31 research outputs found

    Transcriptome analysis of yellow passion fruit in response to cucumber mosaic virus infection.

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    The cultivation and production of passion fruit (Passiflora edulis) are severely affected by viral disease. Yet there have been few studies of the molecular response of passion fruit to virus attack. In the present study, RNA-based transcriptional profiling (RNA-seq) was used to identify the gene expression profiles in yellow passion fruit (Passiflora edulis f. flavicarpa) leaves following inoculation with cucumber mosaic virus (CMV). Six RNA-seq libraries were constructed comprising a total of 42.23 Gb clean data. 1,545 differentially expressed genes (DEGs) were obtained (701 upregulated and 884 downregulated). Gene annotation analyses revealed that genes associated with plant hormone signal transduction, transcription factors, protein ubiquitination, detoxification, phenylpropanoid biosynthesis, photosynthesis and chlorophyll metabolism were significantly affected by CMV infection. The represented genes activated by CMV infection corresponded to transcription factors WRKY family, NAC family, protein ubiquitination and peroxidase. Several DEGs encoding protein TIFY, pathogenesis-related proteins, and RNA-dependent RNA polymerases also were upregualted by CMV infection. Overall, the information obtained in this study enriched the resources available for research into the molecular-genetic mechanisms of the passion fruit/CMV interaction, and might provide a theoretical basis for the prevention and management of passion fruit viral disease in the field

    Synthesis and biological evaluation of 12-N-p-chlorobenzyl sophoridinol derivatives as a novel family of anticancer agents

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    Taking 12-N-p-chlorobenzyl sophoridinol 2 as a lead, a series of novel sophoridinic derivatives with various 3′-substituents at the 11–side chain were synthesized and evaluated for their anticancer activity from sophoridine (1), a natural antitumor medicine. Among them, the sophoridinic ketones 5a–b, alkenes 7a–b and sophoridinic amines 14a–b displayed reasonable antiproliferative activity with IC50 values ranging from 3.8 to 5.4 μmol/L. Especially, compounds 5a and 7b exhibited an equipotency in both adriamycin (AMD)-susceptible and resistant MCF-7 breast carcinoma cells, indicating a different mechanism from AMD. The primary mechanism of action of 5a was to arrest the cell cycle at the G0/G1 phase, consistent with that of parent compound 1. Thus, we consider 12-chlorobenzyl sophoridinic derivatives with a tricyclic scaffold to be a new class of promising antitumor agents with an advantage of inhibiting drug-resistant cancer cells

    Characterization of Key Odorants in Scallion Pancake and Investigation on Their Changes during Storage

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    To characterize key odorants in scallion pancake (SP), volatiles were extracted by solvent extraction-solvent assisted flavor evaporation. A total of 51 odor-active compounds were identified by gas chromatography-olfactometry (GC-O) and chromatography–mass spectrometry (GC-MS). (Z/E)-3,6-Diethyl-1,2,4,5-tetrathiane was detected for the first time in scallion food. Application of aroma extract dilution analysis to extracts showed maltol, methyl propyl disulfide, dipropyl disulfide and 2-pentylfuran had the highest flavor dilution (FD) factor of 4096. Twenty-three odorants with FD factors ≥ 8 were quantitated, and their odor active values (OAVs) were calculated. Ten compounds with OAVs ≥ 1 were determined as the key odorants; a recombinate model prepared from the key odorants, including (E,E)-2,4-decadienal, dimethyl trisulfide, methyl propyl disulfide, hexanal, dipropyl trisulfide, maltol, acetoin, 2-methylnaphthalene, 2-pentylfuran and 2(5H)-furanone, successfully simulated the overall aroma profile of SP. The changes in odorants during storage were investigated further. With increasing concentrations and OAVs during storage, hexanal became an off-flavor compound

    Content-Based Video Search: is there a need, and is it possible?

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    There is a large and rapidly increasing amount of video data on the Internet and in personal or organizational collections. Fast and accurate video search emerges to be an important issue. The need and main technical challenges for video retrieval are similar to those for the content-based image retrieval (CBIR) problem. Lack of meaningful and comprehensive text annotation means that an approach based on content similarity can be promising; and the differences between an often high-level search intention and the low-level features used in content-based search techniques suggest that content-based video retrieval (CBVR) may also suffer from "semantic gap" issues. In this paper, we analyze the problem of CBVR from related work in the literature as well as some current work in our team, focusing on the relationship between CBIR and CBVR, open yet well-defined research issues and practical applications of CBVR

    Integrative Comparative Assessment of Cold Acclimation in Evergreen and Deciduous Iris Species

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    Cold acclimation (CA) is a strategy which plants have evolved to increase freezing tolerance. Global climate change could obstruct CA and raise the probability of winter injury, especially for evergreens. Hence, understanding the regulatory mechanism of CA is crucial to improve freezing tolerance in evergreen plants. A comparative study on a pair of closely related evergreen and deciduous iris species in response to cold through CA was conducive to uncovering and complementing the knowledge of CA. We investigated morphological, physiological and biochemical changes, as well as the expression of associated genes in the functional leaves of both iris species from natural CA to deacclimation. Briefly, fast and strong CA in the evergreen iris might cause early expressions of BAM1, NCED3, GPX6, etc., which leads to strong enzyme activity of starch degradation, abscisic acid biosynthesis and reactive oxygen species scavenging. Additionally, genes belonging to the antioxidant system were mainly induced during deacclimation. These results suggest that interspecies differences in the leaf freezing tolerance of irises are associated with the rate and degree of CA, which activates multiple signaling networks with complex interactions and induces the transcription of cold-responsive genes. Moreover, the ICE–CBF–COR signaling cascade may integrate and initiate diverse cold-responsive pathways during CA of the evergreen iris. The findings of this study provide valuable insight to further research on CA mechanisms and implicate genes which could support breeding strategies in herbaceous perennials under climate changes

