Biodegradable polyesters reinforced with triclosan loaded polylactide micro/nanofibers: Properties, release and biocompatibility

Mechanical properties and drug release behavior were studied for three biodegradable polyester matrices (polycaprolactone, poly(nonamethylene azelate) and the copolymer derived from 1,9-nonanediol and an equimolar mixture of azelaic and pimelic acids) reinforced with polylactide (PLA) fibers. Electrospinning was used to produce suitable mats constituted by fibers of different diameters (i.e. from micro- to nanoscale) and a homogeneous dispersion of a representative hydrophobic drug (i.e. triclosan). Fabrics were prepared by a molding process, which allowed cold crystallization of PLA micro/nanofibers and hot crystallization of the polyester matrices. The orientation of PLA molecules during electrospinning favored the crystallization process, which was slightly enhanced when the diameter decreased. Incorporation of PLA micro/nanofibers led to a significant increase in the elastic modulus and tensile strength, and in general to a decrease in the strain at break. The brittle fracture was clearer when high molecular weight samples with high plastic deformation were employed. Large differences in the release behavior were detected depending on the loading process, fiber diameter size and hydrophobicity of the polyester matrix. The release of samples with the drug only loaded into the reinforcing fibers was initially fast and then became slow and sustained, resulting in longer lasting antimicrobial activity. Biocompatibility of all samples studied was demonstrated by adhesion and proliferation assays using HEp-2 cell cultures

High spatial resolution and high contrast optical speckle imaging with FASTCAM at the ORM

In this paper, we present an original observational approach, which combines, for the first time, traditional speckle imaging with image post-processing to obtain in the optical domain diffraction-limited images with high contrast (1e-5) within 0.5 to 2 arcseconds around a bright star. The post-processing step is based on wavelet filtering an has analogy with edge enhancement and high-pass filtering. Our I-band on-sky results with the 2.5-m Nordic Telescope (NOT) and the lucky imaging instrument FASTCAM show that we are able to detect L-type brown dwarf companions around a solar-type star with a contrast DI~12 at 2" and with no use of any coronographic capability, which greatly simplifies the instrumental and hardware approach. This object has been detected from the ground in J and H bands so far only with AO-assisted 8-10 m class telescopes (Gemini, Keck), although more recently detected with small-class telescopes in the K band. Discussing the advantage and disadvantage of the optical regime for the detection of faint intrinsic fluxes close to bright stars, we develop some perspectives for other fields, including the study of dense cores in globular clusters. To the best of our knowledge this is the first time that high contrast considerations are included in optical speckle imaging approach.Comment: Proceedings of SPIE conference - Ground-based and Airborne Instrumentation for Astronomy III (Conference 7735), San Diego 201

Active galactic nuclei synapses: X-ray versus optical classifications using artificial neural networks

(Abridged) Many classes of active galactic nuclei (AGN) have been defined entirely throughout optical wavelengths while the X-ray spectra have been very useful to investigate their inner regions. However, optical and X-ray results show many discrepancies that have not been fully understood yet. The aim of this paper is to study the "synapses" between the X-ray and optical classifications. For the first time, the new EFLUXER task allowed us to analyse broad band X-ray spectra of emission line nuclei (ELN) without any prior spectral fitting using artificial neural networks (ANNs). Our sample comprises 162 XMM-Newton/pn spectra of 90 local ELN in the Palomar sample. It includes starbursts (SB), transition objects (T2), LINERs (L1.8 and L2), and Seyferts (S1, S1.8, and S2). The ANNs are 90% efficient at classifying the trained classes S1, S1.8, and SB. The S1 and S1.8 classes show a wide range of S1- and S1.8-like components. We suggest that this is related to a large degree of obscuration at X-rays. The S1, S1.8, S2, L1.8, L2/T2/SB-AGN (SB with indications of AGN), and SB classes have similar average X-ray spectra within each class, but these average spectra can be distinguished from class to class. The S2 (L1.8) class is linked to the S1.8 (S1) class with larger SB-like component than the S1.8 (S1) class. The L2, T2, and SB-AGN classes conform a class in the X-rays similar to the S2 class albeit with larger fractions of SB-like component. This SB-like component is the contribution of the star-formation in the host galaxy, which is large when the AGN is weak. An AGN-like component seems to be present in the vast majority of the ELN, attending to the non-negligible fraction of S1-like or S1.8-like component. This trained ANN could be used to infer optical properties from X-ray spectra in surveys like eRosita.Comment: 15 pages, 7 figures, accepted for publication in A&A. Appendix B only in the full version of the paper here: https://dl.dropboxusercontent.com/u/3484086/AGNSynapsis_OGM_online.pd

Effect of the Pt–Pd molar ratio in bimetallic catalysts supported on sulfated zirconia on the gas-phase hydrodechlorination of chloromethanes

