222 research outputs found

    High-order harmonic generation from polyatomic molecules including nuclear motion and a nuclear modes analysis

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    We present a generic approach for treating the effect of nuclear motion in the high-order harmonic generation from polyatomic molecules. Our procedure relies on a separation of nuclear and electron dynamics where we account for the electronic part using the Lewenstein model and nuclear motion enters as a nuclear correlation function. We express the nuclear correlation function in terms of Franck-Condon factors which allows us to decompose nuclear motion into modes and identify the modes that are dominant in the high-order harmonic generation process. We show results for the isotopes CH4_4 and CD4_4 and thereby provide direct theoretical support for a recent experiment [Baker {\it et al.}, Science {\bf 312}, 424 (2006)] that uses high-order harmonic generation to probe the ultra-fast structural nuclear rearrangement of ionized methane.Comment: 6 pages, 6 figure

    Third-order relativistic many-body calculations of energies and lifetimes of levels along the silver isoelectronic sequence

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    Energies of 5l_j (l= s, p, d, f, g) and 4f_j states in neutral Ag and Ag-like ions with nuclear charges Z = 48 - 100 are calculated using relativistic many-body perturbation theory. Reduced matrix elements, oscillator strengths, transition rates and lifetimes are calculated for the 17 possible 5l_j-5l'_{j'} and 4f_j-5l_{j'} electric-dipole transitions. Third-order corrections to energies and dipole matrix elements are included for neutral Ag and for ions with Z60. Comparisons are made with available experimental data for transition energies and lifetimes. Correlation energies and transition rates are shown graphically as functions of nuclear charge Z for selected cases. These calculations provide a theoretical benchmark for comparison with experiment and theory.Comment: 8 page

    Use of alternative and complementary medicine in menopause

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    Objectives: To review the clinical evidence available for the treatment of menopausal symptoms with alternative and complementary medicine. Methods: The MEDLINE, PREMEDLINE and COCHRANE electronic databases for the years 1980–2002 were searched for articles concerning soy products, black cohosh, dong quai, acupuncture, ginseng and evening primrose oil. Studies pertaining to menopausal vasomotor symptoms, lipid profiles and bone mineral densities of postmenopausal women were included. The data from clinical trials were reviewed. Results: Soy isoflavones slightly decrease total cholesterol and LDL levels. The clinical significance of this small change is yet to be determined. The synthetic isoflavone derivative ipriflavone increases bone mineral density in healthy peri‐ and postmenopausal women with moderate bone mineral densities. Although earlier reports have claimed that soy is beneficial for the improvement of vasomotor symptoms, recent data do not support this claim. There are insufficient data on the other alternative therapies for treating menopausal symptoms at this time. Conclusion: Alternative and complementary medicine may play a role in the management of menopause, however, well‐designed large studies are still needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135146/1/ijgo195.pd

    Glycosaminoglycans that bind cold-insoluble globulin in cell-substratum adhesion sites of murine fibroblasts.

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    Glycosaminoglycans (GAGs) and glycoprotein-derived glycopeptide from mouse BALB/c3T3 and simian virus 40-transformed 3T3 whole cells or their adhesion sites, which are left bound to the serum-coated tissue culture substratum after detachment of cells mediated by [ethylenebis-(oxyethylenenitrilo]tetraacetic acid (EGTA), were analyzed for specific binding to Sepharose columns derivatized with cold-insoluble globulin (CIg). CIg is the serum-contained form of fibronectin and is required for the adhesion of these fibroblasts to the substratum. Of the various GAGs present in these fractions of either cell type, only the highly N-sulfated sequences of heparan sulfate and a small subset of dermatan sulfate bind to CIg-Sepharose. There was no detectable binding of glycopeptide, undersulfated heparan sulfate, the various chondroitin species, or hyaluronate. Adhesion sites from newly attaching cells were greatly enriched in CIg-binding heparan sulfate when compared to long-term-growth adhesion sites or EGTA-detached cells. Various properties of binding were determined. The reference standard standard GAGs heparin (or heparan sulfate) and dermatan sulfate were able to displace bound radiolabeled adhesion site GAG from the column, whereas the other GAGs had no effect. CIg has been shown to be the only adhesion-promoting activity in the serum layer of this culture system. Because these fibroblast adhesion sites do not contain collagen, which could potentially mediate adhesion to the substratum-bound CIg, these data support other evidence that multivalent heparan sulfate proteoglycans mediate substratum adhesion of these cells by coordinate binding to fibronectin on the cell surface and CIg on the substratum
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