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2016

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Full-Text Articles in Physical Sciences and Mathematics

Mode-Sum Prescription For The Vacuum Polarization In Odd Dimensions, Peter Taylor, Cormac Breen Dec 2016

Mode-Sum Prescription For The Vacuum Polarization In Odd Dimensions, Peter Taylor, Cormac Breen

Articles

We present a new mode-sum regularization prescription for computing the vacuum polarization of a scalar field in static spherically-symmetric black hole spacetimes in odd dimensions. This is the first general and systematic approach to regularized vacuum polarization in higher dimensions. Remarkably, the regularization parameters can be computed in closed form in arbitrary dimensions and for arbitrary metric function $f(r)$. In fact, we show that in spite of the increasing severity and number of the divergences to be regularized, the method presented is mostly agnostic to the number of dimensions. Finally, as an explicit example of our method, we show plots …


An Examination Of The Neural Unreliability Thesis Of Autism, John Butler, Sophie Molholm, Gizely Andrade, John J. Foxe Dec 2016

An Examination Of The Neural Unreliability Thesis Of Autism, John Butler, Sophie Molholm, Gizely Andrade, John J. Foxe

Articles

An emerging neuropathological theory of Autism, referred to here as “the neural unreliability thesis,” proposes greater variability in moment-to-moment cortical representation of environmental events, such that the system shows general instability in its impulse response function. Leading evidence for this thesis derives from functional neuroimaging, a methodology ill-suited for detailed assessment of sensory transmission dynamics occurring at the millisecond scale. Electrophysiological assessments of this thesis, however, are sparse and unconvincing. We conducted detailed examination of visual and somatosensory evoked activity using high-density electrical mapping in individuals with autism (N = 20) and precisely matched neurotypical controls (N = 20), recording …


Teaching Android Security Through Examples: A Publicly Available Database Of Vulnerable Apps, Daniel E. Krutz, Samuel A. Malachowsky Dec 2016

Teaching Android Security Through Examples: A Publicly Available Database Of Vulnerable Apps, Daniel E. Krutz, Samuel A. Malachowsky

Articles

Security is hard, and teaching security can be even harder. Here we describe a public educational activity to assist in the instruction of both students and developers in creating secure Android apps. Our set of activities includes example vulnerable applications, information about each vulnerability, steps on how to repair the vulnerabilities, and information about how to confirm that the vulnerability has been properly repaired. Our primary goal is to make these activities available to other instructors for use in their classrooms ranging from the K-12 to university settings. A secondary goal of this project is to foster interest in security …


Investigating The Impact Of Green Exercise On Population Health And Well-Being In A Small Community In Ireland:A Novel Approach Using A Natural Laboratory Ecosystem., Nollaig O'Sullivan, Aoife Donnelly, Tadhg Macintyre, Giles Warrington Dec 2016

Investigating The Impact Of Green Exercise On Population Health And Well-Being In A Small Community In Ireland:A Novel Approach Using A Natural Laboratory Ecosystem., Nollaig O'Sullivan, Aoife Donnelly, Tadhg Macintyre, Giles Warrington

Articles

Green exercise is defined as undertaking physical activity whilst being directly exposed to nature (Pretty et al., 2005; 2007). Pretty et al. (2003) were among the first wave of researchers to investigate the synergistic benefits of incorporating physical activity and exposure to the natural environment to produce positive psychological affect. Over the past decade, investigations into the possible additive effects on well-being of green exercise and how it can be used as an influential tool to help combat the rising rate of both physical inactivity and non –communicable disease has gained prominence in scientific literature. However, there is still a …


Modelling Random Antibody Adsorption And Immunoassay Activity, Dana Mackey, Eilis Kelly, Robert Nooney Dec 2016

Modelling Random Antibody Adsorption And Immunoassay Activity, Dana Mackey, Eilis Kelly, Robert Nooney

Articles

One of the primary considerations in immunoassay design is optimizing the concentration of capture antibody in order to achieve maximal antigen binding and, subsequently, improved sensitivity and limit of detection. Many immunoassay technologies involve immobilization of the antibody to solid surfaces. Antibodies are large molecules in which the position and accessibility of the antigen-binding site depend on their orientation and packing density. In this paper we propose a simple mathematical model, based on the theory known as random sequential adsorption (RSA), in order to calculate how the concentration of correctly oriented antibodies (active site exposed for subsequent reactions) evolves during …


