656 resultados para chewing gum
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Gold nanorods (AuNRs) have emerged as an exceptional nanotool for a myriad of applications ranging from cancer therapy to tissue engineering. However, their surface modification with biocompatible and stabilizing biomaterials is crucial to allow their use in a biological environment. Herein, low-acyl gellan gum (GG) was used to coat AuNRs surface, taking advantage of its stabilizing, biocompatible and gelling features. The layer-by-layer based strategy implied the successive deposition of poly(acrylic acid), poly(allylamine hydrochloride) and GG, which allowed the formation of a GG hydrogel-like shell with 7 nm thickness around individual AuNRs. Stability studies in a wide range of pH and salt concentrations showed that the polysaccharide coating can prevent AuNRs aggregation. Moreover, a reversible pH-responsive feature of the nanoparticles was observed. Cytocompatibility and osteogenic ability of GG-coated AuNRs was also addressed. After 14 days of culturing within SaOS-2, an osteoblast-like cell line, in vitro studies revealed that AuNRs-GG exhibit no cytotoxicity, were internalized by the cells and localized inside lysosomes. AuNRs-GG combined with osteogenic media enhanced the mineralization capacity two-fold, as compared to cells exposed to osteogenic media alone. The proposed system has shown interesting features for osteogenesis, and further insights might be relevant for drug delivery, tissue engineering and regenerative medicine.
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"Tissue engineering: part A", vol. 21, suppl. 1 (2015)
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n.s. no.76(1994)
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A collection of chewing lice was studied from the Natural History Museum of the Universidade Católica de Pelotas, Rio Grande do Sul, Brazil. Twenty three samples from 16 bird species were examined. Included therein was a new species of the genus Plegadiphilus Bedford, 1939 which is described, illustrated and compared to P. cayennensis Emerson & Price, 1969. An updated list of chewing lice species recorded from birds of that state is presented.
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Plants activate direct and indirect defences in response to insect egg deposition. However, whether eggs can manipulate plant defence is unknown. In Arabidopsis thaliana, oviposition by the butterfly Pieris brassicae triggers cellular and molecular changes that are similar to the changes caused by biotrophic pathogens. In the present study, we found that the plant defence signal salicylic acid (SA) accumulates at the site of oviposition. This is unexpected, as the SA pathway controls defence against fungal and bacterial pathogens and negatively interacts with the jasmonic acid (JA) pathway, which is crucial for the defence against herbivores. Application of P. brassicae or Spodoptera littoralis egg extract onto leaves reduced the induction of insect-responsive genes after challenge with caterpillars, suggesting that egg-derived elicitors suppress plant defence. Consequently, larval growth of the generalist herbivore S. littoralis, but not of the specialist P. brassicae, was significantly higher on plants treated with egg extract than on control plants. In contrast, suppression of gene induction and enhanced S. littoralis performance were not seen in the SA-deficient mutant sid2-1, indicating that it is SA that mediates this phenomenon. These data reveal an intriguing facet of the cross-talk between SA and JA signalling pathways, and suggest that insects have evolved a way to suppress the induction of defence genes by laying eggs that release elicitors. We show here that egg-induced SA accumulation negatively interferes with the JA pathway, and provides an advantage for generalist herbivores.
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This paper presents a list of 131 Mallophaga type specimens deposited in the Werneck Collection of Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil. It includes 69 holotypes, 62 allotypes, 683 paratypes, 1 syntype and 2 neoparatypes, distributed among 6 families and 35 genera. The types are listed with their respective data and literature.
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This is a map of Genitourinary Medicine (GUM)/Sexual Health services across the five health trust areas. It gives contact details for the GUM/sexual health clinics and opening times.
