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A prospective clinical study was conducted to explore the possible link between peri-implant bone loss and the widespread habits of tobacco smoking and alcohol consumption. One hundred and eighty-five patients who received 514 implants were followed up for 3 years. Peri-implant marginal bone loss was evaluated by digital panoramic radiography and image analysis techniques. Multivariate analysis showed that peri-implant marginal bone loss was significantly related to a daily consumption of >10 g of alcohol, tobacco use and increased plaque levels and gingival inflammation. The present results indicate that daily alcohol consumption and tobacco use may have a negative influence on predictable long-term implant treatment outcomes, producing peri-implant bone loss and compromising restorative treatment with implant-supported prostheses.

The structure of colloidal clusters formed by long-range attractive interactions under diluted conditions is studied by means of Monte Carlo simulations. For a not-too-long attraction range, clusters show self-similar internal structure with lower density than that typical for diffusive aggregation. For long-range interactions, low kappa, nonfractal clusters are formed (dense at short scales but open at long ones). The dependence on the volume fraction shows that more-compact clusters are grown the higher the colloidal density for diffusive aggregation and attraction-driven aggregation in the fractal regime. The whole trend is explained in terms of the interpenetration among aggregates. In attraction-driven aggregations, the interpenetration of clusters competes with aggregation in the tips of the clusters, causing low-density clusters.

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectua: 03-10-2015, El ácido jasmónico (JA) y sus derivados los jasmonatos (JAs) son fitohormonas lipídicas que conforman una familia perteneciente al grupo de las oxilipinas. Tienen un papel esencial en la adaptación de las plantas a distintos tipos de estrés, tanto abiótico como biótico y también participan en la modulación de numerosos aspectos fisiológicos y de desarrollo. A pesar de la importancia de los JAs como moléculas señalizadoras en la regulación de la transcripción génica, el conocimiento de los mecanismos moleculares de su vía de señalización era muy limitado al inicio de este trabajo. En la búsqueda de nuevos componentes de la ruta de la señalización de los JAs, el laboratorio de Roberto Solano aisló mediante cribado genético un nuevo mutante insensible a jasmónico, jai3-1 (jasmonate-insensitive3-1). Este gen codifica JAZ3, miembro fundacional de la familia JAZ (Jasmonate ZIM-domain protein). En esta tesis, nos propusimos definir la función de la proteína JAZ3 y otros miembros de esta familia en la señalización de JAs, así como la búsqueda de nuevos componentes moleculares que nos permitieran avanzar en el conocimiento, desde un punto de vista molecular, de la regulación de las respuestas de la planta ante estímulos relacionados con los JAs. Los resultados de este trabajo han permitido demostrar la existencia de una familia de represores (JAZ) que enlazan la percepción de la hormona con los factores de transcripción (FT) que activan las respuestas a JA. Además, la identificación de NINJA como una proteína adaptadora que recluta a las proteínas TPL y TPL-related para formar, junto con las proteínas JAZ, el complejo represor de los FTs MYC, ha permitido obtener una explicación molecular del mecanismo de represión de la respuesta transcripcional dependiente de JA. Estos resultados también han puesto de manifiesto cómo múltiples vías de señalización hormonal pueden utilizar mecanismos similares para reprimir la expresión génica, ya que los co-represores TPL/TPR pueden ser reclutados a distintas vías mediante distintas combinaciones de proteínas adaptadoras y represoras. Finalmente, en este trabajo se describe un modelo adicional de represión de la vía de JA, donde algunos miembros de la familia JAZ, como JAZ5 y JAZ6, son capaces de interaccionar de forma directa con el co-represor TPL a través de su motivo EAR, sin necesidad de la proteína adaptadora NINJA. La comprensión de los mecanismos mediante los cuales las plantas responden dinámicamente a los cambios en el medio ambiente y se adaptan al entorno es un reto importante. Las proteínas JAZ, junto con NINJA y TOPLESS son parte fundamental de dichos mecanismos y desempeñan un papel crucial en la integración de señales ambientales con los programas basales de desarrollo

