SCANNING ELECTRON-MICROSCOPY OF THE RHODNIUS-NEGLECTUS (HEMIPTERA) LABIAL SALIVARY-GLANDS AFTER STARVATION

Labial salivary glands are found in the majority of insects. They are relatively large, extend back into the thorax, and in Rhodnius, they are cherry red in color due to a pigment derived from traces of hemoglobin absorbed form the gut. In most insects they are acinous shaped, with long excretion channels that present differentiated regions which from salivary reservoirs. The glands may be relatively simple or complexly branched and convoluted. In Rhodnius they are described as being unilobed with no traces of division. The main duct leaves the gland at its anterior extremity. The acini have different kinds of cells but all of them are seen as sources of secretion. Our material has a different shape due to the fact that the animals spent 20 days under starvation conditions. New data are also obtained through treatment with collagenase and HCl. The importance of the study of these glands lies in the fact that it will further understanding of the transmission of Chagas' disease.

Influence of natural weathering on colour stability of materials used for facial prosthesis

Colour stability of resin and silicone is an important factor for longevity of facial prostheses. The aim of this study was to evaluate the colour stability of resins and silicone for facial prostheses. Three brands of acrylic resin and one of facial silicone were evaluated considering pigment incorporation for the colourless materials. Ten samples of each material were fabricated and submitted to measurements of chromatic alteration initially and after 90 and 180 days of weathering natural through visual analysis and spectrophotometry. Data were evaluated by ANOVA and Tukey test (p < 0.05). Statistically significant colour alteration was observed among some materials regardless of the period. The materials did not present a statistical difference between 90 and 180 days except for the pigmented heat-polymerized resin. The colour difference between pigmented Silastic MDX4-4210 and colourless Silastic was statistically significant (p < 0.01) in both periods as well as between pigmented and colourless heat-polymerized resin, and between the resins Rapidaflex and Lentaflex. The visual method demonstrated colour alteration in all materials evaluated during the first 90 days of ageing. All materials exhibited colour alteration due to exposure to environment. © 2012 Informa UK, Ltd.

A priori reformulations for joint rolling-horizon scheduling of materials processing and lot-sizing problem

In many production processes, a key material is prepared and then transformed into different final products. The lot sizing decisions concern not only the production of final products, but also that of material preparation in order to take account of their sequence-dependent setup costs and times. The amount of research in recent years indicates the relevance of this problem in various industrial settings. In this paper, facility location reformulation and strengthening constraints are newly applied to a previous lot-sizing model in order to improve solution quality and computing time. Three alternative metaheuristics are used to fix the setup variables, resulting in much improved performance over previous research, especially regarding the use of the metaheuristics for larger instances. © 2013 Elsevier Ltd. All rights reserved.

Scanning Electron Microscopy of the Tongue, Pharynx, and Larynx of Rats Exposed to Cigarette Smoke

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Scanning Electron Microscopy of Male Terminalia and Its Application to Species Recognition and Phylogenetic Reconstruction in the Drosophila saltans Group

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo comparativo de filmes de corantes fenotiazínicos na superfície de eletrodo de carbono vítreo e adsorvidos em titânio fosfatado e suas aplicações eletroanalíticas

Pós-graduação em Ciência dos Materiais - FEIS

Use of Sludge as Ceramic Materials

Nowadays, with increase amounts of sludge derived from the treatment of domestic sewage put pressure into research on systems for the adequate use of these materials. The aim of the present work is to study the use of sludge ash, from sintering and calcinated process, as a raw material for the ceramic industry. Using the sewage sludge ashes as ceramic raw material there will be no contamination of soil and underground water. Metals and toxic compounds like Al, Fe, Ba, Cr, Cu, Mn and Zn oxides were analyzed and characterized by X-ray fluorescence (XRF), scanning electron microscopy (SEM) and plasma emission spectroscopy (ICP-OES). The leached material was chemically analyzed where the integration of oxides into the ceramic matrix of sludge ash was observed. Residual decomposition was analyzed by TG, DTG and DTA curves.

