Konkuk University

About: Konkuk University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Apoptosis. The organization has 13405 authors who have published 27027 publications receiving 506313 citations.

Measurement of D-meson production at mid-rapidity in pp collisions at √s=7 TeV

Abstract: The production cross sections for prompt charmed mesons $$\mathrm{D^0}$$ , $$\mathrm{D^+}$$ , $$\mathrm{D^{*+}}$$ and $$\mathrm{D_s^+}$$ were measured at mid-rapidity in proton–proton collisions at a centre-of-mass energy $$\sqrt{s}=7~{\mathrm {TeV}}$$ with the ALICE detector at the Large Hadron Collider (LHC). D mesons were reconstructed from their decays $$\mathrm{D}^0 \rightarrow \mathrm{K}^-\pi ^+$$ , $$\mathrm{D}^+\rightarrow \mathrm{K}^-\pi ^+\pi ^+$$ , $$\mathrm{D}^{*+} \rightarrow \mathrm{D}^0 \pi ^+$$ , $$\mathrm{D_s^{+}\rightarrow \phi \pi ^+\rightarrow K^-K^+\pi ^+}$$ , and their charge conjugates.With respect to previous measurements in the same rapidity region, the coverage in transverse momentum ( $$p_\mathrm{T}$$ ) is extended and the uncertainties are reduced by a factor of about two. The accuracy on the estimated total $$\mathrm{c}{\overline{\mathrm{c}}}$$ production cross section is likewise improved. The measured $$p_\mathrm{T}$$ -differential cross sections are compared with the results of three perturbative QCD calculations.

Mitochondrial Dynamics in Stem Cells and Differentiation.

Abstract: Mitochondria are highly dynamic organelles that continuously change their shape. Their main function is adenosine triphosphate (ATP) production; however, they are additionally involved in a variety of cellular phenomena, such as apoptosis, cell cycle, proliferation, differentiation, reprogramming, and aging. The change in mitochondrial morphology is closely related to the functionality of mitochondria. Normal mitochondrial dynamics are critical for cellular function, embryonic development, and tissue formation. Thus, defects in proteins involved in mitochondrial dynamics that control mitochondrial fusion and fission can affect cellular differentiation, proliferation, cellular reprogramming, and aging. Here, we review the processes and proteins involved in mitochondrial dynamics and their various associated cellular phenomena.

Pax6-Dependent Cortical Glutamatergic Neuronal Differentiation Regulates Autism-Like Behavior in Prenatally Valproic Acid-Exposed Rat Offspring

Abstract: Imbalance in excitatory/inhibitory signal in the brain has been proposed as one of the main pathological features in autism spectrum disorders, although the underlying cellular and molecular mechanism is unclear yet. Because excitatory/inhibitory imbalance can be induced by aberration in glutamatergic/GABAergic neuronal differentiation, we investigated the mechanism of dysregulated neuronal differentiation between excitatory and inhibitory neurons in the embryonic and postnatal brain of prenatally valproic acid-exposed rat offspring, which is often used as an animal model of autism spectrum disorders. Transcription factor Pax6, implicated in glutamatergic neuronal differentiation, was transiently increased in embryonic cortex by valproate exposure, which resulted in the increased expression of glutamatergic proteins in postnatal brain of offspring. Chromatin immunoprecipitation showed increased acetylated histone binding on Pax6 promoter region, which may underlie the transcriptional up-regulation of Pax6. Other histone deacetylase (HDAC) inhibitors including TSA and SB but not valpromide, which is devoid of HDAC inhibitor activity, induced Pax6 up-regulation. Silencing Pax6 expression in cultured rat primary neural progenitor cells demonstrated that up-regulation of Pax6 plays an essential role in valproate-induced glutamatergic differentiation. Blocking glutamatergic transmission with MK-801 or memantine treatment, and to a lesser extent with MPEP treatment, reversed the impaired social behaviors and seizure susceptibility of prenatally valproate-exposed offspring. Together, environmental factors may contribute to the imbalance in excitatory/inhibitory neuronal activity in autistic brain by altering expression of transcription factors governing glutamatergic/GABAergic differentiation during fetal neural development, in conjunction with the genetic preload.

Desorption of single-stranded nucleic acids from graphene oxide by disruption of hydrogen bonding

Abstract: Graphene oxide (GO) is known to interact with single-stranded nucleic acids through pi-stacking interactions and hydrogen bonds between the nucleobases and the hexagonal cells of GO. It also quenches the fluorescence when the fluorophore comes near to the GO mesh. When single-stranded (ss) regions of either DNA or RNA are present, those regions were adsorbed onto the surface of GO with a quenching of fluorescence located proximally to the GO surface. We demonstrated that bound single-stranded nucleic acids can be readily dissociated from GO by disrupting hydrogen bonding with urea, which was confirmed with fluorescence measurement and gel electrophoresis. Hydrogen bonding mainly contributes to the interaction between GO and single-stranded nucleic acids such as ssDNA and RNA. The GO-coated mesoporous silica nanoparticles (GO-MSNs) were synthesized for better separation of RNAs from cells. Cellular RNAs were readily adsorbed and eluted with ease by using GO-MSN and urea, respectively, demonstrating that GO-MSN and urea elution is a facile RNA extraction method.

Alteration of miRNA profiles by ionizing radiation in A549 human non-small cell lung cancer cells.

Abstract: Ionizing radiation (IR) is widely used in cancer treatment and in biological studies. It disrupts cellular homeostasis through multiple mechanisms including changes of the expression profile of genes. Although microRNAs (miRNAs) have recently been recognized as important post-transcriptional regulators and are involved in various biological processes, whether miRNAs play any roles in the cellular response to IR, is not well examined. We investigated the profile of miRNA expression following IR in the human lung carcinoma cell line A549, and the expression profiles of IR-responsive miRNAs were confirmed by qRT-PCR. The target mRNAs of IR-responsive miRNAs were predicted with a target prediction tool. Microarray analysis identified 12 and 18 miRNAs in 20- and 40 Gy-exposed A549 cells, respectively, that exhibited more than 2-fold changes in their expression levels. Of these, four were changed in only 20-Gy-treated cells, ten only in 40-Gy-treated cells, and eight miRNAs were found to change after both treatments. qRT-PCR analysis of a subset of the miRNAs showed patterns of regulation as the microarray data, although the magnitude of the changes differed in the two data sets. Target prediction for IR-responsive miRNAs suggests that they target genes related to apoptosis, regulation of cell cycle, and DNA damage and repair. Taken together, these data suggest that miRNA expression is affected by radiation, and they may be involved in the regulation of radiation responses.