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排序方式: 共有215条查询结果,搜索用时 15 毫秒
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Yujie Wang Rong Wen Dongdong Liu Chen Zhang Zhuo A. Wang Yuguang Du 《Molecules (Basel, Switzerland)》2021,26(8)
Intestinal barrier dysfunction is an essential pathological change in inflammatory bowel disease (IBD). The mucus layer and the intestinal epithelial tight junction act together to maintain barrier integrity. Studies showed that chitosan oligosaccharide (COS) had a positive effect on gut health, effectively protecting the intestinal barrier in IBD. However, these studies usually focused on its impact on the intestinal epithelial tight junction. The influence of COS on the intestinal mucus layer is still poorly understood. In this study, we explored the effect of COS on intestinal mucus in vitro using human colonic mucus-secreted HT-29 cells. COS relieved DSS (dextran sulfate sodium)-induced mucus defects. Additionally, the structural characteristics of COS greatly influenced this activity. Finally, we evaluated the protective effect of COS on intestinal barrier function in mice with DSS-induced colitis. The results indicated that COS could manipulate intestinal mucus production, which likely contributed to its intestinal protective effects. 相似文献
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In this paper, we present a method for constructing multivariate tight framelet packets associated with an arbitrary dilation matrix using unitary extension principles.We also prove how to construct various tight frames for L2(Rd) by replac-ing some mother framelets. 相似文献
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无线通信系统设计中的许多问题可建模为优化问题.一方面,这些优化问题常常具有高度的非线性性,一般情况下难于求解;另一方面,它们又有自身的特殊结构,例如隐含的凸性、可分性等.利用优化的方法结合问题的特殊结构求解和处理无线通信系统设计问题是近年来学术界研究的热点.本文重点讨论无线通信系统设计中的两个优化问题和相关优化方法,包括多用户干扰信道最大最小准则下的联合传输/接收波束成形设计和多输入多输出(Multi-Input Multi-Output,MIMO)检测问题,主要介绍现代优化技术结合问题的特殊结构在求解和处理上述两个问题的最新进展. 相似文献
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Grant F. Armstrong 《Applied Mathematical Finance》2013,20(4):197-208
In this paper we study window barrier options, where a single constant continuously-monitored barrier prevails for a period that commences strictly after the start date of the option and terminates strictly before expiry. We determine valuation formulae within a limited deterministic term-structure in terms of trivariate normal distribution functions. These formulae offer a generalization of the valuation formulae for partial barrier options given by Heynan and Kat. 相似文献
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Lihong Cui Ning Zhu Youquan Wang Jianjun Sun Yigang Cen 《Numerical Functional Analysis & Optimization》2016,37(9):1089-1106
In this article, we introduce and study the matrix-valued tight wavelet frames for analyzing matrix-valued signal based on matrix-valued multiresolution analysis (MMRA). We put our emphasis on the existence of the MMRA-based matrix-valued tight wavelet frames by establishing the correspondence with their the unitary extension principle (UEP). Here in particular we introduce the square brackets product and the quasi-interpolatory operator, which makes the certificating process for UEP become relatively simple. Some interesting byproducts, such as features on the quasi-interpolatory operator 𝒫n in the matrix-valued function space case, are the critical foundation for our main work. 相似文献
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The self‐consistent charge density functional tight‐binding theory study of carbon adatoms using tuned Hubbard U parameters 下载免费PDF全文
The self‐consistent charge density functional tight‐binding (DFTB) theory is a useful tool for realizing the electronic structures of large molecular complex systems. In this study, the electronic structure of C61 formed by fullerene C60 with a carbon adatom is analyzed, using the fully localized limit and pseudo self‐interaction correction methods of DFTB to adjust the Hubbard U parameter (DFTB + U). The results show that both the methods used to adjust U can significantly reduce the molecular orbital energy of occupied states localized on the defect carbon atom and improve the gap between highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) of C61. This work will provide a methodological reference point for future DFTB calculations of the electronic structures of carbon materials. 相似文献