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131.
The synthesis of coumarins by hydroxyalkylation of phenols with ethyl acetoacetate (via Pechmann reaction) is attempted using magnetically separable and reusable CuFe2O4 nanoparticles in water.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications ® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
132.
Stable and even microcrystals of Avermectin (AVM) were produced by recrystallization in presence of a stabilizer. Sequential layer growth was achieved by the layer-by-layer (LbL) self-assembly of biocompatible polyelectrolytes (PEs). The coated colloids were characterized using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The in vitro release of Avermectin from microcapsules was studied under the simulated insect midgut conditions. W-doped TiO(2) photocatalysts were synthesized by a simple hydrothermal method, and characterized by Brunauer-Emmett-Teller (BET) surface area measurements and SEM. The photocatalytic activities of photocatalysts, which were undoped with TiO(2) and W-doped TiO(2), were evaluated by the photocatalytic oxidation degradation of AVM microcapsules in aqueous solution under UV illumination. The toxicity of the photodegradable insecticide was evaluated by the adult stage Martianus dermestoides. The results showed that AVM microcrystals which were obtained by association had a mean length of 13.8μm and a zeta potential of -34.7mV. The drug loading and encapsulation efficiency were 65.57±0.96% and 46.15±0.96%, respectively. The in vitro release experiments revealed that the polyelectrolytes prolonged the release time of the encapsulated AVM microcrystals. The sample which was prepared at 120°C with 4.0mol% W-doped amount had the highest photocatalytic activity. Toxicity of the novel photodegradable insecticide was higher in the adult stage compared to the 95% AVM as indicated by the lower LC(50) value. 相似文献
133.
Razieh FAZAELI Hamid ALIYAN Shadpour MALLAKPOUR Zahra RAFIEE Maryam BORDBAR 《催化学报》2011,32(4):582-588
A novel compound constructed from polyoxometalate (H3PW12O40,PW12) and poly(amidoamine) (PA) was prepared at room temperature in an aqueous solution by an impregnation method.A series of novel 1,3,5-triaryl-2-pyrazoline derivatives was synthesized by the reaction between chalcone and phenylhydrazine in the presence of the title compound,PW12/PA,in high yields.The structures of the compounds obtained were determined by IR and 1H NMR spectra. 相似文献
134.
Fatemeh Vahedi Mojtaba Sankian Malihe Moghadam Maryam Mohaddesfar Sirous Ghobadi Abdol Reza Varasteh 《Applied biochemistry and biotechnology》2011,163(7):895-905
Chenopodium album is a weedy annual plant in the genus Chenopodium. C. album pollen represents a predominant allergen source in Iran. The main C. album pollen allergens have been described as Che a 1, Che a 2, and Che a 3. The aim of this work was to clone the Che a 1 in Escherichia coli to establish a system for overproduction of the recombinant Che a 1 (rChe a 1). In order to clone this allergen, the pollens
were subjected to RNA extraction. A full-length fragment encoding Che a 1 was prepared by polymerase chain reaction amplification
of the first-strand cDNA synthesized from extracted RNA. Cloning was carried out by inserting the cDNA into the pET21b (+)
vector, thereafter the construct was transformed into E. coli Top10 cells and expression of the protein was induced by IPTG. The rChe a 1 was purified using histidine tag in recombinant
protein by means of Ni–NTA affinity chromatography. IgE immunoblotting, ELISA, and inhibition ELISA were done to evaluate
IgE binding of the purified protein. In conclusion, the cDNA for the major allergen of the C. album pollen, Che a 1, was successfully cloned and rChe a 1 was purified. Inhibition assays demonstrated allergic subjects sera
reacted with rChe a 1 similar to natural Che a 1 in crude extract of C. album pollen. This study is the first report of using the E. coli as a prokaryotic system for Che a 1 cloning and production of rChe a 1. 相似文献
135.
NiO nanoparticles with an average size of 12 nm and a high specific surface area of 88.5 m2/g were easily prepared via the thermal decomposition of the complex Ni(dmgH)2 and were characterized by TGA, XRD, FT-IR, TEM and BET surface area measurement. This nanosized transition metal oxide was used as a new heterogeneous catalyst for the reduction of nitroarenes under microwave irradiation. The efficient and selective reduction of aromatic nitro compounds into their corresponding amines was observed by using ethanol as a hydrogen donor (reducing agent) and KOH as a promoter under microwave irradiation. This highly regio- and chemoselective method is fast, simple, inexpensive, high yielding, clean and compatible with several sensitive functionalities, such as halogens, -OH, -OCH3, -CHO, -COCH3, -COOH, -COOEt, -CONH2, -CN, -CHCH2 and -NHCOCH3. This method is suitable for the large scale preparation of different substituted anilines as well as other arylamines. In addition, the catalytic activity of nanosized NiO is higher than that of the bulk sample. 相似文献
136.
