High-pressure phase equilibrium in the {carbon dioxide (1) + 1-chloropropane (2)} binary system

Abstract The current study reports original vapour-liquid equilibrium (VLE) for the system {CO2 (1) + 1-chloropropane (2)}. The measurements have been performed over the entire pressure-composition range for the (303.15, 313.15 and 328.15) K isotherms. The values obtained have been used for comparison of four predictive approaches, namely the equation of state (EoS) of Peng and Robinson (PR), the Soave modification of Benedict–Webb–Rubin (SBWR) EoS, the Critical Point-based Revised Perturbed-Chain Association Fluid Theory (CP-PC-SAFT) EoS, and the Conductor-like Screening Model for Real Solvents (COSMO-RS). It has been demonstrated that the three EoS under consideration yield similar and qualitatively accurate predictions of VLE, which is not the case for the COSMO-RS model examined. Although CP-PC-SAFT EoS exhibits only minor superiority in comparison with PR and SBWR EoS in predicting VLE in the system under consideration, its relative complexity can be justified when taking into account the entire thermodynamic phase space and, in particular, considering the liquid densities and sound velocities over a wider pressure-volume-temperature range.

Olefin / Paraffin separation using Task-Specific Materials based on Ionic Liquids: Advances in Gas Processing

In this work, 1-hexene was extracted from its mixtures with n-hexane in varying ratios using a task specific ionic liquid. Herein, the ionic liquid (IL) 1-butyl-3-methylimidazolium nitrate, [BMIM][NO3], was used and examined with and without the addition of a metal salt. The impact of water on both selectivity and distribution coefficient was also tested. Four potential metal salts were investigated, the results of which demonstrate that the dissolution of transition-metal salts in the IL improves the separation of 1-hexene from n-hexane through metal-olefin complexation. Additionally, the presence of water in IL solutions containing metal salt enhances this selectivity. Finally, UNIFAC was used to correlate the experimental LLE data with good accuracy.

Reduction of Carbon Dioxide to Formate at Low Overpotential using a Superbase Ionic Liquid

A new low-energy pathway is reported for the electrochemical reduction of CO2 to formate and syngas at low overpotentials, utilizing a reactive ionic liquid as the solvent. The superbasic tetraalkyl phosphonium ionic liquid [P66614][124Triz] is able to chemisorb CO2 through equimolar binding of CO2 with the 1,2,4-triazole anion. This chemisorbed CO2 can be reduced at silver electrodes at overpotentials as low as 0.17 V, forming formate. In contrast, physically absorbed CO2 within the same ionic liquid or in ionic liquids where chemisorption is impossible (such as [P66614][NTf2]) undergoes reduction at significantly increased overpotentials, producing only CO as the product.

The mitochondrial and autosomal mutation landscapes of prostate cancer

BACKGROUND: Prostate cancer (PCa) is the most common cancer in men. PCa is strongly age associated; low death rates in surveillance cohorts call into question the widespread use of surgery, which leads to overtreatment and a reduction in quality of life. There is a great need to increase the understanding of tumor characteristics in the context of disease progression.

OBJECTIVE: To perform the first multigenome investigation of PCa through analysis of both autosomal and mitochondrial DNA, and to integrate exome sequencing data, and RNA sequencing and copy-number alteration (CNA) data to investigate how various different tumor characteristics, commonly analyzed separately, are interconnected.

DESIGN, SETTING, AND PARTICIPANTS: Exome sequencing was applied to 64 tumor samples from 55 PCa patients with varying stage and grade. Integrated analysis was performed on a core set of 50 tumors from which exome sequencing, CNA, and RNA sequencing data were available.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Genes, mutated at a significantly higher rate relative to a genomic background, were identified. In addition, mitochondrial and autosomal mutation rates were correlated to CNAs and proliferation, assessed as a cell cycle gene expression signature.

