59 research outputs found

    a pore water pressure model calibration based on in situ test results

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    Abstract This paper proposes a procedure for the calibration of a simplified pore water pressure model implemented in 1D effective stress dynamic analyses. The calibration procedure is based on the cyclic strength of the soils as quantified using empirical correlations with in-situ tests, CPT and SPT. Specific relationships have been directly defined among the parameters of the pore water pressure model and the results of in-situ tests. All the steps for the definition of these relationships are described in detail. The proposed calibration procedure has been used to simulate the seismic response of two well-documented reclaimed sites where widespread liquefaction occurred: Port Island, in Kobe (Japan) and Treasure Island in California (US), struck by the 1995 Kobe and the 1989 Loma Prieta earthquakes, respectively. The results of the analyses have been compared to the actual site response as recorded by downhole acceleration arrays, showing that the proposed approach leads to a good estimate of the site response. Guidelines for calibration of the proposed model are finally provided, and the advantages and limitations of its use are discussed in detail

    Genetic and molecular characterization of the human osteosarcoma 3AB-OS cancer stem cell line: a possible model for studying osteosarcoma origin and stemness.

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    Finding new treatments targeting cancer stem cells (CSCs) within a tumor seems to be critical to halt cancer and improve patient survival. Osteosarcoma is an aggressive tumor affecting adolescents, for which there is no second-line chemotherapy. Uncovering new molecular mechanisms underlying the development of osteosarcoma and origin of CSCs is crucial to identify new possible therapeutic strategies. Here, we aimed to characterize genetically and molecularly the human osteosarcoma 3AB-OS CSC line, previously selected from MG63 cells and which proved to have both in vitro and in vivo features of CSCs. Classic cytogenetic studies demonstrated that 3AB-OS cells have hypertriploid karyotype with 71–82 chromosomes. By comparing 3AB-OS CSCs to the parental cells, array CGH, Affymetrix microarray, and TaqMan1 Human MicroRNA array analyses identified 49 copy number variations (CNV), 3,512 dysregulated genes and 189 differentially expressed miRNAs. Some of the chromosomal abnormalities and mRNA/miRNA expression profiles appeared to be congruent with those reported in human osteosarcomas. Bioinformatic analyses selected 196 genes and 46 anticorrelated miRNAs involved in carcinogenesis and stemness. For the first time, a predictive network is also described for two miRNA family (let-7/98 and miR-29a,b,c) and their anticorrelated mRNAs (MSTN, CCND2, Lin28B, MEST, HMGA2, and GHR), which may represent new biomarkers for osteosarcoma and may pave the way for the identification of new potential therapeutic targets

    Site response analyses for complex geological and morphological conditions: relevant case-histories from 3rd level seismic microzonation in Central Italy

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    The paper presents the results of 5 case studies on complex site e ects selected within the project for the level 3 seismic microzonation of several municipalities of Central Italy dam- aged by the 2016 seismic sequence. The case studies are characterized by di erent geo- logical and morphological con gurations: Monte San Martino is located along a hill slope, Montedinove and Arquata del Tronto villages are located at ridge top whereas Capitignano and Norcia lie in correspondence of sediment- lled valleys. Peculiarities of the sites are constituted by the presence of weathered/jointed rock mass, fault zone, shear wave veloc- ity inversion, complex surface and buried morphologies. These factors make the de ni- tion of the subsoil model and the evaluation of the local response particularly complex and di cult to ascertain. For each site, after the discussion of the subsoil model, the results of site response numerical analyses are presented in terms of ampli cation factors and acceleration response spectra in selected points. The physical phenomena governing the site response have also been investigated at each site by comparing 1D and 2D numerical analyses. Implications are deduced for seismic microzonation studies in similar geological and morphological conditions.Published5741–57775T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa

    Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.

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    Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology

    Local site effects and incremental damage of buildings during the 2016 Central Italy earthquake sequence

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    The Central Italy earthquake sequence initiated on 24 August 2016 with a moment magnitude M6.1 event followed by a M5.9 and a M6.5 earthquake, that caused significant damage and loss of life in the town of Amatrice and other nearby villages and hamlets. The significance of this sequence led to a major international reconnaissance effort to thoroughly examine the effects of this disaster. Specifically, this paper presents evidences of strong local site effects (i.e., amplification of seismic waves due to stratigraphic and topographic effects that leads to damage concentration in certain areas). It also examines the damage patterns observed along the entire sequence of events in association with the spatial distribution of ground motion intensity with emphasis on the clearly distinct performance of reinforced concrete and masonry structures under multiple excitations. The paper concludes with a critical assessment of past retrofit measures efficiency and a series of lessons learned as per the behavior of structures to a sequence of strong earthquake events

    Assessing the Carcinogenic Potential of Low-Dose Exposures to Chemical Mixtures in the Environment: The Challenge Ahead

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    Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety \u27Mode of Action\u27 framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology
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