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Paul G Stevenson

Paul G Stevenson
Avance Clinical · Biometrics

Doctor of Philosophy

About

69
Publications
23,629
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925
Citations
Introduction
I am a Biostatistican and Analytical Chemist from Sydney Australia. I am currently in Perth working for the Telethon Kids Institute as an internal consultant performing the analysis on a wide range of children's medical health research programs.
Additional affiliations
April 2018 - present
Telethon Kids Institute
Position
  • Statistician
October 2016 - April 2018
Sun Pharma, Port Fairy, Australia
Position
  • Analytical Development Chemist
February 2013 - present
Deakin University
Position
  • Research Associate
Description
  • Unit Chair: SLE311 Chemical hazards (2015) Unit Chair: SLE155 Chemistry for the Professional Sciences (2014) Lecturer: SLE316 Analytical Chemistry Lecturer: SLE229 Introduction to Separation Science (acting chair 2014)

Publications

Publications (69)
Article
Aim: To determine the clinical outcomes and evaluate the perspectives of children with Type 1 diabetes (T1D) and their parents managing their child on hybrid closed-loop (HCL) therapy. Methods: Children with T1D on HCL attending a tertiary diabetes centre between April 2019 and July 2021 were included. A retrospective analysis of glycaemic data...
Article
Objectives There is a paucity of information regarding the profile of entire paediatric endocrine clinics and how they are changing. This study aimed to analyse the clinic profile of the Western Australian tertiary paediatric endocrine outpatient service over 10 years and compare to national and international data. Methods Retrospective analysis o...
Article
Full-text available
Objectives When the COVID-19 pandemic was declared, Governments responded with lockdown and isolation measures to combat viral spread, including the closure of many schools. More than a year later, widespread screening for SARS-CoV-2 is critical to allow schools and other institutions to remain open. Here, we describe the acceptability of a minimal...
Article
Objectives Glucose monitoring is vital in children with persistent hypoglycaemia to reduce the risk of adverse neuro-behavioural outcomes; especially in children with hyperinsulinism. The role of continuous glucose monitoring (CGM) systems in monitoring glucose levels in this cohort is limited. The objective of this study was to ascertain the effec...
Article
Full-text available
Adaptive optics flood illumination ophthalmoscopy (AO-FIO) is an established imaging tool in the investigation of retinal diseases. However, the clinical interpretation of AO-FIO images can be challenging due to varied image quality. Therefore, image quality assessment is essential before interpretation. An image assessment tool will also assist fu...
Article
Aim To determine the frequency of protracted bacterial bronchitis (PBB) in children referred to tertiary care with chronic cough and describe management prior to referral. Methods A retrospective cohort study of all new patients with a history of ≥4 weeks of cough seen at the only tertiary paediatric outpatient respiratory service in Western Austr...
Article
Delays within the motor domain are often overlooked as an early surveillance marker for autism. The present study evaluated motor difficulties and its potential as an early predictive marker for later autism likelihood in a cohort of infants (N = 96) showing early behavioral signs of autism aged 9–14 months. The motor domain was evaluated using the...
Article
Full-text available
Purpose: Microperimetry measures differential light sensitivity (DLS) at specific retinal locations. The aim of this study is to examine the variation in DLS across the macula and the contribution to this variation of cone distribution metrics and retinal eccentricity. Methods: Forty healthy eyes of 40 subjects were examined by microperimetry (M...
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Introduction: Amidst the evolving COVID-19 pandemic, understanding the transmission dynamics of the SARS-CoV-2 virus is key to providing peace of mind for the community and informing policy-making decisions. While available data suggest that school-aged children are not significant spreaders of SARS-CoV-2, the possibility of transmission in schools...
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Background: Vulvodynia and pudendal neuralgia comprise significant contributors to vulvar-related pain and its impact on daily life. Aim: A retrospective clinical audit was conducted at the Women's Health & Research Institute of Australia, Sydney, to determine the pattern of use and the efficacy of the application of topical amitriptyline 0.5% p...
Article
The use of three-dimensional printing in chemistry education has expanded greatly in the past 10 years. The technique has been used to demonstrate a range of concepts including molecular structure, orbitals, and point groups; to produce chemical equipment such as cuvettes and columns; and even to print out mathematical shapes and functions. Here, 3...
