Modifications in the molecular structure of hydroxyapatite induced by titanium ions

The purpose of this study was to contribute to the understanding of the effect of titanium ions released from a metallic substrate on the molecular structure of hydroxyapatite. The effects of pH, time of incubation and concentration of titanium ions were investigated. The solids were analysed by X-ray diffraction, Fourier transform infrared spectroscopy, Fourier transform Raman spectroscopy, energy dispersive X-ray analysis and thermogravimetric analysis. The results clearly indicate the presence of a titanium phosphate, Ti(HPO₄)₂·nH₂O (n=1–3), which probably has a double layered structure. The formation of this compound is dependent on the titanium concentration and its crystallinity increases with the time of incubation.     

Deductive verification of cryptographic software

We apply state-of-the art deductive verification tools to check security-relevant properties of cryptographic software, including safety, absence of error propagation, and correctness with respect to reference implementations. We also develop techniques to help us in our task, focusing on methods oriented towards increased levels of automation, in scenarios where there are clear obvious limits to such automation. These techniques allow us to integrate automatic proof tools with an interactive proof assistant, where the latter is used off-line to prove once-and-for-all fundamental lemmas about properties of programs. The techniques developed have independent interest for practical deductive verification in general.     

Cardiovascular phenotype characterization in mice by high resolution magnetic resonance imaging

9. Conclusion Due to its high temporal and spatial resolution, magnetic resonance imaging meets the requirements for accurate and robust in vivo visualization of the murine cardiovascular system. As an intrinsically three-dimensional imaging technique, it allows for quantification of LV volumes without relying on geometric models. Therefore, MRI is uniquely suited for the investigation of morphologic and functional changes in models of heart failure. The potential application of MRI in the mouse comprises visualization of cardiovascular anatomy and pathology in newborn and adult mice, detection of LV geometric and functional changes both acutely and chronically, visualization of cardiac microstructures such as cardiac valves and coronary arteries, and characterization and quantification of arteriosclerotic plaques in major murine arteries. Furthermore, MR spectroscopy applied to the mouse heart can give important information on in vivo myocardial metabolism. Thus, we feel confident that high resolution MRI may substantially contribute to the understanding of the basic mechanisms of a variety of cardiovascular diseases.     

Nanosatellite electrical power system architectures: Models,simulations, and tests

This paper presents four of the most employed nanosatellite's Electrical Power System (EPS) architectures, comparing their efficiency through simulations and experiments. Every circuit architecture has been mathematically modeled in order to discuss the solar panel control technique and the overall architecture efficiency. Solar panels and EPS components have been analytically modeled and tested in order to comprehend their impact on the EPS efficiency. A test stand has been proposed to evaluate the circuits, emulating the solar irradiance and the nanosatellite power consumption. The following electrical power systems have been designed, implemented, and tested: the directly coupled architecture, the very low dropout (VLDO) voltage regulator architecture, the maximum power point tracking (MPPT) with an integrated circuit, and the MPPT architecture with a discrete boost regulator. A case study has been presented, testing all the EPS architectures according to the Floripa-Sat I (1U CubeSat) power consumption profile. Experiments results have shown that, although the MPPT boost regulator architecture harvest more energy, it is the VLDO architecture that presents the best overall efficiency.     

Bonding ability of self-adhesive resin-cements after dentin biomodification with hyaluronic acid

Purpose: The present study evaluated the influence of the hyaluronic acid (HA) on the bonding ability of self-adhesive resin cements to dentin regarding the bond strength. Eighty bovine incisors were ground flat to obtain a 2-mm thick slices which received conical preparations. The specimens were randomly distributed into 4 groups (n = 15) according to the dentin pretreatment (1 – control: untreated dentin; 2 – application of HA) and the evaluation time (1 – control: immediate evaluation; 2 – hydrolytic degradation: 6 months of storage in water at 37 °C). Preparations received the application of a self-adhesive resin cement (RelyX U200 or MaxCem Elite). Push-out bond strength test was conducted (0.5 mm/min). The bond strength data was submitted to two-way ANOVA/Tukey’s test (α = 0.05). For U200, no significance was observed when comparing the immediate (24 h) and 6 months means for the control groups (unexposed specimens). Previous application of HA to dentin significantly reduced the bond strength of U200 to dentin in both evaluation times (p < 0.05). HA had no significant influence on the push-out bond strength means for the cement MAX in both evaluation times (p > 0.05). The type 1 failure mode (adhesive mode) occurred in 100% of the specimens, irrespective of the dentin treatment or evaluation times. Pretreatment of dentin with HA produces a material-dependent influence on the push-out bond strength. The bonding ability of RelyX U200 is negatively influenced by the pretreatment of dentin with HA, whereas the biomodification of dentin with this bioactive agent causes no impact for the cement MaxCem Elite.     

