Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 129
Filtrar
1.
J Med Internet Res ; 26: e49227, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38728072

RESUMEN

BACKGROUND: The rise of digital health services, especially following the outbreak of COVID-19, has led to a need for health literacy policies that respond to people's needs. Spain is a country with a highly developed digital health infrastructure, but there are currently no tools available to measure digital health literacy fully. A well-thought-through questionnaire with strong psychometric properties such as the eHealth Literacy Questionnaire (eHLQ) is important to assess people's eHealth literacy levels, especially in the context of a fast-growing field such as digital health. OBJECTIVE: This study aims to adapt the eHLQ and gather evidence of its psychometric quality in 2 of Spain's official languages: Spanish and Catalan. METHODS: A systematic cultural adaptation process was followed. Data from Spanish-speaking (n=400) and Catalan-speaking (n=400) people were collected. Confirmatory factor analysis was used to confirm the previously established factor structure. For reliability, the Cronbach α and categorical ω were obtained for every subscale. Evidence of convergent and discriminant validity was provided through the correlation with the total score of the eHealth Literacy Scale. Evidence based on relations to other variables was evaluated by examining extreme values for educational level, socioeconomic level, and use of technology variables. RESULTS: Regarding the confirmatory factor analysis, the 7-factor correlated model and the 7 one-factor models had adequate goodness-of-fit indexes for both Spanish and Catalan. Moreover, measurement invariance was established between the Spanish and Catalan versions. Reliability estimates were considered adequate as all the scales in both versions had values of >0.80. For convergent and discriminant validity evidence, the eHealth Literacy Scale showed moderate correlation with eHLQ scales in both versions (Spanish: range 0.57-0.76 and P<.001; Catalan: range 0.41-0.64 and P<.001). According to the relationship with external variables, all the eHLQ scales in both languages could discriminate between the maximum and minimum categories in level of education, socioeconomic level, and level of technology use. CONCLUSIONS: The Spanish and Catalan versions of the eHLQ appear to be psychometrically sound questionnaires for assessing digital health literacy. They could both be useful tools in Spain and Catalonia for researchers, policy makers, and health service managers to explore people's needs, skills, and competencies and provide interesting insights into their interactions and engagement regarding their own experiences with digital health services, especially in the context of digital health growth in Spain.


Asunto(s)
Alfabetización en Salud , Psicometría , Telemedicina , Traducciones , Humanos , España , Telemedicina/métodos , Encuestas y Cuestionarios , Femenino , Psicometría/métodos , Masculino , Adulto , Persona de Mediana Edad , COVID-19 , Comparación Transcultural , Reproducibilidad de los Resultados , Adulto Joven , Anciano , Lenguaje
2.
Eur Urol ; 85(4): 333-336, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37684178

RESUMEN

There is a paucity of high-level evidence on small renal mass (SRM) management, as previous classical randomised controlled trials (RCTs) failed to meet accrual targets. Our objective was to assess the feasibility of recruitment to a cohort-embedded RCT comparing cryoablation (CRA) to robotic partial nephrectomy (RPN). A total of 200 participants were recruited to the cohort, of whom 50 were enrolled in the RCT. In the CRA intervention arm, 84% consented (95% confidence interval [CI] 64-95%) and 76% (95% CI 55-91%) received CRA; 100% (95% CI 86-100%) of the control arm underwent RPN. The retention rate was 90% (95% CI 79-96%) at 6 mo. In the RPN group 2/25 (8%) were converted intra-operative to radical nephrectomy. Postoperative complications (Clavien-Dindo grade 1-2) occurred in 12% of the CRA group and 29% of the RPN group. The median length of hospital stay was shorter for CRA (1 vs 2 d; p = 0.019). At 6 mo, the mean change in renal function was -5.0 ml/min/1.73 m2 after CRA and -5.8 ml/min/1.73 m2 after RPN. This study demonstrates the feasibility of a cohort-embedded RCT comparing CRA and RPN. These data can be used to inform multicentre trials on SRM management. PATIENT SUMMARY: We assessed whether patients with a small kidney tumour would consent to a trial comparing two different treatments: cryoablation (passing small needles through the skin to freeze the kidney tumour) and surgery to remove part of the kidney. We found that most patients agreed and a full trial would therefore be feasible.


