Evaluation of chemical and nutritional characteristics of the seed of the rubber tree (Hevea brasiliensis)

Some chemical and nutritional characteristics of the rubber seed Hevea brasiliensis were studied. The protein content, its amino acid composition as well as the iron, calcium, phosphorus and cyanide (free and bound) concentrations, were determined in the dehulled seed. The effect of soaking, cooking, soaking-cooking and cooking-fat extraction procedure of the seed on the cyanide content and its in vivo protein utilization, was also evaluated. The protein quality was biologically assessed using the protein efficiency ratio (PER). The protein content of the seed was 18%, and the most limiting amino acid was threonine, with a chemical score of 71.6. The iron, calcium and phosphorus contents were 6.2, 109 and 429 mg/100 g, respectively. Its fat content was 48% with a total energy value of 702 kcal/100 g (2,948 Kj/100 g). The total cyanide content in the fresh seed was 130-230 mg/100 g; 6% was in the free form and 94% as bound cyanide. The most effective treatment for reducing the cyanide content was found to be 20 hours of soaking in water, combined with one hour of cooking. The raw seed had a low nutritive value and produced weight loss and death when fed to rats. The protein value, however, improved upon the seed treatment, reaching PER values close to those found in traditional cereals such as corn. It is therefore concluded that the seed of Hevea brasiliensis is a good source of energy, calcium, valine, isoleucine, phenylalanine and tyrosine. In contrast, it is a poor source of threonine, leucine and lysine. Its cyanide content is high, but when removed by treatment, such as soaking in water, cooking or fat extraction, the protein utilization can be improved.     

Effect of inulin as a prebiotic to improve growth and counts of a probiotic cocktail in fermented skim milk

Inulin was used as a prebiotic to improve quality of skim milk fermented by pure cultures of Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus bulgaricus and Bifidobacterium lactis, binary co-cultures with Streptococcus thermophilus, or a cocktail containing all them. Inulin supplementation to pure cultures lowered the generation time, with particular concern to S. thermophilus and L. acidophilus. The generation time of all micro-organisms decreased in the following order: mono-cultures, co-cultures, cocktail. It was demonstrated a synergism between S. thermophilus and the other strains and a bifidogenic effect of inulin. Enumerations of L. rhamnosus in cocktail markedly decreased compared to co-cultures likely because of greater competition for the same substrates. The results of this work highlight the industrial potential of the cocktail, mainly in terms of fermentation acceleration.     

Clarification of passion fruit juice by microfiltration: Analyses of operating parameters,study of membrane fouling and juice quality

In this study, the performance of two membranes were compared – tubular ceramic and hollow fiber poly(imide) – under transmembrane pressure of 0.5 and 1 bar, for the clarification of passion fruit pulp pre-treated by centrifugation and enzymatic treatment at the concentrations of 150 and 300 ppm. Nutritional and sensorial qualities of the clarified juice obtained were evaluated. Thus, it was possible to observe that the most adequate condition for the clarification of passion fruit pulp was with enzymatic treatment at 150 ppm and its posterior microfiltration at the ceramic tubular membrane of 0.3 μm with transmembrane pressure of 0.5 bar. The fouling mechanism was identified by estimation of model parameters according to a nonlinear regression by Bayesian inference. Analysis of the fouling mechanism results revealed that hollow fiber membrane is controlled by a cake filtration mechanism, and internal pore blocking fouling mechanism controls ceramic tubular membrane.     

Mechanical and Tribological Properties of Ca/P-Doped Titanium Dioxide Layer Produced by Plasma Electrolytic Oxidation: Effects of Applied Voltage and Heat Treatment

Plasma electrolytic oxidation (PEO) is a technique that produces a hard oxide layer on the titanium surface where its properties can be tailored by changing the process parameters or by a posterior heat treatment (HT). In this work, a TiO₂ layer with different crystallinity was produced by PEO with different applied voltages (250 to 400 V) and post-HT at 600°C. Our aim was to evaluate the influence of the PEO voltage and HT on the mechanical and tribological properties of anodized Ti. There is an increase in pore size, oxide thickness, and Ca/P ratio for the oxide layer with the applied voltage during the PEO process. X-ray diffraction (XRD) results indicated an increase in the crystalline rutile phase in the oxide layer with voltage and HT. Nanoindentation shows an increase in the oxide hardness and elastic modulus with increased voltage and HT, leading to an improvement in the wear resistance.     

