107 resultados para Technological development

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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We describe the development of a label free method to analyze the interactions between Ca(2+) and the porcine S100A12 protein immobilized on polyvinyl butyral (PVB). The modified gold electrodes were characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and surface plasmon resonance (SPR) techniques. SEM analyses of PVB and PVB-S100A12 showed a heterogeneous distribution of PVB spherules on gold surface. EIS and CV measurements have shown that redox probe reactions on the modified gold electrodes were partially blocked due the adsorption of PVB-S100A12, and confirm the existence of a positive response of the immobilized S100Al2 to the presence of calcium ions. The biosensor exhibited a wide linear response to Ca(2+) concentrations ranging from 12.5 to 200 mM. The PVB-S100A12 seems to be bound to the gold electrode surface by physical adsorption: we observed an increase of 1184.32 m degrees in the SPR angle after the adsorption of the protein on the PVB surface (in an indication that 9.84 ng of S100A12 are adsorbed per mm(2) of the Au-PVB electrode), followed by a further increase of 581.66 m degrees after attachment of the Ca(2+) ions. In addition, no SPR response is obtained for non-specific ions. These studies might be useful as a platform for the design of new reusable and sensitive biosensing devices that could find use in the clinical applications. (C) 2010 Elsevier B.V. All rights reserved.

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Internal tapered connections were developed to improve biomechanical properties and to reduce mechanical problems found in other implant connection systems. The purpose of this study was to evaluate the effects of mechanical loading and repeated insertion/removal cycles on the torque loss of abutments with internal tapered connections. Sixty-eight conical implants and 68 abutments of two types were used. They were divided into four groups: groups 1 and 3 received solid abutments, and groups 2 and 4 received two-piece abutments. In groups 1 and 2, abutments were simply installed and uninstalled; torque-in and torque-out values were measured. In groups 3 and 4, abutments were installed, mechanically loaded and uninstalled; torque-in and torque-out values were measured. Under mechanical loading, two-piece abutments were frictionally locked into the implant; thus, data of group 4 were catalogued under two subgroups (4a: torque-out value necessary to loosen the fixation screw; 4b: torque-out value necessary to remove the abutment from the implant). Ten insertion/removal cycles were performed for every implant/abutment assembly. Data were analyzed with a mixed linear model (P <= 0.05). Torque loss was higher in groups 4a and 2 (over 30% loss), followed by group 1 (10.5% loss), group 3 (5.4% loss) and group 4b (39% torque gain). All the results were significantly different. As the number of insertion/removal cycles increased, removal torques tended to be lower. It was concluded that mechanical loading increased removal torque of loaded abutments in comparison with unloaded abutments, and removal torque values tended to decrease as the number of insertion/removal cycles increased. To cite this article:Ricciardi Coppede A, de Mattos MdaGC, Rodrigues RCS, Ribeiro RF. Effect of repeated torque/mechanical loading cycles on two different abutment types in implants with internal tapered connections: an in vitro study.Clin. Oral Impl. Res. 20, 2009; 624-632.doi: 10.1111/j.1600-0501.2008.01690.x.

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This study assessed the antimicrobial activity of a new bioactive glass-ceramic (Biosilicate (R)) against anaerobic, microaerophilic, and facultative anaerobic microorganisms. Evaluation of the antimicrobial activity was carried out by three methods, namely agar diffusion, direct contact, and minimal inhibitory concentration (MIC). For the agar diffusion technique, bio glass-ceramic activity was observed against various microorganisms, with inhibition haloes ranging from 9.0 +/- 1.0 to 22.3 +/- 2.1 mm. For the direct contact technique, Biosilicate (R) displayed activity against all the microorganisms, except for S. aureus. In the first 10 min of contact between the microorganisms and Biosilicate (R), there was a drastic reduction in the number of viable cells. Confirming the latter results, MIC showed that the Biosilicate (R) inhibited the growth of microorganisms, with variations between <= 2.5 and 20 mg/ml. The lowest MIC values (7.5 to <= 2.5 mg/ml) were obtained for oral microorganisms. In conclusion, Biosilicate (R) exhibits a wide spectrum of antimicrobial properties, including anaerobic bacteria.

