A hybrid radiation detector for simultaneous spatial and temporal dosimetry

In this feasibility study an organic plastic scintillator is calibrated against ionisation chamber measurements and then embedded in a polymer gel dosimeter to obtain a quasi-4D experimental measurement of a radiation field. This hybrid dosimeter was irradiated with a linear accelerator, with temporal measurements of the dose rate being acquired by the scintillator and spatial measurements acquired with the gel dosimeter. The detectors employed in this work are radiologically equivalent; and we show that neither detector perturbs the intensity of the radiation field of the other. By employing these detectors in concert, spatial and temporal variations in the radiation intensity can now be detected and gel dosimeters can be calibrated for absolute dose from a single irradiation

Cholesterol reducing and bile-acid binding properties of taioba (Xanthosoma sagittifolium) leaf in rats fed a high-fat diet

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The consumption of vegetables has been correlated with reduced risk of chronic non-communicable diseases due to the high fiber content and bioactive compounds found in vegetables. The arrowleaf elephant ear (Xanthosoma sagittifolium), which is known in Brazil as taioba, is a common plant in tropical America. Although its leafy portion possesses a high nutritional value, it is not widely consumed and has not been well studied. This study assessed the effect of lyophilised taioba leaf (LTL) as a hypolipidemic and prebiotic agent. Thirty-two Wistar rats were assigned to four groups: group 1 was fed a high-fat diet containing 3.67% (w/w) cellulose (low cellulose - LCEL); group 2 received a high-fat diet supplemented with 10% (w/w) cellulose (CEL); group 3 received a high-fat diet supplemented with 10% (w/w) inulin (INU); and group 4 was fed a high-fat diet supplemented with 28.4% LTL (TAI) to provide 10% (w/w) taioba fiber. The groups were fed their respective diets for 4 weeks. The addition of LTL to the diet resulted in reduced weight gain, reduced liver fat, and increased fecal mass and lipid, in addition to higher fecal short chain fatty acid and bile salt concentrations, compared to the LCEL group. Additionally, only the TAI group exhibited a lower serum cholesterol concentration and a higher body ash content (p<0.05) than the LCEL group. Both the high bile salt binding capacity and high fermentability of LTL suggest that this plant may have a protective effect against cardiovascular diseases and bowel cancer. (C) 2013 Elsevier Ltd. All rights reserved.512886891Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Taioba (Xanthosoma sagittifolium) Leaves: Nutrient Composition and Physiological Effects on Healthy Rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Several studies have shown that fruits and vegetables contribute to protect against degenerative pathologies such as cardiovascular diseases, diabetes, and cancer, mainly due to the presence of dietary fiber (DF) and polyphenols. Taioba (Xanthosoma sagittifolium) is an edible aroid widely grown in many parts of Africa, America, and Asia. The tubers portions of taioba are widely consumed; however, the leafy portions are generally discarded, despite their high nutritive value. In this study, we have partly characterized the DF of lyophiized taioba leaf (LTL), and assessed the possible protective effects on biochemical parameters and on bile acid (BA) production in colon and cecum, when fed to healthy rats for 4 wk. Forty-five Wistar rats were assigned to either of 5 groups: group 1 received AIN 93G diet (CG: Control); group 2 received AIN 93G containing 2.5% of cellulose + 2.5% inulin (CEIN_5%); group 3 received AIN 93G containing 2.5% of cellulose + 2.5% taioba fiber (CETA_5%); group 4 received AIN 93G containing 5% cellulose + 2.5% taioba fiber (CETA_7.5%); group 5 received AIN 93G containing 5% cellulose + 2.5% of inulin (CEIN_7.5%). LTL showed high contents of total fiber, predominantly comprising insoluble DF with glucose as the major monomer. Rats receiving LTL had increased fecal mass and fat excretion, and improved BA profiles by diminishing the proportion of secondary acids, thus suggesting that consumption of taioba leaf may have the property of lowering the risk of colon cancer. Practical Application The present study gives new and valuable information about nutrient composition and some of the in vivo functional properties of taioba leaves. The results of this research showed that the taioba leaf contributed to the removal of dietary fat, and reduced the concentrations of colon and cecum secondary bile acids, which are associated with colon cancer. The positive effects may be related to a synergy between the fiber and other bioactive substances.7812H1929H1934Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq