155 research outputs found
Evaluación in vivo de la sustantividad de la clorhexidina al 0,2% en diferentes ecosistemas orales
La placa dental se considera un modelo especializado de biofilm microbiano, que se forma sobre todos los tejidos intraorales duros y blandos, y representa el principal agente etiológico de la caries y de la enfermedad periodontal. La idea de aplicar un antiséptico oral con fines profilácticos exige analizar su eficacia antimicrobiana en diferentes ecosistemas orales, particularmente en los que presentan características estructurales y fisiológicas diferentes a la saliva, como es el caso de la placa dental. El estudio in vivo de la actividad antibacteriana de un antiséptico supone el análisis de su efecto inmediato y de su sustantividad. Se ha demostrado que la clorhexidina tiene un efecto antibacteriano inmediato y una mayor sustantividad in vivo que otros antisépticos empleados en la cavidad oral. En la mayoría de las series publicadas, la cuantificación de la actividad antimicrobiana de la clorhexidina en saliva se realizó empleando técnicas microbiológicas de cultivo en placa. Sin embargo, algunos autores cuestionaron la fiabilidad de estas técnicas y, como alternativa, propusieron el uso de ensayos fluorescentes que utilizan fluorocromos específicos para marcar bacterias viables y no viables, en base a la integridad de su membrana citoplasmática
Induced martensitic transformation during tensile test in nanostructured bainitic steels
Retained austenite in nanostructured bainite is able to undergo mechanically induced martensitic transformation. However, the link between transformation and deformation mechanisms involved makes difficult the understanding of the process. In this work, a model has been developed to assess the effect of the external stress itself on the martensite phase transformation. In addition, after a detailed initial microstructural characterization, the martensite fraction evolution during tensile deformation has been obtained by means of X-ray diffraction analyses after interrupted tensile tests in several nanostructured bainitic steels. Experimental results have been compared to the outputs of the model, as a reference. They suggests that stress partitioning between phases upon tensile deformation is promoted by isothermal transformation at lower temperatures.The authors gratefully acknowledge the support of the European Research Fund for Coal and Steel, the Spanish Ministry of Economy and Competitiveness and the Fondo Europeo de Desarrollo Regional (FEDER) for partially funding this research under the contracts RFSR-CT-2012-00017, RFSR-CT-2014-00016 and MAT2013-47460-C5-1−P respectively. LM-R also acknowledges this same Ministry for financial support with ref. FPI: BES-2011-044186.Peer Reviewe
A procedure for indirect and automatic measurement of prior austenite grain size in bainite/martensite microstructures
An alternative procedure for indirect and automatic measurement of the prior austenite grain
size (PAGS) in bainite/martensite is proposed in this work. It consists in the determination of an
effective grain size (EGS) by means of statistical post-processing of electron backscatter diffraction
(EBSD) data. The algorithm developed for that purpose, which is available on-line, has been applied
to simulated EBSD maps as well as to both a nanocrystalline bainitic steel and a commercial hot-rolled
air-cooled steel with a granular bainitic microstructure. The new proposed method has been proven to
be robust and results are in good agreement with conventional PAGS measurements. The added value
of the procedure comes from its simplicity, as no parent reconstruction is involved during the process,
and its suitability for low-magnification EBSD maps, thus allowing a large step-size and coverage of a
substantially broader area of the sample than the previous methods reported.Spanish Ministry of Economy and
Competitiveness for funding this research under the contract IPT-2012-0320-420000. L.M.-R. also
acknowledges the Spanish Ministry of Economy and Competitiveness for financial support in the form
of a PhD research grant (FPI-Ref. BES-2011-044186).Peer reviewe
Modelos de enseñanza-aprendizaje. Un modelo de aplicación del Aprendizaje Basado en Problemas (ABP) en odontología infantil
Entre las diferentes técnicas de Enseñanza-Aprendizaje utilizadas en las ciencias biomédicas, una de las que mayor popularidad ha adquirido en las últimas décadas es el “Aprendizaje Basado en Problemas” (ABP), considerado un hito en la educación médica. Como ocurre en otros sistemas, el ABP está centrado en el alumno y pretende fomentar un tipo de aprendizaje auto-dirigido. De sus principales virtudes se destaca que favorece el desarrollo de cierto tipo de competencias como la toma de decisiones, el razonamiento crítico, o el trabajo en equipo.
