Optical Fiber Sensor for Temperature and Strain Measurement Based on Multimode Interference and Square-Core Fiber.

A variety of specialty fibers such as no-core fiber (NCF) have already been studied to reveal their sensing abilities. In this work, we investigate a specialty fiber, square-core fiber, for temperature and strain sensing. A simple single-mode-multimode-single-mode (SMS) fiber sensor was fabricated, consisting of a 30-cm-long square-core fiber. The experimental results indicate that the maximal wavelength-temperature and wavelength-strain sensitivities are -15.3 pm/∘C and -1.5 pm/µÎµ, respectively, while the maximal power-temperature and power-strain sensitivities are 0.0896 dBm/∘C and 0.0756 dBm/µÎµ. Analysis of the results suggests that the fiber sensor has the potential to be used as a high-sensitivity temperature sensor with a low strain sensitivity.

Smartphone-based colorimetric detection system for portable health tracking.

Colorimetric tests for at-home health monitoring became popular 50 years ago with the advent of the urinalysis test strips, due to their reduced costs, practicality, and ease of operation. However, developing digital systems that can interface these sensors in an efficient manner remains a challenge. Efforts have been put towards the development of portable optical readout systems, such as smartphones. However, their use in daily settings is still limited by their error-prone nature associated to optical noise from the ambient lighting, and their low sensitivity. Here, a smartphone application (Colourine) to readout colorimetric signals was developed on Android OS and tested on commercial urinalysis test strips for pH, proteins, and glucose detection. The novelty of this approach includes two features: a pre-calibration step where the user is asked to take a photo of the commercial reference chart, and a CIE-RGB-to-HSV color space transformation of the acquired data. These two elements allow the background noise given by environmental lighting to be minimized. The sensors were characterized in the ambient light range 100-400 lx, yielding a reliable output. Readouts were taken from urine strips in buffer solutions of pH (5.0-9.0 units), proteins (0-500 mg dL-1) and glucose (0-1000 mg dL-1), yielding a limit of detection (LOD) of 0.13 units (pH), 7.5 mg dL-1 (proteins) and 22 mg dL-1 (glucose), resulting in an average LOD decrease by about 2.8 fold compared to the visual method.

Human dirofilariasis due to Dirofilaria repens mimicking a scrotal tumor.

Dirofilariasis due to Dirofilaria repens is a rare anthropozoonotic disease, with dogs and cats being the definite hosts for this parasite. This worm is transmitted by various species of mosquitoes and usually presents as a subcutaneous nodule. Human cases have been reported from all around the Mediterranean, Eastern Europe, and Central and Southern Asia. In the present case involving a 28-year-old patient of Tunisian origin, infection manifested as a nodule in the left epididymis. In the context of increasing international travel and migration, dirofilariasis is a diagnosis that should be kept in mind when treating patients who have spent some time in endemic areas and present with unclear subcutaneous or scrotal nodules.