397 research outputs found
Interplay of plasma-induced and fast thermal nonlinearities in a GaAs-based photonic crystal nanocavity
We investigate the nonlinear response of GaAs-based photonic crystal cavities
at time scales which are much faster than the typical thermal relaxation rate
in photonic devices. We demonstrate a strong interplay between thermal and
carrier induced nonlinear effects. We have introduced a dynamical model
entailing two thermal relaxation constants which is in very good agreement with
experiments. These results will be very important for Photonic Crystal-based
nonlinear devices intended to deal with practical high repetition rate optical
signals.Comment: 10 pages, 8 figures, Phys Rev A (accepted
Response of key stress-related genes of the seagrass Posidonia oceanica in the vicinity of submarine volcanic vents
Submarine volcanic vents are being used as natural laboratories to assess the effects of increased ocean acidity and carbon dioxide (CO2) concentration on marine organisms and communities. However, in the vicinity of volcanic vents other factors in addition to CO2, which is the main gaseous component of the emissions, may directly or indirectly confound the biota responses to high CO2. Here we used for the first time the expression of antioxidant and stress-related genes of the seagrass Posidonia oceanica to assess the stress levels of the species. Our hypothesis is that unknown factors are causing metabolic stress that may confound the putative effects attributed to CO2 enrichment only. We analyzed the expression of 35 antioxidant and stress-related genes of P. oceanica in the vicinity of submerged volcanic vents located in the islands of Ischia and Panarea, Italy, and compared them with those from control sites away from the influence of vents. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was used to characterize gene expression patterns. Fifty-one percent of genes analyzed showed significant expression changes. Metal detoxification genes were mostly down-regulated in relation to controls at both Ischia and Panarea, indicating that P. oceanica does not increase the synthesis of heavy metal detoxification proteins in response to the environmental conditions present at the two vents. The up-regulation of genes involved in the free radical detoxification response (e.g., CAPX, SODCP and GR) indicates that, in contrast with Ischia, P. oceanica at the Panarea site faces stressors that result in the production of reactive oxygen species, triggering antioxidant responses. In addition, heat shock proteins were also activated at Panarea and not at Ischia. These proteins are activated to adjust stress-accumulated misfolded proteins and prevent their aggregation as a response to some stressors, not necessarily high temperature. This is the first study analyzing the expression of target genes in marine plants living near natural CO2 vents. Our results call for contention to the general claim of seagrasses as "winners" in a high-CO2 world, based on observations near volcanic vents. Careful consideration of factors that are at play in natural vents sites other than CO2 and acidification is required. This study also constitutes a first step for using stress-related genes as indicators of environmental pressures in a changing ocean.project HighGrass "High-CO2 effects on seagrass photosynthetic ecophysiology" [PTDC/MAREST/3687/2012]; MIUR Italian flagship project RITMARE; ESF COST Action "Seagrass Productivity: from genes to ecosystem management
An Alternative Approach for the Treatment of Major Aphthosis: Case Report
An effective treatment for aphthous stomatitis is not still available and its treatment consists only of therapeutic measures to suppress its symptoms. We report a case of a 60-year caucasian woman presented a 16-year history of episodes of multiple major recurrent ulcers in the oral mucosa. Topical application of Oralmedic® caused an improvement of pain, discomfort and healing of the aphthous ulcer. No adverse events or side effects were recorded. Oralmedic® is an effective topical device for the major aphthous ulcers treatmen
Evidencia del sÃndrome neuropático en un estudio neurofisiológico e inmunohistoquÃmico de las fibras nerviosas en pacientes con sÃndrome de boca ardiente