Article
Background: Birth order effects have been linked to variability in intelligence, educational attainment, and sexual orientation. First- and later-born children have been linked to an increased likelihood of an Autism Spectrum Disorder (ASD) diagnosis, with a smaller body of evidence implicating decreases in cognitive functioning with increased birt...
Article
This study further advances the development of a software program for the analysis of bloodstain patterns formed from a sledgehammer apparatus capable of creating reproducible blood spatter. In this work, a systematic study was performed testing the capacity of the technology to digitally extract a clear impact bloodstain pattern from a very comple...
Article
This project looks at the intersection between gunshot damage to road signs and the use of geographic information systems (GIS) for forensic intelligence. The project has surveyed several distinct regions in Victoria Australia (residential, semi-rural and rural) in order to establish the level and distribution of gunshot damage to signs. The study...
Article
Measures to control the expanding use of synthetic cannabinoids demand new analytical methodology to identify and determine compounds within this rapidly evolving class. Herein, we identify seven synthetic cannabinoids (AM-2201, UR-144, XLR-11, A796,260, 5F-AKB48, PB-22 and 5F-PB-22) present in eleven herbal products sold in Victoria, Australia, pr...
Article
Principal component analysis (PCA) loading plots were used to elucidate key differences between two-dimensional high performance liquid chromatography (2D-HPLC) fingerprint data from samples collected from stages along the Papaver somniferum industrial process chemistry workflow. Data reduction was completed using a 2D-HPLC peak picking approach as...
Article
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In-silico optimisation of a two-dimensional high performance liquid chromatography (2D-HPLC) separation protocol has been developed for the interrogation of methamphetamine samples including model, real world seizure, and laboratory synthesised samples. The protocol used Drylab1 software to rapidly identify the optimum separation conditions from a...
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The recognition of differences between regulated large-scale mass manufactured products and the uncontrolled cultivation of tobaccos for illicit purposes plays a significant role within identification of provenance. This research highlights X-ray fluorescence and Fourier transform infrared spectroscopy as useful analytical techniques for the rapid...
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The selection of two orthogonal columns for two-dimensional high performance liquid chromatography (LC×LC) separation of natural product extracts can be a labour intensive and time consuming process and in many cases is an entirely trial-and-error approach. This paper introduces a blind optimisation method for column selection of a black box of con...
Article
Australian clandestine drug laboratories are constantly utilising alternative methods to produce methamphetamine, in part as restrictions are placed by Government on, for example, chemicals such as phenyl-2-propanone (P2P) (in the early 1980s), or on pseudoephedrine-containing pharmaceuticals, from the mid-2000s. This paper discusses the nitro-aldo...
Article
This work describes a method for two-dimensional high performance liquid chromatography (2D-HPLC) that uses an isocratic mobile phase with a temperature gradient in the first dimension. Temperature programming was used to manipulate solvent elution strength in place of a mobile phase concentration gradient. This ensured that all eluent fractions tr...
Article
Full-text available
As monolithic columns become more extensively used in separation based applications due to their good flow and high surface characteristics, there has arisen the need to establish simple, reliable fabrication methods for fluidic coupling and sealing. In particular, the problem of liquid tracking between a monolith’s outer surface and the sealing wa...
Article
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While data processing methods in metabolomic studies often work with 'n' number of dimensions; analytical techniques, with the notable exception of NMR, have mostly stuck only to one. Peak overlap continues to be a problem and there is an ever-present demand to maximize the number of metabolites that can be separated and identified in a single run....
Article
Widely known for its recreational use, the cannabis plant also has the potential to act as an antibacterial agent in the medicinal field. The analysis of cannabis plants/products in both pharmacological and forensic studies often requires the separation of compounds of interest and/or accurate identification of the whole cannabinoid profile. In ord...
Article
Full-text available
It has previously been shown that irradiation with UV light increases the vitamin D content of certain mushroom species, but the effect on other nutrients is unknown, and is difficult to assess due to the complexity of the sample matrix. Here, an offline reversed phase × reversed phase two-dimensional liquid chromatography methodology was developed...
Article
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The selection of two high performance liquid chromatography (HPLC) columns with vastly different retention mechanisms is vital for performing effective two-dimensional (2D-) HPLC. This paper reports on a systematic method to select a pair of HPLC columns that provide the most different separations for a given sample. This was completed with the aid...
