1,720,954 research outputs found
Tubular segment-specific biomarkers of nephrotoxicity in the rat.
No full textSegment-specific localization of p-aminohippuric acid accumulation and glutamine synthetase activity along the
proximal tubule was investigated in kidneys of rats treated with segment-specific nephrotoxicants such as potassium
dichromate (pars convoluta) and hexachloro-1:3-butadiene (pars recta). Potassium dichromate and the highest dose
(200 mg/kg b.w.) of hexachloro-1:3-butadiene caused a significant, dose-dependent decrease of p-aminohippuric acid
uptake in the renal cortical slices 24 and 48 h after the treatment. In contrast, hexachloro-1:3-butadiene and only the
highest dose (40 mg/kg b.w.) of potassium dichromate, caused a significant dose-dependent decrease of glutamine
synthetase activity in the kidney beginning 24 h after treatment. Finally, potassium dichromate and the highest dose
(200 mg/kg b.w.) of hexachloro-1:3-butadiene (48 h after the treatment) caused a significant dose-dependent loss of
kidney protein content. The results suggest that p-aminohippuric acid accumulation is localized in the pars convoluta
and confirm that glutamine synthetase is in the pars recta of the rat proximal tubule. p-Aminohippuric acid uptake
impairment and glutamine synthetase activity loss caused by the highest doses of hexachloro-1:3-butadiene and
potassium dichromate, respectively, suggests that high doses of segment-specific chemicals may involve other portions
of the proximal tubule; in addition, the decrease of glutamine synthetase activity caused by potassium dichromate
may be related to the protein content loss
Influence of the reaction conditions on the productivity and on the molecular weight of the polyketone obtained by the CO–ethene copolymerisation catalysed by [Pd(TsO)(H2O)(dppp)](TsO) in MeOH
No full textThe influence of the operating conditions on the productivity on the CO-ethene copolymerisation catalysed by the title complex used in combination with TsOH and on the average numerical molecular weight, the limiting viscosity number and the average viscosity molecular weight of the resulting polyketone has been studied. The productivity, LVN and over(M, ̄)v pass through a maximum for a TsOH/Pd ratio = 6/1, whereas over(M, ̄)n reaches a plateau and remains practically constant at higher acid concentration. They increase upon increasing the pressures of the monomers when employed in the ratio 1/1 as well as upon increasing the pressure of CO keeping constant the pressure of the other monomer; the productivity as well as over(M, ̄)n increase, whereas the LVN and over(M, ̄)v pass through a maximum upon increasing the pressure of ethene, keeping constant the pressure of CO. A power law rate equation for the productivity has been obtained. The productivity decreases whereas the molecular weights increase upon lowering the temperature; the productivity decreases upon increasing the reaction time, whereas the molecular weights are little influenced. The results are discussed in the light of the copolymerisation mechanism
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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