653 research outputs found

    Rhodium and Iridium complexes with a new scorpionate phosphane ligand

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    A straightforward synthesis of a new hybrid scorpionate ligand [(allyl)2B(CH2PPh2)(Pz)]− ([A2BPN]−) is reported. Coordination to rhodium resulted in square-planar complexes [Rh(κ2-A2BPN)(L)(L′)] [L = L′ = 1/2cod (1,5-cyclooctadiene), CNtBu, CO (6); L = CO, L′ = NH3, pyridine, PPh3, PMe3] for which spectroscopic data and the molecular structure of [Rh(κ2-A2BPN)(CO)PPh3] (11) indicate the ligand to be κN,κP-bound to rhodium with two dangling free allyl groups. Studies in solution point out that the six-membered Rh–N–N–B–C–P metallacycle undergoes a fast inversion in all of them. The bis(carbonyl) complex 6 easily loses a CO group to give [{Rh(A2BPN)(CO)}2], a dinuclear compound in which two mononuclear subunits are brought together by two bridging allyl groups. Coordination to iridium is dominated by a tripodal κN,κP,η2-C═C binding mode in the TBPY-5 complexes [Ir(κ3-A2BPN)(L)(L′)] [L = L′ = 1/2cod (3), CNtBu (5), CO (7); L = CO, L′ = PPh3 (13), PMe3 (14), H2C═CH2, (17), MeO2CC≡CCO2Me (dmad, 18)], as confirmed by the single-crystal structure determination of complexes 3 and 18. A fast exchange between the two allyl arms is observed for complexes having L = L′ (3, 5, and 7), while those having CO and L ligands (14, 17, and 18) were found to be nonfluxional species. An exception is complex 13, which establishes an equilibrium with the SP-4 configuration. Protonation reactions on complexes 13 and 14 with HCl yielded the hydride complex [Ir(κ2-A2BPN)(CO)(Cl)(H)PPh3] (15) and the C-alkyl compound [Ir{κ3-(allyl)B(CH2CHCH3)(CH2PPh2)(Pz)}(Cl)(CO)PMe3] (16), respectively. The bis(isocyanide) complex 5 reacts with dmad to form [Ir(κ2-A2BPN)(CNtBu)2(dmad)]. On the whole, the electronic density provided to the metal by the [A2BPN]− ligand is very sensitive to the coordination mode. The basicity of the new ligand is similar to that of the TpMe2 ligand in the κN,κP mode but comparable to Tp if coordinated in the κN,κP,η2-C═C mode.This research was supported by the MICINN/FEDER (Project CTQ2011-22516, Spain), Gobierno de Aragón (GA)/FSE (E70), and GA-La Caixa (Grant 2012/GA LC 057). A.L.S. thanks MICINN/FEDER for a fellowship.Peer Reviewe

    Paleoliquefaction in the Bajo Segura basin (eastern Betic Cordillera)

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    The Bajo Segura basin, in the eastern Betic Cordillera, displays a seismic activity characterized by small-magnitude earthquakes (1.5-4.5 mb), with some occasional moderate to high-magnitude events (> 5.0 mb). These earthquakes are produced by the activity of blind faults without surface ruptures. For this reason, the detection of paleoearthquakes in the geological record is limited to indirect evidence of paleoseismicity, mainly liquefaction features. Moreover, such evidence is abundant in the historical record of the 1829 Torrevieja earthquake, in some of its aftershocks and in the 1919 Jacarilla earthquake. In this study several layers of Holocene seismites previously described in the basin were analyzed, and correlated with various radiometric 14C datings. This analysis enabled a recurrence period of approx. 1000 yr to be established for the moderate to high-magnitude earthquakes in the Bajo Segura basin

    The mediating role of sense of coherence on mental health outcomes in carers of older dependent relatives: a longitudinal study

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    Background: Sense of coherence (SOC) is an important protective factor for carer well‐being but research to date remains cross‐sectional, focusing primarily on the direct effects of SOC on carers’ mental health. The study's aim was to investigate the mediating role of SOC in the longitudinal relationship between caregiver strain and carers’ psychological health, and its stability over time. / Methods: Prospective longitudinal study conducted in Jaén (Spain) with a probabilistic sample of 132 carers of older people, with data collected at baseline and at one‐year follow‐up. We measured SOC, caregiver strain, anxiety and depressive symptoms, and several care recipient characteristics and intensity of care provided. We used multiple linear regression modelling and the Sobel test to analyse mediation effects. / Results: SOC was significantly negatively longitudinally associated with both anxiety (β= ‐0.38, p= 0.001) and depressive symptoms (β= ‐0.28, p= 0.023), after controlling for several confounders. SOC mediated both the relationship between caregiver strain and anxiety and caregiver strain and depressive symptoms (Sobel test; p< 0.001 for anxiety and p< 0.001 for depressive symptoms). Differences between baseline and one‐year follow‐up SOC scores were not statistically significant (p= 0.617). / Conclusions: SOC appears to buffer the impact of caregiver strain on symptoms of depression and anxiety in informal carers of older people. Our data showed that SOC is an important psychological resource for carers that remained relatively stable under non‐experimental conditions over a period of one year in this sample. Findings suggest that interventions aimed at strengthening SOC may protect carer psychological well‐being

