The Preparation and Contact Drying Performance of Encapsulated Microspherical Composite Sorbents Based on Fly Ash Cenospheres

Sorption technologies are essential for various industries because they provide product quality and process efficiency. New encapsulated microspherical composite sorbents have been developed for resource-saving contact drying of thermolabile materials, particularly grain and seeds of crops. Magnesium sulfate, known for its high water capacity, fast sorption kinetics, and easy regeneration, was used as an active moisture sorption component. To localize the active component, porous carriers with an accessible internal volume and a perforated glass-crystalline shell were used. These carriers were created by acid etching of cenospheres with different structures isolated from fly ash. The amount of magnesium sulfate included in the internal volume of the microspherical carrier was 38 wt % for cenospheres with ring structures and 26 wt % for cenospheres with network structures. Studies of the moisture sorption properties of composite sorbents on wheat seeds have shown that after 4 h of contact drying the moisture content of wheat decreases from 22.5 to 14.9-15.5 wt %. Wheat seed germination after sorption drying was 95 ± 2%. The advantage of composite sorbents is the encapsulation of the desiccant in the inner volume of perforated cenospheres, which prevents its entrainment and contamination and provides easy separation and stable sorption capacity in several cycles.

Characterization of Silicate Glass/Mullite Composites Based on Coal Fly Ash Cenospheres as Effective Gas Separation Membranes

Membrane technology is a promising method for gas separation. Due to its low energy consumption, environmental safety, and ease of operation, membrane separation has a distinct advantage over the cryogenic distillation conventionally used to capture light inert gases. For efficient gas recovery and purification, membrane materials should be highly selective, highly permeable, thermally stable, and low-cost. Currently, many studies are focused on the development of high-tech materials with specific properties using industrial waste. One of the promising waste products that can be recycled into membrane materials with improved microstructure is cenospheres-hollow aluminosilicate spherical particles that are formed in fly ash from coal combustion during power generation. For this purpose, based on narrow fractions of fly ash cenospheres containing single-ring and network structure globules, silicate glass/mullite composites were prepared, characterized, and tested for helium-neon mixture separation. The results indicate that the fragmented structure of the cenosphere shells with areas enriched in SiO2 without modifier oxides, formed due to the crystallization of defective phases of mullite, quartz, cristobalite, and anorthite, significantly facilitates the gas transport process. The permeability coefficients He and Ne exceed similar values for silicate glasses; the selectivity corresponds to a high level even at a high temperature: αHe/Ne-22 and 174 at 280 °C.

Anomalous Diffusion of Helium and Neon in Low-Density Silica Glass

The diffusion properties of low-density non-porous silica glasses (expanded silica glasses) were researched with the aim of searching for the molecular structure of membrane materials intended for the effective separation of helium-neon gas mixtures. It has been shown on a large number (84) of computer models of such glasses that there are molecular structures of silica in which various helium and neon diffusion mechanisms are simultaneously implemented: superdiffusion for helium and subdiffusion for neon. This makes it possible to significantly (by 3-5 orders of magnitude) increase the helium permeability of such glasses at room temperature and maintain a high selectivity for the separation of helium and neon (at the level of 104-105) at the same time.

[The assessment of a role of muramyl peptides in the treatment of patients with aggressive form of periodontitis]

THE AIM OF THE STUDY

Was to determine the effect of the drug based on the composition of muramyl peptides isolated from the cell walls of gram-negative bacteria on the production of α-defensins and the detectability of Porphyromonas gingivalis in patients with an aggressive form of periodontitis.

MATERIAL AND METHODS

60 patients aged 28 to 40 years with an aggressive form of periodontitis were randomized into two equal groups, the main and control. In both groups, patients were removed dental deposits and taught the rules of oral hygiene, followed by three-fold control. In the main group, 200 micrograms of the drug based on the composition of muramyl peptides were additionally administered intramuscularly daily for 7 days. Initially and after 7, 21, 90 days, the level of human neutrophil peptides (hnp_1-3) in blood serum and periodontal pockets was determined by the enzyme immunoassay, as well as the presence of P. gingivalis in periodontal pockets by polymerase chain reaction (PCR).

RESULTS

In patients of the control group, the concentration of hnp_1-3 in periodontal pockets and blood serum did not change significantly during the entire study. The use of PM in the main group caused an increase in the local and systemic levels of hnp_1-3, which correlated with a persistent decrease in the detectability of P. gingivalis.

CONCLUSION

The drug based on the composition of muramyl peptides of the cell wall of gram-negative bacteria potentiates the eradication of P. gingivalis by stimulating the production of hnp_1-3 in patients with an aggressive form of periodontitis.

