Effects of Structure and Constituent of Prussian Blue Analogs on Their Application in Oxygen Evolution Reaction.

The importance of advanced energy-conversion devices such as water electrolysis has manifested dramatically over the past few decades because it is the current mainstay for the generation of green energy. Anodic oxygen evolution reaction (OER) in water splitting is one of the biggest obstacles because of its extremely high kinetic barrier. Conventional OER catalysts are mainly noble-metal oxides represented by IrO2 and RuO2, but these compounds tend to have poor sustainability. The attention on Prussian blue (PB) and its analogs (PBA) in the field of energy conversion systems was concentrated on their open-framework structure, as well as its varied composition comprised of Earth-abundant elements. The unique electronic structure of PBA enables its promising catalytic potential, and it can also be converted into many other talented compounds or structures as a precursor. This undoubtedly provides a new approach for the design of green OER catalysts. This article reviews the recent progress of the application of PBA and its derivatives in OER based on in-depth studies of characterization techniques. The structural design, synthetic strategy, and enhanced electrochemical properties are summarized to provide an outlook for its application in the field of OER. Moreover, due to the similarity of the reaction process of photo-driven electrolysis of water and the former one, the application of PBA in photoelectrolysis is also discussed.

Near-Field Spectroscopy of Individual Asymmetric Split-Ring Terahertz Resonators.

Metamaterial resonators have become an efficient and versatile platform in the terahertz frequency range, finding applications in integrated optical devices, such as active modulators and detectors, and in fundamental research, e.g., ultrastrong light-matter investigations. Despite their growing use, characterization of modes supported by these subwavelength elements has proven to be challenging and it still relies on indirect observation of the collective far-field transmission/reflection properties of resonator arrays. Here, we present a broadband time-domain spectroscopic investigation of individual metamaterial resonators via a THz aperture scanning near-field microscope (a-SNOM). The time-domain a-SNOM allows the mapping and quantitative analysis of strongly confined modes supported by the resonators. In particular, a cross-polarized configuration presented here allows an investigation of weakly radiative modes. These results hold great potential to advance future metamaterial-based optoelectronic platforms for fundamental research in THz photonics.

Association of immediate reinsertion of new catheters with subsequent mortality among patients with suspected catheter infection: a cohort study.

BACKGROUND: Central venous catheter (CVC) insertion complications are a prevalent and important problem in the intensive care unit (ICU), and source control by immediate catheter removal is considered urgent in patients with septic shock suspected to be caused by catheter-related bloodstream infection (CRBSI). We sought to determine the impact of immediate reinsertion of a new catheter (IRINC) on mortality among patients after CVC removal for suspected CRBSI. METHODS: A propensity score-matched cohort of patients with suspected CRBSI who underwent IRINC or no IRINC in a 32-bed ICU in a university hospital in China from January 2009 through April 2021. Catheter tip culture and clinical symptoms were used to identify patients with suspected CRBSI. The Kaplan-Meier method was used to analyse 30-day mortality before and after propensity score matching, and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality in the matched cohort were estimated with Cox proportional hazards models. RESULTS: In total, 1,238 patients who had a CVC removed due to suspected CRBSI were identified. Among these patients, 877 (70.8%) underwent IRINC, and 361 (29.2%) did not. Among 682 propensity score-matched patients, IRINC was associated with an increased risk of 30-day mortality (HR, 1.481; 95% CI, 1.028 to 2.134) after multivariable, multilevel adjustment. Kaplan-Meier analysis found that IRINC was associated with the risk of mortality both before matching (P = 0.00096) and after matching (P = 0.018). A competing risk analysis confirmed the results of the propensity score-matched analysis. The attributable risk associated with bloodstream infection was not significantly different (HR, 1.081; 95% CI 0.964 to 1.213) among patients with suspected CRBSI in terms of 30-day mortality compared with that associated with other infections. CONCLUSIONS: In this cohort study, IRINC was associated with higher 30-day mortality compared to delayed CVC or no CVC among patients with suspected CRBSI. A large-sample randomized controlled trial is needed to define the best management for CVC in cases of suspected CRBSI because IRINC may also be associated with noninfectious complications. Trial registration This study was registered with the China Clinical Trials Registry (URL: http://www.chictr.org.cn/index.aspx ) under the following registration number: ChiCTR1900022175.