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Distinct chemistries define the diverse biological effects of plasma activated water generated with spark and glow plasma discharges
No full textThe spread of multidrug-resistant bacteria poses a significant threat to human health. Plasma activated liquids (PAL) could be a promising alternative for microbial decontamination, where different PAL can possess diverse antimicrobial efficacies and cytotoxic profiles, depending on the range and concentration of their reactive chemical species. In this research, the biological activity of plasma activated water (PAW) on different biological targets including both microbiological and mammalian cells was investigated in vitro. The aim was to further an understanding of the specific role of distinct plasma reactive species, which is required to tailor plasma activated liquids for use in applications where high antimicrobial activity is required without adversely affecting the biology of eukaryotic cells. PAW was generated by glow and spark discharges, which provide selective generation of hydrogen peroxide, nitrite and nitrate in the liquid. The PAW made by either spark or glow discharges showed similar antimicrobial efficacy and stability of activity, despite the very different reactive oxygen species (ROS) and reactive nitrogen species profiles (RNS). However, different trends were observed for cytotoxic activities and effects on enzyme function, which were translated through the selective chemical species generation. These findings indicate very distinct mechanisms of action which may be exploited when tailoring plasma activated liquids to various applications. A remarkable stability to heat and pressure was noted for PAW generated with this set up, which broadens the application potential. These features also suggest that post plasma modifications and post generation stability can be harnessed as a further means of modulating the chemistry, activity and mode of delivery of plasma functionalised liquids. Overall, these results further understanding on how PAL generation may be tuned to provide candidate disinfectant agents for biomedical application or for bio-decontamination in diverse areas.Science Foundation Irelan
Personal Electronic Records of Medications (PERMs) for medication reconciliation at care transitions: a rapid realist review.
No full textBackground
Medication reconciliation (MedRec), a process to reduce medication error at care transitions, is labour- and resource-intensive and time-consuming. Use of Personal Electronic Records of Medications (PERMs) in health information systems to support MedRec have proven challenging. Relatively little is known about the design, use or implementation of PERMs at care transitions that impacts on MedRec in the ‘real world’. To respond to this gap in knowledge we undertook a rapid realist review (RRR). The aim was to develop theories to explain how, why, when, where and for whom PERMs are designed, implemented or used in practice at care transitions that impacts on MedRec.
Methodology
We used realist methodology and undertook the RRR between August 2020 and February 2021. We collaborated with experts in the field to identify key themes. Articles were sourced from four databases (Pubmed, Embase, CINAHL Complete and OpenGrey) to contribute to the theory development. Quality assessment, screening and data extraction using NVivo was completed. Contexts, mechanisms and outcomes configurations were identified and synthesised. The experts considered these theories for relevance and practicality and suggested refinements.
Results
Ten provisional theories were identified from 19 articles. Some theories relate to the design (T2 Inclusive design, T3 PERMs complement existing good processes, T7 Interoperability), some relate to the implementation (T5 Tailored training, T9 Positive impact of legislation or governance), some relate to use (T6 Support and on-demand training) and others relate iteratively to all stages of the process (T1 Engage stakeholders, T4 Build trust, T8 Resource investment, T10 Patients as users of PERMs).
Conclusions
This RRR has allowed additional valuable data to be extracted from existing primary research, with minimal resources, that may impact positively on future developments in this area. The theories are interdependent to a greater or lesser extent; several or all of the theories may need to be in play to collectively impact on the design, implementation or use of PERMs for MedRec at care transitions. These theories should now be incorporated into an intervention and evaluated to further test their validity
Deposition of Cell Culture Coatings Using a Cold Plasma Deposition Method
No full textCollagen coatings were applied onto polystyrene microplates using a cold atmospheric pressure plasma process. The coatings were compared to standard wet chemical collagen thin films using microscopy, surface energy, infra-red spectroscopy, electrophoresis, and cell culture techniques. Thin films were also deposited on gold electrodes using both coating methods and their structural and barrier properties probed using cyclic voltammetry. While the wet chemical technique produced a thicker deposit, both films appear equivalent in terms of coverage, porosity, structure, and chemistry. Significantly, the cold plasma method preserves both the primary and secondary structure of the protein and this results in high biocompatibility and cell activity that is at least equivalent to the standard wet chemical technique. The significance of these results is discussed in relation to the benefits of a single step plasma coating in comparison to the traditional multi-step aseptic coating technique.European Commission - European Regional Development FundIrish Research CouncilScience Foundation IrelandFutureNeur