Asunto(s)
Criocirugía , Neoplasias Renales , Procedimientos Quirúrgicos Robotizados , Robótica , Humanos , Procedimientos Quirúrgicos Robotizados/efectos adversos , Criocirugía/efectos adversos , Estudios de Factibilidad , Nefrectomía/efectos adversos , Neoplasias Renales/cirugía , Neoplasias Renales/patología , Nefronas/patología , Resultado del Tratamiento , Estudios Retrospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto
3.
ACS Catal ; 13(22): 14782-14791, 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-38026812

RESUMEN

A significant barrier to the commercialization of proton exchange membrane fuel cells (PEMFCs) is the high cost of the platinum-based oxygen reduction reaction (ORR) cathode electrocatalysts. One viable solution is to replace platinum with a platinum-group metal (PGM) free catalyst with comparable activity and durability. However, PGM-free catalyst development is burdened by a lack of understanding of the active site formation mechanism during the requisite high-temperature synthesis step, thus making rational catalyst design challenging. Herein we demonstrate in-temperature X-ray absorption spectroscopy (XAS) to unravel the mechanism of site evolution during pyrolysis for a manganese-based catalyst. We show the transformation from an initial state of manganese oxides (MnOx) at room temperature, to the emergence of manganese-nitrogen (MnN4) site beginning at 750 °C, with its continued evolution up to the maximum temperature of 1000 °C. The competition between the MnOx and MnN4 is identified as the primary factor governing the formation of MnN4 sites during pyrolysis. This knowledge led us to use a chemical vapor deposition (CVD) method to produce MnN4 sites to bypass the evolution route involving the MnOx intermediates. The Mn-N-C catalyst synthesized via CVD shows improved ORR activity over the Mn-N-C synthesized via traditional synthesis by the pyrolysis of a mixture of Mn, N, and C precursors.

4.
ACS Energy Lett ; 8(11): 4746-4752, 2023 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-37969250

RESUMEN

Electrochemical nitrate reduction (NO3 RR) has attracted attention as an emerging approach to mitigate nitrate pollution in groundwater. Here, we report that a highly ordered PdCu alloy-based electrocatalyst exhibits selective (91% N2), stable (480 h), and near complete (94%) removal of nitrate without loss of catalyst. In situ and ex situ XAS provide evidence that structural ordering between Pd and Cu improves long-term catalyst stability during NO3RR. In contrast, we also report that a disordered PdCu alloy-based electrocatalyst exhibits non-selective (44% N2 and 49% NH4+), unstable, and incomplete removal of nitrate. The copper within disordered PdCu alloy is vulnerable to accepting electrons from hydrogenated neighboring Pd atoms. This resulted in copper catalyst losses which were 10× greater than that of the ordered catalyst. The design of stable catalysts is imperative for water treatment because loss of the catalyst adds to the system cost and environmental impacts.

5.
Nat Commun ; 14(1): 7605, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37989737

RESUMEN

The electrochemical reduction of carbon dioxide to formic acid is a promising pathway to improve CO2 utilization and has potential applications as a hydrogen storage medium. In this work, a zero-gap membrane electrode assembly architecture is developed for the direct electrochemical synthesis of formic acid from carbon dioxide. The key technological advancement is a perforated cation exchange membrane, which, when utilized in a forward bias bipolar membrane configuration, allows formic acid generated at the membrane interface to exit through the anode flow field at concentrations up to 0.25 M. Having no additional interlayer components between the anode and cathode this concept is positioned to leverage currently available materials and stack designs ubiquitous in fuel cell and H2 electrolysis, enabling a more rapid transition to scale and commercialization. The perforated cation exchange membrane configuration can achieve >75% Faradaic efficiency to formic acid at <2 V and 300 mA/cm2 in a 25 cm2 cell. More critically, a 55-hour stability test at 200 mA/cm2 shows stable Faradaic efficiency and cell voltage. Technoeconomic analysis is utilized to illustrate a path towards achieving cost parity with current formic acid production methods.

