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In this commentary, we respond to Burnette et al.'s (2021) paper, which gives significant practical recommendations to improve data quality and validity while gathering data via Amazon's Mechanical Turk (MTurk). We argue that it is also important to acknowledge and review the specific ethical issues that might arise when recruiting MTurk workers as participants. We particularly raise three main ethical concerns that need to be addressed when recruiting research participants from participant recruitment platforms: participants' economic vulnerability, participants' sensitivity, and power dynamics between participants and researchers. We elaborate on these issues by discussing the ways in which they may appear and be responded to. We conclude that considering the ethical aspects of data collection and the potential impacts of data collection on those involved would complement Burnette et al.'s recommendations. Consequently, data collection processes should be transparent as well, in addition to data screening processes.
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Colaboración de las Masas , Colaboración de las Masas/normas , Recolección de Datos/normas , HumanosRESUMEN
Electronic graft copolymers with conjugated polymer backbones are emerging as promising materials for various organic electronics. These materials combine the advantages of organic electronic materials, such as molecular tunability of opto-electronic and electrochemical properties, with solution processability and other 'designer' physical and mechanical properties imparted through the addition of grafted polymer side chains. Future development of such materials with complex molecular architecture requires a better understanding of the effect of molecular parameters, such as side chain length, on the structure and, in turn, on the electronic properties. In this study, poly(thiophene)-graft-poly(acrylate urethane) (PTh-g-PAU) was examined as a model system and we investigate the effect of side chain length on the overall shape and size in solution. Furthermore, the changes in the swelling behaviour of the graft copolymer thin films help in understanding their electrochemical redox properties.
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Conducting polymer (CP)-based electrochemical biosensors have gained great attention as such biosensor platforms are easy and cost-effective to fabricate, and provide a direct electrical readout for the presence of biological analytes with high sensitivity and selectivity. CP materials themselves are both sensing elements and transducers of the biological recognition event at the same time, simplifying sensor designs. This review summarizes the advances in electrochemical biosensors based on CPs. Recognition probe immobilisation techniques, transduction mechanisms and detection of various target biomolecules have been discussed in detail. Efforts to miniaturize CP-based electrochemical biosensors and fabrication of sensor arrays are also briefly reviewed.
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Técnicas Biosensibles , Técnicas Electroquímicas , Polímeros/química , Espectroscopía Dieléctrica , Electrodos , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Glucosa/análisis , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/metabolismo , Inmunoglobulina G/química , Inmunoglobulina G/inmunología , Miniaturización , Proteínas/análisis , Proteínas/inmunologíaRESUMEN
Oligonucleotide hybridization to a complementary sequence that is covalently attached to an electrochemically active conducting polymer (ECP) coating the working electrode of an electrochemical cell causes an increase in reaction impedance for the ferro-ferricyanide redox couple. We demonstrate the use of this effect to measure, in real time, the progress of DNA polymerase chain reaction (PCR) amplification of a minor component of a DNA extract. The forward primer is attached to the ECP. The solution contains other PCR components and the redox couple. Each cycle of amplification gives an easily measurable impedance increase. Target concentration can be estimated by cycle count to reach a threshold impedance. As proof of principle, we demonstrate an electrochemical real-time quantitative PCR (e-PCR) measurement in the total DNA extracted from chicken blood of an 844 base pair region of the mitochondrial Cytochrome c oxidase gene, present at â¼1 ppm of total DNA. We show that the detection and semiquantitation of as few as 2 copies/µL of target can be achieved within less than 10 PCR cycles.
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ADN/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Cartilla de ADN/genética , Electroquímica , Ferricianuros/química , Oxidación-Reducción , TemperaturaRESUMEN
Described herein is a new printing method-direct writing of conducting polymers (CPs)-based on pipette-tip localized continuous electrochemical growth. A single barrel micropipette containing a metal wire (Pt) is filled with a mixture of monomer, supporting electrolyte, and an appropriate solvent. A droplet at the tip of the pipette contacts the substrate, which becomes the working electrode of a micro-electrochemical cell confined to the tip droplet and the pipette. The metallic wire in the pipette acts as both counter and reference electrode. Electropolymerization forms the CP on the working electrode in a pattern controlled by the movement of the pipette. In this study, various width poly(pyrrole) 2D and 3D structures are extruded and characterized in terms of microcyclic voltammetry, Raman spectroscopy, and scanning electron microscopy.
