2,775 research outputs found

    Controversies about a common etiology for eating and mood disorders.

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    Obesity and depression represent a growing health concern worldwide. For many years, basic science and medicine have considered obesity as a metabolic illness, while depression was classified a psychiatric disorder. Despite accumulating evidence suggesting that obesity and depression may share commonalities, the causal link between eating and mood disorders remains to be fully understood. This etiology is highly complex, consisting of multiple environmental and genetic risk factors that interact with each other. In this review, we sought to summarize the preclinical and clinical evidence supporting a common etiology for eating and mood disorders, with a particular emphasis on signaling pathways involved in the maintenance of energy balance and mood stability, among which orexigenic and anorexigenic neuropeptides, metabolic factors, stress responsive hormones, cytokines, and neurotrophic factors

    Perovskite-like catalysts for the catalytic flameless combustion of methane

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    Modified LaCoO3 and LaMnO3 were investigated as catalysts for low tvemperature flameless combustion of methane. Modifications were carried out by the substitution part of La for Sr2+ and Ce4+, by the addition of 0.5% of Pt or Pd and by the substitution with Ag, which have limited solubility in the perovskite structure and may exist as intraframework Ag+ and extraframework metallic silver. Catalysts were synthesized by flame pyrolysis, which lead to a significant increase of both surface area and thermal resistance in comparison with the catalysts prepared by traditional sol-gel method. Samples were mainly characterized by XRD, BET and TPR techniques. Catalytic activity for the flameless combustion of methane was investigated by means of bench scale continuous apparatus, equipped with a quadrupolar mass spectrometer. In addition the resistance of every catalysts against sulphur poisoning was tested by using tetrahydrothiophene (THT) as poisoning agent. In most cases modification of perovskites led to an activity improvement, which was much more evident in the case of silver substitution. All the FP-prepared catalysts showed full methane conversion below 600\ub0C, with CO2 and H2O as the sole detected products. Sr-substitution and addition of noble metals increased resistance to sulphur poisoning, while silver was not effective from this point of view, its main advantage being a substantial increase of the initial activity, which lead to satisfactory performance even after poisoning

    Effect of sulphur poisoning on perovskite catalysts prepared by flame-pyrolysis

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    ABO(3) perovskite-like catalysts are known to be sensitive to sulphur-containing compounds. Possible solutions to increase resistance to sulphur are represented by either catalyst bed protection with basic guards or catalyst doping with different transition or noble metals. In the present work La((1-x))A(x)'CoO(3), La((1-x))A(x)'MnO(3) and La((1-x))A(x)'FeO(3), with A' = Ce, Sr and x = 0, 0.1, 0.2, either pure or doped with noble metals (0.5 wt% Pt or Pd), were prepared in nano-powder form by flame-pyrolysis. All the catalysts were tested for the catalytic flameless combustion of methane, monitoring the activity by on-line mass spectrometry. The catalysts were then progressively deactivated in operando with a new procedure, consisting of repeated injection of some doses of tetrahydrothiophene (THT), usually employed as odorant in the natural gas grid, with continuous analysis of the transient response of the catalyst. The activity tests were then repeated on the poisoned catalyst. Different regenerative treatments were also tried, either in oxidising or reducing atmosphere. Among the unsubstituted samples, higher activity and better resistance to poisoning have been observed in general with manganites with respect to the corresponding formulations containing Co or Fe at the B-site. The worst catalyst showed LaFeO(3), from both the points of view of activity and of resistance to sulphur poisoning. La(0.9)Sr(0.1)MnO(3) showed, the best results, exhibiting very high activity and good resistance even after the addition of up to 8.4 mg of THT/g of catalyst. Interesting results were attained also by adding Sr to Co-based perovskites. Sr showed a first action by forcing Mn or Co in their highest oxidation state, but, in addition, it could also act as a sulphur guard, likely forming stable sulphates due to its basicity. Among noble metals, Pt doping proved beneficial in improving the activity of both the fresh and the poisoned catalyst

