SARS-CoV-2 Aptasensors Based on Electrochemical Impedance Spectroscopy and Low-Cost Gold Electrode Substrates.

SARS-CoV-2 diagnostic practices broadly involve either quantitative polymerase chain reaction (qPCR)-based nucleic amplification of viral sequences or antigen-based tests such as lateral flow assays (LFAs). Reverse transcriptase-qPCR can detect viral RNA and is the gold standard for sensitivity. However, the technique is time-consuming and requires expensive laboratory infrastructure and trained staff. LFAs are lower in cost and near real time, and because they are antigen-based, they have the potential to provide a more accurate indication of a disease state. However, LFAs are reported to have low real-world sensitivity and in most cases are only qualitative. Here, an antigen-based electrochemical aptamer sensor is presented, which has the potential to address some of these shortfalls. An aptamer, raised to the SARS-CoV-2 spike protein, was immobilized on a low-cost gold-coated polyester substrate adapted from the blood glucose testing industry. Clinically relevant detection levels for SARS-CoV-2 are achieved in a simple, label-free measurement format using sample incubation times as short as 15 min on nasopharyngeal swab samples. This assay can readily be optimized for mass manufacture and is compatible with a low-cost meter.

ConcrEITS: An Electrical Impedance Interrogator for Concrete Damage Detection Using Self-Sensing Repairs.

Concrete infrastructure requires continuous monitoring to ensure any new damage or repair failures are detected promptly. A cost-effective combination of monitoring and maintenance would be highly beneficial in the rehabilitation of existing infrastructure. Alkali-activated materials have been used as concrete repairs and as sensing elements for temperature, moisture, and chlorides. However, damage detection using self-sensing repairs has yet to be demonstrated, and commercial interrogation solutions are expensive. Here, we present the design of a low-cost tomographic impedance interrogator, denoted the "ConcrEITS", capable of crack detection and location in concrete using conductive repair patches. Results show that for pure material blocks ConcrEITS is capable of measuring 4-probe impedance with a root mean square error of ±5.4% when compared to a commercially available device. For tomographic measurements, ConcrEITS is able to detect and locate cracks in patches adhered to small concrete beam samples undergoing 4-point bending. In all six samples tested, crack locations were clearly identified by the contour images gained from tomographic reconstruction. Overall, this system shows promise as a cost-effective combined solution for monitoring and maintenance of concrete infrastructure. We believe further up-scaled testing should follow this research before implementing the technology in a field trial.

Patient-reported outcomes in cancer survivors: a population-wide cross-sectional study.

PURPOSE: There is a lack of robust population-based data regarding the lived experience of cancer survivors. This study assessed the quality of life (QoL) of survivors of breast, colorectal, or prostate cancer, non-Hodgkin lymphoma or melanoma 1, 3 and 5 years post-diagnosis. Associations between various demographic and disease-related factors and QoL were assessed. METHODS: A cross-sectional postal survey was undertaken. Eligible participants were identified from a population-based cancer registry. Patient-reported outcomes including QoL, symptom issues and information needs were collected using validated questionnaires. RESULTS: Difficulties with all QoL domains were more prevalent amongst cancer survivors compared with the general population, particularly difficulties with usual activities (28 vs 15%) and anxiety or depression (35 vs 22%). Symptoms such as trouble sleeping, always feeling tired, trouble concentrating and fear of cancer recurrence persisted up to 5 years post-diagnosis. Factors associated with reduced QoL included having another long-standing health condition, cancer not responding fully to treatment, not having or not being certain of having a written care plan and being female. CONCLUSIONS: Cancer survivors experience inferior QoL and cancer-related symptoms for years following diagnosis. These results support further investigation into factors that contribute to poorer survivor outcomes and enhanced identification and intervention strategies for those requiring additional support.

Catalyst design in oxidation chemistry; from KMnO4 to artificial metalloenzymes.

