New analogues of green fluorescent protein (GFP) chromophore mGFP-Cn (n = 1, 3, 5, 11) with alkyl chains of different lengths in the imidazolinone rings were synthesized and their crystal structures were determined. These GFP-like chromophores are all emissive in the solid state. And the solid-state emission quantum yields of increase by extending the lengths of alkyl chains, owing to the fact that the intermolecular pi-pi interactions are significantly weakened based on their crystal structures. 相似文献
In the present research, a type of imprinted hydrogels, in which 5-fluorouracil is complexed non-covalently to the monomers and cross-linked into the hydrogel matrix, is synthesized in order to evaluate the possibility of their applications in sustaining the release of 5-fluorouracil due to the drug’s heightened interactions with the imprinted binding sites. Because of the hydrophility, hydrogels can absorb large amounts of water. As a result, drug release mechanisms are different from hydrophobic polymers. Mathematical model has been established to predict the drug release from the hydrogel matrix as a function of time. The drug release mechanism when immersed in release medium is discussed based on mathematical analysis. Swelling studies are performed and the capability of the hydrogels to reload 5-fluorouracil in aqueous solutions is evaluated. In vitro release studies after reloading are conducted. Mathematical analysis suggest that drug release kinetics from the hydrogels fit Fickian mechanism, further evaluation of the fitness for different hydrogel types reveal that the conformation of binding sites can play a very important role in deciding the kind of drug release mechanism. Experiments reveal that all hydrogels show swelling property. The imprinted hydrogels bind much more 5-fluorouracil than non-imprinted ones, and they sustain 5-fluorouracil release better than non-imprinted hydrogels. This research indicates that the imprinted hydrogels would be a potential promising device for drug delivery. 相似文献
A general method for the preparation of 2‐(N‐Substituted)‐2‐imidazolines and 2‐(N‐Substituted)‐1,4,5,6‐tetrahydropyrimidines is described. These heterocycles can be synthesized from their respective anilines with 2‐chloro‐2‐imidazoline or 2‐chloro‐1,4,5,6‐tetrahydropyrimidine, generated in situ from imidazolidin‐2‐one and tetrahydropyrimidin‐2(1H)‐one activated by dimethyl chlorophosphate, in good to excellent yields. 相似文献
We have combined the molecular imprinting and the layer-by-layer assembly techniques to obtain molecularly imprint polymers (MIPs) for the electrochemical determination of p-nitrophenol (p-NPh). Silica microspheres functionalized with thiol groups and gold nanoparticles (Au-NPs) were assembled on a gold electrode surface layer by layer. The electrode was then immersed into a solution of pyrrole and p-NPh (the template), and electropolymerization led to the creation of a polymer-modified surface. After the removal of the silica spheres and the template, electrochemical impedance spectroscopy and differential pulse voltammetry (DPV) were employed to characterize the surface. The results demonstrated the successful fabrication of macroporous MIPs embedded with Au-NPs on the gold electrode. The effects of monomer concentration and scan rate on the performance of the electrode were optimized. Excellent recognition capacity is found for p-NPh over chemically similar species. The DPV peak current is linearly related to concentration of p-NPh in the 0.1 μM to 1.4 mM range, with a 0.1 μM limit of detection (at S/N?=?3).
Figure
Molecularly imprinted polymers (MIPs) and nanomaterials were combined to prepare a novel macroporous structured MIPs based electrochemical sensor for the investigation of an environmental pollutant, p-nitrophenol (p-NPh). The sensor exhibited a fast binding dynamics, good specific adsorption capacities, and high selective recognition to p-NPh. 相似文献
We have combined the molecular imprinting and the layer-by-layer assembly techniques to obtain molecularly imprint polymers (MIPs) for the electrochemical determination of p-nitrophenol (p-NPh). Silica microspheres functionalized with thiol groups and gold nanoparticles (Au-NPs) were assembled on a gold electrode surface layer by layer. The electrode was then immersed into a solution of pyrrole and p-NPh (the template), and electropolymerization led to the creation of a polymer-modified surface. After the removal of the silica spheres and the template, electrochemical impedance spectroscopy and differential pulse voltammetry (DPV) were employed to characterize the surface. The results demonstrated the successful fabrication of macroporous MIPs embedded with Au-NPs on the gold electrode. The effects of monomer concentration and scan rate on the performance of the electrode were optimized. Excellent recognition capacity is found for p-NPh over chemically similar species. The DPV peak current is linearly related to concentration of p-NPh in the 0.1 μM to 1.4 mM range, with a 0.1 μM limit of detection (at S/N = 3).
This paper presents a Monte Carlo code to get response spectrum of ions for the Neutron Depth Profiling (NDP) technique called Monte Carlo NDP (MC-NDP) that simulates the behavior of ions transmitted through a sample matrix and generates the energy spectrum for a specified detector. The MC-NDP model is based on the Ziegler–Biersack–Littmark Model, but incorporates the advantages of TRIM and CORTEO. The Impulse Approximation method is used to determine the flight length with the indexical interpolation method rather than the Magic algorithm for the scattering angle between ions and nucleus. This makes MC-NDP more efficient and convenient to simulate entire ion histories by a Monte Carlo approach. MC-NDP’s results agree well with both TRIM results and the experimental data. 相似文献
Two hydrophilic conjugated polymers, PmP‐NOH and PmP36F‐NOH, with polar diethanolamine on the side chains and main chain structures of poly(meta‐phenylene) and poly(meta‐phenylene‐alt‐3,6‐fluorene), respectively, are successfully synthesized. The films of PmP‐NOH and PmP36F‐NOH show absorption edges at 340 and 343 nm, respectively. The calculated optical bandgaps of the two polymers are 3.65 and 3.62 eV, respectively, the largest ones so far reported for hydrophilic conjugated polymers. PmP‐NOH and PmP36F‐NOH also possess deep‐lying highest occupied molecular orbital levels of −6.19 and −6.15 eV, respectively. Inserting PmP‐NOH and PmP36F‐NOH as a cathode interlayer in inverted polymer solar cells with a PTB7/PC71BM blend as the active layer, high power conversion efficiencies of 8.58% and 8.33%, respectively, are achieved, demonstrating that the two hydrophilic polymers are excellent interlayers for efficient inverted polymer solar cells.
We report a 1.8 μm two-section distributed Bragg reflector laser using butt-jointed In Ga As P bulk material as the waveguide core layer. The threshold current is 17 m A and the output power is 8 m W on average. The threshold current, output power, and emitting wavelength dependences on temperature are measured. The obtained wavelength tuning range is 10 nm. This device has potential applications in simultaneous multiple-gas detection. 相似文献