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Nanocrystalline silicate-substituted hydroxyapatites Ca10−xEux(PO4)4(SiO4)2(OH)2 (where x = 0.5, 1.0, 2.0, 5.0 mol%) doped with Eu3+ ions were synthesized using a microwave assisted hydrothermal method and heat-treated in the temperature range from 700 to 1000 °C. The concentration of optically active Eu3+ ions was established in the range of 0.5–5 mol% to investigate the preference of occupancy sites. The structural and morphological properties of the obtained biomaterials were determined by using XRD (X-Ray Powder Diffraction), TEM (Transmission Electron Microscopy) and SEM (Scanning Electron Microscopy) techniques as well as infrared (IR) spectroscopy. The average particle sizes were calculated to be in the range from 20 nm to 80 nm by the Rietveld method. The charge compensation mechanism in europium(iii)-doped silicate-substituted hydroxyapatite was proposed in the Kröger–Vink-notation. The luminescence properties (the emission, excitation spectra and emission kinetics) of the Eu3+ ion-doped apatite were recorded depending on the dopant concentration. The existence of Eu2+ ions was confirmed by the emission spectra. [ABSTRACT FROM AUTHOR]

The aim of this study was to follow up whether the modification of pro-antioxidant status by oral thiol administration such as Nacetylcysteine and α-lipoic acid affects the hematological response. Twenty-eight healthy men participated in two independent experiments. Subjects were randomly assigned to one of four groups: controls (CNAC and CALA), N-acetylcysteine (NAC) and α-lipoic acid (ALA). 1200 mg of N-acetylcysteine, 600 mg of α-lipoic acid or placebo were administered for 8 days in two doses. NAC or ALA administration significantly elevated plasma total antioxidant status (TAS) and reduced protein carbonylation (PC) and lipid peroxidation (TBARS) by more than 30 %. The reduced glutathione (GSH) and hematological parameters changed only in response to NAC administration. NAC significantly elevated the level of GSH (+33 %), EPO (+26 %), Hb (+9 %) and Hct (+9 %) compared with CNAC. The mean corpuscular volume (MCV) and the mean corpuscular hemoglobin (MCH) also increased by more than 12 % after NAC. The numerous negative or positive correlations between the measures of TAS, PC, TBARS and hematological parameters were found, which suggest the NAC-induced interaction between proantioxidant and hematological values. Our study has shown that both N-acetylcysteine and α-lipoic acid intake reveal an antioxidant action, but only N-acetylcysteine improves the haematological response. [ABSTRACT FROM AUTHOR]

Continuous efforts are ongoing to discover new luminescent materials with appropriate properties for applications in medicine, serving as theranostic agents for healing and bioimaging. In this paper, novel single-phase carbonated calcium chlorapatite (Ca 10 (PO 4 ) 5 (CO 3 )Cl 2 , abbreviated as CaClAp-CO 3 ) phosphors activated with varying concentrations of Sm 3+ ions were successfully fabricated using both co-precipitation and hydrothermal methods to investigate the influence of the synthesis techniques on the physicochemical properties of these materials. The effects of doping concentration of Sm 3+ ions and synthesis techniques on the structure, photoluminescence (PL), energy transfer, substitute sites, fluorescence lifetime and luminescence colour of phosphors were investigated. The synthesized phosphors were characterized by X-ray diffraction (XRD) to confirm their crystal phase structure and purity. Vibrational features and the incorporation of carbonate ions were verified using Fourier-transform infrared (FTIR) spectroscopy. The obtained materials emit reddish-orange light, primarily from the most intense 4 G 5/2 → 6 H 7/2 transition. The electric dipole to magnetic dipole transition ratio (ED/MD), CIE colour coordinates and colour purity were determined to provide additional insights into the spectroscopic attributes of the obtained phosphors. In addition, the concentration quenching was also observed, and its mechanism was proposed based on theoretical calculations showing the multipolar interactions.

