Publications by authors named "Youngjun Son"

Articular cartilage faces challenges in self-repair due to the lack of blood vessels and limited chondrocyte concentration. Polydeoxyribonucleotide (PDRN) shows promise for promoting chondrocyte growth and cartilage regeneration, but its delivery has been limited to injections. Continuous PDRN delivery is crucial for effective cartilage regeneration.

View Article and Find Full Text PDF

COVID-19 has already claimed over 7 million lives and has infected over 775 million people globally [1]. SARS-CoV-2, the virus that causes Covid-19, spreads primarily through droplets from infected people's airways, rendering Heating, Ventilation, and Air Conditioning (HVAC) systems critical in controlling infection risk levels in the indoor environment. To understand the dynamics of exhaled droplets and aerosols and the percentage of particles that are inhaled, escaped, recirculated, or trapped on different surfaces for a variety of environmental settings, we have presented our findings from the Computational Fluid Dynamics (CFD) modeling to investigate the impact of changing HVAC parameters in this paper.

View Article and Find Full Text PDF

Background  Medical simulation allows clinicians to safely practice the procedural skill of endotracheal intubation. Applied force to oropharyngeal structures increases the risk of patient harm, and video laryngoscopy (VL) requires less force to obtain a glottic view. It is unknown how much force is required to obtain a glottic view using commercially available simulation manikins and if variability exists.

View Article and Find Full Text PDF

Hydrogel is a versatile material that can be manipulated to achieve the desired physicochemical properties, such as stiffness, pore size, and viscoelasticity. Traditionally, these properties have been controlled through parameters such as concentration and pH adjustments. In this study, we focused on exploring the potential of hydrolyzed silk fibroin (HSF) as a molecular weight-modulating agent to control the physicochemical properties of double-composite hydrogels.

View Article and Find Full Text PDF

 Current virtual reality (VR) technology allows the creation of instructional video formats that incorporate three-dimensional (3D) stereoscopic footage.Combined with 3D anatomic models, any surgical procedure or pathology could be represented virtually to supplement learning or surgical preoperative planning. We propose a standalone VR app that allows trainees to interact with modular 3D anatomic models corresponding to stereoscopic surgical videos.

View Article and Find Full Text PDF

Most early Bluetooth-based exposure notification apps use three binary classifications to recommend quarantine following SARS-CoV-2 exposure: a window of infectiousness in the transmitter, ≥15 minutes duration, and Bluetooth attenuation below a threshold. However, Bluetooth attenuation is not a reliable measure of distance, and infection risk is not a binary function of distance, nor duration, nor timing. We model uncertainty in the shape and orientation of an exhaled virus-containing plume and in inhalation parameters, and measure uncertainty in distance as a function of Bluetooth attenuation.

View Article and Find Full Text PDF

Mastery of lateral skull base (LSB) surgery requires thorough knowledge of complex, 3-dimensional (3D) microanatomy and techniques. While supervised operation under binocular microscopy remains the training gold standard, concerns over operative time and patient safety often limit novice surgeons' stereoscopic exposure. Furthermore, most alternative educational resources cannot meet this need.

View Article and Find Full Text PDF

Backgound: Functional endoscopic sinus surgery (FESS) can be challenging as novices become accustomed to handling endoscopes and instruments while navigating complex sinonasal anatomy. Experts demonstrate fluid and efficient motions when addressing pathology. The training process from novice to expert relies on hands-on experience in cadaveric laboratories and preceptorship models that require significant time and expense.

View Article and Find Full Text PDF

The surgeon's knowledge of a patient's individual anatomy is critical in skull base surgery. Trainees and experienced surgeons can benefit from surgical simulation; however, current models are expensive and impractical for widespread use. In this study, we report a next-generation mixed-reality surgical simulator.

View Article and Find Full Text PDF

This transdisciplinary study has a three-fold systems approach in evaluating a horticultural technology: 1) horticultural evaluations, 2) economic and resource analyses, and 3) systems engineering analyses, using low temperature storage as an example technology. Vegetable grafting is a technique to produce value-added seedlings but requires labor intensive nursery operations. Low temperature storage of seedlings for a short period of time can reduce peak production, but has not been evaluated at the extent demonstrated in this paper.

View Article and Find Full Text PDF

At a signalized intersection, there exists an area where drivers become indecisive as to either stop their car or proceed through when the traffic signal turns yellow. This point, called a dilemma zone, has remained a safety concern for drivers due to the great possibility of a rear-end or right-angle crash occurring. In order to reduce the risk of car crashes at the dilemma zone, Institute of Transportation Engineers (ITE) recommended a dilemma zone model.

View Article and Find Full Text PDF

Purpose: The aim of our study was to assess the hemodynamic change of liver during the Valsalva maneuver using Doppler ultrasonography.

Methods: Thirty healthy men volunteers were enrolled (mean age, 25.5±3.

View Article and Find Full Text PDF

We investigated the migration of endogenous neural stem cells (NSCs) toward an infarct lesion in a photo-thrombotic stroke model. The lesions produced by using rose bengal dye (20 mg/kg) with cold light in the motor cortex of Sprague-Dawley rats were also evaluated with sequential magnetic resonance imaging (MRI) from 30 minutes through 8 weeks. Migration of NSCs was identified by immunohistochemistry for nestin monoclonal antibody in the lesion cortex, subventricular zone (SVZ), and corpus callosum (CC).

View Article and Find Full Text PDF

A fungal strain, C-4, was isolated from etiolated leaves. Based on taxonomic studies, the fungus C-4 can be classified as a strain of Trichoderma species. When strain C-4 was cultured in Mandels' medium at 28 degrees C for 6 days, the enzyme activities detected in the broth corresponded to 8.

View Article and Find Full Text PDF