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The corrosion-fatigue strength in 3 % aqueous NaCl solution and the resistance against hot salt corrosion (HSC) of the fine-grained near-α alloy Ti-5Al-2V (Russian analogue of Grade 9 titanium alloy with increased aluminium content) have been studied. The properties of the Ti-5Al-2V alloy in the coarse-grained state, in the fine-grained state after cold Rotary Swaging (RS), in the partly recrystallized state and in the fully recrystallized state have been investigated. The mechanical properties of the alloy were characterised using compression tests and microhardness measurements. The effects of RS, the annealing temperature, the time on the characteristics of corrosion destruction of the surface and the composition of the products of the HSC were studied. RS was shown to increase the depth of the intergranular corrosion defects, whereas recrystallization annealing promoted an increase in the corrosion resistance of the Ti-5Al-2V titanium alloy. The parameters of the Basquin equation for the corrosion-fatigue curves for the near-α Ti-5Al-2V alloy in the coarse-grained state, in the severely strained state and after recrystallization annealing were determined for the first time. An effect of non-monotonous dependencies of the slopes of the corrosion-fatigue curves for the strained near-α Ti-5Al-2V alloy on the recrystallization annealing temperature has been observed. • The corrosion resistance of the Ti-5Al-2V alloy depends on the presence of β-particles and the V-rich grain boundaries • Cold Rotary Swaging (RS) leads to an increase in the strength, hardness and corrosion-fatigue strength of the Ti alloy • RS results in a reduction in the corrosion resistance of the titanium alloy Ti-5Al-2V • Recrystallization annealing improves in the resistance to intergranular hat salt corrosion • Recrystallization annealing leads to a non-monotonic change in the slope of the corrosion-fatigue curve σ а (N) [ABSTRACT FROM AUTHOR]

There are several neurogenic niches in the adult mammalian central nervous system. In the central nervous system, neural stem cells (NSC) localize not only to the periventricular area, but are also diffusely distributed in the parenchyma. Here, we assessed neurogenic potential of organotypic cultures prepared from adult mouse spinal cord. Slices were placed on Millipore inserts for organotypic culture and incubated in neurobasal media supplemented with B27 and N2 for up to 9 weeks. After 3–4 weeks, the cell’s aggregates formed in the slices. The aggregate’s cells were BrdU-uptake, nestin and alkaline phosphatase positive. At the later stage of incubation, we observed Oct3/4 in the inner mass of the neurospheres as well as expression of Dppa1 , which is an Oct-4 downstream target gene and a marker for pluripotency. To check differentiation, the formed neurospheres were isolated and cultured for several days in differentiation media. The obtained data demonstrated the cells from isolated neurospheres differentiate into astrocytes and MAP2-positive neurons. Immunostaining for HB9 and Lim2 revealed subsequent differentiation of MAP2-positive cells into motor neurons and interneurons, respectively. We hypothesized neuronal loss and/or long-term culturing of spinal cord slices may trigger a reset of the internal cell program and promote proliferation and further differentiation of NSC. [ABSTRACT FROM AUTHOR]

Abstract: Hormonal differences between males and females have surfaced as a crucial component in the search for effective treatments after experimental models of traumatic brain injury (TBI). Recent findings have shown that selective estrogen receptor modulators (SERMs) may have therapeutic benefit. The present study examined the effects of raloxifene, a SERM, on functional recovery after bilateral cortical contusion injury (bCCI) or sham procedure. Male rats received injections of raloxifene (3.0mg/kg, i.p.) or vehicle (1.0ml/kg, i.p.) 15min, 24, 48, 72, and 96h after bCCI or sham procedure. Rats were tested on both sensorimotor (bilateral tactile removal and locomotor placing tests) and cognitive tests (reference and working memory in the Morris water maze). Raloxifene-treated animals showed a significant reduction in the initial magnitude of the deficit and facilitated the rate of recovery for the bilateral tactile removal test, compared to vehicle-treated animals. The raloxifene-treated animals also showed a significant improvement in the acquisition of working memory compared to vehicle-treated animals. However, raloxifene did not significantly improve the acquisition of reference memory or locomotor placing ability. Raloxifene treatment also did not result in a significant reduction in the size of the lesion cavity. Thus, the task-dependent improvements seen following raloxifene treatment do not appear to be the result of cortical neuroprotection. However, these results suggest that raloxifene improves functional outcome following bCCI and may present an interesting avenue for future research. [Copyright &y& Elsevier]

