Search results for "RESPIRATION"
showing 10 items of 538 documents
Carbohydrate ingestion does not influence the change in energy cost during a 2-h run in well-trained triathletes
1999
The aim of this study was to examine whether the increase in the energy cost of running (C(r)), previously reported to occur at the end of a prolonged run, could be influenced by the ingestion of either an artificially sweetened placebo (Pl) or a 5.5% carbohydrate (CHO) solution. Ten well-trained triathletes completed three testing sessions within a 3-week period. The aim of the first session was to determine maximal oxygen uptake (VO(2)(max)) and the velocity associated with ventilatory threshold (nu(VT)). The second and the third sessions were composed of two submaximal treadmill runs (20 min long, 0% grade, performed at nu(VT)), before and after an 80-min overground run, also conducted a…
Kyphoscoliosis ventilatory insufficiency: noninvasive management outcomes.
2000
Objective: To determine the effects on symptoms, pulmonary function, sleep, and other clinical variables of treating kyphoscoliosis-associated chronic alveolar hypoventilation with nocturnal nasal ventilation. Design: Sixteen patients with kyphoscoliosis were treated with nocturnal nasal ventilation delivered by volume-cycled (seven patients) and pressure-cycled (nine patients) ventilators. Dyspnea, morning headaches, fatigue, hypersomnolence, and perceived sleep quality were assessed. Results: All pretreatment symptoms improved significantly with nasal ventilation. Likewise, Pao 2 (mm Hg), Pao 2 /Fio 2 , Paco 2 (mm Hg), pH, and forced vital capacity (in milliliters and as a percentage of p…
Anaerobic threshold, skeletal muscle enzymes and fiber composition in young female cross-country skiers.
1980
Anaerobic threshold (AT) and maximum oxygen uptake (max VO2) were determined in 15 young female cross-country skiers, aged 15--20 years, during incremental bycycle ergometer exercise. Succinate dehydrogenase (SDH), malate dehydrogenase (MDH), citrate synthase (CS) and lactate dehydrogenase (LDH) were analyzed biochemically and percentage of slow twitch fibres (%ST fibres, myosin adenosine triphosphatase staining) histochemically in muscle samples obtained from m. vastus lateralis. Max VO2 correlated significantly with anaerobic threshold in ml x kg-1 x min-1 (mlAT) but when AT was expressed in percent of max VO2 (%AT) the correlation was insignificant. Significant correlations were found be…
Mechanical efficiency in athletes during running.
2007
The purpose of this study was to compare the external mechanical efficiency (ME) between power-trained athletes (n = 5) and endurance-trained athletes (n = 5). The relationships between biomechanical variables and metabolic cost were also investigated. The subjects ran at 3 different speeds (2.50 m.s-1, 3.25 m.s-1 and 4.00 m.s-1) both on the treadmill and on the track. The external work of the subjects was determined by a kinematic arm, and energy expenditure was determined by measuring oxygen consumption and respiratory exchange ratio. Biomechanical parameters included ground reaction forces, angular displacements of the knee and ankle joints and electromyography (EMG) of the selected musc…
Can the Multidimensional Prognostic Index Improve the Identification of Older Hospitalized Patients with COVID-19 Likely to Benefit from Mechanical V…
2022
Objective: Data on prognostic tools for indicating mechanical ventilation in older people with COVID-19 are still limited. The aim of this research was to evaluate if the Multidimensional Prognostic Index (MPI), based on the Comprehensive Geriatric Assessment (CGA), may help physicians in identifying older hospitalized patients affected by COVID-19 who might benefit from mechanical ventilation.Design: Longitudinal, multicenter study.Settings and Participants: 502 older people hospitalized for COVID-19 in 10 European hospitals.Methods: MPI was calculated using 8 different domains typical of the CGA. A propensity score, Cox's regression analysis was used for assessing the impact of mechanical…
Integrated care pathways for airway diseases (AIRWAYS-ICPs)
2014
International audience; The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patien…
GABA, receptor mediated fast synaptic inhibition in the rabbit brain-stem respiratory system
1991
The involvement of GABA mediated neurotransmission in the central control of respiration was investigated by administration of the specific GABAA receptor agonist muscimol and the specific GABAA receptor antagonist biculline into the fourth cerebral ventricle of the rabbit. Cycle-triggered averaging of the phrenic nerve activity (PNA) was used to quantify drug-induced changes of the central respiratory pattern. Muscimol reduced the peak amplitude of PNA and increased the duration of the respiratory phases. High amounts of muscimol led to a long-lasting but reversible central apnea. Bicuculline very effectively blocked the effects of externally applied muscimol. Blockade of intrinsically act…
Earth system data cubes unravel global multivariate dynamics
2020
Understanding Earth system dynamics in light of ongoing human intervention and dependency remains a major scientific challenge. The unprecedented availability of data streams describing different facets of the Earth now offers fundamentally new avenues to address this quest. However, several practical hurdles, especially the lack of data interoperability, limit the joint potential of these data streams. Today, many initiatives within and beyond the Earth system sciences are exploring new approaches to overcome these hurdles and meet the growing interdisciplinary need for data-intensive research; using data cubes is one promising avenue. Here, we introduce the concept of Earth system data cu…
Requirement for the Proton-Pumping NADH Dehydrogenase I of Escherichia Coli in Respiration of NADH to Fumarate and Its Bioenergetic Implications
1997
In Escherichia coli the expression of the nuo genes encoding the proton pumping NADH dehydrogenase I is stimulated by the presence of fumarate during anaerobic respiration. The regulatory sites required for the induction by fumarate, nitrate and O2 are located at positions around –309, –277, and downstream of –231 bp, respectively, relative to the transcriptional-start site. The fumarate regulator has to be different from the O2 and nitrate regulators ArcA and NarL. For growth by fumarate respiration, the presence of NADH dehydrogenase I was essential, in contrast to aerobic or nitrate respiration which used preferentially NADH dehydrogenase II. The electron transport from NADH to fumarate …
Transport of C(4)-dicarboxylates in Wolinella succinogenes.
2000
ABSTRACT C 4 -dicarboxylate transport is a prerequisite for anaerobic respiration with fumarate in Wolinella succinogenes , since the substrate site of fumarate reductase is oriented towards the cytoplasmic side of the membrane. W. succinogenes was found to transport C 4 -dicarboxylates (fumarate, succinate, malate, and aspartate) across the cytoplasmic membrane by antiport and uniport mechanisms. The electrogenic uniport resulted in dicarboxylate accumulation driven by anaerobic respiration. The molar ratio of internal to external dicarboxylate concentration was up to 10 3 . The dicarboxylate antiport was either electrogenic or electroneutral. The electroneutral antiport required the prese…