In this work, the effects of salt concentration over the swelling of ionic mesoscopic gels will be studied theoretically and verified with experiments. We will restrict ourselves to the weak screening limit where the Debye screening length is larger than the mesh size of the gel. Under this condition, direct electrostatic interactions are negligible and the swelling is driven by the osmotic pressure of the ions. The swelling response of a mesoscopic gel is strongly dependent on the ionization degree of the gel. In particular, a maximum in the size–salt concentration curve appears for a partially ionized gel, when the salt concentration equals the network charge concentration. This maximum is removed for a totally ionized polymer network. Despite these facts, a charge independent asymptotic behavior between size and salt concentration becomes apparent, at sufficiently high values of the latter. The Flory–Huggins mean-field approach together with the Donnan relations describe the observed swelling adequately, thus accounting for the essential physics of the problem. As a final remark, an experimental method for determining gel charge will be inferred from the results.

Colloidal aggregation induced by attractive interactions is tackled experimentally and by Brownian dynamics simulations using a mixture of positive and negative particles. The structure of the aggregates and the aggregation kinetics are used to characterize the aggregation behavior. The clusters show uniform internal structures, with a fractal dimension lower than that of clusters formed in diffusion, indicating a more branched architecture. The aggregation kinetics also differs from the diffusive one, slowing down as time proceeds. Both results are totally confirmed by simulation. The transition from the attractive driven to the diffusion controlled regimes is studied varying the range of interaction. Continuous transitions are observed both for the aggregation kinetics and cluster structure.

Los microgeles son geles coloidales que se emplean por el inflado y/o desinflado que manifiestan ante ciertas condiciones externas. En este trabajo, se describe experimentalmente el inflado y el desinflado de particulas de gel. El pH del medio, su concentracion ionica y el esfuerzo osmotico externo son las variables externas que se emplean para provocar el cambio de fase en las particulas. Todas las transiciones ocurren por encima del punto critico del sistema. Adicionalmente, se presentan algunas de las aplicaciones en donde se emplea la transicion provocada por la variable externa concreta.

In this work we present experimental results on aggregation of mesoscopic systems bearing opposite surface charges. The heteroaggregation is driven by electrostatic attraction. We have studied the effect of the relative particle concentration and of the surface potentials of both systems. The fastest reactions were observed when the discharged system was in excess, which cannot be explained by the kinetic theory usually employed.En este trabajo se presentan resultados experimentales de agregación en sistemas mesoscópicos con cargas opuestas. La heteroagregación está controlada por la atracción electrostática. Se ha estudiado el efecto de la proporción relativa de partículas de uno u otro signo y de los potenciales superficiales de ambos sistemas. Las velocidades de agregación más rápidas se han obtenido cuando el sistema más descargado se encuentra en exceso, lo que no puede ser explicado por la teoría cinética habitualmente empleada.

The objective of this work is to test the very recent Levin's theory for charged colloids (Levin, Y.; Barbosa, M. C.; Tamashiro, M. N. Europhys. Lett. 1998, 41 (2), 123). To accomplish this, the fraction of condensed ions has been experimentally obtained from electrophoretic mobility data and surface charge values. Latexes with different functionalities, surface charges, and sizes were selected in order to support the universality of the ion condensation effect. The good agreement between charge and fraction of condensed ions confirms Levin's theory and makes ion condensation a clear candidate for explaining the observed insensitivity of the electrophoretic mobility to surface charge variations, for sufficiently large charge.

