Mutual passivation of electrically active and isovalent impurities.

The alloy GaN(x) As(1-x) (with x typically less than 0.05) is a novel semiconductor that has many interesting electronic properties because of the nitrogen-induced dramatic modifications of the conduction band structure of the host material (GaAs). Here we demonstrate the existence of an entirely new effect in the GaN(x) As(1-x) alloy system in which the Si donor in the substitututional Ga site (Si(Ga)) and the isovalent atom N in the As sublattice (N(As)) passivate each other's electronic activity. This mutual passivation occurs in Si-doped GaN(x) As(1-x) through the formation of nearest-neighbour Si(Ga) -N(As) pairs and is thermally stable up to 950 degrees C. Consequently, Si doping in GaN(x) As(1-x) under equilibrium conditions results in a highly resistive GaN(x) As(1-x) layer with the fundamental bandgap governed by a net 'active' N, roughly equal to the total N content minus the Si concentration. Such mutual passivation is expected to be a general phenomenon for electrically active dopants and localized state impurities that can form nearest-neighbour pairs.

[Familial subsepsis allergica- a systemic form of chronic juvenile arthritis]. / Zur familiaritt der subsepsis allergica-systemische form der juvenilen chonischen arthritis.

Case report of a baby and his 26-year old mother suffering from Subsepsis allergica. Her disease was discovered when she was 2 years old. Both patients showed common symptoms such as regular bouts of high fever with brief exanthemas resistant to antibiotic treatment. The results of their hematological tests were typical of this illness. The mother has also suffered from sporadic attacks of arthritis for the past ten years, but these have not handicapped her in any way. In spite of extensive diagnostic tests we were unable to shed new light on the etiopathogenesis of this systemic form of chronic juvenile arthritis. Since the baby's illness has so far proved to be of benign nature, long-term medication was found to be unnecessary. The mother finds relief through symptomatic treatment.