| 1. |
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| 2. |
- Patel, Riyaz S., et al.
(författare)
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Subsequent Event Risk in Individuals With Established Coronary Heart Disease : Design and Rationale of the GENIUS-CHD Consortium
- 2019
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Ingår i: Circulation. - 2574-8300. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The Genetics of Subsequent Coronary Heart Disease (GENIUS-CHD) consortium was established to facilitate discovery and validation of genetic variants and biomarkers for risk of subsequent CHD events, in individuals with established CHD.METHODS: The consortium currently includes 57 studies from 18 countries, recruiting 185 614 participants with either acute coronary syndrome, stable CHD, or a mixture of both at baseline. All studies collected biological samples and followed-up study participants prospectively for subsequent events.RESULTS: Enrollment into the individual studies took place between 1985 to present day with a duration of follow-up ranging from 9 months to 15 years. Within each study, participants with CHD are predominantly of self-reported European descent (38%-100%), mostly male (44%-91%) with mean ages at recruitment ranging from 40 to 75 years. Initial feasibility analyses, using a federated analysis approach, yielded expected associations between age (hazard ratio, 1.15; 95% CI, 1.14-1.16) per 5-year increase, male sex (hazard ratio, 1.17; 95% CI, 1.13-1.21) and smoking (hazard ratio, 1.43; 95% CI, 1.35-1.51) with risk of subsequent CHD death or myocardial infarction and differing associations with other individual and composite cardiovascular endpoints.CONCLUSIONS: GENIUS-CHD is a global collaboration seeking to elucidate genetic and nongenetic determinants of subsequent event risk in individuals with established CHD, to improve residual risk prediction and identify novel drug targets for secondary prevention. Initial analyses demonstrate the feasibility and reliability of a federated analysis approach. The consortium now plans to initiate and test novel hypotheses as well as supporting replication and validation analyses for other investigators.
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| 3. |
- Patel, Riyaz S., et al.
(författare)
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Association of Chromosome 9p21 With Subsequent Coronary Heart Disease Events : A GENIUS-CHD Study of Individual Participant Data
- 2019
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Ingår i: Circulation. - 2574-8300. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Genetic variation at chromosome 9p21 is a recognized risk factor for coronary heart disease (CHD). However, its effect on disease progression and subsequent events is unclear, raising questions about its value for stratification of residual risk.METHODS: A variant at chromosome 9p21 (rs1333049) was tested for association with subsequent events during follow-up in 103 357 Europeans with established CHD at baseline from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) Consortium (73.1% male, mean age 62.9 years). The primary outcome, subsequent CHD death or myocardial infarction (CHD death/myocardial infarction), occurred in 13 040 of the 93 115 participants with available outcome data. Effect estimates were compared with case/control risk obtained from the CARDIoGRAMplusC4D consortium (Coronary Artery Disease Genome-wide Replication and Meta-analysis [CARDIoGRAM] plus The Coronary Artery Disease [C4D] Genetics) including 47 222 CHD cases and 122 264 controls free of CHD.RESULTS: Meta-analyses revealed no significant association between chromosome 9p21 and the primary outcome of CHD death/myocardial infarction among those with established CHD at baseline (GENIUSCHD odds ratio, 1.02; 95% CI, 0.99-1.05). This contrasted with a strong association in CARDIoGRAMPlusC4D odds ratio 1.20; 95% CI, 1.18-1.22; P for interaction < 0.001 compared with the GENIUS-CHD estimate. Similarly, no clear associations were identified for additional subsequent outcomes, including all-cause death, although we found a modest positive association between chromosome 9p21 and subsequent revascularization (odds ratio, 1.07; 95% CI, 1.04-1.09).CONCLUSIONS: In contrast to studies comparing individuals with CHD to disease-free controls, we found no clear association between genetic variation at chromosome 9p21 and risk of subsequent acute CHD events when all individuals had CHD at baseline. However, the association with subsequent revascularization may support the postulated mechanism of chromosome 9p21 for promoting atheroma development.
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| 4. |
- Svenningsson, Leo, 1990, et al.
(författare)
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Molecular Orientation Distribution of Regenerated Cellulose Fibers Investigated with Polarized Raman Spectroscopy
- 2019
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 1520-5835 .- 0024-9297. ; 52:10, s. 3918-3924
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Tidskriftsartikel (refereegranskat)abstract
- The molecular orientation distribution of polymeric fibers influences physical properties. We present a novel method of analyzing polarized Raman experiments to determine molecular orientation, which is based on exchanging the Legendre polynomial approach with a wrapped Lorentzian function, as determined from a prescreening of X-ray scattering patterns. This method removes the need for performing right angle scattering experiments while avoiding common approximations. The molecular orientation of regenerated cellulose fibers, using the presented method, is shown to correlate well with X-ray scattering and an analogous experiment using solid-state NMR spectroscopy. Challenges of quantitatively measuring molecular anisotropy occur with semi-crystalline, partially modified, or composite materials. As such, a plethora of techniques, each with a unique chemical selectivity, is paramount for material characterization.