Graphene has been one of the most tested materials since its discovery in 2004. It is known for its special properties, such as electrical conductivity, elasticity and flexibility, antimicrobial effect, and high biocompatibility with many mammal cells. In medicine, the antibacterial, antiviral, and antitumor properties of graphene have been tested as intensively as its drug carrying ability. In this study, the protective effect of graphene oxide against Rubella virus infection of human lung epithelial carcinoma cells and human chondrocyte cells was examined. Cells were incubated with graphene oxide alone and in combination with the Rubella virus. The cytopathic effect in two incubation time periods was measured using DAPI dye as a percentage value of the changed cells. It was shown that the graphene oxide alone has no cytopathic effect on any of tested cell lines, while the Rubella virus alone is highly cytopathic to the cells. However, in combination with the graphene oxide percentage of the changed cells, its cytotopathicity is significantly lower. Moreover, it can be concluded that graphene oxide has protective properties against the Rubella virus infection to cells, lowering its cytopathic changes to the human cells.

The hydroxyapatite nanopowders of the Eu 3+ -doped, Cu 2+ -doped, and Eu 3+ /Cu 2+ -co-doped Ca 10 (PO 4 ) 6 (OH) 2 were prepared by a microwave-assisted hydrothermal method. The structural and morphological properties of the products were investigated by X-ray powder diffraction (XRD), transmission electron microscopy techniques (TEM), and infrared spectroscopy (FT-IR). The average crystal size and the unit cell parameters were calculated by a Rietveld refinement tool. The absorption, emission excitation, emission, and luminescence decay time were recorded and studied in detail. The 5 D 0 → 7 F 2 transition is the most intense transition. The Eu 3+ ions occupied two independent crystallographic sites in these materials exhibited in emission spectra: one Ca(1) site with C 3 symmetry and one Ca(2) sites with C s symmetry. The Eu 3+ emission is strongly quenched by Cu 2+ ions, and the luminescence decay time is much shorter in the case of Eu 3+ /Cu 2+ co-doped materials than in Eu 3+ -doped materials. The luminescence quenching mechanism as well as the schematic energy level diagram showing the Eu 3+ emission quenching mechanism using Cu 2+ ions are proposed. The electron paramagnetic resonance (EPR) technique revealed the existence of at least two different coordination environments for copper(II) ion.

Eu 3+ -doped Sr 10 (PO 4 ) 6 (OH) 2 -Sr 3 (PO 4 ) 2 (SrHAp-TSP) composites were obtained via the microwave-stimulated hydrothermal method and post-heat-treated from 750 to 950 °C. Concentration of the Eu 3+ ions was set to be 0.5, 1, 2, 3, 5 mol% in a ratio of the strontium ions molar content. The structural and morphological properties were investigated by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR) techniques. The average particle size of the studied materials annealed at 750, 850 and 950 °C were counted about 100, 131 and 173 nm, respectively. The luminescence properties depending on the dopant ion concentration, heat-treatment temperature, excitation wavelength and temperature were investigated. In the emission spectra, a broad peak corresponding to the 4f 6 5d 1 → 4f 7 ( 8 S 7/2 ) emission of Eu 2+ ions as well as narrow 4f-4f transitions typical for Eu 3+ ions can be observed. The luminescence intensity of the 1 mol% Eu 3+ :Sr 10 (PO 4 ) 6 (OH) 2 -Sr 3 (PO 4 ) 2 was measured depending on the ambient temperature in the range of 80-550 K. The CIE 1931 (International Commission on Illumination) chromaticity diagram was determined from emission spectra measured in 80, 300 and 550 K. The reduction mechanism of the Eu 3+ to the Eu 2+ was explained by the charge compensation mechanism based on the Kröger-Vink-notation. The decay times were measured and the Judd-Ofelt (J-O) theory was applied to analyze the observed structural and spectroscopic features., Competing Interests: The authors declare no conflicts of interest.

The Eu 3+ and Sr 2+ ions co-doped hydroxyapatite nanopowders (Ca 10 (PO 4 ) 6 (OH) 2 ) were synthesized via a precipitation method and post heat-treated at 500 °C. The concentration of Eu 3+ ions was established in the range of 0.5-5 mol% to investigate the site occupancy preference. The concentration of Sr 2+ ions was set at 5 mol%. The structural and morphological properties of the obtained materials were studied by an X-ray powder diffraction, a transmission electron microscopy techniques and infrared spectroscopy. As synthesized nanoparticles were in the range of 11-17 nm and annealed particles were in the range of 20-26 nm. The luminescence properties in dependence of the dopant concentration and applied temperature were investigated. The 5 D 0  →  7 F 0 transition shown the abnormally strong intensity for annealed materials connected with the increase of covalency character of Eu 3+ -O 2- bond, which arise as an effect of charge compensation mechanism. The Eu 3+ ions occupied three possible crystallographic sites in these materials revealed in emission spectra: one Ca(1) site with C 3 symmetry and two Ca(2) sites with C s symmetry arranged as cis and trans symmetry. The antibacterial properties of Eu 3+ and Sr 2+ ions doped and co-doped hydroxyapatite nanopowders were also determined against Gram-negative pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. Obtained results suggest that both europium and strontium ions may implement antibacterial properties for hydroxyapatites. In the most cases, better antibacterial effect we noticed for dopants at 5 mol% ratio. However, the effect is strongly species- and strain-dependent feature., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

In response to the need for new materials for theranostics application, the structural and spectroscopic properties of composites designed for medical applications, received in the melt mixing process, were evaluated. A composite based on medical grade poly(L-lactide) (PLLA) and calcium hydroxyapatite (HAp) doped with Eu 3+ ions was obtained by using a twin screw extruder. Pure calcium Hap, as well as the one doped with Eu 3+ ions, was prepared using the precipitation method and then used as a filler. XRPD (X-ray Powder Diffraction) and IR (Infrared) spectroscopy were applied to investigate the structural properties of the obtained materials. DSC (Differential Scanning Calorimetry) was used to assess the Eu 3+ ion content on phase transitions in PLLA. The tensile properties were also investigated. The excitation, emission spectra as well as decay time were measured to determine the spectroscopic properties. The simplified Judd-Ofelt (J-O) theory was applied and a detailed analysis in connection with the observed structural and spectroscopic measurements was made and described.

Aim: The goal of the study was to clarify the sequence of cytokines and inflammatory cells in non-athletes performed an intense running exercise., Methods: Sixteen young healthy men participated in the exercise trial that involved 90-min run at 65% VO2max., Results: The plasma concentrations of anti-inflammatory cytokines IL-4, IL-6 and IL-10 increased immediately after exercise simultaneously with number of white blood cells. Between IL-6 and IL-10, and neutrophils the relationships were observed. The correlation value for IL-6 and neutrophils was 0.775 whereas for IL-10 and neutrophils was 0.506. The proinflammatory cytokines IL-1β and TNFα were detected at 6 h after exercise and moderately correlated with monocytes count. The high level of proinflammatory cytokines, monocytes and creatine kinase (CK) remained until 48 h rest. The CK activity significantly correlated with IL-1β (r=0.578) and TNFα (r=0.452), and also with monocytes count (r=0.439)., Conclusion: The results have shown that: 1) exercise induces anti-inflammatory cytokines production first and then proinflammatory cytokines; and 2) prolonged proinflammatory response is closely related with muscle damage present.

The aim of the study was to compare effects of three-day N-acetylcysteine, alpha-lipoic acid or taurine administration on plasma antioxidant status and oxidative damage markers in healthy men after performing muscle-damaging exercise. Fifty-five healthy and trained men were randomly assigned to N-acetylcysteine (NAC, 1.8 g/day, 3 days), alpha-lipoic acid (ALA, 1.2 g/day, 3 days), taurine (TAU, 3 g/day, 3 days) and control group (CON), and exposed to intense resistance exercise. The resistance exercise induced the muscle damage which was observed by significant increase in total creatine kinase (CK) activity at 24 h rest. The administration of NAC and ALA significantly elevated the resting or/and postexercise plasma total antioxidant status (TAS) and total thiols (TT). Uric acid (UA) concentration was decreased by NAC, ALA and TAU at 24 h rest compared with CON. The plasma lipid peroxidation (TBARS) and protein carbonylation (PC) were considerably reduced by NAC and ALA administration at rest and after exercise. TAU did not have any influence on TAS, TT, TBARS and PC levels. Our study has shown that three-day oral N-acetylcysteine and alpha-lipoic acid administration enhanced plasma total antioxidant status and attenuated oxidative damage whereas taurine did not demonstrate any antioxidant action in healthy men after performing a single muscle-damaging exercise.