RESULTS AND LIMITATIONS: Genes not previously reported to be significantly mutated in PCa, such as cell division cycle 27 homolog (Saccharomyces cerevisiae) (CDC27), myeloid/lymphoid or mixed-lineage leukemia 3 (MLL3), lysine (K)-specific demethylase 6A (KDM6A), and kinesin family member 5A (KIF5A) were identified. The mutation rate in the mitochondrial genome was 55 times higher than that of the autosomes. Multilevel analysis demonstrated a tight correlation between high reactive-oxygen exposure, chromosomal damage, high proliferation, and in parallel, a transition from multiclonal indolent primary PCa to monoclonal aggressive disease. As we only performed targeted sequence analysis; copy-number neutral rearrangements recently described for PCa were not accounted for.

CONCLUSIONS: The mitochondrial genome displays an elevated mutation rate compared to the autosomal chromosomes. By integrated analysis, we demonstrated that different tumor characteristics are interconnected, providing an increased understanding of PCa etiology.

Exome sequencing of prostate cancer supports the hypothesis of independent tumour origins

BACKGROUND: Prostate cancer (PCa) is a clinically and pathologically heterogeneous disease. The rapid development of sequencing technology has the potential to deliver new biomarkers with emphasis on aggressive disease and to revolutionise personalised cancer treatment. However, a prostate harbouring cancer commonly contains multiple separate tumour foci, with the potential to aggravate tumour sampling. The level of intraprostatic tumour heterogeneity remains to be determined.

OBJECTIVE: To determine the level of intraprostatic tumour heterogeneity through genome-wide, high-resolution profiling of multiple tumour samples from the same individual.

DESIGN, SETTINGS, AND PARTICIPANTS: Multiple tumour samples were obtained from four individuals following radical prostatectomy. One individual (SWE-1) contained >70% cancer cells in all tumour samples, whereas the other three (SWE-2 to SWE-4) required the use of laser capture microdissection for tumour cell enrichment. Subsequently, DNA was extracted from all tissue samples, and exome sequencing was performed. All tumour foci of SWE-1 were also profiled using a high-resolution array for the identification of copy number alterations (CNA).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Shared somatic high-frequency single nucleotide variants (SNV) and CNAs were used to infer the level of intraprostatic tumour heterogeneity.

RESULTS AND LIMITATIONS: No high-frequency mutations, common for the three tumour samples of SWE-1, were identified. Ten randomly chosen positions were validated with Sanger sequencing in all foci, which verified the exome data. The high level of intraprostatic heterogeneity was consistent in all individuals. In total, three out of four individuals harboured tumours without an apparent common somatic denominator. Although we cannot exclude the presence of common structural rearrangements, a high-density array was used for the detection of deletions and amplifications in SWE-1, which agreed with the exome data.

CONCLUSIONS: We present evidence for the presence of somatically independent tumours within the same prostate. This finding will have implications for personalised cancer treatment and biomarker discovery.

Observation of an intact noncovalent homotrimer of detergent-solubilized rat microsomal glutathione transferase-1 by electrospray mass spectrometry

Microsomal glutathione transferase-1 (MGST1) is a membrane-bound enzyme involved in the detoxification of xenobiotics and the protection of cells against oxidative stress. The proposed active form of the enzyme is a noncovalently associated homotrimer that binds one substrate glutathione molecule/trimer. In this study, this complex has been directly observed by electrospray mass spectrometry analysis of active rat liver MGST1 reconstituted in a minimum amount of detergent. The measured mass of the homotrimer is 53 kDa, allowing for the mass of three MGST molecules in complex with one glutathione molecule. Collision-induced dissociation of the trimer complex resulted in the formation of monomer and homodimer ion species. Two distinct species of homodimer were observed, one unliganded and one identified as a homodimer.glutathione complex. Activation of the enzyme by N-ethylmaleimide through modification of Cys(49) (Svensson, R., Rinaldi, R., Swedmark, S., and Morgenstern, R. (2000) Biochemistry 39, 15144-15149) was monitored by the observation of an appropriate increase in mass in both the denatured monomeric and native trimeric forms of MGST1. Together, the data correspond well with the proposed functional organization of MGST1. These results also represent the first example of direct electrospray mass spectrometry analysis of a detergent-solubilized multimeric membrane protein complex in its native state.

