Covalent grafting onto self-adhesive surfaces based on aryldiazonium salt seed layers

International audienceThe chemistry of aryldiazonium salts has been thoroughly used in recent years to graft in a very simple and robust way ultrathin polyphenylene-like films on a broad range of surfaces. We show here that the same chemistry can be used to obtain self-adhesive surfaces. This target was reached in a simple way by coating various surfaces with chemisorbed organic films containing active aryldiazonium salts. These self-adhesive surfaces are then put into contact with various species (molecules, polymers, nanoparticles, nanotubes, graphene flakes, etc.) that react either spontaneously or under activation with the immobilized aryldiazonium salts. Our self-adhesive surfaces were synthesized following a simple aqueous two-step protocol based on p-phenylenediamine diazotisation. The first diazotisation step results in the robust grafting of thin polyaminophenylene (PAP) layers onto the surface. The second diazotisation step changed the grafted PAP film into a poly-aryldiazonium polymer (PDP) film. The covalent grafting between those self-adhesive surfaces and the target species was achieved by direct contact or by immersion of the self-adhesive surfaces in solution. We present in this preliminary work the grafting of multi-wall carbon nanotubes (MWCNTs), flakes of highly oriented pyrolytic graphite (HOPG), various organic compounds and copper nanoparticles. We also tested these immobilized aryldiazonium salts as electropolymerization initiators for the grafting-to process

Platelet-rich plasma to treat jumper’s knee: preliminary results

peer reviewedIntroduction: Tendinopathies, especially jumper’s knee, often remain rebel to conservative treatments. Several experimental studies have shown the healing properties of platelet and their growth factors. Researches have specifically demonstrated the platelets action as mediator and/or enhancer of tissue healing. The aim of our study was to investigate the effect of 1 injection of PRP in patients suffering from chronic jumper’s knee. Our protocol was approved by Ethic Committee of University and University Hospital of Liège. Methods: Patients performed imaging (US and MRI) and functional assessments, and a clinical examination using an algometer, before treatment and 6 weeks after PRP treatment. They were also invited to answer to questionnaire relative to pain and functional status. PRP was obtained from autologous blood using an apheresis system (COM.TEC, Fresenius). The injection of 6mL of PRP was realised without local anaesthesia into the proximal insertion of the patellar tendon. A 48h rest-time was recommended after infiltration. Afterwards, a submaximal eccentric reeducation was initiated 1 week after infiltration 3 times a week during 5 weeks. In case of pain, anti-inflammatory drugs were prohibited and patient were encouraged to take class I or II painbrakers. Results: At this time, 10 patients with jumper’s knee were included in our study. Pre-injection tests revealed pain of the upper part of the patellar tendon just below the patella, associated with loss of function. Imaging exams confirmed diagnosis. Six weeks post-injection, the clinical status was improved in all patients, with a significant decrease of algo-functional scores. The pain reported during functional assessments was decreased (in particular for the eccentric actions), yet no significant improvement of physical performances was observed. We found no significant differences between imaging exams before and 6 weeks after PRP injection. Conclusion: One in situ injection of PRP clinically improved patients with jumper’s knee 6 weeks after treatment. All the 10 patients reported a decrease of pain during day-life and through physical activities. However nor functional performances neither imaging were improved

