Effect of Controlled Atmospheres with Low Oxygen Levels on Extended Storage of Guava Fruit (Psidium guajava L. 'Pedro Sato')

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of Aspergillus spp. exogenous fibrolytic enzymes on in vitro fermentation of tropical forages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Potential and costs for the production of electrolytic hydrogen in alcohol and sugar cane plants in the central and south regions of Brazil

This project verified the potential for the production of hydrogen via water electrolysis by using the exceeding electrical energy resultant from alcohol and sugar plants that use sugar cane bagasse as fuel. The studies were carried out in cogeneration plants authorized by the Electrical Energy National Agency (ANEEL). The processing history of sugar cane considered was based on the 2006/2007 harvests. The total bagasse produced, electrical energy generated and exceeding electrical energy in a year were calculated. It was obtained an average energy consumption value of 5.2 kWh Nm(-3) and the hydrogen production costs regarding the amount of sugar cane processed that ranged from US$ 0.50 to US$ 0.75 Nm(-3). The results pointed that the costs for the production of hydrogen via the bagasse exceeding energy are close to the production costs that use other sources of energy. As the energy generated from the bagasse is a renewable one, this alternative for the production of hydrogen is economical and environmentally viable. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.

Physical Vapor Deposited Thin Films of Lignins Extracted from Sugar Cane Bagasse: Morphology, Electrical Properties, and Sensing Applications

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of the consumption of a new symbiotic shake on glycemia and cholesterol levels in elderly people with type 2 diabetes mellitus

Background: The consumption of foods containing probiotic and prebiotic ingredients is growing consistently every year, and in view of the limited number of studies investigating their effect in the elderly.Objective: The objective of this study was to evaluate the effect of the consumption of a symbiotic shake containing Lactobacillus acidophilus, Bifidobacterium bifidum and fructooligosaccharides on glycemia and cholesterol levels in elderly people.Methods: A randomized, double-blind, placebo-controlled study was conducted on twenty volunteers (ten for placebo group and ten for symbiotic group), aged 50 to 60 years. The criteria for inclusion in the study were: total cholesterol > 200 mg/dL; triglycerides > 200 mg/dL and glycemia > 110 mg/dL. Over a total test period of 30 days, 10 individuals (the symbiotic group) consumed a daily dose of 200 mL of a symbiotic shake containing 10(8) UFC/mL Lactobacillus acidophilus, 10(8) UFC/mL Bifidobacterium bifidum and 2 g oligofructose, while 10 other volunteers (the placebo group) drank daily the same amount of a shake that did not contain any symbiotic bacteria. Blood samples were collected 15 days prior to the start of the experiment and at 10-day intervals after the beginning of the shake intake. The standard lipid profile (total cholesterol, triglycerides and HDL cholesterol) and glycemia, or blood sugar levels, were evaluated by an enzyme colorimetric assay.Results: The results of the symbiotic group showed a non-significant reduction (P > 0.05) in total cholesterol and triglycerides, a significant increase (P < 0.05) in HDL cholesterol and a significant reduction (P < 0.05) in fasting glycemia. No significant changes were observed in the placebo group.Conclusion: The consumption of symbiotic shake resulted in a significant increase in HDL and a significant decrease of glycemia.

Line-pack management for producing electric power on peak periods

The distribution of natural gas is carried out by means of long ducts and intermediate compression stations to compensate the pressure drops due to friction. The natural gas compressors are usually driven by an electric motor or a gas turbine system, offering possibilities for energy management, one of these consisting in generating energy for use in-plant or to commercialize as independent power producer. It can be done by matching the natural gas demand, at the minimum pressure allowed in the reception point, and the storage capacity of the feed duct with the maximum compressor capacity, for storing the natural gas at the maximum permitted pressure. This allows the gas turbine to drive an electric generator during the time in which the decreasing pressure in duct is above the minimum acceptable by the sink unit. In this paper, a line-pack management analysis is done for an existing compression station considering its actual demand curve for determining the economic feasibility of maintaining the gas turbine system driver generating electricity in a peak and off-peak tariff structure. The potential of cost reduction from the point of view of energy resources (natural gas and electric costs) is also analyzed. (C) 2010 Elsevier Ltd. All rights reserved.

