Dissolution of ribonucleoprotein condensates by the embryonic stem cell protein L1TD1.

L1TD1 is a cytoplasmic RNA-binding protein specifically expressed in pluripotent stem cells and, unlike its mouse ortholog, is essential for the maintenance of stemness in human cells. Although L1TD1 is the only known protein-coding gene domesticated from a LINE-1 (L1) retroelement, the functional legacy of its ancestral protein, ORF1p of L1, and how it is manifested in L1TD1 are still unknown. Here, we determined RNAs associated with L1TD1 and found that, like ORF1p, L1TD1 binds L1 RNAs and localizes to high-density ribonucleoprotein (RNP) condensates.

Global analysis of binding sites of U2AF1 and ZRSR2 reveals RNA elements required for mutually exclusive splicing by the U2- and U12-type spliceosome.

Recurring mutations in genes encoding 3' splice-site recognition proteins, U2AF1 and ZRSR2 are associated with human cancers. Here, we determined binding sites of the proteins to reveal that U2-type and U12-type splice sites are recognized by U2AF1 and ZRSR2, respectively. However, some sites are spliced by both the U2-type and U12-type spliceosomes, indicating that well-conserved consensus motifs in some U12-type introns could be recognized by the U2-type spliceosome.

Toxoplasma gondii and Rickettsia spp. in ticks collected from migratory birds in the Republic of Korea.

Migratory birds disperse ticks and associated tick-borne pathogens along their migratory routes. Four selected pathogens of medical importance (Coxiella burnetii, Rickettsia spp., Francisella tularensis, and Toxoplasma gondii) were targeted for detection in 804 ticks (365 pools) collected from migratory birds at Hong and Heuksan Islands in the Republic of Korea (ROK) from 2010 to 2011 and 2016.

Plastic debris ingestion by seabirds on the Korean Peninsula.

Plastic ingestion studies in seabirds that analyse the frequency of occurrence and the characteristics of the plastics ingested by each species provide valuable information for marine environmental assessments by quantifying the impacts of marine debris on seabirds. We investigated the frequency of plastic ingestion from a sample of 387 individuals of 11 seabird species on the Korean Peninsula. We found evidence of plastic ingestion in red-breasted mergansers (Mergus serrator) (33.

Molecular Detection and Phylogenetic Analysis of and Species in Ticks Collected from Migratory Birds at Heuksan, Hong, and Nan Islands, Republic of Korea.

The extended distribution and potential introduction of exotic ticks and associated tick-borne pathogens along the northern and southern routes of migratory birds pose zoonotic tick-borne disease risks to wild and domestic animals and incidentally to humans. A knowledge of bird migratory patterns, species of attached ticks, and associated pathogens during their migrations to and from their feeding and nesting grounds is central to understanding associated tick-borne disease risks. Tick-borne disease surveillance was conducted from 2010 to 2011 and 2016 at Hong-do (do = island), Heuksan-do, and Nan-do, major stopovers for migratory birds in Republic of Korea (ROK), as part of the Migratory Birds Research Center bird-banding program for studying bird migration patterns in the ROK.

The conserved microRNA miR-8-3p coordinates the expression of V-ATPase subunits to regulate ecdysone biosynthesis for Drosophila metamorphosis.

The steroid hormone ecdysone is the central regulator of insect metamorphosis, during which a growing, immature larva is remodeled, through pupal stages, to a reproductive adult. However, the underlying mechanisms of ecdysone-mediated metamorphosis remain to be fully elucidated. Here, we identified metamorphosis-associated microRNAs (miRNAs) and their potential targets by cross-linking immunoprecipitation coupled with deep sequencing of endogenous Argonaute 1 protein in Drosophila.

MicroRNAs of miR-17-92 cluster increase gene expression by targeting mRNA-destabilization pathways.

MicroRNAs (miRNAs) of the miR-17-92 cluster are overexpressed in human cancers, and their enforced expression is tumorigenic in mouse models. A number of genes are reported to be targets of these miRNAs and are implicated in their tumorigenic potential. However, the mode of action by miRNAs suggests that global analysis of their targets is required to understand their cellular roles.

Ecdysone-responsive microRNA-252-5p controls the cell cycle by targeting Abi in Drosophila.

The steroid hormone ecdysone has a central role in the developmental transitions of insects through its control of responsive protein-coding and microRNA (miRNA) gene expression. However, the complete regulatory network controlling the expression of these genes remains to be elucidated. In this study, we performed cross-linking immunoprecipitation coupled with deep sequencing of endogenous Argonaute 1 (Ago1) protein, the core effector of the miRNA pathway, in Drosophila S2 cells.

Global analysis of AGO2-bound RNAs reveals that miRNAs induce cleavage of target RNAs with limited complementarity.

Among the four Argonaute family members in mammals, only AGO2 protein retains endonuclease activity and facilitates cleavage of target RNAs base-pairing with highly complementary guide RNAs. Despite the deeply conserved catalytic activity, only a small number of targets have been reported to extensively base pair with cognate miRNAs to be cleaved by AGO2. Here, we analyzed AGO2-bound RNAs by CrossLinking ImmunoPrecipitation (CLIP) of genetically modified cells that express epitope-tagged AGO2 from the native genomic locus.

Hybrid Structure White Organic Light Emitting Diode for Enhanced Efficiency by Varied Doping Rate.

Novel materials based on Zn(HPB)2 and Ir-complexes were synthesized as blue or red emitters, respectively. White organic light emitting diodes were fabricated using the Zn(HPB)2 as a blue emitting layer, Ir-complexes as a red emitting layer and Alq3 as a green emitting layer. The obtained experimental results, were based on white OLEDs fabricated using double emission layers of Zn(HPB)2 and Alq3:Ir-complexes.

White OLED in Hybrid Structure for Enhancing Color Purity.

We synthesized the red emission material, bis(1,4-bis(5-phenyloxazol-2-yl)phenyl) iridium(picolate) [Ir-complexes] and the blue emission material, bis (2-(2-hydroxyphenyl) benzoxazolate)zinc [Zn(HPB)2]. White Organic Light Emitting Diodes were fabricated by using Zn(HPB)2 for a blue emitting layer, Ir-complexes for a red emitting layer and a tris (8-hydroxy quinoline)aluminum [Alq3] for a green emitting layer. The important experimental results obtained, white OLED was fabricated by using double emitting layers of Zn(HPB)2 and Alq3:Ir-complexes, and hole blocking layer of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline[BCP].

Characteristics of Intramolecular Charge Transfer by J-Aggregates in Merocyanine Dye LB Films.

In this study, for the development of future molecular electronic devices, we have investigated the characteristics of the aggregates of Langmuir-Blodgett films. The characteristics of intramolecular charge transfer by J-aggregates in merocyanine dye LB films have been studied experimentally by using UV irradiation and heat treatment. In addition to intramolecular charge transfer, we also studied the conjugation and energy changes of the molecules.

Ornithodoros sawaii (Ixodida: Argasidae) Larvae Collected from Hydrobates monorhis on Sogugul and Gaerin Islands, Jeollanam-do (Province), Republic of Korea.

The 65th Medical Brigade and Public Health Command District-Korea, in collaboration with the Migratory Bird Research Center, National Park Research Institute, conducted migratory bird tick surveillance at Sogugul and Gaerin Islands (small rocky bird nesting sites), Jeollanam-do (Province), Republic of Korea (ROK), on 30 July and 1 August 2009. Breeding seabirds captured by hands in their nesting burrows were banded, identified to species, and carefully examined for ticks during the nesting season. A total of 9 Ornithodoros sawaii larvae were removed from 4 adult Hydrobates monorhis (Swinhoe's storm petrel).

A Study on the Rectification Property of Self-Assembled Viologen Single Molecules Using a Scanning Tunneling Microscopy.

An ultrahigh vacuum scanning tunneling microscopy (UHV-STM) and a scanning tunneling spectroscopy (STS) are used measure the rectification property of self-assembled viologen single molecules (VC8SH, VC10SH, HSC8VC8SH, and HSC10VC10SH) in the previous study. Using STM we observe viologen single molecules in the self-assembled octanethiol (OT) SAM matrix. In the OT matrix a mixed phase that includes a c(4 x 2) superlattice of high-density standing up-phase is observed.

Fabrication of White Organic Light Emitting Diode Using Two Types of Zn-Complexes as an Emitting Layer.

We have studied white OLED using two types of Zn-complexes as an emitting layer. We synthesized brand new two emissive materials, Zn(HPQ)2 as a yellow emitting material and Zn(HPB)2 as a blue emitting material. The Zn-complexes are low-molecular compounds and stable thermally.

Synthesis and electroluminescent properties of a novel electroluminescence material of bis-2-(4-(diphenylphosphino)phenyl)benzo[d]oxazole (DPB).

