Polymer long-period raised rib waveguide gratings using nano-imprint lithography

This letter presents the fabrication and demonstration of a long-period raised rib waveguide grating using nano-imprint lithography. The device consists of a lower UV15 cladding, where relief-gratings are implemented, and an NOA73 raised rib core waveguide. Spectral transmission reveals a resonance at 1585 nm with about 10-dB rejection and 12-nm linewidth

Microengineered structures for rapid automatic loading of optical fibre segments

We present a technique to rapidly and automatically produce sections of optical fibre and load them into arrays such that they can be nano-imprinted in parallel. The technique makes use of automated fibre feeding, cutting and alignment with microfabricated groove arrays. The system is analyzed and optimized and it is found that the geometry of the arrays themselves is a critical factor. Three types of array are investigated-simple grooves, grooves with lateral funnels at the input, and bulk silicon machined V-groove arrays with funnels in both lateral and vertical dimensions. It is found that the incorporation of funnels significantly increases the accuracy of loading, overcoming the need for precise alignment, such that a throughput nearing 1000 fibre segments an hour can be achieved. This system forms part of a sequence of novel processes for the production of nano-photonic sensors

Nanocolumnar Preferentially Oriented PSZT Thin Films Deposited on Thermally Grown Silicon Dioxide

We report the first instance of deposition of preferentially oriented, nanocrystalline, and nanocolumnar strontium-doped lead zirconate titanate (PSZT) ferroelectric thin films directly on thermal silicon dioxide. No intermediate seed or activation layers were used between PSZT and silicon dioxide. The deposited thin films have been characterised using a combination of diffraction and microscopy techniques

Coagulopathy as initial manifestation of concomitant celiac disease and cystic fibrosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Celiac disease and cystic fibrosis have many common manifestations, such as malabsorption, steatorrhea and growth failure, and were for many years recognized as one clinical entity. Since their recognition as two separate diseases, their co-existence in a patient has been described sporadically; around 20 cases have been described in the literature. Taking into consideration the incidences of the two diseases, the chance of them occurring together is one in 2,000,000 in the general population.</p> <p>Case presentation</p> <p>We describe the case of a five-year-old boy of Turkish ethnicity with both celiac disease and cystic fibrosis, who presented initially with a skin hemorrhage. The diagnosis of celiac disease was made with a positive serum anti-tissue transglutaminase antibody test and the presence of HLA-DQ2 heterodimer, and confirmed on histology with small intestinal villous atrophy. A positive sweat test confirmed the diagnosis of associated cystic fibrosis.</p> <p>To the best of our knowledge there has been no previous report of this rare presentation of associated celiac disease and cystic fibrosis.</p> <p>Conclusion</p> <p>The clinical significance of this case is the consideration of malabsorption with both celiac disease and cystic fibrosis in patients who present with unexplained coagulopathy.</p

Retained differentiation capacity of human skeletal muscle satellite cells from spinal cord‐injured individuals

Despite the well‐known role of satellite cells in skeletal muscle plasticity, the effect of spinal cord injury on their function in humans remains unknown. We determined whether spinal cord injury affects the intrinsic ability of satellite cells to differentiate and produce metabolically healthy myotubes. We obtained vastus lateralis biopsies from eight spinal cord‐injured and six able‐bodied individuals. Satellite cells were isolated, grown and differentiated in vitro. Gene expression was measured by quantitative PCR. Abundance of differentiation markers and regulatory proteins was determined by Western blotting. Protein synthesis and fatty acid oxidation were measured by radioactive tracer‐based assays. Activated satellite cells (myoblasts) and differentiated myotubes derived from skeletal muscle of able‐bodied and spinal cord‐injured individuals expressed similar (P > 0.05) mRNA levels of myogenic regulatory factors. Myogenic differentiation factor 1 expression was higher in myoblasts from spinal cord‐injured individuals. Desmin and myogenin protein content was increased upon differentiation in both groups, while myotubes from spinal cord‐injured individuals contained more type I and II myosin heavy chain. Phosphorylated and total protein levels of Akt‐mechanistic target of rapamycin and forkhead box protein O signalling axes and protein synthesis rate in myotubes were similar (P > 0.05) between groups. Additionally, fatty acid oxidation of myotubes from spinal cord‐injured individuals was unchanged (P > 0.05) compared to able‐bodied controls. Our results indicate that the intrinsic differentiation capacity of satellite cells and metabolic characteristics of myotubes are preserved following spinal cord injury. This may inform potential interventions targeting satellite cell activation to alleviate skeletal muscle atrophy

The effect of age and unilateral leg immobilisation for 2 weeks on substrate ulilisation during moderate-intensity exercise in human skeletal muscle

Age and inactivity have been associated with intramuscular triglyceride (IMTG) accumulation. Here, we attempt to disentangle these factors by studying the effect of 2 weeks of unilateral leg immobilization on substrate utilization across the legs during moderate-intensity exercise in young (n = 17; 23 ± 1 years old) and older men (n = 15; 68 ± 1 years old), while the contralateral leg served as the control. After immobilization, the participants performed two-legged isolated knee-extensor exercise at 20±1W(_50% maximalwork capacity) for 45 min with catheters inserted in the brachial artery and both femoral veins.Biopsy samples obtained from vastus lateralis muscles of both legs before and after exercise were used for analysis of substrates, protein content and enzyme activities. During exercise, leg substrate utilization (respiratoryquotient) did not differ between groups or legs. Leg fatty acid uptake was greater in older than in young men, and although young men demonstrated net leg glycerol release during exercise, older men showed net glycerol uptake. At baseline, IMTG, muscle pyruvate dehydrogenase complex activity and the protein content of adipose triglyceride lipase, acetyl-CoA carboxylase 2 and AMP-activated protein kinase (AMPK)γ3 were higher in young than in older men. Furthermore, adipose triglyceride lipase, plasma membrane-associated fatty acid binding protein and AMPKγ3 subunit protein contents were lower and IMTG was higher in the immobilized than the contralateral leg in young and older men. Thus, immobilization and age did not affect substrate choice (respiratory quotient) during moderate exercise, but the whole-leg and molecular differences in fatty acid mobilization could explain the age- and immobilization-induced IMTG accumulation

Soft imprinting of microstructured micro-prisms on optical fibre facets

Soft-imprint lithography is used to integrate optical gratings and polymer micro-prisms onto the tips of optical fibres. Light deflection and diffraction is demonstrated

Observation of random lasing action in dye doped polymer incorporating semi-ordered biological nanostructures from the wings of cicadas

We present a study of random lasing action from dye doped polymer with the scattering role of cicada wing nanostructures. Multimode peaks at 605nm with a mode linewidth of 0.55nm emission spectra were observed

Replication of 3-D micro-structures on optical fibre facets using soft-imprint lithography

We demonstrate the realisation and operation of optical gratings and micro-prisms integrated onto the tips of optical fibres using soft-imprint lithography

The optical fiber tip: An inherently light-coupled microscopic platform for micro- and nanotechnologies

The flat tip of an optical fiber is a unique and unconventional platform for micro and nanotechnologies. The small cross-section and large aspect ratio of the fiber provide an inherently light-coupled substrate that is uniquely suited to remote, in vivo and in situ applications. However, these same characteristics challenge established fabrication technologies, which are best suited to large planar substrates. This review presents a broad overview of strategies for patterning the flat tip of an optical fiber. Techniques discussed include self-assembly, numerous lithographies, through-fiber patterning, hybrid techniques, and strategies for mass manufacture, while the diverse applications are discussed in context throughout