Search results for "Missions"
showing 10 items of 380 documents
Transient evoked otoacoustic emissions in vestibular neuritis.
2007
Objectives: Partial or total degeneration of the vestibulocochlear anastomosis at its takeoff from the saccular ganglion and regenerating efferent neural buds under the cochlear outer hair cells (OHCs) have been found in the temporal bones of human patients with a history of vestibular neuritis (VN). We sought to test whether VN has any functional impact on the ipsilateral OHCs by means of transient evoked otoacoustic emission (TEOAE) testing. Methods: We retrospectively analyzed prospectively collected TEOAE data of 28 patients (19 female, 9 male; age range, 21 to 60 years; median age, 42.5 years). The pure tone air conduction hearing thresholds at each standard audiometric frequency (0.12…
Evoked otoacoustic emissions and pure tone threshold audiometry in patients receiving cisplatinum therapy.
1993
Eight children and young adults with cancer were evaluated serially using pure tone audiometry as well as registration of click-evoked otoacoustic emissions (EOAE) 1 day prior to therapy as well as after various numbers of doses of cisplatinum. A reduction of EOAE-amplitudes following cisplatinum therapy was observed in all patients. This reduction tended to recover after the end of cisplatinum administration. Since EOAE are believed to result from cochlear bio-mechanical processes, the reduced emissions are interpreted as signs of cochlear dysfunction. We conclude, that EOAE testing may be a simple, non-invasive method that may detect early, transient functional impairment of hearing due t…
DPOAE‐Grams in Patients with Acute Tonal Tinnitus
2005
To investigate cochlear outer hair cell function in patients with acute tonal tinnitus and normal or near-normal hearing threshold.Prospective controlled study in an academic tertiary health center. Distortion products of otoacoustic emissions (DPOAE)-grams of 32 ears with acute tonal tinnitus and normal hearing or minimal hearing loss were compared with those of 17 healthy nontinnitus ears.Tinnitus ears exhibited relatively increased amplitudes of DPOAE at high frequencies (4-6.3 kHz) when compared with the group of healthy ears and relatively decreased DPOAE amplitudes at middle frequencies (1650-2400 Hz). Statistically significant ( P0.01) increased mean values of DPOAE amplitudes were o…
Clinical observations and risk factors for tinnitus in a Sicilian cohort.
2014
The aims of this study were to determine the distribution of risk factors associated with tinnitus analysing their role in the development of tinnitus and the effects of their interaction; to evidence the importance of a suitable and adequate clinical and audiologic assessment to avoid those modifiable risk factors responsible for cochlear dysfunction and tinnitus onset. 46 subjects with tinnitus and 74 controls were studied according to: age, sex, Body Mass Index (BMI), neck circumference, tobacco smoking, feeling fatigue or headache, self reporting snoring, hypertension, diabetes, coronary heart disease, and/or hyperlipidemia, and laboratory finding as lipid profile and levels of reactive…
Social, Occupational, and Cultural Adaptation During a 12-Month Wintering in Antarctica.
2016
Background and methods Life in isolated and confined environments (ICEs) is subject to important constraints which can generate psychosociologically impaired outcomes. This study investigated psychological, social, occupational, and cultural variables which are among the most important determinants in adaptation to a one-year wintering in Antarctica for 13 international subjects. Results Our findings confirm and give further insight into the role of social (Cohesiveness, Social Support) and occupational (Implementation/Preparedness, Counterproductive Activity, Decision Latitude, and Psychological Job Demands) dimensions of adaptation to ICEs. Relationships between various social and occupat…
Revealing deterministic structures in click-evoked otoacoustic emissions.
2000
Click-evoked otoacoustic emissions (CEOAEs) were studied by means of recurrence quantification analysis (RQA) and were found to be endowed with a relevant amount of deterministic structuring. Such a structure showed highly significant correlation with the clinical evaluation of the signal over a data set including 56 signals. Moreover, 1) one of the RQA variables, Trend, was very sensitive to phase transitions in the dynamical regime of CEOAEs, and 2) appropriate use of principal component analysis proved able to isolate the individual character of the studied signals. These results are of general interest for the study of auditory signal transduction and generation mechanisms.
Nucleation particles in diesel exhaust: composition inferred from in situ mass spectrometric analysis.
2005
Mass spectrometric measurements of size and composition of diesel exhaust particles have been performed under various conditions: chassis dynamometer tests, field measurements near a German motorway, and individual car chasing. Nucleation particles consisting of volatile sulfate and organic material could be detected both at the chassis dynamometer test facility and during individual car chasing. We found evidence that if nucleation occurs, sulfuric acid/water is the nucleating agent. Low-volatile organics species condense only on the preexisting sulfuric acid/water clusters. Nucleation was found to depend strongly on various parameters such as exhaust dilution conditions, fuel sulfur conte…
Possible markers of traffic-related emissions
2007
Looking for robust indicators of motor vehicle emissions it has been found that brake wear and linings are significant contributors of Cu, Mo and Sb to air particulate matter. These trace elements, whose mutual ratios in airborne particulate matter resulted quite different from those in crustal material, appear to be available fingerprinting tools to identify the contribution of on-road vehicles to traffic-derived particulate matter. In this study, the results of analytical determinations of Cu, Mo and Sb on PM(10), PM(2.5), vegetation and brake dust samples, together with gas (CO, NOx) concentrations, are discussed. Highly significant correlations among Cu, Sb and Mo were observed in parti…
Case study: inorganic pollutants associated with particulate matter from an area near a petrochemical plant.
2004
The area of Gela (Sicily, Italy) contains one of the largest petroleum refineries in Europe and also has several oil fields both on land and offshore. This paper discusses how the oil refinery and traffic-related air pollution affect the chemical composition of airborne particulate matter over the town of Gela, using pine needles and urban road dust as the means of survey. Forty-one samples of pine needles from Pinus halepensis (Mill.) and two composite samples of roadway dust, each subdivided into six size fractions, were analyzed for major and trace elements. Information on the natural or anthropogenic origin of the observed heavy metals was deduced from factor analysis and element distri…
Brown Carbon Aerosol in Urban Xi'an, Northwest China: The Composition and Light Absorption Properties.
2018
Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi'an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) w…