[Analysis of urinary stone composition by infrared spectroscopy in the population of the European part of Russia].

INTRODUCTION: Urolithiasis is one of the most common urological diseases, which affect at least 3% of the population. AIM: To study the epidemiology of urolithiasis in the European part of the Russian Federation and to determine the composition of urinary stones in order to understand the pathogenetic mechanisms of urinary stones formation. MATERIALS AND METHODS: Urinary stone were obtained from 2888 patients with urolithiasis and the composition of kidney stones was analyzed using the method of infrared spectroscopy. RESULTS: The predominance of oxalate stones was seen in kidney stones with mixed composition (83%) and the prevalence of uric acid stones (54%) was revealed in "pure" kidney stones. Urinary stones with a predominance of oxalates had significantly less impurities (12,4%) than stones with a predominance of uric acid, phosphates and carbonates with average amount of impurities more than 24%. Conslusion. The analysis of stone composition with a consideration of pathogenic factor showed that disorders of calcium metabolism in the population of the European part of the Russian Federation prevailed (88%).

Validation of the infrared spectroscopy method for analysis of the composition of urine concretes.

The aim of this study was to validate the method for analyzing the composition of calculus using infrared (IR) spectroscopy by studying model mixtures of salts. Study was made with an ALPHA-P IR Fourier spectrometer with OPUS software (Bruker, Germany). The samples of pure chemical salts manufactured by Sigma-Aldrich USA were used to validate the method. Salt mixtures were prepared in ratios of 10/90, 50/50 and 90/10. To assess the effect of the fraction size on the calculus component results, were used calculi of patients with urolithiasis. For each mixture were used 10 repeated measurements. Analysis of the composition of model salts showed that in the study of pure cystine salt CV(%) was 0,79%, calcium carbonate - 0,92%, sodium urate - 0,97%, calcium oxalate monohydrate - 4,94%, magnesium ammonium phosphate - 5,59%. And the most common components were analyzed in the composition of complex mixtures, including 90%, 50% and 10% of the investigated component. Calcium oxalate monohydrate has CV(%) 5.70% in mixture 9 part of it to one part of impurities, in mixture 50/50 - 21.57% and in 10/90 - 5.70%. For uric acid in 90/10 - 2.20%, in 50/50 - 10.09%, in 10/90 - 31.94%. For calcium carbonate in 90/10 - 9.02%, in 50/50 - 11.98%, in 10/90 - 24.70%. The dispersion analysis showed that the weighed portions of salts with a particle diameter of more than 0.8 mm provide reproducibility with a CV - 11.48%, with a diameter of 0.2-0.8 mm - 5.35%, and finally less than 0.1 mm - 2.28%. The accuracy of the method is high, but the reproducibility of the IR-spectroscopy method is relatively low in the analysis of stones of mixed composition, due to the greater error in the determination of impurities. Laboratories should pay special attention to optimizing sample preparation to ensure particle fineness less than 0.1 mm.

[A dynamic model of the neural network, which reproduces the signal of the ganglion cells].

A functional model of the neural network was proposed, which reproduces the signal of a ganglion cell during the formation of receptive fields with the antagonistic center and the periphery.

[A model of the neuronal network using eye micromovements for distinguishing contrasts on an image]. / Model' neironnoi seti, ispol'zuiushchei mikrodvizheniia glaz dlia vydeleniia kontrastov na izobrazhenii.

A monochromatic model of a neuron network of foveal retina with the straight way of information stream of the system "cone-diminutive bipolar-diminutive ganglion cell" is proposed. The network can distinguish contrasts on an image. It is shown that cells of the output level have concentric receptive fields formed due to eye micromovements. The paper discusses the functioning of the model in the case when eye movements contain resetting microsaccades as well as drift. A special attention is paid to the compensation of transient processes.

[Computer modeling of the neural network recognizing the contrasts on the image]. / Komp'iuternoe modelirovanie raboty neironnoi seti, vydeliaiushchei kontrasty na izobrazhenii.

Computer modeling of the neuron network offered in [1] is discussed. Organization and feature of modeling are described, as well as the changes, which are introduced in the network during researches. Results of modeling are present.

[A neuronal network model, discerning faint image contours in the presence of primary receptor parameter scatter]. / Model' neironnoi seti, vydeliaiushchei slabye kontrasty na izobrazhenii pri nalichii razbrosa parametrov pervichnykh retseptorov.

The neuron network model reproducing a number of phenomena concerned with peculiarities of monocular vision of moving and stationary relative to the retina objects was investigated. An analysis has shown that fulfillment of additional requirement of remaining model efficiency under condition of primary receptors parameters scatter may be realised in aforesaid model by insignificant modification of network structure.

[Perception of objects, moving in a slit with random shape]. / O vospriiatii ob''ektov, dvizhushchikhsiia v stvore shcheli proizvol'noi formy.

By means of calculation and instrumental modeling it has been shown that a change of the form and slurring of the object moving in a slit of an arbitrary shape results from a distortion of the retinal projection appearing due to decelerated following.

[The role of tracking in the perception of objects, moving toward each other in a narrow vertical slit line]. / O roli proslezhivaniia v vospriiatii ob''ektov, dvizhushchikhsia navstrechu drug drugu v stvore uzkoi vertikalnoi shcheli.

It has been shown by means of calculation and device modeling that the observed subjective pressure of two objects moving toward one another behind a narrow vertical slit corresponds to the pressure of objects retinal projections, induced in its turn by a slowed down tracing. 180e turn of one of the moving objects is also explained by tracing.

[Subjective compression of an object moving in the line of the rangefinder]. / K voprosu o sub''ektivnom szhatii ob''ekta, dvizhushchegosia v stvore shcheli.

It has been shown by recording eye movements and objective estimation that the value of subjective pressure of the object corresponds to the pressure of its retinal projection, which in its turn is determined by delayed tracing. Dependence of the value of relative subjective pressure on the slit width is determined at three values of the velocity of object movement.

[Tracing eye movements in various types of stroboscopic stimulation]. / Proslezhivaiushchie dvizheniia glaz pri nekotorykh vidakh stroboskopicheskoi stimuliatsii.

Relationship between eye ability to perceive smooth motion under stroboscopic stimulation on forward motion (from which stationary positions of the object) in the plane perpendicular to the look line was found. For diagnostics and occupational selection it is suggested to carry out stimulation in several directions thus obtaining additional information about the visual system of the person under test.