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Polímeros/química , Electrodos , Microscopía Electrónica de Rastreo , Platino (Metal)/química , Pirroles/químicaRESUMEN
Research and teaching conditions have, particularly for those who are junior or from disadvantaged backgrounds, deteriorated considerably over the years in the higher education sector. Unequal opportunities in access and advancement in careers have led to increasing levels of precarity in the higher education sector. Although the concept of precarity has been grasped in many other disciplines, the social-psychological understanding of this concept remains unexplored. In this paper, we aim to develop a social-psychological understanding of precarity to examine how identity dynamics and intergroup relations, as well as associated organizational controls, reinforce inequality regimes and power structures that create precarious conditions in academia. In doing so, we use social identity theory and system justification theory under an inequality regime framework. We argue that even though change towards equality and equity in academia should be possible, it is difficult to achieve this because of entrenched identity interests by power holders and the perceived legitimacy of the existing system. Therefore, academic precarity should be recognized both as a subjective experience and as an organizational practice to make inequalities more visible and decrease the perceptions of legitimacy-and to eventually achieve a fundamental positive transformation in academia.
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Educación , Identificación Social , Humanos , Diversidad, Equidad e InclusiónRESUMEN
In recent years, the scientific community has called for improvements in the credibility, robustness and reproducibility of research, characterized by increased interest and promotion of open and transparent research practices. While progress has been positive, there is a lack of consideration about how this approach can be embedded into undergraduate and postgraduate research training. Specifically, a critical overview of the literature which investigates how integrating open and reproducible science may influence student outcomes is needed. In this paper, we provide the first critical review of literature surrounding the integration of open and reproducible scholarship into teaching and learning and its associated outcomes in students. Our review highlighted how embedding open and reproducible scholarship appears to be associated with (i) students' scientific literacies (i.e. students' understanding of open research, consumption of science and the development of transferable skills); (ii) student engagement (i.e. motivation and engagement with learning, collaboration and engagement in open research) and (iii) students' attitudes towards science (i.e. trust in science and confidence in research findings). However, our review also identified a need for more robust and rigorous methods within pedagogical research, including more interventional and experimental evaluations of teaching practice. We discuss implications for teaching and learning scholarship.
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The study of moral judgements often centres on moral dilemmas in which options consistent with deontological perspectives (that is, emphasizing rules, individual rights and duties) are in conflict with options consistent with utilitarian judgements (that is, following the greater good based on consequences). Greene et al. (2009) showed that psychological and situational factors (for example, the intent of the agent or the presence of physical contact between the agent and the victim) can play an important role in moral dilemma judgements (for example, the trolley problem). Our knowledge is limited concerning both the universality of these effects outside the United States and the impact of culture on the situational and psychological factors affecting moral judgements. Thus, we empirically tested the universality of the effects of intent and personal force on moral dilemma judgements by replicating the experiments of Greene et al. in 45 countries from all inhabited continents. We found that personal force and its interaction with intention exert influence on moral judgements in the US and Western cultural clusters, replicating and expanding the original findings. Moreover, the personal force effect was present in all cultural clusters, suggesting it is culturally universal. The evidence for the cultural universality of the interaction effect was inconclusive in the Eastern and Southern cultural clusters (depending on exclusion criteria). We found no strong association between collectivism/individualism and moral dilemma judgements.
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Juicio , Principios Morales , Humanos , Individualidad , Intención , ConocimientoRESUMEN
Although the bystander intervention model provides a useful account of how people help others, no previous study has applied it to a global emergency. This research aims to develop a scale for measuring global bystander intervention and investigate its potential antecedents in the Syrian refugee emergency. In Study 1 (N = 80) and Study 2 (N = 205), a 12-item scale was established through a substantive-validity assessment and a confirmatory factor analysis, respectively. Study 3 (N = 601) explored the potential antecedents of the global bystander intervention, employing British and German samples. Results show that the global bystander intervention model worked for both samples, but there were significant between-group differences in terms of the extent to which they notice the emergency, know how to help, show political support, and donate money. Overall, the visibility of the global emergency aftermaths within the context has been deduced as a meaningful driver for between-group differences. This research provides the first empirical evidence on global bystander intervention and it offers timely suggestions to promote support for refugees or other victims of global disasters, especially among those who are distant to the disaster zone.
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Refugiados , Humanos , Proyectos de InvestigaciónRESUMEN
The dominant belief is that science progresses by testing theories and moving towards theoretical consensus. While it's implicitly assumed that psychology operates in this manner, critical discussions claim that the field suffers from a lack of cumulative theory. To examine this paradox, we analysed research published in Psychological Science from 2009-2019 (N = 2,225). We found mention of 359 theories in-text, most were referred to only once. Only 53.66% of all manuscripts included the word theory, and only 15.33% explicitly claimed to test predictions derived from theories. We interpret this to suggest that the majority of research published in this flagship journal is not driven by theory, nor can it be contributing to cumulative theory building. These data provide insight into the kinds of research psychologists are conducting and raises questions about the role of theory in the psychological sciences.
