Molecular structure characteristics,functional parameters and in vitro protein digestion of pressure‐cooked soya bean flours with different amounts of water

When a food product is cooked at high temperature with different proportions of water, the differential degradation that occurs in the molecular structure promotes changes in their functional characteristics. In this study, water and soya bean flour (dry base) were mixed in different ratios (3:1, 2:1, 1:1, 0.25:1 and 0:1) and pressure cooked at 130 °C, 1.5 kg cm^?2 for 30 min, cooled down to 40 °C and air dried for 24 h. Protein changes due to thermal process were determined with the ATR‐FTIR, as well as some functional parameters and in vitro protein digestibility. At higher water:soya bean flour ratios (3:1 and 2:1), the protein digestibility increased due to denaturation of tertiary structures, while urease activity (UA) and the functional characteristics of water absorption index (WAI) and water solubility index (WSI) decreased. Pearson's correlation analysis revealed that molecular changes on amide I, II and in α‐helix: β‐sheet ratios were directly related with the amount of added water.     

Nanoscale characterization of the biomechanical hardening of bovine zona pellucida

The zona pellucida (ZP) is an extracellular membrane surrounding mammalian oocytes. The so-called zona hardening plays a key role in fertilization process, as it blocks polyspermy, which may also be caused by an increase in the mechanical stiffness of the ZP membrane. However, structural reorganization mechanisms leading to ZP''s biomechanical hardening are not fully understood yet. Furthermore, a correct estimate of the elastic properties of the ZP is still lacking. Therefore, the aim of the present study was to investigate the biomechanical behaviour of ZP membranes extracted from mature and fertilized bovine oocytes to better understand the mechanisms involved in the structural reorganization of the ZP that may lead to the biomechanical hardening of the ZP. For that purpose, a hybrid procedure is developed by combining atomic force microscopy nanoindentation measurements, nonlinear finite element analysis and nonlinear optimization. The proposed approach allows us to determine the biomechanical properties of the ZP more realistically than the classical analysis based on Hertz''s contact theory, as it accounts for the nonlinearity of finite indentation process, hyperelastic behaviour and material heterogeneity. Experimental results show the presence of significant biomechanical hardening induced by the fertilization process. By comparing various hyperelastic constitutive models, it is found that the Arruda–Boyce eight-chain model best describes the biomechanical response of the ZP. Fertilization leads to an increase in the degree of heterogeneity of membrane elastic properties. The Young modulus changes sharply within a superficial layer whose thickness is related to the characteristic distance between cross-links in the ZP filamentous network. These findings support the hypothesis that biomechanical hardening of bovine ZP is caused by an increase in the number of inter-filaments cross-links whose density should be higher in the ZP inner side.     

The dynamic space allocation problem: Applying hybrid GRASP and Tabu search metaheuristics

This work is devoted to the Dynamic Space Allocation Problem, where project duration is divided into a number of consecutive periods, each of them associated with a number of activities. The resources required by the activities have to be available in the corresponding workspaces and those sitting idle during a period have to be stored. This problem contains the Quadratic Assignment Problem (QAP) as a particular case, which puts it in the NP-hard class. In this context, the difficulty of identifying optimal solutions, even for instances of medium size, justifies the use of heuristic techniques. This work proposes a construction and a hybrid algorithm (HGT) based on the GRASP and Tabu search metaheuristics. Comparisons are presented for values obtained by HGT, pure GRASP versions, Tabu search and literature results. Computational results show the proposed methods to be competitive in relation to instances in the literature and to existing techniques.     

Changes on free amino acids during the alcoholic fermentation of strawberry and persimmon

Changes in amino acids and ammonium were monitored during the alcoholic fermentation of strawberry and persimmon purees. Fermentations were carried out either by autochthonous or by commercial yeasts. The amino acid content in strawberry and persimmon was lower than that of grapes but enough to successfully perform the alcoholic fermentation, showing a different consumption pattern. Arginine, although is not present in the most strawberry substrates, appears in strawberry wines (2.75–3.36 mg L^?1). Additionally, as opposed to grape wine, an exceptional high consumption of proline was observed during the alcoholic fermentation of strawberry purees. The consumption of amino acids was highly influenced by the substrate and the S. cerevisiae strain used for the fermentation process. These results were confirmed by principal component analysis, which was able to group the samples based on substrate, harvest or yeast strain, considering the amino acids as variables.     

Hybridization between multi-objective genetic algorithm and support vector machine for feature selection in walker-assisted gait

Walker devices are often prescribed incorrectly to patients, leading to the increase of dissatisfaction and occurrence of several problems, such as, discomfort and pain.     

