Asymmetric masks for laboratory-based X-ray phase-contrast imaging with edge illumination

We report on an asymmetric mask concept that enables X-ray phase-contrast imaging without requiring any movement in the system during data acquisition. The method is compatible with laboratory equipment, namely a commercial detector and a rotating anode tube. The only motion required is that of the object under investigation which is scanned through the imaging system. Two proof-of-principle optical elements were designed, fabricated and experimentally tested. Quantitative measurements on samples of known shape and composition were compared to theory with good agreement. The method is capable of measuring the attenuation, refraction and (ultra-small-angle) X-ray scattering, does not have coherence requirements and naturally adapts to all those situations in which the X-ray image is obtained by scanning a sample through the imaging system

X-ray phase-contrast microtomography of soft tissues using a compact laboratory system with two-directional sensitivity

X-ray microtomography is a nondestructive, three-dimensional inspection technique applied across a vast range of fields and disciplines, ranging from research to industrial, encompassing engineering, biology, and medical research. Phase-contrast imaging extends the domain of application of x-ray microtomography to classes of samples that exhibit weak attenuation, thus appearing with poor contrast in standard x-ray imaging. Notable examples are low-atomic-number materials, like carbon-fiber composites, soft matter, and biological soft tissues. We report on a compact and cost-effective system for x-ray phase-contrast microtomography. The system features high sensitivity to phase gradients and high resolution, requires a low-power sealed x-ray tube, a single optical element, and fits in a small footprint. It is compatible with standard x-ray detector technologies: in our experiments, we have observed that single-photon counting offered higher angular sensitivity, whereas flat panels provided a larger field of view. The system is benchmarked against known-material phantoms, and its potential for soft-tissue three-dimensional imaging is demonstrated on small-animal organs: a piglet esophagus and a rat heart. We believe that the simplicity of the setup we are proposing, combined with its robustness and sensitivity, will facilitate accessing quantitative x-ray phase-contrast microtomography as a research tool across disciplines, including tissue engineering, materials science, and nondestructive testing in general

Fusarium oxysporum f.sp. radicis-lycopersici induces distinct transcriptome reprogramming in resistant and susceptible isogenic tomato lines

8openInternationalItalian coauthor/editorBackground: Fusarium oxysporum f.sp. radicis-lycopersici (FORL) is one of the most destructive necrotrophic pathogens affecting tomato crops, causing considerable field and greenhouse yield losses. Despite such major economic impact, little is known about the molecular mechanisms regulating Fusarium oxysporum f.sp. radicis-lycopersici resistance in tomato. Results: A transcriptomic experiment was carried out in order to investigate the main mechanisms of FORL response in resistant and susceptible isogenic tomato lines. Microarray analysis at 15 DPI (days post inoculum) revealed a distinct gene expression pattern between the two genotypes in the inoculated vs non-inoculated conditions. A model of plant response both for compatible and incompatible reactions was proposed. In particular, in the incompatible interaction an activation of defense genes related to secondary metabolite production and tryptophan metabolism was observed. Moreover, maintenance of the cell osmotic potential after the FORL challenging was mediated by a dehydrationinduced protein. As for the compatible interaction, activation of an oxidative burst mediated by peroxidases and a cytochrome monooxygenase induced cell degeneration and necrosis. Conclusions: Our work allowed comprehensive understanding of the molecular basis of the tomato-FORL interaction. The result obtained emphasizes a different transcriptional reaction between the resistant and the susceptible genotype to the FORL challenge. Our findings could lead to the improvement in disease control strategies.openManzo, D.; Ferriello, F.; Puopolo, G.; Zoina, A.; D’Esposito, D.; Tardella, L.; Ferrarini, A.; Ercolano, M.R.Manzo, D.; Ferriello, F.; Puopolo, G.; Zoina, A.; D’Esposito, D.; Tardella, L.; Ferrarini, A.; Ercolano, M.R