A bacterial effector protein, HopX1, targets host plant JAZ transcriptional repressors for degradation to activate the jasmonate pathway, thereby promoting bacterial pathogenesis by suppressing host defense responses., Pathogenicity of Pseudomonas syringae is dependent on a type III secretion system, which secretes a suite of virulence effector proteins into the host cytoplasm, and the production of a number of toxins such as coronatine (COR), which is a mimic of the plant hormone jasmonate-isoleuce (JA-Ile). Inside the plant cell, effectors target host molecules to subvert the host cell physiology and disrupt defenses. However, despite the fact that elucidating effector action is essential to understanding bacterial pathogenesis, the molecular function and host targets of the vast majority of effectors remain largely unknown. Here, we found that effector HopX1 from Pseudomonas syringae pv. tabaci (Pta) 11528, a strain that does not produce COR, interacts with and promotes the degradation of JAZ proteins, a key family of JA-repressors. We show that hopX1 encodes a cysteine protease, activity that is required for degradation of JAZs by HopX1. HopX1 associates with JAZ proteins through its central ZIM domain and degradation occurs in a COI1-independent manner. Moreover, ectopic expression of HopX1 in Arabidopsis induces the expression of JA-dependent genes, represses salicylic acid (SA)-induced markers, and complements the growth of a COR-deficient P. syringae pv. tomato (Pto) DC3000 strain during natural bacterial infections. Furthermore, HopX1 promoted susceptibility when delivered by the natural type III secretion system, to a similar extent as the addition of COR, and this effect was dependent on its catalytic activity. Altogether, our results indicate that JAZ proteins are direct targets of bacterial effectors to promote activation of JA-induced defenses and susceptibility in Arabidopsis. HopX1 illustrates a paradigm of an alternative evolutionary solution to COR with similar physiological outcome., Author Summary Bacterial plant pathogens secrete toxins and inject effector proteins into the host cells to promote infection, and the identification of the individual functions of these molecules is essential to understand the infective process. Remarkably, some Pseudomonas strains have evolved a sophisticated strategy for manipulating hormonal balance by producing the toxin coronatine (COR), which mimics the plant hormone jasmonate-isoleucine (JA-Ile). The JA-Ile pathway plays a key role in plant immunity by activating defenses against fungal pathogens, while promoting bacterial growth by inhibiting the salicylic acid (SA)-dependent defenses required for Pseudomonas resistance. Here, we report that the effector HopX1 from a Pseudomonas syringae strain that does not produce COR exploits an alternative evolutionary strategy to activate the JA-Ile pathway. We show that HopX1 encodes a cysteine protease that interacts with and promotes the degradation of key JA pathway repressors, the JAZ proteins. Correspondingly, ectopically expressing HopX1 in the model plant Arabidopsis induces the expression of JA-dependent genes, and natural infection with Pseudomonas producing HopX1 promotes bacterial growth in a similar fashion to COR. Our results highlight a novel example by which a bacterial effector directly manipulates core regulators of hormone signaling to facilitate infection.

Cell reprogramming in response to jasmonates requires a tight control of transcription that is achieved by the activity of JA-related transcription factors (TFs). Among them, MYC2, MYC3 and MYC4 have been described as activators of JA responses. Here we characterized the function of bHLH003, bHLH013 and bHLH017 that conform a phylogenetic clade closely related to MYC2, MYC3 and MYC4. We found that these bHLHs form homo- and heterodimers and also interact with JAZ repressors in vitro and in vivo. Phenotypic analysis of JA-regulated processes, including root and rosette growth, anthocyanin accumulation, chlorophyll loss and resistance to Pseudomonas syringae, on mutants and overexpression lines, suggested that these bHLHs are repressors of JA responses. bHLH003, bHLH013 and bHLH017 are mainly nuclear proteins and bind DNA with similar specificity to that of MYC2, MYC3 and MYC4, but lack a conserved activation domain, suggesting that repression is achieved by competition for the same cis-regulatory elements. Moreover, expression of bHLH017 is induced by JA and depends on MYC2, suggesting a negative feed-back regulation of the activity of positive JA-related TFs. Our results suggest that the competition between positive and negative TFs determines the output of JA-dependent transcriptional activation. © 2014 Fonseca et al., This work was funded by the Spanish Ministry for Science and Innovation grants BIO2010-21739, CSD2007-00057 and EUI2008- 03666 to R.S

The aggregation of polymer colloids is studied in processes induced at high ionic concentration. Cluster-size distributions are measured with a single-cluster light scattering instrument constructed by our team. A brief description of the instrument is given and its proper performance is checked. The results are interpreted with the framework of Smoluchowski's equation. The rate constant for dimer formation is measured and compared with the theoretical prediction. Viscous interaction is taken into account to explain the differences. The temporal evolution of the number-average mean cluster size and the time-independent scaling function are determined from the cluster-size distributions. Dynamic scaling is observed even for small clusters and short aggregation times. Parameters λ and μ from Van Dongen and Ernst's classification scheme for homogeneous kernels are estimated and the aggregation mechanism is identified.

