Low-Temperature Methane Activation Reaction Pathways over Mechanochemically-Generated Ce4+/Cu+ Interfacial Sites.

Methane is a valuable resource and its valorization is an important challenge in heterogeneous catalysis. Here it is shown that CeO2/CuO composite prepared by ball milling activates methane at a temperature as low as 250 °C. In contrast to conventionally prepared catalysts, the formation of partial oxidation products such as methanol and formaldehyde is also observed. Through an in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) and operando Near Edge X-Ray Absorption Fine Structure Spectroscopy (NEXAFS) approach, it can be established that this unusual reactivity can be attributed to the presence of Ce4+/Cu+ interfaces generated through a redox exchange between Ce3+ and Cu2+ atoms facilitated by the mechanical energy supplied during milling. DFT modeling of the electronic properties confirms the existence of a charge transfer mechanism. These results demonstrate the effectiveness and distinctiveness of the mechanical approach in creating unique and resilient interfaces thereby enabling the optimization and refining of CeO2/CuO catalysts in methane activation reactions.

The first COVID-19 new graduate nurses generation: findings from an Italian cross-sectional study.

BACKGROUND: Nursing education has been disrupted by the onset of the COronaVIrus Disease 19 (COVID-19) pandemic, potentially impacting learning experiences and perceived competencies at the time of graduation. However, the learning experiences of students since the onset of COVID-19, their perceived competences achieved and the employment status one month after graduation, have not been traced to date. METHODS: A cross sectional online survey measured the individual profile, the learning experience in the last academic year and the perceived competences of the first COVID-19 new nursing graduates in two Italian universities. Details relating to employment status and place of employment (Covid-19 versus non-COVID-19 units) one month after graduation were also collected and the data compared with those reported by a similar cohort of new graduates pre-pandemic in 2018-2019. All those who graduated in November 2020 and attended their third year after the onset of the COVID-19 pandemic were eligible. The online survey included individual, nursing programme and first working experience variables alongside the Nurse Competence Scale (NCS). Descriptive and inferential statistical analyses were performed. RESULTS: A total of 323 new graduates participated. In their last academic year, they experienced a single, long clinical placement in non-COVID-19 units. One month after graduation, 54.5% (n = 176) were working in COVID-19 units, 22.9% (n = 74) in non-COVID-19 units and 22.6 (n = 73) were unemployed. There was no statistical difference among groups regarding individual variables and the competences perceived. Fewer new graduates working in COVID-19 units experienced a transition programme compared to those working in non-COVID-19 units (p = 0.053). At the NCS, the first COVID-19 new graduate generation perceived significantly lower competences than the pre-COVID-19 generation in the 'Helping role' factor and a significant higher in 'Ensuring quality' and 'Therapeutic interventions' factors. CONCLUSIONS: The majority of the first COVID-19 new graduate generation had been employed in COVID-19 units without clinical experience and transition programmes, imposing an ethical debate regarding (a) the role of education in graduating nurses in challenging times with limited clinical placements; and (b) that of nurse managers and directors in ensuring safe transitions for new graduates. Despite the profound clinical placement revision, the first COVID-19 new graduate generation reported competences similar to those of the pre-COVID-19 generation, suggesting that the pandemic may have helped them to optimise the clinical learning process.

Unveiling Oxygen Vacancy Superstructures in Reduced Anatase Thin Films.

Oxygen vacancies are known to play a crucial role in tuning the physical properties and technological applications of titanium dioxide TiO2. Over the last decades, defects in substoichiometric TiO2 have been commonly associated with the formation of TinO2n-x Magnéli phases, which are extended planar defects originating from crystallographic shear planes. By combining advanced transmission electron microscopy techniques, electron energy-loss spectroscopy and atomistic simulations, we reach new understanding of the oxygen vacancy induced structural modulations in anatase, ruling out the earlier shear-plane model. Structural modulations are instead shown to be due to the formation of oxygen vacancy superstructures that extend periodically inside the films, preserving the crystalline order of anatase. Elucidating the structure of oxygen defects in anatase is a crucial step for improving the functionalities of such material system and to engineer devices with targeted properties.