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Modelos Psicológicos , Teoría Psicológica , HumanosRESUMEN
Polypyrrole (PPy) based electroactive materials are important building blocks for the development of flexible electronics, bio-sensors and actuator devices. As the properties and behavior of PPy depends strongly on the operating environment-electrolyte, solvent, etc., it is desirable to plant immobile ionic species into PPy films to ensure stable response. A premade ionic polymer is not optimal in many cases, as it enforces its own structure on the conducting polymer, therefore, polymerization during fabrication is preferred. Pyrrole (Py) was electropolymerized at low temperature together with a polymerizable ionic liquid (PIL) monomer in a one-step polymerization, to form a stable film on the working electrode. The structure and morphology of the PPyPIL films were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy and solid-state NMR (ssNMR) spectroscopy. The spectroscopy results confirmed the successful polymerization of Py to PPy and PIL monomer to PIL. The presence of (TFSI-) anions that balance the charge in PPyPIL was confirmed by EDX analysis. The electrical properties of PPyPIL in lithium bis(trifluoromethanesulfonyl)-imide (LiTFSI) aqueous and propylene carbonate solutions were examined with cyclic voltammetry (CV), chronoamperometry, and chronopotentiometry. The blend of PPyPIL had mixed electronic/ionic conductive properties that were strongly influenced by the solvent. In aqueous electrolyte, the electrical conductivity was 30 times lower and the diffusion coefficient 1.5 times higher than in the organic electrolyte. Importantly, the capacity, current density, and charge density were found to stay consistent, independent of the choice of solvent.
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Herein, we present that insect odorant receptors reconstituted into the lipid bilayers of liposomes can be successfully immobilized onto a gold surface and selectively and sensitively detect odorant molecules. The odorant receptors (OrXs) Or10a, Or22a, and Or71a from the common fruit fly, Drosophila melanogaster, were recombinantly expressed, purified and integrated into nano-liposomes (100-200â¯nm). These liposomes were covalently attached to the self-assembled monolayers (SAMs) of a 6-mercaptohexanoic acid (MHA)-modified gold surface. X-ray Photo Electron Spectroscopy (XPS) and Quartz Crystal Microbalance with Dissipation (QCM-D) measurements confirmed the successful modification of the gold surface and immobilization of liposomes. Atomic Force Microscopy (AFM) revealed that the liposomes were covalently attached to the surface without any disruption of vesicles. The liposomes tethered to the gold sensor surface were then treated with a range of known ligands of various concentrations. We demonstrated by Electrochemical Impedance Spectroscopy (EIS) that an OrX/liposome EIS sensor can sensitively and selectively detect its known ligand to femtomolar concentrations by detecting a change in electrical signal upon binding. Our study is the first step towards using purified insect odorant receptors alone in biosensors to enable the development of novel ultrasensitive volatile sensors for medical diagnostic, air quality, food safety and border security applications.
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Técnicas Biosensibles , Proteínas de Drosophila/química , Odorantes/análisis , Receptores Odorantes/química , Animales , Espectroscopía Dieléctrica , Drosophila melanogaster/química , Liposomas/química , Microscopía de Fuerza Atómica , Tecnicas de Microbalanza del Cristal de Cuarzo , Propiedades de SuperficieRESUMEN
Direct writing is an effective and versatile technique for three-dimensional (3D) fabrication of conducting polymer (CP) structures. It is precisely localized and highly controllable, thus providing great opportunities for incorporating CPs into microelectronic array devices. Herein we demonstrate 3D writing and characterization of poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT:PSS) pillars in an array format, by using an in-house-constructed variant of scanning ion conductance microscopy (SICM). CP pillars with different aspect ratios were successfully fabricated by optimizing the writing parameters: pulling speed, pulling time, concentration of the polymer solution, and the micropipette tip diameter. Especially, super high aspect ratio pillars of around 7 µm in diameter and 5000 µm in height were fabricated, indicating a good capability of this direct writing technique. Additions of an organic solvent and a cross-linking agent contribute to a significantly enhanced water stability of the pillars, critical if the arrays were to be used in biologically relevant applications. Surface morphologies and structural analysis of CP pillars were characterized by scanning electron microscopy and Raman spectroscopy, respectively. Electrochemical properties of the individual pillars of different heights were examined by cyclic voltammetry using a double-barrel micropipette as an electrochemical cell. Exceptional mechanical properties of the pillars, such as high flexibility and robustness, were observed when bent by applying a force. The 3D pillar arrays are expected to provide versatile substrates for functionalized and integrated biological sensing and electrically addressable array devices.
