A volume-averaged nodal projection method for the Reissner-Mindlin plate model

We introduce a novel meshfree Galerkin method for the solution of Reissner-Mindlin plate problems that is written in terms of the primitive variables only (i.e., rotations and transverse displacement) and is devoid of shear-locking. The proposed approach uses linear maximum-entropy approximations and is built variationally on a two-field potential energy functional wherein the shear strain, written in terms of the primitive variables, is computed via a volume-averaged nodal projection operator that is constructed from the Kirchhoff constraint of the three-field mixed weak form. The stability of the method is rendered by adding bubble-like enrichment to the rotation degrees of freedom. Some benchmark problems are presented to demonstrate the accuracy and performance of the proposed method for a wide range of plate thicknesses

Bone Morphogenetic Protein and its Option as an Alveolar Cleft Treatment

Indexación: Scopus; Scielo.Bone morphogenetic protein (BMP) is an endogenous protein that has shown significant effects in the promotion of bone formation. BMP also has been described in the reconstruction of traumatic and pathological bone defects, including alveolar cleft, alveolar ridge augmentation, maxillary sinus elevation, and applications in post-extraction alveolus graft, and peri-implant surgery among others. Despite the advantages associated with the use of BMP, currently is applied in combination with collagen matrices, which has certain properties such as low mechanical resistance and a high burst initial release that diminish its effectiveness in bone formation. In this context, the development of novel systems with greater mechanical resistance and prolonged release of BMP, that lead to chemotaxis of mesenchymal cells, following by its differentiation to osteoblasts represents a major challenge that holds outstanding clinical potential for the stimulation of bone formation. In this paper, we describe the use of BMP for the reconstruction of alveolar clefts, and its advantages being administrated in polymeric microparticles as sustain release system with promising applications in the stimulation of bone formation.http://ref.scielo.org/ps5w6

Immunoexpression of E-cadherin and Vimentin in Normal Oral Mucosa, Oral Epithelial Displasia and Oral Squamous Cell Carcinoma

Indexación: Web of Science; Scopus; Scielo.El objetivo fue evaluar la inmunoexpresión de E-cadherina y Vimentina en mucosa oral normal (MON), displasia epitelial oral (DEO) y carcinoma oral de células escamosas (COCE). Se realizó un estudio descriptivo de una serie de casos analizandolos mediante técnica de inmunohistoquímica contra E-cadherina y Vimentina 16 muestras de MON, 16 de DEO y 19 de COCE. La inmunotinción fue evaluada cualitativamente considerando extensión e intensidad para E-cadherina e intensidad para Vimentina. El análisis de la extensión e intensidad de la inmunotinción de E-cadherina y Vimentina según diagnóstico reveló una asociación estadísticamente significativa (p<0,001). Siendo la expresión de E-cadherina más alta en MON, seguido por DEO y más baja en COCE, inversamente a lo que se observó con Vimentina. El presente estudio reveló la subregulación del marcador molecular E-cadherina junto con la expresión aberrante por parte de células epiteliales del marcador mesenquimal Vimentina en muestras de MON, DEO y COCE.The aim was to evaluate the expression of E-cadherin and Vimentin in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC), in comparison with normal oral mucosa (NOM) in a descriptive case study using immunohistochemistry. A total of fifty-one (N=51) histological samples were included; as follows: n = 16 (NOM), n = 16 (OED) and n = 19 (OSCC). All samples were analyzed using immunohistochemistry against the expression of E-cadherin and Vimentin. Immunostaining was qualitatively evaluated by extent and intensity of its expression for E-cadherin and intensity for Vimentin. Extension and intensity analysis of E-cadherin and Vimentin immunostaining according to group revealed a statistically significant association (r<0.001). E-cadherin expression was found to be highest in NOM followed by OED and lowest in OSCC, inverse to what was observed with Vimentin. The present study revealed the down regulation of the molecular marker E-cadherin, suggestive of reduction in dysplastic cells on comparison to NOM cells, and aberrant expression of the mesenchymal marker Vimentin by epithelial cells in samples of NOM, OED and OSCC; questioning their value as a prognostic marker.http://ref.scielo.org/pk8s6

Estimulación eléctrica en la reparación ósea de defectos creados en cráneos de conejos

Electrical stimulation has been used in different conditions for tissue regeneration. The aim of this study was to analyze the tissue response of defects created in rabbit skulls to electrical stimulation. Two groups were formed, each with 9 New Zealand rabbits; two 5 mm defects were made, one in each parietal, with one being randomly filled with autogenous bone extracted as particles and the other maintained only with blood clotting. The rabbits were euthanized at 8 weeks and 15 weeks to then study the samples collected histologically. In the 8-week analysis bone formation was observed in the defects in the test and control filled with bone graft, whereas the defects with clotting presented a very early stage of bone formation with abundant connective tissue. At 15 weeks an advanced stage of bone regeneration was identified in the defects with bone graft, whereas no significant differences were found in the electrically stimulated defects. In conclusion, electrical stimulus does not alter the sequence of bone formation; new studies could help establish patterns and influences of the stimulus on bone regeneration.Electrical stimulation has been used in different conditions for tissue regeneration. The aim of this study was to analyze the tissue response of defects created in rabbit skulls to electrical stimulation. Two groups were formed, each with 9 New Zealand r33311461150sem informaçãosem informaçãoLa estimulación eléctrica ha sido empleada en diferentes condiciones para la regeneración de tejidos. El objetivo de esta investigación es analizar la respuesta tisular de defectos creados en cráneo de conejos a la estimulación eléctrica. Se formaron 2 g

COVID-19 and Dentistry: a Review of Recommendations and Perspectives for Latin America

COVID-19 es una enfermedad altamente contagiosa y potencialmente mortal que nos acompañara por largo tiempo. Las profesiones de la salud y la vida en general ha sido afectada de forma significativa en todo lugar del mundo. La odontología ha pasado de una etapa de gran desarrollo clínico a una etapa donde el manejo de barrera de protección, el control de tratamientos y el tiempo asignado a los pacientes cambiará la forma de realizar la profesión. El presente trabajo pretende resumir las indicaciones y recomendaciones basadas en la evidencia disponible y realizar un análisis de la condiciones de salud oral para Latinoamérica en esta época de pandemia.COVID-19 is a profound, highly contagious and life-threatening viral disease that will be with us for a long time. Health Care-related professions and life in its entirety are significantly, and perhaps irreversibly affected, all around the World. COVID-19 is and will continue to transform Dentistry and its practise. Based on the available evidence accrued to date, this work attempts to address such changes, current and anticipated, as well as present recommendations for clinical practise implementation, tailored for Latin/South America, in light of such lifealtering momentous pandemic