689 research outputs found

    Subtalar arthroeresis with peek endorthesis in juvanile flexible flafoot: Short-term results

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    A successful and minimally invasive treatment for adolescent flexible flatfoot is subtalar arthroeresis. This study examines the short-term results of subtalar arthroereisis with a new PEEK device (Pit’Stop®); additional research will be required to determine the device’s true potential, but the preliminary findings are very encour-aging, with a high success rate and a low complication rate (0.08)

    Initial experience with Vanguard(R) total knee arthroplasty

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    Introduction Biomet Vanguard(R) Complete Knee System is a total knee replacement system, introduced into the market in 2003: thissystem boasts a designed kneecap track or groove which allows for greater mobility and decreased loss of healthy bone during the replacement process. Clinical and radiographic results in Varese Orthopaedics Unit initial experience are reported. Materials and methods Clinical and radiographic parameters are evaluated in 29 patients who underwent TKA (Vanguard(R) Complete Knee System- Biomet Inc.) for primary gonarthrosis during the last 2 years at Orthopaedics and Traumatology Unit of Ospedale di Circolo\u2014Fondazione Macchi in Varese. ROM, type of anaesthesia, patellar pain, clinical and functional Knee Score (pre-operative), size of implant, ROM, blooding, patellar pain, VAS, clinical and func- tional Knee Score (post-operative) are analyzed. Radiographic follow-up is made at 6 and 12 months. Results Clinical and Functional Knee Score respectively improve from 47 to 88 pts and from 51 to 88 pts in pre- and post-operative period (p\0.001). Post-operatively no patellar pain, 2 pts VAS and 1215 cc blooding are reported. ROM doesn\u2019t significantly improve from pre- to post-operative. No relevant complications are reported. Due to the short follow-up, radiographic evaluation does not allow to demonstrate polyethylene liner wear. Conclusions Vanguard(R) Knee Replacement significantly shows a clinical and functional improvement in patients affected by primary gonarthrosis. Moreover, post-operative pain decrease allows early mobilization and rehabilitation

    The Ocular Albinism type 1 (OA1) G-Protein Coupled Receptor functions with MART-1 at early stages of melanogenesis to control melanosome identity and composition

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    OA1 (GPR143; GPCR, G-protein-coupled receptor), the protein product of the ocular albinism type 1 gene, encodes a pigment-cell-specific GPCR that localizes intracellularly to melanosomes. OA1 mutations result in ocular albinism due to alterations in melanosome formation, suggesting that OA1 is a key player in the biogenesis of melanosomes. To address the function of OA1 in melanosome biogenesis, we have used siRNA inactivation and combined morphological and biochemical methods to investigate melanosome ultrastructure, melanosomal protein localization and expression in human pigmented melanocytic cells. OA1 loss of function leads to decreased pigmentation and causes formation of enlarged aberrant premelanosomes harboring disorganized fibrillar structures and displaying proteins of mature melanosomes and lysosomes at their membrane. Moreover, we show that OA1 interacts biochemically with the premelanosomal protein MART-1. Inactivation of MART-1 by siRNA leads to a decreased stability of OA1 and is accompanied by similar defects in premelanosome biogenesis and composition. These data show for the first time that melanosome composition and identity are regulated at early stages by OA1 and that MART-1 likely acts as an escort protein for this GPCR

    Spatially Resolved Spitzer-IRS Spectral Maps of the Superwind in M82

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    We have mapped the superwind/halo region of the nearby starburst galaxy M82 in the mid-infrared with SpitzerIRSSpitzer-IRS. The spectral regions covered include the H2S(1)S(3)_2 S(1)-S(3), [NeII], [NeIII] emission lines and PAH features. We estimate the total warm H2_2 mass and the kinetic energy of the outflowing warm molecular gas to be between Mwarm517×106M_{warm}\sim5-17\times10^6 M_{\odot} and EK620×1053E_{K}\sim6-20\times10^{53} erg. Using the ratios of the 6.2, 7.7 and 11.3 micron PAH features in the IRS spectra, we are able to estimate the average size and ionization state of the small grains in the superwind. There are large variations in the PAH flux ratios throughout the outflow. The 11.3/7.7 and the 6.2/7.7 PAH ratios both vary by more than a factor of five across the wind region. The Northern part of the wind has a significant population of PAH's with smaller 6.2/7.7 ratios than either the starburst disk or the Southern wind, indicating that on average, PAH emitters are larger and more ionized. The warm molecular gas to PAH flux ratios (H2/PAH_2/PAH) are enhanced in the outflow by factors of 10-100 as compared to the starburst disk. This enhancement in the H2/PAH_2/PAH ratio does not seem to follow the ionization of the atomic gas (as measured with the [NeIII]/[NeII] line flux ratio) in the outflow. This suggests that much of the warm H2_2 in the outflow is excited by shocks. The observed H2_2 line intensities can be reproduced with low velocity shocks (v<40v < 40 km s1^{-1}) driven into moderately dense molecular gas (102<nH<10410^2 <n_H < 10^4 cm3^{-3}) entrained in the outflow.Comment: 19 pages and 12 figures; accepted in MNRA

