Publications by authors named "Kihyun Lee"

Haploinsufficiency for is associated with congenital heart disease (CHD) with variable comorbidity of pancreatic or diaphragm defects, although the etiology of disease is not well understood. Here, we used cardiac directed differentiation from human embryonic stem cells (hESCs) as a platform to study GATA6 function during early cardiogenesis. GATA6 loss-of-function hESCs had a profound impairment in cardiac progenitor cell (CPC) specification and cardiomyocyte (CM) generation due to early defects during the mesendoderm and lateral mesoderm patterning stages.

View Article and Find Full Text PDF

Electron beams evolved as important tools for modern technologies that construct and analyze nanoscale architectures. While electron-matter interactions at atomic and macro scales are well-studied, a knowledge gap persists at the molecular to nano level─the scale most relevant to the latest technologies. Here, we employ liquid-phase transmission electron microscopy supported by density functional theory calculations and a mathematical random search algorithm to rationalize and quantify electron beam-induced processes at the molecular level.

View Article and Find Full Text PDF

The interlayer displacement has recently emerged as a crucial tuning parameter to control diverse physical properties in layered crystals. Transmission electron microscopy (TEM), an exceptionally powerful tool for structural analysis, directly observes the interlayer stacking and strain fields in various crystals. However, conventional analysis methods based on high-resolution phase-contrast TEM images are inadequate for recognizing spatially varying unit-cell patterns and their associated structure factors, hindering precise determination of interlayer displacements.

View Article and Find Full Text PDF

Bacterial species adapt to cold environments with diverse molecular mechanisms enabling their growth under low ambient temperature. The emergence of cold-adapted species at macro-evolutionary scale, however, has not been systematically explored. In this study, we performed phylogenetic analysis on the growth temperature traits in the genera that occupy broad environmental and host niches and contain known cold-adapted species.

View Article and Find Full Text PDF

Developing microbiome-based markers for pediatric inflammatory bowel disease (PIBD) is challenging. Here, we evaluated the diagnostic and prognostic potential of the gut microbiome in PIBD through a case-control study and cross-cohort analyses. In a Korean PIBD cohort (24 patients with PIBD, 43 controls), we observed that microbial diversity and composition shifted in patients with active PIBD versus controls and recovered at remission.

View Article and Find Full Text PDF

The interlayer stacking shift in van der Waals (vdW) crystals represents an important degree of freedom to control various material properties, including magnetism, ferroelectricity, and electrical properties. On the other hand, the structural phase transitions driven by interlayer sliding in vdW crystals often exhibit thickness-dependent, sample-specific behaviors with significant hysteresis, complicating a clear understanding of their intrinsic nature. Here, the stacking configuration of the recently identified vdW crystal, γ-GeSe, is investigated, and the disordering manipulation of stacking sequence is demonstrated.

View Article and Find Full Text PDF

Since the discovery of graphene and its remarkable properties, researchers have actively explored advanced graphene-patterning technologies. While the etching process is pivotal in shaping graphene channels, existing etching techniques have limitations such as low speed, high cost, residue contamination, and rough edges. Therefore, the development of facile and efficient etching methods is necessary.

View Article and Find Full Text PDF

Haploinsufficiency for is associated with congenital heart disease (CHD) with variable comorbidity of pancreatic or diaphragm defects, although the etiology of disease is not well understood. Here, we used cardiac directed differentiation from human embryonic stem cells (hESCs) as a platform to study GATA6 function during early cardiogenesis. GATA6 loss-of-function hESCs had a profound impairment in cardiac progenitor cell (CPC) specification and cardiomyocyte (CM) generation due to early defects during the mesendoderm and lateral mesoderm patterning stages.

View Article and Find Full Text PDF
Article Synopsis
  • The updated EzBioCloud platform enhances the classification and identification of Bacteria and Archaea using advanced DNA sequencing technologies and a comprehensive taxonomic hierarchy based on 16S rRNA gene and genome sequences.
  • The new version includes a refined classification system that addresses underrepresented lineages and ensures high-quality data by implementing strict screening protocols for whole-genome assemblies from the NCBI Assembly Database.
  • EzBioCloud now features a total of 109,835 species, integrating methods like average nucleotide identity (ANI) and core gene ANI (cgANI) to improve taxonomic placements and accuracy.
View Article and Find Full Text PDF
Article Synopsis
  • The study explores the genomic diversity and antibiotic resistance gene (ARG) profiles of the skin bacterium, emphasizing its potential to cause infections in clinical settings.
  • The analysis includes 405 high-quality genomes, revealing prevalent ARGs linked to multi-locus sequence types and identifying core ARGs associated with antibiotic resistance.
  • Findings also suggest horizontal gene transfer between environmental isolates and pathogenic strains, highlighting significant genomic differences between the skin commensal and opportunistic pathogens despite their ecological overlap.
View Article and Find Full Text PDF

Pancreas serves endocrine and exocrine functions in the body; thus, their pathology can cause a broad range of irreparable consequences. Endocrine functions include the production of hormones such as insulin and glucagon, while exocrine functions involve the secretion of digestive enzymes. Disruption of these functions can lead to conditions like diabetes mellitus and exocrine pancreatic insufficiency.

View Article and Find Full Text PDF

During the coronavirus disease 2019 (COVID-19) pandemic, outbreaks of parainfluenza virus type 3 (PIV-3) decreased due to infection control measures. However, a post-pandemic resurgence of PIV-3 has recently been observed. Nonetheless, the role of viral genetic epidemiology, possibly influenced by a genetic bottleneck effect, remains unexplored.

