420 research outputs found

    L’improvisation spatiale gĂ©nĂ©rĂ©e Ă  partir de motifs polyrythmiques et de sĂ©quences de paramĂštres en boucle via l’outil de performance Live 4 Life

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    Ce projet de recherche-crĂ©ation est axĂ© sur le dĂ©veloppement d’un outil de crĂ©ation sonore, qui vise Ă  faciliter l’improvisation de musiques Ă©lectroacoustiques spatialisĂ©es sur de multiples haut-parleurs. L’outil nommĂ© Live 4 Life permet plus spĂ©cifiquement de composer des polyrythmies spatialisĂ©es, combinĂ©es Ă  des textures enveloppantes en temps rĂ©el. Actuellement, il est particuliĂšrement difficile de contrĂŽler dynamiquement et simultanĂ©ment de multiples sons dans l’espace, en raison en partie de la stratification du processus de composition dans plusieurs logiciels et de la complexitĂ© Ă  spatialiser individuellement chaque Ă©vĂ©nement sonore. En dotant l’improvisateur d’outils de spatialisation flexibles, celui-ci peut exploiter les dimensions spatiales tout au long du processus de crĂ©ation, de la composition jusqu’à la performance. L’intĂ©gration, Ă  mĂȘme l’outil Live 4 Life, des autres paramĂštres sonores, comme le rythme ou les vitesses de lecture, permet Ă©galement de crĂ©er de nouveaux liens dans la composition de l’espace. L’outil, implĂ©mentĂ© sur la plate-forme en source libre SuperCollider, propose une approche comprenant diffĂ©rentes Ă©chelles temporelles, oĂč la spatialisation est dĂ©terminĂ©e autant au niveau local sur des Ă©vĂ©nements individuels que global sur des flux sonores. Des Ɠuvres ouvertes du point de vue spatial et temporel peuvent ainsi ĂȘtre rĂ©alisĂ©es Ă  partir de multiples sĂ©quences prĂ©-composĂ©es, qui sont organisĂ©es et modifiĂ©es en temps rĂ©el. Cet outil de performance spatiale met l’accent sur la construction et la dĂ©formation de boucles de paramĂštres, rythmiques ou spatiales. Il permet, en outre, de questionner le dĂ©veloppement spatio-temporel entre les objets sonores eux-mĂȘmes, leurs traitements ou leurs rĂ©flexions et ouvre sur des questions plus larges sur les liens qui existent entre l’espace et le temps rĂ©el.The research/creation project is focused on the development of a spatialised sound creation tool, which aims at facilitating the improvisation of electroacoustic music on multiple loudspeakers. More specifically, this tool, which is called Live 4 Life, allows to compose spatialised polyrhythms, combined with enveloping textures in real time. Currently, it is particularly difficult to dynamically and simultaneously control multiple sounds in space, due in part to the layering of the composition process in multiple software programs and the complexity of individually spatialising each sound event. By providing the improviser with flexible spatialisation tools, it allows him to exploit spatial dimensions throughout the creative process, from composition to performance. The integration of other sound parameters, such as rhythm, spectrum or playback speeds, in a global creation tool also allows to create new links in the composition of space. The tool, implemented on the open source platform SuperCollider, offers an approach comprising different time scales, where spatialisation is determined both locally on individual events and globally on sound streams. Spatially and temporally open forms can thus be realised from multiple pre-composed sequences, which are organised and modified in real time. This spatial performance tool emphasises the construction and deformation of parameter loops, rhythmic or spatial. It also makes it possible to question the spatio-temporal development between sound objects themselves, their processing or their reflections, and opens up broader questions on the links that exist between space and real time

