An electrocatalytic screen-printed amperometric sensor for the selective measurement of thiamine (Vitamin B1) in food supplements

An electrocatalytic screen-printed sensor has been investigated for the measurement of the biologically important biomolecule vitamin B1 (thiamine) for the first time in food supplements. Under basic conditions, the vitamin was converted to its electrochemically active thiolate anion species. It was shown that an electrocatalytic oxidation reaction occurred with the screen-printed carbon electrode containing the mediator cobalt phthalocyanine (CoPC-SPCE). This had the advantage of producing an analytical response current at an operating potential of 0 V vs. Ag/AgCl compared to +0.34 V obtained with plain SPCEs. This resulted in improved selectivity and limit of detection. Detailed studies on the underlying mechanism occurring with the sensor are reported in this paper. A linear response was obtained between 0.1 and 20 µg mL −1 , which was suitable for the quantification of the vitamin in two commercial products containing vitamin B1. The mean recovery for a multivitamin tablet with a declared content of 5 mg was 101% (coefficient of variation (CV) of 9.6%). A multivitamin drink, which had a much lower concentration of vitamin B1 (0.22 mg/100 mL), gave a mean recovery of 93.3% (CV 7.2%). These results indicate that our sensor holds promise for quality control of food supplements and other food types

Effect of Exercise Training on Interleukin-6, Tumour Necrosis Factor Alpha and Functional Capacity in Heart Failure

Background. We pooled data from four studies, to establish whether exercise training programs were able to modulate systemic cytokine levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). A second aim was to establish if differences in ExT regimens are related to degree of change in cytokines and peak VO2. Methods. Data from four centres relating to training protocol, exercise capacity, and cytokine measures (TNF-alpha and IL-6) were pooled for analysis. Results. Data for 106 CHF patients were collated (98 men, age 62 ± 10 yrs, wt 79 ± 14 Kg). Patients were moderately impaired (peak VO2 16.9 ± 4.4 mls/kg/min), with moderate LV systolic dysfunction (EF 30 ± 6.9%), 78% (83) had ischaemic cardiomyopathy. After ExT, peak VO2 increased 1.4 ± 3.4 ml/kg/min (P < .001), serum TNF-alpha decreased 1.9 ± 8.6 pg/ml (P = .02) and IL-6 was not significantly changed (0.5 ± 5.4 pg/ml, P = .32) for the whole group. Baseline and post-training peak VO2 changes were not correlated with change in cytokine levels. Conclusions. Exercise training reduces levels TNF-alpha but not IL-6 in CHF. However, across a heterogenic patient group, change in peak VO2 was not correlated with alterations in cytokine levels. While greater exercise volume (hours) was superior in improving peak VO2, no particular characteristic of ExT regimes appeared superior in effecting change in serum cytokines

A Variance Gamma model for Rugby Union matches

YesAmid much recent interest we discuss a Variance Gamma model for Rugby Union matches (applications to other sports are possible). Our model emerges as a special case of the recently introduced Gamma Difference distribution though there is a rich history of applied work using the Variance Gamma distribution – particularly in finance. Restricting to this special case adds analytical tractability and computational ease. Our three-dimensional model extends classical two-dimensional Poisson models for soccer. Analytical results are obtained for match outcomes, total score and the awarding of bonus points. Model calibration is demonstrated using historical results, bookmakers’ data and tournament simulations

All for one and one for all: Fully decentralised privacy-preserving dark pool trading using multi-party computation

Financial dark pool trading venues are designed to keep pre-trade order information secret so that it cannot be misused by others. However, dark pools are vulnerable to an operator misusing the information in their system. Prior work has used MPC to tackle this problem by assuming that the dark pool is operated by a small set of two or three MPC parties. However, this raises the question of who plays the role of these operating parties and whether this scenario could be applied in the real world. In this work, we implement an MPC-based dark pool trading venue with up to 100 parties. This configuration would allow a real-world implementation where the operating parties are the active participants that trade in the venue (i.e., a ``no operator\u27\u27 model), or where the parties are the main stakeholders of the venue (e.g., members of a non-profit partnership such as Plato). We use AWS cloud to empirically test the performance of the system. Results demonstrate that the system can achieve trading throughput required for some real-world venues, while the cost of hosting the system is negligible compared with the savings expected from guaranteeing no information leakage

Live-Cell Imaging of Cellular Proteins by a Strain-Promoted Azide–Alkyne Cycloaddition

Live and let dye: Three coumarin-cyclooctyne conjugates have been used to label proteins tagged with azidohomoalanine in Rat-1 fibroblasts. All three fluorophores labeled intracellular proteins with fluorescence enhancements ranging from eight- to 20-fold. These conjugates are powerful tools for visualizing biomolecule dynamics in living cells

Screen-printed carbon based biosensors and their applications in agri-food safety

This review focuses on the ways in which screen-printed carbon electrodes have been tailored with different biorecognition elements, including enzymes, antibodies, and aptamers, often with other modifiers, such as mediators and nanoparticles, to produce electrochemical biosensors for a variety of analytes of importance in agri-food safety. Emphasis is placed on the strategies of biosensor fabrication and the performance characteristics of the devices. As well as biosensors for a range of analytes in different agri-food matrices, we have also included reports on novel devices that have potential in agri-food safety but as yet have not been applied in this area

Scanning electrochemical microscopy for the interrogation of biologically modified surfaces