Ultra-Filtration Of Human Serum For Improved Quantitative Analysis Of Low Molecular Weight Biomarkers Using Atr-Ir Spectroscopy, Franck Bonnier, Helene Blasco, Clement Wasselet, Guillaume Brachet, Renaud Respaud, Luis Felipe Cs. Carvalho, Dominque Bertrand, Mathew J. Baker, Hugh Byrne, Igor Chourpa Nov 2016

Ultra-Filtration Of Human Serum For Improved Quantitative Analysis Of Low Molecular Weight Biomarkers Using Atr-Ir Spectroscopy, Franck Bonnier, Helene Blasco, Clement Wasselet, Guillaume Brachet, Renaud Respaud, Luis Felipe Cs. Carvalho, Dominque Bertrand, Mathew J. Baker, Hugh Byrne, Igor Chourpa

Articles

Infrared spectroscopy is a reliable, rapid and cost effective characterisation technique, delivering a molecular finger print of the sample. It is expected that its sensitivity would enable detection of small chemical variations in biological samples associated with disease. ATR-IR is particularly suitable for liquid sample analysis and, although air drying is commonly performed before data collection, just a drop of human serum is enough for screening and early diagnosis. However, the dynamic range of constituent biochemical concentrations in the serum composition remains a limiting factor to the reliability of the technique. Using glucose as a model spike in human serum, …


Synthesis Of Orthogonally Protected Thioamide Dipeptides For Use In Solid-Phase Peptide Synthesis, Fintan Kelleher, Kim Manzor Nov 2016

Synthesis Of Orthogonally Protected Thioamide Dipeptides For Use In Solid-Phase Peptide Synthesis, Fintan Kelleher, Kim Manzor

Articles

Orthogonally protected thioamide-containing dipeptides were efficiently and cleanly prepared from the precursor dipeptides using Curphey’s method (P4S10, hexamethyldisiloxane (HMDO), reflux, DCM) in 67-96% isolated yield. This was in contrast to the use of Lawesson’s or Berzelius’ reagents where significant issues with reaction non-completion, decomposition and purification were observed. Subsequent clean removal of the dipeptides’ t-butyl ester protecting groups gave thioamide dipeptide acids which were suitable for use in solid-phase peptide synthesis (SPPS).


Short Term Forecasting Of Nitrogen Dioxide (No2) Levels Using A Hybrid Statistical And Air Mass History Modelling Approach, Aoife Donnelly, Owen Naughton, Brian Broderick, Bruce Misstear Sep 2016

Short Term Forecasting Of Nitrogen Dioxide (No2) Levels Using A Hybrid Statistical And Air Mass History Modelling Approach, Aoife Donnelly, Owen Naughton, Brian Broderick, Bruce Misstear

Articles

A novel hybrid model has been developed to support the provision of real-time air quality forecasts. Statistical techniques have been applied in parallel with airmass history modelling to provide an efficient and accurate forecasting system with the ability to identify high NO2 events, which tend to be the episodes ofmost significance in Ireland. Airmass history modelling and k-means clustering are used to identify air mass types that lead to high NO2 levels in Ireland. Trajectory matching techniques allow data associated with these air masses to be partitioned during model development. Non-parametric regression (NPR) has been applied to describe nonlinear variations …


Advancing Android Activity Recognition Service With Markov Smoother: Practical Solutions, Mingyang Zhong, Jiahui Wen, Peizhao Hu, Jadwiga Indulska Sep 2016

Advancing Android Activity Recognition Service With Markov Smoother: Practical Solutions, Mingyang Zhong, Jiahui Wen, Peizhao Hu, Jadwiga Indulska

Articles

Common use of smartphones is a compelling reason for performing activity recognition with on-board sensors as it is more practical than other approaches, such as wearable sensors and augmented environments. Many solutions have been proposed by academia, but practical use is limited to experimental settings. Ad hoc solutions exist with different degrees in recognition accuracy and efficiency. To ease the development of activity recognition for the mobile application eco-system, Google released an activity recognition service on their Android platform. In this paper, we present a systematic evaluation of this activity recognition service and share the lesson learnt. Through our experiments, …


In Vitro Monitoring Of Time And Dose Dependent Cytotoxicity Of Aminated Nanoparticles Using Raman Spectroscopy, Esen Efeoglu, Alan Casey, Hugh Byrne Jul 2016

In Vitro Monitoring Of Time And Dose Dependent Cytotoxicity Of Aminated Nanoparticles Using Raman Spectroscopy, Esen Efeoglu, Alan Casey, Hugh Byrne

Articles

No abstract provided.


Spectroscopic Studies Of Anthracyclines: Structural Characterization And In Vitro Tracking, Zeineb Farhane, Hugh Byrne, Malgorzata Baranska Jul 2016

Spectroscopic Studies Of Anthracyclines: Structural Characterization And In Vitro Tracking, Zeineb Farhane, Hugh Byrne, Malgorzata Baranska

Articles

A broad spectroscopic characterization, using ultraviolet-visible (UV-vis) and Fourier transform infrared absorption as well as Raman scattering, of two commonly used anthracyclines antibiotics (DOX) daunorubicin (DNR), their epimers (EDOX, EDNR) and ten selected analogs is presented. The paper serves as a comprehensive spectral library of UV-vis, IR and Raman spectra of anthracyclines in the solid state and in solution. The particular advantage of Raman spectroscopy for the measurement and analysis of individual antibiotics is demonstrated. Raman spectroscopy can be used to monitor the in vitro uptake and distribution of the drug in cells, using both 488 nm and 785 nm …


Screening The Low Molecular Weight Fraction Of Human Serum Using Atr-Ir Spectroscopy, Franck Bonnier, Matthew J. Baker, Hugh Byrne Jun 2016

Screening The Low Molecular Weight Fraction Of Human Serum Using Atr-Ir Spectroscopy, Franck Bonnier, Matthew J. Baker, Hugh Byrne

Articles

Vibrational spectroscopic techniques can detect small variations in molecular content, linked with disease, showing promise for screening and early diagnosis. Biological fluids, particularly blood serum, are potentially valuable for diagnosis purposes. The so-called Low Molecular Weight Fraction (LMWF) contains the associated peptidome and metabolome and has been identified as potentially the most relevant molecular population for disease-associated biomarker research. Although vibrational spectroscopy can deliver a specific chemical fingerprint of the samples, the High Molecular Weight Fraction (HMWF), composed of the most abundant serum proteins, strongly dominates the response and ultimately makes the detection of minor spectral variations a challenging task. …


A Comparison Of Catabolic Pathways Induced In Primary Macrophages By Pristine Single Walled Carbon Nanotubes And Pristine Graphene, Caroline More, Jennifer Mcintyre, Luke O'Neill, Hugh Byrne Jun 2016

A Comparison Of Catabolic Pathways Induced In Primary Macrophages By Pristine Single Walled Carbon Nanotubes And Pristine Graphene, Caroline More, Jennifer Mcintyre, Luke O'Neill, Hugh Byrne

Articles

Understanding the correlation between the physico-chemical properties of carbonaceous nanomaterials and how these properties impact on cells and subcelluar mechanisms is critical to their risk assessment and safe translation into newly engineered devices. Here the toxicity, uptake and catabolic response of primary human macrophages to pristine graphene (PG) and pristine single walled carbon nanotubes (pSWCNT) are explored, compared and contrasted. The nanomaterial toxicity was assessed using three complementary techniques (live-dead assay, real time impedance technique and confocal microscopic analysis), all of which indicated no signs of acute cytotoxicity in response to PG or pSWCNT. Transmission electron microscopy (TEM) demonstrated that …


The Evaluation And Implementation Of Magnetic Fields For Large Strain Uniaxial And Biaxial Cyclic Testing Of Magnetorheological Elastomers., Dave Gorman, Niall Murphy, Ray Ekins, Stephen Jerrams May 2016

The Evaluation And Implementation Of Magnetic Fields For Large Strain Uniaxial And Biaxial Cyclic Testing Of Magnetorheological Elastomers., Dave Gorman, Niall Murphy, Ray Ekins, Stephen Jerrams

