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51.
This paper studies the dynamics of a class of retarded impulsive differential equations (IDE), which generalizes the delayed cellular neural networks (DCNN), delayed bidirectional associative memory (BAM) neural networks and some population growth models. Some sufficient criteria are obtained for the existence and global exponential stability of a unique equilibrium. When the impulsive jumps are absent, our results reduce to its corresponding results for the non-impulsive systems. The approaches are based on Banach’s fixed point theorem, matrix theory and its spectral theory. Due to this method, our results generalize and improve many previous known results such as [3], [5], [6], [9], [17], [18], [23], [32], [38], [43], [51], [52]. Some examples are also included to illustrate the feasibility and effectiveness of the results obtained. 相似文献
52.
Yonghui Liu 《Journal of Applied Mathematics and Computing》2009,31(1-2):71-80
Suppose that AX=C, XB=D has a common solution and partition its solution $X=\bigl[{\fontsize{7.5}{9}\selectfont \begin{array}{cc}X_{1}&X_{2}\\X_{3}&X_{4}\end{array}}\bigr]$ . In this paper, we give some formulas for the maximal and minimal ranks of the submatrices in a solution X to matrix equations AX=C, XB=D. In addition, we investigate the uniqueness and the independence of submatrices in a solutions X to this equations. 相似文献
53.
Mao J Mukherjee S Zhang Y Cao R Sanders JM Song Y Zhang Y Meints GA Gao YG Mukkamala D Hudock MP Oldfield E 《Journal of the American Chemical Society》2006,128(45):14485-14497
Bisphosphonates are a class of molecules in widespread use in treating bone resorption diseases and are also of interest as immunomodulators and anti-infectives. They function by inhibiting the enzyme farnesyl diphosphate synthase (FPPS), but the details of how these molecules bind are not fully understood. Here, we report the results of a solid-state (13)C, (15)N, and (31)P magic-angle sample spinning (MAS) NMR and quantum chemical investigation of several bisphosphonates, both as pure compounds and when bound to FPPS, to provide information about side-chain and phosphonate backbone protonation states when bound to the enzyme. We then used computational docking methods (with the charges assigned by NMR) to predict how several bisphosphonates bind to FPPS. Finally, we used X-ray crystallography to determine the structures of two potent bisphosphonate inhibitors, finding good agreement with the computational results, opening up the possibility of using the combination of NMR, quantum chemistry and molecular docking to facilitate the design of other, novel prenytransferase inhibitors. 相似文献
54.
A biodegradable and amphiphilic copolymer, mPEG-b-P(LA-co-MAC/TMA) that contains pendant 1,2-bidentate carboxyl groups is synthesized by thiol-ene radical addition and is further used to chelate with the active anticancer species (DACH-Pt) of oxaliplatin to form an mPEG-b-P(LA-co-MAC/TMA-Pt-DACH) complex. The polymer platinum complex can self-assemble into micelles. In vitro studies show that the DACH-Pt micelles display enhanced or comparable cytotoxicity against SKOV-3 and MCF-7 cancer cells, while they show reduced toxicity to HeLa cells compared with oxaliplatin. 相似文献
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Feng X Zhou W Li Y Ke H Tang J Clérac R Wang Y Su Z Wang E 《Inorganic chemistry》2012,51(5):2722-2724
The reactions of [CuTbL(Schiff)(H(2)O)(3)Cl(2)]Cl complexes with A- or B-type Anderson polyoxoanions lead to new polyoxometalate-supported 3d-4f heterometallic systems with single-molecule-magnet behavior. 相似文献
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缺氧是包括肿瘤在内的许多疾病的重要特征,利用缺氧条件来选择性抑制肿瘤生长和演进是一个很有前途的研究方向。随着缺氧诱导因子-1(HIF-1)的发现,在过去15年里在分子和细胞水平上对缺氧有了更加深刻的认识,HIF-1是真核细胞在缺氧条件下进行代谢调控的关键因子,控制众多基因的表达,影响氧的转运、糖摄取、糖酵解和血管生成等。下调HIF-1水平可以作为肿瘤治疗手段。由于细胞内对HIF-1的调控主要通过其α亚基进行,HIF-1α抑制剂成为抗肿瘤药物的研究热点,已经发现的该类抑制剂包括喜树碱类、喹噁啉类、雷帕霉素类、一些甾体化合物、苯氧乙酰氨基苯甲酸类以及白藜芦醇和橙皮苷等天然物质。本文就HIF-1α的结构、功能和以其为靶点的抗肿瘤药物的研究进展做一综述。 相似文献
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