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- Palacios, M.A., et al.
(författare)
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Platinum-group elements: quantification in collected exhaust fumes and studies of catalyst surfaces
- 2000
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Ingår i: The Science of the Total Environment. ; 257, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Automotive catalytic converters, in which Pt, Pd and Rh (platinum-group elements; PGEs) are the active components for eliminating several noxious components from exhaust fumes, have become the main source of environmental urban pollution by PGEs. This work reports on the catalyst morphology through changes in catalyst surface by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and laser-induced breakdown spectrometry (LIBS) from fresh to aged catalytic converters. The distribution of these elements in the fresh catalysts analysed (PtPdRh gasoline catalyst) is not uniform and occurs mainly in a longitudinal direction. This heterogeneity seems to be greater for Pt and Pd. PGEs released by the catalysts, fresh and aged 30 000 km, were studied in parallel. Whole raw exhaust fumes from four catalysts of three different types were also examined. Two of these were gasoline catalysts (PtPdRh and PdRh) and the other two were diesel catalysts (Pt). Samples were collected following the 91441 EUDC driving cycle for light-duty vehicle testing. The results show that at 0 km the samples collected first have the highest content of particulate PGEs and although the general tendency is for the release to decrease with increasing number of samples taken, exceptions are frequent. At 30 000 km the released PGEs in gasoline and diesel catalysts decreased significantly. For fresh gasoline catalysts the mean of the total amount released was approximately 100, 250 and 50 ng km−1 for Pt, Pd and Rh, respectively. In diesel catalysts the Pt release varied in the range 400800 ng km−1. After ageing the catalysts up to 30 000 km, the gasoline catalysts released amounts of Pt between 6 and 8 ng km−1, Pd between 12 and 16 ng km−1 and Rh between 3 and 12 ng km−1. In diesel catalysts the Pt release varied in the range 108150 ng km−1. The soluble portion of PGEs in the HNO3 collector solution represented less than 5% of the total amount for fresh catalysts. For 30 000 km the total amount of soluble PGEs released was similar or slightly higher than for 0 km.
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- Rodriguez-Llera, MC, et al.
(författare)
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Psychiatric comorbidity in young heroin users
- 2006
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Ingår i: Drug And Alcohol Dependence. - : Elsevier BV. - 0376-8716 .- 1879-0046. ; 84:1, s. 48-55
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Tidskriftsartikel (refereegranskat)abstract
- In order to determine the prevalence of psychiatric comorbidity in a population of young heroin users recruited from outside of the healthcare context, a sample was assembled by targeted sampling and nomination techniques; it was comprised of regular current users of heroin aged between 18 and 30 years and resident in Barcelona, Spain. Psychiatric evaluation was done with the Psychiatric Research Interview for Substance and Mental Disorders (PRISM) semi-structured interview. Of 149 individuals evaluated, 33% were women, whose mean age was 25.1 years; 93% received a diagnosis of heroin dependence and 71% of cocaine dependence. Thirty-two percent of the subjects had never been treated for substance use. Around two-thirds (67.1%, 95% CI: 59.6-74.7%) of the sample had lifetime psychiatric comorbidity, with antisocial personality and mood disorders being the most frequent conditions (33% and 26%, respectively). Mood, anxiety and eating disorders were more common among women than men. There were no differences in ever having been in treatment for drug use according to the presence of psychiatric comorbidity, although comorbidity was lower among those currently in treatment. Young heroin users recruited on the street presented a high prevalence of psychiatric comorbidity which was unrelated to past treatment history.
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- Torrens, J., et al.
(författare)
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Advancing urban transitions and transformations research
- 2021
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Ingår i: Environmental Innovation and Societal Transitions. - : Elsevier. - 2210-4224. ; 41, s. 102-105
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Forskningsöversikt (refereegranskat)abstract
- Urban transitions and transformations research fosters a dialogue between sustainability transitions theory an inter- and transdisciplinary research on urban change. As a field, urban transitions and transformations research encompasses plural analytical and conceptual perspectives. In doing so, this field opens up sustainability transitions research to new communities of practice in urban environments, including mayors, transnational municipal networks, and international organizations.
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- Aghaei, Mohammadreza, et al.
