Electrochemical performances and post-operational characterization of a segmented sofc operated under load for 15k hours

In the frame of the ENDURANCE FCH-JU-FP7 project (2014-2017) a segmented cell (20 segments regularly distributed from fuel inlet to fuel outlet) was operated for 15k hours in co-flow at 750\ub0C (average temperature) in hydrogen under load. Each segment was carefully monitored during operation by periodically acquiring the impedance spectra and constantly checking the voltage under current load. After 15k hours of operation the test was stopped and the cell used for further investigations in order to compare the cell evolution with the segment degradation. The overall observation in cross section of the cell has shown a good stability, however some differences were observed in the electrodes that might be related to the local operating conditions: temperature, H2 /H2O ratio in the fuel stream. The gathered results will contribute to increase the understanding the evolution of a SOFC in real operating conditions. Evidences of the effect of temperature, time and fuel pollutants were found

Visceral myxobacteriosis in the rainbow trout, Salmo­Gairdneri R. : a new clinicat form of the Cytophaga psychrophila cold water disease

Une forme nouvelle de la myxobactériose d’eau froide est apparue en France au cours de ces dernières années chez les alevins et les trui- telles arc-en-ciel. L’agent responsable est Cytophaga psychrophila, qui ne sévissait jusqu’ici qu’en Amérique du Nord chez les salmonidés juvéniles, provoquant surtout des lésions ulcératives cutanées. En France, au contraire, les lésions causées par la bactérie sont essentiellement viscé rales. L’infection clinique est observée en saison froide, et assez souvent associée à d’autres pathologies. Le diagnostic repose essentiellement sur la mise en évidence et la caractérisation de la bactérie responsable. La maladie a été transmise expérimentalement et les essais en laboratoire ont montré l’efficacité thérapeutique du chloramphénicol et de l’oxytétra- cycline.A new form of the cold water myxobacteriosis in rainbow trout fry and Engerlings appeared in France during the last years. So far, the aetiological agent has been Cytophaga psychrophila, a myxobacteria occuring on juveniles of salmonids of North America and mostly inducing cutaneous ulcerative lesions. On the opposite, lesions observed in France have essentially been detected on internal organs. The clinical infection is prevalent during the cold season and is often associated with other pathogens. Diagnosis is mainly made on isolation and characterization of aetiological bacteria. The disease was experimentally transmitted. Trials in laboratory have also demonstrated the therapeutic efficiency of chloram phenicol and Oxytetracycline

From crystalline to amorphous calcium pyrophosphates:a solid state Nuclear Magnetic Resonance perspective

Hydrated calcium pyrophosphates (CPP, Ca2P2O7·nH2O) are a fundamental family of materials among osteoarticular pathologic calcifications. In this contribution, a comprehensive multinuclear NMR (Nuclear Magnetic Resonance) study of four crystalline and two amorphous phases of this family is presented. 1H, 31P and 43Ca MAS (Magic Angle Spinning) NMR spectra were recorded, leading to informative fingerprints characterizing each compound. In particular, different 1H and 43Ca solid state NMR signatures were observed for the amorphous phases, depending on the synthetic procedure used. The NMR parameters of the crystalline phases were determined using the GIPAW (Gauge Including Projected Augmented Wave) DFT approach, based on first-principles calculations. In some cases, relaxed structures were found to improve the agreement between experimental and calculated values, demonstrating the importance of proton positions and pyrophosphate local geometry in this particular NMR crystallography approach. Such calculations serve as a basis for the future ab initio modeling of the amorphous CPP phases. Statement of significance The general concept of NMR crystallography is applied to the detailed study of calcium pyrophosphates (CPP), whether hydrated or not, and whether crystalline or amorphous. CPP are a fundamental family of materials among osteoarticular pathologic calcifications. Their prevalence increases with age, impacting on 17.5% of the population after the age of 80. They are frequently involved or associated with acute articular arthritis such as pseudogout. Current treatments are mainly directed at relieving the symptoms of joint inflammation but not at inhibiting CPP formation nor at dissolving these crystals. The combination of advanced NMR techniques, modeling and DFT based calculation of NMR parameters allows new original insights in the detailed structural description of this important class of biomaterials

Enhanced stability and local structure in biologically relevant amorphous materials containing pyrophosphate

There is increasing evidence that amorphous inorganic materials play a key role in biomineralisation in many organisms, however the inherent instability of synthetic analogues in the absence of the complex in vivo matrix limits their study and clinical exploitation. To address this, we report here an approach that enhances long-term stability to >1 year of biologically relevant amorphous metal phosphates, in the absence of any complex stabilisers, by utilising pyrophosphates (P2O7 4-); species themselves ubiquitous in vivo. Ambient temperature precipitation reactions were employed to synthesise amorphous Ca2P2O7.nH2O and Sr2P2O7.nH2O (3.8 < n < 4.2) and their stability and structure were investigated. Pair distribution functions (PDF) derived from synchrotron X-ray data indicated a lack of structural order beyond ~8 A° in both phases, with this local order found to resemble crystalline analogues. Further studies, including 1H and 31P solid state NMR, suggest the unusually high stability of these purely inorganic amorphous phases is partly due to disorder in the P–O–P bond angles within the P2O7 units, which impede crystallization, and to water molecules, which are involved in H-bonds of various strengths within the structures and hamper the formation of an ordered network. In situ high temperature powder X-ray diffraction data indicated that the amorphous nature of both phases surprisingly persisted to ~450° C. Further NMR and TGA studies found that above ambient temperature some water molecules reacted with P2O7 anions, leading to the hydrolysis of some P–O–P linkages and the formation of HPO4 2- anions within the amorphous matrix. The latter anions then recombined into P2O7 ions at higher temperatures prior to crystallization. Together, these findings provide important new materials with unexplored potential for enzyme-assisted resorption and establish factors crucial to isolate further stable amorphous inorganic materials

