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2.
Nat Commun ; 14(1): 4592, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37524721

RESUMO

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.

3.
Pract Lab Med ; 29: e00267, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35198717

RESUMO

Evaluation of patients with acute kidney injury requires comprehensive assessment that includes a urinalysis, which features both semi-quantitative assessment with a urine dipstick and urine microscopy. This process is labor intensive for clinical laboratories, and availability of excellent automated instruments for urinalysis has prompted utilization and acceptance of this strategy by both by laboratories and clinicians. Recently, however, interest in provider performed microscopy has enjoyed a renaissance thanks to both improved microscopy techniques and the endorsement from social media in nephrology. Here, we present two cases of acute kidney injury in which manual microscopy added valuable information to the automated microscopy.

4.
J Clin Neurophysiol ; 35(3): 242-245, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29373396

RESUMO

PURPOSE: The purpose of this study was to describe the characteristics and preferences of clinical neurophysiology (CN) fellows, as well as the resources available for their training, in a developing country such as Mexico. METHODS: An online survey (25 questions) was given to Mexican CN fellows from May to June 2017, covering their reasons for choosing the CN subspecialty, their activities, future plans, institutional resources, and administrative staff. Descriptive statistics were used. RESULTS: Total respondents: 20/22 (90%), 65% female from 7 CN centers (80% public and 20% private hospitals) in Mexico City. Seventy-five percent chose CN out of personal interest, and all were not unsatisfied with their academic program. Most plan to work in private practice (75%) and are interested in learning EEG (85%) and intraoperative monitoring (75%-85%). The highest-reported training time by CN area allocated by the programs was as follows: EEG (27%), electromyography (22%), and evoked potentials (16%). The average number of fellows per center was 4; 75% of the centers perform epilepsy surgery, of which 60% offer invasive intracranial studies for the evaluation of surgical candidates. CONCLUSIONS: Mexican CN fellows are satisfied with their choice and with the academic program. They are increasingly interested in intraoperative monitoring, which is not addressed in current Mexican CN Programs.


Assuntos
Neurologia/educação , Neurofisiologia/educação , Adulto , Escolha da Profissão , Países em Desenvolvimento , Feminino , Hospitais , Humanos , Masculino , México , Admissão e Escalonamento de Pessoal , Médicos/psicologia , Inquéritos e Questionários
5.
Data Brief ; 21: 2643-2650, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30761347

RESUMO

This manuscript provides raw nitrogen gas adsorption data, images and videos obtained from a technique that combines Focused Ion Beam (FIB) and Scanning Electron Microscopy (SEM) known as FIB-SEM tomography and Transmission Electron Microscopy (TEM) micrographs. This collection of data is useful for characterization of the effects of high fluence neutron irradiation in nuclear graphite as described in the associated manuscript, "Mesopores development in superfine grain graphite neutron-irradiated at high fluence" (Contescu et al., 2019). Nitrogen adsorption isotherms at 77 K are provided for graphite samples before and after neutron irradiation at 300, 450, and 750 °C at fluences before and after turnaround. FIB-SEM tomography reveals porosity of unirradiated and irradiated samples. Using this technique, four data sets were obtained, of which the first three are presented in video format, whereas the fourth one is a series of images provided in raw format unique to this manuscript. All microscopy data document the microstructure, surface area and porosity of superfine grain graphite G347A (Tokai Carbon, Japan) before irradiation and irradiated after turnaround at 400 °C. TEM micrographs provide unique information on irradiation damage at high neutron fluence (>27. 8 displacements per atom, dpa) in the microstructure and crystal lattice of graphite. Additional TEM micrographs are provided here, which do not duplicate the research paper published elsewhere (Contescu et al., 2019). These data sets are unique, as samples at high irradiation doses have never been measured or imaged before with the aforementioned techniques.

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