Screening and Selection of Ferric Reducing Bacteria by Electrical Current for Microbial Fuel Cell

The efficiency of microbial fuel cell (MFC) performance depends on the competence of microorganisms on being an essential role in primarily converting organic compound into electricity. In this study, the possibility of using electrical current to select electrochemical active bacteria from sub-sediment for use in MFC was conducted. By using an alternating current (AC) of 0.6 - 12 mA and selective media, 16 Gram-positive ferric reducing bacteria (GP-FRB), 15 Gram-negative ferric reducing bacteria (GN-FRB) and 9 Gram-negative non FRB (GN-nonFRB) were characterized. GN-FRB and GP-FRB were obtained from the current of 0.6 - 6 and 9 - 12 mA, respectively. After tested in MFC, GN-FRB had a greater current density and power density than those from GN-nonFRB and GP-FRB. However, the greatest voltage was obtained from GP-FRB, followed by those of GN-nonFRB and GN-FRB, respectively. The highest current and power density of 13.33 mA/m2 and 0.32 mW/m2, respectively were from GN-FRB namely KL14 which was identified later as Proteus sp. This research could contribute a promising method for screening and selection of ferric reducing bacteria using electrical current. MFC inoculated with our selected bacteria could be a model for next study in wastewater treatment

Novel Approach to Respiratory Rate Measurement Using Resonance Tube with Contradictory Thresholding Technique

In this paper, we propose a novel approach to respiratory rate measurement using resonance tube to enhance the performance of microphone inserted and fixed at the end of the tube to catch breath sound signal from the mouth and/or nose. The signal is amplified and passed into envelope detector circuit after which it is compared with a suitable reference voltage in comparator circuit to generate a pulse train of square wave synchronized with the respiratory cycle. A simple algorithm is developed in a small microcontroller to detect rising edges of each consecutive square wave to calculate respiratory rate together with analysis of breathing status. In order to evade noises which will cause errors and artifacts in the measuring system, the reference voltage is creatively designed to intelligently adapt itself to be low during expiration period and high during inspiration and pause period using the concept of resolving contradiction in the theory of inventive problem solving (TRIZ). This makes the developed device simple and low-cost with no need for complicated filtering system. It can detect breath sound as far as 250 cm from the nose and can perform accurately as tested against End Tidal CO2 Capnography device. The result shows that the developed device can estimate precisely from as low as 0 BrPM to as high as 98 BrPM and it can detect shallow breathing as low as 10 mV of breath sound

The Efficacy of a Newly Developed Cueing Device for Gait Mobility in Parkinson’s Disease

Background. External cues are effective in improving gait in people with Parkinson’s disease (PD). However, the most effective cueing method has yet to be determined. Objective. The aim of this study was to compare the immediate effects of using visual, auditory, or somatosensory cues on their own or in combination during walking compared to no cues in people with PD. Methods. This was a single blinded, randomly selected, controlled study. Twenty people with PD with an age range of 46–79 years and Hoehn and Yahr scores of 1–3 were recruited. Participants were studied under 4 cueing conditions; no cue, visual, auditory, or somatosensory cues, which were randomly selected individually or in a combination. Results. A repeated measures ANOVA with pairwise comparisons using Bonferroni correction showed that any single or combination of the cues resulted in an improvement in gait velocity and stride length compared to no cue. Some significant differences were also seen when comparing different combinations of cues, specifically stride length showed significant improvements when additional cues were added to the light cue. The statistically significant difference was set at p<0.05. Conclusions. Walking using visual, auditory, or somatosensory cues can immediately improve gait mobility in people with PD. Any or a combination of the cues tested could be chosen depending on the ability of the individual to use that cue

Design and Development of Standard 12-Lead ECG Data Acquisition and Monitoring System

AbstractThis paper presents a low cost and portable 12-lead ECG data acquisition and monitoring system based on microcontroller. Surface mount devices (SMDs) are used to realize a compact system. The system consists of two parts, analog pre-data acquisition part and digital data processing part. In analog pre-data acquisition part, it composes of three channels measuring circuits and lead selector. Each channel includes analog 0.7Hz to 20Hz band pass filter and amplifier with the overall gain of 900. In accordance with the tested measurement, percent gain error is low. In digital data processing part, the microcontroller is programmed using C-language. USB interfacing is also used to transfer the data to PC. The 12-lead ECG system can be performed by using the lead selector which is controlled by the microcontroller

Label-free DNA detection by loop- mediated isothermal amplification coupled with quartz crystal microbalance sensor

Loop-mediated isothermal amplification (LAMP) and quartz crystal microbalance (QCM) sensors were used for DNA detection. Porcine DNA as DNA template was amplified and QCM sensors were then used to measure the changes in frequency in positive and negative samples. Mathematical models were employed to extract features from the sensor recordings by fitting the frequency -time plots using polynomial functions. The polynomial function coefficients of the plots gave valuable information for sample classification. Radar graphs and principle component analysis (PCA) were also applied to samples using these coefficients. Both the radar graphs and the PCA indicated differences between the sample groups when using coefficients of high-order functions

Quantitative Assessment of Periodontal Bacteria Using a Cell-Based Immunoassay with Functionalized Quartz Crystal Microbalance

Periodontal disease is an inflammatory disorder that is triggered by bacterial plaque and causes the destruction of the tooth-supporting tissues leading to tooth loss. Several bacteria species, including Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, are considered to be associated with severe periodontal conditions. In this study, we demonstrated a quartz crystal microbalance (QCM) immunoassay for quantitative assessment of the periodontal bacteria, A. actinomycetemcomitans. An immunosensor was constructed using a self-assembled monolayer of 11-mercaptoundecanoic acid (11-MUA) on the gold surface of a QCM chip. The 11-MUA layer was evaluated using a cyclic voltammetry technique to determine its mass and packing density. Next, a monoclonal antibody was covalently linked to 11-MUA using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide to act as the biorecognition element. The specificity of the monoclonal antibody was confirmed by an enzyme-linked immunosorbent assay. A calibration curve, for the relationship between the frequency shifts and number of bacteria, was used to calculate the number of A. actinomycetemcomitans bacteria in a test sample. Based on a regression equation, the lower detection limit was 800 cells, with a dynamic range up to 2.32 × 106 cells. Thus, the QCM biosensor in this study provides a sensitive and label-free method for quantitative analysis of periodontal bacteria. The method can be used in various biosensing assays for practical application and routine detection of periodontitis pathogens