Buena parte del el éxito de una actividad basada en el ABP radica en la planificación de la misma. Los principales factores que deben tenerse en cuenta y detallar son:
- la delimitación de los objetivos a alcanzar
- la selección del/los problemas sobre los que se trabajará
- la definición de las reglas de la actividad
- determinar el tiempo en el que deberá darse solución al problema
A lo largo del siguiente capítulo se detallan cada uno de estos aspectos y se relata una modelo de experiencia educativa inspirada en el ABP. El objetivo de la actividad es poner al alumno frente a situaciones clínicas infrecuentes en la consulta de Odontología Infantil en la Licenciatura/Grado de Odontología pero que son situaciones relativamente cotidianas para un odontólogo general/odontopediatra. Se pretende fomentar la integración de conocimientos de odontología infantil, la responsabilidad colectiva y la toma de decisiones clínicas simulando las condiciones a las que los alumnos se van a enfrentar una vez graduados. Para ello se diseñaron una serie de situaciones clínicas en un paciente virtual. A lo largo de todo el curso académico se realizaron distintas sesiones en las que se facilitaba a los alumnos una serie de datos clínicos (historia clínica, fotos, radiografías) y se les planteaban una serie de preguntas: diagnóstico, plan de tratamiento justificado, etc. que deberían responder en 15 minutos. Los alumnos participaron por equipos en base a los boxes en los que realizaban sus prácticas clínicas pero sólo uno del equipo respondía a las preguntas en cada jornada. A medida que transcurrían las diferentes sesiones clínicas se fue haciendo pública las respectivas calificaciones y el acumulado hasta ese momento de forma que los alumnos podían ir viendo sus progresos en relación al resto de la clase. Para fomentar la implicación en la actividad se estableció un “pódium” con los boxes que obtuvieron una mejor puntuación al acabar el curso académico, que además vieron recompensado su buen hacer con un incremento en su calificación final en la asignatura. La opinión de los alumnos respecto a la actividad fue muy positiva, y un buen complemento para la formación teórico-práctica recibida respecto a Odontología Infantil
Propiedades psicométricas de la Escala de Asertividad Sexual: SAS en universitarios de Chimbote
El estudio de diseño instrumental, concibió determinar las evidencias psicométricas de la
escala de Asertividad sexual (SAS), en una muestra aleatoria de 384 participantes, de ambos
sexos, de 16 a 40 años de edad, que cursan estudios de formación profesional dentro de
cuatro universidades de Chimbote. Los resultados en la validez basada en la estructura
interna por el análisis factorial confirmatorio, reporta índices de ajuste absoluto χ2/gl=4.25,
AGFI=.978, RMSEA=.052, asimismo índices de ajuste comparativo TLI=.953, CFI=.912,
además de cargas factoriales estandarizadas de .25 a .97, y covarianzas de .85 a .88, como
segunda propiedad, la confiabilidad de las puntuaciones se obtuvo mediante el método de
consistencia interna con el reporte del coeficiente omega corregido, para los factores,
Iniciativa se obtuvo un valor de .72, en Rechazo de .71, y para Embarazo-ETS de .79, de
aporte metodológico-teórico-práctico
Orthodontic Treatment in Children with Cerebral Palsy
Cerebral palsy is a permanent neuromuscular motor disorder that gives rise to many functional problems, including impaired swallowing, chewing and speech. Maxillary transverse deficiency and Angle Class II malocclusion are common. Some of these functional problems can be due to maxillary malocclusion. To our knowledge, no case series has yet been published on orthodontic treatment in children with cerebral palsy. In this chapter, we provide an overview of this topic based on the literature and on our own clinical experience. We consider that some patients with cerebral palsy are susceptible to orthodontic treatment. The keys to success are appropriate patient selection, based on anatomical, physiological and behavioural characteristics, and the degree of involvement of parents and caregivers. Among parents of cerebral palsy children undergoing orthodontic therapy, the perceived level of overall satisfaction was very high and expectations were often exceeded; however, these results are conditioned by factors such as the Peer Assessment Rating (PAR) index. Although some authors reported improvements in aesthetics, speech and oral function, an objective assessment of functional improvement is still lacking. In our experience, correction of resting position and management of neuromuscular alterations are essential if successful orthodontic treatment is to be achieved and relapses avoided
Pseudoepitheliomatous hyperplasia after diode laser oral surgery: an experimen tal study
Background
: To examine the process of epithelial reparation in a surgical wound caused by diode laser.
Material and Methods
:
A
n experimental study with 27 Sprage-Dawley rats was undertaken. The animals were
randomly allocated to two experimental groups, whose individuals underwent glossectomy by means of a diode
laser at different wattages, and a control group treated using a number 15 scalpel blade.
The animals were slaughtered at the 2nd, 7th, and 14th day after glossectomy. The specimens were independently
studied by two pathologists (blinded for the specimens’ group).
Results: At the 7th day, re-epithelisation was slightly faster for the control group (conventional scalpel) (
p
=0.011).
At the 14th day, complete re-epithelization was observed for all groups. The experimental groups displayed a
pseudoepitheliomatous hyperplasia.
