73 resultados para Total electron content (TEC)


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Banana flour obtained from unripe banana (Musa acuminata, var. Nanico) under specific drying conditions was evaluated regarding its chemical composition and nutritional value. Results are expressed in dry weight (dw). The unripe banana flour (UBF) presented a high amount of total dietary fiber (DF) (56.24 g/100 g), which consisted of resistant starch (RS) (48.99 g/100 g), fructans (0.05 g/100 g) and DF without RS or fructans (7.2 g/100 g). The contents of available starch (AS) (27.78 g/100 g) and soluble sugars (1.81 g/100 g) were low. The main phytosterols found were campesterol (4.1 mg/100 g), stigmasterol (2.5 mg/100 g) and beta-sitosterol (6.2 mg/100 g). The total polyphenol content was 50.65 mg GAE/100 g. Antioxidant activity, by the FRAP and ORAC methods, was moderated, being 358.67 and 261.00 mu mol of Trolox equivalent/100 g, respectively. The content of Zn, Ca and Fe and mineral dialyzability were low. The procedure used to obtain UBF resulted in the recovery of undamaged starch granules and in a low-energy product (597 kJ/100 g).

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Cultivar, growing conditions and geographical origin are factors that influence the carotenoid composition in fruits. Because the loquat cultivars evaluated in this study, CentenAria, Mizauto, Mizuho, Mizumo and Nectar de Cristal, have not previously been investigated, the present work was carried out to determine and compare the carotenoid composition of these five loquat cultivars, by applying high-performance liquid chromatography connected to a photodiode array and mass spectrometry detectors (HPLC-PDA-MS/MS). Twenty-five carotenoids were separated on a C(30) column, and 23 of them were identified. All-trans-beta-carotene (19-55%), all-trans-beta-cryptoxanthin (18-28%), 5,6:5`,6`-diepoxy-beta-cryptoxantilin (9-18%) and 5,6-epoxy-beta-cryptoxanthin (7-10%) were the main carotenoids. The total carotenoid content ranged from 196 mu g/100 g (cv. Nectar de Cristal) to 3020 mu g/100 g (CV. Mizumo). The carotenoid profile of cv. Nectar de Cristal was different from the other cultivars, which was in agreement with its cream pulp colour, in contrast to the other four cultivars with orange pulp colour. Cultivars Mizauto, Mizuho, Mizumo and CentenAria showed provitamin A values between 89 and 162 mu g RAE/100 g, and can be considered good source of this provitamin. (C) 2009 Elsevier Inc. All rights reserved.

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Fruits of seven fully ripened strawberry cultivars grown in Brazil (Dover, Camp Dover, Camarosa, Sweet Charlie, Toyonoka, Oso Grande, and Piedade) were evaluated for total phenolics, antioxidant activity based on DPPH radical scavenging assay, and functionality such as inhibition of alpha-amylase, alpha-glucosidase, and angiotensin I-converting enzyme (ACE) relevant for potentially managing hyperglycemia and hypertension. The total phenolics content ranged from 966 to 1571 mu g of gallic acid/g of fruit fresh weight for Toyonoka and Dover, respectively. No correlation was found between total phenolics and antioxidant activity. The major phenolic compounds in aqueous extracts of strawberries were ellagic acid, quercetin, and chlorogenic acid. Strawberries had high alpha-glucosidase inhibitory activity. However, alpha-amylase inhibitory activity was very low in all cultivars. This suggested that strawberries could be considered as a potential dietary source with anti-hyperglycemic potential. The evaluated cultivars had no significant ACE inhibitory activity, reflecting low anti-hypertensive potential.

