1,721,002 research outputs found
Evaluation of circulating thyroid-specific transcripts as markers of thyroid cancer relapse.
No full textNovel Method for Simultaneous Aqueous in Situ Derivatization of THC and THC-COOH in Human Urine Samples: Validation and Application to Real Samples
No full textThe present work describes the validation of a novel aqueous
in situ derivatization procedure with trimethyloxonium
tetrafluoroborate (TMO) as methylating agent for the
simultaneous, quantitative analysis of Δ9-tetrahydrocannabinol
(THC) and 11-nor-Δ9-tetrahydrocannabinol carboxylic acid
(THC-COOH) in human urine. The derivatizing agent is directly
added to the urine sample and the methyl-derivatives are then
recovered by liquid–liquid extraction procedure. Gas
chromatography–mass spectrometry was used to detect the
derivatives in selected ion monitoring mode. The limits of
detection were 0.7 ng/mL for THC and 0.5 ng/mL for THC-COOH,
whereas the limits of quantification were 1.9 and 0.9 ng/mL,
respectively. The method has been applied to 60 real samples both
positive and negative to immunochemical screening test resulting
to be very useful and reliable in routine analysis of THC-COOH in
human urine for toxicological and forensic purposes
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
Modelling neurotropic flavivirus infection in human induced pluripotent stem cell-derived systems
Full text linkGeneration of human induced pluripotent stem cells (hiPSCs) and their differentiation into a variety of cells and organoids have allowed setting up versatile, non-invasive, ethically sustainable, and patient-specific models for the investigation of the mechanisms of human diseases, including viral infections and host-pathogen interactions. In this study, we investigated and compared the infectivity and replication kinetics in hiPSCs, hiPSC-derived neural stem cells (NSCs) and undifferentiated neurons, and the effect of viral infection on host innate antiviral responses of representative flaviviruses associated with diverse neurological diseases, i.e., Zika virus (ZIKV), West Nile virus (WNV), and dengue virus (DENV). In addition, we exploited hiPSCs to model ZIKV infection in the embryo and during neurogenesis. The results of this study confirmed the tropism of ZIKV for NSCs, but showed that WNV replicated in these cells with much higher efficiency than ZIKV and DENV, inducing massive cell death. Although with lower efficiency, all flaviviruses could also infect pluripotent stem cells and neurons, inducing similar patterns of antiviral innate immune response gene expression. While showing the usefulness of hiPSC-based infection models, these findings suggest that additional virus-specific mechanisms, beyond neural tropism, are responsible for the peculiarities of disease phenotype in humans
Circulating Genotypes of Hepatitis C Virus in Italian Patients before and after the Application of Wider Access Criteria to HCV Treatment
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