10 research outputs found

    Energy Demand and Supply Simultaneous Optimization to Design a Nearly Zero-Energy House

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    The effective design of nearly zero-energy buildings depends on a large set of interdependent variables, which affect both energy demand and supply. Considering them simultaneously is fundamental when searching for optimal design of nearly zero-energy buildings, as encouraged by the EU in the second recast of the Energy Performance of Building Directive (EPBD). This paper presents the application of the new energy demand and supply simultaneous optimization (EDeSSOpt) methodology to optimize the design of a single-family house in the Italian context. Both primary energy optimization and financial optimization are carried out in the context of European regulations. Robustness of the resulting optimal solution is studied through analysis of optimum neighborhoods. The resulting cost-optimized solution relies on a moderately insulated envelope, a highly efficient system, and 34% of coverage from renewables. The energy-optimized solution requires a higher level of insulation and a higher coverage from renewables, demonstrating that there is still a gap between energy and cost optimums. Beyond the results, integrated optimization by means of EDeSSOpt is demonstrated to better minimize cost functions while improving the robustness of results

    EDeSSOpt – Energy Demand and Supply Simultaneous Optimization for cost-optimized design: Application to a multi-family building

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    In the context of European efforts to reduce energy consumption and CO2 emissions in the building sector, the second recast of the Energy Performance of Buildings Directive promotes the acceleration of the energy renovation of European building stock. To do this, a cost optimization is necessary to find the best combination of energy efficiency measures which minimize the global cost during the entire life-cycle of the building, as suggested in the first recast of the same Directive. Since a great number of combinations must be analyzed, an automated procedure is necessary to reduce the calculation time. In this work, an iterative input-output process is set, thanks to the coupling of a dynamic energy simulation software (TRNSYS) and a generic optimization software (GenOpt). The cost optimization is applied to a new social housing construction – a multi-family building located in Northern Italy. The methodology that was adopted allows the simultaneous optimization of both the building energy demand (building envelope) and the building energy supply (technical systems and renewable sources). Results are compared with those obtained using a more widespread sequential approach whose purpose is firstly the optimization of one of these two factors, and subsequently the optimization of the other one. This study has demonstrated that an integrated approach allows a larger number of possible combinations of energy efficiency measures to be explored with respect to the sequential approach

    Serum IgG2 antibody multicomposition in systemic lupus erythematosus and lupus nephritis (Part 1): cross-sectional analysis

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    Objectives: Serum anti-dsDNA and anti-nucleosome IgGs have been proposed as signatures for SLE and LN in limited numbers of patients. We sought to show higher sensitivity and specificity of the same antibodies with the IgG2 isotype and included IgG2 antibodies vs specific intracellular antigens in the analysis. Methods: A total of 1052 SLE patients with (n = 479) and without (n = 573) LN, recruited at different times from the beginning of symptoms, were included in the study. Patients with primary APS (PAPS, n = 24), RA (RA, n = 24) and UCTD (UCTD, n = 96) were analysed for comparison. Anti-nucleosome (dsDNA, Histone2A, Histone3), anti-intracellular antigens (ENO1), anti-annexin A1 and anti-C1q IgG2 were determined by non-commercial techniques. Results: The presence in the serum of the IgG2 panel was highly discriminatory for SLE/LN vs healthy subjects. Serum levels of anti-dsDNA and anti-C1q IgG2 were more sensitive than those of IgGs (Farr radioimmunoassay/commercial assays) in identifying SLE patients at low-medium increments. Of more importance, serum positivity for anti-ENO1 and anti-H2A IgG2 discriminated between LN and SLE (ROC T0-12 months), and high levels at T0-1 month were detected in 63% and 67%, respectively, of LN, vs 3% and 3%, respectively, of SLE patients; serum positivity for each of these was correlated with high SLEDAI values. Minor differences existed between LN/SLE and the other rheumatologic conditions. Conclusion: Nephritogenic IgG2 antibodies represent a specific signature of SLE/LN, with a few overlaps with other rheumatologic conditions. High levels of anti-ENO1 and anti-H2A IgG2 correlated with SLE activity indexes and were discriminatory between SLE patients limited to the renal complication and other SLE patients

    Evidence for charge-based mimicry in anti dsDNA antibody generation

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    Mechanisms for the generation of anti-dsDNA autoantibodies are still not completely elucidated. One theory states that dsDNA interacts for mimicry with antibodies raised versus other antigens but molecular features for mimicry are unknown. Here we show that, at physiological acid-base balance, anti-Annexin A1 binds IgG2 dsDNA in a competitive and dose-dependent way with Annexin A1 and that the competition between the two molecules is null at pH 9. On the other hand, these findings also show that dsDNA and Annexin A1 interact with their respective antibodies on a strictly pH-dependent basis: in both cases, the binding was minimal at pH 4 and maximal at pH9-10. The anionic charge of dsDNA is mainly conferred by the numerous phosphatidic residues. The epitope binding site of Annexin A1 for anti-Annexin A1 IgG2 was here characterized as a string of 34 amino acids at the NH2 terminus, 10 of which are anionic.Circulating levels of anti-dsDNA and anti-Annexin A1 IgG2 antibodies were strongly correlated in patients with systemic lupus erythematosus (n 496) and lupus nephritis (n 425) stratified for age, sex, etc. These results show that dsDNA competes with Annexin A1 for the binding with anti-Annexin A1 IgG2 on a dose and charged mediated base, being able to display an inhibition up to 75%. This study provides the first demonstration that dsDNA may interact with antibodies raised versus other anionic molecules (anti-Annexin A1 IgG2) because of charge mimicry and this interaction may contribute to anti-dsDNA antibodies generation

    A critical view on autoantibodies in lupus nephritis: Concrete knowledge based on evidence

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    Deposition of autoantibodies in glomeruli is a key factor in the development of lupus nephritis (LN). For a long time, anti-dsDNA and anti-C1q antibodies were thought to be the main cause of the kidney damage. However, recent studies have shown that the list of autoantibidies that have renal tropism and deposit in the kidney in LN is increasing and the link between anti-dsDNA and renal pathology is weak due to potential confounders. Aspecific bindings of dsDNA with cationic antibodies and of anti-dsDNA with several renal antigens such as actinin, laminin, entactin, and annexinA2 raised doubts about the specific target of these antibodies in the kidney. Moreover, the isotype of anti-dsDNA in SLE and LN has never received adequate interest until the recent observation that IgG2 are preponderant over IgG1, IgG3 and IgG4. Based on the above background, recent studies investigated the involvement of anti-dsDNA IgG2 and of other antibodies in LN. It was concluded that circulating anti-dsDNA IgG2 levels do not distinguish between LN versus non-renal SLE, and, in patients with LN, their levels do not change over time. Circulating levels of other antibodies such as anti-ENO1 and anti-H2 IgG2 were, instead, higher in LN vs non-renal SLE at the time of diagnosis and decreased following therapies. Finally, new classes of renal antibodies that potentially modify the anti-inflammatory response in the kidney are emerging as new co-actors in the pathogenetic scenario. They have been defined as 'second wave antibodies' for the link with detoxifying mechanisms limiting the oxidative stress in glomeruli that are classically stimulated in a second phase of inflammation. These findings have important clinical implications that may modify the laboratory approach to LN. Serum levels of anti-ENO1 and anti-H2 IgG2 should be measured in the follow up of patients for designing the length of therapies and identify those patients who respond to treatments. Anti-SOD2 could help to monitor and potentiate the anti-inflammatory response in the kidney
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