Publications by authors named "HyungJun Lim"

: The coronavirus disease 2019 (COVID-19) pandemic has significantly affected both supply and demand for blood transfusion. This study aimed to investigate the prescription patterns of blood products and identify the risk factors for blood transfusion in patients with severe COVID-19. : This nationwide population-based cohort study was performed in the Republic of Korea between January 2021 and December 2021.

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Analyzing the data collected from different sources requires unpaired data analysis to account for the absence of correspondence between the random variable and the covariates . Several attempts have been made to analyze continuous , but it may follow a discrete distribution, which previous methodologies have overlooked. To address these limitations, we propose Poisson matching quantiles estimation (PMQE), the first unpaired data analysis method designed to examine the discrete and the unpaired continuous covariates .

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Background: Bacterial extracellular vesicles (EVs) are pivotal mediators of intercellular communication and influence host cell biology, thereby contributing to the pathogenesis of infections. Despite their significance, the precise effects of bacterial EVs on the host cells remain poorly understood. This study aimed to elucidate ultrastructural changes in host cells upon infection with EVs derived from a pathogenic bacterium, Staphylococcus aureus (S.

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The analysis of membrane vesicles at the nanoscale level is crucial for advancing the understanding of intercellular communication and its implications for health and disease. Despite their significance, the nanoscale analysis of vesicles at the single particle level faces challenges owing to their small size and the complexity of biological fluids. This new vesicle analysis tool leverages the single-molecule sensitivity of super-resolution microscopy (SRM) and the high-throughput analysis capability of deep-learning algorithms.

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Room-temperature liquid metal (LM)-based electronics is expected to bring advancements in future soft electronics owing to its conductivity, conformability, stretchability, and biocompatibility. However, various difficulties arise when patterning LM because of its rheological features such as fluidity and surface tension. Numerous attempts are made to overcome these difficulties, resulting in various LM-patterning methods.

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Nanoimprint lithography (NIL) is suitable for achieving high uniformity and mass production. However, in conventional NIL, a stamp suitable for the substrate size is required to increase the substrate size. To address this issue, we fabricated nanostructures on a large-area substrate using step-and-repeat NIL after making a small stamp.

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We report a laser-pyrolyzed carbon (LPC) electrode prepared from a black photoresist for an on-chip microsupercapacitor (MSC). An interdigitated LPC electrode was fabricated by direct laser writing using a high-power carbon dioxide (CO) laser to simultaneously carbonize and pattern a spin-coated black SU-8 film. Due to the high absorption of carbon blacks in black SU-8, the laser-irradiated SU-8 surface was directly exfoliated and carbonized by a fast photo-thermal reaction.

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Surface-enhanced Raman spectroscopy (SERS) detection in microfluidics is an interesting topic because of its high sensitivity, miniaturization, and ability to perform online detection. However, the difficulties in generating SERS-based microfluidic devices with uniform signal reproducibility and high sensitivity have hindered their widespread application. In addition, the recyclability of the SERS-based microfluidic devices can contribute to their broad commercialization, but the possible contamination in the detection area and cumbersome cleaning procedures remain a challenge.

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As the light-emitting diode (LED) size gradually decreases, it is difficult to conventionally transfer an LED onto a donor substrate. In this paper, we propose a print transfer method that selectively transfers an LED onto a UV release tape, i.e.

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Postsurgical intraocular lens (IOL) infection caused by pathogenic bacteria can result in blindness and often requires a secondary operation to replace the contaminated lens. The incorporation of an antibacterial property onto the IOL surface can prevent bacterial infection and postoperative endophthalmitis. This study describes a polymeric nanopillar array (NPA) integrated onto an IOL, which captures and eradicates the bacteria by rupturing the bacterial membrane.

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The effective production of nanopatterned films generally requires a nanopatterned roll mold with a large area. We report on a novel system to fabricate large-area roll molds by recombination of smaller patterned areas in a step-and-repeat imprint lithography process. The process is accomplished in a method similar to liquid transfer imprint lithography (LTIL).

