RESUMO
Positron Emission Tomography is a non-disruptive and high-sensitive digital imaging technique which allows to measure in-vivo and non invasively the changes of metabolic and transport mechanisms in plants. When it comes to the early assessment of stress-induced alterations of plant functions, plant PET has the potential of a major breakthrough. The development of dedicated plant PET systems faces a series of technological and experimental difficulties, which make conventional clinical and preclinical PET systems not fully suitable to agronomy. First, the functional and metabolic mechanisms of plants depend on environmental conditions, which can be controlled during the experiment if the scanner is transported into the growing chamber. Second, plants need to be imaged vertically, thus requiring a proper Field Of View. Third, the transverse Field of View needs to adapt to the different plant shapes, according to the species and the experimental protocols. In this paper, we perform a simulation study, proposing a novel design of dedicated plant PET scanners specifically conceived to address these agronomic issues. We estimate their expected sensitivity, count rate performance and spatial resolution, and we identify these specific features, which need to be investigated when realizing a plant PET scanner. Finally, we propose a novel approach to the measurement and verification of the performance of plant PET systems, including the design of dedicated plant phantoms, in order to provide a standard evaluation procedure for this emerging digital imaging agronomic technology.
RESUMO
OBJECTIVES: The aim of this study was to implement fasting therapy in an inpatient integrative medicine ward and to evaluate safety, acceptance, and effects on health-related outcomes and lifestyle adherence. DESIGN: This was a prospective observational study with consecutive inpatients over 3 [corrected] years. Inclusion and exclusion criteria for fasting therapy were checked by treating physicians and recommendations given. After receiving full information patients decided whether they would participate in fasting. Outcomes were assessed on admission, at discharge, and 3 and 6 months after discharge. SETTING: The study took place in an integrative medicine department of an academic teaching hospital. SUBJECTS: Subjects were newly admitted inpatients with chronic internal diseases and chronic pain syndromes, with lengths of hospital stay of >3 days. INTERVENTIONS: All patients received intensive integrative treatments including Mind/Body Medicine, acupuncture, nutritional/lifestyle education, and hydrotherapy. Fasting patients participated in a 7-day juice fast (intake <350 kcal/day) with accompanying bowel cleansing, 2 prefasting relief days, and 3 days with stepwise reintroduction of food. OUTCOME MEASURES: Outcomes were assessed based on rate of participation in fasting, severity of main complaint, quality of life (QOL, MOS 36-Item Short-Form Health Survey), safety, lifestyle adherence to recommendations given (relaxation, diet, exercise). RESULTS: Of 2121 patients with complete discharge questionnaires, 952 patients participated in fasting, 873 had a normocaloric vegetarian diet, and 296 patients had other diets and were excluded. Response rates were 71% and 56% at 3- and 6-month follow-up. The main disease-related complaint at discharge was significantly greater improved in fasters versus nonfasters (p < 0.01). Patient QOL increased significantly and comparably from baseline to discharge in both groups. Fasting was well tolerated and no serious fasting-related adverse effects were reported. In all, 743 (78%) of fasting patients reported improvement of their health through fasting. Descriptors of lifestyle adherence showed higher levels of related activities in the 3 and 6 months of follow-up. CONCLUSIONS: Fasting can safely and successfully be implemented in an inpatient integrative medicine concept and is perceived as a health-promoting method by the majority of patients. Potential effects on disease-related complaints and lifestyle adherence should be further evaluated in randomized trials.
