| 1. |
- Engström, Gunnar, et al.
(author)
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Pulmonary function and atherosclerosis in the general population : causal associations and clinical implications
- 2024
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In: European Journal of Epidemiology. - : Springer Nature. - 0393-2990 .- 1573-7284. ; 39:1, s. 35-49
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Journal article (peer-reviewed)abstract
- Reduced lung function is associated with cardiovascular mortality, but the relationships with atherosclerosis are unclear. The population-based Swedish CArdioPulmonary BioImage study measured lung function, emphysema, coronary CT angiography, coronary calcium, carotid plaques and ankle-brachial index in 29,593 men and women aged 50–64 years. The results were confirmed using 2-sample Mendelian randomization. Lower lung function and emphysema were associated with more atherosclerosis, but these relationships were attenuated after adjustment for cardiovascular risk factors. Lung function was not associated with coronary atherosclerosis in 14,524 never-smokers. No potentially causal effect of lung function on atherosclerosis, or vice versa, was found in the 2-sample Mendelian randomization analysis. Here we show that reduced lung function and atherosclerosis are correlated in the population, but probably not causally related. Assessing lung function in addition to conventional cardiovascular risk factors to gauge risk of subclinical atherosclerosis is probably not meaningful, but low lung function found by chance should alert for atherosclerosis.
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| 2. |
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| 3. |
- Ilyas, Aamir, et al.
(author)
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Residual organic matter and microbial respiration in bottom ash: Effects on metal leaching and eco-toxicity.
- 2015
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In: Waste Management & Research. - 1096-3669. ; 33:9, s. 805-811
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Journal article (peer-reviewed)abstract
- A common assumption regarding the residual organic matter, in bottom ash, is that it does not represent a significant pool of organic carbon and, beyond metal-ion complexation process, it is of little consequence to evolution of ash/leachate chemistry. This article evaluates the effect of residual organic matter and associated microbial respiratory processes on leaching of toxic metals (i.e. arsenic, copper, chromium, molybdenum, nickel, lead, antimony and zinc), eco-toxicity of ash leachates. Microbial respiration was quantified with help of a respirometric test equipment OXITOP control system. The effect of microbial respiration on metal/residual organic matter leaching and eco-toxicity was quantified with the help of batch leaching tests and an eco-toxicity assay - Daphnia magna. In general, the microbial respiration process decreased the leachate pH and eco-toxicity, indicating modification of bioavailability of metal species. Furthermore, the leaching of critical metals, such as copper and chromium, decreased after the respiration in both ash types (fresh and weathered). It was concluded that microbial respiration, if harnessed properly, could enhance the stability of fresh bottom ash and may promote its reuse.
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| 4. |
- Lindh, Linnea, et al.
(author)
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Dye-sensitized solar cells based on Fe N-heterocyclic carbene photosensitizers with improved rod-like push-pull functionality
- 2021
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In: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6520 .- 2041-6539. ; 12:48, s. 16035-16053
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Journal article (peer-reviewed)abstract
- A new generation of octahedral iron(ii)-N-heterocyclic carbene (NHC) complexes, employing different tridentate C^N^C ligands, has been designed and synthesized as earth-abundant photosensitizers for dye sensitized solar cells (DSSCs) and related solar energy conversion applications. This work introduces a linearly aligned push-pull design principle that reaches from the ligand having nitrogen-based electron donors, over the Fe(ii) centre, to the ligand having an electron withdrawing carboxylic acid anchor group. A combination of spectroscopy, electrochemistry, and quantum chemical calculations demonstrate the improved molecular excited state properties in terms of a broader absorption spectrum compared to the reference complex, as well as directional charge-transfer displacement of the lowest excited state towards the semiconductor substrate in accordance with the push-pull design. Prototype DSSCs based on one of the new Fe NHC photosensitizers demonstrate a power conversion efficiency exceeding 1% already for a basic DSSC set-up using only the I−/I3−redox mediator and standard operating conditions, outcompeting the corresponding DSSC based on the homoleptic reference complex. Transient photovoltage measurements confirmed that adding the co-sensitizer chenodeoxycholic acid helped in improving the efficiency by increasing the electron lifetime in TiO2. Time-resolved spectroscopy revealed spectral signatures for successful ultrafast (<100 fs) interfacial electron injection from the heteroleptic dyes to TiO2. However, an ultrafast recombination process results in undesirable fast charge recombination from TiO2back to the oxidized dye, leaving only 5-10% of the initially excited dyes available to contribute to a current in the DSSC. On slower timescales, time-resolved spectroscopy also found that the recombination dynamics (longer than 40 μs) were significantly slower than the regeneration of the oxidized dye by the redox mediator (6-8 μs). Therefore it is the ultrafast recombination down to fs-timescales, between the oxidized dye and the injected electron, that remains as one of the main bottlenecks to be targeted for achieving further improved solar energy conversion efficiencies in future work.
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| 5. |
- Lindh, Linnea, et al.
(author)
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Multifaceted Deactivation Dynamics of Fe(II) N-Heterocyclic Carbene Photosensitizers
- 2023
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In: Journal of Physical Chemistry A. - 1089-5639. ; 127:48, s. 10210-10222
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Journal article (peer-reviewed)abstract
- Excited state dynamics of three iron(II) carbene complexes that serve as prototype Earth-abundant photosensitizers were investigated by ultrafast optical spectroscopy. Significant differences in the dynamics between the investigated complexes down to femtosecond time scales are used to characterize fundamental differences in the depopulation of triplet metal-to-ligand charge-transfer (3MLCT) excited states in the presence of energetically accessible triplet metal-centered (3MC) states. Novel insights into the full deactivation cascades of the investigated complexes include evidence of the need to revise the deactivation model for a prominent iron carbene prototype complex, a refined understanding of complex 3MC dynamics, and a quantitative discrimination between activated and barrierless deactivation steps along the 3MLCT → 3MC → 1GS path. Overall, the study provides an improved understanding of photophysical limitations and opportunities for the use of iron(II)-based photosensitizers in photochemical applications.
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| 6. |
- Lindh, Linnea, et al.
(author)
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Side-group switching between metal-to-ligand charge-transfer and metal-centered excited state properties in iron(II) N-heterocyclic carbene complexes
- 2024
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In: Coordination Chemistry Reviews. - 0010-8545. ; 506
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Research review (peer-reviewed)abstract
- Fe(II) N-heterocyclic carbene (NHC) complexes have emerged over the last decade as a promising class of light-harvesting complexes for a variety of photochemical applications relying on the presence of high-energy excited states of mainly charge-transfer character with excited state lifetimes of tens of picoseconds or longer. Recent spectroscopic investigations have significantly refined the understanding of some of the key prototype complexes of this kind and highlighted the subtle balance between population of triplet metal-to-ligand charge-transfer (3MLCT) and triplet metal-centered (3MC) states as a key issue to better understand and ultimately control the excited state dynamics in these complexes. To present a broader perspective on this issue, we here re-examine and discuss the excited state properties of a series of complexes with different side-groups on a common Fe NHC scaffold. Both the steady-state absorption spectrum and excited state dynamics are influenced by the side-group substitution, and the changes are rationalized based on shifting of the lowest metal-to-ligand charge-transfer (MLCT) state in energy based on the electron-withdrawing or electron-donating properties of the side-groups. Only electron-withdrawing substituents such as carboxylic acid groups ensured that the majority excited population stays in the 3MLCT state for ∼20 ps rather than rapidly converting into metal-centered (MC) states. In other complexes, the 3MLCT state survived <300 fs after which the 3MC state was populated for ∼10 ps. The transient absorption results also show that the dynamics can be switched in a simple manner by deprotonating the carboxylic acid group, which renders some of the complexes pH-sensitive. For the here discussed complexes, the results from transient absorption measurements indicate that the 3MLCT and 3MC states were close enough in energy to enable the side-group to determine the photophysics. The emerging understanding of the 3MLCT-3MC balance, as well as the nature and properties of the 3MC state in these complexes with intermediate ligand field strength is used to provide a broader fundamental perspective required to improve the ligand-design of Fe carbene complexes for issues such as to ensure a long-lived 3MLCT state.