We have studied the influence of the surface charge density of polymer colloids on the aggregation processes induced at a high salt concentration. In this way, the effect of the residual interaction between the particles on the aggregation mechanism was studied. The time dependence of the detailed cluster-size distribution and the time-independent scaling distribution were obtained by single particle light scattering. We found a change in the aggregation mechanism, expressed as a variation of the \ensuremath{\mu} exponent value, when the surface charge was modified. \textcopyright{} 1996 The American Physical Society.

Jasmonates (JAs) trigger an important transcriptional reprogramming of plant cells to modulate both basal development and stress responses. In spite of the importance of transcriptional regulation, only one transcription factor (TF), the Arabidopsis thaliana basic helix-loop-helix MYC2, has been described so far as a direct target of JAZ repressors. By means of yeast two-hybrid screening and tandem affinity purification strategies, we identified two previously unknown targets of JAZ repressors, the TFs MYC3 and MYC4, phylogenetically closely related to MYC2. We show that MYC3 and MYC4 interact in vitro and in vivo with JAZ repressors and also form homo- and heterodimers with MYC2 and among themselves. They both are nuclear proteins that bind DNA with sequence specificity similar to that of MYC2. Loss-of-function mutations in any of these two TFs impair full responsiveness to JA and enhance the JA insensitivity of myc2 mutants. Moreover, the triple mutant myc2 myc3 myc4 is as impaired as coi1-1 in the activation of several, but not all, JA-mediated responses such as the defense against bacterial pathogens and insect herbivory. Our results show that MYC3 and MYC4 are activators of JA-regulated programs that act additively with MYC2 to regulate specifically different subsets of the JA-dependent transcriptional response.

Development of new biomaterials is a constant in regenerative medicine. A biomaterial’s surface properties, such as wettability, roughness, surface energy, surface charge, chemical functionalities and composition, are determinants of cell adhesion and subsequent tissue behavior. Thus, the main aim of this study was to analyze the correlation between changes in wettability without topographical variation and the response of osteoblast-like cells. For this purpose oxidized silicon surfaces were methylated to different degrees. Additionally, the influence of nanoroughness, and the subsequent effect of hysteresis on cell behavior, was also analyzed. In this case oxidized silicon pieces were etched with caustic solutions to produce different degrees of nanoroughness. Axisymmetric drop-shape analysis and atomic force microscopy confirmed that the proposed surface treatments increased the nanometer roughness and/or the water contact angles. MG-63 osteoblast-like cells were cultured on the altered surfaces to study proliferation, and for ultrastructural analysis and immunocytochemical characterization. Increasing the nanometer surface roughness or water contact angle enhanced osteoblast behavior in terms of cell morphology, proliferation and immunophenotype, the effect provoked by methylation being more significant than that caused by nanoroughness.

