Physics Commons^™

Raman Spectroscopic Analysis Of Human Serum Samples Of Convalescing Covid-19 Positive Patients, Hugh Byrne, Naomi Jackson, Jaythoon Hassan

Articles

Rapid screening, detection and monitoring of viral infection is of critical importance, as exemplified by the rapid spread of SARS-CoV-2, leading to the worldwide pandemic of COVID-19. This is equally the case for the stages of patient convalescence as for the initial stages of infection, to understand the medium and long terms effects, as well as the efficacy of therapeutic interventions. Optical spectroscopic techniques potentially offer an alternative to currently employed techniques of screening for the presence, or the response to infection. In this study, the ability of Raman spectroscopy to distinguish between samples of the serum of convalescent COVID-19 …

Optical Characterisation Of Holographic Diffusers And Bangerter Foils For Treatment Of Amblyopia, Matthew Hellis, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

Amblyopia is a significant issue for children worldwide, and current treatment methods have drawbacks that can hinder treatment effectiveness and/or patient experience. This study proposes a new treatment method using holographic diffusers while also comparing their optical characteristics to a current treatment method (Bangerter foils). Holographic diffusers were developed by optically patterning thin polymer layers on a micron scale. Two compositions of photopolymer (acrylamide and diacetone acrylamide based) are analysed herein. Characterisation shows that holographic diffusers of either composition can achieve a wide range of on-axis intensity reductions, allowing for precise and customisable treatment levels by altering recording exposure time …

Development Of Holographic Optical Elements For Use In Wound Monitoring, Pamela Stoeva, Tatsiana Mikulchyk, Brian Rogers, M. Oubaha, Suzanne Martin, Dervil Cody, M.A. Ferrara, G. Coppola, Izabela Naydenova

Conference Papers

Wounds that fail to heal impact the quality of life of 2.5 % of the total population. The costs of chronic wound care will reach $15–22 billion by 2024. These alarming statistics reveal the financial strain for both the medical industry and society. A solution can be found in compact and accessible sensors that offer real-time analysis of the wound site, facilitating continuous monitoring and immediate treatment, if required. Benefits of these sensors include reduction of cost and can extend the reach of healthcare to remote areas. The progression of a wound site can be closely monitored with holographic optical …

The Clinical Transferability Of Raman Micro-Spectroscopic Systems For Cervical Cytopathology, Rubina Shaikh Dr, Sarah Loughlin, Alison Malkin, John J. O'Leary, Cara M. Martin, Fiona Lyng

Conference papers

The clinical potential for Raman microscopic systems is well established for early diagnosis via cytology. Although Raman systems offer a complementary diagnostic tool providing molecular information, it is not yet utilised substantially in clinics. A few challenges for the clinical implementation of Raman spectroscopy are system and user variability. In this study, we asked how much variability occurs due to different Raman systems or users. To address these questions, we measured the same set of cells using two different Raman microscopes and by two different users. And classification models were generated using multivariate partial least squares discriminant analysis (PLS-DA) and …

Estimating The Analytical Performance Of Raman Spectroscopy For Quantification Of Active Ingredients In Human Stratum Corneum, Hichem Kichou, Emilie Munnier, Yuri Dancik, Kamilia Kemel, Hugh Byrne, Ali Tfayli, Dominique Bertrand, Martin Soucé, Igor Chourpa, Franck Bonnier

Articles

Confocal Raman microscopy (CRM) has become a versatile technique that can be applied routinely to monitor skin penetration of active molecules. In the present study, CRM coupled to multivariate analysis (namely PLSR—partial least squares regression) is used for the quantitative measurement of an active ingredient (AI) applied to isolated (ex vivo) human stratum corneum (SC), using systematically varied doses of resorcinol, as model compound, and the performance is quantified according to key figures of merit defined by regulatory bodies (ICH, FDA, and EMA). A methodology is thus demonstrated to establish the limit of detection (LOD), precision, accuracy, sensitivity (SEN), and …

Normative Data On The Foveal Avascular Zone In A Young Healthy Irish Population Using Optical Coherence Tomography Angiography, Susan M. O'Shea, Veronica O'Dwyer, Grainne Scanlon

Articles

Purpose: To establish normative data on the size, shape and vascular profile of the foveal avascular zone (FAZ) in a young, healthy, Irish population, using the Cirrus 5000 HD-OCT. Certain diseases may alter FAZ appearance. Normative databases provide normal baseline values for comparison, thus improving diagnostic ability.

