1,720,954 research outputs found
Solid-Phase Synthesis of Gly-Ψ[CH(CF3)NH]-Peptides
Full text linkThe solid-phase synthesis of Gly-Ψ[CH(CF3)NH]-peptides is presented. In order to achieve this goal, the synthesis of Gly-Ψ[CH(CF3)NH]-dipeptides having the C-terminus unprotected, the N-terminus protected as Fmoc- or Teoc-, and possibly side chain functionalities protected with acid-labile protecting groups has been developed. A selected small library of six peptidomimetics, encompassing analogues of biological relevant peptides, have been obtained in high purity
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
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
Development of an efficient Fmoc strategy for the solution/solid phase synthesis of [psi][CH(CF3)NH]Gly-peptides
No full textLAUREA MAGISTRALENegli ultimi decenni, vi è stato un crescente interesse verso i peptidi da parte dell’industria farmaceutica. Inoltre, la scoperta che particolari peptidi siano capaci di attraversare la membrana cellulare pone le premesse per impiegarli come nuovi vettori per il trasporto intracellulare di diverse entità molecolari a utilizzo terapeutico o diagnostico.
Tuttavia, lo sviluppo dei peptidi nel mondo farmaceutico è spesso ostacolato dalla loro elevata velocità di degradazione e scarsa biodisponibilità. Di conseguenza, è alto l’interesse nello sviluppo di strutture peptidomimetiche che mimano la struttura e le proprietà biologiche dei peptidi ma allo stesso tempo possiedono migliori caratteristiche di biodisponibilità.
Ad esempio, l’unità fluorurata [CH(CF3)NH] può essere utilizzata come sostituente di uno dei deboli legami ammidici che caratterizzano la struttura peptidica, incrementandone, quindi, la stabilità. Il nostro progetto prevede, dunque, di sintetizzare una piccola libreria di ψ[CH(CF3)NH]-dipeptidi fluorenilmetilossicarbonil (Fmoc)-protetti, nei quali l’unità trifluoro-etilamminica sostituisce il legame peptidico, utilizzando la classica sintesi chimica in soluzione e, poi, integrare questi piccoli “building block” in una crescente catena peptidica sfruttando la sintesi di peptidi in fase solida (SPPS). Questo lavoro rappresenta, quindi, il primo passo per studiare la possibilità di integrare l’unità fluorurata sopra citata in peptidi di interesse biologico con lo scopo di aumentarne la stabilità senza modificarne la bioattività.In the last decades, there was a growing interest for the use of peptides in the pharmaceutical industry. Moreover, the finding that specific peptides, called cell-penetrating peptides or CPPs, were able to easily cross the cell membrane opened the possibility of using them as novel intracellular delivery vectors for a wide array of molecular cargos, for therapeutic or diagnostic applications. However, peptide-based drug development has often been hindered by peptides short plasma half-life and poor oral bioavailability. Consequently, there is rising concern in the design and synthesis of peptidomimetics which mimic the structure and biological features of native peptides while possessing better drug-like properties.
As example, a fluorinated [CH(CF3)NH] unit can be exploited as substituent for one of the cleavage susceptible amide bonds in peptide backbone to improve peptides stability. Thus, our plan was to synthetize a small library of fluorenylmethyloxycarbonyl (Fmoc)-protected ψ[CH(CF3)NH]-dipeptides, in which a trifluoroethylamine function replaces the original peptide bond, exploiting conventional solution phase chemical synthesis and, then, integrate these small building blocks in a growing peptide chain through solid phase peptide synthesis (SPPS). This is the first step to study the feasibility of incorporating the above-mentioned fluorinated unit in peptide chains of biological interest, such as CPPs, with the aim of improving their degradation resistance without modifying their bioactive features
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
