177 research outputs found

    Study on control strategy of the rotary synchronous fixed-length cutting system

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    According to the characteristics of rotating synchronous fixed-length cutting system and the principle of vector coordinate transformation, it respectively analyzes the mathematical model of three loops which are the position loop, speed loop and current loop of the servo fixed-length cutting system in this paper. In view of the different working conditions of the system and its nonlinear problem, it puts forward that the function of the speed loop is realized by the parameter adaptive fuzzy algorithm; the function of the position loop using is realized by feed forward proportional control algorithm; the function of the current loop is realized by the conventional PI control algorithm. It uses MATLAB to make simulation and verification, the results show that the combined control algorithm can make that the fixed-length cutting system has characteristics of fast speed, high precision and strong robustness properties

    Identification of open crack of beam using model based method

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    This research aims at identifying the position and depth of the open transverse crack of the beam using the model based method. The stiffness matrix of the cracked beam element and the basic principle of the model based method are introduced. It is discussed to estimate the generalized displacement of all nodes of the beam by the measured displacements of a few degrees of freedom. The relative change rate of the equivalent external load between the intact and cracked elements is compared with that of mode shape, nature frequency and displacement amplitude between the intact and cracked beam. The position and depth of the crack are identified by the model based method in two cases. In first case, the measured displacement is assumed not to include noise. The identification results based on the actual displacement and rotation of all nodes are compared with the results using the estimated generalized displacement. In second case, the measured displacement includes noise and the generalized displacement of all nodes is estimated by the displacement of two measurement points. The simulation results shown there is no error to identify the position, the relative depth identification error of the crack with 1 μm depth is 2.34 % without noise, and the relative depth identification error of the crack with 200 μm depth could be down to about 5 % with the energy signal to noise ratio being about 7.00 before denoising

    The effect of CO2 phase on drainage process by analysis of transient differential pressure

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    Authors gratefully acknowledge the financial supports from China Scholarship Council (CSC) and UK India Education & Research Initiative (UKIERI).Peer reviewedPostprin

    Steering of magnetotactic bacterial microrobots by focusing magnetic field for targeted pathogen killing

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    International audienceTargeted steering of magnetotactic bacterial microrobots is a growing tendency for their various biomedical applications. However, real-time monitoring during their movements and targeted cell killing in specific locations remains challenging. Here, we steered bacterial microrobots to target and attach to Staphylococcus aureus that was subsequently killed in a magnetic target device, which can realize guiding, mixing, and killing for targeted therapy. The generated focusing magnetic field was applied to magnetotactic bacterial microrobots, and the realizability of control strategies was analyzed. We successfully guided magnetotactic bacterial microrobots in microfluidic chips without real-time monitoring of their location. After mixing with microrobots under a rotating magnetic field for their attachment, the pathogen was killed under a swinging magnetic field. These results suggest that targeted therapy with these microrobots by using a magnetic target device is a promising approach

    A Subset of CXCR5+CD8+ T Cells in the Germinal Centers From Human Tonsils and Lymph Nodes Help B Cells Produce Immunoglobulins

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    Recent studies indicated that CXCR5+CD8+ T cells in lymph nodes could eradicate virus-infected target cells. However, in the current study we found that a subset of CXCR5+CD8+ T cells in the germinal centers from human tonsils or lymph nodes are predominately memory cells that express CD45RO and CD27. The involvement of CXCR5+CD8+ T cells in humoral immune responses is suggested by their localization in B cell follicles and by the concomitant expression of costimulatory molecules, including CD40L and ICOS after activation. In addition, CXCR5+CD8+ memory T cells produced significantly higher levels of IL-21, IFN-γ, and IL-4 at mRNA and protein levels compared to CXCR5−CD8+ memory T cells, but IL-21-expressing CXCR5+CD8+ T cells did not express Granzyme B and perforin. When cocultured with sorted B cells, sorted CXCR5+CD8+ T cells promoted the production of antibodies compared to sorted CXCR5−CD8+ T cells. However, fixed CD8+ T cells failed to help B cells and the neutralyzing antibodies against IL-21 or CD40L inhibited the promoting effects of sorted CXCR5+CD8+ T cells on B cells for the production of antibodies. Finally, we found that in the germinal centers of lymph nodes from HIV-infected patients contained more CXCR5+CD8+ T cells compared to normal lymph nodes. Due to their versatile functional capacities, CXCR5+CD8+ T cells are promising candidate cells for immune therapies, particularly when CD4+ T cell help are limited

    Gut Microbes Reveal Pseudomonas Medicates Ingestion Preference via Protein Utilization and Cellular Homeostasis Under Feed Domestication in Freshwater Drum, Aplodinotus grunniens

