350 research outputs found

    Highly efficient multilayer organic pure-blue-light emitting diodes with substituted carbazoles compounds in the emitting layer

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    Bright blue organic light-emitting diodes (OLEDs) based on 1,4,5,8,N-pentamethylcarbazole (PMC) and on dimer of N-ethylcarbazole (N,N'-diethyl-3,3'-bicarbazyl) (DEC) as emitting layers or as dopants in a 4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (DPVBi) matrix are described. Pure blue-light with the C.I.E. coordinates x = 0.153 y = 0.100, electroluminescence efficiency \eta_{EL} of 0.4 cd/A, external quantum efficiency \eta_{ext.} of 0.6% and luminance L of 236 cd/m2 (at 60 mA/cm2) were obtained with PMC as an emitter and the 2,9-dimethyl-4,7-diphenyl-1,10-phenantroline (BCP) as a hole-blocking material in five-layer emitting devices. The highest efficiencies \eta_{EL.} of 4.7 cd/A, and \eta_{ext} = 3.3% were obtained with a four-layer structure and a DPVBi DEC-doped active layer (CIE coordinates x = 0.158, y=0.169, \lambda_{peak} = 456 nm). The \eta_{ext.} value is one the highest reported at this wavelength for blue OLEDs and is related to an internal quantum efficiency up to 20%

    Le sexage morphologique du saumon atlantique (Salmo salar)

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    Exemples de résultats de la recherche obtenus sur les populations sauvages de salmonides de Bretagne et de Basse-Normandie et applicables à leur gestion

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    Ces dernières années, un ensemble de méthodes et techniques d'étude a été mis au point ou amélioré à partir de recherches réalisées sur les populations sauvages de salmonides. Dans un premier temps, ces nouvelles techniques peuvent être considérées comme des outils disponibles pour les gestionnaires; ce sont : la mise en place et l'homogénéisation de critères scalimétriques pour la détermination de l'âge des salmonidés migrateurs; la détermination du sexe par sérodiagnostic et à partir de critères morphométriques; l'estimation de la production en smolts de saumon à partir de l'habitat et des caractéristiques des peuplements automnaux. Dans un deuxième temps, l'application de certaines de ces méthodes dans le domaine écologique a permis d'obtenir des éléments essentiels pour la connaissance et/ou la gestion des populations sauvages de salmonides.Turing the fast few years some new techniques for the study of wild populations of salmonids have been developed. The following procedures are intended to provide.1) an improved method for determining age by scale-reading, particularly with migratory salmonids (Atlantic salmon and sea trout). A standard zone for removing scales, the presence of three different zones on each scale (river, run-out, sea) and some criteria for scale interpretation have all been defined. These criteria are mainly concerned with the structure of the scale during the sea-life stage and reproduction. On the other hand, a spawning mark has been determined for both sedentary and migratory salmonids.2) an means of sex determination. Two techniques have been proposed :- the first one is based on the detection by immunoagglutination of the serum vitellogenin of females in active gametogenesis. This method concerns females only; it does not allow a distinction to he made between non spermating males and immature salmonids. It is a very reliable technique which can be used in field conditions, but only by experienced researchers;- the second technique is based on the sexual dimorphism of the relative length of the upper jaw bone. It is very reliable (8 % to 12 % error) and can also be applied in field conditions, but only for large fish (fork length > 40-45 cm).3) a way of estimating Atlantic salmon smolt production. This technique is based on :- the estimation of a 0+ and 1+ salmon population in the whole river from data of density obtained in sectors representative of the different types of habitat ;- the presence of growth bimodality in a 0+ salmon population in autumn, given the following hypothesis : one yearold smolts belong to the upper mode ;- the estimation of mortality for the whole winter season.This technique has been used in the River Oir and compared with a smolt-trapping experiment conducted for two years. A comparison of the results shows that :- the one year-old smolts belong to the upper mode of bimodality;- when based on data on habitat characteristics, this technique can be used in field conditions to evaluate the smolts with sufficient accuracy.All three techniques are immediately available as useful methods for fisheries management. At a second stage, they can also serve in ecological research to advance knowledge on which to base further study and improved management of wild salmonid populations

