Laser energy dependence on femtosecond laser-induced nucleation of protein

We have investigated femtosecond laser-induced nucleation of hen egg-white lysozyme (HEWL) as a function of the laser pulse energy and pulse time width. This is the first recorded study to confirm that the femtosecond laser-induced nucleation of HEWL can be induced at a specific threshold laser energy. The threshold energy is comparable to that of cavitation bubble generation. The results strongly suggest that morphological changes in the solution are key factors for protein nucleation.     

Correlation of magnetic anisotropy with dielectric anisotropy in fluorinated phenyl bicyclohexane liquid crystal

Temperature dependence of magnetic anisotropy of homologous nematic fluorinated phenyl bicyclohexane liquid crystals is measured by a magneto-electric method.The result shows that the diamagnetic property is slightly influenced by the positions and the numbers of fluorine atoms substituted at the phenyl ring.By investigating the correlation of the dielectric anisotropy with the magnetic anisotropy,a novel explanation is proposed for the behaviour of the molecular dipole-dipole dimerization in the polar liquid crystal compounds.     

Relationship between alignment layer polymer surface structures and liquid crystal display parameters

The polar alignment layer (AL) surface provided relatively small liquid crystal (LC) pretilt angles while polyimides with long alkyl side chains gave relatively large LC pretilt angles. The results suggest that LC pretilt angles, in addition to an anchoring effect, are greatly affected by both electronic and steric interactions between LC molecules and a polyimide alignment layer surface. Rubbing with a cotton cloth induces functional groups, side chains, and repeat units at the surface of a liquid crystal polyimide AL to re-orient. It was discovered that rubbing induced polar functional groups and repeat units to re-orient out-of-the-plane of the surface, and it made non-polar aliphatic side chains partially re-orient inwards, toward the bulk of the film.     

Study of types and mixture ratio of organic solvent used to dissolve polymers for preparation of drug-containing PLGA microspheres

The effects of the types and the ratios of various organic solvents used as a mixtures to dissolve poly (lactide-co-glycolide) (PLGA) by using a solvent evaporation method, a technique used to prepare polymer particles, were carefully studied in order to investigate their advantages in developing drug delivery system (DDS) formulations for the prepared microspheres. The particle size and drug loading efficiency of drug-containing PLGA microspheres were found to be dependent on the types of solvent used due to the interfacial tension between the organic solvent and water phase. The drug loading efficiency of monodisperse microspheres prepared by using a membrane emulsification technique employing organic solvents and high interfacial tension for dissolving the PLGA was increased in a controlled manner. The organic solvents with high interfacial tension in the water phase used for the preparation of polymer particles by means of the solvent evaporation method were found to be suitable in terms of improvement in the properties of DDS formulations.     

Selective cleavage of primary MPM ethers with TMSI/Et3N

A useful method for the selective cleavage of primary MPM ethers by using TMSI/Et₃N is described. Other protective groups such as secondary MPM ethers, silyl ethers, and benzylidene acetal were stable under the reaction conditions.     

Fifty-Two Membered Macromonocyclic Polyamine Possessing Twelve Nitrogen Atoms in the Ring: Cyclic Spermine Tetramer

By the reaction of 1, 4-dibromobutane with forty-eight membered acyclic polyamine in the presence of cesium carbonate in DMF, cyclic spermine (or thermospermine) tetramer was prepared in 72% yield.     

Convergent total synthesis of (−)-dactylolide

A convergent total synthesis of (?)-dactylolide is described. Constructing the 2,6-disubstituted exo-methylene THP moiety was achieved by the intramolecular allylation of α-acetoxy ether. The cyclization precursor was prepared from two segments, an alcohol and carboxylic acid derivatives, by esterification followed by reductive acetylation.