1,720,996 research outputs found
Genotossicità della vitamina E e disregolazione dell’omeostasi redox e del metabolismo degli xenobiotici
No full textGoing 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
Impact of e-cig vaping personalization on antioxidant defense: a multidisciplinary approach
No full textVariations 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
The effect of electronic-cigarettes aerosol on rat brain lipid profile
No full textThe electronic cigarettes (e-cigarettes, e-cigs) have become the most sought-after alternative to the traditional cigarettes, partly due to the widespread perception of safety. However, the high temperature reached by e-cig solutions can generate toxic compounds, some of which are listed as known human carcinogens. To evaluate the impact of e-cig aerosol on rat brain lipid profile, twenty male Sprague Dawley rats were exposed to 11 cycles/day (E-cig group), to consume 1 mL/day of e-liquid, for 5 days/week up to 8 weeks. Ten rats were sacrificed after 4 weeks (4w) and ten at the end of treatment (8w). The composition of total fatty acids, sterols and oxysterols of the lipid fraction of rat brains, was analyzed. The results of the E-cig group were compared with those of the control group (not exposed). After 8 weeks, the saturated fatty acids significantly raised up to 7.35 mg/g tissue, whereas polyunsaturated fatty acids decreased reaching 3.17 mg/g. The e-cig vaping increased both palmitic (3.43 mg/g) and stearic acids (3.82 mg/g), while a significant decrement of arachidonic (1.32 mg/g) and docosahexaenoic acids (1.00 mg/g) was found. Atherogenic (0.5) and thrombogenic (1.12) indices also increased in 8w treated animals. The e-cig aerosol significantly impacted the cholesterol homeostasis, since the latter at 8w (21.57 mg/g) was significantly lower than control (24.56 mg/mg); moreover, a significant increase of 7-dehydrocholesterol (1.87 mg/g) was also denoted in e-cig group. The e-cig aerosol also reduced the oxysterols (19.55 μg/g) formation, except triol and 24(S)-hydroxycholesterol (24(S)-HC), diminished after 8 weeks of exposure. The principal component analysis (PCA) separated all E-cig from control groups, evidencing that oxysterols (except triol and 24(S)-HC) were inversely correlated to 7-DHC and TI. The present research revealed that e-cigs aerosol affected the lipid and cholesterol homeostasis in rat brain, which could contribute to the new occurrence of some neurodegenerative diseases
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
Does fried high-oleic sunflower oil impact plasma lipid profile and liver enzymatic activity in rat?
No full textIntroduction: Deep-fat frying is one of the most important and widely spread cooking methods. The characteristics of the oil bath play a preponderant role on frying performance, as well as on the level of neoformation compounds generated by this cooking treatment. Over the past few years, palm oil and its fractions have been widely used as frying oil, due to its stability, low cost and positive impact on the sensory properties of fried food. However, due to its sustainability, process contaminants and health effects, it has been widely replaced with other vegetable oils (such as high-oleic sunflower oil, HOS) or palm-free frying mixtures in the catering sector, which are more unsaturated and thus more prone to oxidation than palm oil. Considering that vegetable oils that oxidize during frying can exert various toxicological effects, it would be interesting to assess the in vivo impact of fried HOS on rat lipid profile and liver Phase I, II and antioxidant enzymatic activity.
Materials and Methods: Twenty-two male Sprague Dawley rats aged 9 weeks and weighing 170-200 g, were housed under 12h-light/12h-dark cycle, 22°C, 60% humidity, and fed ad libitum. After 10-day adaptation, the rats were randomly split into four experimental units: HOS group daily treated with 2.6 g of fresh oil for 7 days; 2) HOS-7F group daily treated for 7 days with 2.6 g of 5-day fried oil (3 cycles at 180°C/day); 3) HOS-14 group daily treated with 2.6 g of fresh oil for 14 days; 4) HOS-14F group daily treated for 14 days with 2.6 g of 5-day fried oil (as described above). The animals were treated by gavage. Rats were fasted 16 h prior to sacrifice, which occurred 24 h after the last treatment, in accordance with approved Ministerial procedures appropriate to the species. Immediately prior to the sacrifice, a blood sample was collected from each animal. The liver was rapidly removed and processed separately.
Results: Only HSO-14F had a significant impact on the animal body weight (5.5% gain, p<0.01 vs HOS-14). HSO-7F group displayed a considerable inactivation of CYP2B1/2 isoform (40% loss, p<0.05 vs. HSO), while an increase (up to 45%, p<0.05 vs. HSO) of QNO1 activity was registered. Concerning plasma lipids, an increase of free cholesterol in fried-oil groups was denoted. On the other hand, no significant changes were observed in the fatty acid composition of both triacylglycerol and phospholipid fractions. In general, the level of cholesterol oxidation products (COPs) in plasma was higher in the fried-oil groups, while a significant reduction of 24-hydroxycholesterol (24-HC) was found in HSO-7F.
Conclusions: Dietary supplementation of fried HSO by gavage did not significantly affect liver Phase I, II and antioxidant enzymes, and fatty acid composition of plasma in rats regardless of the treatment length, so HSO could be considered a valid alternative to palm oil as frying oil. However, the higher presence of COPs in plasma, and in particular the reduction of 24-HC level, could suggest that fried HSO could exert some effect at brain level. A deeper investigation is thus needed to better clarify this result
Dispelling 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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