Estado del arte Phymatotrichopsis omnivora (SHEAR) duggar, revisión y actualidad

Phymatotrichopsis omnivora es un hongo que ocasiona la pudrición de la raíz siendo considerada una de las más serias enfermedades de las plantas debido al amplio rango de hospedantes que afecta, lo que conlleva a grandes pérdidas económicas. Son varios factores son que influyen en el desarrollo de la enfermedad y la sintomatología puede variar de planta a planta. Este hongo coloniza primeramente las células corticales y forma una red que cubre la superficie de las raíces, bloqueando el sistema vascular así como el movimiento del agua en la planta. Los métodos de control químico son costosos y poco eficientes, por lo que se buscan otros métodos como la utilización de plantas resistentes, la aplicación de organismos antagonistas, o el uso de ciertos extractos vegetales, los cuales han demostrado tener cierta actividad en el control de este patógeno

Evaluation of TiO2/CeO2 coating on Ti6Al4V alloy in PBS physiological medium using conventional and near field electrochemical techniques

Ti6Al4V alloy is an exceptional biomaterial compared to other metals used for implants that replace bone tissue. Despite being corrosion-resistant, Ti6Al4V can release ions that may cause adverse effects to tissues after long implantation times. Several researchers have studied the thermal oxidation of this alloy, which generated layers of mainly TiO2 rutile phase to increase its wear and corrosion resistance. However, one of the shortcomings of these layers is their susceptibility to pitting corrosion. To extend the useful life of Ti6Al4V, a coating system consisting of thermally grown TiO2 and CeO2 obtained using chemical conversion treatment was proposed, which would be advantageous owing to its non-toxic, antiseptic, and anticorrosive properties. In this study TiO2 rutile phase was obtained on the surface of Ti6Al4V after quenching at 650 °C for 90 min followed by tempering at 450 °C. Cerium conversion treatments produced a surface film consisting of Ce3+ and Ce4+, which was characterised using X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectronic spectroscopy, cyclic polarisation curves, electrochemical impedance spectroscopy, and scanning Kelvin probe. The obtained coating system reduced the corrosion rate of the substrate: TiO2 worked as main passive film and the cerium coating reduced the susceptibility to pitting corrosion.This study has been financed by the CONACYT Basic science project 2012 Nº183416 and SIP Project 20160107.Peer reviewe

Study of electrochemical proprieties of bio-inspired coating based ErGO

Centro de Investigación en Ciencia aplicada y Tecnología avanzada - INSTITUTO POLITÉCNICO NACIONALIt is stimated that 75% of failures in the articular prosthesis is due to bone resorption, caused by osteolysis due to the presence of wear particles that occur in the daily wear process of the components of the implanted joint. particles, traces and/or ions are accumulated in the surrounding tissues, interacting with cells and even incorporating into the bloodstream. Recent research has revealed the efficacy of sp3-sp2 hybridization carbón structures to reduce wear rate in metallic articular implants. Based on this, films composed of Electrochemically Reduced Graphene Oxide (ErGO) and ErGO functionalized with Hyaluronic Acid (ErGO-HA), which is the main component of the sinovial fluid, will be synthesized on the substrates CoCrMo and Ti6Al4V. The optimum conditions of synthesis, composition, morphology, roughness and, electrochemical and tribological performance, in addition, invitro biocompatibility tests will be performed under electrochemical control

Influence of particle size in the effect of polyethylene on human osteoblastic cells

