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Objective: To evaluate the intra and inter variations of eye drops volume dispensed from bottles available on the market. Methods: Five bottles of lubricant eye drops were studied and nineteen volunteers participated in this study. The average mass from 20µl of eye drops was obtained using accuracy micropipette and balance, and used as standard for comparison with the mass of the drops obtained by the volunteers. Five drops of each vial were individually weighed with the tube perpendicular to the balance, using the first and second fingers of the right hand, so that the pressure was applied only in the middle of the flask. The experiments were performed in a room temperature (21±1°C). Results: All eye drops bottles showed a statistically significant variation on masses of the drops obtained by examiners when compared with the standard average weight of 0.0182±0,0014g, except when compared A with D eye drops, with no statistically significant variation. Conclusion: This study demonstrates the lack of uniformity of drops dispensed by eye drops bottles available in the market and its inadequacy to the real need, since the dispensed drops are larger than indicated. This fact becomes a problem when it comes to long treatment period, especially with expensive drops as indicated for glaucoma therapy. In this sense, the standardization of drops of eye drops is necessary. [ABSTRACT FROM AUTHOR]

Ex vivo cultivation and transplantation of limbal epithelial cells has been reported as an alternative source for ocular surface reconstruction. However, until now, the functional improvement of these patients is limited due to the low survival rate of the transplanted cells. Consequently, the clinical benefits of this therapeutic strategy are only temporary and can assign them to paracrine effects associated with the transplanted cells. With this background in mind, we aimed to analyze the effect of different conditioned media containing growth factors secreted by limbal progenitor cells on corneal epithelial healing, both in vitro and in vivo. Limbal tissue was used to obtain different conditioned media (CM). For the in vitro assay, corneal epithelial cells were treated with CM and the epithelial migration was analyzed. Growth factors in the CM were identified with ELISA and multiplex. For the in vivo assay in rats, total limbal stem cell deficiency (LSCD) was induced with an abrasive injury to the ocular surface, and the animals were treated with different CM. Clinical and histological analyses were performed. In the in vitro assay, treatment with limbal fibroblast (LF CM) was more effective compared to the other CM, and analysis revealed high concentrations of keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF). In the in vivo assay, animals treated with LF CM showed epithelial defect improvement, maintenance of thickness, and decreased opacity and neovascularization. This treatment also allowed better ocular surface tissue organization when compared to the other treatments. The in vitro and in vivo experiments showed better outcomes in the corneal wound healing for the LF CM treatment. The high concentrations of KGF and HGF, linked to epithelial cell migration and proliferation, may correlate to the best results found in this treatment. • Conditioned media secreted by limbal progenitor cells in the modulation of corneal epithelial healing. • Growth factors secreted by limbal fibroblast cells and their role in corneal epithelial healing. • Biological modulation of corneal epithelial healing as a therapeutic strategy for the treatment of ocular surface diseases. [ABSTRACT FROM AUTHOR]

Cell injection therapy is emerging as an alternative to treat corneal endothelial dysfunction (CED) and to avoid corneal scarring due to bullous keratopathy. However, establishing a standardized culture procedure that provides appropriate cell yield while retaining functional features remains a challenge. Here, we describe a detailed framework obtained from in vitro culture of human corneal endothelial cells (HCECs) and comparative in vivo experimental models for CED treatment with a new cell tracking approach. Two digestion methods were compared regarding HCEC morphology and adhesion. The effect of Y-27632 (ROCKi) supplementation on final cell yield was also assessed. Cell adhesion efficacy with two cell delivery systems (superparamagnetic embedding and cell suspension) was evaluated in an ex vivo human cornea model and in an in vivo rabbit CED model. The injection of supplemented culture medium or balanced salt solution (BSS) was used for the positive and negative controls, respectively. HCEC isolation with collagenase resulted in better morphology and adhesion of cultured HCEC when compared to EDTA. Y-27632 supplementation resulted in a 2.6-fold increase in final cell yield compared to the control. Ex vivo and in vivo adhesion with both cell delivery systems was confirmed by cell tracker fluorescence detection. Corneal edema and opacity improved in both animal groups treated with cultured HCEC. The corneas in the control groups remained opaque. Both HCEC delivery systems seemed comparable as treatments for CED and for the prevention of corneal scarring. [ABSTRACT FROM AUTHOR]

Over the past years the performance of microbial fuel cells (MFCs) has significantly improved. However it is still necessary to increase the efficiency in order to make their scaling-up viable. Obtaining polarization curves (PCs) is considered a widely accepted methodology to characterize the electrical efficiency of MFCs. Through PCs it is possible to identify the main potential losses that limit the system, as well as irreversibilities of energy production, so that better operational and constructive conditions can be proposed. This work reviews techniques for obtaining PCs from MFCs, as well as for the interpretation of these curves. It also provides a discussion about the mathematical modeling strategies of PCs as a methodology for obtaining insights into electrochemical phenomena and their effects on MFCs performance. Thus, this study seeks to contribute to the discussion on MFCs characterization for the improvement of these devices and regarding the establishment of better conditions for reproducibility and comparison of polarization data. Furthermore, it hopes to serve as a reference for researchers who want to perform, interpret and model PCs from their own MFC systems. • Microbial Fuel Cells require the use of different diagnostic tools to help understand its behavior • Polarization tests are the most utilized method to diagnose the performance of Microbial Fuel Cells • Through Polarization Curves it is possible to identify the main potential losses that limit a Microbial Fuel Cell • Mathematical modeling of Polarization Curves can provide important insights about performance [ABSTRACT FROM AUTHOR]

