Sökning: "G Hedenstierna"

Hittade 5 avhandlingar innehållade orden G Hedenstierna.

1. 1. Ventilation distribution in the lung periphery measured by inert gas washout : influence of increased gravity, anti-G suit pressure, body posture, and breathing pattern

   Författare :Mikael Grönkvist; Göran Hedenstierna; Linköpings universitet; []
   Nyckelord :acceleration; anti-G suit; body posture; cdi; dcdi; human centrifuge; He; hypergravuty; lung; multiple-breath washout; single-breath washout; SF 6; standing; supune; trapped gas; ventilation distribution; MEDICINE; MEDICIN;

   Sammanfattning : The lung is highly sensitive to forces of gravity and acceleration, and to surrounding pressures. This thesis aimed to assess the effects on ventilation distribution in peripheral lung units when changing the direction or magnitude of the gravitational vector and when compressing the lower body half with an anti-G suit (AGS). LÄS MER

3. 2. PET and the Multitracer Concept: An Approach to Neuroimaging Pathology

   Författare :Henry Engler; Bengt Långström; Göran Hedenstierna; Juha Rinne; Uppsala universitet; []
   Nyckelord :Neurosciences; PET Positron Emission Tomography ; multitracer; neuroimaging pathology; astrocytes; microglia; neurodegeneration; amyloid; AD; CJD; PD; Neurovetenskap;

   Sammanfattning : Patients suffering from different forms of neurodegenerative diseases, such as: Creutzfeldt Jacob Disease (CJD), Alzheimer disease (AD), mild cognitive impairment (MCI), frontotemporal dementia and Parkinson’s disease (PD) were examined with Positron Emission Tomography (PET) and the combination of different radiotracers: 15O-water, N-[11C-methyl]-L-deuterodeprenyl (DED), [18F] 2-fluorodeoxyglucose: (FDG), N-methyl-[11C]2-(4-methylaminophenyl)-6-hydroxybenzothiazole (PIB) and L-[11C]-3,4-dihydroxiphenyl-alanine (DOPA). The radiotracers and the combinations of different radiotracers were selected with the intention to detect, in the brain, patterns of neuronal dysfunction, astrocytosis, axon degeneration or protein aggregation (amyloid), in the brain which are pathognomonic for specific diseases and may contribute to improve clinical differential diagnoses. LÄS MER

4. 3. Improved breath alcohol analysis with use of carbon dioxide as the tracer gas

   Författare :Annika Kaisdotter Andersson; Mikael Ekström; Bertil Hök; Göran Hedenstierna; Johannes Lagois; Mälardalens högskola; []
   Nyckelord :elektronik; Electronics;

   Sammanfattning : State-of-the-art breath analysers require a prolonged expiration into a mouthpiece to obtain the accuracy required for evidential testing and screening of the alcohol concentration. This requirement is unsuitable for breath analysers used as alcolock owing to their frequent use and the fact that the majority of users are sober drivers; as well as for breath testing in uncooperative persons. LÄS MER

5. 4. Ventilation and Lung Volume During Sleep and in Obstructive Sleep Apnea

   Författare :Jonas Appelberg; Göran Hedenstierna; Christer Janson; Karl Franklin; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Physiology; Sleep; Ventilation; Sleep apnea syndromes; Snoring; Lung volume; Respiration; Computed tomography; Ventilatory response; Ventilation-perfusion; Airway closure; Fysiologi; Physiology; Fysiologi; klinisk fysiologi; Clinical Physiology;

   Sammanfattning : Obstructive sleep apnea (OSA) appears to affect up to 5% of the population. The extent to what pulmonary function awake and during sleep relates to obstructive breathing and hypoxemia during sleep in these patients is unclear. LÄS MER

7. 5. The Effect of CO2-Pneumoperitoneum on Ventilation Perfusion Distribution of the Lung

   Författare :Christof Strang; Göran Hedenstierna; Suzanne Odeberg-Wernerman; Uppsala universitet; []
   Nyckelord :lung; atelectasis; computed tomography; multiple inert gas elimination technique; model; pig; Pa–ECO2 ratio; surgery; laparoscopy; lung; blood flow; single photon emission computed tomography; ventilation perfusion distribution; gas exchange; hypoxic pulmonary vasoconstriction; MEDICINE; MEDICIN;

   Sammanfattning : Laparoscopic operations are a common and popular way for abdominal procedures. They are usually performed by insufflation of carbon dioxide (CO2) into the abdominal cavity. However, insufflation of CO2 may interfere with cardiac and circulatory as well as respiratory functions. The CO2-pneumoperitoneum (PP) may cause hypercarbia and acidosis. LÄS MER