Oxidation reactions are an important part of the synthetic organic chemist's toolkit and continued advancements have, in many cases, resulted in high yields and selectivities. This review aims to give an overview of the current state-of-the-art in oxygenation reactions using both chemical and enzymatic processes, the design principles applied to date and a possible future in the direction of hybrid catalysts combining the best of chemical and natural design.

Towards direct detection of tetracycline residues in milk with a gold nanostructured electrode.

Tetracycline antibiotics are used extensively in veterinary medicine, but the majority of the administrated dose is eliminated unmodified from the animal through various excretion routes including urine, faeces and milk. In dairy animals, limits on residues secreted in milk are strictly controlled by legislation. Tetracyclines (TCs) have metal chelation properties and form strong complexes with iron ions under acidic conditions. In this study, we exploit this property as a strategy for low cost, rapid electrochemical detection of TC residues. TC-Fe(III) complexes in a ratio of 2:1 were created in acidic conditions (pH 2.0) and electrochemically measured on plasma-treated gold electrodes modified with electrodeposited gold nanostructures. DPV measurements showed a reduction peak for the TC-Fe(III) complex that was observed at 50 mV (vs. Ag/AgCl QRE). The limit of detection in buffer media was calculated to be 345 nM and was responsive to increasing TC concentrations up to 2 mM, added to 1 mM FeCl3. Whole milk samples were processed to remove proteins and then spiked with tetracycline and Fe(III) to explore the specificity and sensitivity in a complex matrix with minimal sample preparation, under these conditions the LoD was 931 nM. These results demonstrate a route towards an easy-to-use sensor system for identification of TC in milk samples taking advantage of the metal chelating properties of this antibiotic class.

Measuring for primary prevention: An online survey of local community perspectives on family and domestic violence in regional Australia.

BACKGROUND: Family and domestic violence, encompassing diverse behaviours including physical, sexual, emotional and financial abuse, is endemic worldwide and has multiple adverse health and social consequences. Principal drivers include traditional gender values that disempower women. Changing these is a key prevention strategy. In Australia, high-quality national surveys provide data on public perspectives concerning family and domestic violence but may not capture community-level diversity. As part of a project for primary prevention family and domestic violence in outer regional Australia, our aims were to develop and administer a questionnaire-based survey suitable for the local community encompassing knowledge about, attitudes towards, and personal experiences of family and domestic violence, to describe and to investigate the theoretical (factor) structure and local socio-demographic predictors of responses, and to determine the extent to which the survey findings are locally distinctive. METHODS: The online community survey for local residents (≥15 years), comprised items on respondents' sociodemographic characteristics plus questions abridged from pre-existing national instruments on knowledge about, attitudes towards, and personal experiences of family and domestic violence. Responses were rake-weighted to correct census-ascertained sample imbalance and investigated using exploratory factor analysis, with sociodemographic predictors determined using multiple linear regression and dominance analysis. RESULTS: Among 914 respondents, males (27.0%), those from age-group extremes, and less-educated persons were underrepresented. Familiarity with diverse family and domestic violence behaviours was high among all subgroups. Poorer knowledge of the FDV behaviour continuum and attitudes supporting traditional gender roles and FDV were disproportionately evident among males, older respondents and those with lower education levels. Both the factor structure of extracted composite measures reflecting community perspectives and sociodemographic predictors of responses generally aligned with patterns evident in national data. CONCLUSIONS: Local reinforcement of existing nationwide findings on community understanding of and attitudes towards family and domestic violence provides salience for targeted interventions.

Disparities in potentially avoidable emergency department (ED) care: ED visits for ambulatory care sensitive conditions.

INTRODUCTION: Hospital care for ambulatory care sensitive conditions (ACSC) is potentially avoidable and often viewed as an indicator of suboptimal primary care. However, potentially preventable encounters with the health care system also occur in emergency department (ED) settings. We examined ED visits to identify subpopulations with disproportionate use of EDs for ACSC care. METHODS: We analyzed data from the 2007-2009 National Hospital Ambulatory Medical Care Survey for 78,114 ED visits by adults aged 18 and older. Outcomes were ACSC visits determined from the primary ED diagnosis. We constructed analytic groups aligned with Agency for Healthcare Research and Quality's priority populations. Multivariate logistic regression was used to estimate the odds of all-cause, acute, and chronic ACSC visits. We used Stata SE survey techniques to account for the complex survey design. RESULTS: Overall, 8.4% of ED visits were for ACSC, representing over 8 million potentially avoidable ED visits annually. ACSC visits were more likely to result in hospitalization than non-ACSC visits (34.4% vs. 14.0%, P<0.001). Multivariate models revealed significant disparities in ACSC visits to the ED by race/ethnicity, insurance status, age group, and socioeconomic status, although patterns differed for acute and chronic ACSC. CONCLUSIONS: Disproportionately higher use of EDs for ACSC care exists for many priority populations and across a broader range of priority populations than previously documented. These differences constitute disparities in potentially avoidable ED visits for ACSC. To avoid exacerbating disparities, health policy efforts to minimize economic inefficiencies in health care delivery by limiting ED visits for ACSC should first address their determinants.

Emerging Electrochemical Sensors for Real-Time Detection of Tetracyclines in Milk.

Antimicrobial drug residues in food are strictly controlled and monitored by national laws in most territories. Tetracyclines are a major broad-spectrum antibiotic class, active against a wide range of Gram-positive and Gram-negative bacteria, and they are the leading choice for the treatment of many conditions in veterinary medicine in recent years. In dairy farms, milk from cows being treated with antibiotic drugs, such as tetracyclines, is considered unfit for human consumption. Contamination of the farm bulk tank with milk containing these residues presents a threat to confidence of supply and results in financial losses to farmers and dairy. Real-time monitoring of milk production for antimicrobial residues could reduce this risk and help to minimise the release of residues into the environment where they can cause reservoirs of antimicrobial resistance. In this article, we review the existing literature for the detection of tetracyclines in cow's milk. Firstly, the complex nature of the milk matrix is described, and the test strategies in commercial use are outlined. Following this, emerging biosensors in the low-cost biosensors field are contrasted against each other, focusing upon electrochemical biosensors. Existing commercial tests that identify antimicrobial residues within milk are largely limited to beta-lactam detection, or non-specific detection of microbial inhibition, with tests specific to tetracycline residues less prevalent. Herein, we review a number of emerging electrochemical biosensor detection strategies for tetracyclines, which have the potential to close this gap and address the industry challenges associated with existing tests.

An electrochemical SARS-CoV-2 biosensor inspired by glucose test strip manufacturing processes.

Accurate and rapid diagnostic tests are critical to reducing the impact of SARS-CoV-2. This study presents early, but promising measurements of SARS-CoV-2 using the ACE2 enzyme as the recognition element to achieve clinically relevant detection. The test provides a scalable route to sensitive, specific, rapid and low cost mass testing.

Toward a Closed Loop, Integrated Biocompatible Biopolymer Wound Dressing Patch for Detection and Prevention of Chronic Wound Infections.

Chronic wound infections represent a significant burden to healthcare providers globally. Often, chronic wound healing is impeded by the presence of infection within the wound or wound bed. This can result in an increased healing time, healthcare cost and poor patient outcomes. Thus, there is a need for dressings that help the wound heal, in combination with early detection of wound infections to support prompt treatment. In this study, we demonstrate a novel, biocompatible wound dressing material, based on Polyhydroxyalkanoates, doped with graphene platelets, which can be used as an electrochemical sensing substrate for the detection of a common wound pathogen, Pseudomonas aeruginosa. Through the detection of the redox active secondary metabolite, pyocyanin, we demonstrate that a dressing can be produced that will detect the presence of pyocyanin across clinically relevant concentrations. Furthermore, we show that this sensor can be used to identify the presence of pyocyanin in a culture of P. aeruginosa. Overall, the sensor substrate presented in this paper represents the first step toward a new dressing with the capacity to promote wound healing, detect the presence of infection and release antimicrobial drugs, on demand, to optimized healing.