This study compares the effect of different combinations between β-lactoglobulin (β-lact, 1.0–1.5% w/v), a polysaccharide (carrageenan gum, CG, or locust bean gum, LBG, 0.0–0.5% w/v) and a sweetener (sucrose, maltitol or sorbitol, 0.0–0.5% w/v) on the foaming capacity and half-life time. The experimental design was defined according to a simplex centroid mixture design with a restriction of at least 1.0% w/v of β-lact in each mixture. Measurements of particle size, zeta potential, surface tension, flow curve, foaming capacity and foam half-life time were obtained. All mixtures evaluated showed a wide particle size distribution with diameters between 5.35 and 4494 nm. Mixtures containing CG presented higher values for apparent viscosity and average particle size than mixtures containing LBG, according to the gum concentration in solution. All mixtures showed negative zeta potential values (−14.27 to −40.42 mV) due to the presence of negatively charged β-lact at the pH 7. However, CG exerted a dominant effect on the zeta potential when present in the mixtures. The surface tension and foaming capacity were affected by the combined effect of the gums and sweeteners used. These molecules seemed to concentrate the protein at the interface due to the exclusion volume effect. The foam half-life time was mainly improved by the CG due to the higher bulk apparent viscosity, regardless of the sweetener used. Replacing sucrose with maltitol or sorbitol lead to comparable foam characteristics, mainly the foam capacity and foam half-life time, which confirms the potential of these polyols for sucrose replacement in model foams. [ABSTRACT FROM AUTHOR]

Chemical or enzymatic cross-linking of casein micelles (CMs) increases their stability against dissociating agents. In this paper, a comparative study of stability between native CMs and CMs cross-linked with genipin (CMs-GP) as a function of pH is described. Stability to temperature and ethanol were investigated in the pH range 2.0–7.0. The size and the charge (ζ-potential) of the particles were determined by dynamic light scattering. Native CMs precipitated below pH 5.5; CMs-GP precipitated from pH 3.5 to 4.5, whereas no precipitation was observed at pH 2.0–3.0 or pH 4.5–7.0. The isoelectric point of CMs-GP was determined to be pH 3.7. Highest stability against heat and ethanol was observed for CMs-GP at pH 2, where visible coagulation was determined only after 800 s at 140 °C or 87.5% (v/v) of ethanol. These results confirmed the hypothesis that cross-linking by GP increased the stability of CMs. [ABSTRACT FROM AUTHOR]

Sweet potato (Ipomoea batatas (L.) Lam) is one of the most popular and ancient roots of Brazil and it can be consumed at different forms such as boiled, roasted or as sweets. Its cooking can lead to physicochemical transformations altering the nutritional properties. The objective of this study was to evaluate the physicochemical characteristics, bioactive compounds and antioxidant capacity of twelve sweet potato genotypes of varying pulp color in natura and roasted. Soluble solids, acidity, sugars, carotenoids, anthocyanins, phenolic compounds and antioxidant capacity were analyzed in the following sweet potatoes genotypes: cream pulp (Rubissol, Cuia, ILS03, ILS10, ILS12, ILS24 and ILS44); orange pulp (Amelia and Beauregard); and purple pulp (ILS56, ILS16 and ILS71). According to the results, it was observed a wide variation among the sweet potato genotypes for all analyzed parameters, in both preparation forms. The antioxidant capacity was a parameter with wide variation among genotypes, 210.29 to 7870.57μg trolox equivalent/g in in natura form and 673.26 to 17306.22μg trolox equivalent/g in roasted form. Soluble solids, acidity, sugars and bioactive compounds, with the exception of carotenoids, tended to be concentrated, also increases the total antioxidant capacity, in roasted sweet potatoes. In conclusion, genotype and the color of sweet potatoes were parameters that had an influence on its chemical composition. Cultivars such as Amelia and Beauregard stood out by the amounts of total soluble solids and carotenoids, respectively. The selections ILS 16 and ILS 56 are recommended as sources of anthocyanins. Thermal process influenced the concentration of antioxidant compounds and changed some physicochemical characteristics. [ABSTRACT FROM AUTHOR]

BACKGROUND: The objective of this study was to compare the gestational results obtained with vitrified/thawed oocytes by a novel vitrification method (Vitri-ingá) to results obtained with fresh oocytes. [ABSTRACT FROM PUBLISHER]