Fibrils formed by proteins are vital components for cells. However, selective formation of xenogenous nanofibrils of small molecules on mammalian cells has yet to be observed. Here we report an ...unexpected observation of hydrogel/nanonets of a small D‐peptide derivative in pericellular space. Surface and secretory phosphatases dephosphorylate a precursor of a hydrogelator to trigger the self‐assembly of the hydrogelator and to result in pericellular hydrogel/nanonets selectively around the cancer cells that overexpress phosphatases. Cell‐based assays confirm that the pericellular hydrogel/nanonets block cellular mass exchange to induce apoptosis of cancer cells, including multidrug‐resistance (MDR) cancer cells, MES‐SA/Dx5. Pericellular hydrogel/nanonets of small molecules to exhibit distinct functions illustrates a fundamentally new way to engineer molecular assemblies spatiotemporally in cellular microenvironment for inhibiting cancer cell growth and even metastasis.
A small D‐peptide derivative is reported to form fibrils and nanonets in the pericellular space. The pericellular nanonets encapsulate cancer cells, which not only prohibits cell adhesion but also selectively induces cancer cell apoptosis. This is the first example of synthetic peptides to achieve biological function through formation of nanonets.
Even if periaortitis secondary to EVAR is a very rare complication, it is important for the surgeon to know this possible rare complication and its characteristics, in order to immediately recognize ...it and treat it adequately to avoid complications.
During the period 1980–2000, the yellow-legged gull population underwent exponential growth due to an increase in the availability of anthropogenic food resources. The aim of this study was to ...highlight the effect of the gull colonies on the P soil cycle and the associated effects on coastal ecosystems. Samples of soil, water and faecal material were collected in a colony of yellow-legged gulls (Cíes Islands) and in a control area. Four sampling plots were installed in the study areas, and samples were collected in summer and winter in 1997 and 2011. Sample analysis included soil characterization and determination of the total P content (TP), bioavailable-P and fractionated-P forms in the soils and faecal material. The 31P NMR technique was also used to determine organic P forms. Clear differences between the gull colony soils and the control soil were observed. The TP was 3 times higher in the gull colony soil, and the bioavailable P was 30 times higher than in the control soil. The P forms present at highest concentrations in the faecal material (P-apatite, P-residual and P-humic acid) were also present at high concentrations in the colony soil. The absence of any seasonal or annual differences in P concentration indicates that the P has remained stable in the soil over time, regardless of the changes in the gull population density. The degree of P saturation indicated that soils are saturated with P due to the low concentration of Fe/Al-hydroxides, which is consistent with a high P concentration in the run-off from the colonies. The P output from the colony soils to coastal waters may cause eutrophication of a nearby lagoon and the disappearance of a Zostera marina seagrass meadow. Similarly, the enrichment of P concentration in dune system of Muxieiro may induce irreversible changes in the plant communities.
•P concentration in soils did not vary in either the short or long term.•Sandy soils of the seagull colonies in the Cies Islands are saturated with P•Increased P concentration in soil colonies is an irreversible process•New seagull colonies can cause negative effects on already threatened habitats
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•Aided turbulent mixed convection to liquid metal in concentric annulus.•Two radius ratios and heat flux applied on inner, outer or both walls.•Assessment of RANS models and heat flux ...models.•Influence of Reynolds number on onset and magnitude of heat transfer impairment.•Different behavior of liquid metals from ordinary fluids due to different heat transfer mechanism.
Turbulent aided mixed convection of a liquid metal with Pr=0.021 in a concentric heated annulus is investigated by solving the Reynolds-Averaged-Navier-Stokes equations. This geometry approximates rod bundles heat exchangers at high pitch-to-diameter ratios. Two inner-to-outer radius ratios of 0.13 and 0.5 are considered and a constant uniform heat flux is applied only to the inner wall, only to the outer wall or to both walls. Constant thermo-physical properties are assumed and buoyancy is accounted for in the momentum equation using the Boussinesq assumption. Four different eddy-viscosity models are first assessed against the few available experimental data for a pipe flow. The turbulent heat fluxes are modeled with the Simple-Gradient-Diffusion-Hypothesis and the turbulent Prandtl number is locally evaluated either with a correlation or by solving one additional transport equation for the temperature variance and one for its dissipation rate. The first approach gives a better agreement with the experimental data. It is found that, compared to medium-to-high Prandtl number fluids, the Reynolds number has a much greater influence on the onset and magnitude of heat transfer impairment. Its extent and degree are less than for ordinary fluids. It is shown that, contrarily to a pipe flow where liquid metals with Pr≈0.025 behave similar to air or water, in the concentric annulus big differences exist. The reason is the considerable contribution of molecular heat transfer in liquid metals that compensates the reduced turbulent mixing due to buoyancy.
