A miniaturized and low-cost electrochemical 3D-printed system for rapid and accurate quantification of ethanol content in ethanol fuel using electrochemical impedance spectroscopy (EIS) was ...developed. The monolithic design of the system incorporates insulating thermoplastic electrode separators, with only the cover being mobile, allowing for easy assembly and handling. The portable device, measuring approximately 26 × 24 mm, has a maximum capacity of 1 mL, making it suitable for lab-on-a-chip and portable analysis. By utilizing the dielectric constant of ethanol and ethanol fuel mixtures with water, the miniaturized EIS cell quantifies ethanol content effectively. To validate its performance, we compared measurements from four gas stations with a digital densimeter, and the values obtained from the proposed system matched perfectly. Our miniaturized and low-cost electrochemical 3D-printed device can be printed and assembled in two hours, offering a cost-effective solution for fast and precise ethanol quantification. Its versatility, affordability, and compatibility with lab-on-a-chip platforms make it easily applicable, including for fuel quality control and on-site analysis in remote locations.
Most of the practical applications in electrocatalysis require porous electrodes, built by dispersing the nanoparticles (NPs) on a gas diffusion layer, as carbon paper (CP). The lack of correlation ...between classic measurements in clean, controlled surfaces and thin films with those of porous electrodes, used in practical application, is largely neglected. Since catalysis depends on the area available, it is clear that the distribution of the NPs on the porous material is pivotal to the efficiency of the catalyst. Here we show a low‐cost method to disperse NPs on CP assisted in ultrasonic bath. Such method improves the Pt/C NPs distribution over the CP compared to the immersion method. As proof‐of‐concept, we show an increase in output current by using Pt/C/CP for 10 mM glucose electrooxidation and O2 eletroreduction in buffered solution at 37 °C, which is ascribed to the increase in collision factor. Furthermore, the cathodic reaction is facilitated compared to electrodes prepared by immersion, yielding an unprecedented open circuit voltage of 800 mV for the coupled reaction. The glucose/oxygen reaction is also investigated in passive flow in an H‐type cell to produce power. This concept shows promising application to build any kind of porous electrodes with improved area utilization.
Plastic pollution is a worldwide problem, highlighted by the fact that plastic materials degrade into nano-size particles (<100 nm), potentially becoming more bioavailable as well as a source of ...entry of other contaminants into organisms. The present study aimed to assess the effects of polystyrene nanoplastics (PS), individually or combined with carbamazepine (Cbz), on the Mediterranean mussel, Mytilus galloprovincialis. For this purpose, mussels were exposed for 96 h to a concentration range of PS (from 0.05 up to 50 mg L−1), to Cbz (6.3 μg L−1) alone and to the mixture of PS + Cbz (0.05 mg L−1+ 6.3 μg L−1). Molecular and biochemical biomarkers were assessed in the digestive glands, gills and haemolymph. The abundance of mRNA in the digestive glands and gills revealed significant alterations in the expression of genes associated with biotransformation, DNA repair, cell stress-response and innate immunity. Combined exposure of PS + Cbz induced significant downregulation in gene expression (e.g., hsp70) when compared to individual exposure. Total oxidant status increased in digestive glands after exposure to 0.5 mg L−1 PS. Moreover, increased total antioxidant capacity and esterase activity were observed for PS 50 mg L−1, in digestive glands and gills, respectively. The PS induced effects on neurotransmission, measured as inhibition of cholinesterase activity in haemolymph. Genotoxicity was found in haemocytes after exposure to PS, Cbz and their mixture. Moreover, lipid peroxidation was observed for 0.05 mg L−1 PS exposure, showing that nanoplastics can induce oxidative damage. The present study demonstrated that PS, even at low concentrations, led to alterations on the assessed mussels' endpoints.
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•Effects of polystyrene nanoplastics (PS) were assessed at molecular and biochemical levels.•PS induced changes in the expression of biotransformation and immune related genes.•PS exposure inhibits cholinesterase activity in haemolymph.•DNA integrity decreased after exposure to PS, carbamazepine (Cbz) and PS + Cbz.•PS (0.05 mg L−1) induced lipid peroxidation (LPO) in the digestive gland.
•Fully bio-based membranes composed of bacterial cellulose (BC) and fucoidan.•Nanostructured membranes with thermal-oxidative stability in the range 180–200 °C.•Membranes with good dynamic mechanical ...performance (storage modulus ≥ 460 MPa).•BC/fucoidan proton-exchange membranes with protonic conductivity of 1.6 mS cm−1.•Conductive bio-based separators for application in polymer electrolyte fuel cells.