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    With strong demand for aquatic products, as well as a rapid decrease in global fishery resources and capture fisheries, domesticating animals to provide more high-quality proteins is meaningful for humans. Freshwater drum (Aplodinotus grunniens) is widely distributed in the wild habitats of North America. However, the research on A. grunniens and the feed domestication with diets composed of artificial compounds remains unclear. In this study, a 4-month feeding domestication experiment was conducted with A. grunniens larvae to evaluate the underlying mechanism and molecular targets responsible for alternations in the ingestion performance. The results indicated that a significant increase in the final body weight was exhibited by the feed domesticated group (DOM, 114.8 g) when compared to the group that did not ingest the feed (WT, 5.3 g) as the latest version we raised From the result, the final body weight exhibited significant increase between unfavorable with the feed (WT, 5.3 g) and feed domesticated group (DOM, 114.8 g). In addition, the enzyme activity of digestive enzymes like amylase, lipase, and trypsin was increased in DOM. Genes related to appetite and perception, such as NPY4R, PYY, and LEPR, were activated in DOM. 16s rRNA gene sequencing analysis revealed that Pseudomonas sp. increased from 58.74% to 89.77% in DOM, which accounts for the dominant upregulated microbial community at the genus level, followed by Plesiomonas. Analogously, Mycobacterium, Methylocystis, and Romboutsia also accounted for the down-regulated microbes in the diversity. Transcriptome and RT-PCR analysis revealed that feed domestication significantly improved protein digestion and absorption, inhibited apoptosis by AGE-RAGE signaling, and activated extracellular matrix remodeling by relaxin signaling. Integrated analysis of the microbiome and host transcriptome revealed that Pseudomonas-mediated ingestion capacity, protein utilization, and cellular homeostasis might be the underlying mechanism under feed domestication. These results indicate Pseudomonas and its key genes relating to food ingestion and digestion could serve as the molecular targets for feed domestication and sustainable development in A. grunniens

    Nonaqueous Production of Nanostructured Anatase with High-Energy Facets

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    通讯作者地址: Zheng, NF (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Xiamen 361005, Peoples R China 3. Univ Calif Santa Barbara, Dept Chem & Biochem, Santa Barbara, CA 93106 USA 电子邮件地址: [email protected], [email protected] solution-based synthesis is the most powerful and economic method to create nanostructured anatase TiO2, under those synthesis conditions the {101} facets are the most thermodynamically stable, making it difficult to create anatase nanomaterials with a large percentage of high-energy {001} or {010} facets exposed. Here, we report a facile nonaqueous synthetic route to prepare anatase nanosheets with exposed {001} facets and high-quality rhombic-shaped anatase nanocrystals with a large percentage of exposed {010} facets. Including adscititious water in the nonaqueous synthesis and eliminating the use of carboxylic acid type capping agents are the two keys to integrating the structural diversity from aqueous systems into large-quantity synthesis in nonaqueous systems. The nanostructured TiO2 that we prepared exhibits conspicuous activity in the photocatalytic degradation of organic contaminants.Chinese Ministry of Education 108077 NNSFC 20871100 20721001 20423002 MSTC 2007CB815303 2009CB93070

    Activated monocytes in peritumoral stroma of hepatocellular carcinoma foster immune privilege and disease progression through PD-L1

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    Macrophages (Mφ) are prominent components of solid tumors and exhibit distinct phenotypes in different microenvironments. We have recently found that tumors can alter the normal developmental process of Mφ to trigger transient activation of monocytes in peritumoral stroma. We showed that a fraction of monocytes/Mφ in peritumoral stroma, but not in cancer nests, expresses surface PD-L1 (also termed B7-H1) molecules in tumors from patients with hepatocellular carcinoma (HCC). Monocytes activated by tumors strongly express PD-L1 proteins with kinetics similar to their activation status, and significant correlations were found between the levels of PD-L1+ and HLA-DRhigh on tumor-infiltrating monocytes. Autocrine tumor necrosis factor α and interleukin 10 released from activated monocytes stimulated monocyte expression of PD-L1. The PD-L1+ monocytes effectively suppressed tumor-specific T cell immunity and contributed to the growth of human tumors in vivo; the effect could be reversed by blocking PD-L1 on those monocytes. Moreover, we found that PD-L1 expression on tumor-infiltrating monocytes increased with disease progression, and the intensity of the protein was associated with high mortality and reduced survival in the HCC patients. Thus, expression of PD-L1 on activated monocytes/Mφ may represent a novel mechanism that links the proinflammatory response to immune tolerance in the tumor milieu

    Recombinant antigen P29 of Echinococcus granulosus induces Th1, Tc1, and Th17 cell immune responses in sheep

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    Echinococcosis is a common human and animal parasitic disease that seriously endangers human health and animal husbandry. Although studies have been conducted on vaccines for echinococcosis, to date, there is no human vaccine available for use. One of the main reasons for this is the lack of in-depth research on basic immunization with vaccines. Our previous results confirmed that recombinant antigen P29 (rEg.P29) induced more than 90% immune protection in both mice and sheep, but data on its induction of sheep-associated cellular immune responses are lacking. In this study, we investigated the changes in CD4+ T cells, CD8+ T cells, and antigen-specific cytokines IFN-γ, IL-4, and IL-17A after rEg.P29 immunization using enzyme-linked immunospot assay (ELISPOT), enzyme-linked immunosorbent assay (ELISA), and flow cytometry to investigate the cellular immune response induced by rEg.P29 in sheep. It was found that rEg.P29 immunization did not affect the percentage of CD4+ and CD8+ T cells in peripheral blood mononuclear cells (PBMCs), and was able to stimulate the proliferation of CD4+ and CD8+ T cells after immunization in vitro. Importantly, the results of both ELISPOT and ELISA showed that rEg.P29 can induce the production of the specific cytokines IFN-γ and IL-17A, and flow cytometry verified that rEg.P29 can induce the expression of IFN-γ in CD4+ and CD8+ T cells and IL-17A in CD4+ T cells; however, no IL-4 expression was observed. These results indicate that rEg.P29 can induce Th1, Th17, and Tc1 cellular immune responses in sheep against echinococcosis infection, providing theoretical support for the translation of rEg.P29 vaccine applications
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