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The great interest in scintillating crystals, is related to their applications in the high energy physics, biomedicine and security. For this reason a complete characterization and understanding of their structural, optical and mechanical properties at the macroscopic level is necessary. We must give a complete theoretical characterization of the mechanics and optics of bulk prismatic single-crystal bodies in order to design experiments. This work shall deal solely with the theoretical description within the framework of linear theories.

The authors analysed the role of diffusion-weighted imaging (DWI) as an additional tool in magnetic resonance (MR) evaluation of prostate cancer.Forty-one patients with suspected prostate cancer underwent MR imaging (1.5 Tesla). A DWI sequence was added to the standard morphological protocol, with a maximum b value of 1,000 s/mm(2). Diffusion maps were obtained, and the apparent diffusion coefficient (ADC) was calculated by drawing a region of interest (ROI) over healthy tissue and areas suspicious for malignancy. Histology was considered the gold standard.The areas correctly classified by MR imaging (42/51) had a low signal intensity on T2-weighted imaging and low ADC value (0.99 ± 0.15 mm(2)/s; p0.01) compared with the healthy peripheral zone (PZ) (1.73 ± 0.27 mm(2)/s; p0.01). Nine areas classified as suspicious for malignancy on T2-weighted sequences showed high ADC (1.44 ± 0.06 mm(2)/s; p0.01) and were confirmed to be disease free by subsequent histological examination. The accuracy of morphofunctional MR imaging was 81.6% compared with 73.7% of the morphological analysis alone.The addition of DWI to the standard protocol increases the overall diagnostic performance of MR imaging in detecting prostatic cancer. Thus, DWI can help the clinician determine the most appropriate management strategy for the patient.

The magnetic response of granular superconducting YBCO samples with different grain sizes is reported. The analysis is carried out by measuring the low-frequency a.c. magnetic susceptibility as a function of the temperature with an applied magnetic field of amplitude ranging between 0.4 and 800 A/m. The observed magnetic behaviour is interpreted in terms of grain size and weak-links properties. The experimental results evidence the influence of the sample microstructure on the magnetic susceptibility. The intergranular and intragranular onset temperatures are compared with the critical temperature of the samples obtained by means of electrical-resistivity measurements. The temperature dependence of the intergranular critical current density is derived from the susceptibility data.