Conductive natural-based separators for application in polymer electrolyte fuel cells (PEFCs) were fabricated by combining a bacterial polysaccharide, i.e. bacterial cellulose (BC), and an algae sulphated polysaccharide, i.e. fucoidan (Fuc). The diffusion of fucoidan aqueous solution containing a natural-based cross-linker, viz. tannic acid, into the wet BC nanofibrous three-dimensional network, followed by thermal cross-linking, originated fully bio-based proton exchange membranes (PEMs). The PEMs present thermal-oxidative stability in the range of 180–200 °C and good dynamic mechanical performance (storage modulus ≥ 460 MPa). Additionally, the BC/Fuc membranes exhibit protonic conductivity that increases with increasing relative humidity (RH), which is a typical feature for numerous water-mediated proton conductors. The traditional Arrhenius-type plots demonstrate a linear behaviour with a maximum protonic conductivity of 1.6 mS cm−1 at 94 °C and 98 % RH. The results showed that these fully bio-based conductive membranes have potential as eco-friendly alternatives to other PEMs for application in PEFCs.
Background and Aims
The development of an efficient clonal selection process requires the study of genotype‐by‐environment (G × E) interaction. This work aims to evaluate the variability of the G × E ...interaction among genotypes and to identify the less sensitive ones.
Methods and Results
The approach involves the fitting of mixed models to yield data taking into account the correlation induced by the repeated measurements of the same plot over the years. A measure for comparative evaluation of the G × E interaction among genotypes is proposed Interaction Sensitivity (IS), based on the variance of the values of the empirical best linear unbiased predictors of G × E interaction effects across environments. In all cases studied significant G × E interaction variability was found, and the proposed measure to rank the sensitivity to G × E interaction varied widely among genotypes.
Conclusions
The existence of a common contribution shared by all observations made in the same plot was detected, independently of the lag between years. The proposed measure to rank the sensitivity to G × E interaction permitted identification of stable genotypes.
Significance of the Study
This work studied the G × E interaction problem in the context of grapevine and proposes a measure for the comparative evaluation of the G × E interaction among genotypes.
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•Methomyl caused behavioral and biometric effects in Caenorhabditis elegans.•Post-exposure period allowed the worms to reverse from paralysis.•Concentration-dependent recover in the ...biometric changes was recorded.•Acetylcholine increased, but it was not followed by damage in cholinergic neurons.
The neurotoxicity and developmental effects of a widely applied insecticide (methomyl) was investigated by a multi-level approach (behavior and biometry, biochemical alterations and neurodegeneration) in Caenorhabditis elegans upon a short-term exposure (1 h) and a post-exposure period (48 h). The 1-h exposure to sub-lethal concentrations of methomyl (lower than 0.320 g L−1; i.e. below the estimated LC10) triggered significant changes on motor behavior and development impairment. The type of movement was significantly altered in methomyl-exposed worms, as well as biometric parameters (worms frequently idle and moving more backwards than controls; small body area, length and wavelength). These effects were followed by an increase of acetylcholine levels. Interestingly, after the 48-h recovery period, movement of previously exposed worms was similar to controls, and a concentration-dependent reversion of biometric endpoints was recorded, pointing out the transient action of the carbamate in line with an apparent absence of cholinergic neurons damage. This study provided new insight on the neurotoxicity of methomyl by showing that effects on movement and development were transient, and apparently did not result in neurodegeneration in cholinergic neurons. Moreover, these findings reinforced the advantages of using C. elegans in a multi-level approach for pesticide effects assessment.
A study of the potential role of aerosols in modifying clouds and precipitation is presented using a numerical atmospheric model. Measurements of cloud condensation nuclei (CCN) and cloud size ...distribution properties taken in the southwestern Amazon region during the transition from dry to wet seasons were used as guidelines to define the microphysical parameters for the simulations. Numerical simulations were carried out using the Brazilian Development on Regional Atmospheric Modeling System, and the results presented considerable sensitivity to changes in these parameters. High CCN concentrations, typical of polluted days, were found to result in increases or decreases in total precipitation, depending on the level of pollution used as a reference, showing a complexity that parallels the aerosol‐precipitation interaction. Our results show that on the grids evaluated, higher CCN concentrations reduced low‐to‐moderate rainfall rates and increased high rainfall rates. The principal consequence of the increased pollution was a change from a warm to a cold rain process, which affected the maximum and overall mean accumulated precipitation. Under polluted conditions, cloud cover diminished, allowing greater amounts of solar radiation to reach the surface. Aerosol absorption of radiation in the lower layers of the atmosphere delayed convective evolution but produced higher maximum rainfall rates due to increased instability. In addition, the intensity of the surface sensible heat flux, as well as that of the latent heat flux, was reduced by the lower temperature difference between surface and air, producing greater energy stores at the surface.
The current uncertainty on the gluon density extracted from the global parton analysis is large in the kinematical range of small values of the Bjorken-
x
variable and low values of the hard scale
Q
...2
. An alternative to reduces this uncertainty is the analysis of the exclusive vector meson photoproduction in photon–hadron and hadron–hadron collisions. This process offers a unique opportunity to constrain the gluon density of the proton, since its cross section is proportional to the gluon density squared. In this paper we consider current parametrisations for the gluon distribution and estimate the exclusive vector meson photoproduction cross section at HERA and LHC using the leading logarithmic formalism. We perform a fit of the normalisation of the
γ
h
cross section and the value of the hard scale for the process and demonstrate that the current LHCb experimental data are better described by models that assume a slow increasing of the gluon distribution at small
x
and low
Q
2
.
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