1,721,083 research outputs found
Determination of steroid hormones in fish tissues by microwave-assisted extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry
No full textSteroid hormones produce adverse effects on biota as well as bioaccumulation in fish and seafood, making it necessary to develop methodologies to evaluate these compounds in samples related to the food chain. This work presents an analytical method for evaluating 15 steroid hormones in fish tissue. It is based on microwave-assisted extraction and solid-phase extraction coupled to ultra-high-performance liquid chromatography tandem mass spectrometry (MAE-SPE-UHPLC-MS/MS). The proposed method shows appropriate detection limits (0.14–49.0 ng g−1), recoveries in the range of 50% and good repeatability. After optimization, the method was applied to different tissues from two small fishes of the Canary Islands that constitute an important level of the food web (Boops boops and Sphoeroides marmoratus) and were exposed to the outfall of the Las Palmas de Gran Canaria wastewater treatment plant. The concentrations of eight detected compounds ranged from below the quantification limits to 3.95 μg g−1.102010121,7934,946Q1Q1SCI
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
CD38: A Novel Modulator of Morphine Antinociception in the Spinal Cord
No full textAuthor ManuscriptOpioid analgesics remain essential for managing moderate to severe pain, but the development of tolerance and hyperalgesia limits their clinical utility. CD38 is a multifunctional enzyme that generates calcium-mobilizing second messengers and plays a role in the supraspinal actions of opioids, yet its role in pain processing and spinal opioid effects remains undetermined. In this study, we investigated the function of CD38 in basal processing of acute heat and pressure noxious stimuli and spinal morphine antinociception using wild-type (WT) and CD38 knockout (CD38KO) mice of both sexes. CD38 enzymatic activity was highest in the spinal cord and predominantly localized to astrocytes. While CD38 deletion had no effect on baseline thermal or mechanical acute nociception, spinal morphine-induced antinociception was significantly reduced in CD38KO mice across both noxious modalities, with diminished magnitude and duration of response. Morphine-induced thermal hyperalgesia was attenuated in CD38KO females but not in males, indicating a possible sex-dependent role for CD38 in opioid-induced hyperalgesia. In contrast, spinal morphine tolerance developed similarly in both genotypes, suggesting these adaptations occur independently of CD38. Morphine administration did not alter spinal CD38 activity, and μ-opioid receptor expression was comparable between WT and CD38KO mice, indicating that CD38 modulates spinal opioid antinociception downstream or parallel to MOR signaling. These findings suggest that astrocytic CD38 plays a critical role in mediating opioid-induced antinociception without contributing to opioid-induced tolerance, highlighting its potential as a novel target for enhancing opioid efficacy.This work was funded by grants the National Institute of Neurological Diseases and Stroke (grant 1R21NS118499-01A1 to Alonso Guedes), National Institute on Drug Abuse (grant 1R36DA054455-01A1 to Ruth Quintana), and the University of Minnesota College of Veterinary Medicine Signature Program (grants 722, 667 to Alonso Guedes) and Graduate Student/Resident Program (grant 645 to Ruth Quintana).Quintana, Ruth; Singh, Dhananjay; Graeff, Richard; Titus, David; Guedes, Alonso. (2025). CD38: A Novel Modulator of Morphine Antinociception in the Spinal Cord. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/273330
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
An on-line solid phase extraction method coupled with UHPLC-MS/MS for the determination of steroid hormone compounds in treated water samples from waste water treatment plants
No full textAn on-line solid phase extraction coupled with ultra-high performance liquid chromatography in tandem with mass spectrometry (SPE-UHPLC-MS/MS) method for the determination of fourteen hormones (four oestrogens, three androgens, four progestogens and three corticosteroids) in waste water samples has been developed. All of the parameters involved in the on-line extraction process have been optimized: type of cartridge, sample volume, loading solvent, solvent of the wash step and the pH of the sample. Moreover, the chromatographic separation and all of the parameters involved in the detection by mass spectrometry have been studied too600559960,6021,915Q1Q2SCI
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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