    Distant ULIRGs in the SWIRE Survey

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    Covering ~49 square degrees in 6 separate fields, the Spitzer Wide-area InfraRed Extragalactic (SWIRE) Legacy survey has the largest area among Spitzer’s “wedding cake” suite of extragalactic surveys. SWIRE is thus optimized for studies of large scale structure, population studies requiring excellent statistics, and searches for rare objects. We discuss the search for high redshift ultraluminous infrared galaxies (ULIRGs) with SWIRE. We have selected complete samples of F_(24μm) > 200 μJy, optically faint, candidate high redshift (z>1) ULIRGs, based on their mid-infrared spectral energy distributions (SEDs). These can be broadly categorized as star formation (SF)-dominated, based on the presence of a clear stellar peak at rest frame 1.6μm redshifted into the IRAC bands, or AGN-dominated if the SED rises featureless into the mid-infrared. AGN-dominated galaxies strongly dominate at the brightest 24μm fluxes, while SF-dominated objects rise rapidly in frequency as F_(24) drops, dominating the sample below 0.5 mJy. We derive photometric redshifts and luminosities for SFdominated objects sampling the z~1.2-3 range. Luminosity functions are being derived and compared with submm-selected samples at similar redshifts. The clustering, millimeter and IR spectral properties of the samples have also been investigated

    3d printing and testing of rose thorns or limpet teeth inspired anchor device for tendon tissue repair

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    Purposes: Advancements in medical technology have enabled medical specialists to resolve significant problems concerning tendon injuries. However, despite the latest improvements, surgical tendon repair remains challenging. This study aimed to explore the capabilities of the current state-of-the-art technologies for implantable devices. Methods: After performing extensive patent landscaping and literature review, an anchored tissue fixation device was deemed the most suitable candidate. This design was firstly investigated numerically, realizing a Finite Element Model of the device anchored to two swine tendons stumps, to simulate its application on a severed tendon. Two different hook designs, both bio-inspired, were tested while retaining the same device geometry and anchoring strategy. Then, the applicability of a 3D-printed prototype was tested on swine tendons. Finally, the device-tendon stumps ensemble was subjected to uniaxial tensile tests. Results: The results show that the investigated device enables a better load distribution during the immobilized limb period in comparison to standard suture-based approaches, yet it still presents several design flaws. Conclusions: The current implantable solutions do not ensure an optimal result in terms of strength recovery. This and other weak points of the currently available proposals will serve as a starting point for future works on bio-inspired implantable devices for tendon repair

    3d printing and testing of rose thorns or limpet teeth inspired anchor device for tendon tissue repair

    Get PDF
    Purposes. Advancements in medical technology have enabled medical specialists to resolve significant problems concerning tendon injuries. However, despite the latest improvements, surgical tendon repair remains challenging. This study aims to explore the capabilities of the current state-of-the-art technologies for implantable devices. Methods. After performing extensive patent landscaping and literature review, an anchored tissue fixation device was deemed the most suitable candidate. This design was firstly investigated numerically, realizing a Finite Element Model of the device anchored to two swine tendons stumps, to simulate its application on a severed tendon. Two different hook designs, both bio-inspired, were tested while retaining the same device geometry and anchoring strategy. Then, the applicability of a 3D-printed prototype was tested on swine tendons. Finally, the device-tendon stumps ensemble was subjected to uniaxial tensile tests. Results. The results show that the investigated device enables a better load distribution during the immobilized limb period in comparison to standard suture-based approaches, yet it still presents several design flaws. Conclusions. The current implantable solutions do not ensure an optimal result in terms of strength recovery. This and other weak points of the currently available proposals will serve as a starting point for future works on bio-inspired implantable devices for tendon repair

    Mechanical properties of animal ligaments: a review and comparative study for the identification of the most suitable human ligament surrogates

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    : The interest in the properties of animal soft tissues is often related to the desire to find an animal model to replace human counterparts due to the unsteady availability of human tissues for experimental purposes. Once the most appropriate animal model is identified, it is possible to carry out ex-vivo and in-vivo studies for the repair of ligamentous tissues and performance testing of replacement and support healing devices. This work aims to present a systematic review of the mechanical properties of ligaments reported in the scientific literature by considering different anatomical regions in humans and several animal species. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. Moreover, considering the lack of a standard protocol for preconditioning of tissues, this aspect is also addressed. Ninety-six studies were selected for the systematic review and analysed. The mechanical properties of different animal species are reported and summarised in tables. Only results from studies reporting the strain rate parameter were considered for comparison with human ligaments, as they were deemed more reliable. Elastic modulus, ultimate tensile stress, and ultimate strain properties are graphically reported identifying the range of values for each animal species and to facilitate comparison between values reported in the scientific literature in animal and human ligaments. Useful similarities between the mechanical properties of swine, cow, and rat and human ligaments have been found
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