Two new records of Polystichum (Dryopteridaceae) for the Argentine Flora

En este trabajo, dos nuevos taxones de Polystichum se registran para la flora de helechos deArgentina: P. subintegerrimum (Hook. & Arn.) R. Rodr. hallado en la región de los Bosques Patagónicos yP. platylepis Fée colectado en Misiones; hasta ahora, ambas especies eran consideradas endémicas deChile y Brasil, respectivamente. Se describen e ilustran ambas especies.In this paper, two new records for the Argentina fern-flora are reported: P. subintegerrimum (Hook. & Arn.) R. Rodr. found in the Patagonian Forests and P. platylepis Fée collected in Misiones; both have been considered endemic for Chile and Brazil, respectively. The species are described and illustrated.Fil: Morero, Rita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Cordoba. Facultad de Ciencias Quimicas; ArgentinaFil: Giorgis, Melisa Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Condack, Joao P. S.. Universidade Federal do Rio de Janeiro; BrasilFil: Vidoz, Félix F.. Parque Nacional Lago Puelo; ArgentinaFil: Barboza, Gloria Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Cordoba. Facultad de Ciencias Quimicas; Argentin

In situ Raman analyses of the soot oxidation reaction over nanostructured ceria-based catalysts

Abstract To reduce the emissions of internal combustion engines, ceria-based catalysts have been widely investigated as possible alternatives to the more expensive noble metals. In the present work, a set of four different ceria-based materials was prepared via hydrothermal synthesis, studying the effect of Cu and Mn as dopants both in binary and ternary oxides. In situ Raman analyses were carried out to monitor the behaviour of defect sites throughout thermal cycles and during the soot oxidation reaction. Despite ceria doped with 5% of Cu featured the highest specific surface area, reducibility and amount of intrinsic and extrinsic defects, a poor soot oxidation activity was observed through the standard activity tests. This result was confirmed by the calculation of soot conversion curves obtained through a newly proposed procedure, starting from the Raman spectra collected during the in situ tests. Moreover, Raman analyses highlighted that new defectiveness was produced on the Cu-doped catalyst at high temperature, especially after soot conversion, while a slight increase of the defect band and a total reversibility were observed in case of the ternary oxide and pure/Mn-doped ceria, respectively. The major increment was related to the extrinsic defects component; tests carried out in different atmospheres suggested the assignment of this feature to vacancy-free sites containing oxidized doping cations. Its increase at the end of the tests can be an evidence of peroxides and superoxides deactivation on catalysts presenting excessive oxygen vacancy concentrations. Instead, ceria doped with 5% of Mn exhibited the best soot oxidation activity, thanks to an intermediate density of oxygen vacancies and to its well-defined morphology

Chemical modulation of the 1-(Piperidin-4-yl)-1,3-dihydro-2h-benzo[d]imidazole-2-one scaffold as a novel NLRP3 inhibitor

In the search for new chemical scaffolds able to afford NLRP3 inflammasome inhibitors, we used a pharmacophore-hybridization strategy by combining the structure of the acrylic acid derivative INF39 with the 1-(piperidin-4-yl)1,3-dihydro-2H-benzo[d]imidazole-2-one substructure present in HS203873, a recently identified NLRP3 binder. A series of differently modulated benzo[d]imidazole-2-one derivatives were designed and synthesised. The obtained compounds were screened in vitro to test their ability to inhibit NLRP3-dependent pyroptosis and IL-1β release in PMA-differentiated THP-1 cells stimulated with LPS/ATP. The selected compounds were evaluated for their ability to reduce the ATPase activity of human recombinant NLRP3 using a newly developed assay. From this screening, compounds 9, 13 and 18, able to concentration-dependently inhibit IL-1β release in LPS/ATP-stimulated human macrophages, emerged as the most promising NLRP3 inhibitors of the series. Computational simulations were applied for building the first complete model of the NLRP3 inactive state and for identifying possible binding sites available to the tested compounds. The analyses led us to suggest a mechanism of protein–ligand binding that might explain the activity of the compounds

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

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

Optical response with threefold symmetry axis on oriented microdomains of opal photonic crystals

The paper deals with three-dimensional photonic crystals known as artificial opals, namely, fcc lattices of dielectric spheres: such systems have been the subject of numerous investigations. Opal photonic crystals viewed along the [111] direction of the fcc structure have a threefold symmetry axis; however this microscopic symmetry is difficult to observe in optical measurements performed on macroscopic areas containing microdomains with different orientations. In this work polarized transmittance measurements on [111]-stacked silica opals with single oriented microdomains, identified by field-emission scanning electron microscopy and laser-scanning confocal microscopy, demonstrate different optical response of twin structures with the two possible vertical stacking sequences. A detailed comparison with theory shows that microtransmittance experiments probe the photonic band structure along the Gamma-L-K and Gamma-L-U orientations of the Brillouin zone, respectively, thus giving conclusive evidence for macroscopic optical response related to the presence of a threefold (instead of a sixfold) symmetry axis in the photonic microstructure. The paper arises from a collaboration between the University of Pavia and the Politecnico di Torino

Vitamin D and ω-3 Supplementations in Mediterranean Diet During the 1st Year of Overt Type 1 Diabetes: A Cohort Study

Vitamin D and omega 3 fatty acid (\u3c9-3) co-supplementation potentially improves type 1 diabetes (T1D) by attenuating autoimmunity and counteracting inflammation. This cohort study, preliminary to a randomized control trial (RCT), is aimed at evaluating, in a series of T1D children assuming Mediterranean diet and an intake of cholecalciferol of 1000U/day from T1D onset, if \u3c9-3 co-supplementation preserves the residual endogen insulin secretion (REIS). Therefore, the cohort of 22 \u201cnew onsets\u201d of 2017 received \u3c9-3 (eicosapentenoic acid (EPA) plus docosahexaenoic acid (DHA), 60 mg/kg/day), and were compared retrospectively vs. the 37 \u201cprevious onsets\u201d without \u3c9-3 supplementation. Glicosilated hemoglobin (HbA1c%), the daily insulin demand (IU/Kg/day) and IDAA1c, a composite index (calculated as IU/Kg/day 7 4 + HbA1c%), as surrogates of REIS, were evaluated at recruitment (T0) and 12 months later (T12). In the \u3c9-3 supplemented group, dietary intakes were evaluated at T0 and T12. As an outcome, a decreased insulin demand (p < 0.01), particularly as pre-meal boluses (p < 0.01), and IDAA1c (p < 0.05), were found in the \u3c9-3 supplemented group, while HbA1c% was not significantly different. Diet analysis in the \u3c9-3 supplemented group, at T12 vs. T0, highlighted that the intake of arachidonic acid (AA) decreased (p < 0.01). At T0, the AA intake was inversely correlated with HbA1c% (p < 0.05; r;. 0.411). In conclusion, the results suggest that vitamin D plus \u3c9-3 co-supplementation as well as AA reduction in the Mediterranean diet display benefits for T1D children at onset and deserve further investigation