Methods: One hundred and fifty-four subjects aged 18–35 years old were recruited. Superficial FAZ area, diameter, circularity, ganglion cell layer, central macular thickness (CMT), vascular perfusion and density were measured using the Cirrus 5000. Axial length was measured with the IOL Master and blood pressure was measured using the Omron sphygmomanometer. …

International Consensus On Lung Function Testing During Covid-19 Pandemic And Beyond, Aisling Mcgowan, Pierantonio Laveneziana, Sam Bayat, Nicole Beydon, P.W. Boros, Felip Burgos, Matjaž Fležar, Monika Franczuk, Maria-Alejandra Galarza, Adrian H. Kendrick, Enrico Lombardi, Jellien Makonga-Braaksma, Meredith C. Mccormack, Laurent Plantier, Sanja Stanojevic, Irene Steenbruggen, Bruce Thompson, Allan L. Coates, Jack Wanger, Donald W. Cockcroft, Bruce Culver, Karl Sylvester, Frans De Jongh

Articles

Coronavirus disease 2019 (COVID-19) has negatively affected the delivery of respiratory diagnostic services across the world due to the potential risk of disease transmission during lung function testing. Community prevalence, reoccurrence of COVID-19 surges and the emergence of different variants of SARS-CoV-2 have impeded attempts to restore services. Finding consensus on how to deliver safe lung function services for both patients attending and for staff performing the tests are of paramount importance. This international statement presents the consensus opinion of 23 experts in the field of lung function and respiratory physiology balanced with evidence from the reviewed literature. It describes …

Quantitative Raman Analysis Of Carotenoid Protein Complexes In Aqueous Solution, Joy Udensi, Ekaterina Loskutova, James Loughman, Hugh Byrne

Datasets

Carotenoids are naturally abundant fat-soluble pigmented compounds, with dietary, antioxidant and vision protection advantages. The dietary carotenoids, Beta Carotene, Lutein and Zeaxanthin, complexed with in bovine serum albumin (BSA) in aqueous solution, were explored using Raman spectroscopy to differentiate and quantify their spectral signatures. UV visible absorption spectroscopy was employed to confirm the linearity of responses over the concentration range employed (0.05-1mg/ml) and, of the 4 source wavelengths, 785nm, 660nm, 532nm, 473nm, 532nm was chosen to provide the optimal response. After preprocessing to remove water and BSA contributions, and correct for self-absorption, a partial least squares model with R^{2 …}

Raman Spectroscopic Characterisation Of Non Stimulated And Stimulated Human Whole Saliva, Genecy Calado, Isha Behl, Hugh Byrne, Fiona Lyng

Articles

Human saliva is a unique biofluid which can reflect the physiopathological state of an individual. The wide spectrum of molecules present in saliva, compounded by the close association of salivary composition to serum metabolites, can provide valuable information for clinical diagnostic applications through highly sensitive vibrational spectroscopic techniques such as Raman spectroscopy. However, the nature of saliva, in terms of collection and patient-related characteristics, can be considered factors which may strongly affect the Raman spectral profile of salivary samples and disrupt the search for specific salivary biomarkers in the detection of diseases. The main objective of this study was to …

Development Of 3d In Vitro Tissue Models For The Analysis Of Solar Radiation Damage Of Skin, Ulises Lopez Gonzalez

Doctoral

The aim of this work was to investigate changes to the molecular composition and conformation of HaCaT cells as a result of simulated solar radiation in a 3D in vitro skin model by Raman spectroscopy. The process to achieve this goal was performed in three main stages: (1) optimisation of the working concentration and volume of two 3D membranes, used as a structural support in the skin model; (2) the construction of the 3D in vitro skin model and; (3) the investigation of the dose-dependent effects of solar radiation on HaCaT cells in the skin model in comparison with the …

