Peculiarities of designing a wideband detector of pulse radar signals based on real-time spectrum analyzer

Peculiarities of practical design of a wideband detector of pulse radar signals with unknown shape based on real-time spectrum analyzer to be used in passive radars are considered. Quality figures for such detector are obtained using simulation on a PC. Validity of the obtained estimates is proven by testing performed in a prototype unit.     

Experience in conducting course exams on assignments in test form

Analysis of the results of examinations in oral surgery making use of tests in 319 fourth-year students showed that such a method of assessing students' knowledge is highly objective.     

Assessment of the danger of bronchological studies under polyclinic conditions

In 176 ambulatory patients with cancer and inflammatory diseases of the lung the initial parameters of acid-base balance and blood gases were studied. Metabolic acidosis was found in 29.5%, alkalosis--in 54.5%, the values of acid-base balance and blood gases were normal in 15.9% of patients. The degree of bronchoscopy risk under narcosis in ambulatory patients is directly proportional to the kind, character and intensity of disorders in oxidation-reduction processes. Deep, hardly compensated or decompensated disorders in acid-base balance and gas metabolism in pH values higher than 7.54 and lower the 7.26, BE (buffer base shift)--higher than 4.0 meq/1 and lower than 6.0 meq/l, and pO2 lower than 65 mm Hg are the criteria of high risk of bronchological investigation under anesthesia in ambulatory oncological patients.     

Changes in plasma levels of lipid peroxidation products and myoglobin in patients with malignant tumors in the early postoperative period

Changes in the levels of free myoglobin and lipid peroxidation products (hydroperoxides and malonic dialdehyde) were studied in cancer patients. Their baseline levels were found to be higher in patients with cancer of the lung, large bowel, and rectum than those in controls, which indicates higher lipid peroxidation, which led to the destabilization of cellular membranes and seems to cause baseline hypermyoglobinemia. There was a drastic rise in the levels of free myoglobin in the first 24 postoperative hours. The duration and severity of hypermyoglobinemia were much higher in the complicated than uncomplicated postoperative period. There was a less rise in malonic dialdehyde concentrations, whose peak was observed on days 1-2 postsurgery. The content of hydroperoxides decreased in the first 24 postoperative hours and began gradually increased from day 2. The correlation between the concentrations of myoglobin and malonic dialdehyde suggests that there is an association between hypermyoglobinemia and the status of cellular membranes.     

The diagnosis of autoimmune thyroiditis by the symptoms of the upper respiratory tract and the digestive canal

Overall ninety-eight patients with autoimmune thyroiditis (AIT) were studied for the condition of upper respiratory and digestive tracts depending on the hormonal status of the thyroid gland. AIT patients display characteristic alterations in ENT organs, which were found to correlate with the thyroid levels of hormones.     

Enzymatic properties of neuraminidase from corynebacterium diptherial

Enzymatic properties of neuraminidase isolated from non-toxigenic strain C7 of diphteritic bacteria are studied. The enzyme has the pH optimum 5.5--6.0 in acetate buffer and the temperature optimum 38 degrees C. Neuraminidase has the highest substrate affinity to glycoproteins of equine blood serum, the lowest affinity--to 3-N-acetylneuraminosyllactose and ovomucin. The Km values was 4.3-10(-4) at optimal conditions under the hydrolysis of 3-N-acetylneuraminosyllactose, Vm was 0.05+/-0.02 muM NANA/hour/mg of protein. The following esters of N-glyconoyl-glycine were shown to be competitive inhibitors of neuraminidase: 1) methyl ester of 3-aza-4-oxo-2,3,4-trideoxy-D-arabinooctonic acid; 2) methyl ester of 3-aza-4-oxo-2,3,4-trideoxy-D-glucoheptodecanic acid; 3) methyl ester of 3-aza-4-oxo-2,3,4-trideoxy-D-galactonic acid; 4) methyl ester of 3-aza-4-oxo-2,3,4-trideoxy-D-gluconic acid, Ki values being 6.5-10(-4), 4.5-10(-4); 9.5-10(-4) and 7.1-(10-3) M, respectively.