Seabirds form large colonies during the reproductive period, producing substantial changes in coastal ecosystems. The present study quantifies the amount of N and P deposited in colonies of ...yellow-legged gull (Larus michahellis) in the Atlantic Islands of Galicia National Park (AINP). Based on the composition of droppings, the amount of total N (TN), total P (TP) and bioavailable P (Pbio) deposited directly on the area occupied by the colony was determined. In addition, the amount of NH3 released into the atmosphere was also estimated by applying a bioenergetic model. The results indicated that 5.35 t total N, 3.35 t total P and 1.24 t bioavailable P are deposited in the colony annually. The archipelagos that received the greatest amount of nutrients were the Cíes Islands (2.37 t TN y−1, 1.48 t TP y−1, 0.55 t Pbio y−1), Sálvora (1.94 t TN y−1, 1.22 t TP y−1, 0.55 t Pbio y−1) and Ons (1.04 t TN y−1, 0.65 TP y−1, 0.24 t Pbio y−1). Rainwater from the colonies showed higher values of nutrients than in the control plot, possibly also due to gull influence. Therefore, the yellow-legged gull colony seems to be the most important source of nutrients at a local level, exerting a clear influence on the N and P cycles in this National Park. Another aspect worth taking into consideration is that increased N and P bioavailability may have a negative effect on the conservation of rare or threatened habitats and species by promoting the expansion of non-native ruderal species.
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•The yellow-legged gull is the most important local source of nutrients for AINP.•Increased bioavailability of N and P can affect fragile habitats and species.•The yellow-legged gull colony of the AINP emits large amounts of NH3.
The only glaciers existing today in the Iberian Peninsula are small features located in the Pyrenees, though their number and extension has undergone significant changes over the Late Quaternary. The ...wide range of glacial landforms and deposits distributed across different Iberian ranges suggests the occurrence of several past periods with larger glacial systems. The objective of this research is to summarize the current knowledge on the spatial and temporal patterns of glacial activity in the Iberian mountains during the Late Quaternary. To this purpose, the chronological framework was divided in six periods: glaciations prior to the Last Glacial Cycle (Middle Pleistocene), Last Glacial Cycle (Late Pleistocene), Termination-1, Holocene, Little Ice Age (LIA) and present-day. The data were geographically divided considering the mountain systems where glacial evidence exists: Pyrenees, Cantabrian Range, NW ranges, Central Range, Iberian Range and Sierra Nevada. During Quaternary cold stages, ice accumulated in the head valleys of these mountain ranges and glaciers flowed down-valleys. In all cases, glaciers remained confined within the mountain systems and did not reach the surrounding lowlands. Depending on the combination of temperatures and moisture conditions, more or less ice was stored. In some ranges, there is evidence of Middle Pleistocene glaciations, one potentially correlating with marine isotope stage (MIS) 12 and another correlating with MIS 6 with glaciation dated to ca. 130-170 ka. However, most of the glacial records correspond to the Last Glacial Cycle and subsequent Termination. The maximum glacial expansion of this last Pleistocene glaciation stage occurred well before the global Last Glacial Maximum (LGM) between 30 and 60 ka in the Cantabrian Mountains and Pyrenees, at ca. 30 ka in Sierra Nevada and NW ranges, and (almost) synchronously to the LGM in the Central Range and Iberian Range. A massive glacial retreat occurred in all ranges at 19-20 ka, but the long-term deglaciation process was interrupted by cold intervals, such as the Oldest and Younger Dryas, which favoured glacial expansion in the highest mountains. Temperature increase recorded during the Holocene conditioned the melting of glaciers, which only reappeared in the highest massifs during the coldest periods, such as the LIA. However, post-LIA warming led to glacier disappearance in the Cantabrian Mountains, Sierra Nevada and most massifs of the Pyrenees, together with an accelerated shrinkage of the small glaciers still existing in this range at elevations near 3000 m.
