1,720,982 research outputs found
Pregnancy interruption in the bitch by vaginal administration of prostaglandins: comparison between synthetic and natural PGF2alfa
No full textEffect of chronic treatment with pravastatin and simvastatin on excitation-contraction coupling of rat skeletal muscle fibers
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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
Synthesis of Chiral Analogues of Mexiletine and Activity on Skeletal Muscle Sodium Channels
No full textlibro First Italian-Swiss Meeting on Medicinal Chemistry, A14, 68 (Poster
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
Evaluation of the antimyotonic activity of mexiletine and some new analogs on sodium currents of single muscle fibers and on the abnormal excitability of the myotonic ADR mouse
No full textDeLuca A, Pierno S, Natuzzi F, et al. Evaluation of the antimyotonic activity of mexiletine and some new analogs on sodium currents of single muscle fibers and on the abnormal excitability of the myotonic ADR mouse. JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS. 1997;282(1):93-100.To search for use-dependent sodium channel blockers to selectively solve skeletal muscle hyperexcitability in hereditary myotonias, mexiletine (MEX; compound I) and its newly synthetized analogs, 2-(4-chloro-2-methylphenoxy)-benzenethanamine (compound II) and (-)-S-3-(2,6-dimethylphenoxy)-2-methylpropanamine (compound III), were tested on intercostal muscle fibers from the myotonic ADR mouse through use of the standard current-clamp microelectrode technique. in parallel, the effects of these compounds on the sodium channels were measured on frog muscle fibers under voltage-clamp conditions. The tonic and use-dependent blocks of peak sodium currents (I-Namax) produced by each compound were evaluated by using a single depolarizing pulse and a pulse train at 10 Hz frequency, respectively. At 10 and 50 mu M, MEX decreased the occurrence of spontaneous excitability in myotonic muscle fibers; 100 mu M was required to decrease the amplitude of the action potential and the stimulus-induced firing of the membrane as well as to increase the threshold for generation of action potential. At 300 mu M, MEX decreased the latency of the action potential and increased the threshold current to elicit a single action potential. MEX produced a tonic block of I-Namax with an half-maximal concentration (IC50) of 83 mu M, but the IC50 value for use-dependent block was 3-fold lower. Compound III, which differs from MEX in that it has a longer alkyl chain, similarly blocked first the spontaneous and then the stimulus-evoked excitability of myotonic muscle fibers but at 2-fold lower concentrations than MEX. Compound III was less potent than MEX in producing a tonic block of I-Namax (IC50 = 108 mu M) but was a strong use-dependent blocker with an IC50 close to 15 mu M. The more lipophylic compound II irreversibly blocked both spontaneous and stimulus-evoked membrane excitability at concentrations as low as 10 mu M and shortened the latency of the action potential in a concentration-dependent fashion. Compound II produced a potent tonic block of I-Namax (IC50 = 30 mu M), and its potency increased 2-fold during high-frequency stimulation. Both of the new analogs (compound II in particular), but not MEX, were less effective on the excitability parameters of striated fibers of healthy vs. ADR mice, a characteristic that increases their interest as potential antimyotonic agents
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
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