366 resultados para Condensate


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

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

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

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

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

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

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

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Lung cancer is a leading cause of death in developed countries. Although smoking cessation is a primary strategy for preventing lung cancer, former smokers remain at high risk of cancer. Accordingly, there is a need to increase the efficacy of lung cancer prevention. Poor bioavailability is the main factor limiting the efficacy of chemopreventive agents. The aim of this study was to increase the efficacy of cancer chemopreventive agents by using lipid nanoparticles (NPs) as a carrier. This study evaluated the ability of lipid NPs to modify the pharmacodynamics of chemopreventive agents including N-acetyl-L-cysteine, phenethyl isothiocyanate and resveratrol (RES). The chemopreventive efficacy of these drugs was determined by evaluating their abilities to counteract cytotoxic damage (DNA fragmentation) induced by cigarette smoke condensate (CSC) and to activate protective apoptosis (annexin-V cytofluorimetric staining) in bronchial epithelial cells both in vitro and in ex vivo experiment in mice. NPs decreased the toxicity of RES and increased its ability to counteract CSC cytotoxicity. NPs significantly increased the ability of phenethyl isothiocyanate to attenuate CSC-induced DNA fragmentation at the highest tested dose. In contrast, this potentiating effect was observed at all tested doses of RES, NPs dramatically increasing RES-induced apoptosis in CSC-treated cells. These results provide evidence that NPs are highly effective at increasing the efficacy of lipophilic drugs (RES) but are not effective towards hydrophilic agents (N-acetyl-L-cysteine), which already possess remarkable bioavailability. Intermediate effects were observed for phenethyl isothiocyanate. These findings are relevant to the identification of cancer chemopreventive agents that would benefit from lipid NP delivery.

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Background: The analysis of exhaled breath condensate (EBC) is a non-invasive technique that enables the determination of several volatile and nonvolatile substances produced in the respiratory tract, whose measurement may be useful for the diagnosis and monitoring of several respiratory diseases. Objective: The aim of this study was to produce a low-cost reusable device in order to sample exhaled breath condensate in healthy adult volunteers, and to determine the concentration of nitric oxide in the sample collected. Material and methods: The apparatus was made with a U-shaped tube of borosilicate glass. The tube was placed in a container with ice, and unidirectional respiratory valves were fitted to the distal end. Afterwards, nitric oxide was measured in the exhaled breath condensate (EBC) by chemiluminescence. Results: The total cost of the device was $120.20. EBC samples were obtained from 116 volunteers of both sexes, aged between 20 and 70. The mean volume of exhaled breath condensate collected during 10 minutes was 1.0 +/- 0.6 mL, and the mean level of nitric oxide was 12.99 +/- 14.38 mu M (median 8.72 mu M). There was no correlation between the nitric oxide levels in the exhaled breath condensate and age or gender. Conclusion: We demonstrate that it is possible to fabricate a low-cost, efficient, reusable device in order to collect and determine nitric oxide levels in EBC. We have identified no correlation between the nitric oxide levels present in the EBC obtained with this method with either age or sex. (C) 2011 SEPAR. Published by Elsevier Espana, S.L. All rights reserved.

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In a recent study we demonstrated the emergence of turbulence in a trapped Bose-Einstein condensate of Rb-87 atoms. An intriguing observation in such a system is the behavior of the turbulent cloud during free expansion. The aspect ratio of the cloud size does not change in the way one would expect for an ordinary non-rotating (vortex-free) condensate. Here we show that the anomalous expansion can be understood, at least qualitatively, in terms of the presence of vorticity distributed throughout the cloud, effectively counteracting the usual reversal of the aspect ratio seen in free time-of-flight expansion of non-rotating condensates.

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As a noninvasive method, exhaled breath condensate (EBC) has gained importance to improve monitoring of lung diseases and to detect biomarkers. The aim of the study was to investigate, whether erythropoietin (EPO) is detectable in EBC. EBC was collected from 22 consecutive patients as well as from healthy individuals. Using a multiplex fluorescent bead immunoassay, we detected EPO in EBC, as well as tumour necrosis factor-alpha (TNF-alpha) in 13 out of 22 patients simultaneously (EPO 0.21 +/- 0.03 in U/mL and TNF-alpha 34.6 +/- 4.2 in pg/mL, mean +/- SEM). No significant differences for EPO levels or correlation between EPO and TNF-alpha were found but TNF-alpha was significantly higher in patients with chronic obstructive pulmonary disease (COPD) than in non-COPD (obstructive sleep apnoea, OSA, and lung healthy patients). This is the first report of detection of EPO in EBC. Due to the small study size more data is needed to clarify the role of EPO in EBC.

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OBJECTIVE: Increased levels of 8-isoprostane were found in various human lung diseases suggesting 8-isoprostane as a marker of pulmonary oxidative stress in vivo. The exact role in pediatric lung diseases has not been defined yet. The goal of this study was to clarify the role of 8-isoprostane in nasally exhaled breath condensate as possible marker of oxidative stress in children with different lung diseases. METHODS: Levels of 8-isoprostane were measured in nasally exhaled breath condensate of 29 cystic fibrosis patients, 19 children with a history of wheezing episodes, 8 infants with acute respiratory tract infection and 53 healthy subjects using a specific enzyme immunoassay. RESULTS: Levels of 8-isoprostane did neither discriminate between different disease groups nor correlate with lung function in cystic fibrosis patients. CONCLUSIONS: Levels of 8-isoprostane in nasally exhaled breath condensate do not reflect oxidative stress in children with different lung diseases.

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Amylase activity in exhaled breath condensate (EBC) is usually interpreted as an indication of oropharyngeal contamination despite the fact that amylase can be found in pulmonary excretions. The aim of this study was to recruit and refine an amylase assay in order to detect amylase activity in any EBC sample and to develop a method to identify EBC samples containing amylase of pulmonary origin. EBC was collected from 40 volunteers with an EcoScreen condenser. Amylase assays and methods to discriminate between oropharyngeal and pulmonary proteins were tested and developed using matched EBC and saliva samples. Our refined 2-chloro-4-nitrophenyl-α-D-maltotriosid (CNP-G3) assay was 40-fold more sensitive than the most sensitive commercial assay and allowed detection of amylase activity in 30 µl of EBC. We developed a dot-blot assay which allowed detection of salivary protein in saliva diluted up to 150 000-fold. By plotting amylase activity against staining intensity we identified a few EBC samples with high amylase activity which were aligned with diluted saliva. We believe that EBC samples aligned with diluted saliva contain amylase activity introduced during EBC collection and that all other EBC samples contain amylase activity of pulmonary origin and are basically free of oropharyngeal protein contamination.

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0We study the exact solution for a two-mode model describing coherent coupling between atomic and molecular Bose-Einstein condensates (BEC), in the context of the Bethe ansatz. By combining an asymptotic and numerical analysis, we identify the scaling behaviour of the model and determine the zero temperature expectation value for the coherence and average atomic occupation. The threshold coupling for production of the molecular BEC is identified as the point at which the energy gap is minimum. Our numerical results indicate a parity effect for the energy gap between ground and first excited state depending on whether the total atomic number is odd or even. The numerical calculations for the quantum dynamics reveals a smooth transition from the atomic to the molecular BEC.