205 research outputs found

    Supercontinuum Generation in a Silica Spiral Waveguide

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    A low-loss silica spiral waveguide is used for demonstrating on-chip supercontinuum generation. The broadest measured spectrum spans an octave (936 – 1888 nm) at −50 dB from peak when 2.17 nJ pulses are launched

    Electrospun Collagen: A Tissue Engineering Scaffold with Unique Functional Properties in a Wide Variety of Applications

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    Type I collagen and gelatin, a derivative of Type I collagen that has been denatured, can each be electrospun into tissue engineering scaffolds composed of nano- to micron-scale diameter fibers. We characterize the biological activity of these materials in a variety of tissue engineering applications, including endothelial cell-scaffold interactions, the onset of bone mineralization, dermal reconstruction, and the fabrication of skeletal muscle prosthetics. Electrospun collgen (esC) consistently exhibited unique biological properties in these functional assays. Even though gelatin can be spun into fibrillar scaffolds that resemble scaffolds of esC, our assays reveal that electrospun gelatin (esG) lacks intact α chains and is composed of proinflammatory peptide fragments. In contrast, esC retains intact α chains and is enriched in the α 2(I) subunit. The distinct fundamental properties of the constituent subunits that make up esC and esG appear to define their biological and functional properties

    A Comparison of Cervical and Trunk Musculoskeletal Characteristics between Female and Male Army Helicopter Pilots

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    Introduction: Neck pain (NP) and low back pain (LBP) are prevalent among military helicopter pilots. Although there have been few studies on sex differences in the NP/LBP prevalence in this population, females are shown to be at a greater risk of NP/LBP in civilian studies. This disparity may be due to musculoskeletal characteristics differences that predispose females for NP/LBP. The purpose of this study was to compare cervical and trunk musculoskeletal characteristics between male and female pilots. Methods: A total of 8 female pilots (Age: 27.6 ± 4.2yrs, HT: 166.1 ± 7.7cm, WT: 67.9 ± 10.6kg) were tested, and they were matched (1:1 matching ratio) with male pilots (Age: 27.8 ± 4.2yrs, HT: 175.0 ± 6.8cm, WT: 79.5 ± 5.8kg), based on age (± three years) and flight experience (± two years). Cervical/trunk strength and flexibility were tested using the hand-held/isokinetic dynamometer and inclinometers, respectively. Strength values were normalized to body weight for analyses. Paired t-tests or Wilcoxon Signed Rank tests were used to examine sex differences across all variables (p \u3c 0.05). Results: Female pilots had significantly lower cervical flexion strength, trunk flexion strength, and trunk rotation strength (p \u3c 0.05). For flexibility measures, female pilots had significantly greater cervical rotation flexibility (p \u3c 0.05). No significant differences were observed in the lumbar spine flexibility. Discussion/Conclusion: The current preliminary study found sex differences in cervical and trunk musculoskeletal characteristics in Army helicopter pilots. Continued efforts are warranted to explore sex-specific intervention strategy and its effectiveness in reducing the NP/LBP prevalence among military helicopter pilots

    Electrospun Fibrinogen-Polydioxanone Composite Matrix: Potential for In Situ Urologic Tissue Engineering

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    Our objective is to demonstrate an electrospun fibrinogen-PDO (polydioxanone) composite scaffold will retain the superior cellular interaction of fibrinogen while producing a product with the functional strength needed for direct implantation. Fibrinogen-PDO composite scaffolds were electrospun with PDO ratios of 0% (pure fibrinogen), 10%, 20%, 30%, 40%, 50% and 100% (pure PDO) and disinfected using standard methods. Scaffolds were seeded with human BSM (bladder smooth muscle cells) and incubated with twice weekly media changes. Samples were removed at 7, 14 and 21 days for evaluation by collagen assay, scanning electron microscopy and histology. Cell seeding and culture demonstrated human BSM readily migrate throughout and remodel electrospun fibrinogen-PDO composite scaffolds with deposition of native collagen. Cell migration and collagen deposition increased with increasing fibrinogen concentration while scaffold integrity increased with increasing PDO concentration. Electrospun fibrinogen-PDO composite structures promote rapid cellular in-growth by human BSM while maintaining structural integrity. The fibrinogen to PDO ratio can be adjusted to achieve the desired properties required for a specific tissue engineering application. Our ultimate objective is to utilize this innovative biomaterial technology to produce an acellular, bioresorbable product that enables in situ tissue regeneration. While there is still much work to be done, these initial findings indicate fibrinogen-PDO composite scaffolds deserve further investigation

