276 research outputs found

    Immersed Lagrangian Floer Theory

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    Let (M,w) be a compact symplectic manifold, and L a compact, embedded Lagrangian submanifold in M. Fukaya, Oh, Ohta and Ono construct Lagrangian Floer cohomology for such M,L, yielding groups HF^*(L,b;\Lambda) for one Lagrangian or HF^*((L,b),(L',b');\Lambda) for two, where b,b' are choices of bounding cochains, and exist if and only if L,L' have unobstructed Floer cohomology. These are independent of choices up to canonical isomorphism, and have important invariance properties under Hamiltonian equivalence. Floer cohomology groups are the morphism groups in the derived Fukaya category of (M,w), and so are an essential part of the Homological Mirror Symmetry Conjecture of Kontsevich. The goal of this paper is to extend all this to immersed Lagrangians L in M with immersion i : L --> M, with transverse self-intersections. In the embedded case, Floer cohomology HF^*(L,b;\Lambda) is a modified, 'quantized' version of cohomology H^*(L;\Lambda) over the Novikov ring \Lambda. In our immersed case, HF^*(L,b;\Lambda) turns out to be a quantized version of the sum of H^*(L;\Lambda) with a \Lambda-module spanned by pairs (p,q) for p,q distinct points of L with i(p)=i(q) in M. The theory becomes simpler and more powerful for graded Lagrangians in Calabi-Yau manifolds, when we can work over a smaller Novikov ring \Lambda_{CY}. The proofs involve associating a gapped filtered A-infinity algebra over \Lambda or \Lambda_{CY} to i : L --> M, which is independent of nearly all choices up to canonical homotopy equivalence, and is built using a series of finite approximations called A_{N,0} algebras for N=0,1,2,...Comment: 95 pages, LaTe

    AN OVERVIEW OF EPIGENETIC DRUGS, AND THEIR VIRTUAL SCREENING STUDY RETRIEVED FROM ZINC DATABASE ALONG WITH AN AUTODOCK STUDY OF THE BEST INHIBITOR

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    Objective: Over the last 30 y cancer epigenetics research has grown extensively. It is note-worthy to recognize that epigenetic misregulation could substantiate the development of cancer and we need to continue to look for anti-neoplastic epi-drugs. Taking into consideration this phenomenon, our first aim is to search for an effective epi-drugs by virtual screening from ZINC database and to explore the validity of the virtual screening. The second aim is to explore a binding conformation of the top affinity ligands against macromolecules, by docking experiment. Methods: The virtual screening was conducted by our Virtual Screening by Docking (VSDK) algorithm and procedure. Small molecules were randomly downloaded by ZINC database. For docking experiment, AutoDock 4.2.6 and AutoDock Tool were used. Results: It took eight to ten hours for the successful virtual screening of the 2778 small compounds retrieved at random from ZINC database. Among histone H2B E76K mutant (HHEM) inhibitors and DNA methyltransferase (DNMT) inhibitors, the first ranked inhibitors were 1H-1,2,4-triazole-3,5-diamine and 2-ethyl-1,3,4-oxadiazole respectively. Conclusion: As for the molecular structures obtained from virtual screening, most of the top ten HHEM and DNMT inhibitors contained 5-member rings. More than two times in affinity difference between the top and bottom ten compounds would indicate a successful virtual screening experiment. The histogram chart of AutoDock4 runs appeared in the lowest affinity region with two or three hydrogen bonds indicating a reliable conformation docking

    Studies on Regioselective Binding Mode of Steroid Molecules in Homology Modeled Cytochrome P450-2C11

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    In this study, we investigated the regioselective binding mode of steroid molecules and structure requirements for steroid molecules for 16[alpha]-hydroxylation by Cytochrome P450-2C11. Docking study by using the homology Cytochrome P450-2C11 indicated that 16[alpha]-hydroxylation is favored with steroidal molecules possessing the following components, 1) a bent A-B ring configuration (5[beta]-reduced), 2) C-3[alpha]-hydroxyl group, 3) C-17[beta]-acetyl group, and 4) methyl group at both the C-18 and C-19. These respective steroid components requirements such as A-B ring configuration and functional groups at C-3 and C-17 were defined as the inhibitory contribution factor. Overall results by rat CYP2C11 revealed that steroidal structure requirements resulted in causing an effective inhibition of [^3^H]progesterone 16[alpha]-hydroxylation by the adult male rat liver microsome. As far as docking of homology modeled CYP2C11 against investigated steroids is concerned, they are docked at the active site superimposed with flurbiprofen. It was also found that the distance between heme iron and C16[alpha]-H was between 4 to 6 Å and that the related angle was in the range of 180±45°

    Synergic effect of Citric Acid and Red Onion skin extract on the Oxidative stability of Vegetable Oil

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    The antioxidant potentials of citric acid and onion skin extract on the oxidative stability of vegetable oil were examined. Results from the peroxide values showed that citric acid had the best antioxidative potentials at a concentration of 0.2g/100g of vegetable oil. This was followed by the antioxidative potentials of a mixture 0.1g of citric acid and 0.1g onion skin extract in 100g of vegetable oil. 0.2g of onion skin extract in 100g of vegetable oil gave the least antioxidative potential. Using a blend of onion skin extract and citric acid gave a better antioxidative potential than using onion skin extract alone. This suggests that there has been some synergistic effect of citric acid on the onion skin extract. Such a blend could be used in place of citric acid to cut down production cost.J. Appl. Sci. Environ. Manage. Dec, 201
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