The Potential Of Raman Spectroscopy In The Diagnosis Of Dysplastic And Malignant Oral Lesions, Ola Ibrahim, M. Toner, Steven Flint, Hugh Byrne, Fiona Lyng

Articles

Early diagnosis, treatment and/or surveillance of oral premalignant lesions are important in preventing progression to oral squamous cell carcinoma (OSCC). The current gold standard is through histopathological diagnosis, which is limited by inter and intra observer and sampling errors. The objective of this work was to use Raman spectroscopy to discriminate between benign, mild, moderate and severe dysplasia and OSCC in formalin fixed paraffin preserved (FFPP) tissues. The study included 72 different pathologies from which 17 were benign lesions, 20 mildly dysplastic, 20 moderately dysplastic, 10 severely dysplastic and 5 invasive OSCC. The glass substrate and paraffin wax background were …

Biomedical Applications Of Vibrational Spectroscopy: Oral Cancer Diagnostics, Hugh Byrne, Isha Behl, Genecy Calado, Ola Ibrahim, M. Toner, Sheila Galvin, Claire M. Healy, Steven Flint, Fiona Lyng

Articles

Vibrational spectroscopy, based on either infrared absorption or Raman scattering, has attracted increasing attention for biomedical applications. Proof of concept explorations for diagnosis of oral potentially malignant disorders and cancer are reviewed, and recent advances critically appraised. Specific examples of applications of Raman microspectroscopy for analysis of histological, cytological and saliva samples are presented for illustrative purposes, and the future prospects, ultimately for routine, chairside in vivo screening are discussed.

Direct Multiplexing Of Low Order Aberration Modes In A Photopolymerbased Holographic Element For Analog Holographic Wavefront Sensing, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Conference Papers

The fabrication of an analog holographic wavefront sensor, capable of detecting the low order defocus aberration, was achieved in an acrylamide-based photopolymer. While other implementations of holographic wavefront sensors have been carried out digitally, this process utilises a recording setup consisting only of conventional refractive elements so the cost and complexity of holographic optical element (HOE) production could be much reduced. A pair of diffraction spots, corresponding to a maximum and minimum amount of defocus, were spatially separated in the detector plane by multiplexing two HOEs with different carrier spatial frequencies. For each wavefront with a known aberration that was …

An Investigation Into Employee Exposure To Environmental Tobacco Smoke Within Designated Smoking Areas In The Hospitality Industry, With An Analysis Of Legislative Compliance Of Said Designated Smoking Areas, Hannah Byrne

Masters

Background: Occupational exposure to environmental tobacco smoke (ETS) is still occurring in the hospitality industry and the instance of non-compliant smoking areas required investigation. A designated smoking area covered by a roof where more than 50% of the perimeter of that part is surrounded by one or more walls is deemed a non-compliant smoking area. This study aimed to gather evidence of non-compliances across Dublin, determine current employee exposure whilst also measuring PM2.5 concentrations within smoking areas as well as providing insight into possible immediate health effects of ETS exposure.

Methods: Seventy-five smoking areas (41 located in high, 27 in …

Optimisation Of The Performance Of Holographic Beam-Shaping Diffractive Diffusers Through Refinement Of The Recording Process, Cara Jones, Suzanne Martin, Sanjay Keshri, Dervil Cody, Kevin Murphy

Conference Papers

Optical diffusers have uses in laser applications and machine vision. Typical fabrication at a commercial level requires master production and the stamping/copying of individual elements at scale. This expensive, indirect process inhibits custom diffusers at reasonable cost. Previously the authors published a novel, direct, single beam method of recording customizable and controllable volume holographic diffusers by manipulating laser speckle and recording the pattern in photopolymer. This method allows for beam-shaping to produce diffusion patterns of various sizes and shapes. In this work, the direct method of recording controllable holographic diffusers is refined to improve diffuser performance (i.e., a decrease in …