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Consumption of nicotine in the form of smokeless tobacco (snus, snuff, chewing tobacco) or nicotine-containing medication (gum, patch) may benefit sport practice. Indeed, use of snus seems to be a growing trend and investigating nicotine consumption amongst professional athletes is of major interest to sport authorities. Thus, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection and quantification of nicotine and its principal metabolites cotinine, trans-3-hydroxycotinine, nicotine-N'-oxide and cotinine-N-oxide in urine was developed. Sample preparation was performed by liquid-liquid extraction followed by hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) operated in electrospray positive ionization (ESI) mode with selective reaction monitoring (SRM) data acquisition. The method was validated and calibration curves were linear over the selected concentration ranges of 10-10,000 ng/mL for nicotine, cotinine, trans-3-hydroxycotinine and 10-5000 ng/mL for nicotine-N'-oxide and cotinine-N-oxide, with calculated coefficients of determination (R(2)) greater than 0.95. The total extraction efficiency (%) was concentration dependent and ranged between 70.4 and 100.4%. The lower limit of quantification (LLOQ) for all analytes was 10 ng/mL. Repeatability and intermediate precision were ?9.4 and ?9.9%, respectively. In order to measure the prevalence of nicotine exposure during the 2009 Ice Hockey World Championships, 72 samples were collected and analyzed after the minimum of 3 months storage period and complete removal of identification means as required by the 2009 International Standards for Laboratories (ISL). Nicotine and/or metabolites were detected in every urine sample, while concentration measurements indicated an exposure within the last 3 days for eight specimens out of ten. Concentrations of nicotine, cotinine, trans-3-hydroxycotinine, nicotine-N'-oxide and cotinine-N-oxide were found to range between 11 and 19,750, 13 and 10,475, 10 and 8217, 11 and 3396, and 13 and 1640 ng/mL, respectively. When proposing conservative concentration limits for nicotine consumption prior and/or during the games (50 ng/mL for nicotine, cotinine and trans-3-hydroxycotinine and 25 ng/mL for nicotine-N'-oxide and cotinine-N-oxide), about half of the hockey players were qualified as consumers. These findings significantly support the likelihood of extensive smokeless nicotine consumption. However, since such conclusions can only be hypothesized, the potential use of smokeless tobacco as a doping agent in ice hockey requires further investigation.
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PURPOSE: Enhanced recovery after surgery (ERAS) pathways have significantly reduced complications and length of hospital stay after colorectal procedures. This multimodal concept could probably be partially applied to major urological surgery. OBJECTIVES: The primary objective was to systematically assess the evidence of ERAS single items and protocols applied to cystectomy patients. The secondary objective was to address a grade of recommendation to each item, based on the evidence and, if lacking, on consensus opinion from our ERAS Society working group. EVIDENCE ACQUISITION: A systematic literature review was performed on ERAS for cystectomy by searching EMBASE and Medline. Relevant articles were selected and quality-assessed by two independent reviewers using the GRADE approach. If no study specific to cystectomy was available for any of the 22 given items, the authors evaluated whether colorectal guidelines could be extrapolated. EVIDENCE SYNTHESIS: Overall, 804 articles were retrieved from electronic databases. Fifteen articles were included in the present systematic review and 7 of 22 ERAS items were studied. Bowel preparation did not improve outcomes. Early nasogastric tube removal reduced morbidity, bowel recovery time and length of hospital stay. Doppler-guided fluid administration allowed for reduced morbidity. A quicker bowel recovery was observed with a multimodal prevention of ileus, including gum chewing, prevention of PONV and minimally invasive surgery. CONCLUSIONS: ERAS has not yet been widely implemented in urology and evidence for individual interventions is limited or unavailable. The experience in other surgical disciplines encourages the development of an ERAS protocol for cystectomy.
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The effects of guar gum derived from the endosperm of Cyamopsis tetragonoloba (75% soluble fiber, 7.6% insoluble fiber, 2.16% crude protein, 0.78% total lipids, 0.54% ash and 9.55% moisture) on diabetic rats were studied concerning food intake, body weight gain, blood serum cholesterol, triacylglycerols, glucose, LDL-, and HDL-cholesterol concentrations. The effect of gum on indexes of protein absorption and utilization was also investigated. Diets containing 0%, 10% and 20% (w/w) guar gum were fed to diabetic rats for 28 days. In spite of the fact that diabetes elevated blood lipids in all animals, guar gum diet significantly decreased (p <0.05) serum concentrations of cholesterol and triacylglycerols. Furthermore, a concomitant increase in HDL-cholesterol with a substancial elevation of the HDL/LDL cholesterol ratio was found. The most significant result in this assay was the drastic reduction of blood glucose in diabetic rats treated with guar gum diet. The gum promoted a general improvement in the condition of the diabetic rats, in body weight gain and indexes of protein absorption and utilization. The results of this research suggest that guar gum, at concentrations equal to or higher than 10%, should be effective in the treatment of hypercholesterolemia and diabetes, in humans.
