534 research outputs found
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
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
Off-Target Inhibition of Human Dihydroorotate Dehydrogenase (hDHODH) Highlights Challenges in the Development of Fat Mass and Obesity-Associated Protein (FTO) Inhibitors
Air pollution exposure during pregnancy and childhood autistic traits in four European population-based cohort studies : the ESCAPE project
Background: Prenatal exposure to air pollutants has been suggested as a possible etiologic factor
for the occurrence of autism spectrum disorder.
Objectives: We aimed to assess whether prenatal air pollution exposure is associated with
childhood autistic traits in the general population.
Methods: Ours was a collaborative study of four European population-based birth/child cohorts—
CATSS (Sweden), Generation R (the Netherlands), GASPII (Italy), and INMA (Spain). Nitrogen
oxides (NO2, NOx) and particulate matter (PM) with diameters of ≤ 2.5 μm (PM2.5), ≤ 10 μm
(PM10), and between 2.5 and 10 μm (PMcoarse), and PM2.5 absorbance were estimated for birth
addresses by land-use regression models based on monitoring campaigns performed between 2008
and 2011. Levels were extrapolated back in time to exact pregnancy periods. We quantitatively
assessed autistic traits when the child was between 4 and 10 years of age. Children were classified
with autistic traits within the borderline/clinical range and within the clinical range using
validated cut-offs. Adjusted cohort-specific effect estimates were combined using random-effects
meta-analysis.
Results: A total of 8,079 children were included. Prenatal air pollution exposure was not associated
with autistic traits within the borderline/clinical range (odds ratio = 0.94; 95% CI: 0.81, 1.10
per each 10‑μg/m3 increase in NO2 pregnancy levels). Similar results were observed in the different
cohorts, for the other pollutants, and in assessments of children with autistic traits within the
clinical range or children with autistic traits as a quantitative score.
Conclusions: Prenatal exposure to NO2 and PM was not associated with autistic traits in children
from 4 to 10 years of age in four European population-based birth/child cohort studies.NonePublishe
Untargeted UPLC-MS Profiling Pipeline to Expand Tissue Metabolome Coverage: Application to Cardiovascular Disease.
Metabolic
profiling studies aim to achieve broad metabolome coverage
in specific biological samples. However, wide metabolome coverage
has proven difficult to achieve, mostly because of the diverse physicochemical
properties of small molecules, obligating analysts to seek multiplatform
and multimethod approaches. Challenges are even greater when it comes
to applications to tissue samples, where tissue lysis and metabolite
extraction can induce significant systematic variation in composition.
We have developed a pipeline for obtaining the aqueous and organic
compounds from diseased arterial tissue using two consecutive extractions,
followed by a different untargeted UPLC-MS analysis method for each
extract. Methods were rationally chosen and optimized to address the
different physicochemical properties of each extract: hydrophilic
interaction liquid chromatography (HILIC) for the aqueous extract
and reversed-phase chromatography for the organic. This pipeline can
be generic for tissue analysis as demonstrated by applications to
different tissue types. The experimental setup and fast turnaround
time of the two methods contributed toward obtaining highly reproducible
features with exceptional chromatographic performance (CV % < 0.5%),
making this pipeline suitable for metabolic profiling applications.
We structurally assigned 226 metabolites from a range of chemical
classes (e.g., carnitines, α-amino acids, purines, pyrimidines,
phospholipids, sphingolipids, free fatty acids, and glycerolipids)
which were mapped to their corresponding pathways, biological functions
and known disease mechanisms. The combination of the two untargeted
UPLC-MS methods showed high metabolite complementarity. We demonstrate
the application of this pipeline to cardiovascular disease, where
we show that the analyzed diseased groups (<i>n </i>= 120)
of arterial tissue could be distinguished based on their metabolic
profiles
One-hour post-load plasma glucose levels associated with decreased insulin sensitivity and secretion and early makers of cardiometabolic risk.