espanolIntroduccion: El sindrome de la boca ardiente (SBA) es una enfermedad de frecuente aparicion, caracterizada para un dolor quemante y ardiente en la lengua y en la cavidad oral, en ausencia de alteraciones estructurales macroscopicas de las mucosas. La etiopatogenesis del SBA no es todavia conocida y por lo tanto no presenta un esquema diagnostico claro y bien definido. Material y metodos: Para evaluar la hipotesis que contempla una alteracion de las fibras nerviosas perifericas de pequeno calibre, asociada o no con una alteracion trofica de las mucosas, hemos seleccionados 25 pacientes (7 varones y 18 mujeres, con una edad comprendida entre 36 y 75 anos, una media de 54 anos) afectados por SBA, que llegaron a nuestra clinica para una serie de examenes que suelen realizarse de forma rutinaria en las sindromes de dolor neurologico. En todos los pacientes se ha realizado un cuidadoso examen objetivo y una ortopantomografia, con la finalidad de excluir alteraciones de las mucosas y enfermedades odontologicas. En todos los pacientes se han realizado: examenes hematoquimicos, examenes objetivos neurologicos, teletermografia de la lengua y de la cara, examen cuantitativo de la sensibilidad termica de la lengua, de las manos y de la parte dorsal del pie. Los resultados del examen cuantitativo de la sensibilidad termica de la lengua y de la muneca se confrontaban con una poblacion control homogenea. En una poblacion de 10 pacientes (3 varones y 7 mujeres; de una edad comprendida entre 34 y 53 anos, una media de 49 anos) se ha realizado un biopsia de la parte dorsal de la lengua, la biopsias se han analizado con microscopia optica e inmunofluresencia tras un tratamiento con anticuerpos activos para proteinas neuronales citoplasmaticas (protein gene product 9.5). Resultados: Los datos obtenidos evidenciaban la presencia de una polineuropatia subclinica en el 50% de los pacientes. Especialmente se apreciaban signos de baja funcionalidad de las fibras nerviosas de pequeno calibre de la lengua en casi la mitad de los pacientes examinados. El examen histologico de la mucosa lingual evidenciaba una atrofia discreta en el 70% de los pacientes, mientras que la observacion de las fibras nerviosas de pequeno calibre por medio de la inmunofluoresencia hacia suponer la presencia de alteraciones relacionadas con una polineuropatia de tipo periferico. EnglishAims. Burning pain is considered characteristic of chronic neuropathic pain condition in general, and so me recent data seem to suggest peripheral or central nervous system involvement as possible underlying factor in BMS. This study was designed to determinate if burning mouth symptoms could be originated from a peripheal neuropathy of small diameter nerve fibres. Material and methods. The material of the study consisted of 25 patients (18 female, 7 male, 30-75 years; means 54 years). In all patients there were not: oral muco membranes lesions, oral muco membranes diseases, oral correlated diseases, oral dysfunctions, dental and periodontal diseases. Besides there were: no evidence of central nervous system pathology, no evidence of peripheral nervous system pathology, no presence of organic body disfunctions. AIIpatients didn't show significant alterations of blood investigations. AII patients were undermitted to our protocol including: oral and facial clinical examinations, neurological exam, blood investigations, Mc Gill Pain Questionnaire, VAS (visual analogical scale), biopsy of tongue mucosa with hystological and immunofluorescence exams, quantitative somatosensory thermotest and teletermography examination of tongue mucosa. ResuIts. These examinations have showed subclinical polineurophaty in 50% of patients. In particular were observed a loss of function in small diameter nervous fibres in about 50% of patients. Hystological exam of mucosal tongue revealed a moderate atrophy and alterations of structures. Conclusion. Etiology, pathogenetic processes, clinical and diagnostic approaches, therapeutical resolutions and researches of burning mouth syndrome are not clear yet. The local alterations of small diameter sensitive nerve fibres could cause an increase of oral burning, without muco membranes pathologies. These locallesions could justify the bms clinical symptomatology. The hystological alteration of small diameter sensitive nerve fibres could involve meaningful alterations of thermal reactivity of oral and body surfaces. These clinical reactivities are evident in chronic peripheal neuropathy (diabetes). These conclusions and our study results are still provisory. It will be necessary to estend and to increase our results, comparing our research with other bms etio-pathogenetic hypotesis
Conocimiento y actitud del odontólogo frente al manejo del tabaquismo: estudio comparativo entre España, Italia y Venezuela
