Hybrid Petri net model of a traffic intersection in an urban network

Control in urban traffic networks constitutes an important and challenging research topic nowadays. In the literature, a lot of work can be found devoted to improving the performance of the traffic flow in such systems, by means of controlling the red-to-green switching times of traffic signals. Different techniques have been proposed and commercially implemented, ranging from heuristic methods to model-based optimization. However, given the complexity of the dynamics and the scale of urban traffic networks, there is still a lot of scope for improvement. In this work, a new hybrid model for the traffic behavior at an intersection is introduced. It captures important aspects of the flow dynamics in urban networks. It is shown how this model can be used in order to obtain control strategies that improve the flow of traffic at intersections, leading to the future possibility of controlling several connected intersections in a distributed way

Simultaneous left colectomy and standard hepatectomy reformed by laparoscopy

As abordagens laparoscópicas têm sido cada vez mais utilizadas em pacientes com câncer colorretal ou hepático. Colectomia e hepatectomia simultâneas são consideradas técnicas seguras e apresentam resultados oncológicos semelhantes independente da localização do tumor primário quando associada à ressecções hepáticas com menos de quatro metástases, uma vez que não existe aumento da morbimortalidade nem prejuízo na sobrevida. O desenvolvimento de técnicas e materiais laparoscópicos tornou a ressecção combinada do cólon e do fígado uma opção bastante atraente. O objetivo do presente estudo é demonstrar a ressecção de um tumor sincrônico de sigmoide e metástase hepática única tratada por colectomia e setorectomia lateral esquerda puramente laparoscópicaLaparoscopic approaches have been increasingly used in patients with colorectal or liver cancer. Simultaneous colectomy and hepatectomy are considered safe techniques and present similar oncological results regardless of the location of the primary tumor when there are fewer than four liver metastases, since there is no increase in morbidity or decrease in survival. The development of laparoscopic techniques and materials has made the combined resection of the colon and liver a very attractive option. The aim of this study is to demonstrate the synchronous resection of the sigmoid tumor and single liver metastasis treated by purely laparoscopic colectomy and liver left lateral sectorectomy

Evaluación de aves en la laguna El Paraiso, Lima, Perú

Este estudio se realizó en la laguna El Paraíso, departamento de Lima, Perú, de abril de 1999 a abril del 2000. Tuvo como objetivos la determinación de la diversidad específi ca en aves; la densidad poblacional de las principales familias de uso cinegético y la determinación de los microhábitats más importantes para los grupos evaluados. Se reportaron 81 especies de aves las cuales pertenecen a 62 géneros y a 35 familias. En esta cifra se reportan 19 especies nuevas para el área de Paraíso; el 46% de la diversidad de aves está dada por las familias Scolopacidae (14%), Ardeidae (10%), Laridae (7%), Anatidae (5%), Charadriidae (5%) y Columbidae (5%). La familia Rallidae es la más abundante y está representada por dos especies Gallinula chloropus “polla de agua” y Fulica ardesiaca“gallareta”, siendo la primera más numerosa. Asimismo, se dan las recomendaciones para la conservación del área

The Effect Of Hydrofluoric Acid Concentration And Heat On The Bonding To Lithium Disilicate Glass Ceramic

The aim of this study was to evaluate the effects of hydrofluoric acid (HF) concentration and previous heat treatment (PHT) on the surface morphology and micro-shear bond strength (mSBS) of a lithium disilicate glass ceramic (EMX) to resin cement. One hundred four EMX specimens were randomly assigned to two groups (n=52) according to the HF concentration: 5% and 10%. A new random distribution was made according to the PHTs (n=13): control (no PHT); previously heated HF (70 °C); previously heated EMX surface (85 °C); the combination of heated HF + heated EMX surface. The etching time was set at 20 s. All EMX blocks were silanated and received a thin layer of an unfilled resin. Five resin cement cylinders were made on each EMX surface using Tygon tubes as matrices, and then stored for 24 h at 37 °C. One random etched EMX sample from each group was analyzed using field-emission scanning electron microscopy (FE-SEM). The data were subjected to two-way ANOVA and multiple comparisons were performed using the Tukey post hoc test (a=0.05). For the control groups, 5% HF showed statistically lower mSBS values when compared to 10% HF (p<0.05). PHT increased the mSBS values for 5% HF, yielding statistically similar results to non-PHT 10% HF (p<0.05). FE-SEM images showed increased glassy matrix removal when PHT was applied to HF 5%, but not to the same degree as for 10% HF. PHT has the potential to improve the bond strength of 5% HF concentration on lithium disilicate glass ceramic.27672773

