387 research outputs found

    Classical Lie symmetries and reductions of a nonisospectral Lax pair

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    The classical Lie method is applied to a nonisospectral problem associated with a system of partial differential equations in 2+1 dimensions (Maccari A, J. Math. Phys. 39, (1998), 6547-6551). Identification of the classical Lie symmetries provides a set of reductions that give rise to different nontrivial spectral problems in 1+1 dimensions. The form in which the spectral parameter of the 1+1 Lax pair is introduced is carefully described.Comment: 11 pages (v2: A typo corrected in the authors' names

    A methodological approach to upscale toward an agroecology system in EU-LAFSs: The case of the parma bio-district

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    The increasing interest in bio-districts is part of the debate on the capacity to integrate agri-food systems and territory in order to improve the quality of life in rural communities. Considering the goals of developing and promoting an innovative territorial rural development approach, the bio-district can become a process toward a more sustainable model represented by the agroecological agriculture system. The paper presents a case study of the Parma bio-district through the approach of a Localized Agri Food System (LAFS) to verify whether bio-districts can be a tool for scaling up towards agroecology. Stakeholder classification and analysis are conducted using an influence-interest matrix. We identified four groups of stakeholders in relation to their interests and power to influence the process. In the case of the Parma bio-district the role of local institutions in dialogue with consumers and producers' associations is crucial for success. We conclude that bio-districts can be a tool for a scaling-up towards agroecology since they can facilitate a synergetic relation between organic and agroecological agriculture, spreading organic agriculture more widely around the local area. However, the involvement of a wide variety of different stakeholders means that governance is a key element in facilitating "cross fertilization" and preventing the process from becoming purely formulaic

    Ingress of Coolant Event simulation with TRACE code with accuracy evaluation and coupled DAKOTA Uncertainty Analysis

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    Among the Postulated Initiating Events in nuclear fusion plants, the Ingress of Coolant Event (ICE) in the Plasma Chamber is one of the main safety issues. In the present paper, the best estimate thermal-hydraulic system code TRACE, developed by USNRC, has been adopted to study the ICE, and it has been qualified based on experimental results obtained in the Integrated ICE facility at JAERI. A nodalization has been developed in the SNAP environment/architecture, using also the TRACE 3D Vessel component where multidimensional phenomena could occur. The accuracy of the code calculation has been assessed both from a qualitative and quantitative point of view. In addition, an Uncertainty Analysis (UA), with the probabilistic method to propagate the input uncertainties, has been performed to characterize the dispersion of the results. The analysis has been carried out with the DAKOTA toolkit coupled with TRACE code in the SNAP environment/architecture. Results show the adequacy of the 3D nodalization and the capability of the code to follow the transient evolution also at a very low pressure. Response correlations have been computed to characterize the correlation between the selected uncertain input parameters and the Plasma Chamber pressure

    A Methodological Approach to Upscale Toward an Agroecology System in EU-LAFSs: The Case of the Parma Bio-District

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    The increasing interest in bio-districts is part of the debate on the capacity to integrate agri-food systems and territory in order to improve the quality of life in rural communities. Considering the goals of developing and promoting an innovative territorial rural development approach, the bio-district can become a process toward a more sustainable model represented by the agroecological agriculture system. The paper presents a case study of the Parma bio-district through the approach of a Localized Agri Food System (LAFS) to verify whether bio-districts can be a tool for scaling up towards agroecology. Stakeholder classification and analysis are conducted using an influence–interest matrix. We identified four groups of stakeholders in relation to their interests and power to influence the process. In the case of the Parma bio-district the role of local institutions in dialogue with consumers and producers’ associations is crucial for success. We conclude that bio-districts can be a tool for a scaling-up towards agroecology since they can facilitate a synergetic relation between organic and agroecological agriculture, spreading organic agriculture more widely around the local area. However, the involvement of a wide variety of dierent stakeholders means that governance is a key element in facilitating “cross fertilization” and preventing the process from becoming purely formulaic

    Sustained low-efficiency dialysis with regional citrate anticoagulation in critically ill patients with COVID-19 associated AKI: A pilot study

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    Acute Kidney Injury (AKI) is a frequent complication in critically ill patients with Coronavirus disease 2019 (COVID-19), and it has been associated with worse clinical outcomes, especially when Kidney Replacement Therapy (KRT) is required. A condition of hypercoagulability has been frequently reported in COVID-19 patients, and this very fact may complicate KRT management. Sustained Low Efficiency Dialysis (SLED) is a hybrid dialysis modality increasingly used in critically ill patients since it allows to maintain acceptable hemodynamic stability and to overcome the increased clotting risk of the extracorporeal circuit, especially when Regional Citrate Anticoagulation (RCA) protocols are applied. Notably, given the mainly diffusive mechanism of solute transport, SLED is associated with lower stress on both hemofilter and blood cells as compared to convective KRT modalities. Finally, RCA, as compared with heparin-based protocols, does not further increase the already high hemorrhagic risk of patients with AKI. Based on these premises, we performed a pilot study on the clinical management of critically ill patients with COVID-19 associated AKI who underwent SLED with a simplified RCA protocol. Low circuit clotting rates were observed, as well as adequate KRT duration was achieved in most cases, without any relevant metabolic complication nor worsening of hemodynamic status

