Chung-Ang University

About: Chung-Ang University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Thin film. The organization has 13381 authors who have published 26978 publications receiving 416735 citations. The organization is also known as: CAU & Chung.

Revealing the bifurcation in the unfolding pathways of GFP by using single-molecule experiments and simulations

Abstract: Nanomanipulation of biomolecules by using single-molecule methods and computer simulations has made it possible to visualize the energy landscape of biomolecules and the structures that are sampled during the folding process. We use simulations and single-molecule force spectroscopy to map the complex energy landscape of GFP that is used as a marker in cell biology and biotechnology. By engineering internal disulfide bonds at selected positions in the GFP structure, mechanical unfolding routes are precisely controlled, thus allowing us to infer features of the energy landscape of the wild-type GFP. To elucidate the structures of the unfolding pathways and reveal the multiple unfolding routes, the experimental results are complemented with simulations of a self-organized polymer (SOP) model of GFP. The SOP representation of proteins, which is a coarse-grained description of biomolecules, allows us to perform forced-induced simulations at loading rates and time scales that closely match those used in atomic force microscopy experiments. By using the combined approach, we show that forced unfolding of GFP involves a bifurcation in the pathways to the stretched state. After detachment of an N-terminal α-helix, unfolding proceeds along two distinct pathways. In the dominant pathway, unfolding starts from the detachment of the primary N-terminal β-strand, while in the minor pathway rupture of the last, C-terminal β-strand initiates the unfolding process. The combined approach has allowed us to map the features of the complex energy landscape of GFP including a characterization of the structures, albeit at a coarse-grained level, of the three metastable intermediates.

Cognitive Factors of Using Health Apps: Systematic Analysis of Relationships Among Health Consciousness, Health Information Orientation, eHealth Literacy, and Health App Use Efficacy

Abstract: Background: Interest in smartphone health apps has been increasing recently. However, we have little understanding of the cognitive and motivational factors that influence the extent of health-app use. Objective: This study aimed to examine the effects of four cognitive factors—health consciousness, health information orientation, eHealth literacy, and health-app use efficacy—on the extent of health-app use. It also explored the influence of two different use patterns—information and information-behavior use of health apps—with regard to the relationships among the main study variables. Methods: We collected and analyzed 765 surveys in South Korea. According to the results, there was a negligible gender difference: males (50.6%, 387/765) and females (49.4%, 378/765). All participants were adults whose ages ranged from 19 to 59. In order to test the proposed hypotheses, we used a path analysis as a specific form of structural equation modeling. Results: Through a path analysis, we discovered that individuals’ health consciousness had a direct effect on their use of health apps. However, unlike the initial expectations, the effects of health information orientation and eHealth literacy on health-app use were mediated by health-app use efficacy. Conclusions: The results from the path analysis addressed a significant direct effect of health consciousness as well as strong mediating effects of health-app use efficacy. These findings contribute to widening our comprehension of the new, digital dimensions of health management, particularly those revolving around mobile technology. [J Med Internet Res 2014;16(5):e125]

A Planar {Mn19(OH)12}26+ Unit Incorporated in a 60-Tungsto-6-Silicate Polyanion†

Abstract: Polyoxometalates (POMs) are discrete metal–oxo anions of early transition-metals in high oxidation states (e.g. W, Mo, V) and they are usually synthesized in aqueous, acidic medium. Most classical POMs are based on edgeand corner-shared MO6 octahedra. However, the recently discovered POM subclass of noble metalates comprises linked square-planar MO4 units (M = Pd , Au). Lacunary (vacant) POMs can be considered as inorganic, multidentate ligands, and hence they are good candidates for the encapsulation of large, multinuclear dand f-block metal–oxo fragments, sometimes resulting in compounds with interesting magnetic properties. A pioneering result in this area was the synthesis of [Mn12(CH3COO)16(H2O)4O12] (Mn12) by Lis in 1980, which was shown to exhibit single-molecule magnet (SMM) behavior by Gatteschi s group 13 years later. During the past two decades many high-nuclearity, transition-metal based, coordination complexes with interesting electronic and magnetic properties have been prepared. High-nuclearity manganese complexes have been amongst the most studied in this class, and there are examples containing up to 84 manganese ions. 6] To date there are only a few high-nuclearity manganese– oxo-containing POMs, such as {[XW9O34]2[Mn III 4Mn II 2O4(H2O)4]} 12 (X = Si, Ge) and [Mn13Mn O12(PO4)4(PW9O34)4] 31 . Herein we report the synthesis and structure as well as the magnetic and electrochemical properties of a 19 manganese(II) center containing 60-tungsto-6-silicate, [Mn19(OH)12(SiW10O37)6] 34 (1), which was isolated as a hydrated sodium salt, Na34[Mn19(OH)12(SiW10O37)6]·115H2O (Na-1). Single-crystal X-ray diffraction revealed that polyanion 1 consists of a cationic {Mn19(OH)12} 26+ (Mn19) assembly stabilized by six dilacunary [a-SiW10O37] 10 units resulting in a structure with S6 point-group symmetry (Figure 1, top). To the best of our knowledge, 1 is the highest nuclearity manganesecontaining POM known to date. All 19 Mn ions lie in the same plane forming a hexagonal structure based on edgeshared MnO6 octahedra. The Mn II ions in Mn19 are connected by a total of twelve m3-hydroxo bridges, as determined by bond valence sum (BVS) calculations (Supporting Information, Table S1). The discrete Mn19 nanosheet (Figure 1, bottom) is held in place by six dilacunary [a-SiW10O37] 10

Global Existence and Temporal Decay in Keller-Segel Models Coupled to Fluid Equations

Abstract: We consider a Keller-Segel model coupled to the incompressible Navier-Stokes equations in spatial dimensions two and three. We establish the local existence of regular solutions and present some blow-up criteria for both cases that equations of oxygen concentration is of parabolic or hyperbolic type. We also prove that solutions exist globally in time and upper bounds of temporal decays are obtained under the some smallness conditions of initial data.

OsLIC, a Novel CCCH-Type Zinc Finger Protein with Transcription Activation, Mediates Rice Architecture via Brassinosteroids Signaling.

Abstract: Rice architecture is an important agronomic trait and a major limiting factor for its high productivity. Here we describe a novel CCCH-type zinc finger gene, OsLIC (Oraza sativa leaf and tiller angle increased controller), which is involved in the regulation of rice plant architecture. OsLIC encoded an ancestral and unique CCCH type zinc finge protein. It has many orthologous in other organisms, ranging from yeast to humane. Suppression of endogenous OsLIC expression resulted in drastically increased leaf and tiller angles, shortened shoot height, and consequently reduced grain production in rice. OsLIC is predominantly expressed in rice collar and tiller bud. Genetic analysis suggested that OsLIC is epistatic to d2-1, whereas d61-1 is epistatic to OsLIC. Interestingly, sterols were significantly higher in level in transgenic shoots than in the wild type. Genome-wide expression analysis indicated that brassinosteroids (BRs) signal transduction was activated in transgenic lines. Moreover, transcription of OsLIC was induced by 24-epibrassinolide. OsLIC, with a single CCCH motif, displayed binding activity to double-stranded DNA and single-stranded polyrA, polyrU and polyrG but not polyrC. It contains a novel conserved EELR domain among eukaryotes and displays transcriptional activation activity in yeast. OsLIC may be a transcription activator to control rice plant architecture.