A new light-emissive material, bis-2-(4-(diphenylphosphino)phenyl)benzo[d]oxazole (DPB), has been synthesized and characterized by FT-NMR, FT-IR, UV-Vis and elemental analysis. DPB has the band gap of 4.3 eV between HOMO and LUMO levels.

Spatial patterns, ecological niches, and interspecific competition of avian brood parasites: inferring from a case study of Korea.

Since obligate avian brood parasites depend completely on the effort of other host species for rearing their progeny, the availability of hosts will be a critical resource for their life history. Circumstantial evidence suggests that intense competition for host species may exist not only within but also between species. So far, however, few studies have demonstrated whether the interspecific competition really occurs in the system of avian brood parasitism and how the nature of brood parasitism is related to their niche evolution.

Global identification of target recognition and cleavage by the Microprocessor in human ES cells.

The Microprocessor plays an essential role in canonical miRNA biogenesis by facilitating cleavage of stem-loop structures in primary transcripts to yield pre-miRNAs. Although miRNA biogenesis has been extensively studied through biochemical and molecular genetic approaches, it has yet to be addressed to what extent the current miRNA biogenesis models hold true in intact cells. To address the issues of in vivo recognition and cleavage by the Microprocessor, we investigate RNAs that are associated with DGCR8 and Drosha by using immunoprecipitation coupled with next-generation sequencing.

Well-defined all-conducting block copolymer bilayer hybrid nanostructure: selective positioning of lithium ions and efficient charge collection.

A block copolymerization of nonfunctionalized conducting monomers was developed to enable the successful synthesis of a highly insoluble 3,4-(ethylenedioxy)thienyl-based all-conducting block copolymer (PEDOT-b-PEDOT-TB) that could encapsulate nanocrystalline dyed TiO2 particles, resulting in the formation of an all-conducting block copolymer bilayer hybrid nanostructure (TiO2/Dye/PEDOT-b-PEDOT-TB). Lithium ions were selectively positioned on the outer PEDOT-TB surface. The distances through which the positively charged dye and PEDOT-TB(Li(+)) interacted physically or through which the TiO2 electrode and the Li(+) centers on PEDOT-TB(Li(+)) interacted ionically were precisely tuned and optimized within ca.

Electrical characterization of organic monolayers at a nanoscale.

This study investigates the electrical properties of viologen derivatives at a nanoscale and analyzes it using a scanning tunneling microscopy (STM) in order to apply viologen molecules that represent a function in electron transfer mediators as a molecular electronic device. In addition, we measure conformational changes in the viologen molecular protrusions using STM and investigate changes in the width and height of the alkyl group that are due to the change in the polarity of viologen molecules by electron charges. In this experiment, high peak current is observed, such as a rectification at +1.

White organic light-emitting diodes with Zn-complexes.

This paper reviews OLEDs fabricated using Zn-complexes. Zn(HPB)2, Zn(HPB)q, and Zn(phen)q were synthesized as new electroluminescence materials. The electron affinity (EA) and ionization potential (IP) of Zn complexes were also determined and devices were characterized.

Cell cycle-dependent regulation of Aurora kinase B mRNA by the Microprocessor complex.

Aurora kinase B regulates the segregation of chromosomes and the spindle checkpoint during mitosis. In this study, we showed that the Microprocessor complex, which is responsible for the processing of the primary transcripts during the generation of microRNAs, destabilizes the mRNA of Aurora kinase B in human cells. The Microprocessor-mediated cleavage kept Aurora kinase B at a low level and prevented premature entrance into mitosis.

Fabrication of a polymer-metal combined atomic force microscopy probe for coarse food surface imaging.

We fabricated a polymer-metal combined atomic force microscopy (AFM) probe by two steps; a polymeric resin was used at first step, and a metal-ion was used at second step which needs more fabricating time than the resin. At first step, we fabricated a cylindrical base on to a commercial cantilever. At second step, we fabricated a conical probe on to the fabricated cylindrical base.

Facile fabrication of aligned doubly open-ended TiO2 nanotubes, via a selective etching process, for use in front-illuminated dye sensitized solar cells.

A simple selective etching process easily removed a 2nd anodized TiO(2) nanotubes (TNTs) layer from a physically stable 1st anodized TNTs layer to produce noncurling, freestanding, large-area aligned doubly open-ended TNTs. These TNTs were easily transferred to a conducting glass for use in fabricating front-illuminated dye sensitized solar cells.