Effects of Annona squamosa extract on early pregnancy in rats

Annona squamosa Linn., family Annonaceae, is said to show varied medicinal effects, including insecticide, antiovulatory and abortifacient. The purpose of present study was to investigate if A. squamosa seed aqueous extract, in doses higher than that popularly used to provoke abortion, interferes with reproductive performance, and to correlate the ingestion of this extract with possible alterations in rat embryonic implantation. Doses of 300 mg/kg (Treated Group I, n = 17) and 600 mg/kg (Treated Group II, n = 12) body wt. were administered by gavage, during days 1 to 5 of pregnancy (preimplantation period). The control group (n = 13) received water in the same manner, during the same period for comparison with experimental groups. The animals were euthanized on day 10 of pregnancy. Treatment of dams during the preimplantation period showed no signs of toxicity, and no alteration in the corpora lutea, implantations and embryo in terms of development numbers. The percentage of preimplantation and postimplantation losses in treated groups I and II did not differ from those of control. Treatment with aqueous extract of A. squamosa seeds caused no morphological change in the endometrium. The absence of morphological alterations in uterine epithelial cells in treated groups I and II permitted a viable embryonic implantation, as verified by the number of embryos in development at day 10 of pregnancy. Thus, A. squamosa seed aqueous extract did not interfere with the reproductive performance of pregnant rats.

Effects of Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] on the urinary bladder of male Wistar rats

Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide widely used on agricultural crops such as soy, cotton and sugar cane. In a previous long-term study this herbicide exerted carcinogenic activity on the urinary bladder mucosa of male Wistar rats. In general, the genotoxic and mutagenic potentials of Diuron are considered to be negative. The present study aimed to evaluate the mode of action of Diuron on the urinary bladder mucosa of male Wistar rats. Six-week old male Wistar rats were fed pelleted Nuvilab diet mixed with Diuron at 125, 500 and 2500 ppm. As a positive control, 8.3% sodium saccharin (NaS) was fed in the diet. Preceding the sacrifice of the animals at the 20th week, urinary pH was measured and the genotoxic potential of Diuron was evaluated by the comet assay. Histological urothelial lesions in the urinary bladder and in the renal pelvis mucosa, cell proliferation/apoptosis evaluations, and scanning electron microscopy (SEM) of the urinary bladder mucosa were also performed. No DNA changes were found in urothelial or peripheral blood cells, and urinary pH was comparable to controls in all Diuron groups. In the urinary bladder urothelium, the incidence of simple hyperplasia (SH) by light microscopy was significantly increased (7/10; p < 0.005) in the 2500 ppm Diuron group but not at the lower doses. By SEM, three of five animals treated with 2500 ppm Diuron showed urothelial cell necrosis and hyperplasia. In the renal pelvis, the incidence of SH was significantly increased in the Diuron 500 and 2500 ppm and in the NaS 8.3% groups. Cell proliferation was significantly increased in the Diuron 2500 ppm, (p < 0.05) and NaS 8.3% (p < 0.05) groups. The results indicate that a high dietary concentration of Diuron is associated with urothelial necrosis and continuous regenerative cell proliferation that leads to urothelial hyperplasia. (c) 2006 Elsevier B.V.. All rights reserved.

Effect of salivary stimulation on erosion of human and bovine enamel subjected or not to subsequent abrasion: An in situ/ex vivo study

This in situ/ex vivo study evaluated whether saliva stimulated by chewing gum could prevent or reduce the wear and the percent change in microhardness (%SMH) of bovine and human enamel submitted to erosion followed by brushing abrasion immediately or after 1 h. During 2 experimental 7-day crossover phases, 9 previously selected volunteers wore intraoral palatal devices, with 12 enamel specimens (6 human and 6 bovine). In the first phase, the volunteers immersed the device for 5 min in 150 ml of cola drink, 4 times per day (at 8, 12, 16 and 20 h). Immediately after the immersions, no treatment was performed in 4 specimens, 4 other specimens were immediately brushed (0 min) using a fluoride dentifrice, and the device was replaced into the mouth. After 60 min, the remaining 4 specimens were brushed. In the second phase, the procedures were repeated, but after the immersions, the volunteers stimulated the salivary flow rate by chewing a sugar-free gum for 30 min. Changes in wear and %SMH were measured. ANOVA and Tukey's test showed statistical differences (p < 0.05) for the following comparisons. The chewing gum promoted less wear and %SMH. A decreasing %SMH and an increasing enamel wear were observed in the following conditions: erosion only, 60 min and 0 min. The human enamel presented greater %SMH and less wear compared to bovine enamel. The data suggest that the salivary stimulation after an erosive or erosive/abrasive attack can reduce the dental wear and the %SMH.

Morphological changes on the hard palatine mucosa of rats (Rattus norvegicus albinus) after chronic alcohol consumption

In order to examine the effects of alcohol on the hard palatine mucosa of rats, sixty adult female rats (Rattus norvegicus albinus) were divided into two experimental groups. The control group received solid diet (Purina rat chow) and tap water ad libitum. The alcoholic group received the same solid diet and was allowed to drink only sugar cane brandy dissolved in 30% Gay Lussac (v/v). At the end of periods of 90, 180 and 270 days of treatment, the animals at estro were sacrificed and the hard palatine mucosa were prepared for TEM and SEM methods. The basal cells of the alcoholic groups (90, 180 and 270 days of treatment) demonstrated some alterations: the intercellular spaces between these cells were higher, presented cytoplasmatic lipid droplets and autolysis. Also, the connective tissue showed intense lipid droplets accumulation in the alcoholic groups. These modifications suggested that chronic alcohol ingestion was able to modify the integrity of the cells in the rat hard palatine mucosa.

