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551.
Lorigan GA Dave PC Tiburu EK Damodaran K Abu-Baker S Karp ES Gibbons WJ Minto RE 《Journal of the American Chemical Society》2004,126(31):9504-9505
This communication demonstrates for the first time that solid-state NMR spectroscopic studies can be used to investigate aligned phospholipid bilayer nanotube arrays. Also, an integral membrane peptide can be successfully incorporated into the oriented phospholipid bilayer nanotube arrays and studied with 2H solid-state NMR spectroscopy. 相似文献
552.
B.C. Dave J.M. Miller B. Dunn J.S. Valentine J.I. Zink 《Journal of Sol-Gel Science and Technology》1997,8(1-3):629-634
This paper considers the nature of the interactions between the sol-gel derived inorganic matrix and a specific biomolecule,
cytochrome c. Optical absorption and impedance spectroscopies are used to characterize the influence of synthesis conditions
on the protein’s stability and conformation within the silica matrix. In some instances, encapsulation within the sol-gel
matrix provides stabilization. For example, protein denaturation is reversible and aggregation is prevented. Moreover, the
drying process does not negatively affect the protein; it is possible to regenerate the aged gel state by rehydration. The
flexibility of the sol-gel process enables high quality cytochrome c-doped SiO2 thin films to be prepared. These films possess the characteristic reactivity and chemical function of cytochrome c in solution. 相似文献
553.
Dave PR Forohar F Axenrod T Das KK Qi L Watnick C Yazdekhasti H 《The Journal of organic chemistry》1996,61(25):8897-8903
The cyclodimerization of p-toluenesulfonamide and 3-chloro-2-(chloromethyl)-1-propene to prepare N,N'-bis(p-toluenesulfonyl)-3,7-bis(methylene)-1,5-diazacyclooctane (1a) and its ozonation to the corresponding 3,7-dione 2a are reported. Unusual transannular cyclizations initiated by lithium aluminum hydride treatment or bromination of 1a and oxidative coupling of the dioxime derived from 2a are described. These reactions lead, respectively, to the following derivatives of the little-studied 3,7-diazabicyclo[3.3.0]octane ring system: 1,5-dimethyl-3,7-diazabicyclo[3.3.0]octane (5), N,N'-bis(p-toluenesulfonyl)-1,5-bis(bromomethyl)-3,7-diazabicyclo[3.3.0]octane (8), and N,N'-bis(p-toluenesulfonyl)-1,5-dinitro-3,7-diazabicyclo[3.3.0]octane, (12). Acid-catalyzed hydration of 1a, in contrast, gives the expected 5-methyl-3,7-diazabicyclo[3.3.1]nonan-1-ol (10). Reaction of the dibromide 8 with the nucleophiles, sodium sulfide, sodium oxide, and sodium p-toluenesulfonamide conveniently delivers the corresponding novel 3,7,10-triheterocyclic [3.3.3]propellanes. 相似文献
554.
Kirti Patel Sudhir Kapoor Devilal Purshottam Dave Tulsi Mukherjee 《Journal of Chemical Sciences》2005,117(4):311-316
Pt, Pd, Pt-Ag and Pd-Ag bimetallic nanoparticles were synthesized in ethylene glycol and glycerol using the microwave technique
in the presence of a stabilizer poly(N-vinylpyrrolidone) (PVP). It has been observed that PVP is capable of complexing and
stabilizing nanoparticles. Mixed clusters were formed by simultaneous reduction of the metal ions. The clusters were characterized
using UV-Vis spectra, XRD and dynamic light scattering. To understand the mechanism of formation of mixed nanoparticles, several
experimental parameters such asin situ irradiation of mixed metal salts and mixing of individual sols were attempted. 相似文献
555.
