Experimental Measurement of Local Burning Velocity Within a Rotating Flow

The final publication is available at link.springer.com.The work presented in this paper details the implementation of a new technique for the measurement of local burning velocity using asynchronous particle image velocimetry. This technique uses the local flow velocity ahead of the flame front to measure the movement of the flame by the surrounding fluid. This information is then used to quantify the local burning velocity by taking into account the translation of the flame via convection. In this paper the developed technique is used to study the interaction between a flame front and a single toroidal vortex for the case of premixed stoichiometric methane and air combustion. This data is then used to assess the impact of vortex structure on flame propagation rates. The burning velocity data demonstrates that there is a significant enhancement to the rate of flame propagation where the flame directly interacts with the rotating vortex. The increases found were significantly higher than expected but are supported by burning velocities [22-24] found in turbulent flames of the same mixture composition. Away from this interaction with the main vortex core, the flame exhibits propagation rates around the value recorded in literature for unperturbed laminar combustion [18-21]

Presumptive analysis of 4-methylmethcathinone (mephedrone) using Desorption Electrospray Ionisation - Mass Spectrometry (DESI-MS)

© 2014 Australian Academy of Forensic Sciences. 4-Methylmethcathione (4-MMC or mephedrone) is a prevalent drug of abuse globally. 4-MMC is often marketed as bath salts and is readily available over the internet. The need for a rapid universal technique capable of detecting an extensive range of drug compounds has become increasingly important with the continued emergence of novel drug analogues. Desorption electrospray ionisation - mass spectrometry (DESI-MS) is a mass spectrometry technique that allows for the analysis of compounds directly from ambient surfaces, reducing or eliminating the need for sample preparation. Although 4-MMC has gained significant attention in recent years, the application of the DESI-MS technique to the fast presumptive detection and chemical analysis of this analogue has not been presented. In the present study, DESI-MS was applied to the rapid qualitative analysis of 4-MMC. A particularly suitable surface, semi-porous polytetrafluoroethylene (PTFE, Teflon) was utilised, as it generated the least variable signal and reproducibility compared to other surfaces (polymethyl-methacrylate (PMMA) and polyvinyl chloride (PVC)). Selectivity of the technique to the detection of 4-MMC was evaluated by analysing a range of adulterated samples including mixtures containing caffeine, methylamphetamine, cathinone and paracetamol. Specificity based on tandem MS (MS/MS) was also demonstrated by analysing substances with the same molecular formula as 4-MMC. Accuracy (% RE) and precision (% RSD) of the method were found to be within 13% and 38%, respectively; and therefore the quantitative data provided by the DESI-MS method is limited compared to gas chromatography-mass spectrometry (GC-MS; accuracy < 13% and precision < 12%). The results suggest that DESI-MS can greatly aid in the rapid presumptive identification of 4-MMC and other similar novel drug analogues

Leucettines, a family of pharmacological inhibitors of DYRKs and CLKs kinases derived from the marine sponge Leucettamine B

International audienceWe here report on leucettines, a family of kinase inhibitors derived from the marine sponge leucettamine B. Stepwise synthesis of analogues, followed by activity testing on 8 purified kinases led to highly potent inhibitors of CLKs & DYRKs, two families of kinases involved in pre-mRNA splicing and Alzheimer's disease. Leucettine L41 was co-crystallized with DYRK1A, -2, CLK3 and PIM1. Leucettine L41 inhibits phosphorylation of pre-RNA splicing regulating Ser/Arg-rich proteins. Leucettine L41 modulates alternative pre-mRNA splicing in a cellular systems. The selectivity of Leucettine L41 was extensively characterized. Leucettine L41 provides protection against glutamate-induced cell death in cultured HT22 hippocampal cells. It also provides neuroprotection against APP-induced cell death in mouse brain slices. Finally it prevents in vivo cognitive impairments due to icv injection of amyloid-β 25-35. Leucettines should be further explored as pharmacological tools to study and modulate pre-RNA splicing. Leucettines should also be investigated as potential therapeutic drugs in Alzheimer's disease and in diseases involving abnormal pre-mRNA splicing

The PHOENICE Project: A Synergic Use of Innovative Technologies for the Next Generation of Green Hybrid Powertrains

The PHOENICE project aims at developing a C SUV-class plug-in hybrid (P0/P4) vehicle demonstrator whose fuel consumption and pollutant emissions are jointly minimized for real-world driving conditions. Technologies developed in PHOENICE are targeting a TRL 7 paying a specific attention to cost, industrialization, and to the use opportunity for various vehicle classes so as to maximize the economic and environmental impacts. This project is aiming to support the European automobile industry in the medium term and speed up the transition towards a more environmentally friendly mobility in terms of air quality and GHG emissions. The achievement of these ambitious goals will require the optimization of a highly efficient gasoline engine, relying on a dual dilution combustion approach with excess air and EGR, synergizing an innovative in-cylinder charge motion with high-pressure injection, novel ignition technologies, and an electrified turbocharger particularly relevant for hybrid architectures. The potential of alternative fuels produced by P2X processes will also be considered. To achieve the targeted near-zero-emissions in real driving conditions, the demonstrator vehicle will be equipped with a complete and dedicated aftertreatment system, including an electrically heated catalyst, a SCR and a GPF for abating NOx, particle number down to 10 nm, and non-regulated gaseous emissions. Finally, the vehicle overall efficiency will be increased with an exhaust waste heat recovery system for generating an additional electric power contribution for cabin heating or cooling, or for reducing the switch-on time of the internal combustion engine in cold conditions, thereby limiting the engine-out pollutant emissions such as particles

Selectivity, cocrystal structures, and neuroprotective properties of leucettines, a family of protein kinase inhibitors derived from the marine sponge alkaloid leucettamine B.

DYRKs (dual specificity, tyrosine phosphorylation regulated kinases) and CLKs (cdc2-like kinases) are implicated in the onset and development of Alzheimer's disease and Down syndrome. The marine sponge alkaloid leucettamine B was recently identified as an inhibitor of DYRKs/CLKs. Synthesis of analogues (leucettines) led to an optimized product, leucettine L41. Leucettines were cocrystallized with DYRK1A, DYRK2, CLK3, PIM1, and GSK-3β. The selectivity of L41 was studied by activity and interaction assays of recombinant kinases and affinity chromatography and competition affinity assays. These approaches revealed unexpected potential secondary targets such as CK2, SLK, and the lipid kinase PIKfyve/Vac14/Fig4. L41 displayed neuroprotective effects on glutamate-induced HT22 cell death. L41 also reduced amyloid precursor protein-induced cell death in cultured rat brain slices. The unusual multitarget selectivity of leucettines may account for their neuroprotective effects. This family of kinase inhibitors deserves further optimization as potential therapeutics against neurodegenerative diseases such as Alzheimer's disease