Physicochemical Properties,Lipid Oxidation,and Fatty Acid Composition of Sausage Prepared with Meat of Young Nellore Bulls Fed a Diet with Lauric Acid

This study evaluates the quality of sausage obtained from the meat of Nellore cattle fed diets containing different levels (0, 5, 10, and 15 g per kg total DM) of lauric acid (C12:0) from palm kernel cake. A linear reduction (p ≤ 0.05) in lipid oxidation, as reflected by linear decreases in the lightness (L*), yellowness (b*), and saturation (C*) color parameters, is observed on days 7, 14, and 21 of maturation of sausage, and these decreases are accompanied by linear increases in the redness (a*) color and the linoleic (C18:2n–6) and linolenic (C18:3n–3) fatty acid contents. The inclusion of lauric acid in the diet induces linear reductions in the shear force and cooking loss and does not significantly affect various indices, including the centesimal composition, water activity, water holding capacity, composition of most fatty acids (FA), hypocholesterolemic‐to‐hypercholesterolemic FA ratio, atherogenicity, thrombogenicity, and desirable fatty acids. The use of dietary lauric acid from palm kernel cake is recommended at doses up to 15 g per kg because its presence reduces lipid oxidation and improves color parameters, softness, and linoleic and linolenic FA without affecting the FA composition of sausage from Nellore bull's meat. Practical applications : Sausages are products manufactured from chopped or ground meats packaged into animal casings. This product appeared in Brazil through the adaptation of traditional recipes brought by German and Italian immigrant families to weather conditions and the national palate. However, due to its production characteristics, sausage can become a product with lipid characteristics that are undesirable for human consumption. The inclusion of lauric acid (C12:0) in the animal diet might change the biohydrogenation process in the rumen, improve the quality of the deposited FA and reduce lipid oxidation in sausage manufactured from meat. The FA composition and physicochemical properties of sausage predict its acceptance by the consumer market. An optimal advantage would be achieved if these products can be used as not only preservatives but also functional ingredients with antioxidant properties and products for the treatment of metabolic syndrome and cardiovascular diseases through atherogenic action.     

Thermogravimetric Study of Porous Forsterite Synthesis by Hydromagnesite and Silica Gel Chlorination

Silicon - A novel pyrometallurgical process for the synthesis of porous forsterite by calcination in chlorine of a mixture containing hydromagnesite and silica gel was developed. The aim of this...     

Development and application starch films: PBAT with additives for evaluating the shelf life of Tommy Atkins mango in the fresh-cut state

In this study, formulations of cassava starch and poly(butylene adipate-co-terephthalate) flexible films were developed, with glycerol, coconut nanocellulose, annatto, and citric acid in different concentrations, as well as the effectiveness of the selected materials in fresh-cut mangoes storage was evaluated. The tensile strength of the different formulations varied from 1.90 (E4) to 6.65 MPa (E3c), and the strain varied from 206.31 (E1c) to 278.41% (E8); this variation was dependent on the percentage of the polymer matrix incorporated. The a_w values of the formulations ranged from 0.396 (E2) to 0.569 (E3c). The Formulations E4 and E7 (with additives) presented good properties and were selected to condition mangoes. The micrographs of these films showed regions of micropores that can facilitate the diffusion of water from the packaged product to the surface, allowing decreases in moisture and a_w, which is associated with higher color maintenance during fruit storage. E7 presented better barrier properties than E4 (lower values of WVP and water solubility) which may have influenced in a positive way to maintain the stability of the package in the studied period. E7 can be considered as a viable alternative for minimally processed mango storage. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48150.     

Preliminary Studies on Furfural Production from Lignocellulosics

This study focused on the production of furfural from agricultural and industrial biomass residues by a hydrodistillation process. Corncobs, sugarcane bagasse, and eucalypt wood were treated with sulfuric, hydrochloric, and phosphoric acids as catalysts, with different acid concentrations (1.5 to 5.2 mol.L ^?1). In addition, the eucalypt liquor from the auto-hydrolysis, kraft-dissolving pulp production process was also investigated as a source of furfural, using sulfuric and hydrochloric acids as a catalyst (0.9 and 3.9 mol.L ^?1) . Furfural yields of 30.2, 25.8, and 13.9% were achieved for corncob, sugarcane bagasse, and eucalypt wood, respectively, on the basis of biomass dry weight. The efficiency of conversion from pentose to furfural using eucalypt liquor from the auto-hydrolysis kraft process was 71.5% using HCl 3.9 mol.L ^?1 . Due to the presence of a high amount of pentose, corncob produced the highest amount of furfural, followed by sugarcane bagasse and then eucalypt wood.