1,720,969 research outputs found
Novel High Resolution Mass Spectrometry Applications for the Study of Lung Diseases
Full text linkRespiratory Distress Syndrome (RDS) is a respiratory disorder that can affect preterm newborns. It is due to lung immaturity and a deficiency of lung surfactant, a thin lipoprotein layer which allows lung expansion and prevents alveolar collapse during expiration. In these babies, nasal Continuous Positive Airway Pressure (nCPAP) provides non-invasive respiratory support by alveolar recruitment and improves functional residual capacity during spontaneous breathing. In case nCPAP fails, the next step is treatment with exogenous surfactant, which improves gas exchange and survival, reducing the need for mechanical ventilation and then the incidence of chronic lung disease. Although surfactant replacement therapy remains the gold standard for the treatment of RDS, failure rate ranges from 9% to 50%. The possibility of tracing the fate of the administered drug and estimate in vivo the amount of drug reaching the lung could help in improving the therapy and allow the premise to test different delivery systems. RDS is a disorder related to prematurity. Among the factors responsible for premature birth, intrauterine infection (chorioamnionitis) is one of the main causes and it has been reported to have effects on the development of fetal organs. In particular, it has been reported that infants exposed to chorioamnionitis had a reduced risk to develop RDS but an increased risk for chronic lung diseases. Since the function of lung surfactant strictly depends on its composition, a better knowledge on surfactant metabolite and lipid changes would elucidate the effects of the exposition of the foetus to maternal intrauterine infection on RDS. The PhD project focused on 2 objectives: 1. To validate natural abundance stable isotopes approach as a reliable method to quantify the contribution of exogenous surfactant to the alveolar surfactant pool in a rabbit model of RDS treated with a porcine exogenous surfactant; 2. To assess the effect of maternal intrauterine infection on the surfactant composition of newborns affected by RDS by liquid chromatography-mass spectrometry (LC-MS/MS) based metabolomics
Evaluation of venous blood gas analysis in milk fed calves at different period of livestock cycle
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Surfactant Components and Tracheal Aspirate Inflammatory Markers in Preterm Infants with Respiratory Distress Syndrome
No full textIn 93 preterm infants ≤32 weeks of gestational age and 12 control infants, epithelial lining fluid disaturated-phosphatidylcholine, surfactant protein A and B, albumin, and myeloperoxidase activity were assessed after intubation and before exogenous surfactant administration. We found that disaturated-phosphatidylcholine, surfactant protein B, and myeloperoxidase were significantly higher in preterms with chorioamnionitis
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
Evaluation of venous blood gas analysis, blood chemistry and haemocytometric parameters in milk fed veal calves at different periods of livestock cycle
Full text linkAn evaluation of blood chemistry profile in relation to specific stages of livestock cycle can help better understand variations in physiological conditions in order to adjust management systems to animal needs. In addition to basal hematological investigation, the acid-base balance and blood gases are essential tools in evaluating metabolism in calves. The relationship between blood gas parameters, diet and growth should be further investigated.
The aim of this study was to evaluate changes in acid-base status, blood gases, serum chemistry and hematological parameters in veal calves at different periods of livestock cycle.
One hundred twenty-eight healthy cross breeding calves were enrolled in a farm in North-East Italy. Blood samplings were carried out from the jugular vein on day 1 (t1), 60 (t2) and 150 (t3) after arrival. Blood gas analysis was performed and hematological parameters were evaluated. One-way ANOVA and Tukey-Kramer post-hoc test were performed to assess differences between blood par- ameter values at the different periods.
The main differences in blood gas parameter levels during the livestock cycle concerned pH, Base Excess and HCO3 with higher values recorded in t3. Urea, creatinine, gamma-glutamyl transpeptidase and bilirubin mean values were significantly higher in t1 than in t2 and t3. Aspartate aminotransferase increased from t1 to t2 and t3. Alkaline Phosphatase was higher in t2. Fe levels severely dropped in t2 and in t3, and the decrease led to a restrained but significant reduction in haemoglobin values. A correspondent decrease in the other haemocytometric parameters was found
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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