| 1. |
- Bruschi, Maurizio, et al.
(författare)
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Functionally Relevant Interplay between the Fe(4)S(4) Cluster and CN(-) Ligands in the Active Site of [FeFe]-Hydrogenases.
- 2010
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 132:14, s. 4992-4992
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Tidskriftsartikel (refereegranskat)abstract
- [FeFe]-hydrogenases are highly efficient H(2)-evolving metalloenzymes that include cyanides and carbonyls in the active site. The latter is an Fe(6)S(6) cluster (the so-called H-cluster) that can be subdivided into a binuclear portion carrying the CO and CN(-) groups and a tetranuclear subcluster. The fundamental role of cyanide ligands in increasing the basicity of the H-cluster has been highlighted previously. Here a more subtle but crucial role played by the two CN(-) ligands in the active site of [FeFe]-hydrogenases is disclosed. In fact, QM/MM calculations on all-atom models of the enzyme from Desulfovibrio desulfuricans show that the cyanide groups fine-tune the electronic and redox properties of the active site, affecting both the protonation regiochemistry and electron transfer between the two subclusters of the H-cluster. Despite the crucial role of cyanides in the protein active site, the currently available bioinspired electrocatalysts generally lack CN(-) groups in order to avoid competition between the latter and the catalytic metal centers for proton binding. In this respect, we show that a targeted inclusion of phosphine ligands in hexanuclear biomimetic clusters may restore the electronic and redox features of the wild-type H-cluster.
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| 2. |
- Bertini, Claudia, et al.
(författare)
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On the Use of Satellite Rainfall Data to Design a Dam in an Ungauged Site
- 2020
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- The estimation of the design peak discharge is crucial for the hydrological design of hydraulic structures. A commonly used approach is to estimate the design storm through the intensity-duration-area-frequency (IDAF) curves and then use it to generate the design discharge through a hydrological model. In ungauged areas, IDAF curves and design discharges are derived throughout regionalization studies, if any exist for the area of interest, or from using the hydrological information of the closest and most similar gauged place. However, many regions around the globe remain ungauged or are very poorly gauged. In this regard, a unique opportunity is provided by satellite precipitation products developed and improved in the last decades. In this paper, we show weaknesses and potentials of satellite data and, for the first time, we evaluate their applicability for design purposes. We employ CMORPH-Climate Prediction Center MORPHing technique satellite precipitation estimates to build IDAF curves and derive the design peak discharges for the Pietrarossa dam catchment in southern Italy. Results are compared with the corresponding one provided by a regionalization study, i.e., VAPI-VAlutazione delle Piene in Italia project, usually used in Italy in ungauged areas. Results show that CMORPH performed well for the estimation of low duration and small return periods storm events, while for high return period storms, further research is still needed.
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| 3. |
- Carrick, Richard T., et al.
(författare)
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Implantable cardioverter defibrillator use in arrhythmogenic right ventricular cardiomyopathy in North America and Europe
- 2024
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Ingår i: European Heart Journal. - : OXFORD UNIV PRESS. - 0195-668X .- 1522-9645.
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims Implantable cardioverter-defibrillators (ICDs) are critical for preventing sudden cardiac death (SCD) in arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to identify cross-continental differences in utilization of primary prevention ICDs and survival free from sustained ventricular arrhythmia (VA) in ARVC.Methods This was a retrospective analysis of ARVC patients without prior VA enrolled in clinical registries from 11 countries throughout Europe and North America. Patients were classified according to whether they received treatment in North America or Europe and were further stratified by baseline predicted VA risk into low- (<10%/5 years), intermediate- (10%-25%/5 years), and high-risk (>25%/5 years) groups. Differences in ICD implantation and survival free from sustained VA events (including appropriate ICD therapy) were assessed.Results One thousand ninety-eight patients were followed for a median of 5.1 years; 554 (50.5%) received a primary prevention ICD, and 286 (26.0%) experienced a first VA event. After adjusting for baseline risk factors, North Americans were more than three times as likely to receive ICDs {hazard ratio (HR) 3.1 [95% confidence interval (CI) 2.5, 3.8]} but had only mildly increased risk for incident sustained VA [HR 1.4 (95% CI 1.1, 1.8)]. North Americans without ICDs were at higher risk for incident sustained VA [HR 2.1 (95% CI 1.3, 3.4)] than Europeans.Conclusions North American ARVC patients were substantially more likely than Europeans to receive primary prevention ICDs across all arrhythmic risk strata. A lower rate of ICD implantation in Europe was not associated with a higher rate of VA events in those without ICDs.