    Cholesteric flakes in motion driven by the elastic force from nematic liquid crystals

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    \u3cp\u3eThe paper presents a methodology to control the motion and orientation of suspended reflective cholesteric flakes in a nematic liquid crystal (LC) matrix. The flakes exhibit a dielectric anisotropy which controls their alignment with their in-plane axes parallel to an external electrical dc field. The elastic forces imposed by the LC host affect the switching behavior of the flakes and take care of the realignment to the planar state as soon as the dc field is switched off. When the LC host has a positive dielectric anisotropy, the switching voltage of the flakes is reduced by a factor of 2 in comparison with a LC host with negative dielectric anisotropy or in comparison with an isotropic host. We discovered that the LC host further regulates the back relaxation of cholesteric to return to the planar state upon retrieving the electric field. Whereas, in the isotropic fluid, flakes do not exhibit a preferred orientation when relaxed. Based on this newly proposed principle, we demonstrated its application as an optical switch for smart windows. Depending on the pitch of the cholesteric helix of the flakes, the light of a preset wavelength is reflected. Upon application of an electric field, the embedded flakes rotate their planes perpendicular to the substrate and consequently the incident light becomes fully transmitted without reflection or scattering of light.\u3c/p\u3

    Metabolomics analysis reveals that benzo[a]pyrene, a component of PM2.5, promotes pulmonary injury by modifying lipid metabolism in a phospholipase A2-dependent manner in vivo and in vitro

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    Particulate matter with an aerodynamic diameter less than 2.5 μM (PM2.5) is one of the major environmental pollutants in China. In this study, we carried out a metabolomics profile study on PM2.5-induced inflammation. PM2.5 from Beijing, China, was collected and given to rats through intra-tracheal instillation in vivo. Acute pulmonary injury were observed by pulmonary function assessment and H.E. staining. The lipid metabolic profile was also altered with increased phospholipid and sphingolipid metabolites in broncho-alveolar lavage fluid (BALF) after PM2.5 instillation. Organic component analysis revealed that benzo[a]pyrene (BaP) is one of the most abundant and toxic components in the PM2.5 collected on the fiber filter. In vitro, BaP was used to treat A549 cells, an alveolar type II cell line. BaP (4 μM, 24 h) induced inflammation in the cells. Metabolomics analysis revealed that BaP (4 μM, 6 h) treatment altered the cellular lipid metabolic profile with increased phospholipid metabolites and reduced sphingolipid metabolites and free fatty acids (FFAs). The proportion of ω–3 polyunsaturated fatty acid (PUFA) was also decreased. Mechanically, BaP (4 μM) increased the phospholipase A2 (PLA2) activity at 4 h as well as the mRNA level of Pla2g2a at 12 h. The pro-inflammatory effect of BaP was reversed by the cytosolic PLA2 (cPLA2) inhibitor and chelator of intracellular Ca2+. This study revealed that BaP, as a component of PM2.5, induces pulmonary injury by activating PLA2 and elevating lysophosphatidylcholine (LPC) in a Ca2+-dependent manner in the alveolar type II cells

    Natural Conception May Be an Acceptable Option in HIV-Serodiscordant Couples in Resource Limited Settings.

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    Many HIV serodiscordant couples have a strong desire to have their own biological children. Natural conception may be the only choice in some resource limited settings but data about natural conception is limited. Here, we reported our findings of natural conception in HIV serodiscordant couples. Between January 2008 and June 2014, we retrospectively collected data on 91 HIV serodiscordant couples presenting to Beijing Youan Hospital with childbearing desires. HIV counseling, effective ART on HIV infected partners, pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) in negative female partners and timed intercourse were used to maximally reduce the risk of HIV transmission. Of the 91 HIV serodiscordant couples, 43 were positive in male partners and 48 were positive in female partners. There were 196 unprotected vaginal intercourses, 100 natural conception and 97 newborns. There were no cases of HIV seroconversion in uninfected sexual partners. Natural conception may be an acceptable option in HIV-serodiscordant couples in resource limited settings if HIV-positive individuals have undetectable viremia on HAART, combined with HIV counseling, PrEP, PEP and timed intercourse

    Genome and whole-genome resequencing of Cinnamomum camphora elucidate its dominance in subtropical urban landscapes

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    Abstract Background Lauraceae is well known for its significant phylogenetic position as well as important economic and ornamental value; however, most evergreen species in Lauraceae are restricted to tropical regions. In contrast, camphor tree (Cinnamomum camphora) is the most dominant evergreen broadleaved tree in subtropical urban landscapes. Results Here, we present a high-quality reference genome of C. camphora and conduct comparative genomics between C. camphora and C. kanehirae. Our findings demonstrated the significance of key genes in circadian rhythms and phenylpropanoid metabolism in enhancing cold response, and terpene synthases (TPSs) improved defence response with tandem duplication and gene cluster formation in C. camphora. Additionally, the first comprehensive catalogue of C. camphora based on whole-genome resequencing of 75 accessions was constructed, which confirmed the crucial roles of the above pathways and revealed candidate genes under selection in more popular C. camphora, and indicated that enhancing environmental adaptation is the primary force driving C. camphora breeding and dominance. Conclusions These results decipher the dominance of C. camphora in subtropical urban landscapes and provide abundant genomic resources for enlarging the application scopes of evergreen broadleaved trees
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