RESUMO
Hemophilic pseudotumor is an uncommon complication of factor VIII and IX deficiencies in the coagulation cascade and occurs in a wide spectrum of bones and soft tissues. We present a six-year-old boy with hemophilic pseudotumor localized in the right orbit. He showed a favorable response to radiation therapy after unsuccessful treatment with factor VIII replacement therapy with no recurrence till eight months. Radiotherapy in the treatment of pseudotumors in hemophiliacs should be strongly considered, particularly in severely affected patients who do not respond to conservative therapy.
RESUMO
To study electron cylotron resonance (ECR) breakdown and afterglow plasma in an experimental linear plasma system, a pulsed microwave source with rapid rise and fall of microwave power is desired. A pulsed microwave source with fast rise and fall capability for ECR breakdown experiments has been designed and tested for performance in the system. A tetrode, controlled by a modulator card, is used as a fast switch to initiate microwave power from a conventional magnetron operating at 2.45 GHz. The typical rise time of microwave power is approximately 3 micros and a fall time of approximately 10 micros. Using this scheme in a realistic pulsed microwave source at 800 W power, ECR breakdown of neutral gas is achieved and the plasma delay and fall time are observed from the plasma density measurements using a Langmuir probe. The design details of the fast rise pulsed microwave source are presented in this article with initial experimental results.