Effects of extracts from Brazilian sun-mushroom (Agaricus blazei) on the NK activity and lymphoproliferative responsiveness of Ehrlich tumor-bearing mice

Agaricus blazei Murrill, is an edible and medicinal mushroom which is popularly consumed due to its antitumoral properties. The immunomodulatory effects of methanol (METH), dichloromethane (DM) and n-hexane (HEX) extracts of this mushroom were evaluated in Ehrlich tumor-bearing mice. Subcutaneous inoculation of Ehrlich tumor cells inhibited the natural killer (NK) activity of spleen cells (specific lysis = 6.18 +/- 2.56%) compared with normal mice (17.59 +/- 7.77%). Treatment of tumor-bearing mice with the extracts for 10 days restored the natural killer activity against Yac-1 target cells and the best results were observed by treatment with the HEX extract (21.48 +/- 15.26%). Treatment of the animals with the HEX extract for 10 days was also able to stimulate the mitogen-induced lymphoproliferative activity of spleen cells. Thirty days after the treatment, all groups presented low proliferative activity. Specific antibody production was observed to be higher in the groups treated with the DM or METH extract 30 days after the treatment. Analysis of the 3 extracts by gas chromatography mass spectrum (GCMS) and magnetic nuclear resonance (MNR) showed that the HEX extract contains mainly sugar and fatty acids and that the METH extract also contains sugar and possibly amino acids. (C) 2004 Elsevier Ltd. All rights reserved.

Differential effect of plant lectins on mast cells of different origins

Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A), lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA), and demetallized Con A and C. brasiliensis, using 1-300 µg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5%, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A) and on Rowett nude rat (animal free of immunoglobulins) peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA). No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars). Additionally, the lectins also released histamine from Rowett nude mast cells that are free of immunoglobulins.

Sugar digestion in mosquitoes: Identification and characterization of three midgut alpha-glucosidases of the neo-tropical malaria vector Anopheles aquasalis (Diptera : Culicidae)

Dietary carbohydrates provide an important source of energy for flight, and contribute to longevity and fecundity of mosquitoes. The most common sugar mosquitoes ingest is sucrose, and digestion of this substance is carried out mainly by alpha-glucosidases. In the current work, we tested the efficiency of sucrose on Anopheles aquasalis female diet. The best longevity (days) was reached when sugar was available in the diet, whereas most only blood fed females were dead 6 days after emergence. Three alpha-glucosidase isoforms were detected in the adult female midgut, named alpha Glu1, alpha Glu2 and alpha Glu3. These are acidic alpha-glucosidases with optima pH around pH 5.5. alpha Glu1 and alpha Glu2 are present in both secreted and membrane-bound forms, whereas alpha Glu3 only in anchored to membranes. The alpha-glucosidase activity is concentrated mainly in the posterior midgut (70%), both in non-fed or 10% sucrose fed females. The single form of these a-glucosidases seemed to be similar to 70 kDa polypeptides, although alpha Glu2 is presented in >= 600 kDa self-aggregates. K, values of alpha Glu1, alpha Glu2 and alpha Glu3 differed significantly from each other, supporting the statement that three alpha-glucosidases are produced in the female midgut. Together, all data suggest that sugar is an essential component of A. aquasalis female diet. In addition, alpha-glucosidases are synthesized in the same place where sucrose is digested and absorbed, the midgut. (c) 2007 Elsevier B.V. All rights reserved.

Effects of nutrients on feeding activities of the pest termite Heterotermes tenuis (Isoptera : Rhinotermitidae)

Heterotermes tenuis is a native termite of large negative impact on the Brazilian economy. Many studies have focused on optimizing the baiting method for termite control by improving its use and its efficacy. In order to maximize termite bait consumption, this study aimed to select nutrient solutions which are able to enhance termite feeding. The effects of some sugars and urea on feeding preference of the subterranean termite H. tenuis were determined by double choice feeding tests, and the consumption was evaluated by variation in dry mass of filter paper after 28 days of termite feeding. Most of the solutions tested did not significantly influence feeding of H. tenuis. Termites fed preferentially on filter paper treated with 0.03 g/ml trehalose and 0.015 g/ml urea solutions. The data indicate that trehalose and urea solutions are phagostimulants to H. tenuis, and their future use in bait matrices may increase consumption of baits and improve this control technique.

Effects of the polysaccharide beta-glucan on clastogenicity and teratogenicity caused by acute exposure to cyclophosphamide in mice

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)