1,721,337 research outputs found
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
Teoremi di confronto tra diverse nozioni di movimento secondo la curvatura media
No full textComparison theorems between different notions of motion by
mean curvature.
In this note we state some comparison theorems between De Giorgi's
definition of motion by mean curvature using the barriers method
and the evolutions defined with the methods of
Evans-Spruck, Chen-Giga-Goto, Giga-Goto-Ishii-Sato
Some results on minimal barriers in the sense of De Giorgi applied to driven motion by mean curvature
No full textWe prove some properties of the minimal barriers in the sense of De Giorgi for the driven mean curvature flow in codimension one. We compare the resulting evolution with an abstract evolution, and in particular with the evolution defined with the methods of Evans-Spruck, Chen-Giga-Goto, and Giga-Goto-Ishii-Sato
Two examples of fattening for the curvature flow with a driving force
No full textWe provide two examples of a regular curve
evolving by curvature with a
forcing term, which degenerates in a set having an interior part
after a finite time
Quasi-optimal error estimates for the mean curvature flow with a forcing term
Full text linkWe study a singularly perturbed reaction-diffusion equation with a small
parameter .
This problem is viewed as an approximation of the evolution
of an interface by its mean curvature with a forcing term.
We derive a quasi-optimal error estimate of order
\O(\epsilon^2|\log\epsilon|^2) for the interfaces, which is valid before the onset
of singularities, by constructing suitable sub and super solutions.
The proof relies on the behaviour at infinity of functions appearing in
the truncated asymptotic expansion, and by using a modified distance
function combined with a vertical shift
On the area of the graph of a singular map from the plane to the plane taking three values
No full textWe improve an estimate given by Acerbi and Dal Maso in 1994, concerning the area of the graph of a singular map from the disk of R2 into R2, taking only three values, and jumping on three half-lines meeting at the origin in a triple junction
Anisotropic motion by mean curvature in the context of Finsler geometry
No full textWe study the anisotropic motion of a hypersurface in the context of the geometry of Finsler spaces. This amounts in considering the evolution in relative geometry, where all quantities are referred to the given Finsler metric representing the anisotropy, which we allow to be a function of space. Assuming that the anisotropy is strictly convex and smooth, we prove that the natural evolution law is of the form "velocity = ", where is the relative mean curvature vector of the hypersurface. We derive this evolution law using different approches, such as the variational method of Almgren-Taylor-Wang, the Hamilton-Jacobi equation, and the approximation by means of a reaction-diffusion equation
Numerical simulations of measurements of capillary contact angles
No full textIn a recent paper, Fischer and Finn have proposed a procedure
to improve the accuracy in the measurament of capillary contact angles,
based on the use of vessels with canonical cross-sections.
We simulate numerically the behaviour of such shapes for a number
of cross-sections and fluid contact angles.
Our approximation consists of the minimization of a suitable convex
functional discretized by finite elements
Variational properties of an image segmentation functional depending on contours curvature
No full textWe study a problem of image segmentation involving the length and the curvature of the contours. The (possibly linear) curvature term in the energy functional is introduced, following an idea by Mumford and Nitzberg, in order to reconstruct the hidden parts of the image occluded by regions which are closer to the observer
Convex approximations of an inhomogeneous anisotropic functional
No full textThe numerical minimization of the functional
F(u)=\int_\Omega \phi(x,\nu_u)|Du|+\int_{\partial\Omega\mu u -\int_\Omega\kappa u,
, is addressed. The function is continuous, has linear growth, and is convex and positively homogeneous of degree one in the second variable.
We prove that can be equivalently
minimized on the convex set and then regularized
with a sequence of strictly convex functionals.
Then both and can be discretized by continuous linear
finite elements. The convexity property of the functionals on is useful in the numerical minimization of . The -convergence of the discrete functionals to F, as well as the
compactness of any sequence of discrete absolute minimizers, are proven
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