Combining technologies to create bioactive hybrid scaffolds for bone tissue engineering

Combining technologies to engineer scaffolds that can offer physical and chemical cues to cells is an attractive approach in tissue engineering and regenerative medicine. In this study, we have fabricated polymer-ceramic hybrid scaffolds for bone regeneration by combining rapid prototyping (RP), electrospinning (ESP) and a biomimetic coating method in order to provide mechanical support and a physico-chemical environment mimicking both the organic and inorganic phases of bone extracellular matrix (ECM). Poly(ethylene oxide terephthalate)-poly(buthylene terephthalate) (PEOT/PBT) block copolymer was used to produce three dimensional scaffolds by combining 3D fiber (3DF) deposition, and ESP, and these constructs were then coated with a Ca-P layer in a simulated physiological solution. Scaffold morphology and composition were studied using scanning electron microscopy (SEM) coupled to energy dispersive X-ray analyzer (EDX) and Fourier Tranform Infrared Spectroscopy (FTIR). Bone marrow derived human mesenchymal stromal cells (hMSCs) were cultured on coated and uncoated 3DF and 3DF + ESP scaffolds for up to 21 d in basic and mineralization medium and cell attachment, proliferation, and expression of genes related to osteogenesis were assessed. Cells attached, proliferated and secreted ECM on all the scaffolds. There were no significant differences in metabolic activity among the different groups on days 7 and 21. Coated 3DF scaffolds showed a significantly higher DNA amount in basic medium at 21 d compared with the coated 3DF + ESP scaffolds, whereas in mineralization medium, the presence of coating in 3DF+ESP scaffolds led to a significant decrease in the amount of DNA. An effect of combining different scaffolding technologies and material types on expression of a number of osteogenic markers (cbfa1, BMP-2, OP, OC and ON) was observed, suggesting the potential use of this approach in bone tissue engineerin

Towards truly simultaneous PIXE and RBS analysis of layered objects in cultural heritage

For a long time, RBS and PIXE techniques have been used in the field of cultural heritage. Although the complementarity of both techniques has long been acknowledged, its full potential has not been yet developed due to the lack of general purpose software tools for analysing the data from both techniques in a coherent way. In this work we provide an example of how the recent addition of PIXE to the set of techniques supported by the DataFurnace code can significantly change this situation. We present a case in which a non homogeneous sample (an oxidized metal from a photographic plate -heliography- made by Niepce in 1827) is analysed using RBS and PIXE in a straightforward and powerful way that can only be performed with a code that treats both techniques simultaneously as a part of one single and coherent analysis. The optimization capabilities of DataFurnace, allowed us to obtain the composition profiles for these samples in a very simple way.Comment: 9 pages, 3 figure

Correspondence: The One Health concept applied to dirofilariasis-a zoonotic disease

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Characterization of magnetron sputtered sub-stoichiometric CrAlSiNx and CrAlSiOyNx coatings

The influence of varying nitrogen and oxygen partial pressures on microstructure, mechanical and optical properties of magnetron sputtered CrAlSiNx and CrAlSiOyNx coatings has been studied. The partial pressure of nitrogen reactive gaswas varied from0.037 Pa to 0.15 Pa for CrAlSiNx films, and the N2/O2 (85%:15%) partial pressure was varied from 0.046 Pa to 0.21 Pa for CrAlSiOyNx layers. Transmittance and reflectance of samples were measured and were modeled to obtain the spectral optical constants, n and k. Chemical state, composition, morphology and microstructure of films were analyzed by XPS, RBS, XRD, Raman Spectroscopy and SEM. Films' hardness was evaluated using nanoindentation method. XRD results revealed that the two samples CrAlSiNx with PN =0.15 Pa and CrAlSiOyNx with PNO = 0.21 Pa are polycrystalline with cubic (fcc-B1) structure. On contrary, all other films prepared with lower reactive gases partial pressures are amorphous. The chemical composition changed with the variation of reactive gases partial pressure, although the Cr: Al: Si composition ratio remained approximately constant, 1.25:1.5:1. All samples showed low hardness, mainly due to lower content of reactive gases and higher content of Si. However, the sample CrAlSiNx with PN = 0.15 Pa has the highest value of 11.1 GPa. Optical constants are seen to be very sensitive to reactive gases partial pressure. The refractive index and extinction coefficient were lower for coatings with higher reactive gases partial pressure. These coatings are good candidates for designing selective solar absorber stacks for different applications.The authors acknowledge the support of FCT in the framework of the Strategic Funding UID/FIS/04650/2013 and the financial support of FCT, FOCI and PORL operational programs through the project POCI-01-0145-FEDER-016907 (PTDC/C11/1-ENE/2882/2014), co-financed by European community fund FEDER.info:eu-repo/semantics/publishedVersio

