Effect of Aloe vera application on the content and molecular arrangement of glycosaminoglycans during calcaneal tendon healing

Although several treatments for tendon lesions have been proposed, successful tendon repair remains a great challenge for orthopedics, especially considering the high incidence of re‐rupture of injured tendons. Our aim was to evaluate the pharmacological potential of Aloe vera on the content and arrangement of glycosaminoglycans (GAGs) during tendon healing, which was based on the effectiveness of A. vera on collagen organization previously observed by our group. In rats, a partial calcaneal tendon transection was performed with subsequent topical A. vera application at the injury site. The tendons were treated with A. vera ointment for 7 days and excised on the 7^th, 14^th, or 21^st day post‐surgery. Control rats received ointment without A. vera. A higher content of GAGs and a lower amount of dermatan sulfate were detected in the A. vera‐treated group on the 14^th day compared with the control. Also at 14 days post‐surgery, a lower dichroic ratio in toluidine blue stained sections was observed in A. vera‐treated tendons compared with the control. No differences were observed in the chondroitin‐6‐sulfate and TGF‐β1 levels between the groups, and higher amount of non‐collagenous proteins was detected in the A. vera‐treated group on the 21^st day, compared with the control group. No differences were observed in the number of fibroblasts, inflammatory cells and blood vessels between the groups. The application of A. vera during tendon healing modified the arrangement of GAGs and increased the content of GAGs and non‐collagenous proteins. Microsc. Res. Tech. 77:964–973, 2014. © 2014 Wiley Periodicals, Inc.     

In Situ analysis of CO2 laser irradiation on controlling progression of erosive lesions on dental enamel

The present study aimed to evaluate in situ the effect of CO₂ laser irradiation to control the progression of enamel erosive lesions. Fifty‐six slabs of bovine incisors enamel (5 × 3 × 2.5 mm³) were divided in four distinct areas: (1) sound (reference area), (2) initial erosion, (3) treatment (irradiated or nonirradiated with CO₂ laser), (4) final erosion (after in situ phase). The initial erosive challenge was performed with 1% citric acid (pH = 2.3), for 5 min, 2×/day, for 2 days. The slabs were divided in two groups according to surface treatment: irradiated with CO₂ laser (λ = 10.6 µm; 0.5 W) and nonirradiate. After a 2‐day lead‐in period, 14 volunteers wore an intraoral palatal appliance containing two slabs (irradiated and nonirradiated), in two intraoral phases of 5 days each. Following a cross‐over design during the first intraoral phase, half of the volunteers immersed the appliance in 100 mL of citric acid for 5 min, 3×/day, while other half of the volunteers used deionized water (control). The volunteers were crossed over in the second phase. Enamel wear was determined by an optical 3D profilometer. Three‐way ANOVA for repeated measures revealed that there was no significant interaction between erosive challenge and CO₂ laser irradiation (P = 0.419). Erosive challenge significantly increased enamel wear (P = 0.001), regardless whether or not CO₂ laser irradiation was performed. There was no difference in enamel wear between specimens CO₂‐laser irradiated and non‐irradiated (P = 0.513). Under intraoral conditions, CO₂ laser irradiation did not control the progression of erosive lesions in enamel caused by citric acid. Microsc. Res. Tech. 77:586–593, 2014. © 2014 Wiley Periodicals, Inc.     

Use of the jabuticaba (Myrciaria cauliflora) depulping residue to produce a natural pigment powder with functional properties

The aim of this study was to produce a natural pigment powder with functional properties. To optimise the spray-drying process, a central composite design with 17 treatments was used, in which the independent variables were the inlet drying air temperature (138–202 °C), the feed flow rate (20–67 mL/min), and the concentration of the carrier (maltodextrin, 100–300 g/kg of extract). The dependent variables were the moisture content, hygroscopicity, and anthocyanin retention. The samples were analysed by: anthocyanin and phenolic content; antioxidant properties based on the ORAC and DPPH assays; antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Salmonella enteritidis, and Escherichia coli; and inhibitory activity against arginase, an enzyme produced by Leishmania amazonensis. The experimental design was not significant or predictive in the ranges studied. The selected samples contained high concentrations of anthocyanins and phenolics, and high antioxidant capacities. In addition, they exhibited antimicrobial activity against three of the four microorganisms tested, and some of the samples also exhibited a bactericidal effect. Moreover, the powders exerted inhibitory activity (64–69%) against arginase. The results obtained in this study suggest that the jabuticaba depulping residue could be used to produce a natural pigment with functional properties.     

