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1.
Zhu Yongliang; Pagilla Prabhakar R. 《IMA Journal of Mathematical Control and Information》2005,22(2):181-186
We derive some useful and easily computable necessary conditionsfor the existence of a positive semi-definite solution to thealgebraic Ricatti equation (ARE). A motivating example is givento highlight the usefulness of the conditions for controllerand observer designs for nonlinear systems. Further, an upperbound on the trace of the solution to the ARE is also derived. 相似文献
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J.S. Yadav B.V. Subba Reddy A.K. Basak A.V. Narsaiah A. Prabhakar B. Jagadeesh 《Tetrahedron letters》2005,46(4):639-641
Baylis-Hillman acetates undergo SN2′ allylic substitution with indoles in the presence of 20 mol % of indium tribromide under mild conditions to afford a new class of substituted indoles in high yields with (E)-stereoselectivity. The stereochemistry of the products was assigned by various NMR experiments. 相似文献
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Asymmetric hydroboration of appropriate alkenes with diisopinocampheylborane (Ipc2BH) or monoisopinocampheylborane (IpcBH2) produces intermediates that readily eliminate α-pinene on treat- ment with acetaldehyde, providing a direct, convenient route to chiral boronic esters of high enantiomeric purities. Mixed chiral trialkylboranes, readily prepared by stepwise hydroboration of appropriate alkenes with IpcBH2, eliminate α-pinene on treatment with acetaldehyde under very mild conditions. The procedure makes readily available chiral borinic esters of high enantiomeric purities. The synthetic utility of chiral borinic esters is demonstrated by converting them into acyclic ketones including an alarm pheromone of the ant Monica mutica. 相似文献
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Various computational approaches, using molecular mechanics (Amber), semiempirical (AM1), density functional (B3LYP), and various ONIOM methods, have been comparatively investigated for the structure of Escherichia coli NifS CsdB protein. The structure of the entire monomer containing 407 amino acid residues and 579 surrounding water molecules has been optimized. The full geometry optimization in the "active site-only" approach (including only active site atoms) has been found to give the largest root-mean-square (RMS) deviation from the X-ray structure; a much better agreement has been achieved by keeping the atoms leading to the backbones of some amino acids frozen in their positions in the X-ray structure. The best agreement has been attained by including the surrounding protein in the calculations using the two-layer ONIOM (B3LYP:Amber) approach. The results presented in this study conclusively demonstrate the importance of the protein/active-site interaction on the active-site structure of the enzyme. The present theoretical study represents the largest system studied at the ONIOM level to date, containing 7992 atoms, including 84 atoms in the QM region and rest in the MM region. 相似文献
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In a previous DFT study a mechanism for the reductive half-reaction of pea seedling amine oxidase (PSAO) was suggested. In many of the suggested steps a lysine at the active site plays an important role. However, this lysine is not found in other amine oxidases. The primary aim of the present DFT study is therefore to investigate alternative mechanisms for those amine oxidases (CAO) where the lysine residue is not present. One of the most important roles suggested for the lysine in PSAO was to protonate the O2-site of TPQ before the critical Cbond;H bond cleavage of the substrate. In the absence of lysine the O2-site of TPQ is now suggested to be protonated by a water ligand on the copper metal complex, in line with experimental suggestions. In other steps the role of lysine is taken over by an asparagine. All results are compared with experimental observations and good agreement is generally found. 相似文献
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Baby Gargi Prabhakar Semwal Shabaaz Begum Jameel Pasha Pooja Singh Sakshi Painuli Ashish Thapliyal Natlia Cruz-Martins 《Molecules (Basel, Switzerland)》2022,27(20)
The genus Cajanus (Family: Fabaceae) consists of approximately 37 species, and Cajanus cajan (C. cajan) is a significant member of the genus. It is a commercial legume crop widely grown in sub-tropical and semi-arid tropical areas of the world. C. cajan is well known for its folk medicinal uses to treat various disorders, such as toothache, dizziness, diabetes, stomachache, female ailments and chronic infections. These properties have been linked to the presence of several value-added nutritional and bioactive components. Different solvent extracts from C. cajan (leaves, root, stem and seeds) have been evaluated for their phytochemical and biological activities, namely antioxidant, antimicrobial, antidiabetic, neuroprotective, and anti-inflammatory effects. Taken together, and considering the prominent nutraceutical and therapeutic properties of C. cajan, this review article focuses on the important details including ethnomedicinal uses, chemical composition, biological applications and some other medicinal aspects related to C. cajan nutraceutical and pharmacological applications. 相似文献
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