The aim of this study was to examine the effects of LY117018, a selective estrogen receptor modulator, on peripheral nerve regeneration, using a model of sciatic nerve crush injury in mice. Sciatic functional index, an index of functional recovery, was significantly higher in LY117018 treated mice throughout regeneration. Analysis of semi-thin sections revealed a significant increase in both the total number of regenerating nerve fibers at day 7, and the mean axonal area of myelinated fibers at 7, 14, and 21 days after injury, in LY117018 treated mice. Analysis of axonal transport through retrograde labeling of motor neurons showed that LY117018 increased transport, and ICI 182,780 blocked the effects of LY117018, delineating estrogen receptors as its target. Our study suggests that LY117018 may markedly accelerate peripheral nerve regeneration and functional recovery through activation of estrogen receptors. [Copyright &y& Elsevier]

The work was aimed at the investigation of kinetics of Spark Plasma Sintering (SPS) of the α-Al 2 O 3 particles with amorphous surface layers and investigation of the effect of the amorphous layers on the grain growth and on the mechanical properties of alumina. The objects of investigations comprised:(i) submicron α-Al 2 O 3 powder, (ii) submicron α-Al 2 O 3 powder with the amorphous layers on the particles' surfaces, and (iii) the fine-grained α-Al 2 O 3 powder. The submicron powders (i) and (ii) were used to analyze the effect of the amorphous layers on the sintering kinetics. Powders (i) and (iii) were used to analyze the effect of the initial particle sizes on the shrinkage kinetics. The effect of the temperature regime and of the rate (V h) on the shrinkage kinetics of the submicron and fine alumina powders has been studied. The shrinkage curves were analyzed using the Young–Cutler and Coble models. The sintering kinetics was shown to be determined by the intensity of grain boundary diffusion for the submicron powders and by simultaneous lattice diffusion and grain boundary one for the fine powders. The amorphous layers on the surfaces of the submicron α-Al 2 O 3 particles were found to affect the grain boundary migration rate and the Coble equation parameters at the final stages of SPS. The abnormal characteristics of the alumina ceramics sintered from the submicron powder with the amorphous layers on the particles' surfaces were suggested to originate from the increased concentration of the defects and of the excess free volume at the grain boundaries formed during crystallization of the amorphous layers. [ABSTRACT FROM AUTHOR]

The study investigates the density, phase composition, microstructure and mechanical properties of ceramics obtained by the Spark Plasma Sintering (SPS). Three groups of materials were investigated: WC ceramics (Group I), WC + C ceramics (Group II), and WC + C + SiC ceramics (Group III). Nanopowders of α-WC produced by DC arc plasma chemical synthesis and hydrogen annealing. Powder compositions for sintering contained colloidal graphite (0.3, 0.5% wt.) or graphite (0.3% wt.) and β-SiC (1, 3, 5% wt.). The effect of preliminary cold pressing, heating rate, and degassing time on the properties of ceramics has been investigated. The graphite concentration in the WC nanopowder compositions increases the shrinkage rate at the intensive shrinkage stage of SPS. The content of >0.3% wt. of С leads to abnormal grain growth and decreasing in the mechanical characteristics of the ceramics. The addition of SiC particles into the WC nanopowder reduces the maximum shrinkage temperature during SPS by ∼150 °C and allows to reduce the volume fraction of abnormally large grains. The kinetics of the initial sintering stage of WC + C + SiC powders was also analyzed using dilatometry at the conventional pressureless sintering (CPS) conditions. The CPS activation energies of WC + C and WC + C + SiC powders are close to the activation energy of diffusion of the carbon 14C along the α-WC grain boundaries. The SPS activation energies of WC + C + SiC powders turn out to be lower than the activation energy of the 14C of α-WC grain boundary. [Display omitted] • The nanopowders of α-WC produced by DC arc plasma chemical synthesis. • The WC + SiC (1, 3, 5%) + (0.3, 0.5%) C ceramics obtained by SPS. • The ceramics with 0.5% graphite demonstrate abnormal grain growth. • The addition of SiC reduces the fraction of abnormally large grains. • The SPS activation energies were determined using the Young-Cutler model. [ABSTRACT FROM AUTHOR]

