Desenvolvimento de métodos construtivos e de novos materiais empregados na confecção de cartuchos de próteses de membros inferiores

The manufacture of prostheses for lower limb amputees (transfemural and transtibial) requires the preparation of a cartridge with appropriate and custom fit to the profile of each patient. The traditional process to the patients, mainly in public hospitals in Brazil, begins with the completion of a form where types of equipment, plugins, measures, levels of amputation etc. are identified. Currently, such work is carried out manually using a common metric tape and caliper of wood to take the measures of the stump, featuring a very rudimentary, and with a high degree of uncertainty geometry of the final product. To address this problem, it was necessary to act in two simultaneously and correlated directions. Originally, it was developed an integrated tool for viewing 3D CAD for transfemoral types of prostheses and transtibial called OrtoCAD I. At the same time, it was necessary to design and build a reader Mechanical equipment (sort of three-dimensional scanner simplified) able to obtain, automatically and with accuracy, the geometric information of either of the stump or the healthy leg. The methodology includes the application of concepts of reverse engineering to computationally generate the representation of the stump and/or the reverse image of the healthy member. The materials used in the manufacturing of prostheses nor always obey to a technical scientific criteria, because, if by one way it meets the criteria of resistance, by the other, it brings serious problems mainly due to excess of weight. This causes to the user various disorders due to lack of conformity. That problem was addressed with the creation of a hybrid composite material for the manufacture of cartridges of prostheses. Using the Reader Fitter and OrtoCAD, the new composite material, which aggregates the mechanical properties of strength and rigidity on important parameters such as low weight and low cost, it can be defined in its better way. Besides, it brings a reduction of up steps in the current processes of manufacturing or even the feasibility of using new processes, in the industries, in order to obtain the prostheses. In this sense, the hybridization of the composite with the combination of natural and synthetic fibers can be a viable solution to the challenges offered above

Metodologia, Sistema de Codificação e Ferramenta de software para Modelagem de Móveis Modulados

On this research we investigated how new technologies can help the process of design and manufacturing of furniture in such small manufacturers in Rio Grande do Norte state. Google SketchUp, a 3D software tool, was developed in such a way that its internal structures are opened and can be accessed using SketchUp s API for Ruby and programs written in Ruby language (plugins). Using the concepts of the so-called Group Technology and the flexibility that enables adding new functionalities to this software, it was created a Methodology for Modeling of Furniture, a Coding System and a plugin for Google s tool in order to implement the Methodology developed. As resulted, the following facilities are available: the user may create and reuse the library s models over-and-over; reports of the materials manufacturing process costs are provided and, finally, detailed drawings, getting a better integration between the furniture design and manufacturing process

Desenvolvimento de um sistema para aplicação dos conceitos da tecnologia cad3d-bim na indústria moveleira

In this work was developed an information system to apply the concepts of CAD3D-BIM technology for the design activities of the furniture industry. The development of this system was based in an architecture comprised of two modules: a web interface to management the metadata of models from furniture's library and the combination of three-dimensional CAD software with a specific plugin to access the information from this model. To develop this system was also used a Data Base Management System (DBMS) designed to storage the information from models in a hierarchical way, based on concepts of Group Technology (GT). The centralization of information in a single database allows the automatic availability of any changes to all participants involved in a particular project when it‟s happens. Each module from system has its own connection to this database. Finally was developed a prototype from a 3D virtual environment to help create Virtual Reality projects in the web. A study from available technologies to create 3D web applications for execution in websites was done to support this development. The interconnection between modules and the database developed allowed the assembly of a system architecture to support the construction and exhibition of projects of the furniture industry in accordance with the concepts proposed by BIM (Building Information Modeling), using as object of study the furniture industry of state of Rio Grande do Norte

Otimização do fresamento de roscas internas com a técnica de interpolação helicoidal

In machining of internal threads, dedicated tools, known as taps, are needed for each profile type, diameter, and low cutting speed values are used when compared to main machining processes. This restriction in the cutting speed is associated with the difficulty of synchronizing the tool s rotation speed and feed velocity in the process. This fact restricts the flexibility and makes machining lead times longer when manufacturing of components with threads is required. An alternative to the constraints imposed by the tap is the thread milling with helical interpolation technique. The technique is the fusion of two movements: rotation and helical interpolation. The tools may have different configurations: a single edge or multiple edges (axial, radial or both). However, thread milling with helical interpolation technique is relatively new and there are limited studies on the subject, a fact which promotes challenges to its wide application in the manufacturing shop floor. The objective of this research is determine the performance of different types of tools in the thread milling with helical interpolation technique using hardened steel workpieces. In this sense, four tool configurations were used for threading milling in AISI 4340 quenched and tempered steel (40 HRC). The results showed that climb cut promoted a greater number of machined threads, regardless of tool configuration. The upcut milling causes chippings in cutting edge, while the climb cutting promotes abrasive wear. Another important point is that increase in hole diameter by tool diameter ratio increases tool lifetime

Diagnóstico regional do processo de queijo coalho comercializado em Natal/RN

Coalho cheese is a typical product of the Northeastern Brazil, which is consumed both raw and cooked. The present work aimed to study the characteristics of artisanal and industrial processes in the production of coalho cheese sold in Natal / RN in order to evaluate its quality and consumer s profile. Four artisanal cheeses plants were monitored and a questionnaire was sent to different cheese industries. Besides this, eight cheese samples (four artisanal and four industrial) were evaluated in regard to the microbiological quality, physical-chemical and sensory attributes. The sensory acceptance was evaluated by using 108 non-trained panelists by using the hedonic scale. The consumer s profile survey was applied to 400 consumers of coalho cheese. The lack of hygiene control was detected at the artisanal cheese production, which uses raw milk as its raw material. Research has shown that the industrialized cheeses are made from pasteurized milk provided by their own production or by a third party, as observed in cheese making dairies. In general, the results indicate variation in the manufacturing process of coalho cheese, which results in the lack of product standardization. Regarding the physical-chemical analysis, most artisanal and industrial samples presented moisture content between 36 and 40 %, classified as medium moisture cheese, which is the only parameter that showed no significant difference (p>0.05). However, the water activity (Aw), pH and acidity results differed significantly. All artisanal samples showed coliform contamination at 35 °C, which confirms the poor hygienic conditions. In regard to coliforms at 45 °C, 75 % of artisanal coalho cheese samples had value higher than 103 MPN / g, a value above the lawful limits determined by RDC nº 12. Fifty percent of industrial coalho cheese samples showed coagulase-positive Staphylococcus values above the limit allowed by the RDC nº 12, indicating poor handling. The sensory evaluation revealed that the taste was the only parameter that showed significant difference, and this difference was only between two industrial brands. The consumer s survey showed that the coalho cheese flavor is the most important reason for buying this kind of cheese. Although coalho cheese is mainly bought in supermarkets, open street markets and country shops are still important selling points. It is concluded that there is no coalho cheese standardization in the RN state, which leads to variations in physical-chemical and sensory attributes. Moreover, it is necessary greater hygiene control in the production and handling procedures of coalho cheese.

Efeito do ácido lático sobre as características microbiológicas, físico-químicas e sensoriais na carne do sol

The dried beef is a food traditionally eaten by Northeastern and has an extensive trade in the city of Natal-RN. It is usually produced in an empirical manner, without any standardization in production. Characterized as partially dehydrated meat product, so that the activity of water present is not sufficient to prevent microbial growth, degradation or the production of microbial toxins. The guarantee that the market dried beef is to provide a quality product hygienic, microbiological, physicochemical and sensory stable and adequate for the safety and consumer satisfaction, which has been increasingly attracted to food with natural preservatives. Thus, the meat industries are replacing the current seasonings and natural preservatives for similar, with it without affecting the shelf life of products. Lactic acid has been used to meet these requirements. In this sense, this study aimed to evaluate the effect of lactic acid on the physico-chemical, microbiological and sensory, besides knowing the consumer profile of dried meat of the City of Natal / RN. The results demonstrated that the use of lactic acid in concentrations of 1% and 2% during the processing of dried meat, had statistically significant effect (p < 0.05) on the physico-chemical (pH and water activity) and consequently reduced the microbial count does not alter the taste of the new product developed. Regarding the results on the consumer profile, it was found that the majority of respondents (71.75%) did not observe the presence of the stamp of the Federal Inspection Service (SIF) to buy this meat food that 81.55% of consumers check the hygiene conditions of the site and handlers, however, a large proportion of respondents not concerned with the guarantee of origin of typical regional products featuring a hazard to food safety for consumers of the city of Natal-RN

Haptoglobin polymorphism correlated with coronary artery disease

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência da técnica de fabricação e dos materiais sobre o ajuste da interface pilar/implante em infraestruturas implantossuportadas

The aim of this study was to compare the misfit vertical, horizontal and passivity of zirconia and cobalt-chromium frameworks fabricated for CAD / CAM technology and conventional method of casting. Sixteen frameworks in one-piece, were obtained from a metallic matrix containing three Brånemark compatible implants with regular platform (Titamax Cortical Ti, Neodent). Eight frameworks were fabricated by CAD / CAM system (NeoShape, Neodent): four in zirconia (ZirCAD) and four cobalt-chromium (CoCrcad). Eight other frameworks were obtained by conventional casting method: four cobalt-chromium with UCLA abutment premachined Co-Cr (CoCrUCci) and four cobalt-chromium with UCLA abutment castable (CoCrUCc). The fit vertical, horizontal and passivity by one-screw test were measured using scanning electron microscopy with magnification of 250x. Initially evaluated the passivity by one-screw test and subsequently to assess the vertical and horizontal misfit, tightened all the screws with a torque of 20 Ncm. Mean, standard deviation, minimum and maximum values were calculated for each group. Measurements of horizontal misfit were transformed into cumulative frequency for categorization of the variable and the group later comparison groups. To evaluate the existence of quantitative differences between the groups tested for vertical misfit and passivity, we used the Kruskal-Wallis test. The Mann-Whitney test was used to compare group to group statistical differences (p <0.05). Were observed the respective mean and standard deviation for vertical misfit and passivity in micrometers: ZirCAD (5.9 ± 3.6, 107.2 ± 36), CoCrcad (1.2 ± 2.2, 107.5 ± 26 ), CoCrUCci (11.8 ± 9.8, 124.7 ± 74), CoCrUCc (12.9 ± 11.0, 108.8 ± 85). There were statistical differences in measures of vertical misfit (p = 0.000). The Mann-Whitney test revealed statistical differences (p <0.05) between all groups except between CoCrUCci and CoCrUCc (p = 0.619). No statistical difference was observed for the passivity. In relation to the horizontal misfit groups ZirCAD and CoCrcad did not show best values in relation to CoCrUCci and CoCrUCc. Based on the results it can be concluded that frameworks fabricated by CAD / CAM technology had better values of vertical fit than those manufactured by the casting method, nevertheless, the passivity was not influenced by manufacturing technique and material used. The horizontal fit obtained by frameworks manufactured by CAD / CAM was not superior to those manufactured by casting. A lower variability in vertical adjustment and passivity was observed when frameworks were fabricated by CAD / CAM technology

Effect of soluble fiber on hypertriglyceridemia and immune profile in HIV-positive individuals undergoing highly active antiretroviral therapy

The advent of highly active antiretroviral therapy (HAART), since 1996, represented a profound impact on the natural history of HIV-infection by promoting important and sustainable viral replication suppression and increasing survival and quality of life among seropositive patients. Nonetheless, antiretroviral therapy has been observed to be accompanied by metabolic alterations such as dyslipidemia, especially hypertriglyceridemia, insulin resistance, hyperglycemia and lipodystrophy (body fat redistribution). Epidemiological studies have demonstrated a correlation between high triglyceride (TG) levels and higher incidence of coronary artery disease (CAD). Some investigators suggest dietary intervention as part of hyperlipidemia treatment, including an increase in soluble fiber intake (10-25g/day). Whereas some studies have demonstrated that both cholesterol and serum triglyceride levels decrease with the use of food fiber, others have shown just a serum triglyceride decrease, and others failed to observe any alteration in lipid metabolism. The purpose of this study was to assess the effect of soluble fiber (R) (partially hydrolyzed guar gum) supplementation on hypertriglyceridemia and immune profile in HIVpositive individuals on HAART. Nineteen HIV-positive individuals with hypertriglyceridemia (serum levels >= 150 to < 500mg/dl) were studied. of these individuals, 63.16% were males and 36.84% females, with mean age of 43.52 +/- 9.22 years. These individuals had been on the same HAART regimen for at least six months, had no change in therapy during the study and received 20g/day of soluble fiber for four months at pre-established times. Clinical-nutritional, biochemical (total proteins, albumin, globulin, total cholesterol, LDL-c, HDL-c, TG, TG/HDL-c and LDLc/HDL-c), hematimetric (hemoglobin, hematocrit and total lymphocytes), and immunologic (lymphocytes T CD4(+), T CD8(+); T CD4(+)/CD8(+) ratio, viral load, TNF-alpha and IL-6) parameters were assessed in all patients at three time points (M0: pretreatment, M1: 30 days, and M2: four months after intervention). Significance level was set at 5% for all data statistically analyzed. Serum TG and TG/HDL-c ratio reduction was observed at all time points, but statistical significance was found just at M0 and M2. The remaining biochemical, hematimetric and immunologic parameters (lymphocytes T CD4(+), T CD8(+); T CD4(+)/ CD8(+) ratio, and viral load) showed no significant difference at all times. Regarding serum cytokines, TNF-alpha and IL-6 significantly decreased between M0 and M2, and only IL-6 reduced between M1 and M2. The data collected show that dietary and anthropometric parameters remained unchanged excluding potential confounding factors related with the effect of fiber supplementation on serum TG, TNF-alpha and IL-6. Thus, soluble fiber (R) contributed to an important reduction in hypertriglyceridemia and in the serum levels of the proinflammatory cytokines TNF-alpha and IL-6 in HIV-seropositive individuals on HAART. In addition, soluble fiber (R) might have minimized the process of atherosclerosis in these individuals, given that elevated serum levels of TG, TNF-alpha and IL-6 have been associated with the development of these lesions.

Thymic lymphomas in Wistar rats exposed to N-methyl-N-nitrosourea (MNU)

The Brazilian Agency for the Environment (IBAMA) recently adopted an alternative medium-term multiple-organ assay system with the Wistar rat strain for detection of the carcinogenic potential of pesticides. Originally, this initiation-promotion protocol was established in Japan with the isogenic Fischer 344 male rat. Among the initiating agents used in that assay, N-methyl-N-nitrosourea (MNU) rapidly induces malignant lymphoma and leukemia and early mortality of rats from different strains. This study was developed to evaluate whether the outbred Wistar rats are also similarly susceptible to MNU. Particularly, it aimed to evaluate the dose-response relationship and to register the MNUinduced pre-neoplasia and neoplasia that may develop in the lympho-hematopoietic system (LHS) of the Wistar rat within a medium-term period. Four groups of male Wistar rats were treated during 2 weeks with vehicle or with MNU (80, 160 or 240 mg/kg body weight, i.p.). After sacrifice at the 12th and 20th weeks, the thymus, spleen, bone marrow, cervical and mesenteric lymph nodes and liver were collected for analysis. At the 20th week, LHS malignant tumors and benign vascular tumors occurred only in the high- and intermediate-dose MNU-treated animals. Four animals treated with 240 mg/kg developed diffuse thymic lymphomas; two others, treated respectively with 240 mg/kg and 160 mg/kg, developed spleen hemangiomas. The present observations indicate that the Wistar strain is as susceptible as other strains to the early development of MNU-induced LHS (pre)neoplasia. Therefore, this strain seems suitable to be used as test system in bioassay protocols that adopt MNU as an initiating agent for carcinogenesis.

Chlorhexidine induces DNA damage in rat peripheral leukocytes and oral mucosal cells

Objective: Chlorhexidine digluconate is widely used in dental practice for decreasing plaque control, controlling gingivitis and disinfecting root canals. However, the undesirable effects of chlorhexidine digluconate regarding its genotoxicity are conflicting in the literature. Thus, the aim of this study was to investigate the genotoxicity of chlorhexidine digluconate in rat peripheral blood and oral mucosal cells by the single cell gel (comet) assay and micronucleus assay.Methods: Thirty male Wistar rats were distributed into three groups: negative control; experimental group orally treated with 0.5 ml of 0.12% chlorhexidine digluconate, twice daily, during 8 days; and positive control, which received 4-nitroquinoline 1-oxide at 0.5 g/l by drinking water.Results: A statistically significant increase of DNA damage was observed in leukocytes and oral mucosal cells of the chlorhexidine digluconate treated group, as assessed by the comet assay. However, no increase of micronucleated cells was detected in reticulocytes from peripheral blood cells.Conclusions: Taken together, the data indicate that chlorhexidine digluconate is able to induce primary DNA damage in leukocytes and in oral mucosal cells, but no chromosome breakage or loss in erythrocytes.

Metabolic syndrome and dietary components are associated with coronary artery disease risk score in free-living adults: a cross-sectional study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Histological and radiological changes in cranial bone in the presence of bone wax

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

Influence of Cusp Inclination on Stress Distribution in Implant-Supported Prostheses. A Three-Dimensional Finite Element Analysis

Purpose: The aim of this study was to assess the influence of cusp inclination on stress distribution in implant-supported prostheses by 3D finite element method.Materials and Methods: Three-dimensional models were created to simulate a mandibular bone section with an implant (3.75 mm diameter x 10 mm length) and crown by means of a 3D scanner and 3D CAD software. A screw-retained single crown was simulated using three cusp inclinations (10 degrees, 20 degrees, 30 degrees). The 3D models (model 10d, model 20d, and model 30d) were transferred to the finite element program NeiNastran 9.0 to generate a mesh and perform the stress analysis. An oblique load of 200 N was applied on the internal vestibular face of the metal ceramic crown.Results: The results were visualized by means of von Mises stress maps. Maximum stress concentration was located at the point of application. The implant showed higher stress values in model 30d (160.68 MPa). Cortical bone showed higher stress values in model 10d (28.23 MPa).Conclusion: Stresses on the implant and implant/abutment interface increased with increasing cusp inclination, and stresses on the cortical bone decreased with increasing cusp inclination.

Short-term evaluation of the pulpo-dentin complex response to a resin-modified glass-ionomer cement and a bonding agent applied in deep cavities

Objectives. To evaluate the response of the pulpo-dentin complex following application of a resin-modified glass-ionomer cement or an adhesive system in deep cavities performed in human teeth.Methods. Deep class V cavities were prepared on the buccal surface of 26 premolars. In Group I the cavity walls (dentin) and enamel were conditioned with 32% phosphoric acid and the dentin adhesive system One Step (Bisco, Inc., Itasca, IL, USA) was applied. In Groups 2 and 3, before total etching and application of bonding agent, the cavity floor was lined with the resin-modified glass-ionomer cement-Vitrebond (3M ESPE Dental Products Division, St. Paul, MN, USA) or the calcium hydroxide cement-Dycal (control group, Dentsply, Mildford, DE, USA), respectively. The cavities were restored using light-cured Z-100 composite resin (3M ESPE). The teeth were extracted between 5 and 30 days and prepared for microscopic assessment. Serial sections were stained with H/E, Masson's trichrome, and Brown and Brenn techniques.Results. In Group 1, the inflammatory response was more evident than in Groups 2 and 3. Diffusion of dental material components across dentinal tubules was observed only in Group 1, in which the intensity of the pulp response increased as the remaining dentin thickness decreased. Bacteria were evidenced in the lateral walls of two samples (Group 2) which exhibited no inflammatory response or tissue disorganization.Conclusions. Based on the experimental conditions, it was concluded total acid etching followed by application of One Step bonding agent cannot be recommended as adequate procedures. In this clinical condition the cavity walls should be lined with a biocompatible dental material, such as Vitrebond or Dycal. 2003 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.