Sinus grafting is a technique oriented to facilitate implant placement in posterior atrophic maxillae. Several modifications of the original technique and a wide variety of materials have been proposed; most of them associated with implant survival rates. However, the quality of the bone obtained after the application of certain grafting materials has not been fully elucidated yet. The aims of this multicenter study were to analyse histomorphometrical samples obtained 6 months after sinus grafting using a composite graft consisting of anorganic bovine bone (ABB)+ autologous bone (AB), and to compare these samples with maxillary pristine bone biopsies.Ninety maxillary sinus augmentations were performed for delayed implant placement (N = 90) in 45 consecutive patients (test group). Bone cores were harvested 6 months after grafting for histomorphometric and ultrastructural study. Control pristine bone biopsies were taken from the posterior maxilla of 10 patients (control). Bone radiographic changes were assessed up to 24 months after implant loading.The total mean values after analysis of test cores revealed a proportion of 46.08 + or - 16.6% of vital bone, 42.27 + or - 15.1% of non-mineralized connective tissue, and 37.02 + or - 25.1% of the remaining ABB particles. Significant bone remodeling activities were noticed in sinus grafting samples when compared with pristine bone. A statistically significant difference was observed in the number of osteoid lines between two groups, with higher values in the test one (15.1 + or - 11.48% vs. 2.5 + or - 2.2%, P = 0.0005). Ultrastructural study showed that vital trabecular bone was in intimal contact with ABB particles. Radiographic analysis revealed that the higher the proportion of remaining ABB, the lower the total vertical resorption of the graft.Sinus grafting constitutes an excellent model for the study of de novo bone formation patterns and graft consolidation, when a combination of different bone substitutes is applied. The combination of ABB+AB yields highly satisfactory outcomes from both a clinical and a histologic perspective.

Background and objectives: Sinus augmentation is a procedure used for augmenting insufficient bone height that is often observed in the maxillary posterior areas. Many different techniques as well as bone graft regimens have been suggested for performing this procedure. It was the goal of this study to compare, clinically and histologically, two different composite grafting regimens used for sinus augmentation. Material and methods: Five patients, needing a bilateral sinus augmentation to allow implant placement, were recruited for this study. Right sinuses were grafted with cortical bone (collected from overlying the sinus membrane) and bovine hydroxyapatite (HA), while the left side sinuses were grafted with overlying autologous bone plus a bioglass (BG) material. Bone core biopsies were taken at 6 months after sinus graft or at the time of implant insertion. A waiting period of 6 additional months was granted to allow healing, before prosthetic restoration and functional loading. The level of peri-implant bone was evaluated 12 months after loading. A comparative histomorphometric analysis was conducted and a statistical analysis was performed. Results: All implants in both groups were functional after a 12-month loading period. No bone loss was observed radiographically or clinically in both groups. Histologic analysis revealed that both composite grafts had a high biocompatibility. In the bovine HAcontaining group, minimal xenogenic graft absorption was noted. In contrast, BG group samples presented a high absorption rate with some remaining particles imbedded in new normal bone. Conclusions: Sinus augmentation using a combination of autogenous bone plus either bovine HA or BG is a predictable technique.

This work deals with certain kinetic aspects of the coagulation of polymer colloids by immuno gamma globulin molecules. Negatively and positively charged polystyrene microspheres were used as a carrier of antibody molecules and the coagulation was studied experimentally by measuring the change in turbidity with time after addition of various amounts of rabbit immuno gamma globulin (IgG). Coagulation occurred when those pretreated latexes were mixed with a solution containing IgG molecules. The initial change in turbidity with time has been measured upon addition of various amounts of rabbit IgG to a constant amount of positively and negatively charged polystyrene latex. The general form of these curves does not deviate too far from a parabola. In all cases the coagulation rate is maximum with a surface coverage of one-half, and minimum at full coverage. To explain the experimental data, we have used a theory developed by Singer at al. which considers the adsorption of IgG on the polymer colloids and the coagulation of colloid particles as two consecutive processes. Two different mechanisms have been proposed for the action of protein coagulants, i.e., charge neutralization and bridge formation. — Particle concentration plays an important role in the coagulation kinetic; highest sensibility is found at 1010 particles/cm3. Also, pH exerts a decisive influence in the coagulation kinetic of polymer colloids by IgG molecules. The rate of coagulation at pH 5.0 is much larger than that at pH 9.0. Also, from the straight lines expressing the relation between the time variation of turbidity and the latex concentration the number of IgG molecules adsorbed onto each latex particle can be derived. At pH 9.0 that number is 1050 on negatively charged polystyrene latex particles. Finally, the reaction rate constant of two primary particles forming a doublet was determined by Lichtenbelt et al. theory.

