Publications by authors named "Seung-Je Woo"

Immunological conservation across species is crucial for comparative biology. While Natural killer (NK) cells' functions are conserved in humans and mice at the single-cell level, they remain unexplored in chickens due to technical limitations. Single-cell RNA sequencing in a recombination-activating gene 1-deficient ( ) chicken model revealed two NK cell subpopulations (NK-1 and -2) in chickens, analogous to those in humans and mice.

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Optical control of electron spin states is important for quantum sensing and computing applications, as developed with the diamond nitrogen vacancy centre. This requires electronic excitations, excitons, with net spin. Here we report a molecular diradical where two trityl radical groups are coupled via a meta-linked fluorene bridge.

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The tumor virus A receptor (TVA), a member of the low-density lipoprotein receptor (LDLR) family, serves as an entry receptor for Avian Leukosis Virus (ALV) subgroups A and K, as well as a receptor for vitamin B bound to transcobalamin. Naturally occurring genetic variants in the TVA gene determine susceptibility or resistance to ALV-A and -K, but the effects of these mutated TVA on vitamin B uptake have not been investigated systemically. We found four TVA variants comprising the wild type (TVA), a single nucleotide polymorphism variant (TVA), and two partial deletions in the splicing branch point region (TVA).

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Metal halide perovskite light-emitting diodes (PeLEDs) have exceptional color purity but designs that emit deep-blue color with high efficiency have not been fully achieved and become more difficult in the thin film of confined perovskite colloidal quantum dots (PeQDs) due to particle interaction. Here it is demonstrated that electronic coupling and energy transfer in PeQDs induce redshift in the emission by PeQD film, and consequently hinder deep-blue emission. To achieve deep-blue emission by avoiding electronic coupling and energy transfer, a QD-in-organic solid solution is introduced to physically separate the QDs in the film.

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Article Synopsis
  • Japanese quail are important for providing protein but their sexual dimorphism is not well understood compared to other species.
  • Researchers analyzed RNA sequencing data from quails and chickens to identify sex-biased genes in different tissues and stages of development.
  • Results showed that quails and chickens have similar gene expression patterns related to sex determination, but there are unique challenges due to the lack of global dosage compensation in quails that could affect breeding and transgenic efforts.
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Reducing the size of perovskite crystals to confine excitons and passivating surface defects has fueled a significant advance in the luminescence efficiency of perovskite light-emitting diodes (LEDs). However, the persistent gap between the optical limit of electroluminescence efficiency and the photoluminescence efficiency of colloidal perovskite nanocrystals (PeNCs) suggests that defect passivation alone is not sufficient to achieve highly efficient colloidal PeNC-LEDs. Here, we present a materials approach to controlling the dynamic nature of the perovskite surface.

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  • Animals make decisions based on both innate sensory cues and learned information, but the interaction between these two types of memory is not fully understood.
  • The study investigates how dopamine neurons in the Drosophila brain manage both innate and learned sensory valences, affecting memory processes during olfactory conditioning.
  • Findings indicate that specific dopamine neurons regulate short- and long-term memory formation, with implications for understanding memory dynamics in other species.
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Chicken embryos serve as an important model for investigating germ cells due to their ease of accessibility and manipulation within the egg. Understanding the development of germ cells is particularly crucial, as they are the only cell types capable of transmitting genetic information to the next generation. Therefore, gene expression regulation in germ cells is important for genomic function.

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Perovskite light-emitting diodes (PeLEDs) have emerged as a promising new light source for displays. The development roadmap for commercializing PeLEDs should include a tandem device structure, specifically by stacking a thin nanocrystal PeLED unit and an organic light-emitting diode unit, which can achieve a vivid and efficient tandem display; however, simply combining light-emitting diodes with different characteristics does not guarantee both narrowband emission and high efficiency, as it may cause a broadened electroluminescence spectra and a charge imbalance. Here, by conducting optical simulations of the hybrid tandem (h-tandem) PeLED, we have discovered a crucial optical microcavity structure known as the h-tandem valley, which enables the h-tandem PeLED to emit light with a narrow bandwidth.

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  • Monolayer transition metal dichalcogenides (TMDs) are gaining interest for optoelectronic applications due to their direct band gap and high quantum yield, but face challenges like low external quantum efficiencies caused by non-radiative charged excitons.
  • This study demonstrates electrically confined electroluminescence (EL) of neutral excitons in tungsten diselenide (WSe) light-emitting transistors (LETs) by using a local graphene gate to balance electron and hole injection.
  • The balanced injection leads to a strong EL with an external quantum efficiency (EQE) of approximately 8.2% at room temperature, showcasing a method to enhance EQE in 2D light-emitting devices and
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Introduction: Infectious viruses in poultry, such as avian influenza virus (AIV) and Newcastle disease virus (NDV), are one of the most major threats to the poultry industry, resulting in enormous economic losses. AIVs and NDVs preferentially recognize α-2,3-linked sialic acid to bind to target cells. The human beta-1,4-N-acetyl-galactosaminyltransferase 2 (B4GALNT2) modifies α-2,3-linked sialic acid-containing glycan by transferring N-acetylgalactosamine to the sub-terminal galactose of the glycan, thus playing a pivotal role in preventing viruses from binding to cell surfaces.

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The small nanoparticle size and long-chain ligands in colloidal metal halide perovskite quantum dots (PeQDs) cause charge confinement, which impedes exciton dissociation and carrier extraction in PeQD solar cells, so they have low short-circuit current density J , which impedes further increases in their power conversion efficiency (PCE). Here, a re-assembling process (RP) is developed for perovskite nanocrystalline (PeNC) films made of colloidal perovskite nanocrystals to increase J in PeNC solar cells. The RP of PeNC films increases their crystallite size and eliminates long-chain ligands, and thereby overcomes the charge confinement in PeNC films.

