Publications by authors named "Ho-Seung Lee"

Guided exciton-polariton modes naturally exist in bare transition metal dichalcogenide (TMDC) layers due to self-hybridization between excitons and photons. However, these guided polariton modes exhibit a limited propagation distance owing to the substantial exciton absorption within the material. Here, we investigated the impact of hexagonal boron nitride (hBN) layers on guided exciton-polariton modes in WS multilayers.

View Article and Find Full Text PDF

In Walker's nonmetric method, the nuchal crest serves as the representative region for indicating sexual dimorphism in cranial bones. However, the accuracy of sex estimation using the nuchal crest is lower than that using other anatomical regions. Furthermore, because of the protruding processes and structurally challenging features characterized by uneven and rough surfaces, there is a lack of metric methods for sex estimation, making quantification challenging.

View Article and Find Full Text PDF

In the Fourth Industrial Revolution, as the connection between objects and people becomes increasingly important, interest in wearable optoelectronic device-based medical diagnosis is on the rise. Pulse oximetry sensors based on a fiber platform, which is the smallest unit of clothing, could be considered an attractive candidate for this application. In this study, red and green quantum-dot light-emitting fibers (QDLEFs) based on a 250 μm-diameter 1-dimensional fiber were successfully implemented, achieving high current efficiencies of approximately 22.

View Article and Find Full Text PDF

Background/aims: Malignant duodenal obstruction has become more common with the development of palliative therapies.The outcomes of endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) are comparable to those of surgical gastrojejunostomy or duodenal stenting. However, EUS-GJ is technically challenging.

View Article and Find Full Text PDF

Background And Aims: Endoscopic multiple plastic stents are an established first-line treatment for anastomotic biliary stricture (ABS) management after liver transplantation (LT). Fully covered self-expandable metallic stents (FCSEMSs) have recently been used with favorable outcomes, but long-term treatment outcomes remain an issue for ABS. We evaluated the long-term outcomes of FCSEMS for the management of refractory ABS after LT.

View Article and Find Full Text PDF

Increasing demand for real-time healthcare monitoring is leading to advances in thin and flexible optoelectronic device-based wearable pulse oximetry. Most previous studies have used OLEDs for this purpose, but did not consider the side effects of broad full-width half-maximum (FWHM) characteristics and single substrates. In this study, we performed SpO measurement using a fiber-based quantum-dot pulse oximetry (FQPO) system capable of mass production with a transferable encapsulation technique, and a narrow FWHM of about 30 nm.

View Article and Find Full Text PDF

α,β-Unsaturated ketones are common feedstocks for the synthesis of fine chemicals, pharmaceuticals, and natural products. Transition metal-catalysed hydroacylation reactions of alkynes using aldehydes have been recognised as an atom-economical route to access α,β-unsaturated ketones through chemoselective aldehydic C-H activation. However, the previously reported hydroacylation reactions using rhodium, cobalt, or ruthenium catalysts require chelating moiety-bearing aldehydes to prevent decarbonylation of acyl-metal-hydride complexes.

View Article and Find Full Text PDF

Light-emitting fibers have been intensively developed for the realization of textile displays and various lighting applications, as promising free-form electronics with outstanding interconnectivity. These advances in the fiber displays have been made possible by the successful implementation of the core technologies of conventional displays, including high optoelectronic performance and essential elements, in the fiber form-factor. However, although white organic light-emitting diodes (WOLEDs), as a fundamental core technology of displays, are essential for realizing full-color displays and solid-state lighting, fiber-based WOLEDs are still challenging due to structural issues and the lack of approaches to implementing WOLEDs on fiber.

View Article and Find Full Text PDF

Because of its excellent optical properties and good stability, all-inorganic halide perovskite CsPbX (X = I, Br, Cl) has been attracting interest for use in light-emitting diodes (LEDs). One challenge is improving the efficacy of the spatial confinement of excitons for higher luminescence efficiency. Here, we present a simple yet very effective strategy to form fine-grain-structured CsPbBr polycrystalline films prepared by thermal co-evaporation.

View Article and Find Full Text PDF

Advances in material science and nanotechnology have fostered the miniaturization of devices. Over the past two decades, the form-factor of these devices has evolved from 3D rigid, volumetric devices through 2D film-based flexible electronics, finally to 1D fiber electronics (fibertronics). In this regard, fibertronic strategies toward wearable applications (e.

View Article and Find Full Text PDF

Background: The benefits of total transmetatarsal amputation over higher level amputation are well known. However, there are no studies evaluating the effects of first ray- or first two ray-sparing transmetatarsal amputation with flap coverage. The authors evaluated this approach with regard to functional outcome and to identify long-term complications.

View Article and Find Full Text PDF

Fiber-based wearable displays, one of the most desirable requisites of electronic textiles (e-textiles), have emerged as a technology for their capability to revolutionize textile and fashion industries in collaboration with the state-of-the-art electronics. Nonetheless, challenges remain for the fibertronic approaches, because fiber-based light-emitting devices suffer from much lower performance than those fabricated on planar substrates. Here, we report weavable and highly efficient fiber-based organic light-emitting diodes (fiber OLEDs) based on a simple, cost-effective and low-temperature solution process.

View Article and Find Full Text PDF

Recently, the role of clothing has evolved from merely body protection, maintaining the body temperature, and fashion, to advanced functions such as various types of information delivery, communication, and even augmented reality. With a wireless internet connection, the integration of circuits and sensors, and a portable power supply, clothes become a novel electronic device. Currently, the information display is the most intuitive interface using visualized communication methods and the simultaneous concurrent processing of inputs and outputs between a wearer and functional clothes.

View Article and Find Full Text PDF

Background: Major vessels in the diabetic foot are often calcified and inadequate for use as recipient vessels. Thus, a supermicrosurgery technique using small branches or perforators from other collateral vessels with an adequate pulse may be an alternative method. This study evaluated outcome using the supermicrosurgery concept and the risk factors involved.

View Article and Find Full Text PDF

The purpose of this study was to evaluate the outcome of the diabetic foot reconstructed with free flaps and analyse the preoperative risk factors. This study reviews 121 cases of reconstructed diabetic foot in 113 patients over 9 years (average follow-up of 53.2 months).

View Article and Find Full Text PDF

When the number of intensities greatly exceeds the number of unknown atomic coordinates, the problem of obtaining a crystal structure from the intensities is overdetermined and, for a sufficiently small structure, a chemically meaningful solution can be found by direct methods. A difficulty in determining a structure has been historically attributed to the non-uniqueness of such a structure owing to multiple, or homometric, structures that yield the same set of intensities. The number of homometric structures has not been rigorously analyzed owing to the complexity of this problem.

View Article and Find Full Text PDF

To develop a standard growth curve of the lower extremity in Korean children from 3 to 16 yr of age, the lengths from a total of 2087 normal long bone segments (582 femurs and 645 tibias in boys, and 417 femurs and 443 tibias in girls) were measured. Children were grouped by years of bone age, which was determined by using the Korean specific bone age standard; TW2-20 method. The growth spurt occurred in girls from eight to eleven years by bone age, and in boys from eleven to thirteen years.

View Article and Find Full Text PDF