Formation of core-shell Au@Ag nanorods induced by catecholamines: A comparative study and an analytical application.

Gold nanorods (AuNRs) stabilized by cetyltrimethylammonium bromide (CTAB) were synthesized and an interaction of catecholamines (CAs) with silver ions in the presence of the obtained AuNRs was studied. The reaction results into formation of core-shell Au@Ag nanorods (Au@AgNRs) and leads to a hypsochromic shift of the long-wave surface plasmon resonance (SPR) band in the absorption spectrum of AuNRs. The influence of a CA structure, excess of CTAB, interaction time, pH, concentration of AuNRs, silver ions and CAs on this interaction was studied. Based on correlation of the NRs spectral characteristics with the concentration of CAs, a method for spectrophotometric determination of dobutamine, epinephrine, norepinephrine and dopamine with detection limits 27, 18, 16 and 13 µg L(-1), respectively, has been developed. The method can be applied to the analysis of medicines.

[Clinico-pathogenetic role of the structural and functional disorganization of cell membranes in pneumonia in newborn infants]. / Kliniko-patogeneticheskaia rol' strukturno-funktsional'noi dezorganizatsii kletochnykh membran pri pnevmoniiakh u novorozhdennykh.

Based on a study of the function of the enzymes participating in red blood cell transmembrane transport (K+, Na+ATPase, Mg2(+)-ATPase and Ca2(+)-ATPase) in the newborn with pneumonias it was established that there was a decrease in the activity of the enzymes at the height of the clinical manifestations of disease, especially in septic pneumonias. The changes discovered were in agreement with the disease gravity and the intensity of certain clinical symptoms and depended as well on the initial vegetative tone. The activity of the membrane enzymes also depended on the changes in the physicochemical constants of cellular membranes, namely on red blood cell deformability and the phospholipid ratio. The results of the studies demonstrate that the use of the drugs favouring the improvement of reparative functions of cellular membranes and inhibiting the transmembrane calcium flow is advisable in the newborn as part of multimodality treatment.