1,264 research outputs found

    Identification of differentially expressed genes in seeds of two Brassica napus mutant lines with different oleic acid content

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    The regulation of seed oleic acid synthesis in rapeseed is largely unknown. In this study, gene expression pattern during seed development between two Brassica napus mutants was compared. Using immature seeds 27 days after pollination, differentially expressed cDNA clones were identified bysubtractive suppression hybridization (SSH). A total of 480 cDNA clones corresponding to 88 genes were found up-regulated and 18 genes down-regulated in seeds with high oleic acid content. Most ofthe differentially expressed genes are related to metabolism and regulation. The possible role of these genes in seeds was discussed. Further analysis of the function of these genes may provide novel targets for manipulation of fatty acid composition in rapeseed

    On R-duals and the duality principle in Gabor analysis

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    The concept of R-duals of a frame was introduced by Casazza, Kutyniok and Lammers in 2004, with the motivation to obtain a general version of the duality principle in Gabor analysis. For tight Gabor frames and Gabor Riesz bases the three authors were actually able to show that the duality principle is a special case of general results for R-duals. In this paper we introduce various alternative R-duals, with focus on what we call R-duals of type II and III. We show how they are related and provide characterizations of the R-duals of type II and III. In particular, we prove that for tight frames these classes coincide with the R-duals by Casazza et el., which is desirable in the sense that the motivating case of tight Gabor frames already is well covered by these R-duals. On the other hand, all the introduced types of R-duals generalize the duality principle for larger classes of Gabor frames than just the tight frames and the Riesz bases; in particular, the R-duals of type III cover the duality principle for all Gabor frames

    Unusual conservation of mitochondrial gene order in Crassostrea oysters: evidence for recent speciation in Asia

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    <p>Abstract</p> <p>Background</p> <p>Oysters are morphologically plastic and hence difficult subjects for taxonomic and evolutionary studies. It is long been suspected, based on the extraordinary species diversity observed, that Asia Pacific is the epicenter of oyster speciation. To understand the species diversity and its evolutionary history, we collected five <it>Crassostrea </it>species from Asia and sequenced their complete mitochondrial (mt) genomes in addition to two newly released Asian oysters (<it>C. iredalei </it>and <it>Saccostrea mordax</it>) for a comprehensive analysis.</p> <p>Results</p> <p>The six Asian <it>Crassostrea </it>mt genomes ranged from 18,226 to 22,446 bp in size, and all coded for 39 genes (12 proteins, 2 rRNAs and 25 tRNAs) on the same strand. Their genomes contained a split of the <it>rrnL </it>gene and duplication of <it>trnM</it>, <it>trnK </it>and <it>trnQ </it>genes. They shared the same gene order that differed from an Atlantic sister species by as many as nine tRNA changes (6 transpositions and 3 duplications) and even differed significantly from <it>S. mordax </it>in protein-coding genes. Phylogenetic analysis indicates that the six Asian <it>Crassostrea </it>species emerged between 3 and 43 Myr ago, while the Atlantic species evolved 83 Myr ago.</p> <p>Conclusions</p> <p>The complete conservation of gene order in the six Asian <it>Crassostrea </it>species over 43 Myr is highly unusual given the remarkable rate of rearrangements in their sister species and other bivalves. It provides strong evidence for the recent speciation of the six <it>Crassostrea </it>species in Asia. It further indicates that changes in mt gene order may not be strictly a function of time but subject to other constraints that are presently not well understood.</p

    Initial potential effect on the dissociative adsorption of methanol on a roughened platinum electrode in acidic solution

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    In situ Raman spectroscopic and voltammetric studies indicate that dissociative adsorption of methanol on the rough platinum electrode occurs in the hydrogen ad/desorption potential range, and the dissociative extent depends on the initial potential of the electrode before contacting methanol, in addition to the contacting time. As the dissociative product, carbon monoxide competes the site of strongly bound hydrogen preferentially, and shifts the ad/desorption potentials of weakly bound hydrogen towards more positive ones gradually with the increase of CO coverage. Whereas, formaldehyde dissociates more easily by far and completely suppresses H-adsorption. The confocal Raman spectroscopy developed on transition metals shows some intriguing advantages in investigating electrocatalytic oxidation of small organic molecules

    Non-Clinical Safety Evaluation of Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells in Cynomolgus Monkeys

