Compact and low power consumption tunable photonic crystal nanobeam cavity

A proof-of-concept for a new and entirely CMOS compatible tunable nanobeam cavity is demonstrated in this paper. Preliminary results show that a compact nanobeam cavity (~20 μm^2) with high Q-factor (~50,000) and integrated with a micro-heater atop, is able of tuning the resonant wavelength up to 15 nm with low power consumption (0.35nm/mW), and of attaining high modulation depth with only ~100 μW. Additionally, a tunable bi-stable behavior is reported

Análise de proveniência dos sedimentos siliciclásticos do Grupo do Flysch do Baixo Alentejo, Zona Sul Portuguesa

Os estudos de análise de proveniência dos sedimentos siliciclásticos do Grupo do Flysch do Baixo Alentejo sugerem mudanças na natureza das áreas fonte ao longo da sua história deposicional. Petrograficamente regista-se uma mudança de áreas iniciais caracterizadas por rochas magmáticas para áreas representadas por rochas (meta)sedimentares recicladas. Os indicadores geoquímicos de proveniência sugerem mistura de fontes, envolvendo quer rochas ígneas félsicas, quer litologias máficas para a Fm. Mértola, evoluindo para um predomínio de rochas (meta)félsicas associada à área fonte dos sedimentos siliciclásticas da Fm. Brejeira

Steroselective synthesis of imidazolidin-4-ones from α-amino amides of the antimalarial primaquine and substituted benzaldehydes

Imidazolidin-4-ones are commonly employed as skeletal modifications in bioactive oligopeptides, either as proline surrogates or for protection of the N-terminal amino acid against aminopeptidase-catalysed hydrolysis . We have been working on the synthesis of imidazolidin-4-ones of the antimalarial primaquine , through acylation of primaquine with an α-amino acid and subsequent reaction of the resulting α-aminoamide with a ketone or aldehyde. Thus, when using racemic primaquine, an optically pure chiral α-amino acid and an aldehyde as starting materials, four imidazolidin-4-one diastereomers are to be expected (Scheme 1). However, we have recently observed that imidazolidin-4-one synthesis was stereoselective when 2-carboxybenzaldehyde (2CBA)* was used, as only two diastereomers were produced2. Computational studies have shown that the imine formed prior to ring closure had, for structures derived from 2CBA, a quasi-cyclic rigid structure2. This rigid conformation is stabilized by an intramolecular hydrogen bond involving the C=O oxygen atom of the 2-carboxyl substituent in 2CBA and the N-H group of the α-amino amide moiety2. These findings led us to postulate that the 2-carbonyl substituent in the benzaldehyde moiety was the key for the stereoselective synthesis of the imidazolidin-4-ones2

Caracterização geoquímica da formação brejeira (grupo do Flysch do Baixo Alentejo): resultados preliminares

A Formação Brejeira é a unidade litoestratigráfica mais recente do Grupo do Flysch do Baixo Alentejo consistindo, essencialmente, de grauvaques e quartzovaques de natureza turbidítica intercalados com xistos argilosos. A idade da Fm. Brejeira distribui-se entre o Bashkiriano e o Moscoviano superior (Carbonífero Superior). O estudo petrográfico e mineralógico dos grauvaques da Fm. Brejeira relevou a seguinte composição Qt81,6F0,9Lt17,5, resultados que sugerem uma proveniência dos sedimentos de áreas caracterizadas predominantemente por rochas (meta)sedimentares recicladas. Do ponto de vista geoquímico os grauvaques são enriquecidos em SiO2 (>75%) reflectindo uma mineralogia dominada pelo quartzo. Os xistos argilosos apresentam Índices de Variabilidade Composicional (IVC) inferiores a 1 e baixas razões K2O/Al2O3 (0,2±0,02) e Na2O/K2O (0,15±0,06). As litologias da Fm. Brejeira exibem padrões normalizados das Terras Raras caracterizados por enriquecimento em Terras Raras Leves, anomalia de Eu negativa e reduzido fraccionamento das Terras Raras Pesadas. Quer os grauvaques quer os xistos argilosos possuem valores similares das razões Lan/Smn, Gdn/Ybn e Eu/Eu*. O Índice de Meteorização Química (CIW) das litologias da Fm. Brejeira é elevado (>80,93) e o Índice de Alteração da Plagioclase (PIA) apesar de mais variável, é na maioria das amostras elevado (PIA 67,24 – 96,14). Os valores de CIW e PIA sugerem condições de meteorização química de moderada a intensa. Os dados petrográficos e geoquímicos sugerem áreas-fonte dos sedimentos da Fm. Berjeira caracterizadas por rochas félsicas e (meta)sedimentares reciclada

Seasonal variations of the nutritive value and phytotherapeutic potential of Cladium mariscus L. (Pohl.) targeting ruminant’s production

