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Red Fluorescent Turn‐On Ligands for Imaging and Quantifying G Protein‐Coupled Receptors in Living Cells 下载免费PDF全文
Iuliia A. Karpenko Rémy Kreder Christel Valencia Dr. Pascal Villa Dr. Christiane Mendre Dr. Bernard Mouillac Prof. Dr. Yves Mély Prof. Dr. Marcel Hibert Dr. Dominique Bonnet Dr. Andrey S. Klymchenko 《Chembiochem : a European journal of chemical biology》2014,15(3):359-363
Classical fluorescence‐based approaches to monitor ligand–protein interactions are generally hampered by the background signal of unbound ligand, which must be removed by tedious washing steps. To overcome this major limitation, we report here the first red fluorescent turn‐on probes for a G protein‐coupled receptor (oxytocin receptor) at the surface of living cells. The peptide ligand carbetocin was conjugated to one of the best solvatochromic (fluorogenic) dyes, Nile Red, which turns on emission when reaching the hydrophobic environment of the receptor. We showed that the incorporation of hydrophilic octa(ethylene glycol) linker between the pharmacophore and the dye minimized nonspecific interaction of the probe with serum proteins and lipid membranes, thus ensuring receptor‐specific turn‐on response. The new ligand was successfully applied for background‐free imaging and quantification of oxytocin receptors in living cells. 相似文献
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Layer‐by‐Layer Assembled Heteroatom‐Doped Graphene Films with Ultrahigh Volumetric Capacitance and Rate Capability for Micro‐Supercapacitors 下载免费PDF全文
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Jie DuanmuE. Kristofer Gamstedt Andrey PranovichAri Rosling 《Composites Science and Technology》2011,71(4):520-527
In the present work dough moulding compound premixes of allyl glycidyl ether modified (AGE)-potato starch, (DS) = 0.2, has been prepared and tested for its fiber reinforced composite properties. The AGE-starch was hydrolyzed with α-amylase under neutral condition for 6 h at 45 °C for improved process ability. The grafting and hydrolytic scission was confirmed by nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC), respectively. Homogeneous composite premixes of AGE-starch, wood fibers, various amount of glycerol and ethylene glycol dimethacrylate were successfully mixed with a Brabender-kneader at 55 °C and cured by compression molding at 150 °C using 2 wt% of dibenzoyl peroxide. Adding 5 wt% of glycerol did not reduce the ultimate strength of the composites; 10% glycerol reduced the strength from 60 MPa to 40 MPa, and 16% glycerol to 14 MPa. The results with 5 wt% glycerol are comparable with earlier achieved results. The water absorption rate increased with increased glycerol content and the mechanical strength of the composites was lost completely when the moisture uptake reached 15 wt%. 相似文献
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We have coated gold nanorods (NRs) with thermoresponsive microgel shells based on poly(N-isopropylacrylamide) (pNIPAM). We demonstrate by simultaneous laser-heating and optical extinction measurements that the Au NR cores can be simultaneously used as fast optothermal manipulators (switchers) and sensitive optical reporters of the microgel state in a fully externally controlled and reversible manner. We support our results with optical modeling based on the boundary element method and 3D numerical analysis on the temperature distribution. Briefly, we show that due to the sharp increase in refractive index resulting from the optothermally triggered microgel collapse, the longitudinal plasmon band of the coated Au NRs is significantly red-shifted. The optothermal control over the pNIPAM shell, and thereby over the optical response of the nanocomposite, is fully reversible and can be simply controlled by switching on and off a NIR heating laser. In contrast to bulk solution heating, we demonstrate that light-triggering does not compromise colloidal stability, which is of primary importance for the ultimate utilization of these types of nanocomposites as remotely controlled optomechanical actuators, for applications spanning from drug delivery to photonic crystals and nanoscale motion. 相似文献
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Geints YE Zemlyanov AA Kabanov AM Bykova EE Apeksimov DV Bukin OA Sokolova EB Golik SS Ilyin AA 《Applied optics》2011,50(27):5291-5298
We report on the experiments on the interaction of gigawatt femtosecond laser pulses with suspended millimeter-sized water droplets. The transparent droplets experienced laser-induced breakdown and explosive boiling up and emitted a broadband radiation. This radiation covers the spectral range from 450 to 1100?nm and consists of the spectrum of laser pulse scattered and transformed by the droplet due to self-phase modulation and plasma emission produced in water during photoionization. The droplet emission spectrum showed remarkable broadening at all viewing angles and is maximal in the direction of the laser exit from the droplet. The enlargement of the droplet results in additional spectral spreading of the emitted radiation. The depth and amount of laser pulse spectral self-transformations upon propagation through the water droplet are simulated by means of numerical calculations. 相似文献
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Gitin AV 《Applied optics》2011,50(32):6073-6083
The concept of "throughput" is used in traditional radiometry of Lambertian sources for computing and estimating the radiant flux passed through a pair of stops, in particular through the window and the pupil of an optical system. It is shown that in a more general case of quasi-homogeneous sources for energetic calculations of the perfect optical system, one must use instead of the throughput a functional that is similar to the famous "Dirac bra-ket." This functional takes into account the radiation pattern of the source. As the Dirac bra-ket satisfies the axioms of the inner product, powerful mathematical tools of functional analysis for the energy calculation of the optical systems are used. The main equations and principles of radiometry (the principle of reversibility and Maxwell's principle) are reformulated from the concept "throughput" into the concept "Dirac bra-ket." For generalization of Maxwell's principle to the class of quasi-homogeneous sources the concept of "effective stops" is introduced. 相似文献