Age Influences Microglial Activation After Cuprizone-Induced Demyelination

Multiple sclerosis (MS) is a chronic inflammatory CNS disease, which causes demyelinated lesions and damages white and gray matter regions. Aging is a significant factor in the progression of MS, and microglia, the immune cells of the CNS tissue, play an important role in all disease stages. During aging, microglia are functionally altered. These age-related changes probably already begin early and might influence the progression of CNS pathologies. The aim of the present study was to investigate whether microglia in the middle-aged CNS already react differently to demyelination. For this purpose, several microglia markers (ionized calcium binding adaptor molecule 1 (Iba-1), P2RY12, F4/80, CD68, major histocompatibility complex II (MHCII), macrophage receptor with collagenous structure (Marco), Translocator protein 18 kD (TSPO), CD206, and CD163) were analyzed in the acute cuprizone demyelination model in young (2-month-old) and middle-aged (10-month-old) mice. In addition, microglial proliferation was quantified using double-labeling with proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU), which was injected with the onset of remyelination. To compare age-related microglial changes during de- and remyelination in both gray and white matter, the hilus of the dorsal hippocampal dentate gyrus (DG) and the splenium of the corpus callosum (CC) were analyzed in parallel. Age-related changes in microglia of healthy controls were more pronounced in the analyzed gray matter region (higher levels of F4/80 and Marco as well as lower expression of CD68 in middle-aged mice). During de- and remyelination, a stronger increase of the microglial markers Iba-1, CD68 and TSPO was observed in the splenium of the younger groups. There was a significant reduction of P2RY12 during demyelination, however, this was age- and region-dependent. The induction of the anti-inflammatory markers CD206 and CD163 was stronger in the middle-aged group, but also differed between the two analyzed regions. De- and remyelination led to a significant increase in PCNA+ microglia only in young groups within the white matter region. The number of BrdU+ microglia was not changed during de- or remyelination. These results clearly show that microglia are already altered during middle-age and also react differently to CNS demyelination, however, this is highly region-dependent

Laser-Induced Silver Nanoparticles on Titanium Oxide for Photocatalytic Degradation of Methylene Blue

Silver nanoparticles doped on titanium oxide (TiO2) were produced by laser-liquid interaction of silver nitrate (AgNO3) in isopropanol. Characteristics of Ag/TiO2 (Ag doped TiO2) nanoparticles produced by the methods presented in this article were investigated by XRD, TEM, SEM, EDX, and UV-Vis. From the UV-Vis measurements, the absorption of visible light of the Ag/TiO2 photocatalysts was improved (additional absorption at longer wavelength in visible light region) obviously. The photocatalytic efficiency of Ag/TiO2 was tested by the degradation of methylene blue (MB) in aqueous solution. A maximum of 82.3% MB degradation is achieved by 2.0 wt% Ag/TiO2 photocatalyst under 2 h illumination with a halogen lamp

Photocatalytic, sonocatalytic and sonophotocatalytic degradation of Rhodamine B using ZnO/CNTs composites photocatalysts

A series of ZnO nanoparticles decorated on multi-walled carbon nanotubes (ZnO/CNTs composites) was synthesized using a facile sol method. The intrinsic characteristics of as-prepared nanocomposites were studied using a variety of techniques including powder X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), transmission electron microscope (TEM), scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX), Brunauer Emmett Teller (BET) surface area analyzer and X-ray photoelectron spectroscopy (XPS). Optical properties studied using UV–Vis diffuse reflectance spectroscopy confirmed that the absorbance of ZnO increased in the visible-light region with the incorporation of CNTs. In this study, degradation of Rhodamine B (RhB) as a dye pollutant was investigated in the presence of pristine ZnO nanoparticles and ZnO/CNTs composites using photocatalysis and sonocatalysis systems separately and simultaneously. The adsorption was found to be an essential factor in the degradation of the dye. The linear transform of the Langmuir isotherm curve was further used to determine the characteristic parameters for ZnO and ZCC-5 samples which were: maximum absorbable dye quantity and adsorption equilibrium constant. The natural sunlight and low power ultrasound were used as an irradiation source. The experimental kinetic data followed the pseudo-first order model in photocatalytic, sonocatalytic and sonophotocatalytic processes but the rate constant of sonophotocatalysis is higher than the sum of it at photocatalysis and sonocatalysis process. The sonophotocatalysis was always faster than the respective individual processes due to the more formation of reactive radicals as well as the increase of the active surface area of ZnO/CNTs photocatalyst. Chemical oxygen demand (COD) of textile wastewater was measured at regular intervals to evaluate the mineralization of wastewater