6.
EJNMMI Phys ; 10(1): 60, 2023 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-37777689

RESUMEN

BACKGROUND: Monte Carlo (MC) simulations are used in nuclear medicine imaging as they provide unparalleled insight into processes that are not directly experimentally measurable, such as scatter and attenuation in an acquisition. Whilst MC is often used to provide a 'ground-truth', this is only the case if the simulation is fully validated against experimental data. This work presents a quantitative validation for a MC simulation of a single-photon emission computed tomography (SPECT) system. METHODS: An MC simulation model of the Mediso AnyScan SCP SPECT system installed at the UK National Physical Laboratory was developed in the GATE (Geant4 Application for Tomographic Emission) toolkit. Components of the detector head and two collimator configurations were modelled according to technical specifications and physical measurements. Experimental detection efficiency measurements were collected for a range of energies, permitting an energy-dependent intrinsic camera efficiency correction function to be determined and applied to the simulation on an event-by-event basis. Experimental data were collected in a range of geometries with [Formula: see text]Tc for comparison to simulation. The procedure was then repeated with [Formula: see text]Lu to determine how the validation extended to another isotope and set of collimators. RESULTS: The simulation's spatial resolution, sensitivity, energy spectra and the projection images were compared with experimental measurements. The simulation and experimental uncertainties were determined and propagated to all calculations, permitting the quantitative agreement between simulated and experimental SPECT acquisitions to be determined. Statistical agreement was seen in sinograms and projection images of both [Formula: see text]Tc and [Formula: see text]Lu data. Average simulated and experimental sensitivity ratios of ([Formula: see text]) were seen for emission and scatter windows of [Formula: see text]Tc, and ([Formula: see text]) and ([Formula: see text]) for the 113 and 208 keV emissions of [Formula: see text]Lu, respectively. CONCLUSIONS: MC simulations will always be an approximation of a physical system and the level of agreement should be assessed. A validation method is presented to quantify the level of agreement between a simulation model and a physical SPECT system.

7.
Nat Food ; 4(8): 648-653, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37563496

RESUMEN

Terrestrial controlled environment agriculture (CEA) will have an increasingly important role in food production. However, present CEA systems are energy- and resource-hungry and rarely profitable, requiring a step change in design and optimization. Here we argue that the unique nature of space controlled environment agriculture (SpaCEA), which needs to be both highly resource efficient and circular in design, presents an opportunity to develop intrinsically circular CEA systems. Life-cycle analysis tools should be used to optimize the provision and use of natural or electrical light, power, nutrients and infrastructure in CEA and/or SpaCEA systems, and to guide research and development into subsystems that bring strong environmental advantages. We suggest that SpaCEA public outreach can also be used to improve the perception of terrestrial CEA on Earth by using space as a gateway for exhibiting CEA food growing technologies. A substantial focus on SpaCEA development should be viewed as an efficient contribution to addressing major current CEA challenges.


Asunto(s)
Agricultura , Ambiente Controlado , Alimentos , Planeta Tierra
8.
13.
J Am Chem Soc ; 145(32): 17643-17655, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37540107

RESUMEN

Developing low platinum-group-metal (PGM) catalysts for the oxygen reduction reaction (ORR) in proton-exchange membrane fuel cells (PEMFCs) for heavy-duty vehicles (HDVs) remains a great challenge due to the highly demanded power density and long-term durability. This work explores the possible synergistic effect between single Mn site-rich carbon (MnSA-NC) and Pt nanoparticles, aiming to improve intrinsic activity and stability of PGM catalysts. Density functional theory (DFT) calculations predicted a strong coupling effect between Pt and MnN4 sites in the carbon support, strengthening their interactions to immobilize Pt nanoparticles during the ORR. The adjacent MnN4 sites weaken oxygen adsorption at Pt to enhance intrinsic activity. Well-dispersed Pt (2.1 nm) and ordered L12-Pt3Co nanoparticles (3.3 nm) were retained on the MnSA-NC support after indispensable high-temperature annealing up to 800 °C, suggesting enhanced thermal stability. Both PGM catalysts were thoroughly studied in membrane electrode assemblies (MEAs), showing compelling performance and durability. The Pt@MnSA-NC catalyst achieved a mass activity (MA) of 0.63 A mgPt-1 at 0.9 ViR-free and maintained 78% of its initial performance after a 30,000-cycle accelerated stress test (AST). The L12-Pt3Co@MnSA-NC catalyst accomplished a much higher MA of 0.91 A mgPt-1 and a current density of 1.63 A cm-2 at 0.7 V under traditional light-duty vehicle (LDV) H2-air conditions (150 kPaabs and 0.10 mgPt cm-2). Furthermore, the same catalyst in an HDV MEA (250 kPaabs and 0.20 mgPt cm-2) delivered 1.75 A cm-2 at 0.7 V, only losing 18% performance after 90,000 cycles of the AST, demonstrating great potential to meet the DOE targets.

