David Hibbert

Ionic Liquid Microstrips Impregnated with Magnetic Nanostirrers for Sensitive Gas Sensors

Publisher: American Chemical Society (ACS)

Date: 28-11-2017

DOI: 10.1021/ACSAMI.7B14657

Abstract: Ionic liquids (IL) have been regarded as promising electrolytes as substitutes for volatile aqueous or organic solvents for electrochemical gas sensors. However, ILs are viscous, and the slow diffusion of gas molecules leads to poor sensitivity and sluggish response times. Herein, we describe a strategy using an array of microstrips of IL containing magnetic nanoparticles as nanostirrers for enhanced mass transport and gas sensing. Magnetic CoFe

Risk of a false decision on conformity of an environmental compartment due to measurement uncertainty of concentrations of two or more pollutants

Publisher: Elsevier BV

Date: 07-2018

DOI: 10.1016/J.CHEMOSPHERE.2018.03.054

Abstract: Risks of false decisions in conformity assessment of an environmental compartment due to measurement uncertainty of concentrations of two or more pollutants are discussed. Even if the assessment of conformity for each pollutant in the compartment is successful, the total probability of a false decision concerning the compartment as a whole might still be significant. A model of the total probability of a false decision, formulated on the base of the law of total probability, is used, for ex le, for a study of test results of total suspended particulate matter (TSPM) concentration in ambient air near to three independent stone quarries located in Israel, as the sources of the air pollution. Total probabilities of underestimation of TSPM concentration (total risk of the inhabitants) and overestimation (total risk of the stone producers) are evaluated as a combination of the particular risks of air conformity assessment concerning TSPM concentration for each quarry. These probabilities characterize conformity of the TSPM concentration in the region of the quarries as a whole. Core code developed in R programming environment for the calculations is provided.

Terminology of electrochemical methods of analysis (IUPAC Recommendations 2019)

Publisher: Walter de Gruyter GmbH

Date: 04-2020

DOI: 10.1515/PAC-2018-0109

Abstract: Recommendations are given concerning the terminology of methods used in electroanalytical chemistry. Fundamental terms in electrochemistry are reproduced from previous PAC Recommendations, and new and updated material is added for terms in electroanalytical chemistry, classification of electrode systems, and electroanalytical techniques.

Preparation, formatting and review of IUPAC Technical Reports and Recommendations, IUPAC-sponsored books, or other items carrying the IUPAC label

Publisher: Walter de Gruyter GmbH

Date: 12-2022

DOI: 10.1515/PAC-2022-1106

Dual Signaling DNA Electrochemistry: An Approach To Understand DNA Interfaces

Publisher: American Chemical Society (ACS)

Date: 18-01-2018

DOI: 10.1021/ACS.LANGMUIR.7B02787

Abstract: Electrochemical DNA biosensors composed of a redox marker modified nucleic acid probe tethered to a solid electrode is a common experimental construct for detecting DNA and RNA targets, proteins, inorganic ions, and even small molecules. This class of biosensors generally relies on the binding-induced conformational changes in the distance of the redox marker relative to the electrode surface such that the charge transfer is altered. The conventional design is to attach the redox species to the distal end of a surface-bound nucleic acid strand. Here we show the impact of the position of the redox marker, whether on the distal or proximal end of the DNA monolayer, on the DNA interface electrochemistry. Somewhat unexpectedly, greater currents were obtained when the redox molecules were located on the distal end of the surface-bound DNA monolayer, notionally furthest away from the electrode, compared with currents when the redox species were located on the proximal end, close to the electrode. Our results suggest that a limitation in ion accessibility is the reason why smaller currents were obtained for the redox markers located at the bottom of the DNA monolayer. This understanding shows that to allow the quantification of the amount of redox labeled target DNA strand that hybridizes to probe DNA immobilized on the electrode surface, the redox species must be on the distal end of the surface-bound duplex.

Tutorial and spreadsheets for Bayesian evaluation of risks of false decisions on conformity of a multicomponent material or object due to measurement uncertainty

Publisher: Elsevier BV

Date: 11-2018

DOI: 10.1016/J.CHEMOLAB.2018.09.004

Terminology of bioanalytical methods (IUPAC Recommendations 2018)

Publisher: Walter de Gruyter GmbH

Date: 29-05-2018

DOI: 10.1515/PAC-2016-1120

Abstract: Recommendations are given concerning the terminology of methods of bioanalytical chemistry. With respect to dynamic development particularly in the analysis and investigation of biomacromolecules, terms related to bioanalytical s les, enzymatic methods, immunoanalytical methods, methods used in genomics and nucleic acid analysis, proteomics, metabolomics, glycomics, lipidomics, and biomolecules interaction studies are introduced.

