Accurate and low jitter time-interval generators based on phase shifting method.

The paper describes two time-interval generators based on the phase shifting method. The first one utilizes the digital clock manager units integrated in a field programmable gate array (FPGA) device and has jitter below 65 ps (rms) over the range of 4 ns-50 ms, while the second one utilizes a separate direct digital synthesizer and has jitter below 15 ps (rms) over the range of 10.2 ns-50 ms. The phase shifting method can be used to design new low-cost and high-precision time-interval generators using the popular FPGA technology.

[Microbiological evaluation of ciprofloxacin efficacy for treatment of urinary tract infections]. / Mikrobiologiczna ocena skutecznosci ciprofloksacyny w leczeniu zakazen ukladu moczowego.

An attempt has been undertaken to evaluate the aetiology of urinary tract infections in a large group of patients and to determine the resistance to ciprofloxacin during therapy, and the efficacy of the drug in treating of urinary tract infections. 52 patients with urinary tract infections were treated with ciprofloxacin. Ciprobay by BAYER was used in coated 500 mg tablets twice a day and intravenous solutions in 200 mg dosages every 12 hours for 10-14 days depending on the clinical condition. Microbiological tests were made according to general methods. Sensitivity evaluation to ciprofloxacin was done using E-tests by AB Biodisk and dilution tests. The most common a etiology of urinary tract infections were Gram-negative Enterobacteriaceae rods, mainly E. coli. Ciprofloxacin gave the best results against Enterobacteriaceae rods (100% eradications). In other infections, effective therapy was possible after determining of the sensitivity in vitro. S. haemolyticus bacteria tended significantly towards resistance to ciprofloxacin during therapy.

[Effect of subinhibitory doses of some antibiotics on bacteria in vitro]. / Wplyw subinhibicyjnych dawek niektórych antybiotyków na bakterie in vitro.

The study was aimed at observation of influence of subinhibitory doses of selected beta-lactam antibiotics (cefuroxime, ceftazidime, thienamycin) and of ciprofloxacin on morphology and physiology of S. aureus and E. coli. The bacteria were subjected to action of these antibiotics in various subinhibitory concentrations in fluid Mueller-Hinton medium at 37 degrees C for 18 hours, and morphological changes in bacterial cells were observed in light and electronic microscope. In case of E. coli changes appeared as presence of elongated forms, while S. aureus formed giant cells with changes in staining. It was found that intensity of these morphological changes was proportional to concentrations of antibiotics. For determination of influence of tested antibiotics on growth of bacteria they were cultured in the fluid Mueller-Hinton medium containing antibiotics in concentrations of 4, 1 1/4 MIC. The culture lasted for 6 hours, and number of bacterial cells in 1 ml of the medium was periodically determined. Distinct inhibition of growth of bacterial cells was proportional to the used concentrations of antibiotics. Described in this paper morphological changes of bacteria found confirmation in change of their physiology expressed as inhibition of bacterial cell growth.