The influence of ceramic additives on intumescence and thermal activity of epoxy coatings for steel

The article presents results of the research on the influence of graphite/kaolin and graphite/titanium oxide systems on thermal properties, intumescence degree and the integrity of the structure of intumescent protective films based on epoxy resins for steel. The TG/DTG/DSC analysis showed that graphite/kaolin system shifted the decomposition reaction of epoxy resin towards higher temperatures, even by about 30°C. Fire endurance tests and the SEM analysis confirmed these results because more thermally resistant (T_500°C reached after 37.5 min for 1.1 coating thickness), swollen (about 20 times) and homogeneous coatings were obtained. The presented results suggest that ceramic fire retardants can successfully cooperate with organic components in intumescent protective coatings for steel elements.     

Synthesis of Novel Pyrido[1,2-c]pyrimidine Derivatives with 6-Fluoro-3-(4-piperidynyl)-1,2-benzisoxazole Moiety as Potential SSRI and 5-HT1A Receptor Ligands

Two series of novel 4-aryl-2H-pyrido[1,2-c]pyrimidine (6a–i) and 4-aryl-5,6,7,8-tetrahydropyrido[1,2-c]pyrimidine (7a–i) derivatives were synthesized. The chemical structures of the new compounds were confirmed by ¹H and ¹³C NMR spectroscopy and ESI-HRMS spectrometry. The affinities of all compounds for the 5-HT_1A receptor and serotonin transporter protein (SERT) were determined by in vitro radioligand binding assays. The test compounds demonstrated very high binding affinities for the 5-HT_1A receptor of all derivatives in the series (6a–i and 7a–i) and generally low binding affinities for the SERT protein, with the exception of compounds 6a and 7g. Extended affinity tests for the receptors D₂, 5-HT_2A, 5-HT₆ and 5-HT₇ were conducted with regard to selected compounds (6a, 7g, 6d and 7i). All four compounds demonstrated very high affinities for the D₂ and 5-HT_2A receptors. Compounds 6a and 7g also had high affinities for 5-HT₇, while 6d and 7i held moderate affinities for this receptor. Compounds 6a and 7g were also tested in vivo to identify their functional activity profiles with regard to the 5-HT_1A receptor, with 6a demonstrating the activity profile of a presynaptic agonist. Metabolic stability tests were also conducted for 6a and 6d.     

NMR-Based Metabolomics in Investigation of the Radiation Induced Changes in Blood Serum of Head and Neck Cancer Patients and Its Correlation with the Tissue Volumes Exposed to the Particulate Doses

In the present study, we analyze the nuclear magnetic resonance (NMR) blood serum metabolic profiles of 106 head and neck squamous cell carcinoma (HNSCC) patients during radio (RT) and concurrent radio-chemotherapy (CHRT). Four different fractionation schemes were compared. The blood samples were collected weekly, from the day before the treatment until the last week of CHRT/RT. The NMR spectra were acquired on A Bruker 400 MHz spectrometer at 310 K and analyzed using multivariate methods. Seven metabolites were found significantly to be altered solely by radiotherapy: N-acetyl-glycoprotein (NAG), N-acetylcysteine, glycerol, glycolate and the lipids at 0.9, 1.3 and 3.2 ppm. The NMR results were correlated with the tissue volumes receiving a particular dose of radiation. The influence of the irradiated volume on the metabolic profile is weak and mainly limited to sparse correlations with the inflammatory markers, creatinine and the lymphocyte count in RT and the branched-chain amino-acids in CHRT. This is probably due to the optimal planning and delivery of radiotherapy improving sparing of the surrounding normal tissues and minimizing the differences between the patients (caused by the tumor location and size).     

The Preliminary Study on the Proapoptotic Effect of Reduced Graphene Oxide in Breast Cancer Cell Lines

Breast cancer is the most common cancer diagnosed in women, however traditional therapies have several side effects. This has led to an urgent need to explore novel drug approaches to treatment strategies such as graphene-based nanomaterials such as reduced graphene oxide (rGO). It was noticed as a potential drug due to its target selectivity, easy functionalisation, chemisensitisation, and high drug-loading capacity. rGO is widely used in many fields, including biological and biomedical, due to its unique physicochemical properties. However, the possible mechanisms of rGO toxicity remain unclear. In this paper, we present findings on the cytotoxic and antiproliferative effects of rGO and its ability to induce oxidative stress and apoptosis of breast cancer cell lines. We indicate that rGO induced time- and dose-dependent cytotoxicity in MDA-MB-231 and ZR-75-1 cell lines, but not in T-47D, MCF-7, Hs 578T cell lines. In rGO-treated MDA-MB-231 and ZR-75-1 cell lines, we noticed increased induction of apoptosis and necrosis. In addition, rGO has been found to cause oxidative stress, reduce proliferation, and induce structural changes in breast cancer cells. Taken together, these studies provide new insight into the mechanism of oxidative stress and apoptosis in breast cancer cells.     

