Synthesis and electrochemical study of PtIr nanomaterials

Nanomaterials have a number of unique chemical and physical properties and have attracted tremendous attention due to their potential for applications in a variety of areas including fuel cell and biosensor development. The focus of this work was the design of novel platinum iridium electrocatalysts with high electrocatalytic activity towards the key electrochemical processes in direct methanol fuel cells (DMFC) and glucose sensors. N anoporous Ptlr electrodes with different ratios of Pt to Ir were prepared on Ti and carbon nanotube (CNT) substrates using a one-step facile hydrothermal method. The nanostructure and morphology of the fabricated electrocatalysts were characterized using scanning electron microscopy (SEM), energy dispersive x-ray spectrometry (EDS), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). Electrochemical analyses were performed using cyclic voltammetry (CV), chronoamperometry (CA), linear voltammetry (LV) and electrochemical impedance spectroscopy (EIS)

Facile wet-chemical synthesis of differently shaped cuprous oxide particles and a thin film: Effect of catalyst morphology on the glucose sensing performance

Abstract In this work, different facile synthesis routes were developed to create cuprite-based catalyst systems for the amperometric detection of glucose, allowing us to evaluate the impact of important electrode fabrication parameters on the glucose sensing performance. Using homogenous precipitation routes based on a redox system, two differently shaped cuprite particles - skeletons and polyhedrons - could be obtained. Furthermore, a novel electroless deposition technique was introduced that does not require sensitization and activation pretreatments, allowing for the direct modification of the glassy carbon. This technique produced electrodes with dense thin film consisting of merged, octahedral cuprite crystals. Afterward, these materials were tested as potential catalysts for the electrochemical detection of glucose. While the catalyst powders obtained by precipitation required NafionR to be attached to the electrode, the thin film synthesized using electroless plating could be realized with and without additive. Summarizing the results, it was found that NafionR was not required to achieve glucose selectivities typically observed for cuprite catalysts. Also, the type of catalyst application (direct plating vs. ink drop coating) and the particle shape had a pronounced effect on the sensing performance. Compared to the thin film, the powder-type materials showed significantly increased electrochemical responses. The best overall performance was achieved with the polyhedral cuprite particles, resulting in a high sensitivity of 301 μA mmol-1 cm-2, a linear range up to 298 μmol L-1 and a limit of detection of 0.144 μmol L-1

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

From Indentation Shapes to Code Structures

In a previous study, we showed that indentation was regular across multiple languages and the variance in the level of indentation of a block of revised code is correlated with metrics such as McCabe Cyclomatic complexity. Building on that work the current paper investigates the relationship between the “shape ” of the indentation of the revised code block (the “revision”) and the corresponding syntactic structure of the code. We annotated revisions matching these three indentation shapes: “flat ” (all lines are equally indented), “slash ” (indentation becomes increasingly deep), or “bubble ” (indentation increases and then decreases). We then classified the code structure as one of: function definition, loop, expression, comment, etc. We studied thousands of revisions, coming from over 200 software projects, written in a variety of languages. Our study indicates that indentation shape correlates positively with code structure; that is, certain shapes typically correspond to certain code structures. For example, flat shapes commonly correspond to comments while bubble shapes commonly correspond to conditionals and function definitions. These results can form the basis of a tool framework that can analyze code in a language independent way to support browsing targeted to viewing particular code structures such as conditionals or comments. 1

Comparative Study of Nanoporous Pt,PtRu and PtRuIr Catalysts Using Electrochemical FTIR Spectroscopy

近年来,致力于Pt基电催化剂在燃料电池中的应用已取得显著成果.但随贵金属(如Pt)成本的增加,提高催化剂的活性以及降低负载量的需求也日益迫切.为此,作者合成并比较了纳米多孔Pt,PtRu及PtRuIr3种电催化剂.以扫描电镜(SEM)、能量色散谱(EDS)、X射线衍射(XRD)和X射线光电子能谱(XPS)表征水热法制得的纳米多孔电极.CO汽提实验和甲醇氧化反应测试上述纳米多孔材料的电催化活性.结果表明,添加Ir极大改善纳米多孔PtRu的活性.采用现场电化学FTIR光谱技术研究纳米多孔Pt,PtRu及PtRuIr电极上的甲醇氧化反应,以进一步揭示这种显著增强效应的成因.In recent years much effort has been put towards developing efficient Pt-based electrocatalysts for applications in fuel cells. With the rising cost of precious metals such as Pt,the need to enhance the activity and to decrease the load of catalysts is prominent. Herein we report on the synthesis and comparative study of nanoporous Pt,PtRu and PtRuIr electrocatalysts. The nanoporous electrodes were fabricated using a hydrothermal method and characterized by scanning electron microscopy (SEM) ,energy dispersive spectroscopy (EDS) ,X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) . The electrocatalytic activity of the fabricated nanopo- rous materials was evaluated using both CO stripping experiments and methanol oxidation reactions,revealing that the addition of Ir greatly improved the activity of the nanoporous PtRu. To decipher the origin of the significant enhancement,in-situ electrochemical FTIR spectroscopy was employed to study the oxidation of methanol on the nanoporous Pt,PtRu and PtRuIr electrodes.作者联系地址：加拿大湖首大学化学系;Author's Address: Department of Chemistry,Lakehead University,955 Oliver Road,Thunder Bay,Ontario P7B 5E1,Canad

Reading Beside the Lines: Using Indentation to Rank Revisions by Complexity

Maintainers often face the daunting task of wading through a collection of both new and old revisions, trying to ferret out those that warrant detailed inspection. Perhaps the most obvious way to rank revisions is by size in terms of lines of code (LOC); this technique has the advantage of being both simple and fast. However, it is well known that the vast majority of revisions are quite small, and so we would like a way of distinguishing between simple and complex changes of the same size. Classical complexity metrics, such as Halstead’s and McCabe’s, could be used but they are hard to apply to code fragments written in multiple programming languages. We propose using the statistical moments of indentation as a lightweight, language independent, revision/diff friendly metric as a proxy for classical complexity metrics. We have evaluated our approach against the entire CVS histories of the 278 of the most popular and most active SourceForge projects. We found that our results are linearly correlated and rank-correlated with traditional measures of complexity, suggesting that measuring indentation is a cheap and accurate proxy for code complexity of revisions. Thus ranking revisions by the standard deviation and summation of indentation yields results that are very similar to ranking revisions by complexity

What’s Hot and What’s Not: Windowed Developer Topic Analysis

As development on a software project progresses, developers shift their focus between different topics and tasks many times. Managers and newcomer developers often seek ways of understanding what tasks have recently been worked on and how much effort has gone into each; for example, a manager might wonder what unexpected tasks occupied their team’s attention during a period when they were supposed to have been implementing new features. Tools such as Latent Dirichlet Allocation (LDA) and Latent Semantic Indexing (LSI) can be used to extract a set of independent topics from a corpus of commit-log comments. Previous work in the area has created a single set of topics by analyzing comments from the entire lifetime of the project. In this paper, we propose windowing the topic analysis to give a more nuanced view of the system’s evolution. By using a defined time-window of, for example, one month, we can track which topics come and go over time, and which ones recur. We propose visualizations of this model that allows us to explore the evolving stream of topics of development occurring over time. We demonstrate that windowed topic analysis offers advantages over topic analysis applied to a project’s lifetime because many topics are quite local. 1