20 research outputs found

    Human vascular adhesion proteın-1 (VAP-1): Serum levels for hepatocellular carcinoma in non-alcoholic and alcoholic fatty liver disease

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    <p>Abstract</p> <p>Background</p> <p>The incidence of hepatocellular cancer in complicated alcoholic and non-alcoholic fatty liver diseases is on the rise in western countries as well in our country. Vascular adhesion protein-1 (VAP-1) levels have been presented as new marker. In our study protocol, we assessed the value of this serum protein, as a newly postulant biomarker for hepatocellular cancer in patients with a history of alcoholic and non-alcoholic fatty liver diseases.</p> <p>Methods</p> <p>Pre-operative serum samples from 55 patients with hepatocellular cancer with a history of alcoholic and non-alcoholic fatty liver diseases and patients with cirrhosis were assessed by a quantitative sandwich ELISA using anti-VAP-1 mAbs. This technique is used to determine the levels of soluble VAP-1 (sVAP-1) in the serum.</p> <p>Results</p> <p>sVAP-1 levels were evaluated in patients with hepatocellular cancer and liver cirrhosis. There was a significant difference in mean VAP-1 levels between groups. Serum VAP-1 levels were found higher in patients with hepatocellular cancer.</p> <p>Conclusion</p> <p>These findings indicate that the serum level of sVAP-1 might be a beneficial marker of disease activity in chronic liver diseases.</p

    Mathematical models for immunology:current state of the art and future research directions

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    The advances in genetics and biochemistry that have taken place over the last 10 years led to significant advances in experimental and clinical immunology. In turn, this has led to the development of new mathematical models to investigate qualitatively and quantitatively various open questions in immunology. In this study we present a review of some research areas in mathematical immunology that evolved over the last 10 years. To this end, we take a step-by-step approach in discussing a range of models derived to study the dynamics of both the innate and immune responses at the molecular, cellular and tissue scales. To emphasise the use of mathematics in modelling in this area, we also review some of the mathematical tools used to investigate these models. Finally, we discuss some future trends in both experimental immunology and mathematical immunology for the upcoming years

    Adaptive fuzzy-Chebyshev network control of a conducting polymer actuator

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    In this paper, the tip displacement of a conducting polymer actuator (CPA), which has an unknown and time-varying dynamics, is controlled using three different model-free adaptive controllers. First, conventional indirect adaptive fuzzy and Chebyshev functional-link network controllers are introduced. Second, a novel hybrid network which combines the capability of conventional fuzzy system and Chebyshev functional-link network is proposed for online identification and control of the CPA. The stability of the proposed controllers and boundedness of the closed-loop signals are proven using Lyapunov stability approach. The designed adaptive controllers are implemented experimentally in real-time. The performances of the controllers in tracking a square and a sine reference are compared in terms of root-mean-squared error (RMSE), required input signal power (ICVP) and settling time (ts) performances. © SAGE Publications

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    In this paper, the tip displacement of a conducting polymer actuator (CPA), which has an unknown and time-varying dynamics, is controlled using three different model-free adaptive controllers. First, conventional indirect adaptive fuzzy and Chebyshev functional-link network controllers are introduced. Second, a novel hybrid network which combines the capability of conventional fuzzy system and Chebyshev functional-link network is proposed for online identification and control of the CPA. The stability of the proposed controllers and boundedness of the closed-loop signals are proven using Lyapunov stability approach. The designed adaptive controllers are implemented experimentally in real-time. The performances of the controllers in tracking a square and a sine reference are compared in terms of root-mean-squared error (RMSE), required input signal power (ICVP) and settling time (t(s)) performances

    Robust control of a trilayer conducting polymer actuator

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    Performance of the conducting polymer actuators (CPAs) are affected by material uncertainties, operating conditions and time of operation. The same size CPAs may have different actuation capabilities, which can also degrade over the course of operation. For accurate and repeatable position tracking, the uncertainties and variations in the actuator dynamics have to be carefully addressed to achieve a desirable control performance. This paper presents a systematic approach for the identification of parametric uncertainties and designing robust control to achieve a guaranteed performance when the CPA is used for position tracking. We identify the uncertainties in actuator dynamics by performing series of experiments using two geometrically equivalent CPAs

    Hybrid force and position control of a conducting tri-layer electro-active polymer actuator

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    In this study, the displacement and blocking force of the tip point of a cantilevered electro-active polymer (EAP) actuator has been controlled for a cell injection process which consists of approaching, interacting and leaving steps. A vision-based system is used to acquire the tip displacement data for identifying a transfer function model of the actuator and its position control. Discrete time Proportional-Integral controllers are used to control the position and blocking force. A Smith Predictor is utilized in the vision-based position control system to compensate for the time delay due to image processing. Experimental position and blocking force results prove that the proposed control strategies are effective enough to guide the actuator to undertake the cell injection process. This study contributes to the previously published work from the point of view of simultaneously controlling the position and blocking force of the electroactive polymer actuators and widening their application areas

    Emergence of Distinct Genotypes of Cryptosporidium parvum in Structured Host Populations

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    Cryptosporidium parvum is an apicomplexan parasite that infects humans and ruminants. C. parvum isolated from cattle in northeastern Turkey and in Israel was genotyped using multiple polymorphic genetic markers, and the two populations were compared to assess the effect of cattle husbandry on the parasite's population structure. Dairy herds in Israel are permanently confined with essentially no opportunity for direct herd-to-herd transmission, whereas in Turkey there are more opportunities for transmission as animals range over wider areas and are frequently traded. A total of 76 C. parvum isolates from 16 locations in Israel and seven farms in the Kars region in northeastern Turkey were genotyped using 16 mini- and microsatellite markers. Significantly, in both countries distinct multilocus genotypes confined to individual farms were detected. The number of genotypes per farm was higher and mixed isolates were more frequent in Turkey than in Israel. As expected from the presence of distinct multilocus genotypes in individual herds, linkage disequilibrium among loci was detected in Israel. Together, these observations show that genetically distinct populations of C. parvum can emerge within a group of hosts in a relatively short time. This may explain the frequent detection of host-specific genotypes with unknown taxonomic status in surface water and the existence of geographically restricted C. hominis genotypes in humans

    Force control of a tri-layer conducting polymer actuator using optimized fuzzy logic control

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    Conducting polymers actuators (CPAs) are potential candidates for replacing conventional actuators in various fields, such as robotics and biomedical engineering, due to their advantageous properties, which includes their low cost, light weight, low actuation voltage and biocompatibility. As these actuators are very suitable for use in micro-nano manipulation and in injection devices in which the magnitude of the force applied to the target is of crucial importance, the force generated by CPAs needs to be accurately controlled. In this paper, a fuzzy logic (FL) controller with a Mamdani inference system is designed to control the blocking force of a trilayer CPA with polypyrrole electrodes, which operates in air. The particle swarm optimization (PSO) method is employed to optimize the controller\u27s membership function parameters and therefore enhance the performance of the FL controller. An adaptive neuro-fuzzy inference system model, which can capture the nonlinear dynamics of the actuator, is utilized in the optimization process. The optimized Mamdani FL controller is then implemented on the CPA experimentally, and its performance is compared with a non-optimized fuzzy controller as well as with those obtained from a conventional PID controller. The results presented indicate that the blocking force at the tip of the CPA can be effectively controlled by the optimized FL controller, which shows excellent transient and steady state characteristics but increases the control voltage compared to the non-optimized fuzzy controllers
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