338 research outputs found

    Nd-complex-doped polymer channel waveguide laser

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    Laser operation at 1060 nm with slope efficiency of 0.95% and 440 ÎŒW output power for 2% outcoupling was demonstrated in Nd-complex-doped FDA/epoxy channel waveguides, in what to our knowledge is the first report of a rare-earth-ion-doped polymer waveguide laser. The threshold was 45 mW of absorbed pump power

    Continuous-wave Lasers in Polymer waveguides

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    Channel waveguides based on a polymer, 6-fluorinated-dianhydride/epoxy, which is actively doped with a rare-earth-ion-doped complex, Nd(thenoyltrifluoroacetone)3 1,10-phenanthroline, have been fabricated. Photoluminescence peaks at 880 nm, 1060 nm, and 1330 nm have been experimentally observed. By optimization of the fabrication\ud procedure of both, host material and optical structure, continuous-wave laser operation on both, the four-level and quasi-three-level transitions near 1060 nm and 880 nm, respectively, has been demonstrated in channel waveguides

    Continuous-wave lasing in a solid polymer

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    Channel waveguides with a Nd-complex-doped fluorinated polymer guiding core were fabricated. For the first time, continuous-wave lasing was demonstrated in a solid polymer. Lasers near 1060 nm and 878 nm were operated for 2 hours

    Brace technology thematic series: the dynamic derotation brace

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    <p>Abstract</p> <p>Background</p> <p>The dynamic derotation brace (DDB) was designed in Greece in 1982, as a modification of the Boston brace. It is a custom-made, underarm spinal orthosis featuring aluminium blades set to produce derotating and anti-rotating effects on the thorax and trunk of patients with scoliosis. It is indicated for the non-operative correction of most curves, barring the very high thoracic ones, (when the apex vertebra is T5 or above). The purpose of this article is to familiarize physicians with the DDB, analyze the rationale behind its design, and present the published results of its application.</p> <p>Description & Principles</p> <p>The key feature of the DDB is the addition of the aluminium-made derotating blades posteriorly. These function as a force couple, which is added to the side forces exerted by the brace itself. Corrective forces are also directed through pads. One or more of previously proposed pathomechanical models of scoliosis may underline the corrective function of the DDB: it may act directly on the apical intervertebral disc, effecting correction through the Heuter-Volkman principle; the blades may produce an anti-rotatory element against the deforming "spiral composite muscle trunk rotator"; or it may alter the neuro-motor response by constantly providing new somatosensory input to the patient.</p> <p>Results</p> <p>Based on measurements of the Cobb and Perdriolle angles, up to 82% of patients remained stable or improved with the use of the DDB. Results have varied, though, depending on the type/location of the deformity. The overall results showed that 35% of the curves improved, 46% remained stable and 18% became worse, as assessed by measuring the Cobb angle. The DDB has also been shown to improve cosmesis (except for right thoracic curves) and leave several aspects of patient quality of life unaffected during use.</p> <p>Conclusion</p> <p>Conservative treatment of idiopathic scoliosis using the DDB has shown favorable results. Thoracic curves appear more resistant to both angular and rotatory correction. The published outcome data on the DDB support our belief that the incorporation of aluminium blades to other orthoses would likely improve their efficacy.</p

    Methodology of evaluation of morphology of the spine and the trunk in idiopathic scoliosis and other spinal deformities - 6th SOSORT consensus paper

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    <p>Abstract</p> <p>Background</p> <p>Comprehensive evaluation of the morphology of the spine and of the whole body is essential in order to correctly manage patients suffering from progressive idiopathic scoliosis. Although methodology of clinical and radiological examination is well described in manuals of orthopaedics, there is deficit of data which clinical and radiological parameters are considered in everyday practise. Recently, an increasing tendency to extend scoliosis examination beyond the measure of the Cobb angle can be observed, reflecting a more patient-oriented approach. Such evaluation often involves surface parameters, aesthetics, function and quality of life.</p> <p>Aim of the study</p> <p>To investigate current recommendations of experts on methodology of evaluation of the patient with spinal deformity, essentially idiopathic scoliosis.</p> <p>Methods</p> <p>Structured Delphi procedure for collecting and processing knowledge from a group of experts with a series of questionnaires and controlled opinion feedback was performed. Experience and opinions of the professionals - physicians and physiotherapists managing scoliosis patients - were studied. According to Delphi method a Meeting Questionnaire (MQ) has been developed, resulting from a preliminary Pre-Meeting Questionnaire (PMQ) which had been previously discussed and approved on line. The MQ was circulated among the SOSORT experts during Consensus Session on "Measurements" which took place at the Annual Meeting of the Society, totally 23 panellists being engaged. Clinical, radiological and surface topography parameters were checked for agreement.</p> <p>Results</p> <p>90% agreement or more was reached in 35 items and superior than 75% agreement was reached in further 25 items. An evaluation form was proposed to be used by clinicians and researchers.</p> <p>Conclusion</p> <p>The consensus was reached on evaluation of the morphology of the patient with idiopathic scoliosis, comprising clinical, radiological and, to less extend, surface topography assessment. Considering the variety of parameters indicated by the panellists, the Cobb angle, yet the gold standard, can be seen neither as the unique nor the only decisive parameter in the management of patients with idiopathic scoliosis.</p

