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Three green algae, collected from the Romanian Black Sea coast, are studied: Ulva lactuca, Enteromorpha intestinalis, and Cladophora vagabunda, which were collected from six different coastal areas. This paper aims to identify the bioactive compounds of these green algae and their beneficial properties, in order to use them as potential nutraceuticals using different analytical methods. Pharmacognostic, microbiological, and physico-chemical methods used for the analysis of algal materials revealed a rich and diverse array of biocompounds with nutritional value. In the case of green algae, a high percentage of sulphates, carbohydrates and dietary fibers were identified. Moisture, ash, total nitrogen, protein and lipid contents were determined. The contents of pigments, vitamins, and metals determined complement the nutritional qualities of the three seaweed species studied as future nutraceuticals. The content of flavonoid and phenolic compounds identified in the composition of seaweeds justifies their antioxidant and antimicrobial properties. The antioxidant capacity was tested by means of DPPH, reducing power, and TEAC methods, and the algae studied exhibit important antioxidant properties that can be used to enhance their potential as nutraceuticals. The studied algae show good antibacterial activity on both Gram (+) and Gram (−) bacteria, with slightly better activity on Gram (−) bacteria. Biocompounds from green algae from the Black Sea coast may represent an important source of marine nutraceuticals with medical and nutritional potential. [ABSTRACT FROM AUTHOR]

Nanoporous TiO2 film is deposited on grade 5 Ti6Al4V implant alloy by electrochemical oxidation. The nanopores of the film, as highlighted by electron microscopy, have a mean diameter of 58.6 nm, which is measured and calculated from an average value of 10 measurements. The increase in oxygen concentration compared to the untreated alloy, which indicates the oxidation of the titanium alloy surface, is visualized using X-ray spectroscopy coupled to an electron microscope. The beneficial effect of the oxidation and controlled formation of the TiO2 film on the implant alloy is proven by the comparative evaluation of degradation over time through the corrosion of both the untreated alloy and the alloy with an electrochemically formed and controlled TiO2 film in Hank's solution, which simulates the most corrosive biological fluid, blood. The results show that the electrochemical modification of the grade 5 titanium alloy to form a nanoporous TiO2 surface film using the electrochemical oxidation method confirms the potential of improving the anticorrosive properties of titanium alloys used in implant applications. [ABSTRACT FROM AUTHOR]

The aim of this work is to obtain nanocomposite layers having a cobalt matrix with zirconium oxide nanoparticles (mean diameter 30 nm) through the electrodeposition process. The plating electrolyte suspension is prepared by adding ZrO2 nanoparticles in a sulfate-chloride cobalt electrolyte at a concentration of 0 and 10 g·L−1. The electrodeposition is performed at room temperature, using three current densities of 23, 48 and 72 mA·cm−2 and three deposition times of 30, 60 and 90 min. The influence of current density, time and nanoparticles concentrations on the characteristics of the obtained nanostructured layers are also discussed. ZrO2 ceramic nanoparticles as a dispersed phase in the cobalt deposition electrolyte modify the mechanism of its electro-crystallization, so they participate in this process by increasing the rate of cobalt deposition, confirmed by the thickness of the nanocomposite layers obtained. The paper presents some of the comparative results obtained regarding the thickness of the layers, the current efficiency and the inclusion of the nanoparticles into nanocomposite layers depending on the current density and time of the electrodeposition process. The analysis of Co/nano-ZrO2 nanocomposite layers with the help of optical light microscopy and electronic microscopy in cross-section highlights the good degree of adhesion of the layers to the metallic substrate made of 304L stainless steel. The results of the study show that as the current density and time increase, the thickness of the composite layers increases. The efficiency of the process is improved compared to the electrodeposition of pure cobalt layers. The degree of inclusion of ZrO2 nanoparticles increases with time and decreases with increasing of imposed current density on the electrodeposition process. The distribution of the dispersed phase in the cobalt metallic matrix is uniform. The layers obtained in this study can be applied in aircraft technology, in the automotive industry, as well as in biomedical applications in order to improve the properties and to increase the corrosion or tribocorrosion resistance in a specific environment. [ABSTRACT FROM AUTHOR]