RESUMEN
A new prompt-gamma neutron activation analysis (PGNAA) setup has been designed for element determination in aqueous solution with a 300 mCi 241Am-Be neutron source and a 4in.×3in. (diameter×height) BGO detector, uncooled. A polyethylene cylindrical sample container approximately 40cm in outer radius and 80cm in height was used. To reduce the neutron dose in the detector, a block of 5cm thickness Li2CO3 was placed between the source and the detector for separation, but no gamma-blocker was used. By adjusting the position of the detector and optimizing the geometrical conditions of the setup, the element detection limit with a low activity neutron source was further improved. This methodology was checked by simulations with chlorine, mercury and cadmium determination and by experiments with chlorine determination in aqueous samples. The results show a good linear relationship between chlorine concentration and the count of its characteristic peak, and the detection limit of chlorine can reach 41.7mg/L with a collection time of 3600s for each spectrum. Additionally, a linear relationship was identified between mercury concentration and the count of its characteristic peak, but for cadmium, a non-linear relationship was observed in the simulations.
RESUMEN
Objective To study the anatomical basis and clinical causes of splenic infarction with an attempt to improve on the diagnosis and treatment of splenic infarction.Methods This study was conducted on 11 patients with splenic infarction seen in our hospital from December 2003 to September 2012,131 patients with a clinical diagnosis and treatment reported in the literature since 1999,and 25 adult cadavers showing the anatomy of the splenic arteries with an aim to find out the causes of splenic infarction.Results The clinical data showed that splenic infarction occurred more commonly in patients 60 years of age or older (73％ vs 27％,P＜0.05),and in males more than in females (62％ vs 38％,P＜0.05).The diagnosis was first made significantly more often by physicians than by surgeons 88/32 (79％ vs 21％,P＜0.05).The anatomical data showed that the majority of the splenic arteries in the 25 adult cadavers was curved.Conclusions The clinical manifestations of splenic infarction easily led to a misdiagnosis.Improvement in the diagnosis and treatment of splenic infarction would depend on the clinical awareness of this condition,the prothrombotic state detection and the implementation of timely and standardized treatment.