Indice de productivité des taillis-sous-futaie de chêne dans la région Centre

Afin de connaître et de mesurer l’aptitude pour la croissance de la production du chêne de stations portant actuellement des taillis-sous-futaie à base de chênes et souvent pauvres en réserves dans la région Centre, 17 couples > de chêne ont été repérés sur le terrain ; chaque couple se compose de 2 placettes, l’une établie en taillis-sous-futaie, l’autre en futaie, caractérisées par des conditions de station semblables. Le peuplement de futaie de chaque couple a fourni un indice de productivité de référence, défini comme le rapport de la hauteur dominante du peuplement à celle au même âge donnée par la table de production à classe de fertilité unique établie pour le chêne rouvre en secteur ligérien- Les indices de productivité ainsi évalués permettent de situer les 17 couples dans 3 classes de productivité (hauteur dominante à 160 ans du peuplement de futaie comprise entre 28 et 36 mètres). La recherche d’un indice de productivité pour les taillis-sous-futaie a été basée sur l’étude de la croissance en circonférence des arbres de réserve, s’appuyant sur des résultats antérieurs démontrant la bonne liaison existant avec la fertilité des stations. Il a de plus été tenté de rendre compte de l’effet de conditions de concurrence variées pour les réserves, dépendant en partie des traitements sylvicoles suivis, et qui peuvent être détectées et synthétisées par la mesure du rapport de la hauteur du houppier à la hauteur totale actuelle des arbres. Enfin, il a été tenté, par l’échantillonnage réalisé (arbres pris parmi les plus vigoureux dans chaque classe d’âge des taillis-sous-futaie), et lors de la définition de l’indice de productivité, de prendre en compte la variabilité individuelle des arbres, différente d’un peuplement à l’autre, ne serait-ce qu’en regard des grandes variations du nombre d’arbres de réserve à l’hectare.L’indice de productivité défini pour les taillis-sous-futaie de chêne a été identifié à une mesure particulière de la distribution des valeurs du rapport de la circonférence observée des arbres de réserve échantillonnés à la circonférence estimée (à partir de la relation établie entre la circonférence à 1,30 m, l’âge et la hauteur relative du houppier des arbres). L’indice de productivité des taillis-sous-futaie de chêne se trouve lié par une relation linéaire simple à l’indice de productivité défini pour les futaies. Il est rendu possible ainsi de comparer la productivité relative de stations portant des peuplements traités en taillis-sous-futaie et en futaie, donc d’adopter un même classement vis-a-vis de l’aptitude des stations à la croissance du chêne. Il est possible aussi de prévoir, grâce à la table de production pour les futaies de chêne de cette région, le niveau de production en volume qu’aurait un peuplement de taillis-sous-tutaie une fois converti en futaie, après détermination de sa productivité relative.The aim of this study is to know and measure capability for growth and production of oak of sites actually covered with stands treated as oak coppice-with-standards and often poor with standards in the Center region of France. Seventeen pairs of plots a high forest/coppice-with-standards have been established : each pair of plots includes one plot in an oak coppice-with-standards and the other one in an oak high forest, both in the same site conditions.The high forest plot of each « pair » gives a reference index of productivity for oak : it is defined as the ratio of top height of the stand to top height at the same age given by the single fertility class yield table for oak high forests of the Center region. Three productivity classes have been determined tor the seventeen pairs of plots, top height at age 160 varying from 28 to 36 meters. The research of and index of productivity for oak coppice-with-standards has been based on the study of girth development of the standards (previous results had shown a good relationship with fertility of sites). Other factors of girth growth have been considered : past competitive conditions for the standards synthesizecl by the actually measured ratio of crown, height to total height of trees, individual variabilily of trees (in particular by sampling « picked trees » in the population of the standards of each coppice-with-standards). A relationship between breast height girth of the standards, age and relative crown height of trees has been established. The productivity index for oak coppice-with-standards has then been identified as a particular measure of the distribution of values of the ratio of observed to estimated girth (former relation) of sampled standards in each coppice-withstandards plot. A simple linear relationship has been established between the productivity index for oak coppice-with-standards and the productivity index for oak high forests. It allows comparaison of relative productivity of sites with the one or the other type of oak stand. It allows also to predict volume productivity of known relative productivity oak coppicewith-standards which would be converted to high forests stands, with the help of the yield table for oak high forests of the Center region. Practical application of the results of this study, that is estimation of the index of productivity of oak coppice-with-standards, received particular attention : people interested will find in Appendix, with a definite example, all details on the way to use basic relations and figures necessary for this estimation

Effets des éclaircies et du climat sur la croissance de la tige et le développement du houppier du hêtre (Fagus sylvatica L.) dans l'expérience de Souilly

Rapport de convention de collaboration INRA/ONF. Volet 2 du programme "Hêtraies de basse altitude" du GIP ECOFOR "Dynamique de la croissance individuelle et collective du hêtre sous contrainte concurrentielle" *INRA, Centre de Nancy, Equipe Croissance et Production, 54280 Champenoux, (FRA) Diffusion du document : INRA, Centre de Nancy, Equipe Croissance et Production, 54280 Champenoux, (FRA)National audienc

Effet des éclaircies sur la croissance du hêtre. Interaction avec les facteurs climatiques

Fonctionnement des arbres et écosystèmes forestiers. Avancées récentes et conséquences sylvicolesNational audienc

Diagnostic stationnel et potentiel de production

24 ref.;no sp. Diagnostics en foretNational audienc

Effet des éclaircies sur la croissance du hêtre. Interaction avec les facteurs climatiques

National audienc