Search results for "breath"

Multipumping Nitrite Determination in Exhaled Breath Condensate

2006

Abstract A flow system based on multicommutation is proposed for the rapid, clean, and inexpensive determination of nitrites in small volumes of breath condensates. The procedure exploits the colorimetric detection of nitrite with the Griess reagent [0.03% naphthylethylene diamine dihydrochloride (NED), 0.5% sulpfhanilamide, and 3.0% phosphoric acid] in acidic medium at 540 nm correcting the variations of the baseline with measurements at 424 nm. The flow system was designed with a set of solenoid micropumps to minimize sample and reagent consumption and waste generation. The detection limit was estimated as 3.8 ng mL−1 (99.7% confidence level) with a linear response ranging up to 500 ng mL…

Ventilation-Perfusion Ratio in Perflubron During Partial Liquid Ventilation

2010

BACKGROUND: Functional magnetic resonance imaging (fMRI) of fluorine-19 allows for the mapping of oxygen partial pressure within perfluorocarbons in the alveolar space (Pao(2)). Theoretically, fMRI-detected Pao(2) can be combined with the Fick principle approach, i.e., a mass balance of oxygen uptake by ventilation and delivery by perfusion, to quantify the ventilation-perfusion ratio (Va/Q) of a lung region: The mixed venous blood and the inspiratory oxygen fraction, which are equal for all lung regions, are measured. In addition, the local expiratory oxygen fraction and the end capillary oxygen content, both of which may differ between the lung regions, are calculated using the fMRI-detec…

Helicobacter pylori Infection in Type 1 Diabetes Children and Adolescents Using 13C Urea Breath Test

2014

There is a 10–30% prevalence of HP infection in the general pediatric population in Poland. This study aimed to determine its prevalence in T1DM children in Upper Silesia, Poland and estimate its influence on metabolic control of patients. We studied 149(82♀) children with T1DM (duration >12 months, mean HbA1c) and 298(164♀) age-matched controls. In all cases height and weight z-scores and Cole’s index were assessed. In T1DM patients additionally glycated hemoglobin A1c and T1DM duration were analyzed. Presence of HP infection was determined using 13C-isotope-labeled urea breath test (UBT) (fasting and 30min after ingestion 75 mg of 13C urea). HP infection was present in 17 (11.4%) T1DM pat…

The 13C urea breath test in the diagnosis of Helicobacter pylori infection

1999

Summary The urea breath test (UBT) is one of the most important non-invasive methods for detecting Helicobacter pylori infection. The test exploits the hydrolysis of orally administered urea by the enzyme urease, which H pylori produces in large quantities. Urea is hydrolysed to ammonia and carbon dioxide, which diVuses into the blood and is excreted by the lungs. Isotopically labelled CO2 can be detected in breath using various methods. Labelling urea with 13 C is becoming increasingly popular because this non-radioactive isotope is innocuous and can be safely used in children and women of childbearing age. Breath samples can also be sent by post or courier to remote analysis centres. The …

THE COMPETITIVE DEMANDS OF ELITE MALE RINK HOCKEY

2013

The aim of this study was to simulate the activity pattern of rink hockey by designing a specific skate test (ST) to study the energy expenditure and metabolic responses to this intermittent high-intensity exercise and extrapolate the results from the test to competition. Six rink hockey players performed, in three phases, the 20-metre multi-stage shuttle roller skate test, a tournament match and the ST. Heart rate was monitored in all three phases. Blood lactate, oxygen consumption, ventilation and respiratory exchange ratio were also recorded during the ST. Peak HR was 190.7±7.2 beats · min(-1). There were no differences in peak HR between the three tests. Mean HR was similar between the …

Wearable sensor for real-time monitoring of hydrogen peroxide in simulated breath

Effectiveness of Respiratory Hyperoxia, of Normobaric and of Hyperbaric Oxygen Atmospheres in Improving Tumor Oxygenation

1984

A restriction and an inhomogeneous distribution of diffusive and convective oxygen supply is considered the main cause for pronounced radioresistance in solid tumors (Thomlinson and Gray, 1955; Tannock, 1972). One way to alleviate this crucial problem in tumor therapy is the direct enhancement of oxygen delivery to the cancer cells. This can be performed either by the tumor host breathing pure O2 (respiratory hyperoxia, RHO) or by whole body exposure to pure O2 atmospheres at normobaric or hyperbaric pressures (normobaric oxygenation NMO, and hyperbaric oxygenation, HPO, respectively). Numerous investigations have been undertaken both in animals and in man using RHO, NMO, or HPO as an adjuv…

Arterial O2-Partial Pressure at Positve Endexpiratory Pressure in Hyperoxia for Verification of Patent Foramen Ovale?

1990

As a rule, during anaesthesia a time dependent increase in pulmonary shunting occurs even in states of normal lung function. Therefore positive end-expiratory pressure ventilation (PEEP) is often used to decrease intrapulmonary right/left shunting (RL shunt) and thus to increase arterial O2 partial pressure (paO2) without increasing the inspiratory oxygen fraction.

IS HYPOXIA-INDUCIBLE FACTOR (HIF-1) ALPHA INVOLVED IN TARAVANA SYNDROME?

2021

Breath holding diving (BH) is a discipline practiced by an increasing number of people. BH-divers are exposed to extreme environmental conditions such as: increased hyperbaric pressure and low temperature that caused change in arterial blood gases (1-2) and induced an human diving response which includes bradycardia, reduced cardiac output, increased arterial blood pressure and peripheral vasoconstriction (3). Some of these adaptations are still not fully understood, so we decided to investigate some biomarkers that should be involved in this disorders starting to analyse Hypoxia-inducible factor 1 alpha (HIF-1α). We enrolled in our study 31 healthy free divers from different part of Sicily…

L'identité de Fay en théorie des systèmes intégrables

2011

Fay's identity on Riemann surfaces is a powerful tool in the context of algebro-geometric solutions to integrable equations. This relation generalizes a well-known identity for the cross-ratio function in the complex plane. It allows to establish relations between theta functions and their derivatives. This offers a complementary approach to algebro-geometric solutions of integrable equations with certain advantages with respect to the use of Baker-Akhiezer functions. It has been successfully applied by Mumford et al. to the Korteweg-de Vries, Kadomtsev-Petviashvili and sine-Gordon equations. Following this approach, we construct algebro-geometric solutions to the Camassa-Holm and Dym type …