Preliminary communication Liquid crystalline cardanyl β-D-glucopyranosides

Two novel aryl glycosides were synthesized, which varied in the extent of unsaturation in the lipophilic part, from plant/crop-based renewable resource materials. Their liquid crystalline properties were characterized by optical polarizing microscopy, differential scanning calorimetry and X-ray diffraction. All the mesophases are identified as lamellar in structure.     

Magnetic-field-induced deformation of lipid membranes

The substantial effects of relatively low, steady magnetic fields less than 0.5 T up to high magnetic fields up to 30 T on the membrane potential and resistance of black lipid membranes of didodecyl phosphite and dipalmitoylphosphatidylcholine (DPPC) are presented. Also, the magnetic-field-induced fusion and division of DPPC liposomes are demonstrated. Such significant magnetoresponses should result in the magnetic orientation of the lipid molecules and associated undulation of the membranes. Thus, the addition to membranes of diamagnetic aromatics having a large magnetic anisotropy enhanced the magnetoresponses: larger changes in membrane potential and resistance and a lower shift of the onset magnetic-field, with abrupt changes in liposome sizes and membrane potential.     

On Orbits in Double Flag Varieties for Symmetric Pairs

Let G be a connected, simply connected semisimple algebraic group over the complex number field, and let K be the fixed point subgroup of an involutive automorphism of G so that (G, K) is a symmetric pair. We take parabolic subgroups P of G and Q of K, respectively, and consider the product of partial flag varieties G/P and K/Q with diagonal K-action, which we call a double flag variety for a symmetric pair. It is said to be of finite type if there are only finitely many K-orbits on it. In this paper, we give a parametrization of K-orbits on G/P × K/Q in terms of quotient spaces of unipotent groups without assuming the finiteness of orbits. If one of P ? G or Q ? K is a Borel subgroup, the finiteness of orbits is closely related to spherical actions. In such cases, we give a complete classification of double flag varieties of finite type, namely, we obtain classifications of K-spherical flag varieties G/P and G-spherical homogeneous spaces G/Q.     

Improved Method of Molecular Imprinting of Cyclodextrin on Silica-gel Surface for the Preparation of Stable Stationary HPLC Phase

By using N-(3-triethoxysilyl)propylacrylamide (TPAAm), vinyl groups were introduced onto the surface of silica-gel. On the surface of this silica-gel, β-CyD was molecularly imprinted by using a redox initiator, and the composite was used as stationary phase of high performance liquid chromatography (HPLC). The pump pressure was sufficiently low and did not increase even after continuous elution for 24 h. In order to prepare still more stable columns, a new polymerization process was developed. There, the redox initiator was first mixed with the surface-modified silica-gel and then vinylated β-CyD, crosslinker, and the template were added. This modification promoted the immobilization of β-CyD copolymer to the silica-gel, resulting in still lower pump pressure. Concurrently, the imprinting efficiency was increased in comparison with previous method where the redox initiator was directly added to the mixture of the β-CyD–template complex, crosslinker, and surface-modified silica-gel. The molecularly imprinted β-CyD column, prepared by this new method, efficiently discriminated the enantiomers of N-benzyloxycarbonyltyrosine.     

Optimal order-limit policies for an (r, Q) inventory system

The reorder-point-reorder-quantity policies referred to as (r,Q) policies are widely used in industry and extensively studiedin the inventory literature. It should be noted, however, thatshortages often occur in practice even when the optimal reorderpoint and reorder quantity are achieved. In this paper, we presenta mathematical model to control a shortage period by an emergencyorder. The problem is the determination of the best timing todeliver items after a shortage occurs. By applying the conceptof repair-limit replacement policy in the context of maintenancetheory, the optimal order time limits based on three kinds ofcost criteria are derived in the framework of a simple (r, Q)inventory system. Finally, some examples of the inventory controlmodel with a stochastic lead time are given to explain the optimalorder-limit policies.     

The synthesis and mesomorphic properties of ferroelectric liquid crystals with a fluorinated asymmetric frame

A novel series of ferroelectric liquid crystals with a fluorinated asymmetric frame were synthesized by utilizing optically active (S)-2-, (S)-3-, (S)-4- and (S)-5-fluoroalkanols prepared from corresponding (R)-1,2-epoxyalkanes. Their mesomorphic and physical properties, such as spontaneous polarization, optic tilt angle and response time, were investigated systematically in a series of homologous compounds having the chiral centre at different positions on tails of various lengths. All the compounds exhibited the chiral smectic C phase in a wide range of temperatures and were found to possess a fast response time in spite of the small magnitude of the spontaneous polarization.     

Supramolecular Interaction of Keto-substituted Pyrroles

Several types of pyrrole derivatives bearing carbonyl groups were synthesized and their structures in the solid states were elucidated by single crystal X-ray analysis. In the case of α-ketopyrroles, the molecules exist as hydrogen bonding dimers between the pyrrole NH and carbonyl groups, while in the case of β-ketopyrrole derivatives, hydrogen bonding networks are formed. Both the α,β′-diketo-substituted pyrroles and their derivatives are suggested to be suitable for the construction of 1-D chain networks. Overall, the effects of substituents on the supramolecular interactions are discussed in detail.