Non-destructive Assessment of Relief Marking Parameters of Heat Shrinkable Installation Parts for Aviation Technology

The article explains a new method of relief marking of heat-shrinkable tubing and sleeves made of polymer materials with “shape memory effect.” Method of instrument evaluation of relief marking stereometry of installation parts for aviation equipment, made of polyvinyl chloride, polyethyleneterephthalate and polystyrene was developed and the results were explained. Parameters of pin-point relief marking and compliance of point forms to the Braille font standard were determined with the use of the non-destructive method based on the color of interference pattern with precision of 0.02 mm

Non-destructive Assessment of Relief Marking Parameters of Heat Shrinkable Installation Parts for Aviation Technology

The article explains a new method of relief marking of heat-shrinkable tubing and sleeves made of polymer materials with “shape memory effect.” Method of instrument evaluation of relief marking stereometry of installation parts for aviation equipment, made of polyvinyl chloride, polyethyleneterephthalate and polystyrene was developed and the results were explained. Parameters of pin-point relief marking and compliance of point forms to the Braille font standard were determined with the use of the non-destructive method based on the color of interference pattern with precision of 0.02 mm

Chemokine Homeostasis in Healthy Volunteers and during Pancreatic and Colorectal Tumor Growth in Murine Models

Chemokines are involved in the humoral regulation of body homeostasis. Changes in the blood level of chemokines were found in cancer, atherosclerosis, diabetes, and other systemic diseases. It is essential to distinguish the effects of co-morbid pathologies and cancer on the level of chemokines in the blood. We aimed to analyze, by multiplex cytometry, the levels of chemokines in the blood of healthy young volunteers as well as of intact mice and mice with CT26 colon and Pan02 pancreatic tumors. Two types of chemokines were identified both in human and murine plasmas: homeostatic ones, which were found in high concentrations (>100 pg/mL), and inducible ones, which can be undetectable or determined at very low levels (0–100 pg/mL). There was a high variability in the chemokine levels, both in healthy humans and mice. To analyze chemokine levels during tumor growth, C57BL/6 and BALB/c were inoculated with Pan02 or CT26 tumor cells, accordingly. The tumors significantly differed in the growth and the mortality of mice. However, the blood chemokine levels did not change in tumor-bearing mice until the very late stages. Taken collectively, blood chemokine level is highly variable and reflects in situ homeostasis. Care should be taken when considering chemokines as prognostic parameters or therapeutic targets in cancer

Preparation and characterization of cryogels based on pectin and chitosan

Novel cryogels based on pectin and chitosan were obtained by a cryotropic gelation method. Percentage of chitosan in the cryogels was estimated by elemental analysis. The obtained values were from 3.50 to 15.03 % for Apple pectin/Chitosan cryogels and from 9.44 to 17.64 % for Heracleum pectin/Chitosan cryogels. Internal structure and porosity of the cryogels were measured by scanning electron microscopy. According to the scanning electron microscopy, cryogels have a macroporous sheet-like structure. In the future, cryogels can be used in biotechnology and medicine as biocompatible, biodegradable materials

Diversity of the vegetation cover of the zone of potential influence of the Nizhneboguchanskaya HPP (Lower Angara region)

Active economic development of the Lower Angara zone requires the creation of a scientific basis for long-term monitoring of the state of natural ecosystems. The paper gives an assessment of the diversity of vegetation cover in the zone of potential influence of the Nizhneboguchanskaya HPP. An analysis of its typological structure on a landscape-ecological basis is given. The results of the DCA ordination and the interpretation of the leading axes of variation demonstrated the presence of four distinct groups of forest types that form ecological series according to the leading factors - the richness and hydrothermal regimes of soils. The dendrogram of forest types in the study area reflects the floristic integrity of the identified groups of forest types and the floristic relationships between them

Polyvinylpyrrolidone–Alginate Film Barriers for Abdominal Surgery: Anti-Adhesion Effect in Murine Model

Surgical operations on the peritoneum are often associated with the formation of adhesions, which can interfere with the normal functioning of the internal organs. The effectiveness of existing barrier materials is relatively low. In this work, the effectiveness of soluble alginate–polyvinylpyrrolidone (PVP-Alg) and non-soluble Ca ion cross-linked (PVP-Alg-Ca) films in preventing these adhesions was evaluated. Experiments in vivo were performed on mice via mechanical injury to the adjacent peritoneum wall and the caecum, followed by the application of PVP-Alg or PVP-Alg-Ca films to the injured area. After 7 days, samples from the peritoneal wall and caecum were analyzed using histology and quantitative polymerase chain reaction (qPCR). It was shown that the expression of genes responsible for adhesion formation in the caecum in the PVP-Alg group was comparable to that in the control group, while in the PVP-Alg-Ca group, it increased by 5–10 times. These results were consistent with the histology: in the PVP-Alg group, the adhesions did not form, while in the PVP-Alg-Ca group, the adhesions corresponded to five points on the adhesion scale. Therefore, the formation of intraperitoneal adhesions can be effectively prevented by non-crosslinked, biodegradable PVP-Alg films, whereas cross-linked, not biodegradable PVP-Alg-Ca films cause inflammation and adhesion formation

Silicon–Gold Nanoparticles Affect Wharton’s Jelly Phenotype and Secretome during Tri-Lineage Differentiation

Multiple studies have demonstrated that various nanoparticles (NPs) stimulate osteogenic differentiation of mesenchymal stem cells (MSCs) and inhibit adipogenic ones. The mechanisms of these effects are not determined. The aim of this paper was to estimate Wharton’s Jelly MSCs phenotype and humoral factor production during tri-lineage differentiation per se and in the presence of silicon–gold NPs. Silicon (SiNPs), gold (AuNPs), and 10% Au-doped Si nanoparticles (SiAuNPs) were synthesized by laser ablation, characterized, and studied in MSC cultures before and during differentiation. Humoral factor production (n = 41) was analyzed by Luminex technology. NPs were nontoxic, did not induce ROS production, and stimulated G-CSF, GM-CSF, VEGF, CXCL1 (GRO) production in four day MSC cultures. During MSC differentiation, all NPs stimulated CD13 and CD90 expression in osteogenic cultures. MSC differentiation resulted in a decrease in multiple humoral factor production to day 14 of incubation. NPs did not significantly affect the production in chondrogenic cultures and stimulated it in both osteogenic and adipogenic ones. The major difference in the protein production between osteogenic and adipogenic MSC cultures in the presence of NPs was VEGF level, which was unaffected in osteogenic cells and 4–9 times increased in adipogenic ones. The effects of NPs decreased in a row AuNPs > SiAuNPs > SiNPs. Taken collectively, high expression of CD13 and CD90 by MSCs and critical level of VEGF production can, at least, partially explain the stimulatory effect of NPs on MSC osteogenic differentiation