espanolIntroduccion: El Odontologo es capaz de ejercer un gran impacto en el tabaquismo a traves de su contacto con los pacientes y la deteccion precoz de lesiones bucales. El objetivo de este estudio fue determinar el conocimiento y la actitud de los odontologos frente al tabaquismo en tres paises distintos. Materiales y metodos: Se realizo una encuesta a 293 odontologos, 93 de ellos localizados en Caracas (OV), 90 con practica odontologica en Madrid (OE) y 110 en Milan (OI). Resultados: 46 OE y 22 OI indicaron ser fumadores, mientras que tan solo 10 OV admitieron ser fumadores. 80 (86,02%) OV, 66 (73,33%) OE y todos los OI refirieron registrar en la historia datos relacionados con tabaquismo en la primera consulta del paciente. La mayoria motiva a sus pacientes a dejar de fumar, sin embargo, 72,04% (67) OV, 55,55% (50) OE y 100% OI no recomiendan ninguna terapia de apoyo. Solo 7 odontologos (2,38%) (2 OV y 5 OE) reconocieron el medicamento Bupropion pero ningun odontologo lo ha indicado. Finalmente, 137 odontologos han diagnosticado cancer bucal, de los cuales 108 eran OI. Conclusiones: Los odontologos, independientemente del pais, tienen actitudes positivas para participar en el control del tabaquismo, pero no manejan la informacion relacionada ni ejercen un rol activo en la cesacion. Probablemente esta situacion se deba a la falta de entrenamiento durante sus estudios de pre y/o postgrado lo cual amerita una revision de los planes curriculares de Odontologia a nivel mundial. EnglishIntroduction: Health care professionals have an important role in tobacco control. Dentists are capable of having a great impact in smoking cessation due to their regular contact with patients and the rapid detection of oral signs produced by smoking. Unfortunately, there are few dentists actively involved in smoking control. The aim of this study was to investigate various aspects of dentists' beliefs and practices with respect to smoking cessation. Materials & Methods: A questionnaire about smoking cessation was filled in person by 293 dentists. 93 dentists were from Caracas-Venezuela (VD), 90 were from Madrid-Spain (SD) and 110 from Milan-Italy (ID). Results: 46 SD and 22 ID were smokers. Only 10 VD admitted to smoke. 80 (86.02%) VD, 66 (73.33%) SD and 100% of ID said that they recorded smoking status during the first consultation. However, none routinely update their records on smoking status. The majority of respondents encourage their patients to stop smoking, though, 72.04% (67) VD, 55.55% (50) SD and 100% ID do not recommend or prescribe any cessation therapy. Just 7 (2.38%) of all dentists had heard about the use of Bupropion, however, they had never indicated. Finally, 137 dentists (108 ID) have diagnosed oral cancer in their patients. Conclusions: Dentists have positive attitudes to being involved in smoking cessation interventions, but they do not manage all the information related to it. It is probably due to a lack of training or education during their undergraduate and postgraduate studies. Further studies should evaluate inclusion of smoking cessation instruction in Venezuelan, Spanish and Italian dentistry curriculum
The role of blood clot in guided bone regeneration: Biological considerations and clinical applications with titanium foil
In Guided Bone Regeneration (GBR) materials and techniques are essential to achieve the expected results. Thanks to their properties, blood clots induce bone healing, maturation, differenti-ation and organization. The preferred material to protect the clot in Guided Bone Regeneration is the titanium foil, as it can be shaped according to the bone defect. Furthermore, its exposition in the oral cavity does not impair the procedure. We report on five clinical cases in order to explain the management of blood clots in combination with titanium foil barriers in different clinical settings. Besides being the best choice to protect the clot, the titanium foil represents an excellent barrier that is useful in GBR due to its biocompatibility, handling, and mechanical strength properties. The clot alone is the best natural scaffold to obtain the ideal bone quality and avoid the persistence of not-resorbed granules of filler materials in the newly regenerated bone. Even though clot contraction still needs to be improved, as it impacts the volume of the regenerated bone, future studies in GBR should be inspired by the clot and its fundamental properties
Polymerization shrinkage and spherical glass mega fillers: Effects on cuspal deflection
Purpose. The Authors analyzed the effect of spherical glass mega fillers (SGMF) on reducing contraction stress in dental composite resins, by means of a cavity model simulating the cuspal deflection which occurs on filled tooth cavity walls in clinical condition. Materials and methods. 20 stylized MOD cavities (C-factor = 0.83) were performed in acrylic resin. The inner surface of each cavity was sand blasted and adhesively treated in order to ensure a valid bond with the composite resin. Three different diameter of SGMF were used (i.e. 1, 1,5, 2 mm). The samples were divided in 4 groups of 5 each: Group 1 samples filled with the composite only; Group 2 samples filled with composite added with SGMFs, Ø1mm (16 spheres for each sample); Group 3 samples filled with composite added with SGMFs, Ø1,5 mm (5 spheres for each sample); Group 4 samples filled with composite added with SGMFs, Ø2 mm (2 spheres for each sample). Digital pictures were taken, in standardized settings, before and immediately after the polymerization of the composite material, placed into the cavities. With a digital image analysis software the distances from the coronal reference points of the cavity walls were measured. Then the difference between the first and second measurement was calculated. The data were analyzed by means of the ANOVA test. Results. A significative reduction on cavity walls deflection, when the composite resin is used in addiction with the SGMFs was observed. The SGMFs of smallest diameter (1mm) showed the better outcome. Conclusion. The SGMFs are reliable in reducing contraction stress in dental composite resins