The experience of individuals placed in quarantine: A systematic review, meta-summary, and meta-synthesis.

OBJECTIVE: To summarize the experience of individuals placed in quarantine during an outbreak. DESIGN: A meta-summary and a meta-synthesis based upon a systematic review of qualitative studies. SAMPLE: The Cumulative Index of Nursing and Allied Health Literature, MEDLINE, and Scopus databases were all searched up to April 2020. MEASUREMENTS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed; then, the methodological quality of the studies included was assessed with the Critical Appraisal Screening Programme tool for qualitative studies. RESULTS: Five studies have been included documenting the experience of 125 adult individuals. A total of 16 codes emerged: in the meta-summary, the most and least frequent codes were "Thinking about quarantine" (80%) and "Emotional roller coaster," "Being alert for any symptom," "Trusting or not?," "Knowing who brought the infection," and "Living in a surreal world" (20%). The codes which emerged were categorized into three main themes which summarized the whole experience of being placed in quarantine: (a) "Being swamped with a thousand emotions"; (b) "Being restrained"; and (c) "Needing to be considered." CONCLUSIONS: The experience of quarantine for people is a long journey which can feel chaotic due to uncertainty about the consequences on health, work, and the future. The findings of this study can help nurses in caring for quarantined individuals by enabling them to understand people's need for educational and emotional support. Ensuring the supply of consistent information is also important to increase people's compliance.

Missed nursing education: Findings from a qualitative study.

AIM: To understand what nursing education activities are missed in the daily life of nursing programmes, by also identifying antecedents and consequences of missed educational activities. DESIGN: A descriptive qualitative study according to the COnsolidated criteria for REporting Qualitative research guidelines. METHODS: A purposeful sample of 32 participants with different roles (nurse educators, clinical nurses, students, and administrative personnel) and working in different settings (university, administrative, healthcare service levels) were involved in three focus groups and nine face-to-face interviews from 2019-2020. Both focus groups and face-to-face interviews were audio-recorded and transcribed verbatim. The data that emerged were thematically categorized by induction. FINDINGS: Missed Nursing Education reflects those educational activities needed in the process of nursing education that are missed or delayed. Direct educational activities missed include clinical rotations, classroom teaching and students' overall learning experience. Indirect missed educational activities concern continuing professional development of nursing faculty members, nursing discipline development and the organizational processes of the nursing programme. As antecedents, missed nursing education is triggered by factors at the organizational, nursing faculty, and student levels. Consequences have been reported for students, nursing faculty, clinical nurses, and patients. CONCLUSIONS: Missed Nursing Education can be considered a multifaceted, multicausal phenomenon, with multitargeted consequences. IMPACT: To date, missed nursing care has only been investigated in clinical practice. However, care also permeates the relationship between nurse educators and students. Thus, at the point of 'educational care' delivery, aspects can also be omitted. Educational activities at risk of being missed or delayed affect the quality of nursing education and, in the short- and in the long- terms, also the quality of patient care. Some Missed Nursing Education antecedents can be modified by appropriate strategies that should be addressed by policy, health care and academic institutions.

Depicting clinical nurses' priority perspectives leading to unfinished nursing care: A pilot Q methodology study.