The aim of this study was to ascertain the influence of cysteine derivatives on pro-antioxidant equilibrium and to compare the antioxidant effectiveness of N-acetylcysteine, alpha-lipoic acid, and taurine by using Loverro's coefficient (pro-antioxidant ratio) in healthy men exposed to intensity-resistance exercise. Fifty-five men were randomly assigned to one of four groups: control (CON, placebo), N-acetylcysteine (NAC 1.8 g.day(-1), 3 days), alpha-lipoic acid (LIP 1.2 g.day(-1), 3 days), or taurine (TAU 3 g.day(-1), 3 days). The erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities, lipid peroxidation products (TBARS), and plasma protein thiol concentrations were evaluated. The P/A ratio was determined from the mean values of TBARS, SOD, GPx, and CAT. The applied exercise at maximal intensity induced the significant changes in pro-antioxidant equilibrium toward peroxidation, which was proved by a 25% increase in TBARS concentration in the CON group. The peroxidation was significantly diminished by NAC (-14%) and LIP (-16%), whereas TAU had no effect on the TBARS concentration. Cysteine derivatives administration prevented exercise-induced decline in SOD activity and increased in GPx activity during exercise. CAT activity changed only in the LIP group. The estimation of P/A ratio showed the lowest level of pro-antioxidant equilibrium after LIP administration. In the CON group, P/A ratio was directly correlated with the protein thiols level (r = 0.495, p < 0.001). These data confirm the antioxidant action of tested cysteine derivatives, particularly lipoic acid, and demonstrate the practical application of P/A ratio to evaluate the effectiveness of antioxidants in athletes.

Aim: The purpose of this research was to explain whether a single dose of vitamin E influences on disturbances of pro-oxidant-antioxidant equilibrium induced a laboratory 2,000 m rowing test., Methods: The athletes were divided into two groups: vitamin E (1.000 mg alfa-tocopherol acetate) and P (placebo: cod-liver oil) supplemented 3 h before exercise. In the subjects' blood levels of following parameters were estimated: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), lipid peroxidation products (TBARS) and protein carbonyls (PC). Creatine kinase (CK) and beta-glucuronidase (betaG) activities were also measured as markers of muscle damage., Results: The applied exercise at maximal intensity (lactate: vitamin E=14.39+/-1.77 mmol/L, P=14.09+/-1.4 mmol/L) caused significant changes in the tested parameters in both groups: SOD (vitamin E Ø30%, P Ø50%), CAT (vitamin 70%, P 12%), GPx (vitamin 49%, P 45%), TBARS (vitamin 70%, P 71%), PC (vitamin 41%, P 78%), CK (vitamin 19%, P 32%), betaG (vitamin 42%, P 47%). The P/A ratio (TBARS/SOD+CAT+GPx) was significantly lower in vitamin E in comparison with placebo, but after 30 min and 24 h restitution it returned to pre-exercise level. Between P/A ratio and PC concentration there was observed positive correlation (P<0.001). No effect of vitamin E on CK and betaG activities were observed., Conclusions: A single dose of 1,000 mg vitamin E enhances oxidative defense thus attenuates oxidative damage but it is not so much relevant to recommend the antioxidant supplementation by rowers.

Background: One of the effects of burn injury is production of reactive oxygen species increasing general-structural damage. Such a condition is called oxidative stress. The purpose of this research was to find out whether oxidative stress is present in burnt children treated routinely and, if so, in which phase of the disease it is the most severe and how long it persists., Material and Methods: The study was carried out on a group of 84 burnt children. The patients were divided into 2 groups: lightly burnt (LB-N:55) and moderately to severely burnt (SB-N:29). Blood samples were collected based on hospitalization period within the 1st, 2nd, 3rd, 7th and 21st day, respectively, following the injury. Total antioxidative capacity (TAC) in plasma and concentration of lipid peroxidation products (TBARS) in red blood cells were estimated. The test results were compared to control group of 40 healthy children., Results: The research showed a statistically significant decrease in TAC in both groups of burnt children. The TBARS concentration was increased in both groups within the 1st day following burn injury and maintained the high level throughout the research continuation. No statistically significant differences between LB and SB groups were recognized., Conclusions: The observed changes in the tested parameters are attributable to oxidative stress occurring in burn disease. For this reason, burn--injured children are recommended to receive exogenous antioxidants.

The influence of atherogenic diet and "essential" phospholipids (EPL) both on exploratory activity and catecholamine content in the brain of rats has been examined. The atherogenic diet caused a decrease of the animals' exploratory activity as well as a diminution of catecholamines. It was observed that these changes correlated. Prophylactic administration of EPL is capable of preventing such changes. Therapeutic administration of EPL increased exploratory activity and catecholamines in the atherogenic group which subsequently received the basic laboratory diet.