Hemifacial microsomia: Case report and literature review
Hemifacial microsomia (HFM) is a sporadic congenital malformation of the craniofacial structures derived from the first and second branchial arches. The incidence of HFM has been reported to range from 1 in 3,0001 to 1 in 26,0002 live births, making HFM the second most common congenital malformation in the face after cleft lip and/or palate. An 11-year-old girl came at Galeazzi Institute (Milan) in January 2017. She presented left hemifacial microsomia with absence of the left ramus of mandible and the left temporomandibular joint (tmj), part of the zygomatic arch, hypoplasia of the lateral and inferior orbital bone and of the zygomatic bone. She also presented a medial canthal dystopia. She underwent to costochondral bone graft and calvaria bone graft for reconstruction of part of the mandible and the TMJ. An emi-Le Fort I, emi-Le Fort III, and sagittal segmental osteotomy of the right mandible were performed to improve the correct occlusion. Traditionally, the costochondral graft has been considered the gold standard for ramus-condyle reconstruction in the pediatric mandible when appropriate. Some studies cite growth unpredictability and ankylosis as concerns with rib. Further studies examining carefully the factors predicting graft growth, such as size of cartilage cap, surgical technique, and postoperative physiotherapy, are warranted
Oral health status among migrants from middle-and low-income countries to europe: A systematic review
Introduction. Economic inequality, political instability and globalization have contributed to the constant growth of the migration phenomenon in recent years. In particular, a total of 4.2 million people migrated to Europe during 2019 and most of them settled in Germany, France and Italy. Objectives. The objective of this study was to conduct a systematic review of studies analyzing the oral health condition among migrants from middle-and low-income countries to Europe and assessing the eventual association between their sociodemographic and socioeconomic characteristics and oral health status. Materials and Methods. A systematic review was conducted in PubMed, Cochrane Library, Scopus and Science Direct databases. After titles, abstracts and full-text exami-nation, only 27 articles were selected on the basis of inclusion criteria and consequently included for quality assessments and data extraction. Results. Most of the studies reported a higher prevalence of caries experience, a poorer periodontal health and more difficulties in accessing dentalcare services among migrant groups compared with the non-migrant population. Inequalities were mostly associated with ethnic background, economic condition and social grade. Conclusion. Our review demonstrates the lack of dental health among migrants, underlining that their cultural beliefs and their social and economic living conditions could influence their oral health
Drug-induced gingival hyperplasia : an in vitro study using amlodipine and human gingival fibroblasts
Gingival overgrowth is a serious side effect that accompanies the use of amlodipine. Several conflicting theories have been proposed to explain the fibroblast\u2019s function in gingival overgrowth. To determine whether amlodipine alters the inflammatory responses, we investigated its effects on gingival fibroblast gene expression as compared with untreated cells. Fragments of gingival tissue of healthy volunteers (11 years old boy, 68 years old woman, and 20 years old men) were collected during operation. Gene expression of 29 genes was investigated in gingival fibroblast cell culture treated with amlodipine, compared with untreated cells. Among the studied genes, only 15 (CCL1, CCL2D, CCL5, CCL8, CXCL5, CXCL10, CCR1, CCR10, IL1A, IL1B, IL5, IL7, IL8, SPP1, and TNFSF10) were significantly deregulated. In particular, the most evident overexpressed genes in treated cells were CCR10 and IL1A. These results seem to indicate a possible role of amlodipine in the inflammatory response of treated human gingival fibroblasts
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