    La-Ag-Co perovskites for the catalytic flameless combustion of methane

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    Ag represents an interesting dopant for the highly active LaCoO3 perovskites used for the catalytic flameless combustion (CFC) of methane, due to its ability to adsorb and activate oxygen and to the possibility of incorporation into the framework as Ag+ or Ag2+, with formation of oxygen vacancies. In the present work we compared the catalytic activity and resistance to sulphur poisoning of a series of LaCoO3, x%Ag/LaCoO3, La1-xAgxCoO3 samples (nominal composition), the latter two notations indicating post-synthesis Ag loading or direct incorporation during the synthesis, respectively. The samples were prepared by flame pyrolysis (FP) and by the sot-gel (SG) method, leading to different particle size and possibly to different incorporation degree of the dopant, quantified by Rietveld refinement of XRD patterns. Higher activity was observed, in general, with fresh catalysts synthesised by FP. The SG samples demonstrated a slightly better resistance to sulphur poisoning when considering the conversion decrease between the fresh and the poisoned samples, due to lower surface exposure. However, interesting data have been obtained with some of the Ag-doped poisoned FP samples, performing even better than the fresh SG-prepared ones. Ag addition led to a complex change of activity and resistance to poisoning. The activity of FP-prepared samples doped with a small amount of Ag (e.g. 5 mol%) was indeed lower than that of the undoped LaCoO3. By contrast, a further increase of Ag concentration led to increasing catalytic activity, mainly when big extra framework Ag particles were present. By contrast, for SG samples a low Ag amount was beneficial for activity, due to an increased reducibility of Co3+

    Neural detection of complex sound sequences in the absence of consciousness

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    Neural responses to violations of global regularities are thought to require consciousness. However, Tzovara et al. show that some comatose patients can also detect deviations in sequences composed of repeated groups of sounds, suggesting that the unconscious brain has a greater capacity to track sensory inputs than previously believe

    Eosinophilic aseptic arachnoiditis: A neurological complication in HIV-negative drug-addicts

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    Abstract.: The finding of an eosinophilic aseptic meningitis in IV drug abuse is usually suggestive of an opportunistic infection or an allergic reaction. However, HIV-negative patients are at lower risk for developing these complications. Two young HIV-negative patients, with previous intravenous polytoxicomany, developed cystic arachnoiditis over the spinal cord associated with eosinophilic meningitis. Histology of the meningeal spinal cord lesions revealed a vasculocentric mixed inflammatory reaction. In one patient prednisone led to marked clinical improvement. Since infection, vasculitis, sarcoidosis and previous myelography were ruled out, we believe that the syndrome of eosinophilic aseptic arachnoiditis may be related to an hyperergic reaction in the meniges toward drug-adulterants inoculated through the intravenous rout

    Radiology of Mummies

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    In the past, autoptic examinations were usually performed for research. This type of examination, for obvious reasons, did not appeal to paleopathologists as these procedures potentially damaged the finds destined to musealization. Since the discovery of X-ray, radiology has been used to study mummies as a noninvasive technique. The radiology of mummies allows us to discover pathologies, to elaborate on the type of ritual mummification for the artificial embalming, to comprehend the diagenetic process that guaranteed a natural mummification, or to conclude anthropological identification. We present a review on the latest studies on mummies that have shown that the radiological approach has been essential to conduct research

    EEG recording latency in critically ill patients: Impact on outcome. An analysis of a randomized controlled trial (CERTA).

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    OBJECTIVE To assess, in adults with acute consciousness impairment, the impact of latency between hospital admission and EEG recording start, and their outcome. METHODS We reviewed data of the CERTA trial (NCT03129438) and explored correlations between EEG recording latency and mortality, Cerebral Performance Categories (CPC), and modified Rankin Scale (mRS) at 6 months, considering other variables, using uni- and multivariable analyses. RESULTS In univariable analysis of 364 adults, median latency between admission and EEG recordings was comparable between surviving (61.1 h; IQR: 24.3-137.7) and deceased patients (57.5 h; IQR: 22.3-141.1); p = 0.727. This did not change after adjusting for potential confounders, such as lower Glasgow Coma Score on enrolment (p < 0.001) and seizure or status epilepticus detection (p < 0.001). There was neither any correlation between EEG latency and mRS (rho 0.087, p 0.236), nor with CPC (rho = 0.027, p = 0.603). CONCLUSION This analysis shows no correlation between delays of EEG recordings and mortality or functional outcomes at 6 months in critically ill adults. SIGNIFICANCE These findings might suggest that in critically ill adults mortality correlates with underlying brain injury rather than EEG delay
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