Analyzing the Surface Chemistry of Ni-Fe Hydroxide Alloy Nanoparticles as Catalysts for the Oxygen Evolution Reaction by X-ray Photoelectron Spectroscopy Analysis

Water electrolysis has been proposed as a renewable source of hydrogen, a possible replacement to harmful fossil fuels. This process can be broken down into two half reactions, the hydrogen evolution reaction and the oxygen evolution reaction. Because the oxygen evolution reaction has slow kinetics and a high overpotential to overcome, a catalyst is needed to speed up the kinetics and ensure faster and more efficient production of molecular hydrogen. The use of Ni-Fe hydroxide alloy nanoparticles as a catalyst has been shown to significantly improve the efficiency of the reaction by decreasing the overpotential, making the process more energy efficient [1]. Although most catalysts for electrochemical reactions degrade over time, past research conducted in the Greenlee Lab at the University of Arkansas has shown that the Ni-Fe catalysts tend to have low degradation and, in some cases, even improvement in the overall activity [1]. This change in overall activity, however, indicates there may be a significant change in the surface chemistry of the nanoparticle during electrocatalysis. In this research, the atomic level changes on the surface of the Ni-Fe catalyst were analyzed by using x-ray photoelectron spectroscopy (XPS) after the potential was cycled. Ultra-high vacuum (UHV)-XPS and near ambient pressure (NAP)-XPS revealed that metallic forms of nickel and iron are present at the surface of the synthesized nanocatalyst but are quickly gone after electrocatalysis, with only more oxidized forms present on the surface after use in the oxygen evolution reaction (OER). The XPS characterization also revealed that the ratio of nickel to iron significantly increases after catalytic use, showing an increase from 1:1 nickel to iron to 7:2 after just one cyclic voltammetry cycle. Overall, the results of this research enable a better understanding of the origins of the durability and increased performance of the catalyst after use in OER. [1] Acharya, Prashant, et al. Chemical Structure of Fe–Ni Nanoparticles for Efficient Oxygen Evolution Reaction Electrocatalysis. ACS Omega (2019)

A Tribute to Patrick Baude

The Board of Editors dedicates Volume 86 of the Indiana Law Journal to the memory of Patrick Baude, who taught at the School of Law from August 1968 until his death in January 2011, and who served for many years as the faculty advisor for the Indiana Law Journal. As evidenced below, Professor Baude’s influence spread far beyond the bounds of his classroom walls, and his presence in the Law School’s community will be sorely missed

A Tribute to Patrick Baude

The Board of Editors dedicates Volume 86 of the Indiana Law Journal to the memory of Patrick Baude, who taught at the School of Law from August 1968 until his death in January 2011, and who served for many years as the faculty advisor for the Indiana Law Journal. As evidenced below, Professor Baude’s influence spread far beyond the bounds of his classroom walls, and his presence in the Law School’s community will be sorely missed

Pilot evaluation of a perfused robot-assisted partial nephrectomy procedural simulation platform for single port robotic retroperitoneal approaches

Objective: In this study our objective was to develop a simulation platform for use cases in Laparoendoscopic Single Site (LESS) Surgery intended for patient-specific rehearsal prior to Robot-assisted Partial nephrectomy procedures. Patients and Surgical Procedure: This represents a simulation platform requiring no patients, although the fabrication process allows for the platform to be patient-specific. Tissue phantom 3D models were developed from de-identified CT imaging fulfilling the criteria of tumors located in the posterior lower pole of the kidney. Results: Respondents completed surveys on platform novelty and effectiveness. Agreement on simulator novelty was unanimously positive (100% agree or better). Performance evaluations reached a minimum of 80% agreement for all categories, with zero respondents. Conclusions: We have developed a highly realistic simulation platform for use in single-port robot-assisted partial nephrectomy that can be produced in a patient specific manner, which we believe will be highly useful for trainees as well as experts attempting to transfer skills to the newer platform

