1,721,074 research outputs found
Transepithelial water permeability in microperfused distal airways. Evidence for channel-mediated water transport
No full textWater movement across the airway epithelium is important for regulation of the volume and composition of airspace fluid. A novel approach is reported here to measure osmotic and diffusional water permeability in intact airways. Small airways (100-200 mu m diameter, 1-2 mm length) from guinea pig lung were microdissected and perfused in vitro using concentric glass holding and perfusion pipettes. For measurement of osmotic water permeability (P-f), the airway lumen was perfused with PBS (300 mOsM) containing a membrane impermeable fluorophore, fluorescein sulfonate (FS), and the airway was bathed in solutions of specified osmolalities, P-f determination was based on the change in FS fluorescence at the distal end of the airway resulting from transepithelial water transport, P-f was 4-5 X 10(-3) cm/s at 23 degrees C and independent of lumen flow rate (10-100 nl/min) and the magnitude and direction of the osmotic gradient (bath osmolality 50-600 mOsM). Temperature dependence measurements gave an activation energy of 4.4 kcal/mol (15-37 degrees C). P-f was not altered by 0.3 mM HgCl2 or 50 mu M forskolin, but was increased to 31 X 10(-3) cm/s by 100 mu g/ml amphotericin B, indicating that osmosis is not limited by unstirred layers. Diffusional water permeability (P-d) was measured by H2O/(DO)-O-2 (deuterium oxide) exchange using the H2O/D2O-sensitive fluorescent probe aminonapthelane trisulfonic acid in the lumen. Measured P-d was 3-6 X 10(-6) cm/s at 23 degrees C, indicating significant restriction to water diffusion by unstirred layers. Antibody localization of water channels showed strong expression of the mercurial-insensitive water channel (AQP-4) at the basolateral membrane of airway epithelial cells. These results provide functional evidence that water movement across the distal airway epithelium is mediated by water channel
The Beta Agonist Lung Injury TrIal (BALTI) : prevention trial protocol
Full text linkBackground: Acute lung injury complicates approximately 25-30% of subjects undergoing oesophagectomy.
Experimental studies suggest that treatment with beta agonists may prevent the development of acute lung injury by decreasing inflammatory cell infiltration, activation and inflammatory cytokine release, enhancing basal alveolar fluid clearance and improving alveolar capillary barrier function.
Methods/Design: The Beta Agonist Lung Injury TrIal (prevention) is a multi-centre, randomised, double blind,
placebo-controlled trial. The aim of the trial is to determine in patients undergoing elective transthoracic
oesphagectomy, if treatment with inhaled salmeterol 100 mcg twice daily started at induction of anaesthesia and
continued for 72 hours thereafter compared to placebo affect the incidence of early acute lung injury and other
clinical, resource and patient focused outcomes. The primary outcome will be the development of acute lung
injury within 72 hours of oesophagectomy. The trial secondary outcomes are the development of acute lung injury during the first 28 days post operatively; PaO2: FiO2 ratio; the number of ventilator and organ failure free days, 28 and 90 day survival; health related quality of life and resource utilisation. The study aims to recruit 360 patients from 10 UK centres
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
Beta Agonist Lung Injury TrIal-2 (BALTI-2) trial protocol : a randomised, double-blind, placebo-controlled of intravenous infusion of salbutamol in the acute respiratory distress syndrome
Full text linkBackground: The Acute Respiratory Distress Syndrome (ARDS) is a common cause of respiratory failure in critically ill patients. Experimental studies suggest that treatment with beta agonists may be helpful in ARDS. The Beta Agonist Lung Injury TrIal (BALTI-2) is a multicentre, pragmatic, randomised, double-blind, placebo-controlled clinical trial which aims to determine if sustained treatment with intravenous (IV) salbutamol will improve survival in ARDS.
Methods/Design: Patients fulfilling the American-European Consensus Conference Definition of ARDS will be randomised in a 1: 1 ratio to receive an IV infusion either of salbutamol (15 mu g kg ideal body weight(-1) hr(-1)) or placebo (0.9% sodium chloride solution), for a maximum of seven days. Allocation to randomised groups will use minimisation to ensure balance with respect to hospital of recruitment, age group (85 years) and PaO(2)/FiO(2) ratio (= 13.3 kPa). Data will be recorded by participating ICUs until hospital discharge, and all surviving patients will be followed up by post at six and twelve months post randomisation. The primary outcome is mortality at 28 days after randomisation; secondary outcomes are mortality in ICU, mortality in hospital, number of ventilator-free days, number of organ failure-free days, mortality at twelve months post-randomisation, quality of life at six and twelve months, length of stay in ICU, length of stay in hospital, adverse effects (tachycardia, arrhythmia or other side effects sufficient to stop treatment drug). 1,334 patients will be recruited from about fifty ICUs in the UK. An economic evaluation will be conducted alongside the trial
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
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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