Synthèse et caractérisation de systèmes conjugués hybrides thiophène-phénylene pour dispositifs électroniques

Date du colloque&nbsp;: 10/2009</p

Quaterthiophenes with Terminal Indeno[1,2-b]thiophene Units as p-Type Organic Semiconductors

Quaterthiophenes 4T, Oct-4T, and Tol-4T based on a central 2,2′-bithiophene core α,ω-terminated with 4,4-unsubstituted and 4,4-disubstituted n-octyl or p-tolyl indeno[1,2-b]thiophene have been synthesized by Stille or Miyaura−Suzuki couplings. Compound 4T was also synthesized by an alternative route involving a soluble precursor bearing solubilizing trimethylsilyl groups which have been eliminated in the last step. The electronic properties of the compounds have been analyzed by cyclic voltammetry, UV−vis absorption and fluorescence emission spectroscopy. Thermal evaporation of 4T and Oct-4T leads to crystalline thin films and UV−vis absorption and X-ray diffraction data for these films suggest that the molecules adopt a quasi-vertical orientation onto the substrate. Strong π-π intermolecular interactions have been observed for 4T but not for molecules Oct-4T due to the presence of n-octyl chains. Sublimed thin films of Tol-4T show an amorphous character. The characterization of field-effect transistors fabricated from these three materials gave a hole-mobility of 2.2 × 10−2 cm2 V−1 s−1 with an on/off ratio of 2.2 × 104 for 4T while no field-effect was observed for Oct-4T and Tol-4T

Controlled assembly of SNAP-PNA-fluorophore systems on DNA templates to produce fluorescence resonance energy transfer

The SNAP protein is a widely used self-labeling tag that can be used for tracking protein localization and trafficking in living systems. A model system providing controlled alignment of SNAP-tag units can provide a new way to study clustering of fusion proteins. In this work, fluorescent SNAP-PNA conjugates were controllably assembled on DNA frameworks forming dimers, trimers, and tetramers. Modification of peptide nucleic acid (PNA) with the O6-benzyl guanine (BG) group allowed the generation of site-selective covalent links between PNA and the SNAP protein. The modified BG-PNAs were labeled with fluorescent Atto dyes and subsequently chemo-selectively conjugated to SNAP protein. Efficient assembly into dimer and oligomer forms was verified via size exclusion chromatography (SEC), electrophoresis (SDS-PAGE), and fluorescence spectroscopy. DNA directed assembly of homo- and hetero-dimers of SNAP-PNA constructs induced homo- and hetero-FRET, respectively. Longer DNA scaffolds controllably aligned similar fluorescent SNAP-PNA constructs into higher oligomers exhibiting homo-FRET. The combined SEC and homo-FRET studies indicated the 1:1 and saturated assemblies of SNAP-PNA-fluorophore:DNA formed preferentially in this system. This suggested a kinetic/stoichiometric model of assembly rather than binomially distributed products. These BG-PNA-fluorophore building blocks allow facile introduction of fluorophores and/or assembly directing moieties onto any protein containing SNAP. Template directed assembly of PNA modified SNAP proteins may be used to investigate clustering behavior both with and without fluorescent labels which may find use in the study of assembly processes in cells

Gaviscon® vs. omeprazole in symptomatic treatment of moderate gastroesophageal reflux. a direct comparative randomised trial

<p>Abstract</p> <p>Background</p> <p>Medical management of GERD mainly uses proton pump inhibitors. Alginates also have proven efficacy. The aim of this trial was to compare short-term efficacy of an alginate (Gaviscon^®, 4 × 10 mL/day) and omeprazole (20 mg/day) on GERD symptoms in general practice.</p> <p>Methods</p> <p>A 14-day multicentre randomised double-blind double-dummy non-inferiority trial compared Gaviscon^®(4 × 10 mL/day) and omeprazole (20 mg/day) in patients with 2-6 day heartburn episodes weekly without alarm signals. The primary outcome was the mean time to onset of the first 24-h heartburn-free period after initial dosing. Secondary outcomes were the proportion of patients without heartburn by D7, pain relief by D7, and reduction in pain intensity by D7 and D14.</p> <p>Results</p> <p>278 patients were recruited; 120 were included in the Gaviscon^®group and 121 in the omeprazole group for the per protocol non-inferiority analysis. The mean time to onset of the first 24-h heartburn-free period after initial dosing was 2.0 (± 2.2) days for Gaviscon^®and 2.0 (± 2.3) days for omeprazole (<it>p </it>= 0.93); mean intergroup difference was 0.01 ± 1.55 days (95% CI = -0.41 to 0.43): i.e., less than the lower limit of the 95% CI of -0.5 days predetermined to demonstrate non-inferiority. The mean number of heartburn-free days by D7 was significantly greater in the omeprazole group: 3.7 ± 2.3 days vs. 3.1 ± 2.1 (<it>p </it>= 0.02). On D7, overall quality of pain relief was slightly in favour of omeprazole (<it>p </it>= 0.049). There was no significant difference in the reduction in pain intensity between groups by D7 (<it>p = </it>0.11) or D14 (<it>p = </it>0.08). Tolerance and safety were good and comparable in both groups.</p> <p>Conclusion</p> <p>Gaviscon^®was non-inferior to omeprazole in achieving a 24-h heartburn-free period in moderate episodic heartburn, and is a relevant effective alternative treatment in moderate GERD in primary care.</p> <p>Trial registration</p> <p><a href="http://www.controlled-trials.com/ISRCTN62203233">ISRCTN62203233</a>.</p

Anodic cyanation of (S)-(–)-1-(1-phenetyl)piperidine: an expedition synthesis of (S)(+)-Coniine

International audienc

Joint Bone Spine

INTRODUCTION: Physical therapy (PT) represents a major approach in musculoskeletal (MSK) pain. This study aimed to assess kinesiophobia, its impact and management, in patients with MSK pain treated by PT. METHODS: A national multicentre, prospective study was conducted in France in patients with MSK pain referred to PT. Kinesiophobia was scored with the Tampa Scale of Kinesiophobia (TSK). Pain, satisfaction, analgesic intake and acceptability were assessed at the initial visit, at the 5th PT session, and at the end of PT. RESULTS: 700 consecutive outpatients with MSK pain, 54.5% female, referred to PT were recruited by 186 GPs: 501 had significant levels of kinesiophobia (TSK score > 40). Patients with kinesiophobia were significantly older, with less physical activity, more pain and less acceptability. Patients from GPs presenting with kinesiophobia had both higher pain and kinesiophobia levels. After 5 PT sessions, global satisfaction was significantly higher in patients without kinesiophobia. A significant increase of PT satisfaction was observed in patients who had been given preventive analgesics before PT sessions, in 25.6% of patients. Independent predictors for specific management of PT-induced pain were: patient's kinesiophobia (OR = 2.02 [1.07-3.82]), current analgesics treatment (OR=2.05 [1.16-3.63]), GP with postgraduate course on pain (OR = 2.65 [1.29-5.43]), GP's independent practice (OR = 1.88 [1.01-3.48]). CONCLUSION: Kinesiophobia is frequent in patients with MSK pain, is associated to GPs' kinesiophobia and decreases satisfaction of Physical Therapy. Preventive analgesic treatment before PT sessions improves patients' satisfaction and should be proposed to improve MSK pain management