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1.
Sci Rep ; 10(1): 15224, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938969

RESUMO

The aerosol properties of Mount Etna's passive degassing plume and its short-term processes and radiative impact were studied in detail during the EPL-RADIO campaigns (summer 2016-2017), using a synergistic combination of observations and radiative transfer modelling. Summit observations show extremely high particulate matter concentrations. Using portable photometers, the first mapping of small-scale (within [Formula: see text] from the degassing craters) spatial variability of the average size and coarse-to-fine burden proportion of volcanic aerosols is obtained. A substantial variability of the plume properties is found at these spatial scales, revealing that processes (e.g. new particle formation and/or coarse aerosols sedimentation) are at play, which are not represented with current regional scale modelling and satellite observations. Statistically significant progressively smaller particles and decreasing coarse-to-fine particles burden proportion are found along plume dispersion. Vertical structures of typical passive degassing plumes are also obtained using observations from a fixed LiDAR station constrained with quasi-simultaneous photometric observations. These observations are used as input to radiative transfer calculations, to obtain the shortwave top of the atmosphere (TOA) and surface radiative effect of the plume. For a plume with an ultraviolet aerosol optical depth of 0.12-0.14, daily average radiative forcings of [Formula: see text] and [Formula: see text], at TOA and surface, are found at a fixed location [Formula: see text] downwind the degassing craters. This is the first available estimation in the literature of the local radiative impact of a passive degassing volcanic plume.

2.
Eur J Pharmacol ; 588(1): 47-51, 2008 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-18495109

RESUMO

The inhibition of cell proliferation by methyl (2Z,4E)-2-methylsulfanyl-5-(1-naphthyl)-4-nitro-2,4-pentadienoate (1-Naph-NMCB) and (1E,3E)-1,4-bis(2-naphthyl)-2,3-dinitro-1,3-butadiene (2-Naph-DNB) has been studied in vitro against four cell lines selected for their resistance to doxorubicin, cisplatin, taxol and 5-fluorouracil. In previous experiments both compounds showed good in vitro antiproliferative, cytotoxic and pro-apoptotic activities against cell lines of different histologic origin. The results of the experiments presented here suggest that 1-Naph-NMCB is able to overcome all of the different mechanisms of resistance showed by the resistant cell lines used for our experiments. On the contrary, when we used the taxol-resistant A549-T12 cell line, characterized by a mechanism of resistance due to a mutation of the target site of taxol on microtubules, it displayed a partial but significant cross-resistance to 2-Naph-DNB. Although the actual mechanism of this cross-resistance has not yet been definitively elucidated, our results from immunostaining of microtubules suggest that it may be linked to the presence of a shared target site for taxol and 2-Naph-DNB on microtubules.


Assuntos
Antineoplásicos/farmacologia , Butadienos/farmacologia , Ácidos Graxos Insaturados/farmacologia , Naftalenos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Imunofluorescência , Humanos , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Sais de Tetrazólio , Tiazóis
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