Abstract
In this Work a new configuration of a refractometric sensor for aqueous solutions based on the combination of surface plasmon resonance (SPR) with fibre Bragg gratings (FBG) is presented. Two FBGs are selected having reflection maxima in each side of the plasmon resonance peak. These FBGs enable a different processing scheme for the information provided by the SPR transducer. This improved interrogation method increases the sensitivity and resolution of the sensor compared with those obtained with the usual method of tracking the spectral transmittance minimum and makes the system performance independent of optical Source power fluctuations. The experimental results obtained with a double-layer uniform-waist tapered fibre show the feasibility of this approach and its applicability in SPR-based biosensors that Must face very exigent measuring conditions.

Abstract
We study the measurand-induced spectral shift of the photonic bandgap edge of a hollow-core photonic crystal fiber. The physical measurands considered are strain, temperature, curvature, and twist. A noticeable sensitivity to strain, temperature, and twist is observed, with a blueshift to increase strain and twist. An increase in temperature induces a redshift. On the other hand, curvature has no observable effect on the spectral position of the photonic bandgap edge. (C) 2010 Optical Society of America

Abstract
Hollow-core photonic crystal glass fibers have a high potential for gas sensing applications, since large light-gas interaction lengths can be effectively attained. Nevertheless, in order to enhance effective diffusion of gas into the hollow-core fiber, multi-coupling gaps are often needed, which raise coupling loss issues that must be evaluated prior to the development of practical systems. In this paper, a study on the coupling losses dependence on lateral and axial gap misalignment for single-mode fiber and two different types of hollow-core photonic crystal glass fibers is carried out. In addition, an experimental technique on splicing these glass fibers is also described and some results are presented showing that low splice losses can be obtained with high reproducibility. © (2010) Trans Tech Publications.

Abstract
A novel design for a miniature fiber Bragg grating-based temperature probe is presented. The sensor integrates a u-shaped lossless taper thus offering the advantages of a terminal temperature probe free from of strain cross-sensitivity and showing installation flexibility while enabling effective serial multiplexing. The experimental validation of the probe design is reported, being demonstrated lossless operation and effective elimination of strain cross-sensitivity up to 400 degrees C.

Abstract
sThe interrogation of a Fabry-Perot cavity through a dual wavelength Raman fiber laser is reported. The proposed sensing system is based on the use of a dual wavelength Raman fiber laser to generate two quadrature phase-shifted signals that allow the recovery of the temperature change sensed by the Fabry-Perot interferometric cavity. The dual wavelength Raman fiber laser is based on fiber Bragg gratings combined with a distributed mirror. The Fabry-Perot cavity is fabricated by splicing a short length of a suspended-core microstructured fiber to a single mode fiber. The use of this sensing system allows a passive and accurate interrogation of the temperature, while taking advantage of the Rayleigh scattering growth as a distributed mirror in the laser.

Abstract
As mesenchymal stem cells (MSCs) can differentiate into multiple cell types, the delivery of exogenous genes to this type of cell can be an important tool in tissue regeneration and engineering. However transfection of MSCs using nonviral gene delivery vectors is difficult, the development of more efficient and safe DNA vehicles being necessary. Moreover, specific transfection of MSCs may be required to avoid unwanted side effects in other tissues. In this study, a novel family of gene delivery vectors based on poly(amidoamine) (PAMAM) dendrimers functionalized with peptides displaying high affinity toward MSCs was prepared. The vectors were characterized with respect to their ability to neutralize, bind and compact plasmid DNA (pDNA). The complexes formed between the vectors and pDNA were analyzed concerning their size, zeta-potential, capacity of being internalized by cells and transfection efficiency. These new vectors exhibited low cytotoxicity, receptor-mediated gene delivery into MSCs and transfection efficiencies superior to those presented by native dendrimers and by partially degraded dendrimers.