127 results match your criteria: "Pohang University of Science Technology[Affiliation]"

The optimal lookback period for estimating incidence and temporal trends in atrial fibrillation.

Heart Rhythm

August 2025

Division of Cardiology, Department of Internal Medicine, Yonsei University College of Medicine, Republic of Korea; POSTECH Biotech center, Pohang University of Science Technology, Pohang, Republic of Korea. Electronic address:

Background: Accurate measurement of atrial fibrillation (AF) incidence using secondary data is challenging due to variation in lookback period definitions used to distinguish incident from prevalent cases. As the choice of lookback period critically influences incidence estimates, establishing an appropriate duration is essential for sustained surveillance of AF trends.

Objectives: This study aimed to identify a reproducible definition of the lookback period and analyze trends in the incidence rate and prevalence of AF in Korea.

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A monotone single index model for spatially referenced multistate current status data.

Biometrics

July 2025

Department of Biostatistics, School of Public Health, Virginia Commonwealth University, Richmond, Virginia, 23219, United States.

Assessment of multistate disease progression is commonplace in biomedical research, such as in periodontal disease (PD). However, the presence of multistate current status endpoints, where only a single snapshot of each subject's progression through disease states is available at a random inspection time after a known starting state, complicates the inferential framework. In addition, these endpoints can be clustered, and spatially associated, where a group of proximally located teeth (within subjects) may experience similar PD status, compared to those distally located.

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Chlamydia is an intracellular bacterium that reproduces via an unusual developmental cycle that only occurs within a eukaryotic host cell. A replicating form of the bacterium (RB) repeatedly divides to produce about a thousand progeny, which convert in a delayed and asynchronous manner into the infectious form (EB). The regulatory mechanisms that control this developmental switch are unknown, but they could potentially include extrinsic signals from the host cell or other chlamydiae, or an intrinsic signal such as chlamydial cell size.

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A novel single-molecule immunoassay platform, termed DNA Hanger, is developed to address the limitations of conventional surface-based assays. By suspending biotinylated λ-phage DNA across microfabricated quartz barriers, this method enables high-specificity protein detection with minimal nonspecific binding. DNA Hanger significantly reduces background signals, achieving nonspecific binding rates as low as one protein per 236 µm of DNA.

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This study investigated the morphologies of two bacterial and two wooden cellulose nanofiber (CNF) suspensions in water by using synchrotron X-ray scattering and scanning electron microscopy (SEM). The SEM analysis visually confirmed nanofibers. All small-angle X-ray scattering data were satisfactorily analyzed by using a three-phase elliptical cylinder model combined with blob contributions, thereby confirming all CNFs to consist of a core, an interfacial layer, and a solvated layer.

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Carbon dioxide removal (CDR) potential in temperate macroalgal forests: A comparative study of chemical and biological net ecosystem production (NEP).

Mar Pollut Bull

January 2025

Blue Carbon Implementation Division, Fisheries Resources Management Department, Korea Fisheries Resources Agency (FIRA), Busan 46041, South Korea.

The carbon dioxide removal (CDR) capacity of macroalgae, a crucial component in climate regulation, has gained increasing attention. However, accurately estimating the CDR potential of macroalgae in natural conditions remains challenging, necessitating the use of multiple independent methods to reduce the uncertainties in these estimates. In this study, we compared two methods for estimating net ecosystem production (NEP), a key parameter in determining CDR potential: 1) NEP, derived from seawater carbonate chemistry and 2) NEP, based on photorespiratory measurements using benthic tent incubation.

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Phosphorus-Modified Palladium and Tungsten Carbide/Mesoporous Carbon Composite for Hydrogen Oxidation Reaction of Proton Exchange Membrane Fuel Cells.

Nanomaterials (Basel)

June 2024

Department of Chemical Engineering, Department of Integrative Engineering for Hydrogen Safety, Kangwon National University, Chuncheon 24341, Republic of Korea.

Article Synopsis
  • * Palladium (Pd) nanoparticles, modified with phosphorus, were deposited onto this composite to enhance their properties, resulting in very small Pd particles around 4 nm in size.
  • * The resulting Pd nanoparticles showed significantly increased activity for hydrogen oxidation, outperforming traditional platinum-based catalysts in fuel cell applications, making them a promising alternative.
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Microstructural Evolution, Hardness and Wear Resistance of WC-Co-Ni Composite Coatings Fabricated by Laser Cladding.

