Balancing porosity and mechanical properties of titanium samples to favor cellular growth against bacteria

Two main problems limit the success of titanium implants: bacterial infection, which restricts their osseointegration capacity; and the stiffness mismatch between the implant and the host cortical bone, which promotes bone resorption and risk of fracture. Porosity incorporation may reduce this difference in stiffness but compromise biomechanical behavior. In this work, the relationship between the microstructure (content, size, and shape of pores) and the antibacterial and cellular behavior of samples fabricated by the space-holder technique (50 vol % NH4HCO3 and three ranges of particle sizes) is established. Results are discussed in terms of the best biomechanical properties and biofunctional activity balance (cell biocompatibility and antibacterial behavior). All substrates achieved suitable cell biocompatibility of premioblast and osteoblast in adhesion and proliferation processes. It is worth to highlighting that samples fabricated with the 100–200 μm space-holder present better mechanical behavior—in terms of stiffness, microhardness, and yield strength—which make them a very suitable material to replace cortical bone tissues. Those results exposed the relationship between the surface properties and the race of bacteria and mammalian cells for the surface with the aim to promote cellular growth over bacteria.University of Seville (Spain) VI Plan Propio de Investigación y Transferencia—US 2018, I.3A

Electronic structure and vertical transport in random dimer GaAs-Al_xGa_(1-x)As superlattices

We report a systematic study of several GaAs-AlxGa1-xAs semiconductor superlattices grown by molecular-beam epitaxy specifically designed to explore the existence of extended states in random dimer superlattices. We have confirmed our previous results [V. Bellani et al., Phys. Rev. Lett. 82, 2159 (1999)] with much additional evidence that allows us to lay claim to a clear-cut experimental verification of the presence of extended states in random dimer superlattices due to the short-range correlations (dimers) that inhibit the localization effects of the disorder

Interacciones árbol-suelo y funcionamiento del bosque mediterránao: síntesis del proyecto INTERBOS

1 página. Comunicación oral presentada en la Sesión Ecología y Ecofisiología de la referida Reunión, celebrada en Huelva, 9-11, noviembre, 2011.Se conoce como cambio global al conjunto de los cambios ambientales afectados por la actividad humana, con especial referencia a cambios en los procesos que determinan el funcionamiento del sistema Tierra. El cambio global afecta al árbol individual, a su fisiología, crecimiento y composición de sus tejidos, ya su adecuación evolutiva respecto a los individuos vecinos de la misma población. Estos cambios afectan a su vez a las interacciones entre los árboles de las diferentes especies y causan cambios en el ensamblaje de la comunidad y la composición del bosque. En último término, modifican el funcionamiento del ecosistema forestal afectando a la fijación y secuestro del carbono, las tasas de descomposición de la hojarasca y el ciclo de nutrientes.Peer reviewe

Streptococcus porcorum sp. nov., isolated from domestic and wild pigs

Seven isolates of an unidentified Gram-stain-positive, catalase-negative, coccus-shaped organism isolated from domestic and wild pigs were characterized by phenotypic and molecular-genetic methods. Based on cellular morphology and biochemical criteria, the isolates were tentatively assigned to the genus Streptococcus, although the organisms did not appear to correspond to any recognized species. Comparative 16S rRNA gene sequencing showed that the unknown bacterium was phylogenetically closely related to, but distinct from, Streptococcus suis (97.5 % 16S rRNA gene sequence similarity to the type strain). rpoB and sodA sequence analysis showed minimum interspecies divergence from phylogenetically close 16S rRNA gene sequence-based relatives of 13.8 and 18.6 %, respectively. DNA-DNA hybridization of a strain of the unidentified organism demonstrated 8-18 % reassociation with S. suis NCTC 10234(T). The novel bacterium could be distinguished from S. suis and other Streptococcus species using biochemical tests. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown isolates from domestic and wild animals be assigned to a novel species of the genus Streptococcus, Streptococcus porcorum sp. nov. The type strain is 682-03(T) (= CCUG 58479(T) = CECT 7593(T))

