Detection of lead in Zea mays by dual‐energy X‐ray microtomography at the SYRMEP beamline of the ELETTRA synchrotron and by atomic absorption spectroscopy

This study is related to the application of the X‐ray dual‐energy microradiography technique together with the atomic absorption spectroscopy (AAS) for the detection of lead on Zea mays stem, ear, root, and leaf samples. To highlight the places with lead intake, the planar radiographs taken with monochromatic X‐ray radiation in absorption regime with photon energy below and above the absorption edge of a given chemical element, respectively, are analyzed and processed. To recognize the biological structures involved in the intake, the dual‐energy images with the lead signal have been compared with the optical images of the same Z. mays stem. The ear, stem, root, and leaf samples have also been analyzed with the AAS technique to measure the exact amount of the hyperaccumulated lead. The AAS measurement revealed that the highest intake occurred in the roots while the lowest in the maize ears and in the leaf. It seems there is a particular mechanism that protects the seeds and the leaves in the intake process. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc. This article was published online on 1 December 2009. An error was subsequently identified. This notice is included in the online and print version to indicate that both have been corrected 19 February 2010.     

Monitoring of the heavy-metal hyperaccumulation in vegetal tissues by X-ray radiography and by femto-second laser induced breakdown spectroscopy

This article reports on the utilization of X-ray microradiography and laser induced breakdown spectroscopy (LIBS) techniques for investigation of the metal accumulation in different part of leaf samples. The potential of the LIBS-analysis for finding the proper plant species for phytoremediation is compared with the results of microradiography measurements at the HERCULES source at ENEA, Rome (Italy) and X-ray microradiography experiments at the ELETTRA Synchrotron, Trieste (Italy).     

A new classification of varicose veins to compare various surgical strategies

Considering the presupposition that chronic venous insufficiency (CVI) and varicose veins classifications are extremely difficult, and that none of those presently in use are sufficiently complete, the authors propose the classification of the haemodynamic venous disease (HVD) and of the varicose veins from the clinical, anatomotopographical, etiopathogenetical and haemodynamical point-of-view. This type of classification allows us to closely follow the disease's evolution, to distinguish the benign forms from the more aggressive ones, and to evaluate the results of the medical, surgical and schlerotherapical treatments, from the efficiently, functional, instrumental and aesthetically point-of-view.     

Evaluation of microstructural properties of coffee beans by synchrotron X-ray microtomography: a methodological approach

Synchrotron radiation microtomography was used as a nondestructive imaging technique to investigate the microstructural properties of green and roasted coffee beans. After image acquisition, 2D images have been reconstructed and 3D images of the beans have been then obtained. Qualitative and quantitative analysis of the images allow to fully characterize the morphological and structural features of the coffee beans. Roasting causes meaningful changes in the microstructure of the coffee bean tissue with the development in the entire bean of a porous structure with pores of different shape and size depending on the zone of the bean and cracks occurring mainly in the more external regions and between parenchyma and mucilage. The highly contrasted X-ray images have been analyzed to determine the pore size and its distribution in different regions of the coffee beans by selecting Volume-of-Interest (VoI). The use of phase-contrast hard X-rays imaging techniques represents an interesting tool of investigation of the internal structure, morphology, as well as the quality of whole coffee beans. Moreover, the high potentiality of 3D X-ray imaging and the approach used in this study could be applied in understanding the effects of roasting process conditions on the evolution of microstructural properties of the bean that may affect the stability as well the grinding and brewing performances. PRACTICAL APPLICATION: Synchrotron radiation microtomography is an elegant nondestructive imaging technique to investigate the microstructural properties of porous cellular matrices like the green and roasted coffee beans. The quantitative analysis of the resulting 2D and 3D images allows a more comprehensive and objective characterization of the sample under investigation as a whole or of extracted Volumes-of-Interest in the bean. This imaging technique could have a major role in understanding the effects of roasting process conditions on the microstructural properties of the bean.     

