The aim of the study was to evaluate the DNA and chromosomal damage in peripheral blood lymphocytes (PBLs) of patients with acute coronary syndrome (ACS) and to explore the effect of coronary ...angiographies in these patients.
The study included ACS patients who underwent a coronary angiography (CAG) and healthy controls. The ACS sample was divided into two groups: patients with unstable angina pectoris (UAP) and acute myocardial infarction (AMI). The frequency of DNA damage expressed as genetic damage index (GDI) was analyzed using the comet assay pre- and post-CAG. Chromosomal aberrations were measured as micronuclei (MNs) frequency using the cytokinesis-block MN (CBMN) assay. Additionally, detailed anamnestic data were taken from the each patient.
Increased levels of DNA and chromosomal damage have been revealed in ACS patients compared to the healthy controls. GDI values were also significantly higher in AMI patients than in UAP patients. A highly significant increase of DNA damage was also observed in all patients post-CAG. There was significantly higher MN frequency and significantly lower nuclear division index (NDI) in AMI patients than in UAP patients' pre-CAG. After CAG, there was no significant difference in MN frequencies and NDI values between UAP and AMI patients.
Correlated with disease severity, our results showed that AMI patients have higher levels of both DNA and chromosomal damage in PBLs compared to UAP patients. The increased level of genome instability was especially evident post-CAG compared to the observed damage pre-CAG.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Spherical, submicronic TiO2 powder particles were prepared in the low temperature process of ultrasonic spray pyrolysis (150 °C) by using as a precursor aqueous colloidal solutions consisting of ...surface modified 45 Å TiO2 nanoparticles with dopamine. Detailed structural and morphological characterization of colored submicronic TiO2 spheres was performed by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser particle size analysis and FTIR techniques. Also, optical characterization of both dopamine-modified TiO2 precursor nanoparticles and submicronic TiO2 powder particles was performed using absorption and diffuse reflectance spectroscopy, respectively. A significant decrease of the effective band gap (1.9 eV) in dopamine-modified TiO2 nanoparticles compared to the band gap of bulk material (3.2 eV) was preserved after formation of submicronic TiO2 powder particles in the process of ultrasonic spray pyrolysis under mild experimental conditions. Due to the nanostructured nature, surface-modified assemblage of TiO2 nanoparticles preserved unique ability to absorb light through charge transfer complex by photoexcitation of the ligand-to-TiO2 band, conventionally associated with extremely small TiO2 nanoparticles (d < 20 nm) whose surface Ti atoms, owing to the large curvature, have penta-coordinate geometry.
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•The surface-modified TiO2 nanoparticles with dopamine were used as a precursor.•Colored submicronic TiO2 particles were obtained after ultrasonic spray pyrolysis.•CT complex was formed between electron donating ligands and surface Ti atoms.•The effective band-gap of surface modified TiO2 powders decreases to 1.3 eV.
Spherical, submicronic TiO
2
assemblage with high specific surface area and controllable phase composition was prepared in the process of ultrasonic spray drying/pyrolysis in a wide temperature range ...(150–800 °C) by using as a precursor aqueous colloidal solution consisting of TiO
2
nanoparticles (4.5 nm). Submicronic, soft and grained spherical TiO
2
particles (
d
= 370–500 nm) comprising clustered nanocrystals (<10 nm) were obtained at low processing temperature, while particle densification, intensive growth of the clustered primary units and anatase-to-rutile transformation (~30 wt%) were observed at the higher temperatures. Detailed structural and morphological characterisation were performed by X-ray powder diffraction, scanning and field emission electron microscopy, transmission electron microscopy, and laser particle size analysis. Moreover, the surface modification of TiO
2
particles through the formation of charge-transfer (CT) complex was achieved with different ligands: ascorbic acid, dopamine, catechol, 2,3-dihydroxynaphthalene, and anthrarobin. Optical properties of the surface-modified TiO
2
particles were studied by using diffuse reflection spectroscopy. The binding structure between the surface titanium atoms and different ligands was determined by using Fourier transform infrared spectroscopy. The formation of CT complexes induced significant red shift of optical absorption in comparison to unmodified TiO
2
particles.
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•NaYF4:Yb3+/Er3+ up-converting particles (UCPs) are processed via solvothermal route.•Either PEG or PVP are used as structure directing and coating agents.•There is α- and ...β-NaYF4:Yb3+/Er3+ phase coexistence in PEG assisted processing.•PVP leads to the prominent hexagonal β-NaYF4:Yb3+/Er3+ phase formation.•Yellow and green emissions are achieved in PEG and PVP coated NaYF4:Yb3+/Er3+ UCPs.
Owing to their unique optical properties, up-converting rare earth fluorides have attracted extensive attention in recent years. Varieties of synthesis procedures which generate nano- and micro-crystals with controllable compositions have been reported. In the vast majority, surfactants, complexing agents and solvents play essential role in controlling particles morphology and surface characteristics. Here we report on a rapid solvothermal synthesis (200°C, 2h) of either PEG or PVP capped NaYF4:Yb3+/Er3+ particles. Their structural, morphological and luminescence characteristics have been studied based on X-ray powder diffractometry (XRPD), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM) and photoluminescence measurements. Both polymers proved to be a good structure directing agents enabling generation of the well crystalline polymer coated up-converting particles with efficient emissions in visible spectrum. It was shown that generation of the hexagonal P63/m β-NaYF4:Yb3+/Er3+ phase with the most efficient green emission (CIE 0.31, 0.66) is enhanced when PVP is used during synthesis, while promotion of the cubic Fm-3m α-NaYF4:Yb3+/Er3+ phase that has a yellowish spectral output (CIE 0.41, 0.56) was observed in the particles produced in the presence of PEG. Beneficial effect on the luminescence intensity was observed with additional particles annealing in argon atmosphere.
