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The aim of the study was to evaluate effects of shoulder overuse in elite symptomatic or asymptomatic gymnasts.This was a university-based sport traumatology research, a cohort study, with a control group comparison. Patients included were: 21 elite male gymnasts performing in the Italian National team for at least 10 years and a control group of 10 patients (20 shoulders) of the same age and sex, randomly selected among a healthy non-athletic population who underwent shoulder MRI. Magnetic resonance imaging without contrast were performed to all participants and clinical findings were summarized. Two experienced musculoskeletal radiologists interpreted each MRI scan for multiple variables (rotator cuff tendons, labral signal, capsule), including type of measurements performed on soft tissues (muscles, tendons) to assess global modifications of the shoulders.Signal abnormalities were detected in 36/36 (100%) gymnasts' shoulders, and in 4/20 (20%) of the controls. Sixteen of 36 (44.4%) shoulders had findings consistent with SLAP tears, bilateral in four patients; anteroinferior labrum lesions were identified in 10/36 (27.7%) shoulders, as compared with none (0%) in the controls. Eight of 36 (22%) shoulders had findings consistent with partial- or full-thickness tears of the rotator cuff as compared with none (0%) of the controls. Increased thickness of rotator cuff tendons and hypertrophy of rotator cuff muscles and deltoid muscles were recorded: such reports were symmetrical between dominant and non dominant arms, and increased when compared to controls.Gymnasts' shoulders are significantly different from those of the general population. MRI findings, especially SLAP tears, and hypertrophy are symmetrical. SLAP tears seem to be responsible of most early retirement.

We performed second harmonic generation (SHG) measurements in the noncollinear configuration scheme on BR film. The SHG signal which becomes selectively addressed by choosing the appropriate polarization state for the fundamental beam reveals chiral properties of the sample.

We present a study on the design, growth and optical characterization of a GaN/AlGaN microcavity for the enhancement of second order non linear effects. The proposed system exploits the high second order nonlinear optical response of GaN due to the non centrosymmetric crystalline structure of this material. It consists of a GaN cavity embedded between two GaN/AlGaN Distributed Bragg Reflectors designed for a reference mode coincident with a second harmonic field generated in the near UV region (~ 400 nm). Critical issues for this target are the crystalline quality of the material, together with sharp and abrupt interfaces among the multi-stacked layers. A detailed investigation on the growth evolution of GaN and AlGaN epilayers in such a configuration is reported, with the aim to obtain high quality factor in the desiderated spectral range. Non linear second harmonic generation experiments have been performed and the results were compared with bulk GaN sample, highlighting the effect of the microcavity on the non linear optical response of this material.

In this paper we present a reliable process to fabricate GaN/AlGaN one dimensional photonic crystal (1D-PhC) microcavities with nonlinear optical properties. We used a heterostructure with a GaN layer embedded between two Distributed Bragg Reflectors consisting of AlGaN/GaN multilayers, on sapphire substrate, designed to generate a {\lambda}= 800 nm frequency down-converted signal (\chi^(2) effect) from an incident pump signal at {\lambda}= 400 nm. The heterostructure was epitaxially grown by metal organic chemical vapour deposition (MOCVD) and integrates a properly designed 1D-PhC grating, which amplifies the signal by exploiting the double effect of cavity resonance and non linear GaN enhancement. The integrated 1D-PhC microcavity was fabricate combing a high resolution e-beam writing with a deep etching technique. For the pattern transfer we used ~ 170 nm layer Cr metal etch mask obtained by means of high quality lift-off technique based on the use of bi-layer resist (PMMA/MMA). At the same time, plasma conditions have been optimized in order to achieve deeply etched structures (depth over 1 micron) with a good verticality of the sidewalls (very close to 90{\deg}). Gratings with well controlled sizes (periods of 150 nm, 230 nm and 400 nm respectively) were achieved after the pattern is transferred to the GaN/AlGaN heterostructure., Comment: presented at Photonics Europe -SPIE 2010

We report on a strong and tunable magnetic optical nonlinear response of Bacteriorhodopsin (BR) under "off resonance" femtosecond (fs) pulse excitation, by detecting the polarization map of the noncollinear second harmonic signal of an oriented BR film, as a function of the input beam power. BR is a light-driven proton pump with a unique photochemistry initiated by the all trans retinal chromophore embedded in the protein. An elegant application of this photonic molecular machine has been recently found in the new area of optogenetics, where genetic expression of BR in brain cells conferred a light responsivity to the cells enabling thus specific stimulation of neurons. The observed strong tunable magnetic nonlinear response of BR might trigger promising applications in the emerging area of pairing optogenetics and functional magnetic resonance imaging susceptible to provide an unprecedented complete functional mapping of neural circuits.

We have investigated and experimentally proved the robustness of the Bloch vector for one-dimensional, nonlinear, finite, dissipative systems. The case studied is the second harmonic generation from metallo-dielectric filters. Nowadays metallic based nanostructures play a fundamental role in nonlinear nano-photonics and nano-plasmonics. Our results clearly suggest that even in these forefront fields the Bloch vector continues to play an essential role.