47 research outputs found

    Validation study of WindTrax reverse dispersion model coupled with a sensitivity analysis of model-specific settings

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    In last years, atmospheric dispersion models have reached considerable popularity in environmental research field. In this regard, given the difficulties associated to the estimation of emission rate for some kind of sources, and due to the importance of this parameter for the reliability of the results, Backward dispersion models may represent promising tools. In particular, by knowing a measured downwind concentration in ambient air, they provide a numerical value for the emission rate. This paper discusses a critical validation of the WindTrax Backward model: the investigation does not only deal with the strict reliability of the model but also assesses under which conditions (i.e. stability class, number, and location of the sensors) the model shows the greatest accuracy. For this purpose, WindTrax results have been compared to observed values obtained from available experimental datasets. In addition, a sensitivity study regarding model-specific parameters required by WindTrax to replicate the physics and the random nature of atmospheric dispersion processes is discussed. This is a crucial point, since, for these settings, indications on the numerical values to be adopted are not available. From this study, it turns out that the investigated model specific settings do not lead to a significant output variation. Concerning the validation study, a general tendency of the model to predict the observed values with a good level of accuracy has been observed, especially under neutral atmospheric conditions. In addition, it seems that WindTrax underestimates the emission rate during unstable stratification and overestimates during stable con-ditions. Finally, by the definition of alternative scenarios, in which only a portion of the concentration sensors was considered, WindTrax performance appears better than acceptable even with a small number of concen-tration sensors, as long as the positioning is in the middle of the plume and not in the strict vicinity of the source

    Aluminium foam production control by using a combined fuzzy-genetic algorithm model

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    Abstract This study deals with the proposal of a combined fuzzy-genetic algorithm model able to describe the inherent uncertainties related to the manufacture of aluminium foams by using the dissolution and sintering process. The combined method allows taking into account both the uncertainty related to the model and the statistical process variability, with the aim of controlling the capability of this material at absorbing compression energy, for different set of process parameters. The use of genetic algorithms allows the optimization of the fuzzy supports in order to take into account most of the experimental data in combination with the smallest uncertainty

    A workflow to generate physical 3D models of cerebral aneurysms applying open source freeware for CAD modeling and 3D printing

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    Objectives: 3D anatomical models are becoming a new frontier in surgery for planning and simulation on an individualized patient specific basis. Since 1999, 3D cerebral aneurysms models for neurosurgery have been proposed. The possibility of reproducing in a realistic 3D fashion the malformation with the surrounding vascular structures, provides important preoperative information for the treatment strategy. The same models can be used for training and teaching.Unfortunately stereolitography is often burdened by high costs and long times of production. These factors limit the possibility to use 3D models to plan surgeries in an easy daily fashion. Patients and methods: Our study enrolled 5 patients harboring cerebral aneurysms. DICOM data of each aneurysm were elaborated by an open source freeware to obtain CAD molds. Afterwards, the 3D models were produced using a fused deposition or a stereolitography printer. Results: Models were evaluated by Neurosurgeons in terms of quality and usefulness for surgical planning. Costs and times of production were recorded. Conclusions: Models were reliable, economically affordable and quick to produce. Keywords: Stereolitography, Cerebral aneurysms, 3D printing, Surgical planning, Aneurysm model

    Clinical prognostic factors for older people: A systematic review and meta-analysis