Cytotoxic and mutagenic potential of solutions exposed to cold atmospheric plasma
No full textThe exposure of aqueous solutions to atmospheric plasmas results in the generation of relatively long-lived secondary products such as hydrogen peroxide which are biologically active and have demonstrated anti-microbial and cytotoxic activity. The use of plasma-activated solutions in applications such as microbial decontamination or anti-cancer treatments requires not only adequate performance on target cells but also a safe operating window regarding the impact on surrounding tissues. Furthermore the generation of plasma-activated fluids needs to be considered as a by-stander effect of subjecting tissue to plasma discharges. Cytotoxicity and mutagenicity assays using mammalian cell lines were used to elucidate the effects of solutions treated with di-electric barrier discharge atmospheric cold plasma. Plasma-treated PBS inhibited cell growth in a treatment time-dependent manner showing a linear correlation to the solutions\u27 peroxide concentration which remained stable over several weeks. Plasma-treated foetal bovine serum (FBS) acting as a model for complex bio-fluids showed not only cytotoxic effects but also exhibited increased mutagenic potential as determined using the mammalian HPRT assay. Further studies are warranted to determine the nature, causes and effects of the cyto- and genotoxic potential of solutions exposed to plasma discharges to ensure long-term safety of novel plasma applications in medicine and healthcare.Department of Agriculture, Food and the MarineEuropean Commission - Seventh Framework Programme (FP7
Recent advancements and future perspectives of microalgae-derived pharmaceuticals
No full textMicroalgal cells serve as solar-powered factories that produce pharmaceuticals, recombinant proteins (vaccines and drugs), and valuable natural byproducts that possess medicinal properties. The main advantages of microalgae as cell factories can be summarized as follows: they are fueled by photosynthesis, are carbon dioxide-neutral, have rapid growth rates, are robust, have low-cost cultivation, are easily scalable, pose no risk of human pathogenic contamination, and their valuable natural byproducts can be further processed. Despite their potential, there are many technical hurdles that need to be overcome before the commercial production of microalgal pharmaceuticals, and extensive studies regarding their impact on human health must still be conducted and the
results evaluated. Clearly, much work remains to be done before microalgae can be used in the large-scale commercial production of pharmaceuticals. This review focuses on recent advancements in microalgal biotechnology and its future perspectives
Connected and autonomous vehicle injury loss events: potential risk and actuarial considerations for primary insurers
No full textThe published copy of this article was made available in ULIR on the 17/05/2021The introduction of connected and autonomous vehicles (CAVs) to the road transport ecosystem will change the manner of collisions. CAVs are expected to optimize the safety of road users and the wider environment, while alleviating traffic congestion and maximizing occupant comfort. The net result is a reduction in the frequency of motor vehicle collisions, and a reduction in the number of injuries currently seen as “preventable.” A changing risk ecosystem will introduce new challenges and opportunities for primary insurers. Prior studies have highlighted the economic benefit provided by reductions in the frequency of hazardous events. This economic benefit, however, will be offset by the economic detriment incurred by emerging risks and the increased scrutiny placed on existing risks. We posit four plausible scenarios detailing how an introduction of these technologies could result in a larger relative rate of injury claims currently characterized as tail‐risk events. In such a scenario, the culmination of these losses will present as a second “hump” in actuarial loss models. We discuss how CAV risk factors and traffic dynamics may combine to make a second “hump” a plausible reality, and discuss a number of opportunities that may arise for primary insurers from a changing road environment
Data-Clustering-Assisted Digital Predistortion for 5G Millimeter-Wave Beamforming Transmitters With Multiple Dynamic Configurations
No full textMotivated by data science, in this article, a data-clustering-assisted digital predistortion (DPD) is proposed to linearize millimeter-wave (mmWave) beamforming transmitters with multiple dynamic configurations. Based on the data analysis, similar transmitter states with different configurations can be clustered, resulting in a significant reduction of linearization states. Model complexity within the cluster can be further reduced by utilizing a penalty factor method. To validate the proposed concept, experiments were carried out on a 16-channel mmWave beamforming transmitter with configurable beam angle, operating frequency, and input power. Total 216 transmitter states can be reduced to 8, 20, and 40 states with unequal optimal model parameters for each state, without losing much performance. The proposed method can be extended to the scenario where a large scale of dynamic states can occur in complex transmitter structures in future wireless systems.Science Foundation IrelandNational Natural Science Foundation of Chin
U.S. stock prices and the dot.com-bubble: Can dividend policy rescue the efficient market hypothesis?
