1,721,005 research outputs found
Enantioselectivity of Muscarinic Antagonists. 2,2-Dicyclohexyl-5-((dimethylamino)methyl)-1,3-oxathiolane Methiodide and Related 3-oxide.
No full textThe enantiomers of three chiral muscarinic antagonists carrying a 1,3-oxathiolane nucleus were prepared and theirabsolute configuration established. The enantioselectivity and tissue selectivity of such compounds were studiedon rat bladder and guinea pig ileum and heart. The results show that introduction of a sulfoxide function bringsabout a small but definite enantioselectivity in the 1,3-oxathiolane compound (2), which in itself does not showenantioselectivity among the tissues studied. The results obtained point to differences among cardiac and ilealmuscarinic receptors. Comparison of the absolute configuration related shows that the most potent isomersof both series share the same absolute stereochemistry
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
Enantioselectivity of Muscarinic Antagonists. Isomeric 2-Cyclohexyl-2-phenyl-5-(dimethylamino)methyl)-1,3-oxathiolane
No full textThe four isomers of 2-cyclohexyl-2-phenyl-[5 (-d imethylamino)methyl]-l,3-oxathiolanmee thiodide were prepared.Their absolute configuration was attributed by means of X-ray crystallography and circular dichroism. The compoundswere tested on rat bladder and guinea pig ileum and heart, and their antimuscarinic potency was evaluated andexpressed as pA2. The results show that the introduction of a chiral center into position 2 brings about a smallbut definite enantioselectivity on rat bladder and guinea pig ileum which is not seen for guinea pig heart. Thissupports the view that differences exist among the muscarinic receptors of these tissues (M2 receptors). Comparisonof the absolute configuration of the antagonists studied in this and in the preceding papel.2 and that of strictly relatedagonists supports the hypothesis of a common binding site for agonists and antagonists of this kind
Dual HDAC/BRD4 Inhibitors Relieves Neuropathic Pain by Attenuating Inflammatory Response in Microglia After Spared Nerve Injury
Full text linkDespite the effort on developing new treatments, therapy for neuropathic pain is still a clinical challenge and combination therapy regimes of two or more drugs are often needed to improve efficacy. Accumulating evidence shows an altered expression and activity of histone acetylation enzymes in chronic pain conditions and restoration of these aberrant epigenetic modifications promotes pain-relieving activity. Recent studies showed a synergistic activity in neuropathic pain models by combination of histone deacetylases (HDACs) and bromodomain and extra-terminal domain (BET) inhibitors. On these premises, the present study investigated the pharmacological profile of new dual HDAC/BRD4 inhibitors, named SUM52 and SUM35, in the spared nerve injury (SNI) model in mice as innovative strategy to simultaneously inhibit HDACs and BETs. Intranasal administration of SUM52 and SUM35 attenuated thermal and mechanical hypersensitivity in the absence of locomotor side effects. Both dual inhibitors showed a preferential interaction with BRD4-BD2 domain, and SUM52 resulted the most active compound. SUM52 reduced microglia-mediated spinal neuroinflammation in spinal cord sections of SNI mice as showed by reduction of IBA1 immunostaining, inducible nitric oxide synthase (iNOS) expression, p65 nuclear factor-κB (NF-κB) and p38 MAPK over-phosphorylation. A robust decrease of the spinal proinflammatory cytokines content (IL-6, IL-1ß) was also observed after SUM52 treatment. Present results, showing the pain-relieving activity of HDAC/BRD4 dual inhibitors, indicate that the simultaneous modulation of BET and HDAC activity by a single molecule acting as multi-target agent might represent a promise for neuropathic pain relief
“N,N-diethylaminoethanol and N-methyl-4-piperidinol Esters of 2,2-diphenyl-2-Ethylthioacetic Acid as Potent and Selective Muscarinic Antagonist”.
No full textDispelling 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
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