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The nature of the perfect prismatic dislocation loops formed during the post‐growth annealing treatments of moderately heavily Te‐doped (viz. 1018cm−3≦[Te]≦ 8 × 1018cm−3) GaAs in the temperature range 800 to 1000 °C is determined by transmission electron microscopy. The results of the detailed diffraction contrast analysis show unambiguously that these defects are vacancy type in character contradicting an earlier conclusion that the prismatic loops are interstitial type. A divacancy‐model is proposed for the formation of the observed microstructural defects which involves the precipitation of a complex of the type, (TAsVGaVAs). This model would adequately explain the annealing‐induced changes in electrical properties of heavily Te‐doped GaAs reported previously in the literature.

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Posterior ischaemic optic neuropathy following burns is a rare but devastating condition that can result in total bilateral visual loss. Numerous treatment modalities have been trialled yet there is no effective therapy to delay or reverse the disease. Hence, it is imperative for burns surgeons to be aware of the potential risk factors and have a high index of suspicion right from the outset in order to prevent this outcome. Here, we discuss the case of a patient that developed posterior ischaemic optic neuropathy subsequent to a major burn injury. We also present a literature review on optic neuropathies following burns to describe the aetiology, clinical signs, and potential management.

Objective: Metastatic spinal cord compression (MSCC) is a common complication of metastatic disease with neurological morbidity in the thoracic and upper lumbar spine. We describe a modified rib-sparing direct lateral minimally invasive (MIS) approach. for the purpose of vertebrectomy. This technique obviates the need for rib resection and chest drain, facilitating early mobilisation. This is especially applicable to a sub-group of patients who may not be well enough for an open approach. Method: Technical note and retrospective case series in a single centre over a 5 year period. Results: 14 patients were identified who underwent the MIS approach vertebrectomy for MSCC. 12/14 underwent posterior fixation, and 2 underwent vertebroplasty. 11/14 (79%) had less than 1L blood loss during the procedure. The mean duration of the procedure was 5 hours 51 minutes. 5/14 (36%) avoided high dependency unit (HDU) care, and the median duration of time spent in HDU was 1.5 days. The median length of stay in hospital was 16 days, and 4/14 (29%) were discharged within 1 week. There were 1/14 major complications requiring revision surgery. Conclusion: A modified rib-sparing MIS approach for vertebrectomy is well tolerated in the treatment of MSCC and is associated with low blood loss and short hospital stays. This may be an option in patients who otherwise may not be considered for an anterior reconstruction.

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