Magnetism in La2O3(Fe1-xMnx)2Se2 tuned by Fe/Mn ratio

We report the evolution of structural and magnetic properties in La2O3(Fe1-xMnx)2Se2. Heat capacity and bulk magnetization indicate an increased ferromagnetic component of the long-range magnetic order and possible increased degree of frustration. Atomic disorder on Fe(Mn) sites suppresses the temperature of the long-range order whereas intermediate alloys show a rich magnetic phase diagram.Comment: 7 pages, 7 figure

Characterization of the Protein Corona of Three Chairside Hemoderivatives on Melt Electrowritten Polycaprolactone Scaffolds

In tissue engineering, the relationship between a biomaterial surface and the host’s immune response during wound healing is crucial for tissue regeneration. Despite hemoderivative functionalization of biomaterials becoming a common tissue-engineering strategy for enhanced regeneration, the characteristics of the protein–biomaterial interface have not been fully elucidated. This study characterized the interface formed by the adsorbed proteins from various hemoderivatives with pristine and calcium phosphate (CaP)-coated polycaprolactone (PCL) melt electrowritten scaffolds. PCL scaffolds were fabricated by using melt electrospinning writing (MEW). Three hemoderivatives (pure platelet-rich plasma (P-PRP), leucocyte platelet-rich plasma (L-PRP) and injectable platelet-rich fibrin (i-PRF)) and total blood PLASMA (control) were prepared from ovine blood. Hemoderivatives were characterized via SEM/EDX, cross-linking assay, weight loss, pH and protein quantification. The interface between PCL/CaP and hemoderivative was examined via FTIR, XPS and electrophoresis. i-PRF/PCL-CaP (1653 cm−1), PLASMA/PCL-CaP (1652 cm−1) and i-PRF/PCL (1651 cm−1) demonstrated a strong signal at the Amide I region. PLASMA and i-PRF presented similar N1s spectra, with most of the nitrogen involved in N-C=O bonds (≈400 eV). i-PRF resulted in higher adsorption of low molecular weight (LMW) proteins at 60 min, while PLASMA exhibited the lowest adsorption. L-PRP and P-PRP had a similar pattern of protein adsorption. The characteristics of biomaterial interfaces can be customized, thus creating a specific hemoderivative-defined layer on the PCL surface. i-PRF demonstrated a predominant adsorption of LMW proteins. Further investigation of hemoderivative functionalized biomaterials is required to identify the differential protein corona composition, and the resultant immune response and regenerative capacity

Accelerated wound healing phenotype in Interleukin 12/23 deficient mice

Background: The concept that a strong inflammatory response involving the full complement of cytokines and other mediators is critical for unimpaired healing has been challenged by wound healing studies using transgenic and knockout (KO) mice. The present study explored the effect of abrogation of the p40 subunit, which is shared by the pro-inflammatory cytokines interleukin (IL)-12 and IL-23, on wound closure of excisional oral mucosal wounds

Hydrophilic titanium surface‐induced macrophage modulation promotes pro‐osteogenic signalling

Objectives: As biomaterial‐induced modulation of mediators of the immune response may be a potential therapeutic approach to enhance wound healing events, the aim of this study was to delineate the effects of titanium surface modification on macrophage phenotype and function. Material and methods: Rodent bone marrow‐derived macrophages were polarized into M1 and M2 phenotypes and cultured on micro‐rough (SLA) and hydrophilic modified SLA (modSLA) titanium discs. Macrophage phenotype and cytokine secretion were subsequently assessed by immunostaining and ELISA, respectively. Osteoblast gene expression in response to culture in the M1 and M2 macrophage conditioned media was also evaluated over 7 days by RT‐PCR. Results: M1 macrophage culture on the modSLA surface promoted an M2‐like phenotype as demonstrated by marked CD163 protein expression, Arg1 gene expression and the secretion of cytokines that significantly upregulated in osteoblasts the expression of genes associated with the TGF‐ß/BMP signalling pathway and osteogenesis. In comparison, M2 macrophage culture on SLA surface promoted an inflammatory phenotype and cytokine profile that was not conducive for osteogenic gene expression. Conclusions: Macrophages are able to alter or switch their phenotype according to the signals received from the biomaterial surface. A hydrophilic micro‐rough titanium surface topography elicits a macrophage phenotype associated with reduced inflammation and enhanced pro‐osteogenic signalling

A semi-classical over-barrier model for charge exchange between highly charged ions and one-optical electron atoms

Absolute total cross sections for electron capture between slow, highly charged ions and alkali targets have been recently measured. It is found that these cross sections follow a scaling law with the projectile charge which is different from the one previously proposed basing on a classical over-barrier model (OBM) and verified using rare gases and molecules as targets. In this paper we develop a "semi-classical" (i.e. including some quantal features) OBM attempting to recover experimental results. The method is then applied to ion-hydrogen collisions and compared with the result of a sophisticated quantum-mechanical calculation. In the former case the accordance is very good, while in the latter one no so satisfactory results are found. A qualitative explanation for the discrepancies is attempted.Comment: RevTeX, uses epsf; 6 pages text + 3 EPS figures Journal of Physics B (scehduled March 2000). This revision corrects fig.

