100 research outputs found
Psychotic Alzheimer\u27s disease is associated with gender-specific tau phosphorylation abnormalities
Converging evidence suggests that psychotic Alzheimer\u27s disease (AD + P) is associated with an acceleration of frontal degeneration, with tau pathology playing a primary role. Previous histopathologic and biomarker studies have specifically implicated tau pathology in this condition. To precisely quantify tau abnormalities in the frontal cortex in AD + P, we used a sensitive biochemical assay of total tau and 4 epitopes of phospho-tau relevant in AD pathology in a postmortem sample of AD + P and AD - P. Samples of superior frontal gyrus from 26 AD subjects without psychosis and 45 AD + P subjects with psychosis were analyzed. Results of enzyme-linked immunosorbent assay demonstrate that AD + P females, but not males, had significantly higher levels of phosphorylated tau in the frontal cortex. In males, but not females, AD + P was associated with the presence of alpha-synuclein pathology. These results support a gender dissociation of pathology in AD + P. The design of future studies aimed at the elucidation of cognitive and/or functional outcomes; regional brain metabolic deficits; or genetic correlates of AD + P should take gender into consideration. (C) 2014 Elsevier Inc. All rights reserved
Advanced oxidation process for coke removal:A systematic study of hydrogen peroxide and OH-derived-Fenton radicals of a fouled zeolite
The regeneration process of a fouled catalyst typically involves treatments at high temperature which often cause irreversible damages on the catalyst’s properties. In this work, Fenton chemistry-derived •OH species, and H2O2, are proposed as oxidizing agents to reactivate a porous catalyst at mild conditions, below 100 °C. The chosen catalyst is a microporous ZSM-5 zeolite, which is a challenging candidate due to the mass transfer limitations with possible recombination of the hydroxyl radicals; thereby being an obstacle to oxidize organics occluded in the micropores. The organics deposition over a ZSM-5 zeolite during the D-glucose dehydration reaction was confirmed by a number of characterization techniques, which revealed a considerable decrease in the surface area, pore volume and acid site density in the fouled catalyst. By properly selecting the regeneration conditions, reactivation via Fenton or H2O2 was highly effective in terms of removal of the organics as well as recovery of the initial catalytic activity. The properties of the H2O2 treated-zeolite, the optimal treatment in this case study, were preserved with similar structural and textural features and improved acidity. Hot water extraction was ineffective to remove the humins from ZSM-5. Mechanistically, the presence of Fe impurities in the zeolite structure did not allow to discriminate between a homo, heterogeneous, or a direct H2O2 pathway, or a combination of them. The exhibited conversion by the regenerated zeolite was comparable to that of the fresh one
Overcoming the engineering constraints for scaling-up the state-of-the-art catalyst for tail-gas N2O decomposition
An efficient process is reported for preparing a state-of-the-art Fe-ferrierite catalyst for N2O decomposition under industrial tail-gas conditions. In the synthesis procedure we evaluate the very demanding constraints for scale-up; i.e. large reactor volumes are typically needed, long processing times and considerable amounts of waste water is generated. The proposed synthesis minimizes the amount of water used, and therefore the amount produced waste water is minimal; in this approach there is no liquid residual water stream that would need intensive processing. This has remarkable benefits in terms of process design, since the volume of equipment is reduced and the energy-intensive filtration is eliminated. This route exemplifies the concept of process intensification, with the ambition to re-engineer an existing process to make the industrial catalyst manufacture more sustainable. The so-obtained catalyst is active, selective and very stable under tail gas conditions containing H2O, NO and O2, together with N2O; keeping a high conversion during 70 h time on stream at 700 K, with a decay of 0.01%/h, while the standard reference catalyst decays at 0.06%/h; hence it deactivates six times slower, with ~5% absolute points of higher conversion. The excellent catalytic performance is ascribed to the differential speciation
Modeling neurocognitive and neurobiological recovery in addiction
This book focuses on "what to know" and "how to apply" information, prioritizing novel principles and delineating cutting-edge assessment, phenotyping and treatment tools
The clustering and morphology of chondrocytes in normal and mildly degenerate human femoral head cartilage studied by confocal laser scanning microscopy
Health Care for Mitochondrial Disorders in Canada: A Survey of Physicians
