347 research outputs found

    The role of the coherence in the cross-correlation analysis of diffraction patterns from two-dimensional dense mono-disperse systems

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    The investigation of the static and dynamic structural properties of colloidal systems relies on techniques capable of atomic resolution in real space and femtosecond resolution in time. Recently, the cross-correlation function (CCF) analysis of both X-rays and electron diffraction patterns from dilute and dense aggregates has demonstrated the ability to retrieve information on the sample's local order and symmetry. Open questions remain regarding the role of the beam coherence in the formation of the diffraction pattern and the properties of the CCF, especially in dense systems. Here, we simulate the diffraction patterns of dense two-dimensional monodisperse systems of different symmetries, varying the transverse coherence of the probing wave, and analyze their CCF. We study samples with different symmetries at different size scale, as for example, pentamers arranged into a four-fold lattice where each pentamer is surrounded by triangular lattices, both ordered and disordered. In such systems, different symmetry modulations are arising in the CCF at specific scattering vectors. We demonstrate that the amplitude of the CCF is a fingerprint of the degree of the ordering in the sample and that at partial transverse coherence, the CCF of a dense sample corresponds to that of an individual scattering object.Comment: 22 pages, 7 figure

    Reducing CO2 Emissions and Improving Water Resource Circularity by Optimizing Energy Efficiency in Buildings

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    Climate neutrality by 2050 is a priority objective and reducing greenhouse gas (GHG) emissions, increasing energy efficiency, and improving the circularity processes of resources are the imperatives of regulatory and economic instruments. Starting from the central themes of the mitigation of the causes of climate change and the interdependence represented by the water–energy nexus, this research focuses, through the application of the principles of the circular and green economy, on deep energy zero-emission renovation through the improvement of circularity processes of water resources in their integration with energetic ones on the optimization of their management within urban districts, to measure their capacity to contribute towards reducing energy consumption and CO2 emissions during water use and distribution in buildings. After defining the key strategies and the replicable intervention solutions for the circularity of water resources, the investigation focuses on the definition of the research and calculation method set up to define, in parallel, the water consumption of an urban district and the energy consumption necessary to satisfy water requirements and CO2 emissions. Starting from the application of the calculation method in an existing urban district in Rome, 10 indicators of quantities have been developed to define water and energy consumption and their related CO2 emissions, focusing on the obtained results to also define some interventions to reduce water and energy consumption and CO2 emissions in territories that suffer a medium-risk impact from contemporary climatic conditions

    Čimbenici rizika i poslijeoperacijski prediktori za ponavljajuću herniju lumbalnog diska: dugoročno praćenje

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    The purpose of this study is to identify some risk factors and post-operative predictors for recurrent lumbar disc hernia (rLDH) during a long-term follow-up in patients treated with microdiscectomy. Aim of the paper: This study analyzes some risk factors and postoperative predictors for recurrent lumbar disc hernia (rLDH) during a long-term follow-up in patients treated with microdiscectomy. Material and methods. We analyzed retrospectively a consecutive series of patients who underwent lumbar spinal microdiscectomy for lumbar disc herniation (LDH) from January 2013 to June 2018 at our Institute. The rate of rLDH during long-term follow-up was analyzed and correlated with baseline and post-operative data. Results. A total of 263 patients were included with a median follow-up time of 24 months (from 13 to 43 months). Most of the patients had rLDH within the first 36 months after surgery. At multivariate analysis, recurrence of LDH was associated with higher pre-operative body mass index (BMI) and higher post-operative Oswentry disability index (ODI) with statistical significance. Conclusions. Baseline BMI and post-surgery ODI could predict rLDH after surgery during a long-term follow-up.Cilj. Ova studija analizira određene čimbenike rizika i poslijeoperacijske prediktore za ponavljajuću herniju lumbalnog diska (engl. recurrent lumbar disc hernia – rLDH) tijekom dugotrajnog praćenjaa bolesnika liječenih mikrodiskektomijom. Metode. Retrospektivno smo analizirali niz uzastopnih serija pacijenata koji su podvrgnuti lumbalnoj spinalnoj mikrodiskektomiji zbog hernije lumbalnog diska (engl. lumbar disc hernia – LDH) u razdoblju od siječnja 2013. do lipnja 2018. u našem Institutu. Stopa ponavljajuće hernije lumbalnog diska tijekom dugotrajnog praćenja analizirana je i korelirana s početnim anamnestičkim podacima i poslijeoperacijskim podacima. Rezultati. U studiju je uključeno ukupno 263 pacijenta s prosječnim vremenom praćenja od 24 mjeseca (od 13 do 43 mjeseca). Većina pacijenata imala je ponavljajuću herniju lumbalnog diska u prvih 36 mjeseci nakon operacije. Pri multivarijantnoj analizi, recidiv hernije lumbalnog diska povezan je s višim indeksom tjelesne mase (engl. body mass index – BMI) prije operacije i višim Oswestry indeksom invaliditeta nakon operacije (engl. Oswestry disability index – ODI) sa statističkom značajnošću. Zaključak. Početni indeks tjelesne mase i poslijeoperacijski Oswestry indeks invaliditeta mogu poslužiti kao prediktori ponavljajuće hernije lumbalnog diska nakon operacije tijekom dugotrajnog praćenja

