Optically switchable gratings based on azo-dye-doped, polymer-dispersed liquid crystals.

We report a holographically fabricated, optically switchable grating using azo-dye-doped, polymer-dispersed liquid crystals (LCs). Our experiments show that upon photoirradiation, the diffraction of the grating was decreased significantly. We believe that this switching behavior is due to two factors--nematic-isotropic phase transition of LCs and thermal expansion of the grating structure.

Propagation of designer surface plasmons in structured conductor surfaces with parabolic gradient index.

In this work, we investigate the propagation of designer surface plasmons in planar perfect electric conductor structures that are subject to a parabolic graded-index distribution. A three-dimensional, fully vectorial finite-difference time-domain method was used to engineer a structure with a parabolic effective group index by modulating the dielectric constant of the structure's square holes. Using this structure in our simulations, the lateral confinement of propagating designer surface plasmons is demonstrated.

Increased incidence of urinary matrix metalloproteinases as predictors of disease in pediatric patients with inflammatory bowel disease.

Background: Matrix metalloproteinases (MMPs) are a family of metal-dependent enzymes responsible for the degradation and remodeling of extracellular matrix and basement membrane proteins that occurs during both normal physiologic activity and disease. It has been suggested that MMPs may also play a role in the pathogenesis of inflammatory bowel disease (IBD) by mediating mucosal breakdown in response to an enhanced inflammatory cascade. We previously demonstrated that elevated urinary MMP levels are independent predictors of disease status in cancer patients.

Fecal lactoferrin is a sensitive and specific marker of disease activity in children and young adults with inflammatory bowel disease.

Background And Aims: Fecal lactoferrin (FLA) is a neutrophil-derived surrogate marker of intestinal inflammation that is elevated in patients with inflammatory bowel disease. However, the correlation between FLA levels and serological markers of disease activity has not been previously reported, to our knowledge. In the present study we evaluated the ability of FLA levels to reflect disease activity in pediatric patients with inflammatory bowel disease.

Pediatric inflammatory bowel disease.

Purpose Of This Review: The prevalence of early-onset inflammatory bowel disease has been on the rise, with children and adolescents currently accounting for approximately 30% of all patients with this condition. Remarkable new advances in diagnostic modalities and therapy for adults with inflammatory bowel disease, and further information about the role of genetics in determining susceptibility to disease make the review of the recent literature in pediatric inflammatory bowel disease more timely than ever.

Recent Findings: In the area of genetics, new studies provide strong evidence for genetic susceptibility to disease, and match genotype with phenotypic presentation.