A Pyrene-Modified Serinol Nucleic Acid Nanostructure Converts the Chirality of Threoninol Nucleic Acids into Circularly Polarized Luminescence Signals

Herein is reported a circularly polarized luminescent (CPL) probe that can respond to the chirality of nucleic acids. An achiral nanostructure was prepared by the hybridization of symmetric serinol nucleic acid (SNA) containing pyrene-modified residues. When chiral oligomers that were complementary to the SNA were added, they induced helicity into the SNA nanowire. Efficient circular dichroism (CD) signal amplification was observed when pyrene was attached to uracil bases through a rigid alkynyl linker. Both CPL and CD signals were observed; they depended on the chirality of the added acyclic threoninol nucleic acid (aTNA) oligomer. This system can be used to convert the chirality of chiral biomolecules into chiroptical signals.     

The PMe3-catalyzed addition of enantiomerically pure (−)-MenthylO(Ph)P(O)H to electron-deficient alkenes: an efficient way for the preparation of P-stereogenic compounds

A variety of P-stereogenic organophosphorus compounds can be readily prepared by stereoretentive addition. The PMe₃-catalyzed addition of optically active (?)MenthylO(Ph)P(O)H compounds to electron deficient alkenes occur stereospecifically, to produce the corresponding P-stereogenic adducts in high yields. By simply removing the volatiles under vacuum, spectroscopically pure products can be obtained. The present method provides a salt-free clean process for the preparation of P-chiral organophosphorus compounds.     

The teacher’s role in guiding children’s mathematical ideas toward meeting lesson objectives

This paper investigates the classroom interactive pattern, in which the teacher aims to introduce new mathematical content to children by focusing on their mathematical thinking. First, by drawing on the results of studies on the features of social interaction patterns in mathematics classrooms, we develop a framework that we call a “guided focusing pattern,” composed of four phases. Next, we use this framework and Sfard’s (J Res Math Educ 31(3):296–327, 2000) theory of focal analysis to examine the social interaction occurring in a series of mathematics lessons conducted by an experienced teacher. In the ten consecutive lessons that we analyzed, the guided focusing pattern was salient; the teacher introduced key mathematical content to children while offering support and guidance in a variety of forms within each phase and when transitioning to the next phase. On the basis of the results, we highlight the teacher’s key instructional actions that facilitate the pattern of progressing through the mathematical content as closely linked to and guided by her lesson objectives.     

Ribonuclease protection assay on microchip electrophoresis

We describe the potential of microchip electrophoresis with a Hitachi SV1210, which can be used to evaluate the integrity of total RNA, for the analysis of mRNA expression. The ribonuclease (RNase) protection assay was performed by using microchip electrophoresis with cyanine 5 (Cy5) labeled 248-base antisense RNA probe (riboprobe) encoding adipose-type fatty acid binding protein (A-FABP) as the riboprobe. The fluorescence intensity corresponding to the protected RNA fragment increased in a dose-dependent manner with respect to the complementary strand RNA. Results were obtained in 120 s, and the same amount of Cy5-labeled antisense riboprobe as used in the conventional method can be used. Furthermore, 8 times more sensitive detection of mRNA by microchip electrophoresis could be obtained. An obvious increase in the mRNA expression of A-FABP, which is known as a differentiation marker of adipocytes, occurred during the adipocyte differentiation of 3T3-L1 cells. These results clearly indicate the potential of microchip electrophoresis for the analysis of mRNA expression in cells.     

Effect of particle size of drug on conversion of crystals to an amorphous state in a solid dispersion with crospovidone

The effect of particle size on amorphization of drugs in a solid dispersion (SD) was investigated for two drugs, indomethacin (IM) and nifedipine (NP). The SD of drugs were prepared in a mixture with crospovidone by a variety of mechanical methods, and their properties investigated by particle sizing, thermal analysis, and powder X-ray diffraction. IM, which had an initial particle size of 1 μm and tends to aggregate, was forced through a sieve to break up the particles. NP, which had a large initial particle size, was jet-milled. In both cases, reduction of the particle size of the drugs enabled transition to an amorphous state below the melting point of the drug. The reduction in particle size is considered to enable increased contact between the crospovidone and drug particles, increasing interactions between the two compounds.     

Thermotropic liquid crystalline polymers containing five-membered heterocyclic groups IX. Synthesis and optical properties of liquid crystalline semi-rigid polyesters composed of a quinquephenyl analogue containing 1,3,4-thiadiazole and aliphatic chains

Novel semi-rigid polyesters containing a quinquephenyl analogue containing 1,3,4-thiadiazole and a central 1,3-phenylene unit in the main chain were synthesized by high temperature solution polycondensation of a dimethyl ester derivative of 1,3-bis(5-phenyl-1,3,4-thiadiazol-2-yl)benzene with an aliphatic (octa-, deca- and dodecamethylene) diol. The proposed structures were confirmed using FTIR and ¹H NMR spectroscopies, and elemental analyses; their liquid crystalline and photoluminescent (PL) properties were examined by means of differential scanning calorimetry, optical texture observations using polarizing microscopy, powder X-ray diffraction, and UV-vis and PL spectra measurements. These measurements showed that the polymers not only show a monotropic solid smectic or disordered crystal phase, but also PL properties with blue emission in HFIP solutions and in the solid phase, Stokes shifts of 116.5–119?nm being observed.     

The effect of atmospheric plasma treatments on plastic scintillator for beta-ray measurement

A plastic scintillator (PS) can be used for beta-ray measurements using a liquid scintillation counter (LSC) without the necessity for a liquid scintillator when liquid samples of beta-emitters are placed on the PS. However, the measurement efficiency with the PS in this study was not high, especially in the case of tritium. With a sample of tritiated water, a long measurement time was necessary with a conventional LSC. However, the measurement efficiency was improved drastically by modifying the PS surface with atmospheric-pressure glow-plasma processing (the plasma method). A 2 Bq, 20 μL sample of tritiated water placed between two PS sheets was successfully measured within 2 min by an LSC. The measurement efficiency was same as that of using liquid scintillator: 48 ± 2 % for tritiated water. The measurement efficiency was initially increasing over time, and after almost 6 h, it plateaued and remained at a constant value for several weeks. Additionally, the measurement efficiency of the plasma-modified PS was identical when it was used soon after the treatment and after being properly stored for 1 week The results show that plasma-modified PS can be used stably after storage in a freezer or a deep freezer. The plasma method is advantageous because it produces little radioactive waste fluid. This paper presents these results and the results of an investigation of the surface of the plasma-modified PS under observation with an atomic force microscope, and the mechanism behind the high measurement efficiency is discussed.     

Development of a highly selective fluorescence probe for hydrogen sulfide

Hydrogen sulfide (H(2)S) has recently been identified as a biological response modifier. Here, we report the design and synthesis of a novel fluorescence probe for H(2)S, HSip-1, utilizing azamacrocyclic copper(II) ion complex chemistry to control the fluorescence. HSip-1 showed high selectivity and high sensitivity for H(2)S, and its potential for biological applications was confirmed by employing it for fluorescence imaging of H(2)S in live cells.