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Axinelline A e B: due ciclopeptidi con attività antiproliferativa dalla spugna Axinella carteri.
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Crellastatin A : a Cytotoxic Bis-Steroid Sulfate from the Vanuatu Marine Sponge Crella sp.
No full textA new nonsymmetric dimeric steroid, crellastatin A (1), was isolated from the Vanuatu Island marine sponge Crella sp. Structural assignment was accomplished through extensive 2D NMR spectroscopy. The stereochemistry of 1 was established from an analysis of ROESY experiments and from molecular mechanics and dynamics calculations. Crellastatin A (1), which possesses an unprecedented connection through the side chains, exhibits in vitro cytotoxic activity against NSCLC-N6 cells (IC(50) of 1.5 &mgr;g/mL)
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
Axinellins A and B: new proline-rich cyclopeptides from the Vanuatu sponge Axinella carteri
No full textCrellastatins: a new class of cytotoxic dimeric sulphated sterols from the Vanuatu sponge Crella sp.
No full textInvestigation of the polar steroids from an Antarctic starfish of the family Echinasteridae: isolation of twenty seven polyhydroxysteroids and steroidal oligoglycosides, structures and biological activities
No full textAn investigation of the extracts from a starfish collected in the Antarctic Sea, Echinasteridae family, has led to the isolation of thirteen glycosides of polyhydroxysteroids (1-13), fourteen polyhydroxysteroids (14-27), which are the subject of this report, and seven asterosaponins (penta-and hexa-saccharides), described in a previous paper. A selection of fifteen compounds were tested against human non-small-cell lung carcinoma cells and found to be moderately cytotoxic
Starfish saponins. 55. Isolation, structure elucidation, and biological activity of the steroid oligoglycosides from an Antarctic starfish of the family Asteriidae
No full textThis paper reports an analysis of the chemical constituents from an Antarctic starfish of the family Asteriidae. Different steroid glycoside types are represented among its constituents, including the five hexaglycoside steroidal sulfates asteriidosides A-E (1-5), and the two nonsulfated diglycosides asteriidoside F (6) and G (7). Also present are the two sulfated diglycosides asteriidoside H (8) and I (9) and one sulfated monoglycoside asteriidoside L (10). Eight of the compounds were tested against human nonsmall-cell lung carcinoma cells (NSCLC-L16) and found to be moderately cytotoxic
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
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