Investigation Of The Chemical Composition Of Plasma-Treated Water By Midiplexc And Its Antimicrobial Effect On L. Monocytogenes And Pseudomonas Fluorescens Monospecies Suspension Cultures, Oliver Handorf, Harald Below, Uta Schnabel, Katharina Riedel

Articles

Plasma -generated compounds conceived by microwave -induced plasma (MidiPLexc) were physicochemically investigated in their molecular compositions. Therefore, plasma -treated water (PTW) was generated by treatment with the MidiPLexc within a 1 l glass bottle for a pre -treatment time of 100 s, 300 s and 900 s. The PTW was further investigated in its composition of reactive oxygen/nitrogen species. For this purpose, the hydrogen peroxide (H2O2) concentration of the PTW was determined electrochemically using chronoamperometry, and the anionic components were determined using ion chromatography. As a result, H2O2 concentrations of up to 720 mg l−1 , nitrite concentrations of 1600 …

An Investigation Of The Detection Capability Of Pulsed Wave Duplex Doppler Of Low Grade Stenosis Using Ultrasound Contrast Agent Microbubbles – An In-Vitro Study, Jacinta Browne, Deirdre King, Andrew Fagan, Deepa Chari, Carmel Moran

Articles

Objective: The objective of the study was to investigate whether clinically used ultrasonic contrast agents improved the accuracy of spectral Doppler ultrasound in the detection of low grade (< 50%) renal artery stenosis. Low grade stenoses in the renal artery are notoriously difficult to reliably detect using Doppler ultrasound due to difficulties such as overlying fat and bowel gas.

Methods: A range of anatomically-realistic renal artery phantoms with varying low degrees of stenosis (0, 30 and 50%) were constructed and peak velocity data was measured from within the pre-stenotic and mid-stenotic regions in each phantom, for both unenhanced and contrast-enhanced spectral Doppler data acquisitions. The effect of a 20mm overlying fat layer on the ultrasound beam distortion and phase aberration, and hence on the measured peak velocity data, was also …

Use Of Novel Anthropomorphic Breast Ultrasound Phantoms For Radiology Resident Education, Jacinta Browne, Chris Gu, Robert Fazzio, Andrew Fagan, Donald Tradup, Nicholas Hangiandreou

Articles

Purpose: This study evaluated the training and assessment role of anthropomorphic breast ultrasound phantoms which simulated both the morphological and sonographic characteristics of breast tissue, including lesions, in a group of radiology residents at a large academic medical center. Methods: This was a prospective study involving 9 residents across all years (2^nd–4^th year) of a radiology residency program. Baseline assessments of all residents ability to detect and characterize lesions in P-I were carried out, followed by a two-hour teaching session on the same phantom. All residents underwent a post-training, final assessment on P-II to evaluate changes in …

Investigation Of The Assessment Of Low Degree (<50%) Renal Artery Stenosis Based On Velocity Flow Profile Analysis Using Doppler Ultrasound: An In-Vitro Study, Andrew Malone, Deepa Chari, Sean Cournane, Izabela Naydenova, Andrew Fagan, Jacinta Browne

Articles

Purpose: Renal arterial stenosis can lead to disrupted renal function due to reduced blood flow to the kidneys and is largely thought to be caused by atherosclerosis. Current diagnostic strategies for renal arterial stenosis rely on detecting large degree stenoses (>50%). This study aimed to test the viability of using Doppler ultrasound to assess velocity profiles to detect the presence of low degree (<50%) stenoses.