    Easy ruthenium-catalysed oxidation of primary amines to nitriles under oxidant free conditions

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    International audienceA dehydrogenation of primary amine to give the corresponding nitrile under oxidant-and base-free conditions catalysed by simple [Ru(p-cym)Cl2]2 with no extra ligand is reported. The system is highly selective for alkyl amine whereas benzylamine derivatives gave the nitrile product together with the imine in ratio ranging from 14:1 to 4:1 depending on the substrate. Preliminary mechanistic investigations have been performed to identify the key factors that govern the selectivity

    Synthesis of alternating metallocopolymers by chiral recognition

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    International audienceWe report the synthesis of chiral enantiopure polytopic bridging ligands, which may lead to the formation of metallosupramolecular polymers with zinc (II) as metal linker. We show that chiral C2‐symmetric bisoxazoline ligands are useful moieties to efficiently generate heterochiral complexes and thus polymeric entities. The corresponding metallopolymers were further characterized by powder X‐ray diffraction (PXRD) to obtain information on the level of crystallinity of our different metallopolymers

    Limites de la méthode de reconnaissance de l'origine (marine ou dulcicole) de la truite (Salmo trutta L.) au moyen de l'analyse de la teneur en strontium des écailles

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    National audienceStrontium content of scales of anadromous and freshwater trout caught in rivers in Basse-Normandie, varies with drainage basin, time spent in the sea and date of capture. The influence of this last factor is probably in relation to sexual maturation.La teneur en strontium des écailles de truites, d'origines anadrome et dulcicole, capturées dans des rivières de Basse-Normandie, dépend du réseau hydrographique, du temps de séjour en mer et de la date de capture. L'influence de ce dernier facteur est probablement liée à la maturation sexuelle

    Treatment with biologic agents in child and adolescent

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    OBJETIVO: Revisar os mecanismos fisiopatológicos e novos alvos terapêuticos, os agentes biológicos disponíveis, principais indicações e a evidência científica atual para o uso de terapias biológicas na população pediátrica. FONTES DE DADOS: Pesquisa na base de dados Medline e SciELO, nas línguas inglesa e portuguesa, entre 2000 e 2009. As palavras-chave usadas foram "agentes biológicos", "crianças" e "adolescentes". SÍNTESE DOS DADOS: Os agentes biológicos são uma importante opção terapêutica para tratar as doenças autoimunes refratárias às terapias convencionais na infância e na adolescência. Com exceção da artrite idiopática juvenil, a maioria dos estudos em outras doenças autoimunes não é controlada. CONCLUSÕES: Os agentes biológicos têm demonstrado eficácia no tratamento de doenças autoimunes pediátricas como artrite idiopática juvenil, miopatias idiopáticas inflamatórias, lúpus eritematoso juvenil, vasculites, uveítes crônicas, doenças inflamatórias intestinais e púrpura trombocitopênica imune crônica, assim como no linfoma não-Hodgkin. Considerando-se o custo elevado e os potenciais eventos adversos, o uso desses agentes deve ser individualizado e acompanhado por especialista.OBJECTIVE: To review the physiopathology and new therapeutical targets, the available biologic agents, the main indications and the current scientific evidence for the use of biological therapies in the pediatric population. DATA SOURCES: A bibliographical search was obtained from Medline and SciELO databases in English and Portuguese from 2000 to 2009. The key-words included were "biologic agent", "children" and "adolescent". DATA SYNTHESIS: Biologic agents are important therapeutic options to treat refractory autoimmune diseases to conventional therapies in childhood and adolescence. Excluding juvenile idiopathic arthritis, the majority of studies in other autoimmune diseases are uncontrolled trials. CONCLUSIONS: Biologic agents have shown efficacy in the treatment of pediatric autoimmune diseases such as juvenile idiopathic arthritis, idiopathic inflammatory myositis, juvenile systemic lupus erythematosus, vasculitis, chronic uveitis, inflammatory bowel diseases, and chronic immune thrombocytopenic purpura, as well as in non-Hodgkin lymphoma. Considering the high cost and the potential adverse events, the choice to use them must be individualized and followed by a specialist

