1,721,016 research outputs found
Epithelial injury and repair in airways diseases
No full textAsthma is a common chronic disease characterized by variable respiratory distress with underlying airway inflammation and airflow obstruction. The incidence of asthma has risen inexorably over the past 50 years, suggesting that environmental factors are important in its etiology. All inhaled environmental stimuli interact with the lung at the respiratory epithelium, and it is a testament to the effectiveness of the airway innate defenses that the majority of inhaled substances are cleared without the need to elicit an inflammatory response. However, once this barrier is breached, effective communication with immune and inflammatory cells is required to protect the internal milieu of the lung. In asthma, the respiratory epithelium is known to be structurally and functionally abnormal. Structurally, the epithelium shows evidence of damage and has more mucus-producing cells than normal airways. Functionally, the airway epithelial barrier can be more permeable and more sensitive to oxidants and show a deficient innate immune response to respiratory virus infection compared with that in normal individuals. The potential of a susceptible epithelium and the underlying mesenchyme to create a microenvironment that enables deviation of immune and inflammatory responses to external stimuli may be crucial in the development and progression of asthma. In this review, we consider three important groups of environmental stimuli on the epithelium in asthma: oxidants, such as environmental pollution and acetaminophen; viruses, including rhinovirus; and agents that cause barrier disruption, such as house dust mite allergens. The pathology associated with each stimulus is considered, and potential future treatments arising from research on their effects are presented
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
Delayed low-dose supplemental oxygen improves survival following phosgene-induced acute lung injury
No full textPhosgene is a chemical widely used in the plastics industry and has been used in warfare. It produces life-threatening pulmonary edema within hours of exposure; no antidote exists. This study examines pathophysiological changes seen following treatment with elevated inspired oxygen concentrations (Fio2), in a model of phosgene-induced acute lung injury. Anesthetized pigs were exposed to phosgene (Ct 2500?mg min m?3) and ventilated (intermittent positive pressure ventilation, tidal volume 10?ml kg?1, positive end-expiratory pressure 3?cm H2O, frequency 20 breaths min?1). The Fio2 was varied: group 1, Fio2 0.30 (228?mm Hg) throughout; group 2, Fio2 0.80 (608?mm Hg) immediately post exposure, to end; group 3, Fio2 0.30 from 30?min post exposure, increased to 0.80 at 6?h post exposure; group 4, Fio2 0.30 from 30?min post exposure, increased to 0.40 (304?mm Hg) at 6?h post exposure. Group 5, Fio2 0.30 from 30?min post exposure, increased to 0.40 at 12?h post exposure. The current results demonstrate that oxygen is beneficial, with improved survival, arterial oxygen saturation, shunt fraction, and reduced lung wet weight to body weight ratio in all treatment groups, and improved arterial oxygen partial pressure in groups 2 and 3, compared to phosgene controls (group 1) animals. The authors recommend that treatment of phosgene-induced acute lung injury with inspired oxygen is delayed until signs or symptoms of hypoxia are present or arterial blood oxygenation falls. The lowest concentration of oxygen that maintains normal arterial oxygen saturation and absence of clinical signs of hypoxia is recommended.<br/
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
Airway surfactant protein D deficiency in adults with severe asthma
No full textBackground: Surfactant protein D (SP-D) is an essential component of the innate immune defence against pathogens within the airways. In addition SP-D regulates allergic inflammation and promotes the removal of apoptotic cells. SP-D dysregulation is evident in several pulmonary diseases. Our aim was to investigate whether airway and serum levels of SP-D are altered in treatment-resistant severe asthma.Methods: SP-D concentrations were measured in matched serum and bronchoalveolar lavage (BAL) samples collected from 10 healthy controls (HC) and 50 asthmatics (22 mild [MA] and 28 severe [SA]). These samples were also evaluated by Western blots to investigate variations in SP-D size.Results: SP-D levels in BAL were significantly lower in SA compared to HC and MA (P < .001) and inversely correlated with BAL eosinophil cationic protein (ECP) concentrations in severe asthma (P < .01). Serum SP-D was significantly increased in SA when compared to HC and MA (P < .001), BAL/serum ratios were significantly lower in SA compared to HC and MA (P < .001). Reduced SP-D levels in in BAL with concomitant rises in serum in SA were associated with degraded fragments of SP-D in the serum and increased BAL neutrophils and lipopolysaccharide levels.Conclusions: These findings suggest defective innate immunity within the airways in severe asthma, as reflected by low BAL SP-D concentrations and altered bacterial presence with airway neutrophilia. Furthermore, BAL SP-D leakage into the serum in severe asthmatics may provide a peripheral blood biomarker reflecting increased epithelial damage and/or epithelial permeability within the peripheral airways.<br/
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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