A high-entropy manganite in an ordered nanocomposite for long-term application in solid oxide cells.

The implementation of nano-engineered composite oxides opens up the way towards the development of a novel class of functional materials with enhanced electrochemical properties. Here we report on the realization of vertically aligned nanocomposites of lanthanum strontium manganite and doped ceria with straight applicability as functional layers in high-temperature energy conversion devices. By a detailed analysis using complementary state-of-the-art techniques, which include atom-probe tomography combined with oxygen isotopic exchange, we assess the local structural and electrochemical functionalities and we allow direct observation of local fast oxygen diffusion pathways. The resulting ordered mesostructure, which is characterized by a coherent, dense array of vertical interfaces, shows high electrochemically activity and suppressed dopant segregation. The latter is ascribed to spontaneous cationic intermixing enabling lattice stabilization, according to density functional theory calculations. This work highlights the relevance of local disorder and long-range arrangements for functional oxides nano-engineering and introduces an advanced method for the local analysis of mass transport phenomena.

Louse-borne relapsing fever in Ethiopian children: a clinical study.

An outbreak of louse-borne relapsing fever, caused by the return to their original recruitment areas of soldiers at the end of 30 years of fighting in northern Ethiopia, was reported in the Arsi region. We studied 103 infants and children with louse-borne relapsing fever who were admitted to Asella Hospital between 1 May 1991 and 30 April 1992. Twenty-one per cent of the patients had a clear history of contact with sick ex-soldiers; 42% were students admitted to the hospital following the re-opening of schools after the summer vacation. The common clinical features of the disease were fever in 100%, headache in 84.5%, chills in 74%, abdominal pain in 51%, epistaxis in 20%, hepatomegaly in 26%, splenomegaly in 14%, petechial rash in 34% and jaundice in 10%. Differences in symptoms and signs according to age are described. Observed complications were pneumonia in 14% and central nervous system involvement in 10%. Four children went into deep coma, and two of them died. Severe disease was associated with a high density of spirochaetes in blood smears. Patients were treated with two low doses of penicillin or one dose of penicillin followed by, according to age, chloramphenicol or tetracycline, and with intravenous fluids. The case fatality rate was 1.9%. Jarisch-Herxheimer reactions occurred in 61% of patients. There were relapses in 2.9% of treated patients.