The role of causal criteria in causal inferences: Bradford Hill's "aspects of association".

As noted by Wesley Salmon and many others, causal concepts are ubiquitous in every branch of theoretical science, in the practical disciplines and in everyday life. In the theoretical and practical sciences especially, people often base claims about causal relations on applications of statistical methods to data. However, the source and type of data place important constraints on the choice of statistical methods as well as on the warrant attributed to the causal claims based on the use of such methods. For example, much of the data used by people interested in making causal claims come from non-experimental, observational studies in which random allocations to treatment and control groups are not present. Thus, one of the most important problems in the social and health sciences concerns making justified causal inferences using non-experimental, observational data. In this paper, I examine one method of justifying such inferences that is especially widespread in epidemiology and the health sciences generally - the use of causal criteria. I argue that while the use of causal criteria is not appropriate for either deductive or inductive inferences, they do have an important role to play in inferences to the best explanation. As such, causal criteria, exemplified by what Bradford Hill referred to as "aspects of [statistical] associations", have an indispensible part to play in the goal of making justified causal claims.

Development of a needle shaped microelectrode for electrochemical detection of the sepsis biomarker interleukin-6 (IL-6) in real time.

This paper outlines a simple label-free sensor system for the sensitive, real time measurement of an important protein biomarker of sepsis, using a novel microelectrode integrated onto a needle shaped substrate. Sepsis is a life threatening condition with a high mortality rate, which is characterised by dysregulation of the immune response following infection, leading to organ failure and cardiovascular collapse if untreated. Currently, sepsis testing is typically carried out by taking blood samples which are sent to a central laboratory for processing. Analysis times can be between 12 and 72 h making it notoriously difficult to diagnose and treat patients in a timely manner. The pathobiology of sepsis is becoming increasingly well understood and clinically relevant biomarkers are emerging, which could be used in conjunction with a biosensor to support real time diagnosis of sepsis. In this context, microelectrodes have the analytical advantages of reduced iR drop, enhanced signal to noise ratio, simplified quantification and the ability to measure in hydrodynamic situations, such as the bloodstream. In this study, arrays of eight (r = 25 µm) microelectrodes were fabricated onto needle shaped silicon substrates and electrochemically characterised in order to confirm successful sensor production and to verify whether the observed behaviour agreed with established theory. After this, the electrodes were functionalised with an antibody for interleukin-6 (IL-6) which is a protein involved in the immune response to infection and whose levels in the blood increase during progression of sepsis. The results show that IL-6 is detectable at physiologically relevant levels (pg/mL) with incubation times as short as 2.5 min. Electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) measurements were taken and DPV was concluded to be the more suitable form of measurement. In contrast to the accepted view for macro electrodes that the impedance increases upon antigen bind, we report herein a decrease in the micro electrode impedance upon binding. The small size of the fabricated devices and their needle shape make them ideal for either point of care testing or insertion into blood vessels for continuous sepsis monitoring.

Virtual exclusion and telework: barriers and opportunities of technocentric workplace accommodation policy.