14.
Nat Commun ; 14(1): 4592, 2023 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-37524721

RESUMEN

Clean hydrogen production requires large-scale deployment of water-electrolysis technologies, particularly proton-exchange-membrane water electrolyzers (PEMWEs). However, as iridium-based electrocatalysts remain the only practical option for PEMWEs, their low abundance will become a bottleneck for a sustainable hydrogen economy. Herein, we propose high-performing and durable ionomer-free porous transport electrodes (PTEs) with facile recycling features enabling Ir thrifting and reclamation. The ionomer-free porous transport electrodes offer a practical pathway to investigate the role of ionomer in the catalyst layer and, from microelectrode measurements, point to an ionomer poisoning effect for the oxygen evolution reaction. The ionomer-free porous transport electrodes demonstrate a voltage reduction of > 600 mV compared to conventional ionomer-coated porous transport electrodes at 1.8 A cm-2 and <0.1 mgIr cm-2, and a voltage degradation of 29 mV at average rate of 0.58 mV per 1000-cycles after 50k cycles of accelerated-stress tests at 4 A cm-2. Moreover, the ionomer-free feature enables facile recycling of multiple components of PEMWEs, which is critical to a circular clean hydrogen economy.

15.
Adv Mater ; 35(39): e2301264, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37337428

RESUMEN

Polymer-electrolyte-membrane fuel cells (PEMFCs) hold great promise for applications in clean energy conversion, but cost and durability continue to limit commercialization. This work presents a new class of catalyst/electrode architecture that does not rely on Pt particles or carbon supports, eliminating the primary degradation mechanisms in conventional electrodes, and thereby enabling transformative durability improvements. The coaxial nanowire electrode (CANE) architecture consists of an array of vertically aligned nanowires, each comprising an ionomer core encapsulated by a nanoscale Pt film. This unique design eliminates the triple-phase boundary and replaces it with two double-phase boundaries, increasing Pt utilization. It also eliminates the need for carbon support and ionomer binder, enabling improved durability and faster mass transport. Fuel cell membrane electrode assemblies based on CANEs demonstrate extraordinary durability in accelerated stress tests (ASTs), with only 2% and 5% loss in performance after 5000 support AST cycles and 30000 catalysts AST cycles, respectively. The high power density and extremely high durability provided by CANEs can enable a paradigm shift from random electrodes based on unstable platinum nanoparticles dispersed on carbon to ordered electrodes based on durable Pt nanofilms, facilitating rapid deployment of fuel cells in transportation and other clean energy applications.