Articles

Magnetorheological Elastomers (MREs) are “smart” materials whose physical properties are altered by the application of magnetic fields. In previous studies the properties of MREs have been evaluated under a variety of conditions, however little attention has been paid to the recording and reporting of the magnetic fields used in these tests [1]. Currently there is no standard accepted method for specifying the magnetic field applied during MRE testing. This study presents a detailed map of a magnetic field applied during MRE tests as well as providing the first comparative results for uniaxial and biaxial testing under high strain fatigue test …


Theoretical Modeling Of The Effect Of Polymer Chain Immobilization Rates On Holographic Recording In Photopolymers, Dana Mackey, Paul O'Reilly, Izabela Naydenova Apr 2016

Theoretical Modeling Of The Effect Of Polymer Chain Immobilization Rates On Holographic Recording In Photopolymers, Dana Mackey, Paul O'Reilly, Izabela Naydenova

Articles

This paper introduces an improved mathematical model for holographic grating formation in an acrylamide-based photopolymer, which consists of partial differential equations derived from physical laws. The model is based on the two-way diffusion theory of \cite{izabela}, which assumes short polymer chains are free to diffuse, and generalizes a similar model presented in \cite{josab} by introducing an immobilization rate governed by chain growth and cross-linking. Numerical simulations were carried out in order to investigate the behaviour of the photopolymer system for short and long exposures, with particular emphasis on the effect of recording parameters (such as illumination frequency and intensity), as …


Photocatalytic Properties Of G-C3n4–Tio2 Heterojunctions Under Uv And Visible Light Conditions, Rachel Fagan, Declan Mccormack, Steven J. Hinder, Suresh Pillai Apr 2016

Photocatalytic Properties Of G-C3n4–Tio2 Heterojunctions Under Uv And Visible Light Conditions, Rachel Fagan, Declan Mccormack, Steven J. Hinder, Suresh Pillai

Articles

Graphitic carbon nitride (g-C3N4) and titanium dioxide (TiO2) were chosen as a model system to investigate photocatalytic abilities of heterojunction system under UV and visible light conditions. The use of g-C3N4 has been shown to be effective in the reduction in recombination through the interaction between the two interfaces of TiO2 andg-C3N4. A simple method of preparing g-C3N4 through the pyrolysis of melamine was employed, which was then added to undoped TiO2 material to form the g-C3N4–TiO2 system. These materials were then fully characterized by X-ray diffraction (XRD), Brunauer Emmett Teller (BET), and various spectroscopic techniques including Raman, X-ray photoelectron …


Evaluation Of Cytotoxicity Profile And Intracellular Localisation Of Doxorubicin-Loaded Chitosan Nanoparticles, Gabriele Dadalt Souto, Zeineb Farhane, Esen Efeoglu, Alan Casey, Jennifer Mcintyre, Hugh Byrne Apr 2016

Evaluation Of Cytotoxicity Profile And Intracellular Localisation Of Doxorubicin-Loaded Chitosan Nanoparticles, Gabriele Dadalt Souto, Zeineb Farhane, Esen Efeoglu, Alan Casey, Jennifer Mcintyre, Hugh Byrne

Articles

In the emerging field of nanomedicine, targeted delivery of nanoparticle encapsulated active pharmaceutical ingredients (API) is seen as a potential significant development, promising improved pharmacokinetics and reduced side effects. In this context, understanding the cellular uptake of the nanoparticles and subsequent subcellular distribution of the API is of critical importance. Doxorubicin (DOX) was encapsulated within chitosan nanoparticles to investigate its intracellular delivery in A549 cells in vitro. Unloaded (CS-TPP) and doxorubicin-loaded (DOX-CS-TPP) chitosan nanoparticles were characterised for size (473±41 nm), polydispersity index (0.3±0.2), zeta potential (34±4 mV), drug content (76±7 µM) and encapsulation efficiency (95±1%). The cytotoxic response to …


Challenges And Opportunities In Dfo-At: A Study Of E-Nable, Jeremiah L. Parry-Hill, Daniel L. Ashbrook Apr 2016

Challenges And Opportunities In Dfo-At: A Study Of E-Nable, Jeremiah L. Parry-Hill, Daniel L. Ashbrook