    FOLFIRI as second-line treatment of metastatic biliary tract cancer patients

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    The combination of cisplatin and gemcitabine is the standard first-line treatment of metastatic biliary tract cancer (BTC) patients. The benefit of second-line chemotherapy in these patients is controversial. This study aims to evaluate the activity of FOLFIRI (fluorouracil and irinotecan) after failure to the first-line platinum and gemcitabine-based chemotherapy in metastatic BTC patients. We present a single-institution, retrospective cohort study. Patients with locally advanced or metastatic BTC who progressed after at least one line of chemotherapy, consecutively treated at our Institution between 2007 and 2017 were included. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival (OS), clinical benefit rate (CBR) and safety profile of FOLFIRI. Twelve patients were included in the analysis, with a median follow up of 5 months (95% CI 2.77-7.20). The median number of cycles received was 3 (range 1 to 9). Four grade 3 toxicities were recorded; no grade 4 toxicities and no treatment-related deaths occurred. The median PFS was 1.7 months (95% CI; 0.66-2.67), and median OS was 5 months (95% CI; 2.77-7.20). Two patients presented stable disease, providing a CBR of 17%. We concluded that FOLFIRI presented a favorable toxicity profile and a modest activity in metastatic BTC patients who had progressed to platinum and gemcitabine and may be considered in patients who are able to tolerate additional lines of chemotherapy. Immunotherapy and targeted therapies selected according to the tumoral genomic profile are promising alternatives to improve the outcomes of second-line treatment in BTC

    First Evidence of Dinosaurian Secondary Cartilage in the Post-Hatching Skull of Hypacrosaurus stebingeri (Dinosauria, Ornithischia)

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    Bone and calcified cartilage can be fossilized and preserved for hundreds of millions of years. While primary cartilage is fairly well studied in extant and fossilized organisms, nothing is known about secondary cartilage in fossils. In extant birds, secondary cartilage arises after bone formation during embryonic life at articulations, sutures and muscular attachments in order to accommodate mechanical stress. Considering the phylogenetic inclusion of birds within the Dinosauria, we hypothesized a dinosaurian origin for this “avian” tissue. Therefore, histological thin sectioning was used to investigate secondary chondrogenesis in disarticulated craniofacial elements of several post-hatching specimens of the non-avian dinosaur Hypacrosaurus stebingeri (Ornithischia, Lambeosaurinae). Secondary cartilage was found on three membrane bones directly involved with masticatory function: (1) as nodules on the dorso-caudal face of a surangular; and (2) on the bucco-caudal face of a maxilla; and (3) between teeth as islets in the alveolar processes of a dentary. Secondary chondrogenesis at these sites is consistent with the locations of secondary cartilage in extant birds and with the induction of the cartilage by different mechanical factors - stress generated by the articulation of the quadrate, stress of a ligamentous or muscular insertion, and stress of tooth formation. Thus, our study reveals the first evidence of “avian” secondary cartilage in a non-avian dinosaur. It pushes the origin of this “avian” tissue deep into dinosaurian ancestry, suggesting the creation of the more appropriate term “dinosaurian” secondary cartilage

    Decellularized vascularized bone grafts: A preliminary in vitro porcine model for bioengineered transplantable bone shafts

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    Introduction: Durable reconstruction of critical size bone defects is still a surgical challenge despite the availability of numerous autologous and substitute bone options. In this paper, we have investigated the possibility of creating a living bone allograft, using the perfusion/decellularization/recellularization (PDR) technique, which was applied to an original model of vascularized porcine bone graft.Materials and Methods: 11 porcine bone forelimbs, including radius and ulna, were harvested along with their vasculature including the interosseous artery and then decellularized using a sequential detergent perfusion protocol. Cellular clearance, vasculature, extracellular matrix (ECM), and preservation of biomechanical properties were evaluated. The cytocompatibility and in vitro osteoinductive potential of acellular extracellular matrix were studied by static seeding of NIH-3T3 cells and porcine adipose mesenchymal stem cells (pAMSC), respectively.Results: The vascularized bone grafts were successfully decellularized, with an excellent preservation of the 3D morphology and ECM microarchitecture. Measurements of DNA and ECM components revealed complete cellular clearance and preservation of ECM’s major proteins. Bone mineral density (BMD) acquisitions revealed a slight, yet non-significant, decrease after decellularization, while biomechanical testing was unmodified. Cone beam computed tomography (CBCT) acquisitions after vascular injection of barium sulphate confirmed the preservation of the vascular network throughout the whole graft. The non-toxicity of the scaffold was proven by the very low amount of residual sodium dodecyl sulfate (SDS) in the ECM and confirmed by the high live/dead ratio of fibroblasts seeded on periosteum and bone ECM-grafts after 3, 7, and 16 days of culture. Moreover, cell proliferation tests showed a significant multiplication of seeded cell populations at the same endpoints. Lastly, the differentiation study using pAMSC confirmed the ECM graft’s potential to promote osteogenic differentiation. An osteoid-like deposition occurred when pAMSC were cultured on bone ECM in both proliferative and osteogenic differentiation media.Conclusion: Fully decellularized bone grafts can be obtained by perfusion decellularization, thereby preserving ECM architecture and their vascular network, while promoting cell growth and differentiation. These vascularized decellularized bone shaft allografts thus present a true potential for future in vivo reimplantation. Therefore, they may offer new perspectives for repairing large bone defects and for bone tissue engineering

