Darren Freeman

  • Citations Per Year
Learn More
Pneumothoraces and pneumohemathoraces have been described in adults with systemic lupus erythematosus (SLE). Although a spectrum of pulmonary involvement has been associated with SLE in childhood and adolescence, recurrent pneumothoraces have not been reported. We describe a case of a 13-year-old adolescent with fulminant SLE and a recurrent left(More)
Sjogren's syndrome is a chronic autoimmune disorder characterized by keratoconjunctivitis sicca, xerostomia, and recurrent enlargement of the salivary glands. Most commonly noted in adults, it rarely affects adolescents. We describe a 15-year-old adolescent with recurrent parotid enlargement as an initial manifestation of this disease.
It has been reported that adult women prefer the semi-sitting position over the supine position for the pelvic examination. We determined the effect of the pelvic examination position and the examiner's gender on adolescent anxiety with the pelvic examination. Adolescent girls (n = 112) aged 12 to 19 years were randomly assigned to a semi-sitting or supine(More)
We demonstrate highly efficient evanescent coupling between a highly nonlinear chalcogenide glass two dimensional photonic crystal waveguide and a silica fiber nanowire. We achieve 98% insertion efficiency to the fundamental photonic crystal waveguide mode with a 3dB coupling bandwidth of 12nm, in good agreement with theory. This scheme provides a promising(More)
We demonstrate a direct, single measurement technique for characterizing the dispersion of a photonic crystal waveguide (PCWG) using a tapered fiber evanescent coupling method. A highly curved fiber taper is used to probe the Fabry-Pérot spectrum of a closed PCWG over a broad k-space range, and from this measurement the dispersive properties of the(More)
We demonstrate resonant guiding in a chalcogenide glass photonic crystal membrane. We observe strong resonances in the optical transmission spectra at normal incidence, associated with Fano coupling between free space and guided modes. We obtain good agreement with modeling results based on three-dimensional finite-difference time-domain simulations, and(More)
Free-standing "AMTIR-1" (Ge33As12Se55) chalcogenide glass films have been patterned using a focused ion beam (FIB) to create two-dimensional photonic crystal membranes. The triangular lattices were selected for a photonic bandgap relevant to fiber telecommunications. Optical measurements of transmission spectra as a function of incident angle showed clear(More)
External content sources such as MEDLINE(®), National Institutes of Health (NIH) grants and conference websites provide access to the latest breaking biomedical information, which can inform pharmaceutical and biotechnology company pipeline decisions. The value of the sites for industry, however, is limited by the use of the public internet, the limited(More)
We experimentally and computationally demonstrate high transmission through arrays of coaxial apertures with different geometries and arrangements in silver films. By studying both periodic and random arrangements of apertures, we were able to isolate transmission enhancement phenomena owing to surface plasmon effects from those owing to the excitation of(More)