EFFECT of ULTRASONIC EXCITATION on THE MICROTENSILE BOND STRENGTH of GLASS IONOMER CEMENTS TO DENTIN AFTER DIFFERENT WATER STORAGE TIMES

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of electrolytic and chemical lesion by ibotenic acid of the septal area on water and salt intake

Water and sodium chloride intake was studied in male Holtzman rats weighing 250-300 g that had been subjected to electrolytic and chemical lesions of the septal area (SA). Water intake increased in animals with electrolytic lesion of the SA bilaterally from 169.37 +/- 8.55 (sham) to 214.87 +/- 23.10 ml/5 days (lesioned). Water intake decreased after ibotenic acid lesion of the SA from 229.33 +/- 27.60 to 127.33 +/- 22.84 ml/5 days. Sodium chloride intake (1.5%) increased in animals with electrolytic lesion of the SA from 10.0 +/- 1.73 to 15.5 +/- 1.95 ml/5 days after lesion. Also sodium chloride (1.5%) intake increased after ibotenic acid injection into the SA to a greater extent (from 7.83 +/- 1.25 to 14.33 +/- 1.87 ml/5 days). The results indicate that the water intake response may be due to lesions that involve cell bodies and fibers of passage and that the sodium intake response can also be induced by lesions which involve only cell bodies. Finally, these results led us to conclude that the SA uses its cell bodies and afferent bodies and fibers for processing inputs mediating water intake and salt appetite and that the cells bodies of the SA are implicated in increased water intake. (C) 1998 Elsevier B.V.

Effect of relining, water storage and cyclic loading on the flexural strength of a denture base acrylic resin

Objectives: This study investigated the effect of relining, water storage and cyclic loading on the ultimate flexural strength (FSU) and on the flexural strength at the proportional limit (FSPl) of a denture base acrylic resin (Lucitone 550-L).Methods: Rectangular bars of L were made (64 mm x 10 mm x 2 mm) and relined (1.3 mm) with four relining resins (Kooliner-K, Ufi Gel Hard-UGH, Tokuso Rebase Fast-TR and New Truliner-NT). In addition, specimens relined with L and intact L specimens were made (64 mm x 10 mm x 3.3 mm). A three-point flexural test was applied on the specimens (n = 10) after (1) polymerization; (2) water storage (30 days); (3) cyclic loading (10,000 cycles at 5 Hz) and (4) water storage (30 days) + cyclic loading. Data (MPa) were analyzed with three-way ANOVA and Tukey's HSD tests (alpha = 0.05). To test for a possible correlation between FSU and FSPl, a linear regression coefficient 'r' was calculated.Results: After water storage, L-UGH and L-TR demonstrated an increased FSU (41.4950.64 MPa and 49.95-57.36 MPa, respectively) (P < 0.05). Only L-TR demonstrated an increased FSPl (20.58-24.21 MPa) after water storage (P < 0.05). L-L had the highest FSU (between 78.57 and 85.09 MPa) and FSPl (between 31.30 and 34.17 MPa) (P < 0.05). The cyclic loading decreased the FSU and FSPl of all materials (P < 0.05). Regression analysis showed a strong linear correlation between the two variables (r = 0.941).Conclusions: Water storage improved the FSU of L-UGH and L-TR and the FSPl of L-TR. L-L produced the highest FSU and FSPl. The FSU and FSPl of all materials were detrimentally influenced by cyclic loading.

Effect of microwave irradiation and water storage on the viscoelastic properties of denture base and reline acrylic resins

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

Effect of long-term water immersion on the fracture toughness of denture base and reline resins

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of disinfection by microwave irradiation on the strength of intact and relined denture bases and the water sorption and solubility of denture base and reline materials

This study evaluated the influence of microwave disinfection on the strength of intact and relined denture bases. Water sorption and solubility were also evaluated. A heat-polymerized acrylic resin (Lucitone 550) was used to construct 4-mm-thick (n = 40) and 2-mm-thick (n = 160) denture bases. Denture bases (2mm) were relined with an autopolymerizing resin (Tokuso Rebase Fast, Ufi Gel Hard, Kooliner, or New Truliner). Specimens were divided into four groups (n = 10): without treatment, one or seven cycles of microwave disinfection (650 W for 6 min), and water storage at 37 degrees C for 7 days. Specimens were vertically loaded (5 mm/min) until failure. Disc-shaped specimens (50 min x 0.5 mm) were fabricated (n = 10) to evaluate water sorption and solubility. Data on maximum fracture load (N), deflection (%), and solubility (%) were analyzed by two-way analysis of variance and Student-Newman-Keuls tests (alpha = 0.05). One cycle of microwave disinfection decreased the deflection at fracture and fracture energy of Tokuso Rebase Fast and New Truliner specimens. The strength of denture bases microwaved daily for 7 days was similar to the strength of those immersed in water for 7 days. Microwave disinfection increased the water sorption of all materials and affected the solubility of the reline materials. (C) 2007 Wiley Periodicals, Inc.

