1,720,965 research outputs found
New synthetic isoxazole derivatives as potent inducer of fetal hemoglobin (HbF) in beta-thalassemia
No full textXylitol as a Hydrophilization Moiety for a Biocatalytically Synthesized Ibuprofen Prodrug
No full textBiocatalyzed synthesis can be exploited to produce high‐value products, such as prodrugs. The replacement of chemical approaches with biocatalytic processes is advantageous in terms of environmental prevention, embracing the principles of green chemistry. In this work, we propose the covalent attachment of xylitol to ibuprofen to produce an IBU–xylitol ester prodrug. Xylitol was chosen as a hydrophilizer for the final prodrug, enhancing the water solubility of ibuprofen. Ibuprofen is a nonsteroidal anti‐inflammatory drug (NSAID) extensively used as an analgesic, anti‐inflammatory, and antipyretic. Despite being the third‐most‐prescribed medicine in the world, the aqueous solubility of ibuprofen is just 21 mg/L. This poor water solubility greatly limits the bioavailability of ibuprofen. We aimed to functionalize ibuprofen with xylitol using the reusable immobilized N435 biocatalyst. Instead of a biphasic media, we proposed a monophasic reaction environment. The characterization of the IBU–xylitol ester was performed by1H,13C‐NMR, DEPT, COSY, HMQC, HMBC, FTIR, and MS spectroscopy. Preliminary in vitro tests showed that this enzymatically synthesized prodrug of ibuprofen reduced the expression of the interleukin 8 genes in human bronchial epithelial cells (IB3‐1) from cystic fibrosis (CF) patients
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
Combined Treatment of Cancer Cells Using Allyl Palladium Complexes Bearing Purine-Based NHC Ligands and Molecules Targeting MicroRNAs miR-221-3p and miR-222-3p: Synergistic Effects on Apoptosis
Full text linkCombined treatments employing lower concentrations of different drugs are used and studied to develop new and more effective anticancer therapeutic approaches. The combination therapy could be of great interest in the controlling of cancer. Regarding this, our research group has recently shown that peptide nucleic acids (PNAs) that target miR-221 are very effective and functional in inducing apoptosis of many tumor cells, including glioblastoma and colon cancer cells. Moreover, in a recent paper, we described a series of new palladium allyl complexes showing a strong antiproliferative activity on different tumor cell lines. The present study was aimed to analyze and validate the biological effects of the most active compounds tested, in combination with antagomiRNA molecules targeting two miRNAs, miR-221-3p and miR-222-3p. The obtained results show that a “combination therapy”, produced by combining the antagomiRNAs targeting miR-221-3p, miR-222-3p and the palladium allyl complex 4d, is very effective in inducing apoptosis, supporting the concept that the combination treatment of cancer cells with antagomiRNAs targeting a specific upregulated oncomiRNAs (in this study miR-221-3p and miR-222-3p) and metal-based compounds represents a promising therapeutic strategy to increase the efficacy of the antitumor protocol, reducing side effects at the same time
Pro‐apoptotic activity of novel synthetic isoxazole derivatives exhibiting inhibitory activity against tumor cell growth in vitro
No full textIn order to develop potential anticancer agents stimulating apoptosis, novel 3,4‐isoxazolediamide and 4,5,6,7‐tetrahydro‐isoxazolo‐[4,5‐c]‐pyridine derivatives have been synthetized. The original structures of geldanamycin and radicicol, which are known natural heat shock protein (HSP) inhibitors, were deeply modified because both of them exhibit several drawbacks, such as poor solubility, hepatotoxicity, intrinsic chemical instability or deprivation of the in vivo activity. This novel class of synthetic compounds containing the isoxazole nucleus exhibited potent and selective inhibition of HSP90 in previous studies. Biological assays (focusing on in vitro antiproliferative effects and pro‐apoptotic activity) in human erythroleukemic K562 cells (as a model system referring to tumor cells grown in suspension), glioblastoma U251‐MG and glioblastoma temozolomide (TMZ)‐resistant T98G cell lines (two model systems referring to tumor cells grown attached to the flask), were performed. Almost all isoxazole derivatives demonstrated significant antiprolif‐ erative and pro‐apoptotic activities, showing induction of both early and late apoptosis of K562 cells. Different effects were observed on the glioma U251‐MG and T98G cells, depending on the structure of the analogues. Antiproliferative and pro‐apoptotic activities in K562 cells were associated with the activation of the erythroid differentiation program. The present study demonstrated that 3,4‐isoxazolediamide and 4,5,6,7‐tetrahydro‐isoxazolo‐[4,5‐c]‐pyridine derivatives should be considered for in vivo studies focusing on the development of anticancer drugs acting, at least partially, via activation of apoptosis
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