A finite element model using a unified formulation for the analysis of viscoelastic sandwich laminates

In this paper we present a layerwise finite element model for the analysis of sandwich laminated plates with a viscoelastic core and laminated anisotropic face layers. The stiffness and mass matrices of the element are obtained by Carrera's Unified Formulation (CUF). The dynamic problem is solved in the frequency domain with viscoelastic frequency-dependent material properties for the core. The dynamic behaviour of the model is compared with solutions found in the literature, including experimental data

Radiopacity Of Glass-ionomer/composite Resin Hybrid Materials.

This study visually compared the radiopacity of seven restorative materials (3 resin-modified glass-ionomer cements, 3 polyacid-modified composite resins, and 1 conventional glass-ionomer cement) to a sound tooth structure sample, and an aluminium stepwedge. All hybrid materials were more radiopaque, except for one resin-modified glass-ionomer cement, than both the tooth structure and conventional glass-ionomer cement.122858

Causal explanation for observed superluminal behavior of microwave propagation in free space

In this paper we present a theoretical analysis of an experiment by Mugnai and collaborators where superluminal behavior was observed in the propagation of microwaves. We suggest that what was observed can be well approximated by the motion of a superluminal X wave. Furthermore the experimental results are also explained by the so called scissor effect which occurs with the convergence of pairs of signals coming from opposite points of an annular region of the mirror and forming an interference peak on the intersection axis traveling at superluminal speed. We clarify some misunderstandings concerning this kind of electromagnetic wave propagation in vacuum.Comment: 9 pages, 3 figures, accepted for publication in Physics Letters

Multivariate analysis of the water quality variation in the Serra da Estrela (Portugal) Natural Park as a consequence of road deicing with salt.

The concentration of some anions (Cl, F, NO3, and SO4), cations (Na, K, Ca, and Mg), pH and conductivity was determined in seven sampling points in the Serra da Estrela Mountains (Portugal) to verify if the application of road deicing with salt provokes impact in the water quality. Multivariate chemometric data analysis techniques of clustering and factor analysis were used. Preliminary analysis shows an overall conductivity increase in late spring and a decrease in late summer. A strong association between sodium chloride and the conductivity was observed by cluster analysis. Factor analysis supports the previous results and shows that the variation of the concentration of sodium chloride is the main source of the variance of the data along the year. In conclusion, the spreading of salt during the winter creates a local and seasonal impact on the water quality

Antibody response among portuguese healthcare workers prior to sars-cov-2 vaccine booster administration

Prioritizing healthcare workers (HCWs) for vaccination against the coronavirus disease 2019 (COVID-19) allowed to study the vaccine effectiveness in this professional group. The quantification of antibodies levels after vaccination among HCWs could give insights about SARS-CoV-2 protection. The aim of this study is to investigate SARS-CoV-2 immune response based on quantitation of antibodies against the spike receptor binding domain (RBD) of the S protein (anti-SRBD) and nucleocapside (anti-N) after the first vaccination stage in HCWs from the Local Health Unit of the Northeast of Portugal. Methods: Serum samples from 427 vaccinated HCW were tested for anti-SARS-CoV-2 immunoglobulin with chemiluminescent microparticle SARS-CoV-2 2 IgG I (anti-N) and IgG II (anti-SRBD) immunoassays detected by using ARCHITECT i1000SR (Abbot) equipment. Blood samples were collected between November and December of 2021, before the administration of 3rd vaccine dose. The chemiluminescent reaction anti-N immunoassay was expressed as an index classified as positive for values higher than 0.6. Anti-SRBD was quantified between 21.0 and 40,000.0 arbitrary units per ml (AU/mL) and values ≥ 50 AU/ml were considered positive. We obtained data about age, gender), infection with SARS-CoV-2 (PCR+), smoking habits and number of days between complete vaccination and blood sample collection Median, interquartile interval IIQ) and frequencies were obtained. Multivariate regression linear model was conducted to assess the factors affecting the values of anti-SRBD (logarithmized variable). Results: From all 427 HCW with median age 45.7 years [IIQ: 37.8-55.0], 89 (20.8%) were males, 89 (20.8%) had PCR+, 422 (98.8%) and 46 (21%) tested positive for IgG anti-SRBD and anti-N, respectively. The median of anti- SRBD was 737.3 (IIQ: 376.2-2270.1). According to the multivariate regression analysis, anti-SRBD values decrease as increase age (p = 0.004) and number of days since vaccination (p =0.004). Also, be a smoker decreases but a PCR+ increases anti-SRBD values. Conclusions/Recommendations: The SARS-CoV-2 antibody measurements suggested that quantitative anti-SRBD responses fall over the time (from days of complete immunization) and are lower among older vaccinated HCW.info:eu-repo/semantics/publishedVersio

