Growth and texture of Spark Plasma Sintered Al2O3 ceramics: a combined analysis of X-rays and Electron Back Scatter Diffraction

Textured alumina ceramics were obtained by Spark Plasma Sintering (SPS) of undoped commercial a-Al2O3 powders. Various parameters (density, grain growth, grain size distribution) of the alumina ceramics, sintered at two typical temperatures 1400{\deg}C and 1700{\deg}C, are investigated. Quantitative textural and structural analysis, carried out using a combination of Electron Back Scattering Diffraction (EBSD) and X-ray diffraction (XRD), are represented in the form of mapping, and pole figures. The mechanical properties of these textured alumina ceramics include high elastic modulus and hardness value with high anisotropic nature, opening the door for a large range of applicationsComment: 16 pages, 6 figures, submitted to J. Appl. Phy

Pathophysiological and cognitive mechanisms of fatigue in multiple sclerosis

Fatigue is one of the most common symptoms in multiple sclerosis (MS), with a major impact on patients’ quality of life. Currently, treatment proceeds by trial and error with limited success, probably due to the presence of multiple different underlying mechanisms. Recent neuroscientific advances offer the potential to develop tools for differentiating these mechanisms in individual patients and ultimately provide a principled basis for treatment selection. However, development of these tools for differential diagnosis will require guidance by pathophysiological and cognitive theories that propose mechanisms which can be assessed in individual patients. This article provides an overview of contemporary pathophysiological theories of fatigue in MS and discusses how the mechanisms they propose may become measurable with emerging technologies and thus lay a foundation for future personalised treatments

A new paraclinical CSF marker for hypoxia‐like tissue damage in multiple sclerosis lesions

Recent studies on the immunopathology of multiple sclerosis revealed a heterogeneity in the patterns of demyelination, suggesting interindividual differences in the mechanism responsible for myelin destruction. One of these patterns of demyelination, characterized by oligodendrocyte dystrophy and apoptosis, closely mimics myelin destruction in acute white matter ischaemia. In the course of a systematic screening for virus antigen expression in multiple sclerosis brains, we identified a monoclonal antibody against canine distemper virus, which detects a cross‐reactive endogenous brain epitope, highly expressed in this specific subtype of actively demyelinating multiple sclerosis lesions with little or no immunoreactivity in other active multiple sclerosis cases. The respective epitope, which is a phosphorylation‐dependent sequence of one or more proteins of 50, 70 and 115kDa, is also expressed in a subset of active lesions of different virus‐induced inflammatory brain diseases, but is present most prominently and consistently in acute lesions of white matter ischaemia. Its presence is significantly associated with nuclear expression of hypoxia‐inducible factor‐1α within the lesions of both inflammatory and ischaemic brain diseases. The respective epitope is liberated into the CSF and, thus, may become a useful diagnostic tool to identify clinically a defined multiple sclerosis subtyp

Effect of the cerium loading on the HMS structure. Preparation, characterization and catalytic properties

Ce–HMS mesoporous materials were prepared by incipient wetness method starting from HMS synthesized in acid condition. The effect of ceriumquantity, in the range of Ce/Si atomic ratio 0.02–0.3, on its structure and properties was investigated. Results showed that the HMS hexagonal structure was maintained after the cerium adding. Furthermore, the surface area and the pore volume were reduced. The presence of the cerianite nanoparticles located within the HMS channels up to 0.05, thus covering the HMS surface at higher Ce/Si atomic ratio,was observed. The catalytic performances of the materials were tested in ethanol partial oxidation reactio

Effect of Processing and Orientation on Structural and Mechanical Properties of Polypropylene Products

Polypropylene (PP) represents one of the most worldwide used plastics with a large variety of products and applications. As usual for semicrystalline polymers, the properties of PP products strictly depend on the processing (fiber spinning, film extrusion, injection, etc.), where orientation and crystallization phenomena are involved. The object of this communication is the mechanical and structural characterization of oriented products from iPP homopolymers, i.e., injection molded dumbbell specimens (IM), lab-scale single fibers and commercial bulk continuous filament (BCF), woven non-woven fabrics (WNW) by using differential scanning calorimetry (DSC), dynamical mechanical thermal analysis (DMTA), tensile measurements, and X-ray diffraction (XRD) analysis. In particular, a recent methodology to analyze diffraction images of oriented polymers to obtain crystal structure, texture, and microstructural information is presented. The higher the orientation, the higher the mechanical properties and the sharper the texture, as revealed by a quantitative texture analysis that has been also developed and successfully applied to oriented PP nanocomposites