Teleworking, a restructuring of the manner in which work occurs, based on information communication technologies (ICTs), is a promising way of further integrating people with disabilities into the workplace. In contrast to telecommuting, in which the work is primarily shifted in locale, telework is a restructuring of the tasks to be accomplished within the larger work setting which could result in "work" being done remotely, or collaboratively with coworkers (remotely or not) using ICTs. Drawing upon a review of the literature, this paper explores the relationship between telework and people with disabilities. While the advent of telecommuting and subsequently "teleworking" might open increased opportunities for the hiring of people with disabilities, it may also place severe constraints on the type of work, workplace environment and interactions, and accumulation of social capital for people with disabilities. Whereas much of the prevailing literature on telework and disability is often proscriptive in nature and is written with an audience of employers in mind, it is just as important to consider policy options from the standpoint of the employee as well. This paper proposes a number of policy approaches for the creation of an inclusive work environment for teleworkers with disabilities that can minimize, as much as possible, the social isolation faced by teleworkers with disabilities while maximizing their participation within the workplace community. Policy objectives for enhancing telework for people with disabilities fall into three general categories: 1) research, 2) outreach, and 3) interventions.

Pseudomonas aeruginosa can be detected in a polymicrobial competition model using impedance spectroscopy with a novel biosensor.

Electrochemical Impedance Spectroscopy (EIS) is a powerful technique that can be used to elicit information about an electrode interface. In this article, we highlight six principal processes by which the presence of microorganisms can affect impedance and show how one of these--the production of electroactive metabolites--changes the impedance signature of culture media containing Pseudomonas aeruginosa. EIS, was used in conjunction with a low cost screen printed carbon sensor to detect the presence of P. aeruginosa when grown in isolation or as part of a polymicrobial infection with Staphylococcus aureus. By comparing the electrode to a starting measurement, we were able to identify an impedance signature characteristic of P. aeruginosa. Furthermore, we are able to show that one of the changes in the impedance signature is due to pyocyanin and associated phenazine compounds. The findings of this study indicate that it might be possible to develop a low cost sensor for the detection of P. aeruginosa in important point of care diagnostic applications. In particular, we suggest that a development of the device described here could be used in a polymicrobial clinical sample such as sputum from a CF patient to detect P. aeruginosa.

Development of a diagnostic device to detect different Pseudomonas aeruginosa phenotypes in medically relevant contexts.

Pseudomonas aeruginosa, widely present in the environment, is well known for its ability to cause infection in immune compromised individuals. For example, P. aeruginosa is the leading cause of morbidity and mortality in patients with cystic fibrosis (CF). Here, we describe how Electrochemical Impedance Spectroscopy (EIS) can be used to detect the presence of four different strains of P. aeruginosa. Using a low cost, screen printed carbon electrode significant changes can be seen in impedance data in the presence of P. aeruginosa after 24 hours. Furthermore, through the use of a normalization technique whereby the phase angle of the impedance (a commonly used parameter) is divided by a starting measurement, it is possible to identify differences between a non-mucoid and mucoid strain of P. aeruginosa. Sensors based upon the techniques described here could be used in a number of healthcare scenarios, where there is a need for low cost, real time detection of P. aeruginosa, such as CF.

Disabilities and impairments: strategies for workplace integration.

This article argues that disabilities are, within many of the U.S. debates, best understood as certain kinds of impairment affecting a person's capabilities to perform socially defined roles and functions within specific environments. We also argue that it is not the impairments per se that lead to claims about what we ought to do or ought not do for people with disabilities. Rather, it is only within the context of capabilities being linked to the concept of freedom--almost universally valued in the current U.S. socio-political environment--that disability issues take on an ethical tenor. Additionally, we link the notion of disability to that of social capital. In particular, we argue that any social organization that discriminates against people with disabilities by attenuating their opportunities within that environment also decreases the social cohesion that exists within that organization. Such corporate climates promote organizational structures and processes that fail to optimize facilitation of the mutual benefits of the members. Finally, we discuss three different kinds of accommodation strategy: assistive technologies, systemic personal change, and universal design. We suggest a case-based (casuistic) approach to problems caused by disabilities. Using methods from both philosophy and public policy, we then build policies for accommodations incrementally, based on an application of those methods to the cases, and resulting in a more nuanced process enabling the creation of policies that take account of the experiences of both disabled and non-disabled people.