Physical and mechanical properties of phosphonium based poly(ionic liquids)

Currently for applications in materials science, there is a growing interest in Ionogels i.e. polymers with ionic liquids (ILs) integrated such that they retain their specific properties within the polymer/gel environment. However one disadvantage of ionogels is the leaching of the IL in the liquid phase1. To overcome this, ‘poly (ionic liquids) PILs, are gaining momentum in the literature. Interesting applications for the incorporation of PILs into polymers have been published such as ultrasensitive and selective chemiresistive CO2 sensors2, and potential applications in fuel cell technology as some reported PIL films, display very high ionic conductivities (exceeding 90 mS cm-1 at 100 oC and 75% relative humidity)3. However the range of possible monomeric IL structures is far greater than has so far been explored4 In recent years functional materials have been developed to respond to a wide variety of stimuli, but their use in practical macro-scale devices has been hindered by slow response times arising mainly due to the diffusion processes that typically govern polymer swelling/contraction. The scaling-down to microfluidic devices should improve response times, due to the improved surface-to-volume ratios of these actuators. At these dimensions, stimuli-responsive PIL materials could dramatically enhance the capabilities of micro-fluidic systems by allowing self-regulated flow control. In this study we synthesis, characterise and photopattern a family of PILs, Tributyl 4-Vinylbenzylphosphonium ([P4,4,4,4VB]+ ), Trihexyl 4-Vinylbenzylphosphonium ([P6,6,6,4VB]+) and Trihexyl-allyl phosphonium [P6,6,6,allyl]+ cations coupled with commonly found anions in the ionic liquid literature (chloride, dicyanamide and bis(trifluoromethylsulfonyl)imide). As one might expect varying the anion of the PIL gave varying behaviour (thermal stability and electrochemically). The resulting polymer gels from the PILs also gave drastic mechanical stability differences. Finally the synthesised polymer gels have been photo-structured to submicron resolution as both planar and 3D patterns employing both single and multi- photon polymerisation (MPP) techniques. These materials will form a platform for the next generation of sensors & actuators currently being developed

Are we living in a time of particularly rapid social change? And how might we know?

n an editorial for this journal a decade ago, then-Editor-in-Chief Fred Phillips asserted that social change was proceeding at hyper-speed and, moreover, that it had consequently come to outpace technological change. This paper submits these claims to empirical assay. In so doing, we address the myriad problems attendant upon determining and interpreting the sort of data that might support us in our cause. Notwithstanding the innu�merable caveats that this necessarily entails, and restricting ourselves to considering US data, we conclude that a wide range of indicators suggest that millennial Americans are not living in a time of particularly rapid social change, at least not when compared to the period 1900–1950. Furthermore, our analysis suggests that the data that we have considered does not easily support a contention that significant variation in social change occurs in long wave-like cycles. The evidence is more supportive of a punctuated equilibrium model of change

Temperature & pH triggered release characteristics of water/fluorescein from 1-ethyl-3-methylimidazolium ethylsulfate based ionogels.

A crosslinked Poly(N-isopropylacrylamide) ionogel encapsulating an ionic liquid exhibits improved transmittance properties, enhanced water uptake/release, greater thermal actuation behaviour and distinct solvatomorphology over its hydrogel equivalent. It was also found that the rate of release of fluorescein pre-loaded into membranes was considerably enhanced for ionogels compared to equivalent hydrogels, and could be triggered through changes in pH and temperature

In vitro monoamine oxidase inhibition potential of alpha-methyltryptamine analog new psychoactive substances for assessing possible toxic risks

