Publications by authors named "JiaJia Tu"

As a key equipment in highway and railway construction, bridge erecting machines directly affect the feasibility, progress, and quality of project implementation. In order to solve the problem that traditional bridge building machines are only suitable for application scenarios with large turning radii and large lifting sites, and have low lifting efficiency, which cannot meet the requirements of urban elevated bridge construction, a small radius bottom feeding beam bridge building machine suitable for urban highway and railway construction is proposed. The feasibility and reliability were verified through force analysis and finite element analysis; Design a secondary turning structure and bridge construction process for the front leg, adjusting the turning angle to around 7°, significantly reducing the turning radius of the bridge building machine; Propose a technology for feeding and lifting beams at the bottom of dual-use bridge decks for highways and railways.

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The automated replacement of empty tubes in the yarn bank is a critical step in the process of automatic winding machines with yarn banks, as the real-time detection of depleted yarn on spools and accurate positioning of empty tubes directly impact the production efficiency of winding machines. Addressing the shortcomings of traditional methods, such as poor adaptability and low sensitivity in optical and visual tube detection, and aiming to reduce the computational and detection time costs introduced by neural networks, this paper proposes a lightweight yarn spool detection model based on YOLOv8. The model utilizes Darknet-53 as the backbone network, and due to the dense spatial distribution of yarn spool targets, it incorporates large selective kernel units to enhance the recognition and positioning of dense targets.

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The application and removal of personal protective equipment (PPE) by health care workers (HCWs) is pivotal to their health and safety and the comprehensive efficacy of hospital infection control measures. This investigation was orchestrated to elucidate the challenges that HCWs may encounter during the donning and doffing of PPE. A total of 110 participants from a tertiary hospital in China were engaged.

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Automatic replacement of bobbins on the frame is one of the core problems that must be solved in the textile industry. In the process of changing the bobbin, it is faced with problems such as the position offset of the bobbin, the loosening and deformation of the bobbin, which will lead to the failure of replacing the bobbin. Therefore, it is necessary to initialize the creel coordinates regularly, also considering the labor intensity and poor reliability of manual positioning.

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We have previously shown deep-sea-derived SCSIO 5802 to produce two types of active secondary metabolites, abyssomicins and candicidins. Here, we report the complete genome sequence of SCSIO 5802 employing bioinformatics to highlight its potential to produce at least 21 categories of natural products. In order to mine novel natural products, the production of two polycyclic tetramate macrolactams (PTMs), the known 10--HSAF () and a new compound, koyanamide A (), was stimulated via inactivation of the abyssomicin and candicidin biosynthetic machineries.

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Diels-Alder (DA) [4 + 2]-cycloaddition reactions rank among the most powerful transformations in synthetic organic chemistry; biosynthetic examples, however, are few and far between. We report here a heme-binding cyclase, AbmU, that catalyzes an essential [4 + 2] cycloaddition during neoabyssomicin scaffold assembly. In vivo genetic and in vitro biochemical analyses strongly suggest that AbmU catalyzes an intramolecular and stereoselective [4 + 2] cycloaddition to form a spirotetronate skeleton from an acyclic substrate featuring both a terminal 1,3-diene and an exo-methylene group.

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Members of the abyssomicin class of natural products are characterized by a novel vinylic bridged ether ring. In this study, in vivo gene inactivation, structure elucidation of the accumulated intermediate abyssomicin 6, and in vitro enzyme assays enabled the identification of a cytochrome P450 enzyme, AbmV. AbmV carries out domino reactions involving bridged ether installation and C-11 hydroxylation during the biosynthesis of neoabyssomicins/abyssomicins in S.

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Biocatalysis of ursolic acid (UA 1) by CGMCC 3.3657 was investigated. Baeyer-Villiger oxidation was found to occur during the reaction.

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Background: The deep-sea-derived microbe Streptomyces koyangensis SCSIO 5802 produces neoabyssomicins A-B (1-2) and abyssomicins 2 (3) and 4 (4). Neoabyssomicin A (1) augments human immunodeficiency virus-1 (HIV-1) replication whereas abyssomicin 2 (3) selectively reactivates latent HIV and is also active against Gram-positive pathogens including methicillin-resistant Staphylococcus aureus (MRSA). Structurally, neoabyssomicins A-B constitute a new subtype within the abyssomicin family and feature unique structural traits characteristic of extremely interesting biosynthetic transformations.

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