The electrical heating industry also experimented with aluminium oxide, but it is not used anymore. As a reagent in the installation of the carboxybenzyl (Cbz) group using benzyl chloroformate in EtOAc for the N-protection of amines and amides. It is also used as an insulator in heat-resistant electrical cable. MgO doping has been shown to effectively inhibit grain growth in ceramics and improve their fracture toughness by transforming the mechanism of crack growth at nanoscale. Pressed MgO is used as an optical material. It is transparent from 0.3 to 7 μm. The refractive index is 1.72 at 1 μm and the Abbe number is 53.58. It is sometimes known by the Eastman Kodak trademarked name Irtran-5, although this designation is obsolete. Crystalline pure MgO is available commercially and has a small use in infrared optics. MgO is packed in bags around transuranic waste in the disposal cells (panels) at the Waste Isolation Pilot Plant, as a CO2 getter to minimize the complexation of uranium and other actinides by carbonate ions and so to limit the solubility of radionuclides. The use of MgO is preferred to this of CaO as the resulting hydration product (Mg(OH)2) is less soluble and releases less hydration heat. Another advantage is to impose a lower pH value of ~ 10.5 in case of accidental water ingress in the dry salt layers while the more soluble Ca(OH)2 would create a higher pH of 12.5 (strongly alkaline conditions).
Diagnosis
X-ray and CT scan show lytic expansion lesions with clear borders. Expansion of cortex gives the lesion a balloon-like appearance. Larger lesions may appear septated. MRI reveals fluid levels. Bone scan shows outer radiotracer uptake, with a central dark area. Differential diagnosis
Following conditions are excluded before diagnosis can be confirmed:
Unicameral bone cyst
Giant cell tumor
Telangiectatic osteosarcoma
Secondary aneurysmal bone cyst

Treatment
Curettage is performed on some people, and is sufficient for inactive lesions. The recurrence rate with curettage is significant in active lesions, and marginal resection has been advised. Liquid nitrogen, phenol, methyl methacrylate are considered for use to kill cells at margins of resected cyst. Prognosis
20–70% recur after curettage. Epidemiology
It is rare. The incidence is around 0.15 cases per one million per year. 80% occur in people age less than 20 years. It is second most common tumor of spine and most common benign tumor of pelvis in pediatric population. Males are affected as equally as females. Additional images
See also
Simple bone cyst (SBC)
Giant cell tumor of bone
Traumatic bone cyst

References


== External links ==