Micropropagación de caña de azúcar en Ecuador

Ecuador is a country where sugar cane (Saccharum spp. hybrid) exceeds 82 000 ha for sugar production. The Research Center of the National Union of sugar cane farming in Ecuador (UNCE) is plotted as objective to obtain plants of different varieties by micropropagation, to multiply quickly and efficiently, genotypes with excellent performance under the conditions of production and result in a high quality certified seed and plant genetics. It were used as initial explants shoots, of the varieties ‘Cenicaña 1985-1992’ (CC85-92), ‘Ragnar’, ‘BJ 7046’, ‘CR 74-250’, ‘SP70-1143’, ‘PCG 12 745’ ‘RD7511’ and ‘Mexico 73-0523’. The obtained seedlings were multiplied, rooted and acclimatised. Then be planted in areas where sugar cane is grown in the country. In the case of the variety ‘Ragnar’ planted an area of approximately 0.3 ha, which was determined yield (ton/ha). Micropropagation of selected varieties allowed to obtain 268 600 plants in 12 months. It was found that the varieties showed differences in their rates of multiplication. The survival of plants in the acclimatization phase was higher than 88.0%. The harvest for the experimental plot planted with the variety ‘Ragnar’ contributed 55 tons. This equates to an output of 183 ton/ha. These values are much higher than the national average. The results confirmed the non-appearance of diseased plants or Scalding RSD. These results are one of the first reports for Ecuador from the use of biotechnological methods, being the pioneers in the mass propagation of sugarcane plants.Keywords: mass propagation, Saccharum spp. hybrid, seedEcuador es un país donde la caña de azúcar (Saccharum spp. híbrido) supera las 82 000 ha dedicadas a la producción de azúcar. El Centro de Investigación de la Unión Nacional de Cañicultores del Ecuador (UNCE) se trazó como objetivo obtener plantas de diferentes variedades por micropropagación, que permitiera multiplicar de manera rápida y eficaz, genotipos con excelente comportamiento en las condiciones de producción y que resultaran en una semilla certificada de alta calidad genética y fitosanitaria. Se emplearon como explantes iniciales meristemos apicales de las variedades ‘CeniCaña 85-92’ (CC85-92),‘Ragnar’, ‘BJ 7046’, ‘CR 74-250’, ‘SP70-1143’, ‘PCG 12745’, ‘RD7511’ y ‘México 73-0523’. Las plántulas obtenidas se multiplicaron, enraizaron y aclimatizaron. Posteriormente, se sembraron en áreas donde se cultiva caña de azúcar en el país. En el caso de la variedad ‘Ragnar’ se plantó un área de aproximadamente 0.3 ha, en la cual se determinó el rendimiento (t/ha). La micropropagación de las variedades seleccionadas permitió obtener 268 600 plantas en 12 meses. Se comprobó que las variedades mostraron diferencias en sus coeficientes de multiplicación. La supervivencia de las plantas en la fase de aclimatización fue superior al 88.0%. La cosecha correspondiente a la parcela experimental sembrada con la variedad ‘Ragnar’ aportó 55 t. esto equivale a una producción de 183 t/ha. Estos valores son muy superiores a la media nacional. Los resultados confirmaron la no aparición de plantas enfermas por RSD o Escaldadura. Estos resultados constituyen uno de los primeros informes para Ecuador de la utilización de métodos biotecnológicos, siendo los pioneros en la propagación masiva de plantas de caña de azúcar.Palabras clave: propagación masiva, Saccharum spp. híbrido, semill

Ascending Aortic Aneurysm in Angiotensin II–Infused Mice: Formation, Progression, and the Role of Focal Dissections

Objective To understand the anatomy and physiology of ascending aortic aneurysms in angiotensin II-infused ApoE(-/-) mice. Approach and Results We combined an extensive in vivo imaging protocol (high-frequency ultrasound and contrast-enhanced microcomputed tomography at baseline and after 3, 10, 18, and 28 days of angiotensin II infusion) with synchrotron-based ultrahigh resolution ex vivo imaging (phase contrast X-ray tomographic microscopy) in n=47 angiotensin II-infused mice and 6 controls. Aortic regurgitation increased significantly over time, as did the luminal volume of the ascending aorta. In the samples that were scanned ex vivo, we observed one or several focal dissections, with the largest located in the outer convex aspect of the ascending aorta. The volume of the dissections moderately correlated to the volume of the aneurysm as measured in vivo (r(2)=0.46). After 3 days of angiotensin II infusion, we found an interlaminar hematoma in 7/12 animals, which could be linked to an intimal tear. There was also a significant increase in single laminar ruptures, which may have facilitated a progressive enlargement of the focal dissections over time. At later time points, the hematoma was resorbed and the medial and adventitial thickness increased. Fatal transmural dissection occurred in 8/47 mice at an early stage of the disease, before adventita remodeling. Conclusions We visualized and quantified the dissections that lead to ascending aortic aneurysms in angiotensin II-infused mice and provided unique insight into the temporal evolution of these lesions

X-ray dark-field tomography using edge-illumination

X-ray dark-field imaging is used to visualize the ultra-small angle x-ray scattering signal that originates from sub-resolution density fluctuations within the sample microstructure. Dark-field tomography using the edge-illumination x-ray imaging system is presented as a tool for measuring this scattering signal in a sample in three dimensions. Its applicability to different fields is shown through example images of a multi-material phantom, a tissue-engineered esophagus, a pouch cell battery and a short-fiber reinforced composite material. The multichannel contrast available in edge-illumination helps with material identification, with high contrast at boundaries enhancing dark-field reconstructions