    A Preliminary Study on the Potential of Manuka Honey and Platelet-Rich Plasma in Wound Healing

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    Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, and a combination of PRGF and MH. Results. All three cell types demonstrated increases in cellular activity in the presence of PRGF, with further increases in activity seen in the presence of PRGF+MH. hDFs proved to be the most positively responsive cells, as they experienced enhanced proliferation, collagen matrix production, and migration into an in vitro wound healing model with the PRGF+MH-supplemented media. Conclusion. This preliminary in vitro study is the first to evaluate the combination of PRGF and Manuka honey, two products with the potential to increase regeneration individually, as a combined product to enhance dermal regeneration

    A Preliminary Study on the Potential of Manuka Honey and Platelet-Rich Plasma in Wound Healing

    Get PDF
    Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, and a combination of PRGF and MH. Results. All three cell types demonstrated increases in cellular activity in the presence of PRGF, with further increases in activity seen in the presence of PRGF+MH. hDFs proved to be the most positively responsive cells, as they experienced enhanced proliferation, collagen matrix production, and migration into an in vitro wound healing model with the PRGF+MH-supplemented media. Conclusion. This preliminary in vitro study is the first to evaluate the combination of PRGF and Manuka honey, two products with the potential to increase regeneration individually, as a combined product to enhance dermal regeneration

    Supercontinuum generation in an on-chip silica waveguide

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    Supercontinuum generation is demonstrated in an on-chip silica spiral waveguide by launching 180 fs pulses from an optical parametric oscillator at the center wavelength of 1330 nm. With a coupled pulse energy of 2.17 nJ, the broadest spectrum in the fundamental TM mode extends from 936 to 1888 nm (162 THz) at −50  dB from peak. There is a good agreement between the measured spectrum and a simulation using a generalized nonlinear Schrödinger equation

    A Preliminary Study on the Potential of Manuka Honey and Platelet-Rich Plasma in Wound Healing

    Get PDF
    Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, and a combination of PRGF and MH. Results. All three cell types demonstrated increases in cellular activity in the presence of PRGF, with further increases in activity seen in the presence of PRGF+MH. hDFs proved to be the most positively responsive cells, as they experienced enhanced proliferation, collagen matrix production, and migration into an in vitro wound healing model with the PRGF+MH-supplemented media. Conclusion. This preliminary in vitro study is the first to evaluate the combination of PRGF and Manuka honey, two products with the potential to increase regeneration individually, as a combined product to enhance dermal regeneration

    A curvilinear effect of height on reproductive success in human males

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    Human male height is associated with mate choice and intra-sexual competition, and therefore potentially with reproductive success. A literature review (n = 18) on the relationship between male height and reproductive success revealed a variety of relationships ranging from negative to curvilinear to positive. Some of the variation in results may stem from methodological issues, such as low power, including men in the sample who have not yet ended their reproductive career, or not controlling for important potential confounders (e.g. education and income). We investigated the associations between height, education, income and the number of surviving children in a large longitudinal sample of men (n = 3,578; Wisconsin Longitudinal Study), who likely had ended their reproductive careers (e.g. > 64 years). There was a curvilinear association between height and number of children, with men of average height attaining the highest reproductive success. This curvilinear relationship remained after controlling for education and income, which were associated with both reproductive success and height. Average height men also married at a younger age than shorter and taller men, and the effect of height diminished after controlling for this association. Thus, average height men partly achieved higher reproductive success by marrying at a younger age. On the basis of our literature review and our data, we conclude that men of average height most likely have higher reproductive success than either short or tall men
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