and alternative source for bioenergy production

Microbial fuel cell (MFC) represents one of the green technologies for the production of bioenergy. MFCs using microalgae produce bioenergy by converting solar energy into electrical energy as a function of metabolic and anabolic pathways of the cells. In the MFCs with bacteria, bioenergy is generated as a result of the organic substrate oxidation. MFCs have received high attention from researchers in the last years due to the simplicity of the process, the absence in toxic by-products, and low requirements for the algae growth. Many studies have been conducted on MFC and investigated the factors affecting the MFC performance. In the current chapter, the performance of MFC in producing bioenergy as well as the factors which influence the efficacy of MFCs is discussed. It appears that the main factors affecting MFC’s performance include bacterial and algae species, pH, temperature, salinity, substrate, mechanism of electron transfer in an anodic chamber, electrodes materials, surface area, and electron acceptor in a cathodic chamber. These factors are becoming more influential and might lead to overproduction of bioenergy when they are optimized using response surface methodology (RSM)

Large-Scale Fabrication of Boron Nitride Nanotubes via a Facile Chemical Vapor Reaction Route and Their Cathodoluminescence Properties

Cylinder- and bamboo-shaped boron nitride nanotubes (BNNTs) have been synthesized in large scale via a facile chemical vapor reaction route using ammonia borane as a precursor. The structure and chemical composition of the as-synthesized BNNTs are extensively characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and selected-area electron diffraction. The cylinder-shaped BNNTs have an average diameter of about 100 nm and length of hundreds of microns, while the bamboo-shaped BNNTs are 100–500 nm in diameter with length up to tens of microns. The formation mechanism of the BNNTs has been explored on the basis of our experimental observations and a growth model has been proposed accordingly. Ultraviolet–visible and cathodoluminescence spectroscopic analyses are performed on the BNNTs. Strong ultraviolet emissions are detected on both morphologies of BNNTs. The band gap of the BNNTs are around 5.82 eV and nearly unaffected by tube morphology. There exist two intermediate bands in the band gap of BNNTs, which could be distinguishably assigned to structural defects and chemical impurities