Shuhei Takeuchi

Chemiluminescent Visualization for Evaluation of Gaseous Ethanol Distribution During ‘La France’ Pear Maturation

A 2-D visualization system for gaseous ethanol is constructed and tested in visualization of standard gaseous ethanol and maturation of fruit. This visualization system measures ethanol concentrations as intensities of chemiluminescence (CL) by luminol reaction induced by alcohol oxidase and a horseradish peroxidase-luminol-hydrogen peroxide system. Conversion of ethanol distribution and concentration to 2-D CL is conducted on an enzyme-immobilized mesh that contains alcohol oxidase, horseradish peroxidase and luminol solution. We visualize ethanol emission from a pear with maturation in which the concentration is typically at sub-parts per million (sub-ppm) level. Thus, a high-purity luminol sodium salt HG solution and an enhancer of fluorescence dye of eosin Y are optimized for the improvement of chemiluminescent intensity for visualization. The detection limit is improved sub-ppm using these solutions. Owing to high sensitivity, the emission of gaseous ethanol during La France pear (Pyruscommnis L.) maturation is successfully visualized and the intensity of each pixel is the reflection of ethanol concentrations. Therefore, this system is sufficiently useful for assessment of ethanol measurement for the maturation characteristic.

Mouthguard biosensor integrated with wireless module for monitoring human oral information

We have developed “Cavitas sensors” into human cavitas sites of oral cavity for non-invasive monitoring of saliva glucose. A salivary biosensor based on the integration of working electrode with an enzyme membrane on a mouthguard was fabricated and demonstrated. This mouthguard biosensor was integrated with a glucose sensor and wireless measurement system. In the investigation of in-vitro characterization, the biosensor showed excellent relationship between the output current and the glucose concentration. In artificial saliva consisting of salts and proteins, the glucose sensor exhibits highsensitive detection in a range of 5–1000 μmol/L. We demonstrated the capability of the sensor and wireless communication module to characterize an inclusion in oral phantom that imitative structure of human oral cavity. The mouthguard biosensor would be useful for real-time and non-invasive method as a novel health care management.

The prognosis of dysphagia patients over 100 years old

Several reports have recently been published regarding dysphagia in very elderly patients, and centenarian dysphagia patients have become more common in Japan. The aim of this study was to assess the prognosis of dysphagia in very elderly patients. Participants were 24 centenarian dysphagia patients. For each patient, we collected information on age, care level, past medical history, and changes in oral intake according to the Functional Oral Intake Scale (FOIS). Patients were divided into two groups based on the mode of food intake at the time of transfer or discharge: the per oral-only group (the PO-only group, i.e., oral intake alone) and the tube feeding-dependent group (the TF-dependent group, i.e., combination of oral intake and tube feeding, or tube feeding alone). In both groups, the FOIS score decreased significantly from pre-hospitalization to the time of transfer or discharge (p=0.006 for both). The FOIS score at initial assessment was higher in the PO-only group with the TF-dependent group (p=0.0004). Furthermore, the frequency of a FOIS score of 4 at initial assessment was significantly higher in the PO-only group, and the frequency of a FOIS score of 1 was significantly higher in the TF-dependent group (p=0.0006). These findings collectively suggest that oral intake can be recovered if the FOIS score is ≥ 4 at initial assessment, is difficult if the score is 1, and may be possible with a FOIS score of 2.