Tracking moving objects through scattering media via speckle correlations.

Scattering can rapidly degrade our ability to form an optical image, to the point where only speckle-like patterns can be measured. Truly non-invasive imaging through a strongly scattering obstacle is difficult, and usually reliant on a computationally intensive numerical reconstruction. In this work we show that, by combining the cross-correlations of the measured speckle pattern at different times, it is possible to track a moving object with minimal computational effort and over a large field of view.

Calculating coherent light-wave propagation in large heterogeneous media.

Understanding the interaction of light with a highly scattering material is essential for optical microscopy of optically thick and heterogeneous biological tissues. Ensemble-averaged analytic solutions cannot provide more than general predictions for relatively simple cases. Yet, biological tissues contain chiral organic molecules and many of the cells' structures are birefringent, a property exploited by polarization microscopy for label-free imaging. Solving Maxwell's equations in such materials is a notoriously hard problem. Here we present an efficient method to determine the propagation of electro-magnetic waves in arbitrary anisotropic materials. We demonstrate how the algorithm enables large scale calculations of the scattered light field in complex birefringent materials, chiral media, and even materials with a negative refractive index.

Scattering lens resolves sub-100 nm structures with visible light.

The smallest structures that conventional lenses are able to optically resolve are of the order of 200 nm. We introduce a new type of lens that exploits multiple scattering of light to generate a scanning nanosized optical focus. With an experimental realization of this lens in gallium phosphide we imaged gold nanoparticles at 97 nm optical resolution. Our work is the first lens that provides a resolution better than 100 nm at visible wavelengths.

Observation of resonant behavior in the energy velocity of diffused light.

In this Letter we demonstrate Mie resonances mediated transport of light in randomly arranged, monodisperse dielectric spheres packed at high filling fractions. By means of both static and dynamic optical experiments we show resonant behavior in the key transport parameters and, in particular, we find that the energy transport velocity, which is lower than the group velocity, also displays a resonant behavior.

Wave transport in random systems: multiple resonance character of necklace modes and their statistical behavior.

We present the experimental observation of multiple resonance transport of light waves, due to necklace states, in disordered one-dimensional systems. Transmission phase measurements allow us to identify these states unambiguously and investigate their statistical properties. A theoretical model is developed to describe the resonance statistics and the frequency dependance of the localization length.

Hallazgos ultrasonograficos en la gastroenteriris eosinofilica / Ultrasonographic findings in eosinophilic gastroenteritis

We evaluated radiologic and ultrasonographic findings in 2 patients with eosinophilic gastroenteritis with gastrointestinal afectation and their tratment results.

Hallazgos ultrasonograficos en la gastroenteriris eosinofilica / Ultrasonographic findings in eosinophilic gastroenteritis

We evaluated radiologic and ultrasonographic findings in 2 patients with eosinophilic gastroenteritis with gastrointestinal afectation and their tratment results. (AU)

[Hepatobiliary ascaridiasis in childhood: echographic diagnosis]. / L'ascaridiasi epatobiliare nell'infanzia: diagnostica ecografica.

Ascaris lumbricoides infestation in the liver and biliary tract causes various clinical manifestations due to the migration of larvae and adult organisms. Parasites in the bile ducts cause obstruction and such complications as cholecystitis, cholangitis and liver abscesses. We report the US findings of biliary ascaridiasis as observed in a series of 13 children over a 3-year period. The patients (6 females and 7 males) presented hepatosplenomegaly, abdominal distension, right subcostal pain; 3 of 13 exhibited subicteric features and fever. The US features of Ascaris lumbricoides infestation are: hyperechoic linear images due to parasites within the dilated bile ducts, target images; mobile hyperechoic linear images within the gallbladder; intrahepatic abscesses with different features and sizes. Microscopic sections of hepatic tissue show inflammatory infiltration around the Ascaris eggs. Emergency surgery is sometimes to be performed. The value of US, as we assessed it, has been already stressed by other authors.