Impact of Chitosan on Water Stability and Wettability of Soils

Chitosan has become increasingly applied in agriculture worldwide, thus entering the soil environment. We hypothesized that chitosan should affect the water stability of soil. Since this problem has not been studied to date, we examined, for the first time, the influence of chitosan on the water stability and wettability of soil aggregates. The aggregates were prepared from four soils with various properties amended with different amounts of two kinds of powdered chitosan, and subjected to 1 and/or 10 wetting–drying cycles. The water stability was measured by monitoring air bubbling after aggregate immersion in water, and the wettability was measured by a water drop penetration test. The biopolymer with a lower molecular mass, lower viscosity, and higher degree of deacetylation was more effective in increasing the water stability of the soil than the biopolymer with a higher molecular mass, higher viscosity, and lower deacetylation degree. After a single wetting-drying cycle, the water stability of the soil aggregates containing chitosan with a higher molecular mass was generally lower than that of the soil; after ten wetting–drying cycles, the water stability increased 1.5 to 20 times depending on the soil. The addition of low-molecular-mass chitosan after a single wetting-drying cycle caused the water stability to become one to two hundred times higher than that of the soil. A trial to find out which soil properties (pH, C and N content, bulk density, porosity, and particle size distribution) are responsible for the effectiveness of chitosan action was not successful, and this will be the objective of further studies.

Forces of RBC interaction with single endothelial cells in stationary conditions: Measurements with laser tweezers

Red blood cells (RBCs) are able to interact and communicate with endothelial cells (ECs). Under some pathological or even normal conditions, the adhesion of RBCs to the endothelium can be observed. Presently, the mechanisms and many aspects of the interaction between RBCs and ECs are not fully understood. In this work, we considered the interaction of single RBCs with single ECs in vitro aiming to quantitatively determine the force of this interaction using laser tweezers. Measurements were performed under different concentrations of proaggregant macromolecules and in the presence or absence of tumor necrosis factor (TNF-[Formula: see text]) activating the ECs. We have shown that the strength of interaction depends on the concentration of fibrinogen or dextran proaggregant macromolecules in the environment. A nonlinear increase in the force of cells interaction (from 0.4 pN to 21 pN) was observed along with an increase in the fibrinogen concentration (from 3[Formula: see text]mg/mL to 9[Formula: see text]mg/mL) in blood plasma, as well as with the addition of dextran macromolecules (from 10[Formula: see text]mg/mL to 60[Formula: see text]mg/mL). Dextran with a higher molecular mass (500[Formula: see text]kDa) enhances the adhesion of RBCs to ECs greater compared to the dextran with a lower molecular mass (70[Formula: see text]kDa). With the preliminary activation of ECs with TNF-[Formula: see text], the force of interaction increases. Also, the adhesion of echinocytes to EC compared to discocytes is significantly higher. These results may help to better understand the process of interaction between RBCs and ECs.

Chitosan of Peppery Milky Cap Fungi (Lactarius Pergamenus (Fr.) Fr): Isolation, Study of Physico-Chemical Properties and Biological Activity

Chitosan is widely used in biology and medicine. Usually, it is isolated from chitin of crustaceans, while chitosan of the basidiomycetes fungi is poorly studied. The purpose of this study was: 1) to develop a method for isolation of chitosan from dried pomace of the peppery milky cap (Lactarius pergamenus); 2) to study of physico-chemical and biological properties of the isolated chitosan. As tradicionally, chitosan was obtained by the alkaline hydrolysis of chitin. The determination of its molecular mass was performed using the viscometric method and further analyzed by disk electrophoresis (pH 5.0). The anti-microbial and cytotoxic activities were measured spectrophoto�metrically as a convertion of MTT dye to formazan, while the antifungal activity was evaluated using by counting colony-forming units (CFU). Chitosan of L. pergamenus fungi was shown to have lower molecular mass and a lower degree of deacetylation compared to shrimp chitosan. A yield of chitosan from a pomace of L. pergamenus was 6.27%. A heterogeneous product was obtained with an average molecular mass of 72 kDa and a degree of deacetylation equal - 87.1%. In 10 mg/ml dose, it inhibited by 29% the growth of gram-positive of Staphylococcus aureus (ATCC25923) bacteria and inhibited growth of gram-negative Echerichia coli dH5a - by 86% and Pseudomonas aeruginosa (ATCC9027) bacteria by 55%. Approximately 50 and 90 % of Candida albicans (pat.) cells were killed at the action of chitosan in doses of 0.025 mg/mL and 0.1 mg/mL correspondingly. It should be noted that this chitosan preparation did not affect a growth of human embryonic kidney pseudonormal cells of HEK 293 line and human breast carcinoma cells of MCF7 line.

Failure Analysis of the Propylene Parts Used in Trucks

The paper provides the results of failure analysis of the air intake pipe in the truck compressor. The thermal studies were carried out to identify a material, and to analyze the thermal oxidative degradation caused by excessively high operating temperatures. The study of the vehicle component part showed that it was made from polypropylene block copolymer. Analysis of the thermo-physical properties of the warranty polypropylene part showed that the thermal degradation led to a higher polymer crystallization and, as a result, a lower molecular mass due to high temperatures. The results of the thermal studies showed that the polypropylene part was subjected to excessively high operating temperatures which caused the thermal degradation and, as a result, catastrophic failure of the material.

