277 research outputs found

    PtRu nanoparticles supported on noble carbons for ethanol electrooxidation

    Get PDF
    In this work, three cytosine derived nitrogen doped carbonaceous materials (noble carbons, NCs) with different atomic C/N ratios and porous networks have been synthesized and used as supports for PtRu electrocatalysts in the ethanol oxidation reaction (EOR) for clean hydrogen production. Both, the metal phase and the carbon support play critical roles in the electrocatalysts final performance. Lower NPs size distribution was obtained over supports with low atomic C/N ratios (i.e., 4 and 6) and defined porosity (i.e., 1701 m2 g−1 for PtRu/CNZ and 1834 m2 g−1 for PtRu/CLZ, respectively). In contrast, a lower C/N ratio and poor porous network (i.e., 65 m2 g−1, PtRu/CLK) led to the largest particle size and fostered an increase of the alloying degree between Pt and Ru NPs (i.e., 3 for C/N ~ 6 and 28 for C/N ~ 3). Electrochemical active surface area was found to increase with decreasing NPs size and the alloy extent, due to a higher availability of Pt active sites. Accelerated degradation tests showed that PtRu/NCs outperform similar to PtRu NPs on commercial carbon pointing at the stabilizing effect of NCs. PtRu/CNZ exhibited the best electrochemical performance (i.e., 69.1 mA mgPt−1), outperforming PtRu/CLZ and PtRu/CLK by 3- and 9-fold, respectively, due to a suitable compromise between particle sizes, degree of alloy, textural properties and elemental composition. Best anodes were scaled-up to a proton exchange membrane cell and PtRu/CNZ was proved to provide the best electrocatalytic activity (262 mA cm−2 and low energy requirements), matching the values obtained by the state of the art of EOR electrocatalysts

    A New Fossil Amiid from the Eocene of Senegal and the Persistence of Extinct Marine Amiids after the Cretaceous–Paleogene Boundary

    Get PDF
    We report a new fossil amiid from Eocene rocks of West Africa representing the first record of this clade from Senegal. The new specimen has a maxilla that is very similar in size to that of Amia calva. It is distinctly smaller than reported remains of another West African Eocene taxon, Maliamia gigas. We tentatively refer the Senegal specimen to Vidalamiini because it has the large postmaxillary process diagnostic of this clade; however, it also exhibits anatomical features not previously described in extinct amiids. We recovered the specimen in rocks of the Lam-Lam Formation in Central-Western Senegal that we interpret to have been a shallow marine depositional environment. The occurrence of an Eocene marine amiid contradicts existing hypotheses that marine amiids were generally absent after the Cretaceous– Paleogene boundary having been replaced by freshwater taxa. Research completed since the initial discovery of Maliamia gigas indicates that this Eocene taxon was also found in shallow marine rocks

    Nursing workload and staff allocation in an Italian hospital: a quality improvement initiative based on nursing care score

    Get PDF
    Aim: To develop, implement, and evaluate a Nursing Care Score (NCS) system, built into the electronic health record, to optimize nursing workload and staff allocation. Design: A quality improvement (QI) initiative with a pre- and post-implementation design was conducted by an interprofessional team in the 33-bed cardio-thoracic unit of a 72-bed hospital in Palermo, Italy. Methods: A seven-phase process was used to develop, implement, and evaluate the NCS, which lists 53 nursing work tasks, each assigned a score from 1.5 to 5.0. The nurse-to-patient ratio on all shifts was determined by the NCS. Nurse satisfaction with both the existing system and the NCS workload system was assessed. Descriptive statistics and McNemar's test were used to analyze the data. Results: At pre-implementation, 92.5% of nurses reported that the existing system was not effective, 87.5% reported it did not enable them to provide adequate nursing care, and 20.0% believed that workload was fairly distributed. At post-implementation, 75.0% of nurses reported that the NCS system was effective (p = 0.0348), 85.0% reported that the NCS system enabled them to provide adequate care, and 85.0% believed that workload was fairly distributed. An NCS score of 65 ± 5 was found to distribute workload most fairly. Conclusion: An automatic electronic operating system to generate a daily workload report based on the NCS was successfully implemented and evaluated. The NCS provided relevant information to guide nurse managers in defining nurse-to-patient ratio and determining staff allocation. Nurses were satisfied with the NCS system. The steps used to develop, implement, and evaluate the NCS system may be transferable to other units and other hospitals

    Bdnf-Nrf-2 crosstalk and emotional behavior are disrupted in a sex-dependent fashion in adolescent mice exposed to maternal stress or maternal obesity