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A method to directly collect negatively charged nucleic acids, such as DNA and RNA, in the biosamples simply by applying an electric field in between the sample and collection buffer separated by the nanofilter membrane is proposed. The nanofilter membrane was made of low-stress silicon nitride with a thickness of 100 nm, and multiple pores were perforated in a highly arranged pattern using nanoimprint technology with a pore size of 200 nm and a pore density of 7.22 × 10/cm.

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To achieve an effective surface-enhanced Raman scattering (SERS) sensor with periodically distributed "hot spots" on wafer-scale substrates, we propose a hybrid approach combining physical nano-imprint lithography and a chemical deposition method to form a silver microbead array. Nano-imprint lithography (NIL) can lead to mass-production and high throughput, but is not appropriate for generating strong "hot-spots." However, when we apply electrochemical deposition to an NIL substrate and the reaction time was increased to 45 s, periodical "hot-spots" between the microbeads were generated on the substrates.

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A spectrophotometer that uses a localized surface plasmon resonance phenomenon is a powerful measurement tool in the biotechnology and bioanalysis fields. We propose a novel cuvette design type that can be used for universal spectrophotometers. The novel cuvette design needs a few l reagent for measuring, and also two chips for measurement can be loaded and measured at the same time.

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A numerical method using the modified squeeze model is proposed in this paper in order to overcome the limitation of the established squeeze equation and obtain filling ratios for nanoimprint lithography (NIL). Because the imprinting velocity is overestimated when the ratio of indenter width to polymer thickness is close to unity, the modified equation is critical. For verification, the numerical results are compared with the experimental data according to the various stamp geometries and pressure variation rates, for which a maximum difference of 10% is indicated.

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Electrodes with several tens nanometer gap are very important parts in the nano devices such as SETs (Single Electron Transistor), and quantum dots. However, fabricating nanometer electrode with the EBL (Electron Beam Lithography) process is too costly and time consuming to be commercially feasible. To overcome these disadvantages and to enable mass production, nano imprint lithography is applied to a master fabrication technique via EBL.

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This paper shows an improved mold replication process that uses polyurethane acrylate (PUA) and polyethylene terephthalate (PET) for the fabrication of an ultraviolet (UV) imprinting mold used in substrate conformal imprint lithography (SCIL). With the conventional replication process, which uses hard polydimethylsiloxane (h-PDMS) as a pattern layer, it is difficult to detach the mold from a silicon master for metal oxide semiconductor field effect transistor (MOSFET) that has patterns with over 1-micron depth. However, the method proposed in this paper allows us to easily replicate patterns that have more than 1-micron depth.

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We present a process based on nanoimprint lithography for the fabrication of a microchannel mold having nanopatterns formed at the bottoms of its microchannels. A focused laser beam selectively cures the resist in the micrometer scale during nanoimprint lithography. Nanopatterns within the microchannels may be used to control microfluidic behavior.

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This paper shows a novel nano-imprint method with a polydimethylsiloxane (PDMS) replica mold that was bonded on a cylindrically inflated polycarbonate (PC) film via a low air pressure. The PDMS mold, which was deformed in terms of its cylindrical shape, made a line contact with a substrate from the center region and the contact region, then expanded gradually to the outside of the substrate when the contact force increased. This contact procedure squeezed the resin that was dropped on the substrate from the center to the outside, which prevented the trapping of air bubbles while the cavities were filled with the patterns on the PDMS mold.

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This paper proposes a new motion-compensated frame interpolation (MCFI) method. The proposed method utilizes a symmetric motion estimation (SME) method, which is a new pixel-wise motion estimation method for intermediate frame interpolation. By using an adaptive search range for the motion estimation, the proposed method can obtain a more reliable motion vector for each pixel than previous MCFI methods that use a conventional block matching algorithm (BMA).

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Results of various studies have indicated a potential association between exposures to electrical and/or magnetic fields and risks of various cancers. The authors used a cross-sectional ecological study design to investigate such a potential association. In areas proximate to 42 amplitude modulated (AM) radio transmitters, 11 high-power study sites (i.

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For self-controlled endoscopes, many kinds of systems have been proposed. Among these, pneumatic actuators show significant potential. However, existing actuators, such as those used in endoscopes, have many weak points.

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