16.
Nanomicro Lett ; 15(1): 144, 2023 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-37269447

RESUMEN

Nanostructured catalyst-integrated electrodes with remarkably reduced catalyst loadings, high catalyst utilization and facile fabrication are urgently needed to enable cost-effective, green hydrogen production via proton exchange membrane electrolyzer cells (PEMECs). Herein, benefitting from a thin seeding layer, bottom-up grown ultrathin Pt nanosheets (Pt-NSs) were first deposited on thin Ti substrates for PEMECs via a fast, template- and surfactant-free electrochemical growth process at room temperature, showing highly uniform Pt surface coverage with ultralow loadings and vertically well-aligned nanosheet morphologies. Combined with an anode-only Nafion 117 catalyst-coated membrane (CCM), the Pt-NS electrode with an ultralow loading of 0.015 mgPt cm-2 demonstrates superior cell performance to the commercial CCM (3.0 mgPt cm-2), achieving 99.5% catalyst savings and more than 237-fold higher catalyst utilization. The remarkable performance with high catalyst utilization is mainly due to the vertically well-aligned ultrathin nanosheets with good surface coverage exposing abundant active sites for the electrochemical reaction. Overall, this study not only paves a new way for optimizing the catalyst uniformity and surface coverage with ultralow loadings but also provides new insights into nanostructured electrode design and facile fabrication for highly efficient and low-cost PEMECs and other energy storage/conversion devices.

17.
J Am Chem Soc ; 145(27): 14737-14747, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37379566

RESUMEN

While improved activity was recently reported for bimetallic iron-metal-nitrogen-carbon (FeMNC) catalysts for the oxygen reduction reaction (ORR) in acid medium, the nature of active sites and interactions between the two metals are poorly understood. Here, FeSnNC and FeCoNC catalysts were structurally and catalytically compared to their parent FeNC and SnNC catalysts. While CO cryo-chemisorption revealed a twice lower site density of M-Nx sites for FeSnNC and FeCoNC relative to FeNC and SnNC, the mass activity of both bimetallic catalysts is 50-100% higher than that of FeNC due to a larger turnover frequency in the bimetallic catalysts. Electron microscopy and X-ray absorption spectroscopy identified the coexistence of Fe-Nx and Sn-Nx or Co-Nx sites, while no evidence was found for binuclear Fe-M-Nx sites. 57Fe Mössbauer spectroscopy revealed that the bimetallic catalysts feature a higher D1/D2 ratio of the spectral signatures assigned to two distinct Fe-Nx sites, relative to the FeNC parent catalyst. Thus, the addition of the secondary metal favored the formation of D1 sites, associated with the higher turnover frequency.

18.
ChemSusChem ; 16(16): e202300350, 2023 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-37198136

RESUMEN

Lithium-ion battery cathode materials suffer from bulk and interfacial degradation issues, which negatively affect their electrochemical performance. Oxide coatings can mitigate some of these problems and improve electrochemical performance. However, current coating strategies have low throughput, are expensive, and have limited applicability. In this article, we describe a low-cost and scalable strategy for applying oxide coatings on cathode materials. We report synergistic effects of these oxide coatings on the performance of aqueously processed cathodes in cells. The SiO2 coating strategy developed herein improved mechanical, chemical, and electrochemical performance of aqueously processed Ni-, Mn- and Co-based cathodes. This strategy can be used on a variety of cathodes to improve the performance of aqueously processed Li-ion cells.

19.
ACS Appl Mater Interfaces ; 15(9): 11703-11712, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36812428

RESUMEN

Electrochemical conversion of nitrogen to green ammonia is an attractive alternative to the Haber-Bosch process. However, it is currently bottlenecked by the lack of highly efficient electrocatalysts to drive the sluggish nitrogen reduction reaction (N2RR). Herein, we strategically design a cost-effective bimetallic Ru-Cu mixture catalyst in a nanosponge (NS) architecture via a rapid and facile method. The porous NS mixture catalysts exhibit a large electrochemical active surface area and enhanced specific activity arising from the charge redistribution for improved activation and adsorption of the activated nitrogen species. Benefiting from the synergistic effect of the Cu constituent on morphology decoration and thermodynamic suppression of the competing hydrogen evolution reaction, the optimized Ru0.15Cu0.85 NS catalyst presents an impressive N2RR performance with an ammonia yield rate of 26.25 µg h-1 mgcat.-1 (corresponding to 10.5 µg h-1 cm-2) and Faradic efficiency of 4.39% as well as superior stability in alkaline medium, which was superior to that of monometallic Ru and Cu nanostructures. Additionally, this work develops a new bimetallic combination of Ru and Cu, which promotes the strategy to design efficient electrocatalysts for electrochemical ammonia production under ambient conditions.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA