283 research outputs found
PtRu nanoparticles supported on noble carbons for ethanol electrooxidation
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., 1701Â m2 gâ1 for PtRu/CNZ and 1834Â m2 gâ1 for PtRu/CLZ, respectively). In contrast, a lower C/N ratio and poor porous network (i.e., 65Â m2 gâ1, 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/NÂ ~Â 6 and 28 for C/NÂ ~Â 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., 69.1Â mA mgPtâ1), 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 (262Â mAÂ cmâ2 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 CretaceousâPaleogene Boundary
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 Cretaceousâ 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
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
Efficacy of colchicine in addition to anakinra in patients with recurrent pericarditis
Aim Anakinra, an anti IL-1 agent targeting IL-1 alfa and beta, is available for the treatment of recurrent pericarditis in cases with corticosteroid dependence and colchicine resistance after failure of conventional therapies. However, it is unclear if the combination with colchicine, a non-specific inhibitor of the inflammasome targeting the same inflammatory pathway of IL-1, could provide additional benefit to prevent further recurrences. The aim of the present observational study is to assess whether the addition of colchicine on top of anakinra could prolong the time to first recurrence and prevent recurrences better than anakinra alone. Methods International, all-comers, multicentre, retrospective observational cohort study analysing all consecutive patients treated with anakinra for corticosteroid-dependent and colchicine-resistant recurrent pericarditis. The efficacy endpoint was recurrence rate and the time to the first recurrence. Results A total of 256 patients (mean age 45.0±15.4 years, 65.6% females, 80.9% with idiopathic/viral aetiology) were included. 64 (25.0%) were treated with anakinra as monotherapy while 192 (75.0%) with both anakinra and colchicine. After a follow-up of 12 months, 56 (21.9%) patients had recurrences. Patients treated with colchicine added to anakinra had a lower incidence of recurrences (respectively, 18.8% vs 31.3%; p=0.036) and a longer event-free survival (p=0.025). In multivariable analysis, colchicine use prevented recurrences (HR 0.52, 95% CI 0.29 to 0.91; p=0.021). Conclusions The addition of colchicine on top of anakinra treatment could be helpful to reduce recurrences and prolong the recurrence-free survival
Bdnf-Nrf-2 crosstalk and emotional behavior are disrupted in a sex-dependent fashion in adolescent mice exposed to maternal stress or maternal obesity
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.
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
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
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LA-ICPMS U-Pb geochronology of detrital zircon grains from the Coconino, Moenkopi, and Chinle Formations in the Petrified Forest National Park (Arizona)
Uraniumâlead (UâPb) geochronology was conducted by laser ablation â inductively coupled plasma mass spectrometry (LA-ICPMS) on 7175 detrital zircon grains from 29 samples from the Coconino Sandstone, Moenkopi Formation, and Chinle Formation. These samples were recovered from âŒâ520âm of drill core that was acquired during the Colorado Plateau Coring Project (CPCP), located in Petrified Forest National Park (Arizona).
A sample from the lower Permian Coconino Sandstone yields a broad distribution of Proterozoic and Paleozoic ages that are consistent with derivation from the Appalachian and Ouachita orogens, with little input from local basement or Ancestral Rocky Mountain sources. Four samples from the Holbrook Member of the Moenkopi Formation yield a different set of Precambrian and Paleozoic age groups, indicating derivation from the Ouachita orogen, the East Mexico arc, and the Permo-Triassic arc built along the Cordilleran margin.
A total of 23 samples from the Chinle Formation contain variable proportions of Proterozoic and Paleozoic zircon grains but are dominated by Late Triassic grains. LA-ICPMS ages of these grains belong to five main groups that correspond to the Mesa Redondo Member, Blue Mesa Member and lower part of the Sonsela Member, upper part of the Sonsela Member, middle part of the Petrified Forest Member, and upper part of the Petrified Forest Member. The ages of pre-Triassic grains also correspond to these chronostratigraphic units and are interpreted to reflect varying contributions from the Appalachian orogen to the east, Ouachita orogen to the southeast, Precambrian basement exposed in the ancestral Mogollon Highlands to the south, East Mexico arc, and PermianâTriassic arc built along the southern Cordilleran margin. Triassic grains in each chronostratigraphic unit also have distinct U and thorium (Th) concentrations, which are interpreted to reflect temporal changes in the chemistry of arc magmatism.
Comparison of our LA-ICPMS ages with available chemical abrasion thermal ionization mass spectrometry (CA-TIMS) ages and new magnetostratigraphic data provides new insights into the depositional history of the Chinle Formation, as well as methods utilized to determine depositional ages of fluvial strata. For parts of the Chinle Formation that are dominated by fine-grained clastic strata (e.g., mudstone and siltstone), such as the Blue Mesa Member and Petrified Forest Member, all three chronometers agree (to within âŒâ1âMyr), and robust depositional chronologies have been determined. In contrast, for stratigraphic intervals dominated by coarse-grained clastic strata (e.g., sandstone), such as most of the Sonsela Member, the three chronologic records disagree due to recycling of older zircon grains and variable dilution of syn-depositional-age grains. This results in LA-ICPMS ages that significantly predate deposition and CA-TIMS ages that range between the other two chronometers. These complications challenge attempts to establish a well-defined chronostratigraphic age model for the Chinle Formation
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
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
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