Corpo, maturação biológica e actividade física: um olhar interactivo em crianças e jovens madeirenses

Cada vez mais a sociedade moderna é olhada através da sua condição física, enquanto factor de bem-estar, saúde, qualidade de vida e longevidade dos seus membros. Os indicadores demográficos actuais da população madeirense apontam no sentido de uma considerável componente juvenil, adolescente e jovem. No entanto, a evolução demográfica prevista, decorrente de um acentuado decréscimo da natalidade, leva a prever um comportamento diverso da pirâmide de idades, assumindo particular ênfase as questões relacionadas com o estudo e a investigação do corpo, a procura de padrões, a descrição normativa, a interpretação das mudanças e o espaço morfológico externo, que se vem enquadrar no território de investigação reservado à somatotipologia

Phosphorus removal by a fixed-bed hybrid polymer nanocomposite biofilm reactor

Eutrophication is one of the main challenges regarding the ecological quality of surface waters, phosphorus bioavailability being its main driver. In this context, a novel hybrid polymer nanocomposite (HPN-Pr) biofilm reactor aimed at integrated chemical phosphorus adsorption and biological removal was conceived. The assays pointed to removal of 1.2 mg P/g of reactive phosphorus and 1.01 mg P/g of total phosphorus under steady-state conditions. A mathematical adsorption–biological model was applied to predict reactor performance, which indicated that biological activity has a positive effect on reactor performance, increasing the amount of reactive phosphorus removed.The authors acknowledge the Portuguese Foundation for Science and Technology for the financial support under Project SFRH/BD/39085/2007

Cissus Sicyoides: Pharmacological Mechanisms Involved In The Anti-inflammatory And Antidiarrheal Activities

The objective of this study was to evaluate the pharmacological mechanisms involved in anti-inflammatory and antidiarrheal actions of hydroalcoholic extract obtained from the leaves of Cissus sicyoides (HECS). The anti-inflammatory effect was evaluated by oral administration of HECS against acute model of edema induced by xylene, and the mechanisms of action were analysed by involvement of arachidonic acid (AA) and prostaglandin E2 (PGE2). The antidiarrheal effect of HECS was observed and we analyzed the motility and accumulation of intestinal fluid. We also analyzed the antidiarrheal mechanisms of action of HECS by evaluating the role of the opioid receptor, α2 adrenergic receptor, muscarinic receptor, nitric oxide (NO) and PGE2. The oral administration of HECS inhibited the edema induced by xylene and AA and was also able to significantly decrease the levels of PGE2. The extract also exhibited significant anti-diarrheal activity by reducing motility and intestinal fluid accumulation. This extract significantly reduced intestinal transit stimulated by muscarinic agonist and intestinal secretion induced by PGE2. Our data demonstrate that the mechanism of action involved in the anti-inflammatory effect of HECS is related to PGE2. The antidiarrheal effect of this extract may be mediated by inhibition of contraction by acting on the intestinal smoothmuscle and/or intestinal transit. © 2016 by the authors; licensee MDPI, Basel, Switzerland.17