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| 4. |
- Lee, Jui-Chi, et al.
(författare)
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Geomorphological mapping of comet 67P/Churyumov-Gerasimenko's Southern hemisphere
- 2016
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 462, s. S573-S592
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Tidskriftsartikel (refereegranskat)abstract
- In 2015 May, the Southern hemisphere of comet 67P/Churyumov-Gerasimenko became visible by the OSIRIS cameras on-board the Rosetta spacecraft. The resolution was high enough to carry out a detailed analysis of the surface morphology, which is quite different from the Northern hemisphere. Previous works show that fine particle deposits are the most extensive geological unit in the Northern hemisphere. In contrast, the Southern hemisphere is dominated by outcropping consolidated terrain. In this work, we provide geomorphological maps of the Southern hemisphere with the distinction of both geological units and linear features. The geomorphological maps described in this study allow us to gain a better understanding of the processes shaping the comet nucleus and the distribution of primary structures such as fractures and strata.
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| 5. |
- Marcos, Rocio, et al.
(författare)
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Mechanistic Studies on NaHCO3 Hydrogenation and HCOOH Dehydrogenation Reactions Catalysed by a Fe-II Linear Tetraphosphine Complex
- 2018
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Ingår i: Chemistry - A European Journal. - : John Wiley & Sons. - 0947-6539 .- 1521-3765. ; 24:20, s. 5366-5372
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Tidskriftsartikel (refereegranskat)abstract
- We present a theoretical extension of the previously published bicarbonate hydrogenation to formate and formic acid dehydrogenation catalysed by Fe-II complexes bearing the linear tetraphosphine ligand tetraphos-1. The hydrogenation reaction was found to proceed at the singlet surface with two competing pathways: A)H-2 association to the Fe-H species followed by deprotonation to give a Fe(H)(2) intermediate, which then reacts with CO2 to give formate. B)CO2 insertion into the Fe-H bond, followed by H-2 association and subsequent deprotonation. B was found to be slightly preferred with an activation energy of 22.8kcalmol(-1), compared to 25.3 for A. Further we have reassigned the Fe-H complex, as a Fe(H)(H-2), which undergoes extremely rapid hydrogen exchange.
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| 6. |
- Rossi, Rachele, et al.
(författare)
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Circadian Genes as Exploratory Biomarkers in DMD : Results From Both the mdx Mouse Model and Patients
- 2021
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Duchenne muscular dystrophy (DMD) is a rare genetic disease due to dystrophin gene mutations which cause progressive weakness and muscle wasting. Circadian rhythm coordinates biological processes with the 24-h cycle and it plays a key role in maintaining muscle functions, both in animal models and in humans. We explored expression profiles of circadian circuit master genes both in Duchenne muscular dystrophy skeletal muscle and in its animal model, the mdx mouse. We designed a customized, mouse-specific Fluidic-Card-TaqMan-based assay (Fluid-CIRC) containing thirty-two genes related to circadian rhythm and muscle regeneration and analyzed gastrocnemius and tibialis anterior muscles from both unexercised and exercised mdx mice. Based on this first analysis, we prioritized the 7 most deregulated genes in mdx mice and tested their expression in skeletal muscle biopsies from 10 Duchenne patients. We found that CSNK1E, SIRT1, and MYOG are upregulated in DMD patient biopsies, consistent with the mdx data. We also demonstrated that their proteins are detectable and measurable in the DMD patients' plasma. We suggest that CSNK1E, SIRT1, and MYOG might represent exploratory circadian biomarkers in DMD.
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