399 research outputs found
Hydrogen Bonding in Ionic Liquids Probed by Linear and Nonlinear Vibrational Spectroscopy
Three imidazolium-based ionic liquids of the type [Cnmim][NTf2] with varying
alkyl chain lengths (n = 1, 2 and 8) at the 1 position of the imidazolium ring
were studied applying IR, linear Raman, and multiplex CARS spectroscopy. The
focus has been on the CH-stretching region of the imidazolium ring, which is
supposed to carry information about a possible hydrogen bonding network in the
ionic liquid. The measurements are compared to calculations of the
corresponding anharmonic vibrational spectra for a cluster of [C2mim][NTf2]
consisting of four ion pairs. The results support the hypothesis of weak
hydrogen bonding involving the C(4)-H and C(5)-H groups and somewhat stronger
hydrogen bonds of the C(2)-H groups.Comment: revised manuscript, accepted for publication in New J. Phy
Vapor Pressure of Ionic Liquids
We argue that the extremely low vapor pressures of room temperature ionic
liquids near their triple points are due to the combination of strong ionic
characters and of low melting temperatures.Comment: Initially submitted manuscript of article M. Bier and S. Dietrich,
Mol. Phys. 108, 211 (2010) [Corrigendum: Mol. Phys. 108, 1413 (2010)
‘Everything’s from the inside out with PCOS’:exploring women’s experiences of living with Polycystic Ovary Syndrome (PCOS) and co-morbidities through Skype™ interviews
Polycystic ovary syndrome is an endocrine disorder affecting 1 in 10 women. Women with polycystic ovary syndrome can experience co-morbidities, including depressive symptoms. This research explores the experience of living with polycystic ovary syndrome and co-morbidities. Totally, 10 participants with polycystic ovary syndrome took part in Skype™ interviews and analysed using thematic analysis. Four themes emerged from the data: change (to life plans and changing nature of condition); support (healthcare professionals, education and relationships); co-morbidities (living with other conditions and depression, self-harm and suicidal ideation) and identity (feminine identity and us and them). The findings highlight the need for screening of women with polycystic ovary syndrome for depressive disorders
Solutions of ionic liquids with diverse aliphatic and aromatic solutes – Phase behavior and potentials for applications:A review article
This article principally reviews our research related to liquid–liquid and solid–liquid phase behavior of imidazolium- and phosphonium-based ionic liquids, mainly having bistriflamide ([NTf2]−) or triflate ([OTf]−) anions, with several aliphatic and aromatic solutes (target molecules). The latter include: (i) diols and triols: 1,2-propanediol, 1,3-propanediol and glycerol; (ii) polymer poly(ethylene glycol) (PEG): average molecular mass 200, 400 and 2050 – PEG200 (liquid), PEG400 (liquid) and PEG2050 (solid), respectively; (iii) polar aromatic compounds: nicotine, aniline, phenolic acids (vanillic, ferulic and caffeic acid,), thymol and caffeine and (iv) non-polar aromatic compounds (benzene, toluene, p-xylene). In these studies, the effects of the cation and anion, cation alkyl chain and PEG chain lengths on the observed phase behaviors were scrutinized. Thus, one of the major observations is that the anion – bistriflamide/triflate – selection usually had strong, sometimes really remarkable effects on the solvent abilities of the studied ionic liquids. Namely, in the case of the hydrogen-bonding solutes, the ionic liquids with the triflate anion generally exhibited substantially higher solubility than those having the bistriflamide anion. Nevertheless, with the aromatic compounds the situation was the opposite – in most of the cases it was the bistriflamide anion that favoured solubility. Moreover, our other studies confirmed the ability of PEG to dissolve both polar and non-polar aromatic compounds. Therefore, two general possibilities of application of alternative, environmentally acceptable, solvents of tuneable solvent properties appeared. One is to use homogeneous mixtures of two ionic liquids having [NTf2]− and [OTf]− anions as mixed solvents. The other, however, envisages the application of homogeneous and heterogeneous (PEG + ionic liquid) solutions as tuneable solvents for aromatic solutes. Such mixed solvents have potential applications in separation of the aforesaid target molecules from their aqueous solutions or in extraction from original matrices. From the fundamental point of view the phase equilibrium studies reviewed herein and the diversity of the pure compounds – ionic liquids and target molecules – represent a good base for the discussion of interactions between the molecules that exist in the studied solutions
Interventional radiology virtual simulator for liver biopsy
Purpose
Training in Interventional Radiology currently uses the apprenticeship model, where clinical and technical skills of invasive procedures are learnt during practice in patients. This apprenticeship training method is increasingly limited by regulatory restrictions on working hours, concerns over patient risk through trainees’ inexperience and the variable exposure to case mix and emergencies during training. To address this, we have developed a computer-based simulation of visceral needle puncture procedures.