PRODUCTION OF β-GLUCAN CONCENTRATE BY OAT GERMINATION

Today industrial processes manufacturing functional food with elevated β-glucan fraction are vulnerable due to heavy losses in energy and valuable human nutrients, and that calls for new technological solutions. Oat malting is discussed as an approach to obtain β-glucan concentrates rich with protein, vitamins, enzymes by reducing starch level. Hulless (or naked) oat malting duration was evaluated to control polysaccharide composition in grains. Amylolytic enzymes complex was demonstrated to degrade starch in 15 days from 59.5% to 31%, with β-glucan level rising correspondingly from 6.1% to 16.0%. It was noted that up to 6% of β-glucan can be synthesized in sprouts. Simultaneously, sprouting was accompanied by activation of endo-β-1,3-glucanase in aleuronic layer, and the maximal activity was observed on the 6th to 7th days of malting. This enzyme converts β-glucans to oligomers with lower molecular mass — β-glucan oligosaccharides, with concentration of the latter reaching 6% on the 15th day of malting.

Thermal and Thermorheologic Characterization of Different Polyolefin Waste Fractions

In this study, melt flow index values from several household waste fractions containing mainly polypropylene and high-density polyethylene, were measured at 190 °C for polyethylene and 230 °C for polypropylene-rich fractions. High values of MFI (low shear viscosities) have been reported probably due to the lower molecular mass of the polymer waste and/or the presence of surfactant compounds on the surface of the polymer flakes. Also, by extruding the same batch in different cycles at the same temperature values, the number of processing cycles on which the polymer could be recycled has been determined.

DNA-hydrolysing activity of IgG antibodies from the sera of patients with schizophrenia

It is believed that damage to the membranes of brain cells of schizophrenia (SCZ) patients induces the formation of autoantigens and autoantibodies. Nevertheless, the importance of immunological changes leading to the loss of tolerance to self-antigens in the genesis of SCZ has not been established. The MALDI mass spectra of the IgG light chains of 20 healthy donors were relatively homogeneous and characterized by one peak with only one maximum. In contrast to the healthy donors, the MALDI mass spectra of IgG light chains corresponding to 20 SCZ patients demonstrated, similarly to 20 autoimmune systemic lupus erythematosus (SLE) patients, two maxima of a comparable intensity. In addition, the MALDI spectra of the IgG light chains of five SLE and four SCZ patients contained a small additional brightly pronounced peak with remarkably lower molecular mass compared with the main one. DNase autoantibodies (abzymes) can be found in the blood of patients with several autoimmune diseases, while the blood of healthy donors or patients with diseases without a significant disturbance of the immune status does not contain DNase abzymes. Here, we present the first analysis of anti-DNA antibodies and DNase abzymes in the sera of SCZ patients. Several strict criteria have been applied to show that the DNase activity is an intrinsic property of IgGs from the sera of SCZ patients. The sera of approximately 30% of SCZ patients displayed a higher content of antibodies (compared with 37% of SLE) interacting with single- and double-stranded DNA compared with healthy donors. Antibodies with DNase activity were revealed in 80% of the patients. These data indicate that some SCZ patients may show signs of typical autoimmune processes to a certain extent.

Pediatric Neurocysticercosis: Usefulness of Antibody Response in Cysticidal Treatment Follow-Up

Serum and urine samples were collected from 33 NCC patients before the albendazole treatment, 3–6 and 12 months PT. At 3 months PT, 24 (72.7%) patients had no detectable CT/MRI lesions and 9 (27.2%) patients had persistent lesions. Antibody response to crude soluble extract (CSE), excretory secretory (ES), and lower molecular mass (LMM) (10–30 KDa) antigenic fraction ofT. soliumcysticerci was detected in serum and urine samples by ELISA. Before the treatment, out of 33 NCC children, 14 (42.4%), 22 (66.6%), and 11 (33.3%) serum samples were found positive with the use of CSE, ES, and LMM antigen, respectively. At 3–6 months PT, positivity rate was 5 (15.1%), 2 (6%), and 4 (12.1%) and at 12 months PT, positivity rate was 5 (15.1%), 0, and 3 (9%) with the use of CSE, ES, and LMM antigen, respectively. There was no significant difference in the positivity with the use of three antigens in pretreatment and PT urine samples. The study suggests that the use of ES antigen to detect antibody in serum samples may serve better purpose to evaluate the therapeutic response in patients with NCC.

Comparative study on the acrosin activity in sperm of the marine crab Charybdis japonica (A. Milne-Edwards, 1861) (Brachyura, Portunidae) under different environmental conditions

The optimal environmental conditions for acrosin activity in sperm of Charybdis japonica were assessed by orthogonal experiments, and the variation of the acrosin activity in sperm was analysed under hypothermic preservation at 4°C and cryopreservation in liquid nitrogen at −196°C, respectively. The acrosin activity and protein component in sperm from the female spermatheca and from the male seminal receptacle, were also compared. The highest acrosin activity was obtained at pH 8, 25°C and 30‰ salinity. The acrosin activity and viability rates of sperm decreased with the preservation time elapsed at 4°C, and a positive correlation between acrosin activity and viability rates (; ) was recorded. These two indices decreased significantly before and after cryopreservation at −196°C, and subsequently changed slowly in the liquid nitrogen. The cryoprotectant had a significant effect on the viability rates of sperm, but not much on the acrosin activity. The acrosin activity of sperm from the male seminal receptacle was (122.53 ± 1.66) × 10−6 μIU under optimal environmental conditions, which was significantly higher than that of the sperm from the female spermatheca (105.65 ± 2.91) × 10−6 μIU (). Three kinds of protein subunits in sperm acrosin from the male seminal receptacle were observed by dissociating SDS-PAGE (71.7, 69.2 and 67.3 kDa), which were degraded to some degree in the female spermatheca (70.4, 66.7 and 64.9 kDa). Several special components were noted in the female spermatheca, with one of higher molecular mass and five of lower molecular mass, which may play an important role in preserving the sperm in the female spermatheca.