Correction to “Machine Learning Color Feature Analysis of a High Throughput Nanoparticle Conjugate Sensing Assay

Publisher: American Chemical Society (ACS)

Date: 15-05-2023

DOI: 10.1021/ACS.ANALCHEM.3C01892

Single injection of PTH improves osteoclastic parameters of remodeling at a stress fracture site in rats

Publisher: Wiley

Date: 21-03-2019

DOI: 10.1002/JOR.24262

Abstract: Stress fractures (SFx) result from repetitive cyclical loading of bone. They are frequent athletic injuries and underlie atypical femoral fractures following long-term bisphosphonate (BP) therapy. We investigated the effect of a single PTH injection on the healing of SFx in the rat ulna. SFx was induced in 120 female Wistar rats (300 ± 15 g) during a single loading session. A single PTH (8 µg.100g

IUPAC/CITAC Guide: Evaluation of risks of false decisions in conformity assessment of a multicomponent material or object due to measurement uncertainty (IUPAC Technical Report)

Publisher: Walter de Gruyter GmbH

Date: 30-10-2020

DOI: 10.1515/PAC-2019-0906

Abstract: Risks of a false decision on conformity of the chemical composition of a multicomponent material or object due to measurement uncertainty are defined using the Bayesian approach. Even if the conformity assessment for each particular component of a material is successful, the total probability of a false decision (total consumer’s risk or producer’s risk) concerning the material as a whole might still be significant. This is related to the specific batch, lot, s le, environmental compartment, or other item of material or object (specific consumer’s and producer’s risks), or to a population of these items (global consumer’s and producer’s risks). A model of the total probability of such false decisions for cases of independent actual (‘true’) concentrations or contents of the components and the corresponding measurement results is formulated based on the law of total probability. It is shown that the total risk can be evaluated as a combination of the particular risks in the conformity assessment of components of the item. For a more complicated task, i.e. for a larger number of components under control, the total risk is greater. When the actual values of the components’ concentrations or contents, as well as the measurement results, are correlated, they are modelled by multivariate distributions. Then, a total global risk of a false decision on the material conformity is evaluated by the calculation of integrals of corresponding joint probability density function. A total specific risk can be evaluated as the joint posterior cumulative function of actual property values of a specific item lying outside the multivariate specification (tolerance) domain when the vector of measured values obtained for the item is inside this domain. The effect of correlation on the risk is not easily predictable. Ex les of the evaluation of risks are provided for conformity assessment of denatured alcohols, total suspended particulate matter in ambient air, a cold/flu medication, and a PtRh alloy.

Nucleic acid hybridization on an electrically reconfigurable network of gold-coated magnetic nanoparticles enables microRNA detection in blood

Publisher: Springer Science and Business Media LLC

Date: 27-08-2018

DOI: 10.1038/S41565-018-0232-X

Abstract: There is intense interest in quantifying the levels of microRNA because of its importance as a blood-borne biomarker. The challenge has been to develop methods that can monitor microRNA expression both over broad concentration ranges and in ultralow amounts directly in a patient's blood. Here, we show that, through electric-field-induced reconfiguration of a network of gold-coated magnetic nanoparticles modified by probe DNA (DNA-Au@MNPs), it is possible to create a highly sensitive sensor for direct analysis of nucleic acids in s les as complex as whole blood. The sensor is the first to be able to detect concentrations of microRNA from 10 aM to 1 nM in unprocessed blood s les. It can distinguish small variations in microRNA concentrations in blood s les of mice with growing tumours. The ultrasensitive and direct detection of microRNA using an electrically reconfigurable DNA-Au@MNPs network makes the reported device a promising tool for cancer diagnostics.

Siderophore‐Assisted Dissolution of Iron(III) Hydroxide Oxides from Iron‐Rich Fossil Matrices

Publisher: Wiley

Date: 08-2020

DOI: 10.1002/CPLU.202000407

Nitrogenase-Inspired Atomically Dispersed Fe–S–C Linkages for Improved Electrochemical Reduction of Dinitrogen to Ammonia

Publisher: American Chemical Society (ACS)

Date: 10-01-2022

DOI: 10.1021/ACSCATAL.1C05174

A chemical view of analogue drug laws in Australia: what is structural similarity?