Effect of green Coffea arabica L. seed oil on extracellular matrix components and water-channel expression in in vitro and ex vivo human skin models

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

Effect of fertilization in water quality and in zooplankton community in open plankton-culture ponds

The effect of swine manure fertilization on the water quality of zooplankton artificial culture in two ponds was measured in diel cycles on different months (October 1999, January and March 2000). Fertilization affected directly water quality; values for total phosphorus were above 1.4 mgL(-1) and maximum rates for ammonia reached 108 mu gL(-1). Zooplankton community comprised four species, namely, Brachionus calyciflorus, B. falcatus, Moina sp. and Thermocyclops sp. B. falcatus (Rotifera) and Moina sp (Cladocera) were dominant respectively in January and in March. There was no difference in abundance of zooplankton between the two ponds (p>0.05), although adult cyclopoid Thermocyclops sp was different between diel cycles (p<0.05). There were significant differences (p<0.05) in dissolved oxygen, ammonia, total phosphorus, orthophosphate, nitrite and nitrate between ponds. In fact, only dissolved oxygen and pH were significantly different (p<0.05) between the ponds' surface and bottom. Organic fertilization also provided greater amount of nutrients and higher pH and conductivity, coupled to greater oscillations in the concentration of dissolved oxygen, directly affecting the zooplanktonic composition.

The effect of sodium chloride on the formation of W/O microemulsions in soy bean oil/surfactant/water systems and the solubilization of small hydrophilic molecules

Partial pseudoternary phase diagrams were constructed for soy bean oil (SBO)/surfactant/NaCl aqueous solution systems, at 25 degrees C, using the anionic sodium bis(2-ethylhexyl) sulfosuccinate (ACT) and zwiterionic phosphatidylcholine (PC) or mixtures of these surfactants. The isotropic single phase of water-in-oil (W/O) microemulsions (MEs) is shown in the phase diagram and their viscosity reported. ME samples containing small amount of surfactant exhibit slightly higher viscosity than pure SBO, and were used in the solubilization of small water soluble molecules. NaCl enhances the area of the ME phase and MEs with different surfactant composition exhibit different induction time as obtained from tests of oxidative stability, and so are the MEs enriched with ascorbic acid, folic acid and FeSO4, with the latter exhibiting lower stability. The so prepared enriched soy bean oil has potential application in food industry since the surfactants are food grade. (C) 2007 Elsevier B.V. All rights reserved.

The effect of gastric dilatation in rats submitted to gasified water ingestion under the hepatic metabolic function

INTRODUÇÃO: O excesso de peso na população aumentou de forma significante nas últimas décadas e as bebidas gasosas tornaram-se um fator ambiental importante no comportamento alimentar das pessoas, sendo os EUA, México e Brasil, nesta ordem, os três maiores paises produtores e consumidores de refrigerantes. OBJETIVO: Investigar os efeitos da dilatação gástrica em ratos submetidos a ingestão de água gaseificada, veículo uniforme para todos os refrigerantes, sobre parâmetros metabólicos da função hepática. MÉTODOS: Foram constituídos dois grupos de 15 ratos acompanhados por 15 semanas. Ao Grupo-I, foram oferecidos 200 g/dia de ração ad libitum e 100 ml de água não gaseificada em 3 períodos diários, ao Grupo-II, foram oferecidos 200 g/dia de ração ad libitum e 100 ml de água gaseificada em 3 períodos diários; em cada grupo,foram calculados a média (x) e o desvio padrão (s); para todos os atributos estudados foi utilizado o método estatístico de teste t pareado, comparando-se GI com GII, testando-se o efeito dos tipos de água. RESULTADOS: Os resultados identificaram que os animais que foram submetidos ao tratamento com água gaseificada (Grupo-II), apresentaram um aumento de transaminase glutâmica pirúvica (TGP) e fosfatase alcalina p<0,01), tendência de aumento da transaminase glutâmica oxalacética (TGO) (0,10>p>0,05) e aumento da área gástrica com alterações morfológicas macroscópicas como o desaparecimento do pregueamento mucoso característico. CONCLUSÃO: A água gaseificada favoreceu o aumento da área gástrica com conseqüente desaparecimento macroscópico do pregueamento mucoso do órgão, que ocasionou alterações metabólicas da função hepática.

