4,267 research outputs found

    Convergence on Gauss-Seidel iterative methods for linear systems with general H-matrices

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    It is well known that as a famous type of iterative methods in numerical linear algebra, Gauss-Seidel iterative methods are convergent for linear systems with strictly or irreducibly diagonally dominant matrices, invertible HH-matrices (generalized strictly diagonally dominant matrices) and Hermitian positive definite matrices. But, the same is not necessarily true for linear systems with nonstrictly diagonally dominant matrices and general HH-matrices. This paper firstly proposes some necessary and sufficient conditions for convergence on Gauss-Seidel iterative methods to establish several new theoretical results on linear systems with nonstrictly diagonally dominant matrices and general HH-matrices. Then, the convergence results on preconditioned Gauss-Seidel (PGS) iterative methods for general HH-matrices are presented. Finally, some numerical examples are given to demonstrate the results obtained in this paper

    Study on Barriers and Countermeasures of Technological Innovation of Ecological Service Function Assessment of Urban Greenbelt

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    AbstractAs the main body of the natural productivity, the urban greenbelt, an irreplaceable comprehensive ecological service system, plays a leading role in beautifying the urban appearance, improving the quality of the urban ecological environment, adjusting the urban ecological balance. The research of ecological service function assessment is a hot research of many domains in recent times, such as ecology, environmental science, sociology, science of culture, economics, etc. Technological innovation is not only the urgent need and significant support system of technological development, but also the urgent need of solving the existing problems of the ecological service function assessment of urban greenbelt. This paper analyzes the main barriers and corresponding countermeasures of the technological innovation, such as unsound innovation mechanism, dated technological means, fault information transform, unsound assessment system, etc., which provides enlightenment and reference for the assessment, planning, construction, management and sustainable development of the ecological service function of urban greenbelt

    Enhancing Hydrogen Generation Through Nanoconfinement of Sensitizers and Catalysts in a Homogeneous Supramolecular Organic Framework.

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    Enrichment of molecular photosensitizers and catalysts in a confined nanospace is conducive for photocatalytic reactions due to improved photoexcited electron transfer from photosensitizers to catalysts. Herein, the self-assembly of a highly stable 3D supramolecular organic framework from a rigid bipyridine-derived tetrahedral monomer and cucurbit[8]uril in water, and its efficient and simultaneous intake of both [Ru(bpy)3 ]2+ -based photosensitizers and various polyoxometalates, that can take place at very low loading, are reported. The enrichment substantially increases the apparent concentration of both photosensitizer and catalyst in the interior of the framework, which leads to a recyclable, homogeneous, visible light-driven photocatalytic system with 110-fold increase of the turnover number for the hydrogen evolution reaction

    The therapeutic evaluation and mechanism on treating bronchial hyper-responsiveness cough by ziyinqingre prescription

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    Objective: Discussing the effects of Ziyinqingre prescription on the level of airway resistance (Rrs), airway response threshold (Dmin), airway conductance (sGrs) and the level of inflammatory cytokines interleukin-4 (IL-4) and interferon-γ (IFN-γ) of the bronchial hyper-responsiveness (BHR) cough patients.Method: 84 subjects diagnosed as BHR were randomly divided into 42 Chinese Traditional medicine group and 42 control group. The Chinese Traditional Medicine group received Ziyinqingre prescription twice a day and the control group received 10mg Montelukast Sodium tablets once a day for two weeks. Observe the clinical symptoms improvement and the changes of the level of the Rrs, Dmin, sGrs and IL-4, IFN-γ.Results: After receiving the medicine, the symptoms of the Chinese medicine group were obviously alleviated, the outcome was more satisfied than that of the control group. Compared with the control group, the level of Dmin increased and sGrs level decreased more obviously (P<0.05); the level of IL-4 decreased and IFN-γlevel increased more obviously in the Chinese medicine group (P<0.05).Conclusion: Ziyinqingre prescription can not only improve BHR patients’ symptoms, but reduce the level of bronchial responsiveness, which proved a better curative effect of Chinese medicine. The mechanism is probably due to relieving the airway inflammation by keeping the balance between Th1 and Th2 cells.Keywords: Ziyinqingre prescription; cough; bronchial hyper-responsiveness; therapeutic mechanis

    Fish species-specific TRIM gene FTRCA1 negatively regulates interferon response through attenuating IRF7 transcription

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    In mammals and fish, emerging evidence highlights that TRIM family members play important roles in the interferon (IFN) antiviral immune response. Fish TRIM family has undergone an unprecedented expansion leading to generation of finTRIM subfamily, which is exclusively specific to fish. Our recent results have shown that FTRCA1 (finTRIM C. auratus 1) is likely a fish species-specific finTRIM member in crucian carp C. auratus and acts as a negative modulator to downregulate fish IFN response by autophage-lysosomal degradation of protein kinase TBK1. In the present study, we found that FTRCA1 also impedes the activation of crucian carp IFN promoter by IRF7 but not by IRF3. Mechanistically, FTRCA1 attenuates IRF7 transcription levels likely due to enhanced decay of IRF7 mRNA, leading to reduced IRF7 protein levels and subsequently reduced fish IFN expression. E3 ligase activity is required for FTRCA1 to negatively regulate IRF7-mediated IFN response, because ligase-inactive mutants and the RING-deleted mutant of FTRCA1 lose the ability to block the activation of crucian carp IFN promoter by IRF7. These results together indicate that FTRCA1 is a multifaceted modulator to target different signaling factors for shaping fish IFN response in crucian carp.</p

    Osthole induces G2/M arrest and apoptosis in lung cancer A549 cells by modulating PI3K/Akt pathway

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    <p>Abstract</p> <p>Background</p> <p>To explore the effects of Osthole on the proliferation, cell cycle and apoptosis of human lung cancer A549 cells.</p> <p>Methods</p> <p>Human lung cancer A549 cells were treated with Osthole at different concentrations. Cell proliferation was measured using the MTT assay. Cell cycle was evaluated using DNA flow cytometry analysis. Induction of apoptosis was determined by flow cytometry and fluorescent microscopy. The expressions of Cyclin B1, p-Cdc2, Bcl-2, Bax, t-Akt and p-Akt were evaluated by Western blotting.</p> <p>Results</p> <p>Osthole inhibited the growth of human lung cancer A549 cells by inducing G2/M arrest and apoptosis. Western blotting demonstrated that Osthole down-regulated the expressions of Cyclin B1, p-Cdc2 and Bcl-2 and up-regulated the expressions of Bax in A549 cells. Inhibition of PI3K/Akt signaling pathway was also observed after treating A549 cells with Osthole.</p> <p>Conclusions</p> <p>Our findings suggest that Osthole may have a therapeutic application in the treatment of human lung cancer.</p

    RNA Nanoparticle for Treatment of Gastric Cancer

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    The presently-disclosed subject matter relates to RNA-based composition and method to treat gastric cancer in a subject. More particularly, the presently disclosed subject matter relates to a RNA nanostructure and composition containing a multiple branched RNA nanoparticle, a gastric cancer targeting module, and an effective amount of a therapeutic agent. Further, the presently disclosed subject matter relates to a method of using the RNA nanoparticle composition to treat gastric cancer in a subject having or at risk of having gastric cancer
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