Publisher: Informa UK Limited

Date: 29-06-2017

DOI: 10.1080/00450618.2016.1195875

IUPAC/CITAC Guide: Evaluation of risks of false decisions in conformity assessment of a substance or material with a mass balance constraint (IUPAC Technical Report)

Publisher: Walter de Gruyter GmbH

Date: 05-10-2023

DOI: 10.1515/PAC-2022-0801

Ordinal Analysis of Variation of Sensory Responses in Combination with Multinomial Ordered Logistic Regression vs. Chemical Composition: A Case Study of the Quality of a Sausage from Different Produce

Publisher: Hindawi Limited

Date: 13-12-2022

DOI: 10.1155/2022/4181460

Abstract: The newly developed statistical technique of two-way ordinal analysis of variation (ORDANOVA) was applied for the first time to sensory responses in combination with multinomial ordered logistic regression of a response category vs. chemical composition. A corresponding tutorial is provided. As a case study, s les of a sausage from different producers, purchased at the same time from a market, were compared based on sensory responses of experienced experts. A decomposition of total variation of the ordinal data and simulation of the multinomial distribution of the relative frequencies of the responses in different categories showed a statistically significant difference between the producers’ s les, and an insignificant difference between the experts’ responses related to the same s le. The capabilities of experts were also evaluated. The influence of chemical composition of a sausage s le on the probability of a response category was modeled using multinomial ordered logistic regression of the response on mass fractions of the main sausage components. This statistical technique can be helpful for understanding sources of variation of sensory responses on food quality properties. It is also promising for a revision of specification limits for chemical composition, as well as for the prediction of sensory properties when the chemical composition of the product is subject to quality control.

Chemical data evaluation: general considerations and approaches for IUPAC projects and the chemistry community (IUPAC Technical Report)

Publisher: Walter de Gruyter GmbH

Date: 21-08-2023

DOI: 10.1515/PAC-2022-0802

Abstract: The International Union of Pure and Applied Chemistry has a long tradition of supporting the compilation of chemical data and their evaluation through direct projects, nomenclature and terminology work, and partnerships with international scientific bodies, government agencies, and other organizations. The IUPAC Inter isional Subcommittee on Critical Evaluation of Data has been established to provide guidance on issues related to the evaluation of chemical data. In this first report, we define the general principles of the evaluation of scientific data and describe best practices and approaches to data evaluation in chemistry.

Oxygen solubility in austenitic Fe-Ni alloys at high temperatures

Publisher: Elsevier BV

Date: 2018

DOI: 10.1016/J.JALLCOM.2017.10.226

A rapid readout for many single plasmonic nanoparticles using dark-field microscopy and digital color analysis

Publisher: Elsevier BV

Date: 10-2018

DOI: 10.1016/J.BIOS.2018.06.066

Abstract: The integration of plasmonic nanoparticles into biosensors has the potential to increase the sensitivity and dynamic range of detection, through the use of single nanoparticle assays. The analysis of the localized surface plasmon resonance (LSPR) of plasmonic nanoparticles has allowed the limit of detection of biosensors to move towards single molecules. However, due to complex equipment or slow analysis times, these technologies have not been implemented for point-of-care detection. Herein, we demonstrate an advancement in LSPR analysis by presenting a technique, which utilizes an inexpensive CMOS-equipped digital camera and a dark-field microscope, that can analyse the λ

Vocabulary of radioanalytical methods (IUPAC Recommendations 2020)

Publisher: Walter de Gruyter GmbH

Date: 19-11-2021

DOI: 10.1515/PAC-2019-0302

Abstract: These recommendations are a vocabulary of basic radioanalytical terms which are relevant to radioanalysis, nuclear analysis and related techniques. Radioanalytical methods consider all nuclear-related techniques for the characterization of materials where ‘characterization’ refers to compositional (in terms of the identity and quantity of specified elements, nuclides, and their chemical species) and structural (in terms of location, dislocation, etc. of specified elements, nuclides, and their species) analyses, involving nuclear processes (nuclear reactions, nuclear radiations, etc. ), nuclear techniques (reactors, accelerators, radiation detectors, etc. ), and nuclear effects (hyperfine interactions, etc. ). In the present compilation, basic radioanalytical terms are included which are relevant to radioanalysis, nuclear analysis and related techniques.

Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)

Publisher: Walter de Gruyter GmbH

Date: 06-2021

DOI: 10.1515/PAC-2019-0203

Abstract: Recommendations are given concerning the terminology of concepts and methods used in spectroscopy in analytical chemistry, covering nuclear magnetic resonance spectroscopy, atomic spectroscopy, and vibrational spectroscopy.

