Glycan and lectin biosensorš

A short description about the importance of glycan biorecognition in physiological (blood cell type) and pathological processes (infections by human and avian influenza viruses) is provided in this review. Glycans are described as much better information storage media, compared to proteins or DNA, due to the extensive variability of glycan structures. Techniques able to detect an exact glycan structure are briefly discussed with the main focus on the application of lectins (glycan-recognising proteins) in the specific analysis of glycans still attached to proteins or cells/viruses. Optical, electrochemical, piezoelectric and micromechanical biosensors with immobilised lectins or glycans able to detect a wide range of analytes including whole cells/viruses are also discussed

Association between TCF7L2

Previous studies showed associations between variants in TCF7L2 gene and the therapeutic response to sulfonylureas. All sulfonylureas stimulate insulin secretion by the closure of ATP-sensitive potassium (KATP) channel. The aim of the present study was to compare TCF7L2 genotype specific effect of gliclazide binding to KATP channel A-site (Group 1) with sulfonylureas binding to AB-site (Group 2). A total of 101 patients were treated with sulfonylureas for 6 months as an add-on therapy to the previous metformin treatment. TCF7L2 rs7903146 C/T genotype was identified by real-time PCR with subsequent melting curve analysis. Analyses using the dominant genetic model showed significantly higher effect of gliclazide in the CC genotype group in comparison with combined CT + TT genotype group (1.32±0.15% versus 0.73±0.11%, Padj=0.005). No significant difference in ΔHbA1c between the patients with CC genotype and the T-allele carriers was observed in Group 2. In the multivariate analysis, only the TCF7L2 genotype (P=0.006) and the baseline HbA1c (P<0.001) were significant predictors of ΔHbA1c. After introducing an interaction term between the TCF7L2 genotype and the sulfonylurea type into multivariate model, the interaction became a significant predictor (P=0.023) of ΔHbA1c. The results indicate significantly higher difference in ΔHbA1c among the TCF7L2 genotypes in patients treated with gliclazide than in patients treated with glimepiride, glibenclamide, or glipizide

Polypyrrole nanotubes decorated with gold particles applied for construction of enzymatic bioanodes and biocathodes

The novel composites of gold nanoparticles and polypyrrole nanotubes (Au-x@PNT) were prepared and used as a platform for fabrication of bioelectrode interfaces. Changing the conditions of composite preparation caused variations in a gold architecture, electrical conductivity and a biocompatibility. These features could be easily adjusted by setting up a proper fabrication protocol. The Au-x@PNT-chitosan matrix was utilized for fabrication of bioelectrode interfaces with physisorbed oxidoreductases. Biocatalytic activity of such physisorbed fructose dehydrogenase (FDH), laccase (Lac) and bilirubin oxidase (BOD) was investigated with biocatalytic current density up to j = 2.45 mA cm(-2) obtained for a bioanode based on direct electron transfer of FDH. Performance of biocathodes with immobilized Lac and BOD showed current density up to 232 mu A cm(-2) in presence of a redox mediator.NPRP grant from the Qatar National Research Fund (Qatar Foundation) [6-381-1-078

RESEARCH OF LIMITED AND UNLIMITED EMISSION EFFECT ON THE ENVIRONMENT DURING THE BURNING OF ALTERNATIVE FUELS IN AGRICULTURAL TRACTORS

This work is aimed at the basic analysis of diesel oil and rapeseed methyl ester and evaluation of limited and unlimited emission produced by their combustion. Thereafter, test results are compared, and there is also done the evaluation of emission – greenhouse gases, dangerous exhaust gases and strong carcinogens and their contents during fuel combustion. These measurements were performed at the Research Station Agroscope ART in Tänikon (AAT) in Switzerland and in cooperation with the Department of Transport and Handling (DTH), Faculty of Engineering, Slovak University of Agriculture in Nitra

EFFECT OF ECOLOGICAL ENERGY CARRIERS ON FLOW CHARACTERISTICS OF TRACTOR HYDRAULIC PUMP

This paper deals with the effect of ecological energy carrier on flow characteristics of a hydraulic pump. A hydraulic oil MOL Farm UTTO Synt was used as an ecological energy carrier. After completing 900 engine hours, the flow efficiency of the hydraulic pump decreased by Δηpr = 1.197 %. Oil samples were taken from the agricultural tractor Zetor Forterra 114 41. These samples were subjected to an IR spectroscopy analysis in an accredited laboratory WearCheck, Hungary. The following oil properties were examined: kinematic viscosity at 40 °C, viscosity index, silicium and ferrum content

Tailoring electrocatalytic properties of Pt nanoparticles grown on Ti3C2Tx MXene surface

In this work, the spontaneous and NaBH4-induced reduction of chloroplatinic acid on the surface of Ti3C2TX MXene was investigated to synthesize a hybrid PtNP-decorated MXene nanomaterial (MX-Pt) with potential as hydrogen evolution (HER) or oxygen reduction reaction (ORR) catalyst properties. The initial Pt concentration, reduction time and presence of additional reducing agents were varied, and as-synthesized nanocomposites were characterized thoroughly by XRD, EDX, SEM and XPS analysis and by electrochemical methods. Composites containing 14 wt% Pt showed HER with an onset potential of -75.9 mV and a current density of -10 mA cm(-2) achieved at -226 mV. The spontaneous deposition of PtNPs on MXene improved the electrocatalytic properties over using an external reducing agent to form PtNP, which was explained based on the different rates of oxidation of Ti in the initial MXene support. Furthermore, good stability of the electrode modified by the MX-Pt was achieved without any polymeric binder and the HER reaction achieved only a negligible decrease over 3 000 potentiodynamic cycles. (C) 2019 The Electrochemical Society.Qatar National Research Fund (a member of The Qatar Foundation) NPRP grant [9-219-2-105

