73 research outputs found

    Immobilized Talaromyces thermophilus lipase as an efficient catalyst for the production of LML-type structured lipids

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    LML-type structured lipids are one type of medium- and long-chain triacylglycerols. LML was synthesized using immobilized Talaromyces thermophilus lipase (TTL)-catalyzed interesterification of tricaprylin and ethyl linoleate. The resin AB-8 was chosen, and the lipase/support ratio was determined to be 60 mg/g. Subsequently, the immobilized TTL with strict sn-1,3 regiospecificity was applied to synthesize LML. Under the optimized conditions (60 °C, reaction time 6 h, enzyme loading of 6% of the total weight of substrates, substrate of molar ratio of ethyl linoleate to tricaprylin of 6:1), Triacylglycerols with two long- and one medium-chain FAs (DL-TAG) content as high as 52.86 mol% was obtained. Scale-up reaction further verified the industrial potential of the established process. The final product contained 85.24 mol% DL-TAG of which 97 mol% was LML after purification. The final product obtained with the high LML content would have substantial potential to be used as functional oils

    Synthesis of conjugated linoleic acid-rich triacylglycerols by immobilized mutant lipase with excellent capability and recyclability

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    Conjugated linoleic acid (CLA)-rich triacylglycerols (TAG) have received significant attention owing to their health promoting properties. In this study, CLA-rich TAG were successfully synthesized by an immobilized mutant lipase (MAS1-H108A)-catalyzed esterification of CLA-rich fatty acids and glycerol under vacuum. MAS1-H108A was first immobilized onto ECR1030 resin. Results showed that the lipase/support ratio of 41 mg/g was suitable for the immobilization and the thermostability of immobilized MAS1-H108A was greatly enhanced. Subsequently, the immobilized MAS1-H108A was employed for the synthesis of CLA-rich TAG and 95.21% TAG with 69.19% CLA was obtained under the optimized conditions. The TAG content (95.21%) obtained by immobilized MAS1-H108A is the reported highest value thus far, which was significantly higher than that (9.26%) obtained by Novozym 435 under the same conditions. Although the TAG content comparable to the results obtained in this study could also be obtained by Novozym 435, the used enzyme amount is approximately 5-fold of the immobilized MAS1-H108A. Additionally, the immobilized MAS1-H108A exhibited excellent recyclability during esterification retaining 95.11% of its initial activity after 10 batches. Overall, such immobilized mutant lipase with superior esterification activity and recyclability has the potential to be used in oils and fats industry

    Emerging roles of i-motif in gene expression and disease treatment

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    As non-canonical nucleic acid secondary structures consisting of cytosine-rich nucleic acids, i-motifs can form under certain conditions. Several i-motif sequences have been identified in the human genome and play important roles in biological regulatory functions. Due to their physicochemical properties, these i-motif structures have attracted attention and are new targets for drug development. Herein, we reviewed the characteristics and mechanisms of i-motifs located in gene promoters (including c-myc, Bcl-2, VEGF, and telomeres), summarized various small molecule ligands that interact with them, and the possible binding modes between ligands and i-motifs, and described their effects on gene expression. Furthermore, we discussed diseases closely associated with i-motifs. Among these, cancer is closely associated with i-motifs since i-motifs can form in some regions of most oncogenes. Finally, we introduced recent advances in the applications of i-motifs in multiple areas

    Deep eutectic solvents enable the enhanced production of n-3 PUFA-enriched triacylglycerols

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    Efficient synthesis of n‐3 PUFA‐enriched triacylglycerol (TAG) by the esterification of glycerol with n‐3 PUFA in deep eutectic solvents (DES) is reported. There was a 1.2‐fold increase of TAG yield in DES compared with that in the solvent‐free system. Adsorption of the produced water by DES during esterification contributed to enhance the conversion efficiency by changing the reaction equilibrium. DES also served as an effective solvent for enriching the n‐3 PUFA of TAG in the upper layer of reaction media. A TAG yield of 55% was achieved under the optimal condition. Practical Applications: Enzymatic synthesis of n‐3 PUFA‐enriched triacylglycerol (TAG) is challenged by low yields. Here, deep eutectic solvents show great potential for enhancing the production of n‐3 PUFA‐enriched TAG

    Gut Microbial Metabolite TMAO Enhances Platelet Hyperreactivity and Thrombosis Risk