Effect of short training on vaginal fluid microscopy (wet mount) learning

Objective: Is it feasible to learn the basics of wet mount microscopy of vaginal fluid in 10 hours?Materials and Methods: This is a pilot project wherein 6 students with different grades of education were invited for being tested on their ability to read wet mount microscopic slides before and after 10 hours of hands-on training. Microscopy was performed according to a standard protocol (Femicare, Tienen, Belgium). Before and after training, all students had to evaluate a different set of 50 digital slides. Different diagnoses and microscopic patterns had to be scored. kappa indices were calculated compared with the expert reading. Results: All readers improved their mean scores significantly, especially for the most important types of altered flora (p < .0001). The mean increase in reading concordance (kappa from 0.64 to 0.75) of 1 student with a solid previous experience with microscopy did not reach statistical significance, but the remaining 5 students all improved their scores from poor performance (all kappa < 0.20) to moderate (kappa = 0.53, n = 1) to good (kappa > 0.61, n = 4) concordance. Reading quality improved and reached fair to good concordance on all microscopic items studied, except for the detection of parabasal cells and cytolytic flora. Conclusions: Although further improvement is still possible, a short training course of 10 hours enables vast improvement on wet mount microscopy accuracy and results in fair to good concordance of the most important variables of the vaginal flora compared to a reference reader.

Zirconium-methacrylate oxoclusters as new hybrid materials for the modification of epoxy systems

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Characterization of a wollastonite glass-ceramic material prepared using sugar cane bagasse ash (SCBA) as one of the raw materials

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of the bleached human enamel by scanning electron microscopy

Since bleaching has become a popular procedure, the effect of peroxides on dental hard tissues is of great interest in research. Purpose: The aim of this in vitro study was to perform a qualitative analysis of the human enamel after the application of in-office bleaching agents, using Scanning Electron Microscopy (SEM). Materials and Methods: Twenty intact human third molars extracted for orthodontic reasons were randomly divided into four groups (n=5) treated as follows: G1- storage in artificial saliva (control group); G2- four 30-minute applications of 35% carbamide peroxide (total exposure: 2h); G3- four 2-hour exposures to 35% carbamide peroxide (total exposure: 8h); G4- two applications of 35% hydrogen peroxide, which was light-activated with halogen lamp at 700mW/cm2 during 7min and remained in contact with enamel for 20min (total exposure: 40min). All bleaching treatments adopted in this study followed the application protocols advised by manufacturers. Evaluation of groups submitted to 35% carbamide peroxide was carried out after two time intervals (30 minutes and 2 hours per session), following the extreme situations recommended by the manufacturer. Specimens were prepared for SEM analysis performing gold sputter coating under vacuum and were examined using 15kV at 500x and 2000x magnification. Results: Morphological alterations on the enamel surface were similarly detected after bleaching with either 35% carbamide peroxide or 35% hydrogen peroxide. Surface porosities were characteristic of an erosive process that took place on human enamel. Depression areas, including the formation of craters, and exposure of enamel rods could also be detected. Conclusion: Bleaching effects on enamel morphology were randomly distributed throughout enamel surface and various degrees of enamel damage could be noticed. Clinical significance: In-office bleaching materials may adversely affect enamel morphology and therefore should be used with caution.

Al-based anodic oxide films structure observation using field emission gun scanning electron microscopy

In the present work, the anodic oxide films of Al, Al-Cu 4.5% and Al-Si 6.5% alloys are formed using direct and pulse current. In the case of Al-Cu and Al-Si alloys, the electrolyte used contains sulfuric acid and oxalic acid, meanwhile for Al the electrolyte contains sulfuric acid only. Al-Cu alloy was submitted to a heat treatment in order to decrease the effect of inter metallic phase theta upon the anodic film structure. Fractured samples were observed using a field emission gun scanning electron microscope JSM-6330F at (LME)/Brazilian Synchrotron Light Laboratory (LNLS), Campinas, SP, Brazil. The oxide film images enable evaluation of the pore size and form with a resolution similar to the transmission electron microscope (TEM) resolution. It is also observed that the anodizing process using pulse current produces an irregular structure of pore walls, and by direct cur-rent it is produced a rectilinear pore wall. (c) 2005 Elsevier B.V. All rights reserved.

Blends of poly(3-hydroxybutyrate) and poly(p-dioxanone): miscibility, thermal stability and biocompatibility

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)