New kind of polymer materials based on selected complexing star-shaped polyethers

In today’s analytical trends, there is an ever-increasing importance of polymeric materials for low molecular weight compounds including amines and drugs because they can act as carriers or capture amines or drugs. The use of this type of materials will allow the development of modern materials for the chromatographic column beds and the substrates of selective sensors. Moreover, these kinds of materials could be used as a drug carrier. Therefore, the aim of this study is presenting the synthesis and complexing properties of star-shaped oxiranes as a new sensor for the selective complexation of low molecular weight compounds. Propylene oxide and selected oxirane monomers with carbazolyl in the substituent were selected as the monomers in this case and tetrahydrofuran as its solvent. The obtained polymer structures were characterized using the MALDI-TOF. It was found that in the initiation step potassium hydride deprotonates the monomer molecule and takes also part in the nucleophilic substitution. The resulting polymeric material preferably cross-linked with selected di-oxiranes (1,2,7,8-diepoksyoktan in respect ratio 3:1 according to active center) was then used as a stationary phase in the column and thin layer chromatography for amine separation and identification. Sorption ability of the resulting deposits was determined using a quartz microbalance (QCMB). The study was carried out in stationary mode and flow cells to simulate actual operating phase conditions. Based on changes in electrode vibration frequency, the maximum amount of adsorbed analyte and the best conditions for its sorption were determined

Corrosion resistance of heat-treated Ni-W alloy coatings

The paper presents research on evaluation of corrosion resistance of Ni-W alloy coatings subjected to heat treatment. The corrosion resistance was tested in 5% NaCl solution by the use of potentiodynamic polarization technique and electrochemical impedance spectroscopy. Characteristics of the Ni-W coatings after heat treatment were carried out using scanning electron microscopy, scanning Kelvin probe technique and X-ray di raction. Suggested reasons for the improvement of properties of the heat treated Ni-W coating, obtained at the lowest current density value (125 mA cm2), are the highest tungsten content (c.a. 25 at.%) as well as the smallest and the most homogeneous electrochemically active surface area

The influence of crown ether and alcohol on unsaturation and molar mass of poly(propylene oxide)s prepared by use of potassium t-butoxide: reinvestigation of chain transfer reactions

Potassium t-butoxide dissolved in tetrahydrofuran effectively initiates homogeneous polymerization of propylene oxide at room temperature. Unsaturation and molar mass (M n) of the polymers prepared depend on the presence of additives, such as macrocyclic ligand 18-crown-6 (L) and t-butanol. Application of the ligand alone results in distinct increase of unsaturation and decrease of M n, whereas use of t-BuOH leads to simultaneous decrease of unsaturation and M n. Activation of t-BuOK/t-BuOH system with the ligand causes further decrease of unsaturation, that is, from 12.0 to 3.5 mol % for OK/OH (1/3) and OK/OH/L (1/3/2) systems, respectively. Unexpectedly, M n of the polymers obtained does not practically change (4800). This result differs from that reported earlier for neat PO polymerization initiated potassium 1-methoxy-2-propoxide/1-methoxy-2-propanol, in which in the presence of the same ligand M n increases to 12 400 for the same ratio of reagents. The mechanism of studied processes was discussed

Comprehensive molecular and clinical analysis of adalimumab and etanercept therapeutic potentialin patients with psoriatic arthritis

Introduction: Adalimumab and etanercept are drugs used in anti-TNF therapy in patients with psoriasis and psoriatic arthritis. Despite the molecular targeting of these drugs, the loss of pharmacological response to treatment is observed in patients. The development of personalized medicine makes it possible to use not only clinical parameters of disease severity, but also molecular marker systems. Aim: The aim of the study was to evaluate the changes in TNF-α, TNFR1, and TNFR2 expression in relation to parameters of disease severity (PASI, BSA, DAS28) in patients treated with adalimumab and etanercept. We have attempted to determine whether changes in the TNF-α, TNFR1, and TNFR2 expression profile may be a useful molecular marker of the therapeutic potential of anti-TNF drugs. Material and methods: The study group consisted of 3 patients initially treated with adalimumab, followed by etanercept. The control group included 20 healthy volunteers. The expression profile of TNFR1 and TNFR2 was determined at the mRNA level, while TNF-α expression was evaluated at the transcriptome and proteome levels using the RT-qPCR method (transcriptional activity assay) and MALDI-TOF MS (protein level assessment). Results: Depending on the drug, different expression profiles of the studied cytokines are observed. Conclusions: The obtained data indicate that TNF-α, TNFR1, and TNFR2 may be useful markers of the efficacy of anti-TNF therapy, thus complementing clinical parameters

Novel organic material induced by electron beam irradiation for medical application

This study analyzed the e ects of irradiation of polytetrafluoroethylene (PTFE) containing 40% of bronze using an electron beam with energy of 10 MeV. Dosages from 26 to156 kGy (2.6–15.6 Mrad) were used. The impact of a high-energy electron beam on the thermal, spectrophotometric, mechanical, and tribological properties was determined, and the results were compared with those obtained for pure PTFE. Thermal properties studies showed that such irradiation caused changes in melting temperature Tm and crystallization temperature Tc, an increase in crystallization heat DHc, and a large increase in crystallinity c proportional to the absorbed dose for both polymers. The addition of bronze decreased the degree of crystallinity of PTFE by twofold. Infrared spectroscopy (FTIR) studies confirmed that the main phenomenon associated with electron beam irradiation was the photodegradation of the polymer chains for both PTFE containing bronze and pure PTFE. This had a direct e ect on the increase in the degree of crystallinity observed in DSC studies. The use of a bronze additive could lead to energy dissipation over the additive particles. An increase in hardness H and Young’s modulus E was also observed. The addition of bronze and the irradiation with an electron beam improved of the operational properties of PTFE

