Search results for "Chambers"
showing 10 items of 59 documents
RUPTURE OF A LEFT SINUS OF VALSALVA ANEURYSM INTO THE PULMONARY ARTERY.
2006
Sinus of Valsalva aneurysm is a rare congenital defect and the diagnosis is usually made after it ruptures. Very few cases of non-complicated sinus of Valsalva aneurysm have been published. The anomaly most often involves the right coronary sinus and less frequently the non-coronary sinus. A case with left sinus of Valsalva has not been reported. Since the aortic valve occupies a central position in the base of the heart, rupture of a sinus of Valsalva aneurysm can occur in any of the four heart chambers. Rupture into the pulmonary artery is very rare and is mostly associated with other congenital cardiopathies. ª 2005 The European Society of Cardiology. Published by Elsevier Ltd. All right…
Predicting hypoxia in cystic fibrosis patients during exposure to high altitudes
2006
Abstract Background For patients with cystic fibrosis (CF)-related partial respiratory insufficiency and reduced arterial oxygen tension at ground level, the mild hypobaric environment on commercial jet aircraft poses the risk of severe hypoxemia. Thus, physicians should be able to estimate the extent of in-flight hypoxia. Objectives To derive tools for estimating the expected drop in arterial oxygen partial pressure (paO 2 ) and oxygen saturation (saO 2 ) in young adult CF patients with mild to moderate airway obstruction during exposure to the hypobaric conditions aboard commercial aircraft and to test the predictive power of a hypobaric chamber simulation. Methods Blood gases of 12 CF pa…
Technical standards in allergen exposure chambers worldwide - an EAACI Task Force Report
2021
Allergen exposure chambers (AECs) can be used for controlled exposure to allergenic and non-allergenic airborne particles in an enclosed environment, in order to (i) characterize the pathological features of respiratory diseases and (ii) contribute to and accelerate the clinical development of pharmacological treatments and allergen immunotherapy for allergic disease of the respiratory tract (such as allergic rhinitis, allergic rhinoconjunctivitis, and allergic asthma). In the guidelines of the European Medicines Agency for the clinical development of products for allergen immunotherapy (AIT), the role of AECs in determining primary endpoints in dose-finding Phase II trials is emphasized. A…
Tissue gradients of energy metabolites mirror oxygen tension gradients in a rat mammary carcinoma model
2001
Abstract Purpose: It has been shown that oxygen gradients exist in R3230AC tumors grown in window chambers. The fascial surface is better oxygenated than the tumor surface. The purpose of the present study was to determine whether gradients exist for energy metabolites and other end points related to oxygen transport. Methods and Materials: Imaging bioluminescence was used to measure ATP, glucose, and lactate in cryosections of R3230AC tumors. Mean vessel density and hypoxic tissue fraction were assessed using immunohistochemistry. Tumor redox ratio was assessed by redox ratio scanning. Results: Lactate content and hypoxic fraction increased, whereas ATP, glucose, redox ratio, and vessel de…
CO2 uptake of Opuntia ficus-indica (L.) Mill. whole trees and single cladodes, in relation to plant water status and cladode age
2013
Most of net photosynthesis determinations in Opuntia ficus-indica come from measurements on individual cladodes. However, they have limitations when used to scale up to whole canopy gas exchange, because a large variability of carbon assimilation may occur within the canopy, due to, among others, differences in cladode age and intercepted radiation or individual cladode response to abiotic stresses. The aim of this work was to evaluate the application of open gas exchange chambers, simultaneously applied around the whole canopy, to measure net CO 2 uptake, continuously over a 24 h period, in single Opuntia ficus-indica (L.) Mill. potted trees and in relation with their water status. Net CO2…
Nortriptyline hydrochloride skin absorption: development of a transdermal patch.
2007
The influence of propylen glycol (PG), ethanol, and oleic acid (OA) on nortriptyline hydrochloride (NTH) penetration through human epidermis was studied in vitro at two different pH values (5.5 and 7.4). The influence of lactic acid and polysorbate 80 was studied for a pH of 5.5. Permeation studies through Heat Separated Epidermis, as well as the enhancing effect of the different vehicles, showed a pH dependency. A pH value of 5.5 in the donor solution decreases significantly the permeability coefficient (Kp) with respect to a pH value of 7.4 (0.011+/-0.004 x 10(-6) versus 0.36+/-0.04 x 10(-6)cm/s). The vehicles showed an increasing enhancement effect in the order: polysorbate 80>ethanol/PG…
Ozone-induced reductions in below-ground biomass: an anatomical approach in potato
2010
[EN] Potato plants were grown in open-top chambers under three ozone concentrations during two complete cropping seasons (93 and 77 d in 2004 and 2005, respectively). The effects of chronic exposure to ozone on leaf anatomy, cell ultrastructure and crop yield were studied. Severe cell damage was found, even at ambient ozone levels, mainly affecting the spongy parenchyma and areas near the stomata. Damage to the cell wall caused loss of cell contact, and loss of turgor pressure due to tonoplast disintegration, contributed to cell collapse. Phloem sieve plates were obstructed by callose accumulation, and damaged mesophyll cells increased their starch stores. Tuber yield fell sharply (24–44%),…
High-performance liquid chromatographic determination of sumatriptan after in vitro transdermal diffusion studies.
2004
A simple, accurate, precise and rapid HPLC method with UV detection has been validated in order to determine the in vitro transdermal absorption of sumatriptan succinate. The HPLC method is a modification of that described by Nozal et al. [M.J. Nozal, J.L. Bernal, L. Toribio, M.T. Martin, F.J. Diez, J. Pharm. Biomed. Anal. 30 (2002) 285-291]. Separation was carried out on a 250 mm Kromasil C18 column at room temperature. The detector response, at 282.7 nm, was found to be linear in a concentration range between 0.145 and 145 microM. The limit of detection (LOD) was 0.019 microM and the limit of quantification (LOQ) was 0.145 microM.
Insights into the compositional evolution of crustal magmatic systems from coupled petrological-geodynamical models
2020
Funding was provided by the VAMOS Research Center, University of Mainz (Germany) and by the ERC Consolidator Grant MAGMA (project #771143). The evolution of crustal magmatic systems is incompletely understood, as most studies are limited either by their temporal or spatial resolution. Exposed plutonic rocks represent the final stage of a long-term evolution punctuated by several magmatic events with different chemistry and generated under different mechanical conditions. Although the final state can be easily described, the nature of each magmatic pulse is more difficult to retrieve. This study presents a new method to investigate the compositional evolution of plutonic systems while consid…
Design and characterization of the SiPM tracking system of NEXT-DEMO, a demonstrator prototype of the NEXT-100 experiment
2013
NEXT-100 experiment aims at searching the neutrinoless double-beta decay of the Xe-136 isotope using a TPC filled with a 100 kg of high-pressure gaseous xenon, with 90% isotopic enrichment. The experiment will take place at the Laboratorio Subterraneo de Canfranc (LSC), Spain. NEXT-100 uses electroluminescence (EL) technology for energy measurement with a resolution better than 1% FWHM. The gaseous xenon in the TPC additionally allows the tracks of the two beta particles to be recorded, which are expected to have a length of up to 30 cm at 10 bar pressure. The ability to record the topological signature of the beta beta 0 nu events provides a powerful background rejection factor for the bet…