Microfluidic Platform for Examination of Effect of Chewing Xylitol Gum on Salivary pH, O2, and CO2

Miniaturization of different measurement processes and a scaled-down approach open the possibility for rapid measurements with the small amounts of samples and reagents into a compact platform with integrated sensors and different measuring components. In this paper, we report a microfluidic approach for measurements of salivary pH, dissolved O2, and CO2 during chewing xylitol gum. The study was done with the samples of 30 healthy volunteers who were chewing a xylitol gum, and the measurements were performed in the microfluidic (MF) chip with integrated commercial PreSens sensors. Xylitol exhibited a significant effect on the pH of saliva in terms of its initial drop, which was the most significant between the 5th and 10th minutes. The effect of xylitol on the amount of oxygen and carbon dioxide in saliva cannot be confirmed. The employed microfluidic platform was shown to be applicable and effective in the analysis of salivary biomarkers relevant to caries development.

NIR Computer Vision for Rapid Measurements of Some Physical Properties of Mangoes

Quality assessment through quick sorting and grading of mangoes is today’s need, for not only to enhance the post harvest management process but also to minimize the post harvest losses and to recover more economic and nutritional values. Near infrared (NIR) based computer vision (CV) which is very close to human vision was used for rapid measurements of some physical properties of mangoes (Chausa, Dashehari). Lab View s/w was used to process the image and development of algorithm steps for analysis of the image properties. Fruit’s diameters were measured and compared with manual measurements using paired t-test, the 95% limits of agreement (Bland-Altman plot) and both measurements correlated using regression analysis. The results obtained were consistent and the correlations of the mean dimensions between both methods were found to be noticeably high. Coefficient of determination (R2) for all diameters was found between 0.951 and 0.90. Various fruit’s shape attributes important in design of harvest and post harvest equipment were also evaluated using NIR-CV technique. The present research, thus, could be the basis for the development of real time CV systems which would be near to human vision.

Visual assessment of diffusion weighted imaging infarct volume lacks accuracy and reliability

PurposeThe DAWN trial (Diffusion weighted imaging or CT perfusion Assessment with clinical mismatch in the triage of Wake-up and late presenting strokes undergoing Neurointervention with Trevo) has demonstrated the benefits of thrombectomy in patients with unknown or late onset strokes, using automated software (RAPID) for measurement of infarct volume. Because RAPID is not available in all centers, we aimed to assess the accuracy and repeatability of visual infarct volume estimation by clinicians and the consequences for thrombectomy decisions based on the DAWN criteria.Materials and methods18 physicians, who routinely depend on MRI for acute stroke imaging, assessed 32 MR scans selected from a prospective databaseover two independent sessions. Raters were asked to visually estimate the diffusion weighted imaging (DWI) infarct volume for each case. Sensitivity, specificity, and accuracy of the estimated volumes were compared with the available RAPID measurements for various volume cut-off points. Thrombectomy decisions based on DAWN criteria with RAPID measurements and raters’ visual estimates were compared. Inter-rater and intra-rater agreement was measured using kappa statistics.ResultsThe mean accuracy of raters was <90% for all volume cut-points. Inter-rater agreement was below substantial for each DWI infarct volume cut-off points. Intra-rater agreement was substantial for 55–83% of raters, depending on the selected cut-off points. Applying DAWN criteria with visual estimates instead of RAPID measurements led to 19% erroneous thrombectomy decisions, and showed a lack of reproducibility.ConclusionThe visual assessment of DWI infarct volume lacks accuracy and repeatability, and could lead to a significant number of erroneous decisions when applying the DAWN criteria.