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Mateusz Wierzbicki,1 Magdalena Kot,2 Agata Lange,1 Aleksandra Kalińska,2 Marcin Gołębiewski,2 Sławomir Jaworski1 1Department of Nanobiotechnology, Warsaw University of Life Sciences, Warsaw, 02-786, Poland; 2Animal Breeding Department, Warsaw University of Life Sciences, Warsaw, 02-786, PolandCorrespondence: Sławomir Jaworski, Department of Nanobiotechnology, Warsaw University of Life Sciences, Ciszewskiego 8 street, Warsaw, 02-786, Poland, Email slawomir_jaworski@sggw.edu.plPurpose: Mastitis in dairy cows is a worldwide problem faced by dairy producers. Treatment mainly involves antibiotic therapy, however, due to widespread antibiotic resistance among bacteria, such treatments are no longer effective. For this reason, scientists are searching for new solutions to combat mastitis, which is caused by bacteria, fungi, and algae. One of the most promising solutions, nanotechnology, is attracting research due to its biocidal properties. The purpose of this research was to determine the biocidal properties of nanocomposites as a potential alternative to antibiotics in the control of mastitis, as well as to determine whether the use of nanoparticles and what concentration is safe for the breeder and the animal.Patients and Methods: In this study, the effects of Ag, Au, Cu, Fe, and Pt nanoparticles and their complexes were evaluated in relation to the survival of bacteria and fungi isolated from cattle diagnosed with mastitis, their physicochemical properties, and their toxicity to bovine and human mammary epithelial cells BME-UV1 and HMEC (human microvascular endothelial cells). Moreover, E. coli, S. aureus, C. albicans, and Prototheca sp. invasion was assessed using the alginate bead (bioprinted) model. The NPs were tested at concentrations of 25, 12.5, 6.25, 3.125, 1.56 mg/l for Au, Ag, Cu and Fe NPs, and 10, 5, 2.5, 1.25, 0.625 mg/l for Pt.Results: With the exception of Fe and Pt, all exhibited biocidal properties against isolates, while the AgCu complex had the best effect. In addition, nanoparticles showed synergistic effects, while the low concentrations had no toxic effect on BME-UV1 and HMEC cells.Conclusion: Synergistic effects of nanoparticles and no toxicity to bovine and human cells might, in the future, be an effective alternative in the fight against microorganisms responsible for mastitis, and the implementation of research results in practice would reduce the percentage of dairy cows suffering from mastitis. The problem of increasing antibiotic resistance is posing a global threat to human’s and animal’s health, and requires comprehensive research to evaluate the potential use of nanoparticles – especially their complexes – as well as to determine whether nanoparticles are safe for the breeders and the animals. The conducted series of studies allows further consideration of the use of the obtained results in practice, creating a potentially new alternative to antibiotics in the treatment and prevention of mastitis in dairy cattle.Keywords: cattle, mastitis, bacteria, fungi, nanocomposites

This paper presents the results of the optimization of electrophoretic deposition parameters for manufacturing of nc-TiO2/chitosan composite coatings on X2CrNiMo17-12-2 steel as well as characterization of their microstructure, electrochemical properties and adhesion to the substrate. The parameters of the deposition, such as composition, pH and zeta potential of suspensions as well as voltage and process time were investigated. The microstructure of the coatings was characterized using scanning and transmission electron microscopy. Obtained coatings were crack-free and uniform. The adhesion strength to the substrate was measured by scratch-test method. The deposited coatings improve corrosion resistance of steel, what was confirmed by the results of the potentiodynamic polarization test in Ringer’s solution.

Porous hydroxyapatite doped SiO2 coatings were electrophoretically deposited (EPD) on commercially pure titanium. The influence of EPD parameters on coatings quality was investigated. Microstructural observation was done using transmission and scanning electron microscopy as well as X-ray diffractometry.

