External PIXE analysis of a handwritten Persian endowment deed belonging to the Timurid dynasty.

The external PIXE analysis yielded valuable information on the constituent elements of the paper, inks, and illumination of a handwritten document belonging to the Timurid dynasty (1485 A.D). The inks were found to be different in terms of their constituent matrix and trace elements. The applied inks are classified into three groups according to their relative concentration of Ca and Fe. The characteristic elements of the pigments suggested their origin. The chemical interaction of the green pigment, which influences the degradation of the paper, is discussed. The results aid the conservator in making treatment decisions. Moreover, the presented data allows the assignment of the provenance and a probable dating of similar samples via the chronology of the used pigments.

Feasibility of breast cancer screening by PIXE analysis of hair.

To reveal the role of key elements present in the hair of breast cancer patients on cancer development, the levels of a number of elements in scalp hair samples of 82 people including healthy individuals, people suffering from benign breast disease, and breast cancer patients were measured by PIXE analysis. Pellets of hair samples were prepared and bombarded by 2.2 MeV proton beam of a 3-MV Van de Graaff accelerator. The number of incident ions hitting the sample was indirectly measured using the RBS spectrum of a thin Ag film placed in the beam path. The concentrations of S, Cl, K, Ca, Fe, and Cu in the hair of healthy individuals were in agreement with those observed in the hair of hyperplasia and cancer patients within standard deviations. However, a lower average level of zinc was found in samples from hyperplasia and breast cancer patients. Strong positive correlations were found between iron and potassium as well as between calcium and potassium in the cancer patients. These results could be of significance in the screening for breast cancer.

Physical dose distribution due to multi-sliced kV X-ray beam in labeled tissue-like media: an experimental approach.

Radiotherapy remains a major modality of cancer therapy. Thanks to high flux and high brilliance of synchrotron-generated X-ray, laboratory research with planar microscopically thin X-ray beam promise exciting new opportunities for treatment of cancer. High tolerance of normal tissues at doses up to several hundred Gy in a single dose fraction and preferential damage of tumors at very high doses have been uniquely observed in animal models exposed to microbeams. The fact that beams as thick as 0.68 mm could retain a part of these effects, opens the possibility that the required beam can be produced by high power X-ray tubes besides a dedicated synchrotron. Fortunately, dose distribution due to kilovolt X-rays could be enhanced by the introduction of high-Z contrast agents to tissue-like media. In this work, dose deposition in a phantom--partially loaded with Au and I as contrast agents--irradiated by multi-sliced kV X-ray beam was experimentally investigated in the peak and valley regions both on the surface and in the depth of phantom. The results of experimental dosimetry using Gaf-chromic films were compared with corresponding Monte-Carlo simulation. Relative reduction in the deposited dose in the peak regions downstream the area containing contrast agents in comparison with the adjacent areas was experimentally observed.