High precision measurement of the hyperfine fields of substitutional and defect associated Cd in single crystalline hcp cobalt

The hyperfine fields of Cd in single crystalline hcp Co were measured after simultaneous implantation of 111mCd and 111In. High statistics measurements could be done separately for each parent isotope combining the e--g and g-g PAC techniques. The hyperfine coupling constants wL(CdCo)=422.8(1) Mrad/s and w0(CdCo)=6.14(11) Mrad/s are determined for Cd probes in undisturbed substitutional sites. Several defect associated sites in the hcp Co lattice are clearly seen in the data. Most of the radiation damage created by the ion implantation anneals out at temperatures below 503 K, with only one dominating component surviving at this temperature. This defect is assigned as a probe atom in an interstitial site, surrounded by a vacancy tetrahedron. The corresponding magnetic field and electric field gradient are collinear with the c-axis of the Co lattice, and the respective coupling constants are wL(defect)= 216.7(2) Mrad/s and w0(defect)= 45.3(6) Mrad/s

Functional and optical properties of Au :TiO2 nanocomposite films : the influence of thermal annealing

A set of nanocomposite thin films consisting of Au nanoclusters dispersed in a TiO2 dielectric matrix was deposited by reactive magnetron sputtering, and subjected to thermal annealing in vacuum, at temperatures ranging from 200 to 800 ◦C. The obtained results show that the structure and the size of Au clusters, together with the matrix crystallinity, changed as a result of the annealing, and were shown to be able to change the optical properties of the films and keeping good mechanical properties, opening thus a wide number of possible applications. The crystallization of the gold nanoclusters induced by the annealing was followed by a systematic change in the overall coating behaviour, namely the appearance of surface plasmon resonance (SPR) behaviour. This effect enables to tailor the thin films reflectivity, absorbance and colour coordinates, contributing to the importance of this thin film system. The different attained optical characteristics (reflectance values ranging from interference to metallic-like behaviours and colour varying for interference rainbow-like to several tones of red-brownish), associated with a reasonable mechanical resistance of the coatings (good adhesion to different substrates and hardness values ranging from 5 to 7.5 GPa), induce the possibility to use this film system in a wide range of decorative applications.Fundac¸ ão para a Ciência e Tecnologia (FCT) - PTDC/CTM/70037/2006

Prednisone and azathioprine in patients with inflammatory cardiomyopathy: systematic review and meta-analysis

Aims: Chronic non-viral myocarditis, also called inflammatory cardiomyopathy, can be treated with immune suppression on tops of optimal medical therapy (OMT) for heart failure, using a combination of prednisolone and azathioprine (IPA). However, there has been inconsistency in the effects of immunosuppression treatment. This meta-analysis is the first to evaluate all available data of the effect of this treatment on left ventricular ejection fraction (LVEF) and the combined clinical endpoint of cardiovascular mortality and/or heart transplantation-free survival. Methods and results: All trials with using IPA vs. OMT in this syndrome were searched using OVID Medline and ClinicalTrials. gov, following the PRISMA guidelines. Missing data were retrieved after contacting the corresponding authors. All data was reviewed and analysed using and standard meta-analysis methods. A random effect model was used to pool the effect sizes. A total of four trials (three randomised controlled trials and one propensity-matched retrospective registry) including 369 patients were identified. IPA on top of OMT did not improve LVEF [mean difference 9.9% (95% confidence interval -1.8, 21.7)] with significant heterogeneity. When we limited our pooled estimate to the published studies only, significant LVEF improvement by IPA was observed [14% (1.4, 26.6)]. No cardiovascular mortality benefit was observed with the intervention [risk ratio 0.34 (0.08, 1.51)]. Conclusions: At the moment, there is insufficient evidence supporting functional and prognostic benefits of IPA added to OMT in virus negative inflammatory positive cardiomyopathy. Further adequate-powered well-designed prospective RCTs should be warranted to explore the potential effects of adding immunosuppressive therapy to OMT