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Background: Diabetes and periodontitis produce a protein discharge that can be reflected in saliva. This study evaluates the salivary concentrations of interleukin (IL)-6, matrix metalloproteinase (MMP)-8, and osteoprotegerin (OPG) in patients with periodontitis with type 2 diabetes. Methods: Whole saliva samples were obtained from 90 subjects who were divided into four groups: healthy (control; n = 22), untreated periodontitis (UPD; n = 24), diabetes mellitus (DM; n = 20), and UPD + DM (n = 24) groups. Clinical and metabolic data were recorded. Salivary IL-6, MMP-8, and OPG concentrations were determined by a standard enzyme-linked immunosorbent assay. Results: The UPD and UPD + DM groups exhibited higher salivary IL-6 than the control and DM groups (P <0.01). The salivary MMP-8 concentrations in all diseased groups (UPD, DM, and UPD + DM) were higher than in the control group (P <0.01). The salivary OPG concentrations in the DM group were higher than in the UPD and control groups (P<0.05). In the UPD + DM group, salivary IL-6 was correlated with glycated hemoglobin (HbA1c) levels (r = 0.60; P<0.05). The regression analysis indicated that the number of remaining teeth, clinical attachment level, and IL-6 might have influenced the HbA1c levels in patients with diabetes. Conclusions: Salivary 1L-6 concentrations were elevated in patients with periodontitis with or without diabetes. Salivary MMP-8 and OPG concentrations were elevated regardless of periodontal inflammation in patients with diabetes. Therefore, periodontitis and diabetes are conditions that may interfere with protein expression and should be considered when using saliva for diagnoses. J Periodontol 2010;81:384-391.

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Introduction: The objective of this study was to investigate the expression of matrix metalloproteinases (MM Ps) in apical periodontitis and during the periapical healing phase after root canal treatment. Methods: Apical periodontitis was induced in dog teeth, and root canal treatment was performed in a single visit or by using an additional calcium hydroxide root canal dressing. One hundred eighty days after treatment the presence of inflammation was examined, and tissues were stained to detect bacteria. Bacterial status was correlated to the degree of tissue organization, and to further investigate molecules involved in this process, tissues were stained for MMP-1, MMP-2, MMP-8, and MMP-9. Data were analyzed by using one-way analysis of variance followed by Tukey test or Kruskal-Wallis followed by Dunn test. Results: Teeth with apical periodontitis that had root canal therapy performed in a single visit presented an intense inflammatory cell infiltrate. Periapical tissue was extremely disorganized, and this was correlated with the presence of bacteria. Higher MMP expression was evident, similar to teeth with untreated apical periodontitis. In contrast, teeth with apical periodontitis submitted to root canal treatment with calcium hydroxide presented a lower inflammatory cell infiltrate. This group had moderately organized connective tissue, lower prevalence of bacteria, and lower number of MMP-positive cells, similar to healthy teeth submitted to treatment. Conclusions: Teeth treated with calcium hydroxide root canal dressing exhibited a lower percentage of bacterial contamination, a lower MMP expression, and a more organized extracellular matrix, unlike those treated in a single visit. This suggests that calcium hydroxide might be beneficial in tissue repair processes. (J Endod 2010;36:231-237)

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Objective: Using checkerboard DNA-DNA hybridisation (CDDH) assay, this randomised clinical study evaluated the contamination of metallic brackets by four cariogenic bacterial strains (Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei and Lactobacillus acidophilus) and the efficacy of 0.12% chlorhexidine gluconate (CHX) mouthwashes in reducing bacterial contamination. Methods: Thirty-nine 11-33-year-old patients under treatment with fixed orthodontic appliances were enrolled in the study and had 2 new metallic brackets bonded to premolars. Nineteen patients used a 0.12% CHX mouthwash (Periogard (R)) and 20 patients used a placebo mouthwash (control) twice a week. After 30 days, the brackets were removed and samples were obtained for analysis by CDDH. Data were analysed statistically by the Kruskal-Wallis test (alpha = 0.05) using the SAS software. Results: S. mutans, S. sobrinus, L. casei and L. acidophilus were detected in 100% of the samples from both groups. However, brackets of the control group were more heavily contaminated by S. mutans and S. sobrinus (P < 0.01). In the experimental group, although all counts decreased after rinsing with the chlorhexidine solution, there was significant difference only for S. mutans (P = 0.03). Conclusions: The use of 0.12% chlorhexidine gluconate mouthwashes can be useful in clinical practice to reduce the levels of cariogenic microorganisms in patients under treatment with fixed orthodontic appliances. (C) 2011 Elsevier Ltd. All rights reserved.

