The interaction of peripheral blood leukocytes with alpha1-acid glycoprotein, its carbohydrate chains and neoglycoconjugates

The interaction of human peripheral blood leukocytes with alpha 1-acid glycoprotein (AGP), its glycoforms as well as neoglyco-conjugates representing carbohydrate chains of AGP or its fragments was studied by flow cytometry. It was shown that the main target cells for AGP as well as for conjugates of its carbohydrate chains with polyacrylamide (PAA) are monocytes and polymorphonuclear leukocytes but not lymphocytes. The interaction of AGP with monocytes and granulocytes are mediated by its carbohydrate chains: the binding of AGP with cells was inhibited by AGP, AGP oligosaccharides as well as conjugates of oligosaccharides and its fragments with PAA. The data obtained show the existence of monocyte (and granulocyte) receptors which interact with complex type sialooligosaccharides of AGP.     

Control and diagnosis in the biotechnical systems of artificial clearance

Controlling and diagnostic processes in the bioengineering artificial clearance systems despite of the procedures applied, their functional use and design seem to occur in the artificial organs, each of them consists of controlling and actuating processors ensuring their homogeneous (material, energy-producing, informational) or combined interaction with the patient's body. Centralized control over artificial clearance is proposed by using universal controlling processes which are informationally connected with the operator, the central computer and other controlling processes of the bioengineering system.     

A Nom historical document recognition system for digital archiving

A Nom historical document recognition system is being developed for digital archiving that uses image binarization, character segmentation, and character recognition. It incorporates two versions of off-line character recognition: one for automatic recognition of scanned and segmented character patterns (7660 categories) and the other for user handwritten input (32,695 categories). This separation is used since including less frequently appearing categories in automatic recognition increases the misrecognition rate without reliable statistics on the Nom language. Moreover, a user must be able to check the results and identify the correct categories from an extended set of categories, and a user can input characters by hand. Both versions use the same recognition method, but they are trained using different sets of training patterns. Recursive X–Y cut and Voronoi diagrams are used for segmentation; k–d tree and generalized learning vector quantization are used for coarse classification; and the modified quadratic discriminant function is used for fine classification. The system provides an interface through which a user can check the results, change binarization methods, rectify segmentation, and input correct character categories by hand. Evaluation done using a limited number of Nom historical documents after providing ground truths for them showed that the two stages of recognition along with user checking and correction improved the recognition results significantly.     

Benign and efficient preparation of thioethers by solvent-free S-alkylation of thiols with alkyl halides catalyzed by potassium fluoride on alumina

The preparation of thioethers by S-alkylation of various thiols with alkyl halides under solvent-free reaction conditions using potassium fluoride on alumina (KF/Al₂O₃) as a solid catalyst has been investigated in detail with respect to three different modes of reaction activation (ultrasound irradiation, microwave irradiation, and conventional heating) for obtaining maximum yield of the thioether. The importance of KF/Al₂O₃ as a particularly efficient catalyst was corroborated for all three modes of reaction activation, although the reaction time was found to be strongly dependent on the mode of activation. The yield of the thioethers was also found to depend on the amount of the solid catalyst relative to the equimolar amounts of the two reactants.     

Rodent thyroid gland function under hot climatic conditions

Studies have been made on the effect of high temperature and intensive insolation upon the uptake of iodide and hormone formation in the thyroid of rodents (Rhombomys opimus, Spermophilopsis leptodactylus, Citellus fulvus) with different adaptation to the environment. It was shown that high temperature in combination with solar radiation significantly decreases functional activity of the thyroid and affects some of the physiological indices of the organism. Animals with different ecological specialization differ in their reaction to factors of the hot climate.     

Symmetric Orthogonal Complex-Valued Filter Bank Design by Semidefinite Programming

A new design method for complex-valued two-channel finite impulse response (FIR) filter banks with both orthogonality and symmetry properties is developed. Based on a novel linear matrix inequality (LMI) characterization of trigonometric curves, the optimal design of perfect-reconstruction filter banks is cast into a semidefinite programming (SDP) problem. The dimension of the resulting SDP problem is further reduced by exploiting convex duality. Consequently, the globally optimal solution can be found for any practical filter length and desired regularity order.     

Effect of combined vitamin D and E deficiencies on calcium metabolism and bone tissue of the rat

In experiments on young rats a study was made of the influence of combined vitamin D and E deficiency on biochemical signs of rickets. It was shown that in intact animals vitamin E deficiency induced moderate hypocalcemia, a tendency to decreased Ca active transport in the small intestine and mineral saturation of the bone tissue, as well as a significantly increased Ca content in the skeletal muscles and heart. The concentration of 25-oxyvitamin D (25-OVD) in the blood serum of these animals was not changed. Combined vitamin D and E deficiency intensified disorders typical for rickets; sometimes synergy of such a negative effect was recorded. A delay in the recovery of Ca metabolism parameters, bone tissue condition and 25-OVD circulating concentration persisted, when the animals with vitamin D and E deficiency were injected cholecalciferol during 6 days. The data obtained have evidenced a possible role of vitamin E deficiency in the rickets development, that is, probably, mediated, to a certain extent, by its influence on metabolism and (or) biochemical function of vitamin D.     

The synthesis and crystal structure of unsubstituted 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)

The fully unsubstituted 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) was synthesized for the first time by oxidation of dipyrromethane followed by treatment with boron trifluoride diethyl etherate in the presence of a base. The compound was fully characterized and its X-ray crystal structure is reported.     

Ultrasonic through-transmission method of evaluating the modulus of elasticity of Al2O3–ZrO2 composite

The elastic properties of Al2O3–ZrO2 composite were determined from ultrasonic velocity measurements, and were found to be dependent upon the amount of ZrO2 phase, the compacting pressure of the green ceramic and sintering time. The velocity in the Al2O3–ZrO2 composite increased to a maximum for about 3 wt% unstabilized ZrO2 dispersed in Al2O3. The velocity decreased monotonically thereafter. The increase in moduli, as shown by an increase in velocity, has been attributed to phase transformation of the unstabilized ZrO2 from tetragonal to a monoclinic phase, which presumably leads to a toughening and strengthening effect, and also due to the action of ZrO2 in stopping grain growth of Al2O3 during densification. The excessive shear strain, induced by the tetragonal→monoclinic transformation phase, with greater than 50 wt% ZrO2 content, caused microcracks to appear in the composite. This reduced the elastic moduli of the composite. It was found that the composition dependence of the elastic moduli lie outside the theoretical bound of Voigt and Reuss for the elastic moduli of two-phase materials, and that by increasing the compacting pressure, an improvement in the elastic moduli of the sintered composite occurred irrespective of ZrO2 content. The thermal expansion of the composites showed no appreciable change with addition of zirconia up to 5 wt% ZrO2. However, dimensional changes due to phase transformation particularly with high zirconia content have been established. This revised version was published online in November 2006 with corrections to the Cover Date.