排序方式: 共有108条查询结果,搜索用时 62 毫秒
41.
S. Civiš V. Horká J. Cihelka T. Šimeček E. Hulicius J. Oswald J. Pangrác A. Vicet Y. Rouillard A. Salhi C. Alibert R. Werner J. Koeth 《Applied physics. B, Lasers and optics》2005,81(6):857-861
We describe results obtained with a new type of GaSb-based semiconductor distributed feedback multiple quantum well lasers
operating in continuous-wave mode at room temperature and above. The lasers show good tunability both by the excitation current
and the temperature from -1 °C to +60 °C (4170 to 4360 cm-1). They operate in a high-power (more than 1 mW) single-mode regime and can be tuned without hopping in the methane and ammonia
absorption spectral range of up to 15 cm-1. Application to photoacoustic detection is also described. Potential use lies in the areas of analytical chemistry of gases
and in atmospheric pollution research.
PACS 82.80.Kq; 42.62.Fi; 42.55.Px 相似文献
42.
Gilbert Balavoine Sabine Berteina Aurore Gref Jean-claude Fischer André Lubineau 《Journal of carbohydrate chemistry》2013,32(8):1237-1249
Abstract Constant potential electrolysis of the glycosyl donors p-methylphenyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-glucopyranoside (1) and p-methylphenyl 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-1-thio-β-D-glucopyranoside (4) in dry acetonitrile in the presence of various primary and secondary sugar alcohols, performed in an undivided cell, gave β-linked disaccharide derivatives selectively in good yields. Oxidative coupling of p-methoxyphenyl 2,3,4-tri-O-benzyl-1-thio-β-L-fucopyranoside (2 1) with p-methoxybenzyl 4,6-O-benzylidene-2-deoxy-2-phthalimido-β-D-glucopyranoside (16) gave selectively the α-linked disaccharide 22 in good yield. 相似文献
43.
44.
Stefan L Guédin A Amrane S Smith N Denat F Mergny JL Monchaud D 《Chemical communications (Cambridge, England)》2011,47(17):4992-4994
DOTASQ (for DOTA-templated Synthetic G-quartet) is the first prototype of nature-inspired G-quadruplex ligand: its design, founded on a possible intramolecular G-quartet formation, enables it to interact with G-quadruplex DNA via an unprecedented nature-mimicking binding mode, based on the association between two G-quartets, one being native (quadruplex) and the other one artificial (ligand). 相似文献
45.
Olivier A Meyer F Desbief S Verge P Raquez JM Lazzaroni R Damman P Dubois P 《Chemical communications (Cambridge, England)》2011,47(4):1163-1165
The selective adsorption of carbon nanotubes (CNTs) on a pH-reversible PDMAEMA patterned gold surface is presented. In acidic conditions, a selective CNTs adsorption onto the polymer brushes is obtained due to ammonium-π interactions. The reversible behavior was shown by successive treatments in both alkaline and acidic solutions with CNTs. 相似文献
46.
47.
Previous published methods for the analysis of ETU and PTU are time-consuming and furthermore use dichloromethane (DCM) for extraction or clean-up. This study details the development and validation of a rapid method that combines a simple extraction step with UHPLC-ESI(+)-MS/MS. This is the first application of UHPLC-MS/MS to analyse these compounds. Besides that, we replaced DCM with a more environmental-friendly solvent. The analytical performance was evaluated with the analysis of spiked celery samples at 50 μg kg(-1) (LOQ) and 300 μg kg(-1). The recoveries were between 65% and 90% for ETU and between 71% and 127% for PTU with RSDs in repeatability and reproducibility conditions below 10% for ETU. This method is rapid (a chromatographic run time of 2 min) and can easily be performed (no laborious clean-up). The presented method is environmental friendly with significant reduction in solvent consumption. 相似文献
48.
