Regular poly(para-phenylene) films bound to gold surfaces through the electrochemical reduction of diazonium salts followed by electropolymerization in an ionic liquid

International audienceBy combining the electroreduction of diazonium salts and the electropolymerization of conducting polymers in an ionic liquid, the electrografting of a regular poly(para-phenylene) film on a gold substrate is achieved, leading to the strong and robust anchoring of the PPP polymers on the substrate (Au-PPP hybrid). A thin layer covalently bound to the substrate is first prepared by the reduction of benzenediazonium salt (BD), then, on top of this layer, a thicker layer of poly(para-phenylene) (PPP) is easily grown by the electrochemical oxidation of biphenyl in the [BMIm][PF6] ionic liquid. The resulting material is thoroughly characterized by IR, ToF-SIMS and fluorescence spectroscopies. The analyses show the formation of well regular PPP layers that are wired to the substrate. The key role of the [BMIm][PF6] ionic liquid in the structuration of the polymer is emphasized

Jedediah Sklower, Free Jazz, la catastrophe féconde

Il y a incontestablement, depuis quelques années, un regain d’intérêt pour le free jazz. Pourquoi  ? Sans doute parce qu’il est cette inclassable « chose », comme l’appelait Georges Perec, qui incite la musique à ne pas céder au commerce et l’invite par son exemple à s’arracher à la « soupe » où elle risque toujours de s’engluer. Si elle a commencé aux États-Unis, l’aventure du free jazz a cependant connu en France un moment important de son histoire. Un livre en a déjà proposé une analyse fo..

Outcome of anterior lumbar interbody fusion : a retrospective study of clinical and radiologic parameters

Objective. This study aims to critically evaluate the long-term results of stand-alone anterior lumbar interbody fusion (ALIF), without use of rhBMP-2, as a therapeutic option for symptomatic patients with degenerative disc disease (DDD). Furthermore this study intends to identify predictive parameters for anterior lumbar interbody fusion outcome. Methods. A retrospective cohort study with additional telephone interview to obtain missing data was performed. All patients who underwent a L4-L5 and/or L5-S1 ALIF-procedure in the period between 2006 and 2011 were identified. The medical files of 123 patients with 154 fusion levels were reviewed. All patients were contacted by phone to gather supplementary and missing information. Pain and functionality scores (Visual Analogue Scale [VAS] and Oswestry Disability Index [ODI]), radiological (intervertebral disc height, Modic and Pfirrmann classifications) and different clinical parameters were gathered. Results. The mean age at surgery of the population was 46.2 years. Overall, 59 female and 64 male patients were included in the study. The mean visual analogue scales (VAS) for back and leg pain improved significantly (P<0.001) with 5 and 4.4 points respectively at 3 years follow-up. Modic-type I changes are associated with a better improvement in VAS-score for back pain (P=0.026), Pfirrmann-grades IV and V and an intervertebral disc height of less than 5 mm are associated with a better improvement in leg pain (respective P-values: 0.045 and 0.033). Overall, 89% of patients would reconsider the surgical intervention. Conclusions. The ALIF-technique is a durable treatment option for patients with DDD. This study suggests different predictive parameters for treatment outcome

Using IDPR to characterize recharge area of karst aquifers from catchment to regional scales

International audienceThe shape and the nature of hydrographic networks on karst environments are closely linked to the infiltration capacity of geological formations. Thus, the presence or absence of a river in a favorable topographic context can be interpreted in terms of karstic aquifers recharge potential. We present the GIS built index of infiltration and runoff properties of landscape (called IDPR) as an interesting tool for the characterization of the karst extension and for the further recharge estimation of such aquifers. A new version of the IDPR tool has been released over France in 2017 which spatial resolution (25 m) becomes very useful for the detection of contributive zones for karst aquifers recharge. Examples of the IDPR application at the river basin scale (Fontaine de Vaucluse) and at the regional scale (Rhone river basin) will be presented. Base flow estimation methods are used for the calibration of the IDPR index in terms of infiltration capacity, leading the IDPR index to be useful for recharge estimation

Indirect Electrografting of Aryl Iodides

International audienceThe electrografting of 4-iodonitrobenzene that is not possible directly is demonstrated whilst that of 5-iodo-2-amino-pyridine, 4-iodoaniline and iodobenzene is performed with a decrease of overpotential > 2 V. The electrografting of aryl iodides is achieved through a iodine abstraction reaction: in the presence of a sterically hindered diazonium salt (2,6-dimethylbenzenediazonium), the aryl iodide is grafted to gold at the much less negative reduction potential of the diazonium salt

Proteasome- and SCF-dependent degradation of yeast adenine deaminase upon transition from proliferation to quiescence requires a new F-box protein named Saf1p.

In response to nutrient limitation, Saccharomyces cerevisiae cells enter into a nonproliferating state termed quiescence. This transition is associated with profound changes in gene expression patterns. The adenine deaminase encoding gene AAH1 is among the most precociously and tightly down-regulated gene upon entry into quiescence. We show that AAH1 down regulation is not specifically due to glucose exhaustion but is a more general response to nutrient limitation. We also found that Aah1p level is tightly correlated to RAS activity indicating thus an important role for the proteine kinase A pathway in this regulation process. We have isolated three deletion mutants, srb10, srb11 and saf1 (ybr280c) affecting AAH1 expression during post-diauxic growth and in early stationary phase. We show that the Srb10p cyclin-dependent kinase and its cyclin, Srb11p, regulate AAH1 expression at the transcriptional level. By contrast, Saf1p, a previously uncharacterized F-box protein, acts at a post-transcriptional level by promoting degradation of Aah1p. This post-transcriptional regulation is abolished by mutations affecting the proteasome or constant subunits of the SCF (Skp1-Cullin-F-box) complex. We propose that Saf1p targets Aah1p for proteasomedependent degradation upon entry into quiescence. This work provides the first direct evidence for active degradation of proteins in quiescent yeast cells

Identification of Yeast and Human 5-Aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAr) Transporters

International audienc