Addition time plays a major role in the inhibitory effect of chitosan on the production of Pseudomonas aeruginosa virulence factors.

Pseudomonas aeruginosa is a gram-negative bacterium capable of forming persistent biofilms that are extremely difficult to eradicate. The species is most infamously known due to complications in cystic fibrosis patients. The high mortality of cystic fibrosis is caused by P. aeruginosa biofilms occurring in pathologically overly mucous lungs, which are the major cause facilitating the organ failure. Due to Pseudomonas biofilm-associated infections, remarkably high doses of antibiotics must be administered, eventually contributing to the development of antibiotic resistance. Nowadays, multidrug resistant P. aeruginosa is one of the most terrible threats in medicine, and the search for novel antimicrobial drugs is of the utmost importance. We have studied the effect of low molecular weight chitosan (LMWCH) on various stages of P. aeruginosa ATCC 10145 biofilm formation and eradication, as well as on production of other virulence factors. LMWCH is a well-known naturally occurring agent with a vast antimicrobial spectrum, which has already found application in various fields of medicine and industry. LMWCH at a concentration of 40 mg/L was able to completely prevent biofilm formation. At a concentration of 60 mg/L, this agent was capable to eradicate already formed biofilm in most studied times of addition (2-12 h of cultivation). LMWCH (50 mg/L) was also able to suppress pyocyanin production when added 2 and 4 h after cultivation. The treatment resulted in reduced formation of cell clusters. LMWCH was proved to be an effective antibiofilm agent worth further clinical research with the potential to become a novel drug for the treatment of P. aeruginosa infections.

[Prevalence of small anomalies of the heart development in preterm born children].

The purpose of work was an assessment heart small anomalies prevalence at children that was born as late-pretrem. By echocardiography method the 93 children at the age of 10-12 years were investigated. Frequency of detection heart small anomalies was 59% and at children with disproportional development at the birth--77%. Prevailing anomalies of development were anomalies of the left side of the heart, the mainly left ventricle abnormally located chords.

Determination of the diameter distribution of single-wall carbon nanotubes from the Raman G-band using an artificial neural network.

A novel, artificial neural network-based method is now available for obtaining the mean diameter of single wall carbon nanotube (SWCNT) samples from the diameter dispersive features of their Raman G-band. The method is demonstrated here for six different diameter SWCNT samples and 14 different excitation wavelengths. With an adequately large pool of standard nanotube samples, the suggested method is a useful complementary technique for SWCNT diameter analysis as it is capable of rapid diameter evaluation without prior knowledge of the relevant phonon dispersion relations.