Morel_Moreau_Morella. The Metamorphoses of Adolfo Bioy Casares Invention in a (Re) Animating Universe

Adolfo Bioy Casares short novel The Invention of Morel (La invención de Morel, 1940) envisioned the wish of human beings to define themselves through technology, indeed to reanimate the human as a technological double in an environment that gradually becomes virtual. This article develops the relationships connecting The Invention of Morel with three animating forms: the phantasmagoria, the automaton, and the machine-environment, to stress the privileged association they make between invention and (re)animation. With this purpose, the paper examines key contributions to our understanding of simulation and automata in the field of animation theory, such as Alan Cholodenko s Speculations on the Animation Automaton , but also Joubert-Laurencin s La lettre volante. Quatre essais sur le cinema d animation, which directly addresses Bioy Casares story as a metaphor of animated cinema. Sigmund Freud s psychoanalytical approach to the field of aesthetics in The Uncanny , and subsequent theories like Masahiro Mori s The Uncanny Valley , are also taken into consideration.Lorenzo Hernández, MC. (2013). Morel_Moreau_Morella. The Metamorphoses of Adolfo Bioy Casares Invention in a (Re) Animating Universe. Animation: An interdisciplinary journal. 8(2):185-202. doi:10.1177/1746847713485535S18520282Buchan, S. (2011). The Quay Brothers. doi:10.5749/minnesota/9780816646586.001.0001Cholodenko, A. (2013). The Crypt, the Haunted House, of Cinema. Cultural Studies Review, 10(2), 99-113. doi:10.5130/csr.v10i2.3474Crafton, D. (1993). Before Mickey. doi:10.7208/chicago/9780226231020.001.000

ACL reconstruction with unicondylar replacement in knee with functional instability and osteoarthritis

Severe symptomatic osteoarthritis in young and active patients with pre-existing deficiency of the anterior cruciate ligament and severe functionally instability is a difficult subgroup to manage. There is considerable debate regarding management of young patients with isolated unicompartment osteoarthritis and concomitant ACL deficiency. A retrospective analysis of was done in 9 patients with symptomatic osteoarthritis with ACL deficiencies and functional instability that were treated with unicompartment knee arthroplasty and ACL reconstruction between April 2002 and June 2005. The average arc of flexion was 119° (range 85° to 135°) preoperatively and 125° (range 105° to 140°). There were no signs of instability during the follow up of patients. No patients in this group were reoperated. In this small series we have shown that instability can be corrected and pain relieved by this combined procedure

The Impact of Biomechanics in Tissue Engineering and Regenerative Medicine

Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue replacements in vitro have recently begun to harness advances in understanding of how cells and tissues sense and adapt to their mechanical environment. It is clear that biomechanical considerations will be fundamental to the successful development of clinical therapies based on principles of tissue engineering and regenerative medicine for a broad range of musculoskeletal, cardiovascular, craniofacial, skin, urinary, and neural tissues. Biomechanical stimuli may in fact hold the key to producing regenerated tissues with high strength and endurance. However, many challenges remain, particularly for tissues that function within complex and demanding mechanical environments in vivo. This paper reviews the present role and potential impact of experimental and computational biomechanics in engineering functional tissues using several illustrative examples of past successes and future grand challenges.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78125/1/ten.teb.2009.0340.pd

Controlled Anchoring of Iron-Oxide Nanoparticles on Polymeric Nanofibers: Easy Access to Core@Shell Organic-Inorganic Nanocomposites for Magneto-Scaffolds

Composites combining superparamagnetic iron oxide nanoparticles (SPIONs) and polymers are largely present in modern (bio)materials. However, while SPIONs embedded in polymer matrices are classically reported, the mechanical and degradation properties of the polymer scaffold are impacted by the SPIONs. Therefore, the controlled anchoring of SPIONs onto polymer surfaces is still a major challenge. Herein, we propose an efficient strategy for the direct and uniform anchoring of SPIONs on the surface of functionalized-polylactide (PLA) nanofibers via a simple free ligand exchange procedure to design PLA@SPIONs core@shell nanocomposites. The resulting PLA@SPIONs hybrid biomaterials are characterized by electron microscopy (SEM and TEM) and EDXS analysis, to probe the morphology and detect elements present at the organic/inorganic interface, respectively. A monolayer of SPIONs with a complete and homogeneous coverage is observed on the surface of PLA nanofibers. Magnetization experiments show that magnetic properties of the nanoparticles are well-preserved after their grafting on the PLA fibers and that the size of the nanoparticles does not change. The absence of cytotoxicity, combined with a high sensitivity of detection in MRI both in vitro and in vivo make these hybrid nanocomposites attractive for the development of magnetic biomaterials for biomedical applications