Silicone-Supported Cinchona Alkaloid Derivatives as Insoluble Organocatalysts in the Enantioselective Dimerization of Ketenes

A straightforward procedure is presented for the covalent immobilization of ester and silyl ether derivatives of the Cinchona alkaloid 10,11-dihydroquinidine within insoluble cross-linked silicone elastomeric films. These materials were effective heterogeneous organocatalysts in the asymmetric dimerization of ketenes, which provided chiral Weinreb β-ketoamides in 28–83 yield and 79–99 ee in the course of several recycles. A productivity/enantioselectivity protocol is also proposed to better assess the relative merits of soluble and supported asymmetric catalytic systems towards process intensification

Value of ultrasonography as a marker of early response to abatacept in patients with rheumatoid arthritis and an inadequate response to methotrexate: results from the APPRAISE study

Objectives: To study the responsiveness of a combined power Doppler and greyscale ultrasound (PDUS) score for assessing synovitis in biologic-naïve patients with rheumatoid arthritis (RA) starting abatacept plus methotrexate (MTX). Methods: In this open-label, multicentre, single-arm study, patients with RA (MTX inadequate responders) received intravenous abatacept (∼10 mg/kg) plus MTX for 24 weeks. A composite PDUS synovitis score, developed by the Outcome Measures in Rheumatology–European League Against Rheumatism (OMERACT–EULAR)-Ultrasound Task Force, was used to evaluate individual joints. The maximal score of each joint was added into a Global OMERACT–EULAR Synovitis Score (GLOESS) for bilateral metacarpophalangeal joints (MCPs) 2–5 (primary objective). The value of GLOESS containing other joint sets was explored, along with clinical efficacy. Results: Eighty-nine patients completed the 24-week treatment period. The earliest PDUS sign of improvement in synovitis was at week 1 (mean change in GLOESS (MCPs 2–5): −0.7 (95% CIs −1.2 to −0.1)), with continuous improvement to week 24. Early improvement was observed in the component scores (power Doppler signal at week 1, synovial hyperplasia at week 2, joint effusion at week 4). Comparable changes were observed for 22 paired joints and minimal joint subsets. Mean Disease Activity Score 28 (C reactive protein) was significantly reduced from weeks 1 to 24, reaching clinical meaningful improvement (change ≥1.2) at week 8. Conclusions: In this first international prospective study, the composite PDUS score is responsive to abatacept. GLOESS demonstrated the rapid onset of action of abatacept, regardless of the number of joints examined. Ultrasound is an objective tool to monitor patients with RA under treatment. Trial registration number: NCT00767325

26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)

Physical modelling of surface fire under non-parallel wind and slope conditions

International audienceThe physical model we developed in a previous work (Balbi et al., 2007) predicts fire behaviour with a computational time that is faster than real time. However it has the inconvenient of introducing an empirical law (McCaffrey, 1979) which provides flame height according to heat release rate. The present study introduces two improvements of this model: the triangular flame hypothesis and a modification taking into account the air cooling on the rear fire front. To test this variant of our simplified model, it was compared with important experimental results (Viegas, 2004). The experiments were performed in homogeneous and plane fuel beds made with dead Pinus pinaster needles under high values of wind and slope. In spite of these high values this physical model provides a good approximation of the fire front perimeter

A 3D physical model of surface fires under critical conditions at laboratory scale

International audienceThe physical model we developed in a previous work [1] predicts fire behaviour with a computational time faster than real time, but it has the inconvenient of introducing an empirical law [2] which provides flame height according to heat release rate. The present study introduces two improvements of this model: the triangular flame hypothesis and a modification taking into account the air cooling on the rear fire front. To test this variant of our simplified model, it has been compared with important experimental results [3]. The experiments were performed in homogeneous and plane fuel beds made with dead needles of Pinus pinaster under high values of wind and slope. In spite of high values of wind and slope this physical model provides a good approximation of the fire front perimeter

Upslope fire and eruptive fire

International audienc

A 3D physical real-time model of surface fires across fuel beds

International audienceThis work presents a new modelling approach to the elaboration of a simple model of surface fire spread. This model runs more fastly than real-time and will be integrated in management tools. Up to now, models used in such tools have been based on empirical relationship. These tools may be efficient for conditions that are comparable to those of test-fires but the absence of a physical description makes them inapplicable to other situations. This paper proposes a physical 3D model of surface fire able to predict fire behaviour faster than real-time. This model is tested on experiments carried out across fuel beds under slope and wind conditions

A review of current knowledge of wildfire firefighter safety zones

International audienc

Dominant preheating transfer mechanism in wildfire propagation: radiation or convection ?

International audienceSeveral studies in the literature explore the connection between rate of spread (ROS) and wind speed in wildland fires. This relationship is often expressed as a power function but the exponents differ from an author to another one. The main goal of this work is to propose a simplified physical propagation model for surface fires that gives the relative contributions of the two transfer modes to the fuel preheating. The dominant heat transfer mode, radiation or convection, involve different curve shapes of the ROS as function of the wind speed which match all the empirical power functions found in the literature. The model exhibits two wind speed threshold that are defined as transitions between radiation and convection. The predicted ROS is compared with 226 laboratory experimental fires of the literature, with differing fuel bed arrangements (continuous or discontinuous fuel), a wide range of fuel bed properties (such as surface-area-to-volume ratio, moisture content, loading, depth...) and varying slope conditions. Statistical tools are used to check the agreement between predicted and observed ROS