1,720,959 research outputs found
Photosensitization of Colpoda inflata cysts by meso-substituted cationic porphyrins
No full textColpoda inflata cysts accumulate significantly large amounts of meso-substituted cationic porphyrins, including
meso-tetrakis(N-methyl-4-pyridyl)porphine (TMP-C1) and its mono-N-methyldecyl (TMP-C10) and -tetradecyl
(TMP-C14) analogues, upon incubation for 1 h with 1–48 μM porphyrin concentrations. All three porphyrins at
concentrations greater than 10 μM exhibited a significant toxicity toward the cysts, in particular lowering the degree
of excystment. Upon visible light irradiation of the porphyrin-loaded cysts, extensive photodamage was observed
even in the presence of 1 μM porphyrin, as shown by light microscopy observations and counting of vegetative
emerging cells. The presence of one decyl or tetradecyl hydrocarbon chain caused about 10-fold enhancement
of the phototoxic effects
Porphyrins and related compounds as photoactivatable insecticides - I. Phototoxic activity of hematoporphyrin toward Ceratitis capitata and Bactrocera oleae
No full textPhotosensitized inactivation of Acanthamoeba palestinensis in the cystic stage.
No full textAims: To develop alternative approaches for medical and environmental control of pathogenic Acanthamoeba spp. by means of photodynamic treatment with a tetracationic Zn(II)-phthalocyanine (RLP068).
Methods and Results: Incubation of cyst cultures with RLP068 for 1 h caused an accumulation of readily detectable concentrations of the phthalocyanine, even at doses as low as 0•5 μmol l-1. RLP068 exhibited no dark toxicity towards cysts up to 5 μmol -1 concentration. A decrease of c. 50% in cyst survival in comparison with controls was measured upon incubation of the cysts with 0•5 μmol -1 RLP068, followed by exposure to light (600-700 nm) for 20 min at a fluence rate of 50 mW cm-2 (60 J cm -2). After incubation with 3 and 5 μmol -1 RLP068 and irradiation, the cysts lost their excystment ability as early as day 5 and up to day 10, and were clearly damaged when observed under an interference contrast microscope. Conclusions: These data indicate the promising use of RLP068 in phototreatment of diseases caused by pathogenic amoebae and in initial disinfection of wastewaters.
Significance and Impact of the Study: Rapid and extensive photodamage may be induced in the highly resistant cystic stages by means of 600- to 700-nm light sources
Studi sulla possibilità dell'uso dell'ematoporfirina come agente fotosterilizzante delle acque di rifiuto
No full text
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
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