Achieving synergy between inexpensive metals and metal oxides is a key challenge for the development of highly active, economical catalysts. We report the synthesis and characterization of a highly active oxygen reduction reaction (ORR) catalyst composed of Ag particles (3 nm) in intimate contact with thin (∼1 nm) MnO x domains on Vulcan carbon (VC) as shown via electron microscopy. A new electroless co-deposition scheme, whereby MnO4 – ions are reduced by carbon, formed nanosized MnO x reduction centers for Ag nanoparticle deposition. A bifunctional mechanism for ORR is proposed, in which the HO2 – intermediate is formed electrochemically and is regenerated via disproportionation into OH– and O2. A 3× mass activity enhancement is observed for Ag-MnO x /VC (125 mA/mgAg+MnO x ) over the linear combination of pure component activities using rotating disk voltammetry. The Ag-MnO x /VC mass activity is comparable to commercial Pd/VC (111 mA/mgPd) and Pt/VC (136 mA/mgPt). Furthermore, the number of electrons transferred for ORR reaches 3.5 for Ag-MnO x , higher than for MnO x (2.8) and close to the full four-electron ORR. The synergy can be rationalized by ensemble effects, where Ag and MnO x domains facilitate the formation and disproportionation of HO2 –, respectively, and ligand effects from the unique electronic interaction at the Ag-MnO x interface.
The isolation of human monoclonal antibodies (hmAb) has emerged as a versatile platform in a wide variety of contexts ranging from vaccinology to therapeutics. In particular, the presence of high titers of circulating auto-antibodies is implicated in the pathology and outcome of autoimmune diseases. Therefore, the molecular characterization of these hmAb provides an avenue to understanding the pathogenesis of autoimmune diseases. Additionally, the phenotype of the auto-reactive B cells may have direct relevance for therapeutic intervention. In this report, we describe a high-throughput single-cell assay, microengraving, for the screening, characterization and isolation of anti-citrullinated protein antibodies (ACPA) from peripheral blood mononuclear cells (PBMC) of rheumatoid arthritis (RA) patients. Stimulated B cells are profiled at the single-cell level in a large array of sub-nanoliter nanowells (~105), assessing both the phenotype of the cells and their ability to secrete cyclic-citrullinated peptide (CCP)-specific antibodies. Single B cells secreting ACPA are retrieved by automated micromanipulation, and amplification of the immunoglobulin (Ig) heavy and light chains is performed prior to recombinant expression. The methodology offers a simple, rapid and low-cost platform for isolation of auto-reactive antibodies from low numbers of input cells and can be easily adapted for isolation and characterization of auto-reactive antibodies in other autoimmune diseases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.