Study on Calibration of Extracorporeal Pacemaker.

Extracorporeal pacemaker is cardiac rhythm management device with non-implantable pulse generator and is widely used medical institutions. Parameters such as pulse duration, pulse amplitude, pulse rate, sensibility, and PVARP can directly decide the metrological performance of the instrument. However, at present, there is no relevant calibration specification for extracorporeal pacemaker in China to calibrate the important parameters. This article presents a novel calibration method for extracorporeal pacemaker by determining corresponding environmental conditions, calibration standards, and calculation equations. The calibration results of the important parameters can meet the requirements of GB 16174.2-2015 Implants for surgery - Active implantable medical devices - Part 2 Cardiac pacemakers, which shows that the calibration method is scientific and practical for metrological performance evaluation of extracorporeal pacemaker.

In Situ Simultaneous Cavitation-Doping Approach for Constructing Bimetallic Metal-Organic Framework Hollow Nanospheres with Enhanced Electrocatalytic Hydrogen Production.

This Communication demonstrates a novel and in situ simultaneous cavitation-doping (SCD) approach to construct bimetallic metal-doped cobalt metal-organic framework hollow nanospheres (CoM-MOF HNSs, with M = Ru or Fe). The key point of the SCD approach is the careful balance between the kinetics of Co-MOF being etched and the coordinative growth of a more stable CoM-MOF shell induced by Lewis acid (MCl3, with M = Ru or Fe). Our work provides a new method to synthesize bimetallic hollow MOFs and benefits the development of electrocatalysts.

Detection of enrofloxacin by flow injection chemiluminescence immunoassay based on cobalt hydroxide nanozyme.

The emergence and development of low-cost and high-efficiency nanozymes are promising to replace natural enzymes promoting the application of chemiluminescence immunoassays. Herein, a rapid and highly sensitive flow injection chemiluminescence immunoassay based on cobalt hydroxide (Co(OH)2) nanozyme was established to detect enrofloxacin (ENR) residues in food. In this system, Co(OH)2 nanosheets act as nanozymes to catalyze and amplify the chemiluminescence signal of the luminol-PIP-H2O2 system, as well as a carrier for immobilizing antibodies to form stable immunoprobes. In addition, carboxyl resin beads with good stability and biocompatibility were used as the base of the immunosensor to carry more coating antigens, based on the principle of competitive immunity and to achieve the rapid detection of ENR. Under optimal conditions, the linear working range is 0.0001 ~ 1000 ng/mL, and the limit of detection (LOD) is 0.041 pg/mL (S/N = 3). The method has been successfully applied to the analysis of aquatic products and poultry food. A non-enzyme immunosensor using Co(OH)2 nanosheets as antibody-conjugated carriers and peroxidase mimics for catalytic amplification of the chemiluminescence signal of luminol and using carboxyl resin beads as platform was designed to detect ENR residues in food.

Synthesis of the Platinum Nanoribbons Regulated by Fluorine and Applications in Electrocatalysis.

Controlling the morphology of highly homogeneous nanoribbons is one of the main goals for synthesizing catalysts with excellent activity and durability. In this Communication, platinum (Pt) nanoribbons were synthesized by a one-pot method. We used ammonium fluoride (NH4F) as the regulator, under 8 atm of hydrogen (H2), to synthesize zigzag-shaped two-dimensional Pt nanoribbons. Benefiting from their unique morphology, the Pt nanoribbons display superior electrocatalytic activity and stability.

Ultrathin amorphous iron-doped cobalt-molybdenum hydroxide nanosheets for advanced oxygen evolution reactions.

Developing the highly efficient and low-cost electrocatalysts for the oxygen evolution reactions (OERs), as vital half reactions of water splitting, is crucial for renewable energy technology. The electrocatalysts based on multi-component and hierarchically structured non-noble metal hydr(oxy)oxide materials are of great prospects. Herein, we report an efficient strategy at low temperatures for synthesizing amorphous iron-doped cobalt-molybdenum ultrathin hydroxide (Fe-CoMo UH) nanosheets. Benefiting from the ultrathin amorphous structure and multi-metal coordination, Fe-CoMo UH nanosheets exhibit outstanding performance for OERs with a low overpotential of 245 mV at 10 mA cm-2, a small Tafel slope of 37 mV dec-1 and an excellent stability for 90 h. The mass activity of Fe-CoMo UH is higher than that of commercial Ir/C and most of the transition metal hydroxide catalysts. This work provides a feasible consideration for the construction of promising efficient non-noble metal catalysts.