Influence of Pressure and Temperature on the Velocity of a Turbulent Jet Flow 3D

To investigate the influence of pressure and temperature on the jet velocity of a three-dimensional flow was the main goal of this study. Using a precipitation chamber with approximate capacity of 600 mL, it was studied the thermodynamic behavior of supercritical carbon dioxide mixture, dichloromethane and grape seed extract via SAS （supercritical antisolvent process）. For the numerical solution, the Navier-Stokes equations were used along with the model of turbulence k-ε and Peng-Robinson equation of state with quadratic mixing rules of Van der Waals. The method of Chung was employed to determine the viscosity, thermal conductivity and mass diffusivity of the flow numerically solved through commercial code based on CFD （computational fluid dynamics）. Simulations for pressures between 80 bar and 160 bar and temperatures between 308.15 K and 318.15 K showed large variations in the jet velocity, an important property in the dynamic mixing process that involves the size, size distribution and particle morphology.     

Aroma volatiles recovered in the water phase of cashew apple (Anacardium occidentale L.) juice during concentration

BACKGROUND: There is a considerable loss of volatile compounds during the thermal concentration of cashew apple juice, damaging product quality, and as yet there is little research on the subject. Thus the purpose of this research was to identify the aroma volatiles evaporated off from cashew apple juice and recovered in the water phase during concentration of this beverage in an industrial plant. Water phase volatiles were extracted using dichloromethane, concentrated under a nitrogen flow, separated by gas chromatography (GC) and identified by GC‐mass spectrometry. In order to determine the contribution of each volatile to the cashew aroma, five trained judges evaluated the GC effluents using the Osme GC‐olfactometry technique. RESULTS: 71 volatiles were identified; of these, 47 were odour active. Alcohols were preferentially recovered in the cashew water phase, notably heptanol, trans ‐3‐hexen‐1‐ol and 3‐methyl‐1‐butanol, representing 42% of the total chromatogram area and imparting green grass and fruity aroma notes to the water phase. Esters represented 21% of the total chromatogram area, especially ethyl 2‐hydroxyhexanoate, ethyl trans ‐2‐butenoate and ethyl 2‐methylbutanoate, and were responsible for the fruity/cashew‐like aroma of the water phase. On the other hand, 3‐methylbutanoic and 2‐methylbutanoic acids were the volatiles that presented the greatest odour impact in the GC effluents of the water phase. CONCLUSION: Overall, the results of the present study strongly indicated that further concentration of the esters recovered in the water phase, either by partial distillation or by alternative technologies such as pervaporation, could generate a higher‐quality natural cashew apple essence. Copyright © 2011 Society of Chemical Industry     

Nanocomposites derived from cellulose acetate and highly branched alkoxysilane

Highly branched alkoxysilane (HB) units were prepared in situ via a Michael‐type reaction between pentaerythrithol triacrylate and aminopropyltriethoxysilane. These units were used as an inorganic component for the modification of cellulose acetate (CA) films using the sol–gel process. The thermal and dynamic‐mechanical behaviors, the morphology, and the dimensional stability of the modified CA films were analyzed. The siloxane‐modified CA films showed thermal stability similar to pure CA, but the residue content at 900°C increased with the addition of HB units. The morphology of these films was characterized by siloxane nanodomains dispersed in the CA matrix, with good interfacial adhesion between the phases. Moreover, the CA/siloxane nanocomposite films showed improved dimensional stability in comparison with CA, i.e., in the presence of HB, the dimensional change was reduced to around 50% of the value observed for pure CA. Finally, a complex dynamic‐mechanical behavior was obtained for the nanocomposite films, as a consequence of the heterogeneous morphology. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Inhibitory action of aqueous coffee ground extracts on the corrosion of carbon steel in HCl solution

The effects of aqueous extracts of spent coffee grounds on the corrosion of carbon steel in a 1 mol L⁻¹ HCl were examined. Two methods of extraction were studied: decoction and infusion. The inhibition efficiency of C-steel in 1 mol L⁻¹ HCl increased as the extract concentration and temperature increased. The coffee extracts acted as a mixed-type inhibitor with predominant cathodic effectiveness. In this study, the adsorption process of components of spent coffee grounds extracts obeyed the Langmuir adsorption isotherm. The chlorogenic acids isolated do not seem to explain the corrosion inhibition observed during the use of the coffee extracts.     

Experimental evaluation of a R-EAM and noise impact analysis for UWB and Wi-Fi transmission in RoF networks

The performance of a reflective electro-absorption modulator transceiver is assessed in terms of both slope efficiency (SE) and responsivity in a radio-over-fiber network. Different biasing schemes are analyzed, specifically zero bias (passive solution), bias for maximum SE, and bias for maximum responsivity. Finally, two case studies on multiband orthogonal frequency division multiplexing ultra-wide band and Wi-Fi are presented, for which the optimum setup parameters are determined.