Production of thin-walled pipe on a system with a three-roller mill

The manufacture of thin-walled pipe on a three-roller screw-rolling mill is described. The optimal reduction on the reduction mill is noted, and a formula is given for the aperture. A rolling technology for the rear end of the pipe without triangulation is outlined.     

On particle path generation based on quadrilinear interpolation andBernstein-Bezier polynomials

Particle path computation in unsteady 3D vector fields given in discrete, structured form (i.e., as a hexahedral curvilinear grid) requires the local approximation of the vector field and the path. Quadrilinear interpolation and Bernstein-Bezier polynomials are used for the local vector field and path approximation. The next point in a sequence of points on a particle path is computed using this local approximation. Bernstein-Bezier polynomials are primarily used in geometric modeling, and their properties allow direct computation of points on a particle path     

The prevalence, structure and clinical problems of multiple sclerosis in the Transcarpathian area based on epidemiological study data

As many as 230 patients with disseminated sclerosis were examined in the Transcarpathian region. Sick male- and female populations were found out to be almost similar. There were more sick persons in the medium-range areas of the Carpathian Mountains, with a mean age being 35 +/- 5 years. It has been established that intake of spirulina makes for lengthening of remission in those patients with disseminated sclerosis.     

Preparation of the myristoylated and nonmyristoylated form of recombinant recoverin in E. coli cells and comparison of their functional activity]

Numerous data strongly suggest the involvement of cytokines and the matrix metalloproteinase collagenase (MMP-1) in the pathogenesis of periodontitis. Recently, we have demonstrated that, upon culturing under the influence of IL-1 alpha + EGF, a large amount of inactive procollagenase (MMP-1) is stored in the extracellular matrix of periosteal tissue. We now show that this endogenous reservoir of proenzyme can be operative after activation with plasmin and is able to induce a rapid and almost complete breakdown of the collagenous extracellular matrix. The level of collagen degradation following activation showed a strong correlation with the amount of proenzyme that was incorporated in the tissue. The highest level of degradation (70% of the total amount of collagenous proteins) was found with the IL-1 alpha + EGF-treated explants, followed by those treated with IL-1 alpha alone (35%). Explants cultured with EGF or in the absence of cytokines, containing only small amounts of procollagenase, showed little collagen breakdown following plasmin activation (7%). Inhibition of metalloproteinases by EDTA, or blockage of plasmin by PMSF, prevented the degradation in all explants irrespective of the amount of proenzyme present in the tissue. Our findings demonstrate that endogenous proenzyme stored in a native connective tissue matrix can be activated at a later time interval which results in a massive breakdown of the tissue. This study shows a possible pathway of collagenase-induced breakdown without recent de novo synthesis of the enzyme. Such a sequence may be operative in chronic inflammatory diseases, such as periodontitis, where production of procollagenase under the influence of cytokines spans a longer time period, whereas breakdown is often characterized by a cyclic behaviour.     

Diagnosis of hyperventilation for elimination of false-positive results of physical exercise test

The study was conducted in 55 patients with cardiac pains. Electrocardiography was used successively prior to, during and following physical exercises, followed by Seldinger selective coronary angiography, and electrocardiography prior to, during and following hyperventilation tests. In 2 of 55 patients the result of the exercise test was interpreted as false-positive, since the coronary angiography demonstrated intact vessels, and during hyperventilation ECG recorded a decreased ST segment. To avoid false-positive results in patients with suspected angina pectoris the physical exercises tests can be considered positive only in cases in which hyperventilation caused no ECG changes typical for angina pectoris.     

Synchronous amplification of subpicosecond pulses

In high-gain dye amplifiers, the effective storage time of the gain medium is only a few hundred picoseconds. Therefore, efficient amplification of ultrashort pulses places a stringent requirement on the synchronization between the pump pulse and the pulse to be amplified. We present a technique of short pulse generation using a dye laser synchronously pumped by a frequency-doubled CW mode locked Nd:YAG laser. Pulses as short as 70 fs are produced. The short optical pulses are subsequently amplified with two different synchronous amplification schemes using 100 ps pulses to establish the gain in the dye amplifier stages. Subpicosecond pulses with energies from a few hundred nanojoules at 500 Hz to a few hundred microjoules at 7 Hz can be obtained.