La Licenciatura de Medicina explora ante el reto del Espacio Europeo de Educación Superior (EEES) y la estructuración de los nuevos planes de estudios, el desarrollo de programas curriculares innovadores y la aplicación de nuevas metodologías que sin romper de forma brusca con el sistema tradicional, cumpla con la nuevas y crecientes demandas de la sociedad actual. Este intento de modular la enseñanza para reemplazar los enfoques clásicos por otros integrados y conseguir el inicio de la convergencia hacia un sistema que permita la lectura común de los conocimientos adquiridos ha sido el objetivo desarrollado en nuestra experiencia utilizando una metodología activa para el aprendizaje. Los participantes en este proyecto desde el Área que les compete, la Anatomía, entienden que enseñanza integrada, puede solucionar los problemas de la educación ocasionados por el aumento de los conocimientos científicos y debe desarrollarse mediante programas de estudios basados en la síntesis interdisciplinaria y en la generalización de los conocimientos. Desde los objetivos a alcanzar por las diferentes disciplinas implicadas en el estudio de un caso clínico, hemos desarrollado una estrategia metodológica basada la construcción del conocimiento por parte de Grupos reducidos de alumnos que han sido tutorizados de forma continúa por Profesores de diferentes disciplinas. El resultado ha sido la integrando de conocimientos procedentes no sólo de las clásicas Áreas afines de Fisiología y Anatomía sino de aportaciones desde las áreas de Histológica, Genética y Bioquímica que han permitido lograr nuestro objetivo: desarrollar un sistema cooperativo y activo en el que el alumno se convierte en el centro del proceso de enseñanza-aprendizaje para si mismo y para sus compañeros. SIN FINANCIACIÓN No data 2008

We have studied the influence of the surface charge density of polymer colloids on aggregation processes induced at a high salt concentration. In this way, the effect of the residual interaction between the particles on the aggregation mechanism was studied. The time dependence of the detailed cluster-size distribution and the time-independent scaling distribution were obtained by single particle light scattering. We found a change in the aggregation mechanism, expressed as a variation of the μ exponent value, when the surface charge is modified.

Esta tesis abarca el análisis, extracción, síntesis y estabilidad de los capsaicinoides y capsinoides presentes en los pimientos., 288 paginas

Se presenta el desarrollo de un método de extracción de capsaicinoides en pimientos mediante la técnica de extracción mediante fluidos presurizados.

A prospective clinical study was conducted to explore the possible link between peri-implant bone loss and the widespread habits of tobacco smoking and alcohol consumption. One hundred and eighty-five patients who received 514 implants were followed up for 3 years. Peri-implant marginal bone loss was evaluated by digital panoramic radiography and image analysis techniques. Multivariate analysis showed that peri-implant marginal bone loss was significantly related to a daily consumption of10 g of alcohol, tobacco use and increased plaque levels and gingival inflammation. The present results indicate that daily alcohol consumption and tobacco use may have a negative influence on predictable long-term implant treatment outcomes, producing peri-implant bone loss and compromising restorative treatment with implant-supported prostheses.

We use electrophoretic mobility (mu) measurements of charged colloidal particles under the presence of multivalent counterions as a probe of the electrostatic correlations between them; they become important for sufficiently high surface charge densities of the colloid (sigma) and result in a decreasing mu upon increasing sigma. The physics of this decrease is the same as that giving rise to charge inversion. We account qualitatively for the observations by considering recent theoretical arguments that assume the counterions next to the colloid surface as a strongly correlated liquid of properties similar to that of a Wigner crystal.

Se ha desarrollado un método de extracción de capsaicinoides en pimientos mediante la extracción con fluidos presurizados

Se ha llevado a cabo el desarrollo de un método de separación y cuantificación de capsaicinoides mediante el empleo de la HPLC empleando columnas monolíticas

We perform static light scattering experiments on a dilute suspension of microgel particles and model the resultant form factors P(q) by assuming an exponentially decaying dielectric permittivity. The result is that P(q) is a Lorentzian function of the scattering wavevector q for length scales greater than the particle size; the width approximately corresponding to twice the particle radius. This simple model reasonably accounts for scattered light from both swollen and shrunken microgel phases.