Interlaboratory comparison of the intensity of drinking water odor and taste by two-way ordinal analysis of variation without replication

Publisher: IWA Publishing

Date: 26-05-2022

DOI: 10.2166/WH.2022.060

Abstract: A case study of ordinal data from human organoleptic examination (sensory analysis) of drinking water obtained in an interlaboratory comparison of 49 ecological laboratories is described. The recently developed two-way ordinal analysis of variation (ORDANOVA) is applied for the first time for the treatment of responses on the intensity of chlorine and sulfurous odor of water at 20 and 60 °C, which is classified into the six categories from ‘imperceptible’ to ‘very strong’. The one-way ORDANOVA is used for the analysis of the ‘salty taste’ intensity of the water. A decomposition of the total variation of the ordinal data and simulation of the multinomial distribution of the data-relative frequencies in different categories allowed the determination of the statistical significance of the difference between laboratories in classifying chlorine or sulfurous odor intensity by categories, while the effect of temperature was not significant. No statistical difference was found between laboratories on salty taste intensity. The capabilities of experts to identify different categories of the intensity of the odor and taste are also evaluated. A comparison of the results obtained with ORDANOVA and ANOVA showed that ORDANOVA is a more useful and reliable tool for understanding categorical data such as the intensity of drinking water odor and taste.

Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)

Publisher: Walter de Gruyter GmbH

Date: 11-2020

DOI: 10.1515/PAC-2019-0404

Abstract: This glossary provides a formal vocabulary of terms for concepts in surface analysis and gives clear definitions to those who utilize surface chemical analysis or need to interpret surface chemical analysis results but are not themselves surface chemists or surface spectroscopists.

Setting Multivariate and Correlated Acceptance Limits for Assessing the Conformity of Items

Publisher: Informa UK Limited

Date: 26-02-2022

DOI: 10.1080/00032719.2022.2042549

IUGS–IUPAC recommendations and status reports on the half-lives of 87Rb, 146Sm, 147Sm, 234U, 235U, and 238U (IUPAC Technical Report)

Publisher: Walter de Gruyter GmbH

Date: 09-2022

DOI: 10.1515/PAC-2021-1202

Abstract: The IUPAC–IUGS joint Task Group “Isotopes in Geosciences” (TGIG) has evaluated the published literature on the half-lives of six long-lived, geologically relevant radioactive nuclides. Where conflicting literature estimates are present, it is necessary to first identify any systematic bias in accordance with metrological traceability and to exclude the biased estimates from further consideration. The TGIG recommends three robust half-life estimates: 49.61 ± 0.16 Ga for 87 Rb, corresponding to a decay constant λ ( 87 Rb) = (1.3972 ± 0.0045) × 10 −11 a −1 106.25 ± 0.38 Ga for 147 Sm, and a corresponding decay constant λ ( 147 Sm) = (6.524 ± 0.024) × 10 −12 a −1 4.4683 ± 0.0096 Ga for 238 U, i.e . a decay constant λ ( 238 U) = (1.55125 ± 0.00333) × 10 −10 a −1 . All cited uncertainties have a coverage factor k = 2. For other radionuclides of Sm and U, no unambiguous consensus value can be endorsed at present by TGIG, which limits its evaluation to a status report highlighting unaccounted-for potential sources of bias. The improved repeatability of mass spectrometric measurements has revealed systematic bias effects that had been dismissed as subordinate in the past. These issues can only be resolved by future dedicated investigations.

Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)

Publisher: Walter de Gruyter GmbH

Date: 06-08-2021

DOI: 10.1515/PAC-2019-0819

Abstract: Recommendations are given for metrological terminology in analytical chemistry. Analytical chemistry is defined, and concepts related to laboratory practice are termed and defined. Recommendations are given concerning the terminology of quality assurance in analytical chemistry. Terms draw on the extensive quality literature, particularly from ISO.

Methods to evaluate the scavenging activity of antioxidants toward reactive oxygen and nitrogen species (IUPAC Technical Report)

