Magnetic anisotropy reversal driven by structural symmetry-breaking in monolayer α-RuCl.

Layered α-RuCl is a promising material to potentially realize the long-sought Kitaev quantum spin liquid with fractionalized excitations. While evidence of this state has been reported under a modest in-plane magnetic field, such behaviour is largely inconsistent with theoretical expectations of spin liquid phases emerging only in out-of-plane fields. These predicted field-induced states have been largely out of reach due to the strong easy-plane anisotropy of bulk crystals, however.

Imaging Domain Reversal in an Ultrathin Van der Waals Ferromagnet.

The recent isolation of 2D van der Waals magnetic materials has uncovered rich physics that often differs from the magnetic behavior of their bulk counterparts. However, the microscopic details of fundamental processes such as the initial magnetization or domain reversal, which govern the magnetic hysteresis, remain largely unknown in the ultrathin limit. Here a widefield nitrogen-vacancy (NV) microscope is employed to directly image these processes in few-layer flakes of the magnetic semiconductor vanadium triiodide (VI ).

Magneto-Memristive Switching in a 2D Layer Antiferromagnet.

Memristive devices whose resistance can be hysteretically switched by electric field or current are intensely pursued both for fundamental interest as well as potential applications in neuromorphic computing and phase-change memory. When the underlying material exhibits additional charge or spin order, the resistive states can be directly coupled, further allowing electrical control of the collective phases. The observation of abrupt, memristive switching of tunneling current in nanoscale junctions of ultrathin CrI , a natural layer antiferromagnet, is reported here.

Tailored Tunnel Magnetoresistance Response in Three Ultrathin Chromium Trihalides.

Materials that demonstrate large magnetoresistance have attracted significant interest for many decades. Extremely large tunnel magnetoresistance (TMR) has been reported by several groups across ultrathin CrI by exploiting the weak antiferromagnetic coupling between adjacent layers. Here, we report a comparative study of TMR in all three chromium trihalides (CrX, X = Cl, Br, or I) in the two-dimensional limit.

Evolution of interlayer and intralayer magnetism in three atomically thin chromium trihalides.

We conduct a comprehensive study of three different magnetic semiconductors, CrI, CrBr, and CrCl, by incorporating both few-layer and bilayer samples in van der Waals tunnel junctions. We find that the interlayer magnetic ordering, exchange gap, magnetic anisotropy, and magnon excitations evolve systematically with changing halogen atom. By fitting to a spin wave theory that accounts for nearest-neighbor exchange interactions, we are able to further determine a simple spin Hamiltonian describing all three systems.

Observation of unconventional chiral fermions with long Fermi arcs in CoSi.

Chirality-the geometric property of objects that do not coincide with their mirror image-is found in nature, for example, in molecules, crystals, galaxies and life forms. In quantum field theory, the chirality of a massless particle is defined by whether the directions of its spin and motion are parallel or antiparallel. Although massless chiral fermions-Weyl fermions-were predicted 90 years ago, their existence as fundamental particles has not been experimentally confirmed.

Ferromagnetic van der Waals Crystal VI.

We report structural properties, physical properties, and the electronic structure of van der Waals (vdW) crystal VI. Detailed analysis reveals that VI exhibits a structural transition from monoclinic C2/ m to rhombohedral R3̅ at T ≈ 79 K, similar to CrX (X = Cl, Br, I). Below T, a long-range ferromagnetic (FM) transition emerges at T ≈ 50 K.

Raman fingerprint of two terahertz spin wave branches in a two-dimensional honeycomb Ising ferromagnet.

Two-dimensional (2D) magnetism has been long sought-after and only very recently realized in atomic crystals of magnetic van der Waals materials. So far, a comprehensive understanding of the magnetic excitations in such 2D magnets remains missing. Here we report polarized micro-Raman spectroscopy studies on a 2D honeycomb ferromagnet CrI.

One Million Percent Tunnel Magnetoresistance in a Magnetic van der Waals Heterostructure.

