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A novel electrochemical detection methodology is described for the femtomolar detection of proteins which utilizes both DNA aptamer-functionalized nanoparticles and a surface enzymatic reaction. Immunoglobulin E (IgE) was used as a model protein biomarker, which possesses two distinct epitopes for antibody (anti-IgE) and DNA aptamer binding. A surface sandwich assay format was utilized involving the specific adsorption of IgE onto a gold electrode surface that was pre-modified with a monolayer of aptamer-nanoparticle conjugates followed by the specific interaction of alkaline phosphatase (ALP) conjugated anti-IgE. To clearly demonstrate the signal enhancement associated with nanoparticle use, anodic current measurements of the ALP catalyzed oxidation of the enzyme substrate 4-aminophenylphosphate (APP) were also compared with electrode surfaces upon which the aptamer was directly attached. The detection of an unlabelled protein at concentrations as low as 5 fM is a significant improvement compared to conventional electrochemical-based immunoassay approaches and provides a foundation for the practical use and incorporation of nanoparticle-enhanced detection into electrochemical biosensing technologies.

ObjectiveTo examine the effects of age, gender and bolus consistency in normal populations using the temporal measurement of Pharyngeal Transit Duration (PTD), which reflects the duration of bolus flow from the ramus of the mandible to the upper esophageal sphincter.Method40 normal and healthy subjects had Videofluoroscopic Swallowing Examinations (VFSEs) of 5 ml thin and nectar thick liquids, and puree consistencies. A slow motion and frame by frame analysis was performed. Three-way analysis of variance (ANOVA) was performed to examine the main effect and interactions, and paired t-tests for the three consistency comparisons.ResultsOlder subjects had a significantly longer PTD than younger subjects (p<0.01). In addition, men had significantly shorter PTDs than women (p<0.01). Puree showed a significantly longer PTD than the other two consistencies, regardless of age and gender (p<0.05).ConclusionPTD is an indicative of motor weakness in pharyngeal swallowing secondary to aging. In addition, the results supported the assumption that there is a functional difference in pharyngeal swallowing between men and women. It is expected that the results of this study will be used for further investigation of patients with dysphagia.

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SUMMARYFor a few decades, various approximate techniques have been developed to calculate the eigenvalues in a reduced manner. In order to construct reliable reduced systems it is essential to select the proper primary degrees of freedom (PDOFs). Unless the PDOFs are selected properly, the selection of PDOFs might be localized and the eigenvalue prediction might emphasize excessively the lower modes or lose the important modes. Moreover, sometimes, it takes considerable amount of computing time to construct a reduced system in large-scale problem. These troubles in constructing reduced system can be avoided by applying reduction scheme in sub-domain level. After dividing global system into a number of subdomains, reduced system which has only the PDOFs is constructed in each sub-domain. This paper presents new algorithms to construct efficient reduction system through three different schemes. They are version 1, version 2 and version 3 systems. The version 3 system is constructed by combining the advantages of the version 1 and the version 2 systems. Numerical examples demonstrate that the proposed version 3 method saves computational cost effectively and provides a reduced system which can predict accurate eigenvalues of global system.