Resists, problems with small feature

An example of a complex material used in syngas applications is Lag jSro gFeo g. Coo.iCro.203 [26]. This composition contains many of the features previously discussed. It is predominately an iron-based perovskite, providing both electronic and ionic conductivity. In order to improve the chemical stability and resistance to chemical expansion, the B-site is doped with chromium. A small amount of cobalt is added in order to improve the electronic conductivity, and cobalt wiU also increase the ionic conductivity slightly. Strontium is used as the A-site dopant in order to avoid the problems associated with calcium, and particularly with barium, in regard to reaction with CO2. In addition, the material has been made substantially A-site deficient to improve its stability. 

The possibility of immunisation against malaria [1, 20, 216, 217] is not strictly within the context of this review of chemotherapy, but it deserves mention because of the potential value in the eventual conquest of the disease just as in other communicable diseases. Immunity to plasmodia shares many features in common with other microbiological infections but, owing to the complicated life cycles of the parasites, the problem is not a simple reaction of the host to a single stage of the parasite, and the factors involved in resistance to plasmodial infection are multiple and varied. Moreover, sterile immunity is frequently not achieved, relatively small numbers of organisms may continue to survive in the immune host, and splenectomy during this state of premunition may lead to recrudescences of infection. 

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