Neural-Net Analysis of the Plasticity of ÉP-450 Ferrite–Martensite Steel with Different Alloying Element Concentrations

The results of a computational experiment with a neural-net model simulating the effect of the chemical composition on the plastic properties of ÉP-450 steel are presented. It is shown that computer-aided development of reactor steel with prescribed properties is, in principle, possible.     

Activity of renin-angiotensin-aldosterone system (RAAS) and vasopressin level in patients with primary pulmonary hypertension

AIM: Assessment of RAAS and vasopressin in patients with primary pulmonary hypertension (PPH). MATERIALS AND METHODS: Activity of plasma renin (APR), angiotensin-converting enzyme (ACE), plasma levels of angiotensin II (AII) and vasopressin (VP), serum concentration of aldosteron (AS) were measured by radioimmunoassay and enzyme immunoassay in 21 PPH patients with circulatory failure (age 34.7 +/- 2.1 years), 11 patients with NYHA functional class II-III, 10 with class IV, and 10 control subjects (age 29.8 +/- 1.5 years). RESULTS: Compared to controls, 21 PPH patients had elevated RAAS parameters: APR up to 3.52 ng/ml/h (p < 0.05), activity of ACE up to 43.13 units, AII level up to 33.93 ng/ml (p < 0.01), AS up to 468.86 ng/ml (p < 0.01), VP up to 5.26 ng/ml (p < 0.001). Circulatory failure progression resulted in activation of all the RAAS components. This and VP activation was the greatest in PPH patients with ACE > 5 ng/ml/h. PPH patients with mean pressure in the pulmonary artery higher than 60 mm Hg demonstrated higher ARP, AS, VP, AII, ACE than those who had this pressure under 60 mm Hg. CONCLUSION: PPH patients display a noticeable activation of RAAS and VP. This activation seems to be secondary as the changes increase with elevation of the pressure in the pulmonary artery and aggravation of circulatory insufficiency. Plasma renin activity determines the degree of RAAS activation as a whole. The discovered activation of RAAS in PPH gives grounds for doubts in the validity of using ACE inhibitors in the treatment of PPH.     

Effect of polyvitamin preparations on blood coagulation in experimental hypercoagulation]

The influence of polyvitamin compounds on the course and outcome of experimental hypercoagulemia was studied. "Hendevitum", "Aerovitum" and "Undevitum" proved to be most effective in reducing negative results of thromboplastemia. "Glutamevitum" was insignificantly effective, while "Quadevitum" and "Complevitum" did not reduce animals' death rate after intravascular injection of thromboplastin in LD50. Positive effects of polyvitamin compounds might be associated with their capacity for stimulating anticoagulation potential, especially, in accelerated continuous intravascular blood coagulation.     

Metal–carbothermal methods of reducing the degree of oxidation of dispersed metal in electric arc metallizing

At present, there are no system solutions for preventing extensive oxidation of the dispersed metal in electric arc metallizing (EM). To solve the problem of reducing the negative effect of oxidation, investigations were carried out at the GOSNITI GNU Institute into the application of the metal–carbothermal processes.