Explicit solution forp-q duality in two-dimensional quantum gravity

By using Sato's infinite dimensional Grassmannian theory of the KP hierarchy, we study the global structure of the theory space of 2D quantum gravity coupled to various minimal conformal fields labeled by a pair of integers (p, q). After giving a rigorous proof of the equivalence of Douglas's equation and the Schwinger-Dyson equation (W-constrainton a function), we establish thep-q duality of the (p, q) quantum gravity at Green's function level. As an application, we discuss the metamorphosis of operators under unitarity-preserving renormalization group flows.Address after September 1, 1992: Newman Laboratory, Cornell University, Ithaca, NY 14853-5001, USA.     

Dynamics of a bilayer membrane with membrane-solvent partial slip boundary conditions

We discuss the dynamics of a bilayer membrane with partial slip boundary conditions between the monolayers and the bulk fluid. Using Onsager’s variational principle to account for the associated dissipations, we derive the coupled dynamic equations for the membrane height and the excess lipid density. The newly introduced friction coe?cients appear in the renormalized fluid viscosities. For ordinary lipid bilayer membranes, we find that it is generally justified to ignore the e?ects of permeation and parallel slip at the membrane surface.     

Electrospray ionization mass spectrometric analysis of chemical reactions of dissolution of selenium in strongly basic amines

When elemental selenium was added to a strongly basic amine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) or 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), the selenium started to dissolve and the solution turned dark brown. We investigated the chemical reaction of this selenium dissolution process by electrospray ionization mass spectrometry (ESI-MS). The study reveals for the first time that cleavage of Se-Se bonds by the amine initiates the reaction to form molecular Se2, which then abstracts hydrogen from the amine molecule. ESI-MS with the use of a nanospray technique was shown to be a useful tool for studying the dissolution of elements in strongly basic or acidic solvents.     

Flavonol glycosides in leaves of two Diospyros species

Fourteen flavonol glycosides including two new compounds were isolated from the leaves of two Diospyros plants (D. cathayensis and D. rhombifolia). The structures of isolated compounds were determined by spectroscopic analysis. The scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical of the isolated compounds was also investigated.     

Linear viscoelastic properties of electro-rheological nano-suspension confined to narrow gap between electrodes

The linear viscoelastic properties of a suspension composed of titanium dioxide nanoparticles were measured under the direct current (dc) electric field with narrow gap distances between the electrodes. The yielding behavior under no external electric fields was also discussed. The wall slip at the interface between the parallel plates and the nano-suspension was briefly discussed. Under the dc electric field, a fine chain-like microstructure was optically found within a narrow gap of 50 μm between the electrodes in the quiescent state. The nano-suspension confined to a narrow gap of 65 μm between the parallel plates was rather viscoelastic even at the highest strength of the electric field of 16 kV·mm⁻¹. Furthermore, fast and slow relaxations of the dynamic moduli were found after removal of the electric field. It was pointed out that the linear viscoelasticity was an appropriate measure of the microstructure before yielding.     

A convenient route to the furopyran core of dysiherbaine

The bicyclic core, furo[3,2-b]pyran, of the dysiherbaines has been synthesized via two routes involving the imino 1,2-Wittig rearrangement of allyl furohydroximate and the asymmetric dihydroxylation of furylpropenol derivative.     

Collisional-activated decomposition of benzyloxycarbonyl-protected tripeptide derivatives containing proline in fast atom bombardment mass spectrometry

The effect on the fragmentations of N-benzyloxycarbonyl-protected tripeptide ethyl esters due to the existence of L -proline in the gas phase was examined by the collisional-activated decomposition of the deprotonated molecule and the fragment ions produced by the cleavage of the tripeptide derivatives containing the neutral amino acids (L -alanine, L -leucine and L -phenylalanine) and L -proline, in which changes in both the numbers and positions of the prolyl residues were observed, in negative-ion fast atom bombardment mass spectrometry. The cleavage patterns of these ions in the collisional-activated decomposition mass spectra were observed to depend on the numbers and positions of prolyl residues in the peptide derivatives. These results indicate that the conformational differences in the peptide derivatives due to the existence of L -proline affect the decomposition of the ions containing the neutral amino acids in the gas phase.     

Steric-control for the enantioselective hydrolysis of amino acid esters in hybrid membrane systems

The enantioselective hydrolysis of the amino acid esters, p-nitrophenyl-N-dodecanoyl-D(L)-phenylalaninates (C(12)-D(L)-Phe-PNP) catalyzed by active tripeptide, N-(benzyloxycarbonyl)-L-phenylalanyl-L-histidyl-L-leucine (Z-PheHisLeu) in the presence of coaggregates (hybrid membranes) composed of native phospholipid, L-alpha-dimyristoylphosphatidylcholine (DMPC) and nonionic surfactant, polyoxyethylene (8) lauryl ether (C(12)(EO)(8)) was easily controlled by regulating the reaction temperature and changing the composition of coaggregates. Furthermore, excellent correlations were observed between the enantioselectivity in the hydrolysis of C(12)-D(L)-Phe-PNP catalyzed by Z-PheHisLeu in the presence of coaggregates and physical properties of hybrid membranes. It is assumed that catalytic activities of tripeptide catalyst in hybrid membranes should be regulated by changing the microenvironments of reaction fields.     

Synthesis of l-α-phosphatidyl-d-myo-inositol 3,5-bisphosphate from d-glucose

Efficient synthesis of l-α-phosphatidyl-d-myo-inositol 3,5-bisphosphate was achieved from 1,2,5,6-diisopropylidene-d-glucose by utilizing ring-closing metathesis and catalytic OsO₄ dihydroxylation.     

Low temperature ionic conductor: ionic liquid incorporated within a metal–organic framework

Ionic liquids (ILs) show promise as safe electrolytes for electrochemical devices. However, the conductivity of ILs decreases markedly at low temperatures because of strong interactions arising between the component ions. Metal–organic frameworks (MOFs) are appropriate microporous host materials that can control the dynamics of ILs via the nanosizing of ILs and tunable interactions of MOFs with the guest ILs. Here, for the first time, we report on the ionic conductivity of an IL incorporated within a MOF. The system studied consisted of EMI-TFSA (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide) and ZIF-8 (Zn(MeIM)₂, H(MeIM) = 2-methylimidazole) as the IL and the MOF, respectively. While the ionic conductivity of bulk EMI-TFSA showed a sharp decrease arising from freezing, the EMI-TFSA@ZIF-8 showed no marked decrease because there was no phase transition. The ionic conductivity of EMI-TFSA@ZIF-8 was higher than that of bulk EMI-TFSA below 250 K. This result points towards a novel method by which to design electrolytes for electrochemical devices such as batteries that can operate at low temperatures.