Seismically induced slope instability maps validated at an urban scale by site numerical simulations

Maps of seismically induced instability at the urban scale can be drawn by means of geographic information system (GIS) tools that integrate different information layers such as (1) a landslide inventory; (2) a digital elevation model (DEM); (3) geo-hydro-mechanical site characterization, and (4) measured peaks or integral parameters at seismic stations. These maps are used to guide planning activities and emergency actions, but their main limitation is typically the lack of reliable analyses or calibrations. In this study, a possible method is proposed to control and increase the overall reliability of an hazard scenario map of earthquake-induced slope instability. The procedure can be summarized in the following steps: (1) GIS tools are used to describe the spatial distribution of the hydro-mechanical properties of the surface lithologies; (2) seismically induced instability maps of permanent displacements are drawn from the preceding information layers combined with seismic parameters spatially propagated by means of spatial interpolation tools; (3) point dynamic and stability numerical analyses are carried out by means of a commercial finite element method (FEM) code (e.g., Geostudio2004) to calculate permanent displacement by the Newmark’s method along representative cross-sections. The numerical analyses are used to calculate a “depth factor”, which can be considered as the contribution of the seismic local amplification to the surface calculations addressed by GIS tools. The ratio between the results drawn from the two approaches (GIS-based and FEM-based implementing Newmark's method) can be assumed as a scale factor related to the in-depth site-specific geo-lithotechnical characters to be addeded to GIS maps.     

Low-dose phase contrast x-ray medical imaging

Phase contrast x-ray imaging is a powerful technique for the detection of low-contrast details in weakly absorbing objects. This method is of possible relevance in the field of diagnostic radiology. In fact, imaging low-contrast details within soft tissue does not give satisfactory results in conventional x-ray absorption radiology, mammography being a typical example. Nevertheless, up to now all applications of the phase contrast technique, carried out on thin samples, have required radiation doses substantially higher than those delivered in conventional radiological examinations. To demonstrate the applicability of the method to mammography we produced phase contrast images of objects a few centimetres thick while delivering radiation doses lower than or comparable to doses needed in standard mammographic examinations (typically approximately 1 mGy mean glandular dose (MGD)). We show images of a custom mammographic phantom and of two specimens of human breast tissue obtained at the SYRMEP bending magnet beamline at Elettra, the Trieste synchrotron radiation facility. The introduction of an intensifier screen enabled us to obtain phase contrast images of these thick samples with radiation doses comparable to those used in mammography. Low absorbing details such as 50 microm thick nylon wires or thin calcium deposits (approximately 50 microm) within breast tissue, invisible with conventional techniques, are detected by means of the proposed method. We also find that the use of a bending magnet radiation source relaxes the previously reported requirements on source size for phase contrast imaging. Finally, the consistency of the results has been checked by theoretical simulations carried out for the purposes of this experiment.     

Observations on the vertebro-basilar system studied by ultrasound

Vertebro-basilar circulation is complex because conditioned by several factors. Ultrasounds allow the study of many of its aspect, both hemodynamic and anatomical. Data were obtained from the examination of 50,000 patients over 25 years, of which the last 1,000 patients were examined by means of transcranial Doppler, duplex scanner color and power. 40% of these patients were found normal, 20% only had arterial thickening, 26% various types of stenosis, 10.6% subclavian steal, 14% short vertigo. The basilar artery (BA) flow (230 ml/min +/- 40) is similar to that of the internal carotid (245 ml/min +/- 50). In elderly patients, the absence of a posterior communicating artery (28%) or of both arteries (13%) is more frequent than the absence of the anterior communicating artery (7%). In normal patients decubitus variations do not modify the BA flow. In patients with vertigo due to decubitus variations, BA flow velocity increases from 20% to 40% during vertigo. Subclavian steal completely modifies the hemodynamics of vertebral arteries, while in the BA it can vary in part or completely. In conclusion, vertebral hemodynamics is different from BA hemodynamics. BA must be considered as one side of the Willis' polygon because it is an anastomosis between the vertebral arteries and is a "hemodynamic damper" between intracranial and extracranial circulation.