RESUMEN
The Hall effect has played a vital role in unraveling the intricate properties of electron transport in solid materials. Here, we report on a crystal symmetry-dependent in-plane Hall effect (CIHE) observed in a CuPt/CoPt ferromagnetic heterostructure. Unlike the planar Hall effect (PHE), the CIHE in CuPt/CoPt strongly depends on the current flowing direction (ÏI) with respect to the crystal structure. It reaches its maximum when the current is applied along the low crystal-symmetry axes and vanishes when applied along the high crystal-symmetry axes, exhibiting an unconventional angular dependence of cos(3ÏI). Utilizing a symmetry analysis based on the Invariant Theory, we demonstrate that the CIHE can exist in magnetic crystals possessing C3v symmetry. Using a tight-binding model and realistic first-principles calculations on the metallic heterostructure, we find that the CIHE originates from the trigonal warping of the Fermi surface. Our observations highlight the critical role of crystal symmetry in generating new types of Hall effects.
RESUMEN
Transition metal dichalcogenides (TMDCs) are promising materials for applications in nanoelectronics and correlated fields, where their metallic edge states play a fundamental role in the electronic transport. In this work, we investigate the transport properties of MoS2 zigzag nanoribbons under a butadiene (C4H6) atmosphere, as this compound has been used to obtain MoS2 flakes by exfoliation. We use density functional theory combined with non-equilibrium Green's function techniques, in a methodology contemplating disorder and different coverages. Our results indicate a strong modulation of the TMDC electronic transport properties driven by butadiene molecules anchored at their edges, producing the suppression of currents due to a backscattering process. Our results indicate a high sensitivity of the TMDC edge states. Thus, the mechanisms used to reduce the dimensionality of MoS2 considerably modify its transport properties.
RESUMEN
BACKGROUND: Therapeutic plasma exchange (TPE) is an extracorporeal procedure which consists of removing the patient's plasma and replacing it with an appropriate replacement fluid. Plasma and blood cells are separated by a centrifugation process. Our department has used TPE for several years, and in 2013 we introduced an institutional apheresis protocol. The main objective of this report is to describe the TPE procedures performed between 2013 and 2016 in the Peruvian population. METHODS: We analyzed the technical and clinical aspects of 864 centrifugal TPE procedures as well as the associated complications. We evaluated 230 patients treated in our institution. RESULTS: The therapeutic indications included 16 different diseases: 89.5% (N = 206/230) neurological, 7.3% (N = 17/230) hematological, 1.7% (N = 4/230) rheumatologic, 0.8% (N = 2/230) dermatological and 0.4% (N = 1/230) nephrological. 70.4% (N = 142/230) of patients were diagnosed with Guillain-Barré syndrome. Albumin 5% solution was the most frequent replacement solution, used in 65.8% (N = 569/864) of the procedures. The mean plasma volume (PV) replaced was 2451.73 ml, corresponding to 1.0 PV in all procedures. Complications occurred in 10.9% (N = 95/864) of the sessions. Allergic reactions were the most common events and cardiopulmonary arrests were recorded in two patients. CONCLUSION: This is the first report of TPE performed in the Peruvian population. The use of an institutional apheresis protocol was beneficial to improve registries in our service and our professional health attention. This study reports a low rate of complications, suggesting that TPE is safe. There is a need to create a multicenter Peruvian apheresis registry to assess the benefits and risks of TPE in Peru.