1,373 research outputs found

    Evolution of rubisco complex small subunit transit peptides from algae to plants

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    Chloroplasts evolved from a free-living cyanobacterium acquired by the ancestor of all photosynthetic eukaryotes, including algae and plants, through a single endosymbiotic event. During endosymbiotic conversion, the majority of genes in the endosymbiont were transferred to the host nucleus and many of the proteins encoded by these genes must therefore be transported into the chloroplast after translation in the cytosol. Chloroplast-targeted proteins contain a targeting signal, named the transit peptide (TP), at the N-terminus. However, the evolution of TPs is not well understood. In this study, TPs from RbcS (rubisco small subunit) were compared between lower and higher eukaryotes. Chlamydomonas reinhardtii RbcS (CrRbcS) TP was non-functional in Arabidopsis. However, inclusion of a critical sequence motif, FP-RK, from Arabidopsis thaliana RbcS (AtRbcS) TP allowed CrRbcS TP to deliver proteins into plant chloroplasts. The position of the FP-RK motif in CrRbcS TP was critical for function. The QMMVW sequence motif in CrRbcS TP was crucial for its transport activity in plants. CrRbcS TPs containing additional plant motifs remained functional in C. reinhardtii. These results suggest that TPs evolved by acquiring additional sequence motifs to support protein targeting to chloroplasts during evolution of land plants from algae.113Ysciescopu

    Modeling Non-Stationary Asymmetric Lens Blur By Normal Sinh-Arcsinh Model

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    Department of Electrical EngineeringImages acquired by a camera show lens blur due to imperfection in the optical system. Lens blur is non-stationary in a sense the amount of blur depends on pixel locations in a sensor. Lens blur is also asymmetric in a sense the amount of blur is different in the radial and tangential directions, and also in the inward and outward radial directions. This paper presents parametric blur kernel models based on the normal sinh-arcsinh distribution function. The proposed models can provide flexible shapes of blur kernels with different symmetry and skewness to model complicated lens blur accurately. Blur of single focal length lenses is estimated and the accuracy of the models is compared with existing parametric blur models. Advantage of the proposed models is demonstrated through deblurring experiments.ope

    Precise stacking of decellularized extracellular matrix based 3D cell-laden constructs by a 3D cell printing system equipped with heating modules

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    Three-dimensional (3D) cell printing systems allow the controlled and precise deposition of multiple cells in 3D constructs. Hydrogel materials have been used extensively as printable bioinks owing to their ability to safely encapsulate living cells. However, hydrogel-based bioinks have drawbacks for cell printing, e.g. inappropriate crosslinking and liquid-like rheological properties, which hinder precise 3D shaping. Therefore, in this study, we investigated the influence of various factors (e.g. bioink concentration, viscosity, and extent of crosslinking) on cell printing and established a new 3D cell printing system equipped with heating modules for the precise stacking of decellularized extracellular matrix (dECM)-based 3D cell-laden constructs. Because the pH-adjusted bioink isolated from native tissue is safely gelled at 37 degrees C, our heating system facilitated the precise stacking of dECM bioinks by enabling simultaneous gelation during printing. We observed greater printability compared with that of a non-heating system. These results were confirmed by mechanical testing and 3D construct stacking analyses. We also confirmed that our heating system did not elicit negative effects, such as cell death, in the printed cells. Conclusively, these results hold promise for the application of 3D bioprinting to tissue engineering and drug development.119Ysciescopu

    Highly Oriented Liquid Crystal Semiconductor for Organic Field-Effect Transistors

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    We report a mesogenic compound which introduces nematic liquid crystal (LC) ordering into the benzothienobenzothiophene (BTBT) family of LCs, creating a new class of LC semiconducting materials which respond in a facile way to anisotropic surfaces, and can, thereby, be effectively processed into highly oriented monodomains. Measurement on these domains of the electrical conductivity, with in situ monitoring of domain quality and orientation using LC birefringence textures in electroded cells, brings a new era of precision and reliability to the determination of anisotropic carrier mobility in LC semiconductors

    Downregulation of protein kinase CK2 activity induces age-related biomarkers in C. elegans

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    Studies show that a decrease in protein kinase CK2 (CK2) activity is associated with cellular senescence. However, the role of CK2 in organism aging is still poorly understood. Here, we investigated whether protein kinase CK2 (CK2) modulated longevity in Caenorhabditis elegans. CK2 activity decreased with advancing age in the worms. Knockdown of kin-10 (the ortholog of CK2 beta) led to a short lifespan phenotype and induced age-related biomarkers, including retardation of locomotion, decreased pharyngeal pumping rate, increased lipofuscin accumulation, and reduced resistance to heat and oxidative stress. The long lifespan of age-1 and akt-1 mutants was significantly suppressed by kin-10 RNAi, suggesting that CK2 acts downstream of AGE-1 and AKT-1. Kin-10 knockdown did not further shorten the short lifespan of daf-16 mutant worms but either decreased or increased the transcriptional activity of DAF-16 depending on the promoters of the target genes, indicating that CK2 is an upstream regulator of DAF-16 in C. elegans. Kin-10 knockdown increased production of reactive oxygen species (ROS) in the worms. Finally, the ROS scavenger N-acetyl-L-cysteine significantly counteracts the lifespan shortening and lipofuscin accumulation induced by kin-10 knockdown. Therefore, the present results suggest that age-dependent CK2 downregulation reduces longevity by associating with both ROS generation and the AGE-1-AKT-1-DAF-16 pathway in C. elegans. Β© Copyright 2017 Elsevier B.V., All rights reserved.1111sci