Abstract: Recent observations have demonstrated that nanomaterials may be toxic to human tissue. While the ability of nano-scaled particulate matter is known to cause a range of problems in respiratory system, recent observations suggest that the nervous system may be vulnerable as well. In the current paper we asked whether exposure of primary neuronal cell cultures to nanoparticles might compromise regenerative axon growth. Regenerative response was triggered by performing a conditioning lesion of sciatic nerve five days prior to collection of dorsal root ganglia (DRG). DRG neurons were plated at a low density and incubated with multi-walled carbon nanotubes (MWCNTs) (0.1–10μg/ml in 10% of surfactant in saline) overnight. The experiments showed that exposure of DRG cultures to MWCNT significantly impaired regenerative axonogenesis without concomitant cell death. These results indicate that MWNCTs may have detrimental effect on nerve regeneration and may potentially trigger axonal pathology. [Copyright &y& Elsevier]

Abstract: Recent observations have demonstrated neuroprotective role of erythropoietin (Epo) and Epo receptor in the central nervous system. Here we examined Epo function in the murine spinal cord after transplantation of pluripotent mouse embryonic stem (ES) cells pre-differentiated towards neuronal type following spinal cord injury. Expression of Epo was measured at both mRNA and protein levels in the ES cells as well as in the spinal cords after 1 and 7 days. Our data demonstrated that expression of Epo mRNA, as well as its protein content, in ES cells was significantly decreased after differentiation procedure. In the spinal cords, analysis showed that Epo mRNA level was significantly decreased after 1 day of ES cell injections in comparison to media-injected control. Epo protein level detected by Western blot was diminished as well. Examination of Epo production in the injured spinal cords after media or ES cells injections by indirect immunofluorescence showed increased Epo-immunopositive staining after media injections 1 day after injection. In contrast, ES cell transplantation did not induce Epo expression. Seven days after ES cell injections, Epo-immunopositive cells’ distribution in the ipsilateral side was not changed, while the intensity of immunostaining on the contralateral side was increased, approaching levels in control media-injected tissues. Our data let us to presume that previously described immediate positive effects of ES cells injected into the injured zone of spinal cord are not based on Epo, but on other factors or hormones, which should be elucidated further. [ABSTRACT FROM AUTHOR]

Abstract: Embryonic stem (ES) cells have been investigated in many animal models of injury and disease. However, few studies have examined the ability of pre-differentiated ES cells to improve functional outcome following traumatic brain injury (TBI). The purpose of the present study was to compare the effect of murine ES cells that were pre-differentiated into GABAergic neurons or astrocytes on functional recovery following TBI. Neural and astrocyte induction was achieved by co-culturing ES cells on a bone marrow stromal fibroblast (M2-10B4) feeder layer and incubating them with various mitogenic factors. Rats were initially prepared with a unilateral controlled cortical contusion injury of the sensorimotor cortex or sham procedure. Rats were transplanted 7 days following injury with ∼100K GABAergic neurons, astrocytes, fibroblasts, or media. Animals were assessed on a battery of sensorimotor tasks following transplantation. The stromal fibroblast cells (M2-10B4), as a control cell line, did not differ significantly from media infusions. Transplantation of GABAergic neurons facilitated complete and total recovery on the vibrissae-forelimb placing test as opposed to all other groups, which failed to show any recovery. It was also found that GABAergic neurons reduced the magnitude of the initial impairment on the limb use test. Histological analysis revealed infiltration of host brain with transplanted neurons and astrocytes. The results of the present study suggest that transplantation of pre-differentiated GABAergic neurons significantly induces recovery of sensorimotor function; whereas, astrocytes do not. [Copyright &y& Elsevier]

Abstract: The activity of NFATc family transcription factors is tightly regulated in T cells via signaling pathways initiated by stimulation of the T cell receptor or its downstream effectors such as the Pim-1 serine/threonine kinase. Here, we demonstrate that NFATc-dependent transcription is inducible also in NGF-differentiated rat PC12 pheochromocytoma cells treated with phorbol esthers, calcium ionophores and/or forskolin and that the Pim-1 kinase can further potentiate the effects of these agents. PC12 cells share many characteristics with sympathetic neurons and can be induced to produce and release catecholamines, such as dopamine and noradrenaline, and inflammatory cytokines, such as interleukin 6. Interestingly, Pim-1 can synergize with forskolin-induced signaling pathways to stimulate also neuroendocrine functions of PC12 cells. [Copyright &y& Elsevier]