    Dopamine Transmission Imbalance in Neuroinflammation: Perspectives on Long-Term COVID-19

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    Dopamine (DA) is a key neurotransmitter in the basal ganglia, implicated in the control of movement and motivation. Alteration of DA levels is central in Parkinson's disease (PD), a common neurodegenerative disorder characterized by motor and non-motor manifestations and deposition of alpha-synuclein (alpha-syn) aggregates. Previous studies have hypothesized a link between PD and viral infections. Indeed, different cases of parkinsonism have been reported following COVID-19. However, whether SARS-CoV-2 may trigger a neurodegenerative process is still a matter of debate. Interestingly, evidence of brain inflammation has been described in postmortem samples of patients infected by SARS-CoV-2, which suggests immune-mediated mechanisms triggering the neurological sequelae. In this review, we discuss the role of proinflammatory molecules such as cytokines, chemokines, and oxygen reactive species in modulating DA homeostasis. Moreover, we review the existing literature on the possible mechanistic interplay between SARS-CoV-2-mediated neuroinflammation and nigrostriatal DAergic impairment, and the cross-talk with aberrant alpha-syn metabolism

    Eubiosis and dysbiosis: the two sides of the microbiota

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    The microbial ecosystem of the gastrointestinal tract is characterized by a great number of microbial species living in balance by adopting mutualistic strategies. The eubiosis/dysbiosis condition of the gut microbiota strongly influences our healthy and disease status. This review briefly describes microbiota composition and functions, to then focus on eubiosis and dysbiosis status: the two sides of the microbiot

    Anti-carbamylated protein antibodies as a new biomarker of erosive joint damage in systemic lupus erythematosus

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    Background: The application of more sensitive imaging techniques, such as ultrasonography (US), changed the concept of non-erosive arthritis in systemic lupus erythematosus (SLE), underlining the need for biomarkers to identify patients developing the erosive phenotype. Anti-citrullinated peptide antibodies (ACPA), associated with erosions in inflammatory arthritis, have been identified in about 50% of patients with SLE with erosive arthritis. More recently, anti-carbamylated proteins antibodies (anti-CarP) have been associated with erosive damage in rheumatoid arthritis. We aimed to assess the association between anti-CarP and erosive damage in a large SLE cohort with joint involvement. Methods: We evaluated 152 patients (male/female patients 11/141; median age 46years, IQR 16; median disease duration 108months, IQR 168). All patients underwent blood draw to detect rheumatoid factor (RF) and ACPA (commercial enzyme-linked immunosorbent assay (ELISA) kit), and anti-CarP ("home-made" ELISA, cutoff 340aU/mL). The bone surfaces of the metacarpophalangeal and proximal interphalangeal joints were assessed by US: the presence of erosions was registered as a dichotomous value (0/1), obtaining a total score (0-20). Results: The prevalence of anti-CarP was 28.3%, similar to RF (27.6%) and significantly higher than ACPA (11.2%, p=0.003). Erosive arthritis was identified in 25.6% of patients: this phenotype was significantly associated with anti-CarP (p=0.004). Significant correlation between anti-CarP titer and US erosive score was observed (r=0.2, p=0.01). Conclusions: Significant association was identified between anti-CarP and erosive damage in SLE-related arthritis, in terms of frequency and severity, suggesting that these antibodies can represent a biomarker of severity in patients with SLE with joint involvement

    Local photo-mechanical stiffness revealed in gold nanoparticles supracrystals by ultrafast small-angle electron diffraction