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| 5. |
- Abdurrokhman, Iqbaal, 1991, et al.
(författare)
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Protic Ionic Liquids Based on the Alkyl-Imidazolium Cation: Effect of the Alkyl Chain Length on Structure and Dynamics
- 2019
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 123:18, s. 4044-4054
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Tidskriftsartikel (refereegranskat)abstract
- Protic ionic liquids are known to form extended hydrogen-bonded networks that can lead to properties different from those encountered in the aprotic analogous liquids, in particular with respect to the structure and transport behavior. In this context, the present paper focuses on a wide series of 1-alkyl-imidazolium bis(trifluoromethylsulfonyl)imide ionic liquids, [HC n Im][TFSI], with the alkyl chain length (n) on the imidazolium cation varying from ethyl (n = 2) to dodecyl (n = 12). A combination of several methods, such as vibrational spectroscopy, wide-angle X-ray scattering (WAXS), broadband dielectric spectroscopy, and 1 H NMR spectroscopy, is used to understand the correlation between local cation-anion coordination, nature of nanosegregation, and transport properties. The results indicate the propensity of the -NH site on the cation to form stronger H-bonds with the anion as the alkyl chain length increases. In addition, the position and width of the scattering peak q 1 (or the pre-peak), resolved by WAXS and due to the nanosegregation of the polar from the nonpolar domains, are clearly dependent on the alkyl chain length. However, we find no evidence from pulsed-field gradient NMR of a proton motion decoupled from molecular diffusion, hypothesized to be facilitated by the longer N-H bonds localized in the segregated ionic domains. Finally, for all protic ionic liquids investigated, the ionic conductivity displays a Vogel-Fulcher-Tammann dependence on inverse temperature, with an activation energy E a that also depends on the alkyl chain length, although not strictly linearly.
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| 6. |
- Abrahamsson, Johanna, 1990, et al.
(författare)
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A Raman spectroscopic approach to investigate the production of biodiesel from soybean oil using 1-alkyl-3-methylimidazolium ionic liquids with intermediate chain length
- 2015
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Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 154, s. 763-770
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Tidskriftsartikel (refereegranskat)abstract
- We present a Raman spectroscopic study of the conversion of soybean oil into biodiesel by methanol using the lipase B enzyme pseudomonas cepacia as the bio-catalyst and 1-alkyl-3-methylimidazolium ionic liquids (CnC1Im) as co-solvents, where the alkyl chain length is varied from ethyl (n=2) to decyl (n=10). We have limited this study to a low reaction temperature, 40°C, and a low enzyme concentration to investigate the possibility of producing biodiesel with low energy and cost demands. We also demonstrate that Raman spectroscopy is a powerful and straightforward method to estimate the yield of the transesterification reaction, by analysis of the characteristic CO stretching mode found in the range ~1730-1750cm-1. Our results indicate that both reaction yield and reaction rate increase with the chain length, but also that for chains longer than decyl further improvements are marginal. We discuss these results from the viewpoint of local interactions and local structure of the investigated ionic liquids.
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| 7. |
- Björkegren, Sanna, 1984, et al.
(författare)
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A new emulsion liquid membrane based on a palm oil for the extraction of heavy metals
- 2015
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Ingår i: Membranes. - : MDPI AG. - 2077-0375. ; 5:2, s. 168-179
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Tidskriftsartikel (refereegranskat)abstract
- The extraction efficiency of hexavalent chromium, Cr(VI), from water has been investigated using a vegetable oil based emulsion liquid membrane (ELM) technique. The main purpose of this study was to create a novel ELM formulation by choosing a more environmentally friendly and non-toxic diluent such as palm oil. The membrane phase so formulated includes the mobile carrier tri-n-octylmethylammonium chloride (TOMAC), to facilitate the metal transport, and the hydrophilic surfactant Tween 80 to facilitate the dispersion of the ELM phase in the aqueous solution. Span 80 is used as surfactant and butanol as co-surfactant. Our results demonstrate that this novel ELM formulation, using the vegetable palm oil as diluent, is useful for the removal of hexavalent chromium with an efficiency of over 99% and is thus competitive with the already existing, yet less environmentally friendly, ELM formulations. This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5. Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water) does not significantly influence the extraction rate.
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| 8. |
- Cabeza, O., et al.