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Avian models are valuable for studies of development and reproduction and have important implications for food production. Rapid advances in genome-editing technologies have enabled the establishment of avian species as unique agricultural, industrial, disease-resistant, and pharmaceutical models. The direct introduction of genome-editing tools, such as the clustered regularly interspaced short palindromic repeats (CRISPR) system, into early embryos has been achieved in various animal taxa.

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  • Mitotic arrest is crucial for the proper embryonic development of male germ cells, and understanding the related signaling pathways is essential.
  • Researchers conducted single-cell transcriptome analysis on male embryonic chicken germ cells to examine these signaling pathways during mitotic arrest.
  • They discovered that key components of BMP, Notch, and JAK-STAT pathways were downregulated during arrest but reactivated after hatching, while MAPK, Hedgehog, and thyroid-hormone pathways showed a steady increase, indicating complex interactions among multiple signaling pathways.
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Primordial germ cells (PGCs) in chickens polarize and move passively toward the anterior region by the morphogenetic movement of the embryo. Further migration of PGCs towards the genital ridge via the germinal crescent region and blood vessels occurs actively through the chemoattractive signals. The mechanisms of initiation of PGCs migration, lodging the PGCs in the vascular system, and colonization of PGCs in the gonads are well-studied.

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Metal halide perovskites are attracting a lot of attention as next-generation light-emitting materials owing to their excellent emission properties, with narrow band emission. However, perovskite light-emitting diodes (PeLEDs), irrespective of their material type (polycrystals or nanocrystals), have not realized high luminance, high efficiency and long lifetime simultaneously, as they are influenced by intrinsic limitations related to the trade-off of properties between charge transport and confinement in each type of perovskite material. Here, we report an ultra-bright, efficient and stable PeLED made of core/shell perovskite nanocrystals with a size of approximately 10 nm, obtained using a simple in situ reaction of benzylphosphonic acid (BPA) additive with three-dimensional (3D) polycrystalline perovskite films, without separate synthesis processes.

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Multi-resonance thermally activated delayed fluorescence (MR-TADF) molecules based on boron and nitrogen atoms are emerging as next-generation blue emitters for organic light-emitting diodes (OLEDs) due to their narrow emission spectra and triplet harvesting properties. However, intermolecular aggregation stemming from the planar structure of typical MR-TADF molecules that leads to concentration quenching and broadened spectra limits the utilization of the full potential of MR-TADF emitters. Herein, a deep-blue MR-TADF emitter, pBP-DABNA-Me, is developed to suppress intermolecular interactions effectively.

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Although birds have been used historically as a model animal for immunological research, resulting in remarkable achievements, immune cell development in birds themselves has yet to be fully elucidated. In this study, we firstly generated an immunodeficient chicken model using a CRISPR/Cas9-mediated recombination activating gene 1 () knockout, to investigate avian-specific immune cell development. Unlike previously reported immunoglobulin (Ig) heavy chain knockout chickens, the proportion and development of B cells in both and embryos were significantly impaired during B cell proliferation (embryonic day 16 to 18).

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Avian germ cells can be distinguished by certain characteristics during development. On the basis of these characteristics, germ cells can be used for germline transmission. However, the dynamic transcriptional landscape of avian germ cells during development is unknown.

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Innate immune system is triggered by pattern recognition receptors (PRRs) recognition. Retinoic acid-inducible gene 1 (RIG-I) is a major sensor that recognizes RNA ligands. However, chickens have no homologue of RIG-I; instead, they rely on melanoma differentiation-associated protein 5 (MDA5) to recognize RNA ligands, which renders chickens susceptible to infection by influenza A viruses (IAVs).

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DNA is susceptible to damage by various sources. When the DNA is damaged, the cell repairs the damage through an appropriate DNA repair pathway. When the cell fails to repair DNA damage, apoptosis is initiated.

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Triplet harvesting is important for the realization of high-efficiency fluorescent organic light-emitting diodes (OLEDs). Triplet-triplet annihilation (TTA) is one triplet-harvesting strategy. However, for blue-emitting anthracene derivatives, the theoretical maximum radiative singlet-exciton ratio generated from the TTA process is known to be 15% in addition to the initially generated singlets of 25%, which is insufficient for high-efficiency fluorescent devices.

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The acidic nuclear phosphoprotein 32 family member A (ANP32A) is a cellular host factor that determines the host tropism of the viral polymerase (vPol) of avian influenza viruses (AIVs). Compared with human ANP32A (hANP32A), chicken ANP32A contains an additional 33 amino acid residues (176-208) duplicated from amino acid residues 149-175 (27 residues), suggesting that these residues could be involved in increasing vPol activity by strengthening interactions between ANP32A and vPol. However, the molecular interactions and functional roles of the 27 residues within hANP32A during AIV vPol activity remain unclear.

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Reverse intersystem crossing (RISC) rate of a thermally activated delayed fluorescence (TADF) molecule is sensitive to the energy alignment of the singlet charge-transfer state (CT), triplet charge-transfer state (CT), and locally excited triplet state (LE). However, the energy distribution of the charge-transfer states originating from the conformational distribution of TADF molecules in a solid matrix inevitably generated during the preparation of a solid sample due to the rotatable donor-acceptor linkage is rarely considered. Moreover, the investigation of the energy distribution of the CT state is both theoretically and experimentally difficult due to the triplet instabilities of time-dependent density functional (TD-DFT) calculations and difficulties in phosphorescence measurements, respectively.

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Background: The initial step of influenza infection is binding of the virus to specific sialic acid receptors expressed by host cells. This is followed by cell entry via endocytosis. Cleavage of the influenza virus hemagglutinin (HA) protein is critical for infection; this is performed by host cell proteases during viral replication.

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