6 research outputs found

    MGMT hypermethylation and BCL-2 overexpression associated with superficial bladder cancer and recurrence

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    BACKGROUND: Urinary bladder carcinoma is one of the leading causes of death among men, and its high recurrence rates make it one of the most solid tumors to treat. The silencing of the tumor suppressor gene by hypermethylation of the CpG islands and overexpression of proto-oncogene proteins are the main mechanisms in cancers. Here, we investigate methylation status of O6-methylguanine-DNA-methyltransferase (MGMT), a tumor suppressor gene and expression level of BCL-2 a proto-oncogene protein that is frequently observed in bladder carcinoma and its recurrences. MATERIALS AND METHODS: We analyzed the methylation of MGMT in 80 tissue samples of patients suffering from bladder cancer and 80 urine samples of cancer-free individuals by MS-PCR. Additionally, BCL-2 protein expression level was analyzed on these 80 tissue samples by immunohistochemistry. RESULTS: 45 of patients had MGMT methylation, of which this hypermethylation does not have significant association with an increase in grade, but there was significant association in cases with recurrence tumors and metastasis tumors. Among patients with recurrence tumor, 92.5 patients showed MGMT hypermethylation; 66 of these showed BCL-2 overexpression. CONCLUSION: Our data indicate that MGMT hypermethylation and BCL-2 overexpression may have an intense role in superficial bladder cancer recurrences. © 2016 - IOS Press and the authors

    A hybrid solver based on efficient BEM-potential and LBM-NS models: Recent LBM developments and applications to naval hydrodynamics

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    We report on recent progress and validation of a 3D hybrid model for naval hydrodynamics problems based on a perturbation method, in which both velocity and pressure are expressed as the sum of an inviscid flow with a viscous perturbation. The far-to near-field inviscid flows can be solved with a Boundary Element Method (BEM), based on fully nonlinear potential flow theory, and the near-field perturbation flow is solved with a NS model based on a Lattice Boltzmann Method (LBM) with a Large Eddy Simulation (LES) of the turbulence. We summarize the hybrid model formulation and latest developments regarding the LES, and particularly a new wall model for the viscous/turbulent sub-layer near solid boundaries, that is generalized for an arbitrary geometry. The latter are validated by simulating turbulent flows over a flat plate for Re ∈ [3.7×104;1.2×106], for which the friction coefficient computed on the plate agrees well with experiments. We then simulate the flow past a NACA0012 foil using the hybrid LBM-LES with the wall model, for Re = 1×106, and show a good agreement of lift and drag forces with experiments. Results obtained with the hybrid LBM model are either nearly identical or improved relative to those of the standard LBM, but for a smaller computational domain, demonstrating the benefits of the hybrid approach

    A hybrid solver based on efficient BEM-potential and LBM-NS models: Recent BEM developments and applications to naval hydrodynamics

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    We report on recent developments of a 3D hybrid model for naval hydrodynamics based on a perturbation method, in which velocity and pressure are decomposed as the sum of an inviscid flow and a viscous perturbation. The far-to near-field inviscid flows are solved with a Boundary Element Method (BEM), based on fully nonlinear potential flow theory, accelerated with a fast multipole method (FMM), and the near-field perturbation flow is solved with a Navier-Stokes (NS) model based on a Lattice Boltzmann Method (LBM) with a LES modeling of turbulent properties. The BEM model is efficiently parallelized on CPU clusters and the LBM model on massively parallel GPGPU co-processors. The hybrid model formulation and its latest developments and implementation, in particular, regarding the improvement and validation of the model for naval hydrodynamics applications, are presented in a companion paper by O\u27Reilly et. al (2017), in this conference. In this paper, we concentrate on the BEM model aspects and show that the BEM-FMM can accurately solve a variety of problems while providing a nearly linear scaling with the number of unknowns (up to millions of nodes) and a speed-up with the number of processors of 35-50%, for small (e.g., 24 cores) to large (e.g., hundreds of cores) CPU clusters

    StEER-EERI: 2023 Mw 7.8 Kahramanmaras, Türkiye earthquake sequence joint Preliminary Virtual Reconnaissance Report (PVRR)

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    An Mw 7.8 earthquake occurred at a depth of 17.9 km and with epicenter coordinates 37.174°N 37.032°E near the city of Nurdağı in the Gaziantep province of Türkiye at about 4:17 AM local time on February 6, 2023. As a result of this sequence of earthquakes and aftershocks, around 28,500 buildings partially or completely collapsed, while another 66,000 buildings were severely damaged in Türkiye. In Syria, more than 22,000 buildings were affected by the earthquakes, with 2,850 partially/completely collapsed or severely damaged. As of March 8, the total official death toll due to these earthquakes was reported to be 45,968 confirmed deaths in Türkiye and 7,259 in Syria. In Türkiye alone, more than 100,000 people were reported as injured. The province of Hatay in Türkiye was severely impacted by this sequence of ground shaking, including an Mw 6.4 earthquake that occurred on February 20, two weeks after the main event. Around half of the buildings in the affected regions of Türkiye were constructed before 2000, i.e., before modern principles of earthquake design were implemented in the Turkish Seismic Code. Fragility functions developed for the building stock in the area showed that collapse under large shaking was possible for these relatively older buildings. However, several collapses of buildings constructed after 2000 were also observed. The performance of infrastructures was generally acceptable, with most bridges, roads, and tunnels remaining operational and no significant issues with the power grid and water supply infrastructure. In terms of good performance, the 12 seismically isolated hospitals in the earthquake-impacted region were operational after the earthquakes and, more importantly, allowed these healthcare facilities to serve their emergency response functions in the aftermath of the extraordinary destruction. Their operational performance greatly contrasted with the observed collapses of some hospitals that were not seismically isolated. This project encompasses the joint products of the StEER and EERI LFE program's response to this event: Preliminary Virtual Reconnaissance Report (PVRR)
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