134 research outputs found
Possible Implication of Red Blood Cells in the Prothrombotic Risk in Early Rheumatoid Arthritis
Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that can be considered as a prothrombotic state1. A great number of studies have investigated the possible role of reactive oxygen species (ROS) in the etiology and pathogenesis of this disease. The presence of large amounts of superoxide radicals and hydrogen peroxide produced by activated neutrophils has been reported in the synovial fluid of patients with RA. This may cause lipid peroxidation that yields a wide variety of end products, including malondialdehyde (MDA), a known marker of oxidative stress. These products are therefore transported from the synovial fluid to the blood circulation system2. Considering that elevated levels of MDA have been observed in the blood plasma of patients with RA2, the aim of this pilot study was to investigate whether the elevated levels of plasmatic MDA could be associated with a modification of the total antioxidant capacity (TAC) of blood plasma that is usually indicative of a “systemic” oxidative imbalance3. In addition, in view of their activity as redox effectors or scavengers4, as well as determinants of thrombus formation5, we evaluated red blood cell (RBC) features in terms of their redox state and lifespan marker molecules
On the range of validity of perturbative models for galaxy clustering and its uncertainty
We explore the reach of analytical models at one-loop in Perturbation Theory
(PT) to accurately describe measurements of the galaxy power spectrum from
numerical simulations in redshift space. We consider the validity range in
terms of three different diagnostics: 1) the goodness of fit; 2) a
figure-of-bias quantifying the error in recovering the fiducial value of a
cosmological parameter; 3) an internal consistency check of the theoretical
model quantifying the running of the model parameters with the scale cut. We
consider different sets of measurements corresponding to an increasing
cumulative simulation volume in redshift space. For each volume we define a
median value and the associated scatter for the largest wavenumber where the
model is valid (the -reach of the model). We find, as a rather general
result, that the median value of the reach decreases with the simulation
volume, as expected since the smaller statistical errors provide a more
stringent test for the model. This is true for all the three definitions
considered, with the one given in terms of the figure-of-bias providing the
most stringent scale cut. More interestingly, we find as well that the error
associated with the -reach value is quite large, with a significant
probability of being as low as 0.1 (or, more generally,
up to 40% smaller than the median) for all the simulation volumes considered.
We explore as well the additional information on the growth rate parameter
encoded in the power spectrum hexadecapole, compared to the analysis of
monopole and quadrupole, as a function of simulation volume. While our analysis
is, in many ways, rather simplified, we find that the gain in the determination
of the growth rate is quite small in absolute value and well within the
statistical error on the corresponding figure of merit.Comment: 7 pages, 3 figure
Adhesion of sea-urchin living cells on nano-patterned anodic porous alumina
In this work we investigated the possibility of using living cells as stress sensing material in biosensors, in the light of the three Rs principle \u2013 Replacement, Reduction and Refinement . This approach requires the necessity to cultivate them on biocompatible electrical conducting substrate and to insert the circuit into a culture chamber that must assure both the transport of oxygen and the diffusion of the medium containing the potential stressor to the cells, without modifying their response and the structure of the culture. To this aim we fabricated nano-patterned substrates of anodic porous alumina to be used for enhancing cell adhesion, and culture chambers made in polylactic acid. Sea-urchin cells (coelomocytes) were cultured on these substrates at different times of 1, 3 and 5 days in vitro. Since these cells are progenitors of immune cells in vertebrate systems (blood cells), they carry out similar functions. For this reason, although they can differ considerably from vertebrates, they have been proved to be very promising sentinels of environmental water qualit
Implantation of a poly-L-lactide GCSF-functionalized scaffold in a model of chronic myocardial infarction
A previously developed poly-l-lactide scaffold releasing granulocyte colony-stimulating factor (PLLA/GCSF) was tested in a rabbit chronic model of myocardial infarction (MI) as a ventricular patch. Control groups were constituted by healthy, chronic MI and nonfunctionalized PLLA scaffold. PLLA-based electrospun scaffold efficiently integrated into a chronic infarcted myocardium. Functionalization of the biopolymer with GCSF led to increased fibroblast-like vimentin-positive cellular colonization and reduced inflammatory cell infiltration within the micrometric fiber mesh in comparison to nonfunctionalized scaffold; PLLA/GCSF polymer induced an angiogenetic process with a statistically significant increase in the number of neovessels compared to the nonfunctionalized scaffold; PLLA/GCSF implanted at the infarcted zone induced a reorganization of the ECM architecture leading to connective tissue deposition and scar remodeling. These findings were coupled with a reduction in end-systolic and end-diastolic volumes, indicating a preventive effect of the scaffold on ventricular dilation, and an improvement in cardiac performance
