464 research outputs found
Non-stoichiometric mixed lead and tin niobates
Novel non-stoichiometric mixed lead and tin niobates with the pyrochlore structure have been synthesized via a solid-state route. The materials have been characterized by bulk chemical analysis, single-crystal and powder X-ray diffraction, 207Pb, 119Sn and 93Nb (single and triple quantum) solid-state NMR spectroscopy. The structures of the new non-stoichiometric mixed lead–tin niobate pyrochlore compounds have been Rietveld refined in the cubic system, space group Fd-3m. The steroactivity of the Sn(II) free electron pair leads to the general formula (Sn1.6−xPbx)(Nb2−ySny)O6.6−0.5y, where x (0–1.6) is the Pb(II) and y (0–0.34) is the Sn(IV) contents. 207Pb, 119Sn and (in particular) 93Nb NMR support the isomorphous substitution of tin for lead in the compounds studied. 93Nb triple-quantum magic-angle spinning NMR spectroscopy show that the materials contain, at least, two distinct niobium sites, in a 2:1 population ratio, which may be associated with different sampleinfo:eu-repo/semantics/publishedVersio
Whole Genome Association Analysis of Idiopathic Eosinophilic Enteritis in Brown Egg Layers
Idiopathic Eosinophilic Enteritis (IEE) is an intestine disease that affects absorption of nutrients and performance. Hens of a commercial breeding layer line and its two reciprocal crosses with another line were recorded for IEE related traits and genotyped for over 40,000 genetic markers across the genome. Whole genome association analysis was performed on 288 daughters from high and low incidence sire families. Single marker association analyses of IEE incidence in separate lines showed consistent significant regions on chromosomes 4 and 5 (p\u3c0.001). Simultaneous analyses of all SNPs in all 3 lines using Bayesian whole genome selection methods indicated evidence of associations on chromosomes 1, 2 and 4 for additive effects and on chromosome 5 for dominance effects. Line specific regions also appeared on chromosome Z. With further investigation, these results can be used to develop genetic markers to select against this disease and to understand its genetic basis
Condução da Touriga Nacional no Dão. Interacções, forma, carga porta-enxerto
A casta ‘Touriga Nacional’, a mais nobre e recomendada casta do Douro e Dão, não
obstante a sua elevada fertilidade, tem-se revelado nos últimos decénios pouco produtiva o
que levou ao seu abandono progressivo nos respectivos encepamentos. O presente estudo
refere-se a um ensaio instalado em 1989 na região do Dão, em Nelas, com o objectivo de
encontrar alternativas culturais conducentes a ganhos de rendimento no respeito pelos
tradicionais nÃveis de qualidade. São introduzidas diversas alternativas de condução
(estrutura do coberto vegetal, sistemas de poda e cargas), com três porta-enxertos. Os
sistemas de condução alternativos ao Guyot duplo tradicional - Cordão Royat e Lira -
originaram melhores produções, sobretudo a Lira. O maior rendimento parece estar
relacionado com um efeito favorável do microclima do coberto na redução do desavinho.
Em termos de vigor o comportamento dos três sistemas de condução foi oposto ao
verificado no rendimento. Os resultados referentes ao porta-enxerto evidenciam uma
ausência de efeito no rendimento, mas parecem indicar que o 99R induz menor vigor. Em
qualquer dos sistemas de condução, a carga teve um efeito significativamente positivo no
rendimento sem afectar o vigor e, no caso do 99R, não afectou a maturaçãoinfo:eu-repo/semantics/publishedVersio
Cosmic Acceleration in Brans-Dicke Cosmology
We consider Brans-Dicke theory with a self-interacting potential in Einstein
conformal frame. We show that an accelerating expansion is possible in a
spatially flat universe for large values of the Brans-Dicke parameter
consistent with local gravity experiments.Comment: 10 Pages, 3 figures, To appear in General Relativity and Gravitatio
Metabolic and nutritional triggers associated with increased risk of liver complications in SARS-CoV-2
Obesity, diabetes, cardiovascular and respiratory diseases, cancer and smoking are risk factors for negative outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can quickly induce severe respiratory failure in 5% of cases. Coronavirus disease-associated liver injury may occur during progression of SARS-CoV-2 in patients with or without pre-existing liver disease, and damage to the liver parenchyma can be caused by infection of hepatocytes. Cirrhosis patients may be particularly vulnerable to SARS-CoV-2 if suffering with cirrhosis-associated immune dysfunction. Furthermore, pharmacotherapies including macrolide or quinolone antibiotics and steroids can also induce liver damage. In this review we addressed nutritional status and nutritional interventions in severe SARS-CoV-2 liver patients. As guidelines for SARS-CoV-2 in intensive care (IC) specifically are not yet available, strategies for management of sepsis and SARS are suggested in SARS-CoV-2. Early enteral nutrition (EN) should be started soon after IC admission, preferably employing iso-osmolar polymeric formula with initial protein content at 0.8 g/kg per day progressively increasing up to 1.3 g/kg per day and enriched with fish oil at 0.1 g/kg per day to 0.2 g/kg per day. Monitoring is necessary to identify signs of intolerance, hemodynamic instability and metabolic disorders, and transition to parenteral nutrition should not be delayed when energy and protein targets cannot be met via EN. Nutrients including vitamins A, C, D, E, B6, B12, folic acid, zinc, selenium and ω-3 fatty acids have in isolation or in combination shown beneficial effects upon immune function and inflammation modulation. Cautious and monitored supplementation up to upper limits may be beneficial in management strategies for SARS-CoV-2 liver patients
The Time-Reversal- and Parity-Violating Nuclear Potential in Chiral Effective Theory
We derive the parity- and time-reversal-violating nuclear interactions
stemming from the QCD theta term and quark/gluon operators of effective
dimension 6: quark electric dipole moments, quark and gluon chromo-electric
dipole moments, and two four-quark operators. We work in the framework of
two-flavor chiral perturbation theory, where a systematic expansion is
possible. The different chiral-transformation properties of the sources of
time-reversal violation lead to different hadronic interactions. For all
sources considered the leading-order potential involves known one-pion
exchange, but its specific form and the relative importance of short-range
interactions depend on the source. For the theta term, the leading potential is
solely given by one-pion exchange, which does not contribute to the deuteron
electric dipole moment. In subleading order, a new two-pion-exchange potential
is obtained. Its short-range component is indistinguishable from one of two
undetermined contact interactions that appear at the same order and represent
effects of heavier mesons and other short-range QCD dynamics. One-pion-exchange
corrections at this order are discussed as well.Comment: 39 pages, 8 figure
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