Publications by authors named "Maurizio D"

13 Publications

  • Page 1 of 1

Heterogeneity of paclitaxel distribution in different tumor models assessed by MALDI mass spectrometry imaging.

Sci Rep 2016 12 21;6:39284. Epub 2016 Dec 21.

Department of Oncology, IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa, 19 - 20156 Milan, Italy.

The penetration of anticancer drugs in solid tumors is important to ensure the therapeutic effect, so methods are needed to understand drug distribution in different parts of the tumor. Mass spectrometry imaging (MSI) has great potential in this field to visualize drug distribution in organs and tumor tissues with good spatial resolution and superior specificity. We present an accurate and reproducible imaging method to investigate the variation of drug distribution in different parts of solid tumors. The method was applied to study the distribution of paclitaxel in three ovarian cancer models with different histopathological characteristics and in colon cancer (HCT116), breast cancer (MDA-MB-231) and malignant pleural mesothelioma (MPM487). The heterogeneous drug penetration in the tumors is evident from the MALDI imaging results and from the images analysis. The differences between the various models do not always relate to significant changes in drug content in tumor homogenate examined by classical HPLC analysis. The specificity of the method clarifies the heterogeneity of the drug distribution that is analyzed from a quantitative point of view too, highlighting how marked are the variations of paclitaxel amounts in different part of solid tumors.
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http://dx.doi.org/10.1038/srep39284DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5175283PMC
December 2016

Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory.

Phys Rev Lett 2016 Nov 31;117(19):192001. Epub 2016 Oct 31.

Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Grenoble-Alpes, CNRS/IN2P3, France.

Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (E_{CM}=110-170  TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.
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http://dx.doi.org/10.1103/PhysRevLett.117.192001DOI Listing
November 2016

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy.

Phys Rev Lett 2016 Jun 14;116(24):241101. Epub 2016 Jun 14.

University of Adelaide, Adelaide, South Australia, Australia.

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8±0.7(stat)±6.7(syst)  MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.
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http://dx.doi.org/10.1103/PhysRevLett.116.241101DOI Listing
June 2016

Ecotoxicological effects of sediments from Mar Piccolo, South Italy: toxicity testing with organisms from different trophic levels.

Environ Sci Pollut Res Int 2016 Jul 1;23(13):12755-69. Epub 2015 Oct 1.

CNR- Institute of Marine Sciences (ISMAR), Arsenale-Tesa 104, Castello 2737/F, 30122, Venezia, VE, Italy.

The Mar Piccolo of Taranto (Ionian Sea, Southern Italy) is a semi-enclosed and strongly polluted basin. For decades, it has been subjected to different anthropogenic impacts. These stressors caused severe sediments contamination with high concentration of different pollutants (PAHs, PCB, heavy metals). In order to assess the current status of sediments contamination, an ecotoxicological investigation combined with chemical analysis (heavy metals, PAH, and PCB) has been performed. In order to derive ecologically relevant conclusions, a multiorganisms and multiend-points approach has been applied, exposing organisms from different trophic levels to elutriate and whole sediment. The battery of bioassays consists of a microalgal growth inhibition test (Dunaliella tertiolecta), acute and sublethal assays (end-points: mortality, immobilization and swimming speed alteration) on crustaceans larvae and juveniles, and rotifers (Amphibalanus amphitrite, Artemia salina, Corophium insidiosum and Brachionus plicatilis), and embryotoxicity test on echinoderms (Paracentrotus lividus). Considering the high levels of sediment contamination highlighted from chemical analysis, an unexpected very low toxic effect was observed, even considering the sublethal end-point (larval swimming speed alteration). The results of this study suggest a very complex contaminants dynamic in the Mar Piccolo sediments that, despite a strong level of contamination, seems to not affect in a proportional manner the biological compartment.
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http://dx.doi.org/10.1007/s11356-015-5471-xDOI Listing
July 2016

The sperm motility pattern in ecotoxicological tests. The CRYO-Ecotest as a case study.

Ecotoxicol Environ Saf 2016 Jan 28;123:53-9. Epub 2015 Aug 28.

Dipartimento di Biologia, Università degli Studi Federico II, Napoli, Italy.

