Application of chemometric tools in the development of food bars based on cocoa shell,soy flour and green banana flour

In this study, exploratory methods and the simplex-centroid design were applied in the development of food bars with cocoa shell, soy and green banana flours that were evaluated sensorially. The results of the chemical composition and texture were submitted to the Scott-Knott test and the Principal Component Analysis, and was observed a significant difference between the treatments (P < 0.05), as well as a tendency to form five groups, according to its nutritional characteristics. The design used to optimise the sensorial acceptance of the food bars was effective, whose contour surface indicated an optimal region with greater acceptance, with all formulations having good acceptance (scores above 5.52). Check-All-That-Apply, Contingency Analysis and Hierarchical Cluster Analysis allowed describing the products, demonstrating the sensory differences between treatments with the presence/absence of cocoa shell. It is concluded that the studied ingredients can be used in food bars, providing nutritional and sensory characteristics acceptable to the consumer.     

Antiproliferative activity of Dioclea violacea lectin in CaCO3 particles on cancer cells after controlled release

Journal of Materials Science - Cancer is a serious health problem mainly characterized by unregulated cell divisions. It is known that malign cells display cancer-specific glycans that can be...     

Therapeutic miR-21 Silencing Reduces Cardiac Fibrosis and Modulates Inflammatory Response in Chronic Chagas Disease

Chagas disease, caused by the parasite Trypanosoma cruzi (T. cruzi), remains a serious public health problem for which there is no effective treatment in the chronic stage. Intense cardiac fibrosis and inflammation are hallmarks of chronic Chagas disease cardiomyopathy (CCC). Previously, we identified upregulation of circulating and cardiac miR-21, a pro-fibrotic microRNA (miRNA), in subjects with CCC. Here, we explored the potential role of miR-21 as a therapeutic target in a model of chronic Chagas disease. PCR array-based 88 microRNA screening was performed in heart samples obtained from C57Bl/6 mice chronically infected with T. cruzi and serum samples collected from CCC patients. MiR-21 was found upregulated in both human and mouse samples, which was corroborated by an in silico analysis of miRNA-mRNA target prediction. In vitro miR-21 functional assays (gain-and loss-of-function) were performed in cardiac fibroblasts, showing upregulation of miR-21 and collagen expression upon transforming growth factor beta 1 (TGFβ1) and T. cruzi stimulation, while miR-21 blockage reduced collagen expression. Finally, treatment of T. cruzi-infected mice with locked nucleic acid (LNA)-anti-miR-21 inhibitor promoted a significant reduction in cardiac fibrosis. Our data suggest that miR-21 is a mediator involved in the pathogenesis of cardiac fibrosis and indicates the pharmacological silencing of miR-21 as a potential therapeutic approach for CCC.     

Functionalization of Crosslinked Sodium Alginate/Gelatin Wet-Spun Porous Fibers with Nisin Z for the Inhibition of Staphylococcus aureus-Induced Infections