Largy E Hamon F Rosu F Gabelica V De Pauw E Guédin A Mergny JL Teulade-Fichou MP 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(47):13274-13283
Fifteen complexes of palladium, platinum, and copper, featuring five different N‐donor tridentate (terpyridine‐like) ligands, were prepared with the aim of testing their G‐quadruplex–DNA binding properties. The fluorescence resonance energy transfer melting assay indicated a striking positive effect of palladium on G‐quadruplex DNA stabilization compared with platinum and copper, as well as an influence of the structure of the organic ligand. Putative binding modes (noncoordinative π stacking and base coordination) of palladium and platinum complexes were investigated by ESI‐MS and UV/Vis spectroscopy experiments, which all revealed a greater ability of palladium complexes to coordinate DNA bases. In contrast, platinum compounds tend to predominantly bind to quadruplex DNA in their aqua form by noncoordinative interactions. Remarkably, complexes of [Pd(ttpy)] and [Pd(tMebip)] (ttpy=tolylterpyridine, tMebip=2,2′‐(4‐p‐tolylpyridine‐2,6‐diyl)bis(1‐methyl‐1H‐benzo[d]imidazole)) coordinate efficiently G‐quadruplex structures at room temperature in less than 1 h, and are more efficient than their platinum counterparts for inhibiting the growth of cancer cells. Altogether, these results demonstrate that both the affinity for G‐quadruplex DNA and the binding mode of metal complexes can be modulated by modifying either the metal or the organic ligand. 相似文献
49.
Bertrand H Granzhan A Monchaud D Saettel N Guillot R Clifford S Guédin A Mergny JL Teulade-Fichou MP 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(16):4529-4539
We report the synthesis of two new series of triangular aromatic platforms, either with three aminoalkyl side chains (triazatrinaphthylene series, TrisK: six compounds), or without side chains (triazoniatrinaphthylene, TrisQ). The quadruplex-DNA binding behavior of the two series, which differ essentially by the localization of the cationic charges, was evaluated by means of FRET-melting and G4-FID assays. For the trisubstituted triazatrinaphthylenes (TrisK), the length of the substituents and the presence of terminal hydrogen-bond-donor groups (NH(2)) were shown to be crucial for ensuring a high quadruplex affinity (ΔT(1/2) values of up to 20 °C at 1 μM for the best candidate, TrisK3-NH) and selectivity versus duplex DNA. Subsequently, comparison of data collected on both the telomeric- and c-myc-quadruplex showed that the nonsubstituted TrisQ is even more efficient than TrisK3-NH, both in terms of quadruplex affinity (ΔT(1/2)=26 °C in K(+) buffer) and selectivity versus duplex DNA. Structural considerations conducted with the c-myc quadruplex indicate that both TrisK3-NH and TrisQ stack well onto the G-quartet but in an offset position, which might be influenced by the formation of multiple hydrogen bonds with the target in the former case. Finally, the nonsubstituted TrisQ displays a binding profile very similar to some of the best quadruplex binders, BRACO-19 and bisquinolinium 360A, used herein as references, and thereby represents a highly promising novel molecular design for quadruplex recognition. 相似文献
50.
Dr. Aurore Fraix Dr. Vladimir Kirejev Dr. Milo Malanga Dr. Éva Fenyvesi Prof. Szabolcs Béni Prof. Marica B. Ericson Prof. Salvatore Sortino 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(29):7091-7095
A supramolecular nanoassembly, of about 30 nm in diameter, that consists of a green-fluorescent, β-cyclodextrin-based, branched polymer co-encapsulating a red-emitting singlet oxygen (1O2) photosensitizer and a nitric oxide (NO) photoreleaser, which comprises a blue fluorescent reporter, is here reported. The system exhibits “five-in-one” photofunctionalities. All components can be simultaneously excited in the phototherapeutic window with two-photons by using near-infrared light at 740 nm and despite their close proximity, behave as independent units. This allows for their in vitro visualization in carcinoma cancer cells, due to their distinct green, red, and blue fluorescence, and for the production of both cytotoxic 1O2 and biofunctional NO. 相似文献