Peripheral accumulation of newly produced T and B lymphocytes in natalizumab-treated multiple sclerosis patients

The anti-α4 monoclonal antibody natalizumab inhibits lymphocyte extravasation into the central nervous system and increases peripheral T and B lymphocytes in multiple sclerosis patients. To investigate whether the lymphocyte accumulation was due to a higher lymphocyte production, an altered homeostasis, or a differential transmigration of lymphocyte subsets through endothelia, T-cell receptor excision circles and kappa-deleting recombination excision circles were quantified before and after treatment, T-cell receptor repertoire was analyzed by spectratyping, and T- and B-lymphocyte subset migration was studied using transwell coated with vascular and lymphatic endothelial cells. We found that the number of newly produced T and B lymphocytes is increased because of a high release and of a low propensity of naïve subsets to migrate across endothelial cells. In some patients this resulted in an enlargement of T-cell heterogeneity. Because new lymphocyte production ensures the integrity of immune surveillance, its quantification could be used to monitor natalizumab therapy safety

Olfactory identification testing as a predictor of the development of Alzheimer's dementia: A systematic review

Objectives/Hypothesis: To evaluate the utility of olfactory identification tests as prognostic instruments for Alzheimer's dementia (AD). Study Design: Systematic review. Methods: In accordance with PRISMA guidelines, PubMed and Ovid MEDLINE, EMBASE, ISI Web of Science, PsycINFO, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were searched to determine the quality and quantity of longitudinal and cross‐sectional research on this topic. Results: Two prospective longitudinal cohort studies and 30 cross‐sectional studies met inclusion criteria. The prospective longitudinal studies evaluated subjects with or without mild cognitive impairment (MCI) while also using olfactory identification testing as part of a neurocognitive evaluation. The first study reported an increased risk of later onset of AD in subjects with baseline hyposmia, whereas the second study suggested a possible relationship between decreased olfaction in participants with MCI and conversion to AD but was inconclusive due to low follow‐up rates. Wide variability in the type of olfactory identification test used and the reporting of results precluded meta‐analysis. The cross‐sectional studies demonstrated a positive association between poorer performance on olfactory identification testing and AD. Conclusions: Although there is evidence suggesting an association between decreased olfaction and AD, rigorously designed longitudinal cohort studies are necessary to clarify the value of olfactory identification testing in predicting the onset of AD.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92127/1/23365_ftp.pd

Cytotoxicity of ZnO Nanoparticles Can Be Tailored by Modifying Their Surface Structure: A Green Chemistry Approach for Safer Nanomaterials

ZnO nanoparticles (NP) are extensively used in numerous nanotechnology applications; however, they also happen to be one of the most toxic nanomaterials. This raises significant environmental and health concerns and calls for the need to develop new synthetic approaches to produce safer ZnO NP, while preserving their attractive optical, electronic, and structural properties. In this work, we demonstrate that the cytotoxicity of ZnO NP can be tailored by modifying their surface-bound chemical groups, while maintaining the core ZnO structure and related properties. Two equally sized (9.26 ± 0.11 nm) ZnO NP samples were synthesized from the same zinc acetate precursor using a forced hydrolysis process, and their surface chemical structures were modified by using different reaction solvents. X-ray diffraction and optical studies showed that the lattice parameters, optical properties, and band gap (3.44 eV) of the two ZnO NP samples were similar. However, FTIR spectroscopy showed significant differences in the surface structures and surface-bound chemical groups. This led to major differences in the zeta potential, hydrodynamic size, photocatalytic rate constant, and more importantly, their cytotoxic effects on Hut-78 cancer cells. The ZnO NP sample with the higher zeta potential and catalytic activity displayed a 1.5-fold stronger cytotoxic effect on cancer cells. These results suggest that by modifying the synthesis parameters/conditions and the surface chemical structures of the nanocrystals, their surface charge density, catalytic activity, and cytotoxicity can be tailored. This provides a green chemistry approach to produce safer ZnO NP