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1,3-diastereocontrol With Bromoallenes - Synthesis of Enantiomerically Pure Beta-branched Alpha-amino-acids
No full textBromoallenes 3a and 3b derived from (D)-Serine undergo S(N)2' alkylation with organo copper reagents to give alkynyl amino alcohol derivatives. These compounds can be further transformed into blanched enantiomerically enriched alpha-amino acids as, for example (L)-Isolcucine and (L)-Alloisoleucine
Ligands of the peripheral-type benzodiazepine binding sites (PBS) structure-activity relationships and computer-aided conformational analysis
No full textDiastereoselectivity In Conjugate Addition of Alkylcuprates To Vinylogous Ester of N,o-diprotected Serinal
No full textVarious alkylcuprates were added to the Z and E vinylogous esters of N,O-diprotected (D) or (L) serinal 1. Good to excellent yields and asymmetric inductions were observed. © 1990
Synthesis of 2- or/and 6-methylated analogues of isoguvacine (1,2,3,6-tetrahydropyridine-4-carboxylic acid) a GABA(A) agonist
No full text1,2,3,6-Tetrahydropyridine-4-carboxylic acid (isoguvacine) and related 2-and/or 6-methylated analogues (1-4) were synthesized using the methoxycarbonylation [Pd(OAc)(2), PPh(3), CO, MeOH)] of their corresponding vinylic triflates. Analogue (5), the 6-methyl-1,2,3,6-tetrahydropyridine-4-carboxylic acid was obtained after a reductive deoxygenation of the corresponding beta-keto ester
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Estrogenic activity: An example of considering effectuation models in biological data interpretation and QSAR
No full textOn a preliminary series of 1,2-dialkylated 1,2-bis(hydroxyphenyl)ethanes and -ethenes, the interrelations of affinity (pKD on estrogen receptor from calf uterus cytosol) and activity parameters (maximal estrogenic activity emax compared to estrone = 1, the Hill coeff. nH, and pD2 = log ED50) were investigated by principal component anal., leading to some first results about the structural dependence of the different steps of ligand-receptor interactions
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