    Estado de salud y demanda de servicios de salud de la población ecuatoriana en España

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    Análisis del estado de salud y del grado de acceso a los servicios de salud de los inmigrantes ecuatorianos en la provincia de Alicante. La finalidad es descriptiva y práctica: realizar un diagnóstico comunitario de salud básico y una aproximación al nivel de demanda de los servicios sanitarios. El análisis se centra en la evaluación de la hipótesis del inmigrante sano, pero vulnerable, y en el tipo de consumo de servicios de salud realizado. Para valorar esta hipótesis se ha procedido a comparar los datos obtenidos en una encuesta a población ecuatoriana residente en la provincia de Alicante, con los de la última Encuesta Nacional de Salud 2003 y el PHOGUE (2000). Los resultados indican que el estado de salud de la población ecuatoriana es similar al de la población española que participa en el mismo mercado de trabajo que la inmigración económica (trabajadores con baja cualificación), aunque se observan algunos elementos de vulnerabilidad (en especial, en términos de salud emocional).La presente investigación ha sido financiada por el Instituto de Salud Carlos III, ref. PI042287

    High prevalence and diversity of extended-spectrum β-lactamase and emergence of OXA-48 producing Enterobacterales in wildlife in Catalonia

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    Most of the studies focused on antimicrobial resistance (AMR) performed in wildlife describe Escherichia coli as the principal indicator of the selective pressure. In the present study, several species of Enterobacterales with a large panel of cephalosporin resistant (CR) genes have been isolated from wildlife in Catalonia. A total of 307 wild animals were examined to determine the prevalence of CR enterobacteria, AMR phenotypes and the presence of common carbapenem and CR genes. The overall prevalence of CR-phenotype was 13% (40/ 307): 17.3% in wild mammals (18/104) and 11.5% in wild birds (22/191) (p<0.01). Hedgehogs showed the highest prevalence (13.5% of 104) of the mammal specimens, and raptors the highest in bird specimen (7.3% of 191). Although CR E. coli was the most frequently isolated (45%), other CR- Enterobacterales like Klebsiella pneumoniae (20%), Citrobacter freundii (15%), Enterobacter cloacae (5%), Proteus mirabilis (5%), Providencia spp (5%) and Serratia marcescens (2.5%) were also isolated. A high diversity of CR genes was identified among the isolates, with 50% yielding blaCMY-2, 23% blaSHV-12, 20% blaCMY-1 and 18% blaCTX-M-15. Additionally, resistance to carbapenems associated to OXA-48 gene was found. Most of the CR isolates, principally K. pneumoniae and C. freundii, were multiresistant with co-resistance to fluoroquinolones, tetracycline, sulphonamides and aminoglycosides. This study reports high prevalence of Enterobacterales harbouring a variety of CR genes and OXA-48 mediated-carbapenem resistance, all of them frequently associated to nosocomial human infections, for the first time in wild mammals and wild birds. Implementation of control measures to reduce the impact of anthropogenic pressure in the environment is urgently needed.info:eu-repo/semantics/publishedVersio

    High prevalence and diversity of extended-spectrum β-lactamase and emergence of OXA-48 producing Enterobacterales in wildlife in Catalonia

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    The contract of LMG was supported by the Instituto Nacional de Investigaci?n y Tecnolog?a Agraria y Alimentaria (INIA) and the European Social Fund. AV was supported by a PIF grant from the Universitat Aut?noma de Barcelona. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Our grateful thanks to the Torreferrussa WRC staff. A.C. was student of the Master?s Degree in Zoonosis and One Health (UAB). The authors are also grateful to the Centres de Recerca de Catalunya (CERCA) Programme.Most of the studies focused on antimicrobial resistance (AMR) performed in wildlife describe Escherichia coli as the principal indicator of the selective pressure. In the present study, several species of Enterobacterales with a large panel of cephalosporin resistant (CR) genes have been isolated from wildlife in Catalonia. A total of 307 wild animals were examined to determine the prevalence of CR enterobacteria, AMR phenotypes and the presence of common carbapenem and CR genes. The overall prevalence of CR-phenotype was 13% (40/ 307): 17.3% in wild mammals (18/104) and 11.5% in wild birds (22/191) (p<0.01). Hedgehogs showed the highest prevalence (13.5% of 104) of the mammal specimens, and raptors the highest in bird specimen (7.3% of 191). Although CR E. coli was the most frequently isolated (45%), other CR- Enterobacterales like Klebsiella pneumoniae (20%), Citrobacter freundii (15%), Enterobacter cloacae (5%), Proteus mirabilis (5%), Providencia spp (5%) and Serratia marcescens (2.5%) were also isolated. A high diversity of CR genes was identified among the isolates, with 50% yielding blaCMY-2, 23% blaSHV-12, 20% blaCMY-1 and 18% blaCTX-M-15. Additionally, resistance to carbapenems associated to OXA-48 gene was found. Most of the CR isolates, principally K. pneumoniae and C. freundii, were multiresistant with co-resistance to fluoroquinolones, tetracycline, sulphonamides and aminoglycosides. This study reports high prevalence of Enterobacterales harbouring a variety of CR genes and OXA-48 mediated-carbapenem resistance, all of them frequently associated to nosocomial human infections, for the first time in wild mammals and wild birds. Implementation of control measures to reduce the impact of anthropogenic pressure in the environment is urgently needed