We report on the possibility to build hierarchically organized three-dimensional (3D) titania spherical particles having high surface-to-volume-ratio, by aerosol processing of nanotubular building ...blocks. Morphology and crystal structure of titania based spherical assemblies, obtained in the temperature range from 150 to 650°C, were characterized by means of scanning and transmission electron microscopy, x-ray powder diffraction and Raman spectroscopy. Initial shape of 1D building units, nanotubes, was well preserved in the spherical assemblies processed at 150 and 450°C. Processing at 650°C resulted in a collapse of the nanotubular building blocks and formation of the assemblies of irregularly shaped TiO2 nanoparticles. Structural analysis revealed several phase transitions in titania spherical assemblies in course with the temperature increase indicating possibility of in-situ phase composition adjustment during aerosol processing.
The red light emitting down-converting Ag@Y2O3:Eu3+ phosphor particles were synthesized by one-step ultrasonic spray pyrolysis and exposed further to the heat treatment at 1000°C (12h). A detailed ...investigation on structural and functional properties of the as-prepared and heat treated particles was conducted in a comparative manner. High-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRPD) and focus ion beam milling (FIB) revealed in a great consistency the poorly crystallized and porous nature of the as-prepared particles. Well-crystallized coarser primary nanocrystals of Y2O3:Eu3+and Ag, which are hierarchically organized in dense spherical Ag@Y2O3:Eu3+ phosphor particles, were obtained through the heat treatment. Along with the change of structural properties, down conversion (red luminescence at 612nm owing to the Eu3+5D0→7F2 electric dipole transition) and mechanical endurance were enhanced 4-fold and 5-fold via heat treatment, respectively. This comparative study implies a good correlation between mechanical and luminescence behavior of phosphors, both strongly influenced by the particles structural properties.
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•Yb3+/Er3+ doped YF3 and NaYF4 particles are processed via EDTA assisted hydrothermal route.•Particles exhibit compositional and morphological dependence on the nucleation rate.•With ...course of processing time transformation of α→β→α NaYF4:Yb3+/Er3+ is observed.•Up-conversion is phase dependent and can be tuned from green to yellowish-orange.
In this feature article, we highlight our works on compositional and structural dependence of up-converting rare earth (RE) fluorides obtained through ethylenediamine tetraacetic acid (EDTA) assisted hydrothermal synthesis. Various nanostructures were obtained by tuning of experimental conditions, such as precursor’s concentration, degree of doping, reaction time and solvent used during synthesis. We correlated in detail the structural, morphological and optical properties of YF3 and NaYF4 compounds co-doped with Yb3+ and Er3+ (introduced in total mol% of 8 and 20). For this purpose, X-ray powder diffraction, scanning and transmission electron microscopy, energy dispersive X-ray and Furrier transform infrared spectroscopy, as well as, the photoluminescence spectra and decay times were recorded and analyzed. The particle size and phase content were found to be dependent on the nucleation rate, which, in turn, was governed by the precursor concentration, degree of doping and solvent type. The transformation from cubic to hexagonal NaYF4:Yb3+/Er3+ phase was found to be sensitive to the reaction time and precursors concentration, while the crystallization of orthorhombic YF3:Yb3+/Er3+ phase is achieved through lowering of dopants concentration or by changing of solvent during hydrothermal treatment. The up-conversion photoluminescence demonstrated morphology and crystal phase dependence and is found to be superior in microcrystalline samples, independent on their phase composition.
Chromosomal instability could be one of primary causes for malignant cell transformation. The objective of the present study was to evaluate the spontaneous genetic damages in circulated lymphocytes ...of newly diagnosed cancer patients by using cytokinesis-block micronucleus (CBMN) assay, with respect to the factors that might affect micronucleus frequency (i.e. age, gender, smoking habits and cancer sites). Micronuclei (MN) are small nuclei that are originated from chromosome fragments or whole chromosomes. The analyzed samples included 44 untreated cancer patients (19 females and 25 males with mean age of 60.89 years) with different cancer sites (12 patients with breast cancer, 5 with uterine cancer and 27 with cancer of pharynx). Control group included 40 healthy donors (28 females and 12 males with mean age of 43.95 years). The mean baseline MN frequency was significantly higher (p < 0.001) in cancer patients (15.18 ± 5.05 MN/1000 BN cells ranging from 4 to 27) than the baseline frequency in healthy controls (6.45 ± 2.75 MN/1000 BN cells, ranging from 1 to 11). There was no gender difference in baseline MN frequency in cancer patients and healthy controls. Moreover, the MN frequency did not significantly differ among cancer sites, and between smokers and non-smokers in both patient and control samples. In conclusion, untreated cancer patients may be associated with an increase of chromosomal instability in peripheral blood lymphocytes, irrespective of gender, cigarette smoking and cancer sites.
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