    Continuous-wave biexciton lasing at room temperature using solution-processed quantum wells

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    Solution-processed inorganic and organic materials have been pursued for more than a decade as low-threshold, high-gain lasing media, motivated in large part by their tunable optoelectronic properties and ease of synthesis and processing. Although both have demonstrated stimulated emission and lasing, they have not yet approached the continuous-wave pumping regime. Two-dimensional CdSe colloidal nanosheets combine the advantage of solution synthesis with the optoelectronic properties of epitaxial two-dimensional quantum wells. Here, we show that these colloidal quantum wells possess large exciton and biexciton binding energies of 132 meV and 30 meV, respectively, giving rise to stimulated emission from biexcitons at room temperature. Under femtosecond pulsed excitation, close-packed thin films yield an ultralow stimulated emission threshold of 6 ÎŒJ cm(-2), sufficient to achieve continuous-wave pumped stimulated emission, and lasing when these layers are embedded in surface-emitting microcavities

    Concomitant CIS on TURBT does not impact oncological outcomes in patients treated with neoadjuvant or induction chemotherapy followed by radical cystectomy

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    © Springer-Verlag GmbH Germany, part of Springer Nature 2018Background: Cisplatin-based neoadjuvant chemotherapy (NAC) for muscle invasive bladder cancer improves all-cause and cancer specific survival. We aimed to evaluate whether the detection of carcinoma in situ (CIS) at the time of initial transurethral resection of bladder tumor (TURBT) has an oncological impact on the response to NAC prior to radical cystectomy. Patients and methods: Patients were identified retrospectively from 19 centers who received at least three cycles of NAC or induction chemotherapy for cT2-T4aN0-3M0 urothelial carcinoma of the bladder followed by radical cystectomy between 2000 and 2013. The primary and secondary outcomes were pathological response and overall survival, respectively. Multivariable analysis was performed to determine the independent predictive value of CIS on these outcomes. Results: Of 1213 patients included in the analysis, 21.8% had concomitant CIS. Baseline clinical and pathologic characteristics of the ‘CIS’ versus ‘no-CIS’ groups were similar. The pathological response did not differ between the two arms when response was defined as pT0N0 (17.9% with CIS vs 21.9% without CIS; p = 0.16) which may indicate that patients with CIS may be less sensitive to NAC or ≀ pT1N0 (42.8% with CIS vs 37.8% without CIS; p = 0.15). On Cox regression model for overall survival for the cN0 cohort, the presence of CIS was not associated with survival (HR 0.86 (95% CI 0.63–1.18; p = 0.35). The presence of LVI (HR 1.41, 95% CI 1.01–1.96; p = 0.04), hydronephrosis (HR 1.63, 95% CI 1.23–2.16; p = 0.001) and use of chemotherapy other than ddMVAC (HR 0.57, 95% CI 0.34–0.94; p = 0.03) were associated with shorter overall survival. For the whole cohort, the presence of CIS was also not associated with survival (HR 1.05 (95% CI 0.82–1.35; p = 0.70). Conclusion: In this multicenter, real-world cohort, CIS status at TURBT did not affect pathologic response to neoadjuvant or induction chemotherapy. This study is limited by its retrospective nature as well as variability in chemotherapy regimens and surveillance regimens.Peer reviewedFinal Accepted Versio

    Introduction to the "Scoliosis" Journal Brace Technology Thematic Series: increasing existing knowledge and promoting future developments

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    Bracing is the main non-surgical intervention in the treatment of idiopathic scoliosis during growth, in hyperkyphosis (and Scheuermann disease) and occasionally for spondylolisthesis; it can be used in adult scoliosis, in the elderly when pathological curves lead to a forward leaning posture or in adults after traumatic injuries. Bracing can be defined as the application of external corrective forces to the trunk; rigid supports or elastic bands can be used and braces can be custom-made or prefabricated. The state of research in the field of conservative treatment is insufficient and while it can be stated that there is some evidence to support bracing, we must also acknowledge that today we do not have a common and generally accepted knowledge base, and that instead, individual expertise still prevails, giving rise to different schools of thought on brace construction and principles of correction. The only way to improve the knowledge and understanding of brace type and brace function is to establish a single and comprehensive source of information about bracing. This is what the Scoliosis Journal is going to do through the "Brace Technology" Thematic Series, where technical papers coming from the different schools will be published
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