Development of alpha surface contamination monitor based on THGEM for contamination distribution

In cases of high radiation emergencies,we propose a surface contamination monitor(SCM)that can quickly measure and pinpoint the contamination distribution in the affected population.Thick gaseous electron multiplier(THGEM)has several advantages,including fast response time and good spatial resolution.Based on new THGEMs,a two-dimensional imaging detector was developed for alpha detection,with a position resolution greater than 3 mm.The detector design and test results are described in this paper.Fast radiation imaging SCMs,with a 40mm×40 mm sensitive area,are currently under development.

Analysis of the risk factors of rebleeding after endoscopic therapy in patients with non-variceal upper gastrointestinal bleeding

Objective:To explore the risk factors of rebleeding after endoscopic therapy in patients with non-variceal upper gastrointestinal bleeding (NVUGIB). Methods:A total of 254 patients with NVUGIB who were admitted in our hospital for endoscopic therapy were included in the study and divided into the rebleeding group (n=76) and non-bleeding group (n=178) according to whether there was rebleeding or not. The general materials and laboratory examination results in the two groups were recorded. The single factor and multiple factor logistic regression analysis was used to evaluate the risk factors of rebleeding after endoscopic therapy in patients with NVUGIB.Results:The single factor analysis showed that the comparison of heart rate after admission >100 times/min, upper gastrointestinal tumor bleeding, gradeⅠa bleeding, initial endoscopic therapy time>24 h, bleeding lesion diameter>2 cm, single endoscopic therapy method, amount of bleeding>800 mL, sequential PPIs insufficiency, and PT≥17 s between the two groups was statistically significant. The multiple factor logistic regression analysis showed that gradeⅠa bleeding, malignant tumor bleeding, bleeding lesion diameter>2 cm, single endoscopic therapy method, and sequential PPIs insufficiency were significantly positively correlated with the occurrence of rebleeding after endoscopic therapy in patients with NVUGIB.Conclusions: GradeⅠa bleeding, malignant tumor bleeding, bleeding lesion diameter>2 cm, sequential PPIs insufficiency, and PT≥17 s are the independent risk factors for developing rebleeding after endoscopic therapy in patients with NVUGIB.