Materials (Basel)

April 2024

Graduate Institute of Ferrous & Eco Materials Technology, Pohang University of Science & Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang-si 37673, Gyeongsangbuk-do, Republic of Korea.

This study investigated how process parameters of laser cladding affect the microstructure and mechanical properties of WC-12Co composite coating for use as a protective layer of continuous caster rolls. WC-Co powders, WC-Ni powders, and Ni-Cr alloy powder with various wear resistance characteristics were evaluated in order to determine their applicability for use as cladding materials for continuous caster roll coating. The cladding process was conducted with various parameters, including laser powers, cladding speeds, and powder feeding rates, then the phases, microstructure, and micro-hardness of the cladding layer were analyzed in each specimen.

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2D covalent organic frameworks (COFs) are highly porous crystalline materials with promising applications in organic electronics. Current methods involve either on-surface synthesis (solid surface) or interfacial synthesis (liquid/liquid, liquid/gas interface) to create thin films for these applications, each with its drawbacks. On-surface synthesis can lead to contamination from COF powder or unreacted chemicals, while interfacial synthesis risks damaging the film during post-transfer processes.

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Over the past decade, molecular-switch-embedded memory devices, particularly field-effect transistors (FETs), have gained significant interest. Molecular switches are integrated to regulate the resistance or current levels in FETs. Despite substantial efforts, realizing large memory window with a long retention time, a critical factor in memory device functionality, remains a challenge.

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Identifying the external N and Hg inputs to the estuary ecosystem based on the triple isotopic information (δN, ΔO and δO).

Mar Pollut Bull

March 2024

Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea; OJEong Resilience Institute, Korea University, Seoul 02481, Republic of Korea. Electronic address:

The supply and sources of N and Hg in the Geum estuary of the western coast of Korea were evaluated. Triple isotope proxies (δN, ΔO and δO) of NO combined with conservative mixing between river and ocean waters were used to improve isotope finger-printing methods. The N pool in the Geum estuary was primarily influenced by the Yellow Sea water, followed by riverine discharge (821 × 10 mol yr) and atmospheric deposition (51 × 10 mol yr).

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Mechanically deformable photodetectors (PDs) are key device components for wearable health monitoring systems based on photoplethysmography (PPG). Achieving high detectivity, fast response time, and an ultrathin form factor in the PD is highly needed for next-generation wearable PPG systems. Self-powered operation without a bulky power-supply unit is also beneficial for point-of-care application.

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Indocyanine green (ICG) has been used in clinical practice for more than 40 years and its safety and preferential accumulation in tumors has been reported for various tumor types, including colon cancer. However, reports on clinical assessments of ICG-based molecular endoscopy imaging for precancerous lesions are scarce. We determined visualization ability of ICG fluorescence endoscopy in colitis-associated colon cancer using 30 lesions from an azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model and 16 colon cancer patient tissue-samples.

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The past few decades have seen robust research on questions regarding the existence, form, and properties of stationary distributions of stochastically modeled reaction networks. When a stochastic model admits a stationary distribution an important practical question is: what is the rate of convergence of the distribution of the process to the stationary distribution? With the exception of [1] pertaining to models whose state space is restricted to the non-negative integers, there has been a notable lack of results related to this rate of convergence in the reaction network literature. This paper begins the process of filling that hole in our understanding.

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Translation is mediated by precisely orchestrated sequential interactions among translation initiation components, mRNA, and ribosomes. Biochemical, structural, and genetic techniques have revealed the fundamental mechanism that determines what occurs and when, where and in what order. Most mRNAs are circularized via the eIF4E-eIF4G-PABP interaction, which stabilizes mRNAs and enhances translation by recycling ribosomes.

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The uniqueness of multivariate metal-organic frameworks (MTV-MOFs) has been widely explored to discover their unknown opportunities. While mesoscopic apportionments have been studied, macroscopic heterogeneity and its spatial effects remain unexplored in MTV-MOFs. In this study, we investigated the effect of macroscopic heterogeneity on MTV-MOFs on their uptake behaviors by comparing three types of MTV-MOFs having the functional groups in inner, outer, or entire parts of crystals.

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RNAs not only offer valuable information regarding our bodies but also regulate cellular functions, allowing for their specific manipulations to be extensively explored for many different biological and clinical applications. In particular, rather than temporary hybridization, permanent labeling is often required to introduce functional tags to target RNAs; however, direct RNA labeling has been revealed to be challenging, as native RNAs possess unmodifiable chemical moieties or indefinable dummy sequences at the ends of their strands. In this work, we demonstrate the combinatorial use of RNA-compatible restriction endonucleases (REs) and RNA-extending polymerases for sequence-specific RNA cleavage and subsequent RNA functionalization.