No full textThis paper thoroughly integrates speculative bubbles to corporate finance literature by focusing on dividend policy issues. More specifically, we examine the importance of dividend policy when testing for speculative bubbles in the S&P 500 equity index on a dataset spanning 1871 to 2014. Given the phenomenon of dividend smoothing, in particular in the U.S., we question the usefulness of observed dividend payments as fundamental factor in testing for bubbles. Circumventing dividend smoothing, we construct hypothetical dividend payouts which are based on reported corporate earnings instead. The empirical evidence presented here indeed suggests that the dividend policy of firms affects testing for speculative bubbles. While the dot.com-bubble—commonly seen as the prime example for a stock price bubble not only in the NASDAQ but also in other, broader equity indices—is detected with the observed dividend series as fundamental factor, this is not necessarily the case with our adjusted dividend time series. Some of our results argue against a speculative price bubble in the broader U.S. stock market in the late 1990s
Properties of lightweight fibrous materials made using a foam-forming technique
No full textThis thesis concerns the production and characterisation of foam-formed fibrous materials made from wood, peat fibres and spent grain. Such materials might find commercial applications for insulating purposes when produced at low density, or replace cardboard when produced at higher densities. The materials are produced by axially shearing a fibre-laden aqueous solution to which a surfactant has been added. The dispersion is then poured into a drainage vessel, where the liquid drains via gravity resulting in a lightweight fibrous sample.
The addition of fibres to an aqueous foam changes its properties. By adding fibres, a foam?s lifetime can be greatly extended. Furthermore, the fibres place an upper limit on the average bubble size by arresting bubble growth during coarsening.
The influence of fibre concentration and liquid content of a foam-fibre dispersion is explored. We report a minimum fibre concentration required for sample stability. We show how both fibre concentration and the liquid content of the dispersion affects sample density. Uniaxial compression testing shows that the compressive modulus scales linearly with sample density. The liquid content of the dispersion can also be used to tune the sample compressive strength, when compressed in all three axial directions. The compressive modulus is increased by a factor of up to seven, just by changing the liquid content of the dispersion from 25% to 50% (with no change to sample density). The higher the sample density, the larger the range over which we can vary the compressive strength through the liquid content.
The role of liquid drainage is explored by comparing samples made using dispersions with the same volume of liquid, but varying the drainage rate. We find that the rate of liquid drainage has a larger impact on the compressive strength than the volume of liquid.
We image our samples using uCT scanning and relate the fibre orientation distributions to both the compressive strength of the material and the liquid content of the dispersions. Void size is shown to be similar to the average bubble size of the dispersion from which it was produced.
Our samples display an anisotropic response to uniaxial compression when compressed in different directions. We attribute this behaviour to a layering of fibres that occurs during sample production. Increasing the liquid content of the dispersion increases the number of fibres which orientate out of these layers, changing the material?s compressive strength. Using Euler?s formula for buckling we propose an explanation for the observed stress-strain response.
We present a case study in which we use the foam-forming technique to create beer coasters from brewers spent grain. We probe our samples for the key requirements of commercial beer coasters, such as the rate of liquid absorption, quantity of liquid absorbed and tensile strength. The experiments show that the spent grain coasters absorb liquid at a faster rate and absorb more liquid during a fixed period of time than the commercial coasters.
We conclude our results and, focusing on a theme in which we encourage industry to replace non-sustainable materials with foam-formed fibrous alternatives, we identify and propose a direction for the continuation of the project to further explore and improve typical key material requirements. Experiments on compressive strength, recovery and thermal conductivity are proposed. We also set out the preliminary results of an experiment to measure bubble size from the vibrational response emitted as it ruptures. This is a non-invasive method to measure coarsening and may be useful in an industrial setting
Radial Basis Function Data Descriptor (RBFDD) Network: An Anomaly Detection Approach
No full textODD v5.0: Outlier Detection De-constructed: Workshop organized in conjunction with ACM SIGKDD, London, UK, 20 August 2018In this paper, we propose a modification to the standard Ra-dial Basis Function (RBF) network that transforms it into a one-class classifier suitable for anomaly detection. We name this new approach the Radial Basis Function Data Descriptor (RBFDD) network. The RBFDD network is of interest as it has inherent adaptability in its architecture making it suitable for domains in which concept drift is a concern. Also, features learned by an RBFDD network (i.e., centers and spreads of Gaussian kernels and associated weights) provide us with a level of interpretability that has potential to be quite informative in terms of understanding the model learned and the reasoning behind flagging anomalies. In a set of evaluation experiments we compare the performance of the RBFDD network with some state of the art algorithms for anomaly detection over a collection of benchmark anomaly detection datasets. The results show that the RBFDD network is a promising approach and suggest potential for more investigations and promising directions for future work. We also investigate how RBFDD networks can be interpreted.Science Foundation IrelandInsight Research Centr