AIMS: To highlight (a) trends common to all nurses on priorities attributed to interventions, and (b) whether there are profiles of nurses working in the same context who prioritize interventions in a similar way. BACKGROUND: The underlying prioritization of interventions leading to unfinished nursing care has been minimally investigated. METHODS: A 2017 pilot Q methodology study. Full-time nurses, with at least 6 months of experience in a surgical unit, were involved. Eleven nurses rated the priority given in daily practice (from -3 as the lowest to +3 as the highest) to 35 Q-sample statements representing nursing care, non-nursing and organisational interventions. RESULTS: Overall, the intervention receiving the lowest priority was 'Providing patient hygiene', while the highest was 'Answering phone calls'. In the by-person factor analysis (total variance = 60.79%), three profiles of nurses emerged, (a) 'Patient safety-oriented' (variance = 31.66%); (b) 'Nursing task-oriented' (=16.32%); and (c) 'Team process-oriented' (=12.81%). CONCLUSIONS: Three profiles of nurses emerged in the same setting with significant differences both in the statistical order of priorities and in their practical implications. IMPLICATIONS FOR NURSING MANAGEMENT: Understanding levels of prioritization, which are not only affected by the unit but also by sub-groups of nurses who rank priorities in a similar way, can support nurse managers in their role.

The experiences of patients electrically shocked by an implantable cardioverter defibrillator: Findings from a descriptive qualitative study.

BACKGROUND: To date, few studies have explored cases of implantable cardioverter defibrillator (ICD) shock delivery with the intent of understanding patients' educational and supportive needs. AIMS AND OBJECTIVES: To explore patient experiences as lived before, during and after one or more shocks. DESIGN: A descriptive qualitative study carried out between 2016 and 2017. METHODS: Semi-structured face-to-face audio-recorded interviews were performed and analysed using a content analysis methodology. RESULTS: A total of 50 patients (average age = 68.3 years; largely male = 49; 98%) were interviewed. Four themes emerged: (a) "Feeling surprised vs. alerted by the changes inside me"; (b) "Living an intense, mono-dimensional vs. living a multidimensional storm experience", (c) "Facing the event vs. being supported"; and (d) "Living a drama vs. being used to it". CONCLUSIONS: Findings suggest that ICD use can trigger negative physical and emotional effects in patients. Moreover, nurses should recognize patients' educational needs according to the stage of adaptation that each patient is experiencing with the aim of tailoring appropriate supportive interventions. RELEVANCE TO CLINICAL PRACTICE: Therefore, it is necessary to consider the psychological needs of patients by integrating these into clinical care at different levels (emergency department, hospital ward, home). Specific structured support aimed at helping patients overcome intense negative experiences is suggested, especially in the first stage of the adaptation process. Nurses should also ensure that appropriate education programmes with adequate follow-up interventions are offered to improve the experience of living with an ICD. In addition, patient-reported outcomes should be routinely collected from patients with an ICD.

Heterogeneous reactions of SO2 on the hematite(0001) surface.

Heterogeneous reactions at the surfaces of mineral dusts represent a key process in the formation of atmospheric aerosols. To quantify the rate of aerosol formation in climate modeling as well as combat hazardous aerosols, a deep understanding of the mechanisms of these reactions is essential. In the present work, density functional theory calculations, including a Hubbard-like +U correction, were employed to elucidate the reaction between SO2 and the hematite(0001) surface. Three reaction conditions are considered: dry, wet, and aerobic. In the absence of water and oxygen, adsorption energies of SO2 on the clean Fe-O3-Fe-termination were found to be about -0.8 to -1.0 eV and resulted in the formation of an adsorbed SO3-like species. The addition of water leads to surface hydroxylation and has little effect on promoting the SO2 adsorption. Under such circumstances, an HSO3-like species was formed with a smaller adsorption energy of about -0.5 eV. By contrast, the presence of molecular oxygen enhances the SO2 adsorption significantly as the two species combine to form sulfate SO4 2-, with adsorption energies of -1.31 to -1.64 eV. The calculated vibrational frequencies of the adsorbate species provide insight into the surface bonding and a useful spectral fingerprinting for experimental measurements. These results elucidate the atomistic mechanism of the reaction between SO2 and hematite and highlight the important role of atmospheric O2 in the formation of sulfates.

Counting electrons on supported nanoparticles.

