ColoriSens: An open-source and low-cost portable color sensor board for microfluidic integration with wireless communication and fluorescence detection

Microfluidic colorimetric biosensors have shown promising potential for detecting metal cations, anions, organic dyes, drugs, pesticides. As for today, most colorimetric sensors are read by a smartphone or professional optical imaging system, and there is still a lack of an affordable and reliable colorimetric detector for the microfluidic chip. Integrating those reading and detection capabilities into a microfluidic system is essential for point-of-care (POC) detection and can enable more complex microfluidic operations, such as lab-on-a-chip experiments or programmable microfluidics. We developed an open-source colorimetric detection sensor board that can be integrated into the existing microfluidic system. This sensor board has a built-in UV source that enables fluorescence detection. With built-in USB and Wi-Fi connectivity and a set of simple APIs, microfluidic systems can communicate directly with this sensor board, even wirelessly. The sensor was designed for low-cost. With a total build cost of less than 12 EUR per unit, it is ideal for low-cost systems and DIY microfluidic users. Along with the sensor board, we also designed a companion microfluidic chip carrier cartridge which can be modified depending on the chip's dimension. To demonstrate the sensor, we also developed a cross-platform open-source client application to demonstrate the communication APIs and the functionality of the sensor board.

Portable all-in-one automated microfluidic system (PAMICON) with 3D-printed chip using novel fluid control mechanism

State-of-the-art microfluidic systems rely on relatively expensive and bulky off-chip infrastructures. The core of a system—the microfluidic chip—requires a clean room and dedicated skills to be fabricated. Thus, state-of-the-art microfluidic systems are barely accessible, especially for the do-it-yourself (DIY) community or enthusiasts. Recent emerging technology—3D-printing—has shown promise to fabricate microfluidic chips more simply, but the resulting chip is mainly hardened and single-layered and can hardly replace the state-of-the-art Polydimethylsiloxane (PDMS) chip. There exists no convenient fluidic control mechanism yet suitable for the hardened single-layered chip, and particularly, the hardened single-layered chip cannot replicate the pneumatic valve—an essential actuator for automatically controlled microfluidics. Instead, 3D-printable non-pneumatic or manually actuated valve designs are reported, but their application is limited. Here, we present a low-cost accessible all-in-one portable microfluidic system, which uses an easy-to-print single-layered 3D-printed microfluidic chip along with a novel active control mechanism for fluids to enable more applications. This active control mechanism is based on air or gas interception and can, e.g., block, direct, and transport fluid. As a demonstration, we show the system can automatically control the fluid in microfluidic chips, which we designed and printed with a consumer-grade 3D-printer. The system is comparably compact and can automatically perform user-programmed experiments. All operations can be done directly on the system with no additional host device required. This work could support the spread of low budget accessible microfluidic systems as portable, usable on-the-go devices and increase the application field of 3D-printed microfluidic devices.

Endoscopic Holmium:YAG laser-assisted lithotripsy: A Preliminary Report

PROBLEM/OBJECTIVE

Laser-assisted lithotripsy under sialendoscopy has the potential to overcome the limitations of traditional sialendoscopic lithotripsy when facing salivary stones. In this preliminary study, we report our experience with Holmium:YAG laser-assisted lithotripsy.

METHODS

Data from 11 Asian patients receiving sialendoscopies for laser-assisted lithotripsy performed in our department from August 2013 to June 2014 were recorded and reviewed.

RESULTS

A total of 18 procedures were performed in 11 Taiwanese patients with symptoms of obstructive sialoadenitis who were diagnosed with sialolithiasis. The sizes of the stones ranged between 3 mm and 13 mm. The endoscopic lithotomy procedures were performed in all 11 patients, and stone fragmentation with the Holmium:YAG laser was done successfully in all patients. All patients were followed for a minimum of 3 months, and there was no evidence of complications or recurrences over the follow up period.

CONCLUSION

The Holmium:YAG laser allowed successful fragmentation of stones in all 11 patients. Our experience with this procedure supports the use of Holmium:YAG laser-assisted lithotripsy through sialendoscopy in Asian patients.

An unexpected route for otolaryngology bacterial contamination with a Venturi atomizer

BACKGROUND

The Venturi-principle atomizer is a commonly used device in otolaryngology practices. The purpose of this study is to evaluate the possible route of bacterial contamination from the nasal vestibule to the atomizer tip through the jet airflow created during the use of the Venturi atomizer.