View Article and Find Full Text PDF

Monolayer transition metal dichalcogenides (TMDs) have emerged as highly promising candidates for optoelectronic applications due to their direct band gap and strong light-matter interactions. However, exfoliated TMDs have demonstrated optical characteristics that fall short of expectations, primarily because of significant defects and associated doping in the synthesized TMD crystals. Here, we report the improvement of optical properties in monolayer TMDs of MoS, MoSe, WS, and WSe, by hBN-encapsulation annealing.

View Article and Find Full Text PDF

Magnetic materials in reduced dimensions are not only excellent platforms for fundamental studies of magnetism, but they play crucial roles in technological advances. The discovery of intrinsic magnetism in monolayer 2D van der Waals systems has sparked enormous interest, but the single-chain limit of 1D magnetic van der Waals materials has been largely unexplored. This paper reports on a family of 1D magnetic van der Waals materials with composition MX (M = Cr, V, and X = Cl, Br, I), prepared in fully-isolated fashion within the protective cores of carbon nanotubes.

View Article and Find Full Text PDF

Advancements in the synthesis of large-area, high-quality two-dimensional transition metal dichalcogenides such as MoS play a crucial role in the development of future electronic and optoelectronic devices. The presence of defects formed by sulfur vacancies in MoS results in low photoluminescence emission and imparts high n-type doping behavior, thus substantially affecting material quality. Herein, we report a new method in which single-phase (liquid) precursors are used for the metal-organic chemical vapor deposition (MOCVD) growth of a MoS film.

View Article and Find Full Text PDF

Recent advances in two-dimensional semiconductors, particularly molybdenum disulfide (MoS), have enabled the fabrication of flexible electronic devices with outstanding mechanical flexibility. Previous approaches typically involved the synthesis of MoS on a rigid substrate at a high temperature followed by the transfer to a flexible substrate onto which the device is fabricated. A recurring drawback with this methodology is the fact that flexible substrates have a lower melting temperature than the MoS growth process, and that the transfer process degrades the electronic properties of MoS.

View Article and Find Full Text PDF

Elemental phosphorus exhibits fascinating structural varieties and versatile properties. The unique nature of phosphorus bonds can lead to the formation of extremely complex structures, and detailed structural information on some phosphorus polymorphs is yet to be investigated. In this study, we investigated an unidentified crystalline phase of phosphorus, type-II red phosphorus (RP), by combining state-of-the-art structural characterization techniques.

View Article and Find Full Text PDF
Article Synopsis
  • The study focuses on how tetrahedral units are arranged and connected, impacting the properties of certain solids.
  • Researchers created one-dimensional chains of GeX (where X can be S or Se) and explored how their connectivity changes based on the diameter of carbon nanotubes they are confined in.
  • Advanced imaging techniques confirmed the existence of different GeX chains, and theoretical calculations showed that their stability and electronic properties are influenced by the tetrahedral connections and the specific materials used.
View Article and Find Full Text PDF

The widespread usage of antimicrobials has driven the evolution of resistance in pathogenic microbes, both increased prevalence of antimicrobial resistance genes (ARGs) and their spread across species by horizontal gene transfer (HGT). However, the impact on the wider community of commensal microbes associated with the human body, the microbiome, is less well understood. Small-scale studies have determined the transient impacts of antibiotic consumption but we conduct an extensive survey of ARGs in 8972 metagenomes to determine the population-level impacts.

View Article and Find Full Text PDF

Research on the gut microbiota in irritable bowel syndrome (IBS) shows discordant results due to inconsistent study designs or small sample sizes. This study aimed to characterize how gut microbiota in IBS patients differs from that in healthy controls by performing a case-control study and cross- and mega-cohort analysis. Multiple publicly shared data sets were examined by using a unified analytical approach.

View Article and Find Full Text PDF

Pseudomonas is widespread in various environmental and host niches. To promote rejuvenation, cellular protein homeostasis must be finely tuned in response to diverse stresses, such as extremely high and low temperatures, oxidative stress, and desiccation, which can result in protein homeostasis imbalance. Molecular chaperones function as key components that aid protein folding and prevent protein denaturation.

View Article and Find Full Text PDF

Peripheral arterial disease (PAD) is common in elderly patients. Lower-extremity CT angiography (LE-CTA) can be useful for detecting PAD and planning its treatment. PAD can also be accurately evaluated on reconstructed monoenergetic images (MEIs) from low kiloelectron volt (keV) to high keV images using dual-energy CT.

View Article and Find Full Text PDF

The goal of this study was to identify the genomic variants and determine molecular epidemiology of SARS-CoV-2 virus during the early pandemic stage in Bangladesh. Viral RNA was extracted, converted to cDNA, and amplified using Ion AmpliSeq™ SARS-CoV-2 Research Panel. 413 unique mutants from 151 viral isolates were identified.

View Article and Find Full Text PDF

Background: The increasing prevalence of resistance against the last-resort antibiotic colistin is a significant threat to global public health. Here, we discovered a novel colistin resistance mechanism via enzymatic inactivation of the drug and proposed its clinical importance in microbial communities during polymicrobial infections.

Results: A bacterial strain of the Gram-negative opportunistic pathogen Stenotrophomonas maltophilia capable of degrading colistin and exhibiting a high-level colistin resistance was isolated from the soil environment.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the impact of large-scale wildfires on health by comparing medical usage in affected and non-affected areas of Eastern Gangwon-do, Korea.
  • The research utilized data from the Korean National Health Insurance Corporation and analyzed medical use rates before and after a 2019 wildfire.
  • Findings revealed a significant increase in medical care usage among residents in the wildfire-affected region over time, highlighting the health effects of wildfires in Korea for the first time.
View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessiontd817q5vpcadb0jalhfihb4gfm708c6v): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once