1,720,959 research outputs found
ANALYSIS OF POLYNUCLEAR AROMATIC HYDROCARBONS (PAH) IN THE – TOSSICOLOGICAL DATA BANK OF SOIL AND DERIVATIVE PRODUCTS –
No full text“RIARRANGIAMENTI STEREOSELETTIVI 1,2 E 2,3 DI WITTIG DI ETEROARILALCHIL ALLYL E PROPARGIL ETERI”
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1,2- AND 2,3-WITTIG STEREOSELECTIVE REARRANGEMENT OF HETEROARYLALLYL AND PROPARGYL ETHERS
No full textThe Stereoselective Synthesis of Alkenyl-β-lactams by Palladium-Catalyzed [2+2] Carbonylative Cycloaddition.
No full textAllyl halides of different structures, under CO pressure, in
the presence of Et3N, a catalytic amount of Pd(OAc)2, and
triphenylphosphane as ligand, undergo a [2+2] cycloaddition
reaction with various imines. The reaction is highly regioand
stereoselective: β-lactams are formed in good yields andwith trans diastereoselectivity in both the β-lactam ring and
the vinylic moiety. New and important information is suggested
regarding the known reaction mechanism
Stereoselective synthesis of 2-acyl-3,4-dihydro-1,4-benzothiazines
No full text2-Benzylidene-4-methyl-3-oxo-2H-1,4-benzothiazine 2 undergoes 1,2-addition with MeMgI and allylic magnesium halides to give 2-acyl-4-methyl-3-phenyl-3,4-dihydro-2H-1,4-benzothiazines 3a-d. Lithiation of 3a and subsequent reaction with MeI and PhCH2Br leads to compounds 3e, 3f, 3h and 3i. In contrast, the reaction of lithiated 3a with benzaldehyde and 2,6-dichlorobenzaldehyde furnished compounds 3k and 3l respectively. © 1994
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
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