NLO Polymers and Optical Waveguides based Thereon

NLO Polymers and Optical Waveguides based Thereo

Percolative Small-polarons conduction regime in Ce1-xGdxO2-x/2, probed by the EPR spectral intensity of Gd3

EPR analysis is carried out with Ce1 xGdxO(4 x)/2 (x=0.1; 0.2) nanopowders aimingat obtaininginformation about their oxidation and reduction properties. The EPR spectrum of these systems is composed of a single feature. The first derivative peak-topeak spectral intensity decreases at higher temperatures, but this trend deviates from that of Curie\u2019s law with the x=0.1 sample, at difference with the x=0.2 sample. This unexpected result is related to oxygen deficiency, due to gas\u2013solid equilibrium, present in the former sample only. As a consequence, some Ce3+ ions would form providingit with conduction electrons propagating as small polarons in a percolative way. This would result in a thinner skin depth at higher temperatures, able to explain the deviation of the spectral intensity from its expected value. Indeed, this deviation from Curie\u2019s law is reduced or disappears at all after thermal treatment of the x=0.1 sample with O2

PHOTOCHROMIC OPTICAL WAVEGUIDES AND METHOD FOR THE PREPARATION THEREOF

The present invention relates to an optical waveguide based on a photochromic diarylethene polymer dispersed in a polymeric matrix, and to a method for preparing such waveguide

Structural effects on third order nonlinear optical properties of PPV derivatives

The third order nonlinear optical properties of a series of poly(p-phenylenevinylene) (PPV) derivatives were measured on thin film by the Third Harmonic Generation technique, in the infrared range between 1.2 mum and 2.1 mum useful for optical telecommunications applications, in order to study the effect of various structural parameters on the third order nonlinear optical coefficient chi((3))

The potential of electromyography, diagnostic transcranial magnetic stimulation, and multiparametric magnetic resonance imaging in the combinatory assessment of facial nerve disorders: a literature review and clinical case series

Facial neuropathy (FN) is a complex multicausal problem that, with a seemingly obvious clinical picture, might be challenging to diagnose. Up to 5% of FN cases could be caused by neoplastic or otogenic processes, necessitating an interdisciplinary approach to its treatment by various specialties and in some cases a surgical intervention. In addition, in the early stages of FN, it is difficult to predict its outcomes. Therefore, beyond usual neurological exam and widely used electromyography (EMG), other additional diagnostic tools are used to ensure extended diagnosis, including cancer awareness. In this paper we have analyzed the principles, role and value of computed tomography, magnetic resonance imaging (MRI), diagnostic transcranial magnetic stimulation combined with EMG, and ultrasound assessment with a high-frequency linear transducer in acute FN. We present our own clinical cases of pediatric patients with FN, who were assessed with EMG and multiparametric MRI including diffusion tensor imaging. These cases illustrate both the abnormalities found in the typical course of Bell's palsy, as well as the abnormalities in neoplasm-associated FN that clinically fully mimic the Bell's palsy. Based on the world experience in multiparametric MRI, including the use of extended protocols in the Pediatric Research and Clinical Center for Infectious Diseases, in case of suspected FN, the most important are high-resolution structural submillimeter sequences based on the gradient echo (SSFP) and diffusion tensor imaging (DTI). Measurement and assessment of fractional anisotropy at the motor nuclei of the facial nerves in the pons look promising for further research. The paper is the first to describe a modified combination diagnostic approach to Bell's palsy with the use of diagnostic transcranial magnetic stimulation with round coil, supramaximal stimulation with identification of the motor evoked response threshold (minimal inducer power to register a reproducible evoked motor response of 50-100 mV in amplitude) in the occipito-parietal area of the ipsilateral muscle

Propylene polymerization with catalysts containing divalent titanium.

The behaviour in propylene polymerization of divalent titanium compounds, both as such and supported on activated MgCl2, has been studied . The Ti-arene complexes were active both in the presence and in the absence of hydrogen, in contrast to earlier reports