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    Normal platelet function is critical to blood hemostasis and maintenance of a closed circulatory system. Heightened platelet reactivity, however, is associated with cardiometabolic diseases and enhanced potential for thrombotic events. We now show gut microbes, through generation of trimethylamine N-oxide (TMAO), directly contribute to platelet hyperreactivity and enhanced thrombosis potential. Plasma TMAO levels in subjects (n \u3e 4,000) independently predicted incident (3 years) thrombosis (heart attack, stroke) risk. Direct exposure of platelets to TMAO enhanced sub-maximal stimulus-dependent platelet activation from multiple agonists through augmented Ca2+ release from intracellular stores. Animal model studies employing dietary choline or TMAO, germ-free mice, and microbial transplantation collectively confirm a role for gut microbiota and TMAO in modulating platelet hyperresponsiveness and thrombosis potential and identify microbial taxa associated with plasma TMAO and thrombosis potential. Collectively, the present results reveal a previously unrecognized mechanistic link between specific dietary nutrients, gut microbes, platelet function, and thrombosis risk

    The Chinese pine genome and methylome unveil key features of conifer evolution

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    Conifers dominate the world's forest ecosystems and are the most widely planted tree species. Their giant and complex genomes present great challenges for assembling a complete reference genome for evolutionary and genomic studies. We present a 25.4-Gb chromosome-level assembly of Chinese pine (Pinus tabuliformis) and revealed that its genome size is mostly attributable to huge intergenic regions and long introns with high transposable element (TE) content. Large genes with long introns exhibited higher expressions levels. Despite a lack of recent whole-genome duplication, 91.2% of genes were duplicated through dispersed duplication, and expanded gene families are mainly related to stress responses, which may underpin conifers' adaptation, particularly in cold and/or arid conditions. The reproductive regulation network is distinct compared with angiosperms. Slow removal of TEs with high-level methylation may have contributed to genomic expansion. This study provides insights into conifer evolution and resources for advancing research on conifer adaptation and development

    Transmission of Atherosclerosis Susceptibility with Gut Microbial Transplantation

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    Recent studies indicate both clinical and mechanistic links between atherosclerotic heart disease and intestinal microbial metabolism of certain dietary nutrients producing trimethylamine N-oxide (TMAO). Here we test the hypothesis that gut microbial transplantation can transmit choline diet-induced TMAO production and atherosclerosis susceptibility. First, a strong association was noted between atherosclerotic plaque and plasma TMAO levels in a mouse diversity panel (n = 22 strains, r = 0.38; p = 0.0001). An atherosclerosis-prone and high TMAO-producing strain, C57BL/6J, and an atherosclerosis-resistant and low TMAO-producing strain, NZW/LacJ, were selected as donors for cecal microbial transplantation into apolipoprotein e null mice in which resident intestinal microbes were first suppressed with antibiotics. Trimethylamine (TMA) and TMAO levels were initially higher in recipients on choline diet that received cecal microbes from C57BL/6J inbred mice; however, durability of choline diet-dependent differences in TMA/TMAO levels was not maintained to the end of the study. Mice receiving C57BL/6J cecal microbes demonstrated choline diet-dependent enhancement in atherosclerotic plaque burden as compared with recipients of NZW/LacJ microbes. Microbial DNA analyses in feces and cecum revealed transplantation of donor microbial community features into recipients with differences in taxa proportions between donor strains that were transmissible to recipients and that tended to show coincident proportions with TMAO levels. Proportions of specific taxa were also identified that correlated with plasma TMAO levels in donors and recipients and with atherosclerotic lesion area in recipients. Atherosclerosis susceptibility may be transmitted via transplantation of gut microbiota. Gut microbes may thus represent a novel therapeutic target for modulating atherosclerosis susceptibility

    Topology-inspired Cross-domain Network for Developmental Cervical Stenosis Quantification

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    Developmental Canal Stenosis (DCS) quantification is crucial in cervical spondylosis screening. Compared with quantifying DCS manually, a more efficient and time-saving manner is provided by deep keypoint localization networks, which can be implemented in either the coordinate or the image domain. However, the vertebral visualization features often lead to abnormal topological structures during keypoint localization, including keypoint distortion with edges and weakly connected structures, which cannot be fully suppressed in either the coordinate or image domain alone. To overcome this limitation, a keypoint-edge and a reparameterization modules are utilized to restrict these abnormal structures in a cross-domain manner. The keypoint-edge constraint module restricts the keypoints on the edges of vertebrae, which ensures that the distribution pattern of keypoint coordinates is consistent with those for DCS quantification. And the reparameterization module constrains the weakly connected structures in image-domain heatmaps with coordinates combined. Moreover, the cross-domain network improves spatial generalization by utilizing heatmaps and incorporating coordinates for accurate localization, which avoids the trade-off between these two properties in an individual domain. Comprehensive results of distinct quantification tasks show the superiority and generability of the proposed Topology-inspired Cross-domain Network (TCN) compared with other competing localization methods.Comment: We have discovered that some authors' contributions have been overlooked. We need to spend some time confirming whether the authors adhere to the paper's authorship guidelines and whether their authorship order complies with the standards. After discussion with all co-authors, we decide to withdraw this pape
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