(författare)
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Mesostructure and physical properties of aqueous mixtures of the ionic liquid 1-ethyl-3-methyl imidazolium octyl sulfate doped with divalent sulfate salts in the liquid and the mesomorphic states
- 2018
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 20:13, s. 8724-8736
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Tidskriftsartikel (refereegranskat)abstract
- This paper extends the study of the induced temperature change in the mesostructure and in the physical properties occurring in aqueous mixtures of the ionic liquid 1-ethyl-3-methyl imidazolium octyl-sulfate [EMIm][OSO 4 ]. For some compositions, these mixtures undergo a phase transition between the liquid (isotropic in the mesoscale) and the mesomorphic state (lyotropic liquid crystalline) at about room temperature. The behavior of mixtures doped with a divalent metal sulfate was investigated in order to observe their applicability as electrolytes. Calcium sulfate salt is almost insoluble even in the 20 wt% water mixture. The magnesium salt, in contrast, can be dissolved up to concentrations of 730 ppm in the same mixture and it has a profound impact on its properties. Six aqueous mixtures (with water content from 10 wt% to 33 wt%) of [EMIm] [OSO 4 ] were saturated with magnesium sulfate salt, producing the ternary mixture [EMIm] [OSO 4 ] + H 2 O + MgSO 4 . Viscosity, density and ionic conductivity for these samples were measured from 10 °C to 90 °C. In addition, SAXS, FTIR, diffussion NMR and Raman spectroscopy of the most interesting samples have been performed, and structural data indicate a transition between a hexagonal lyotropic liquid crystalline phase below and an isotropic solution phase above room temperature. The octyl sulfate anions of the cylindrical micelles in the hexagonal phase are coordinated with water molecules through H-bonds (about four per sulfate anion), while the [EMIm] cations seem to be poorly coordinated and so free to move. Inorganic salt addition reinforces that network, increasing the phase transition temperature.
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| 9. |
- Cabeza, O., et al.
(författare)
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Tuning physical properties and mesomorphic structures in aqueous 1-ethyl-3-methylimidazolium octylsulfate rigid-gel with univalent salt doping
- 2017
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Ingår i: Journal of Chemical Thermodynamics. - : Elsevier BV. - 0021-9614 .- 1096-3626. ; 112, s. 267-275
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Tidskriftsartikel (refereegranskat)abstract
- We report measurements of density, viscosity and electrical (ionic) conductivity of three aqueous mixtures of 1-ethyl-3-methyl imidazolium octyl-sulfate ([EMIm][OSO4] or C(2)C(1)Im-C8SO4) saturated with univalent sulfate salts in the temperature range 10 degrees C-90 degrees C. This ionic liquid presents a lyotropic mesophase about room temperature when mixed with about a 20 wt% of water. The salts used are lithium, sodium and potassium sulfates, and the amount of water varies from 16 wt% to 22 wt% depending on the given mixture. As a reference, we have also prepared and characterized four aqueous IL mixtures (without salt addition) in the same water concentration range. The solubility of the different salts is scarce in the pure ILs (less than 20 x 10(-6)), while in the aqueous mixtures prepared it varies, going from 200 x 10(-6) for Na up to 700 x 10(-6) for Li. As expected, we find that with the addition of the salts, both density and viscosity increase while the ionic conductivity decreases. However, the extent of these effects depends very much on the nature of the salt and the amount of water (which also influence the solubility of the salt). The measured results are rationalized in terms of water content and salt solubility in the ternary mixtures. We observed that the transition from the liquid to the rigid-gel phases takes some temperature degrees, where the sample is in a stable quasi-gel state. Those transition temperatures, from the liquid to the quasi-gel states, and from the quasi-gel to rigid-gel states are related to the nature of the salt metal present in the mixture for samples with the same water content.
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| 10. |
- Danyliv, Olesia, 1989, et al.
(författare)
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Nafion/Protic Ionic Liquid Blends: Nanoscale Organization and Transport Properties
- 2019
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 123:23, s. 14813-14824
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 American Chemical Society. In this work, the possibility of using the protic ionic liquids N-ethylimidazolium trifluoromethylsulfonate, [EIm][TfO], and N-ethylimidazolium bis(trifluoromethylsulfonyl)imide, [EIm][TFSI], as charge carriers in appropriately modified Nafion membranes has been investigated. The superior thermal stability of ionic liquids, as compared to that of water-based electrolytes, hypothetically offers a wider temperature range of fuel cell operation as well as an increased electrochemical performance even at low-humidity conditions. The nano- and microstructure of Nafion membranes swollen with these protic ionic liquids has been studied in detail, with focus on the correlation with the observed ionic conductivity. Although the presence of the ionic liquid within the hydrophilic domains of Nafion suppresses the thermomechanical properties of the polymer, satisfactory conductivities are achieved between 90 and 150 °C, namely, in the range 0.2-1.2 × 10-3 S/cm.
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