排序方式: 共有44条查询结果,搜索用时 0 毫秒
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Romberg R Heckmair N Frigo SP Ogurtsov A Menzel D Feulner P 《Physical review letters》2000,84(2):374-377
We observe photochemical selectivity for N 1s to pi(*) excitations of chemisorbed N2. By narrow bandwidth synchrotron radiation we selectively excite one of the two atoms of the molecule. Photon stimulated desorption of neutral N atoms predominates for excitations of the N atom close to the surface, whereas excitation of the outer atom ejects predominantly N02 and small amounts of N+, demonstrating the predominant breaking of the inner or outer bond, respectively, of the N2 adsorbate. Analysis on the basis of previously obtained decay electron spectra after atom-selective excitation can explain the mechanism of localized bond breaking. 相似文献
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Vlaar MJ Ehlers AW de Kanter FJ Schakel M Spek AL Lammertsma K 《Angewandte Chemie (International ed. in English)》2000,39(16):2943-2945
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Marcos RL Leal Junior EC Messias Fde M de Carvalho MH Pallotta RC Frigo L dos Santos RA Ramos L Teixeira S Bjordal JM Lopes-Martins RÁ 《Photochemistry and photobiology》2011,87(6):1447-1452
Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used and can reduce musculoskeletal pain in spite of the cost of adverse reactions like gastrointestinal ulcers or cardiovascular events. The current study investigates if a safer treatment such as low-level laser therapy (LLLT) could reduce tendinitis inflammation, and whether a possible pathway could be through inhibition of either of the two-cyclooxygenase (COX) isoforms in inflammation. Wistar rats (six animals per group) were injected with saline (control) or collagenase in their Achilles tendons. Then, we treated them with three different doses of IR LLLT (810 nm; 100 mW; 10 s, 30 s and 60 s; 3.57 W cm(-2); 1 J, 3 J, 6 J) at the sites of the injections, or intramuscular diclofenac, a nonselective COX inhibitor/NSAID. We found that LLLT dose of 3 J significantly reduced inflammation through less COX-2-derived gene expression and PGE(2) production, and less edema formation compared to nonirradiated controls. Diclofenac controls exhibited significantly lower PGE(2) cytokine levels at 6 h than collagenase control, but COX isoform 1-derived gene expression and cytokine PGE(2) levels were not affected by treatments. As LLLT seems to act on inflammation through a selective inhibition of the COX-2 isoform in collagenase-induced tendinitis, LLLT may have potential to become a new and safer nondrug alternative to coxibs. 相似文献