Changes in environmental stressors inevitably lead to an increasing need for innovative and more flexible monitoring tools. The aim of this work has been the characterization of the motility pattern of the cryopreserved sea bream semen after exposure to a dumpsite leachate sample, for the identification of the best representative parameters to be used as endpoints in an ecotoxicological bioassay. Sperm motility has been evaluated either by visual and by computer-assisted analysis; parameters concerning motility on activation and those describing it in the times after activation (duration parameters) have been assessed, discerning them in terms of sensitivity, reliability and methodology of assessment by means of multivariate analyses. The EC50 values of the evaluated endpoints ranged between 2.3 and 4.5ml/L, except for the total motile percentage (aTM, 7.0ml/L), which proved to be the less sensitive among all the tested parameters. According to the multivariate analyses, a difference in sensitivity among "activation" endpoints in respect of "duration" ones can be inferred; on the contrary, endpoints seem to be equally informative either describing total motile sperm or the rapid sub-population, as well as the assessment methodology seems to be not discriminating. In conclusion, the CRYO-Ecotest is a multi-endpoint bioassay that can be considered a promising innovative ecotoxicological tool, characterized by a high plasticity, as its endpoints can be easy tailored each time according to the different needs of the environmental quality assessment programs.
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http://dx.doi.org/10.1016/j.ecoenv.2015.08.018DOI Listing
January 2016

Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory.

Eur Phys J C Part Fields 2015;75(6):269. Epub 2015 Jun 20.

Karlsruhe Institute of Technology - Campus South - Institut für Experimentelle, Kernphysik (IEKP), Karlsruhe, Germany.

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with [Formula: see text] eV by analyzing cosmic rays with energies above [Formula: see text] eV arriving within an angular separation of approximately 15[Formula: see text]. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.
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http://dx.doi.org/10.1140/epjc/s10052-015-3471-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4477714PMC
June 2015

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory.

Phys Rev Lett 2012 Aug 10;109(6):062002. Epub 2012 Aug 10.

LIP and Instituto Superior Técnico, Technical University of Lisbon, Lisbon, Portugal.

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.
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http://dx.doi.org/10.1103/PhysRevLett.109.062002DOI Listing
August 2012

Development of a multiplex PCR for the simultaneous amplification and genotyping of glycoprotein N among human cytomegalovirus strains.

New Microbiol 2010 Jul;33(3):257-62

Department of Haematology, Oncology and Laboratory Medicine, Clinical Unit of Microbiology, St. Orsola Malpighi General Hospital, University of Bologna, Bologna, Italy.

Genomic variation among human cytomegalovirus (HCMV) strains is probably involved in HCMV-induced pathogenesis. The envelope glycoprotein N (gN) showed extensive genetic polymorphism as HCMV isolates have been clustered into four distinct gN variants (gN-1, gN-2, gN-3, gN-4) whose distribution has been analyzed worldwide using different methodological approaches (PCR-RFLP, PCR-Cloning, PCR-Sequencing). This paper describes a new method for concurrent detection of gN genotypes among HCMV strains using a multiplex gN-variants specific PCR plus visualization on agarose gel, avoiding subsequent steps such as cloning, restriction or sequencing. This novel approach will reduce costs and shorten the detection time of gN polymorphisms among HCMV clinical isolates.
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July 2010

Measurement of the depth of maximum of extensive air showers above 10{18} eV.

Phys Rev Lett 2010 Mar 1;104(9):091101. Epub 2010 Mar 1.

National Technological University, Faculty Mendoza (CONICET/CNEA), Mendoza, Argentina.

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.
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http://dx.doi.org/10.1103/PhysRevLett.104.091101DOI Listing
March 2010

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV.

Phys Rev Lett 2008 Aug 4;101(6):061101. Epub 2008 Aug 4.

Universidad Tecnológica Nacional, FR-Mendoza, Argentina.

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.
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http://dx.doi.org/10.1103/PhysRevLett.101.061101DOI Listing
August 2008

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory.

Phys Rev Lett 2008 May 27;100(21):211101. Epub 2008 May 27.

Centro de Investigaciones en Laseres y Aplicaciones, CITEFA and CONICET, Argentina.

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.
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http://dx.doi.org/10.1103/PhysRevLett.100.211101DOI Listing
May 2008

Correlation of the highest-energy cosmic rays with nearby extragalactic objects.

Science 2007 Nov;318(5852):938-43

Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above 6 x 10(19) electron volts and the positions of active galactic nuclei (AGN) lying within approximately 75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these cosmic rays with at least a 99% confidence level from a prescribed a priori test. The correlation we observed is compatible with the hypothesis that the highest-energy particles originate from nearby extragalactic sources whose flux has not been substantially reduced by interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.
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http://dx.doi.org/10.1126/science.1151124DOI Listing
November 2007
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