31 research outputs found

    Tissue-specific transcriptome analysis reveals candidate genes for terpenoid and phenylpropanoid metabolism in the medicinal plant ferula assafoetida

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    © 2019 ABRF. Methionine oxidation plays a critical role in many processes of biologic and biomedical importance, including cellular redox responses and stability of protein pharmaceuticals. Bottom-up methods for analysis of methionine oxidation can suffer from incomplete sequence coverage, as well as an inability to readily detect correlated oxidation between 2 or more methionines. However, the methodology for quantifying protein oxidation in top-down analyses is lacking. Previous work has shown that electron transfer dissociation (ETD)–based tandem mass spectrometry (MS/MS) fragmentation offers accurate and precise quantification of amino acid oxidation in peptides, even in complex samples. However, the ability of ETD-based MS/MS fragmentation to accurately quantify amino acid oxidation of proteins in a top-down manner has not been reported. Using apomyoglobin and calmodulin as model proteins, we partially converted methionines into methionine sulfoxide by incubation in H2O2. Using top-down ETD-based fragmentation, we quantified the amount of oxidation of various ETD product ions and compared the quantified values with those from traditional bottom-up analysis. We find that overall quantification of methionine oxidation by top-down MS/MS ranges from good agreement with traditional bottom-up methods to vast differences between the 2 techniques, including missing oxidized product ions and large differences in measured oxidation quantities. Care must be taken in transitioning ETD-based quantitation of oxidation from the peptide level to the intact protein level

    An Efficient Detection Technique for Synchronous CDMA Communication Systems Based on the Expectation Maximization Algorithm

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    Journal PaperMaximum likelihood detection of superimposed signals in code-division multiple access (CDMA) communication systems has a computational complexity that is exponential in the number of users, and its implementation is practically prohibitive even for a moderate number of users. Applying the expectation maximization algorithm to this problem, we decompose the multiuser detection problem into a series of single-user problems, and thus present an iterative computationally efficient algorithm for detection of superimposed signals in synchronous direct-sequence CDMA communication systems. The resulting structure includes the well-known multistage detector as one of its special cases. With a proper choice of its parameters, the new detector can achieve the advantages of both the multistage and conventional detector and have good performance for both strong and weak users

    Evaluation of biochemical, physiological traits and percentage of essential oil of sickleweed (Falcaria vulgaris) population in different geographical and climatic regions

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    Sickleweed (Falcaria vulgaris) is the name of a species of annual, and perennial herbaceous plants of the genus Falcaria. Climate change could negatively influnces the performance of various plant species in plant kingdom. In this study, 15 different sickleweed populations from seven provinces of the country were collected based on an unbalanced nest design with 10 replications and the percentage of essential oil, types of chlorophyll, phenol, proline, protein, and carotenoids were measured on them. The results showed that there was a significant difference between populations at the level of one percent for the studied traits. The results of the mean comparison showed that populations Ard-Shaban and Qaz-Ilan in terms of the evaluated traits and especially the percentage of essential oil were at the upper of the studied samples and selected as suitable populations. In addition, populations Gilan-Deylaman and Kur-Gerger-e Sofla were also identified as superior populations in terms of studied traits by cluster analysis and principle component analysis (PCA). Since the high level of proline and biochemical and physiological traits in plants can play a role in plants’ tolerance to stresses, therefore, populations with high values of these traits can be used in stress tolerance breeding programs. Therefore, in this study, populations Gilan-Deylaman and Kur-Gerger-e Sofla can be suitable populations for this purpose. In addition, the essential oil of this plant is used in the treatment of diseases, and therefore populations Ard-Shaban and Qaz-Ilan, which showed a high percentage of essential oil, can be used in breeding programs to increase the performance of this trait

    Comparative study of adsorptive role of carbonaceous materials in removal of UV-active impurities of paclitaxel extracts

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    Graphite oxide (GO) and reduced graphene oxide (rGO) nanosheets were synthesized with a low-cost manufacturing method. The morphology and structures of the synthesized samples were studied using X-ray diffraction (XRD), atomic force microscopy (AFM), Fourier-transform infrared (FTIR) and Raman spectroscopy. The efficiencies of GO and rGO as novel candidate adsorbents in the pre-purification of paclitaxel were compared and contrasted with those of commercial graphite (Gt), graphene (G) and multi-wall carbon nanotube (MWCNT). According to UV–vis and HPLC analyses, rGO was evaluated as the best absorbent for the removal of impurities in pre-purification of paclitaxel from plant cell cultures. In contrast, the GO had the poorest proficiency for paclitaxel pre-purification in comparison with the other carbonaceous adsorbents. This is attributed to the existence of many localized defects in the π-structure of GO that is related to weakness of π–π stacking interactions between crude extract impurities and GO

    The mean comparison of physiological and biochemical studied traits for sickleweed populations using Duncan’s method.

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    The mean comparison of physiological and biochemical studied traits for sickleweed populations using Duncan’s method.</p

    The correlation diagram of studied traits in sickleweed populations.

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    The correlation diagram of studied traits in sickleweed populations.</p

    Characteristics of the collection areas of Sickleweed plant samples.

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    Characteristics of the collection areas of Sickleweed plant samples.</p

    Unbalanced nest variance analysis of physiological and biochemical traits in sickleweed populations.

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    Unbalanced nest variance analysis of physiological and biochemical traits in sickleweed populations.</p

    Estimation of the variance components of the sources of variation in the unbalanced nest design of the studied physiological and biochemical traits.

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    Estimation of the variance components of the sources of variation in the unbalanced nest design of the studied physiological and biochemical traits.</p
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