1,721,174 research outputs found
Autonomic and circulatory alterations persist despite adequate resuscitation in a 5-day sepsis swine experiment.
Full text linkAutonomic and vascular failures are common phenotypes of sepsis, typically characterized by tachycardia despite corrected hypotension/hypovolemia, vasopressor resistance, increased arterial stiffness and decreased peripheral vascular resistance. In a 5-day swine experiment of polymicrobial sepsis we aimed at characterizing arterial properties and autonomic mechanisms responsible for cardiovascular homeostasis regulation, with the final goal to verify whether the resuscitation therapy in agreement with standard guidelines was successful in restoring a physiological condition of hemodynamic profile, cardiovascular interactions and autonomic control. Twenty pigs were randomized to polymicrobial sepsis and protocol-based resuscitation or to prolonged mechanical ventilation and sedation without sepsis. The animals were studied at baseline, after sepsis development, and every 24 h during the 3-days resuscitation period. Beat-to-beat carotid blood pressure (BP), carotid blood flow, and central venous pressure were continuously recorded. The two-element Windkessel model was adopted to study carotid arterial compliance, systemic vascular resistance and characteristic time constant τ. Effective arterial elastance was calculated as a simple estimate of total arterial load. Cardiac baroreflex sensitivity (BRS) and low frequency (LF) spectral power of diastolic BP were computed to assess autonomic activity. Sepsis induced significant vascular and autonomic alterations, manifested as increased arterial stiffness, decreased vascular resistance and τ constant, reduced BRS and LF power, higher arterial afterload and elevated heart rate in septic pigs compared to sham animals. This compromised condition was persistent until the end of the experiment, despite achievement of recommended resuscitation goals by administered vasopressors and fluids. Vascular and autonomic alterations persist 3 days after goal-directed resuscitation in a clinically relevant sepsis model. We hypothesize that the addition of these variables to standard clinical markers may better profile patients' response to treatment and this could drive a more tailored therapy which could have a potential impact on long-term outcomes
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
Varying practices in tumor regression grading of gastrointestinal carcinomas after neoadjuvant therapy: results of an international survey
No full textTumor regression grading is routinely performed on neoadjuvantly treated gastrointestinal cancer resections. Challenges in tumor regression grading include grossing standards, multiple grading systems, and difficulty interpreting therapy-induced changes. We surveyed gastrointestinal pathologists around the world for their practices in handling neoadjuvantly treated gastrointestinal cancer specimens and reporting tumor regression using a 23-question online survey. Topics addressed grossing, histologic work-up, tumor regression grading systems, and degree of difficulty identifying and estimating residual cancer within treatment effect. Two-hundred three responses were received, including 173 participants who completed the entire questionnaire. Fifty percent of the participants were from Europe, 29% from North America, 10% from Australia, and 11% from other continents. Ninety-five percent routinely report a tumor regression grade and 92% have standardized grossing and histologic work-up: 27% always completely embed the entire tumor bed, 54% embed the complete tumor site if not a grossly apparent, large mass. Fifty-nine percent use hematoxylin & eosin alone for assessment; the remaining use additional stains. In North America and Australia, the American Joint Committee on Cancer (AJCC)/College of American Pathologists (CAP)/Ryan system is routinely used for gastroesophageal (71%) and rectal carcinomas (77%). In Europe, the Mandard system is common (36%) for gastroesophageal tumors, followed by AJCC/CAP/Ryan (22%), and Becker (10%); for rectal CA, the Dworak system (30%) is followed by AJCC/CAP/Ryan (24%) and Mandard (14%). This regional differences were significant (p < 0.001 each). Fifty-one percent prefer a four-tiered system. Sixty-six percent think that regressive changes in lymph nodes should be part of a regression grade. Sixty-nine percent consider identifying residual tumor straight-forward, but estimating therapy-induced fibrosis difficult (57%). Free comments raised issues of costs for work-up and clinical relevance. In conclusion, this multinational survey provides a comprehensive overview of grossing and histologic work-up with regards to tumor regression grading in gastrointestinal cancers with partly significant regional differences particularly between North America and Europe
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