Materials Literature
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Synchrotron radiation beamlines offer automated data collection with faster and larger detectors, a choice of wavelength(s), intense beams and fine collimation. An increasing output of protein crystal structures sustains an interest in streamlining data collection protocols. Thus, more and more investigators are looki…
Since lead titanate was first grown in single-crystal form in the 1930s, several independent reports of its linear birefringence have been published. Whilst there is overall qualitative agreement on its behaviour with temperature, the absolute values show some degree of variation. At 298 K they range from −0.009 to −0…
The photophysical and photochemical properties of a cationic porphyrin [bis(arginyl)porphyrin (BAP)] complexed to [poly(dG-dC)] 2 and [poly(dA-dT)] 2 have been investigated and compared to those of free BAP in aqueous solution. A drastic enhancement of the quantum yield of nonradiative deactivation of the lowest excit…
The conversion of the spin state of complexes exhibiting thermal spin crossover from the 1 A 1 low-spin (LS) state to the 5 T 2 high-spin (HS) state is accompanied by a deformation of the lattice due to the larger bond lengths in the HS state as compared with the LS state. In a previous work [Kusz et al. (2000). J. Ap…
The program CRYSTALS [Betteridge, Carruthers, Cooper, Prout & Watkin (2003). J. Appl. Cryst. 36 , 1487] has been extended to include an option for the refinement of a continuous electron density distribution lying along a line, a ring or on the surface of a sphere. These additional non-atomic electron distribution…
The in vitro release behaviour of indomethacin (IMC, 1-[p-chlorobenzoyl]-2-methyl-5-methoxy-3-indoleacetic acid) encapsulated in poly(lactic acid-co-ethylene oxide) (PLA-PEO) nanospheres is investi ...
Bisphosphoglycerate mutase is a trifunctional enzyme of which the main function is to synthesize 2,3-bisphosphoglycerate, the allosteric effector of hemoglobin. The gene coding for bisphosphoglycerate mutase from the human cDNA library was cloned and expressed in Escherichia coli. The protein crystals were obtained an…
An ABC intracolumn stacking scheme was discovered in a discotic columnar liquid-crystalline phase, which formed by self-assembly of hexameric supramolecular disks. Strong DDA-AAD hydrogen bonding dictated the formation of hexameric disks. Molecular structural simulation suggested that interplay among secondary interac…
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-sta…
In high-throughput crystallography experiments, it is possible to measure over 1000 powder diffraction patterns on a series of related compounds, often polymorphs or salts, in less than one week. The analysis of these patterns poses a difficult statistical problem. A computer program is presented that can analyse such…
Temperature induced structural phase transitions in the lead doped Aurivillius oxides Ba 1− x Pb x Bi 2 Nb 2 O 9 ( x = 0.375,0.625) are explored using powder neutron diffraction methods in the context of the pure parent compounds, PbBi 2 Nb 2 O 9 and BaBi 2 Nb 2 O 9 . At both lead concentrations the system is found to…
The capacity of intentionally created defects to act as possible channels for oxygen incorporation into the subsurface region has been studied by means of thermal desorption spectroscopy and ultraviolet photoelectron spectroscopy (21.2 eV). Thermal-energy atom scattering has been applied to determine the overall surfa…
Strain sensing characteristic of carbon nanotubes has been established in the past at nanoscale. In this study, it is shown that the carbon nanotube film sensors, made up of randomly oriented carbon nanotubes, can be used as strain sensors at macro level. A nearly linear trend between the change in voltage, measured u…
An analytical method to estimate the thickness of the interface between two phases from small-angle scattering (SAS) data has been developed using Porod's law modified by a triangular smoothing function. The convolution with a `top-hat' function describing a sharp density profile results in a semi-sigmoidal density pr…
Detailed strain relaxation studies of epitaxial magnetite, Fe 3 O 4 , films on MgO(100) substrates grown by magnetron sputtering reveal the accommodation of strain up to 600 nm thickness, a thickness far above the critical thickness ( t c ) predicted by theoretical models. The results are in agreement with the suggest…
The Rietveld method is the most straightforward and statistically correct approach for the refinement of crystal structure parameters from powder diffraction data. The equivalent two-stage approach, involving the refinement of structural parameters based on integrated intensities extracted using the Pawley method, is…
An analysis of simulated framework structures based on the rigid-unit model quantifies the distortion of polyhedra from their ideal geometric forms and decomposes the motions of the structure into components of rigid-unit displacement, rigid-unit rotation and distortion. Case studies analysing the behaviour of quartz…
Diacetylene-containing polycarboranylenesiloxane copolymers were prepared by two different methods to yield either alternating or block copolymers with respect to the diacetylene distribution along the backbone. With each method, a set of copolymers was prepared with trisiloxane:carborane:diacetylene molar ratios of 1…
The electronic structure of a monolayer-protected gold cluster, [Au 13 (SCH 3 ) 8 ] 3+, has been investigated by performing density functional calculations. The cluster has a characteristic structure with O h molecular symmetry, and eight (111) facets of a centered cuboctahedral Au 13 core cluster are fully passivated…
Atomically well-defined discrete fully coordinated spherical and elongated nanocages constructed from SiO 2 are shown, via density functional calculations, to be structurally stable. Generally the spherical nanocages are energetically preferred over the elongated nanocages. With increasing size, both types of nanostru…