Articles

In this paper, we present the results of a study of the e‑NABLE community–a distributed, collaborative volunteer effort to design and fabricate upper-limb assistive technology devices for distant strangers. We position e‑NABLE as the prototypical example of “Do-it-yourself For Others Assistive Technology” (DFO‑AT) and describe three key findings: how the project does and does not meet the recipient's nuanced needs for functional and social support; how e‑NABLE volunteers' motivations compare to those of volunteers for other efforts, including open source software projects; and we explore the challenges inherent in the distance between volunteers and recipients. We also describe opportunities for …


Novel Mitochondrial Complex I Inhibitors Restore Glucose-Handling Abilities Of High-Fat Fed Mice, Darren Martin, Siobhan Leonard, Robert Devine, Clara Redondo, Gemma Kinsella, Conor Breen, Victoria Mceneaney, Mary Rooney, Tim Munsey, Richard Porter, Asipu Sivaprasadarao, John Stephens, John Findlay Apr 2016

Novel Mitochondrial Complex I Inhibitors Restore Glucose-Handling Abilities Of High-Fat Fed Mice, Darren Martin, Siobhan Leonard, Robert Devine, Clara Redondo, Gemma Kinsella, Conor Breen, Victoria Mceneaney, Mary Rooney, Tim Munsey, Richard Porter, Asipu Sivaprasadarao, John Stephens, John Findlay

Articles

Metformin is the main drug of choice for treating type 2 diabetes, yet the therapeutic regimens and side effects of the compound are all undesirable and can lead to reduced compliance. The aim of this study was to elucidate the mechanism of action of two novel compounds which improved glucose handling and weight gain in mice on a high-fat diet. Wildtype C57Bl/6 male mice were fed on a high-fat diet and treated with novel, anti-diabetic compounds. Both compounds restored the glucose handling ability of these mice. At a cellular level, these compounds achieve this by inhibiting complex I activity in …


Modification Of The In Vitro Uptake Mechanism And Anti-Oxidant Levels In Hacat Cells And Resultant Changes To Toxicity And Oxidative Stress Of G4 And G6 Poly (Amido Amine) Dendrimer Nanoparticles, Marcus A. Maher, Hugh Byrne Mar 2016

Modification Of The In Vitro Uptake Mechanism And Anti-Oxidant Levels In Hacat Cells And Resultant Changes To Toxicity And Oxidative Stress Of G4 And G6 Poly (Amido Amine) Dendrimer Nanoparticles, Marcus A. Maher, Hugh Byrne

Articles

The mechanism of cellular uptake by endocytosis and subsequent oxidative stress has been identified as the paradigm for the toxic response of cationically surface charged nanoparticles. In an attempt to circumvent the process, the effect of increased cellular membrane permeability on the uptake mechanisms of poly (amidoamine) dendrimers generation 4 (G4) and 6 (G6) in vitro was investigated. Immortalised, non-cancerous human keratinocyte (HaCaT) cells were treated with DL-Buthionine-(S,R)-sulfoximine (BSO). Active uptake of the particles was monitored using fluorescence microscopy to identify and quantify endosomal activity and resultant oxidative stress, manifest as increased levels of reactive oxygen species, monitored using the …


Hawking Radiation Screening And Penrose Process Shielding In The Kerr Black Hole, Eamon Mccaughey Mar 2016

Hawking Radiation Screening And Penrose Process Shielding In The Kerr Black Hole, Eamon Mccaughey

Articles

The radial motion of massive particles in the equatorial plane of aKerr black hole is considered. Screening of the Hawking radiation and shielding of the Penrose process are examined (both inside and outside the ergosphere) and their effect on the evaporation of the black hole is studied. In particular, the locus and width of a classically forbidden region and their dependence on the particle’s angular momentum and energy is analysed. Tunneling of particles between the boundaries of this region is considered and the transmission coefficient determined.