Collective decision-making on triadic graphs

Many real-world networks exhibit community structures and non-trivial clustering associated with the occurrence of a considerable number of triangular subgraphs known as triadic motifs. Triads are a set of distinct triangles that do not share an edge with any other triangle in the network. Network motifs are subgraphs that occur significantly more often compared to random topologies. Two prominent examples, the feedforward loop and the feedback loop, occur in various real-world networks such as gene-regulatory networks, food webs or neuronal networks. However, as triangular connections are also prevalent in communication topologies of complex collective systems, it is worthwhile investigating the influence of triadic motifs on the collective decision-making dynamics. To this end, we generate networks called Triadic Graphs (TGs) exclusively from distinct triadic motifs. We then apply TGs as underlying topologies of systems with collective dynamics inspired from locust marching bands. We demonstrate that the motif type constituting the networks can have a paramount influence on group decision-making that cannot be explained solely in terms of the degree distribution. We find that, in contrast to the feedback loop, when the feedforward loop is the dominant subgraph, the resulting network is hierarchical and inhibits coherent behavior

Non-Linear 3D Hybrid Kinetic-MHD Simulations of Alfvén Eigenmodes in the ASDEX Upgrade Tokamak

EUROfusion Consortium 63305

Foot Pain and Morphofunctional Foot Disorders in Patients with Rheumatoid Arthritis: A Multicenter Cross-Sectional Study

[Abstract] Foot problems are highly prevalent in people with rheumatoid arthritis. This study aims to explore the foot morphology, pain and function in rheumatoid arthritis patients and the relation with the time of disease debut. A cross-sectional study was designed. Footprint, the Foot Posture Index, the hallux valgus prevalence, foot pain and function in 66 rheumatoid arthritis patients and the association with time since diagnosis, were recorded. The Foot Function Index, the Manchester Foot Pain and Disability Index, the Visual Analogic Scale, and the Manchester Scale for hallux valgus were administered and analyzed in two groups, with less and more than 10 years of diagnosis of the disease. A high prevalence of pronated (right 36.8% and left 38.6%) and highly pronated (right 15.8% and left 15.8%) feet was observed, as well as an elevated percentage of low arched footprints (right 68.4 and left 66.7%) and hallux valgus (right 59.6% and left 54.4%). Hallux valgus prevalence, toe deformities and Foot Function Index (Functional limitation) factors were significantly associated with the time since RA diagnosed adjusted for the other factors. The adjusted odds ratio of Hallux valgus prevalence was 4.9 (1.2–19.7). In addition, the foot function was diminished, and foot pain was present in most participants. In conclusion, rheumatoid arthritis patients’ feet showed altered morphology and function, and with longer rheumatoid arthritis history, metatarsophalangical stability and foot function, but not pain and global foot posture, were likely to deteriorat

Relationship of Body Mass Index and Footprint Morphology to the Actual Height of the Medial Longitudinal Arch of the Foot

[Abstract] The medial longitudinal arch height of the foot is linked to individual characteristics such as sex and body mass index, and these characteristics have been shown to be associated with conditions such as flat feet. In this cross-sectional descriptive study, we examined the medial longitudinal arch morphology in an adult population to determine if there are differences related to sex and body mass index, and values were obtained for the foot posture index. Normalized anthropometric measurements and arch indices were calculated from footprints. Groups, defined by sex and body mass index, were compared, and the correlations between body mass index and the variables were determined. In the population studied (266 women and 177 men), significant differences between men and women for the foot posture index and normalized arch measurements were found. Analysis of the variables related to body mass index indicated there were significant differences in arch indices. Significant differences and positive correlations were also found between the arch index and body mass index for the left and right feet among the men and women studied. The results obtained allow us to reflect on and analyze whether the medial longitudinal arch morphology classification methods used in the clinical and research setting are adequate or whether the influence of factors such as body mass index can generate confusion

Evaluation of GenoFlow DR-MTB array test for detection of rifampin and isoniazid resistance in mycobacterium tuberculosis

The aim of this study was to evaluate the GenoFlow DR-MTB array test (DiagCor Bioscience, Hong Kong) on 70 cultured isolates and 50 sputum specimens. The GenoFlow array test showed good sensitivity and specificity compared to the phenotypic Bactec 460TB. This array accurately detected mutations in rpoB, katG, and inhA associated with resistance to rifampin and isoniazid