Methods: A series of anatomically realistic renal artery flow phantoms were constructed exhibiting a range of low degree stenoses (symmetric and asymmetric). The behaviour of fluid flow in the phantoms was examined using Doppler ultrasound …

Multivariate Statistical Methodologies Used In In-Vitro Raman Spectroscopy: Simulations And Applications For Drug And Nanoparticle Interactions, Mark Edward Keating

Doctoral

Raman spectroscopy is a growing technology in the fields of in-vitro drug and nanoparticle screening. The label free capability provided by vibrational spectroscopy, as well as the ability of the technique to probe the chemical nature of samples, makes it a good candidate for use in these fields. Crucial to the progress of these methods is the development and validation of robust and accurate multivariate statistical analysis protocols. In this thesis, both established and novel methods are examined using both real and simulated datasets. In particular, simulated datasets are used to validate and assess the accuracy of these methods in …

Exploring Subcellular Responses Of Prostate Cancer Cells To X-Ray Exposure By Raman Mapping, Maciej Roman, Agnieszka Panek, Hugh Byrne, Tomasz P Wrobel, Esen Efeoglu, Czeslawa Paluszkiewicz, Wojciech Maria Kwiatek

Articles

Understanding the response of cancer cells to ionising radiation is a crucial step in modern radiotherapy. Raman microspectroscopy, together with Partial Least Squares Regression (PLSR) analysis has been shown to be a powerful tool for monitoring biochemical changes of irradiated cells on the subcellular level. However, to date, the majority of Raman studies have been performed using a single spectrum per cell, giving a limited view of the total biochemical response of the cell. In the current study, Raman mapping of the whole cell area was undertaken to ensure a more comprehensive understanding of the changes induced by X-ray radiation. …

Raman Spectral Analysis For Rapid Screening Of Dengue Infection, Tahir Mahmood, Haq Nawaz, A. Ditta, M.I. Majeed, M.A. Hanif, N. Rashid, H.N. Bhatti, H.F. Nargis, M. Saleem, Franck Bonnier, Hugh Byrne

Articles

Infection with the dengue virus is currently clinically detected according to different biomarkers in human blood plasma, commonly measured by enzyme linked immunosorbent assays, including non-structural proteins (Ns1), immunoglobulin M (IgM) and immunoglobulin G (IgG). However, there is little or no mutual correlation between the biomarkers, as demonstrated in this study by a comparison of their levels in samples from 17 patients. As an alternative, the label free, rapid screening technique, Raman spectroscopy has been used for the characterisation/diagnosis of healthy and dengue infected human blood plasma samples. In dengue positive samples, changes in specific Raman spectral bands associated with …

Enabling Quantification Of Protein Concentration In Human Serum Biopsies Using Attenuated Total Reflectance – Fourier Transform Infrared (Atr-Ftir) Spectroscopy, Kate Spalding, Franck Bonnier, Clément Bruno, Hélène Blasco, Ruth E. Board, Isabelle Benz-De-Bretagne, Hugh Byrne, Holly J. Butler, Igor Chourpa, Pretheepan Radhakrishnan, Matthew J. Baker

Articles

Changes in protein concentrations within human blood are used as an indicator for nutritional state, hydration and underlying illnesses. They are often measured at regular clinical appointments and the current analytical process can result in long waiting times for results and the need for return patient visits. Attenuated total reflectance – Fourier transform infrared (ATR-FTIR) spectroscopy has the ability to detect minor molecular differences, qualitatively and quantitatively, in biofluid samples, without extensive sample preparation. ATR-FTIR can return an analytical measurement almost instantaneously and therefore could be deemed as an ideal technique for monitoring molecular alterations in blood within the clinic. …

A Mathematical Analysis Of Drug Dissolution In The Usp Flow Through Apparatus, David Mcdonnell, Deirdre M. D'Arcy, Lawrence J. Crane, Brendan Redmond

Articles

This paper applies boundary layer theory to the process of drug dissolution in the USP (United States Pharmacopeia) Flow Through Apparatus. The mass transfer rate from the vertical planar surface of a compact within the device is examined. The theoretical results obtained are then compared with those of experiment. The paper also examines the effect on the dissolution process caused by the interaction between natural and forced convection within the apparatus and the introduction of additional boundaries.