The addition of CO2 to four superbase ionic liquids: a DFT study

The addition of carbon dioxide to four superbase ionic liquids, [P3333][Benzim], [P3333][124Triz], [P3333][123Triz] and [P3333][Bentriz] was studied using a molecular DFT approach involving anions alone and individual ion pairs. Intermolecular bonding within the individual ion pairs is characterised by a number of weak hydrogen bonds, with the superbase anion geometrically arranged so as to maximize interactions between the heterocyclic N atoms and the cation. The pairing energies show no correlation to the observed CO2 adsorption capacity. Addition of CO2 to the anion alone clearly resulted in the formation of a covalently-bound carbamate function with the strength of binding correlated to experimental capacity. In the ion pair however the cation significantly alters the nature of the bonding such that the overall cohesive energy is reduced. Formation of a strong carbamate function occurs at the expense of weakening the interaction between anion and cation. In the more weakly absorbing ion pairs which contain [123Triz]- and [Bentriz]-, the carbamate-functionalised systems are very close in energy to adducts in which CO2 is more weakly bound, suggesting an equilibrium between the chemi- and physisorbed CO2.

Effect of the Presence of MEA on the CO2 Capture Ability of Superbase Ionic Liquids

The miscibility of monoethanolamine (MEA) in five superbase ionic liquids (ILs), namely the trihexyl-tetradecylphosphonium benzotriazolide ([P66614][Bentriz]), trihexyl-tetradecylphosphonium benzimidazolide ([P66614][Benzim]), trihexyl-tetradecylphosphonium 1,2,3-triazolide ([P66614][123Triz]), trihexyl-tetradecylphosphonium 1,2,4-triazolide ([P66614][124Triz]), and trihexyl-tetradecylphosphonium imidazolide ([P66614][Im]) was determined at 295.15 K using 1H NMR spectroscopy. The solubility of carbon dioxide (CO2) in equimolar (IL + MEA) mixtures was then studied experimentally using a gravimetric technique at 295.15 K and 0.1 MPa. The effect of MEA on the CO2 capture ability of these ILs was investigated together with the viscosity of these systems in the presence or absence of CO2 to evaluate their practical application in CO2 capture processes. The effect of the presence of MEA on the rate of CO2 uptake was also studied. The study showed that the MEA can enhance CO2 absorption over the ideal values in the case of [P66614][123Triz] and [P66614][Bentriz] while in the other systems the mixtures behave ideally. A comparison of the effect of MEA addition with the addition of water to these superbase ILs showed that similar trends were observed in each case for the individual ILs studied.

Gene regulatory mechanisms underpinning prostate cancer susceptibility

Molecular characterization of genome-wide association study (GWAS) loci can uncover key genes and biological mechanisms underpinning complex traits and diseases. Here we present deep, high-throughput characterization of gene regulatory mechanisms underlying prostate cancer risk loci. Our methodology integrates data from 295 prostate cancer chromatin immunoprecipitation and sequencing experiments with genotype and gene expression data from 602 prostate tumor samples. The analysis identifies new gene regulatory mechanisms affected by risk locus SNPs, including widespread disruption of ternary androgen receptor (AR)-FOXA1 and AR-HOXB13 complexes and competitive binding mechanisms. We identify 57 expression quantitative trait loci at 35 risk loci, which we validate through analysis of allele-specific expression. We further validate predicted regulatory SNPs and target genes in prostate cancer cell line models. Finally, our integrated analysis can be accessed through an interactive visualization tool. This analysis elucidates how genome sequence variation affects disease predisposition via gene regulatory mechanisms and identifies relevant genes for downstream biomarker and drug development.

