1,720,967 research outputs found
Nutraceuticals, a new challenge for medicinal chemistry
No full text"Nutraceuticals" are food-derived products largely used for their presumed health-promoting or disease-preventing effects. In recent years, many efforts have been aimed at assessing nutraceutical efficacy and safety, but these factors are difficult to address because of the complex chemical compositions and multiple mode of actions. Thus, the study of nutraceutical ingredients poses several challenges for the medicinal chemistry field, some of which are related to extraction and chemical characterization, some to in vitro and in vivo bioactivity evaluation, and some to the bioavailability and interaction of these natural mixtures with organs and microbiota. Furthermore, because of their nature as medicinal and food products, these nutraceuticals can also be considered as a valuable source of new "lead compounds", creating the opportunity to discover new classes of therapeutic agents. This review provides information on these themes, showing the new challenges that comprehensive medicinal chemistry research is called to answer in the field of nutraceuticals
Local Completeness for Program Correctness and Incorrectness (Invited Talk)
No full textProgram correctness techniques aim to prove the absence of bugs, but can yield false alarms because they tend to over-approximate program semantics. Vice versa, program incorrectness methods are aimed to detect true bugs, without false alarms, but cannot be used to prove correctness, because they under-approximate program semantics. In this invited talk we will overview our ongoing research on the use of the abstract interpretation framework to combine under- and over-approximation in the same analysis and distill a logic for program correctness and incorrectness
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
Antitrypanosomal activity of Tithonia Diversifolia
No full textThe African Trypanosomiases, also commonly called African sleeping sickness in humans (HAT) and
“Nagana” in domestic livestock, are fatal neglected diseases that occur in 36 sub-Saharan African
countries. The disease progresses through two stages and is caused by two subspecies of the
parasite T. brucei: T. b. gambiense (West Africa; Tbg) and T. b. rhodesiense (East Africa; Tbr).
T. brucei is also pathogenic to wild and domestic animals causing “Nagana”, a disease that has a
significant impact on socioeconomic development in many parts of rural Africa. Current treatments are
considered unsatisfactory due to treatment failures and high toxicity. Therefore, there is a great need
of new and cost-effective drugs to treat the disease, especially at later stages when the parasites
infect the brain. Drug discovery efforts are nowadays directed towards natural products and medicinal
plants represent a validated source for discovery of new lead compounds and standardized herbal
medicines against trypanosomiases [1].
Tithonia diversifolia (Hemsl.) A.Gray, well-known as Mexican sunflower, is a bushy perennial weed
commonly found on the fields, wasteland and road sides of tropical areas in South America, Asia and
Africa. The plant belongs to the Asteraceae family and used as traditional medicine for the treatment
of various diseases, including malaria [2]. The phytochemical analyses of T. diversifolia indicate1d the
presence of bioactive substances such as alkaloids, saponins, glycosides, flavonoid, tannins,
terpenoid and phenols in the methanolic extract [3]. The leaves methanolic extract showed a quite
remarkable inhibitory activity against Trypanosoma brucei brucei TC221. For this reason, a
chromatographic separation of total methanolic extract has been performed, obtaining 17 fractions.
The phytochemical composition of crude extract and purified fractions were investigated using HPLCESI-
MS/MS and 1D and 2D NMR spectra. The isolated fractions have been selected as valid
candidates for investigation as potential inhibitors of T. brucei. The results of this study will be
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
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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