نتایج جستجو برای: altitude

تعداد نتایج: 21619  

Journal: :The European respiratory journal 2007
A M Luks E R Swenson

The pathophysiology of high-altitude illnesses has been well studied in normal individuals, but little is known about the risks of high-altitude travel in patients with pre-existing lung disease. Although it would seem self-evident that any patient with lung disease might not do well at high altitude, the type and severity of disease will determine the likelihood of difficulty in a high-altitud...

Journal: :Journal of applied physiology 2007
Philip N Ainslie Katie Burgess Prajan Subedi Keith R Burgess

We tested the hypothesis that, following exposure to high altitude, cerebrovascular reactivity to CO2 and cerebral autoregulation would be attenuated. Such alterations may predispose to central sleep apnea at high altitude by promoting changes in brain PCO2 and thus breathing stability. We measured middle cerebral artery blood flow velocity (MCAv; transcranial Doppler ultrasound) and arterial b...

The focus of the present study was to investigate the chemical composition of essential oil of Salvia hydrangea DC. ex Benth. growing wild in Kiasar-Hezarjrib, Iran. In addition, effects of altitude and some soil properties on the essential oil quality and quantity of S. hydrangea was identified. The samples collected from two altitudes (1100 and 2000 m) in blossoming period, were analyzed by h...

Journal: :Journal of applied physiology 1996
M N Sawka A J Young P B Rock T P Lyons R Boushel B J Freund S R Muza A Cymerman R C Dennis K B Pandolf C R Valeri

We studied sea-level residents during 13 days of altitude acclimatization to determine 1) altitude acclimatization effects on erythrocyte volume and plasma volume, 2) if exogenous erythrocyte volume expansion alters subsequent erythrocyte volume and plasma volume adaptations, 3) if an increased blood oxygen content alters erythropoietin responses during altitude acclimatization, and 4) mechanis...

2014
Tae-Suk Kim Douglas G Kondo Namkug Kim Perry F Renshaw

OBJECTIVE Methamphetamine (MA) use rates in the United States (US) have consistently demonstrated geographical variation and have been higher in the West and Midwest. This uneven pattern of use could be explained by regional differences in MA manufacturing and distribution, but may also result from differences in altitude. The hypobaric hypoxia found at high altitude alters neurotransmitter syn...

افلاطون مهرآئین, , رضا علیزاده, , علی موافق, , محمدرضا آزادی, , مسعود یونسیان, , وحید ضیائی, ,

Background: Both hypoxia and hypocapnia can cause broncho-constriction in humans, and this could have a bearing on performance at high altitude. The objective of this study was to examine how pulmonary ventilatory function during high-altitude trekking.Methods: This study was a before and after study on spirometric parameters at Base line (1150 m above sea level), and after ascending at 4150 m ...

Hatamnia, Ali Asghar, Mohammadkhani, Nayer, Naji, Hamid Reza, Parvizi, Ali,

Increasing the altitude causes extensive changes in the environmental conditions. Three species of Quercus brantii Lindl., Pistacia atlantica Desf. and Crataegus pontica C. Koch. are the dominant species in the forests of Ilam province. The sampling was done from Qalajeh Mountain at the altitude from 1300-2000 m a.s.l. The effect of altitude on photosynthesis, photosynthetic pigments and some b...

2011
Andrew T. Taylor

High-altitude illnesses encompass the pulmonary and cerebral syndromes that occur in non-acclimatized individuals after rapid ascent to high altitude. The most common syndrome is acute mountain sickness (AMS) which usually begins within a few hours of ascent and typically consists of headache variably accompanied by loss of appetite, nausea, vomiting, disturbed sleep, fatigue, and dizziness. Wi...

Journal: :Respiratory physiology & neurobiology 2006
Graham R Scott William K Milsom

The ability of some bird species to fly at extreme altitude has fascinated comparative respiratory physiologists for decades, yet there is still no consensus about what adaptations enable high altitude flight. Using a theoretical model of O(2) transport, we performed a sensitivity analysis of the factors that might limit exercise performance in birds. We found that the influence of individual p...

2016
Sheng Li Hu Wei Xiong Zhi Qiang Dai Heng Li Zhao Hua Feng Nanette H Bishopric

Hypersensitive C-reaction protein (hsCRP) may be a risk factor for cognitive impairment resulting from Alzheimer's disease (AD), stroke, and vascular dementia. This study explored the correlation of peripheral blood hsCRP level with cognitive decline due to high altitude exposure. The study was conducted on 100 male military participants who had never been to high altitude. Cerebral oxygen satu...

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