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  1. Article ; Online: Collective effects in confined active Brownian particles.

    Caprini, Lorenzo / Maggi, Claudio / Marini Bettolo Marconi, Umberto

    The Journal of chemical physics

    2021  Volume 154, Issue 24, Page(s) 244901

    Abstract: We investigate a two-dimensional system of active particles confined to a narrow annular domain. Despite the absence of explicit interactions among the velocities or the active forces of different particles, the system displays a transition from a ... ...

    Abstract We investigate a two-dimensional system of active particles confined to a narrow annular domain. Despite the absence of explicit interactions among the velocities or the active forces of different particles, the system displays a transition from a disordered and stuck state to an ordered state of global collective motion where the particles rotate persistently clockwise or anticlockwise. We describe this behavior by introducing a suitable order parameter, the velocity polarization, measuring the global alignment of the particles' velocities along the tangential direction of the ring. We also measure the spatial velocity correlation function and its correlation length to characterize the two states. In the rotating phase, the velocity correlation displays an algebraic decay that is analytically predicted together with its correlation length, while in the stuck regime, the velocity correlation decays exponentially with a correlation length that increases with the persistence time. In the first case, the correlation (and, in particular, its correlation length) does not depend on the active force but the system size only. The global collective motion, an effect caused by the interplay between finite-size, periodicity, and persistent active forces, disappears as the size of the ring becomes infinite, suggesting that this phenomenon does not correspond to a phase transition in the usual thermodynamic sense.
    Language English
    Publishing date 2021-07-08
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3113-6
    ISSN 1089-7690 ; 0021-9606
    ISSN (online) 1089-7690
    ISSN 0021-9606
    DOI 10.1063/5.0051315
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Vascular Remodeling of Visceral Arteries Following Interruption of the Splenic Artery During Liver Transplantation.

    Dondossola, Daniele / Maggi, Umberto / Rossi, Giorgio

    Liver transplantation : official publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society

    2019  Volume 25, Issue 9, Page(s) 1459–1460

    MeSH term(s) Aneurysm ; Humans ; Liver Transplantation ; Splenic Artery ; Vascular Remodeling
    Language English
    Publishing date 2019-08-09
    Publishing country United States
    Document type Letter ; Comment
    ZDB-ID 2006866-9
    ISSN 1527-6473 ; 1527-6465
    ISSN (online) 1527-6473
    ISSN 1527-6465
    DOI 10.1002/lt.25605
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Erratum: Heat, temperature and Clausius inequality in a model for active Brownian particles.

    Marconi, Umberto Marini Bettolo / Puglisi, Andrea / Maggi, Claudio

    Scientific reports

    2018  Volume 8, Page(s) 46870

    Abstract: This corrects the article DOI: 10.1038/srep46496. ...

    Abstract This corrects the article DOI: 10.1038/srep46496.
    Language English
    Publishing date 2018-06-08
    Publishing country England
    Document type Published Erratum
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/srep46870
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Surgical site infections in liver transplantation in the era of multidrug-resistant bacteria.

    Brigati, Emilietta / Bandera, Alessandra / Consonni, Dario / Grancini, Anna / Maggi, Umberto / Piconi, Stefania / Alagna, Laura / Palomba, Emanuele / Caccamo, Lucio

    Minerva surgery

    2023  Volume 78, Issue 4, Page(s) 345–354

    Abstract: Background: Surgical site infection (SSI) is the major complication in orthotopic liver transplantation (LT). It is of prime importance to assess the incidence of infections in liver transplants and to analyze the risk factors associated with morbidity ... ...

    Abstract Background: Surgical site infection (SSI) is the major complication in orthotopic liver transplantation (LT). It is of prime importance to assess the incidence of infections in liver transplants and to analyze the risk factors associated with morbidity and mortality.
    Methods: Between 2014 and 2019, we performed a retrospective cohort study at the Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy. The liver transplant procedure and its related infections were examined in 4 timepoints, both prior and post-surgery. Multiple random-intercept Poisson regression models with robust variance were fitted to calculate the adjusted risk ratios (RR) and the 95% confidence intervals (CI) according to selected recipient and donor variables.
    Results: We included in the analysis 249 transplants (in 241 patients). The SSIs (mostly due to S. aureus, E. faecium, and K. pneumoniae) were 7 (2.8%) in the days following LT, increasing to 61 (24.5%) within the first month after LT, and declining to 35 (14.1%) between 31 and 60 days, and to 19 (7.6%) afterwards. The factors associated with increased risk of infection were age (RR=1.17 per 10 years, CI: 0.99-1.38), BMI (RR=1.04 per BMI Unit, CI: 0.99-1.08), donor age (RR=0.88 per 10 years, CI: 0.78-0.98), re-interventions (30 infections, RR=2.02, CI: 1.21-3.38) and the Roux-en-Y approach (25 infections, RR=2.75, CI: 1.47-5.15).
    Conclusions: The risk of infection occurred mainly in the first two months after LT. Important determinants were age and BMI, donor age, reinterventions, and Roux-en-Y procedure. Our study suggests that these factors should be assessed when performing LT.
    MeSH term(s) Humans ; Child ; Surgical Wound Infection/epidemiology ; Surgical Wound Infection/etiology ; Liver Transplantation/adverse effects ; Liver Transplantation/methods ; Retrospective Studies ; Staphylococcus aureus ; Liver
    Language English
    Publishing date 2023-01-18
    Publishing country Italy
    Document type Journal Article
    ZDB-ID 3067899-7
    ISSN 2724-5438
    ISSN (online) 2724-5438
    DOI 10.23736/S2724-5691.22.09807-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Unusual oral presentation of HSV-1 lesions in an adult liver transplant recipient.