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The aim of this research was to perform a stability testing of spray- and spouted bed-dried extracts of Passiflora alata Dryander (Passion flower) under stress storage conditions. Spouted bed- and spray-dried extracts were characterized by determination of the average particle diameter (dP), apparent moisture content (XP), total flavonoid content (TF), and vitexin content. Smaller and more irregular particles were generated by the spouted bed system due to a higher attrition rate (surface erosion) inside the dryer. The SB dryer resulted in an end product with higher concentration of flavonoids (approximate to 10%) and lower moisture content (1.6%, dry basis) than the spray dryer, even with both dryers working at similar inlet drying air temperature and ratio between the extract feed flow rate to drying air flow rate (Ws/Wg). Samples of the spouted bed- and spray-dried extracts were stored at two different temperatures (34 and 45 degrees C) and two different relative humidities (52 and 63% RH for 34 degrees C; 52 and 60% RH for 45 degrees C) in order to perform the stability testing. The dried extracts were stored for 28 days and were analyzed every 4 days. The flavonoid vitexin served as the marker compound, which was assayed during the storage period. Results revealed shelf lives ranging from 9 to 184 days, depending on the drying process and storage conditions.

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Vitamin A (13-cis-retinol, all-trans-retinol and total carotenes) content was evaluated in 15 samples of enteral feeding formulas during 3-6,9 and 12 months of storage in closed containers, protected from light and at room temperature (22-30 degrees C). All formulas were nutritionally complete and/or recommended for different diseases. Equivalent batches were also evaluated after preparation and refrigerated storage for 24 h. Nutrient content did not decrease during both storage scenarios. Stability of vitamin A in the enteral feeding formulas, as determined in this study, is probably due to production and storage conditions, e.g. absence of oxygen in contact with the packaged product, the technological process used in the microencapsulation of vitamins, and protected storage in the absence of light and at a temperature maximum of 30 degrees C. (C) 2010 Elsevier Ltd. All rights reserved.

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The antioxidant capacity of propolis from the southern region of Uruguay was evaluated using in vitro as well as cellular assays. Free radical scavenging capacity was assessed by ORAC, obtaining values significantly higher than those of other natural products (8000 mu mol Trolox equiv/g propolis). ORAC values correlated well with total polyphenol content (determined by Folin-Ciocalteu method) and UV absorption. Total polyphenol content (150 mg gallic acid equiv/g propolis) and flavonoids (45 mg quercetin equiv/g propolis) were similar to values reported for southern Brazilian (group 3) and Argentinean propolis. Flavonoid composition determined by RP-HPLC indicates a strong poplar-tree origin. Samples high in polyphenols efficiently inhibit low-density lipoprotein lipoperoxidation and tyrosine nitration. In addition, Uruguayan propolis was found to induce the expression of endothelial nitric oxide synthase and inhibit endothelial NADPH oxidase, suggesting a potential cardiovascular benefit by increasing nitric oxide bioavailability in the endothelium.

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Background: Glutamine and proline are metabolized in the liver and may collaborate on its regeneration. Parenteral nutrition (PN) containing either glutamine or proline was given to partially hepatectomized rats. The total RNA content and growth factor gene expression in hepatic remnants was measured, to determine the effects of these amino acid supplementation on the expression of growth factors during liver regeneration. Methods: Wistar rats nourished (HN) and malnourished (HM) were hepatectomized and divided in two groups: 20 receiving PN enriched with Alanyl-Glutamine (HN-Gln and HM-Gln) and 20 PN enriched with proline+alanine (HN-Pro and HM-Pro). The control groups comprised 7 nourished (CN) and 7 malnourished (CM) rats that didn`t undergo surgery. Growth factor and thymidine kinase mRNA levels were measured by RT-PCR. Results: In nourished rats, total hepatic RNA levels were lower in the HN-Gln and HN-Pro groups (0.75 and 0.63 mu g/mg tissue, respectively) than in control group (1.67 mu g/mg tissue) (P<0.05). In malnourished rats, total hepatic RNA content was higher in the HM-Pro group than FIN-Pro, HM-Gln, and CM (3.18 vs. 0.63, 0.93 and 1.10 mu g/mg, respectively; P<0.05). Hepatocyte growth factor mRNA was more abundant in the HM-Gln group when compared to CM (031 vs. 0.23 arbitrary units) and also in HM-Pro in relation to HM-Gln, HN-Pro, and CM (0.46 vs. 033 and 0.23, respectively, P<0.05). Conclusions: Proline or glutamine supplementation in malnourished rats improves total RNA content in the remnant hepatic tissue. Amino acids administration increased HGF gene expression after partial hepatectomy in malnourished rats, with a greater effect of proline than glutamine.