An Ultrasonic Relaxation Study of 1-Alkyl-3-Methylmidazolium-Based Room Temperature Ionic Liquids: Probing the Role of Alkyl Chain Length in the Cation

Ultrasound absorption spectra of four 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were determined as a function of the alkyl chain length on the cation from 1-propyl- to 1-hexyl- from 293.15 to 323.15 K at ambient pressure. Herein, the ultrasound absorption measurements were carried out using a standard pulse technique within a frequency range from 10 to 300 MHz. Additionally the speed of sound, density and viscosity have been measured. The presence of strong dissipative processes during the ultrasound wave propagation was found experimentally, i.e. relaxation processes in the megahertz range were observed for all compounds over the whole temperature range. The relaxation spectra (both relaxation amplitude and relaxation frequency) were shown to be dependent on the alkyl side chain length of the 1-alkyl-3-methylimidazolium ring. In most cases, a single Debye model described the absorption spectra very well. However, a comparison of the determined spectra with the spectra of a few other imidazolium-based ionic liquids reported in the literature (in part recalculated in this work) shows that the complexity of the spectra increases rapidly with the elongation of the alkyl chain length on the cation. This complexity indicates that both the volume viscosity and the shear viscosity are involved in relaxation processes even in relatively low frequency ranges. As a consequence, the sound velocity dispersion is present at relatively low megahertz frequencies.

Effect of cation structure on the oxygen solubility and diffusivity in a range of bis{(trifluoromethyl)sulfonyl}imide anion based ionic liquids for lithium-air battery electrolytes

This paper reports on the solubility and diffusivity of dissolved oxygen in a series of ionic liquids (ILs) based on the bis{(trifluoromethyl)sulfonyl}imide anion with a range of related alkyl and ether functionalised cyclic alkylammonium cations. Cyclic voltammetry has been used to observe the reduction of oxygen in ILs at a microdisk electrode and chronoamperometric measurements have then been applied to simultaneously determine both the concentration and the diffusion coefficient of oxygen in the different ILs. The viscosity of the ILs and the calculated molar volume and free volume is also reported. It is found that, within this class of ILs, the oxygen diffusivity generally increases with decreasing viscosity of the neat IL. An inverse relationship between oxygen solubility and IL free volume is reported for the two IL families implying oxygen is not simply occupying the available empty space. In addition, it is reported that the introduction of ether-group into the IL cation structure promotes the diffusivity of dissolved oxygen but reduces the solubility of the gas.

The Influence of Cation Structure on the Chemical-Physical Properties of Protic Ionic Liquids

In this study we investigated the influence of five different cations on the physical-chemical properties of protic ionic liquids (PILs) based on bis(trifluoromethanesulfonyl)imide (TFSI-). We showed that the viscosities, ionic conductivities, densities and thermal properties of these PIL are strongly affected by the structure of the protic cation. Furthermore, the influence of the cation structure on the lithium coordination was investigated by Raman spectroscopy for all investigated PIL-based electrolytes for lithium-ion batteries (LIBs). This investigation clearly demonstrates, that the lithium average coordination number in PIL-based electrolytes is strongly affected by (ring) size and the number of protons on the cations structure and, more importantly, it might be significantly lower (more than 60 of that of electrolytes containing aprotic ionic liquids (AILs). Electrochemical performances of these PILs-based electrolytes were then also investigated to dress some conclusion on their applicability for LIB.

Temperature and Pressure Induced Structural Changes of Cobalt (II) in a Phosphonium Based Ionic Liquid

In this paper the temperature and pressure induced paramagnetic switching of cobalt (II) complex in binary mixture of phosphonium based ionic liquid [P6,6,6,14]SCN and [Co(NCS)2], is reported. This arises from a structural change in the coordination of the cobalt (II) center from tetrahedral [Co(NCS)4]2- to octahedral [Co(NCS)6]4- when mobile thiocyanate ions are added. These properties are reflected in the abrupt change of conductivity behavior of the magnetic ionic liquid. Therefore, as demonstrated herein the reversible switching in coordination of cobalt from tetrahedral to octahedral can be easily monitored at ambient as well as elevated pressure by tracking the dc-conductivity changes.