Broadband Acoustic Measurement Of The Agar-Based Tissue Mimicking Material – A Longitudinal Study, Adela Rabell-Montiel, Jacinta Browne, Stephen Pye, Tom Anderson, Carmel Moran

Articles

Commercially available ultrasound quality assurance test phantoms rely upon the long-term acoustic stability of tissue-mimicking-materials (TMMs). The measurement of the acoustic properties can be technically challenging and it is important to ensure its stability. The standard technique is to film-wrap samples of TMM and to measure the acoustic properties in a water bath. In this study, a modified technique is proposed whereby the samples of TMM are measured in a preserving fluid that is intended to maintain their characteristics. The acoustic properties were evaluated using a broadband pulse-echo substitution technique over the frequency range of 4.5 – 50 MHz at …

Ultra-Filtration Of Human Serum For Improved Quantitative Analysis Of Low Molecular Weight Biomarkers Using Atr-Ir Spectroscopy, Franck Bonnier, Luis Felipe Cs. Carvalho, Matthew 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, …

Extraoral Maxillofacial Prosthesis Implant Retention Systems: A Critical Review., Hugh Byrne, Marina L. Pimentel

Articles

Objectives: The purpose of this literature review is to provide information on the different available techniques for implant-supported prosthetic retention, which are bar-clip, o-ring or magnets. Through presenting the practitioner preferences reported in literature, although limited from strict comparison due to the heterogeneity of methodologies and studied individuals, this review aims to identify the choices for maxillofacial prosthesis implant retention systems, regarding patient comfort and good aesthetic outcome, as an aid to surgical and prosthetic planning for implant-supported extraoral maxillofacial prosthetics. With proper knowledge of each implant retention system, a practitioner can design a treatment plan which allows for a …

Retention Systems For Extraoral Maxillofacial Prosthetic Implants: A Critical Review, M.V. Cobein, N.P. Coto, O. Crivello Junior, J.B.D. Lemos, L.M. Vieira, M.L. Pimentel, Hugh Byrne, R.B. Dias

Articles

We describe the techniques available for retention of implant-supported prostheses: bar-clips, O-rings, and magnets. We present reported preferences and, although this is limited by the heterogeneity of methods used and patients studied, we hope we have identified the best retention systems for maxillofacial prosthetic implants. If practitioners know the advantages and disadvantages of each system, they can choose the most natural and comfortable prosthesis. We searched the PubMed and Scopus databases, and restricted our search to papers published 2001–13. MeSH terms used were Maxillofacial prosthesis and Craniofacial prosthesis OR Craniofacial prostheses. We found a total of 2630 papers, and after …

Advancing Vibrational Spectroscopy For Cellular And Sub Cellular Analysis: Raman Spectroscopy As An In Vitro Chemotherapeutic Screeening And Assessment Protocol, Zeineb Farhane

Doctoral

Vibrational spectroscopy, including Raman micro-spectroscopy, has attracted considerable attention over the last few years, as a powerful, non-invasive tool for clinical applications, especially in cancer diagnosis, in vivo and ex vivo. As a molecular fingerprinting technique with optical resolution, Raman micro-spectroscopy is able to monitor biochemical processes, drug uptake, efficacy and mode of action and mechanisms of interaction of chemotherapeutic drugs at a subcellular level. In vitro applications may be more strategically achievable, and can help guide drug design and discovery, and eventually evaluate To this end, different lung cell lines were used and Raman micro-spectroscopy was coupled to valuable …

Linking Atr-Ftir And Raman Features To Phenolic Extractability And Other Attributes In Grape Skin, Hugh Byrne, Abigain Rooney, Julio Nogales-Bueno, Jose Miguel Hernandez-Hierro, Francisco Jose Heredia

Articles

The importance of wine phenolics on the sensory characteristic of red wines is well-known. Therefore, it is necessary to control the extractability of phenolic compounds from grape skins, which depends significantly on grape ripeness and hence, on cell wall degradation.

In the present study, attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman spectra of grape skin have been recorded. Then, these spectral matrices have been studied and the main spectral features have been linked to extractabilities of phenolic compounds (anthocyanins, flavanols and total phenols). Moreover, spectral differences between external and internal grape skin surfaces also have been studied.

It …