Ultra microelectrodes increase the current density provided by electroactive biofilms by improving their electron transport ability

Electroactive biofilms were formed from garden compost leachate on platinum wires under constant polarisation at -0.2 V vs. SCE and temperature controlled at 40 C. The oxidation of 10 mM acetate gave maximum current density of 7 A/m2 with the electrodes of largest diameters (500 and 1000 µm). The smaller diameter wires exhibited an ultra-microelectrode (UME) effect, which increased the maximum current density up to 66 A/m2 with the 25 µm diameter electrode. SEM imaging showed biofilms around 75 µm thick on the 50 µm diameter wire, while they were only 25 µm thick on the 500 µm diameter electrode. Low scan cyclic voltammetry (CV) curves were similar to those already reported for biofilms formed with pure cultures of G. sulfurreducens. Concentrations of the redox molecules contained in the biofilms, which were derived from the non-turnover CVs, were around 0.4 to 0.6 mM, which was close to the value of 1 mM extracted from literature data for G. sulfurreducens biofilms. A numerical model was designed, which demonstrated that the microbial anodes were not controlled here by microbial kinetics. Introducing the concept of average electron transport length made the model well fitted with the experimental results, which indicates rate control by electron transport through the biofilm matrix. According to this model, the UME effect improved the electron transport network in the biofilm, which allowed the biofilm to grow to greater thickness

Diagnostic Assessment of Autism in Children Using Telehealth in a Global Context: a Systematic Review

Reflecting the significant delays in autism assessments globally, studies have explored whether autism assessments conducted via telehealth are feasible and accurate. This systematic review investigated the psychometric properties of autism assessment tools for children administered via telehealth and examined the diagnostic accuracy of telehealth assessment procedures compared to care-as-usual in-person assessments. Relevant databases (MEDLINE, Embase and PsycInfo) were searched for eligible studies (PROSPERO: CRD42022332500). In total, 18 studies were included, collectively assessing 1593 children for autism. Telehealth assessments for autism were largely comparable to in-person assessments, with a diagnostic agreement of 80–88.2%. Individual behavioral observation tools, diagnostic interviews, and clinician-administered screening tools demonstrated acceptable validity. For many children, diagnostic decision-making can be expedited without loss of validity using telehealth

Electrochemical genosensor for the direct detection of tailed PCR amplicons incorporating ferrocene labelled dATP

An electrochemical genosensor for the detection and quantification of Karlodinium armiger is presented. The genosensor exploits tailed primers and ferrocene labelled dATP analogue to produce PCR products that can be directly hybridised on a gold electrode array and quantitatively measured using square wave voltammetry. Tailed primers consist of a sequence specific for the target, followed by a carbon spacer and a sequence specifically designed not to bind to genomic DNA, resulting in a duplex flanked by single stranded binding primers. The incorporation of the 7-(ferrocenylethynyl)-7-deaza-2′-deoxyadenosine triphosphate was optimised in terms of a compromise between maximum PCR efficiency and the limit of detection and sensitivity attainable using electrochemical detection via hybridisation of the tailed, ferrocene labelled PCR product. A limit of detection of 277aM with a linear range from 315aM to 10 fM starting DNA concentration and a sensitivity of 122 nA decade−1 was achieved. The system was successfully applied to the detection of genomic DNA in real seawater samples.info:eu-repo/semantics/acceptedVersio

Colorimetric DNA-based assay for the specific detection and quantification of Ostreopsis cf. ovata and Ostreopsis cf. siamensis in the marine environment

Ostreopsis is a toxic benthic dinoflagellate largely distributed worldwide in tropical and temperate areas. In the Mediterranean Sea, periodic summer blooms have been reported and have become a serious concern due to their direct impact on human health and the environment. Current microalgae identification is performed via light microscopy, which is time-consuming and is not able to differentiate among Ostreopsis species. Therefore, there is mature need for rapid, specific and easy-to-use detection tools. In this work, a colorimetric assay exploiting a combination of recombinase polymerase amplification (RPA) and a sandwich hybridisation assay was developed for O. cf. ovata and O. cf. siamensis detection and quantification. The specificity of the system was demonstrated by cross-reactivity experiments and calibration curves were successfully constructed using genomic DNA, achieving limits of detection of 10 and 14 pg/μL for O. cf. ovata and O. cf. siamensis, respectively. The assay was applied to the analysis of planktonic and benthic environmental samples from different sites of the Catalan coast. Species-specific DNA quantifications were in agreement with qPCR analysis, demonstrating the reliability of the colorimetric approach. Significant correlations were also obtained between DNA quantifications and light microscopy counts. The approach may be a valuable tool to provide timely warnings, facilitate monitoring activities or study population dynamics, and paves the way towards the development of in situ tools for the monitoring of harmful algal blooms.info:eu-repo/semantics/acceptedVersio