Salivary small extracellular vesicles associated miRNAs in periodontal status-a pilot study

This pilot study aims to investigate whether salivary small extracellular vesicle (sEV)-associated microRNAs could act as potential biomarkers for periodontal disease status. Twenty-nine participants (10 who were healthy, nine with gingivitis, 10 with stage III/IV periodontitis) were recruited and unstimulated whole saliva samples were collected. Salivary sEVs were isolated using the size-exclusion chromatography (SEC) method and characterised by morphology, EV-protein and size distribution using transmission electron microscopy (TEM), Western Blot and Nanoparticle Tracking Analysis (NTA), respectively. Ten mature microRNAs (miRNAs) in salivary sEVs and saliva were evaluated using RT-qPCR. The discriminatory power of miRNAs as biomarkers in gingivitis and periodontitis versus healthy controls was evaluated by Receiver Operating Characteristics (ROC) curves. Salivary sEVs were comparable to sEVs morphology, mode, size distribution and particle concentration in healthy, gingivitis and periodontitis patients. Compared to miRNAs in whole saliva, three significantly increased miRNAs (hsa-miR-140-5p, hsa-miR-146a-5p and hsa-miR-628-5p) were only detected in sEVs in periodontitis when compared to that of healthy controls, with a good discriminatory power (area under the curve (AUC) = 0.96) for periodontitis diagnosis. Our study demonstrated that salivary sEVs are a non-invasive source of miRNAs for periodontitis diagnosis. Three miRNAs that are selectively enriched in sEVs, but not whole saliva, could be potential biomarkers for periodontal disease status.Pingping Han, Peter Mark Bartold, Carlos Salomon and Saso Ivanovsk

Expression of bone matrix mRNAs by primary and cloned cultures of the regenerative phenotype of human periodontal fibroblasts

The successful regeneration of periodontal tissues is dependent, in part, on the ability of cells to reconstitute the mineralized tissues of cementum and bone. The aim of the present study was to characterize regeneration-associated cells in terms of their ability to express mineralized tissue macromolecules. Following guided tissue regeneration, cell cultures were established from regenerating tissue, periodontal ligament, and gingiva. Additionally, these cells were transfected, and single-cell-derived clones were established. Following treatment with platelet-derived growth factor-BB and insulin-derived growth factor-1, the presence of mRNA for alkaline phosphatase, osteocalcin, bone sialoprotein, osteopontin, and bone morphogenetic proteins-2 and -4 was assessed. The three cell types expressed similar mRNA levels for alkaline phosphatase, bone morphogenetic protein-2, and bone morphogenetic protein-4, whereas the expression of osteopontin, osteocalcin, and bone sialoprotein was greater in the periodontal ligament and regenerating tissue fibroblasts compared with the gingival fibroblasts. The two growth factors did not affect the expression of any of the genes. This study has identified markers that correlate with the known ability of periodontal ligament and regenerating tissue-derived fibroblasts to facilitate regeneration of the mineralized tissues of the periodontium

Climate and atmospheric models of rocky planets: habitability and observational properties

The quest for atmospheric spectral signatures that may witness biological activity in exoplanets is focused on rocky planets. The best targets for future, challenging spectroscopic observations will be selected among potentially habitable planets. Surface habitability can be quantified and explored with climate and atmospheric models according to temperature-based criteria. The conceptual, modellistic, technological and interpretative complexity of the problem requires to develop flexible climate and atmospheric models suited for a comprehensive exploration of observationally unconstrained parameters, and to simulate and interpret definitely non-terrestrial conditions. We present a summary and preliminary results on the work we are performing on multi-parametric explorations of the habitability and observational properties of rocky planets.Comment: to appear on MemSAIt, vol 94. Proceedings of the Hack100 Conference: Past, Present and Future of Astrophysical Spectroscopy, 6-10 June 2022, Trieste, Ital

The dust-to-ices ratio in comets and Kuiper belt objects

Comet 67P/Churyumov-Gerasimenko (67P hereinafter) is characterized by a dust transfer from the southern hemi-nucleus to the night-side northern dust deposits, which constrains the dust-to-ices mass ratio inside the nucleus to values a factor of 2 larger than that provided by the lost mass of gas and non-volatiles. This applies to all comets because the gas density in all night comae cannot prevent the dust fallback. Taking into account Grain Impact Analyser and Dust Accumulator (GIADA) data collected during the entire Rosetta mission, we update the average dust bulk density to ρD=785 +520/−115 $\rho {}{}_{\rm D} = 785_{-115}^{+520}$ kg m$^-3$ that, coupled to the 67P nucleus bulk density, confirms an average dust-to-ices mass ratio δ = 7.5 inside 67P. The improved dust densities are consistent with a mixture of (20 ± 8) per cent of ices, (4 ± 1) per cent of Fe sulphides, (22 ± 2) per cent of silicates and (54 ± 5) per cent of hydrocarbons, on average volume abundances. These values correspond to solar chemical abundances, as suggested by the elemental C/Fe ratio observed in 67P. The ice content in 67P matches that inferred in Kuiper belt objects, (20 ± 12) per cent on average volume abundance and suggests a water content in all trans-Neptunian objects lower than in CI chondrites. The 67P icy pebbles and the dust collected by GIADA have a microporosity of (49 ± 5) and (59 ± 8) per cent, respectively