Article
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This paper explores the analytical figures of merit of two-dimensional high-performance liquid chromatography for the separation of antioxidant standards. The cumulative two-dimensional high-performance liquid chromatography peak area was calculated for 11 antioxidants by two different methods-the areas reported by the control software and by fitti...
Article
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This paper describes a non-destructive “peak parking” protocol in order to assess the axial heterogeneity of an in-situ modified monolithic column for high performance liquid chromatography; a “gradient stationary phase” was designed whereby the ligand density decreases along the length of the rod in the “forward flow” configuration. Results of mul...
Article
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This study investigated approaches for the profiling of coffee using two multidimensional approaches: (1) a multi-detection process and (2) a multi-separation process employing HPLC. The first approach compared multidetection techniques of conventional High Performance Liquid Chromatography (HPLC) hyphenated with a detector (DPPH•, UV-Vis and MS),...
Article
The synthesis and chromatographic behaviour of an analytical size mixed mode bonded silica monolith was investigated. The monolith was functionalised by an in situ modification process of a bare silica rod with chloro(3-cyanopropyl)dimethyl silane and chlorodimethyl propyl phenyl silane solutions. These ligands were selected in order to combine bot...
Technical Report
This application note presents a simple, user-friendly technique for a comprehensive two-dimensional analysis of complex matrices when the operator only has access to a one-dimensional liquid chromatography system. In this example an 1260 Agilent Infinity chromatograph coupled to a fraction collector was used for an offline study of biochemical com...
Article
Full-text available
To achieve the greatest peak capacity in two-dimensional high performance liquid chromatography (2D-HPLC) a gradient should be operated in both separation dimensions. However, it is known that when an injection solvent that is stronger than the initial mobile phase composition is deleterious to peak performance, thus causing problems when cutting a...
Article
Five methods for controlling the mobile phase flow rate for gradient elution analyses using very high pressure liquid chromatography (VHPLC) were tested to determine thermal stability of the column during rapid gradient separations. To obtain rapid separations, instruments are operated at high flow rates and high inlet pressure leading to uneven th...
Article
Full-text available
High-performance liquid chromatography with chemiluminescence detection based on the reaction with acidic potassium permanganate and formaldehyde was explored for the determination of neurotransmitters and their metabolites. The neurotransmitters norepinephrine and dopamine were quantified in the left and right hemispheres of rat hippocampus, nucle...
Article
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Two multidimensional HPLC separations of an Australian red wine are presented, greater than 70% of the available separation space was used. A porous graphitic carbon stationary phase was used as the first dimension in both separations with both RP core-shell and hydrophilic interaction chromatography fully porous columns used separately in the seco...
Article
A series of experiments was conducted to evaluate the degree of band broadening in very high pressure LC due to column connections. Different column manufacturers use slightly different designs for their column fittings. If the same column connections are repeatedly used to attach columns of different origins, different void volumes form between ca...
Article
This manuscript evaluates the performance of the Eilers' smoothing algorithm by comparing the third central statistical peak moment of simulated peaks to their true value. Peaks were simulated by imposing an exponentially modified Gaussian peak profile onto a random segment of pre-recorded high performance liquid chromatography baseline. Prior to m...
Article
The calculation of the first few moments of elution peaks is necessary to determine: the amount of component in the sample (peak area or zeroth moment), the retention factor (first moment), and the column efficiency (second moment). It is a time consuming and tedious task for the analyst to perform these calculations, thus data analysis is generall...
Article
The significant divergence between the retention of 16 terpene standards on porous graphitized carbon (PGC) and C₁₈ packing materials are illustrated. The PGC surface is shown to provide a selectivity toward shape, polarity, and structure that is not afforded by the C₁₈ surface. This observation is illustrated by plots of the retention factors simi...
Article
Elution peaks were generated by summing up a mathematical function and a previously recorded experimental noise. The first three statistical moments of these peaks were calculated using several data processing methods. The results obtained were analyzed. From this analysis, a method is developed for the calculation with a satisfying accuracy of the...
Chapter
Full-text available
Chemical fingerprinting is a means of providing a chemical profile or signature that represents the components that are present in a sample and describes a range of methods where the primary aim is to provide a unique graphical representation of the sample by identifying the chemical elements within a matrix in comparison to similar matrices. Chemi...