Methods
A real-time framework has been built that includes: segmentation, physically based modelling, haptics rendering, pseudo-ultrasound generation and the concept of a physical mannequin. It is the result of a close collaboration between different universities, involving computer scientists, clinicians, clinical engineers and occupational psychologists.
Results
The technical implementation of the framework is a robust and real-time simulation environment combining a physical platform and an immersive computerized virtual environment. The face, content and construct validation have been previously assessed, showing the reliability and effectiveness of this framework, as well as its potential for teaching visceral needle puncture.
Conclusion
A simulator for ultrasound-guided liver biopsy has been developed. It includes functionalities and metrics extracted from cognitive task analysis. This framework can be useful during training, particularly given the known difficulties in gaining significant practice of core skills in patients
A qualitative investigation of the impact of peer to peer online support for women living with Polycystic Ovary Syndrome
Background: Polycystic Ovary Syndrome is a common, chronic condition which affects women living with the condition both physically and psychologically. Social support may be beneficial to sufferers in coping with chronic conditions and the Internet is becoming a common place for accessing social support and information. The aim of this study was to consider the experiences of women living with Polycystic Ovary Syndrome who access and participate in an online support group discussion forum dedicated to issues surrounding this condition.
Methods: Fifty participants responded to a series of open-ended questions via an online survey.
Results: Thematic analysis revealed a number of empowering and disempowering experiences associated with online support group participation. The empowering processes reported by members of the group included: Connecting with others who understand; Access to information and advice; Interaction with healthcare professionals; Treatment-related decision making; Improved adjustment and management. In terms disempowering processes, only two were described by group participants: Reading about the negative experiences of others and Feeling like an outsider.
Conclusions: For women living with Polycystic Ovary Syndrome, participation within an online support group may help to empower them in a range of important ways however, there may be some disempowering consequences
Extraction of Biomolecules Using Phosphonium-Based Ionic Liquids + K3PO4 Aqueous Biphasic Systems
Aqueous biphasic systems (ABS) provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs) to form ABS with aqueous K3PO4 solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K3PO4 at 298 K, were measured and are reported. The studied phosphonium-based ILs have shown to be more effective in promoting ABS compared to the imidazolium-based counterparts with similar anions. Moreover, the extractive capability of such systems was assessed for distinct biomolecules (including amino acids, food colourants and alkaloids). Densities and viscosities of both aqueous phases, at the mass fraction compositions used for the biomolecules extraction, were also determined. The evaluated IL-based ABS have been shown to be prospective extraction media, particularly for hydrophobic biomolecules, with several advantages over conventional polymer-inorganic salt ABS
Conductive films based on composite polymers containing ionic liquids absorbed on crosslinked polymeric ionic-like liquids (SILLPs)
Polymerization of styrenic monomers containing imidazolium subunits in the presence of crosslinking monomers and using ionic liquids (ILs) as porogenic agents provides composite materials with excellent mechanical properties and displaying conductivities that are in the same order of magnitude than those shown by bulk ILs. This approach allows the use of high crosslinking degrees and low IL-loadings without compromising the required properties of the resulting composites. Besides, no appreciable leaching of the bulk IL component is detected.Financial support by Ministerio de Ciencia e Innovacion (CTQ2011-28903-C02-01 and SP-ENE-20120718), Generalitat Valenciana (PROMETEO/2012/020) and Universitat Jaume I (P11B2013-38) is acknowledged.Altava Benito, B.; Compañ Moreno, V.; Andrio Balado, A.; Del Castillo Davila, LF.; Mollá Romano, S.; Burguete, MI.; García-Verdugo Cepeda, E.... (2015). Conductive films based on composite polymers containing ionic liquids absorbed on crosslinked polymeric ionic-like liquids (SILLPs). Polymer. 72:69-81. https://doi.org/10.1016/j.polymer.2015.07.009S69817
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