Suchergebnisse

The spin Hall magnetoresistance (SMR) emerged as a reference tool to investigate the magnetic properties of materials with an all-electrical setup. Its sensitivity to the magnetization of thin films and surfaces may turn it into a valuable technique to characterize van der Waals magnetic materials, which support long-range magnetic order in atomically thin layers. However, realistic surfaces can be affected by defects and disorder, which may result in unexpected artifacts in the SMR, rather than the sole appearance of electrical noise. Here, we study the SMR response of heterostructures combining a platinum (Pt) thin film with the van der Waals antiferromagnet MnPSe3 and observe a robust SMR-like signal, which turns out to originate from the presence of strong interfacial disorder in the system. We use transmission electron microscopy (TEM) to characterize the interface between MnPSe3 and Pt, revealing the formation of a few nanometer-thick platinum–chalcogen amorphous layer. The analysis of the transport and TEM measurements suggests that the signal arises from a disordered magnetic system formed at the Pt/MnPSe3 interface, washing out the interaction between the spins of the Pt electrons and the MnPSe3 magnetic lattice. Our results show that the damaged interfaces can yield an important contribution to SMR, questioning a widespread assumption on the role of disorder in such measurements. ; The authors also thank SGIker Medidas Magneticas Gipuzkoa (UPV/EHU/ ERDF, EU) for the technical and human support. This work is supported by the European Union H2020 under the Marie Sklodowska-Curie Actions (796817-ARTEMIS and 748971-SUPER2D) and by the Spanish MICINN under project nos. RTI2018-094861-B-I00, PID2019-108153GA-I00, and the Maria de Maeztu Units of Excellence Programme (MDM-2016-0618 and CEX2020-001038-M). J.M.G.-P. and M.X.A.-P. thank the Spanish MICINN for a Ph.D. fellowship (grants no. BES-2016-077301 and PRE-2019-089833, respectively). M.G. acknowledges support from la Caixa Foundation for a Junior Leader ...

Circulating mannose-binding lectin (MBL) plays an important role in the progression of tissue damage caused by ischemic events, an account of its high-affinity, multivalent binding to carbohydrate arrays exposed on damaged endothelium (damage-associated molecular patterns, DAMPS). MBL inhibitors have therefore been proposed as a novel protective therapeutic strategy to prevent secondary injury. We developed a new, convenient, robust surface plasmon resonance (SPR) assay for in vitro screening of compounds interfering with the binding of native human MBL to an appropriate chip surface functionalized with a pattern of sugar moieties mimicking DAMPS. We also characterized the procedure to regenerate the chip surface after each experimental session, accomplished by sequential cleaning with piranha solution followed by UV exposure. The SPR assay detects the specific binding of human recombinant MBL and native MBL present in human serum, and can identify inhibitors of this binding. We observed inhibitory effects of mannose (IC50 5 mM), of a nine mannose residues carrying glycan (IC50 0.33 mg/mL, corresponding to ~ 175 mu M), and mainly mannose-coated gold nanoparticles (IC50 1.1 mu g /mL). These in vitro results serve as a basis for testing the protective properties of these molecules/nanoparticles later inthe more expensive and time-consuming studies in cells and animal models of MBL mediated-injuries. ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 814236.