Composition-Structure Relationship and Routes of Formation of Blocklike Ferrospheres Produced by Pulverized Combustion of Two Coal Types

The composition-structure relationship of blocklike ferrospheres (FSs) isolated from fly ash produced during the combustion of two different types of coal was studied systematically by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. Monoblock globules were shown to consist of large sintered crystallites of Mg, Mn ferrospinel, which are formed from excluded siderite particles containing isomorphic impurities of magnesium and manganese carbonates. The common groups of globules for which the gross composition of polished sections corresponds to the general equations for the relationship of the concentrations SiO₂ = f(Al₂O₃) and CaO = f(SiO₂) were highlighted from FSs of two series. These globules are formed during the thermochemical transformation of associates of siderite, quartz, calcite, and anorthite, which have a silicate modulus of SiO₂/Al₂O₃ equal to 1.18, which corresponds to the coefficients in the general equations of the relationship SiO₂ = f(Al₂O₃). SEM analysis of polished cross-sections of the globules of selected FS groups demonstrates that the crystallite size of ferrospinel decreases, while the content of the glass phase increases with the declining FeO concentration in individual globules. The crystallite size and shape are found to depend on the size of the local melt area where the concentration of spinel-forming oxides is >85 wt %. The observed increase in the glass-phase content is attributed to the broadening of the liquation zone in the FeO-Fe₂O₃-SiO₂ system as the oxidative potential increases and to the higher content of [Fe³⁺O₂]^- and [Fe³⁺ ₂O₅]^4- ferrite complexes in calcium-rich melts.

[Antibacterial effect of a non-specific immunomodulator based on muramilpeptides in chronic periodontitis]

THE AIM OF THE STUDY

Was to investigate the efficacy of immunomodulatory drug based on muramilpeptides for treatment of chronic generalized periodontitis.

MATERIALS AND METHODS

The study group comprised 20 patients aged 25 to 64 with severe chronic periodontal disease. Periodontal pockets content was inoculated for specific microbial pathogens before and after treatment. Twenty patients receiving conventional treatment with no muramilpeptides-based agent served as controls.

RESULTS

In the main group prolonged suppression of periodontal disease provoking microbiota was seen, while in controls conventional treatment was not sufficiently effective resulting in germs growth relapse at day 21.

CONCLUSION

The dynamics of the microbiological landscape of periodontal pockets after treatment proves the necessity for a correction of innate immunity in inflammatory periodontal disease.

Magnetic Fractions of PM2.5, PM2.5-10, and PM10 from Coal Fly Ash as Environmental Pollutants

Characterization of magnetic particulate matter (PM) in coal fly ashes is critical to assessing the health risks associated with industrial coal combustion and for future applications of fine fractions that will minimize solid waste pollution. In this study, magnetic narrow fractions of fine ferrospheres related to environmentally hazardous PM_2.5, PM_2.5-10, and PM₁₀ were for the first time separated from fly ash produced during combustion of Ekibastuz coal. It was determined that the average diameter of globules in narrow fractions is 1, 2, 3, and 7 μm. The major components of chemical composition are Fe₂O₃ (57-60) wt %, SiO₂ (25-28 wt %), and Al₂O₃ (10-12 wt %). The phase composition is represented by crystalline phases, including ferrospinel, α-Fe₂O₃, ε-Fe₂O₃, mullite, and quartz, as well as the amorphous glass phase. Mössbauer spectroscopy and magnetic measurements confirmed the formation of nanoscale particles of ε-Fe₂O₃. Stabilization of the ε-Fe₂O₃ metastable phase, with quite ideal distribution of iron cations, occurs in the glass matrix due to the rapid cooling of fine globules during their formation from mineral components of coal.

[Classification of periodontal and peri-implant tissues diseases (Euro-Perio, 2018). Advantages and inconveniences]

The article presents the «Classification of periodontal diseases and the state of perimplant tissues», adopted at the international Congress Euro-Perio-9 in 2018. The advantages and disadvantages of this systematics in comparison with the previous ones and with the classification currently adopted in the Russian Federation are noted.

[Clinical effectiveness of an immunomodulatory drug based on a muramylpeptide composition in the treatment of patients with chronic generalized periodontitis]

THE AIM OF THE STUDY

To assess the efficacy of an immunomodulatory drug based on a muramylpeptide composition in the treatment of patients with chronic generalized periodontitis.

MATERIALS AND METHODS

The study comprised 40 patients with chronic generalized periodontitis. In controls the treatment consisted in oral hygiene instructions, professional oral hygiene procedures and root scalling while in main study group the conventional treatment protocol was combined with intramuscular injections of muramylpeptide composition.

RESULTS

The study showed significant reduction of inflammatory symptoms in periodontal tissues in muramylpeptide composition group.

CONCLUSION

Muramylpeptide composition increases the threshold of tissue protection against constantly present microbial accumulations in periodontal disease patients thus providing opportunity for excluding toxic antimicrobial agents and/or antibiotics (or reducing their dosages).

