Giant room temperature anomalous Hall effect and magnetically tuned topology in the ferromagnetic Weyl semimetal Co2MnAl

Weyl semimetals (WSM) have been extensively studied due to their exotic properties such as topological surface states and anomalous transport phenomena. Their band structure topology is usually predetermined by material parameters and can hardly be manipulated once the material is formed. Their unique transport properties appear usually at very low temperature, which sets challenges for practical device applications. In this work, we demonstrate a way to modify the band topology via a weak magnetic field in a ferromagnetic topological semimetal, Co2MnAl, at room temperature. We observe a tunable, giant anomalous Hall effect, which is induced by the transition between Weyl points and nodal rings as rotating the magnetization axis. The anomalous Hall conductivity is as large as that of a 3D quantum anomalous Hall effect (QAHE), with the Hall angle reaching a record value (21%) at the room temperature among magnetic conductors. Furthermore, we propose a material recipe to generate the giant anomalous Hall effect by gaping nodal rings without requiring the existence of Weyl points. Our work reveals an ideal intrinsically magnetic platform to explore the interplay between magnetic dynamics and topological physics for the development of a new generation of spintronic devices.Comment: 4 figures, 8 pages for the main text. The supplementary materials are included to

Kidney damage in COVID-19 patients with or without chronic kidney disease: Analysis of clinical characteristics and related risk factors

COVID-19 poses more risk to patients who already suffer from other diseases, particularly respiratory disorder. In this study, we analyzed the clinical characteristics and related risk factors during hospitalization of COVID-19 patients admitted with kidney damage. A total of 102 COVID-19 patients with kidney damage [irrespective of their chronic kidney disease (CKD) history] during hospitalization were included in this study. The patients were divided into a core group and a group who developed critical illness or death. Clinical data included age, gender, length of hospitalization, clinical manifestations, medical history, hypersensitive C-reactive protein (hs -CRP), high serum creatinine, low cardiac troponin I (cTnI), and hemoglobin. Univariate and multivariate logistic regression models were used to analyze the risk factors of patients' outcome. Among the outcomes, 75 patients (73.53%) were cured, 27 (26.47%) developed to critical illness or death, 20 (19.61%) of them died. A total of 36 (4.26%) out of 845 COVID-19 patients, developed acute kidney injury (AKI). Decreased oxygen saturation, elevated hs-CRP, elevated serum creatinine, elevated cTnI, and anemia were related factors for COVID-19 patients who developed to critical illness or death (P <0.05). Decreased oxygen saturation, elevated hs-CRP and anemia were not independent factors, but elevated serum creatinine and elevated cTnI were independent factors for COVID-19 patients who developed to critical illness or death (P <0.05). Among COVID-19 patients with or without CKD but with kidney damage during hospitalization, patients with elevated serum creatinine and elevated TnI, more likely to developed critical illness or death

Activin A and BMP4 Signaling Expands Potency of Mouse Embryonic Stem Cells in Serum-Free Media.

Inhibitors of Mek1/2 and Gsk3β, known as 2i, and, together with leukemia inhibitory factor, enhance the derivation of embryonic stem cells (ESCs) and promote ground-state pluripotency (2i/L-ESCs). However, recent reports show that prolonged Mek1/2 suppression impairs developmental potential of ESCs, and is rescued by serum (S/L-ESCs). Here, we show that culturing ESCs in Activin A and BMP4, and in the absence of MEK1/2 inhibitor (ABC/L medium), establishes advanced stem cells derived from ESCs (esASCs). We demonstrate that esASCs contributed to germline lineages, full-term chimeras and generated esASC-derived mice by tetraploid complementation. We show that, in contrast to 2i/L-ESCs, esASCs display distinct molecular signatures and a stable hypermethylated epigenome, which is reversible and similar to serum-cultured ESCs. Importantly, we also derived novel ASCs (blASCs) from blastocysts in ABC/L medium. Our results provide insights into the derivation of novel ESCs with DNA hypermethylation from blastocysts in chemically defined medium