    Yiu, Daniel / Ballabio, Michele / Fornoni, Gianluca / Maggi, Umberto

    BMJ case reports

    2019  Volume 12, Issue 3

    Abstract: Herpes Simplex Virus (HSV) hepatitis in liver transplant patients is a rarely reported infective complication of HSV with severe consequences, often leading to fulminant hepatitis if left untreated. The clinical signs are often atypical, leading to under- ...

    Abstract Herpes Simplex Virus (HSV) hepatitis in liver transplant patients is a rarely reported infective complication of HSV with severe consequences, often leading to fulminant hepatitis if left untreated. The clinical signs are often atypical, leading to under-reporting in the literature and potential delays in treatment. Our case report describes such atypical mucocutaneous lesions in a liver transplant recipient. We highlight the need for further reports, especially those with images, in order to aid the diagnosis of HSV infection, and to allow prompt treatment to prevent complications such as HSV hepatitis.
    MeSH term(s) Adult ; Female ; Hepatitis, Viral, Human/virology ; Herpes Simplex/virology ; Herpesvirus 1, Human ; Humans ; Liver Transplantation/adverse effects ; Mouth/virology ; Postoperative Complications/virology ; Stomatitis, Herpetic/virology
    Language English
    Publishing date 2019-03-08
    Publishing country England
    Document type Case Reports ; Journal Article
    ISSN 1757-790X
    ISSN (online) 1757-790X
    DOI 10.1136/bcr-2018-227492
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Book ; Online: Collective effects in confined Active Brownian Particles

    Caprini, Lorenzo / Maggi, Claudio / Marconi, Umberto Marini Bettolo

    2021  

    Abstract: We investigate a two-dimensional system of active particles confined to a narrow annular domain. Despite the absence of explicit interactions among the velocities or the active forces of different particles, the system displays a transition from a ... ...

    Abstract We investigate a two-dimensional system of active particles confined to a narrow annular domain. Despite the absence of explicit interactions among the velocities or the active forces of different particles, the system displays a transition from a disordered and stuck state to an ordered state of global collective motion where the particles rotate persistently clockwise or anticlockwise. We describe this behavior by introducing a suitable order parameter, the velocity polarization, measuring the global alignment of the particles' velocities along the tangential direction of the ring. We also measure the spatial velocity correlation function and its correlation length to characterize the two states. In the rotating phase, the velocity correlation displays an algebraic decay that is analytically predicted together with its correlation length while in the stuck regime the velocity correlation decays exponentially with a correlation length that increases with the persistence time. In the first case, the correlation (and, in particular, its correlation length) does not depend on the active force but the system size only. The global collective motion, an effect caused by the interplay between finite-size, periodicity, and persistent active forces, disappears as the size of the ring becomes infinite, suggesting that this phenomenon does not correspond to a phase transition in the usual thermodynamic sense.
    Keywords Condensed Matter - Statistical Mechanics ; Condensed Matter - Soft Condensed Matter
    Subject code 612
    Publishing date 2021-03-24
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Effective equilibrium picture in the xy model with exponentially correlated noise.

    Paoluzzi, Matteo / Marconi, Umberto Marini Bettolo / Maggi, Claudio

    Physical review. E

    2018  Volume 97, Issue 2-1, Page(s) 22605

    Abstract: We study the effect of exponentially correlated noise on the xy model in the limit of small correlation time, discussing the order-disorder transition in the mean field and the topological transition in two dimensions. We map the steady states of the ... ...

