914 resultados para Compósito de pinhão


Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper we present a weak maximum principle for optimal control problems involving mixed constraints and pointwise set control constraints. Notably such result holds for problems with possibly nonsmooth mixed constraints. Although the setback of such result resides on a convexity assumption on the extended velocity set, we show that if the number of mixed constraints is one, such convexity assumption may be removed when an interiority assumption holds. © 2008 IEEE.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The objective of this paper is to utilize the SIPOC, flowchart and IDEF0 modeling techniques combined to elaborate the conceptual model of a simulation project. It is intended to identify the contribution of these techniques in the elaboration of the computational model. To illustrate such application, a practical case of a high-end technology enterprise is presented. The paper concludes that the proposed approach eases the elaboration of the computational model. © 2008 IEEE.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The objective of this article is to apply the Design of Experiments technique along with the Discrete Events Simulation technique in an automotive process. The benefits of the design of experiments in simulation include the possibility to improve the performance in the simulation process, avoiding trial and error to seek solutions. The methodology of the conjoint use of Design of Experiments and Computer Simulation is presented to assess the effects of the variables and its interactions involved in the process. In this paper, the efficacy of the use of process mapping and design of experiments on the phases of conception and analysis are confirmed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Introduction. Gait becomes the individual independence for their daily activities. The functional deficit caused by central lesion as stroke, makes difficult this motor independence, mainly the locomotion. Objective. Analyze the kinematics gait in stroke patients. Method. It was included 8 patients with clinical diagnosis of stroke, 4 with hemiparesia on the right and 4 on the left. It was analyzed gait spatial-temporal parameters as: length, duration and average speed of the step, using the register in videotape and the software of image 6.3 Dvideow Barros. Results. All patients presented alterations in the kinematics standards of the gait, with lesser duration and length of step, and greater speed than normal subjects. Conclusion. The motor disorder caused by the central lesions produces alterations in the kinematics standards of the gait, in order to adapt the neuro-sensorial sequels, the demands of the task and the way where they live.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Lymphoma studies deals with morphological classification and immunophenotypic features and they have to be amplified for cellular kinetics evaluation. This evaluation can only be safely made, when the proliferative index are evaluated. In men the proliferation index have, most of the time, important influence in the neoplasia prognosis and treatment In this work it was used 40 canine lymphomas that were classified according to Kiel methods and immunophenotype was achieved with CD3 (T lymphocyte) and CD79a (B lymphocyte). Cellular proliferation was evaluated by AgNORs and Ki-67 (MIB-1) According to Kiel classification system, high grade lymphomas were more frequent and T and B lymphoma showed the same frequency.When cellular proliferation was evaluated, there was a significant difference between high grade and low grade lymphomas by AgNOR and Ki-67 (MIB-1) methods, but did not differ when comparing immunophenotype. Among high grade malignancy lymphomas the NORs medium number per cell nucleoli was 1.37± 0.32 and in low grade was 0.98± 0.36, concerning Ki-67 the positive cellular percentual was 43.19% ± 19.01, e 14.09% ± 11.74 in high and low grade, respectively.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Human respiratory syncytial virus (HRSV) is the major cause of lower respiratory tract infections in children under 5 years of age and the elderly, causing annual disease outbreaks during the fall and winter. Multiple lineages of the HRSVA and HRSVB serotypes co-circulate within a single outbreak and display a strongly temporal pattern of genetic variation, with a replacement of dominant genotypes occurring during consecutive years. In the present study we utilized phylogenetic methods to detect and map sites subject to adaptive evolution in the G protein of HRSVA and HRSVB. A total of 29 and 23 amino acid sites were found to be putatively positively selected in HRSVA and HRSVB, respectively. Several of these sites defined genotypes and lineages within genotypes in both groups, and correlated well with epitopes previously described in group A. Remarkably, 18 of these positively selected tended to revert in time to a previous codon state, producing a flipflop phylogenetic pattern. Such frequent evolutionary reversals in HRSV are indicative of a combination of frequent positive selection, reflecting the changing immune status of the human population, and a limited repertoire of functionally viable amino acids at specific amino acid sites.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background. About 130 million people are infected with the hepatitis C virus (HCV) worldwide, but effective treatment options are not yet available. One of the most promising targets for antiviral therapy is nonstructural protein 3 (NS3). To identify possible changes in the structure of NS3 associated with virological sustained response or non-response of patients, a model was constructed for each helicase NS3 protein coding sequence. From this, the goal was to verify the interaction between helicases variants and their ligands. Findings. Evidence was found that the NS3 helicase portion of non-responder patients contained substitutions in its ATP and RNA binding sites. K210E substitution can cause an imbalance in the distribution of loads, leading to a decrease in the number of ligations between the essential amino acids required for the hydrolysis of ATP. W501R substitution causes an imbalance in the distribution of loads, leading and forcing the RNA to interact with the amino acid Thr269, but not preventing binding of ribavirin inhibitor. Conclusions. Useful information is provided on the genetic profiling of the HCV genotype 3, specifically the coding region of the NS3 protein, improving our understanding of the viral genome and the regions of its protein catalytic site. © 2010 Rahal et al; licensee BioMed Central Ltd.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We consider free time optimal control problems with pointwise set control constraints u(t) ∈ U(t). Here we derive necessary conditions of optimality for those problem where the set U(t) is defined by equality and inequality control constraints. The main ingredients of our analysis are a well known time transformation and recent results on necessary conditions for mixed state-control constraints. ©2010 IEEE.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Lymphoma is among the most frequent canine neoplasia and share many similarities with human non-Hodgkin's lymphoma in respect of etiology, epidemiology, clinical, morphological and immunophenotipical aspects. Human classification schemes have been used in canine lymphoma. The aim of this work was apply Kiel, Working Formulation and Fournel-Fleury's et al. (1994) classification in Fine Needle Aspiration (FNA) cytology matherial. According to Kiel scheme 61.02% (36 cases) were high-grade lymphomas and 38.98% (23 cases) low grade. The Working Formulation, showed 11.86% (7 cases) of low grade, 61.02% (36 cases) intermediary grade and 27.12% (16 cases) high grade. In Fournel-Fleury's protocol revealed a predominance of high-grade lymphoma, with 61.02% (36 cases) over 38.98% (23 cases) of low grade. In conclusion, FNA can be used as a diagnostic method and in canine lymphoma cytological classification. Kiel's system showed the best results, once is based on cytologic basis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objectives: The aim of this study was to assess a suggested association between periodontitis and renal insufficiency by assaying kidney disease markers. Methods: Variables used to diagnose periodontitis were: (i) probing pocket depth (PPD), (ii) attachment loss (AL), (iii) bleeding on probing (BOP), (iv) plaque index (PI) and (v) extent and severity index. Blood and urine were collected from 60 apparently healthy non-smokers (men and women), consisting of a test group of 30 subjects with periodontitis (age 46±6 yrs) and a control group of 30 healthy subjects (age 43±5 yrs). Kidney function markers (urea, creatinine, uric acid and albumin contents) were measured in the serum and urine. Also, the glomerular filtration rate was estimated from creatinine clearance, from the abbreviated Modification of Diet in Renal Disease formula and from the albumin: creatinine ratio in a 24-h sample of urine. Results: It was found that the control group had a greater mean number of teeth than the test group and that the two groups also differed in PPD, AL, BOP and PI, all these variables being higher in the test group (P=0.006). For the extent and severity index of both PPD and AL, the test group had much higher medians of both extent and severity than the control group (P=0.001). With regard to kidney function, none of the markers revealed a significant difference between the control and test groups and all measured values fell within the reference intervals. Conclusions: It is proposed that severe periodontitis is not associated with any alteration in kidney function.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Cardiovascular disease is the leading cause of death in Brazil, and hypertension is its major risk factor. The benefit of its drug treatment to prevent major cardiovascular events was consistently demonstrated. Angiotensin-receptor blockers (ARB) have been the preferential drugs in the management of hypertension worldwide, despite the absence of any consistent evidence of advantage over older agents, and the concern that they may be associated with lower renal protection and risk for cancer. Diuretics are as efficacious as other agents, are well tolerated, have longer duration of action and low cost, but have been scarcely compared with ARBs. A study comparing diuretic and ARB is therefore warranted.Methods/design: This is a randomized, double-blind, clinical trial, comparing the association of chlorthalidone and amiloride with losartan as first drug option in patients aged 30 to 70 years, with stage I hypertension. The primary outcomes will be variation of blood pressure by time, adverse events and development or worsening of microalbuminuria and of left ventricular hypertrophy in the EKG. The secondary outcomes will be fatal or non-fatal cardiovascular events: myocardial infarction, stroke, heart failure, evidence of new subclinical atherosclerosis and sudden death. The study will last 18 months. The sample size will be of 1200 participants for group in order to confer enough power to test for all primary outcomes. The project was approved by the Ethics committee of each participating institution.Discussion: The putative pleiotropic effects of ARB agents, particularly renal protection, have been disputed, and they have been scarcely compared with diuretics in large clinical trials, despite that they have been at least as efficacious as newer agents in managing hypertension. Even if the null hypothesis is not rejected, the information will be useful for health care policy to treat hypertension in Brazil. Clinical trials registration number: ClinicalTrials.gov: NCT00971165. © 2011 Fuchs et al; licensee BioMed Central Ltd.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Brazilian National Electricity Conservation Program - PROCEL - runs regular surveys in the electric-energy-consumption market. These studies are used as valuable data to better plan the actions of this program. These data also evaluate the program's performance by identifying the level of penetration of the most efficient electric equipment within the residential sector. PROCEL's main lines of action is to promote and make available the most efficient technologies. Based on the results from the latest survey, it is estimated that 24% of the electric-energy consumption of the residential sector is used by electric shower devices, which instantaneously heat the water that flows through them, normally using an electric resistance of 5 kW. These are an important factor in a country where electric-heating devices are present in about 73% of Brazilian households. Keeping that in mind, the purpose of this work is to present the main results of the Brazilian Solar-Water-Heating-Systems Evaluation, finished in 2010, where 535 installations were visited and more than 50 researchers from different universities participated in the project. Moreover, seven Brazilian cities were selected to be studied. The information was collected from field research and statistically treated. The collected information focused on the adequacy of the project to the household, installation, operation and life cycle of the systems, as well as the users' satisfaction level. Technical questionnaires were developed to summarize all the required information, such as a Web site designed to organize and manage the data collected and a Matlab application that performed the dimensioning and F-chart systems evaluation. Quality indicators were created through a full system monitoring, with thermographic analysis and evaluation of shading influence at the system's efficiency, using the Ecotect software.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Considering knowledge organization and representation as a theoretical line used by Information Science to face the subject approach to information, in a dialogical relation with subject cataloguing, indexing and analyse documentaire, this article carries out a domain-analysis of Scire journal (1995-2010) in order to identify the scientific production in the mentionned theoretical lines as well as their relationships. Scire constitutes an environment where members of the different paradigms have found an space to relate each other.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A low-Reynolds-number k-ω model for Newtonian fluids has been developed to predict drag reduction of viscoelastic fluids described by the FENE-P model. The model is an extension to viscoelastic fluids of the model for Newtonian fluids developed by Bredberg et al. (Int J Heat Fluid Flow 23:731-743, 2002). The performance of the model was assessed using results from direct numerical simulations for fully developed turbulent channel flow of FENE-P fluids. It should only be used for drag reductions of up to 50 % (low and intermediate drag reductions), because of the limiting assumption of turbulence isotropy leading to an under-prediction of k, but compares favourably with results from k-ε models in the literature based on turbulence isotropy. © 2012 Springer Science+Business Media Dordrecht.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: The quasispecies composition of Hepatitis C virus (HCV) could have important implications with regard to viral persistence and response to interferon-based therapy. The complete NS5A was analyzed to evaluate whether the composition of NS5A quasispecies of HCV 1a/1b is related to responsiveness to combined interferon pegylated (PEG-IFN) and ribavirin therapy.Methods: Viral RNA was isolated from serum samples collected before, during and after treatment from virological sustained responder (SVR), non-responder (NR) and the end-of-treatment responder patients (ETR). NS5A region was amplified, cloned and sequenced. Six hundred and ninety full-length NS5A sequences were analyzed.Results: This study provides evidence that lower nucleotide diversity of the NS5A region pre-therapy is associated with viral clearance. Analysis of samples of NRs and the ETRs time points showed that genetic diversity of populations tend to decrease over time. Post-therapy population of ETRs presented higher genetic distance from baseline probably due to the bottleneck phenomenon observed for those patients in the end of treatment. The viral effective population of those patients also showed a strong decrease after therapy. Otherwise, NRs demonstrated a continuous variation or stability of effective populations and genetic diversity over time that did not seem to be related to therapy. Phylogenetic relationships concerning complete NS5A sequences obtained from patients did not demonstrate clustering associated with specific response patterns. However, distinctive clustering of pre/post-therapy sequences was observed. In addition, the evolution of quasispecies over time was subjected to purifying or relaxed purifying selection. Codons 157 (P03), 182 and 440 (P42), 62 and 404 (P44) were found to be under positive selective pressure but it failed to be related to the therapy.Conclusion: These results confirm the hypothesis that a relationship exists between NS5A heterogeneity and response to therapy in patients infected with chronic hepatitis C. © 2013 Jardim et al.; licensee BioMed Central Ltd.