An Effective Method For The Preparation Of High Temperature Stable Anatase Tio2 Photocatalysts, Rachel Fagan, Declan Mccormack, Suresh Pillai, Damian Synnott Mar 2016

An Effective Method For The Preparation Of High Temperature Stable Anatase Tio2 Photocatalysts, Rachel Fagan, Declan Mccormack, Suresh Pillai, Damian Synnott

Articles

An efficient, rapid and straightforward method for the preparation of nitrogen and fluorine (N, F) codoped high temperature stable anatase using a microwave pre-treatment is reported. Using a single source, ammonium fluoride (NH4F) for both nitrogen and fluorine, effective doping of the precursor titanium isopropoxide (TTIP) was possible. These samples were characterised for their structural and optical properties using X-ray diffraction (XRD), Fourier transform IR (FTIR), Raman spectroscopy and UV-vis spectroscopy. In terms of the anatase to rutile transition enhancement using a novel microwave assisted technique, the sample prepared in a composition of 1:8 TiO2: NH …


Chemotherapeutic Efficiency Of Drugs In Vitro: Comparison Of Doxorubicin Exposure In 3d And 2d Culture Matrices, Alan Casey, Mahmoud Gargotti, Franck Bonnier, Hugh Byrne Mar 2016

Chemotherapeutic Efficiency Of Drugs In Vitro: Comparison Of Doxorubicin Exposure In 3d And 2d Culture Matrices, Alan Casey, Mahmoud Gargotti, Franck Bonnier, Hugh Byrne

Articles

The interest in the use of 3D matrices for in vitro analysis, with a view to increasing the relevance of in vitro studies and reducing the dependence on in vivo studies, has been growing in recent years. Cells grown in a 3D in vitro matrix environment have been reported to exhibit significantly different properties to those in a conventional 2D culture environment. However, comparison of 2D and 3D cell culture models have recently been noted to result in differing responses of cytotoxic assays, without any associated change in viability. The effect was attributed to differing conversion rates and effective concentrations …


Recent Advances In Optical Diagnosis Of Oral Cancers: Review And Future Perspectives, Ola Ibrahim, Hugh Byrne, Fiona Lyng, Surya Singh, Jopi Mikkonen, Arto Koistinen, Arja Kullaa Mar 2016

Recent Advances In Optical Diagnosis Of Oral Cancers: Review And Future Perspectives, Ola Ibrahim, Hugh Byrne, Fiona Lyng, Surya Singh, Jopi Mikkonen, Arto Koistinen, Arja Kullaa

Articles

Optical diagnosis techniques offer several advantages over traditional approaches, including objectivity, speed and cost, and these label-free, non-invasive methods have the potential to change the future work-flow of cancer management. The oral cavity is particularly accessible and thus such methods may serve as alternate/adjunct tools to traditional methods. Recently, in vivo human clinical studies have been initiated with a view to clinical translation of such technologies. A comprehensive review of optical methods in oral cancer diagnosis is presented. Following an introduction to the epidemiology and aetiological factors associated with oral cancers currently employed diagnostic methods and their limitations are presented. …


Mobilaudio – A Multimodal Content Delivery Platform For Geo-Services, James Carswell, Keith Gardiner, Charlie Cullen Mar 2016

Mobilaudio – A Multimodal Content Delivery Platform For Geo-Services, James Carswell, Keith Gardiner, Charlie Cullen

Articles

Delivering high-quality context-relevant information in a timely manner is a priority for location-based services (LBS) where applications require an immediate response based on spatial interaction. Previous work in this area typically focused on ever more accurately determining this interaction and informing the user in the customary graphical way using the visual modality. This paper describes the research area of multimodal LBS and focuses on audio as the key delivery mechanism. This new research extends familiar graphical information delivery by introducing a geoservices platform for delivering multimodal content and navigation services. It incorporates a novel auditory user interface (AUI) that enables …


Spectral Pre And Post Processing For Infrared And Raman Spectroscopy Of Biological Tissues And Cells, Hugh Byrne, Peter Knief, Mark Keating, Franck Bonnier Mar 2016

Spectral Pre And Post Processing For Infrared And Raman Spectroscopy Of Biological Tissues And Cells, Hugh Byrne, Peter Knief, Mark Keating, Franck Bonnier

Articles

Vibrational Spectroscopy, both infrared absorption and Raman spectroscopy, have attracted increasing attention for biomedical applications, from in vivo and ex vivo disease diagnostics and screening, to in vitro screening of therapeutics. There remain, however, many challenges related to the accuracy of analysis of physically and chemically inhomogeneous samples, across heterogeneous sample sets. Data preprocessing is required to deal with variations in instrumental responses and intrinsic spectral backgrounds and distortions in order to extract reliable spectral data. Data postprocessing is required to extract the most reliable information from the sample sets, based on often very subtle changes in spectra associated with …


