NATURAL RADIOACTIVITY STUDIES OF PHOSPHATE FERTILIZERS APPLIED ON GREEK FARM SOILS USED FOR WHEAT CULTIVATION.

Naturally Occurring Radionuclide Materials (NORM) such as fertilizers, agricultural soils fertilized and wheat grain cultivated at those soils were studied regarding the radiation hazard to the public and workers. Activity of 238U, 226Ra, 232Th and 40K was measured hermitical sealing the marinelli beaker using the Stopaq FN 2100L material that prevent 222Rn escape from the baker. The phosphate fertilization of soil did not affect natural radioactivity in comparison with non-fertilized soils and also did not affect natural radioactivity of wheat grain cultivated since only 40K was measured. The high mean value of Dair 211 nGy h-1 for fertilizers compared to soils fertilized 53 nGy h-1 highlights the raising concern about radioprotection of workers occupied with tasks involving fertilizers. The maximum external dose rate 1.15 mSv y-1 calculated for truck drivers involved to transportation section is similar to annual external effective dose limit 1 mSv. Real concerns rise for workers in the fertilizers storage and supply department since the maximum dose rate estimated is 1.98 mSv y-1, while the mean value is 0.89 mSv y-1.

Diffusion Tensor Imaging in brain tumors: A study on gliomas and metastases.

PURPOSE: To explore the role of Diffusion Tensor Imaging in preoperative glioma grading, as well as in differentiation between gliomas and metastatic brain tumors. We measured diffusion tensor variables in enhancement and edema regions, which were compared between the different subject groups. MATERIALS AND METHODS: We performed DTI in 48 patients (11 Low Grade Gliomas, 27 High Grade Gliomas, 10 Single Metastatic brain tumors). We measured FA, λ1, λ2, λ3, ADC, Cl, Cp, Cs, RA, and VR in enhancing portions of tumors and edema regions. Additionally, ratios of enhancement to edema values were created for each variable. RESULTS: In peritumoral edema, Cl and RA were proven to be significantly different in pair-wise comparisons, in addition to ADC, Cp, Cs and VR in enhancement regions. Enhancement to edema values were significantly different as well. CONCLUSION: Diffusion tensor indices could be used for the differentiation between low and high grade gliomas, as well as for distinction between gliomas and metastases.

A review of physical and cognitive interventions in aging.

Maintaining a healthy brain is a critical factor for the quality of life of elderly individuals and the preservation of their independence. Challenging aging brains through cognitive training and physical exercises has shown to be effective against age-related cognitive decline and disease. But how effective are such training interventions? What is the optimal combination/strategy? Is there enough evidence from neuropsychological observations, animal studies, as well as, structural and functional neuroimaging investigations to interpret the underlying neurobiological mechanisms responsible for the observed neuroplasticity of the aging brain? This piece of work summarizes recent findings toward these questions, but also highlights the role of functional brain connectivity work, an emerging discipline for future research in healthy aging and the study of the underlying mechanisms across the life span. The ultimate aim is to conclude on recommended multimodal training, in light of contemporary trends in the design of exergaming interventions. The latter issue is discussed in conjunction with building up neuroscientific knowledge and envisaged future research challenges in mapping, understanding and training the aging brain.

Radiation exposure to patients and radiologists during interventional procedures.

Patients who undergo interventional radiological examinations and the medical doctors who perform them receive a noticeable radiation dose. Twenty-six angiographies and six angioplasties were included in the present study. They were classified as examinations of lower limbs, abdominal aorta and aortic arch/carotid artery. Thermoluminescent dosemeters (TLDs) were placed underneath and over the lead apron of the doctors at all of the 32 examinations as well as next to the eyes and over the thyroid of 22 patients. Dose area product (DAP) values, time duration and other parameters were registered. Patients' effective dose (ED) and doses to the various organs were calculated with the aid of ODS-60 software. The EDs were normalised to DAP measured in each procedure. Based on TLD measurements, the Niklason method was applied for the calculation of doctors' ED. The calculated ED by ODS-60 were in the range of 0.00-1.46, 2.63-49.32 and 0.07-45.12 mSv for the three groups, respectively, while E/DAP indices were 0.023, 0.310 and 0.105 mSv Gy(-1) cm(-2). Very good correlation was found between TLD measurements of the eye and the thyroid of the patients and the relative values calculated by ODS-60. The ED for the radiologists ranged from 0.4 to 47.0 µSv for all the procedures. Taking into consideration the annual number of examinations performed in the department, the estimated dose to the radiologists' eyes is considerably high, so wearing leaded glasses is recommended for the optimisation of the procedure.