Academic tenure,risk-taking and the diversification of scientific research

We discuss two competing hypotheses linking the relative job security granted by tenure in academic employment to scientists’ choices between diversifying vs. specialising their research portfolio. To test our hypotheses, we develop a new methodology, using an algorithm of semantic analysis that partitions scientists’ publications into research themes, and we compute the Blau’s diversification index for 562 scientists observed over 15 years. The results of a Fractional Probit Model with fixed effects show that tenure is associated to more diversification of research interests. We discuss the implications for policy-makers and granting agencies wishing to incentivise explorative research.     

A theoretical and experimental study of the crossflow microfiltration process of silica particles in an aqueous suspension

This work presents a theoretical and experimental analysis of a crossflow microfiltration process of silica particles in suspension. The silica suspensions were 0.001 M of NaCl with a pH of 6 (to maintain a constant ionic force within the medium to produce a stable silica particle suspension) for three different concentrations of silica particles: 100, 300, and 500 mg L⁻¹. The membrane used in the crossflow microfiltration experiments was a commercial polymeric membrane, microporous, asymmetric with a nominal pore diameter of 0.2 µm, manufactured by OSMONICS (Minnetonka, MN). The experiments were performed in a bench scale crossflow microfiltration system with a flat rectangular membrane cell. The permeate flux was obtained as a function of the transmembrane pressure, the crossflow velocities, and the silica particles concentration. The mathematical model describing the process takes into account the variation of the physical properties of the suspension (dynamic viscosity and mass diffusivity) with the silica concentration. The experimental data are used to predict the maximum silica concentration at the membrane surface as a function of the operating conditions.     

The use of scanning electrochemical microscopy for the characterisation of patinas on copper alloys

The scanning electrochemical microscopy (SECM) was employed in the feedback mode for the visualisation of the local changes of morphology and reactivity, occurring on the surface of a quaternary copper-based alloy, due to exposure to environment. First, samples artificially aged by exposure to leaching acid rain were tested. The layer of corrosion products (“patina”) was investigated by performing SECM scans and approach curves, and the information provided by this electrochemical technique was compared with SEM–EDX–Raman characterisation. Successively, to highlight the early stages of localised corrosion processes, in situ examination of the surface exposed to an acidic environment was performed. The results show that SECM is a powerful characterisation tool of the deterioration process and is able to map the precursor sites of corrosion on the bronze surface.     

PRKAR1B-AS2 Long Noncoding RNA Promotes Tumorigenesis,Survival, and Chemoresistance via the PI3K/AKT/mTOR Pathway

Many long noncoding RNAs have been implicated in tumorigenesis and chemoresistance; however, the underlying mechanisms are not well understood. We investigated the role of PRKAR1B-AS2 long noncoding RNA in ovarian cancer (OC) and chemoresistance and identified potential downstream molecular circuitry underlying its action. Analysis of The Cancer Genome Atlas OC dataset, in vitro experiments, proteomic analysis, and a xenograft OC mouse model were implemented. Our findings indicated that overexpression of PRKAR1B-AS2 is negatively correlated with overall survival in OC patients. Furthermore, PRKAR1B-AS2 knockdown-attenuated proliferation, migration, and invasion of OC cells and ameliorated cisplatin and alpelisib resistance in vitro. In proteomic analysis, silencing PRKAR1B-AS2 markedly inhibited protein expression of PI3K-110α and abrogated the phosphorylation of PDK1, AKT, and mTOR, with no significant effect on PTEN. The RNA immunoprecipitation detected a physical interaction between PRKAR1B-AS2 and PI3K-110α. Moreover, PRKAR1B-AS2 knockdown by systemic administration of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine nanoparticles loaded with PRKAR1B-AS2–specific small interfering RNA enhanced cisplatin sensitivity in a xenograft OC mouse model. In conclusion, PRKAR1B-AS2 promotes tumor growth and confers chemoresistance by modulating the PI3K/AKT/mTOR pathway. Thus, targeting PRKAR1B-AS2 may represent a novel therapeutic approach for the treatment of OC patients.     

Disclosing the Interaction of Gold Nanoparticles with Aβ(1–40) Monomers through Replica Exchange Molecular Dynamics Simulations

Amyloid-β aggregation is one of the principal causes of amyloidogenic diseases that lead to the loss of neuronal cells and to cognitive impairments. The use of gold nanoparticles treating amyloidogenic diseases is a promising approach, because the chemistry of the gold surface can be tuned in order to have a specific binding, obtaining effective tools to control the aggregation. In this paper, we show, by means of Replica Exchange Solute Tempering Molecular Simulations, how electrostatic interactions drive the absorption of Amyloid-β monomers onto citrates-capped gold nanoparticles. Importantly, upon binding, amyloid monomers show a reduced propensity in forming β-sheets secondary structures that are characteristics of mature amyloid fibrils.