Clostridium difficile is a major cause of antibiotic-associated colitis and is associated with significant morbidity and mortality. Glutamine (Gln) is a major fuel for the intestinal cell population. Alanyl-glutamine (Ala-Gln) is a dipeptide that is highly soluble and well tolerated. IEC-6 cells were used in the in vitro experiments. Cell morphology was evaluated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Cell proliferation was assessed by WST-1 and Ki-67 and apoptosis was assessed by TUNEL. Cytoskeleton was evaluated by immunofluorescence for RhoA and F-actin. RhoA was quantified by immunoblotting. TcdA induced cell shrinkage as observed by AFM, SEM, and fluorescent microscopy. Additionally, collapse of the F-actin cytoskeleton was demonstrated by immunofluorescence. TcdA decreased cell volume and area and increased cell height by 79%, 66.2%, and 58.9%, respectively. Following TcdA treatment, Ala-Gln and Gln supplementation, significantly increased RhoA by 65.5% and 89.7%, respectively at 24 h. Ala-Gln supplementation increased cell proliferation by 137.5% at 24 h and decreased cell apoptosis by 61.4% at 24 h following TcdA treatment. In conclusion, TcdA altered intestinal cell morphology and cytoskeleton organization, decreased cell proliferation, and increased cell apoptosis. Ala-Gln and Gln supplementation reduced intestinal epithelial cell damage and increased RhoA expression.

PurposeThis paper seeks to report a preliminary study that was conducted in order to investigate the corrosion behavior of aluminum surfaces in aqueous solution in the presence of microorganisms. For this purpose, the fungus Aspergillus niger was tested in chloride‐containing aqueous media.Design/methodology/approachWeight loss and pH measurements were performed to verify the activity of the fungus on the aluminum surface and the atomic force microscopy technique was used to examine the surface after removing the biological film.FindingsThe pH of the media depended on the immersion time. Pitting attack was observed on the surface. The findings confirmed that the corrosion reaction of the aluminum was catalyzed by the presence of fungus and, simultaneously, the mean roughness of the aluminum surface was altered. After removing the biofilm, fungal hyphae hallmark was evident.Originality/valueUp until low, relatively few studies have addressed biofilm attack on materials, and especially attack on metallic surfaces in media contaminated by fungi. Hence, this paper is important for its contribution to the body of knowledge about biofilm action on metallic surfaces.

The appearance of dark sunspots over the solar photosphere is not considered to be symmetric between the northern and southern hemispheres. Among the different conclusions obtained by several authors, we can point out that the North-South asymmetry is a real and systematic phenomenon and is not due to random variability. In the present work, we selected the sunspot area data of a sample of 13 solar cycles divided by hemisphere extracted from the Marshall Space Flight Centre (MSFC) database to investigate the behavior of probability distributions using an out-of-equilibrium statistical model a.k.a nonextensive statistical mechanics. Based on this statistical framework, we obtained that the non-extensive entropic parameter q has a semi-sinusoidal variation with a period of ∼22 year (Hale cycle). Among the most important results, we can highlight that the asymmetry index q(A) revealed the dominance of the northern hemisphere against the southern one. Thus, we concluded that the parameter q(A) can be considered an effective measure for diagnosing long-term variations

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