Total synthesis of Crotogossamide using an on-resin concomitant cyclization/cleavage reaction

Crotogossamide, a cyclic peptide isolated from the latex of Croton gossypifolius, has been synthesized by a rapid and efficient Boc solid-phase peptide synthesis. The strategy takes advantage of the oxime resin nucleophile susceptibility and comprises the synthesis of a linear precursor followed by on-resin head-to-tail concomitant cyclization/cleavage. In addition, we report the first antimicrobial and antibiofilm investigations on Crotogossamide

Three distinct sarcomeric patterns of skeletal muscle revealed by SHG and TPEF microscopy.

International audienceWe have extensively characterized the sarcomeric SHG signal as a function of animal species (rat versus xenopus), age (adult versus larval) and tissue preparation (fixed or fresh) and we found that the main feature of this signal is a single peak per mature sarcomere (about 85% of all sarcomeres). The remaining (15%) was found to be either double peak per mature sarcomere or mini sarcomeres (half of a sarcomere) using alpha-actinin immuno detection of the Z-band. The mini sarcomeres are often found in region of pitchfork-like SHG pattern. We suggest that double peak SHG pattern could indicate regions of sarcomeric proteolysis whereas pitchfork-like SHG pattern could reveal sarcomeric assembly

Protective effect of Ruta Chalepensis L. extract on oxidative stress and liver-kidney function induced by polymicrobial sepsis in rats

Sepsis, a systemic inflammatory disease developed after an infectious insult and remains the major cause of death in intensive care units. The aim of this study was to examine the protective effect of the ethanolic extract of Ruta chalepensis L. (ERC) against oxidative stress and liver-kidney functions in cecal and ligation puncture (CLP) rats. In vitro, the results showed that ERC rich in phenolic compounds possessed important antioxidant activity. In vivo, CLP-induced oxidative stress evidenced by the increase of the TBARS and decrease in the enzymatic antioxidants (SOD, CAT, GPX) in liver and kidney. Moreover, CLP induced liver-kidney toxicities showed by an increase in the ALT, AST, PAL, LDH, BUN and creatinine in the plasma. However, the administration of ERC to CLP-rats prevents all these disorders. Positive action of ERC was confirmed by histo-pathological examination. Therefore this study suggests that ERC could be a potential therapeutic agent for sepsis treatment

Hydrolytic kinetic model predicting embrittlement in thermoplastic elastomers

A hydrolytic kinetic model predicting chains scissions of a polyurethane elastomer (TPU) containing an anti-hydrolysis agent (stabilization via carbodiimide) was developed. This model is based on four components: uncatalysed hydrolysis, acid-catalysed hydrolysis, carboxylic acid dissociation and competitive carbodiimide-based deactivation of acid. Protons were considered as the key catalyst responsible for the hydrolysis. Model parameters were determined by fitting experimental data measured on unstabilized and stabilized TPUs, aged in immersion from 40 to 90 °C. Scission kinetics were predicted for immersion and 50% relative humidity conditions, from 10 to 100 °C. Structure-failure property relationships were also investigated, between molar mass and elongation at break. A master curve was established for elongation at break with molar mass, including both TPUs at four ageing temperatures. By combining predictions for scission kinetics with the molar mass-elongation at break master curve and an embrittlement molar mass as the end-of-life criterion, non-Arrhenian lifetime predictions are proposed for all exposure conditions considered

Efficient second harmonic generation in nanophotonic waveguides for optical signal processing

International audienceWe report very efficient second harmonic generation in membrane photonic crystal waveguide. The combination of absorption-free material and slow-light enhancement enables a large harmonic generation efficiency. A peak pump power of about 450 mW generates up to 45 lW peak second harmonic power over a broad spectral range. The signal is exploited to demonstrate optical performance monitoring of data at 42 Gb/s

Free-carrier-induced soliton fission unveiled by in situ measurements in nanophotonic waveguides

Solitons are localized waves formed by a balance of focusing and defocusing effects. These nonlinear waves exist in diverse forms of matter yet exhibit similar properties including stability, periodic recurrence and particle-like trajectories. One important property is soliton fission, a process by which an energetic higher-order soliton breaks apart due to dispersive or nonlinear perturbations. Here we demonstrate through both experiment and theory that nonlinear photocarrier generation can induce soliton fission. Using near-field measurements, we directly observe the nonlinear spatial and temporal evolution of optical pulses in situ in a nanophotonic semiconductor waveguide. We develop an analytic formalism describing the free-carrier dispersion (FCD) perturbation and show the experiment exceeds the minimum threshold by an order of magnitude. We confirm these observations with a numerical nonlinear Schrödinger equation model. These results provide a fundamental explanation and physical scaling of optical pulse evolution in free-carrier media and could enable improved supercontinuum sources in gas based and integrated semiconductor waveguides

Efficient Second Harmonic Generation in Photonic Crystal Waveguides for Optical Performance Monitoring in the Full C- Band at 42.5 Gb/s

International audienceWe demonstrate 20 µW second harmonic generation in a photonic crystal waveguide. The collected signal has been used for optical performance monitoring of the chromatic dispersion and optical signal to noise ratio of a 42.5 Gb/s Return to Zero signal all over the C-band

The systematic early integration of palliative care into multidisciplinary oncology care in the hospital setting (IPAC), a randomized controlled trial : the study protocol

Background: Previous studies in the US and Canada, have shown the positive impact of early palliative care programs for advanced cancer patients on quality of life (QoL) and even survival time. There has been a lack of similar research in Europe. In order to generalize the findings from the US and Canada research on a larger scale, similar studies are needed in different countries with different care settings. The aim of this paper is to describe the research protocol of a randomized controlled trial, situated in Flanders, Belgium, evaluating the effect of systematic early integration of palliative care in standard oncology care. Methods/Design: A randomized controlled trial will be conducted as follows: 182 patients with advanced cancer I be recruited from the departments of Medical Oncology, Digestive Oncology and Thoracic Oncology of the Ghent University Hospital. The trial will randomize patients to either systematic early integration of palliative care in standard oncology care or standard oncology care alone. Patients and informal caregivers will be asked to fill out questionnaires on QoL, mood, illness understanding and satisfaction with care at baseline, 12 weeks and every six weeks thereafter. Other outcome measures are end-of-life care decisions and overall survival time. Discussion: This trial will be the first randomized controlled trial in the Belgian health care setting to evaluate the effect of systematic early integration of palliative care for advanced cancer patients. The results will enable us to evaluate whether systematic early integration of palliative care has positive effects on QoL, mood and patient illness-understanding and which components of the intervention contribute to these effects