1,720,970 research outputs found
Frequency of disorders of cardiac rhythm during respiratory insufficiency and their relation to the blood gas analytical picture
No full textCorrelazione tra incidenza di aritmie cardiache e dati emogasometrici in soggetti affetti da insufficienza respiratoria
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Effects of an inhaled bronchodilator on gas distribution and over-all ventilatory efficiency in patients with chronic obstructive pulmonary disease
No full textThe effects of an inhaled bronchodilator on the distribution of inspired gas and over-all efficiency of ventilation were studied by the nitrogen washout technic in 16 patients with chronic obstructive pulmonary disease; three normal subjects and two patients with asymptomatic asthma (and normal spirometric values) were also studied. In normal and asthmatic subjects and in patients with chronic obstructive pulmonary disease and mild to moderate functional impairment, the nitrogen clearance did not vary significantly or showed changes suggesting less uniform gas distribution and reduced ventilatory efficiency. In most patients with advanced chronic obstructive pulmonary disease, the bronchodilator caused changes suggesting more uniform distribution of inspired gas and increased efficiency of ventilation. Multiple regression analysis showed that the behavior of the nitrogen clearance after treatment was also related to the response of the anatomic dead space. The effects of the bronchodilator varied with time. The results are consistent with the assumption that the changes in nitrogen clearance after bronchodilator therapy reflect the concourse of multiple factors, which may be expected to have favorable or unfavorable effects on the distribution of inspired gas and the efficiency of ventilation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Informative value of simple multibreath nitrogen washout measurements for clinical and research purposes
No full textSome simple multibreath nitrogen washout indexes quantifying inspired gas distribution and ventilatory efficiency were obtained in a group of patients with mild to advanced chronic obstructive pulmonary disease (COPD) and studied in their relationships with routine pulmonary function tests. The indexes (lung clearance index (LCI), mixing ratio (MR) and data obtained by graphic analysis of the washout curve) were correlated with spirometric, pulmonary mechanics and arterial blood gas measurements, but only 8-38% of the interindividual variation in these indexes was explained by the above routine tests. An additional 5-13% of the variation was explained by the washout tidal volume (VT); this finding may reflect changes in gas distribution with VT and/or the influence of the dead space on ventilatory efficiency. Our data indicate that, in patients with COPD, nitrogen washout indexes tend to change in parallel with routine pulmonary function tests, reflecting the severity of the disease; these indexes also contain specific information (in addition to that provided by routine physiologic tests), presumably related to the distribution and efficiency of ventilation. Nitrogen washout measurements may thus represent a helpful adjunct to routine pulmonary function testing; LCI and MR appear to be particularly convenient for practical purposes because of their simplicity, and an informative content comparable with that of more complex indexe
Effects of bronchodilators on the behavior of pulmonary resistance and dynamic compliance as functions of respiratory frequency
No full textThe effects of bronchodilator treatment (intravenous atropine or inhaled metaproterenol) on the behavior of pulmonary resistance (RL) and dynamic compliance (Cdyn) as functions of respiratory frequency were studied in patients with chronic obstructive pulmonary disease and in apparently normal smokers. No systematic changes in the frequency-dependent behavior of RL and Cdyn were observed after bronchodilator treatment; the degree of frequency dependence increased in some subjects, and decreased or remained unchanged in others. The present results suggest that the effects of bronchodilators on the relationships between lung mechanical properties and respiratory frequency are not based on a single mechanism, but probably reflect the interaction of multiple factors possibly associated with the bronchodilator treatmen
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