This thesis describes two novel applications of scanning electrochemical microscopy (SECM) to biological systems. The first involves the characterisation of a novel, impedance based genomic DNA biosensor - previously developed within the group. SECM in feedback mode was used to interrogate a DNA-polyelectrolyte film to determine whether the changes observed by impedance were detectable by SECM. Using the SECM micropositioning device to pattern a carbon ink substrate, a dotted array of polyethylenimine (PEI) and single stranded DNA (ssDNA) was fabricated. Using hexamine ruthenium chloride as the redox couple, the array was then interrogated by a SECM area scan before and following exposure to complementary and non-complementary DNA. Upon the exposure of the DNA/PEI array to complementary DNA, the feedback current over the functionalised region was observed to increase, whereas on exposure of the array to non-complementary DNA, an increase in feedback current was also observed - but to a lesser degree. The second SECM application described involves the use of SECM to detect protein expression in cells. Using an established immunochemical protocol, the transmembrane protein, CD44, expressed by cultured RT112 cells was labelled via a primary/secondary antibody complex to horseradish peroxidase. Using hydrogen peroxide and hydroquinone, the activity of the HRP label was subsequently detected by SECM in feedback mode. The microelectrode tip was biased at a potential of -0.4V, a potential sufficient for the reduction of benzoquinone - the redox active product of the HRP catalysed reaction. The work presented represents the first application of SECM to detecting protein expression in cells and effectively demonstrates the promise this technique holds for immunochemical applications. An analysis of Uniscan’s innovation network is also presented, which provides a valuable insight into the management of such resources and how they may be orchestrated to extract maximal innovative value for all parties involved in a collaborative relationship.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Orally administered oxygen nanobubbles enhance tumor response to sonodynamic therapy

Suspensions of oxygen-filled bubbles are under active investigation as potential means of relieving tissue hypoxia. Intravenous administration of large quantities of bubbles is, however, undesirable. Previous work by the authors has demonstrated that tumor oxygen levels can be increased following oral administration of phospholipid stabilized oxygen nanobubbles. The aim of this study was to determine whether this would enhance the efficacy of sonodynamic therapy (SDT), which is known to be inhibited in hypoxic tissue. Experiments were conducted in a murine model of pancreatic cancer. Animals were treated with SDT (intratumoural injection of 1 mM Rose Bengal followed by exposure to 1 MHz ultrasound, 0.1 kHz pulse repetition frequency, 30% duty cycle, 3.5 W cm−2 for 3.5 minutes) either with or without a prior gavage of oxygen bubbles. A statistically significant reduction in the rate of tumor growth was observed in the groups receiving oxygen nanobubbles either 5 or 20 minutes before SDT. Separate measurements of tumor oxygen using a fiber optic probe and expression of hypoxia inducible factor (HIF)1α following tumor excision, confirmed the change in tumor oxygen levels. These findings offer a potentially promising new approach to relieving tissue hypoxia in order to facilitate cancer therapy

The meaning of life in a developing universe

The evolution of life on Earth has produced an organism that is beginning to model and understand its own evolution and the possible future evolution of life in the universe. These models and associated evidence show that evolution on Earth has a trajectory. The scale over which living processes are organized cooperatively has increased progressively, as has its evolvability. Recent theoretical advances raise the possibility that this trajectory is itself part of a wider developmental process. According to these theories, the developmental process has been shaped by a larger evolutionary process that involves the reproduction of universes. This evolutionary process has tuned the key parameters of the universe to increase the likelihood that life will emerge and develop to produce outcomes that are successful in the larger process (e.g. a key outcome may be to produce life and intelligence that intentionally reproduces the universe and tunes the parameters of ‘offspring’ universes). Theory suggests that when life emerges on a planet, it moves along this trajectory of its own accord. However, at a particular point evolution will continue to advance only if organisms emerge that decide to advance the evolutionary process intentionally. The organisms must be prepared to make this commitment even though the ultimate nature and destination of the process is uncertain, and may forever remain unknown. Organisms that complete this transition to intentional evolution will drive the further development of life and intelligence in the universe. Humanity’s increasing understanding of the evolution of life in the universe is rapidly bringing it to the threshold of this major evolutionary transition

Development and validation of a recommended checklist for assessment of surgical videos quality: the LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS) video assessment tool

Introduction There has been a constant increase in the number of published surgical videos with preference for open-access sources, but the proportion of videos undergoing peer-review prior to publication has markedly decreased, raising questions over quality of the educational content presented. The aim of this study was the development and validation of a standard framework for the appraisal of surgical videos submitted for presentation and publication, the LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS) video assessment tool. Methods An international committee identified items for inclusion in the LAP-VEGaS video assessment tool and finalised the marking score utilising Delphi methodology. The tool was finally validated by anonymous evaluation of selected videos by a group of validators not involved in the tool development. Results 9 items were included in the LAP-VEGaS video assessment tool, with every item scoring from 0 (item not presented in the video) to 2 (item extensively presented in the video), with a total marking score ranging from 0 to 18. The LAP-VEGaS video assessment tool resulted highly accurate in identifying and selecting videos for acceptance for conference presentation and publication, with high level of internal consistency and generalisability. Conclusions We propose that peer review in adherence to the LAP-VEGaS video assessment tool could enhance the overall quality of published video outputs.[GRAPHICS]