1,720,966 research outputs found
Fluorinated Porphyrinic Crystalline Solids: Structural Elucidation and Study of Intermolecular Interactions
Mono- and di-(2,3,5,6-tetrafluoro-4-N,N-dimethylaminophenyl) <i>meso</i>-tetraarylporphyrins: Synthesis, spectral, structural and electrochemical studies
A new series of mono-/di-aminated meso-tetraarylporphyrins has been synthesized and characterized by conventional spectroscopic methods. Crystal structure analysis shows that interactions involving halogens are the major contributors, and the relative contributions are 56% and 53% respectively for MB2c and MB3c. All the compounds were electrochemically analyzed under different reaction conditions and showed a positive shift in the reduction and oxidation potentials. The HOMO–LUMO energy gap was altered with respect to the nature of the supporting electrolyte and reference electrodes used. The linear behavior of Randles-Sevcik plots indicate that the redox processes are diffusion controlled; the first reduction/oxidation is a reversible one-electron step whereas the second reduction/oxidation is a quasi-reversible one-electron process. Results also reveal that the mono-aminated porphyrins are more electron deficient than non-aminated and di-aminated porphyrins. </jats:p
A “turn-on-and-off” pH sensitive BODIPY fluorescent probe for imaging <i>E. coli</i> cells
Highly selective fluorescent BODIPY probes towards H+ ions displayed good photostability and reversibility and the utility of acid sensitive behavior to visualize extreme acidity in E. coli cells is also demonstrated.</p
Pentafluorophenyl dipyrrin as probe for transition metal ion detection and bioremediation in Bacillus subtilis and Bacillus cereus
Recognition of transition metal ions and bioaccumulation in B. subtilis and B. cereus were examined using pentafluorophenyl dipyrrin probe.</p
Synthesis, Crystal Structure and Hirshfeld Surface Analysis of Copper(II) Complex with Pentacoordinated N5 ligands [Cu(AEPN)(2PN)](ClO4)2
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
Dispelling the Myths Behind First-author Citation Counts
We 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
- …