Conditions for the growth of smooth La0.7Sr0.3MnO3 thin films by pulsed electron ablation
We report on the optimisation of the growth conditions of manganite
La0.7Sr0.3MnO3 (LSMO) thin films prepared by Channel Spark Ablation (CSA). CSA
belongs to pulsed electron deposition methods and its energetic and deposition
parameters are quite similar to those of pulsed laser deposition. The method
has been already proven to provide manganite films with good magnetic
properties, but the films were generally relatively rough (a few nm
coarseness). Here we show that increasing the oxygen deposition pressure with
respect to previously used regimes, reduces the surface roughness down to unit
cell size while maintaining a robust magnetism. We analyse in detail the effect
of other deposition parameters, like accelerating voltage, discharging energy,
and temperature and provide on this basis a set of optimal conditions for the
growth of atomically flat films. The thicknesses for which atomically flat
surface was achieved is as high as about 10-20 nm, corresponding to films with
room temperature magnetism. We believe such magnetic layers represent appealing
and suitable electrodes for various spintronic devices.Comment: original paper, thin film optimization, 25 pages, 9 figure
Global assessment of innovative solutions to tackle marine litter
AbstractMarine litter is one of the most relevant pollution problems that our oceans are facing today. Marine litter in our oceans is a major threat to a sustainable planet. Here, we provide a comprehensive analysis of cutting-edge solutions developed globally to prevent, monitor and clean marine litter. Prevention in this research includes only innovative solutions to prevent litter entering oceans and seas rather than interventions such as waste reduction and recycling. On the basis of extensive search and data compilation, our analysis reveals that information is dispersed across platforms and is not easily accessible. In total, 177 solutions—the equivalent to <0.9% of the search hits—fulfilled our validation criteria and were evaluated. Most solutions (n = 106, 60%) primarily address monitoring and were developed during the past 3 years, with the scientific community being the key driver. Few solutions reached mature technical readiness and market availability, while none were validated for efficiency and environmental impact. Looking ahead, we elaborate on the limitations of the existing solutions, the challenges of developing new solutions, and provide recommendations for funding schemes and policy instruments to prevent, monitor and clean marine litter globally. In doing so, we encourage researchers, innovators and policy-makers worldwide to act towards achieving and sustaining a cleaner ocean for future generations
Microplastics ingestion in the ephyra stage of Aurelia sp. triggers acute and behavioral responses
For the first time, we report a correspondence between microplastics (MP) ingestion and ecotoxicological effects in gelatinous zooplankton (Cnidarian jellyfish). The ephyra stage of the jellyfish Aurelia sp. was exposed to both environmental and high concentrations of fluorescent 1–4 μm polyethylene MP (0.01–10 mg/L). After 24 and 48 h, MP accumulation, acute (Immobility) and behavioral (Frequency pulsation) endpoints were investigated. MP were detected by confocal and tomographic investigations on gelatinous body and mouth, either attached on the surface or ingested. This interaction was responsible for impairing ephyrae survival and behavior at all tested concentrations after 24 h. Acute and behavioral effects were also related to mechanical disturbance, caused by MP, triggering a loss of radial symmetry. Contaminated ephyrae exposed to clean seawater showed full recovery after 72 h highlighting the organisms without the microspheres, attached on body jellyfish surface around the mouth and lappets. In conclusion, short-term exposure to MP affects ephyrae jellyfish health, impairing both their survival and behavior. Polyethylene MP temporarily affect both Immobility and Frequency of pulsation of Aurelia sp. jellyfish. This study provides a first step towards understanding and clarifying the potential impacts of MP contamination in gelatinous zooplankton
Detecting Mediterranean White Sharks with Environmental DNA
The white shark (Carcharodon carcharias) is a globally distributed, ecologically important top predator whose biology and population dynamics are challenging to study. Basic biological parameters remain virtually unknown in the Mediterranean Sea due to its historically low population density, dwindling population size, and lack of substantial sightings. White sharks are considered Critically Endangered in the Mediterranean Sea, and recent analyses suggest that the population has declined by 52% to 96% from historical levels in different Mediterranean sectors (Moro et al., 2020). Thus, white shark sightings dating back to 1860 are being used to estimate population trajectories throughout the entire region. Though the population size is unknown, remaining individuals are thought to be primarily restricted to a handful of hotspots deemed important for their reproduction and foraging. One of these hypothesized hotspots is the Sicilian Channel, which accounts for 19% of total historical sightings
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