1,720,982 research outputs found
Nonequivalence of erythrocyte sedimentation rate assessed in whole blood anticoagulated with K2EDTA or sodium citrate
No full textBackground: According to the International Council for Standardization in Hematology (ICSH), the Westergren method is the reference technique for measuring erythrocyte sedimentation rate (ESR). Although this assay has been originally validated on whole blood anticoagulated with sodium citrate, the use of whole blood anticoagulated with dipotassium ethylenediaminetetraacetic acid (K2EDTA) is commonplace and acknowledged by ICSH. This study was hence planned to define how ESR values compare between these two sample matrices. Methods: A total number of 148 consecutive paired blood samples collected either in 3.5 mL, 3.2% trisodium citrate or 3.0 mL, 5.4 mg K2EDTA were randomly selected from all routine samples conveyed on a working day and assessed with the fully automated analyzer TEST 1. Results: The median [and interquartile range (IQR)] ESR value was more than double in K2EDTA (36 mm/h; IQR, 56 mm/h) than in citrate tubes (17 mm/h; IQR, 41 mm/h; P<0.001). The percentage of samples with ESR >20 mm/h was significantly higher in K2EDTA than in sodium citrate (66% vs. 47%; P=0.001). Conclusions: Although both K2EDTA and citrate tubes can be used for measuring ESR, results are not interchangeable and specific reference ranges shall be implemented
Effects of recombinant SARS-CoV-2 spike protein variants on red blood cells parameters and red blood cell distribution width
No full textWe planned a series of experiments to investigate the possible role of spike protein of different SARS-CoV-2 variants in influencing erythrocyte biology. The values of erythrocyte count, hemoglobin, and mean corpuscular hemoglobin (MHC) did not vary across all samples challenged with both concentrations of the four different SARS-CoV-2 recombinant spike proteins. A significant increase in mean corpuscular volume (MCV) was observed with the recombinant SARS-CoV-2 Alpha and Delta spike proteins at both 2 and 20 ng/mL final concentrations. Red blood cell distribution width (RDW) values increased significantly in samples treated with 20 ng/mL of all SARS-CoV-2 recombinant spike proteins and reached the highest values in samples treated with Omicron recombinant spike protein. Blood smear revision evidenced hemagglutination and rouleaux in samples to which recombinant SARS-CoV-2 spike proteins were added, especially in those with Alpha and Delta variants
Assessment of haematopoietic progenitor cell counting with the Sysmex® XN-1000 to guide timing of apheresis of peripheral blood stem cells.
No full textBACKGROUND: Successful peripheral blood stem cell (PBSC) collection depends on optimal timing of apheresis, as usually determined by flow cytometry CD34-positive (+) cell count in peripheral blood (PB). Since this method is costly and labour-intensive, we evaluated the use of the Hematopoietic Progenitor Cell count programme on a Sysmex® XN haematologic analyser (XN-HPC) as a rapid and inexpensive alternative for predicting CD34+ cell count in PB samples. MATERIALS AND METHODS: Haematopoietic progenitor cell and CD34+ cell counts were compared using 273 PB samples collected from 78 healthy donors and 72 patients who underwent PBSC transplantation. We assessed the effectiveness of the XN-HPC in safely predicting pre-harvest CD34+ counts. The most efficient cut-off values of XN-HPC were identified. We also evaluated the imprecision (coefficient of variation, CV) and functional sensitivity. RESULTS: Imprecision of the XN-HPC count was <6.3% on daily measurement of three levels of quality control material. Functional sensitivity was 8.9×106/L. A cut-off value of ≥62×106/L XN-HPC for multiple myeloma (MM) patients and ≥30×106/L for all other subjects had both 100% specificity and 100% positive predictive value for identifying samples with CD34+ cells ≥20×106/L. An XN-HPC threshold of <13×106/L identified pre-harvest CD34+ cell count <10×106/L with 100% sensitivity and 100% negative predictive value. DISCUSSION: The XN-HPC is a fast, easy and inexpensive test that can safely improve apheresis workflow thus possibly replacing other more expensive CD34 counts currently performed and promoting optimal timing of PBSC collection
Additional insights on SARS-CoV-2 spike protein variants and red blood cells biology
No full textAdditional insights on SARS-CoV-2 spike protein variants and red blood cells biolog
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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