    Get PDF
    Maternal obesity has been recognized as a stressor affecting the developing fetal brain, leading to long-term negative outcomes comparable to those resulting from maternal psychological stress, although the mechanisms have not been completely elucidated. In this study, we tested the hypothesis that adverse prenatal conditions as diverse as maternal stress and maternal obesity might affect emotional regulation and stress response in the offspring through common pathways, with a main focus on oxidative stress and neuroplasticity. We contrasted and compared adolescent male and female offspring in two mouse models of maternal psychophysical stress (restraint during pregnancy - PNS) and maternal obesity (high-fat diet before and during gestation - mHFD) by combining behavioral assays, evaluation of the hypothalamic-pituitary-adrenal (HPA) axis reactivity, immunohistochemistry and gene expression analysis of selected markers of neuronal function and neuroinflammation in the hippocampus, a key region involved in stress appraisal. Prenatal administration of the antioxidant N-acetyl-cysteine (NAC) was used as a strategy to protect fetal neurodevelopment from the negative effects of PNS and mHFD. Our findings show that these two stressors produce overlapping effects, reducing brain anti-oxidant defenses (Nrf-2) and leading to sex-dependent impairments of hippocampal Bdnf expression and alterations of the emotional behavior and HPA axis functionality. Prenatal NAC administration, by restoring the redox balance, was able to exert long-term protective effects on brain development, suggesting that the modulation of redox pathways might be an effective strategy to target common shared mechanisms between different adverse prenatal conditions

    Evaluation of potato clones for heat tolerance in the southern region of Minas Gerais, Brazil.

    Get PDF
    The purpose of this study was to evaluate potato clones previously selected for heat tolerance as to choose the most adapted and stable ones for use as parent varieties in future breeding programs or as new cultivars for the market

    Self-Association of an Activating Natural Killer Cell Receptor, KIR2DS1

    Get PDF
    As a major component of the innate immune system, natural killer cells are responsible for activating the cytolytic killing of certain pathogen-infected or tumor cells. The self-recognition of natural killer cells is achieved in part by the killer cell immunoglobulin-like receptors (KIRs) protein family. In the current study, using a suite of biophysical methods, we investigate the self-association of an activating KIR, KIR2DS1. This KIR is of particular interest because when in the presence of the HLA-Cw6 protein, KIR2DS1 becomes a major risk factor for psoriasis, an autoimmune chronic skin disease. Using circular dichroism spectroscopy, dynamic light scattering, and atomic force microscopy, we reveal that KIR2DS1 self-associates in a well-defined fashion. Our novel results on an activating KIR allow us to suggest a working model for the KIR2DS1- HLA class I molecular mechanism

    Psycho-educational group therapy in acute psychiatric units: creating a psychosocial culture. An update of spread and effectiveness of a psychosocial intervention in Italian psychiatric wards

    Get PDF
    The implementation of a Cognitive-Behavioural Group Intervention (CBGI) in Italian general hospital psychiatric units started in the years 2000-2001 in two Italian regions. Over the years it has became more and more popular also in other psychiatric units located in the rest of the country. Based on the "stress-vulnerability-coping" theory, the CBGI is a replicable and innovative psychosocial intervention that promotes the active involvement of inpatients in decisions concerning their individual objectives and care. In the present article, the authors briefly describe this intervention and the main findings regarding its implementation in several psychiatric units in different Regions of Italy. The authors emphasize that such a psychosocial approach to inpatient care is needed because it can produce improved clinical outcomes, reduction in untoward events and increased staff and inpatient satisfaction. However, its introduction and use still represent a major cultural and managerial challenge in our country

    Emergency hernia repair in the elderly. multivariate analysis of morbidity and mortality from an Italian registry

    Get PDF
    Purpose The incidence of inguinal hernia is higher in elderly because of aging-related diseases like prostatism, bronchitis, collagen laxity. A conservative management is common in elderly to reduce surgery-related risks, however watchful waiting can expose to obstruction and strangulation. The aim of the present study was to assess the impact of emergency surgery in a large series of elderly with complicated groin hernia and to identify the independent risk factors for postoperative morbidity and mortality. The predictive performance of prognostic risk scores has been also assessed. Methods This is a prospective observational study carried out between January 2017 and June 2018 in elderly patients who underwent emergency surgery for complicated hernia in 38 Italian hospitals. Pre-operative, surgical and postoperative data were recorded for each patient. ASA score, Charlson's comorbidity index, P-POSSUM and CR-POSSUM were assessed. Results 259 patients were recruited, mean age was 80 years. A direct repair without mesh was performed in 62 (23.9%) patients. Explorative laparotomy was performed in 56 (21.6%) patients and bowel resection was necessary in 44 (17%). Mortality occurred in seven (2.8%) patients. Fifty-five (21.2%) patients developed complications, 12 of whom had a major one. At univariate and multivariate analyses, Charlson's comorbidity index >= 6, altered mental status, and need for laparotomy were associated with major complications and mortality Conclusion Emergency surgery for complicated hernia is burdened by high morbidity and mortality in elderly patients. Preoperative comorbidity played a pivotal role in predicting complications and mortality and therefore Charlson's comorbidity index could be adopted to select patients for elective operation
    • 

    corecore