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    Objective: To explore the accuracy and precision of prognostic tools used in older people in predicting mortality, hospitalization, and nursing home admission across different settings and timings. Design: Systematic review and meta-analysis of prospective and retrospective studies. Data sources: A systematic search from database inception until 01st February 2023 was run in Medline, Embase, Cinhal, Cochrane Library. Eligibility criteria: Studies were eligible if they reported accuracy (area under the curve [AUC]) and/or precision (C-index) for the prognostic index in relation to any of the following outcomes: mortality, hospitalization, and nursing home admission. Data extraction and synthesis: Two independent reviewers extracted data. Data were pooled using a random effects model. The risk of bias was assessed with the Quality in Prognosis Studies (QUIPS) tool. If more than three studies for the same setting and time were available, a meta-analysis was performed and evaluated using the GRADE tool; other data were reported descriptively. Results: Among 16,082 studies initially considered, 159 studies with a total of 2398856 older people (mean age: 78 years) were included. The majority of the studies was carried out in hospital or medical wards. In the community setting, only two tools (Health Assessment Tool and the Multidimensional Prognostic Index, MPI) had good precision for long-term mortality. In emergency department setting, Barthel Index had an excellent accuracy in predicting short-term mortality. In medical wards, the MPI had a moderate certainty of the evidence in predicting short-term mortality (13 studies; 11,787 patients; AUC=0.79 and 4 studies; 3915 patients; C-index=0.82). Similar findings were available for MPI when considering longer follow-up periods. When considering nursing home and surgical wards, the literature was limited. The risk of bias was generally acceptable; observed bias was mainly owing to attrition and confounding. Conclusions: Several tools are used to predict poor prognosis in geriatric patients, but only those derived from a multidimensional evaluation have the characteristics of precision and accuracy

    Decoding the Complexity of Systemic Inflammation Predictors in Locally Advanced Cervical Cancer, with Hemoglobin as the Hidden Key (the ESTHER Study)

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    Simple Summary We explored whether specific factors, like inflammation indicators in the blood, could help predict treatment outcomes for locally advanced cervical cancer (LACC). LACC is generally treated with a combination of chemotherapy and radiation. We wanted to see if these factors could help physicians personalize treatments for better results. Our study involved looking at various aspects, including inflammation indices in the blood and various clinical treatment details, in LACC patients. While some factors, such as age and hemoglobin levels, seemed to predict outcomes, there was no clear connection between inflammation indicators in the blood and results. These findings challenge previous ideas and highlight the importance of considering multiple factors to predict the prognoses of LACC patients.Abstract Locally advanced cervical cancer (LACC) is treated with concurrent chemoradiation (CRT). Predictive models could improve the outcome through treatment personalization. Several factors influence prognosis in LACC, but the role of systemic inflammation indices (IIs) is unclear. This study aims to assess the correlation between IIs and prognosis in a large patient cohort considering several clinical data. We retrospectively analyzed pretreatment IIs (NLR, PLR, MLR, SII, LLR, COP-NLR, APRI, ALRI, SIRI, and ANRI) in 173 LACC patients. Patient, tumor, and treatment characteristics were also considered. Univariate and multivariate Cox's regressions were conducted to assess associations between IIs and clinical factors with local control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS). Univariate analysis showed significant correlations between age, HB levels, tumor stage, FIGO stage, and CRT dose with survival outcomes. Specific pretreatment IIs (NLR, PLR, APRI, ANRI, and COP-NLR) demonstrated associations only with LC. The multivariate analysis confirmed Hb levels, CRT dose, and age as significant predictors of OS, while no II was correlated with any clinical outcome. The study findings contradict some prior research on IIs in LACC, emphasizing the need for comprehensive assessments of potential confounding variables

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

    FIMEC Test to Evaluate the Water Uptake of Coated and Uncoated CFRP Composites

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    This study focuses on the application of the FIMEC (flat-top cylinder indenter for mechanical characterization) indentation test to evaluate the effect of water uptake on the mechanical properties of high-performance materials, in particular CFRP (carbon fibre reinforced polymer) composites. Coated and uncoated samples were analyzed. Silicon-based and siloxane coatings were formulated and applied to CFRP to reduce the moisture absorption of the material. The FIMEC test was adopted to study the reduction of the stiffness of CFRP plates for different ageing in water. The evolution of mechanical properties is reported as a function of the water uptake. IR analyses and weight variation measures were used as supporting data. Experimental results show that the FIMEC test is suitable to assess the stiffness reduction due to the aging in water and to identify coatings able to minimize the water uptake
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