Results 41 to 50 of about 10,602 (234)

Confined spaces in space: Cerebral implications of chronic elevations of inspired carbon dioxide and implications for long‐duration space travel

Experimental Physiology, EarlyView.
Abstract Cerebrovascular regulation is critically dependent upon the arterial partial pressure of carbon dioxide (PaCO2${P_{{\mathrm{aC}}{{\mathrm{O}}_{\mathrm{2}}}}}$), owing to its effect on cerebral blood flow, tissue PCO2${P_{{\mathrm{C}}{{\mathrm{O}}_{\mathrm{2}}}}}$, tissue proton concentration, cerebral metabolism and cognitive and neuronal ...
Jay M. J. R. Carr, Philip N. Ainslie, Trevor Day   +2 more
wiley   +1 more source

Regional changes in cerebral blood flow between the upright and supine posture and over 3 days of bed rest

Experimental Physiology, EarlyView.
Abstract A reduction in cerebral blood flow (CBF) has been observed during spaceflight and bed rest. We aimed to examine the magnitude and regional heterogeneity of the decrease in CBF during bed rest compared to posture changes on Earth. Seventeen participants (age, 29 ± 9 years, 7 females) were studied in the upright and supine posture and over 3 ...
Carmen Possnig, Kyohei Marume, Gautam Babu, Sylvan L. J. E. Janssen, Christopher M. Hearon Jr, Katrin A. Dias, Satyam Sarma, Justin S. Lawley, Benjamin D. Levine   +8 more
wiley   +1 more source

Lung function and stress echocardiography in pulmonary arterial hypertension: a cross-sectional study

São Paulo Medical Journal, 2021
BACKGROUND: The mechanism of exercise limitation in idiopathic pulmonary arterial hypertension (IPAH) is not fully understood. The role of hemodynamic alterations is well recognized, but mechanical, ventilatory and gasometric factors may also contribute ...
Guilherme Casagrande de Almeida, Mônica Corso Pereira, Marcos Mello Moreira, José Roberto Matos Souza, Ilma Aparecida Paschoal   +4 more
doaj   +1 more source

Assessment of maximum inspiratory pressure: Prior submaximal respiratory muscle activity (‘warm-up’) enhances maximum inspiratory activity and attenuates the learning effect of repeated measurement [PDF]

, 2001
The official published version can be obtained from the link belowBackground: The variability of maximal inspiratory pressure (PImax) in response to repeated measurement affects its reliability; published studies have used between three and twenty PImax ...
Jones, DA, McConnell, AK, Volianitis, S
core   +1 more source

Linking dynamic cerebral autoregulation and inhibitory executive function: Role of modifiable behaviours

Experimental Physiology, EarlyView.
Abstract Dynamic cerebral autoregulation (dCA) stabilises cerebral blood flow (CBF) against rapid fluctuations in perfusion pressure and may serve as a key physiological mediator of cognitive function. Inhibitory executive function, a core domain essential for goal‐directed behaviour, is influenced by modifiable lifestyle factors such as physical ...
Hayato Tsukamoto, Damian M. Bailey
wiley   +1 more source

Hypercapnia does not shorten emergence time from propofol anesthesia: a pilot randomized clinical study [PDF]

Korean Journal of Anesthesiology, 2018
Background The elimination of anesthetic agents is a decisive factor in the emergence from general anesthesia. In this pilot study, we hypothesized that hypercapnia would decrease the emergence time from propofol anesthesia by increasing cardiac output ...
Ki-hyug Kwon, Hansu Bae, Hyun Gu Kang, Junyong In   +3 more
doaj   +1 more source

A brief review of self-asphyxial risk-taking behaviour in adolescents [PDF]

, 2015
Adolescence is often viewed as a time for experimentation and risk-taking behaviour. For instance, when I was a teenager, my friends and I used to occasionally play a game that we called ‘Headrush’ where we would have our breathing temporarily stopped by
Griffiths, MD
core  

Modulation of cerebral blood flow and cognition by hyperthermia and hypoxia: An electroencephalographic event‐related potentials perspective

Experimental Physiology, EarlyView.
Abstract Cerebral blood flow (CBF) is essential for sustaining neuronal metabolism and cognitive performance; however, the precise relationship between perfusion and cognition remains unclear. Although ageing and disease are associated with progressive declines in CBF and cognitive impairment, the acute effects of altered CBF under environmental ...
Hiroki Nakata, Shigehiko Ogoh, Manabu Shibasaki   +2 more
wiley   +1 more source

Time‐course analysis of cerebral circulation and cardiorespiratory responses to acute central blood volume reduction in healthy young males

Experimental Physiology, EarlyView.
Abstract Central blood volume (CBV) reduction challenges circulatory and respiratory homeostasis, particularly during the initial compensatory phase (0–2 min), when rapid physiological adaptations occur. In this study, we examined dynamic cardiorespiratory responses to CBV reduction using lower‐body negative pressure (LBNP) in 11 healthy young males ...
Marina Feeley, Tomoki Watada, Go Ito, Ai Shimada, Toru Sawai, Hideomi Nakata, Shingo Otsuki, Tadayoshi Miyamoto   +7 more
wiley   +1 more source

A novel alveolar Krebs cycle-triggered CO2 sensing mechanism regulates regional pulmonary ventilation. [PDF]

, 2011
Pulmonary perfusion disorders provoke atelectasis in order to minimize ventilation/perfusion mismatch. However, the underlying mechanisms remain unknown.
Alwin Goetz, Kai Heckel, Leoni Schulte-Uentrop, Martina Kiefmann, Oliver Tritt, Paula Keller, Rainer Kiefmann, Sascha Tank   +7 more
core   +1 more source