Antimicrobial, Oxidant, Cytotoxic, and Eco-Safety Properties of Sol-Gel-Prepared Silica-Copper Nanocomposite Materials.

The present work is devoted to the biological effects of sol-gel-derived silica (Si)-copper (Cu) nanomaterials. Tetraethyl orthosilane (TEOS) was used as a silica precursor; copper was introduced as a solution in ethanol with Cu(OH). The obtained samples were denoted as Si/Cu (gel) and Si/Cu/500 (500 °C heat-treated).

Antimicrobial and Oxidative Activities of Different Levels of Silver-Exchanged Zeolites X and ZSM-5 and Their Ecotoxicity.

Objectives: The antimicrobial, oxidative activities, and ecotoxicity of synthesized silver-loaded zeolites (X and ZSM-5(MFI), Si-to-Al ratios 12 and 25) were studied, linking antimicrobial properties to material structure and released active silver species.

Methods: The materials were characterized by SEM, EDX, TEM, and XRPD. All materials, with a silver content of 1-3%wt for the Ss and about 35%wt for the X-zeolites, were tested against and .

Optical Properties and Antimicrobial Activity of Si/PVP Hybrid Material Combined with Antibiotics.

Silica-poly (vinylpyrrolidone) hybrid material was prepared using the sol-gel method. Tetramethyl ortosilane (TMOS) was used as a silica precursor. XRD analysis established that the as-prepared material is amorphous.

Sol-Gel Synthesis of Silica-Poly (Vinylpyrrolidone) Hybrids with Prooxidant Activity and Antibacterial Properties.

The present work deals with the sol-gel synthesis of silica-poly (vinylpyrrolidone) hybrid materials. The nanohybrids (Si-PVP) have been prepared using an acidic catalyst at ambient temperature. Tetramethyl ortosilane (TMOS) was used as a silica precursor.

Phytoplankton abundance and structural parameters of the critically endangered protected area Vaya Lake (Bulgaria).

Vaya (Ramsar site, protected area and Natura 2000 site) is the biggest natural lake in Bulgaria and the shallowest Black Sea coastal lake, which during the last decades has undergone significant changes and was included as critically endangered in the Red List of Bulgarian Wetlands. Our studies were conducted during the summer and autumn months of three years - 2004-2006. The paper presents results on the phytoplankton abundance (numbers, biomass and carbon content) in combination with the indices of species diversity, evenness and dominance.