    Predictive value of sarcopenia components for all-cause mortality: findings from population-based cohorts

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    Background: Low grip strength and gait speed are associated with mortality. However, investigation of the additional mortality risk explained by these measures, over and above other factors, is limited. Aim: We examined whether grip strength and gait speed improve discriminative capacity for mortality over and above more readily obtainable clinical risk factors. Methods: Participants from the Health, Aging and Body Composition Study, Osteoporotic Fractures in Men Study, and the Hertfordshire Cohort Study were analysed. Appendicular lean mass (ALM) was ascertained using DXA; muscle strength by grip dynamometry; and usual gait speed over 2.4–6 m. Verified deaths were recorded. Associations between sarcopenia components and mortality were examined using Cox regression with cohort as a random effect; discriminative capacity was assessed using Harrell’s Concordance Index (C-index). Results: Mean (SD) age of participants (n = 8362) was 73.8(5.1) years; 5231(62.6%) died during a median follow-up time of 13.3 years. Grip strength (hazard ratio (95% CI) per SD decrease: 1.14 (1.10,1.19)) and gait speed (1.21 (1.17,1.26)), but not ALM index (1.01 (0.95,1.06)), were associated with mortality in mutually-adjusted models after accounting for age, sex, BMI, smoking status, alcohol consumption, physical activity, ethnicity, education, history of fractures and falls, femoral neck bone mineral density (BMD), self-rated health, cognitive function and number of comorbidities. However, a model containing only age and sex as exposures gave a C-index (95% CI) of 0.65(0.64,0.66), which only increased to 0.67(0.67,0.68) after inclusion of grip strength and gait speed. Conclusions: Grip strength and gait speed may generate only modest adjunctive risk information for mortality compared with other more readily obtainable risk factors

    Guidelines for delineation of lymphatic clinical target volumes for high conformal radiotherapy: head and neck region

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    The success of radiotherapy depends on the accurate delineation of the clinical target volume. The delineation of the lymph node regions has most impact, especially for tumors in the head and neck region. The purpose of this article was the development an atlas for the delineation of the clinical target volume for patients, who should receive radiotherapy for a tumor of the head and neck region. Literature was reviewed for localisations of the adjacent lymph node regions and their lymph drain in dependence of the tumor entity. On this basis the lymph node regions were contoured on transversal CT slices. The probability for involvement was reviewed and a recommendation for the delineation of the CTV was generated

    Perfusion-decellularization of human ear grafts enables ECM-based scaffolds for auricular vascularized composite tissue engineering

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    Introduction: Human ear reconstruction is recognized as the emblematic enterprise in tissue engineering. Up to now, it has failed to reach human applications requiring appropriate tissue complexity along with an accessible vascular tree. We hereby propose a new method to process human auricles in order to provide a poorly immunogenic, complex and vascularized ear graft scaffold. Methods: 12 human ears with their vascular pedicles were procured. Perfusion-decellularization was applied using a SDS/polar solvent protocol. Cell and antigen removal was examined by histology and DNA was quantified. Preservation of the extracellular matrix (ECM) was assessed by conventional and 3D-histology, proteins and cytokines quantifications. Biocompatibility was assessed by implantation in rats for up to 60 days. Adipose-derived stem cells seeding was conducted on scaffold samples and with human aortic endothelial cells whole graft seeding in a perfusion-bioreactor. Results: Histology confirmed cell and antigen clearance. DNA reduction was 97.3%. ECM structure and composition were preserved. Implanted scaffolds were tolerated in vivo, with acceptable inflammation, remodeling, and anti-donor antibody formation. Seeding experiments demonstrated cell engraftment and viability. Conclusions: Vascularized and complex auricular scaffolds can be obtained from human source to provide a platform for further functional auricular tissue engineered constructs, hence providing an ideal road to the vascularized composite tissue engineering approach