The tilted mutant mouse, which lacks otoconia in the inner ear, was used to study development of the mouse vestibular system in the absence of gravity perception. Otoconia are dense particles composed of proteins and calcium carbonate crystals suspended in the gelatinous macular membrane. They enhance, and are largely responsible for, sensitivity to gravity. Morphometric analysis of the vestibular ganglion showed that the mutant developed more slowly than the normal controls, both in rate of development and cell number, particularly during the first week of post-natal development. The mutant ganglia also exhibited a reduction of cells during the first 6 days of post-natal development. [Copyright &y& Elsevier]

The hallmarks of neurodegenerative diseases, including neural fibrils, reactive oxygen species, and cofilin-actin rods, present numerous challenges in the development of in vivo diagnostic tools. Biomarkers such as β-amyloid (Aβ) fibrils and Tau tangles in Alzheimer's disease are accessible only via invasive cerebrospinal fluid assays, and reactive oxygen species can be fleeting and challenging to monitor in vivo. Although remaining a challenge for in vivo detection, the protein-protein interactions underlying these disease-specific biomarkers present opportunities for the engineering of in vitro pathology-sensitive biosensors. These tools can be useful for investigating early stage events in neurodegenerative diseases in both cellular and animal models and may lead to clinically useful reagents. Here, we report a light- and cellular stress-gated protein switch based on cofilin-actin rod formation, occurring in stressed neurons in the Alzheimer's disease brain and following ischemia. By coupling the stress-sensitive cofilin-actin interaction with the light-responsive Cry2-CIB blue-light switch, referred to hereafter as the CofActor, we accomplished both light- and energetic/oxidative stress-gated control of this interaction. Site-directed mutagenesis of both cofilin and actin revealed residues critical for sustaining or abrogating the light- and stress-gated response. Of note, the switch response varied depending on whether cellular stress was generated via glycolytic inhibition or by both glyco-lytic inhibition and azide-induced ATP depletion. We also demonstrate light- and cellular stress-gated switch function in cultured hippocampal neurons. CofActor holds promise for the tracking of early stage events in neurodegeneration and for investigating actin's interactions with other proteins during cellular stress. [ABSTRACT FROM AUTHOR]

A glycine–nitrate self-propagating high temperature synthesis (SHS) was developed to produce composite Y 2 O 3 –MgO nanopowders. Based on the thermodynamic calculations a 0.25YMg 2 (NO 3) 7 -0.75NH 2 CH 2 COOH precursor composition was selected to prepare low agglomerated uniform composite yttria-magnesia powder. Near full dense composite ceramics were fabricated based on the prepared powders by the spark plasma sintering method. IR-transmittance and hardness of the Y 2 O 3 –MgO ceramics were studied in correlation with sintering conditions. The best transmittance of 80.9%@5 μm and H v = 10.2 GPa were measured for the sample obtained at 1150 °C. [ABSTRACT FROM AUTHOR]

Abstract The sol-gel synthesis of ZnAl 2 O 4 ceramic powders from alkoxide and acetate sources of metals, as well as the microstucture and the hardness of the hot-pressed ZnAl 2 O 4 specimens were considered. ZnAl 2 O 4 powders were prepared by the hydrolysis of an alcohol solution of aluminium isopropoxide using an aqueous solution of zinc acetate followed by heat treatment. The thermal evolution of the ZnAl 2 O 4 precursor was investigated. The effect of calcination temperature on the morphology and the specific surface area of ZnAl 2 O 4 powders were also studied. The sintering of the resultant powders to the high transparent ceramic using a hot pressing with 1 wt% ZnF 2 , as a sintering additive was successfully demonstrated. The in-line transmittance of ZnAl 2 O 4 ceramics (1 mm thickness) achieved 80% in the visible region and 85% at 5 µm; Vickers hardness was 11.6 GPa. [ABSTRACT FROM AUTHOR]

A new telescope-spectrometer was installed at Verkhnetulomsky observatory (68 ∘ 36'N, 31 ∘ 47'E) to supplement the data from all-sky cameras with measurements of the fine space–time structure of the auroral luminescence. The telescope uses 5 cm ultraviolet (UV) transparent lens as an optical system and a matrix of multi-anode photomultiplier tubes as a photo detector. The angular resolution of the telescope is 1.2 ∘ and the temporal resolution is 0.3 ms. The telescope observes a central part (20 ∘) of the all-sky camera field of view (FOV). Description of both optical instruments and results of the first joint measurements are presented. [Display omitted] • A new instrumental complex for pulsating aurora studies was developed and put into operation. • This complex allows to measure fine space-time structures of aurora emission. • First overnight data of observations are analyzed and presented. [ABSTRACT FROM AUTHOR]