787 research outputs found

    Neuropsychiatric systemic lupus erythematosus: where are we now?

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    When dealing with neuropsychiatric Systemic Lupus Erythematosus (NPSLE) there are still many controversial topics. In 1999 the American College of Rheumatology gave classification criteria for 19 clinical syndromes. However major problems are still related to low specificity of some of them such as headache, cognitive impairment or mood disorders. Even though a frequency of CNS involvement from 14 to 75% has been described, depending on both the population studied and the methodology of assessment, a lower frequency ranging from 21 to 28 % derived by larger case series seems more realistic. The introduction of the concept of "borderline cases", proposed by Italian Study Group for NP-SLE, is based both on clinical and instrumental evaluation and could represent a useful tool when dealing with conditions which do not fulfil ACR classification. Also the relationship between SLE activity and NP involvement is a debated issue. Concerning pathogenesis, it seems reasonable to consider multifactorial mechanisms related to antibody-mediated damage, antiphospholipid pro-thrombotic effect, non-inflammatory vasculopathy and cytokines mediated cytotoxycity. However, direct and unequivocal evidence for the implication of any of the above-mentioned mechanisms is still lacking. Although a wide range of neuroimaging tools have been used to evaluate CNS involvement, no single technique has proven to be definitive and, when dealing with a patient with suspected NPSLE, it is important to combine different diagnostic techniques. Due to the lack of effective imaging along with limitation in knowledge of underlying pathogenetic mechanisms and paucity of histopathologic findings, therapeutic approach in NPSLE remains a difficult issue and is currently based on personal experience. Italian Study Group for NP-SLE proposes the creation of a national registry on NPSLE to validate ACR classification criteria. Furthermore, the possibility to collect large series and stratifying them for each of the included neuro-psychiatric syndromes seems a good strategy for planning multicentric controlled therapeutic trials in the near future

    CuZnAl-oxide nanopyramidal mesoporous materials for the electrocatalytic CO2 reduction to syngas: Tuning of H2/CO ratio

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    Inspired by the knowledge of the thermocatalytic CO2 reduction process, novel nanocrystalline CuZnAl-oxide based catalysts with pyramidal mesoporous structures are here proposed for the CO2 electrochemical reduction under ambient conditions. The XPS analyses revealed that the co-presence of ZnO and Al2O3 into the Cu-based catalyst stabilize the CuO crystalline structure and introduce basic sites on the ternary as-synthesized catalyst. In contrast, the as-prepared CuZn-and Cu-based materials contain a higher amount of superficial Cu0 and Cu1+ species. The CuZnAl-catalyst exhibited enhanced catalytic performance for the CO and H2 production, reaching a Faradaic efficiency (FE) towards syngas of almost 95% at −0.89 V vs. RHE and a remarkable current density of up to 90 mA cm−2 for the CO2 reduction at −2.4 V vs. RHE. The physico-chemical characterizations confirmed that the pyramidal mesoporous structure of this material, which is constituted by a high pore volume and small CuO crystals, plays a fundamental role in its low diffusional mass-transfer resistance. The CO-productivity on the CuZnAl-catalyst increased at more negative applied potentials, leading to the production of syngas with a tunable H2/CO ratio (from 2 to 7), depending on the applied potential. These results pave the way to substitute state-of-the-art noble metals (e.g., Ag, Au) with this abundant and cost-effective catalyst to produce syngas. Moreover, the post-reaction analyses demonstrated the stabilization of Cu2O species, avoiding its complete reduction to Cu0 under the CO2 electroreduction conditions

    Investigation of Cu-doped ceria through a combined spectroscopic approach: Involvement of different catalytic sites in CO oxidation

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    Copper-ceria mixed oxides are widely considered promising catalysts for oxidation reactions, especially when the participation of lattice oxygen is required. However, the mechanistic understanding of these catalytic systems is still incomplete, due to their considerable complexity. In fact, copper doping of ceria results in the formation of a significant number of different interacting sites in continuous evolution during the catalytic processes. In the present study, pure and Cu-doped ceria samples were deeply investigated through combined spectroscopic techniques, i.e. XPS, EPR, and in situ FTIR and Raman spectroscopy. Through this systematic approach, the copper sites and lattice defects responsible for the enhanced CO oxidation activity of doped ceria were eluci-dated. Superficial Cu+ species and small Cu0 clusters promote the adsorption of CO at low temperature, while isolated Cu2+ monomers and dimers well-dispersed in the ceria matrix foster lattice oxygen mobility, involving the sub-surface in the redox phenomena. Consequently, the structure of Cu-doped ceria undergoes substantial modifications throughout CO oxidation in the absence of O2, with the formation of oxygen vacancy clusters. Anyway, these changes are reversible, and structural reorganization in the presence of O2 can occur even at room temperature. The excellent performance of Cu-doped ceria eventually stems from the effective cooperation among the different catalytic sites in the mixed oxide

    Protein kinase B controls transcriptional programs that direct cytotoxic T cell fate but is dispensable for T cell metabolism

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    SummaryIn cytotoxic T cells (CTL), Akt, also known as protein kinase B, is activated by the T cell antigen receptor (TCR) and the cytokine interleukin 2 (IL-2). Akt can control cell metabolism in many cell types but whether this role is important for CTL function has not been determined. Here we have shown that Akt does not mediate IL-2- or TCR-induced cell metabolic responses; rather, this role is assumed by other Akt-related kinases. There is, however, a nonredundant role for sustained and strong activation of Akt in CTL to coordinate the TCR- and IL-2-induced transcriptional programs that control expression of key cytolytic effector molecules, adhesion molecules, and cytokine and chemokine receptors that distinguish effector versus memory and naive T cells. Akt is thus dispensable for metabolism, but the strength and duration of Akt activity dictates the CTL transcriptional program and determines CTL fate

    Developing Quantitative Nondestructive Characterization of Nanomaterials: A Case Study on Sequential Infiltration Synthesis of Block Copolymers

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    The sequential infiltration synthesis (SIS) of inorganic materials in nanostructured block copolymer templates has rapidly progressed in the last few years to develop functional nanomaterials with controllable properties. To assist this rapid evolution, expanding the capabilities of nondestructive methods for quantitative characterization of the materials properties is required. In this paper, we characterize the SIS process on three model polymers with different infiltration profiles through ex situ quantification by reference-free grazing incidence X-ray fluorescence. More qualitative depth distribution results were validated by means of X-ray photoelectron spectroscopy and scanning transmission electron microscopy combined with energy-dispersive X-ray spectroscopy
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