High-intensity ultrasound processed acerola juice containing oligosaccharides and dextran promotes Lacticaseibacillus casei NRRL B-442 growth

In the present study, a prebiotic acerola juice containing gluco-oligosaccharides and dextran was produced and processed by high-intensity ultrasound (HIUS). After a simulated in vitro digestion, the gluco-oligosaccharides and dextran maintained 90% and 80% of their initial concentration in all prebiotic’s juices. At the same time, Vitamin C and phenolic compounds concentration increased significantly by 19% and 7% (P < 0.05). After the in vitro digestion, the prebiotic juice HIUS processed by 10 min showed the highest increase in gluco-oligosaccharides and bioactive compound concentrations. The HIUS processing imparted some dextran hydrolysis and improved its fermentability by Lacticaseibacillus casei. Gluco-oligosaccharides were extensively consumed as substrate in simulated intestinal conditions, promoting the L. casei NRRL B-442 growth and production of organic acids and short-chain organic acids. The prebiotic juice HIUS processed for 6 min showed the best responses regarding the metabolism of L. casei NRRL B-442. The results showed high-intensity ultrasound processed acerola juices containing gluco-oligosaccharides and dextran as a prebiotic food.     

Tailored-Made Polydopamine Nanoparticles to Induce Ferroptosis in Breast Cancer Cells in Combination with Chemotherapy

Ferroptosis is gaining followers as mechanism of selective killing cancer cells in a non-apoptotic manner, and novel nanosystems capable of inducing this iron-dependent death are being increasingly developed. Among them, polydopamine nanoparticles (PDA NPs) are arousing interest, since they have great capability of chelating iron. In this work, PDA NPs were loaded with Fe³⁺ at different pH values to assess the importance that the pH may have in determining their therapeutic activity and selectivity. In addition, doxorubicin was also loaded to the nanoparticles to achieve a synergist effect. The in vitro assays that were performed with the BT474 and HS5 cell lines showed that, when Fe³⁺ was adsorbed in PDA NPs at pH values close to which Fe(OH)₃ begins to be formed, these nanoparticles had greater antitumor activity and selectivity despite having chelated a smaller amount of Fe³⁺. Otherwise, it was demonstrated that Fe³⁺ could be released in the late endo/lysosomes thanks to their acidic pH and their Ca²⁺ content, and that when Fe³⁺ was co-transported with doxorubicin, the therapeutic activity of PDA NPs was enhanced. Thus, reported PDA NPs loaded with both Fe³⁺ and doxorubicin may constitute a good approach to target breast tumors.     

Saddle-node equilibrium points on the stability boundary of nonlinear autonomous dynamical systems

A complete characterization of the stability boundary of an asymptotically stable equilibrium point in the presence of type-k saddle-node non-hyperbolic equilibrium points, with k ≥ 0, on the stability boundary is developed in this paper. Under the transversality condition, it is shown that the stability boundary is composed of the stable manifolds of the hyperbolic equilibrium points on the stability boundary, the stable manifolds of type-0 saddle-node equilibrium points on the stability boundary and the stable centre and centre manifolds of the type-r saddle-node equilibrium points with r ≥ 1 on the stability boundary. This characterization is the first step to understanding the behaviour of stability regions and stability boundaries in the occurrence of saddle-node bifurcations on the stability boundary.     

Role of the bolus degree of structure on the protein digestibility during in vitro digestion of a pea protein-fortified sponge cake chewed by elderly

This study investigated the digestibility of proteins in a pea protein-fortified sponge cake, as well as the impact of the degree of structure of the bolus produced by elderly subjects on the digestibility of proteins by combining ex vivo and in vitro approaches via the standardized protocol INFOGEST. The sponge cakes were consumed by a group of 20 elderly subjects with contrasting physiology, their boli were recovered just before swallowing, and their apparent viscosity was measured to delineate the bolus degree of structure. According to this criterion, two pools were formed with boli from subjects selected at the extremes: low viscosity and high viscosity, with apparent viscosity values (at 120 s⁻¹) of 124 ± 18 and 208 ± 19 Pa s, respectively. The sponge cakes and the two pools underwent in vitro digestion. Protein hydrolysis kinetics was followed by measuring the released primary amino groups (NH₂) and by sodium-dodecyl-sulfate polyacrylamide gel electrophoresis at different time points. For all samples, the representative bands of pea proteins disappear gradually during digestion, accompanied by the appearance of bands indicating the presence of proteins with M_W < 15 kDa. In addition, the NH₂ concentrations increase over time and do not differ between sponge cake and pea protein isolate. Moreover, the degree of structure of the food bolus has no significant effect on the concentration of NH₂ released. These results showed that pea proteins in a fortified sponge cake are bioaccessible under standardized conditions and that the degree of structure of the bolus did not influence protein digestibility for these foods.     

Effects of nisin concentration on properties of gelatin film-forming solutions and their films

The addition of nisin into a gelatin matrix can change properties of the film. The aim of this work was to develop gelatin-based films containing different nisin concentrations in order to study their influence on the film's antimicrobial and physical properties and their rheological properties as a film-forming solution (FFS). The FFS was characterised by rheological assays, and the gelatin-based active films were characterised and assessed by the effects of nisin concentrations on their various properties, including antimicrobial activity. Nisin's concentration affected not only its viscoelastic properties of FFS but also its film solubility in water, film surface roughness and light barrier. The addition of nisin also slightly modified the water contact angle and the mechanical properties of the gelatin films. Finally, the films demonstrated activity against Staphylococcus aureus and Listeria monocytogenes at concentrations above 56 mg of nisin g⁻¹ of gelatin.     

Monthly Streamflow Modeling Based on Self-Organizing Maps and Satellite-Estimated Rainfall Data

Hydrological data provide valuable information for the decision-making process in water resources management, where long and complete time series are always desired. However, it is common to deal with missing data when working on streamflow time series. Rainfall-streamflow modeling is an alternative to overcome such a difficulty. In this paper, self-organizing maps (SOM) were developed to simulate monthly inflows to a reservoir based on satellite-estimated gridded precipitation time series. Three different calibration datasets from Três Marias Reservoir, composed of inflows (targets) and 91 TRMM-estimated rainfall data (inputs), from 1998 to 2019, were used. The results showed that the inflow data homogeneity pattern influenced the rainfall-streamflow modeling. The models generally showed superior performance during the calibration phase, whereas the outcomes varied depending on the data homogeneity pattern and the chosen SOM structure in the testing phase. Regardless of the input data homogeneity, the SOM networks showed excellent results for the rainfall-runoff modeling, presenting Nash–Sutcliffe coefficients greater than 0.90.

Graphical Abstract

     

Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate

Titanium-rich (Sr/Ti?=?0.995) strontium titanate (ST) ceramics, air-sintered in a temperature range of 1400–1625?°C, were reported to possess anomalies in the grain growth and analogous anomalies in the grain boundary (GB) conductivity activation energy. However, these two interface-related phenomena, occurring at GBs, could not be associated with each other using a simple “brick-layer” model. In this work we revise the topic and advocate that the deviation from the model comes from the oxygen vacancies localized at GBs of the rapidly-cooled ST ceramics. To verify this, we annealed the ceramics in oxygen and performed their systematic and comparative analysis using impedance spectroscopy. A levelling-off in the GB conductivity activation energy, which increases for ≤1.24?eV, and a four-fold decrease in the GB permittivity are observed after annealing. Thus, we confirm a key role of oxygen vacancies in relation between the grain growth and GB conductivity anomalies of as-sintered Ti-rich ST ceramics.