Publisher: Walter de Gruyter GmbH

Date: 15-11-2021

DOI: 10.1515/PAC-2020-0902

Abstract: This project was aimed to identify the quenching chemistry of biologically important reactive oxygen and nitrogen species (ROS/RNS, including radicals), to show antioxidant action against reactive species through H‐atom and electron transfer reactions, and to evaluate the ROS/RNS scavenging activity of antioxidants with existing analytical methods while emphasizing the underlying chemical principles and advantages/disadvantages of these methods. In this report, we focused on the applications and impact of existing assays on potentiating future research and innovations to evolve better methods enabling a more comprehensive study of different aspects of antioxidants and to provide a vocabulary of terms related to antioxidants and scavengers for ROS/RNS. The main methods comprise the scavenging activity measurement of the hydroxyl radical (•OH), dioxide(•1–) (O 2 •– : commonly known as the superoxide radical), dihydrogen dioxide (H 2 O 2 : commonly known as hydrogen peroxide), hydroxidochlorine (HOCl: commonly known as hypochlorous acid), dioxidooxidonitrate(1–) (ONOO − : commonly known as the peroxynitrite anion), and the peroxyl radical (ROO•). In spite of the ersity of methods, there is currently a great need to evaluate the scavenging activity of antioxidant compounds in vivo and in vitro . In addition, there are unsatisfactory methods frequently used, such as non-selective UV measurement of H 2 O 2 scavenging, producing negative errors due to incomplete reaction of peroxide with flavonoids in the absence of transition metal ion catalysts. We also discussed the basic mechanisms of spectroscopic and electrochemical nanosensors for measuring ROS/RNS scavenging activity of antioxidants, together with leading trends and challenges and a wide range of applications. This project aids in the identification of reactive species and quantification of scavenging extents of antioxidants through various assays, makes the results comparable and more understandable, and brings a more rational basis to the evaluation of these assays and provides a critical evaluation of existing ROS/RNS scavenging assays to analytical, food chemical, and biomedical/clinical communities by emphasizing the need for developing more refined, rapid, simple, and low‐cost assays and thus opening the market for a wide range of analytical instruments, including reagent kits and sensors.

Redox Recycling Amplification Using an Interdigitated Microelectrode Array for Ionic Liquid-Based Oxygen Sensors

Publisher: American Chemical Society (ACS)

Date: 26-02-2018

DOI: 10.1021/ACS.ANALCHEM.7B04945

Abstract: A new design for a membrane-free gas sensor modified with a thin layer of ionic liquid is described. The new approach uses miniaturized interdigitated microelectrodes for detecting gases having reversible electrochemistry, for ex le, dioxygen. Analyte molecules are reduced on the first working electrode, creating an intermediate species (e.g., superoxide, O

Machine Learning Color Feature Analysis of a High Throughput Nanoparticle Conjugate Sensing Assay

Publisher: American Chemical Society (ACS)

Date: 10-04-2023

DOI: 10.1021/ACS.ANALCHEM.2C05292

Interpretation and use of standard atomic weights (IUPAC Technical Report)

Publisher: Walter de Gruyter GmbH

Date: 26-04-2021

DOI: 10.1515/PAC-2017-1002

Abstract: Many calculations for science or trade require the evaluation and propagation of measurement uncertainty. Although relative atomic masses (standard atomic weights) of elements in normal terrestrial materials and chemicals are widely used in science, the uncertainties associated with these values are not well understood. In this technical report, guidelines for the use of standard atomic weights are given. This use involves the derivation of a value and a standard uncertainty from a standard atomic weight, which is explained in accordance with the requirements of the Guide to the Expression of Uncertainty in Measurement. Both the use of standard atomic weights with the law of propagation of uncertainty and the Monte Carlo method are described. Furthermore, methods are provided for calculating uncertainties of relative molecular masses of substances and their mixtures. Methods are also outlined to compute material-specific atomic weights whose associated uncertainty may be smaller than the uncertainty associated with the standard atomic weights.

UNSW Sydney

Location: Australia

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Kings College, University Of London

Location: United Kingdom of Great Britain and Northern Ireland

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Kings College, Univeristy Of London

Location: United Kingdom of Great Britain and Northern Ireland

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Discovery Projects - Grant ID: DP110105290

Start Date: 07-2011

End Date: 03-2015

Amount: $300,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0343634

Start Date: 01-2003

End Date: 06-2006

Amount: $162,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0989946

Start Date: 04-2009

End Date: 12-2010

Amount: $357,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP130100526

Start Date: 06-2013

End Date: 05-2017

Amount: $460,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0667062

Start Date: 2006

End Date: 12-2009

Amount: $267,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0559327

Start Date: 2005

End Date: 08-2008

Amount: $195,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP140100403

Start Date: 06-2015

End Date: 12-2018

Amount: $372,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP210103892

Start Date: 2021

End Date: 12-2023

Amount: $430,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0209180

Start Date: 03-2002

End Date: 06-2005

Amount: $166,000.00

Funder: Australian Research Council

Special Research Initiatives - Grant ID: SR0354560

Start Date: 01-2004

End Date: 12-2004

Amount: $10,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0989680

Start Date: 2009

End Date: 12-2009

Amount: $300,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP150101861

Start Date: 03-2015

End Date: 12-2017

Amount: $401,300.00

Funder: Australian Research Council

Special Research Initiatives - Grant ID: SR0354804

Start Date: 2003

End Date: 12-2003

Amount: $10,000.00

Funder: Australian Research Council