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    Xin-Mei Hu,1,&ast; Can-Can Wang,1,&ast; Yu Xiao,1 Yu Liu,1 Hong-Ri Huang,2 Peng Jiang,1 Ying-Kai Wang,1 Yun-Jin Lin,1 Liang-Cheng Li,3 Zhong-Quan Qi1 1Medical College, Guangxi University, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China; 2Department of Research and Development, Guangxi Taimei Rensheng Biotechnology Co., Ltd, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China; 3School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian Province, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Zhong-Quan Qi, Guangxi University, Da-Xue-Dong Road No. 100, Xixiangtang District, Nanning, Guangxi Zhuang Autonomous Region, 530004, People’s Republic of China, Tel +8613806001271, Email [email protected] Liang-Cheng Li, Xiamen University, No. 4221-115, Rm 355, Xiang’an District, Xiang’an, Xiamen Fujian Province, 361102, People’s Republic of China, Tel +8618359206906, Email [email protected]: In recent years, exosomes have been proved to be used to treat many diseases. However, due to the lack of uniform quality control standards for exosomes, the safety of exosomes is still a problem to be solved, especially now more and more exosomes are used in clinical trials, and its non-clinical safety evaluation is particularly important. However, there is no safety evaluation standard for exosomes at present. Therefore, this study will refer to the evaluation criteria of therapeutic biological products, adopt non-human primates to evaluate the non-clinical safety of human umbilical cord mesenchymal stem cell exosomes from the general pharmacology and immunotoxicity, aiming at establishing a safety evaluation system of exosomes and providing reference for the clinical application of exosomes in the future.Methods: 3.85 × 1012 exosomes derived from human umbilical cord mesenchymal stem cells were injected into cynomolgus monkeys intravenously. The changes of general clinical conditions, hematology, immunoglobulin, Th1/Th2 cytokines, T lymphocytes and B lymphocytes, and immune organs were observed before and within 14 days after injection.Results: The results showed that exosomes did not have obvious pathological effects on the general clinical conditions, blood, coagulation function, organ coefficient, immunoglobulin, Th1/Th2 cytokines, lymphocytes, major organs, and major immune organs (spleen, thymus, bone marrow) of cynomolgus monkeys. However, the number of granulocyte-macrophage colonies in exosomes group was significantly higher than that in control group.Conclusion: To sum up, the general pharmacological results and immunotoxicity results showed that the injection of 3.85 × 1012 exosomes may have no obvious adverse reactions to cynomolgus monkeys. This dose of exosomes is relatively safe for treatment, which provides basis research for non-clinical safety evaluation of exosomes and provides reliable research basis for future clinical application of exosomes.Keywords: exosomes, cynomolgus monkeys, safety, immunotoxicit

    An Irish perspective on Cryptosporidium. Part 1

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    Cryptosporidiosis, a protozoal disease which causes significant morbidity in humans, is one of the chief causes of diarrhoea in neonatal ruminants. Although the parasite poses a significant threat to public health and animal health in Ireland, its epidemiology on the island is only poorly understood. Environmental studies have shown the waterborne parasite to be widespread in some untreated waterbodies around Ireland. The island's hydrogeological situation, combined with high stocking rates of livestock and the absence of filtration from regular water treatment, render it vulnerable to large-scale outbreaks. This review discusses the parasite in the Irish context and underlines the need for a reference facility to provide active surveillance on the island

    5-Hydroxymethylfurfural (HMF) formation during subcritical water extraction

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    The aim of this study was to investigate the effect of material type (artichoke leave, lemon peel, flaxseed meal), extraction temperature (50, 100, 120, 140, 160, 180, 200 C) and static extraction time (5, 15, 30, 45 min) on 5-hydroxymethylfurfural (5-HMF) formation during subcritical water extraction. 5-HMF content of artichoke leave and lemon peel extracts increased 7.2 and 26.1 times with the rise of extraction temperature from 160 to 180 C for 5 min during subcritical water extraction, respectively. Besides, 5-HMF content of artichoke leave, lemon peel and flaxseed meal extracts increased 1.4, 2.0 and 4.5 times as static extraction time increased from 15 to 45 min at 180 C during subcritical water extraction, respectively. The highest 5-HMF content of artichoke leave and lemon peel extracts were obtained as 58.83 and 231.21 mg/L at 180 C and 45 min, respectively. However, for flaxseed meal, the highest 5-HMF content (222.94 mg/L) was obtained at 200 C and 15 min during subcritical water extraction.Project Nos. 2014.M80.02.03, 2014.M80.02.04 by Artvin Coruh University Scientific Research Project Uni

    Optimal Estimation of Ion-Channel Kinetics from Macroscopic Currents

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    Markov modeling provides an effective approach for modeling ion channel kinetics. There are several search algorithms for global fitting of macroscopic or single-channel currents across different experimental conditions. Here we present a particle swarm optimization(PSO)-based approach which, when used in combination with golden section search (GSS), can fit macroscopic voltage responses with a high degree of accuracy (errors within 1%) and reasonable amount of calculation time (less than 10 hours for 20 free parameters) on a desktop computer. We also describe a method for initial value estimation of the model parameters, which appears to favor identification of global optimum and can further reduce the computational cost. The PSO-GSS algorithm is applicable for kinetic models of arbitrary topology and size and compatible with common stimulation protocols, which provides a convenient approach for establishing kinetic models at the macroscopic level
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