Influence of the Addition of Alumina Nanofibers on the Strength of Epoxy Resins.

The paper describes the effect of the addition of alumina nanofibers on the mechanical properties of the epoxy resin. Alumina nanofibers functionalized with epoxypropyl functional groups are used in this work. The dependence of the mechanical characteristics on the amount of the additive, as well as the features of its distribution in the material, is investigated. In the work, nanocomposites were obtained, which are epoxy resin with aluminum oxide nanofibers. The mechanical properties of the samples were studied by bending tests and differential mechanical analysis (DMA). It has been shown that the addition of alumina nanofibers leads to an increase in ultimate flexural strength. The maximum of this increase is near the percolation threshold of alumina nanofibers in epoxy resin. With the addition of 0.2% alumina nanofibers, the ultimate flexural strength increases from 41 to 71 MPa. It is shown that after exceeding the percolation threshold of nanofibers, the ultimate strength decreases. In this case, the elastic modulus increases from 0.643 to 0.862 GPa. DMA is shown that the glass transition temperature decreases with increasing amount of the additive. This indicates a decrease in the molecular weight of the polymer. By implication, this suggests that the hardener connects the epoxypropyl functional groups on the nanofibers and the epoxy groups in the resin, and as a result of this process, the nanofibers become natural polymer chain length limiters. The data obtained from mechanical testing and differential mechanical analysis can be used to strengthen epoxy resins in polymer composite materials and molding compositions.

Data on the synergistic effect of a hybrid filler based on graphene nanoplates and multiwalled nanotubes for increasing the thermal conductivity of an epoxy composite.

The dataset contains raw files related to the manuscript "The synergistic effect of a hybrid filler based on graphene nanoplates and multiwalled nanotubes for increasing the thermal conductivity of an epoxy composite" (Shalygina T.A. et al., 2021). The study presents the values of the heat capacity used to calculate the coefficients of thermal conductivity of epoxy composites by combining one-dimensional multiwalled nanotubes (MWCNTs) and two-dimensional graphene nanoplates (GNPs) in the role of a heat-conducting filler. To determine the heat capacity of materials with different concentrations of hybrid filler (GNP/MWCNT), the method of differential scanning calorimetry in the mode of the heat flux modulation was used. The analysis of the heat flux modulation samples is presented in raw and processed form. The materials scientists may apply the dataset to an in-depth study of the thermal conductivity formation mechanisms in composites doped with carbon-containing substances.

Data for determining the surface properties of carbon fiber in contact interaction with polymeric binders.

The data presented in this study are the supplementary materials related to the research paper "Determining the Surface Properties of Carbon Fiber in Contact Interaction with Polymeric Binders" (Voronina S.Yu. et al., 2018). The carbon fiber wettability properties before and after heat treatment and the coupling agent IR analysis results are presented. The coupling agent composition affects the fiber wettability and the capillary rise. The polymer binder impregnation rate drives the manufacturing process and the final composite quality. The data would be useful for researchers who study the interphase properties in composites and may help with determining the efficiency of applying certain polymers for wetting carbon fabrics.

Use of oligonucleotides conjugated to gold nanoparticles and streptavidin for amplification of optical biosensor signal during detection of telomeric repeats.

Hybridization of telomeric repeats with a complementary oligonucleotide probe was studied by the surface plasmon resonance method. Conjugation of the probe with streptavidin and gold nanoparticles was shown to amplify the signal at similar concentrations of this probe (by 60 and 300 times, respectively). Nanoparticles can be used for biosensor signal amplification in studying the telomerase activity of malignant cells.

Calcium signalling and pancreatic cell death: apoptosis or necrosis?

Secretagogues, such as cholecystokinin and acetylcholine, utilise a variety of second messengers (inositol trisphosphate, cADPR and nicotinic acid adenine dinucleotide phosphate) to induce specific oscillatory patterns of calcium (Ca(2+)) signals in pancreatic acinar cells. These are tightly controlled in a spatiotemporal manner, and are coupled to mitochondrial metabolism necessary to fuel secretion. When Ca(2+) homeostasis is disrupted by known precipitants of acute pancreatitis, for example, hyperstimulation or non-oxidative ethanol metabolites, Ca(2+) stores (endoplasmic reticulum and acidic pool) become depleted and sustained cytosolic [Ca(2+)] elevations replace transient signals, leading to severe consequences. Sustained mitochondrial depolarisation, possibly via opening of the mitochondrial permeability transition pore (MPTP), elicits cellular ATP depletion that paralyses energy-dependent Ca(2+) pumps causing cytosolic Ca(2+) overload, while digestive enzymes are activated prematurely within the cell; Ca(2+)-dependent cellular necrosis ensues. However, when stress to the acinar cell is milder, for example, by application of the oxidant menadione, release of Ca(2+) from stores leads to oscillatory global waves, associated with partial mitochondrial depolarisation and transient MPTP opening; apoptotic cell death is promoted via the intrinsic pathway, when associated with generation of reactive oxygen species. Apoptosis, induced by menadione or bile acids, is potentiated by inhibition of an endogenous detoxifying enzyme NAD(P)H:quinone oxidoreductase 1 (NQO1), suggesting its importance as a defence mechanism that may influence cell fate.