The role of ETG modes in JET-ILW pedestals with varying levels of power and fuelling

We present the results of GENE gyrokinetic calculations based on a series of JET-ITER-like-wall (ILW) type I ELMy H-mode discharges operating with similar experimental inputs but at different levels of power and gas fuelling. We show that turbulence due to electron-temperature-gradient (ETGs) modes produces a significant amount of heat flux in four JET-ILW discharges, and, when combined with neoclassical simulations, is able to reproduce the experimental heat flux for the two low gas pulses. The simulations plausibly reproduce the high-gas heat fluxes as well, although power balance analysis is complicated by short ELM cycles. By independently varying the normalised temperature gradients (omega(T)(e)) and normalised density gradients (omega(ne )) around their experimental values, we demonstrate that it is the ratio of these two quantities eta(e) = omega(Te)/omega(ne) that determines the location of the peak in the ETG growth rate and heat flux spectra. The heat flux increases rapidly as eta(e) increases above the experimental point, suggesting that ETGs limit the temperature gradient in these pulses. When quantities are normalised using the minor radius, only increases in omega(Te) produce appreciable increases in the ETG growth rates, as well as the largest increases in turbulent heat flux which follow scalings similar to that of critical balance theory. However, when the heat flux is normalised to the electron gyro-Bohm heat flux using the temperature gradient scale length L-Te, it follows a linear trend in correspondence with previous work by different authors

Spectroscopic camera analysis of the roles of molecularly assisted reaction chains during detachment in JET L-mode plasmas

The roles of the molecularly assisted ionization (MAI), recombination (MAR) and dissociation (MAD) reaction chains with respect to the purely atomic ionization and recombination processes were studied experimentally during detachment in low-confinement mode (L-mode) plasmas in JET with the help of experimentally inferred divertor plasma and neutral conditions, extracted previously from filtered camera observations of deuterium Balmer emission, and the reaction coefficients provided by the ADAS, AMJUEL and H2VIBR atomic and molecular databases. The direct contribution of MAI and MAR in the outer divertor particle balance was found to be inferior to the electron-atom ionization (EAI) and electron-ion recombination (EIR). Near the outer strike point, a strong atom source due to the D+2-driven MAD was, however, observed to correlate with the onset of detachment at outer strike point temperatures of Te,osp = 0.9-2.0 eV via increased plasma-neutral interactions before the increasing dominance of EIR at Te,osp < 0.9 eV, followed by increasing degree of detachment. The analysis was supported by predictions from EDGE2D-EIRENE simulations which were in qualitative agreement with the experimental observations

Shattered pellet injection experiments at JET in support of the ITER disruption mitigation system design

A series of experiments have been executed at JET to assess the efficacy of the newly installed shattered pellet injection (SPI) system in mitigating the effects of disruptions. Issues, important for the ITER disruption mitigation system, such as thermal load mitigation, avoidance of runaway electron (RE) formation, radiation asymmetries during thermal quench mitigation, electromagnetic load control and RE energy dissipation have been addressed over a large parameter range. The efficiency of the mitigation has been examined for the various SPI injection strategies. The paper summarises the results from these JET SPI experiments and discusses their implications for the ITER disruption mitigation scheme

New H-mode regimes with small ELMs and high thermal confinement in the Joint European Torus

New H-mode regimes with high confinement, low core impurity accumulation, and small edge-localized mode perturbations have been obtained in magnetically confined plasmas at the Joint European Torus tokamak. Such regimes are achieved by means of optimized particle fueling conditions at high input power, current, and magnetic field, which lead to a self-organized state with a strong increase in rotation and ion temperature and a decrease in the edge density. An interplay between core and edge plasma regions leads to reduced turbulence levels and outward impurity convection. These results pave the way to an attractive alternative to the standard plasmas considered for fusion energy generation in a tokamak with a metallic wall environment such as the ones expected in ITER.& nbsp;Published under an exclusive license by AIP Publishing