Electronic interactions between metal nanoparticles and oxide supports control the functionality of nanomaterials, for example, the stability, the activity and the selectivity of catalysts. Such interactions involve electron transfer across the metal/support interface. In this work we quantify this charge transfer on a well-defined platinum/ceria catalyst at particle sizes relevant for heterogeneous catalysis. Combining synchrotron-radiation photoelectron spectroscopy, scanning tunnelling microscopy and density functional calculations we show that the charge transfer per Pt atom is largest for Pt particles of around 50 atoms. Here, approximately one electron is transferred per ten Pt atoms from the nanoparticle to the support. For larger particles, the charge transfer reaches its intrinsic limit set by the support. For smaller particles, charge transfer is partially suppressed by nucleation at defects. These mechanistic and quantitative insights into charge transfer will help to make better use of particle size effects and electronic metal-support interactions in metal/oxide nanomaterials.

Catalytic Proton Dynamics at the Water/Solid Interface of Ceria-Supported Pt Clusters.

Wet conditions in heterogeneous catalysis can substantially improve the rate of surface reactions by assisting the diffusion of reaction intermediates between surface reaction sites. The atomistic mechanisms underpinning this accelerated mass transfer are, however, concealed by the complexity of the dynamic water/solid interface. Here we employ ab initio molecular dynamics simulations to disclose the fast diffusion of protons and hydroxide species along the interface between water and ceria, a catalytically important, highly reducible oxide. Up to 20% of the interfacial water molecules are shown to dissociate at room temperature via proton transfer to surface O atoms, leading to partial surface hydroxylation and to a local increase of hydroxide species in the surface solvation layer. A water-mediated Grotthus-like mechanism is shown to activate the fast and long-range proton diffusion at the water/oxide interface. We demonstrate the catalytic importance of this dynamic process for water dissociation at ceria-supported Pt nanoparticles, where the solvent accelerates the spillover of ad-species between oxide and metal sites.

Reactivity of atomically dispersed Pt(2+) species towards H2: model Pt-CeO2 fuel cell catalyst.

The reactivity of atomically dispersed Pt(2+) species on the surface of nanostructured CeO2 films and the mechanism of H2 activation on these sites have been investigated by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy in combination with density functional calculations. Isolated Pt(2+) sites are found to be inactive towards H2 dissociation due to high activation energy required for H-H bond scission. Trace amounts of metallic Pt are necessary to initiate H2 dissociation on Pt-CeO2 films. H2 dissociation triggers the reduction of Ce(4+) cations which, in turn, is coupled with the reduction of Pt(2+) species. The mechanism of Pt(2+) reduction involves reverse oxygen spillover and formation of oxygen vacancies on Pt-CeO2 films. Our calculations suggest the existence of a threshold concentration of oxygen vacancies associated with the onset of Pt(2+) reduction.

Effects of Thermal Electronic Excitations on the Diffusion of Oxygen Adatoms on Graphene.

We conduct first-principles calculations to study oxygen diffusion on the graphene surface as a function of temperature up to 3000 K. The minimum energy migration path and the corresponding activation energy are determined by the nudged elastic band method with explicit inclusion of thermal electronic excitations. Below 1000 K the activation energy for epoxy oxygen to migrate remains close to its room temperature value (0.72 eV). Above 1000 K the activation energy decreases near linearly with temperature, from 0.70 eV at 1000 K to 0.47 eV at 3000 K. We show that this reduction originates from thermal electronic excitations. In particular, the effect is determined by the large contrasts in the electronic structures of the initial and transition states: the transition state exhibits much larger electronic density of states near the Fermi level and is more susceptible to thermal electronic excitations. The reduction in activation energy leads to appreciable enhancement in the diffusivity of oxygen adatoms. A moderate decrease in the vibrational prefactor, also caused by thermal electronic excitations, does not alter this trend. These findings may facilitate future works to accurately describe the dynamics of O adatoms on graphene at high T, which are critical for determining surface thermodynamic properties such as equilibrium coverage.

Water oxidation surface mechanisms replicated by a totally inorganic tetraruthenium-oxo molecular complex.