Nicotinamide-based supergelator self-assembling via asymmetric hydrogen bonding NH⋯OC and H⋯Br− pattern for reusable, moldable and self-healable nontoxic fuel gels

Hypothesis: Development of highly efficient low-molecular weight gelators (LMWGs) for safe energy storage materials is of great demand. Energy storage materials as fuel gels are often achieved by construction of hybrid organic frameworks capable of multiple noncovalent interactions in self-assembly, which allow tuning required properties at the molecular level by altering individual building blocks of the LMWG. However, LMWGs have limited rechargeable capability due to their chemical instability. Experiments: We designed, synthesized and characterized a novel, bio-inspired chiral gemini amphiphile derivative 1 containing N-hexadecyl aliphatic tails from quaternized nicotinamide-based segment and bromide anion showing supergelation ability in water, alcohols, aprotic polar and aromatic solvents, with critical gel concentrations as low as 0.1 and 0.035 wt% in isopropanol and water, respectively. Findings: Nanostructural architecture of the network depended on the solvent used and showed variations in size and shape of 1D nanofibers. Supergelation is attributed to a unique asymmetric NH⋯OC, H⋯Br− hydrogen bonding pattern between H-2 hydrogens from nicotinamide-based segment, amide functional groups from chiral trans-cyclohexane-1,2-diamide-based segment and bromide ions, supporting the intermolecular amide–amide interactions appearing across one strand of the self-assembly. Gels formed from 1 exhibit high stiffness, self-healing, moldable and colorable properties. In addition, isopropanol gels of 1 are attractive as reusable, shape-persistent non-toxic fuels maintaining the chemical structure with gelation efficiency for at least five consecutive burning cycles. © 2021 Elsevier Inc.Chemical Institute, Slovak Academy of Sciences [IRCC-2020004]; Slovak Research and Development AgencySlovak Research and Development Agency [APVV-17-0324]; Ministry of Education of the Slovak Republic [1/0712/18, 1/0145/20]; European Union's Horizon 2020 research and innovation programme [810701]; Ministry of Education, Youth and Sports of the Czech Republic-DKRVO [RP/CPS/2020/003]; Qatar National Library; Qatar University [IRCC-2020004]RP/CPS/2020/003; Univerzita Komenského v Bratislave; Horizon 2020 Framework Programme, H2020: 810701; Slovenská Akadémia Vied, SAV: IRCC-2020-004; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Ministerstvo školstva, vedy, výskumu a športu Slovenskej republiky; Qatar University, QU; Agentúra na Podporu Výskumu a Vývoja, APVV: APVV-17-0324; Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGA: 1/0145/20, 1/0712/18; Horizon 202

Identification of molecular fluorophore as a component of carbon dots able to induce gelation in a fluorescent multivalent-metal-ion-free alginate hydrogel

We introduce a simple approach to fabricate fluorescent multivalent metal ion-free alginate hydrogels, which can be produced using carbon dots accessible from natural sources (citric acid and L-cysteine). Molecular fluorophore 5-oxo-2,3-dihydro-5H-[1,3]-thiazolo[3,2-a] pyridine-3,7-dicarboxylic acid (TPDCA), which is formed during the synthesis of carbon dots, is identified as a key segment for the crosslinking of hydrogels. The crosslinking happens through dynamic complexation of carboxylic acid groups of TPDCA and alginate cages along with sodium ions. The TPDCA derived hydrogels are investigated regarding to their thermal, rheological and optical properties, and found to exhibit characteristic fluorescence of this aggregated molecular fluorophore. Moreover, gradient hydrogels with tunable mechanical and optical properties and controlled release are obtained upon immersion of the hydrogel reactors in solutions of divalent metal ions (Ca2+, Cu2+, and Ni2+) with a higher affinity to alginate. © 2019, The Author(s).Qatar National Research Fund (Qatar foundation) [8-878-1-172]; Qatar University grant [QUCG-CAM-19/20-2]; Germany/Hong Kong Joint Research Scheme - Research Grants Council of Hong Kong; Germany Academic Exchange Service of Germany [G-CityU103/16]; VEGA Scientific Grant AgencyVedecka grantova agentura MSVVaS SR a SAV (VEGA) [2/0158/17

Operation of distributed energy sources

Renewable energy sources are becoming more prominent in securing the energy needs of mankind. Increasing share of renewable distributed electricity sources is one of possibilities how to cover growth of electricity consumption. So far, these sources have insignificant contribution in energy balance in Slovakia. Interest of investors in sources installing is very intensive and reaches some GW. This article is focused to possibilities of modelling of operation of distributed energy sources

Distributed generation and renewable energy sources for sustainable life

This article deals with utilisation of renewable energy sources with orientation on their benefits and handicaps. Possibilities of distributed generation and utilisation of the renewable energy sources are also mentioned. Actual conditions of these sources within the European Union are analysed, and their external costs are compared with the external costs of conventional energy sources. The continual development of the renewable energy sources utilisation is emphasised