Although pulmonary function testing plays a key role in the diagnosis and management of chronic pulmonary conditions in children under 6 years of age, objective physiologic assessment is limited in ...the clinical care of infants and children less than 6 years old, due to the challenges of measuring lung function in this age range. Ongoing research in lung function testing in infants, toddlers, and preschoolers has resulted in techniques that show promise as safe, feasible, and potentially clinically useful tests. Official American Thoracic Society workshops were convened in 2009 and 2010 to review six lung function tests based on a comprehensive review of the literature (infant raised-volume rapid thoracic compression and plethysmography, preschool spirometry, specific airway resistance, forced oscillation, the interrupter technique, and multiple-breath washout). In these proceedings, the current state of the art for each of these tests is reviewed as it applies to the clinical management of infants and children under 6 years of age with cystic fibrosis, bronchopulmonary dysplasia, and recurrent wheeze, using a standardized format that allows easy comparison between the measures. Although insufficient evidence exists to recommend incorporation of these tests into the routine diagnostic evaluation and clinical monitoring of infants and young children with cystic fibrosis, bronchopulmonary dysplasia, or recurrent wheeze, they may be valuable tools with which to address specific concerns, such as ongoing symptoms or monitoring response to treatment, and as outcome measures in clinical research studies.
The electric-field and wave experiment (EFW) on Cluster is designed to measure the electric-field and density fluctuations with sampling rates up to 36000 samples s^sup -1^. Langmuir probe sweeps can ...also be made to determine the electron density and temperature. The instrument has several important capabilities. These include (1) measurements of quasi-static electric fields of amplitudes up to 700 mV m^sup -1^ with high amplitude and time resolution, (2) measurements over short periods of time of up to five simualtaneous waveforms (two electric signals and three magnetic signals from the seach coil magnetometer sensors) of a bandwidth of 4 kHz with high time resolution, (3) measurements of density fluctuations in four points with high time resolution. Among the more interesting scientific objectives of the experiment are studies of nonlinear wave phenomena that result in acceleration of plasma as well as large- and small-scale interferometric measurements. By using four spacecraft for large-scale differential measurements and several Langmuir probes on one spacecraft for small-scale interferometry, it will be possible to study motion and shape of plasma structures on a wide range of spatial and temporal scales. This paper describes the primary scientific objectives of the EFW experiment and the technical capabilities of the instrument.PUBLICATION ABSTRACT
Airway permeability PERSSON, C. G. A.; ANDERSSON, M.; GREIFF, L. ...
Clinical and experimental allergy,
September 1995, Letnik:
25, Številka:
9
Journal Article
Recenzirano
Odprti dostop
The upper airway mucosa is a main site for deposition of potentially noxious environmental molecules. As one might expect this mucosa is also well equipped to protect both itself and the rest of the ...body from harmful influences of foreign material. The regulation of the permeability of nasal and tracheobronchial mucosa is such that blood plasma may enter the airway lumen without making it any easier for foreign surface molecules to penetrate into the airway tissue. Thus, circulating humoral defence systems would be allowed to neutralize offending stimuli on the surface of a mucosa that maintains its absorption barrier uncompromised. Mechanisms involved in the direction-selective paracellular flux of solutes across the intact airway mucosa are the basis for the first part of this overview. If the inhalational insult or disease process are severe enough for epithelial lining cells to be shed, even this may occur without a deleterious loss of barrier function. If basal cells remain they may promptly flatten out and establish cell to cell contacts. If both columnar and basal cells are removed a provisional plasma-derived gel immediately covers the denuded basement membrane. Furthermore, beneath the gel restitution of a new epithelium proceeds speedily. These novel aspects on barrier restitution after shedding are the basis for the second part of the present overview. Most of the data that will be discussed have been generated in the human nose and the guinea-pig trachea. The focus is primarily on in vivo observations. Explanatory or expanding ex vivo findings have thus been included when the functional in vivo aspects have been first assessed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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