Solar-to-fuel energy conversion relies on the invention of efficient catalysts enabling water oxidation through low-energy pathways. Our aerobic life is based on this strategy, mastered by the natural Photosystem II enzyme, using a tetranuclear Mn-oxo complex as oxygen evolving center. Within artificial devices, water can be oxidized efficiently on tailored metal-oxide surfaces such as RuO2. The quest for catalyst optimization in vitro is plagued by the elusive description of the active sites on bulk oxides. Although molecular mimics of the natural catalyst have been proposed, they generally suffer from oxidative degradation under multiturnover regime. Here we investigate a nano-sized Ru4-polyoxometalate standing as an efficient artificial catalyst featuring a totally inorganic molecular structure with enhanced stability. Experimental and computational evidence reported herein indicates that this is a unique molecular species mimicking oxygenic RuO2 surfaces. Ru4-polyoxometalate bridges the gap between homogeneous and heterogeneous water oxidation catalysis, leading to a breakthrough system. Density functional theory calculations show that the catalytic efficiency stems from the optimal distribution of the free energy cost to form reaction intermediates, in analogy with metal-oxide catalysts, thus providing a unifying picture for the two realms of water oxidation catalysis. These correlations among the mechanism of reaction, thermodynamic efficiency, and local structure of the active sites provide the key guidelines for the rational design of superior molecular catalysts and composite materials designed with a bottom-up approach and atomic control.

Interface structure and reactivity of water-oxidation Ru-polyoxometalate catalysts on functionalized graphene electrodes.

We combine classical empirical potentials and density functional theory (DFT) calculations to characterize the catalyst/electrode interface of a promising device for artificial photosynthesis. This system consists of inorganic Ru-polyoxometalate (Ru-POM) molecules that are supported by a graphitic substrate functionalized with organic dendrimers. The experimental atomic-scale characterization of the active interface under working conditions is hampered by the complexity of its structure, composition, as well as by the presence of the electrolyte or solvent. We provide a detailed atomistic model of the electrode/catalyst interface and show that the catalyst anchoring is remarkably dependent on water solvation. A tight host-guest binding geometry between the surface dendrimers and the Ru-POM catalyst is predicted under vacuum conditions. The solvent destabilizes this geometry, leads to unfolding of the dendrimers and to their flattening on the graphitic surface. The Ru-POM catalyst binds to this organic interlayer through a stable electrostatic link between one POM termination and the charged terminations of the dendrimers. The calculated dynamics and mobility of the Ru-POM catalyst at the electrode surface are in fair agreement with the available high-resolution transmission electron microscopy data. In addition, we demonstrate that the high thermodynamic water-oxidation efficiency of the Ru-POM catalyst is not affected by the binding to the electrode, thus rationalizing the similar electrochemical performances measured for homogeneous and heterogeneous Ru-POM catalysts.

Watch the screw. An unusual complication of orbital reconstruction.

Traumatic intraocular foreign bodies are a particular subset of open globe injuries usually caused by metal processing, blasts, or yard work. This case report presents a retained intraocular screw as a complication of mesh positioning during lateral orbit reconstruction after resection of a left spheno-orbital infiltrating meningioma.

Rigid- and polarizable-ion potentials for modeling Ru-polyoxometalate catalysts for water oxidation.

This work assesses the predictive power and capabilities of classical interatomic potentials for describing the atomistic structure of a fully inorganic water-oxidation catalyst in the gas phase and in solution. We address a Ru-polyoxometalate molecule (Ru-POM) that is presently one of the most promising catalysts for water oxidation due to its efficiency and stability under reaction conditions. The Ru-POM molecule is modeled with two interatomic potentials, the rigid ion model and the shell model potentials, which are used to perform molecular dynamics simulations. The predictions of these two approaches are discussed and compared to the available ab-initio data. These results allow us to establish the suitable level of theory to model complex heterogeneous interfaces between the Ru-POM and electrodes in solution.

