No abstract

Aphanomyces astaci is the causative agent of crayfish plague, a disease responsible for numerous mass mortalities of native crayfish across Europe. In this study, we aim to extend knowledge about the A. astaci distribution in Eastern Europe, with specific focus on the River Dnieper (Ukraine), and summarize presently available information about the distribution of genotypes of this pathogen across the Western Palaearctic. We compiled published records about genotype groups of A. astaci, assembled them to a comprehensive map, and added the newly obtained results from Ukraine. The native narrow-clawed crayfish Pontastacus leptodactylus was sampled from the river Dnieper in Svydivok and Kiev, ca 170 km apart, and screened for the pathogen presence in soft cuticles by quantitative PCR. We confirmed infections by A. astaci at both sites, with prevalence exceeding 30% and low to medium agent levels in infected crayfish. Pathogen genotyping confirmed the presence of the A. astaci haplogroup B, associated with the signal crayfish Pacifastacus leniusculus but also known from some chronically infected narrowclawed crayfish from Turkey and Moldova. Our results support the notion that latent A. astaci infections among narrow-clawed crayfish populations may be widespread in Eastern Europe and the Middle East.

Fiber-reinforced composites are used as restorative materials for prosthetic oral rehabilitation. Gastroesophageal reflux disease (GERD) is an accustomed affection with various oral manifestations. This study aimed to evaluate the behavior of two high-performance CAD/CAM milled reinforced composites (Trinia™, TriLor) in artificial saliva at different pH levels through immersion tests, and to determine if changes in mass or surface morphology at variable pH, specific for patients affected by GERD, appear. After investigating the elemental composition and surface morphology, the specimens were immersed in Carter Brugirard artificial saliva for 21 days at different pH values (5.7, 7.6, and varying the pH from 5.7 to 3). The values of the weighed masses during the immersion tests were statistically processed in terms of mean and standard deviation. Results suggested that irrespective of the medium pH, the two composites presented a similar mass variation in the range of −0.18 (±0.01)–1.82 (±0.02) mg after immersion, suggesting their stability when in contact with artificial saliva, an aspect which was also highlighted by scanning electron microscope (SEM) analysis performed on the immersed surfaces. Novel composite biomaterials can be a proper alternative for metal alloys used for prosthetic frameworks in patients suffering from GERD.

The current research aim is to biofunctionalize pure titanium (Ti, grade IV) substrate with titania nanotubes and Zn doped hydroxyapatite-based coatings by applying a duplex electrochemical treatment, and to evaluate the influence of Zn content on the physico-chemical properties of hydroxyapatite (HAp). The obtained nanostructured surfaces were covered with HAp-based coatings doped with Zn in different concentrations by electrochemical deposition in pulsed galvanostatic mode. The obtained surfaces were characterized in terms of morphology, elemental and phasic composition, chemical bonds, roughness, and adhesion. The nanostructured surface consisted of titania nanotubes (NT), aligned, vertically oriented, and hollow, with an inner diameter of ~70 nm. X-Ray Diffraction (XRD) analysis showed that the nanostructured surface consists of an anatase phase and some rutile peaks as a secondary phase. The morphology of all coatings consisted of ribbon like-crystals, and by increasing the Zn content the coating became denser due to the decrement of the crystals’ dimensions. The elemental and phase compositions evidenced that HAp was successfully doped with Zn through the pulsed galvanostatic method on the Ti nanostructured surfaces. Fourier Transform Infrared spectroscopy (FTIR) and XRD analysis confirmed the presence of HAp in all coatings, while the adhesion test showed that the addition of a high quantity leads to some delamination. Based on the obtained results, it can be said that the addition of Zn enhances the properties of HAp, and through proper experimental design, the concentration of Zn can be modulated to achieve coatings with tunable features.

In this study, the adsorption of Pb2+ and Zn2+ ions from aqueous solutions onto lignin obtained from unmodified Sarkanda grass was analyzed. To ensure optimal process conditions, the retention of lead and zinc ions was tested at different experimental parameters (pH of the initial solution and adsorbent, the dose of adsorbent, the concentration of aqueous solutions and contact time). The experimental results have been interpreted using the classic Langmuir and Freundlich isotherm models, as well as two kinetic models (the Lagergren pseudo-first order and the Ho and McKay pseudo-second order models). Based on the analysis of the experimental data, it has been concluded that unmodified Sarkanda grass lignin can be recommended as an efficient alternative, considering its practical applicability, in the retention of Pb2+and Zn2+ ions from aqueous solutions, both in terms of the amount of adsorbate and pollutant species retained, as well as in terms of adsorption time.