In this study, chitosan coatings were electrophoretically deposited (EPD) on near-β Ti-13Nb-13Zr alloy. The influence of colloidal solution composition and EPD parameters on the quality of chitosan coatings was investigated. It was established that the uniformity of as-deposited chitosan coatings is highly dependent on the chemical composition of the solution used for EPD, the pH, electrophoretic mobility and zeta potential of chitosan colloidal molecules, as well as EPD parameters, such as potential difference value and deposition time. The microstructure of the coatings was investigated using electron microscopy and X-ray diffractometry. The coatings 350 nm thick were homogeneous and exhibited an amorphous structure. The coatings had low hardness and Young’s modulus. The effect of surface of the substrate preparation prior to coating deposition on the adhesion of chitosan coatings to the Ti-13Nb-13Zr alloy was also investigated. The coatings exhibited good adhesion to the non-acid-etched surface of the titanium alloy.

The paper presents the deformation and fracture analysis of coating-substrate systems during spherical indentation. CrN and TiN ceramic coatings with a thickness of 1-5 μm were tested using 10 to 200 μm tip radius spherical indenters. The typical results of indentation tests i.e. force-penetration depth curves were transformed into stress-strain curves using an algorithm developed by the author. The test results are compared with the results of numerical analysis conducted using FEM modelling. Such a complex analysis allows users to determine the level of tensile stress leading to the formation of cracks observed using SEM and TEM microscopy, and to define the failure maps for the coating substrate-systems.

Achieving fast and strong adhesion to jawbone is essential for dental implants. Thin deposited films may improve osseointegration, but they are prone to cohesive and adhesive fracture due to high stresses while screwing the implant into the bone, leading to bared, less osteoconductive substrate surfaces and nano- and micro-particles in the bone. Aim of this work is the investigation of the cohesion and adhesion failure stresses of osteoconductive tantalum, titanium, silicon, zirconium and aluminium oxide and diamond-like carbon films. The tribological behaviour under dry and lubricated conditions (Ringer solution) reveals best results for diamond-like carbon, while cohesion and adhesion of zirconium oxide films is highest.

Goal of this work is the investigation of roughness influences on the abrasive wear behaviour of magnetron sputtered multi-layered, low-friction coatings on carbon-fibre reinforced polymers (CFRP). Higher coating roughness at similar CFRP quality was realized by higher deposition rates, leading to increased heat flux to the substrates during deposition. Thermal expansion of the epoxy matrix on the micro scale results in a wavy, wrinkled surface topography. Both in scratch and reciprocal sliding testing against alumina, the friction coefficients are lower for the smooth coatings, but their wear rate is higher due to low-cycle fatigue caused abrasion.

Homogeneous and heterogeneous reactions are significant because many chemically reactive systems, such as biochemical systems, involve both types of reactions. This paper sheds light on the effects of homogeneous–heterogeneous reactions on magnetohydrodynamic blood flow through the catheterized multi-irregular vertically stenosed artery in non-Darcy porous media. The governing partial differential equations are simplified using mild stenosis approximations and then transformed into the computational domain to simplify the numerical calculations. It has been noticed that the fluid velocity and the flow rate go to their maximum values after a short time, and they decrease with fluctuation in the case of pulsating, but in the case of nonpulsatile, the behavior is steady. Moreover, an increase in the homogeneous heat reaction parameter decelerates the blood velocity, the flow rate and elevates the fluid temperature. Furthermore, the concentration reaches the steady state faster in the absence of a homogeneous thermal reaction. [ABSTRACT FROM AUTHOR]

The nutrition of modern dairy cows is a crucial factor affecting milk yield, its parameters and production economics. Nutritional supplementation is often necessary to ensure that cows receive all the required proteins in their diet. The aim of the study was to analyse the impact of fluidised dried yeast (Saccharomyces cerevisiae) on daily milk yield, milk yield for all lactation stages, and udder condition. Milk samples were collected before the experiment, during a 4-week period of yeast supplementation, and 4 weeks after the experiment to analyse changes in milk composition and yield. The results demonstrated a significant positive effect (P < 0.01) on daily milk yield at all stages of lactation, as well as improved udder condition, as evidenced by lower somatic cell counts in milk. Therefore, the results have confirmed that fluidised dried yeast can be a valuable component of the diet for high-yielding dairy cows. However, further analyses are necessary to determine the long-term influence of yeast supplementation on milk production and the overall health of cows. [ABSTRACT FROM AUTHOR]