One-dimensional ladder gallium coordination polymer.

A one-dimensional ladder-type coordination polymer, poly[[(µ2-hydroxido)(µ2-1H-pyrazole-3,5-di-carboxyl-ato)gallium(III)] monohydrate], [Ga(C5H2N2O4)(OH)(H2O)] n or [Ga(HPDC)(OH)(H2O)] n , I, isotypic with a V3+ coordination polymer previously reported by Chen et al. [J. Coord. Chem. (2008). 61, 3556-3567] was prepared from Ga3+ and pyrazole-3,5-di-carb-oxy-lic acid monohydrate (H3PDC·H2O). Compound I was isolated using three distinct experimental methods: hydro-thermal (HT), microwave-assisted (MWAS) and one-pot (OP) and the crystallite size should be fine-tuned according to the method employed. The coordination polymeric structure is based on a dimeric Ga3+ moiety comprising two µ2-bridging hydroxide groups, which are inter-connected by HPDC2- anionic organic linkers. The close packing of individual polymers is strongly directed by the supra-molecular inter-actions, namely several O-H⋯O and N-H⋯O hydrogen-bonding inter-actions.

A surdez evitavel: predominancia de fatores ambientais na etiologia da surdez neurossensorial profunda / The deafness evitable:predominance of ambiental factors in the etiology of the neurosensorial deafness profound

Sabendo que a surdez pode resultar de uma ampla variedade de anomalias geneticamente determinadas, bem como, de diversos fatores do ambiente, os autores verificam a etiologia da deficiencia auditiva em amostra de 27criancas matriculadas em centro de reabilitacao de Campinas, SP. Na maioria dos casos (18/27), a surdez foi considerada de causa ambiental, com predominio dos casos de rubeola congenita e anoxia neonatal, seguindo-se os casos de etiologia indefinida (5/27) e os de heranca autossomica recessiva (4/27). A predominancia acentuada dos casos de etiologia dos casos de etiologia ambiental, reflete as condicoes medico-sanitarias da populacao, de cuja melhoria depende a profilaxia auditiva em nosso meio .