Atomic environment and interfacial structural order of TiAlN/Mo multilayers

Multilayered TiAlN/Mo coatings were deposited by dc reactive magnetron sputtering in a custom-made chamber. In order to assess the composition of these coatings, a combined study of Extended X-ray Absorption Fine Structure (EXAFS) and Rutherford Backscattering Spectrometry (RBS) experiments were performed. Through the simulation of the EXAFS spectra, giving the local environment of the titanium atoms inside the nitride (TiAlN), a cubic phase has been evidenced with aluminium atoms occupying titanium sites. For modulation periods in the range of 3.6–11.8 nm, RBS simulations on these multilayers also enabled the determination of the level of intermixing that occurs at the interfaces as a function of the negative bias voltage and number of layers. It was observed that the intermixing width could be as high as 2.1 nm for the roughest samples (larger periods) or as low as 0.4 nm for those with the sharpest interfaces (smaller periods).Comunidade Europeia (CE). Fundo Europeu de Desenvolvimento Regional (FEDER) -Ministério da Ciência e Tecnologia.Cooperação Científica e Tecnológica Internacional (ICCTI) - Ambassade de France in Portugal - Project no. 543 B3/2001.Fundação para a Ciência e a Tecnologia (FCT) - Programa Operacional “Ciência, Tecnologia, Inovação - POCTI/32670/CTM/2000

Agent based demand flexibility management for wind power forecasting error mitigation using the SG-BEMS framework

The integration process of renewable energy sources (RES) and distributed energy resources (DER) into the power system, is characterized by concerns that originate from their stochastic and uncontrollable nature. This means that system operators require reliable forecasting tools, in order to ensure efficient and reliable operation. Accordingly, this paper proposes the use of demand flexibility, to counteract the RES forecasting errors. For this purpose, distributed and decentralized intelligence is used, via the SG-BEMS framework, to invoke demand flexibility in a timely and effective fashion, while taking into account the negative effects on the building occupants comfort. Lastly, numerical results from a simulated case of study are presented, which confirm that demand flexibility can be used to mitigate the magnitude of forecast errors

Analytical simulation of RBS spectra of nanowire samples

Almost all, if not all, general purpose codes for analysis of Ion Beam Analysis data have been originally developed to handle laterally homogeneous samples only. This is the case of RUMP, NDF, SIMNRA, and even of the Monte Carlo code Corteo. General-purpose codes usually include only limited support for lateral inhomogeneity. In this work, we show analytical simulations of samples that consist of a layer of parallel oriented nanowires on a substrate, using a model implemented in NDF. We apply the code to real samples, made of vertical ZnO nanowires on a sapphire substrate. Two configurations of the nanowires were studied: 40 nm diameter, 4.1 μm height, 3.5% surface coverage; and 55 nm diameter, 1.1 μm height, 42% surface coverage. We discuss the accuracy and limits of applicability of the analysisAuthors thank funding from projects CTQ2014-53334-C2-2-R (MINECO, Spain) and NANOAVANSENS S2013/MIT 3029 (Comunidad de Madrid). A.R.C. acknowledges Juan de la Cierva program (under contract number JCI-2012-14509). This work was partially funded by Fundação para a Ciência e Tecnologia under grant UID/Multi/04349/201