Evaluación de aves en la laguna El Paraiso, Lima, Perú

This study was carried out at El Paraíso lagoon, Lima, Peru, from April 1999 to April 2000. The main goals was determinated the birds specifi c diversity, the population density of main cinegetic bird families and the determination of the most important microhabitats for the studied groups. 81 birds species (19 species are new for the area) were reported, distribuited in 62 generas and 35 families. 46% of the diversity is given for the following families: Scolopacidae (14%), Ardeidae (10%), Laridae (7%), Anatidae (5%), Charadriidae (5%) and Columbidae (5%). The Rallidae family is the most abundant and is represented for two species Gallinula chloropus“Common Moorhen” y Fulica ardesiaca“Slate-colored Coot”. It is given recommendations for the conservation of the area.Este estudio se realizó en la laguna El Paraíso, departamento de Lima, Perú, de abril de 1999 a abril del 2000. Tuvo como objetivos la determinación de la diversidad específi ca en aves; la densidad poblacional de las principales familias de uso cinegético y la determinación de los microhábitats más importantes para los grupos evaluados. Se reportaron 81 especies de aves las cuales pertenecen a 62 géneros y a 35 familias. En esta cifra se reportan 19 especies nuevas para el área de Paraíso; el 46% de la diversidad de aves está dada por las familias Scolopacidae (14%), Ardeidae (10%), Laridae (7%), Anatidae (5%), Charadriidae (5%) y Columbidae (5%). La familia Rallidae es la más abundante y está representada por dos especies Gallinula chloropus “polla de agua” y Fulica ardesiaca“gallareta”, siendo la primera más numerosa. Asimismo, se dan las recomendaciones para la conservación del área

Localized mechanics of dentin self-etching adhesive system

The bond strength of composite resins (CRs) to dentin is influenced by the interfacial microstructure of the hybrid layer (HL) and the resin tags (TAG). The contemporary self-etching primer adhesive systems overcame the inconvenient of the etch-and-rinse protocol. Studies, however, have demonstrated that HL thickness and TAG length vary according to the wetting time and additional use of acid-etching prior to self-etching primers. This study investigated the localized stress distribution in the HL and the dentin/adhesive interface. Two HL thicknesses (3 or 6 µm), two TAG lengths (13 or 17 µm) and two loading conditions (perpendicular and oblique-25º) were investigated by the finite element (FE) analysis. Five two-dimensional FE models (M) of a dentin specimen restored with CR (38 x 64 µm) were constructed: M1 - no HL and no TAG; M2 - 3 µm of HL and 13 µm of TAG; M3 - 3 µm of HL and 17 µm of TAG; M4 - 6 µm of HL and 13 µm of TAG; and M5 - 6 µm of HL and 17 µm of TAG. Two distributed loadings (L) (20N) were applied on CR surface: L1 - perpendicular, and L2 - oblique (25º). Fixed interfacial conditions were assigned on the border of the dentin specimen. Ansys 10.0 (Ansys®, Houston, PA, USA) software was used to calculate the stress fields. The peak of von Mises (sigmavM) and maximum principal stress (sigmamax) was higher in L2 than in L1. Microstructures (HL and TAG) had no effect on local stresses for L1. Decreasing HL decreased sigmavM and sigmamax in all structures for L2, but the TAG length had influence only on the peributular dentin. The thickness of HL had more influence on the sigmavM and sigmamax than TAG length. The peritubular dentin and its adjacent structures showed the highest sigmavM and sigmamax, mainly in the oblique loading

Microabrasion in tooth enamel discoloration defects: three cases with long-term follow-ups

Superficial irregularities and certain intrinsic stains on the dental enamel surfaces can be resolved by enamel microabrasion, however, treatment for such defects need to be confined to the outermost regions of the enamel surface. Dental bleaching and resin-based composite repair are also often useful for certain situations for tooth color corrections. This article presented and discussed the indications and limitations of enamel microabrasion treatment. Three case reports treated by enamel microabrasion were also presented after 11, 20 and 23 years of follow-ups224347354sem informaçã

Microabrasion in tooth enamel discoloration defects: three cases with long-term follow-ups

Superficial irregularities and certain intrinsic stains on the dental enamel surfaces can be resolved by enamel microabrasion, however, treatment for such defects need to be confined to the outermost regions of the enamel surface. Dental bleaching and resin-based composite repair are also often useful for certain situations for tooth color corrections. This article presented and discussed the indications and limitations of enamel microabrasion treatment. Three case reports treated by enamel microabrasion were also presented after 11, 20 and 23 years of follow-ups

Conservative reconstruction of the smile by orthodontic, bleaching, and restorative procedures

The following is a clinical case report of a patient whose chief complaint was the presence of generalized spacing in the maxillary anterior segment following orthodontic treatment. After meticulous clinical analyses and discussions of the clinical procedures to be adopted, dental bleaching was performed in both arches with 10% hydrogen peroxide (Opalescence Trèswhite Supreme 10% Hydrogen Peroxide - Ultradent Products, Inc., South Jordan, USA) after the conclusion and stabilization of orthodontic treatment. Then, the orthodontic appliance was removed and the diastemas in the maxillary anterior teeth were closed with Amelogen Plus (Ultradent Products, Inc., South Jordan, USA) resin composite. It was observed that the association of orthodontic, bleaching, and restorative procedures was capable of restoring dental shape, function, and esthetics, allowing the patient to smile without hesitation