101 research outputs found

    The “resurrection method” for modification of specific proteins in higher plants

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    AbstractWe describe a new method designated “the resurrection method” by which a modified protein is expressed in higher plants in place of the original protein. The modified gene constructed by introducing synonymous codon substitutions throughout the original gene to prevent the sequence-specific degradation of its mRNA during RNA silencing is expressed while the expression of the original gene is suppressed. Here, we report the successful alteration of the biochemical properties of green fluorescent protein expressed in transgenic Nicotiana benthamiana, suggesting that this method could be useful for gene control in living plants

    Spectrocolorimetric evaluation of repaired articular cartilage after a microfracture

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    <p>Abstract</p> <p>Background</p> <p>In clinical practice, surgeons differentiate color changes in repaired cartilage compared with surrounding intact cartilage, but cannot quantify these color changes. Objective assessments are required. A spectrocolorimeter was used to evaluate whether intact and repaired cartilage can be quantified.</p> <p>Findings</p> <p>We investigated the use of a spectrocolorimeter and the application of two color models (L* a* b* colorimetric system and spectral reflectance distribution) to describe and quantify articular cartilage. In this study, we measured the colors of intact and repaired cartilage after a microfracture. Histologically, the repaired cartilage was a mixture of fibrocartilage and hyaline cartilage. In the L* a* b* colorimetric system, the L* and a* values recovered to close to the values of intact cartilage, whereas the b* value decreased over time after the operation. Regarding the spectral reflectance distribution at 12 weeks after the operation, the repaired cartilage had a higher spectral reflectance ratio than intact cartilage between wavelengths of 400 to 470 nm.</p> <p>Conclusion</p> <p>This study reports the first results regarding the relationship between spectrocolorimetric evaluation and the histological findings of repair cartilage after a microfracture. Our findings demonstrate the ability of spectrocolorimetric measurement to judge the repair cartilage after treatment on the basis of objective data such as the L*, a* and b* values and the SRP as a coincidence index of the spectral reflectance curve.</p

    A Host Small GTP-binding Protein ARL8 Plays Crucial Roles in Tobamovirus RNA Replication

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    Tomato mosaic virus (ToMV), like other eukaryotic positive-strand RNA viruses, replicates its genomic RNA in replication complexes formed on intracellular membranes. Previous studies showed that a host seven-pass transmembrane protein TOM1 is necessary for efficient ToMV multiplication. Here, we show that a small GTP-binding protein ARL8, along with TOM1, is co-purified with a FLAG epitope-tagged ToMV 180K replication protein from solubilized membranes of ToMV-infected tobacco (Nicotiana tabacum) cells. When solubilized membranes of ToMV-infected tobacco cells that expressed FLAG-tagged ARL8 were subjected to immunopurification with anti-FLAG antibody, ToMV 130K and 180K replication proteins and TOM1 were co-purified and the purified fraction showed RNA-dependent RNA polymerase activity that transcribed ToMV RNA. From uninfected cells, TOM1 co-purified with FLAG-tagged ARL8 less efficiently, suggesting that a complex containing ToMV replication proteins, TOM1, and ARL8 are formed on membranes in infected cells. In Arabidopsis thaliana, ARL8 consists of four family members. Simultaneous mutations in two specific ARL8 genes completely inhibited tobamovirus multiplication. In an in vitro ToMV RNA translation-replication system, the lack of either TOM1 or ARL8 proteins inhibited the production of replicative-form RNA, indicating that TOM1 and ARL8 are required for efficient negative-strand RNA synthesis. When ToMV 130K protein was co-expressed with TOM1 and ARL8 in yeast, RNA 5′-capping activity was detected in the membrane fraction. This activity was undetectable or very weak when the 130K protein was expressed alone or with either TOM1 or ARL8. Taken together, these results suggest that TOM1 and ARL8 are components of ToMV RNA replication complexes and play crucial roles in a process toward activation of the replication proteins' RNA synthesizing and capping functions

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

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    Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

    Laboratory evaluation of the resistance of plastics to the subterranean termite Coptotermes formosanus (Blattodea: Rhinotermitidae)

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    Since preliminary studies demonstrated unsuitability of the existing Japanese standardized methods for evaluating the termite-resistance of plastics, a new laboratory method was tested for its applicability. Assembled units, each consisting of a plastic material and a wood attachment surrounding a plastic sample, were placed around a laboratory nest of Coptotermes formosanus for 6 weeks at 28 ± 2 °C and over 80% relative humidity, and the termite attack was assessed visually. Amorphous polyamide performed best, and low-density polyethylene did worst. This new laboratory method succeeded in demonstrating termite damage to materials that are susceptible under actual service conditions, although it is not applicable to evaluating insecticide-incorporated plastics. A modified JWPA Standard No. 17 test method was employed to determine the minimum number of termites required to attack high-density polyethylene film so that it was possible to standardize the method to compare termite-resistance of non-woody materials with or without chemical treatment. It was concluded that 300 workers of C. formosanus in 12.6 cm2 of foraging area, which was equivalent to the termite density (pressure) of 24 workers cm−2 foraging area, were required for termites to attack from a straight scratched surface

    ブロム モザイク ウイルス RNA イソン RNA ゴウセイ コウソ フクゴウタイ ニ カンスル ケンキュウ

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    京都大学0048新制・論文博士博士(農学)乙第11674号論農博第2557号新制||農||912(附属図書館)学位論文||H17||N4057(農学部図書室)23487UT51-2005-D592京都大学大学院農学研究科農林生物学専攻(主査)教授 奥野 哲郎, 教授 遠藤 隆, 教授 西岡 孝明学位規則第4条第2項該当Doctor of Agricultural ScienceKyoto UniversityDA

    Gompertz software reliability model : Estimation algorithm and empirical validation

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    Gompertz Curve has been used to estimate the number of residual faults in testing phases of software development, especially by Japanese software development companies. Since the Gompertz curve is a deterministic function, the curve cannot be applied to estimating software reliability which is the probability that software system does not fail in a prefixed time period. In this article, we propose a stochastic model called the Gompertz software reliability model based on non-homogeneous Poisson processes. The proposed model can be derived from the statistical theory of extreme-value, and has a similar asymptotic property to the deterministic Gompertz curve. Also, we develop an EM algorithm to determine the model parameters effectively. In numerical examples with software failure data observed in real software development projects, we evaluate performance of the Gompertz software reliability model in terms of reliability assessment and failure prediction
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