Caracterização dos óleos de algumas sementes de frutas como aproveitamento de resíduos industriais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização do óleo das sementes de Pachira aquatica Aublet para aproveitamento alimentar

Os frutos de Pachira aquatica Aublet apresentam sementes comestíveis com características organolépticas muito apreciadas pelas populações amazônicas, sendo pouco utilizados em outras regiões. Este trabalho teve como objetivo caracterizar as sementes quanto à composição centesimal e determinar as características físico-químicas e perfil de ácidos graxos. A determinação da composição centesimal das sementes (teores de umidade, lipídios, proteínas, cinzas e carboidratos) e análises do óleo extraído das mesmas (ácidos graxos livres, índices de peróxido, iodo, refração, saponificação, ponto de fusão e perfil de ácidos graxos) foram realizadas seguindo metodologia oficial. O teor de óleo nas sementes 38,39% demonstrou que estas têm potencial para aproveitamento industrial. Das características físico-químicas analisadas, o óleo extraído das sementes apresentou 39,2% de ácidos graxos livres (expresso em % ácido oleico), índice de iodo de 27,4 g I2.100 g-1, índice de saponificação de 208,0 mg.KOH g-1, índice de refração (40 °C) de 1,4569 e ponto de fusão de 41,9 °C. Quanto à composição de ácidos graxos do óleo predominaram os ácidos palmítico (44,93%), oleico (39,27%) e linoleico (11,35%). Tal fato favorece o uso deste óleo como matéria-prima para as indústrias alimentícia, farmacêutica e de cosméticos.

Soil Carbon Turnover Measurement by Physical Fractionation at a Forest-to-Pasture Chronosequence in the Brazilian Amazon

The effect of conversion from forest-to-pasture upon soil carbon stocks has been intensively discussed, but few studies focus on how this land-use change affects carbon (C) distribution across soil fractions in the Amazon basin. We investigated this in the 20 cm depth along a chronosequence of sites from native forest to three successively older pastures. We performed a physicochemical fractionation of bulk soil samples to better understand the mechanisms by which soil C is stabilized and evaluate the contribution of each C fraction to total soil C. Additionally, we used a two-pool model to estimate the mean residence time (MRT) for the slow and active pool C in each fraction. Soil C increased with conversion from forest-to-pasture in the particulate organic matter (> 250 mu m), microaggregate (53-250 mu m), and d-clay (< 2 mu m) fractions. The microaggregate comprised the highest soil C content after the conversion from forest-to-pasture. The C content of the d-silt fraction decreased with time since conversion to pasture. Forest-derived C remained in all fractions with the highest concentration in the finest fractions, with the largest proportion of forest-derived soil C associated with clay minerals. Results from this work indicate that microaggregate formation is sensitive to changes in management and might serve as an indicator for management-induced soil carbon changes, and the soil C changes in the fractions are dependent on soil texture.

Physicochemical characteristics of LR3-IGF1 protein inclusion bodies: Electrophoretic mobility studies

A knowledge of the physicochemical properties of inclusion bodies is important for the rational design of potential recovery processes such as flotation and precipitation. In this study, measurement of the size and electrophoretic mobility of protein inclusion bodies and cell debris was undertaken. SDS-PAGE analysis of protein inclusion bodies subjected to different cleaning regimes suggested that electrophoretic mobility provides a qualitative measure of protein inclusion body purity. Electrophoretic mobility as a function of electrolyte type and ionic strength was investigated. The presence of divalent ions produced a stronger effect on electrophoretic mobility compared with monovalent ions. The isoelectric point of cell debris was significantly lower than that for the inclusion bodies. Hence, the contaminating cell debris may be separated from inclusion bodies using flotation by exploiting this difference in isoelectric points. Separation by this method is simple, convenient, and a possible alternative to the conventional route of centrifugation.

Effect of different radiopacifying agents on the physicochemical properties of white portland cement and white mineral trioxide aggregate

Introduction: The aim of this study was to evaluate the pH, calcium ion release, setting time, and solubility of white mineral trioxide aggregate (WMTA) and white Portland cement (WPC) combined with the following radiopacifying agents: bismuth oxide (BO), calcium tungstate (CT), and zirconium oxide (ZO). Methods: Fifty acrylic teeth with root-end filling material were immersed in ultrapure water for measurement of pH and calcium release (atomic absorption spectrophotometry) at 3, 24, 72, and 168 hours. For evaluation of setting time, each material was analyzed according to the American Society for Testing and Materials guidelines 266/08. The solubility test was performed according to American National Standards Institute/American Dental Association specification no. 57/2000. Solubility, setting time, and pH values were compared by using analysis of variance and Tukey test, and the values of calcium release were compared by the Kruskal-Wallis and Miller tests. The significance level was set at 5%. Results: The pH and calcium release were higher at 3 and 24 hours. WPC was the material with the higher values for both properties. WMTA had the greatest solubility among all materials (P <.05). All radiopacifiers increased the setting time of WPC, and WMTA had the shortest setting time among all materials (P < .05). Conclusions: All materials released calcium ions. Except for WPC/CT at 168 hours, all materials promoted an alkaline pH. On the basis of the obtained results, ZO and CT can be considered as potential radiopacifying agents to be used in combination with Portland cement. Copyright © 2012 American Association of Endodontists.