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A highly selective, label-free sensor for the non-Hodgkin lymphoma gene, with an aM detection limit, utilizing electrochemical impedance spectroscopy (EIS) is presented. The sensor consists of a conducting electrospun fibre mat, surface-grafted with poly(acrylic acid) (PAA) brushes and a conducting polymer sensing element with covalently attached oligonucleotide probes. The sensor was fabricated from electrospun NBR rubber, embedded with poly(3,4-ethylenedioxythiophene) (PEDOT), followed by grafting poly(acrylic acid) brushes and then electrochemically polymerizing a conducting polymer monomer with ssDNA probe sequence pre-attached. The resulting non-Hodgkin lymphoma gene sensor showed a detection limit of 1aM (1 × 10-18mol/L), more than 400 folds lower compared to a thin-film analogue. The sensor presented extraordinary selectivity, with only 1%, 2.7% and 4.6% of the signal recorded for the fully non-complimentary, T-A and G-C base mismatch oligonucleotide sequences, respectively. We suggest that such greatly enhanced selectivity is due to the presence of negatively charged carboxylic acid moieties from PAA grafts that electrostatically repel the non-complementary and mismatch DNA sequences, overcoming the non-specific binding.
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Resinas Acrílicas/química , Técnicas Biosensibles/métodos , Compuestos Bicíclicos Heterocíclicos con Puentes/química , ADN/análisis , Linfoma no Hodgkin/genética , Polímeros/química , Disparidad de Par Base , ADN/genética , Humanos , Linfoma no Hodgkin/diagnóstico , Polielectrolitos , PorosidadRESUMEN
Insect Odorant receptors (OrXs) can be used as the recognition element in a biosensor as they demonstrate high levels of sensitivity and selectivity towards volatile organic compounds. Herein, we describe a method to express and purify insect odorant receptors and reconstitute them into artificial lipid bilayers (liposomes). These OrX/liposomes were covalently attached to a gold surface and characterized using quartz crystal microbalance with dissipation monitoring (QCM-D). The interaction of OrX/liposomes immobilized on a gold surface to positive and negative odorants were studied by means of electrochemical impedance spectroscopy (EIS) and QCM-D. The data presented in this article are related to the research article titled "An ultrasensitive electrochemical impedance-based biosensor using insect odorant receptors to detect odorants" [1].
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We present a versatile and facile procedure for the immobilisation of bioprobe molecules to an electrochemical sensing element. We eliminate lengthy preparation procedures for direct functionalisation of electrode surfaces by pre-attaching probe molecules to carboxylic acid bearing termonomers of pyrrole phenylenes or thiophene phenylenes. We demonstrate that these conjugates can be electrodeposited at low potentials to form nano-scale porous, electroactive conducting polymer films, exposing the bioprobe and retaining activity and specificity for binding, exemplified here with DNA sensors. The electrochemical reaction impedance for Fe(CN)63-/4- on oligonucleotide-modified electrodes showed remarkable (down to aM) detection sensitivity for target DNA sequences present in solution. Cross-sensitivity to non-complementary target sequences is small and multi-target arrays are easily made. There is no need for labelling of either probe or target oligonucleotide.
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Técnicas Biosensibles/métodos , ADN/análisis , Técnicas Electroquímicas/métodos , Sondas de Oligonucleótidos/química , Pirroles/química , Tiofenos/química , Ácidos Carboxílicos/química , Electrodos , Galvanoplastia/métodosRESUMEN
This paper reports on the creation of a low-cost, disposable sensor for low flow velocities, constructed from extruded micro-sized 'hair' of conducting polymer PEDOT. These microstructures are inspired by hair strands found in many arthropods and chordates, which play a prime role in sensing air flows. The paper describes the fabrication techniques and the initial prototype testing results toward employing this sensing mechanism in applications requiring sensing of low flow rates such as a flow sensor in neonatal resuscitators. The fabricated 1000 µm long, 6 µm diameter micro-hairs mimic the bending movement of tactile hair strands to sense the velocity of air flow. The prototype sensor developed is a four-level direct digital-output sensor and is capable of detecting flow velocities of up to 0.97 m s(-1).