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E-cigarettes induce toxicological effects that can raise the cancer risk. The contribute of EPR radical trapping technique
No full textE-cigarettes induce toxicological effects that can raise the cancer
risk. The contribute of EPR radical probe technique
Donatella Canistro1, Fabio Vivarelli1, Silvia Cirillo1, Andrea Sapone1, Moreno Paolini1,
Paola Franchi2, Marco Lucarini2
1Department of Pharmacy and Biotechnology (University of Bologna, Via Irnerio 48, I-40126 Bologna, Italy)
2Department of Chemistry “G. Ciamician” (University of Bologna, Via San Giacomo 11, I-40126 Bologna, Italy)
E-mail: [email protected]
Electronic cigarettes (e-cigs) are devices designed to deliver nicotine in a vaping solution rather than smoke and without tobacco combustion. Perceived as a safer alternative to conventional cigarettes, e-cigs are aggressively marketed as lifestyle-choice consumables, thanks to few restrictions and a lack of regulatory guidelines. Despite the burgeoning worldwide consumption of e-cigs, their safety remains largely unproven and it is unknown whether these devices cause in vivo toxicological effects
that could contribute to cancer. Here we illustrate the contribute of EPR radical probe technique in a study where it was possible to demonstrate the co-mutagenic and cancer-initiating effects of e-cig vapour in a rat lung model. It was found that e-cig have a powerful booster effect on phase-I carcinogen-bioactivating enzymes, and increase oxygen free radical production and DNA oxidation.
We are able to indirectly evaluate the content of reactive oxygen species (ROS) in lungs tissues of exposed rats, by using an appropriate hydroxylamine that in the presence of transient radical species gives rise to a persistent nitroxide radical. (see Scheme 1)
Scheme 1
We found a significant increase of radical species production in samples of lungs tissues from exposed rats compared to samples from non-exposed animals.
[1] Canistro, D.; Vivarelli, F.; Cirillo, S.; Babot Marquillas, C.; Buschini, A.; Lazzaretti, M.;Marchi, L.; Cardenia, V.; Rodriguez-Estrada, M.T.; Lodovici, M.; Cipriani, C.; Lorenzini, A.; Croco, E.; Marchionni, S.; Franchi, P.; Lucarini, M.; Longo, V.; Della Croce, C.M.; Vornoli, A.; Colacci, A.; Vaccari, M.; Sapone, A.; Paolini, M. SCIENTIFIC REPORTS. 2017, DOI:10.1038/s41598-017-02317-8
[2] Vivarelli, F.; Canistro, D.; Franchi, P.; Sapone, A.; Vornoli, A.; Della Croce, C.; Lucarini, M.; Paolini, M. Life Sciences, 2016, 145, 166-173. DOI:10.1016/j.lfs.2015.12.033
[3] Fabbri, R.; Sapone, A.; Paolini, M.; Vivarelli, F.; Franchi, P.; Lucarini, M.; Pasquinelli, G.; Vicenti, R.; Macciocca, M.; Venturoli, S.; Canistro, D. Hystology and Hystopatology, 2015, 30, 725-730 DOI: 10.14670/HH-30.72
Avoidance of bioflavonoid supplements during pregnancy: A pathway to infant leukemia?
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Determination of lipophilicity by means of reversed-phase thin-layer chromatography. I. Basic aspects and relationship between slope and intercept of TLC equations
No full textThe main aspects of the authors' chromatographic work are reviewed. The determination of lipophilicity by means of TLC techniques is mainly based on the linear relationship between RM values and organic solvent concentrations in the mobile phase, as described by the TLC equation. The very good correlation between experimental and extrapolated RM values supports the validity of the extrapolation technique. Another interesting aspect is that the nature of the organic solvent does not affect the measurement of lipophilicity. However, the main purpose of this paper was to re-examine all the TLC equations in order to assess whether the relationship between intercepts and slopes is a basic feature of the chromatographic determination of lipophilicity. The analysis of more than 700 TLC equations showed that the above relationship holds only when dealing with series of strictly congeneric compounds. The structural meaning of chromatographic congenerity is discussed. © 1994
Determination of lipophilicity by means of reversed-phase thin-layer chromatography. II. Influence of the organic modifier on the slope of the thin-layer chromatographic equation
No full textThe RM values measured for a series of steroids were very close to those determined more than 15 years ago using the same chemicals. This finding supports the reliability of RM values as a lipophilicity parameter. However, the point at issue in this work was the influence of the organic solvent in the mobile phase on the slopes of the TLC equations. In fact, the slopes of the TLC equations were shown to be related to the reciprocal of the solvent strength (1/E0). As a consequence, the ratio between the slopes of the TLC equations in different solvent systems are close to the ratio between the 1/E0 values for the corresponding solvent pairs. A further interesting aspect seems to arise from the analysis of the equations correlating slopes and intercepts of the TLC equations. In particular, the ratios between the b values of such equations in different solvent systems are close to the ratios between the corresponding E0 values. © 1994
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
Thin-layer chromatographic study of the lipophilicity of triazine herbicides. Influence of different organic modifiers
No full textThe RM values of a series of triazine herbicides were measured using a reversed-phase TLC system with acetone, methanol or acetonitrile as the organic modifier of the mobile phase. The overlapping of the extrapolated RM values from three different systems shows that they are not dependent on the nature of the organic solvent. However, a more interesting point arises from a comparison of the b values of the TLC equation. The slopes of the straight lines describing the relationship between RM values and composition of the mobile phase are related to the solvent strength of the solvents. © 1992
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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