Microbiological,immunological, and histological changes in the gut of Salmonella Enteritidis-challenged rats fed goat cheese containing Lactobacillus rhamnosus EM1107

Cheeses are able to serve as suitable matrices for supplying probiotics to consumers, enabling appropriate conditions for bacteria to survive gastric transit and reach the gut, where they are assumed to promote beneficial processes. The present study aimed to evaluate the microbiological, immunological, and histological changes in the gut of Salmonella Enteritidis-challenged rats fed goat cheese supplemented with the probiotic strain Lactobacillus rhamnosus EM1107. Thirty male albino Wistar rats were randomly distributed into 5 experimental groups with 6 animals each: negative (NC) and positive (PtC) control groups, control goat cheese (CCh), goat cheese added with L. rhamnosus EM1107 (LrCh), and L. rhamnosus EM1107 only (EM1107). All animals, except NC group were challenged with Salmonella Enteritidis (10⁹ cfu in 1 mL of saline through oral gavage). Microbial composition was assessed with high-throughput 16S rRNA sequencing by means of Illumina MiSeq (Illumina, San Diego, CA). Nuclear factor kappa B (NF-κB) from the animal cecum tissue was determined by real-time PCR and interleukins (TNF-α, IL-1β, IL-10, and IFN-γ) by means of ELISA. Myeloperoxidase and malondialdehyde levels were determined biochemically. The administration of the L. rhamnosus EM1107 probiotic strain, either as a pure culture or added to a cheese matrix, was able to reduce Salmonella colonization in the intestinal lumen and lessen tissue damage compared with rats from PtC group. In addition, the use of cheese for the probiotic strain delivery (LrCh) was associated with a marked shift in the gut microbiota composition toward the increase of beneficial organisms such as Blautia and Lactobacillus and a reduction in NF-κB expression. These findings support our hypothesis that cheeses might be explored as functional matrices for the efficacious delivery of probiotic strains to consumers.     

Multivariate Analysis of the Stability of Spray-Dried Eupenicillium javanicum Peptidases

Peptidases occupy a central position in the enzyme market because of their importance in many areas, such as for physiological processes, foods, and detergents, as well as in the pharmaceutical, leather, and biotechnology industries. Microbial production is among the major sources of peptidases because it presents many advantages when compared with other methods. In this study, the metallopeptidases produced by the fungus Eupenicillium javanicum under a solid-state fermentation bioprocess were spray-dried. The enzymatic extract was dried using drying adjuvants, and optimal conditions for preserving enzymatic activity were studied following a Box-Behnken experimental design. The spray process factors studied were the air-drying temperature, enzyme feed flow rate, and the proportion of enzyme/additive. The responses analyzed were the dry extract yield and enzymatic activity after spray drying. Additionally, the stability of the dry extracts was assessed during 180 days at 4°C and 25°C. The results revealed extract yields of up to 66.12% and good enzymatic activity for intermediate values of temperature and adjuvant proportions. Furthermore, the dried enzymatic extracts showed potential for future commercial applications because of their stability at 25°C for 180 days.     

A new sheep model with automatized analysis of biomaterial-induced bone tissue regeneration

Presently, several bone graft substitutes are being developed or already available for clinical use. However, the limited number of clinical and in vivo trials for direct comparison between these products may complicate this choice. One of the main reasons for this scarcity it is the use of models that do not readily allow the direct comparison of multiple bone graft substitutes, due especially to the small number of implantation sites. Although sheep cancellous bone models are now well established for these purposes, the limited availability of cancellous bone makes it difficult to find multiple comparable sites within a same animal. These limitations can be overcome by the monocortical model here proposed as it consists in 5–6 holes (5 mm Ø), in the femoral diaphysis, with similar bone structure, overlying soft tissue and loading pattern for all defects. Associated to this model, it is also described a fast histomorphometric analysis method using a computer image segmentation test (Threshold method) to assess bone regeneration parameters. The information compiled through the experimental use of 45 sheep in several studies allowed determining that this ovine model has the potential to demonstrate differences in bone-forming performance between various scaffolds. Additionally, the described histomorphometric method is fast, accurate and reproducible.     

Troubleshooting in geoelectrical prospecting using real‐coded genetic algorithm with chromosomal extrapolation

This work presents a genetic operator developed from mathematical methods of curve extrapolation applied in solving problems in geoelectrical prospection. This operator will assist the production of fitter individuals in the population of a genetic algorithm in which inherent patterns of the best individuals of each generation are recognized. The proposed operator in conjunction with a real‐coded genetic algorithm is compared to five alternative optimization techniques known and used in the application to problems in geoelectrical prospection. Copyright © 2014 John Wiley & Sons, Ltd.     

Sustained release of potassium diclofenac from a pH‐responsive hydrogel based on gum arabic conjugates into simulated intestinal fluid

This work describes the preparation, the swelling properties and the potassium diclofenac (KDF) release profile of hydrogels of gum arabic (GA), N′,N′‐dimethylacrylamide, and methacrylic acid. In order to convert GA into a hydrogel, the polysaccharide was vinyl‐modified with glycidyl methacrylate. The hydrogels showed pH‐responsive swelling changes, which were more expressive in the basic environment. Release data of KDF were adjusted to a diffusion‐based kinetic model that provides an important insight on affinity of the drug for hydrogel and solvent, which may be the leading parameter for release of guest molecules from polymers. The KDF release from the hydrogels into simulated intestinal fluid decreases when the amount of modified GA increases. This was demonstrated to be due to the higher affinity of KDF for GA‐richer hydrogel, which makes the anti‐inflammatory release less favorable. The analysis of released drug half‐time (t_1/2 = 16.10 and 21.51 h) indicated sustained release characteristics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43319.     

Application of titanium machining chips in welding consumables for wear-resistant hardfacing

Equipment of sugar cane plants and mineral extraction are submitted to severe abrasive wear conditions. Welded hardfacings are usually applied to repair this kind of damage, where commercial chromium/carbon-rich welding consumables have usually been employed. In the present work we investigated the microstructure of experimental hardfacings made by addition of residues (chips) collected from the machining of ASTM F67 (unalloyed Ti, grade 4) alloy. Mixtures with different carbide-formers (Cr/Nb ferro-alloys) were also tested. Two layers of ‘pure’ chips (Ti), chips plus Fe–Cr (Ti–Cr), and chips plus Fe–Nb (Ti–Nb) were applied on low-carbon steel specimens by the GTAW/TIG process. The microstructure of hardfacing layers was observed by optical and scanning electron microscopy (SEM) equipped with EDS microanalysis. The microstructural characterization has determined that carbide distributions change significantly with the chemical nature of the hardfacing. SEM observations coupled with EDS microanalysis have confirmed the formation of complex carbides within the metal weld, whose stoichiometry was determined by X-ray diffraction (XRD) analysis. Mixed carbides of MC type and some cementite have been found. As a result it was suggested that use of ASTM F67 chips as carbide formers for composition of welding consumables can contribute to improved wear resistance of hardfacings, if compared with traditional chromium-based hardfacings.