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Banana fruits are important foods, but there have been very few studies evaluating the phenolics associated with their cell walls. In the present study, (+) catechin, gallocatechin, and (-) epicatechin, as well as condensed tannins, were detected in the soluble extract of the fruit pulp; neither soluble anthocyanidins nor anthocyanins were present. In the soluble cell wall fraction, two hydroxycinnamic acid derivatives were predominant, whereas in the insoluble cell wall fraction, the anthocyanidin delphinidin, which is reported in banana cell walls for the first time, was predominant. Cell wall fractions showed remarkable antioxidant capacity, especially after acid and enzymatic hydrolysis, which was correlated with the total phenolic content released after the hydrolysis of the water-insoluble polymer, but not for the posthydrolysis water-soluble polymer. The acid hydrolysis released various monosaccharides, whereas enzymatic hydrolysis released one peak of oligosaccharides. These results indicate that banana cell walls could be a suitable source of natural antioxidants and that they could be bioaccessible in the human gut.

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The endocannabinoid system includes important signaling molecules that are involved in several homeostatic and neuroendocrine functions. In the present study, we evaluated the effects of the type 1 cannabinoid (CB(1)) receptor antagonist, rimonabant (10 mg/kg, p.o.), on hormone secretion, neuronal activation and mRNA expression in the hypothalamus following isotonic (I-) or hypertonic (H-) extracellular volume expansion (EVE). The total nitrate content in the PVN and SON was also assessed under the same experimental conditions. Our results showed that OT and AVP plasma concentrations were increased in response to H-EVE, while decreased AVP levels were found following I-EVE. Accordingly, both I- and H-EVE stimulated oxytocinergic neuronal activation, as evidenced by the increased number of c-Fos/OT double labeled neurons in the hypothalamus. The vasopressinergic cells of the PVN and SON, however, were only activated in response to H-EVE. Furthermore, increased amounts of both AVP and OT mRNAs were found in the hypothalamus following EVE. Pretreatment with rimonabant significantly potentiated hormone secretion and also vasopressinergic and oxytocinergic neuronal activation induced by EVE, although decreased AVP and OT mRNA expression was found in the hypothalami of rimonabant pretreated groups. In addition, the nitrate content in the PVN and SON was not altered in response to EVE or rimonabant pretreatment. Taken together, these results suggest that the CB(1) receptor may modulate several events that contribute to the development of appropriate responses to increased fluid volume and osmolality. (C) 2010 Elsevier Inc. All rights reserved.

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Aim: The aim of the present study was to assess the influence of the chemical characteristics and roughness of titanium surfaces on the viability, proliferation and differentiation of osteoblast-like cells cultured in a medium supplemented with recombinant human bone morphogenetic protein-7 (rhBMP-7). Material and methods: Osteo-1 cells were grown on titanium disks presenting with the following surfaces: (1) machined, (2) coarse grit-blasted and acid-attacked (SLA) and (3) chemically modified SLA (SLAmod) in the absence or presence of 20 ng/ml rhBMP-7 in culture medium. The viability and number of osteo-1 cells were evaluated after 24 h. Analyses of total protein content (TP) and alkaline phosphatase (AP) activity at 7, 14 and 21 days, collagen content at 7 and 21 days and mineralized matrix formation at 21 days were performed. Results: Cell viability (P=0.5516), cell number (P=0.3485), collagen content (P=0.1165) and mineralized matrix formation (P=0.5319) were not affected by the different surface configurations or by the addition of rhBMP-7 to the medium. Osteo-1 cells cultured on SLA surfaces showed a significant increase in TP at 21 days. The ALPase/TP ratio (P=0.00001) was affected by treatment and time. Conclusion: The results suggest that the addition of rhBMP-7 to the culture medium did not exert any effect on the viability, proliferation or differentiation of osteoblast-like cells grown on the different surfaces tested. All titanium surfaces analyzed allowed the complete expression of the osteoblast phenotype such as matrix mineralization by osteo-1 cells.