The influence of two different sizes of polyethylene particles (<30 and 20-200μm) on osteoblastic function has been studied in primary human bone cell cultures. Cells were obtained from trabecular bone fragments of patients undergoing knee reconstructive surgery. On reaching confluency, cells were subcultured in three flasks: <30μm polyethylene particles were added to the first flask, 20-200μm particles to the second flask and none to the third flask, which was the control. The resulting subcultures were incubated until confluence. Osteoblastic function was evaluated by assaying the secretion of osteocalcin, alkaline phosphatase, and C-terminal type I procollagen (PICP), with or without 1,25(OH)2D3 stimulation in the cell-conditioned medium. Adding <30μm polyethylene particles to these osteoblastic cell cultures increased the levels of osteocalcin secreted after 1,25(OH)2D3 stimulation. Treating stimulated or basal osteoblastic cultures with either polyethylene particle size did not affect alkaline phosphatase secretion. However, the addition of <30μm polyethylene particles decreased PICP levels in the basal and stimulated cultures. A parallel series of osteoblastic cultures was treated with <30μm polyethylene particles and stimulated or not with 1,25(OH)2D3 to determine the effect on osteocalcin mRNA expression using RT-PCR amplification. Polyethylene particle-treated cultures had higher osteocalcin mRNA expression regardless of whether they had been stimulated with 1,25(OH)2D3 or not. We conclude that particle size affects the influence of polyethylene on osteoblastic function markers. Particles with a diameter of less than 30μm increase osteocalcin expression and secretion. Copyright © 2001 Elsevier Science B.V.Peer Reviewe

Characterization of the ODS MA 956 superalloy for biomedical surgical implants

[ES] Desde que la MA 956 fue propuesta como posible nuevo biomaterial en base a su buena resistencia a la corrosión frente a sueros fisiológicos, un largo camino, aún sin finalizar, se ha recorrido, en el que se ha llevado a cabo una caracterización exhaustiva de esta aleación a temperatura ambiente con fines tecnológicos bien definidos: su posible uso en aplicaciones biomédicas, bien sea como prótesis de cadera o de rodilla y para implantes dentales. Los estudios se han llevado a cabo comparando esta aleación con los materiales más comúnmente utilizados en implantes ortopédicos como aleaciones de titanio y polietileno.[EN] Since the MA 956 was proposed as a possible new biomaterial due to its good corrosión resistance valúes in physiological fluids a long way, still not finished, has been done. An exhaustive characterization of this alloy at room temperature has been developed. The technological objetives are well established: the possible use of this material for biomedical applications as hip or knee prostheses and as dental implants. The study was performed comparing the results of this alloy with the materials used nowadays as surgical implants, i.e., titanium alloys and polyethylene.Este trabajo ha sido realizado gracias a la financiación, por parte de la CICYT, del proyecto MAT0249, que consta de tres subproyectos 01, 02 y 03.Peer reviewe

Clinical and genetic characteristics of late-onset Huntington's disease

Background: The frequency of late-onset Huntington's disease (&gt;59 years) is assumed to be low and the clinical course milder. However, previous literature on late-onset disease is scarce and inconclusive. Objective: Our aim is to study clinical characteristics of late-onset compared to common-onset HD patients in a large cohort of HD patients from the Registry database. Methods: Participants with late- and common-onset (30–50 years)were compared for first clinical symptoms, disease progression, CAG repeat size and family history. Participants with a missing CAG repeat size, a repeat size of ≤35 or a UHDRS motor score of ≤5 were excluded. Results: Of 6007 eligible participants, 687 had late-onset (11.4%) and 3216 (53.5%) common-onset HD. Late-onset (n = 577) had significantly more gait and balance problems as first symptom compared to common-onset (n = 2408) (P &lt;.001). Overall motor and cognitive performance (P &lt;.001) were worse, however only disease motor progression was slower (coefficient, −0.58; SE 0.16; P &lt;.001) compared to the common-onset group. Repeat size was significantly lower in the late-onset (n = 40.8; SD 1.6) compared to common-onset (n = 44.4; SD 2.8) (P &lt;.001). Fewer late-onset patients (n = 451) had a positive family history compared to common-onset (n = 2940) (P &lt;.001). Conclusions: Late-onset patients present more frequently with gait and balance problems as first symptom, and disease progression is not milder compared to common-onset HD patients apart from motor progression. The family history is likely to be negative, which might make diagnosing HD more difficult in this population. However, the balance and gait problems might be helpful in diagnosing HD in elderly patients