186,563 research outputs found
Sponge-associated fungi and their bioactive compounds - the Suberites case
No full textSpecimens of Suberites domuncula that had been cultured in aquaria for 4 weeks were analyzed for their associated fungi. A total of 81 fungal strains belonging to 20 different genera was isolated and identified by morphological and molecular methods. The most frequently isolated taxa were Cladosporium spp., Penicillium spp., Petriella sp., Phialophora spp. and Engyodontium album. Based on chromatographic and mass spectrometric analysis of fungal extracts, as well as on bioassay results, Aspergillus ustus, Penicillium sp., Petriella sp. and Scopulariopsis sp. were selected for in-depth analysis of their natural products. A total of 19 different fungal metabolites, including three new natural products, was isolated and structurally identified. A. ustus yielded two sesquiterpenes, a drimane derivative and deoxyuvidin, as well as a sesterterpene ophiobolin H. The drimane derivative had an ED50 value against L5178Y cells of 1.9 mu g ml(-1) in vitro. The crude extract of Petriella sp. was also strongly cytotoxic against the L5178Y cell line. The cyclic tetrapeptide WF-3161 was primarily responsible for the activity; the ED50 value was <0.1 mu g ml(-1). It was identical to the known compound WF-3161 and had been previously isolated from Petriella guttulata. In addition to WF-3161, three further natural products were obtained and unequivocally identified as new derivatives of infectopyrone by one-and two-dimensional NMR spectroscopy and by mass spectroscopy. Of the new compounds, only dihydroinfectopyrone was active against L5178Y cells; the ED50 value was 0.2 mu g ml(-1). Penicillium sp. yielded the largest number of metabolites. Viridicatin, viridicatol, cyclopenin and cyclopenol suppressed larval growth of the polyphagous pest insect Spodoptera littoralis when incorporated into an artificial diet at an arbitrarily chosen concentration of 237 ppm. Viridicatol was the most active compound and had an ED50 value of ca. 50 ppm. Scopulariopsis sp. yielded three metabolites, including the known acetylcholinesterase inhibitors quinolactacin A1 and A2
New C-methylated flavonoids and alpha-pyrone derivative from roots of Talinum triangulare growing in Nigeria
No full textThe first chemical examination of roots of the traditionally used medicinal plant Talinum triangulare (Portulacaceae) from Nigeria led to the isolation of two new C-methylated flavonoids, 5,6-dimethoxy-7-hydroxy-8-methyl-flavone (1), 5,6-dimethoxy-8-methyl-2-phenyl-7H-1-benzopyran-7-one (2), and one new a-pyrone derivative, 4-methoxy-6-(2-hydroxy-4-phenylbutyl)-2H-pyran-2-one (3), along with thirteen known compounds, including nine amides (4-12), indole-3-carboxylic acid (13), p-hydroxy benzoic acid (14), and two steroids (15-16). Their structures were elucidated by extensive spectroscopic measurements including 1D, 2D NMR, MS, and by comparison with the literature. All isolated compounds were screened for their cytotoxic and antifungal activities. However, none of them showed significant activity. (C) 2016 Elsevier B.V. All rights reserved.Society for Medicinal Plant and Natural Product Research (GA)SCI(E)[email protected]; [email protected]
Jean-Marie Auwers, Concordance du Siracide (Grec II et Sacra Parallela) avec la collaboration d'Églantine Proksch-Strajtmann (coll. Cahiers de la Revue Biblique, 58). 2005
No full textBogaert Pierre-Maurice. Jean-Marie Auwers, Concordance du Siracide (Grec II et Sacra Parallela) avec la collaboration d'Églantine Proksch-Strajtmann (coll. Cahiers de la Revue Biblique, 58). 2005. In: Revue théologique de Louvain, 36ᵉ année, fasc. 4, 2005. p. 569
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Intercomparison of snow density measurements: bias, precision, and vertical resolution
No full textDensity is a fundamental property of porous media such as snow. A wide range of snow properties and physical processes are linked to density, but few studies have addressed the uncertainty in snow density measurements. No study has yet quantitatively considered the recent advances in snow measurement methods such as micro-computed tomography (uCT) in alpine snow. During the MicroSnow Davos 2014 workshop, different approaches to measure snow density were applied in a controlled laboratory environment and in the field. Overall, the agreement between uCT and gravimetric methods (density cutters) was 5 to 9 %, with a bias o
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
sj-docx-1-anz-10.1177_14413582231153191 – Supplemental material for How Micro-Influencers’ Personality Influences the Personality of Novice and Established Brands
No full textSupplemental material, sj-docx-1-anz-10.1177_14413582231153191 for How Micro-Influencers’ Personality Influences the Personality of Novice and Established Brands by Sebastian Zwicker, Liudmila Tarabashkina, Michael Proksch and Marco Hardiman in Australasian Marketing Journal</p
An E-business Strategy
No full textOn the last decade the integration of e-business into organizations has increased, but there are still difficulties during this process. In the present environment any organization must include into their business plan the possibility of identifying the e-business integration method, the implementation cost, and the expected results. The article's aim is to analyze the necessary means and steps in e-business integration into the business plan of an organization.e-business, e-strategy, business plan, digital economy
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
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