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We have studied current induced magnetization switching in W/CoFeB/MgO based three terminal magnetic tunnel junctions. The switching driven by spin-orbit torque (SOT) is evaluated in the so-called type-Y structure, in which the magnetic easy-axis of the CoFeB layer lies in the film plane and is orthogonal to the current flow. The effective spin Hall angle estimated from the bias field dependence of critical current (Ic) is ~ 0.07. The field and current dependence of the switching probability are studied. The field and DC current induced switching can be described using a model based on thermally assisted magnetization switching. In contrast, the 50 ns long pulse current dependence of the switching probability shows significant deviation from the model, even if contribution from the field-like torque is included. The deviation is particularly evident when the threshold switching current is larger. These results show that conventional thermally assisted magnetization switching model cannot be used to describe SOT induced switching using short current pulses.
RESUMO
BACKGROUND: Extirpation of tumors arising in the pterygopalatine fossa is challenging because of its anatomic complexity. METHODS AND RESULTS: A 67-year-old man was referred to our department with a diagnosis of a tumor in his left pterygoid fossa. An incisional biopsy through the canine fossa was diagnosed as myxofibrosarcoma. The upper part of the maxilla was swung laterally to remove the tumor while the hard plate was preserved. The defect was reconstructed using rectus abdominis musculocutaneous free and ipsilateral temporal. The postoperative course was uneventful, without facial palsy or mastication disorders. CONCLUSION: Our experience with this case suggests that the modified partial maxillary swing approach with preservation of the hard palate and orbital floor in combination with infratemporal and cervical approaches is useful for lesions in the pterygoid process without causing severe complications. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2519-E2522, 2016.
Assuntos
Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Mixossarcoma/patologia , Mixossarcoma/cirurgia , Fossa Pterigopalatina/patologia , Retalhos Cirúrgicos/transplante , Idoso , Biópsia por Agulha , Seguimentos , Humanos , Imageamento Tridimensional , Imuno-Histoquímica , Masculino , Maxila/cirurgia , Invasividade Neoplásica/patologia , Estadiamento de Neoplasias , Fossa Pterigopalatina/diagnóstico por imagem , Doenças Raras , Procedimentos de Cirurgia Plástica/métodos , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoRESUMO
A 30-year-old woman suffered cerebellar hemorrhage during the delivery of her first child. She had undergone surgical removal of a symptomatic cerebellar hemangioblastoma 6 years previously. Neuroradiological examinations indicated recurrent hemangioblastoma, confirmed by histological examination of the surgical specimen. She was discharged with no neurological deficit. Hemangioblastomas are benign tumors that are curable with surgical removal, but can grow during pregnancy. Women of reproductive age who have been treated for hemangioblastoma need careful long-term follow up, even if they show no signs of lesion recurrence.