Ceramic biomaterial pores stereology analysis by the use of microtomography

The main aim of this study was to analyze microtomographic data to determine the geo-metric dimensions of a ceramic porous material’s internal structure. Samples of a porous corundum biomaterial were the research material. The samples were prepared by chemical foaming and were measured using an X-ray scanner. In the next stage, 3D images of the samples were generated and analyzed using Thermo Scientific Avizo software. The analysis enabled the isolation of individual pores. Then, the parameters characterizing the pore geometry and the porosity of the samples were calculated. The last part of the research consisted of verifying the developed method by compar-ing the obtained results with the parameters obtained from the microscopic examinations of the biomaterial. The comparison of the results confirmed the correctness of the developed method. The developed methodology can be used to analyze biomaterial samples to assess the geometric dimensions of biomaterial pores

Electrolytic production and characterization of nickel-rhenium alloy coatings

Electrolytic Ni–Re alloy coatings were obtained in galvanostatic conditions from nickel–rhenium baths with different contents of ammonium rhenate(vii) (0.5, 1.25, 2.5 and 5 g·L−1). The surface morphology, chemical, and phase composition of the obtained materials were determined. The coatings’ corrosion resistance tests were carried out in a 5% NaCl solution. Based on the tests, it was found that the highest corrosion resistance characterizes the coating with the highest rhenium content (37%). This material can be recommended for practical use as a protective coating. The density of the deposited Ni–37Re alloy was determined, and its specific surface area was assessed. The melting point, hardness, and electrical conductivity were also determined

Evaluation of Structure and Corrosion Behavior of FeAl Alloy after Crystallization, Hot Extrusion and Hot Rolling

The paper presents the results of tests on the corrosion resistance of Fe40Al5Cr0.2TiB alloy after casting, plastic working using extrusion and rolling methods. Examination of the microstructure of the Fe40Al5Cr0.2TiB alloy after casting and after plastic working was performed on an Olympus GX51 light microscope. The stereological relationships of the alloy microstructure in the state after crystallization and after plastic working were determined. The quantitative analysis of the structure was conducted after testing with the EBSD INCA HKL detector and the Nordlys II analysis system (Channel 5), which was equipped with the Hitachi S-3400N microscope. Structure tests and corrosion tests were performed on tests cut perpendicular to the ingot axis, extrusion direction, and rolling direction. As a result of the tests, it was found that the crystallized alloy has better corrosion resistance than plastically processed material. Plastic working increases the intensity of the electrochemical corrosion of the examined alloy. It was found that as-cast alloy is the most resistant to corrosion in a 5% NaCl compared with the alloys after hot extrusion and after hot rolling

Effect of 12-Week functional training intervention on the speed of young footballers

The aim of the research was to verify the functional state of young football players using selected tests of the Functional Movement Screen (FMS) protocol, as well as the impact of the 12 weeks of functional training on the speed parameters. The research was conducted on 20 highly competitive young (U17) football players. Research project was conducted in two stages: in the first part of the study, the functional assessment was made by using the FMS test, then the measurement of the speed parameters was done with the Microgate photocells system. Results showed a significant improvement in the functional state of young football players: FMS 1 (45.2% of difference, p = 0.004), FMS 2 (24.3% of difference, p = 0.012), FMS 3 (48.5% of difference, p = 0.001). After the functional training program, there was also an improvement in the parameters of the acceleration and velocity: acceleration between 5-10 m and speed between 10-30 m shows significant improvement (expressed during covering a given distance) of the footballers, amounting to 0.02 s (2.4%) and 0.04 s (1.5%). But there was no improvement in acceleration between 0-5 m. An appropriate training schedule, based on FMS results, should be adopted in the annual training program to improve basic motor skills of the football players and minimize their injuries

Relationship between vertical jump tests and ice-skating performance in junior Polish ice hockey players

The aim of this study was to determine the relationships between vertical jumps (VJ) and various on-ice skating performances of junior ice hockey players (n = 19). The three modes of VJ or off-ice measures were countermovement jump with arm swing (CMJ), squat jump (SJ) and depth drop jump (DDJ). The on-ice skating performance was measured by the skating multistage aerobic test (SMAT), forward and backward acceleration test, top speed test, and repeated sprint ability (RSA) test. The relationships between the variables were quantified using Pearson’s product-moment correlation. DDJ showed a significant positive correlation with forward average skating speed (FASS) (r = 0.62) and strong correlations with backward average skating speed (BASS) (r = 0.81), and maximum skating speed (MSS) (r = 0.71). SJ was found to be strongly correlated with BASS (r = 0.82) and MSS (r = 0.76), whereas the only on-ice performance that significantly correlated with CMJ was BASS (r = 0.68). All three modes of VJ were inversely and non-significantly correlated with performance decrement index and fatigue index, as determined by the RSA test. SMAT was not significantly correlated with either VJ or RSA. Correlations between all three modes of VJ tests were significant. Therefore, this study concludes that: (1) DDJ can be used as a predictor of all the ice skating speed tests, whereas SJ can predict BASS and MSS. CMJ, on the other hand, can predict the performance of only BASS. (2) RSA performance cannot be predicted from CMJ, SJ, or DDJ tests, and (3) neither any of the VJ nor RSA can predict skating endurance of junior ice hockey players