Publications by authors named "Youn Sung Kim"

Members of the FLOWERING LOCUS T (FT)-like clade of phosphatidylethanolamine-binding proteins (PEBPs) induce flowering by associating with the basic leucine zipper (bZIP) transcription factor FD and forming regulatory complexes in angiosperm species. However, the molecular mechanism of the FT-FD heterocomplex in Chinese cabbage ( ssp. ) is unknown.

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Peptidyl-prolyl isomerase-like 1 (PPIL1) is associated with the human spliceosome complex. However, its function in pre-mRNA splicing remains unclear. In this study, we show that Arabidopsis thaliana CYCLOPHILIN 18-2 (AtCYP18-2), a PPIL1 homolog, plays an essential role in heat tolerance by regulating pre-mRNA splicing.

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In plants, heat stress induces changes in alternative splicing, including intron retention; these events can rapidly alter proteins or downregulate protein activity, producing nonfunctional isoforms or inducing nonsense-mediated decay of messenger RNA (mRNA). Nuclear cyclophilins (CYPs) are accessory proteins in the spliceosome complexes of multicellular eukaryotes. However, whether plant CYPs are involved in pre-mRNA splicing remain unknown.

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Precise flowering timing is critical for the plant life cycle. Here, we examined the molecular mechanisms and regulatory network associated with flowering in Chinese cabbage ( L.) by comparative transcriptome profiling of two Chinese cabbage inbred lines, "4004" (early bolting) and "50" (late bolting).

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Gibberellic acid (GA) is one of the factors that promotes flowering in radish ( L.), although the mechanism mediating GA activation of flowering has not been determined. To identify this mechanism in radish, we compared the effects of GA treatment on late-flowering (NH-JS1) and early-flowering (NH-JS2) radish lines.

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Late bolting after cold exposure is an economically important characteristic of radish ( L.), an important Brassicaceae root vegetable crop. However, little information is available regarding the genes and pathways that govern flowering time in this species.

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Operational scars, especially those located on the exposed parts of the body, can be distressing. Despite high demand for an early intervention to minimize surgical scars, there is yet no universal consensus on optimal treatment. A split-scar, double-blind randomized controlled trial was held to assess the safety and efficacy of early postoperative botulinum toxin type A (BTA) injection in surgical scars.

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Results of transcriptome analyses suggest that expansin genes play an active role in seed development and yield, but gain- or loss-of-function studies have not yet elucidated the functional role(s) of the expansin gene(s) in these processes. We have overexpressed a sweetpotato expansin gene (IbEXP1) in Arabidopsis under the control of cauliflower mosaic 35S promoter in an attempt to determine the effect of the expansin gene in seed development and yield in heterologous plants. The growth rate was enhanced in IbEXP1-overexpressing (ox) plants relative to wild-type Col-0 plants during early vegetative growth stage.

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Background: The use of botulinum toxin has rapidly expanded into various aesthetic applications. Any guideline representing a consensus for aesthetic treatments using botulinum toxin type A (BTA) in Asians has not been published.

Objectives: To provide consensus recommendations on common aesthetic problems which are treated by neurotoxin in Asians.

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Background: The extraneuronal cholinergic system has been implicated in numerous functions in the skin, such as terminal differentiation, barrier formation, sweat secretion and the microcirculation. However, the evidence for cholinergic signalling in sebaceous glands is lacking, and its role needs to be clarified.

Objective: We investigated the role of acetylcholine signalling in sebaceous glands using human sebocytes and a clinical study using botulinum toxin.

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Reference materials for quantitative determination of Cd, Cr, Hg and Pb in polycarbonate were developed. Reference materials with two concentration level of elements were prepared by adding appropriate amounts of chemicals to a blank polycarbonate base material. It was shown that ten bottles with triplicate analysis are enough to demonstrate the homogeneity of these candidate reference materials.

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Transcriptional reprogramming forms a major part of a plant's response to pathogen infection. Many individual components and pathways operating during plant defense have been identified, but our knowledge of how these different components interact is still rudimentary. We generated a high-resolution time series of gene expression profiles from a single Arabidopsis thaliana leaf during infection by the necrotrophic fungal pathogen Botrytis cinerea.

