271 research outputs found
High-performance lead-acid batteries enabled by Pb and PbO2 nanostructured electrodes: Effect of operating temperature
Lead-acid batteries are now widely used for energy storage, as result of an established and reliable technology. In the last decade, several studies have been carried out to improve the performance of this type of batteries, with the main objective to replace the conventional plates with innovative electrodes with improved stability, increased capacity and a larger active surface. Such studies ultimately aim to improve the kinetics of electrochemical conversion reactions at the electrode-solution interface and to guarantee a good electrical continuity during the repeated charge/discharge cycles. To achieve these objectives, our contribution focuses on the employment of nanostructured electrodes. In particular, we have obtained nanostructured electrodes in Pb and PbO2 through electrosynthesis in a template consisting of a nanoporous polycarbonate membrane. These electrodes are characterized by a wider active surface area, which allows for a better use of the active material, and for a consequent increased specific energy compared to traditional batteries. In this research, the performance of lead-acid batteries with nanostructured electrodes was studied at 10 C at temperatures of 25, â20 and 40 °C in order to evaluate the efficiency and the effect of temperature on electrode morphology. The batteries were assembled using both nanostructured electrodes and an AGM-type separator used in commercial batteries
Impact of Candida species colonization and azoles resistance in a neonatal intensive care unit
Background: Candida species are among the top 10 most frequently isolated nosocomial bloodstream pathogens in Europe. In particular, in neonatal intensive care units (NICUs) Candida infections are an emerging concern because of the increasing incidence, the related high morbidity and mortality rates reported. Moreover, the epidemiology of Candida infection rapidly changed in these years leading to the selection of less sensitive strains and species. Surveillance studies are mandatory to identify the local distribution of species, their antifungal susceptibility profiles and the emergence of resistance strains.
Material/methods: From December 2012 we performed a cohort prospective surveillance study in our NICU, collecting weekly nasal and rectal swabs. Swabs were placed on Sabouraud agar. Candida growth on agar plates was confirmed by microscopic observation. Furthermore, Candida spp. was identified through Candida chromogenic agar (Candida chromogenic agar, Laboratorios Conda) and API\uae 20C AUX (Biom\ue9rieux). The first isolated non-C.albicans Candida (NCAC) species from colonized patients were tested with the main antifungal agents (YeastOne\uae Y010 Thermo Fisher Scientific) and the obtained MIC values were read according to CLSI.
Results: From December 2012 to June 2016 we enrolled 874 neonates and analyzed respectively 2014 nasal and rectal swabs. 20/2014 (0,99%) of nasal swabs and 128/2014 (6,35%) of rectal swabs tested positive for Candida spp. The species distribution is showed in the Graph 1. 89/874 (10,18%) neonates tested positive at least in one swab. 59 isolates of NCAC species were tested with the main antifungal agents. All the tested strains were susceptible to echinocandins and amphotericin B. The susceptibility patterns for azoles are shown in the Table 1. Conclusions: Our study confirm the rule of surveillance in the prevention and control of Candida spp. healthcare related infections especially in an high risk ward such as NICU. In particular, in our NICU fluconazole prophylaxis is administered according to standard protocols from 2009.Antifungal susceptibility testes allowed to identify resistant and mutant strains whom acquired resistance so to obtain both clinical and epidemiological data promptly
The emerging role of p53 in stem cells
Among the hundreds of oncogenes and tumor suppressors that have been identified in the past 50 years, p53 is probably the best characterized; nevertheless, new functions are constantly being discovered. As a tumor suppressor, p53 regulates cellular responses to different stress stimuli by inducing reversible cell cycle arrest and DNA repair, or triggering senescence or apoptosis. Recent findings on the regulation of stem cell (SC) division and reprogramming suggest the intriguing possibility that p53 also carries out its tumor suppression function by regulating SC homeostasis. Specifically, p53 activation may counteract SC expansion by several emerging mechanisms including restriction of self-renewing divisions, inhibition of symmetric division and block of reprogramming of somatic/progenitor cells into SCs