Ethylene vinyl acetate copolymer/halloysite nanotubes nanocomposites with enhanced mechanical and thermal properties

Ethylene vinyl acetate (EVA) nanocomposites filled with halloysite nanotubes (HNTs) were prepared by melt compounding. The homogenous dispersion of HNTs into the EVA matrix was evaluated by SEM and TEM analysis. The addition of HNTs does not influence on the phase separation structure and crystallinity of EVA nanocomposites. Due to the reinforcing effect of HNTs embedded in the EVA elastomer matrix, along with an increase of HNTs concentration, the improvement in tensile properties, by means of modulus at an elongation of 100% and tensile strength, was observed. It was found that tensile strength increased by 27% for EVA nanocomposite with 8 wt% of the HNTs. The values of elongation at break at low HNTs' loading increase and subsequently at higher loading are comparable to the neat EVA copolymer. The elastic deformability and reversibility of the EVA nanocomposites with different HNTs content was analyzed. The cyclic tensile tests showed that prepared nanocomposites have values of permanent set slightly higher than for neat EVA copolymer. Furthermore, the limiting oxygen index value for the EVA based nanocomposite with the highest HNTs content (8 wt%) increased from 19.5 to 24.8%. The results show, that thermo-oxidative stability were improved by the incorporation of HNTs into EVA copolymer matrix.     

Physical and sensory characteristics and probiotic survival in ice cream sweetened with various polyols

The effect of polyols (xylitol, erythritol, maltitol and isomalt) on physical and sensory properties of probiotic ice cream, as well as the survival of Bifidobacterium BB‐12 during freezing over 28 days of frozen storage, was investigated. The control sample of ice cream, sweetened with sugar, showed a lower pH and higher overrun than those sweetened with polyols. The viable bifidobacteria counts remained above 8 log cfu/g in all samples. The amount of erythritol added was not enough to obtain a similar sweetness as in control, but too high to get an ice cream with good textural properties.     

Identification of New QTLs for Dietary Fiber Content in Aegilops biuncialis

Grain dietary fiber content is an important health-promoting trait of bread wheat. A dominant dietary fiber component of wheat is the cell wall polysaccharide arabinoxylan and the goatgrass Aegilops biuncialis has high β-glucan content, which makes it an attractive gene source to develop wheat lines with modified fiber composition. In order to support introgression breeding, this work examined genetic variability in grain β-glucan, pentosan, and protein content in a collection of Ae. biuncialis. A large variation in grain protein and edible fiber content was revealed, reflecting the origin of Ae. biuncialis accessions from different eco-geographical habitats. Association analysis using DArTseq-derived SNPs identified 34 QTLs associated with β-glucan, pentosan, water-extractable pentosan, and protein content. Mapping the markers to draft chromosome assemblies of diploid progenitors of Ae. biuncialis underlined the role of genes on chromosomes 1M^b, 4M^b, and 5M^b in the formation of grain β-glucan content, while other QTLs on chromosome groups 3, 6, and 1 identified genes responsible for total- and water-extractable pentosan content. Functional annotation of the associated marker sequences identified fourteen genes, nine of which were identified in other monocots. The QTLs and genes identified in the present work are attractive targets for chromosome-mediated gene transfer to improve the health-promoting properties of wheat-derived foods.     

The Involvement of the Endogenous Opioid System in the Gastrointestinal Aging in Mice and Humans

Nearly 20% of elderly patients suffer from constipation, but the age-related changes in the gastrointestinal (GI) tract remain insufficiently elucidated. In this study, the alterations within the endogenous opioid system (EOS) as a potential cause of constipation in the elderly were evaluated. The GI functions were assessed in vitro and in vivo and compared between 6-, 12- and 18-month old mice. Moreover, the effect of opioid receptor (MOP, DOP, KOP) agonists on the mouse GI tract functions and the EOS components expression in mouse tissues and colonic biopsies from patients with functional constipation were determined. In the oldest mice, the GI peristalsis was significantly impaired as compared to the younger groups. The tissue response to MOP and DOP, but not KOP, agonists weakened with age in vitro; for DOP, it was confirmed in vivo. In the mouse upper GI tract, Oprm1, Oprd1, Oprk1 expression decreased with age; in the colon, Oprm1 expression increased. There were no differences in the expression of these genes in the colonic biopsies from patients >50 years old as compared to the younger group. In conclusion, the age-related impairment of the GI peristalsis may result from reduced MOP and DOP response to the activation with opioid agonists or the alterations in the EOS expression.     

The optimum choice of trenchless pipe laying technologies

A mathematical model AZ-01, which enables the choice of optimum trenchless pipe laying technology for given input data, has been presented. In the framework of AZ-01 presentation, a classification of trenchless methods applied in the model has been given, together with the assumptions, limiting conditions, input and output quantities. The algorithm of the model has been also discussed.