METHODS

Thirty nostrils from 15 enrolled volunteers were tested. The aerosols generated by spraying sterilized saline into the nostrils were collected using a specially made aerosol-collecting nozzle cap. The collected samples were sent for bacterial culture, and nasal vestibular swab cultures were performed for comparison.

RESULTS

In the aerosol-exposed group, 18 out of 30 samples (60%) were positive for bacterial growth, confirming the bacterial contamination from the nasal vestibule to the atomizer tip through the reverse jet airflow. The bacteria species in 8 of the 18 positive samples were identical to those from the nasal swab culture results from the same nostril.

CONCLUSION

In ordinary otolaryngology practices, there are significant risks for bacterial contamination from the nasal vestibule to the tip of the Venturi atomizer even without direct contact. Clinicians must be more aware of this pattern of contamination, which has not been reported in the existing literature.

An improved micro-incubation well for immunocytochemical staining procedures

A shallow "micro-incubation well" was made with a piece of the square plastic slide and a glass slide. A circular hole (10-12 mm in diameter) was cut out of the center of the square plastic slide. This plastic slide was then attached to the glass slide with a drop of Epon-Araldite and cured in the 60 degrees C oven for 2 days. One to three small sections of tissue mounted within corresponding circles on an ordinary microscopic slide could be stained when placed upside-down on the well in a moisture chamber. The moisture chamber was modified by a disposable square Petri dish (100 x 15 mm) containing a small amount of water and a shallow slide stage which was made by cutting a half inch rim from the bottom of a round disposable Petri dish (100 x 15 mm). This method provided the following advantages in immunocytochemical staining: (1) an even distribution of micro-amounts of antibody solution for long periods of time, and (2) greatly reduced the cost of the immunostaining technique by using micro-amounts of antibody solution.

The somatotopy of the masticatory neurons in the rat trigeminal motor nucleus as revealed by HRP study

Young adult albino rats of Wistar strain were used for the present study. 0.5 to 15 microliters of 20-50% of horseradish peroxidase (HRP) were injected into each individual muscle of mastication to label neurons in the trigeminal motor nucleus (TMON) for light microscopic study. The results reveal that: (1) Many HRP-labeled, multipolar neurons are observed in the motor nucleus in each jaw-closing muscle (JCM) with less in each the jaw-opening muscle (JOM). (2) The motor neurons innervating each masticatory muscle in the motor nucleus show a somatotopic arrangement: (a) those innervating the temporalis muscle are located in the medial and dorsomedial parts; (b) those innervating the masseter muscle are located in the intermediate and lateral; (c) those innervating the medial and lateral pterygoid muscles are located in the lateral, ventrolateral and ventromedial parts, respectively; and (d) those innervating the mylohyoid and the anterior belly of the digastric muscles are located in the most ventromedial part of the caudal one-third of the nucleus. Axons of most masticatory motor neurons run ventrolaterally in between the motor and the chief sensory nuclei of the trigeminal nerve. However, those of the mylohyoid and anterior belly of the digastric muscles ascend dorsally to the dorsal aspect of the caudal nucleus and then turn ventrolaterally to join the motor root of the trigeminal nerve. Furthermore, the dendrites of the motor neuron of JCM converge dorsocaudally to the supratrigeminal region. The diameters of neurons of each JCM display a bimodal distribution. However, an unimodal distribution is present in the motor neurons from each JCM. It is suggested that the motor nucleus innervating the JCM is comprised of comprised of alpha- and gamma-motor neurons. It, thus, may provide a neural basis for the regulation of the muscle tone and biting force.

Changes in the nuclear volume of rat hypothalamic neurons in old age

Nuclear volumes (NV) of neurons in the preoptic are (POA), suprachiasmatic nucleus (SC), paraventricular nucleus (PVN), supraoptic nucleus (SO), anterior hypothalamic area (AHA), arcuate nucleus (ARN), ventromedial nucleus (VMN), dorsomedial nucleus (DMN) and lateral mammillary nucleus (ML) were measured in 3.5- to 5-month-old female and male rats and in old female and male rats over 22 months of age. Young adult female rats had larger NV than males in the neurons of all measured areas except for the SC during estrus and the ARN. NV of the hypothalamic neurons of female rats decreased in old age in all measured areas except for the VMN of rats exhibiting prolonged vaginal cornification (PVC). Old male rats showed decreased NV only in the neurons of the SC, SO and ML. The extent of NV decrease of the hypothalamic neurons was not similar in different areas. The sexual difference in neuronal NV in most of the areas disappeared in old age. Only the POA of rats with PVC and the ML of old female rats had larger NV than those of old male rats.