In our endeavor to identify salt-tolerant plants with potential veterinary uses in ruminants' production strategies, we focused on Cladium mariscus L. Pohl (sawgrass), due to its high total phenolic and tannin content, anti-radical properties, and ethnomedicinal uses. Aerial parts were collected along the year in Southern Portugal and evaluated for the nutritional profile and in vitro organic matter digestibility (IVOMD), aiming for its use as feed. Acetone extracts were appraised for total contents in phenolics (TPC), flavonoids (TFC), and tannins (CTC), as well as the chemical composition by HPLC-DAD and in vitro antioxidant and anti-inflammatory properties, targeting its exploitation as phytotherapeutic products. Sawgrass biomass has a limited nutritive value, due to its high neutral detergent fiber (NDF; 596-690 g kg-1 dry matter (DM)) and acid detergent fiber (ADF; 330-418 g kg-1 DM) contents, low crude protein (51.8-87.3 g kg-1 DM) and IVOMD (172-317 g kg-1 organic matter (OM)). Despite differences among seasons, the mineral profile was adequate. The extracts were rich in TPC (88-112 mg g-1), CTC (115-169 mg g-1), and TFC (18.5-20.2 mg g-1), and displayed significant antioxidant capacity, particularly in summer and autumn, whilst no seasonal influence was detected for anti-inflammatory properties (30% reduction of nitric oxide production). Eleven phenolics were quantified: chlorogenic, ferulic, and syringic acids were the most abundant, especially in the autumn sample. Overall, despite the low nutritional interest, sawgrass extracts hold the potential as a source of antioxidant and anti-inflammatory phenolic compounds.FCT: GreenVet-ALG-01-0145-FEDER-028876/ UIDB/04326/2020/ SFRH/BD/116604/2016/ CEECIND/00425/2017.info:eu-repo/semantics/publishedVersio

Self-avoiding fractional Brownian motion - The Edwards model

In this work we extend Varadhan's construction of the Edwards polymer model to the case of fractional Brownian motions in $\R^d$, for any dimension $d\geq 2$, with arbitrary Hurst parameters $H\leq 1/d$.Comment: 14 page

Biosynthesis of Indole-3-Acetic Acid by New Klebsiella oxytoca Free and Immobilized Cells on Inorganic Matrices

While many natural and synthetic compounds exhibit auxin-like activity in bioassays, indole-3-acetic acid (IAA) is recognized as the key auxin in most plants. IAA has been implicated in almost all aspects of plant growth and development and a large array of bacteria have been reported to enhance plant growth. Cells of Klebsiella oxytoca isolated from the rhizosphere of Aspidosperma polyneuron and immobilized by adsorption on different inorganic matrices were used for IAA production. The matrices were prepared by the sol-gel method and the silica-titanium was the most suitable matrix for effective immobilization. In operational stability assays, IAA production was maintained after four cycles of production, obtaining 42.80 ± 2.03 μg mL−1 of IAA in the third cycle, which corresponds to a 54% increase in production in relation to the first cycle, whereas free cells began losing activity after the first cycle. After 90 days of storage at 4°C the immobilized cells showed the slight reduction of IAA production without significant loss of activity

Directional field-dependence of magnetoimpedance effect on integrated YIG/Pt-stripline system

We investigated the magnetization dynamics through the magnetoimpedance effect in an integrated YIG/Pt-stripline system in the frequency range of 0.5 up to 2.0 GHz. Specifically, we explore the dependence of the dynamic magnetic behavior on the field orientation by analyzing beyond the traditional longitudinal magnetoimpedance effect of the transverse and perpendicular setups. We disclose here the strong dependence of the effective damping parameter on the field orientation, as well as verification of the very-low damping parameter values for the longitudinal and transverse configurations. We find considerable sensitivity results, bringing to light the facilities to integrate ferrimagnetic insulators in current and future technological applications.This research was funded by CNPq grand numbers 304943/2020-7 and 407385/2018-5, Capes grand number 88887.573100/2020-00 and FCT grant number CTTI-31/18-CF(2)

Metastable States in High Order Short-Range Spin Glasses

The mean number of metastable states in higher order short-range spin glasses is estimated analytically using a variational method introduced by Tanaka and Edwards for very large coordination numbers. For lattices with small connectivities, numerical simulations do not show any significant dependence on the relative positions of the interacting spins on the lattice, indicating thus that these systems can be described by a few macroscopic parameters. As an extremely anisotropic model we consider the low autocorrelated binary spin model and we show through numerical simulations that its landscape has an exceptionally large number of local optima

Low triglyceride levels are associated with a better metabolic control in patients with type 1 diabetes

<p>Abstract</p> <p>Background</p> <p>Although it is well known in the literature that high triglyceride serum (TG) levels can jeopardize the metabolic control, little is known about the influence of low TG on type 1 diabetes patients (T1D). The aim of this study is to investigate the distribution of TG serum levels in individuals with T1D and its relationship with metabolic control.</p> <p>Findings</p> <p>We reviewed the medical charts of 180 patients with T1D, who were classified in groups according to TG levels: 1) low (below 50 mg/dL); 2) normal (50-150 mg/dL); 3) high (above 150 mg/dL). TG were low in 21.1% (n = 38; group 1), normal in 68.6% (n = 123; group 2) and high in 10.6% (n = 19; group 3). High TG was associated with a poor metabolic control (p < 0.001). Patients with TG lower than 50 mg/dL had a lower HbA1c than those with TG between 50 and 150 mg/dL (7.41+/-1.50% vs 8.56%+/-1.94%; p = 0.002).</p> <p>Conclusion</p> <p>TG lower than 50 mg/dL was common and might be associated with a better metabolic control in patients with T1D, although it is not clear whether the former is the cause or consequence for the latter.</p