1,720,977 research outputs found
The role of an internal nasal dilator in athletes
Full text linkThe nasal valve area has the minimal cross-sectional area of the upper airways. Nasal dilators have been found able to improve sport performance in athletes. The aim of this study was to investigate whether the use an internal nasal dilator may be able to affect respiratory pattern in a group of athletes. The use of internal nasal dilator induced a significant reduction of fatigue perception (p=0.000) and was optimally accepted. In conclusion, the present study demonstrates that Nas-air® is an internal nasal dilator able to reduce the fatigue perception and is preferred to external nasal dilator. © Mattioli 1885
Six consecutive days reproducibility of exhaled volatile organic compounds analysis by e-nose
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Influence of circadian rhythm on exhaled breath profiling by electronic nose
No full textElectronic noses (e-noses) are a cheap and easy method for exhaled Volatile Organic Compound (VOC)-analysis which has shown its potential in several diseases. Before obtaining a full validation of these instruments in clinical settings, a number of methodological issues still have to be established. We aimed to investigate a potential influence of circadian variation on VOC-profile analyzed by an e-nose in healthy subjects. We enrolled 22 adults free of any known diseases. A sequence of exhaled breath samplings were performed on all participants at predetermined hours (7am, 12pm, 17pm, 23pm) and analyzed by an e-nose (Cyranose 320). According to Principal Component Analysis, significant circadian variations of the exhaled VOC-profile were shown for Principal Component (PC) 1 and 3. In detail, PC1 and PC3 values were significantly higher in the morning compared to the afternoon and evening (for all parameters p<0.05). Successive Linear Discriminant analysis confirmed the findings above. The daily variations in VOCs-profile, with the peak in the morning, could be relevant for future clinical applications, especially in the choice of optimal time for sampling patients
Nocturnal Hypoventilation May Have a Protective Effect on Ischemic Heart Disease in Patients with Obesity Hypoventilation Syndrome
No full textThe importance of nocturnal hypoventilation (nHyp) in the development of cardiovascular comorbidity (CVM) in patients with obesity hypoventilation syndrome (OHS) is controversial. We recently hypothesized that nHyp may have a protective effect on CVM in OHS. The aim of this study was to evaluate the link between nHyp and CVM in patients with OHS. We performed a retrospective analysis of the clinical records of 60 patients with OHS. The initial population was divided into two groups: (1) 31 subjects with OHS and nHyp (nhOHS); (2) 29 individuals with OHS without nHyp (wnhOHS). All patients had also obstructive sleep apnea. Anthropometric data, medical history, electrocardiogram, pulmonary function testing, arterial blood gas test, and sleep recordings were collected. Patients with nhOHS, compared with those wnhOHS, showed higher values of PaCO 2 (48.75 ± 3.78 vs. 46.91 ± 2.09 mmHg; p = 0.023), lower percentage of ischemic heart disease (3.2% vs. 20.7%; p = 0.042), higher oxygen desaturation index (ODI; 55.10/h ± 28.76 vs. 38.51/h ± 23.21; p = 0.017), and higher total sleep time (TST90) with SpO 2 <90% (53.58% ± 26.90 vs. 25.64% ± 21.67; p = 0.000). Moreover, individuals in the nhOHS group showed a significantly different (p = 0.031) distribution of the three ODI tertiles 0-32/h, 33-72/h, >72/h compared with those in wnhOHS group (19.4% vs. 37%, 41.9% vs. 51.7%, 38.7% vs. 10.3%, respectively). Subsequent discriminant analysis correctly classified nhOHS and wnhOHS in 66.7% of the cases. Ours is the first study analyzing the correlation between nHyp and CVM in patients with OHS. We showed that nHyp in OHS may have a protective effect on cardiovascular morbidity, in particular on ischemic cardiac disease
Moderate to severe vitamin D deficiency increases the risk of mortality due to COVID-19 in patients treated in a respiratory intensive care unit
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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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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