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The role of an expansin gene (IbEXP1) in the formation of the storage root (SR) was investigated by expression pattern analysis and characterization of IbEXP1-antisense sweetpotato (Ipomoea batatas cv. Yulmi) plants in an attempt to elucidate the molecular mechanism underlying SR development in sweetpotato. The transcript level of IbEXP1 was high in the fibrous root (FR) and petiole at the FR stage, but decreased significantly at the young storage root (YSR) stage.

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Coordination of the onset of flowering with developmental status and seasonal cues is critical for reproductive success in plants. Molecular genetic studies on Arabidopsis mutants that have alterations in flowering time have identified a wide array of genes that belong to distinct genetic flowering pathways. The flowering time genes are regulated through versatile molecular and biochemical mechanisms, such as controlled RNA metabolism and chromatin modifications.

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Iron is an essential micronutrient that acts as a cofactor in a wide variety of pivotal metabolic processes, such as the electron transport chain of respiration, photosynthesis and redox reactions, in plants. However, its overload exceeding the cellular capacity of iron binding and storage is potentially toxic to plant cells by causing oxidative stress and cell death. Consequently, plants have developed versatile mechanisms to maintain iron homoeostasis.

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Seed germination is regulated through elaborately interacting signaling networks that integrate diverse environmental cues into hormonal signaling pathways. Roles of gibberellic acid and abscisic acid in germination have been studied extensively using Arabidopsis (Arabidopsis thaliana) mutants having alterations in seed germination. Auxin has also been implicated in seed germination.

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Leaf senescence is an essential developmental process that impacts dramatically on crop yields and involves altered regulation of thousands of genes and many metabolic and signaling pathways, resulting in major changes in the leaf. The regulation of senescence is complex, and although senescence regulatory genes have been characterized, there is little information on how these function in the global control of the process. We used microarray analysis to obtain a high-resolution time-course profile of gene expression during development of a single leaf over a 3-week period to senescence.

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An organic-assisted alkaline extraction method was developed for the determination of hexavalent chromium (Cr(VI)) in plastics. The solubilization of polymer as a pre-step of the alkaline extraction provided good extraction efficiency of Cr(VI) from the sample. The optimization of the experimental conditions affecting the extraction and UV-vis spectrophotometric analysis was accomplished by evaluating the recovery rate of Cr(VI) through the analysis of Cr(VI) in in-house polymer reference materials (RMs).

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The tapetum is a layer of cells covering the inner surface of pollen sac wall. It contributes to anther development by providing enzymes and materials for pollen coat biosynthesis and nutrients for pollen development. At the end of anther development, the tapetum is degenerated, and the anther is dehisced, releasing mature pollen grains.

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Microsomal oleic acid desaturase (FAD2) catalyzes the first committed step of the biosynthesis of polyunsaturated fatty acids via extra-plastidial desaturation of oleic acid to linoleic acid. In the regulatory mechanism controlling seed-specific SeFAD2 expression, trans-activation of the seed-specific SeFAD2 promoter is mediated by the SebHLH transcription factor (Kim et al. in Plant Mol Biol 64:453-466, 2007).

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Changes in membrane fluidity are the earliest cellular events that occur in plant cells upon exposure to cold. This subsequently triggers physiological processes, such as calcium influx and reorganization of actin cytoskeletons, and induces expression of cold-responsive genes. The plasma-membrane-anchored NAC (NAM/ATAF/CUC) transcription factor NTL6 is of particular interest.

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A helmet-based system that was able to monitor the drowsiness of a soldier was developed. The helmet system monitored the electrocardiogram, electrooculogram and electroencephalogram (alpha waves) without constraints. Six dry electrodes were mounted at five locations on the helmet: both temporal sides, forehead region and upper and lower jaw strips.

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Shoot apical meristem (SAM) development is coordinately regulated by two interdependent signaling events: one maintaining stem cell identity and the other governing the initiation of lateral organs from the flanks of the SAM. The signaling networks involved in this process are interconnected and are regulated by multiple molecular mechanisms. Class III homeodomain-leucine zipper (HD-ZIP III) proteins are the most extensively studied transcription factors involved in this regulation.

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