231 research outputs found
SEISMIC RELIABILITY-BASED DESIGN OF STRUCTURES EQUIPPED WITH DFPS
This work deals with seismic reliability-based design (SRBD) for softening and hardening structures equipped with double friction pendulum system (DFPS) isolators. The isolated system is represented by means of an equivalent 3dof model having a softening/hardening post-yield slope for the superstructure and velocity-dependent rules for the two surfaces of the DFP devices. The yielding characteristics of the superstructures are defined in compli-ance with the seismic hazard of L’Aquila site (Italy) and with NTC18 assuming ordinary characteristics. Considering several natural seismic records and the relevant random varia-bles, incremental dynamic analyses are carried out for assessing the seismic fragility and the seismic reliability of these systems. Finally, seismic reliability-based design (SRBD) curves for these systems are proposed
Seismic reliability-based design of softening structures equipped with double sliding devices
This study deals with seismic reliability-based design (SRBD) relationships in terms of beha-vior factors and displacement demands for softening structures equipped with double friction pendulum system (DFPS) bearings. An equivalent 3dof system having a softening post-yield slope is adopted to describe the superstructure behavior, whereas velocity-dependent laws are assumed to model the responses of the two surfaces of the DFPS. The yielding characte-ristics of the superstructures are defined for increasing behavior factors in compliance with the seismic hazard of L’Aquila site (Italy) and with NTC18 assuming a lifetime of 50 years. Considering several natural seismic records and building properties under the hypothesis of modelling the friction coefficients of the two surfaces of the DFPS as random variables, in-cremental dynamic analyses are performed to evaluate the seismic fragility and the seismic reliability of these systems. Finally, seismic reliability is assessed and seismic reliability-based design (SRBD) curves for the two surfaces of the double sliding devices are described
Reply to the letter of Dr Merdin
Dr Merdin kindly makes suggestions about the design of our study and asks for more information about the infectious and immunosuppressive history of our monoclonal B‐cell lymphocytosis (MBL) patients with monoclonal B‐cell lymphocytosis (MBL). In our study, we incidentally found the coexistence of five cases of MBL and monoclonal gammopathy of undetermined significance (MGUS) in a cohort of kidney transplant recipients at a median of 15 years after transplantation.1 MBL and MGUS are two pre‐malignant lymphoproliferative disorders of terminally differentiated B cells. Clinically, MBL and MGUS share common features, such as an indolent course, a late‐onset age distribution, a low rate of progression and an increased susceptibility to infections. MBL and MGUS are also the precursor states of two hematologic malignancies: chronic lymphocytic leukemia (CLL) and multiple myeloma (MM), respectively
Pressure Ulcers due to a Tunneled Central Venous Catheter in a Patient on Chronic Maintenance Hemodialysis
We describe a rare complication given by tunneled central venous catheter (CVC) in a 95-years-old woman on chronic maintenance hemodialysis (HD)
A Random Matrix Model for mmWave MIMO Systems
Random matrices are nowadays classical tools for modeling multiantenna wireless channels. Scattering phenomena typical of cellular frequencies and channel reciprocity features led to the adoption of matrices sampled either from the Gaussian Unitary Ensemble (GUE) or from more general Polynomial Ensembles (PE). Such matrices can be used to model the random impairments of the radio channel on the transmitted signal over a wireless link whose transmitter and receiver are both equipped with antenna arrays. The exploitation of the millimeter-wave (mmWave) frequency band, planned for 5G and beyond mobile networks, prevents the use of GUE and PE elements as candidate models for channel matrices. This is mainly due to the lack of scattering richness compared to microwave-based transmissions. In this work, we propose to model mmWave Multi-Input–MultiOutput (MIMO) systems via products of random Vandermonde matrices. We illustrate the physical motivation of our model selection, discuss the meaning of the parameters and their impact on the spectral properties of the random matrix at hand, and provide both a list of results of immediate use for performance analysis of mmWave MIMO systems, as well as a list of open problems in the field
Successful treatment of BK virus associated-nephropathy in a human immunodeficiency virus-positive kidney transplant recipient
BK virus (BKV) is an opportunistic pathogen in those with impaired immunity. Viral replication is generally asymptomatic but is able to induce cytopathic alterations in renal cells. If BKV infection is left untreated, it leads to BKV-associated nephropathy (BKVAN) and graft loss. There is scarce experience in the management of BKV infection in kidney transplant recipients living with HIV. We report the successful treatment of BKVAN in an HIV-positive kidney transplant recipient who experienced BKV replication in the immediate post-transplantation period. A change in therapy from calcineurin inhibitor to sirolimus, steroid withdrawal and a short course of an immunomodulatory agent (leflunomide) controlled BKV viremia in the absence of drug side-effects or impairment of graft function
Seismic reliability-based design of hardening structures equipped with double sliding devices
This study deals with seismic reliability-based design (SRBD) relationships in terms of beha-vior factors and displacement demands for hardening structures equipped with double fric-tion pendulum system (DFPS) bearings. An equivalent 3dof system having a hardening post-yield slope is adopted to describe the superstructure behavior, whereas velocity-dependent laws are assumed to model the responses of the two surfaces of the DFPS. The yielding cha-racteristics of the superstructures are defined for increasing behavior factors in compliance with the seismic hazard of L’Aquila site (Italy) and with NTC18 assuming a lifetime of 50 years. Considering several natural seismic records and building properties under the hypo-thesis of modelling the friction coefficients of the two surfaces of the DFPS as random variables, incremental dynamic analyses are performed to evaluate the seismic fragility and the seismic reliability of these systems. Finally, seismic reliability is evaluated and seismic relia-bility-based design (SRBD) curves for the two surfaces of the double sliding devices are de-scribed
Kidney Disease in HIV Infection
Antiretroviral therapy (ART) has significantly improved life expectancy of infected subjects, generating a new epidemiological setting of people aging withHuman Immunodeficiency Virus (HIV). People living with HIV (PLWH), having longer life expectancy, now face several age-related conditions as well as side effects of long-term exposure of ART. Chronic kidney disease (CKD) is a common comorbidity in this population. CKD is a relentlessly progressive disease that may evolve toward end-stage renal disease (ESRD) and significantly affect quality of life and risk of death. Herein, we review current understanding of renal involvement in PLWH, mechanisms and risk factors for CKD as well as strategies for early recognition of renal dysfunction and best care of CKD
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