Effect of Different Radiopacifying Agents on the Physicochemical Properties of White Portland Cement and White Mineral Trioxide Aggregate

Introduction: The aim of this study was to evaluate the pH, calcium ion release, setting time, and solubility of white mineral trioxide aggregate (WMTA) and white Portland cement (WPC) combined with the following radiopacifying agents: bismuth oxide (BO), calcium tungstate (CT), and zirconium oxide (ZO). Methods: Fifty acrylic teeth with root-end filling material were immersed in ultrapure water for measurement of pH and calcium release (atomic absorption spectrophotometry) at 3, 24, 72, and 168 hours. For evaluation of setting time, each material was analyzed according to the American Society for Testing and Materials guidelines 266/08. The solubility test was performed according to American National Standards Institute/American Dental Association specification no. 57/2000. Solubility, setting time, and pH values were compared by using analysis of variance and Tukey test, and the values of calcium release were compared by the Kruskal-Wallis and Miller tests. The significance level was set at 5%. Results: The pH and calcium release were higher at 3 and 24 hours. WPC was the material with the higher values for both properties. WMTA had the greatest solubility among all materials (P < .05). All radiopacifiers increased the setting time of WPC, and WMTA had the shortest setting time among all materials (P < .05). Conclusions: All materials released calcium ions. Except for WPC/CT at 168 hours, all materials promoted an alkaline pH. On the basis of the obtained results, ZO and CT can be considered as potential radiopacifying agents to be used in combination with Portland cement. (J Endod 2012;38:394-397)

Measurement Of Longitudinal Spin Asymmetries For Weak Boson Production In Polarized Proton-proton Collisions At Rhic.

We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510  GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

Measurement Of The Hydrodynamic Radius Of Quantum Dots By Fluorescence Correlation Spectroscopy Excluding Blinking.

One of the most important properties of quantum dots (QDs) is their size. Their size will determine optical properties and in a colloidal medium their range of interaction. The most common techniques used to measure QD size are transmission electron microscopy (TEM) and X-ray diffraction. However, these techniques demand the sample to be dried and under a vacuum. This way any hydrodynamic information is excluded and the preparation process may alter even the size of the QDs. Fluorescence correlation spectroscopy (FCS) is an optical technique with single molecule sensitivity capable of extracting the hydrodynamic radius (HR) of the QDs. The main drawback of FCS is the blinking phenomenon that alters the correlation function implicating in a QD apparent size smaller than it really is. In this work, we developed a method to exclude blinking of the FCS and measured the HR of colloidal QDs. We compared our results with TEM images, and the HR obtained by FCS is higher than the radius measured by TEM. We attribute this difference to the cap layer of the QD that cannot be seen in the TEM images.

[construction Of Measurement Instruments In The Area Of Health].

Measurement instruments are an integral part of clinical practice, health evaluation and research. These instruments are only useful and able to present scientifically robust results when they are developed properly and have appropriate psychometric properties. Despite the significant increase of rating scales, the literature suggests that many of them have not been adequately developed and validated. The scope of this study was to conduct a narrative review on the process of developing new measurement instruments and to present some tools which can be used in some stages of the development process. The steps described were: I-The establishment of a conceptual framework, and the definition of the objectives of the instrument and the population involved; II-Development of the items and of the response scales; III-Selection and organization of the items and structuring of the instrument; IV-Content validity, V-Pre-test. This study also included a brief discussion on the evaluation of the psychometric properties due to their importance for the instruments to be accepted and acknowledged in both scientific and clinical environments.

Physicochemical characterization of two deproteinized bovine xenografts

Calcium phosphate salts, or more specifically hydroxyapatite, are products of great interest in the fields of medical and dental science due to their biocompatibility and osteoconduction property. Deproteinized xenografts are primarily constituted of natural apatites, sintered or not. Variations in the industrial process may affect physicochemical properties and, therefore, the biological outcome. The purpose of this work was to characterize the physical and chemical properties of deproteinized xenogenic biomaterials, Bio-Oss (Geistlich Biomaterials, Wolhuser, Switzerland) and Gen-Ox (Baumer S.A., Brazil), widely used as bone grafts. Scanning electron microscopy, infrared region spectroscopy, X-ray diffraction, thermogravimetry and degradation analysis were conducted. The results show that both materials presented porous granules, composed of crystalline hydroxyapatite without apparent presence of other phases. Bio-Oss presented greater dissolution in Tris-HCl than Gen-Ox in the degradation test, possibly due to the low crystallinity and the presence of organic residues. In conclusion, both commercial materials are hydroxyapatite compounds, Bio-Oss being less crystalline than Gen-Ox and, therefore, more prone to degradation.