Article
A 2D comprehensive chromatographic separation of blackberry sage fragrant oil was performed by using HPLC in the first dimension and SFC in the second. A C(18)-bonded silica column eluted with an ACN gradient was used in the HPLC dimension and an amino-bonded silica column eluted with ACN as a modifier in the SFC dimension. This 2D separation was c...
Article
Several simple techniques are presented for the identification of the boundaries of chromatographic peaks. These methods provide a significant reduction in the time needed to perform the rapid, automatic calculation of the central peak moments and to evaluate the quality of a separation while improving the accuracy of the measurements of column eff...
Article
Mixed mode stationary phases utilize secondary retention mechanisms to add a dimensionality to the surface of high performance liquid chromatography (HPLC) adsorbents. This approach was used by several authors to improve the separation performance of single dimension separations. We explored the magnitude of these secondary interactions by performi...
Article
The multidimensional high-performance liquid chromatography separations of the complex sample matrix found in café espresso coffee were completed on the propyl phenyl and butyl phenyl columns that contain 3 and 4 carbon atoms in the spacer chain, respectively. Phenyl type stationary phases are able to undergo unique π-π interactions with aromatic c...
Article
Differences between alkyl, dipole-dipole, hydrogen bonding, and pi-pi selective surfaces represented by non-resonance and resonance pi-stationary phases have been assessed for the separation of 'Ristretto' café espresso by employing 2DHPLC techniques with C18 phase selectivity detection. Geometric approach to factor analysis (GAFA) was used to meas...
Article
In this study, an activity based screening technique combining two-dimensional liquid chromatography (2DHPLC) with UV-absorbance and chemiluminescence detection was applied to study "Ristretto", "Decaffeinatto" and "Volluto" espresso coffees. This technique, which coupled the separation power of 2DHPLC with the sensitivity and selectivity of the ch...
Article
Chromatographic detection responses are recorded digitally. A peak is represented ideally by a Guassian distribution. Raising a Guassian distribution to the power 'n' increases the height of the peak to that power, but decreases the standard deviation by radicaln. Hence there is an increasing disparity in detection responses as the signal moves fro...
Article
The frontal analysis method was used to measure the adsorption isotherms of phenol, 4-chlorophenol, p-cresol, 4-methoxyphenol and caffeine on a series of columns packed with home-made alkyl-phenyl bonded silica particles. These ligands consist of a phenyl ring tethered to the silica support via a carbon chain of length ranging from 0 to 4 atoms. Th...
Article
The retention characteristics of phenyl type stationary phases for reversed phase high performance liquid chromatography are still largely unknown. This paper explores the retention process of these types of stationary phases by examining the retention behaviour of linear PAHs and n-alkylbenzenes on a series of propyl phenyl stationary phases that...
Article
Phenyl type stationary phases of increasing spacer chain length (phenyl, methyl phenyl, ethyl phenyl, propyl phenyl and butyl phenyl, with 0-4 carbon atoms in the spacer chain, respectively) were synthesised and packed in house to determine the impact that the spacer chain length has on the retention process. Two trends in the aromatic selectivity,...
Article
Full-text available
An algorithm was developed for 2DHPLC that automated the process of peak recognition, measuring their retention times, and then subsequently plotting the information in a two-dimensional retention plane. Following the recognition of peaks, the software then performed a series of statistical assessments of the separation performance, measuring for e...
Article
In this manuscript, we investigate the importance that must be placed on the selection of standard compounds when undertaking studies to optimize the performance of 2-D-HPLC separations. A geometric approach to factor analysis and a measure of peak density across the separation space were applied to assess localized measures of component distributi...
Article
The performance of the new Kinetex-C(18) column was investigated. Packed with a new brand of porous shell particles, this column has an outstanding efficiency. Once corrected for the contribution of the instrument extra column volume, the minimum values of the reduced plate heights for a number of low molecular weight compounds (e.g., anthracene an...
Article
Full-text available
A commercial silica monolithic rod column (100 × 4.6 mm) was cut into smaller sections using a saw. Each time a section was cut from the column, the performance of the remaining intact monolith was retested. No significant change in the performance of the bed was recorded following the removal of 40 mm of the column in three separate cut sections....
Article
C1 and phenyl-type stationary phases were assessed in terms of their environmental impact on separations using as test solutes polycyclic aromatic hydrocarbons. Methanol (MeOH) and acetonitrile (ACN) mobile-phase gradients were employed. These stationary phases were examined to determine if different physical and chemical properties possessed by th...