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Aims: To assess the prevalence of primary headaches (HA) in adults with temporomandibular disorders (TMD) who were assessed in a specialty orofacial pain clinic, as well as in controls without TMD. Methods: The sample consisted of 158 individuals with TMD seen at a university-based specialty clinic, as well as 68 controls. The Research Diagnostic Criteria for TMD were used to diagnose the TMD patients. HAs were assessed using a structured interview and classified according to the Second Edition of the International Classification for Headache Disorders. Data were analyzed by chi-square tests with a significance level of 5% and odds ratio (OR) tests with a 95% confidence interval (CI). Results: HAs occurred in 45.6% of the control group (30.9% had migraine and 14.7% had tension-type headache [TTH]) and in 85.5% of individuals with TMD. Among individuals with TMD, migraine was the most prevalent primary HA (55.3%), followed by TTH (30.2%); 14.5% had no HA. In contrast to controls, the odds ratio (OR) for HA in those with TMD was 7.05 (95% confidence interval [CI] = 3.65-13.61; P = .000), for migraine, the OR was 2.76 (95% CI = 1.50-5.06; P = .001), and for TTH, the OR was 2.51 (95% CI = 1.18-5.35; P = .014). Myofascial pain/arthralgia was the most common TMD diagnosis (53.2%). The presence of HA or specific HAs was not associated with the time since the onset of TMD (P = .714). However, migraine frequency was positively associated with TMD pain severity (P = .000). Conclusion: TMD was associated with increased primary HA prevalence rates. Migraine was the most common primary HA diagnosis in individuals with TMD. J OROFAC PAIN 2010;24:287-292

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Purpose. To describe the occurrence of self-reported problems of accessibility to health services used by persons with disabilities in terms of social and health services variables. Methods. We performed a cross-sectional household survey designed to assess problems with accessibility to health services faced by persons with disabilities. We interviewed 333 persons in Sao Paulo city, in 2007. Variables related to the presence of accessibility problems, disabilities, gender, age, family head income, ethnicity, use of health services and others were analysed using frequencies, percentages, chi(2)-test, ANOVA and Poisson regression models. Results. 15.92% of the interviewed persons reported problems with accessibility to health services. Persons having multiple (prevalence ratios; PR = 2.91) or mobility disability (PR = 6.46) had more problems with accessibility than persons with hearing disability. Persons younger than 78 years old had more problems with accessibility; those who needed help to go to the health service (PR = 3.01) also. Conclusions. Persons with multiple or mobility disability, younger than 78 years, and those who needed help of others to go to the health service were more likely to have problems with accessibility to health services. This information could be one of the first steps to the management and/or planning of appropriate health services for persons with disabilities.

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Objectives. To investigate health self-assessment and to estimate the prevalence of chronic diseases and recent illnesses in people with and without physical disabilities (PD) in the state of Sao Paulo, southeastern Brazil. Study design. A Cross-sectional study comprising two population-based health surveys conducted in 2002 and 2003. Methods. A total of 8317 persons (165 with PD) were interviewed in the two studies. Variables concerning to health self-assessment; chronic disease and recent illness were compared in the people with and without PD. Negative binomial regression was used in the analysis. Results. Subjects with PD more often assessed their health as poor/very poor compared to non-disabled ones. They reported more illnesses in the 15 days prior to interview as well as more chronic diseases (skin conditions, anaemia, chronic kidney disease, stroke, depression/anxiety, migraine/headache, pulmonary diseases, hypertension, diabetes, arthritis/arthrosis/rheumatic conditions and heart disease). This higher disease prevalence can be either attributed to disability itself or be associated to gender, age and schooling. Conclusions. Subjects with PD had more recent illnesses and chronic diseases and poorer health self-assessment than non-disabled ones. Age, gender, schooling and disability have individual roles in disease development among disabled people.

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The objective of this paper was to assess sex and socioeconomic inequalities in lung cancer mortality in two major cities of Europe and South America. Official information on mortality and population allowed the estimation of sex- and age-specific death rates for Barcelona, Spain and Sao Paulo, Brazil (1995-2003). Mortality trends and levels were independently assessed for each city and subsequently compared. Rate ratios assessed by Poisson regression analysis addressed hypotheses of association between the outcome and socioeconomic covariates (human development index, unemployment and schooling) at the inner-city area level. Barcelona had a higher mortality in men (76.9/100000 inhabitants) than Sao Paulo (38.2/100 000 inhabitants); although rates were decreasing for the former (-2%/year) and levelled-off for the [after. Mortality in women ranked similarly (9.1 for Barcelona, 11.5 for Sao Paulo); with an increasing trend for women aged 35-64 years (+ 7.7%/year in Barcelona and + 2.4%/year in Sao Paulo). The socioeconomic gradient of mortality in men was negative for Barcelona and positive for Sao Paulo; for women, the socioeconomic gradient was positive in both cities. Negative gradients indicate that deprived areas suffer a higher burden of disease; positive gradients suggest that prosmoking lifestyles may have been more prevalent in more affluent areas during the last decades. Sex and socioeconomic inequalities of lung cancer mortality reinforce the hypothesis that the epidemiologic profile of cancer can be improved by an expanded access to existing technology of healthcare and prevention. The continuous monitoring of inequalities in health may contribute to the concurrent promotion of well-being and social justice.

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Brazil is a large complex country that is undergoing rapid economic, social, and environmental change In this Series of six articles, we have reported important improvements in health status and life expectancy, which can be ascribed largely to progress in social determinants of health and to implementation of a comprehensive national health system with strong social participation. Many challenges remain, however. Socioeconomic and regional disparities are still unacceptably large, reflecting the fact that much progress is still needed to improve basic living conditions for a large proportion of the population. New health problems arise as a result of urbanisation and social and environmental change, and some old health issues remain unabated. Administration of a complex, decentralised public-health system, in which a large share of services is contracted out to the private sector, together with many private insurance providers, inevitably causes conflict and contradiction. The challenge is ultimately political, and we conclude with a call for action that requires continuous engagement by Brazilian society as a whole in securing the right to health for all Brazilian people.

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The sum of wheat flour and corn starch was replaced by 10, 20, or 30% whole amaranth flour in both conventional (C) and reduced fat (RF) pound cakes. and the effects on physical and sensory properties of the cakes were investigated. RF presented 33% fat reduction. The increasing amaranth levels darkened crust and crumb of cakes, which decreased color acceptability. Fresh amaranth-containing cakes had similar texture characteristics to (he controls, evaluated both instrumentally and sensorially. Sensory evaluation revealed that replacement by 30% amaranth flour decreased C cakes overall acceptability scores, clue to its lower specific volume and darker color. Amaranth flour levels had no significant effect on overall acceptability of RF cakes. Hence, the sum of wheat flour and corn starch could be successfully replaced by up to 20% amaranth flour in C and up to 30% in RF pound cakes without negatively affecting sensory quality in fresh cakes. Moisture losses for all the cakes were similar, approximate to 1% per day during storage. After six days of storage, both C and RF amaranth-containing cakes had higher hardness and chewiness values than control cakes. Further experiments involving sensory evaluation during storage are necessary to determine the exact limit of amaranth flour replacement.

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Objective: To evaluate the impact of an educational and environmental intervention on the availability and consumption of fruits and vegetables in workplace cafeterias. Design: This was a randomized intervention study involving a sample of companies that were divided into intervention and control groups. The intervention, which focused on change in the work environment, was based on an ecological model for health promotion. It involved several different aspects including menu planning, food presentation and motivational strategies to encourage the consumption of fruits and vegetables. The impact of the intervention was measured by changes (between baseline and follow-up) in the availability of fruits and vegetables that were eaten per consumer in meals and the consumption of fruits and vegetables in the workplace by workers. We also evaluated the availability of energy, macronutrients and fibre. Settings: Companies of Sao Paulo, Brazil. Subjects: Twenty-nine companies and 2510 workers. Results: After the intervention we found an average increase in the availability of fruits and vegetables of 49 g in the intervention group, an increase of approximately 15 %, whereas the results for the control group remained practically equal to baseline levels. During the follow-up period, the intervention group also showed reduced total fat and an increase in fibre in the meals offered. The results showed a slight but still positive increase in the workers` consumption of fruits and vegetables (about 11 g) in the meals offered by the companies. Conclusions: Interventions focused on the work environment can be effective in promoting the consumption of healthy foods.

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In the first part some information and characterisation about an AC distribution network that feeds traction substations and their possible influences on the DC traction load flow are presented. Those influences are investigated and mathematically modelled. To corroborate the mathematical model, an example is presented and their results are confronted with real measurements.

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A technique to calculate the current waveform for both close-up and remote short-circuit faults on DC supplied railways and subways is presented. Exact DC short-circuit current calculation is best performed by sophisticated computer transient simulations. However, an accurate simplified calculation method based on second-order approximation which can be easily executed with the help of a calculator or a spreadsheet program is proposed.