    Synthesis of paramagnetic tetranuclear rhodium and iridium complexes with the 2,6-pyridinedithiolate ligand. Redox-induced degradation to diamagnetic triiridium compounds

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    The tetranuclear complexes [M4(μ-PyS2)2(diolefin)4] [PyS2 = 2,6-pyridinedithiolate; M = Rh, diolefin = cod (1,5-cyclooctadiene) (1), tfbb (tetrafluorobenzo[5,6]bicyclo[2.2.2]octa-2,5,7-triene) (2); M = Ir, diolefin = cod (3), tfbb (4)] exhibit two one-electron oxidations at a platinum disk electrode in dichloromethane at potentials accessible by chemical reagents. The rhodium tetranuclear complexes were selectively oxidized to the monocationic complexes [Rh4(μ-PyS2)2(diolefin)4] + (1+, 2+) by mild one-electron oxidants such as [Cp2Fe]+ or [N(C6H4Br-4)3]+ and isolated as the PF6 -, BF4 -, and ClO4 - salts. Silver salts behave as noninnocent one-electron oxidants for the reactions with the rhodium complexes 1 and 2 since they give sparingly soluble coordination polymers. The complex [Ir4(μ-PyS2)2(cod)4] + (3+) was obtained as the tetrafluoroborate salt by reaction of 3 with 1 molar equiv of AgBF4, but the related complex 4+ could not be isolated from the chemical oxidation of [Ir4(μ-PyS2)2(tfbb)4] (4) with AgBF4. Oxidation of 3 and 4 with 2 molar equiv of common silver salts resulted in the fragmentation of the complexes to give the diamagnetic triiridium cations [Ir3(μ-PyS2)2(diolefin)3] +. The molecular structure of [Ir3(μ-PyS2)2(cod)3]BF 4, determined by X-ray diffraction methods, showed the three metal atoms within an angular arrangement. Both 2,6-pyridinedithiolate tridentate ligands bridge two metal-metal bonded d7 centers in pseudo octahedral environments and one d8 square-planar iridium center. An interpretation of the EPR spectra of the 63-electron mixed-valence paramagnetic tetranuclear complexes suggests that the unpaired electron is delocalized over two of the metal atoms in the complexes 1+-3+.The generous financial support from Dirección General de Enseñanza Superior e Investigación (DGES) (Projects PB98-641 and PB94-1186), and a fellowship (M. A. Casado) are gratefully acknowledged.Peer Reviewe

    Isolation and transfection of strawverry protoplasts for gene editing

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    Strawberry is the most economically important soft fruit. The improvement of the organoleptic qualities of ripe fruit and the postharvest shelf life are main objectives of strawberry breeding programs. Fruit softening is mainly due to the disassembly of cell walls and the dissolution of middle lamella. In strawberry, functional analyses of genes encoding polygalacturonases (PGs) indicate that these enzymes play a key role in fruit softening, i.e. the antisense downregulation of PG genes FaPG1 or FaPG2 increased fruit firmness and postharvest shelf life (Paniagua et al., 2020). These results suggest that PG encoding genes are excellent targets for gene editing to improve strawberry fruit quality. Transfection of protoplasts with CRISPR/Cas9 ribonucleoprotein complexes is currently being explored in many species to produce DNA-free edited plants. In this research, a protocol for strawberry protoplasts transfection has been optimized with the final goal of producing non-transgenic strawberry plants with the FaPG1 gene edited. Protoplasts were isolated from 9 weeks old in vitro grown plants of Fragaria x ananassa, cv. ‘Chandler’, micropropagated in Murashige and Skoog (MS) medium supplemented with 2 mg/L of BA. Protoplast extraction and purification was performed as described by Barceló et al. (2019). Using this protocol, a yield of 1 x 105 protoplast/g fresh tissue was obtained and nearly 50-70% of them were viable. Protoplasts were transfected with the plasmid pHBT-sGFP(S65T)-NOS using a PEG-mediated transformation system, as reported by Yoo et al. (2007). To improve the efficiency of protoplast transfection, different variables were evaluated: PEG concentration, time of incubation on PEG and DNA concentration. At 48 h after transfection, the highest percentage of protoplasts showing GFP expression, 18%, was obtained with 15 minutes incubation in 20% of PEG and 5 µg of DNA
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