Maryam MohammadiReza Mokhtari 《Journal of Computational and Applied Mathematics》2011,235(14):4003-4014
On the basis of a reproducing kernel space, an iterative algorithm for solving the generalized regularized long wave equation is presented. The analytical solution in the reproducing kernel space is shown in a series form and the approximate solution un is constructed by truncating the series to n terms. The convergence of un to the analytical solution is also proved. Results obtained by the proposed method imply that it can be considered as a simple and accurate method for solving such evolution equations. 相似文献
137.
Ebrahimi M Huang K Lu X McNab IR Polanyi JC Waqar Z Yang J Lin H Hofer WA 《Journal of the American Chemical Society》2011,133(41):16560-16565
Adsorbates on metals, but not previously on semiconductors, have been observed to display long-range repulsive interactions. On metals, due to efficient dissipation, the repulsions are weak, typically on the order of 5 meV at 10 ?. On the 7×7 reconstruction of the Si(111) surface, charge transport through the surface has been demonstrated by others using charge injection by STM tips. Here we show that for both physisorbed brominated molecules, and for chemisorbed Br-atoms, induced charge-transfer in the Si(111)-7×7 surface can lead to a strong repulsive interaction between adsorbates, calculated as 200 meV at 13.4 ?. This large repulsive interaction must be channeled through the surface since it causes widely spaced "one-per-corner-hole" patterns of physisorption (three cases--directly observed here) and subsequent chemisorption (four cases observed). The patterns were observed by ultrahigh vacuum scanning tunneling microscopy for four different brominated hydrocarbon adsorbates; 1,2-dibromoethane, 1-bromopropane, 1-bromopentane, and bromobenzene, deposited individually on the surface. In every case, adsorbates were overwhelmingly more likely to be found singly than multiply adjacent to a corner-hole, constituting a distinctive pattern having a probability p = 7 × 10(-5) compared to a random distribution. 相似文献
138.
Habibi MH Mokhtari R Mikhak M Amirnasr M Amiri A 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1524-1527
Cu(II) and Ni(II) complexes of the general type [M(N2O2)] are described. The N2O2 ligands used are [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,3-diamine] (HOMeSalpn) and [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,2-diamine (HOMeSalpr). These complexes have been characterized by IR, UV-vis, CV, TG-DTA and 1H NMR spectroscopy. The electrochemical behavior of these complexes at a glassy carbon electrode in acetonitrile solution indicates that the first reduction process corresponding to Cu(II)-Cu(I) and Ni(II)-Ni(I) is electrochemically irreversible. The new copper complexes have been applied for the preparation of copper nanoparticles using non-ionic surfactant (Triton X-100) by thermal reduction. The copper nanoparticles with average size of 48nm were formed by thermal reduction of [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,3-diamine]copper(II) in the presence of triphenylphosphine thus releasing the reduced copper and affording the high-purity copper nanoparticles. 相似文献
139.
Fahimeh Saberi Zafarghandi Maryam Mohammadi Robert Schaback 《Mathematical Methods in the Applied Sciences》2019,42(11):3877-3899
The paper provides the fractional integrals and derivatives of the Riemann‐Liouville and Caputo type for the five kinds of radial basis functions, including the Powers, Gaussian, Multiquadric, Matérn, and Thin‐plate splines, in one dimension. It allows to use high‐order numerical methods for solving fractional differential equations. The results are tested by solving two test problems. The first test case focuses on the discretization of the fractional differential operator while the second considers the solution of a fractional order differential equation. 相似文献
140.
In this paper the analytical equation of state (EoS) proposed by Ihm‐Song‐Mason was applied to calculate molar volume of mixtures of carbon dioxide with nitrogen and methane. The pair interaction potential has been used to evaluate the second virial coefficients and the ISM EoS parameters (i.e. α and b). The calculated values of the aforesaid quantities were applied to predict the molar volumes for mixtures of carbon dioxide with nitrogen and methane. Agreement with experiment was excellent for both mixtures. 相似文献