Materials Literature
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A simple, new, systematic method has been developed to evaluate the structural similarity of proteins. Firstly, similar protein fragments of a definable length are detected, combined in pairs and superimposed. The fits are improved until a maximum number of C alpha atoms show a distance below a given threshold value.…
The synthesis of tetra[oligo(ethyleneoxy)]phthalocyanines is described. Preliminary characterization of both thermotropic and lyotropic mesophases obtained from examples of this series are reported.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTViscoelastic properties of poly(styrene-co-acrylate) and poly(vinylcyclohexane-co-acrylate) ionomersJoon Seop Kim, Gaoming Wu, and Adi EisenbergCite this: Macromolecules 1994, 27, 3, 814–824Publication Date (Print):January 1, 1994Publication History Published online1 May 200…
All articles of this category Benzyl esters of 5-unsubstituted pyrrole-2-carboxylic acids were prepared in excellent yields by the base-catalyzed condensation of benzyl isocyanoacetate with α-acetoxynitro compounds, or nitroalkenes,in refluxing tetrahydrofuran. These pyrrolic products are important intermediates in th…
Two new porphyrins bearing several electron-withdrawing β-substituents were obtained in one step, in yields of about 50%, by nitration of meso-tetra(2,6-dichlorophenyl)porphyrin (TDCPPH2) and meso-tetrapentafluorophenylporphyrin (TFPPH2) with HNO3; the iron(III) complex of β-hexanitro-TDCPPH2 was a remarkable catalyst…
The reaction of [NH4]2[MoO2S2], Cul and NEt4Br in the solid state produced [NEt4]4[Cu6Mo2S6O2Br2I4]. Single-crystal X-ray analysis reveals that the cluster anion consists of two nest-shaped fragments interconnected through a Cul2Cu bridge with Cu–I and Cu ⋯ I bond lengths of 2.502 and 2.972 Å respectively. The cluster…
An extremely high tensile strength (σf) of 1340 MPa combined with good bending ductility was obtained as a mixed structure consisting of nanoscale icosahedral (I) particles with a size of about 40 nm surrounded by a thin fcc-Al layer with a thickness of about 2 nm in rapidly solidified Al99−x−yCrxCe1Coy alloys contain…
Amberlite-supported iron and manganese sulfonated phthalocyanines are efficient catalysts for the oxidation of chlorinated phenols by H2O2; these support catalysts can be recycled several times without important loss of catalytic activity.
CoCrTa films were sputter-deposited on either NiAl or Cr underlayers on glass substrates and their coercivities were compared. The NiAl film was found have the B2 structure with a lattice parameter of /spl sim/0.288 nm. The grain size of a 100 nm NiAl film is /spl sim/15 nm, which is about 50% smaller than a similarly…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrogen binding to and fluxional behavior of Ir(H)2X(P-tert-Bu2R)2 (X = Cl, Br, I; R = Me, Ph)Bryan E. Hauger, Dmitry Gusev, and Kenneth G. CaultonCite this: J. Am. Chem. Soc. 1994, 116, 1, 208–214Publication Date (Print):January 1, 1994Publication History Published online1…
Pyrolysis of a silica gel hybrid with a starburst dendrimer gives porous silica, in which the pore-size is successfully controlled by the size of the organic component used.
A protein activator of Ca(2+)-calmodulin-dependent protein kinase Ia (CaM kinase Ia) was purified to near homogeneity from pig brain. In the final step of purification, sucrose density gradient centrifugation, CaM kinase Ia activating activity correlated with the presence of a approximately 52-kDa protein band detecte…
The amino acid composition of proteins from mesophilic and extremophilic organisms is commonly assumed to reflect the mechanisms of molecular adaptation to extremes of physical conditions. In this context, halophilic behaviour has been attributed to significantly increased numbers of aspartic and glutamic acid residue…
Surfactant mesophase formation during the synthesis of M41S, the mesoporous material, has been studied using 14N nuclear magnetic resonance spectroscopy. Siliceous gels producing M41S materials displaying hexagonal and lamellar powder X-ray diffraction patterns have been observed to contain hexagonal mesophases which…
OBJECTIVE: The purpose of this study in rodents was to determine the pathologic basis for enhancement patterns of hyperplastic and tumours lymph nodes shown by MR lymphography after IV injection of superparamagnetic iron oxide nanoparticles (AMI-227). MATERIALS AND METHODS: Hyperplastic and tumorous lymph nodes were i…
High-resolution transmission electron microscopy of MCM-41 shows for the first time clearly the hexagonal shape of the pores, and allows direct observation of the transition from a lamellar to the hexagonal phase.
Recent measurements of sonoluminescence produced by a single, stable, pulsating gas bubble indicate that the spectrum can be modeled by that for a blackbody at a temperature of nearly 40 000 K [R. Hiller, S. J. Putterman, and B. P. Barber, ‘‘Spectrum of synchronous picosecond sonoluminescence,’’ Phys. Rev. Lett. 69, 1…
A series of nitrophenyl-amidophenyl-substituted porphyrins with n-Cl7H35 tails have been synthesized and fully characterized. Good Langmuir-Blodgett films of these materials can be prepared on water and transferred successfull to glass slides. Mean molecular areas for the series were measured and found to increase fro…
Employing an explicit atom (EA) model of polymethylene, we have carried out molecular dynamics simulations of n-tridecane (C13H28) melts at experimental densities to compute both equilibrium and dynamic properties. The calibrated EA model reproduces quite well the experimental results of pressure, x-ray diffraction pa…
The piezoelectric properties of ferroelectric and antiferroelectric thin layers were investigated by interferometry as a function of frequency and dc electric bias. Materials included: a ferroelectric lead zirconate titanate (PZT) with a Zr/Ti ratio of 53/47; a relaxor ferroelectric La-modified PZT with a Zr/Ti ratio…