Tephrochronology in faulted Middle Pleistocene tephra layer in the Val dâAgri area (Southern Italy)
The High Agri River Valley is a Quaternary Basin located along the hinge of the Southern Apennines fold-andthrust
belt. The inner margin of the orogen has been affected by intense transtensional and normal faulting, which
accompanied vigorous volcanism during the Quaternary. Marker tephra layers are distributed across the whole of
Southern Italy and provide a powerful tool to constrain both the size of eruptions and the regional activity of extensional
faults controlling basin evolution. Paleoseismological trenching within the Monti della Maddalena
range, that borders the Agri River Valley to the south-west, has exposed a faulted stratigraphic sequence and recovered
a 10 cm thick tephra layer involved in deformation. This is the first tephra horizon recognized in the high
Agri Valley, which, based on the stratigraphic study of the trench, lies in a primary position. 40Ar/39Ar dating
constrain its age to 266 ka and provide an important marker for the Middle Pleistocene tephrochronology of the
region. Together with dating, geochemical analysis suggests a possible volcanic source in the Campanian region
Surveillance of Multidrug-Resistant Pathogens in Neonatal Intensive Care Units of Palermo, Italy, during SARS-CoV-2 Pandemic
Background: Antimicrobial resistance (AMR) is a topic of concern, especially in high-level care departments like neonatal intensive care units (NICUs). The systematic use of an âactiveâ epidemiological surveillance system allows us to observe and analyze any changes in microbial distribution, limiting the risk of healthcare-associated infection (HAI) development. Methods: We have conducted a longitudinal observational study in the five NICUs of Palermo, comparing the âpre-pandemic periodâ (March 2014âFebruary 2020) with the âpandemicâ one (March 2020âFebruary 2022). The primary aim of the study was to evaluate the cumulative prevalence of carriage from multi-drug resistant (MDR) bacteria in the cumulative NICUs (NICU C). Results: During the âpre-pandemic periodâ, 9407 swabs were collected (4707 rectal, 4700 nasal); on the contrary, during the âpandemic periodâ, a total of 2687 swabs were collected (1345 rectal, 1342 nasal). A statistically significant decrease in MDR-Gram-negative bacteria (GNB) carriage prevalence was detected during the pandemic. At the same time, there was a general worsening of the carriage of carbapenemase-forming MDR-GNB (CARBA-R+) and methicillin-resistant Staphylococcus aureus (MRSA) during the pandemic period. A significant reduction in methicillin-susceptible Staphylococcus aureus (MSSA) carriage was detected too. Conclusions: The surveillance of MDRO carriage in NICUs is fundamental for limiting the social and economic burden of HAIs
The burden of Candida species colonization in NICU patients: a colonization surveillance study
Fungal infections are an important cause
of morbidity and mortality in neonatal
intensive care units (NICUs). The identification
of specific risk factors supports prevention
of candidemia in neonates. Effective
prophylactic strategies have recently
become available, but the identification
and adequate management of high-risk infants
is still a priority. Prior colonization is
a key risk factor for candidemia. For this
reason, surveillance studies to monitor incidence,
species distribution, and antifungal
susceptibility profiles, are mandatory.
Among 520 infants admitted to our NICU
between January 2013 and December
2014, 472 (90.77%) were included in the
study. Forty-eight out of 472 (10.17%) patients
tested positive for Candida spp. (C.),
at least on one occasion. All the colonized
patients tested positive for the rectal swab,
whereas 7 patients also tested positive for
the nasal swab. Fifteen out of 472 patients
(3.18%) had more than one positive rectal
or nasal swab during their NICU stay.
Moreover, 9 out of 15 patients tested negative
at the first sampling, suggesting they
acquired Candida spp. during their stay.
