Biomaterials in cardiovascular research: applications and clinical implications

Cardiovascular biomaterials (CB) dominate the category of biomaterials based on the demand and investments in this field. This review article classifies the CB into three major classes, namely, metals, polymers, and biological materials and collates the information about the CB. Blood compatibility is one of the major criteria which limit the use of biomaterials for cardiovascular application. Several key players are associated with blood compatibility and they are discussed in this paper. To enhance the compatibility of the CB, several surface modification strategies were in use currently. Some recent applications of surface modification technology on the materials for cardiovascular devices were also discussed for better understanding. Finally, the current trend of the CB, endothelization of the cardiac implants and utilization of induced human pluripotent stem cells (ihPSCs), is also presented in this review. The field of CB is growing constantly and many new investigators and researchers are developing interest in this domain. This review will serve as a one stop arrangement to quickly grasp the basic research in the field of C

A Perspective on the Recent Amelioration of Co₃O₄ and MnO₂ Bifunctional Catalysts for Oxygen Electrode Reactions

Metal-air batteries with the aid of high theoretical energy density and affability are trusted as propitious energy storage systems in today’s energy research. However, enforcement of the technology is still hindered by the sluggish kinetics of their electrode reactions, that is, oxygen evolution and oxygen reduction reaction (OER/ORR). Developing a catalyst with inherently greater bifunctional activity and durability is the finest solution to confront the aforementioned challenges. Transition metal oxides (TMOs) are the most appropriate choice of materials for that purpose since they are highly active, inexpensive, abundant and non-hazardous. Among the various transition metal oxides, MnO2 and Co3O4 are gaining much attention due to their superior bifunctional performance and alkaline stability owing to their structural features and physicochemical properties. With the inspiration from promoted catalytic activity of MnO2 and Co3O4, this chapter is fully devoted to these two catalysts. The activity structural relationship, recent developments and future directions of these materials for bifunctional catalysis have been discussed in more detail. Besides, the significant parameters judging the bifunctional activity, that is, phase, crystal facets, morphology, defects, strains and mixed metals oxide formations, have been illustrated with suitable evidence. In addition, the fundamentals of water oxidation and reduction reactions are explained with the mechanisms. Moreover, the physiochemical properties of MnO2 and Co3O4 materials and their influence on the catalytic activity are related for a better understanding of bifunctional catalysis. This collective perception will be highly useful for the comprehension and designing of advanced metal oxide catalysts to further improve bifunctional catalysis

The effects of morphology, microstructure and mixed-valent states of MnO2 on the oxygen evolution reaction activity in alkaline anion exchange membrane water electrolysis

In this work, we focused on the evaluation of oxygen evolution reaction (OER) activity of three different shapes of α-MnO2 nanowires (NWs), nanorods (NRs) and nanotubes (NTs) in alkaline anion exchange water electrolyser. We have attempted to separate the effect of shape, surface area, Mn3+ content and crystal facets on OER activity and stability. X-ray Photoelectron Spectroscopy (XPS) measurements showed that NTs had the highest surface concentration of Mn3+ on the as prepared samples with average Mn oxidation state of 3.33. However, after activation an increase in the average oxidation state of all three shapes to 3.9 was confirmed by XPS. X-Ray Diffraction (XRD) showed surface restructuring after testing. MnO2 NWs showed the highest OER mass activity of 60.6 A g−1 (10 mA cm−2 at 1.67 V (RHE)) due to the higher surface area of 72.2 m2 g−1. While NTs showed the highest specific activity due to highest content of 211 facet, high Mn3+ surface concentration/surface defects. Similar trend was observed in electrolyser testing with 2 mg cm−2 loading. Poor electronic conductivity of MnO2 resulted in decrease in performance with increased loading to 4 mg cm−2. All the studied shapes showed good stability over 36 h of electrolyser testing

Pattern of ethionamide susceptibility and its association with isoniazid resistance among previously treated tuberculosis patients from India

Letter to the Edito