Context-Responsive Anticoagulation Reduces Complications in Pediatric Extracorporeal Membrane Oxygenation

Purpose: We sought to determine the impact of a comprehensive, context-responsive anticoagulation and transfusion guideline on bleeding and thrombotic complication rates and blood product utilization during extracorporeal membrane oxygenation (ECMO).Design: Single-center, observational pre- and post-implementation cohort study.Setting: Academic pediatric hospital.Patients: Patients in the PICU, CICU, and NICU receiving ECMO support.Interventions: Program-wide implementation of a context-responsive anticoagulation and transfusion guideline.Measurements: Pre-implementation subjects consisted of all patients receiving ECMO between January 1 and December 31, 2012, and underwent retrospective chart review. Post-implementation subjects consisted of all ECMO patients between September 1, 2013, and December 31, 2014, and underwent prospective data collection. Data collection included standard demographic and admission data, ECMO technical specifications, non-ECMO therapies, coagulation parameters, and blood product administration. A novel grading scale was used to define hemorrhagic complications (major, intermediate, and minor) and major thromboembolic complications.Main Results: Seventy-six ECMO patients were identified: 31 during the pre-implementation period and 45 in the post-implementation period. The overall observed mortality was 33% with no difference between groups. Compared to pre-implementation, the post-implementation group experienced fewer major hemorrhagic and major thrombotic complications and less severe hemorrhagic complications and received less RBC transfusion volume per kg.Conclusions: Use of a context-responsive anticoagulation and transfusion guideline was associated with a reduction in hemorrhagic and thrombotic complications and reduced RBC transfusion requirements. Further evaluation of guideline content, compliance, performance, and sustainability is needed

Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists

Cachimbos europeus de cerâmica branca, séculos XVI ao XIX: parâmetros básicos para análise arqueológica

O tabaco foi introduzido na Europa no final do século XV. Desde então, uma das formas mais comuns para o seu consumo foi o cachimbo, além do rapé, do tabaco de mascar, do charuto e, mais recentemente, dos cigarros. Os cachimbos de cerâmica branca, largamente produzidos e utilizados na Europa desde o século XV, são encontrados em sítios arqueológicos históricos ao redor do mundo, incluindo no Brasil, em decorrência do comércio internacional, que gradualmente se intensificou após o início da conquista europeia. Eles funcionam como excelentes elementos para datação de sítios e estratos arqueológicos, tendo sido estudados em vários países a partir dessa abordagem. Ainda, esse tipo de artefato, mais que fornecer datações, permite identificar redes comerciais entre nações e desenvolver discussões de cunho social e cultural. Contudo, eles foram pouco estudados no Brasil. Visando contribuir com os estudos nacionais dessa categoria material, este artigo oferece uma revisão da literatura internacional acerca do histórico da produção dos cachimbos europeus de caulim, incluindo apresentação dos principais centros produtores; da morfologia e decoração desses produtos, considerando a cronologia do fabrico; e dos métodos de análise dos diferentes cachimbos de caulim no âmbito da arqueologia histórica.Tobacco was introduced in Europe at the end of the 15th century. Since then, one of the most traditional means for its use has been the pipe, next to the powder version, chewing, cigars, and, more recently, cigarettes. White clay tobacco pipes, widely produced and used in Europe since the 15th century, are found in historical archaeological sites around the world, including Brazil, due to international trade, which gradually intensified with the European conquest of the New World. They are excellent guides for dating archaeological sites and layers. In addition, this type of artifact, more than a dating tool, permits identifying trading networks between nations and developing discussions of cultural and social nature. These pipes, however, have been understudied in Brazil. In order to contribute to studies of this type of artifact in our country, this paper offers a revision of the international literature on the history of clay pipe production in Europe, including the presentation of main production centers; morphology and decoration of these products, considering issues of fabrication chronology; and the methods used in Historical Archaeology for analyzing clay tobacco pipes

Global urban environmental change drives adaptation in white clover

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale