Online Intelligent Controllers for an Enzyme Recovery Plant: Design Methodology and Performance

This paper focuses on the development of intelligent controllers for use in a process of enzyme recovery from pineapple rind. The proteolytic enzyme bromelain (EC 3.4.22.4) is precipitated with alcohol at low temperature in a fed-batch jacketed tank. Temperature control is crucial to avoid irreversible protein denaturation. Fuzzy or neural controllers offer a way of implementing solutions that cover dynamic and nonlinear processes. The design methodology and a comparative study on the performance of fuzzy-PI, neurofuzzy, and neural network intelligent controllers are presented. To tune the fuzzy PI Mamdani controller, various universes of discourse, rule bases, and membership function support sets were tested. A neurofuzzy inference system (ANFIS), based on Takagi-Sugeno rules, and a model predictive controller, based on neural modeling, were developed and tested as well. Using a Fieldbus network architecture, a coolant variable speed pump was driven by the controllers. The experimental results show the effectiveness of fuzzy controllers in comparison to the neural predictive control. The fuzzy PI controller exhibited a reduced error parameter (ITAE), lower power consumption, and better recovery of enzyme activity

Detection and on-line prediction of leak magnitude in a gas pipeline using an acoustic method and neural network data processing

Considering the importance of monitoring pipeline systems, this work presents the development of a technique to detect gas leakage in pipelines, based on an acoustic method, and on-line prediction of leak magnitude using artificial neural networks. On-line audible noises generated by leakage were obtained with a microphone installed in a 60 m long pipeline. The sound noises were decomposed into sounds of different frequencies: 1 kHz, 5 kHz and 9 kHz. The dynamics of these noises in time were used as input to the neural model in order to determine the occurrence and the leak magnitude. The results indicated the great potential of the technique and of the developed neural network models. For all on-line tests, the models showed 100% accuracy in leak detection, except for a small orifice (1 mm) under 4 kgf/cm² of nominal pressure. Similarly, the neural network models could adequately predict the magnitude of the leakages.14515

Qualidade do café arábica em diferentes altitudes no Espírito Santo.

Este trabalho teve como objetivo avaliar a influência de diferentes altitudes na qualidade do café arabica, avaliada pela análise sensorial. Para tanto, foram avaliados grãos de três cultivares de café arábica colhidos em três ambientes com altitudes diferentes, ou seja, a 700 m, 950 m e 1100 m, nos municípios de Venda Nova do Imigrante, Domingos Martins e Santa Maria do Jetiba, respectivamente. Os cafés foram secos em terreiro suspenso coberto até que alcançassem 12% de umidade. A classificação sensorial foi realizada por um provador especializado, sem prévio conhecimento das amostras. Verificou-se que cafés cultivados em maiores altitudes originaram melhores bebidas. Não houve diferença significativa entre as cultivares Rubi, Catuai Vermelho IAC 44 e Catuai Vermelho IAC 81 para a qualidade da bebida

Current options to manage clopidogrel poor responsiveness

Antiplatelet therapy (aspirin + clopidogrel) is the cornerstone of treatment for patients with acute coronary syndromes and/or undergoing percutaneous coronary interventions (PCI). More than 40 million patients worldwide receive clopidogrel, but about 20% of them are nonresponders or poor responders. Many studies using different techniques, platelet agonists and definitions have shown that patients who are poor responders to clopidogrel have an increased risk of death, reinfarction and stent thrombosis. The mechanisms leading to poor responsiveness are not fully elucidated and are likely multifactorial: genetic factors, accelerated platelet turnover, up-regulation of the P2Y12 pathways, high baseline platelet reactivity, poor compliance, underdosing and drug-drug interactions. The management of these patients is very difficult, but evidence does exist showing that a strategy of higher maintenance dose or switch to different thienopyridines (e.g. ticlopidine or prasugrel) or use of glycoprotein IIb/IIIa inhibitors during PCI may be helpful to overcome poor responsiveness and improve the long-term clinical outcome. This review describes the impact of poor responsiveness to clopidogrel on clinical outcomes, the mechanisms leading to poor effect, and the different assays to assess it. Finally, current and future options for its management are discussed

Long-term outcome after percutaneous coronary intervention in patients with essential thrombocythemia

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Medical and interventional management of patients with severe thrombocytopenia undergoing percutaneous coronary intervention.

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Long-term clinical outcome based on aspirin and clopidogrel responsiveness status after elective percutaneous coronary intervention: a 3T/2R (tailoring treatment with tirofiban in patients showing resistance to aspirin and/or resistance to clopidogrel) trial substudy

Objectives The purpose of this study was to investigate the long-term outcome after elective percutaneous coronary intervention in low-risk patients screened for aspirin and/or clopidogrel responsiveness in the 3T/2R (Tailoring Treatment With Tirofiban in Patients Showing Resistance to Aspirin and/or Resistance to Clopidogrel) trial. Background The impact of aspirin and/or clopidogrel poor response on long-term outcome is debated. Methods Aspirin and clopidogrel response was measured with the VerifyNow system aspirin and P2Y12 assays. After percutaneous coronary intervention (PCI), death, stroke, and myocardial infarction were assessed up to 1 year. Results Overall, 1,277 patients were screened, and 826 (65%) were treated with PCI. In all, 124 patients were found to be aspirin poor responders, and there were 179 clopidogrel poor responders (totally, 278 poor responders). The 1-year end point was significantly higher in poor responders as compared to full responders (15.8% vs. 8.6%, p = 0.002), which is principally due to more myocardial infarction occurrence. At multivariable analysis, clopidogrel poor response emerged as an independent predictor (hazard ratio: 1.15, 95% confidence interval: 1.03 to 1.28). Receiver-operator characteristic analysis identifies ≤23 of percentage of platelet inhibition and <208 of P2Y12 reactivity units as optimal cut offs to predict 1-year end point. Excluding periprocedural events, also peri-PCI myocardial infarction, which is strongly related to aspirin/clopidogrel poor response, was an independent predictor (hazard ratio: 1.25, 95% confidence interval: 1.14 to 1.37). Glycoprotein IIb/IIIa inhibitor administration reduces this risk in poor responders (21.2% vs. 34.7%, p = 0.02), but not in full responders (6.3% vs. 6.5%, p = 0.8). Conclusions Poor response to clopidogrel is an independent predictor of periprocedural myocardial infarction and worse 1-year outcome in low-risk patients undergoing PCI, whereas poor response to aspirin failed to predict a worse outcome. Contrary to what was observed in poor responders, glycoprotein IIb/IIa inhibitor therapy failed to provide a benefit in aspirin and/or clopidogrel full responders

Thrombin generation assay: a new tool to predict and optimize clinical outcome in cardiovascular patients?

Antithrombotic therapy (including antiplatelet and anticoagulant drugs) is the cornerstone of the current medical treatment of patients with acute coronary syndromes (ACS). This therapy and particularly the new antiplatelet and anticoagulant drugs have significantly reduced the ischemic risk, but have increased bleeding complications. Recently, several studies have emphasized the negative prognostic impact on long-term mortality of these bleeding adverse events. Thus, new assays to estimate the bleeding risk and the efficacy of these antithrombotic drugs are clearly in demand. Regarding the anticoagulant drugs, new promising data have emerged about the thrombin generation assay (TGA). TGA measures the ability of plasma to generate thrombin. TGA may be used to check coagulation function, to value risk of thrombosis and to compare the efficacy of different anticoagulants employed in clinical management of patients with ACS. The TGA result is a curve which describes the variation of thrombin's amount during the activation of the coagulation cascade. All available anticoagulant drugs influence the principal parameters generated by TGA and so it is possible to evaluate the effects of the medical treatment. In this review we provide a brief description of the assay and we summarize the principals of previous studies by analyzing the relationship between anticoagulant drugs and TGA. Moreover, a brief summary of its ability to predict ischemic and bleeding risks has been provided