Acellular Reactivity Of Polymeric Dendrimer Nanoparticles As An Indicator Of Oxidative Stress In Vitro, Marcus Maher, Humza Khalid, Hugh Byrne Feb 2016

Acellular Reactivity Of Polymeric Dendrimer Nanoparticles As An Indicator Of Oxidative Stress In Vitro, Marcus Maher, Humza Khalid, Hugh Byrne

Articles

The need for rapid and cost effective pre-screening protocols of the toxicological response of the vast array of emerging nanoparticle types is apparent and the emerging consensus on the paradigm of oxidative stress by generation of intracellular reactive oxygen species as a primary source of the toxic response suggests the development of acellular assays to screen for nanoparticle surface reactivity. This study explores the potential of the monoamine oxidase A (MAO-A) enzyme based assay with polymeric dendrimers as cofactors and serotonin as substrate, which generates H2O2, quantified by the conversion of the Carboxy-H2DCFDA dye …


Second Order Approximation For Heat Conduction: Dissipation Principle And Free Energies, Giovambattista Amendola, Mauro Fabrizio, John Murrough Golden, Barbara Lazzari Feb 2016

Second Order Approximation For Heat Conduction: Dissipation Principle And Free Energies, Giovambattista Amendola, Mauro Fabrizio, John Murrough Golden, Barbara Lazzari

Articles

In the context of new models of heat conduction, the second-order approximation of Tzou’s theory, derived by Quintanilla and Racke, has been studied recently by two of the present authors, where it was proved equivalent to a fading memory material. The importance of determining free energy functionals for such materials, and indeed for any material with memory, is emphasized. Because the kernel does not satisfy certain convexity restrictions that allow us to obtain various traditional free energies for materials with fading memory, it is necessary to restrict the study to the minimum and related free energies, which do not require …


Structural Dependence Of The In Vitro Cytotoxicity, Oxidative Stress And Uptake Mechanisms Of Poly(Propylene Imine) Dendritic Nanoparticles, Humza Khalid, Sourav Prasanna Mukherjee, Luke O'Neill, Hugh Byrne Feb 2016

Structural Dependence Of The In Vitro Cytotoxicity, Oxidative Stress And Uptake Mechanisms Of Poly(Propylene Imine) Dendritic Nanoparticles, Humza Khalid, Sourav Prasanna Mukherjee, Luke O'Neill, Hugh Byrne

Articles

The in vitro cytotoxic and intracellular oxidative stress responses to exposure to poly (propylene imine) (PPI) dendritic nanoparticles of increasing generation (number of repeated branching cycles) (G0-G4) were assessed in an immortal non-cancerous human keratinocyte cell-line (HaCaT). Confocal fluorescence microscopy with organelle staining was used to explore the uptake and intracellular trafficking mechanisms. A generation and dose dependent cytotoxic response was observed, increasing according to generation and therefore number of surface amino groups. A comparison of the cytotoxic response of G4 PPI and the related G4 Poly (amido amine) dendrimer indicates that the PPI with the same number of surface …


Atypical Visual And Somatosensory Adaptation In Schizophrenia-Spectrum Disorders, Gizely Andrade, John Butler, Gregory Peter, Sophie Molholm, John J. Foxe Jan 2016

Atypical Visual And Somatosensory Adaptation In Schizophrenia-Spectrum Disorders, Gizely Andrade, John Butler, Gregory Peter, Sophie Molholm, John J. Foxe

Articles

Neurophysiological investigations in patients with schizophrenia consistently show early sensory processing deficits in the visual system. Importantly, comparable sensory deficits have also been established in healthy first-degree biological relatives of patients with schizophrenia and in first-episode drug-naive patients. The clear implication is that these measures are endophenotypic, related to the underlying genetic liability for schizophrenia. However, there is significant overlap between patient response distributions and those of healthy individuals without affected first-degree relatives. Here we sought to develop more sensitive measures of sensory dysfunction in this population, with an eye to establishing endophenotypic markers with better predictive capabilities. We used …