(författare)
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Collective Intelligence for Energy Flexibility - Collectief : An EU H2020 Project for Enhancing Energy Efficiency and Flexibility in Existing Buildings
- 2023
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Ingår i: 2023 International Conference on Future Energy Solutions, FES 2023. - 9798350332308
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Konferensbidrag (refereegranskat)abstract
- COLLECTiEF (Collective Intelligence for Energy Flexibility) is an EU-funded H2020 project running from June 2021 to May 2025. COLLECTiEF aims to enhance, implement, test, and evaluate an interoperable and saleable energy management system based on collective intelligence that allows easy and seamless integration of legacy equipment into a collaborative network within and between existing buildings and urban energy systems with reduced installation cost, data transfer, and computational power while increasing user comfort, energy flexibility, climate resilience, and data security. To achieve this goal, the COLLECTiEF solution requires the development of software and hardware packages to smart up buildings and their legacy equipment on a large scale while maintaining simple and robust communication with the energy grid. Here, we present the project concept, structure, objectives, and working packages. Furthermore, the main progress and achievements obtained during the first two years of the project are presented.
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- Barceló, Isabel M., et al.
(författare)
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Filling knowledge gaps related to AmpC-dependent β-lactam resistance in Enterobacter cloacae
- 2024
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Enterobacter cloacae starred different pioneer studies that enabled the development of a widely accepted model for the peptidoglycan metabolism-linked regulation of intrinsic class C cephalosporinases, highly conserved in different Gram-negatives. However, some mechanistic and fitness/virulence-related aspects of E. cloacae choromosomal AmpC-dependent resistance are not completely understood. The present study including knockout mutants, β-lactamase cloning, gene expression analysis, characterization of resistance phenotypes, and the Galleria mellonella infection model fills these gaps demonstrating that: (i) AmpC enzyme does not show any collateral activity impacting fitness/virulence; (ii) AmpC hyperproduction mediated by ampD inactivation does not entail any biological cost; (iii) alteration of peptidoglycan recycling alone or combined with AmpC hyperproduction causes no attenuation of E. cloacae virulence in contrast to other species; (iv) derepression of E. cloacae AmpC does not follow a stepwise dynamics linked to the sequential inactivation of AmpD amidase homologues as happens in Pseudomonas aeruginosa; (v) the enigmatic additional putative AmpC-type β-lactamase generally present in E. cloacae does not contribute to the classical cephalosporinase hyperproduction-based resistance, having a negligible impact on phenotypes even when hyperproduced from multicopy vector. This study reveals interesting particularities in the chromosomal AmpC-related behavior of E. cloacae that complete the knowledge on this top resistance mechanism.
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- Barceló, Isabel M., et al.
(författare)
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Role of enzymatic activity in the biological cost associated with the production of ampC b-lactamases in pseudomonas aeruginosa
- 2022
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Ingår i: Microbiology Spectrum. - : American Society for Microbiology. - 2165-0497. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- In the current scenario of growing antibiotic resistance, understanding the interplay between resistance mechanisms and biological costs is crucial for designing therapeutic strategies. In this regard, intrinsic AmpC β-lactamase hyperproduction is probably themost important resistancemechanismof Pseudomonas aeruginosa, proven to entail important biological burdens that attenuate virulence mostly under peptidoglycan recycling alterations. P. aeruginosa can acquire resistance to new β-lactam-β-lactamase inhibitor combinations (ceftazidime-avibactam and ceftolozane-tazobactam) through mutations affecting ampC and its regulatory genes, but the impact of these mutations on the associated biological cost and the role that β-lactamase activity plays per se in contributing to the above-mentioned virulence attenuation are unknown. The same questions remain unsolved for plasmid-encoded AmpC-type β-lactamases such as FOX enzymes, some of which also provide resistance to new β-lactam-β-lactamase inhibitor combinations. Here, we assessed from different perspectives the effects of changes in the active center and, thus, in the hydrolytic spectrum resistance to inhibitors of AmpC-type β-lactamases on the fitness and virulence of P. aeruginosa, using site-directed mutagenesis; the previously described AmpC variants T96I, G183D, and ΔG229-E247; and, finally, blaFOX-4 versus blaFOX-8. Our results indicate the essential role of AmpC activity per se in causing the reported full virulence attenuation (in terms of growth, motility, cytotoxicity, and Galleria mellonella larvae killing), although the biological cost of the above-mentioned AmpC-type variants was similar to that of the wild-type enzymes. This suggests that there is not an important biological burden that may limit the selection/spread of these variants, which could progressively compromise the future effectiveness of the above-mentioned drug combinations.
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