    In search for multi-target ligands as potential agents for diabetes mellitus and its complications—a structure-activity relationship study on inhibitors of aldose reductase and protein tyrosine phosphatase 1b

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    Diabetes mellitus (DM) is a complex disease which currently affects more than 460 million people and is one of the leading cause of death worldwide. Its development implies numerous metabolic dysfunctions and the onset of hyperglycaemia-induced chronic complications. Multiple ligands can be rationally designed for the treatment of multifactorial diseases, such as DM, with the precise aim of simultaneously controlling multiple pathogenic mechanisms related to the disease and providing a more effective and safer therapeutic treatment compared to combinations of selective drugs. Starting from our previous findings that highlighted the possibility to target both aldose reductase (AR) and protein tyrosine phosphatase 1B (PTP1B), two enzymes strictly implicated in the development of DM and its complications, we synthesised 3-(5-arylidene-4-oxothiazolidin-3-yl)propanoic acids and analogous 2-butenoic acid derivatives, with the aim of balancing the effectiveness of dual AR/PTP1B inhibitors which we had identified as designed multiple ligands (DMLs). Out of the tested compounds, 4f exhibited well-balanced AR/PTP1B inhibitory effects at low micromolar concentrations, along with interesting insulin-sensitizing activity in murine C2C12 cell cultures. The SARs here highlighted along with their rationalization by in silico docking experiments into both target enzymes provide further insights into this class of inhibitors for their development as potential DML antidiabetic candidates

    Human respiratory viruses, including SARS-CoV-2, circulating in the winter season 2019–2020 in Parma, Northern Italy

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    Objectives: The aim of this study was to determine the prevalence of respiratory virus infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), during the winter period December 2019 to March 2020, via a tertiary care hospital-based survey in Parma, Northern Italy. Methods: A total of 906 biological samples from the respiratory tract were analysed by both conventional assays (including culture) and molecular assays targeting nucleic acids of SARS-CoV-2 and other respiratory viruses. Results: Overall, 474 samples (52.3%) were positive for at least one virus, with a total of 583 viruses detected. Single infections were detected in 380 (80.2%) samples and mixed infections were detected in 94 (19.8%). Respiratory syncytial virus (138/583, 23.7%) and rhinovirus (130/583, 22.3%) were the most commonly identified viruses, followed by SARS-CoV-2 (82/583, 14.1%). Respiratory syncytial virus predominated until February, with 129 detections; it then decreased drastically in March to only nine detections. SARS-CoV-2 was absent in the study area until February 26, 2020 and then reached 82 detections in just over a month. SARS-CoV-2 was found in mixed infections in only three cases, all observed in children younger than 1 year old. Conclusions: This study showed a completely different trend between SARS-CoV-2 and the ‘common’ respiratory viruses: the common viruses mostly affected children, without any distinction according to sex, while SARS-CoV-2 mostly affected adult males

    Proton therapy and src family kinase inhibitor combined treatments on U87 human glioblastoma multiforme cell line

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    Glioblastoma Multiforme (GBM) is the most common of malignant gliomas in adults with an exiguous life expectancy. Standard treatments are not curative and the resistance to both chemotherapy and conventional radiotherapy (RT) plans is the main cause of GBM care failures. Proton therapy (PT) shows a ballistic precision and a higher dose conformity than conventional RT. In this study we investigated the radiosensitive effects of a new targeted compound, SRC inhibitor, named Si306, in combination with PT on the U87 glioblastoma cell line. Clonogenic survival assay, dose modifying factor calculation and linear-quadratic model were performed to evaluate radiosensitizing effects mediated by combination of the Si306 with PT. Gene expression profiling by microarray was also conducted after PT treatments alone or combined, to identify gene signatures as biomarkers of response to treatments. Our results indicate that the Si306 compound exhibits a radiosensitizing action on the U87 cells causing a synergic cytotoxic effect with PT. In addition, microarray data confirm the SRC role as the main Si306 target and highlights new genes modulated by the combined action of Si306 and PT. We suggest, the Si306 as a new candidate to treat GBM in combination with PT, overcoming resistance to conventional treatments
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