43 research outputs found

    Icnofacies y sedimentación en zona costera. Plioceno superior(?), litorial de Huelva

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    La Formación Arenas de Bonares (Plioceno superior -?-) representa un depósito siliciclástico en una zona de foreshore, caracrerizado por la presencia dominante de estratificación cruzada de bajo ángulo y la icnofacies de  Skolitos, donde Ophiomorpha nodosa Lundgren es el icnogénero más dominante. También están presentes galerías verticales y horizontales de pequeña escala, galerías verticales con Spreiten y Gyrolithes sp. Se  distinguen dos unidades ORI, en unas condiciones iniciales de oxigenación estables y determinadas (SO) y un estado final al producirse un aumento gradual de las condiciones de oxigenación (GOE)

    Pursuit of optimal synthetic conditions for obtaining colloidal zero-valent iron nanoparticles by scanning pulsed laser ablation in liquids

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    Liquid-Assisted Pulsed Laser Ablation (LA-PLA) is a promising top-down method to directly synthesize colloidal dispersions of nanoparticles in a eco-friendly manner. However, the role of LA-PLA synthesis parameters is not yet fully agreed. This work seeks to optimize the production of nanoscale zero-valent iron (nZVI) particles suitable for biomedical or environmental applications using nanosecond LA-PLA on iron targets with different ablation media, laser and target scanning parameters. The use of alcohols as solvents produces iron-iron oxide core-shell nanoparticles with amorphous cores, except for a small crystalline fraction corresponding to the biggest core sizes. Decreasing carbon chain length and complexity leads to a thinning of the carbonaceous material coatings and an increase of the colloidal stability and the nanoparticle productivity. Moreover, a decrease of solvent density and surface tension allows obtaining reduced sizes and polydispersity values. Among, laser and scanning parameters, the pulse accumulation per spot displayed a clear effect in boosting size and productivity. As main outcome, aqueous dispersions with suitable colloidal properties are obtained, either by transferring to water of optimized nZVI particles produced in ethanol, or by direct formation of nZVI particles and in situ coating with hydrophilic molecules in aqueous solutions of these moleculesThis research has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO) and FEDER [research projects MAT2015-67354R, MAT2014-53961-R, and MAT2017- 86826-R] and by the Aragón government (DGA) [grant for consolidated group PLATON E31_17R]. OBM thanks the financial support from the “Ramón y Cajal Program” [research project RYC2010-07332] of the Spanish Ministry of Economy and Competitiveness (MINECO) and the H2020 Action H2020-MSCA-IF-2014_ST [grant 656908-NIMBLIS] of the Executive Agency for Research Manages of EU Commissio

    Tuning the energetics and tailoring the optical properties of silver clusters confined in zeolites

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    The integration of metal atoms and clusters in well-defined dielectric cavities is a powerful strategy to impart new properties to them that depend on the size and geometry of the confined space as well as on metal-host electrostatic interactions. Here, we unravel the dependence of the electronic properties of metal clusters on space confinement by studying the ionization potential of silver clusters embedded in four different zeolite environments over a range of silver concentrations. Extensive characterization reveals a strong influence of silver loading and host environment on the cluster ionization potential, which is also correlated to the cluster's optical and structural properties. Through fine-tuning of the zeolite host environment, we demonstrate photoluminescence quantum yields approaching unity. This work extends our understanding of structure property relationships of small metal clusters and applies this understanding to develop highly photoluminescent materials with potential applications in optoelectronics and bioimaging

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

    Crowded tubular tidalites in Miocene shelf sandstones of southern Iberia

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    The passive and active fill of burrows potentially stores information about sedimentary processes that are otherwise not preserved in the rock record. In recent years, abandoned passively-filled vertical burrows were introduced as "tubular tidalites" when their infilling displays rhythmic lamination reflecting a tidal signature. In the shallow-marine Miocene sandstones exposed at Oura (southern Portugal), 36 tubular tidalites occur in a 1.5 m-thick interval. Their high abundance is likely a consequence of both an environment favourable for the production of open burrows in a tidal setting, and post-depositional conditions facilitating the preservation of the tubular tidalites. Besides vertical tubes, 13 horizontal burrows preserve a tidal signature indicating draughtfill processes. All specimens belong to Thalassinoides and, for the first time, to Gyrolithes. The rhythmic infill of two well-preserved specimens shows two significant features: (1) The thickness pattern allows for differentiation into groups having 7 couplets (consisting of a dark and a light lamina) or multiples thereof, and (2) the thickness patterns of both, consecutive couplets as well as dark and light laminae match sine curves. Both patterns indicate a diurnal tidal cyclicity. The tidalites record up to four spring-tide and three neap-tide cycles. In addition to the neap-spring cycles, a long-period lunar fortnightly tide regime can be envisaged. The tubular tidalites imply diurnal tides during the Miocene in contrast to the Recent semidiurnal tides affecting southern Portugal

    Coevalness of insect trace fossils and trace-bearing rocks, a case study from the Plio?-Pleistocene of SW Spain

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    Plio?-Pleistocene outcrops located at the southwestern edge of the Guadalquivir Basin in the area of Lepe (Huelva, Spain) provide an interesting example for studying the contemporaneity of traces with the rocks that contain them. Two different types of cells compatible with the ichnogenera Celliforma (Type 1) and Palmiraichnus (Type 2) were found in these outcrops. Their walls were constructed with the same material as the matrix and our first research in the area showed no extant bees producing them suggesting that they were coeval with the trace-bearing rocks. The case of the ‘‘Palmiraichnus-like’’ Type 2 cells was misleading because of its similarity with Palmiraichnus described from the region in the Canary Islands and Balearic Archipelago (Spain). Two determining features were vital in clarifying this first appearance. In the Palmiraichnus-like cells we found remains of a larval cocoon in one cell that could be dated by C14, giving a modern age. In the Celliforma-like cells more field research in the area allow us to observe extant bees nesting in these rocks in autumn. Ichnological literature show a few cases of asynchronies involving extant traces found mostly in Paleozoic and Mesozoic rocks. In contrast, the case presented herein indicates the time gap between the bearing rocks and the Lepe traces was shorter (ca. 12 ky–2.6 My), enhancing the similarity of traces and rocks and thus their potential coevalness. This case may serve as a warning about other potential examples in the fossil record in which relatively short asynchronies between traces and paleosols exist.Fil: Mayoral, Eduardo. Universidad de Huelva; EspañaFil: Genise, Jorge Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Rodríguez Tovar, Francisco J.. Universidad de Granada; EspañaFil: Santos, Ana. Universidad de Huelva; Españ
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