1,721,038 research outputs found
Solvent 1H NMRD study of biotinylated paramagnetic liposomes containing Gd-bis-SDA-DTPA or Gd-DMPE-DTPA
No full text2-Heteroarylimino-5-benzylidene-4-thiazolidinones as new inhibitors of matrix metalloproteinase-13
No full textA Calix[4]arene GdIII Complex Endowed with High Stability, Relaxivity and Binding Affinity to Serum Albumin
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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
X-ray structures of ternary enzyme-product-inhibitor complexes of MMP
No full textA helicoidal filament results from the approach of the N-terminus of the mutated variant of the catalytic domain of MMP-12 with the catalytic zinc center of another molecule (see X-ray structure); adjacent filaments are arranged in double helices. The N-terminal fragment is proposed to be analogous to an N-terminal polypeptide product after cleavage. Crystals yield two contrasting structures, in which the NH3+ ion is either triply hydrogen bonded, or only exhibits van der Waals interactions
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
1H NMR Relaxometric Study of Chitosan-Based Nanogels Containing Mono- And Bis-Hydrated Gd(III) Chelates: Clues for MRI Probes of Improved Sensitivity
No full textHydrogel nanoparticles composed of chitosan and hyaluronate and incorporating Gd-based MRI contrast agents with different hydration number (e.g., [Gd(DOTA)(H2O)]- and [Gd(AAZTA)(H2O)2]-) were prepared and fully characterized. In particular, 1H NMR relaxometric data, acquired as a function of temperature and applied magnetic field strength, were for the first time thoroughly analyzed using a theoretical model that includes the effects of a static zero-field splitting and an anisotropic molecular tumbling. The paramagnetic nanoparticles show excellent stability in aqueous solution for over 150 h and do not release the load of Gd(III) chelates. These nanoparticles exhibit enhanced efficacy (relaxivity) as relaxation agents, over 6 times that of the free complexes, thanks to the combination of a restricted molecular dynamics in the presence of a fast exchange of metal-bound water molecule(s) and between the water inside the nanogel and the bulk water. The knowledge of the molecular parameters that control the effectiveness of these MRI nanoprobes and those that limit their further increase will be crucial for the development of optimized systems with high sensitivity and stability
Solvent 1H NMRD study of biotinylated paramagnetic liposomes containing Gd-bis-SDA-DTPA or Gd-DMPE-DTPA
No full textThe relaxometric properties of two biotinylated paramagnetic liposomes with different lipophilic complexes have been investigated by water proton nuclear magnetic resonance dispersion. The proton retaxivity was found to have a peak at the proton Larmor frequencies generally used in MRI, and to be largely affected by the residence lifetime of the water molecule in the coordination site of the metal chelate. The measurements also indicate that a local motion in the nanosecond time scale, i.e, much faster than the rotational time of the whole liposome, is effective. Possible explanations for this behavior are discussed, that may provide guidelines for the design of second-generation paramagnetic liposomes as contrast agents. (C) 2002 Elsevier Science B.V. All rights reserved
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