Pathways of processing of the gastrin precursor in rat antral mucosa.

The precursor of the acid-stimulating hormone gastrin gives rise to multiple peptides differing markedly in biological activity, but the relevant biosynthetic pathways are poorly understood. We have used antibodies to amidated gastrins, gastrins with COOH-terminal glycine (Gly) gastrins with COOH-terminal hydroxyglycine (GlyOH) and to the COOH terminus of progastrin, to immunoprecipitate peptides labeled with [35S]sulfate or [3H]tyrosine during incubation of rat antral mucosa in vitro. Labeled progastrin was detectable after 30 min of continuous incubation with isotopic precursors, G34 and G34-Gly after 60 min, and G17 and G17-Gly after 120 min. Pulse chase experiments indicated that progastrin is converted to G34-Gly which then follows one of two pathways: (a) hydroxylation of COOH-terminal Gly and conversion to G34 followed by cleavage yielding G17, or (b) cleavage to G17-Gly. The kinetics of G17-Gly and G17 labeling were similar, suggesting that G17-Gly is a product in its own right, and not simply an intermediate in G17 synthesis. Since the two peptides are reported to have distinct biological activities, they appear to be alternative mature products of progastrin processing.

[Use of probiothic subalin for correction of endogenous intoxication syndrome in children with chronic hepatitis].

The authors conducted the study on efficiency of Subalin medication for treatment children with chronic virus hepatitis. The use of improved curative complex including Subalin medication enables the regression of clinical signs of the disease, allows decreasing the signs of intoxication which alleviates the state of the children. Treatment with Subalin normalizes biochemical parameters of blood serum of the children: increase in content of whole protein, decreasing -thymol test index.

[Identification of an alien chromosome in the common wheat line multi 6R].

The chromosome of Agropyron intermedium (Host) Beauv. substituting chromosome 6D has been identified in the karyotype of the Triticum aestivum L. line Multi 6R with the use of C-banding. The alien chromosome, temporarily designated 6Ag1, contains gene(s) of the resistance to the Saratov population of Puccinia recondita Rob. ex. Desm. f. tritici. It has been demonstrated that the resistance gene(s) is(are) highly efficient and that chromosome 6Ag1 is preferably transferred through gametes.

[Titration of SH-groups of histone H3 in a DNP preparation of normal and neoplastic animal cells with a mercury-containing spin marker and with a DTNB preparation]. / Titrovanie SH-grupp gistona N3 v DNP normal'nykh i opukholevykh kletok zhivotnykh rtut'soderzhashchei spinovoi metkoi i preparatom DTNB.

DNP samples isolated from the cells of calf thymus and Ehrlich ascite carcinoma of mice were examined. SH-groups of histone H3 of chromatin from these cells were titrated with mercury-containing spin label and with DTNB under joint action of different salt and sarcosyl concentrations on DNP. The results revealed differences in accessibility and titration of histone H3 SH-groups in DNP of normal and tumor cells with DTNB, as well as in molecular dynamics of the mercury-containing spin label introduced to these SH-groups.

[Effects of plant growth regulators ambiol and phonk: biolphysical aspects]. / Biofizicheskie aspekty deistviia reguliatorov rosta ambiola i fonka.

The antioxidative activity of two plant growth promoters, ambiol and phonk, in a model system of photo-induced glycyltriptophane oxidation was measured. It was shown that ambiol has a significant antioxidative activity, whereas phonk is a weak antioxidant. The effects of these compounds on DNA conformation were studied in vitro and in vivo (on wheat seed shoots). In vitro ambiol had a stronger effect as compared with phonk, whereas in vivo the latter produced a more essential effect than ambiol. The assumption was done that both compounds affect indirectly the genome expression activity. Possible mechanisms of biological activity of each compound are discussed.

[Clinical assessment of immediate results of various methods of myocardial revascularization in ischemic heart disease patients with isolated anterior descending coronary artery disease]. / Klinicheskaia otsenka neposredstvennykh rezul'tatov razlichnykh metodov revaskuliarizatsii miokarda u bol'nykh ishemicheskoi bolezn'iu serdtsa s izolirovannym porazheniem perednei niskhodiashchei arterii.

