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Free-standing ZnO nanorods alloyed with Er/Mo were synthesized by the hydrothermal growth method. To characterize them, the number of experimental techniques was applied including X-ray diffraction (XRD), scanning emission microscopy (SEM), electron paramagnetic resonance (EPR), photo- and radioluminescence (PL, RL). EPR confirmed the existence of F+ centres common for ZnO-based structures in the ZnO:Er(30%) nanorods whereas in the ZnO:Mo(30%) this kind of defect was absent. Air annealing at elevated temperatures results in the reduction of F+ centres in all the materials studied. Moreover, Er3+ EPR signal also undergoes changes including broadening in the ZnO:Er. This allowed suggesting oxidation of Er ions on the ZnO nanorods surface. Red luminescence (~680 nm) appears in all studied samples regardless the dopant origin and doping level after the annealing in air. The exciton-related band at 380 nm never observed in the samples before the annealing appears upon the annealing at 350 °C in ZnO:Mo(10%) and ZnO:Er(30%). No such band was observed in the ZnO:Mo(30%) sample under the same conditions. According to SEM there are nanorods no more but microrods upon the content of Mo/Er as compared to the as-grown untreated ZnO as reported in a recent work.

Sodium chloride (NaCl) is one of the best known and most studied materials in the history of materials science. It has a wide range of applications from material’s research, chemical industry, to common household use or as a material for sprinkling in winter. Interestingly, NaCl was recently also used as a catalyst for nanodiamond purification, rounding, and shape modifications; however, the origin of such an effect still remains unclear. This work is motivated to investigate the NaCl behavior deeper and reveal the cause, which could lead to such behavior. In this work, several NaCl powder samples and a single crystal of NaCl were studied by thermal analyses such as differential scanning calorimetry (DSC) and thermogravimetry (TG), mass spectrometry (MS), optical stereomicroscopy (OM), optical thermomicroscopy (OTM), and powder X-ray diffraction (XRPD). XRPD analysis was used to determine the structure and phase composition, confirming the presence of only NaCl. The OTM revealed an effect at ∼450 °C, determined as well by DSC, TG and also TMA methods, which corresponded to cracking and bouncing of NaCl grains. MS analysis proved the presence of a small content of H2O, which was released at temperatures similar to those where ND rounding was reported, indicating a possible contribution of water in the NaCl catalytic action on NDs.

In this work, we report on the growth of red-emitting lithium manganese(II) chloride (Li2MnCl4, LMC), a potential candidate for thermal neutron detection. The doping of Li2MnCl4 was proposed to optimize scintillation efficiency and three single crystals of Li2MnCl4:Sm2+, Li2MnCl4:Ti3+, and Li2MnCl4:In+ were grown by miniaturized vertical Bridgman method (mVB). While crystal growth was successful, the results from optical measurements indicated limited achievement in the optimization of luminescence properties. Ti3+ incorporation into the Li2MnCl4 lattice was highly uncertain, as neither the absorbance data nor the radioluminescence (RL) spectrum exhibited bands corresponding to the Ti3+ 2E → 2T2 radiative transition. In the case of Sm2+- and In+_doping, the RL efficiencies achieved only 3.39 and 2.14% of the bismuth germanate (Bi4Ge3O12, BGO) reference sample, respectively. Since the Li2MnCl4:Sm2+ photoluminescence (PL) spectra revealed line emissions corresponding to the Sm2+ forbidden 4f6 → 4f6 transitions, the temperature-dependent PL was measured. At higher temperatures (specifically, from 437 K), the broad emission of the 4f55d → 4f6 transition dominated, which indicated the thermal population of the 5d state.

Stem cells biology is one of the most frequent topic of physiological research of today. Spinal fusion represents common bone biology challenge. It is the indicator of osteoinduction and new bone formation on ectopic model. The purpose of this study was to establish a simple model of spinal fusion based on a rat model including verification of the possible use of titanium microplates with hydroxyapatite scaffold combined with human bone marrow-derived mesenchymal stem cells (MSCs). Spinous processes of two adjacent vertebrae were fixed in 15 Wistar rats. The space between bony vertebral arches and spinous processes was either filled with augmentation material only and covered with a resorbable collagen membrane (Group 1), or filled with augmentation material loaded with 5 × 106 MSCs and covered with a resorbable collagen membrane (Group 2). The rats were sacrificed 8 weeks after the surgery. Histology, histomorphometry and micro-CT were performed. The new model of interspinous fusion was safe, easy, inexpensive, with zero mortality. We did not detect any substantial pathological changes or tumor formation after graft implantation. We observed a nonsignificant effect on the formation of new bone tissue between Group 1 and Group 2. In the group with MSCs (Group 2) we described minor inflamatory response which indicates the imunomodulational and antiinflamatory role of MSCs. In conclusion, this new model proved to be easy to use in small animals like rats.

The transplantation of mesenchymal stem cells (MSC) is currently under study as a therapeutic approach for spinal cord injury, and the number of transplanted cells that reach the lesioned tissue is one of the critical parameters. In this study, intrathecally transplanted cells labeled with superparamagnetic iron oxide nanoparticles were guided by a magnetic field and successfully targeted near the lesion site in the rat spinal cord. Magnetic resonance imaging and histological analysis revealed significant differences in cell numbers and cell distribution near the lesion site under the magnet in comparison to control groups. The cell distribution correlated well with the calculated distribution of magnetic forces exerted on the transplanted cells in the subarachnoid space and lesion site. The kinetics of the cells' accumulation near the lesion site is described within the framework of a mathematical model that reveals those parameters critical for cell targeting and suggests ways to enhance the efficiency of magnetic cell delivery. In particular, we show that the targeting efficiency can be increased by using magnets that produce spatially modulated stray fields. Such magnetic systems with tunable geometric parameters may provide the additional level of control needed to enhance the efficiency of stem cell delivery in spinal cord injury.

Sodium hyaluronate (HA) was associated with dopamine (DPA) and introduced as a coating for maghemite (γ-Fe(2)O(3)) nanoparticles obtained by the coprecipitation of iron(II) and iron(III) chlorides and oxidation with sodium hypochlorite. The effects of the DPA anchorage of HA on the γ-Fe(2)O(3) surface on the physicochemical properties of the resulting colloids were investigated. Nanoparticles coated at three different DPA-HA/γ-Fe(2)O(3) and DPA/HA ratios were chosen for experiments with rat bone marrow mesenchymal stem cells and human chondrocytes. The nanoparticles were internalized into rat bone marrow mesenchymal stem cells via endocytosis as confirmed by Prussian Blue staining. The efficiency of mesenchymal stem cell labeling was analyzed. From among the investigated samples, efficient cell labeling was achieved by using DPA-HA-γ-Fe(2)O(3) nanoparticles with DPA-HA/γ-Fe(2)O(3) = 0.45 (weight/ weight) and DPA/HA = 0.038 (weight/weight) ratios. The particles were used as a contrast agent in magnetic resonance imaging for the labeling and visualization of cells.