Experimental and theoretical investigations of the adhesion time of Penicillium spores to cedar wood surface

In this study, the adhesion of 4 Penicillium strains (Penicillium granulatum, Penicillium crustosum, Penicillium commune and Penicillium chrysogenum) on cedar wood was examined qualitatively and quantitatively by using the extended DLVO (XDLVO) approach and the environmental scanning electronic microscopy (ESEM) technique. A comparison between the XDLVO theories and the ESEM technique was also investigated. The adhesion tests revealed that P. chrysogenum was not able to adhere on the cedar wood substrata, as predicted by the XDLVO approach. We have also found by ESEM that the three Penicillium strains (P. granulatum, P. crustosum, P. commune) adhered on wood, as not predicted theoretically.Moreover, the time of adhesion (3 h and 24 h) was used not only to compare the capacity of adhesion according to contact time but also to explain the discrepancies between the XDLVO approach prediction and the adhesion experiments. A positive relationship between the XDLVO approach and adhesion experiments has been observed after 3 h of adhesion. In contrast, a contradiction between the XDLVO predictions and the adhesion test results has been noted after 24 h of adhesion of Penicillium strains to the wood surface.     

Intramyocardial Inflammation after COVID-19 Vaccination: An Endomyocardial Biopsy-Proven Case Series

Myocarditis in response to COVID-19 vaccination has been reported since early 2021. In particular, young male individuals have been identified to exhibit an increased risk of myocardial inflammation following the administration of mRNA-based vaccines. Even though the first epidemiological analyses and numerous case reports investigated potential relationships, endomyocardial biopsy (EMB)-proven cases are limited. Here, we present a comprehensive histopathological analysis of EMBs from 15 patients with reduced ejection fraction (LVEF = 30 (14–39)%) and the clinical suspicion of myocarditis following vaccination with Comirnaty^® (Pfizer-BioNTech) (n = 11), Vaxzevria^® (AstraZenica) (n = 2) and Janssen^® (Johnson & Johnson) (n = 2). Immunohistochemical EMB analyses reveal myocardial inflammation in 14 of 15 patients, with the histopathological diagnosis of active myocarditis according the Dallas criteria (n = 2), severe giant cell myocarditis (n = 2) and inflammatory cardiomyopathy (n = 10). Importantly, infectious causes have been excluded in all patients. The SARS-CoV-2 spike protein has been detected sparsely on cardiomyocytes of nine patients, and differential analysis of inflammatory markers such as CD4⁺ and CD8⁺ T cells suggests that the inflammatory response triggered by the vaccine may be of autoimmunological origin. Although a definitive causal relationship between COVID-19 vaccination and the occurrence of myocardial inflammation cannot be demonstrated in this study, data suggest a temporal connection. The expression of SARS-CoV-2 spike protein within the heart and the dominance of CD4⁺ lymphocytic infiltrates indicate an autoimmunological response to the vaccination.     

A technical and economical assessment of hydrogen production potential from solar energy in Morocco

In this study, a techno-economic analysis of the capacity of Morocco to produce hydrogen from solar energy has been conducted. For this reason, a Photovoltaic-electrolyze system was selected and the electricity and hydrogen production were simulated for 76 sites scattered all over the country. The Global Horizontal Irradiation (GHI) data used for the simulation were extracted from the CAMS-Rad satellite database and meteorological stations at ground level.Before simulations, the accuracy of the GHI values from the satellite dataset has been checked, and their uncertainties was calculated against accurate data measured in-situ. After that, the simulated values of the hydrogen mass were interpolated using a GIS software to create a Hydrogen production map of Morocco. Finally, an economical investigation of electricity and hydrogen production costs has been conducted by calculating the $LCOE$ and $LC{O}_{H_2}$.Results show that the satellite dataset has a mean average deviation of 6.8% which is a very acceptable error rang. Also, it was found that Morocco have a high potential for hydrogen production, with a daily annual production that varies between 6489 and 8308 Tons/km². Moreover, the cost of electricity and hydrogen production in the country are in the range of 0.077–0.099 $/kWh and 5.79–4.64 $/Kg respectively.The findings of this study are with high importance as they provide an overall perspective of the country potential of hydrogen production for policy makers and investors, and it was motivated by the lack of information on the subject in the literature since it's, at the best of our knowledge, the first study assessing the hydrogen production from solar for the whole country.     

