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101.
Estruch T Jaeck J Pardo F Derelle S Primot J Pelouard JL Haidar R 《Optics letters》2011,36(16):3160-3162
We investigate the strong electromagnetic coupling that settles in dual metallic grating structures. This coupling is evidenced to lead to a perfect optical extinction in the transmission spectrum. The behavior of this perfect extinction that strongly depends on the longitudinal space and the lateral displacement between the two gratings can be explained by a simple model that describes the interference between a propagating mode and a couple of evanescent modes. The results show that the electromagnetic transmission of the structure can be tuned by controlling the position of this perfect transmission extinction and thus pave the way to new types of infrared tunable filters. 相似文献
102.
Zhao Z Bouchoule S Song J Galopin E Harmand JC Decobert J Aubin G Oudar JL 《Optics letters》2011,36(22):4377-4379
Near-transform-limited subpicosecond pulses at 1.56 μm were generated from an optically pumped InP-based vertical-external-cavity surface-emitting laser (VECSEL) passively mode-locked at 2 GHz repetition rate with a fast InGaAsNSb/GaAs semiconductor saturable absorber mirror (SESAM). The SESAM microcavity resonance was adjusted via a selective etching of phase layers specifically designed to control the magnitude of both the modulation depth and the intracavity group delay dispersion of the SESAM. Using the same VECSEL chip, we observed that the mode-locked pulse duration could be reduced from several picoseconds to less than 1 ps with a detuned resonant SESAM. 相似文献
103.
Tiffany G. Chan Carmen L. Ruehl Sophie V. Morse Michelle Simon Viktoria Rakers Helena Watts Francesco A. Aprile James J. Choi Ramon Vilar 《Chemical science》2021,12(27):9485
One of the key hallmarks of Alzheimer''s disease is the aggregation of the amyloid-β peptide to form fibrils. Consequently, there has been great interest in studying molecules that can disrupt amyloid-β aggregation. While a handful of molecules have been shown to inhibit amyloid-β aggregation in vitro, there remains a lack of in vivo data reported due to their inability to cross the blood–brain barrier. Here, we investigate a series of new metal complexes for their ability to inhibit amyloid-β aggregation in vitro. We demonstrate that octahedral cobalt complexes with polyaromatic ligands have high inhibitory activity thanks to their dual binding mode involving π–π stacking and metal coordination to amyloid-β (confirmed via a range of spectroscopic and biophysical techniques). In addition to their high activity, these complexes are not cytotoxic to human neuroblastoma cells. Finally, we report for the first time that these metal complexes can be safely delivered across the blood–brain barrier to specific locations in the brains of mice using focused ultrasound.We report a series of non-toxic cobalt(iii) complexes which inhibit Aβ peptide aggregation in vitro; these complexes can be safely delivered across the blood–brain barrier in mice using focused ultrasound. 相似文献
104.
Sophie H. Dale Mark R. J. Elsegood Sarita Kainth 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):m76-m78
The title compound, [Pb(C8H4O4)(H2O)]n, forms as an insoluble product in the reaction of sodium terephthalate(2−) with Pb(NO3)2 in water. Analysis has shown that the crystal structure is centrosymmetric, with the asymmetric unit containing one formula unit. The lead geometry is hemidirected seven‐coordinate, with both monodentate and bidentate carboxylate coordination modes present. The combination of hydrogen bonds and coordination bonds produces a three‐dimensional structure, including the first example, in a lead complex, of the common metal‐coordinated carboxylate/water (6) graph‐set motif. 相似文献
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106.
Josiane Courtois Jean-Paul Seguin Sophie Declomesnil Alain Heyraud Philippe Colin-Morel Luciana Dantas 《Journal of carbohydrate chemistry》2013,32(4-5):441-448
Abstract A mutant of the R. meliloti M5N1 strain has been selected. This strain, R. meliloti M5N1 CS (NCIMB 40472), excretes an extracellular material composed of 2-O-Ac-β-GlcpA, 3-O-Ac-β-GlcpA, 2,3-di-O-Ac-β-GlcpA and three species of β-GlcpA residues 1→4 linked. For the culture conditions used, the weight average molecular weight of the polymer varied in the range of 6 × 104 < Mw < 4 × 105. High molecular weight glucuronate forms thermoreversible gels at 5 g L?l. In the presence of divalent cation such as Ca2+ or trivalent cations such as Cr3+ or Fe3 +, cross linking of the polymer occurs. This polysaccharide is the first exocellular (1→4)-β-D-glucuronan produced by a R. meliloti strain. 相似文献
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108.
Ohne Zusammenfassung 相似文献
109.
110.
Caterpillar Track Complexes in Template‐Directed Synthesis and Correlated Molecular Motion 下载免费PDF全文
Shiqi Liu Dr. Dmitry V. Kondratuk Dr. Sophie A. L. Rousseaux Dr. Guzmán Gil‐Ramírez Dr. Melanie C. O'Sullivan Jonathan Cremers Prof. Tim D. W. Claridge Prof. Harry L. Anderson 《Angewandte Chemie (International ed. in English)》2015,54(18):5355-5359
Small alterations to the structure of a star‐shaped template totally change its mode of operation. The hexapyridyl template directs the conversion of a porphyrin dimer to the cyclic hexamer, but deleting one pyridine site changes the product to the cyclic decamer, while deleting two binding sites changes the product to the cyclic octamer. This surprising switch in selectivity is explained by the formation of 2:1 caterpillar track complexes, in which two template wheels bind inside the nanoring. Caterpillar track complexes can also be prepared by binding the hexapyridyl template inside the 8‐ and 10‐porphyrin nanorings. NMR exchange spectroscopy (EXSY) experiments show that these complexes exhibit correlated motion, in which the conrotatory rotation of the two template wheels is coupled to rotation of the nanoring track. In the case of the 10‐porphyrin system, the correlated motion can be locked by binding palladium(II) dichloride between the two templates. 相似文献