Xylella fastidiosa Esterase Rather than Hydroxynitrile Lyase

In 2009, we reported that the product of the gene SCJ21.16 (XFa0032) from Xylella fastidiosa, a xylem‐restricted plant pathogen that causes a range of diseases in several important crops, encodes a protein (XfHNL) with putative hydroxynitrile lyase activity. Sequence analysis and activity tests indicated that XfHNL exhibits an α/β‐hydrolase fold and could be classified as a member of the family of FAD‐independent HNLs. Here we provide a more detailed sequence analysis and new experimental data. Using pure heterologously expressed XfHNL we show that this enzyme cannot catalyse the cleavage/synthesis of mandelonitrile and that this protein is in fact a non‐enantioselective esterase. Homology modelling and ligand docking simulations were used to study the active site and support these results. This finding could help elucidate the common ancestor of esterases and hydroxynitrile lyases with an α/β ‐hydrolase fold.     

SCC of X‐52 and X‐60 weldements in diluted NaHCO3 solutions with chloride and sulfate ions

Stress corrosion cracking tests were performed in both X‐52 and X‐60 weldments in sodium bicarbonate (NaHCO₃) solutions at 50°C using the Slow Strain Rate Testing (SSRT) technique. Solution concentrations varied between 0.1 to 0.0001 M, and to simulate the NS‐4 solution, chloride (Cl^?) and/or sulfate ( ) ions were added to the 0.01 M solution. Tests were complemented with hydrogen permeation measurements and polarization curves. It was found that the corrosion rate, taken as the corrosion current, I_corr, was maximum in 0.01 M NaHCO₃ and with additions of ions. Higher or lower solution concentrations or additions of Cl^? alone decreased the corrosion rate of the weldment. The SSC susceptibility, measured as the percentage reduction in area, was maximum in 0.01M NaHCO₃. Higher or lower solution concentrations of additions of Cl^? or decreased the SCC susceptibility of the weldment. The amount of hydrogen uptake for the weldment was also highest in 0.01 M NaHCO₃ solution, but it was minimum with the addition of Cl^? or ions. Thus, the most likely mechanism for the cracking susceptibility of X‐52 and X‐60 weldments in diluted NaHCO₃ solutions seems to be hydrogen‐assisted anodic dissolution.     

Tamoxifen Sensitizes Acute Lymphoblastic Leukemia Cells to Cannabidiol by Targeting Cyclophilin-D and Altering Mitochondrial Ca2+ Homeostasis

Cytotoxic effects of cannabidiol (CBD) and tamoxifen (TAM) have been observed in several cancer types. We have recently shown that CBD primarily targets mitochondria, inducing a stable mitochondrial permeability transition pore (mPTP) and, consequently, the death of acute lymphoblastic leukemia (T-ALL) cells. Mitochondria have also been documented among cellular targets for the TAM action. In the present study we have demonstrated a synergistic cytotoxic effect of TAM and CBD against T-ALL cells. By measuring the mitochondrial membrane potential (ΔΨm), mitochondrial calcium ([Ca²⁺]_m) and protein-ligand docking analysis we determined that TAM targets cyclophilin D (CypD) to inhibit mPTP formation. This results in a sustained [Ca²⁺]_m overload upon the consequent CBD administration. Thus, TAM acting on CypD sensitizes T-ALL to mitocans such as CBD by altering the mitochondrial Ca²⁺ homeostasis.     

Effect of Ni promoter in the oxide precursors of MoS2/MgO–Al2O3 catalysts tested in dibenzothiophene hydrodesulphurization

NiMoS catalysts supported on MgO–Al₂O₃ oxides, with 95 and 80 mol% of MgO, were synthesized by sol–gel method. In order to study the Ni promoter effect, MgO–Al₂O₃ supports were impregnated with a pH = 9 solution of Mo and Ni–Mo, respectively; the catalysts were dried (D) and calcinated (C). Catalytic tests showed a Ni promoter effect of 4.5 on the NiMoMg95Al5-D catalyst and 8.5 on the calcinated one. The latter catalyst is more active than a commercial NiMo/Al₂O₃ catalyst. On the other side, the catalyst supported on Mg80Al20 solid did not show any Ni promoter effect. Raman and UV–vis diffuse reflectance spectroscopy showed that during the impregnation step, a strong support interaction with the ion MoO₄^2? takes place on the Mo/MgO–Al₂O₃ solids. After calcination, MoO₄^2? ion remained on the catalyst surface, but increased its interaction with the support. The presence of Ni²⁺_Th, Ni²⁺_Oh and MoO₄^2? ions on dried NiMo/Mg95Al5 catalysts was confirmed, as well as the presence of Ni²⁺_Th, Ni²⁺_Oh, MoO₄^2? and Mo₇O₂₄^6? ions on the calcinated catalyst. This suggests that Ni²⁺ ion allows polymerization of MoO₄^2? to Mo₇O₂₄^6?, produced by Ni²⁺_Oh–MoO₄^2? and Ni²⁺_Oh–Mo₇O₂₄^6? close interactions. The NiMo/Mg80Al20 solids also showed MoO₃ species and a high Ni²⁺_Th concentration. Thus, the Ni promoter effect and therefore, catalytic activity decreased, due to the formation of Ni²⁺_Th–MgO and Ni²⁺_Th–Al₂O₃ spinels.     

