1,720,969 research outputs found
Metabolomic Reprogramming Detected by 1H-NMR Spectroscopy in Human Thyroid Cancer Tissues
Get PDFThyroid cancer cells demonstrate an increase in oxidative stress and decreased antioxidant action, but the effects of this increased oxidative stress on cell function remain unknown. We aimed to identify changes in the metabolism of thyroid cancer cells caused by oxidative stress, using proton nuclear magnetic resonance (1H-NMR) spectroscopy. Samples of thyroid cancer and healthy thyroid tissue were collected from patients undergoing thyroidectomy and analyzed with 1H-NMR spectroscopy for a wide array of metabolites. We found a significant increase in lactate content in thyroid cancer tissue compared to healthy tissue. Metabolomic analysis demonstrated significant differences between cancer tissue and healthy tissue, including an increase in aromatic amino acids, and an average decrease in citrate in thyroid cancer tissue. We hypothesize that these changes in metabolism may be due to an oxidative stress-related decrease in activity of the Krebs cycle, and a shift towards glycolysis in cancer tissue. Thus, thyroid cancer cells are able to reprogram their metabolic activity to survive in conditions of high oxidative stress and with a compromised antioxidant system. Our findings, for the first time, suggested a connection between oxidative stress and the alteration of the metabolic profile in thyroid tumors
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
Changes in metabolic patterns during tumor development and progression in HER2/neu spontaneous breast cancer: a role for endogenous type I Interferon
No full textChanges in metabolic patterns during tumor development and progression in HER2/neu spontaneous breast cancer: a role for endogenous type I Interferon
In the last decades, cell metabolism emerged as a key factor involved in tumor development, progression and therapy resistance. Our group reported that the disruption of endogenous type I Interferon (IFN-I) system affects spontaneous Her2/neu-driven carcinogenesis through intrinsic control of cancer stem cells (Castiello et al, 2018). In order to investigate whether the possible remodeling of metabolic pathways was involved in this phenomenon, we applied non invasive in vivo MRS and ex vivo high resolution (HR)-MRS to analyze the changes in metabolic profiles occurring in healthy mammary glands and spontaneous tumors developed in Her2/ neu transgenic mice, with particular focus on IFN-I. Both in vivo MRS and ex vivo high resolution (HR)-MRS revealed that, in the absence of a functional endogenous IFN-I (IFNARI-/-), normal (non-tumoral) mammary glands had increased fatty acids concentration with respect to the wild type counterpart. This result paralleled the observation that IFNARI-/- normal mammary glands exhibited decreased expression of genes involved in OXPHOS and mitochondrial activity and increased expression of Sterol regulatory element-binding proteins, a known regulator of fatty acids biosynthesis. Interestingly, Her2+ early tumor lesions developed in IFNARI-/- mice also exhibited increased fatty acids content versus wild type mice. In contrast, bigger tumor masses (>500 um3) presented a more dysregulated and less consistent metabolic profile in both groups. As expected, the metabolic fingerprint of Her2+ tumors lesions of all sizes, assessed by HR-MRS analyses of aqueous metabolites, was significantly different from normal mammary glands in IFNARI+/+ and IFNARI-/- mice. Nevertheless, the impact of the lack of endogenous IFN-I could be observed in early stage Her2+ tumors. The alterations in myo-inositol and gluthathione concentrations observed in IFNARI-/- tumors suggest that endogenous IFN-I may exert its antitumor activity also by affecting key metabolic regulators of tumor cells proliferation. Our study provide the first evidence that endogenous IFN-I takes part in the regulation of some metabolic pathways occurring in normal mammary glands and affecting early phase of spontaneous breast cancer development. How these metabolic changes eventually provide a proliferation advantage to breast cancer cells is a matter of further investigation
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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