Variability in growth and biosynthetic activity of Calendula officinalis hairy roots
Calendula officinalis is a widespread medicinal plant with a sufficiently well-studied chemical composition. Secondary metabolites synthesized by C.officinalis plants have pharmacological value for...
Overcoming Antibiotic Resistance to Tetracycline in Staphylococcus aureus by Gold and Silver Nanoparticles - Cytology and Genetics
Abstract The use of tetracyclines in medicine, veterinary medicine, and stock raising has led to the spread of bacterial resistance to tetracycline, particularly among dangerous representatives of Staphylococcus aureus. Therefore, the analysis of resistance to tetracycline and the creation of approaches to overcome it are extremely relevant. Studies of 64 clinical isolates of S. aureus, which were characterized by moderate biofilm formation, showed that 33 of them contained plasmid DNA. A significant spread (in 96% of studied isolates) of the known transmissible tetracycline resistance genes tet(K) and tet(M) was shown in the examined plasmid-containing doxycycline-resistant clinical isolates of S. aureus. Plasmid-containing doxycycline-resistant clinical isolates with tet(K) and tet(M) genes lost resistance to the tetracycline antibiotic doxycycline after treatment of their cells with gold nanoparticles of 30 nm in a concentration of 3.2–9.6 μg/mL or medium-sized silver of 30 nm in a concentration of 20–40 μg/mL. Elimination of tet genes responsible for acquired resistance was confirmed by PCR.
Silver nanoparticles spark key advance in thermoelectricity for power generation
Several high-performance thermoelectric materials have been discovered over the past two decades, but without efficient devices to convert the energy they produce into emission-free power, their promise has been unfulfilled. Now an international team of scientists led by a University of Houston physicist and several of his former students has reported a new approach to constructing the thermoelectric modules, using silver nanoparticles to connect the modules' electrode and metallization layers.
Cytology and Genetics
Phys.org