Effect of ibotenate lesions of the ventromedial hypothalamus on the water and salt intake induced by activation of the median preoptic nucleus in sodium-depleted rats

In this study we investigated the influence of a ventromedial hypothalamus (VMH) lesion with ibotenic acid on water and sodium intake and presser responses induced by combined treatment of the median preoptic nucleus (MnPO) with angiotensin Il (ANG II) and adrenergic agonists (phenylephrine, norepinephrine, isoproterenol and clonidine). Male Holtzman rats with a stainless steel cannula implanted into the MnPO and bilateral sham (vehicle) or VMH lesions with ibotenic acid were used. The ingestion of water and sodium and mean arterial pressure (MAP) were determined in separate groups submitted to sodium depletion with the diuretic furosemide (20 mg/rat). ANG II (10 pmol) injection into the MnPO of sham-lesioned rats induced water and sodium intake and presser responses. VMH-lesion reduced ANG II-induced water intake and increased saline intake, In sham rats phenylephrine (80 nmol) into MnPO increased, whereas norepinephrine (80 nmol) and clonidine (40 nmol) reduced ANG II-induced water intake while sodium intake was reduced only by clonidine into MnPO. In VMH-lesioned rats, phenylephrine reduced, noradrenaline increased and clonidine produced no effect on ANG II-induced water intake. In lesioned rats ANG II-induced sodium intake was reduced by phenylephrine and noradrenaline, whereas clonidine produced no change. ANG II-induced presser response was reduced in VMH-lesioned rats, but the presser response combining ANG II and phenylephrine or noradrenaline in VMH-lesioned rats was bigger than sham rats. These results show that the VMH is important for the changes in water and sodium intake and cardiovascular responses induced by angiotensinergic and adrenergic activation of the MnPO. (C) 1997 Elsevier B.V. B.V.

Mechanical properties, hydrophilicity and water activity of starch-gum film: effect of additives and deacetylated xanthan gum

The effect of deacetylated xanthan gum, additives (sucrose, soybean oil, sodium phosphate and propylene glycol) and pH modifications on mechanical properties, hydrophilicity and water activity of cassava starch-xanthan gum films has been studied. Sucrose addition resulted in the highest effect observed on cassava starch films elongation at break. The deacetylated xanthan gum had higher effect on elongation at break when comparing to the acetylated gum, although both gums presented an inferior effect in relation to the obtained with sucrose. However, when comparing to the control and PVC films, lower tensile strength resistance values were observed when adding sucrose. Increased water activity was observed for films added with sucrose, thus, increasing the material biodegradation. Sucrose and deacetylated xanthan gum addition resulted in a slight hydrophilicity increase. (C) 2004 Elsevier Ltd. All rights reserved.

EFFECT OF LATERAL HYPOTHALAMUS LESIONS ON THE WATER AND SALT INTAKE, AND SODIUM AND URINE EXCRETION INDUCED BY ACTIVATION OF THE MEDIAN PREOPTIC NUCLEUS IN CONSCIOUS RATS

In this-study we investigated the influence of electrolytic lesion of the lateral hypothalamus (LH) on the water and salt appetite, and the natriuretic, diuretic and cardiovascular effects induced by angiotensinergic, cholinergic and noradrenergic stimulation of the median preoptic nucleus (MnPO) in rats. Male Holtzman rats were implanted with a cannula into the MnPO. Other groups of sham- and LH-lesioned rats received a stainless steel cannula implanted into the MnPO. ANGII injection into the MnPO induced water and sodium intake, and natriuretic, diuretic, presser and tachycardic responses. Carbachol induced water intake, and natriuretic, presser and bradycardic responses, whereas noradrenaline increased urine, sodium excretion and blood pressure, and induced bradycardia. In rats submitted to LH-lesion only, water and sodium intake was reduced compared with sham rats. LH lesion also reduced the sodium ingestion induced by ANGII (12 ng) into the MnPO. In LH-lesioned rats, the dipsogenic, diuretic and presser responses induced by ANGII (12 ng), carbachol (2 nmol) and noradrenaline (20 nmol) injection into the MnPO were reduced. The same occurred with sodium excretion when carbachol (2 nmol) and noradrenaline (20 nmol) were injected into the MnPO of LH-lesioned rats, whereas ANGII(12 ng) induced an increase in sodium excretion. These data show that electrolytic lesion of the LH reduces fluid and sodium intake, and presser responses to angiotensinergic, cholinergic and noradrenergic activation of the MnPO. LH involvement with MnPO excitatory and inhibitory mechanisms related to water and sodium intake, sodium excretion and cardiovascular control is suggested.

Effect of rinsing with water immediately after APF gel application on enamel demineralization in situ

This double-blind crossover in situ study evaluated the effect of rinsing with water immediately after the application of acidulated phosphate fluoride (APF) on enamel demineralization. APF application was followed by: no rinsing or consuming of liquids or solids for the next 30 min; immediately washing with water jet or drinking of a glass of water. All treatments showed a statistically significant decrease in enamel mineral loss compared to the control (p < 0.05), but the differences among treatments were not significant (p > 0.05). The data suggest that the recommendation of asking patients to refrain from drinking water following professional APF application does not seem to have an influence on the anticaries effect of fluoride. Copyright (C) 2005 S. Karger AG, Basel.