Ultrawide-range radiation detection based on dynamic identification and analysis of the response of a monolithic active pixel sensor.

In this paper, we present an ultrawide-range radiation detection method based on dynamic recognition and analysis of the response signal of a monolithic active pixel sensor (MAPS). Our analysis of the MAPS response mechanism determined that adaptive adjustment of the sensor's integral time is key to quantification of ionizing radiation in an ultrawide range. We also determined that different data processing methods are required for accurate quantification of high and low radiation dose rates. The results of experiments conducted after calibration demonstrate that our technique is capable of radiation detection across five orders of magnitude (ranging from milligrays per hour to hundreds of grays per hour), with errors of less than 5%. Chip-based nuclear radiation detection can be realized using our technique, enabling MAPS to be used as a supplement to traditional detectors in characterization of unknown and complex radiation environments.

Identification and Analysis of Apigenin Metabolites in Rats / 中国药房

OBJECTIVE:To clarify the bio-transformation form of apigenin in rats,and to speculate its possible metabolic path-way. METHODS:Rats were divided into blank group and medication group(apigenin 200 mg/kg,i.g.)with 6 rats in each group. Urine and feces samples were collected from 2 groups within 24 h after medication. After corresponding treatment,urine and feces samples were analyzed and detected by HPLC-IT-TOF-MSn under cation mode and anion mode. RESULTS:9 metabolites were iden-tified in urine sample of rats from medication group,i.e. 2,3-double bond reduction of apigenin (U1,U7,U8,U9),bonded to glucuronic acid(U2,U3,U4),bonded to sulphate(U5,U6,U7,U8,U9)and bonded to glucose(U2). 4 metabolites were iden-tified in feces sample of rats from medication group,i.e. 2,3-double bond reduction of apigenin(F3),bonded to glucuronic acid (F2)and bonded to glucose(F1). CONCLUSIONS:Apigenin mainly exists in form of prototype drug in rats. The reduction hap-pens on 2,3-double bond by the intestinal bacteria,and the product of apigenin boned to glucuronic acid or glucose can be formed when excreting in intestinal tract and rats in vivo,while the product of apigenin boned to sulphate can be formed only when excret-ing in rats in vivo.