Isothermal crystallization kinetics and morphology of PP/TiO2 nanocomposites using titanium n‐butoxide precursor

This study investigates the influence of the addition of TiO₂, obtained by hydrolysis–condensation reaction of titanium dioxide precursors, on the kinetics of polypropylene (PP) isothermal crystallization. The dispersion of nanoparticle and its relation to the degree of crystallinity by XRD was also investigated. The results indicated that the addition of the TiO₂ increased the degree of crystallinity of PP and its crystallization temperature. Likewise, the nucleation and crystal growth processes were also affected, as indicated by the TEM morphology, the Avrami kinetic model, and the optical microscopy, in which a nucleation effect was detected. POLYM. COMPOS. 36:517–526, 2015. © 2014 Society of Plastics Engineers     

Short-Term Immune Responses of Gilthead Seabream (Sparus aurata) Juveniles against Photobacterium damselae subsp. piscicida

Photobacteriosis is a septicaemic bacterial disease affecting several marine species around the globe, resulting in significant economic losses. Although many studies have been performed related to the pathogen virulence and resistance factors, information regarding the host defence mechanisms activated once an infection takes place is still scarce. The present study was designed to understand innate immune responses of farmed juvenile gilthead seabream (Sparus aurata) after Photobacterium damselae subsp. piscicida (Phdp) infection. Therefore, two groups of seabream juveniles were intraperitoneally injected with 100 µL of PBS (placebo) or 100 µL of exponentially growing Phdp (1 × 10⁶ CFU/mL; infected). The blood, plasma, liver, and head kidney of six fish from each treatment were sampled immediately before infection and 3, 6, 9, 24 and 48 h after infection for the broad screening of fish immune and oxidative stress responses. Infected animals presented marked anaemia, neutrophilia and monocytosis, conditions that are correlated with an increased expression of genes related to inflammation and phagocytic activity. Similar studies with different fish species and bacteria can be useful for the definition of health biomarkers that might help fish farmers to prevent the occurrence of such diseases.     

Characterization of novel thermoresponsive poly(butylene adipate-co-terephthalate)/poly(N-isopropylacrylamide) electrospun fibers

Polymer Bulletin - In this work, electrospun fibers of poly(butylene adipate-co-terephthalate) (PBAT) and poly(N-isopropylacrylamide) (PNIPAAm) blends, PBAT/PNIPAAm, with different mass ratios,...     

Convolutional Neural Networks for Mechanistic Driver Detection in Atrial Fibrillation

The maintaining and initiating mechanisms of atrial fibrillation (AF) remain controversial. Deep learning is emerging as a powerful tool to better understand AF and improve its treatment, which remains suboptimal. This paper aims to provide a solution to automatically identify rotational activity drivers in endocardial electrograms (EGMs) with convolutional recurrent neural networks (CRNNs). The CRNN model was compared with two other state-of-the-art methods (SimpleCNN and attention-based time-incremental convolutional neural network (ATI-CNN)) for different input signals (unipolar EGMs, bipolar EGMs, and unipolar local activation times), sampling frequencies, and signal lengths. The proposed CRNN obtained a detection score based on the Matthews correlation coefficient of 0.680, an ATI-CNN score of 0.401, and a SimpleCNN score of 0.118, with bipolar EGMs as input signals exhibiting better overall performance. In terms of signal length and sampling frequency, no significant differences were found. The proposed architecture opens the way for new ablation strategies and driver detection methods to better understand the AF problem and its treatment.     

Probing molecular mobility during crosslinking process of commercial resins by NMR multiexponential relaxation data analysis

In this study, we present the experimental results for the crosslinking process of a commercial polyester resin based on measurements of the spin lattice relaxation time T₁ of protons, as function of the crosslinking time evolution. Multiexponential decomposition of the evolution of magnetization measured in inversion‐recovery experiments is performed. The population of “rigid” and “mobile” nuclear spin sites was estimated as function of time evolution. In analogy to the usual monomer conversion u, site conversion from “mobile” to “rigid” sites u_M were also estimated as a function of time evolution and initial concentrations of the reagents. The multiexponential decomposition approach of T₁ relaxation data allows one to follow crosslinking processes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011