Operant measurement of auditory threshold in prelingually deaf users of cochlear implants: II

Two experiments evaluated an operant procedure for establishing stimulus control using auditory and electrical stimuli as a baseline for measuring the electrical current threshold of electrodes implanted in the cochlea. Twenty-one prelingually deaf children, users of cochlear implants, learned a Go/No Go auditory discrimination task (i.e., pressing a button in the presence of the stimulus but not in its absence). When the simple discrimination baseline became stable, the electrical current was manipulated in descending and ascending series according to an adapted staircase method. Thresholds were determined for three electrodes, one in each location in the cochlea (basal, medial, and apical). Stimulus control was maintained within a certain range of decreasing electrical current but was eventually disrupted. Increasing the current recovered stimulus control, thus allowing the determination of a range of electrical currents that could be defined as the threshold. The present study demonstrated the feasibility of the operant procedure combined with a psychophysical method for threshold assessment, thus contributing to the routine fitting and maintenance of cochlear implants within the limitations of a hospital setting.

Study of C- and O-glycosylflavones in sugarcane extracts using liquid chromatography: exact mass measurement mass spectrometry

The flavonoids present in sugarcane (Saccharum officinarum) extracts were analyzed by liquid chromatography - mass spectrometry (LC-MS), and a study of the fragmentation patterns of selected flavonoids was conducted using orthogonal acceleration time-of-flight electrospray ionization mass spectrometry (ESI-oa-ToF MS). Seven C- and O-glycosylflavones were identified in the extracts, namely, schaftoside, isoschaftoside, luteolin-8-C-(rhamnosylglucoside), vitexin, orientin, tricin-7-O-neohesperidoside and tricin-7-O-glucoside. Of these, five were identified in the absence of direct comparison with their respective standards. The described method also permitted the differentiation of the 6-C and 8-C isomeric flavones, schaftoside and isoschaftoside. The combination of fragmentation data and exact mass measurement showed to be complimentary to the HPLC-UV-MS techniques previously utilized for isomers discrimination in sugarcane studies.

Effect of the kappa-casein gene polymorphism, breed and seasonality on physicochemical characteristics, composition and stability of bovine milk

The objective of this study was to evaluate the effect of genetic polymorphism of kappa-casein, breed and seasonality on the physicochemical characteristics, composition and stability of milk in commercial dairy herds. A total of 879 milk and blood samples were collected from 603 Holstein and 276 Girolando cows, obtained during rainy and dry seasons. Milk samples were analyzed to determine the physicochemical characteristics, composition and ethanol stability, while blood samples were subjected to polymerase chain reaction to identify the kappa-casein genotype. The frequencies of genotypes AA, AB and BB of k-casein were respectively, 66.83, 31.84 and 1.33% for Holstein, and 71.38, 27.90 and 0.72% for the Girolando cows, respectively. The A allele was more frequent than the B allele, both for Holstein (0.827 and 0.173) and Girolando cows (0.853 and 0.147), respectively. Cows of AB and BB genotypes showed a higher milk fat content compared to the AA genotype. There was an interaction between breed and seasonality on the concentration of milk urea with higher values for Holstein and Girolando cows in the rainy and dry season, respectively. The levels of lactose, total solids, crude protein, true protein, casein and the casein:true protein ratio were higher during the dry season, while during the rainy season, the somatic cell count and milk urea concentration were higher. There was no association between milk stability and k-casein genotypes, but Holstein cows showed higher milk stability than Girolando cows, and milk was more stable during the rainy season than during the dry season.

Direct measurement of intrinsic atomic scale magnetostriction

Using differential x-ray absorption spectroscopy (DiffXAS) we have measured and quantified the intrinsic, atomic-scale magnetostriction of Fe(81)Ga(19). By exploiting the chemical selectivity of DiffXAS, the Fe and Ga local environments have been assessed individually. The enhanced magnetostriction induced by the addition of Ga to Fe was found to originate from the Ga environment, where lambda(gamma,2)(approximate to (3/2)lambda(100)) is 390 +/- 40 ppm. In this environment, < 001 > Ga-Ga pair defects were found to exist, which mediate the magnetostriction by inducing large strains in the surrounding Ga-Fe bonds. For the first time, intrinsic, chemically selective magnetostrictive strain has been measured and quantified at the atomic level, allowing true comparison with theory.