1,720,969 research outputs found
Caspofungin in combination with itraconazole and amphotericin B for the treatment of invasive aspergillosis in humans, with a method to test ex vivo synergism
No full textVancomycin-Resistant Enterococcus faecium (VRE) Bacteremia in Infective Endocarditis Successfully Treated with Combination Daptomycin and Tigecycline
No full textSynthesis of chromatin phospholipids
No full textThe presence of a phospholipid fraction associated with chromatin has been demonstrated by biochemical technique in rat hepatocytes. The composition of this fraction determined by chromatography with respect to that of the nuclei is characterized by low content of phosphatidylserine and high content in phosphatidylethanolamine. Also the synthesis and turnover studied after injection of [32P]O4(2-) show a different behaviour: the peak of activity is after 6 hrs in nuclei and microsomes, whereas in chromatin it occurs after 9 hrs. A second peak is evident after 24 hrs in chromatin and microsome phospholipids. Differences have been also shown by analyzing the single phospholipid radioactivity in time. The behaviour of chromatin phospholipids has also been studied during DNA premitotic synthesis in regenerating liver. It has been shown that there is no difference in synthesis in relation to that of DNA in nuclear phospholipids, whereas the specific activity of chromatin phospholipids begins to increase twelve hours after hepatectomy and continues throughout the period of the first mitotic wave, thus bringing to a summation with the beginning of the second wave. The role of this phospholipid fraction in relation to DNA synthesis and gene expression is discussed
Chromatin phospholipids and DNA synthesis in hepatic cells
No full textThe synthesis of phospholipids found in microsomes, in the nuclei and in chromatin has been studied in rat liver after partial hepatectomy. [32P]O4(2-)incorporation in phospholipids has been compared with that of (3H) thymidine over a period of 48 h after operation. The presence of two peaks of DNA synthesis has been observed at 18 and 36 h; nuclear phospholipids show a continuous synthesis starting from 12 h, whereas the microsomes show two peaks at 12 and 24-30 h. The specific activity of the chromatin phospholipid fraction increases at 12h, doubles its initial value at 18 h, shows a peak at 30 h and comes back to the initial value at 48 h. It is concluded that chromatin phospholipids increase their synthesis in relation to the S phase of the cell cycle, whereas those of the nuclear membranes do not change the rate of synthesis throughout the cell cycle. The possibility is suggested that chromatin phospholipids are synthesized in the microsomes and transferred to the nucleus
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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