Adams DJ Bennett JA Cole-Hamilton DJ Hope EG Hopewell J Kight J Pogorzelec P Stuart AM 《Dalton transactions (Cambridge, England : 2003)》2005,(24):3862-3867
Highly fluorophilic phosphines incorporating at least one aromatic ring containing two directly attached perfluoroalkyl groups have been synthesised, their partition coefficients (organic phase : fluorous phase) measured and their electronic properties probed using (1)J(PtP) data for their trans-[PtCl(2)L(2)] complexes. These phosphines have been used as modifying ligands for the rhodium catalysed hydroformylation of 1-octene in perfluorocarbon solvents. Catalyst activity, regioselectivity and the levels of rhodium leaching to the product phase vary with the substitution patterns of the modifying ligands that do not correlate with the electronic properties or partition coefficients of these ligands, but can be interpreted in terms of differences in the resting states of the catalysts. 相似文献
556.
Hartner FW Hsiao Y Eng KK Rivera NR Palucki M Tan L Yasuda N Hughes DL Weissman S Zewge D King T Tschaen D Volante RP 《The Journal of organic chemistry》2004,69(25):8723-8730
The preparation of 3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propan-1-amine 2a and 3-[(7R)-7-methyl-5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl]propan-1-amine 2b, key intermediates in the synthesis of alpha(V)beta(3) antagonists, is described. The syntheses rely on the efficient double Sonogashira reactions of 2,5-dibromopyridine 3 with acetylenic alcohols 4a/4b and protected propargylamines 10a-e followed by Chichibabin cyclizations of 3,3'-pyridine-2,5-diyldipropan-1-amines 9a/9b. 相似文献
557.
The β-ZnMoO4/MWCNT nanocrystal composites were synthesized using hydrothermal method. The physicochemical properties such as structure, morphology and bandgap of synthesized photocatalysts were characterized using PXRD, UV-vis DRS, FTIR, FT-Raman, SEM and TEM analytical methods. PXRD pattern shows the peak shift in the case of synthesized ZnMoO4/MWCNT which confirms the formation of nanocomposites. Moreover, the strong absorbance in UV region which was evidenced in UV-vis DRS spectra for all the case of synthesized ZnMoO4 and ZnMoO4/MWCNT composites. From the SEM and TEM images, the MWCNT was found to have adhered over the ZnMoO4 nanocrystals. Compared to bare β-ZnMoO4, β-ZnMoO4/MWCNT nanocrystal composites exhibited significant higher photocatalytic activity under ultraviolet light emitting diodes (UVLEDs) irradiation for the degradation of nitrobenzene (NB; 2.606 × 10?4 M). This may be due to the effective charge transfer in the composite and optimized electron hole pair recombination. The photocatalytic activity of the synthesized photocatalysts was also studied under visible LEDs and it is observed that the photocatalytic degradation of NB was 97%, 77%, 65% and 52% under the irradiation of UV, blue, green, and red LEDs respectively. 相似文献
558.
The cupferron complex of copper has been precipitated from homogeneous solution by the addition of phenylhydroxylamine and sodium nitrite to a cold, acidic solution containing copper(II) ions. The precipitate can be dried at 90 +/- 5 degrees and weighed without ignition to the oxide. Less than 3 mg of copper can be determined. A fairly high concentration of acetic acid is tolerable. Separation from large quantities of zinc, nickel and silver has been achieved. 相似文献
559.
Dave J. Adams James A. BennettDaniel Duncan Eric G. HopeJonathan Hopewell Alison M. StuartAndrew J. West 《Polyhedron》2007
Variations in the magnitude of the 1JSeP coupling constants for a range of phosphorus(V) selenides allow the efficiency of different spacer groups at insulating the phosphorus centre in triarylphosphines from highly electron-withdrawing perfluoroalkyl groups to be established. 相似文献
560.
Louis G. M. Th. Tuinstra Arie H. Roos Dave E. Wells Ben Griepink 《Mikrochimica acta》1989,97(1-2):1-7
A comparison is made between interlaboratory studies in which individual chlorobiphenyls (CBs) are measured in fish and sludge samples. The target coefficient of variation (CV(R)) between laboratories at CB levels of 0.01–1.0 mg/kg should be in the order of 20–30%. An improvement in the CV(R) is clearly shown in studies in which a learning program, paying attention to the optimization of gas Chromatographic operating conditions, is included. For standard solutions, where no interference problems of the matrix occur, excellent CV(R)s are obtained in the order of 6%. In fish oil CV(R)s of 10–30% and in sludge CV(R)s of 20–30% are reached. 相似文献