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The study investigated whether chronic ethanol (ETH) intake and subsequent ETH exposure of cell cultures affects osteoblast differentiation by evaluating key parameters of in vitro osteogenesis. Rats were treated with 5-20% (0.85-3.43 mM) ETH, increasing by 5% per week for a period of 4 weeks (habituation), after which the 20% level was maintained for 15 days (chronic intake). Bone-marrow stem cells from control (CONT) or ETH-treated rats were cultured in osteogenic medium which was either supplemented (ETH) or not supplemented (CONT) with 1.3 mm ethanol. Thus, four groups relating to rat treatment/culture supplementation were evaluated: (1) CONT/CONT, (2) ETH/CONT, (3) CONT/ETH and (4) ETH/ETH Cell morphology, proliferation and viability, total protein content, alkaline phosphatase (ALP) activity and bone-like nodule formation were evaluated. Chronic ethanol intake significantly reduced both food and liquid consumption and body weight gain. No difference was seen in cell morphology among treatments. Cell number was affected at 7 and 10 days as follows: CONT/CONT = CONT/ETH < ETH/CONT = ETH/ETH. Doubling time between 3 and 10 days was greater in groups of CONT animals: ETH/ETH = ETH/CONT < CONT/ETH = CONT/CONT. Cell viability and ALP activity were not affected by either animal treatment or culture exposure to ethanol. At day 21, the total protein content was affected as follows: ETH/ETH = CONT/ETH < ETH/CONT = CONT/CONT. Bone-like nodule formation was affected as follows: ETH/ETH < CONT/ETH < ETH/CONT < CONT/CONT. These results show that chronic ethanol intake, followed by the exposure of osteoblasts to ethanol, inhibited the differentiation of osteoblasts, as indicated by an increased proliferation rate and reduced bone-like nodule formation. Copyright (C) 2007 John Wiley & Sons, Ltd.

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The aim of this study was to evaluate the response of osteoblastic cells to the composite of Ricinus cominunis polyurethane (RCP) and alkaline phosphatase (ALP) incubated in synthetic body fluid (SBF). RCP pure (RCPp) and RCP blended with ALP 6 mg/mL polymer (RCP+ALP) were incubated in SBF for 17 days. Four groups of RCP were tested: RCPp, RCP+ALP, and RCPp and RCP+ALP incubated in SBF (RCPp/SBF and RCP+ALP/SBF). Stem cells from rat bone marrow were cultured in conditions that allowed osteoblastic differentiation on RCP discs and were evaluated: cell adhesion, culture growth, cell viability, total protein content, ALP activity, and bone-like nodule formation. Data were compared by ANOVA or Kruskal-Wallis test. The group RCP-A P was highly cytotoxic and, therefore, was not considered here. Cell adhesion (p = 0.14), culture growth (p = 0.39), viability (p = 0.46) and total protein content (p = 0.12) were not affected by either RCP composition or incubation in SBE ALP activity was affected (p = 0.0001) as follows: RCPp < RCPp/SBF < RCP+ALP/SBF. Bone-like nodule formation was not observed on all evaluated groups. The composite RCP+ALP prior to SBF incubation is cytotoxic and must not be considered as biomaterial, but the incorporation of ALP to the RCP followed by SBF incubation could be a useful alternative to improve the biological properties of the RCP. (c) 2007 Wiley Periodicals, Inc.