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    We demonstrate that highly-ordered two-dimensional crystals of ligand-capped gold nanoparticles display a local photo-mechanical stiffness as high as that of solids such as graphite. In out-of equilibrium electron diffraction experiments, a strong temperature jump is induced in a thin film with a femtosecond laser pulse. The initial electronic excitation transfers energy to the underlying structural degrees of freedom, with a rate generally proportional to the stiffness of the material. With femtosecond small-angle electron diffraction, we observe the temporal evolution of the diffraction feature associated to the nearest-neighbor nanoparticle distance. The Debye-Waller decay for the octanethiol-capped nanoparticles supracrystal, in particular, is found to be unexpectedly fast, almost as fast as the stiffest solid known and observed by the same technique, i.e. graphite. Our observations unravel that local stiffness in a dense supramolecular assembly can be created by Van der Waals interactions up to a level comparable to crystalline systems characterized by covalent bonding

    Clinical and psychological outcome after surgery for lumbar spinal stenosis: A prospective observational study with analysis of prognostic factors

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    Background The identification of psychological risk factors is important for the selection of patients before spinal surgery. Moreover, the effect of surgical decompression in lumbar spinal stenosis (LSS) on psychological outcome is not previously well analyzed. Aim of paper to investigate clinical and psychological outcome after surgery for LSS and the effect of depressive symptoms and anxiety on the clinical outcome. Materials and methods A total of 25 patients with symptomatic LSS underwent decompressive surgery with or without spinal stabilization were prospectively enrolled in this observational surgery. The Symptom Checklist-90-Revised (SCL-90-R) was used to assess global psychological distress with a summary score termed Global Severity Index (GSI) and single psychological disorders including depression (DEP) and anxiety (ANX). The clinical outcome of surgery was evaluated with the Oswestry Disability Index (ODI) and visual analogue scale (VAS) pain assessment. Results Compared with baseline, there was a statistically significant improvement in VAS, ODI and GSI after surgery (p<0.05) in all patients. Univariate analysis revealed that patients with high GSI and anxiety and depression scores had significantly higher ODI and VAS scores in the follow-up with a bad outcome. Conclusions Surgery for spinal stenosis was effective to treat pain and disability. In this prospective study baseline global psychological distress, depression and anxiety were associated with poorer clinical outcome

    Accelerometer Based Methodology for Combustion Parameters Estimation

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    Due to increasingly stringent emission regulations and the need of more efficient powertrains, obtaining information about combustion process becomes a key factor. Low-cost in-cylinder pressure sensors are being developed, but they still present longterm reliability issues, and represent a considerable part of the engine management system cost. Research is being conducted in order to develop methodologies for extracting relevant combustion information using standard sensors already installed on-board. The present work introduces a methodology for combustion parameters estimation, through a control-oriented analysis of structureborne sound. The paper also shows experimental results obtained applying the estimation methodology to different passenger car engines. © 2015 The Authors. Published by Elsevier Ltd

    Transient Spark Advance Calibration Approach

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    Combustion control is assuming a crucial role in reducing engine tailpipe emissions while maximizing performance. The effort in the calibration of control parameters affecting the combustion development can be very demanding. One of the most effective factors influencing performance and efficiency is the combustion phasing: in Spark Ignition (SI) engines it is affected by factors such as Spark Advance (SA), Air-Fuel Ratio (AFR), Exhaust Gas Recirculation (EGR), Variable Valve Timing (VVT). SA optimal values are usually determined by means of calibration procedures carried out in steady state conditions on the test bench by changing SA values while monitoring performance indicators, such as Brake and Indicated Mean Effective Pressure (BMEP, IMEP), Brake Specific Fuel Consumption (BSFC) and pollutant emissions. The effect of SA on combustion is stochastic, due to the cycle-to-cycle variation: the analysis of mean values requires many engine cycles to be significant of the performance obtained with the given control setting. Moreover, often the effect of SA on engine performance must be investigated for different settings of other control parameters (EGR, VVT, AFR). The calibration process is time consuming involving exhaustive tests followed by off-line data analysis. This paper presents the application of a dynamic calibration methodology, with the objective of reducing the calibration duration. The proposed approach is based on transient tests, coupled with a statistical investigation, allowing reliable performance analysis even with a low number of engine cycles. The methodology has been developed and tested off-line, then it has been implemented in Real-Time. The combustion analysis system has been integrated with the ECU management software and the test bench controller, in order to perform a fully automatic calibration. © 2013 The Authors
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