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Recent improvements in the performance of solution-processed semiconductor materials and optoelectronic devices have shifted research interest to the diversification/advancement of their functionality. Embedding a molecular switch capable of transition between two or more metastable isomers by light stimuli is one of the most straightforward and widely accepted methods to potentially realize the multifunctionality of optoelectronic devices. A molecular switch embedded in a semiconductor can effectively control various parameters such as trap-level, dielectric constant, electrical resistance, charge mobility, and charge polarity, which can be utilized in photoprogrammable devices including transistors, memory, and diodes.

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Single polysome analysis of mRNP.

Biochem Biophys Res Commun

August 2022

Department of Physics, Pohang University of Science & Technology (POSTECH), Pohang, 37673, South Korea; School of Interdisciplinary Bioscience & Bioengineering, POSTECH, Pohang, 37673, South Korea. Electronic address:

Eukaryotic translation is a complex process that involves the interplay of various translation factors to convert genetic information into a specific amino acid chain. According to an elegant model of eukaryotic translation initiation, the 3' poly(A) tail of an mRNA, which is occupied by poly(A)-binding proteins (PABPs), communicates with the 5'-cap bound by eIF4E to enhance translation. Although the circularization of mRNA resulting from the communication is widely understood, it has yet to be directly observed.

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Owing to the low productivity per unit area of a single basin solar still, a stacked solar still configuration which has two basins stacked together has gained popularity due to its increased output for the same area. This paper delivers a detailed comparison between single basin and stacked solar still configurations based on thermodynamic and economic analysis. A single slope single basin and double basin solar still of same base area of 0.

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Theoretical considerations suggest that the strength of carbon nanotube (CNT) fibers be exceptional; however, their mechanical performance values are much lower than the theoretical values. To achieve macroscopic fibers with ultrahigh performance, we developed a method to form multidimensional nanostructures by coalescence of individual nanotubes. The highly aligned wet-spun fibers of single- or double-walled nanotube bundles were graphitized to induce nanotube collapse and multi-inner walled structures.

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High-Resolution Single-Molecule Magnetic Tweezers.

Annu Rev Biochem

June 2022

School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea; email:

Single-molecule magnetic tweezers deliver magnetic force and torque to single target molecules, permitting the study of dynamic changes in biomolecular structures and their interactions. Because the magnetic tweezer setups can generate magnetic fields that vary slowly over tens of millimeters-far larger than the nanometer scale of the single molecule events being observed-this technique can maintain essentially constant force levels during biochemical experiments while generating a biologically meaningful force on the order of 1-100 pN. When using bead-tether constructs to pull on single molecules, smaller magnetic beads and shorter submicrometer tethers improve dynamic response times and measurement precision.

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On-skin healthcare patch-type devices have great technological challenges in monitoring full-day activities and wearing for multiple days without detachment. These challenges can be overcome when the sensor is air permeable but waterproof. This study presents a light-weight, highly stable, and stretchable Au electrode that is fabricated by sputtering on an imidized nanofiber mat.

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A rigid inositol-derived monomer functionalized with azide and alkyne as the complementary reactive groups (CRGs) crystallized as three distinct polymorphs I-III. Despite the unsuitable orientation of CRGs in the crystals for complete polymerization, all the three polymorphs underwent regiospecific and quantitative topochemical azide-alkyne cycloaddition (TAAC) polymerization upon heating to yield three different polymorphs of 1,2,3-triazol-1,4-diyl-linked-poly-neo-inositol. The molecules in these polymorphs exploit the weak intermolecular interactions, free space in the crystal lattice, and heat energy for their large and cooperative molecular motion to attain a transient reactive orientation, ultimately leading to the regiospecific TAAC reaction yielding distinct crystalline polymers.

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We present a comprehensive experimental rheological dataset for purified entangled ring polystyrenes and their blends with linear chains in nonlinear shear and elongation. In particular, data for shear stress growth coefficient, steady-state shear viscosity, and first and second normal stress differences are obtained and discussed as functions of shear rate as well as molecular parameters (molar mass, blend composition and decreasing molar mass of linear component in blend). Over the extended parameter range investigated, rings do not exhibit clear transient undershoot in shear, in contrast to their linear counterparts and ring-linear blends.

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