Nisin Z, an amphipathic peptide, with a significant antibacterial activity against Gram-positive bacteria and low toxicity in humans, has been studied for food preservation applications. Thus far, very little research has been done to explore its potential in biomedicine. Here, we report the modification of sodium alginate (SA) and gelatin (GN) blended microfibers, produced via the wet-spinning technique, with Nisin Z, with the purpose of eradicating Staphylococcus aureus-induced infections. Wet-spun SAGN microfibers were successfully produced at a 70/30% v/v of SA (2 wt%)/GN (1 wt%) polymer ratio by extrusion within a calcium chloride (CaCl₂) coagulation bath. Modifications to the biodegradable fibers’ chemical stability and structure were then introduced via crosslinking with CaCl₂ and glutaraldehyde (SAGNCL). Regardless of the chemical modification employed, all microfibers were labelled as homogeneous both in size (≈246.79 µm) and shape (cylindrical and defect-free). SA-free microfibers, with an increased surface area for peptide immobilization, originated from the action of phosphate buffer saline solution on SAGN fibers, were also produced (GNCL). Their durability in physiological conditions (simulated body fluid) was, however, compromised very early in the experiment (day 1 and 3, with and without Nisin Z, respectively). Only the crosslinked SAGNCL fibers remained intact for the 28 day-testing period. Their thermal resilience in comparison with the unmodified and SA-free fibers was also demonstrated. Nisin Z was functionalized onto the unmodified and chemically altered fibers at an average concentration of 178 µg/mL. Nisin Z did not impact on the fiber’s morphology nor on their chemical/thermal stability. However, the peptide improved the SA fibers (control) structural integrity, guaranteeing its stability for longer, in physiological conditions. Its main effect was detected on the time-kill kinetics of the bacteria S. aureus. SAGNCL and GNCL loaded with Nisin Z were capable of progressively eliminating the bacteria, reaching an inhibition superior to 99% after 24 h of culture. The peptide-modified SA and SAGN were not as effective, losing their antimicrobial action after 6 h of incubation. Bacteria elimination was consistent with the release kinetics of Nisin Z from the fibers. In general, data revealed the increased potential and durable effect of Nisin Z (significantly superior to its free, unloaded form) against S. aureus-induced infections, while loaded onto prospective biomedical wet-spun scaffolds.     

CeO2 and CeO2:Pr nanocrystalline powders prepared by the polymeric precursor method: Yellow and red pigments with tunable color

The development of stable and reproducible inorganic pigments is noteworthy for industrial applications mainly considering more intense shades and low toxicity. Among the various candidates to substitute non-hazardous red and yellow pigments, CeO₂ and CeO₂:Pr have been attracting attention because of their opacity and high-temperature stability besides being environmental-friendly and health-friendly. In this study, nanostructured CeO₂ and CeO₂:Pr samples were synthesized using the polymeric precursor method and structural and optical characterizations were performed. Scanning electron microscopy reveals the morphology of CeO₂ nanoparticles in which the particle size ranges from 22 to 28 nm as a function of the annealing temperature. Pr-doping does not show influence on the particle size. XRD results show that CeO₂ and CeO₂:Pr samples crystallize in the cubic fluorite lattice with Fm3m space group. Raman spectra show the fluorite F_2g mode, confirming the XRD results. With Pr-doping and the annealing of the samples, two bands are observed between 550 and 600 cm⁻¹, which are related to the defects in the fluorite structure associated with oxygen vacancies. XPS spectra reveal an increase in the ratio of Ce³⁺ ions depending on the annealing temperature and Pr-doping. This increase is associated with the carbon removal from the lattice by annealing. This behavior causes a change in the hue of the powders as the annealing temperature increases. According to diffuse reflectance and colorimetric measurements, CeO₂ shows a light-yellow color due to the O 2p­Ce 4f transitions whose b* parameter mainly decreases with annealing, becoming almost white. The CeO₂:Pr sample exhibits a red-orange color because of the electronic transitions between 4f² → 5d¹ states of Pr³⁺. Upon annealing, L* and b* parameters decrease, resulting in a red-brown shade. The charge compensation or charge transfer is responsible for the modification of the hue of these pigments.     

Bioactive compounds and antioxidant activities of Brazilian hop (Humulus lupulus L.) extracts

Bioactive compounds from Brazilian hop (Humulus lupulus L.) cultivars were extracted by ultrasound and their phenolic profile compared with commercial hop from the USA. The most effective extraction conditions (solution of ethanol 49%, at 52 °C and a solid/liquid ratio of 1 g per 34 mL) for the total phenolic compounds (TPC) were determined using a Central Composite Rotatable Design. The Brazilian hop showed higher content of TPC (33.93 ± 0.67 mg GAE g⁻¹), total flavonoids (54.47 ± 0.10 mg QE g⁻¹) and higher antioxidant activity (ABTS: EC₅₀ 21.29 ± 1.36 μL mL⁻¹; DPPH: EC₅₀ 3.91 ± 0.17 μL mL⁻¹) when compared with the USA hop. The main phenolic compounds present in the extracts were the flavonoids isoquercitrin and quercetin. The antioxidant properties of the Brazilian hop extract had not been reported yet in the literature for this raw material, thus showing potential to be incorporated in polymeric films used as active packaging.     