    Long-Term Results up to 12 Months After Catheter-Based Alcohol-Mediated Renal Denervation for Treatment of Resistant Hypertension

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    Background: Primary results of this prospective, open-label, multicenter trial suggested that alcohol-mediated renal denervation with perivascular injection of dehydrated alcohol using the Peregrine System Infusion Catheter safely reduces blood pressure (BP) in patients with resistant hypertension. To date, maintenance of the BP-lowering effect beyond 6 months using this novel technology has not been reported. This article describes the final, 12-month follow-up data on the safety and efficacy of alcohol-mediated renal denervation in these patients. Methods: Forty-five patients with resistant hypertension on a stable regimen of on average 5.1±1.5 antihypertensive medications underwent successful bilateral renal denervation using the Peregrine Catheter with alcohol as the neurolytic agent (0.6 mL per renal artery). Apart from 2 vascular access pseudoaneurysms (both without sequelae), no major procedural complications occurred. Results: At 12 months post-procedure, mean 24-hour ambulatory systolic and diastolic BP were reduced by 10 mm Hg (95% CI, −16 to −5) and 7 mm Hg (−10 to −3), respectively (P<0.001). Office systolic/diastolic BP was reduced by 20/10 mm Hg (−27, −13/−14, −6; <0.001). Compared with baseline, the number of antihypertensive medications was reduced in 21% of patients, while it was increased in 19%. From baseline to 12 months, serum creatinine, urea, cystatin C, and spot urine albumin levels remained unchanged. The change in estimated glomerular filtration rates (−3.9±10.3 mL/minute per 1.73 m2 [95% CI, −7.1 to −0.75]; P=0.02) was within the expected range. There were no cases of renal artery stenosis up to 12-month follow-up. Conclusions: Catheter-based chemical renal denervation with dehydrated alcohol using the Peregrine Catheter seems to safely reduce BP at follow-up of up to 12 months. Further randomized and sham controlled studies are underway to further validate these findings

    3D histopathology of stenotic aortic valve cusps using ex vivo microfocus computed tomography

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    BackgroundCalcific aortic stenosis (AS) is the most prevalent heart valve disease in developed countries. The aortic valve cusps progressively thicken and the valve does not open fully due to the presence of calcifications. In vivo imaging, usually used for diagnosis, does not allow the visualization of the microstructural changes associated with AS.MethodsEx vivo high-resolution microfocus computed tomography (microCT) was used to quantitatively describe the microstructure of calcified aortic valve cusps in full 3D. As case study in our work, this quantitative analysis was applied to normal-flow low-gradient severe AS (NF-LG-SAS), for which the medical prognostic is still highly debated in the current literature, and high-gradient severe AS (HG-SAS).ResultsThe volume proportion of calcification, the size and number of calcified particles and their density composition was quantified. A new size-based classification considering small-sized particles that are not detected with in vivo imaging was defined for macro-, meso- and microscale calcifications. Volume and thickness of aortic valve cusps, including the complete thickness distribution, were also determined. Moreover, changes in the cusp soft tissues were also visualized with microCT and confirmed by scanning electron microscopy images of the same sample. NF-LG-SAS cusps contained lower relative amount of calcifications than HG-SAS. Moreover, the number and size of calcified objects and the volume and thickness of the cusps were also lower in NF-LG-SAS cusps than in HG-SAS.ConclusionsThe application of high-resolution ex vivo microCT to stenotic aortic valve cusps provided a quantitative description of the general structure of the cusps and of the calcifications present in the cusp soft tissues. This detailed description could help in the future to better understand the mechanisms of AS
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