Bimetallic Pt:Pd catalysts with different molar ratios and 0.5 wt.% overall metal load supported on sulfated zirconia catalysts were synthesized and tested in the gas-phase hydrodechlorination (HDC) of chloromethanes and their mixtures. The catalysts were characterized by adsorption–desorption of N2 at −196 °C, X-ray diffraction, X-ray photoelectronic spectroscopy, temperature-programmed reduction, and aberration-corrected scanning transmission electron microscopy (STEM). The effect of the Pt:Pd molar ratio on the activity, stability, and selectivity was analyzed. The high acidity of the sulfated zirconia results in metal particles of small size (mainly <5 nm), as confirmed by STEM. The bimetallic catalysts showed higher stability than the monometallic ones, as demonstrated in long-term experiments (80 h on stream), confirming the positive effect of combining the two metallic phases. Turnover frequency (TOF) values in the range 0.0007–0.0168 s−1 and apparent activation energies between ≈41 and 44 kJ·mol−1 were obtained. TOF values for dichloromethane HDC increased with increasing mean metal particle size within the range of this work (≈1.2–2.3 nm). The catalysts with Pt:Pd molar ratios of 1:3 and 1:1 showed significantly better performance than the 3:1 one for overall dechlorination due to their higher atomic metal content and TOF at the same total metal weight load (0.5%)The authors are grateful to the Spanish ‘‘Ministerio de Economíay Competitividad (MINECO)” for financial support (ProjectsCTM2011-28352 and CTM2014-53008-

Bounds for Lepton Flavor Violation and the Pseudoscalar Higgs in the General Two Higgs Doublet Model using g−2g-2 muon factor

Current experimental data from the $g-2$ muon factor, seems to show the necessity of physics beyond the Standard Model (SM), since the difference between SM and experimental predictions is 2.6$\sigma$. In the framework of the General Two Higgs Doublet Model (2HDM), we calculate the muon anomalous magnetic moment to get lower and upper bounds for the Flavour Changing (FC) Yukawa couplings in the leptonic sector. We also obtain lower bounds for the mass of the pseudoscalar Higgs ($m_{A^0}$) as a function of the parameters of the model.Comment: 12 pages, RevTex4, 5 figures. Improved presentation, updated experimental data, amplified analysis, new figures added. Subbmited to Phys. Rev.

Madera de compresión en Pinus radiata III: Propiedades de pulpas kraft

Estudios anteriores en estos mismos árboles de Pinus radiata con fustes levemente inclinados, demostraron que la madera de compresión leve que ellos exhibían presentaba: traqueidas más cortas, mayor densidad, mayor proporción de lignina, mayor proporción de extraíbles en etanol tolueno y menor proporción de alfa celulosa que la madera opuesta y que la madera de árboles sin madera de compresión.En el presente estudio se analiza las propiedades pulpables de la madera de compresión y la de sus respectivas maderas opuestas de los quince árboles de Pinus radiata estudiados, crecidos en suelos de arena húmeda en Chile. Se estudió separadamente la madera de compresión y la madera opuesta. Con distintas proporciones, de entre 0, 40, 70 y 100 % de madera de compresión y madera opuesta, se efectuaron pulpajes kraft  para cada una de las mezclas.De estos pulpajes con y sin blanqueo se informan valores de 501 y 695 kg/m3 de densidad; 28 a 51 Nm/g en índice de tensión, 18 a 25 mNm2/g en índice de rasgado, 2.2 a 4.1 kPam2/g en índice de explosión y rendimiento de 44 a 50.6 % en las mezclas de la pulpa estudiada.En la pulpa cruda de MC, de la madera pulpable y de la madera exterior aserrable, se registró me-nor densidad, mayor índice de tensión, de rasgado y de explosión, en comparación con los resultados obtenidos en la pulpa cruda de MO. En el caso de las pulpas blanqueadas, la densidad y el índice de tensión resultaron mayores en la MC.En el resto de las propiedades las diferencias entre MC y MO fueron oscilantes y reducidas. El aumento de la proporción de MC en la mezcla de MC y MO, produjo una reducción de rendimiento. Los rendimiento de las mezclas de la madera pulpable indicaron para el 100 % de MO un 50.6 % y para el 100% de MC un 44 %: En los casos de las pulpas de madera exterior aserrable el 100% de MO tuvo un rendimiento de de 48.4% en cambio el 100% de la MC registró un 44.3%.Los resultados obtenidos indicaron que la MC leve, que se encuentra en árboles con inclinaciones menores, tuvo un efecto de menor magnitud que él que se produce en la MC severa sobre las características y rendimiento de la pulpa kraft. AbstractPrevious studies with radiata pine trees growing slightly leaned towards one side showed that they have small amounts of compression wood with different characteristics than the opposite wood at the other side of the annual rings. These differences include shorter tracheids, higher density, higher proportion of lining, higher proportion of extractives in toluene ethanol, and a smaller amount of alpha-cellulose.The present study compares the properties of kraft pulp, with and without bleaching, for mixtures of compression and opposite wood obtained from fifteen 22-year-old radiata pine trees that grew in humid sand soils of Chile. The kraft pulp mixture was studied for different proportions of 0, 40, 70 and 100% compression wood. Considering all mixtures with and without bleaching, the study reports values between 501 and 695 kg/m3 density, 28 and 51 Nm/g tension index, 18 and 25 mNm2/g tear index, 2,2 and 4,1 kPam2 burst index, and 44% and 50,6% pulp yield.It was found that the pulp without bleaching from compression wood (for both the internal pulp and the external lumber areas) had lower density, but higher tension, tear, and burst indexes. The pulp with bleaching from compression wood had both higher density and tension index, but the other properties only show small random differences with respect to opposite wood.A higher proportion of compression wood in the mixture reduced pulp yield. The yield for the internal pulp area was 50,6 % with pure opposite wood and 44% with pure compression wood, while the yield for external lumber area was 48,4% with pure opposite wood and 44,3% with pure compression wood. I was concluded, however, that the relatively small amount of compression wood found in these trees had only a minor effect in the properties and yield of kraft pulp