Measurement of an arbitrary parallel displacement of a rigid body by using polychromatic speckle patterns

A novel speckle method for measuring the parallel displacement of a rigid body in an arbitrary direction is presented. The amount of displacement as well as its angle made with the optical axis is to be measured from the Fourier transform patterns of a doubly exposed photographic plate.     

Fisher information under restriction of Shannon information in multi-terminal situations

Fisher information generally decreases by summarizing observed data into encoded messages. The present paper studies the amount of Fisher information included in independently summarized messages from correlated information sources; that is, the amount of Fisher information when sequences x ^N and y ^N of N independent observations of random variables x and y are encoded (summarized) independently of each other into meassages m _X and m _Y . The problem is to obtain the maximal amount of Fisher information when the size of the summarized data or Shannon message information is limited. The problem is solved in the case of completely compressed symmetric data summarization. An achievable bound is given in the general case. Information geometry, which is a powerful new differential geometrical method applicable to statistics and systems theory, is applied to this problem, proving its usefulness in information theory as well.The present work is supported in part by Grant-in-Aid for Scientific Research #61030014, Ministry of Education, Science and Culture of Japan.     

Pressure and temperature effects on the conformational equilibria between the rotational isomers of sec- and iso-butyl halides

The conformational changes of iso-butyl halides and sec-butyl halides in pure liquid state have been analyzed by Raman spectroscopy as a function of temperature and pressure. The enthalpy and volume differences in the conformer of these halogenoalkanes have been obtained. The relation between ΔH and ΔV was discussed according to the thermodynamical consideration and the configurational entropy difference of each rotational isomer in liquid state was estimated by combining the spectroscopic and ultrasonic relaxation data reported in the literature.     

Analysis of a fluorescence depletion process of Rhodamine 6G in a PMMA matrix induced by nano- and picosecond lasers

The two-color fluorescence depletion process of Rhodamine 6G in PMMA matrixes was investigated using nano- and picosecond lasers. Erase-lasers of 1064 and 599 nm depleted the fluorescence from the S₁ state. Fluorescence depletion with 1064 nm was analyzed by the up-conversion from state S₁ to S₂, while that with 599 nm was simulated based on both the up-conversion and the stimulated emission. A three-state model describes this process due to a nanosecond laser well, while it could not reproduce that by picosecond lasers. Significant contributions of vibrational relaxation in S₁ and re-absorption from S₀ are suggested in the picosecond region.     

“Armed-disarmed” glycosidation strategy based on glycosyl donors and acceptors carrying phosphoroamidate as a leaving group: A convergent synthesis of globotriaosylceramide

A stereocontrolled synthesis of globotriaosylceramide with three different glycosidic linkages has been accomplished by linear and convergent routes exploiting “armed-disarmed” glycosidation methodology based on glycosyl donors and acceptors carrying tetramethylphosphoroamidate as a leaving group. In particular, the convergent strategy featuring a coupling of a galactosyl-(1→4)-galactosyl donor with a glucosylceramide derivative has proven to be extremely efficient.     

Design and synthesis of a dimeric derivative of RK-682 with increased inhibitory activity against VHR, a dual-specificity ERK phosphatase: implications for the molecular mechanism of the inhibition

BACKGROUND: VHR is a dual-specificity phosphatase, which dephosphorylates activated ERK1/2 and weakens the ERK signaling cascade in mammalian cells. A selective inhibitor is expected to be useful for revealing the physiological function of VHR. RESULTS: First, we investigated the molecular mechanism of VHR inhibition by a known natural product, RK-682. Kinetic analysis indicated that inhibition was competitive toward the substrate, and two molecules of RK-682 were required to inhibit one molecule of VHR. Based on the structure-activity relationships for VHR inhibition by RK-682 derivatives, we constructed a binding model using molecular dynamics calculation. Based on this model, we designed and synthesized a novel dimeric derivative. As expected, the dimeric derivative showed increased inhibition of VHR, supporting our proposed mechanism of VHR inhibition by RK-682. CONCLUSION: We have developed a novel inhibitor of VHR based on the results of kinetic analysis and docking simulation.     

Enzymatic Precision Polymerization for Synthesis of Glycosaminoglycans and Their Derivatives

Hyaluronidase (HAase)-catalyzed polymerization was performed to provide synthetic hyaluronan (HA), chondroitin (Ch) and their derivatives. The 2-methyl oxazoline derivatives derived from their repeating disaccharides of N-acetylhyalobiuronate ( 1a ) and N-acetylchondrosine ( 3a ) were effectively polymerized by the enzyme, giving rise to synthetic HA and synthetic Ch in good yields through regio-selective and stereo-controlled ring-opening polyaddition. The oxazoline derivatives of 2-ethyl ( 1b , 3b ), 2-n-propyl ( 1c , 3c ), 2-isopropyl ( 1d , 3d ), 2-phenyl ( 1e , 3e ), 2-vinyl ( 1f , 3f ) and 2-isopropenyl ( 1g ) were synthesized and subjected to the enzymatic reaction. Monomers 1b , 1c , 1f , 3b and 3f were polymerized to corresponding polysaccharides 2b , 2c , 2f , 4b and 4f , all of which are unnatural glycosaminoglycans. Compounds 1d , 3c and 3d were also catalyzed by the enzyme, affording oligomers of 2d , 4c and 4d were produced in trace amounts. Monomers 1e , 1g and 3e were not catalyzed by HAase.