PURPOSE: Obese adults with normal glucose tolerance (NGT) but with 1-hour post-load plasma glucose (1hPG) ≥ 155 mg/dl are at higher risk of developing type 2 diabetes (T2D) and cardiometabolic complications. Little information is available for the pediatric population, where recently, a lower cutoff, 132.5 mg/dl, has been suggested as being more sensitive to identify subjects at risk of T2D. Our aim was to assess whether obese Caucasian youth with 1hPG ≥ 132.5 mg/dl have worse insulin sensitivity and secretion and a worse cardiometabolic profile compared to obese youth with 1hPG < 132.5 mg/dl. METHODS: Medical records of 244 (43% male; age: 11.1 ± 2.7years) overweight/obese children and adolescents, who had undergone an oral glucose tolerance test (OGTT), were retrieved. Anthropometric and biochemical data were collected from the hard copy archive. Indexes of insulin resistance (HOMA-IR), insulin sensitivity (WBISI), and insulin secretion (Insulinogenic Index, Disposition Index) were calculated. RESULTS: Of the 244 records analyzed, 215 fulfilled criteria for NGT and had complete biochemical data. Among NGT patients, 42 (19.5%) showed 1hPG ≥ 132.5 mg/dL (high-NGT), while the remaining had 1hPG < 132.5 mg/dL (low-NGT). The high-NGT group showed a higher male prevalence (59.5 vs 37%), lower Disposition Index (0.54 [0.39-0.71] vs 0.79 [0.47-1.43]), and WBISI (0.24 [0.18-0.35] vs 0.33 [0.23-0.50]) than the low-NGT group. High-NGT subjects also showed a trend towards lower HDL-cholesterol and higher triglycerides/HDL-cholesterol ratio (2.13 [1.49-3.41] vs 1.66 [1.24-2.49]). CONCLUSIONS: In overweight/obese NGT Caucasian youth a 1hPG ≥ 132.5 mg/dL was able to identify those with impaired insulin sensitivity and secretion and a trend towards a worse cardio-metabolic profile, a group likely at risk for future T2D
Contextos colaborativos para la formación de profesores
Thirty-five elementary teacher education candidates, three university professors, a school administrator in charge of curriculum and technology, a school principal, a lead teacher, fifteen cooperating teachers, and an IBM educational consultant were engaged in a school/university collaboration designed for candidates to complete teacher education coursework in meaningful contexts of real classrooms in real schools. Evidence from the collaboration demonstrates that the key elements of communication, trust, funding, and sharing responsibility contributed to the success of this collaborative effort. Treinta y cinco candidatos de pedagogía básica, tres profesores universitarios, un administrador escolar a cargo de currículo y tecnología, un director de colegio, un profesor guía, quince profesores cooperadores y un consultor educacional de IBM, participaron en un proyecto de colaboración escuela/universidad diseñado para que los candidatos a profesor finalizaran sus cursos de formación docente en contextos significativos de aulas reales en colegios reales. La evidencia recogida en la colaboración demuestra que los elementos claves de comunicación, confianza, apoyo y responsabilidad compartida contribuyeron al éxito de este esfuerzo colaborativo
Reverse Micelle Strategy for the Synthesis of MnOx-TiO2Active Catalysts for NH3-Selective Catalytic Reduction of NOxat Both Low Temperature and Low Mn Content
MnOx-TiO2catalysts (0, 1, 5, and 10 wt % Mn nominal content) for NH3-SCR (selective catalytic reduction) of NOxhave been synthesized by the reverse micelle-assisted sol-gel procedure, with the aim of improving the dispersion of the active phase, usually poor when obtained by other synthesis methods (e.g., impregnation) and thereby lowering its amount. For comparison, a sample at nominal 10 wt % Mn was obtained by impregnation of the (undoped) TiO2sample. The catalysts were characterized by using an integrated multitechnique approach, encompassing X-ray diffraction followed by Rietveld refinement, micro-Raman spectroscopy, N2isotherm measurement at −196 °C, energy-dispersive X-ray analysis, diffuse reflectance UV-vis spectroscopy, temperature-programmed reduction technique, and X-ray photoelectron spectroscopy. The obtained results prove that the reverse micelle sol-gel approach allowed for enhancing the catalytic activity, in that the catalysts were active in a broad temperature range at a substantially low Mn loading, as compared to the impregnated catalyst. Particularly, the 5 wt % Mn catalyst showed the best NH3-SCR activity in terms of both NOxconversion (ca. 90%) and the amount of produced N2O (ca. 50 ppm) in the 200-250 °C temperature range
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
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