25 research outputs found
Worms and the Treatment of Inflammatory Bowel Disease: Are Molecules the Answer?
The lack of exposure to helminth infections, as a result of improved living
standards and medical conditions, may have contributed to the increased incidence of
IBD in the developed world. Epidemiological, experimental, and clinical data sustain the
idea that helminths could provide protection against IBD. Studies investigating the underlying
mechanisms by which helminths might induce such protection have revealed the importance
of regulatory pathways, for example, regulatory T-cells. Further investigation on how helminths
influence both innate and adaptive immune reactions will shed more light on the complex
pathways used by helminths to regulate the hosts immune system. Although therapy with
living helminths appears to be effective in several immunological diseases, the disadvantages
of a treatment based on living parasites are explicit. Therefore, the identification and
characterization of helminth-derived immunomodulatory molecules that contribute to the
protective effect could lead to new therapeutic approaches in IBD and other immune diseases
Direct slow-light excitation in photonic crystal waveguides forming ultra-compact splitters
Transition and self-healing process between chaotic and self-organized patterns observed during femtosecond laser writing
We report evidence of intermittent behavior between chaotic and self-organized patterns while writing lines with a femtosecond lasers on the surface of a fused silica substrate. The patterns are accompanied by resolidified sub-microspheres and non-aligned grating lamellae. We observe that such dynamic behavior exhibits a striking similarity with the fluctuating content of a queuing system which alternate between random busy and idle period
Enhanced type IIA gratings for high-temperature operation
The inscription of type IIA. fiber Bragg gratings in standard boron-codoped germanosilicate fiber has been demonstrated to show marked differences from that reported in the literature. These gratings were subjected to high temperatures, and their decay behavior was evaluated. Gratings resistant to heat up to 800°C for a moderate length of time are demonstrated. © 2004 Optical Society of America
Hypersensitisation in germanosilicate optical fibres through standard polymer coating
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Strain and temperature characterization of photonic crystal fiber Bragg gratings
A Bragg grating in a photonic crystal fiber was written and its dependence with temperature and strain analyzed. The two observed Bragg wavelengths correspond to a fundamental and a higher-order mode in the optical fiber. The temperature and strain calibration curves for both modes are measured and found to be distinct. The general properties of gratings in these fibers, and their implications, are enunciated. © 2005 Optical Society of America