Background: An improved understanding of diagnostic and treatment practices for patients with rare primary mitochondrial disorders can support benchmarking against guidelines and establish priorities for evaluative research. We aimed to describe physician care for patients with mitochondrial diseases in Canada, including variation in care. Methods: We conducted a cross-sectional survey of Canadian physicians involved in the diagnosis and/or ongoing care of patients with mitochondrial diseases. We used snowball sampling to identify potentially eligible participants, who were contacted by mail up to five times and invited to complete a questionnaire by mail or internet. The questionnaire addressed: personal experience in providing care for mitochondrial disorders; diagnostic and treatment practices; challenges in accessing tests or treatments; and views regarding research priorities. Results: We received 58 survey responses (52% response rate). Most respondents (83%) reported spending 20% or less of their clinical practice time caring for patients with mitochondrial disorders. We identified important variation in diagnostic care, although assessments frequently reported as diagnostically helpful (e.g., brain magnetic resonance imaging, MRI/MR spectroscopy) were also recommended in published guidelines. Approximately half (49%) of participants would recommend mitochondrial cocktails for all or most patients, but we identified variation in responses regarding specific vitamins and cofactors. A majority of physicians recommended studies on the development of effective therapies as the top research priority. Conclusions: While Canadian physicians\u27 views about diagnostic care and disease management are aligned with published recommendations, important variations in care reflect persistent areas of uncertainty and a need for empirical evidence to support and update standard protocols
A Blessing and a Curse? Political Institutions in the Growth and Decay of Generalized Trust: A Cross-National Panel Analysis, 1980–2009
Despite decades of research on social capital, studies that explore the relationship between political institutions and generalized trust–a key element of social capital–across time are sparse. To address this issue, we use various cross-national public-opinion data sets including the World Values Survey and employ pooled time-series OLS regression and fixed- and random-effects estimation techniques on an unbalanced panel of 74 countries and 248 observations spread over a 29-year time period. With these data and methods, we investigate the impact of five political-institutional factors–legal property rights, market regulations, labor market regulations, universality of socioeconomic provisions, and power-sharing capacity–on generalized trust. We find that generalized trust increases monotonically with the quality of property rights institutions, that labor market regulations increase generalized trust, and that power-sharing capacity of the state decreases generalized trust. While generalized trust increases as the government regulation of credit, business, and economic markets decreases and as the universality of socioeconomic provisions increases, both effects appear to be more sensitive to the countries included and the modeling techniques employed than the other political-institutional factors. In short, we find that political institutions simultaneously promote and undermine generalized trust
Metabolic basis to Sherpa altitude adaptation.
The Himalayan Sherpas, a human population of Tibetan descent, are highly adapted to life in the hypobaric hypoxia of high altitude. Mechanisms involving enhanced tissue oxygen delivery in comparison to Lowlander populations have been postulated to play a role in such adaptation. Whether differences in tissue oxygen utilization (i.e., metabolic adaptation) underpin this adaptation is not known, however. We sought to address this issue, applying parallel molecular, biochemical, physiological, and genetic approaches to the study of Sherpas and native Lowlanders, studied before and during exposure to hypobaric hypoxia on a gradual ascent to Mount Everest Base Camp (5,300 m). Compared with Lowlanders, Sherpas demonstrated a lower capacity for fatty acid oxidation in skeletal muscle biopsies, along with enhanced efficiency of oxygen utilization, improved muscle energetics, and protection against oxidative stress. This adaptation appeared to be related, in part, to a putatively advantageous allele for the peroxisome proliferator-activated receptor A (PPARA) gene, which was enriched in the Sherpas compared with the Lowlanders. Our findings suggest that metabolic adaptations underpin human evolution to life at high altitude, and could have an impact upon our understanding of human diseases in which hypoxia is a feature.The work was supported by PhD studentships from the BBSRC to JH (BB/F016581/1) and British Heart Foundation to AK (FS/09/050), an Academic Fellowship to AM from the Research Councils UK (EP/E500552/1), a Physiological Society grant and support from Oroboros Instruments. JG thanks the MRC (MC UP A90 1006) and AB Sciex. MF thanks the MRC and Faculty of Medicine, Southampton University. For full acknowledgements see SI
Musicking with an interactive musical system: The effects of task motivation and user interface mode on non-musicians' creative engagement
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