Untethered Feel-Through Haptics Using 18-µm Thick Dielectric Elastomer Actuators

Head-mounted displays for virtual reality (VR) and augmented reality (AR) allow users to see highly realistic virtual worlds. The wearable haptics that enable feeling and touching these virtual objects are typically bulky, tethered, and provide only low fidelity feedback. A particularly challenging type of wearable human-machine interface is feel-through haptics: ultra-thin wearables so soft as to be mechanically imperceptible when turned off, yet generating sufficient force when actuated to make virtual objects feel tangible, or to change the perceived texture of a physical object. Here, 18 µm thick soft dielectric elastomer actuators (DEA), directly applied on the skin, reports rich vibrotactile feedback generation from 1 Hz to 500 Hz. Users correctly identifies different frequency and sequence patterns with success rates from 73 to 97% for devices applied on their fingertips. An untethered version weighing only 1.3 grams allowed blindfolded users to correctly identify letters by “seeing” them through their fingers. The silicone-based DEA membrane is mechanically transparent, enabling wearable haptics for the many applications where hand dexterity is critical. The feel-through DEA can be placed in array format anywhere on the body.     

The Anti-Adherent Activity of Plant Extracts on Penicillium Commune Spores Causing Cedar Wood Decay: An ESEM Analysis

Decay and deterioration of wood by bacteria and fungi are becoming very serious problems because of the resistance of microorganisms to antimicrobial agents. Thus, this study was aimed at investigating the anti-adhesion effect of Myrtus communis and Thymus vulgaris extracts obtained by classical and ultrasonic extraction, against of Penicillium commune spores isolated from fez Medina cedar wood. According to environmental scanning electron microscopy (ESEM) analysis, the results showed that all extracts tested have proven their ability to inhibit the adhesion of the fungal spores studied. In addition, the extract of each plant obtained by ultrasonication showed a low percentage (47% and 33%) of fungal spores adherent to a wood substrate compared to those recovered by maceration (68%). Furthermore, M. communis extracts have shown outstanding anti-adhesive activity, similar to that demonstrated by those of T. vulgaris. Finally, the treatment of wood by M. communis extracts obtained by ultrasonication showed a very important anti-adhesive activity at a concentration of 20 mg/mL compared to that at 5 mg/mL. Therefore, these extracts can be considered a potential source of bioactive metabolites acting as anti-adhesion molecules in novel formulations for the cedar wood preservation.     

Correlation between cell surface physicochemical properties of bacterial strains and their chromium removal potential

Physicochemical characterization of microbes has gained recently a great interest by scientific community. It is proved of extreme importance in several fields of science and technology applications such as bioremediation. In this work, we investigated the establishment of a possible correlation between chromium removal capacity of seven bacterial strains isolated from contaminated sites with industrial wastes including tanning processing and their cell surface physicochemical properties. Thus, hydrophobicity and donor/acceptor electrons character were obtained using contact angle measurements. Statistical analysis showed a high significant positive correlation between hexavalent chromium (Cr(VI)) removal by the strains and their acceptor electron character γ⁺(r = 0.90). While significant negative correlation between the Cr(VI) removal potential and the ΔGiwi value (r = ?0.844) and also with their donor electron character γ^? (r = ?0.746) were observed. These results may contribute to determine a selectrion criteria of bacteria that can be operated in bioremediation applications.     

Impact of enzymatic treatment on wood surface free energy: contact angle analysis

The aim of this study was to investigate the effect of cellulase treatment on wood surface physicochemical characteristics. The cedar wood samples were treated by cellulase for 30 min at different concentrations: 0.2, 0.4, 0.6, 0.8, 1, and 1.2 mg/ml. Then the physicochemical properties (the wetting behavior and interfacial free energy) of the cedar samples surfaces were characterized by the sessile drop technique. The obtained results showed that the untreated cedar wood samples exhibited a hydrophobic character with a high water contact angle (θ_w = 71.9°) and a negative value of the interfacial free energy (?Giwi = ?59.3 mJ/m²). Thereafter, the wood hydrophobicity decreased continuously until it reached the hydrophilicity qualitatively (at the first concentration of cellulase (0.2 mg/ml)) and quantitatively (at 0.8 mg/ml of cellulase). The cedar wood surface treatment with cellulase also revealed a significant evolution of the acid-base parameters. Moreover, a linear relationship between the degree of hydrophobicity and the cellulase concentration has been found. This study clearly shows the impact that could have the produced enzyme by micro-organisms involved in wood biodegradation and especially their consequences on the physicochemical surface properties of the wooden materials.