Seabird colonies exert a strong influence on coastal ecosystems, increasing soil nitrogen bioavailability and modifying plant communities. Previous studies have evidenced that increased N in soils ...leads to changes in plant cell wall composition; however, this effect has not been assessed in seabird colonies. The main objective of this study was to determine the influence of seabird colonies on nitrogen, cellulose and lignin content in cell walls. For this purpose, analyses were performed on droppings, soils and three native plant species (Armeria pubigera, Armeria pungens and Corema album) growing in yellow-legged gull colonies. The results showed that N excreted by yellow-legged gull is assimilated by plants, increases N content in plant tissues and reduces cellulose and lignin synthesis, therefore potentially altering plant resistance against phytoparasites.
•The soils of the colonies of the Yellow-legged gull are enriched in nitrogen.•The plant tissues growing in the colonies are enriched in nitrogen.•The cell walls of plants growing in colonies have less cellulose and lignin.
Marine-derived nutrients are known accumulate in seabird breeding colonies due to the deposition of nutrient-rich biological materials, thus greatly altering the functioning and dynamics of these ...terrestrial ecosystems. Here we present the results of a sampling survey carried out during three years in yellow-legged gull colonies in the Atlantic Islands of Galicia National Park (NW Spain) with the aim of evaluating the influence of the colonies on the accumulation of trace elements, including micronutrients (Cu, Zn, Se, Co, Mo, Ni) and toxic elements (Cr, Cd, Hg, Pb, As, Ag), in the surrounding environments. For this purpose, we analysed samples of biological materials produced by the seabirds (pellets, excrement, feathers, eggs) and of soil, plants and inland water from several different subcolonies and control zones without seabirds.
The concentrations of most of the elements were higher in excrement and pellets (mean values: Zn: 152, As: 50 mg kg−1, Cd: 6, Co: 5 mg kg−1) than in feathers and eggs. The flow of trace elements into the breeding colonies, considering only the excrement, revealed a very high level of trace element deposition for a supposedly pristine environment (Zn: 2667, Cd: 70, Cu: 315, As: 64 g ha−1). The total concentrations of trace elements in soil were consistent with the long-term impact of the seabirds. Thus, the values in areas which this impact was greatest were significantly higher than in the control zones, particularly considering the most labile geochemical fractions of the soil. The concentrations of some elements (i.e. Co, As, Cd) were also higher in the inland waters in the colonies than in control zones. Finally, the concentration of trace elements in plants varied depending on the species and element considered.
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•Excrement and pellets are the biological materials containing the highest levels of trace elements.•The most reactive fractions of the colony soils are clearly enriched in trace elements.•The inland waters in the colonies are enriched in trace elements.•The trace element content of plants is not affected by seabird activity.
The Ría de Ortigueira is an environmentally well conserved; however, the sediments show high concentrations of toxic elements. In some zones, the concentrations of Ni (60–1080 mg kg−1) and Cr ...(9–567 mg kg−1) were extremely high, while the concentrations of other toxic elements were within normal ranges. PCA revealed that metal enrichment was due to dumping of waste sludge from a peridotite mine. The study of marine currents showed that the exit of the contaminated waste towards the external zone is restricted by the low energy of the residual currents, and the sludge therefore remains trapped in the internal zones. The potential ecological risk was moderate for all areas of the ría, reaching high values close to the mouth of the river Landoi. Finally, geochemical fractioning showed that most of the metals are associated with Fe oxyhydroxides which can become unstable and release adsorbed or coprecipitated metals, especially Ni.
•Sediments showed high concentrations of toxic elements.•The concentrations of Ni and Cr were extremely high.•Metal enrichment was due to dumping of sludge from a peridotite mine.•The potential ecological risk was moderate.
We report on a precision measurement of gravitational acceleration using ultracold strontium atoms confined in an amplitude-modulated vertical optical lattice. An uncertainty Δg/g ≈ 10(-7) is reached ...by measuring at the 5th harmonic of the Bloch frequency. The value obtained with this microscopic quantum system is consistent with the one measured with a classical gravimeter. Using lattice modulation to prepare the atomic sample, we also achieve high visibility of Bloch oscillations for ∼ 20 s. These results can be of relevance for testing gravitational redshift and Newtonian law at micrometer scale.
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