1,720,960 research outputs found
The effects of 99mTc-HMPAO-labelled leucocyte scan on human karyotype
Technetium-99m hexamethylpropylene amine oxime (HMPAO) white blood cell scan (WBCS) requires separation and labelling of mixed leucocytes, which include particularly radiosensitive cells, lymphocytes. Lymphocytes labelled during the mixed leucocyte labelling procedure could represent a problem for patients owing to the possible induction of chromosomal aberrations. Lymphocytes labelled in mixed leucocyte preparations are probably killed by the high-dose radiation. Nevertheless, it has been reported that some of these lymphocytes can proliferate after in vitro stimulation. If these cells were to reproduce themselves in vivo, onset of, or increase over time in, chromosomal aberrations could occur on peripheral blood lymphocytes. The present study was performed on 21 patients who underwent WBCS for suspected infection/inflammation. Blood samples of these patients were submitted to cytogenetic study, comprising karyotype determination, evaluation of sister chromatid exchanges (SCE) and evaluation of induced chromosomal breakages or rearrangement rate (B/R). This study was performed 2 h before and 7 days and 6 months after the WBCS. The results demonstrated no statistically significant differences between SCE and B/R values before and after WBCS. No cause-effect relationship appeared to exist between WBCS and the onset of chromosomal aberrations in peripheral blood lymphocytes, at least during the first 6 months post WBCS and within the limits of this study's approach. The high-dose radiation administered to lymphocytes was almost certainly sufficient to kill these cells
INNALZAMENTO TERMICO IN CAMERA PULPARE NELLA VETRIFICAZIONE DENTINALE MEDIANTE LASER CO - NOTA PRELIMINARE
Detection of axillary lymph node metastases in breast cancer with Tc-99m tetrofosmin scintigraphy
UN NUOVO METODO PER LO STUDIO DELLE ABRASIONI SUI TESSUTI DENTALI: CONSIDERAZIONI PRELIMINARI
Arrhytmia Prophylaxis after Coronary Bypass Grafting: Regimens of Magnesium Sulfate Administration
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
We 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
- …
