Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography

Hot tears can arise during the late part of alloy solidification because of the shrinkage of isolated liquid as it turns to solid and may have a catastrophic effect on cast tensile properties. Although there are correlations to suggest alloy hot tear sensitivity to casting conditions, they do not capture the influence of microstructure on tearing, such as second-phase particles or intermetallic compounds (IMCs) commonly present in engineering alloys. We use in situ X-ray radiography to quantify the formation and growth behaviour of hot tears in Al-5Cu and Al-5Cu-1Fe alloys during solidification. An automated hot tear detection, tracking and merging algorithm is developed and applied to reveal the role of Fe-rich IMC particles, typical of recycled alloys, on hot tear behaviour. These defects are termed hot tears here on the basis of their complex, extended inter-connected morphology, distinct from more rounded shrinkage porosity. We also visualise and quantify the velocity of interdendritic flow driven by solidification shrinkage, and estimate the pressure changes due to shrinkage. Hot tearing starts at lower solid fraction when IMCs are present due to reduced interdendritic flow, and hot tear formation is more spatially homogeneous, less clustered and more numerous. We show that the largest, most damaging hot tears form from many merging events, that is enhanced by the presence of IMCs

Covid-19 vaccines in children with cow’s milk and food allergies

The COVID-19 pandemic is the most challenging global health crisis of our times. Vaccination against COVID-19 plays a key role to control the current pandemic situation. The risk of allergic reactions to new COVID-19 vaccines is low. However, there is a debate on the safety in allergic patients following post marketing findings by different agencies. Our aim is to understand from current experiences whether children with cow’s milk or food allergy are at higher risk than a general population for allergic reactions to COVID-19 vaccines. Current data indicate that patients with a history of allergy to cow’s milk or other foods, even if severe, should receive COVID-19 vaccine in a setting with availability of treatments for anaphylactic reactions and under medical supervision. Recipients should be discharged after a protracted observation period of 30 min if no reaction developed

Antibiosis of actinomycetes from Paullina cupana var. sorbilis (mart.) Ducke against fungi pathogenic.

Guarana (Paullinia cupana var. Sorbilis (Mart.) Ducke) is a native species of economic and social importance in Brazil serving the domestic and international demands. This culture is attacked by Colletotrichum guaranicola Albuq. and Fusarium decencellulare Brick, causal agents of anthracnose and overbudding, respectively. Actinomycetes are bacteria that may produce secondary metabolites with antibacterial and antifungal potential. The isolation of endophytic with antibiosis agaist pathogenic fungi is the first step in biological control and bioprospecting antimicrobial compounds programs

Resistante to mercury of endophytic bacteria obtained in contaminated sites.

Strategies for remediation of soils contaminated with mercury (Hg) are important and necessary. Several bacterial species interfere with biogeochemical cycle of mercury and are potential tools in bioremediation and/or phytoremediation programs. These bacteria are resistant to mercury and the main mechanism of resistance is mediated by proteins codificated by operon mer. This study aims to determine the level of resistance to mercury of endophytic bacteria and detect the presence of merA gene

Isolation of endophytic fungi in environments with and without traces of mercury contamination, Pantanal of Mato Grosso.

The mining activity in Mato Grosso is an economic source for many cities, especially in Poconé, where this activity is responsible for significant change in the landscape and the contamination of the ecosystem by mercury. This results in serious damage to biota enhanced by bioaccumulation capacity. Mercury is toxic to all organisms, however, some microorganisms have innate or acquired tolerance to metal. Therefore, our hypothesis is based on the premise that plants in contaminated environments with mercury harbor a specific community of endophytic fungi, therefore, variations in the colonization frequency of the endophytes in these plants are expected, when compared to places without contamination

Capacity resistance of endophytic fungi the mercury.

Contamination of biological systems by mercury represents a global concern, given the difficulty of degradation, persistence and potential toxicity of this metal in the environment. Remediation strategies of soils contaminated with mercury are required and the use of microorganisms as bioremediation agents is fully justified, in particular, the various mechanisms of tolerance to heavy metals allocated to them, particularly for fungi arising from various chemical processes, such as transformation valence, intra and extracellular precipitation and oxidation. Our hypothesis is that endophytic fungi isolated from areas contaminated by mercury present higher resistance to this metal

Endophytic bacterium isolated of hosts present in contaminated areas by mercury in Pantanal mato-grossense.

The mercury is a contaminant in gold mining in the city of Poconé. This heavy metal is a toxic in different organisms and affect the human by bioaccumulation process causing a serie of cronic diseases. Mercury can be easily absorbed by plants and be accumulated in the human body through the food chain. The hypothesis is microorganism that is in association with plants, that survive in contaminated areas with mercury, provide greater resistance to contaminant and possibly an increased frequency of colonization. In this way, the aim of this study was to isolate endophytic bacterium that exhibit resistance to mercury

Microbiol diversity in rhizosphere resistant and susceptible guarana collected in Maués and Manaus.

The rhizosphere is the soil region subject to influence of exudates released by plants and microorganisms (epiphytic and endophytic). In addition, this region has large variety of bacteria that can contribute to plant growth and/or inhibiting the activity of plant pathogens. The culture of guarana (Paullinia cupana var. Sorbilis (Mart.) Ducke) is threatened by the presence of the fungus Colletotrichum guaranicola Albuq. and Fusarium decencellulare Brick, causal agents of anthracnose and overbudding, respectively. In this work, the metabolic diversity of rhizospheric bacteria was studied in resistant (R) and susceptible (S) clones collected in Manaus (Mn) and Maués (Mu)

Evaluating the newly developed BioFire COVID-19 test for SARS-CoV-2 molecular detection

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