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Objectives: This study evaluated key parameters of the in vitro osteogenesis induced by osteoblastic cells obtained from sites submitted to sinus grafting with anorganic bovine bone (ABB) in comparison with cells derived from bone sites of the same patients. Materials and methods: In three patients, the augmentation of maxillary sinus was carried out using ABB (Bio-Oss (R)). After at least 6 months, during the surgical intervention for titanium implants placement, biopsies were taken from these areas using trephine burs (grafted group). Bone fragments, of the same patients, from sites that had not received graft were also obtained with trephine burs and used as a control group. Osteoblastic cells were obtained from grafted and control groups by enzymatic digestion and cultured under standard osteogenic condition until subconfluence. First passaged cells were cultured in 24-well culture plates. Cell adhesion was evaluated at 24 h. For proliferation and viability assay, cells were cultured for 1, 3, 7, and 10 days. Total protein content and alkaline phosphatase (ALP) activity were measured at 3, 7, 10, 14, 17, and 21 days. Cultures were stained with Alizarin red S at 21 days, for detection of mineralized matrix. Data were compared by Student`s t-test. Results: Cell adhesion and viability were not affected by cell source (P>0.05). Total protein content was greater (P<0.05) for grafted group. Cell proliferation, ALP activity, and bone-like nodule formation were all greater (P<0.05) for the control group. Conclusions: Taken together, these results indicate that the in vivo long-term contact of cells with ABB downregulates the expression of osteoblast phenotype and consequently the in vitro osteogenesis.

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The mm of this work was to evaluate the biocompatibility of poly(vinylidene fluoride-trifluoroethylene)/barium titanate (P(VDF-TrFE)/BT) membrane to be used in guided tissue regeneration (GTR) Fibroblasts from human periodontal ligament (hPDLF) and keratinocytes (SCC9) were plated on P(VDF-TrFE)/BT and polytetrafluorethylene membranes at a cell density of 20.000 cells well(-1) and Cultured for up to 21 days Cell morphology, adhesion and proliferation were evaluated in hPDLF and keratinocytes, while total protein content and alkaline phosphatase (ALP) activity were assayed only for hPDLF Using a higher cell density. real-time polymerase chain reaction (PCR) was performed to assess the expression of typical genes of hPDLF, such as periostin, PDLs17, S100A4 and fibromodulin, and key phenotypic markers of keratinocytes, including involucrin, keratins 1. 10 and 14 Expression of the apoptotic genes bax, bcl-2 and Survivin was evaluated for both cultures hPDLF adhered and spread more oil P(VDF-TrFE)/BT, whereas keratinocytes showed a round shape on both membranes. hPDLF adhesion was greater oil P(VDF-TrFE)/BT at 2 and 4 h, while keratinocyte adhesion was similar for both membranes. Whereas proliferation was significantly higher for hPDLF on P(VDF-TrFE)/BT at days 1 and 7. no signs of keratinocyte proliferation could be noticed for both membranes Total protein content was greater on P(VDF-TrFE)/BT at 7, 14 and 21 days, and higher levels of ALP activity were observed oil P(VDF-TrFE)/BT at 21 days. Real-time PCR revealed higher expression of phenotypic markers of hPDLF and keratinocytes as well as greater expression of apoptotic genes in cultures grown on P(VDF-TrFE)/BT. These results indicate that, by favoring hPDLF adhesion. spreading. proliferation and typical mRNA expression, P(VDF-TrFE)/BT membrane should be considered an advantageous alternative for GTR (C) 2009 Acta Materialia Inc Published by Elsevier Ltd All rights reserved

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Objective: This study aimed at investigating the influence of the porous titanium (Ti) structure on the osteogenic cell behaviour. Materials and methods: Porous Ti discs were fabricated by the powder metallurgy process with the pore size typically between 50 and 400 mm and a porosity of 60%. Osteogenic cells obtained from human alveolar bone were cultured until subconfluence and subcultured on dense Ti (control) and porous Ti for periods of up to 17 days. Results: Cultures grown on porous Ti exhibited increased cell proliferation and total protein content, and lower levels of alkaline phosphatase (ALP) activity than on dense Ti. In general, gene expression of osteoblastic markers-runt-related transcription factor 2, collagen type I, alkaline phosphatase, bone morphogenetic protein-7, and osteocalcin was lower at day 7 and higher at day 17 in cultures grown on porous Ti compared with dense Ti, a finding consistent with the enhanced growth rate for such cultures. The amount of mineralized matrix was greater on porous Ti compared with the dense one. Conclusion: These results indicate that the porous Ti is an appropriate substrate for osteogenic cell adhesion, proliferation, and production of a mineralized matrix. Because of the three-dimensional environment it provides, porous Ti should be considered an advantageous substrate for promoting desirable implant surface-bone interactions.