RESUMEN
Studying antiferromagnetic domains is essential for fundamental physics and potential spintronics applications. Despite their importance, few systematic studies have been performed on antiferromagnet (AFM) domains with high spatial resolution in van der Waals (vdW) materials, and direct probing of the Néel vectors remains challenging. In this work, we found multidomain states in the vdW AFM NiPS3, a material extensively investigated for its unique magnetic exciton. We employed photoemission electron microscopy combined with the X-ray magnetic linear dichroism (XMLD-PEEM) to image the NiPS3's magnetic structure. The nanometer-spatial resolution of XMLD-PEEM allows us to determine local Néel vector orientations and discover thermally fluctuating Néel vectors that are independent of the crystal symmetry even at 65 K, well below the TN of 155 K. We demonstrate that an in-plane orbital moment of the Ni ion is responsible for the weak magnetocrystalline anisotropy. The observed thermal fluctuations of the antiferromagnetic domains may explain the broadening of magnetic exciton peaks at higher temperatures.
RESUMEN
A 70-year-old man with dilated cardiomyopathy underwent left ventricular assist device (LVAD) implantation, using a HeartWare ventricular assist device, as a bridge to candidacy. After 26 months, computed tomography (CT) angiography indicated stenosis in the LVAD outflow graft; however, the patient was asymptomatic, prompting a decision to manage his condition with close monitoring. Ten months later, the patient presented with dizziness and low-flow alerts. Subsequent CT angiography revealed a critical obstruction involving the entire LVAD outflow graft. The patient underwent emergency surgery, during which an organized seroma causing the graft obstruction was found between a wrapped expanded polytetrafluoroethylene (ePTFE) graft and a Dacron outflow graft. The covering of the outflow graft was removed, along with the organized seroma. Following removal of the ePTFE wrap and decompression of the outflow graft, normal LVAD flow was reestablished. The practice of wrapping the outflow graft with synthetic material, commonly done to facilitate later redo sternotomy, may pose a risk for outflow graft obstruction.
RESUMEN
Understanding the phase transition mechanisms in two-dimensional (2D) materials is a key to precisely tailor their properties at the nanoscale. Molybdenum ditelluride (MoTe2) exhibits multiple phases at room temperature, making it a promising candidate for phase-change applications. Here, we fabricate lateral 2H-Td interfaces with laser irradiation and probe their phase transitions from micro- to atomic scales with in situ heating in the transmission electron microscope (TEM). By encapsulating the MoTe2 with graphene protection layers, we create an in situ reaction cell compatible with atomic resolution imaging. We find that the Td-to-2H phase transition initiates at phase boundaries at low temperatures (200-225 °C) and propagates anisotropically along the b-axis in a layer-by-layer fashion. We also demonstrate a fully reversible 2H-Td-2H phase transition cycle, which generates a coherent 2H lattice containing inversion domain boundaries. Our results provide insights on fabricating 2D heterophase devices with atomically sharp and coherent interfaces.
RESUMEN
Background: This study analyzed and described the clinical characteristics and surgical outcomes of diaphragmatic hernia (DH) repair according to the operative approach. Methods: After excluding cases with a combined approach and hiatal hernias, we analyzed 26 patients who underwent DH repair between 1994 and 2018. The baseline and perioperative characteristics of the thoracic approach group and the abdominal approach group were described and analyzed. Results: Fifteen of the 26 patients were treated through the thoracic approach, including 5 patients who underwent video-assisted thoracic surgery (VATS). Eleven patients underwent the abdominal approach. The thoracic approach was associated with a longer duration of DH than the abdominal approach (2 vs. 0.1 months), herniation of the right-sided abdominal organs, and herniation of the retroperitoneal organs. During the median follow-up of 23 months, there was no recurrence of DH. Conclusion: The surgical approach should be chosen considering the duration of DH and the location of herniated organs. VATS might be a safe and feasible option for repairing DH.
RESUMEN
A child being supported with an extracorporeal ventricular assist device, such as the Berlin Heart EXCOR (Berlin Heart GmbH, Berlin, Germany), must have at least 2 large cannulae for a long period. Management of cannula wounds is crucial since a cannula forms a track of prosthetic material passing the mediastinum to the heart. Deep wound complications, if they occur, can be troublesome and difficult to control with conventional methods. We applied vacuum-assisted closure to a patient who had Berlin-Heart EXCOR and a gap at the cannulation site. Herein, we describe the technical aspects of management in detail.
