The cubic structure of Li3As stabilized by substitution - Li8TtAs4 (Tt = Si, Ge) and Li14TtAs6 (Tt = Si, Ge, Sn) and their lithium ion conductivity.

The new lithium arsenidotetrelates Li8SiAs4, Li8GeAs4, Li14SiAs6, Li14GeAs6 and Li14SnAs6 were synthesized via ball milling and structurally characterized by Rietveld analysis of X-ray powder diffraction data. The aliovalent substitution of lithium in hexagonal Li3As by introducing a tetravalent tetrel cation stabilizes cubic structures for Li8TtAs4 (Tt = Si, Ge) in the space group Pa3̄ and for the lithium richer compound Li14TtAs6 (Tt = Si, Ge, Sn) in the higher symmetrical space group Fm3̄m (no. 225). Thermal properties of the arsenidotetrelates were investigated via high temperature powder diffraction and differential thermal analysis revealing a decomposition process of the lithium richer arsenidotetrelate (Li14TtAs6 → Li8TtAs4 + 2Li3As) into the lithium poorer arsenidotetrelates and lithium arsenide at moderate temperatures. Impedance spectroscopy shows moderate to good lithium ion conductivity for the lithium arsenidotetrelates.

201 cases of foreign body ingestion in a Surgical Emergency Unit A 16-year retrospective study.

AIM: The aim of this study is to analyse clinical characteristics of FB ingestion and predictive factors for complications, in order to reduce mortality and morbidity. MATERIALS AND METHODS: A retrospective study of emergency surgical consultation records has been carried out from June 2005 through June 2015 yielded 201 episodes with the diagnosis of ingestion of foreign objects at the Surgical Unit of the University of Bari. RESULTS: Natural Removal in 44,8% of cases; Endoscopic retrieval in 42,4%, Surgical Procedures 4,4%. Statistical analysis was based on multivariate analysis and the model R2 of the Naegelkerke value. DISCUSSION: First of all, the approach to ingestion should be endoscopic. The second approach is surgical in selected cases. The most frequent site of impaction were oesophagus, stomach and right colon. An EGD proved to be the most used procedure with a no morbidity and no mortality. CONCLUSION: The ingestion of foreign bodies is a frequent, complex and expensive condition to treat. Observation and endoscopy are the most appropriate procedures to be considered to manage the ingestion of FB in Emergency Surgery Unit. KEY WORDS: Emergency surgery, Foreign bodies, Ingestion.