1,720,982 research outputs found

    Covid-19, chloroquine repurposing, and cardiac safety concern: Chirality might help

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    The desperate need to find drugs for COVID-19 has indicated repurposing strategies as our quickest way to obtain efficacious medicines. One of the options under investigation is the old antimalarial drug, chloroquine, and its analog, hydroxychloroquine. Developed as synthetic succedanea of cinchona alkaloids, these chiral antimalarials are currently in use as the racemate. Besides the ethical concern related to accelerated large-scale clinical trials of drugs with unproven efficacy, the known potential detrimental cardiac effects of these drugs should also be considered. In principle, the safety profile might be ameliorated by using chloroquine/hydroxychloroquine single enantiomers in place of the racemate

    Human ether-à-go-go-related potassium channel: exploring SAR to improve drug design

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    hERG is best known as a primary anti-target, the inhibition of which is responsible for serious side effects. A renewed interest in hERG as a desired target, especially in oncology, was sparked because of its role in cellular proliferation and apoptosis. In this study, we survey the most recent advances regarding hERG by focusing on SAR in the attempt to elucidate, at a molecular level, off-target and on-target actions of potential hERG binders, which are highly promiscuous and largely varying in structure. Understanding the rationale behind hERG interactions and the molecular determinants of hERG activity is a real challenge and comprehension of this is of the utmost importance to prioritize compounds in early stages of drug discovery and to minimize cardiotoxicity attrition in preclinical and clinical studies. We report how the understanding of SAR and the informed use of reliable data and models are pivotal to modulate the interplay with hERG channels

    Lactoferrin-derived peptides as a control strategy against skinborne staphylococcal biofilms

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    Coagulase-negative staphylococci (CoNS) widely colonize the human skin and play an active role in host defense. However, these bacteria may cause malodours and increase infection incidence rate in immune-compromised patients and individuals with catheters and implants. CoNS spreading is favored by biofilm formation that also promotes the release of virulence factors and drug resistance. Biofilm control or eradication by antimicrobial peptides (AMPs) represents an attractive strategy which is worth investigating. In this work, bovine lactoferrin (BLF) hydrolysate (HLF) was in vitro evaluated for its antimicrobial and antibiofilm activities against skin-related coagulase negative and positive staphylococci. Despite a minimal inhibitory concentration (MIC) recorded for HLF ranging from 10 to more than 20 mg/mL, a minimal biofilm inhibitory concentration (MIBC) equal to 2.5 mg/mL was found for most target strains. Conversely, MIBC values referred to the individual peptides, LFcinB or LFmpin (herein purified and identified) were significantly lower. Finally, the application of 2.5 mg/mL HLF solution by dipping and spraying on biofilm-attached glass surfaces also caused a high biofilm eradication rate depending on the incubation time, thus attracting interest for future applications in cosmetic formulation for skin care

    Ultrasound and deep eutectic solvents: An efficient combination to tune the mechanism of steviol glycosides extraction

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    Ultrasound-assisted extraction is widely recognized as an eco-friendly technique due to low solvent consumption and time extraction as well as enhanced extraction efficiency with respect to conventional methods. Nevertheless, it would be convenient to avoid the usually used organic solvents to reduce the environment pollution. In this regard, Deep Eutectic Solvents (DES) represent nowadays a green and sustainable alternative for the extraction of bioactive compounds from natural sources. In this study, an efficient extraction of stevioside and rebaudioside A from Stevia rebaudiana coupling ultrasound with DES was developed. A solvent screening was performed using the predictive approach COnductor-like Screening MOdel for Real Solvent (COSMO-RS). The effect of three independent variables, namely % of water, temperature, and sonication amplitude, were investigated by the response surface methodology (RSM). Comparing ultrasound-assisted extraction (UAE) with conventional extraction, it has been demonstrated that the amount of steviol glycosides through UAE is almost three times higher than that obtained by the conventional method. Possible physicochemical factors involved in the UAE mechanism were discussed

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    Inhibition of lysophosphatidic acid receptor 6 upregulated by the choline-deficient l-amino acid-defined diet prevents hepatocarcinogenesis in mice

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    Hepatocellular carcinoma (HCC) is one of the most worrying tumors worldwide today, and its epidemiology is on the rise. Traditional pharmacological approaches have shown unfavorable results and exhibited many side effects. Hence, there is a need for new efficacious molecules with fewer side effects and improvements on traditional approaches. We previously showed that lysophosphatidic acid (LPA) supports hepatocarcinogenesis, and its effects are mainly mediated by LPA receptor 6 (LPAR6). We also reported that 9-xanthylacetic acid (XAA) acts as an antagonist of LPAR6 to inhibit the growth of HCC. Here, we report that LPAR6 is involved in the choline-deficient l-amino acid-defined (CDAA) diet-induced hepatocarcinogenesis in mice. Our data demonstrate that CDAA diet-induced metabolic imbalance stimulates LPAR6 expression in mice and that XAA counteracts diet-induced effects on hepatic lipid accumulation, fibrosis, inflammation, and HCC development. These conclusions are corroborated by results on LPAR6 gain and loss-of-function in HCC cells
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