Green and rapid preparation of long-term stable aqueous dispersions of fullerenes and endohedral fullerenes: The pros and cons of an ultrasonic probe

A green, scalable, and sustainable approach to prepare aqueous fullerene dispersions (AFD) C60, C70, endohedral metallofullerene Gd@C82, and their derivatives C60Cl6, C70Cl10, and supramolecular and ester-like derivatives, 10 fullerene species total, is proposed. For the first time, an immersed ultrasonic probe was used to preparing dispersions for pristine fullerenes without addends. Both ultrasound-assisted solvent-exchange and direct sonication techniques for AFD preparation using an immersed probe were tested. The average time for AFD preparation decreases 10-15 times compared to an ultrasound-bath-assisted technique, while final fullerene concentrations in AFDs remained at tens of ppm (up to 80 ppm). The aqueous dispersions showed long-term stability, a negatively charged surface with a zeta potential up to -32 mV with an average nanocluster diameter of no more than 180 nm. The total anionic and cationic compositions of samples were found by inductively coupled plasma atomic emission spectroscopy and chromatographic techniques. The highlights and challenges of using an ultrasound probe for AFD production are discussed.

[The chemotherapeutic efficacy of ciprofloxacin and lomefloxacin in the inhalation method of infecting white mice with tularemia]

Peculiarities of the protective effect of ciprofloxacin and lomefloxacin were studied and the optimal regimens of their use were determined in multifactor experiments on albino mice infected with finally dispersed aerosol of the virulent strain of the European subspecies of Francisella tularensis. As for protective effect, the fluoroquinolones provided high percentage of the animal survival. The optimal course of the treatment was at least 7 days. The interval of 0 to 48 hours between the infection and the start of the treatment had no statistically significant effect on chemotherapeutic efficacy of fluoroquinolones.

[Protective properties of doxycycline, rifampicin and sisomycin in experimental pulmonary tularemia of albino mice]

The protective effects of doxycycline, rifampicin and sisomicin were compared in a multifactor experiment with animal infection induced by finally dispersed aerosol of a virulent strain of the European variant of the tularemia causative agent and the optimal regimens for the antibiotic use were determined. By the values of the protective effect rifampicin and sisomicin were shown to provide a high percentage of the animal survival: more than 80 and up to 50-70 per cent of the animals survived when the aerosol infective doses were 100 and 10,000 LD50, respectively. A characteristic feature of doxycycline was its activity only in the infection induced by low doses of the biological agent. The optimal course of the antibiotic therapy in inhalation tularemia was 6 to 8 days. The interval of 1 to 3 days between the infection and the therapy start had no significant effect on the protective efficacies of the antibiotics.