Preparation and Properties of Zr-Bearing Sorption Materials Based on Coal Fly Ash Microspheres

The influence of hydrothermal conditions on synthesis of analcime and a composite material ZrO2- analcime as well as zirconomolybdate coverings with ion exchange properties was studied using narrow fractions of aluminosilicate microspheres with a high content of a glass phase (91-95 wt. %). The possibility to synthesize ZrO2-analcime composites of narrow particle size distributions with maximum of about 40 μm and 6 μm under hydrothermal treatment at 150 °С was demonstrated starting from microspheres with Si/Al=2.7 and applying different regimes of a reaction mixture agitation. A microsphere material of a “core-shell” type such as ZrMo2O7(OH)2(H2O)2@(SiO2-Al2O3)glass with the nanostructured covering was prepared. Sorption properties of the materials regarding Nd3+, Sr2+ and Cs+ were studied under equilibrium conditions by means of determination of sorption isotherms and their fitting by the Langmuir model. Sorption parameters were determined including distribution coefficients which reach the values of 104−105 mL/g

Effect of Selank on Morphological Parameters of Rat Liver in Chronic Foot-Shock Stress

We studied the effects of Selank on morphological parameters of the liver in Wistar male rats subjected to chronic foot-shock stress. Selank was injected intraperitoneally in doses of 100, 300 and 1000 μg/kg 15 min before each stress session. Morphological and morphometrical analysis showed that chronic foot-shock stress induced hydropic degeneration of hepatocytes, an increase of the nucleus/cytoplasm ratio due to an increase in the area of nuclei and reduction of the cytoplasm area, the appearance of focal necroses, and lymphohistiocyte infiltration. Injection of Selank in all doses reduced the intensity of stress-induced degenerative changes. Administration of Selank in doses of 300 and 1000 μg/kg restored the nucleus/cytoplasm ratio in hepatocytes. The maximum stress-limiting effect was attained after administration of 300 μg/kg Selank.

Effect of Selank on Functional State of Rat Hepatocytes under Conditions of Restraint Stress

We studied the effect of Selank administered intraperitoneally in doses of 100, 300, and 1000 μg/kg to male Wistar rats 15 min prior to restraint stress on the content of aminotransferases and total protein concentration in blood serum and intensity of free radical oxidation in the liver. Under conditions of acute restraint stress, Selank in doses of 100 and 300 μg/kg decreased catalase and superoxide dismutase activities and malondialdehyde concentration and increased total antioxidant activity in the liver homogenate. Administration of Selank in a dose of 1000 μg/kg reduced the content of aminotransferases in blood serum, decreased superoxide dismutase activity in the liver, and increased total antioxidant activity. Under conditions of chronic stress, Selank in all doses produced similar effects: reduced superoxide dismutase activity and malondialdehyde concentration in the liver tissue and AST activity in the serum. The other parameters remained unchanged.

Ni(2+)-zeolite/ferrosphere and Ni(2+)-silica/ferrosphere beads for magnetic affinity separation of histidine-tagged proteins

Magnetic Ni(2+)-zeolite/ferrosphere and Ni(2+)-silica/ferrosphere beads (Ni-ferrosphere beads - NFB) of a core-shell structure were synthesized starting from coal fly ash ferrospheres having diameters in the range of 0.063-0.050 mm. The strategy of NFB fabrication is an oriented chemical modification of the outer surface preserving the magnetic core of parent beads with the formation of micro-mesoporous coverings. Two routes of ferrosphere modification were realized, such as (i) hydrothermal treatment in an alkaline medium resulting in a NaP zeolite layer and (ii) synthesis of micro-mesoporous silica on the glass surface using conventional methods. Immobilization of Ni(2+) ions in the siliceous porous shell of the magnetic beads was carried out via (i) the ion exchange of Na(+) for Ni(2+) in the zeolite layer or (ii) deposition of NiO clusters in the zeolite and silica pores. The final NFB were tested for affinity in magnetic separation of the histidine-tagged green fluorescent protein (GFP) directly from a cell lysate. Results pointed to the high affinity of the magnetic beads towards the protein in the presence of 10 mM EDTA. The sorption capacity of the ferrosphere-based Ni-beads with respect to GFP was in the range 1.5-5.7 mg cm(-3).

Gas permeation properties of hollow glass-crystalline microspheres

Microsphere materials for helium capture have been prepared on a base of narrow fractions of fly ash cenospheres.

[Affine magnetic sorbents supported on coal ash microspheres for recombinant protein isolation]

The results of the development and utilization of an affine magnetic sorbent with Ni2+ ions immobilized on coal ash microspheres are reported. The applicability of the material in the isolation of Histag proteins is demonstrated by examples of the recombinant green fluorescent protein from Clytia gregarium and the Ca2+ regulated photoprotein obelin from Obelia longissima. The specific sorption capacity of the sorbent was 2-7 mg/cm3 for medium-size proteins (20-30 kDa). The particles are suitable for chromatography with the presence of chaotropic agents and EDTA. They are easy to manipulate as isolation of a target protein takes 30-35 min. On one hand, the elevated affinity of the sorbent to proteins rich in native histidines may result in a high degree of irreversible sorption; on the other hand, it allows isolation of such proteins without the introduction of artificial polyhistidine tracts.

[Use of probiotics Bifidumbacterin and Acilact in tablets in therapy of periodontal inflammations]

The results of the use of russian probiotics Acilact and Bifidumbacterin in complex treatment of gingivitis and different degrees of parodontitis are presented. The treatment of the patients of control group was added by the italien drug Tantum Verde. The effect of Acilact and Bifidumbacterin to the normalisation of Mycroflora higher in comparison with Tantum-Verde, particulary in the cases of gingivitis and parodontitis superficialis.