Influence of jam processing upon the contents of phenolics,organic acids and free amino acids in quince fruit (<Emphasis Type="Italic">Cydonia oblonga</Emphasis> Miller)

Phenolic compounds, organic acids and free amino acids of quince were evaluated, before and after jam processing, to test the effect of thermal processing in these compounds. In addition, the composition of jams prepared with peeled and unpeeled quinces was compared. Phenolics, organic acids and free amino acids were analysed by HPLC/DAD, HPLC/UV and GC/FID, respectively.     

One-step synthesis of LaNiO3 with chitosan for dry reforming of methane

This paper presents a new preparation method of a catalytic precursor LaNiO₃ perovskite type in one-step using chitosan as a chelating agent. During synthesis La and Ni nitrates were added into a solution containing chitosan, placed into an oven to decompose the reagents and subsequently calcined. The perovskite was characterized by X-ray diffraction (XRD), scanning electron microscopy with chemical microanalysis (SEM-EDS), temperature-programmed reduction (TPR) and thermogravimetric analysis (TGA). The catalytic tests were conducted in a space velocity of 18 Lh^?1g^?1 at three temperatures: 600, 700 and 800°C. The characterization results indicated the formation above 95% of LaNiO₃ phase with good chemical homogeneity at lower temperature with metallic area and dispersion compatible with literature. The catalytic test results showed good levels of CH₄ and CO₂ conversions and good yields of CO and H₂. Therefore, the described method is a simple, fast and low-cost route to prepare LaNiO₃ for hydrogen production via dry reforming of methane.     

The influence of gelation rate on the physical properties/structure of salt-induced gels of soy protein isolate–gellan gum

The cold-set gelation of soy protein isolate (SPI)-gellan gum was induced by the addition of salts (KCl or CaCl₂) using two different procedures: the direct addition of salts (fast gelation) or the diffusion of salts through a membrane (slow gelation). The mechanical properties, syneresis and microstructure of the mixed gels were evaluated, as well as for gellan and SPI gels. The mixed gels induced by calcium diffusion were stronger and more deformable than gels induced by the direct addition of calcium, while the opposite occurred for potassium-induced gels. All the mixed gels were macroscopically homogeneous, but at the microscopic level two independent networks could be observed. These two separate networks were more evident for the calcium-induced gels, and the structural characteristics depended strongly on the concentration of the protein and the polysaccharide. However an organized microstructure with the formation of microtubes surrounded by other network was only observed for the mixed gels induced by calcium diffusion at the higher protein/polysaccharide (10:1) ratio. Thus besides the composition and concentration of the biopolymers, the results showed that the type of salt and its velocity of incorporation led to gels with different structures and consequently different mechanical properties.     

Biosensors for efficient diagnosis of leishmaniasis: innovations in bioanalytics for a neglected disease

The need for reliable, fast diagnostics is closely linked to the need for safe, effective treatment of the so-called "neglected" diseases. The list of diseases with no field-adapted diagnostic tools includes leishmaniasis, shigella, typhoid, and bacterial meningitis. Leishmaniasis, in particular, is a parasitic disease caused by Leishmania spp. transmitted by infected phlebotomine sandfly, which remains a public health concern in developing countries with ca. 12 million people infected and 350 million at risk of infection. Despite several attempts, methods for diagnosis are still noneffective, especially with regard to specificity due to false positives with Chagas' disease caused by Trypanosoma cruzi . Accepted golden standards for detecting leishmaniasis involve isolation of parasites either microscopically, or by culture, and in both methods specimens are obtained by invasive means. Here, we show that efficient distinction between cutaneous leishmaniasis and Chagas' disease can be obtained with a low-cost biosensor system made with nanostructured films containing specific Leishmania amazonensis and T. cruzi antigens and employing impedance spectroscopy as the detection method. This unprecedented selectivity was afforded by antigen-antibody molecular recognition processes inherent in the detection with the immobilized antigens, and by statistically correlating the electrical impedance data, which allowed distinction between real samples that tested positive for Chagas' disease and leishmaniasis. Distinction could be made of blood serum samples containing 10(-5) mg/mL of the antibody solution in a few minutes. The methods used here are generic and can be extended to any type of biosensor, which is important for an effective diagnosis of many other diseases.     

Forgetting curve models: A systematic review aimed at consolidating the main models and outlining possibilities for future research in production

This research surveys current knowledge about forgetting curves and their application in production, aiming to identify the main characteristics and tendencies and research gaps on this topic. Faced with the need to improve tools that allow production planners to predict programmed batches with greater precision, it was found that there are still gaps to be filled that allow the application of learning and forgetting techniques in the production process. To compose the scope of this research, a systematization of the existing literature was carried out, using the keywords ‘forgetting curves’, ‘total forgetting’, ‘learning and forgetting curve’ and ‘forgetting effects’, in the databases of Science Direct, Scielo, Scopus, Web of Science and Google Academics, which allowed classifying and organizing the developed models into 3 groups: Deterministic models, Statistical models and Functional models. This systematic process consisted of selecting databases, filtering publications, reviewing information, and analysing models, providing a detailed analysis on a topic that, despite being promising, is poorly explored in the industry, demonstrating and indicating gaps in research and application. To be filled.     

Olive response to potassium applications under different water regimes and cultivars

Although potassium (K) is a macronutrient few studies have evaluated the response of olive tree to K fertilization. In this work results of two field and two pot K fertilizer experiments are presented. One of the field trials was conducted in a commercial young olive grove. The second was conducted in a plantation purposely established for this study. In the two field and the first pot experiment, the K supply was the single variation factor. The second pot experiment was arranged as a factorial with two K rates, two water regimes and two cultivars (‘Arbequina’ and ‘Cobrançosa’). K supply did not increase olive tree growth or yield. Accumulated olive yield in the first field experiment, for instance, varied from 2.46 and 2.84 kg tree^?1, respectively in K treated and untreated plants. K supply increased the shoot/root ratio (1.6–2.0 from the control to the most fertilized treatment) and the concentration of K in roots (2.9–11.2 g kg^?1) to a greater extent than in leaves (7.0–11.9 g kg^?1), suggesting that shoots are a priority sink for K and roots may store the nutrient as a reserve. Plant water status and chlorophyll a fluorescence were not significantly affected by K applications. Plants suffering from water stress yielded less phytomass (40.2–56.4 g pot^?1, respectively in control and well-watered plants) and showed higher K concentrations in leaves (14.2–11.6 g kg^?1) and lower in roots (4.9–6.8 g kg^?1) which is probably due to the reduction of K uptake from the dry soil. ‘Cobrançosa’ appeared to be more tolerant to water stress than ‘Arbequina’. These experiments showed a poor response of olive tree to K fertilization. Considering that K is usually applied by farmers every year, it seems that further studies on K fertilization in olive are needed in order to adjust K fertilizer rates to crop needs.