    Optimization of somatic cell injection in the perspective of nuclear transfer in goldfish

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    <p>Abstract</p> <p>Background</p> <p>Nuclear transfer has the potential to become one strategy for fish genetic resources management, by allowing fish reconstruction from cryopreserved somatic cells. Survival rates after nuclear transfer are still low however. The part played by unsuitable handling conditions is often questioned, but the different steps in the procedure are difficult to address separately. In this work led on goldfish (<it>Carassius auratus</it>), the step of somatic cells injection was explored. Non-enucleated metaphase II oocytes were used as a template to explore the toxicity of the injection medium, to estimate the best location where the cell should be injected, and to assess the delay necessary between cell injection and oocyte activation.</p> <p>Results</p> <p>Trout coelomic fluid was the most suitable medium to maintain freshly spawned oocytes at the metaphase II stage during oocyte manipulation. Oocytes were then injected with several media to test their toxicity on embryo development after fertilization. Trout coelomic fluid was the least toxic medium after injection, and the smallest injected volume (10 pL) allowed the same hatching rates as the non injected controls (84.8% ± 23). In somatic cell transfer experiments using non enucleated metaphase II oocytes as recipient, cell plasma membrane was ruptured within one minute after injection. Cell injection at the top of the animal pole in the oocyte allowed higher development rates than cell injection deeper within the oocyte (respectively 59% and 23% at mid-blastula stage). Embryo development rates were also higher when oocyte activation was delayed for 30 min after cell injection than when activation was induced without delay (respectively 72% and 48% at mid-blastula stage).</p> <p>Conclusions</p> <p>The best ability of goldfish oocytes to sustain embryo development was obtained when the carrier medium was trout coelomic fluid, when the cell was injected close to the animal pole, and when oocyte activation was induced 30 min after somatic cell injection. Although the experiments were not designed to produce characterized clones, application of these parameters to somatic cell nuclear transfer experiments in enucleated metaphase II oocytes is expected to improve the quality of the reconstructed embryos.</p

    Trochanteric locking nail versus arthroplasty in unstable intertrochanteric fracture in patients aged over 75 years

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    SummaryIntroductionIn trochanteric fracture, whatever its anatomic type, internal fixation is currently the standard attitude, with arthroplasty as a relatively unusual option.HypothesisHip implants are an excellent alternative to osteosynthesis in unstable trochanteric fracture in patients aged over 75 years.Patients and methodsA non-randomised prospective multicenter study compared osteosynthesis by trochanteric nailing (n=113) to hip arthroplasty (n=134) in unstable trochanteric fracture (AO types 31 A2.2 and 3 and A3.3) in 247 patients over the age of 75 years. The series was recruited during 2007 in seven centres, four of which included only arthroplasties, two only osteosyntheses and one both. The two groups were comparable in age, sex, preoperative Parker score, pre-fracture place of residence, fracture type, time to surgery and preoperative comorbidity. The sole difference was in operators, with more senior surgeons in arthroplasty (62% versus 27%).ResultsThree-month mortality was identical in the two groups (21.2% versus 21%). General complications did not differ, although mechanical complications were more frequent in the nailing group (12.5% versus 2.8%). Functional results (Parker and PMA scores) were better in the implant than in the nail group.DiscussionThe present study validated hip arthroplasty in these indications. Cemented stems associated to a dual-mobility acetabular component gave the best results.Type of studyProspective, level of evidence III

    Assistência Médica por Ciclos de Vida

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    As competências de um Médico de Família necessárias para atuação na estratégia de saúde da família, extrapolam seu núcleo de formação, geralmente voltadas à resolução de patologias instaladas e com pouca ênfase na promoção à saúde dos indivíduos. Para trabalhar na Estratégia de Saúde da Família, exigem-se do profi ssional médico outras habilidades e conhecimentos, para que possa aprender a administrar seu tempo ao realizar as ações indicadas no Pacto de Atenção à Saúde, planejar e gerenciar as ações voltadas às situações de risco à saúde, avaliar essas ações. Além disso precisa desenvolver competências para trabalhar em equipe, partilhando responsabilidades e decisões.1.0MINISTÉRIO DA SAÚDEUna-SU
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