Binary information propagation in circular magnetic nanodot arrays using strain induced magnetic anisotropy.

Nanomagnetic logic has emerged as a potential replacement for traditional Complementary Metal Oxide Semiconductor (CMOS) based logic because of superior energy-efficiency (Salahuddin and Datta 2007 Appl. Phys. Lett. 90 093503, Cowburn and Welland 2000 Science 287 1466-68). One implementation of nanomagnetic logic employs shape-anisotropic (e.g. elliptical) ferromagnets (with two stable magnetization orientations) as binary switches that rely on dipole-dipole interaction to communicate binary information (Cowburn and Welland 2000 Science 287 1466-8, Csaba et al 2002 IEEE Trans. Nanotechnol. 1 209-13, Carlton et al 2008 Nano Lett. 8 4173-8, Atulasimha and Bandyopadhyay 2010 Appl. Phys. Lett. 97 173105, Roy et al 2011 Appl. Phys. Lett. 99 063108, Fashami et al 2011 Nanotechnology 22 155201, Tiercelin et al 2011 Appl. Phys. Lett. 99 , Alam et al 2010 IEEE Trans. Nanotechnol. 9 348-51 and Bhowmik et al 2013 Nat. Nanotechnol. 9 59-63). Normally, circular nanomagnets are incompatible with this approach since they lack distinct stable in-plane magnetization orientations to encode bits. However, circular magnetoelastic nanomagnets can be made bi-stable with a voltage induced anisotropic strain, which provides two significant advantages for nanomagnetic logic applications. First, the shape-anisotropy energy barrier is eliminated which reduces the amount of energy required to reorient the magnetization. Second, the in-plane size can be reduced (∼20 nm) which was previously not possible due to thermal stability issues. In circular magnetoelastic nanomagnets, a voltage induced strain stabilizes the magnetization even at this size overcoming the thermal stability issue. In this paper, we analytically demonstrate the feasibility of a binary 'logic wire' implemented with an array of circular nanomagnets that are clocked with voltage-induced strain applied by an underlying piezoelectric substrate. This leads to an energy-efficient logic paradigm orders of magnitude superior to existing CMOS-based logic that is scalable to dimensions substantially smaller than those for existing nanomagnetic logic approaches. The analytical approach is validated with experimental measurements conducted on dipole coupled Nickel (Ni) nanodots fabricated on a PMN-PT (Lead Magnesium Niobate-Lead Titanate) sample.

Delayed ruptures of the extensor tendon secondary to the use of volar locking compression plates for distal radial fractures.

The use of volar locking compression plates for the treatment of fractures of the distal radius is becoming increasingly popular because of the stable biomechanical construct, less soft-tissue disturbance and early mobilisation of the wrist. A few studies have reported complications such as rupture of flexor tendons. We describe three cases of rupture of extensor tendons after the use of volar locking compression plates. We recommend extreme care when drilling and placing the distal radial screws to prevent damaging the extensor tendons.

Large tumoral calcinosis in the gluteal region: a case report.

BACKGROUND. Tumoral calcinosis is a poorly understood phenomenon. It can be described as a syndrome of calcium deposits principally affecting the juxta-articular areas. It is a rare entity that has been poorly understood. Our aim is to highlight a special and unusual case of an 11-year-old with a large, relatively painless lump in her buttock. CLINICAL CASE. An 11-year-old girl of African descent presented to our Bone Tumour Unit after being referred by her local hospital. The girl presented with a large lump on the posterolateral aspect of the right buttock, measuring 15cm in diameter. Due to the delay in referral/diagnosis, tethering of the skin had progressed to necrosis, with a sinus discharging milky-white fluid. A MRI scan further characterised the lump as a densely calcified area within the gluteus maximus, extending to the subcutaneous tissue. The characteristic features of the calcified mass on the images led to the diagnosis of tumoral calcinosis. Laboratory test did not demonstrate any metabolic disturbances. Pathology reports further confirmed the diagnosis and the lump was successfully resected. There were no recurrences on follow-up. CONCLUSION. Several cases of tumoral calcinosis have been described in the literature; however, it remains a rare entity. Being aware of the possibility and having knowledge of tumoral calcinosis is paramount in preventing confusion and delay in diagnosis for patients and clinicians.