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Propagation of dipolar-coupled transverse domain walls in a permalloy/non-magnetic/permalloy trilayer was investigated using micromagnetic modeling. Circulating stray fields meant that the walls adopted a composite structure with behavior analogous to walls seen in nanotubes. Wall velocities were sensitive to the chirality of the stray field circulation, with velocities of the most favored chirality enhanced by 32% compared with velocities seen in the individual constituent layers just below their Walker breakdown field. Additionally, Walker breakdown was completely suppressed within the trilayer for both chiralities, despite occurring in the constituent layers when modelled in isolation, leading to a maximum of 317% velocity enhancement. Wall velocity saturated around 1100 m/s due to the Cherenkov-like emission of spin waves, comparable to the magnonic regime of nanotubes. By reproducing the advantageous domain wall dynamics of nanotubes within a planar system, we demonstrate that ultrafast magnetic switching may feasibly be realized within a lithographically produced system. [ABSTRACT FROM AUTHOR]

Finite element modelling software has been used to allow secondary school students to study nanoscale magnetic materials for hard drive recording applications. The students were introduced to the basic concepts of finite element modelling using a freely available internet game before modelling the magnetization reversal of single magnetic grains. This approach allowed the students to see the underlying physics of magnetization switching emerge from their investigations and introduced them to the principles of scientific research. The students have also now been included as authors of a published scientific research article. The learning model used here could easily be adapted for university-school interactions in other areas of physics. (Contains 6 figures.)

We have investigated the propagation of transverse domain walls in magnetic nanowires under axial and transverse magnetic fields using three-dimensional micromagnetic modeling. Transverse magnetic fields change the domain wall width and, below the Walker field, either increase or decrease the domain wall velocity depending when the field and wall magnetization are parallel or antiparallel, respectively. Furthermore, differences in the Walker field also appear for opposite transverse fields, and a surprising result is that under relatively high axial and transverse fields, Walker breakdown can be completely suppressed and the domain wall velocity returns to several hundreds of m s-1. [ABSTRACT FROM AUTHOR]

Endothelial cell (EC) sensing of fluid shear stress direction is a critical determinant of vascular health and disease. Unidirectional flow induces EC alignment and vascular homeostasis, whereas bidirectional flow has pathophysiological effects. ECs express several mechanoreceptors that respond to flow, but the mechanismfor sensing shear stress direction is poorly understood.We determined, by using in vitro flow systems and magnetic tweezers, that β1 integrin is a key sensor of force direction because it is activated by unidirectional, but not bidirectional, shearing forces. β1 integrin activation by unidirectional forcewas amplified in ECs that were pre-sheared in the same direction, indicating that alignment and β1 integrin activity has a feedforward interaction, which is a hallmark of system stability. En face staining and EC-specific genetic deletion studies in themurine aorta revealed that β1 integrin is activated and is essential for EC alignment at sites of unidirectional flow but is not activated at sites of bidirectional flow. In summary, β1 integrinsensing of unidirectional force isa keymechanism for decoding blood flow mechanics to promote vascular homeostasis. [ABSTRACT FROM AUTHOR]

Author(s): James D. R. Buchanan [1]; Russell P. Cowburn (corresponding author) [1]; Ana-Vanessa Jausovec [1]; Dorothée Petit [1]; Peter Seem [1]; Gang Xiong [1]; Del Atkinson [2]; Kate Fenton [2]; [...]

We report on a reciprocal magnetic interaction mechanism in micrometer-sized hybrid Co/Pd-Permalloy square elements. Time-resolved scanning transmission X-ray microscopy using X-ray magnetic circular dichroism contrast together with micromagnetic simulations demonstrate that there exists a mutual imprint of vortices in the Permalloy and in the stripe domains of the Co/Pd. This results in a hybrid magnetic domain structure leading to a domain confined gyroscopic vortex precession. These observations open the exciting possibility for topological control of vortex core motion. [ABSTRACT FROM AUTHOR]

Highlights: [•] An in-plane organic spin valve based on Ni80Fe20 nanowires was realised. [•] Due to the high shape anisotropy, the switching field of Ni80Fe20 nanowires was controlled only by the wire width. [•] Parallel and anti-parallel magnetisation configurations were observed. [•] A magnetoresistance of −0.35% was observed at room temperature using PTCDI-C13. [ABSTRACT FROM AUTHOR]

Passive immunization with an antibody directed against the N terminus of amyloid β (Aβ) has recently been reported to exacerbate cerebral amyloid angiopathy (CAA)-related microhemorrhage in a transgenic animal model. Although the mechanism responsible for the deleterious interaction is unclear, a direct binding event may be required. We characterized the binding properties of several monoclonal anti-Aβ antibodies to deposited Aβ in brain parenchyma and CAA. Biochemical analyses demonstrated that the 3D6 and 10D5, two N-terminally directed antibodies, bound with high affinity to deposited forms of A β, whereas 266, a central domain antibody, lacked affinity for deposited Aβ. To determine whether 266 or 3D6 would exacerbate CAA-associated microhemorrhage, we treated aged PDAPP mice with either antibody for 6 weeks. We observed an increase in both the incidence and severity of CAA- associated microhemorrhage when PDAPP transgenic mice were treated with the N-terminally directed 3D6 antibody, whereas mice treated with 266 were unaffected. These results may have important implications for future immune-based therapeutic strategies for Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Targeted delivery, in which therapeutic agents are preferentially concentrated at the diseased site, has the potential to improve therapeutic outcomes by minimizing off-target interactions in healthy tissue. Both passive and active methods of targeting delivery have been proposed, often with particular emphasis on cancer treatment. Passive methods rely on the overexpression of a biomarker in diseased tissue that can then be used to target the therapy. Active techniques involve physically guiding therapeutic agents toward the target region. Since the motion of magnetic particles can be remotely controlled by external magnetic fields, magnetic technologies have the potential to drive and hold drugs or other cargo at the required therapeutic site, increasing the localized dose while minimizing overall exposure. Directed motion may be generated either by simple magnetic attraction or by causing the particles to perform swimming strokes to produce propulsion. This chapter will compare the different strategies using magnetic nanotechnology to produce directed motion compatible with that required for targeted cargo delivery and magnetically assisted therapies and assess their potential to meet the challenges of operating within the human body., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Passive immunization with an antibody directed against the N terminus of amyloid beta (Abeta) has recently been reported to exacerbate cerebral amyloid angiopathy (CAA)-related microhemorrhage in a transgenic animal model. Although the mechanism responsible for the deleterious interaction is unclear, a direct binding event may be required. We characterized the binding properties of several monoclonal anti-Abeta antibodies to deposited Abeta in brain parenchyma and CAA. Biochemical analyses demonstrated that the 3D6 and 10D5, two N-terminally directed antibodies, bound with high affinity to deposited forms of Abeta, whereas 266, a central domain antibody, lacked affinity for deposited Abeta. To determine whether 266 or 3D6 would exacerbate CAA-associated microhemorrhage, we treated aged PDAPP mice with either antibody for 6 weeks. We observed an increase in both the incidence and severity of CAA-associated microhemorrhage when PDAPP transgenic mice were treated with the N-terminally directed 3D6 antibody, whereas mice treated with 266 were unaffected. These results may have important implications for future immune-based therapeutic strategies for Alzheimer's disease.