Tryptamines have emerged as new psychoactive substances (NPS), which are distributed and consumed recreationally without preclinical studies or safety tests. Within the alpha-methylated tryptamines, some of the psychoactive effects of the prototypical alpha-methyltryptamine (AMT) have been described decades ago and a contributing factor of its acute toxicity appears to involve the inhibition of monoamine oxidase (MAO). However, detailed information about analogs is scarce. Therefore, thirteen AMT analogs were investigated for their potential to inhibit MAO. An in vitro assay analyzed using hydrophilic interaction liquid chromatography–high resolution-tandem mass spectrometry was developed and validated. The AMT analogs were incubated with recombinant human MAO-A or B and kynuramine, a non-selective MAO substrate to determine the IC50 values. The known MAO-A inhibitors 5-(2-aminopropyl)indole (5-IT), harmine, harmaline, yohimbine, and the MAO-B inhibitor selegiline were tested for comparison. AMT and all analogs showed MAO-A inhibition properties with IC50 values between 0.049 and 166 μM, whereas four analogs inhibited also MAO-B with IC50 values between 82 and 376 μM. 7-Me-AMT provided the lowest IC50 value against MAO-A comparable to harmine and harmaline and was identified as a competitive MAO-A inhibitor. Furthermore, AMT, 7-Me-AMT, and nine further analogs inhibited MAO activity in human hepatic S9 fraction used as model for the human liver which expresses both isoforms. The obtained results suggested that MAO inhibition induced by alpha-methylated tryptamines might be clinically relevant concerning possible serotonergic and adrenergic effects and interactions with drugs (of abuse) particularly acting as monoamine reuptake inhibitors. However, as in vitro assays have only limited conclusiveness, further studies are needed

Challenging dyke ascent models using novel laboratory experiments: Implications for reinterpreting evidence of magma ascent and volcanism

Volcanic eruptions are fed by plumbing systems that transport magma from its source to the surface, mostly fed by dykes. Here we present laboratory experiments that model dyke ascent to eruption using a tank filled with a crust analogue (gelatine, which is transparent and elastic) that is injected from below by a magma analogue (dyed water). This novel experimental setup allows, for the first time, the simultaneous measurement of fluid flow, sub-surface and surface deformation during dyke ascent. During injection, a penny-shaped fluid-filled crack is formed, intrudes, and traverses the gelatine slab vertically to then erupt at the surface. Polarised light shows the internal stress evolution as the dyke ascends, and an overhead laser scanner measures the surface elevation change in the lead-up to dyke eruption. Fluorescent passive-tracer particles that are illuminated by a laser sheet are monitored, and the intruding fluid's flow dynamics and gelatine's sub-surface strain evolution is measured using particle image velocimetry and digital image correlation, respectively. We identify 4 previously undescribed stages of dyke ascent. Stage 1, early dyke growth: the initial dyke grows from the source, and two fluid jets circulate as the penny-shaped crack is formed. Stage 2, pseudo-steady dyke growth: characterised by the development of a rapidly uprising, central, single pseudo-steady fluid jet, as the dyke grows equally in length and width, and the fluid down-wells at the dyke margin. Sub-surface host strain is localised at the head region and the tail of the dyke is largely static. Stage 3, pre-eruption unsteady dyke growth: an instability in the fluid flow appears as the central fluid jet meanders, the dyke tip accelerates towards the surface and the tail thins. Surface deformation is only detected in the immediate lead-up to eruption and is characterised by an overall topographic increase, with axis-symmetric topographic highs developed above the dyke tip. Stage 4 is the onset of eruption, when fluid flow is projected outwards and focused towards the erupting fissure as the dyke closes. A simultaneous and abrupt decrease in sub-surface strain occurs as the fluid pressure is released. Our results provide a comprehensive physical framework upon which to interpret evidence of dyke ascent in nature, and suggest dyke ascent models need to be re-evaluated to account for coupled intrusive and extrusive processes and improve the recognition of monitoring signals that lead to volcanic eruptions in nature

In vitro metabolic fate of the synthetic cannabinoid receptor agonists (quinolin-8-yl 4-methyl-3-(morpholine-4-sulfonyl)benzoate [QMMSB]) and (quinolin-8-yl 4-methyl-3-((propan-2-yl)sulfamoyl)benzoate [QMiPSB]) including isozyme mapping and carboxylesterases activity testing

The synthetic cannabinoid receptor agonists (SCRAs) (quinolin-8-yl 4-methyl-3-(morpholine-4-sulfonyl)benzoate [QMMSB]) and (quinolin-8-yl 4-methyl-3-((propan-2-yl)sulfamoyl)benzoate [QMiPSB], also known as SGT-46) are based on the structure of quinolin-8-yl 4-methyl-3-(piperidine-1-sulfonyl)benzoate (QMPSB) that has been identified on seized plant material in 2011. In clinical toxicology, knowledge of the metabolic fate is important for their identification in biosamples. Therefore, the aim of this study was the identification of in vitro Phase I and II metabolites of QMMSB and QMiPSB in pooled human liver S9 fraction (pHLS9) incubations for use as screening targets. In addition, the involvement of human monooxygenases and human carboxylesterases (hCES) was examined. Analyses were performed by liquid chromatography coupled with high-resolution tandem mass spectrometry. Ester hydrolysis was found to be an important step in the Phase I metabolism of both SCRAs, with the carboxylic acid product being found only in negative ionization mode. Monohydroxy and N-dealkyl metabolites of the ester hydrolysis products were detected as well as glucuronides. CYP2C8, CYP2C9, CYP3A4, and CYP3A5 were involved in hydroxylation. Whereas enzymatic ester hydrolysis of QMiPSB was mainly catalyzed by hCES1 isoforms, nonenzymatic ester hydrolysis was also observed. The results suggest that ester hydrolysis products of QMMSB and QMiPSB and their glucuronides are suitable targets for toxicological screenings. The additional use of the negative ionization mode is recommended to increase detectability of analytes. Different cytochrome P450 (CYP) isozymes were involved in the metabolism; thus, the probability of drug–drug interactions due to CYP inhibition can be assessed as low

A review of laboratory and numerical modelling in volcanology

Modelling has been used in the study of volcanic systems for more than 100 years, building upon the approach first applied by Sir James Hall in 1815. Informed by observations of volcanological phenomena in nature, including eye-witness accounts of eruptions, geophysical or geodetic monitoring of active volcanoes, and geological analysis of ancient deposits, laboratory and numerical models have been used to describe and quantify volcanic and magmatic processes that span orders of magnitudes of time and space. We review the use of laboratory and numerical modelling in volcanological research, focussing on sub-surface and eruptive processes including the accretion and evolution of magma chambers, the propagation of sheet intrusions, the development of volcanic flows (lava flows, pyroclastic density currents, and lahars), volcanic plume formation, and ash dispersal. When first introduced into volcanology, laboratory experiments and numerical simulations marked a transition in approach from broadly qualitative to increasingly quantitative research. These methods are now widely used in volcanology to describe the physical and chemical behaviours that govern volcanic and magmatic systems. Creating simplified models of highly dynamical systems enables volcanologists to simulate and potentially predict the nature and impact of future eruptions. These tools have provided significant insights into many aspects of the volcanic plumbing system and eruptive processes. The largest scientific advances in volcanology have come from a multidisciplinary approach, applying developments in diverse fields such as engineering and computer science to study magmatic and volcanic phenomena. A global effort in the integration of laboratory and numerical volcano modelling is now required to tackle key problems in volcanology and points towards the importance of benchmarking exercises and the need for protocols to be developed so that models are routinely tested against real world data

A review of analogue and numerical modelling in volcanology

Abstract. Modelling has been used in the study of volcanic systems for more than one hundred years, building upon the approach first described by Sir James Hall in 1815. Informed by observations of volcanological phenomenon in nature, including eye-witness accounts of eruptions, geophysical or geodetic monitoring of active volcanoes and geological analysis of ancient deposits, analogue and numerical models have been used to describe and quantify volcanic and magmatic processes that span orders of magnitudes of time and space. We review the use of analogue and numerical modelling in volcanological research, focusing on sub-surface and eruptive processes including the accretion and evolution of magma chambers, the propagation of sheet intrusions, the development of volcanic flows (lava flows, pyroclastic density currents and lahars), volcanic plume formation and ash dispersal. When first introduced into volcanology, analogue experiments and numerical simulations marked a transition in approach from broadly qualitative to increasingly quantitative research. These methods are now widely used in volcanology to describe the physical and chemical behaviours that govern volcanic and magmatic systems. Creating simplified depictions of highly dynamical systems enables volcanologists to simulate and potentially predict the nature and impact of future eruptions. These tools have provided significant insights into many aspects of the volcanic plumbing system and eruptive processes. The largest scientific advances in volcanology have come from a multidisciplinary approach, applying developments in diverse fields such as Engineering and Computer Science to study magmatic and volcanic phenomenon. A global effort in the integration of analogue and numerical volcano modelling is now required to tackle key problems in volcanology, and points towards the importance of benchmarking exercises and the need for protocols to be developed so that models are routinely tested against real world data. </jats:p

Un peu moins de vingt mille incipit inédits de Georges Perec

Un peu moins de vingt mille incipit inédits de Georges Pere