Conclusions: It is concluded that, considering the limitations of this kind of experimental studies, early re-epithelisation occurs slightly faster when a conventional scalpel is used for incision, although re-epithelisation is completed in two weeks no matter the instrument used. In addition, pseudoepitheliomatous hyperplasia is a potential
event after oral mucosa surgery with diode laser. Knowledge about this phenomenon (not previously described)
may prevent diagnostic mistakes and inadequate treatment approaches, particularly when dealing with potentially
malignant oral lesions
Distribución territorial del poder durante la pandemia
La distribución del poder territorial ha experimentado modulaciones diversas a lo largo de la pandemia. Las más intensas se han producido durante los estados de alarma, por la irrupción de una competencia estatal general que condiciona el ejercicio de las competencias ordinarias de las demás entidades territoriales (autonómicas y locales). Pero incluso al margen de los estados de alarma, en el sistema competencial ordinario se han producido varios fenómenos de adaptación. Aún es pronto para decir cuáles de estos fenómenos perdurarán una vez se acabe la pandemia. Por ahora son, únicamente, identificables para el análisis: flexibilización de los títulos competenciales; utilización de criterios de prevalencia frente a criterios de competencia; redefinición de los espacios propios de la ley orgánica y de la ley ordinaria; nuevos tipos de delegaciones intergubernamentales; ampliación de las facultades estatales de coordinación; y mayor extensión de la Administración indirectaThe distribution of territorial power among the different jurisdictions has undergone a number of modulations throughout the pandemic. The most intense ones have occurred during the states of alarm, due to the irruption of a general state power that conditions the exercise of the ordinary powers of the other jurisdictions, both regional and local. But even
beyond the states of alarm, several phenomena of adaptation have occurred in the constitutional
and legal distribution of powers. It is still too early to say which of these phenomena
will persist once the pandemic is over. For the time being, these phenomena are only identifiable
for analytical purposes: a relaxation in the rigidity of the legal distribution of powers;
an increased relevance of preemption versus colliding decisions of different jurisdictions;
redefinition of the limits of the organic law and the ordinary law; new types of intergovernmental
delegations; widening of the state powers of coordination; and greater extension of
the indirect Administratio
Biomarkers in ocular chronic graft versus host disease: tear cytokine- and chemokine-based predictive model.
Producción CientíficaPurpose: To develop a tear molecule level-based predictive model based on a panel of tear cytokines and their correlation with clinical features in ocular chronic graft versus host disease (cGVHD).
Methods: Twenty-two ocular cGVHD patients and 21 healthy subjects were evaluated in a controlled environmental research laboratory (CERLab). Clinical parameters were recorded, and tears were collected. Levels of 15 molecules (epidermal growth factor [EGF], IL receptor antagonist [IL-1Ra], IL-1β, IL-2, IL-6, IL-8/CXCL8, IL-10, IL-12p70, IL-17A, interferon inducible protein [IP]-10/CXCL10, IFN-γ, VEGF, TNF-α, eotaxin 1, and regulated on activation normal T cell expressed and secreted [RANTES]) were measured by multiplex-bead assay and correlated with clinical parameters. Logistic regression was used to develop a predictive model. Leave-one-out cross-validation was applied. Classification capacity was evaluated in a cohort of individuals with dry eye (DE) of other etiologies different from GVHD.
Results: Epidermal growth factor and IP-10/CXCL10 levels were significantly decreased in ocular cGVHD, positively correlating with tear production and stability and negatively correlating with symptoms, hyperemia, and vital staining. Interleukin-1Ra, IL-8/CXCL8, and IL-10 were significantly increased in ocular cGVHD, and the first two correlated positively with symptoms, hyperemia, and ocular surface integrity while negatively correlating with tear production and stability. Predictive models were generated, and the best panel was based on IL-8/CXCL8 and IP-10/CXCL10 tear levels along with age and sex, with an area under the receiving operating curve of 0.9004, sensitivity of 86.36%, and specificity of 95.24%.
Conclusions: A predictive model based on tear levels of IL-8/CXCL8 and IP-10/CXCL10 resulted in optimal sensitivity and specificity. These results add further knowledge to the search for potential biomarkers in this devastating ocular inflammatory disease.Ministry of Economy and Competitiveness, Madrid, Spain, SAF-2010 15631 (AES)
Antibiotic Prophylactic Regimens for Infective Endocarditis in Patients Undergoing Dental Procedures
Up to date causal relationship has been demonstrated between dental manipulations and the onset of infective endocarditis (IE). However, since 1955, numerous expert committees have proposed antibiotic prophylaxis (AP) to prevent bacteraemia of oral origin. Controversy regarding the efficacy of AP prior to the dental procedures has intensified in recent years because of the lack of conclusive evidence on its efficacy for the prevention of IE and on its cost-effectiveness, as well as the possibility of allergic reactions and the emergence of antibiotic resistance. Accordingly, AP is now maintained exclusively for patients at highest risk and who require the manipulation of the gingival or periapical regions of the teeth or perforation of the oral mucosa. In the context of a restrictive policy, the National Institute for Health and Clinical Excellence (NICE) of the United Kingdom published a new guideline in 2008 stating that “AP against IE is not recommended for persons undergoing dental procedures”, regardless of risk status and of the nature of the procedure to be performed. The NICE guideline has generated further controversy, and expert committees in other countries continue to publish prophylactic regimens for the prevention of IE secondary to dental procedures. In this chapter, we discuss the principal guidelines currently applicable in Europe, the USA and Australia, and we draw particular attention to the need for randomised clinical trials
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