1,720,959 research outputs found
New copper(II) complexes of the anti-inflammatory drug mefenamic acid: A concerted study including synthesis, physicochemical characterization and their biological evaluation
No full textReaction of hydrated copper(ii) mefenamate in the presence of diverse N-donor ligands such as N,N,N′,N′-tetramethylethylenediamine (temed), ethylenediamine (en), β-picoline (β-pic) in a methanol:water mixture (4:1, v/v) yielded crystalline monomeric copper(ii) complexes [Cu(temed) (mefenamato)2], 1, [Cu(en)2(H2O)2](mefenamato)2, 2 and [Cu(β-pic)2(mefenamato)2]·H2O, 3. The newly synthesized complexes have been characterized by elemental analysis, spectroscopic methods (FT-IR, UV-Vis and EPR), thermogravimetric analyses and single-crystal X-ray structure determination in the case of complexes 2 and 3. The ground-state geometry optimization of complex 1 was performed by DFT calculations. In order to verify the complexes capability to get bound and possibly transported by the albumin towards their biological targets (cells and/or tissues), the interaction with bovine (BSA) and human serum albumin (HSA) was studied by fluorescence emission spectroscopy. The interaction of complexes 1-3 with calf-thymus DNA (CT DNA) was monitored by UV-Vis spectroscopy, cyclic voltammetry, viscosity measurements and via the ethidium bromide (EB) displacement from the EB-DNA conjugate performed by fluorescence emission spectroscopy, as a preliminary approach to evaluate their potential biological activity
Synthesis, characterization, single crystal X-ray structure, EPR and theoretical studies of a new hybrid inorganic-organic compound [Cu(Hdien)2(H2O)2](pnb)4·4H2O and its structural comparison with related [Cu(en)2(H2O)2](pnb)2
No full textA new hybrid inorganic-organic compound [Cu(Hdien)2(H2O)2](pnb)4·4H2O (1) (where pnb = p-nitrobenzoate), in which the tridentate ligand diethylenetriamine (dien) shows an unusual coordination behavior acting as a bidentate ligand when present in its monoprotonated form (Hdien+) has been synthesized by the reaction of copper(II) p-nitrobenzoate and slight excess of dien in methanol-water mixture (4:1v/v). Re-crystallization of the violet precipitated product from hot water gave single crystals suitable for X-ray diffraction studies. The newly synthesized compound 1 has been characterized by spectroscopic techniques (UV-Vis, FT-IR, EPR), and theoretical methods (DFT and MRCI/SORCI). Single crystal X-ray structure determination revealed the existence of the cationic species [Cu(Hdien)2(H2O)2]4+, four p-nitrobenzoate as counter anions and four water molecules are present as solvent of crystallization. Packing analyses of title compound as well as of the structurally similar [Cu(en)2(H2O)2](pnb)2, 2 has shown similarities in the crystalline architecture that both hybrid inorganic-organic compounds is stabilized by various non-covalent interactions such as N-H⋯O, C-H⋯O, O-H⋯O etc
Hybrid inorganic-organic complexes: Synthesis, spectroscopic characterization, single crystal X-ray structure determination and antimicrobial activities of three copper(II)-diethylenetriamine-p-nitrobenzoate complexes
No full textThree new hybrid inorganic-organic complexes: [Cu(dien)(pnb)2]·H2O, 1; [Cu(dien)2](pnb)2, 2; and [Cu(dien)(pnb)(H2O)](pnb)(Hpnb), 3 (where pnb = p-nitrobenzoate, dien = diethylenetriamine, tridenate N-donor ligand), have been synthesized at room temperature and characterized by spectroscopic (FT-IR, UV–Vis, EPR) methods. The structures of all newly synthesized complexes 1–3 have been unambiguously established by single crystal X-ray structure determination. All the complexes 1–3 showed variation in the coordination environment around copper(II) metal center obtained under slightly different reaction conditions by using same reactants but different synthetic routes at room temperature. Crystal lattices of coordination complexes 1–3 are stabilized by various non-covalent interactions such as N-H...O, C-H...O, O-H...O etc. All the three copper(II) complexes 1–3 show significant antimicrobial activity against gram positive bacteria
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
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
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