    Analysis On Runoff Characteristics Of Decentralized Rainwater Management System Using XP-SWMM Simulation

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    In recent years, impervious areas are increasing in residential zone as well as unsettled area with rapid urbanization and land use. Consequently, this phenomenon influences weak urban environmental compositions about climate change including urban flooding accidents. Therefore, a new paradigm on rainwater management is needed for sound and sustainable restoration of hydrological circulation. Recently, a novel rainwater management system has been developed and recommended for irrigation and flood control in Korea. Especially, P city is now planning a new rainwater management system adopting LID (Low Impact Development) techniques on a small scale development area. In this study, XP-SWMM was used to simulate effects on runoff characteristics by installation of 8 kinds of rainwater management facilities on small scale development area (4.2 ha) of P city in Korea. Also, flood control safety analysis under the condition of localized torrential downpour event was carried out and effects of rainwater recycling facility was evaluated to measure annual water resource amount and water cost reduction. Peak rate runoff was reduced 11.8% and 36.4% in restrict A and B, respectively. Total amount of annual water source substitution was estimated 3,000㎑/yr with LID adoption in land use planning. Acknowledgement : This research was supported by a grant (12-TI-C01) from Advanced Water Management Research Program funded by Ministry of Land , Infrastructure, and Transport of Korean government

    Treatment outcomes of re-irradiation using stereotactic ablative radiotherapy to lung: a propensity score matching analysis

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    Background The purpose of this study was to compare the treatment efficacy and safety of re-irradiation (re-RT) using stereotactic ablative radiotherapy (SABR) and initial SABR for primary, recurrent lung cancer or metastatic lung tumor. Methods A retrospective review of the medical records of 336 patients who underwent lung SABR was performed. Re-RT was defined as the overlap of the 70% isodose line of second-course SABR with that of the initial radiotherapy, and 20 patients were classified as the re-RT group. The median dose of re-RT using SABR was 54Gy (range 48–60Gy), and the median fraction number was 4 (range 4–6). One-to-three case-matched analysis with propensity score matching was used, and 60 patients were included in the initial SABR group of the matched cohort. Results The 1- and 2-year local control rates for the re-RT group were 73.9% and 63.3% and those for the initial SABR group in the matched cohort were 92.9% and 87.7%, respectively (P = 0.013). There was no difference in distant metastasis-free, progression-free, and overall survival rates. The crude grade β‰₯ 2 toxicity rates were 40.0% for the re-RT group and 25.0% for the initial SABR group (P = 0.318). Re-RT group had higher acute grade β‰₯ 2 toxicity rates (25.0% vs 5.0%, P = 0.031). One incident of grade 3 toxicity (pulmonary) was reported in the re-RT group; there was no grade 4β€’5 toxicity. Conclusions The local control rate of the in-field re-RT SABR was lower than that of the initial SABR without compromising the survival rates. The toxicity of re-RT using SABR was acceptable

    ADMM in Krylov Subspace and Its Application to Total Variation Restoration of Spatially Variant Blur

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    In this paper we propose an efficient method for a convex optimization problem which involves a large nonsymmetric and non-Toeplitz matrix. The proposed method is an instantiation of the alternating direction method of multipliers applied in Krylov subspace. Our method offers significant advantages in computational speed for the convex optimization problems involved with general matrices of large size. We apply the proposed method to the restoration of spatially variant blur. The matrix representing spatially variant blur is not block circulant with circulant blocks (BCCB). Efficient implementation based on diagonalization of BCCB matrices by the discrete Fourier transform is not applicable for spatially variant blur. Since the proposed method can efficiently work with general matrices, the restoration of spatially variant blur is a good application of our method. Experimental results for total variation restoration of spatially variant blur show that the proposed method provides meaningful solutions in a short time.clos

    Soluble Epoxide Hydrolase Activity Determines the Severity of Ischemia-Reperfusion Injury in Kidney

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    Soluble epoxide hydrolase (sEH) in endothelial cells determines the plasma concentrations of epoxyeicosatrienoic acids (EETs), which may act as vasoactive agents to control vascular tone. We hypothesized that the regulation of sEH activity may have a therapeutic value in preventing acute kidney injury by controlling the concentration of EETs. In this study, we therefore induced ischemia-reperfusion injury (IRI) in C57BL/6 mice and controlled sEH activity by intraperitoneal administration of the sEH inhibitor 12-(3-adamantan-1-ylureido)-dodecanoic acid (AUDA). The deterioration of kidney function induced by IRI was partially moderated and prevented by AUDA treatment. In addition, AUDA treatment significantly attenuated tubular necrosis induced by IRI. Ischemic injury induced the down-regulation of sEH, and AUDA administration had no effect on the expression pattern of sEH induced by IRI. In vivo sEH activity was assessed by measuring the substrate epoxyoctadecenoic acid (EpOME) and its metabolite dihydroxyoctadec-12-enoic acid (DHOME). Ischemic injury had no effects on the plasma concentrations of EpOME and DHOME, but inhibition of sEH by AUDA significantly increased plasma EpOME and the EpOME/DHOME ratio. The protective effect of the sEH inhibitor was achieved by suppression of proinflammatory cytokines and up-regulation of regulatory cytokines. AUDA treatment prevented the intrarenal infiltration of inflammatory cells, but promoted endothelial cell migration and neovascularization. The results of this study suggest that treatment with sEH inhibitors can reduce acute kidney injury
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