Time-to-event analysis of individual variables associated with nursing students' academic failure: a longitudinal study.

Empirical studies and conceptual frameworks presented in the extant literature offer a static imagining of academic failure. Time-to-event analysis, which captures the dynamism of individual factors, as when they determine the failure to properly tailor timely strategies, impose longitudinal studies which are still lacking within the field. The aims of this longitudinal study were to investigate the time which elapses from a nursing student's admission to a Bachelor of Nursing program to their academic failure and to estimate the predictive power of individual variables on academic failure. Enrolled students (n = 170) in two Italian nursing degree programs during academic year 2008-2009, received at the beginning of each years a questionnaire which evaluated individual variables. Academic failure rate was 37.2 %. Time-to-event analysis has shown that academic failure occurred after an average of 664.52 days of course attendance ((95 %)CI = 623.2-705.8). Kaplan-Meier analyses demonstrated a high likelihood of failure among males (χ(2) 7.790, p 0.005) and among those who had obtained a final average grade in their secondary education ≤73/100 (χ(2)11.676, p 0.001). Cox regression analysis confirmed an increased likelihood of failure over time among males as compared to females (HR 1.931, (95 %)CI = 1.017-3.670), and among students living more than a 30 min commute from their place of study (HR 1.898, (95 %)CI = 1.015-3.547). The effect of these two factors on academic failure has been seen to manifest primarily toward the end of students' second academic year; students at risk might be supported by the appropriate university staff prior to this period.

Mechanisms for oxidative unzipping and cutting of graphene.

We identify mechanisms and surface precursors for the nucleation and growth of extended defects on oxidized graphene. Density functional theory calculations show that the formation of surface structures capable to initiate the unzipping and cracking of the oxidized C network is strongly influenced by the constraint of the graphitic lattice on the surface functional groups. Accounting for this effect on the preferential spatial patterning of O adsorbates allows us to revise and extend the current models of graphene oxidative unzipping and cutting. We find that these processes are rate limited by O diffusion and driven by the local strain induced by the O adspecies. Adsorbate mobility is ultimately recognized as a key factor to control and to prevent the C-network breakdown during thermal processing of oxidized graphene.

Nanometer-range strain distribution in layered incommensurate systems.

We adopt fringe counting from classical moiré interferometry on moiré patterns observed in scanning tunneling microscopy of strained thin films on single crystalline substrates. We analyze inhomogeneous strain distribution in islands of CeO2(111) on Cu(111) and identify a generic source of strain in heteroepitaxy--a thickness-dependent lattice constant of the growing film. This observation is mediated by the ability of ceria to glide on the Cu substrate. The moiré technique we are describing has a potential of nanometer-scale resolution of inhomogeneous two dimensional strain in incommensurate layered systems, notably in supported graphene.

Structural phases of ordered FePc-nanochains self-assembled on Au(110).

Iron-phthalocyanine molecules deposited on the Au(110) reconstructed channels assemble into one-dimensional molecular chains, whose spatial distribution evolves into different structural phases at increasing molecular density. The plasticity of the Au channels first induces an ordered phase with a 5×5 symmetry, followed by a second long-range ordered structure composed by denser chains with a 5×7 periodicity with respect to the bare Au surface, as observed in the low-energy electron-diffraction (LEED) and grazing incidence X-ray diffraction (GIXRD) patterns. The geometry of the FePc molecular assemblies in the Au nanorails is determined by scanning tunneling microscopy (STM). For the 5×7 phases, the GIXRD analysis identifies a "4-3" rows profile along the [001] direction in the Au surface and an on-top FePc adsorption site, further confirmed by density functional theory (DFT) calculations. The latter also reveals the electronic mixing of the interface states. The chain assembly is driven by the molecule-molecule interaction and the chains interact with the Au nanorails via the central metal atom, while the chain-chain distance in the different structural phases is primarily driven by the plasticity of the Au surface.