Origin of the enhanced copper spin echo decay rate in the pseudogap regime of the multilayer high-T(c) cuprates

We report measurements of the anisotropy of the spin echo decay for the inner layer Cu site of the triple layer cuprate Hg(0.8)Re(0.2)Ba(2)Ca(2)Cu(3)O(8) (T(c)=126 K). The angular dependence of the second moment (T(-2)(2M) identical with ) deduced from the decay curves indicates that T(-2)(2M) for H0 parallel c is enhanced in the pseudogap regime below T(pg) approximately 170 K, as seen in bilayer systems. Comparison of T(-2)(2M) between H0 parallel c and H0 perpendicular c indicates that this enhancement is caused by electron spin correlations between the inner and the outer CuO2 layers. The results provide the answer to the long-standing controversy regarding the opposite T dependences of (T1T)(-1) and T(-2)(2G) (T(2G): Gaussian component) in the pseudogap regime of multilayer systems.     

Finite homological dimension and primes associated to integrally closed ideals

Let be an integrally closed ideal in a commutative Noetherian ring . Then the local ring is regular (resp. Gorenstein) for every if the projective dimension of is finite (resp. the Gorenstein dimension of is finite and satisfies Serre's condition (S)).

     

Retention of configuration on the oxidative addition of P-H bond to platinum (0) complexes: the first straightforward synthesis of enantiomerically pure P-chiral alkenylphosphinates via palladium-catalyzed stereospecific hydrophosphinylation of alkynes

The oxidative addition of pure (R(P))-menthyl phenylphosphinate 1 to a platinum (0) complex proceeds readily with retention of configuration at the chiral phosphorus center which was unambiguously confirmed by an X-ray analysis. In the presence of a catalytic amount of palladium, the hydrophosphinylation of a variety of alkynes with 1 also takes place stereospecifically, with retention of configuration, affording high yields of the corresponding vinylphosphinates bearing a single chirality at phosphorus.     

Fluorescence delineation of the surfactant microstructures in the CTAB-sOS-H2O catanionic system

A key feature of amphiphilic molecules is their ability to undergo self-assembly, a process in which a complex hierarchical structure is established without external intervention. Ternary systems consisting of aqueous mixtures of cationic and anionic surfactants exhibit a rich array of self-assembled microstructures such as spherical and rodlike micelles, unilamellar and multilamellar vesicles, planar bilayers, and bicontinuous structures. In general, multiple complementary techniques are required to explore the phase behavior and morphology of aqueous systems of oppositely charged surfactants. As a novel and effective alternative approach, we use fluorescence spectroscopic measurements to examine the microstructures of aqueous cationic/anionic surfactant systems in the dilute surfactant region. In particular, we demonstrate that the polarity-sensitive fluorophore prodan can be used to demarcate the surfactant microstructures of the ternary system of cetyltrimethylammonium bromide, sodium octyl sulfate, and water. As the fluorescence signature of this probe is dependent on the nature of the surfactant aggregates present, our method is a promising new approach to effectively map complex surfactant phase diagrams.     

Sequence-selective visual recognition of nonprotected dipeptides

[structure: see text] A receptor 1 with phenolphthalein and two crown ethers in the molecule develops brilliant purple color in the presence of dipeptides with a specific amino acid-sequence containing a C-terminal lysine. This type of color development could be extended to the detection of oligopeptides of a specific sequence at the N-terminal such as scyliorhinin I and APP(770)(394-410).     

Graphical analysis of the relative orientation of molecular alignment tensors for a protein dissolved in two different anisotropic media

In order to determine precise three-dimensional structures of proteins by residual dipolar coupling constants as the major or even exclusive structural constraints, it is essential to use two anisotropic media. In doing so, a reliable and versatile method for estimating the relative orientation of the alignment tensors for the molecules dissolved in different anisotropic media is required. In this communication, we present a new graphical approach for this purpose, which does not require structural information of the target molecules. The correlation map for the two independent data sets of residual dipolar coupling constants, which can be obtained for the molecules in different anisotropic media, strongly depends on the relative orientation of the alignment tensors. We have simulated the correlation maps for all possible combinations of the Euler angles, which transform one alignment tensor to the other, and compared them to the experimental data sets reported for labeled human ubiquitin. This simple graphical method affords a useful starting point for the structural determinations using residual dipolar couplings.