Alternatives for the Purification of the Blend Butanol/Ethanol from an Acetone/Butanol/Ethanol Fermentation Effluent

Biobutanol is a biofuel with potential to substitute gasoline. It can be generated through fermentation of lignocellulosic material, by which acetone, butanol, and ethanol (ABE) are obtained and subsequently separated. Nevertheless, the blend ethanol/butanol itself is a fuel, so its separation could be not even necessary. An alternative is proposed to simplify the purification step of the ABE mixture, avoiding the separation of the ethanol/butanol blend. Intensification alternatives are suggested for the resulting structure. The proposed schemes are optimized through a stochastic approach, minimizing the total annual cost and the eco‐indicator 99. The individual risk index is computed for selected designs. The suggested designs reduce the individual risk index by around 30–66 %.     

Integral bread development with soybean, chia, linseed, and folic acid as a functional food for women

Six bread formulations were developed, using different proportions of whole-wheat flour, chia seeds and flaxseed flour. All of our formulations were added with folic acid. Sensorial and texture evaluations were performed, showing good acceptance of the products. Proximal chemical analysis was carried out; in addition, the following parameters were determined: calcium, phosphorus, total dietary fiber, folic acid, water hydration capacity, Glucose Dialysis Retardation Index (GDRI) and fatty acids. The results obtained showed higher protein levels in the developed breads (23.23-30.24 (g/100g dry matter) as compared to a control (21.00% of proteins in bread elaborated without chia or flaxseed). Furthermore, the breads contained 10.07-12.15 of lipids (g/100g dry matter) (linoleic acid: 2.43-4.05%; linolenic acid: 1.12-4.46 %; oleic acid: 2.93-6.13 %), GDRI values were between 89.1 and 98.1 % and folic acid was in the range 699.44 - 991.3 (microg/100g dry matter). The same parameters were determined in the chia seed and in the flaxseed flour. It was concluded that; due to their high levels of protein, insaturated fatty acids (omega-3 and omega-6), dietary fiber and folic acid, these breads have a high nutritional value, so they could have special benefits for woman.     

Emergence of synchronicity in a self-organizing spiking neuron network: an approach via genetic algorithms

Based on the Theory of Neuronal Group Selection (TNGS), we have investigated the emergence of synchronicity in a network composed of spiking neurons via genetic algorithm. The TNGS establishes that a neuronal group is the most basic unit in the cortical area of the brain and, as a rule, it is not formed by a single neuron, but by a cluster of tightly coupled neural cells which fire and oscillate in synchrony at a predefined frequency. Thus, this paper describes a method of tuning the parameters of the Izhikevich spiking neuron model through genetic algorithm in order to enable the self-organization of the neural network. Computational experiments were performed considering a network composed of neurons of the same type and another composed of neurons of different types.     

An Efficient Simulated Annealing Algorithm for Regional Wastewater System Planning

Abstract:   Planning solutions for wastewater system problems are often sought at a local level—that is, each city develops its own solution. However, in many cases, it would be possible to find solutions that are better both from the economic and the environmental viewpoints if they were looked for at a regional level. In this article, we present an efficient simulated annealing (SA) algorithm for solving a regional wastewater system planning model. The model is aimed at determining the minimum-cost configuration for the system that will drain the wastewater generated by the population centers of a region, while complying with all relevant regulations. In particular, the system must ensure that the wastewater discharged from each treatment plant will not exceed a given maximum amount, consistent with the water quality standards defined for the receiving water body. The SA algorithm is termed efficient because its parameters were calibrated to ensure optimum or near-optimum solutions to the model within reasonable computing time. The calibration was performed using a particle swarm algorithm for a large set of test instances designed to replicate real-world problems.     

Propranolol hydrochloride degradation using La@TiO2 functionalized with CMCD

Propranolol hydrochloride can be considered a persistent and bioaccumulative pharmaceutical in the environment. This drug and its by-products are potentially toxic and have adverse effects, since these compounds have been associated with endocrine-disrupting effects, reproductive deficiencies, embryo abnormalities and pericardial oedema. TiO₂–La 0.05%–carboxymethyl-β-cyclodextrin (CMCD) nanoparticles were successfully prepared by a simple two-step method, which consists of sonification and functionalization. The characterization analyses reveal that lanthanum is dispersed on the semiconductor surface, probably forming Ti–O–La bonds, which can induce oxygen vacancies and surface defects that effectively restrain the recombination of photogenerated electron/holes pairs. The efficiency of TiO₂–La 0.05%–CMCD samples in degradation of propranolol under UV-light irradiation is higher than that of pristine TiO₂ within 20 min reaction, probably due to complex formation between the β-blocker and the oligosaccharide, which allows us to propose a photocatalytic mechanism based on the formation of intermediates and competition of these compounds to the radicals and CMCD cavities.