We report the observation of a very large negative magnetoresistance effect in a van der Waals tunnel junction incorporating a thin magnetic semiconductor, CrI, as the active layer. At constant voltage bias, current increases by nearly one million percent upon application of a 2 T field. The effect arises from a change between antiparallel to parallel alignment of spins across the different CrI layers.

Serum-glucocorticoid-regulated kinase 1 contributes to mechanical stretch-induced inflammatory responses in cardiac fibroblasts.

Excessive mechanical stretch induces production of proinflammatory mediators in cardiac fibroblasts, which could act as inflammatory supporter cells in heart failure. Accumulation evidence and our previous studies suggest that serum-glucocorticoid-regulated kinase 1 (SGK1) contributes to cardiac remodeling and fibrosis, development of heart failure. However, the role and mechanism of SGK1 in mechanical stretch-induced inflammation of cardiac fibroblasts remain unclear.

The SGK1 inhibitor EMD638683, prevents Angiotensin II-induced cardiac inflammation and fibrosis by blocking NLRP3 inflammasome activation.

Inflammation has emerged as a critical biological process contributing to hypertensive cardiac remodeling. Effective pharmacological treatments targeting the cardiac inflammatory response, however, are still lacking. Prior studies suggested that the serum- and glucocorticoid-inducible kinase (SGK1) plays a key role in inflammation and cardiac remodeling.

Flow versus permeability weighting in estimating the forward volumetric transfer constant (K) obtained by DCE-MRI with contrast agents of differing molecular sizes.

Purpose: To quantify the differential plasma flow- (F-) and permeability surface area product per unit mass of tissue- (PS-) weighting in forward volumetric transfer constant (K) estimates by using a low molecular (Gd-DTPA) versus high molecular (Gadomer) weight contrast agent in dynamic contrast enhanced (DCE) MRI.

Materials And Methods: DCE MRI was performed using a 7T animal scanner in 14 C57BL/6J mice syngeneic for TRAMP tumors, by administering Gd-DTPA (0.9kD) in eight mice and Gadomer (35kD) in the remainder.

Pretreatment Dynamic Contrast-Enhanced MRI Improves Prediction of Early Distant Metastases in Patients With Nasopharyngeal Carcinoma.

The identification of early distant metastases (DM) in patients with newly diagnosed, previously untreated nasopharyngeal carcinoma (NPC) plays an important role in selecting the most appropriate treatment approach. Here, we sought to investigate the predictive value of distinct MRI parameters for the detection of early DM.Between November 2010 and June 2011, a total of 51 newly diagnosed NPC patients were included.

Assessment of vessel permeability by combining dynamic contrast-enhanced and arterial spin labeling MRI.

The forward volumetric transfer constant (K(trans)), a physiological parameter extracted from dynamic contrast-enhanced (DCE) MRI, is weighted by vessel permeability and tissue blood flow. The permeability × surface area product per unit mass of tissue (PS) in brain tumors was estimated in this study by combining the blood flow obtained through pseudo-continuous arterial spin labeling (PCASL) and K(trans) obtained through DCE MRI. An analytical analysis and a numerical simulation were conducted to understand how errors in the flow and K(trans) estimates would propagate to the resulting PS.

Study of the toxicity of 1-Bromo-3-chloro-5,5-dimethylhydantoin to zebrafish.

Objective: 1-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) is a solid oxidizing biocide for water disinfection. The objective of this study was to investigate the toxic effect of BCDMH on zebrafish.

Methods: The developmental toxicity of BCDMH on zebrafish embryos and the dose-effect relationship was determined.

Intravenous repeated-dose toxicity study of ZnPcS2P2-based-photodynamic therapy in beagle dogs.

The purpose of current study was to investigate the potential repeated dosed toxicity of ZnPcP(2)S(2)-based photodynamic therapy (ZnPc-PDT) in Beagle dogs. Twenty-four Beagle dogs were randomly allocated to four groups, in which they were administered ZnPcS(2)P(2) preparation intravenously at dosages of 0, 0.5, 1.