Twenty-five of forty-eight (52.1%) colonized
patients carried C.albicans and 15/48
(31.25%) C.parapsilosis. We identified as
risk factors for Candida spp. colonization:
antibiotic therapy, parenteral nutrition,
the use of a central venous catheter, and
nasogastric tube. Our experience suggests
that effective microbiological surveillance
can allow for implementing proper, effective
and timely control measures in a highrisk
setting
Efficacy of a coordinated strategy for containment of multidrug-resistant Gram-negative bacteria carriage in a Neonatal Intensive Care Unit in the context of an active surveillance program
Background: Antimicrobial resistance in neonatal intensive care unit (NICU) patients is a threat, due to the frequent use of antimicrobial treatment and invasive devices in fragile babies. Since 2014 an active surveillance program of multidrug-resistant Gram-negative bacteria (MDR-GNB) carriage has been in place in the five NICUs of Palermo, Italy. In 2017 an increase in the prevalence of MDR-GNB, and in particular of extended-spectrum ÎČ-lactamases-producing Klebsiella pneumoniae (ESBL-KP), was observed in âCivicoâ hospital NICU. Aim: To assess the impact of a coordinated intervention strategy in achieving long-lasting reduction of MDR-GNB prevalence in the NICU. Methods: Rectal swabs were obtained monthly and processed to detect MDR-GNB using standard methods. MDR-GNB were characterized by pulsed-field gel electrophoresis (PFGE). Since November 2017 the following intervention measures were applied: (a) two-months intensification of sample collection; (b) stakeholders meetings; (c) improvement of prevention measures and antimicrobial policies. Findings: During the intensified microbiological surveillance MDR-GNB and ESBL-KP were detected in rectal swabs (34.8%; 23.2%), nasal swabs (24.6%; 14.5%), oral swabs (14.5%; 5.4%), milk samples (32.1%; 17.9%), pacifiers swabs (30.8%; 17.9%) and from sub-intensive room surfaces. Thirteen ESBL-KP strains isolated from clinical and environmental samples showed identical PFGE patterns. The prevalence of MDR-GNB and ESBL-KP carriage significantly decreased in the year after intervention compared to the previous year (20.6% vs 62.2%; p < 0.001 and 11.1% vs 57.8%; p < 0.001). MDR-GNB were not detected at all for three months and ESBL-KP for five months. Multivariate analysis of the principal exposure variables showed that admission in the post-intervention period significantly reduced the risk of MDR-GNB carriage (adj-OR = 0.21, 95% CI = 0.076â0.629; p < 0.001). Conclusions: MDR-GNB broadly circulate in NICU setting, they can colonize different body sites and spread through various vehicles. A coordinated strategy of multiple interventions with active cooperation between epidemiologists and clinicians in the NICU can effectively reduce their circulation and in particular the carriage of the most dangerous ESBL-KP strains
A Snapshot on MRSA epidemiology in a neonatal intensive care unit network, Palermo, Italy
Objectives: We performed a 1-year prospective surveillance study on MRSA colonization within the five NICUs of the metropolitan area of Palermo, Italy. The purpose of the study was to assess epidemiology of MRSA in NICU from a network perspective. Methods: Transfer of patients between NICUs during 2014 was traced based on the annual hospital discharge records. In the period February 2014-January 2015, in the NICU B, at the University teaching hospital, nasal swabs from all infants were collected weekly, whereas in the other four NICUs (A, C, D, E) at 4 week-intervals of time. MRSA isolates were submitted to antibiotic susceptibility testing, SCCmec typing, PCR to detect lukS-PV and lukF-PV (lukS/F-PV) genes and the gene encoding the toxic shock syndrome toxin (TSST-1), multilocus variable number tandem repeat fingerprinting (MLVF), and multilocus sequence typing (MLST). Results: In the period under study, 587 nasal swabs were obtained from NICU B, whereas 218, 180, 157, and 95 from NICUs A, C, D, and E, respectively. Two groups of NICUs at high prevalence and low prevalence of MRSA colonization were recognized. Overall, 113 isolates of MRSA were identified from 102 infants. Six MLVF types (A-F) were detected, with type C being subdivided into five subtypes. Five sequence types (STs) were found with ST22-IVa being the most frequent type in all NICUs. All the MRSA molecular subtypes, except for ST1-IVa, were identified in NICU B. Conclusions: Our findings support the need to approach surveillance and infection control in NICU in a network perspective, prioritizing referral healthcare facilities
Recent Trends and Perspectives on Defect-Oriented Testing
Electronics employed in modern safety-critical systems require severe qualification during the manufacturing process and in the field, to prevent fault effects from manifesting themselves as critical failures during mission operations. Traditional fault models are not sufficient anymore to guarantee the required quality levels for chips utilized in mission-critical applications. The research community and industry have been investigating new test approaches such as device-aware test, cell-aware test, path-delay test, and even test methodologies based on the analysis of manufacturing data to move the scope from OPPM to OPPB. This special session presents four contributions, from academic researchers and industry professionals, to enable better chip quality. We present results on various activities towards this objective, including device-aware test, software-based self-test, and memory test
DISFUNZIONE MULTIORGANO (MOF) IN CORSO DI ENCEFALOPATIA NEONATALE. INDAGINE EPIDEMIOLOGICA SU UN CAMPIONE DI NEONATI OSSERVATI NEL PERIODO GENNAIO 2009 - MAGGIO 2016
encefalopatia, disfunzione multirogan
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