Multicriteria Decision Support for Selection of Alternatives Directed to Integrated Urban Water Management

Water Resources Management - The management of water resources in medium and large cities has been changing in recent years, mainly as a result of climate change and the sharp increase of...     

Contracting in Brazilian public administration: A machine learning approach

The risk of non-fulfilment of a contract can harm public administration or even interrupt public services. Therefore, models that assist manager decision making in the audit and control of contracts with a higher disqualification risk may be important tools, with economic and even social repercussions. In this article, public contracts are classified with respect to the risk of non-compliance with their terms of delivery. The quantitative tools used are statistical and machine learning models, similar to credit risk rating of loans. As dependent variables, the models use data found in electronic databases present in e-government implementations. A previously classified listing of suspended companies is used as a proxy for risky contracts, as it contains private companies which failed with their contractual obligations. The classification techniques utilized are logistic regression, k-nearest neighbours, discriminant analysis, support vector machine and random forests. Although the methods can be applied to any government with electronic procurement and contracts systems, Brazilian data is used to illustrate the benefits of contract governance for emerging economies. It is concluded that the credit rating techniques used directly apply to contractual risk in public administration. Considering real public administration contract data, the classification algorithm that generates the best performance is k-nearest neighbours.     

Thermal and morphological properties of high‐density polyethylene/ethylene–vinyl acetate copolymer composites with polyhedral oligomeric silsesquioxane nanostructure

The demand for improved properties of common polymers keeps increasing, and several new approaches have been investigated. In the study reported here, composites with a polymer matrix comprising a blend of high‐density polyethylene with ethylene–vinyl acetate copolymer (EVA), and with polyhedral oligomeric silsesquioxane (POSS) as a nanostructure, were processed and characterized in terms of their thermal and morphological properties. For the preparation of the composites, the concentrations of the blend components (0, 50 and 100 wt%) and of the POSS (0, 1 and 5 wt%) were varied. X‐ray diffraction results indicated that the presence of EVA in the composites led to the appearance of crystalline domains at lower POSS concentrations. Transmission and scanning electron microscopy showed that samples with 1 wt% of POSS had a homogeneous distribution in the polymer matrix with average dimensions of ca 150 nm. However, the formation of aggregates occurred in samples with 5 wt% of POSS. Differential scanning calorimetry and thermogravimetic analyses indicated that the POSS did not affect the melt and degradation temperatures of the polymer matrix. POSS underwent aggregation at higher concentrations during the composite processing, indicating a solubility limit of around 1 wt%. The presence of EVA in the composite favors POSS aggregation due to an increase in the polarity of the polymer matrix. Copyright © 2009 Society of Chemical Industry     

A fibre-optic UV system for H2SO4 production in aerosol chambers causing minimal thermal effects

A novel fibre-optic UV illumination system for sulphuric acid (H₂SO₄) production has been developed. The illumination system described in this paper provides sufficient ultraviolet light (UV) power while causing practically no thermal effect on the aerosol chamber (temperature variation <0.005 °C at full UV illumination). A similar thermal stability has not been achieved in other comparable experimental set-ups so far. The spectrum provided by the fibre-optic UV system corresponds to the UVB region, illuminates the chamber in a reasonably uniform way and is comparable to the ground level actinic flux. The UV system has been installed for the Cosmics Leaving OUtdoor Droplets (CLOUD) chamber experiments at CERN. Precise, easily-adjustable and reproducible concentrations of H₂SO₄ were generated by adjusting the UV light intensity. This paper gives an overview on the design of this new system as well as insights on its performance and application.