Open heart coronary artery bypass grafting (CABG), minimally invasive coronary artery surgery, transluminal balloon coronary angioplasty (TBCA) and coronary stenting were carried out in 25, 35, 12 and 38 patients with isolated anterior descending coronary artery disease, respectively. In immediate period after procedures there were 2 deaths (among patients subjected to open heart CABG and TBCA) and 2 nonfatal myocardial infarctions (among patients treated with TBCA and stenting). In 2 patients repeat interventions were performed during initial hospitalization (in 1 after TBCA and in 1 after stenting). Exercise tolerance increased by 40+/-8, 44+/-7, 45+/-8, 53+/-9 W in patients treated with open heart CABG, minimally invasive surgery, TBCA and stenting, respectively. Thus surgical and endovascular methods of treatment of patients with isolated anterior descending coronary artery lesions produced beneficial clinical effect and were associated with relatively low rate of postoperative complications.

[Forlax in the treatment of the constipation syndrome in children with combined digestive organ pathology]. / Forlaks u likuvanni syndromu zapou u ditei z poiednanoiu patolohiieiu orhaniv travlennia.

Submitted in the paper are data on efficacy of the drug Forlax (Beaufour Ipsen, France) in the treatment of the constipation syndrome in those children presenting with associated pathology of the digestive system. The drug was found out to be effective in children, its therapeutic effect being recordable over one month in 76% of patients, which fact warrants further study of the curative potencies of the drug in children.

Downstream from calcium signalling: mitochondria, vacuoles and pancreatic acinar cell damage.

Ca(2+) is one of the most ancient and ubiquitous second messengers. Highly polarized pancreatic acinar cells serve as an important cellular model for studies of Ca(2+) signalling and homeostasis. Downstream effects of Ca(2+) signalling have been and continue to be an important research avenue. The primary functions regulated by Ca(2+) in pancreatic acinar cells--exocytotic secretion and fluid secretion--have been defined and extensively characterized in the second part of the last century. The role of cytosolic Ca(2+) in cellular pathology and the related question of the interplay between Ca(2+) signalling and bioenergetics are important current research lines in our and other laboratories. Recent findings in these interwoven research areas are discussed in the current review.

Movement of calcium signals and calcium-binding proteins: firewalls, traps and tunnels.

In the board game 'Snakes and Ladders', placed on the image of a pancreatic acinar cell, calcium ions have to move from release sites in the secretory region to the nucleus. There is another important contraflow - from calcium entry channels in the basal part of the cell to ER (endoplasmic reticulum) terminals in the secretory granule region. Both transport routes are perilous as the messenger can disappear in any place on the game board. It can be grabbed by calcium ATPases of the ER (masquerading as a snake but functioning like a ladder) and tunnelled through its low buffering environment, it can be lured into the whirlpools of mitochondria uniporters and forced to regulate the tricarboxylic acid cycle, and it can be permanently placed inside the matrix of secretory granules and released only outside the cell. The organelles could trade calcium (e.g. from the ER to mitochondria and vice versa) almost depriving this ion the light of the cytosol and noble company of cytosolic calcium buffers. Altogether it is a rich and colourful story.

Genetic control for resistance to leaf rust in wheat-Agropyron lines: Agro 139 and Agro 58.

Leaf rust resistance lines of Triticum aestivum carry highly effective Lr genes from Agropyron intermedium (Host) Beauv. This Agro 58 and Agro 139 resistance segregated independently of Agropyron leaf-rust resistance genes Lr-19, Lr-24 and Lr-9 from Ae. umbellulata. Monosomic analysis showed that the Lr gene in Agro 139 was incorporated into wheat chromosome 6D. C-banding analysis could not determine the C-banding pattern of A. intermedium in wheat -Agropyron lines Agro 58 and Agro 139. It is assumed that the transfers occurred from the euchromatin regions of the Agropyron chromosomes to the euchromatin regions of the wheat chromosomes. It is suggested that the Lr gene from Agro 139 be designated LrAg (i)-1 and the Lr gene from Agro 58 designated LrAg (i)-2.

[The Ca2+-activated photoprotein obelin as a calcium transport inducer in proteoliposomes in the membrane of the T-system of skeletal muscles]. / Ca2+-aktiviruemyi fotoprotein obelin kak indikator kal'tsievogo transporta v proteoliposomakh, vkliuchaiushchikh membrany T-sistemy skeletnykh myshts.

The calcium-binding photoprotein obelin extracted and purified from the luminescent hydroid Obelia longissima was used to record the processes of Ca2+ release from proteoliposomes. It has been shown that lecithin proteoliposomes with incorporated rabbit skeletal muscle T-system membranes possess a BAY K-8644-activated permeability which is inhibited by nitrendipine. The Ca(2+)-activated photoprotein obelin is a convenient and perspective tool in studies of fast calcium fluxes.