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| 7. |
- Naseri-Rad, Mehran, et al.
(author)
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Inside-t : A groundwater contamination transport model for sustainability assessment in remediation practice
- 2021
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In: Sustainability (Switzerland). - : MDPI AG. - 2071-1050. ; 13:14
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Journal article (peer-reviewed)abstract
- Current sustainability assessment (SA) tools to help deal with contaminated groundwater sites are inherently subjective and hardly applied. One reason may be lack of proper tools for addressing contaminant spread which are basically objective. To fill this gap, there is a need for contaminant transport models that provide site managers with needed room for applying their judgments and considerations about the efficiency of each remediation method based on their experiences in similar cases. INSIDE-T uses trend analysis and inverse modeling to estimate transport parameters. It then simulates contaminant transport both with and without the inclusion of remedial actions in a transparent way. The sustainability of each remedy measure can then be quantified based on the underlying SA tool (INSIDE). INSIDE-T was applied to a site in south Sweden, contaminated with pentachlorophenol. Simulation scenarios were developed to enable comparison between various remediation strategies and combinations of these. The application indicated that natural attenuation was not a viable option within the timeframe of interest. Although pump-and-treat combined with a permeable reactive barrier was found to be just as effective as bioremediation after five years, it received a much lower sustainability score overall. INSIDE-T outcomes enable site managers to test and evaluate different scenarios, a necessity in participatory decision-making practices such as remediation projects.
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| 8. |
- Persson, Magnus, et al.
(author)
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Tendenser och trender i tidskriften Vattens artiklar under 75 år
- 2019
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In: Vatten: tidskrift för vattenvård /Journal of Water Management and research. - 0042-2886. ; 75:1, s. 7-22
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Journal article (other academic/artistic)abstract
- The Journal of Water Management and Research (Vatten) celebrates 2019 its 75th anniversary with a special issue, republishing one article per decade from 1940 to 2010. In the present article, we summarize the development of Swedish water research and management based upon the material published in the journal. We read all issues of the journal, noting important trends, percentage of female authors etc. In total, 2015 articles have been published over 20,600 pages, written by 3,309 authors. During the first decades of the journal history, articles mainly dealt with pollution issues, manifested in, e.g., poor bathing water quality. During the 1950s and 1960s many papers described the expanding municipal waste water treatment with international outlooks, getting inspiration mainly from Germany. Acidification was a hot topic during the 70s and 80s. At the same time articles concerning storm water started to show up and subsequently increased in frequency. During the 90s and 00s wetlands gained popularity, which decreased again in the 10s. The first article on climate change was published already in 1987, but this topic did not become frequent until the 10s.
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| 9. |
- Persson, N, et al.
(author)
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Biologisk denitrifikation av dricksvatten - Biological denitrification of drinking water
- 2006
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In: Vatten: tidskrift för vattenvård /Journal of Water Management and research. - 0042-2886. ; 62:4, s. 323-333
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Journal article (other academic/artistic)abstract
- A pilot-plant study, made to clarify whether biological denitrification is a possible and suitable method for nitrate reduction of drinking water in Sweden is presented. The concentration of nitrate-nitrogen in un-treated water was 10–15 mg/l. The reactor was a 1.2 m aluminium tube with a inner diameter of 0.19 m. 0.75 m was filled with Filtralite®, expanded clay, through which the nitrate-contaminated water was forced to flow upwards with a velocity of 0.5 m/h. The system was run with artificial nitrate-polluted potable water from the three pumps during a week. The nitrate was then added to the water by using a solution of sodium nitrate. As carbon-source, sodium acetate was used. The Hydraulic Retention Time (HRT) of the system was 5.9 h, of which approximately 2.6 hours were within the bacterial support material. The C:N ratio was found to be below 1.5 and the system was very stable. Since the process will not work as long as oxygen is present, oxygen was degassed, but the importance of trace oxygen amounts could not be decided, since it wasn’t possible to decrease the oxygen to really low concentrations in the water prior inlet to the reactor. It was concluded that it is possible to use biological denitrification for drinking water. Post-treatment in an aerated reactor will be needed to ensure that no carbon or nitrite-nitrogen comes into the potable water.
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