    Abstract We study the effect of exponentially correlated noise on the xy model in the limit of small correlation time, discussing the order-disorder transition in the mean field and the topological transition in two dimensions. We map the steady states of the nonequilibrium dynamics into an effective equilibrium theory. In the mean field, the critical temperature increases with the noise correlation time τ, indicating that memory effects promote ordering. This finding is confirmed by numerical simulations. The topological transition temperature in two dimensions remains untouched. However, finite-size effects induce a crossover in the vortices proliferation that is confirmed by numerical simulations.
    Language English
    Publishing date 2018-03-20
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2844562-4
    ISSN 2470-0053 ; 2470-0045
    ISSN (online) 2470-0053
    ISSN 2470-0045
    DOI 10.1103/PhysRevE.97.022605
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  8. Article ; Online: Further details from the first human liver transplantation in Europe.

    Maggi, Umberto / Azoulay, Daniel

    Transplantation

    2013  Volume 96, Issue 6, Page(s) e47–8

    MeSH term(s) Aged ; Europe ; History, 20th Century ; Humans ; Liver Neoplasms/history ; Liver Neoplasms/secondary ; Liver Neoplasms/surgery ; Liver Transplantation/history ; Male ; Tissue Donors/history
    Language English
    Publishing date 2013-09
    Publishing country United States
    Document type Historical Article ; Letter
    ZDB-ID 208424-7
    ISSN 1534-6080 ; 0041-1337
    ISSN (online) 1534-6080
    ISSN 0041-1337
    DOI 10.1097/TP.0b013e3182a37432
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  9. Article ; Online: Heat, temperature and Clausius inequality in a model for active Brownian particles.

    Marconi, Umberto Marini Bettolo / Puglisi, Andrea / Maggi, Claudio

    Scientific reports

    2017  Volume 7, Page(s) 46496

    Abstract: Methods of stochastic thermodynamics and hydrodynamics are applied to a recently introduced model of active particles. The model consists of an overdamped particle subject to Gaussian coloured noise. Inspired by stochastic thermodynamics, we derive from ... ...

    Abstract Methods of stochastic thermodynamics and hydrodynamics are applied to a recently introduced model of active particles. The model consists of an overdamped particle subject to Gaussian coloured noise. Inspired by stochastic thermodynamics, we derive from the system's Fokker-Planck equation the average exchanges of heat and work with the active bath and the associated entropy production. We show that a Clausius inequality holds, with the local (non-uniform) temperature of the active bath replacing the uniform temperature usually encountered in equilibrium systems. Furthermore, by restricting the dynamical space to the first velocity moments of the local distribution function we derive a hydrodynamic description where local pressure, kinetic temperature and internal heat fluxes appear and are consistent with the previous thermodynamic analysis. The procedure also shows under which conditions one obtains the unified coloured noise approximation (UCNA): such an approximation neglects the fast relaxation to the active bath and therefore yields detailed balance and zero entropy production. In the last part, by using multiple time-scale analysis, we provide a constructive method (alternative to UCNA) to determine the solution of the Kramers equation and go beyond the detailed balance condition determining negative entropy production.
    Language English
    Publishing date 2017-04-21
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/srep46496
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  10. Article ; Online: Pressure in an exactly solvable model of active fluid.

    Marini Bettolo Marconi, Umberto / Maggi, Claudio / Paoluzzi, Matteo

    The Journal of chemical physics

    2017  Volume 147, Issue 2, Page(s) 24903

    Abstract: We consider the pressure in the steady-state regime of three stochastic models characterized by self-propulsion and persistent motion and widely employed to describe the behavior of active particles, namely, the Active Brownian particle (ABP) model, the ... ...

    Abstract We consider the pressure in the steady-state regime of three stochastic models characterized by self-propulsion and persistent motion and widely employed to describe the behavior of active particles, namely, the Active Brownian particle (ABP) model, the Gaussian colored noise (GCN) model, and the unified colored noise approximation (UCNA) model. Whereas in the limit of short but finite persistence time, the pressure in the UCNA model can be obtained by different methods which have an analog in equilibrium systems, in the remaining two models only the virial route is, in general, possible. According to this method, notwithstanding each model obeys its own specific microscopic law of evolution, the pressure displays a certain universal behavior. For generic interparticle and confining potentials, we derive a formula which establishes a correspondence between the GCN and the UCNA pressures. In order to provide explicit formulas and examples, we specialize the discussion to the case of an assembly of elastic dumbbells confined to a parabolic well. By employing the UCNA we find that, for this model, the pressure determined by the thermodynamic method coincides with the pressures obtained by the virial and mechanical methods. The three methods when applied to the GCN give a pressure identical to that obtained via the UCNA. Finally, we find that the ABP virial pressure exactly agrees with the UCNA and GCN results.
    Language English
    Publishing date 2017-07-14
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3113-6
    ISSN 1089-7690 ; 0021-9606
    ISSN (online) 1089-7690
    ISSN 0021-9606
    DOI 10.1063/1.4991731
    Database MEDical Literature Analysis and Retrieval System OnLINE

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