LEDs based upon AlGaInP heterostructures with multiple quantum wells: comparison of fast neutrons and gammaquanta irradiation

The paper presents the research results of watt and volt characteristics of LEDs based upon AlGaInP heterostructures with multiple quantum wells in the active region. The research is completed for LEDs (emission wavelengths 624 nm and 590 nm) under irradiation by fast neutron and gamma-quanta in passive powering mode. Watt-voltage characteristics in the average and high electron injection areas are described as a power function of the operating voltage. It has been revealed that the LEDs transition from average electron injection area to high electron injection area occurs by overcoming the transition area. It disappears as it get closer to the limit result of the irradiation LEDs that is low electron injection mode in the entire supply voltage range. It has been established that the gamma radiation facilitates initial defects restructuring only 42% compared to 100% when irradiation is performed by fast neutrons. Ratio between measured on the boundary between low and average electron injection areas current value and the contribution magnitude of the first stage LEDs emissive power reducing is established. It is allows to predict LEDs resistance to irradiation by fast neutrons and gamma rays

RADIOSYNOVIORTHESIS IN THERAPY FOR INFLAMMATORY JOINT DISORDERS

Radiosynoviorthesis (RSO), also known as radiosynovectomy, is an approved method of treatment for inflammatory joint disorders that is commonly used both in the industrialized American and European countries as well as in the developing Asian and African countries. In terms of frequency of its use, this method ranks second among all the methods for radionuclide therapy in Germany. The treatment includes intra-articular administration of radiopharmaceuticals as microparticles (colloidal forms, macroaggregates, or microspheres) containing radioactive isotopes, which are rapidly phagocytized by the synovial membrane cells. Indications for therapy include inflammatory joint disorders of different genesis: rheumatoid arthritis, psoriatic arthritis, osteoarthritis and intra-articular effusion after joint endoprosthetics. RSO is the optimal method for local therapy for arthritis in patients with hemophilic arthropathy, since it both heals the inflammation and reduces the frequency of bleeding relapses. This aspect is of particular significance for the developing countries where the disease is often complicated by arthropathies due to the lack of coagulation factor. The main advantages include the low frequency of undesired reactions and low radiation burden to a patient. Depending on the degree to which a joint is affected, the frequency of responses to therapy is 50–80%, reaching 90% in patients with hemophilic arthropathy