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The effect of Brea Gum (BG) addition on a basic bread formulation is described. The aim of the study was to investigate the effect of BG on the characteristics of wheat bread in terms of changes in moisture, texture, retrogradation of amylopectin, and microstructure. Bread quality was assessed by the physical parameters (volume, specific volume index, width/height ratio, crumb moisture, color, and hardness) and crumb grain structure (total cell number, total cell area, average size of cells, and number of cells per unit area). The effect of BG on the characteristics of the crumb during 24, 48, and 72 hours of storage was determined according to changes in moisture, hardness, and amylopectin retrogradation. Furthermore, the microstructure of the crumb was analyzed by scanning electron microscopy (SEM). The results show the ability of BG to retain moisture in the bread crumb, which was expressed by the lower hardness of the bread crumbs with the addition of the hydrocolloid at 48 and 72 hours of storage. This effect was also evident in the microstructure.
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The effect of protein lupine isolate (LI) and addition of brea gum (BG) on a basic bread formulation is described. The major objective of this research was to evaluate the influence of the addition of LI on the quality and quantity of the proteins of fresh bread with BG. Protein quality was determinate by the Chemical Score method corrected for protein digestibility (CSCD%). The bread dough characteristics were determined by farinograph and alveograph. Fresh bread characterization was performed by measuring the physical parameters and evaluating the crumb structure. The effect of LI and BG on available lysine, the loss of available lysine ratio, and the chemical composition of the breads were also determined. The addition of LI on the bread formulation improved the protein content and the CSCD% of lysine. The dough with LI was less resistant to prolonged kneading and less manageable. With BG addition, the dough became stickier. The quality of fresh bread was affected by the addition of LI: the fresh bread had lower specific volume and more heterogeneous crumbs than that of the control group. The addition of BG did not influence the quality of the bread made with the mixed flour, but it had a positive effect on the loss of available lysine.
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Recent studies have shown the beneficial effect of peptides, an unexploited source could be Phaseolus lunatus being an important raw material for those functional products in order to improve their utilization. In addition to improve the beneficial effect of bioactive peptides the microencapsulation could be a way to protect the peptides against the environment to which they are exposed. P. lunatus protein fraction (<10 kDa of weight) was encapsulated using a blend of carboxymethylated flamboyant gum (CFG) and sodium alginate (SA) at different concentrations of CaCl2 and hardening times. After in vitro digestion of microcapsules the residual activity, in the intestinal system, both inhibition of agiotensin-converting enzyme (I-ACE) and antioxidant activity obtained were in a range of 0.019-0.136 mg/mL and 570.64-813.54 mM of TEAC respectively. The microencapsulation employed CFG/SA blends could be used controlled delivery of peptide fractions with potential use as a nutraceutical or therapeutic agents.
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The aim of this work was to study the changes induced by BG in the behaviour of wheat starch, and observe the influence of these variations on the quality of a basic white bread. The effect of four BG addition levels in the wheat flour functional characteristics (WAI, WSI, and pasting properties) and bread quality (physical parameters, crumb grain structure, moisture and hardness) was investigated. The highest levels of BG (1% and 2%) decreased the peak viscosity, and increased the stability and setback of the flour. This was due to a lower gelatinization of the starch granules, caused by a competition for water between the hydrocolloid and starch. These changes influenced the bread quality. The loaves added with 1% and 2% of BG presented smaller alveoli: this resulted in more compact, hard and less airy crumbs. Nevertheless, the moisture of the samples at 1% and 2% of added gum was higher than the control bread. However, the incorporation of BG at 0.5% did not affect the pasting parameters and bread quality, but increased moisture of crumb, so this concentration would be most recommended for baking, since higher humidity could favour the shelf- life of the product.