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81.
In recent years,the hydrogel-based tissue adhesives have been extensively investigated for their excellent biocompatibility and the ability to be administered directly within the adherent tissue.To meet the requirement for more controllable release in various physiological settings,the components of hydrogel adhesive should be more precisely tailored.In this work,the POSS-ace-PEG hydrogel adhesive was fabricated with the polyacetal dendrimer G1'-[NH3Cl]16 and poly(ethylene glycol) succinimidyl carbonate (PEG-SC) due to the regular peripheral amino structure of G1'-[NH3Cl]16.Rheological and adhesion tests demonstrated that the hydrogel adhesive had good mechanical and adhesive properties,which could effectively adhere to the pigskin and severed nerves.Moreover,the tissue adhesive exhibited good stability under neutral conditions and the rapid degradation under acidic conditions,allowing for the release of doxycycline hydrochloride (DOX) drug in response to pH.Together,these results suggested that the POSS-ace-PEG adhesive had the potential to provide an alternative to tissue adhesives for applications in pathological environments (inflammation,tumors,etc.). 相似文献
82.
A. Jabar 《Phase Transitions》2017,90(11):1112-1120
In this paper, the magnetic properties of ternary mixed spins (σ,S,q) Ising model on a dendrimer nanostructure are studied using Monte Carlo simulations. The ground state phase diagrams of dendrimer nanostructure with ternary mixed spins σ = 1/2, S = 1 and q = 3/2 Ising model are found. The variation of the thermal total and partial magnetizations with the different exchange interactions, the external magnetic fields and the crystal fields have been also studied. The reduced critical temperatures have been deduced. The magnetic hysteresis cycles have been discussed. In particular, the corresponding magnetic coercive filed values have been deduced. The multiples hysteresis cycles are found. The dendrimer nanostructure has several applications in the medicine. 相似文献
83.
An account is given of the preparation and structural investigations of silyllithium compounds, including X-ray and NMR data. This review covers the chemistry of lithiosilanes with alkyl, aryl, functional substituents and lithiooligosilanes with Si---Si bonds. Application of lithiosilanes for the synthesis of polysilane dendritic molecules is also described. 相似文献
84.
Monika Zynek Marina Serantoni Sergey Beloshapkin Eithne Dempsey Timothy McCormac 《Electroanalysis》2007,19(6):681-689
The successful formation of organized multilayer assemblies, formed from the Dawson type mixed addenda heteropolyanion, [P2W17 VIVO62]8?, and a Ru2+ pentaerythritol based metallodendrimer, [RuDen]8+, has been achieved on carbon electrode surfaces. Cyclic voltammetric studies of the assembly across a wide pH domain, namely, 2 to 7 was possible. Upon redox switching, the redox couples associated with the RuIII/II redox system, of the cationic metallodendrimer, and both the VIV/V and the tungsten‐oxo framework of the heteropolyanion, were clearly evident. The multilayer assembly exhibited good stability towards both redox cycling and soaking over extended periods of time in aqueous buffer solutions. In addition, the constructed multilayer films were found to be quite compact in nature. The films were further characterized by X‐ray photoelectron spectroscopy (XPS) to determine their elemental composition. Surface morphology of the multilayer films was determined by atomic force microscopy (AFM). The electrocatalytic reduction of iodate by the multilayer film was also investigated. 相似文献
85.
CHEN Min CHEN Xiaonong YUAN Xinhua ZHANG Yan ZHANG Chunyan LIU Hua DAI Qixun 《反应性高分子(英文版)》2006,15(2):108-114
To obtain new functional aromatic polymer material. 3.3'-biacenophthene. which is used as macrotnolecule intermediate of function aromatic polymer material. was synthesized through the coupling reaction of acenaphthene catalyzing by ionic liquid (/bmim/Cl/FeCl3) at mild reaction condition. Pure 3,3' -biacenaphthene was obtained by recrystalling and column chromatography from the reaction mixture, and was determined by GC/MS. 1HNMR and FTIR analysis. The influence of various reaction conditions on the yield of 3,3'-biacenaphthene were studied by GC analysis. The result shows that the optimun synthesis conditions of the coupling reaction are as following: the molar ratio of FeCl3 to [Bmim]Cl being 3. the mole ratio of FeCl3 in [Bmim]Cl/FeCl3 to acenaphthene being 4. the reaction temperature being 20 ℃, the reaction time being 4h and the solvent of the reaction system being PhNO2. Under those conditions, the yield of the 3,3'-biacenaphthene will be 48.71% and selectivity of that will be 78.56 %. Further more.[bmim ]Cl/FeCl3 has no pollution to environments and can be reused. 相似文献
86.
87.
Chuan‐Jian Zhou Rui‐Fang Guan Sheng‐Yu Feng David J. Berg Stephen R. Stobart 《中国化学会会志》2005,52(5):947-952
Using the divergent method, carbosilane dendrimers with p‐bromophenyl core were synthesized by using alternating Grignard and hydrosilylation reactions. And then, α‐naphthalenyl was connected to the core by using Suzuki coupling reaction. This gave a new carbosilane dendrimer with a 4‐(naphthalen‐1‐yl)phenyl core. All the products were characterized by IR, 1H NMR, 13C NMR, 29Si NMR, and MS. The study shows that Suzuki Coupling reaction is an effective and powerful core‐functionalization method and a satisfactory result can be achieved through prolonging the reaction time. 相似文献
88.
A type of novel electroanalytical sensing nanobiocomposite material was prepared by electropolymerization of pyrrole containing poly(amidoamine) dendrimers‐encapsulated platinum nanoparticles (Pt‐PAMAM), and glucose oxidase (GOx). The Pt nanoparticles encapsulated in PAMAM are nearly monodisperse with an average diameter of 3 nm, and they provide electrical conductivity. Polypyrrole acts as a polymer backbone to give stable and homogeneous cast thin films, and it also defines the electrical conductivity. Both Polypyrrole and PAMAM can provide a favorable microenvironment to keep the bioactivity of enzymes such as glucose oxidase. The homogeneity of GOx/Pt‐PAMAM‐PPy nanobiocomposite films was characterized by atomic force microscopy (AFM). Amperometric biosensors fabricated with these materials were characterized electrochemically using cyclic voltammetry (CV), electrochemical impedance spectra (EIS) and amperometric measurements in the presence of hydrogen peroxide or glucose. All those show the resultant biosensor sensitivity was strongly enhanced within the nanobiocomposite film. The optimized glucose biosensor displayed a sensitivity of 164 μA mM?1 cm?1, a linear range of 0.2 to 600 μM, a detection limit of 10 nM, and a response time of <3 s. 相似文献
89.
A new series of novel polyamidoamine (PAMAM) dendrimers 4, 5 and 6 possessing azobenzene units specifically at the core were prepared and their reversible trans/cis photoisomerization properties were studied. PAMAM dendritic wedges as well as azo-based PAMAM dendrimers were fully characterized by means of FT-IR, NMR (1H and 13C), mass spectrometry (MALDI-MS), thermogravimetric and elemental analysis. 相似文献
90.
A newly designed anthryl dendron having perfluoroalkyl chains at terminals showed thermotropic liquid crystallinity, which was characterized using polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction. The anthryl dendron forms SB phase at room temperature below 53 °C, at which temperature a phase transition to Colrd takes place. In a fluorous solvent, regioselective photodimerization of the anthryl dendron occurred to give head-to-head photodimers, although photodimerization in the SB phase and chloroform gave both head-to-head and head-to-tail photodimers. 相似文献