Rapid qualitative evaluation of DNA transcription factor NF-κB by microchip electrophoretic mobility shift assay in mammalian cells

We have developed a separation technique for DNA-protein complex based on electrophoretic mobility shift assay (EMSA) by microchip electrophoresis, which we call microchip electrophoretic mobility shift assay (μEMSA). To evaluate the μEMSA, we employed recombinant human nuclear factor-κB (rhNF-κB) and its consensus double-stranded oligonucleotide (dsOligo) fluorescently labeled with Cy5. We carried out the electrophoretic separation of the consensus dsOligo-rhNF-κB complex and the unbound dsOligo in methylcellulose solution and confirmed rapid (～200 s) and reliable identification and semi-quantitation of the specific interaction between dsOligo and rhNF-κB. The binding specificity of rhNF-κB was confirmed by introducing non-fluorescently labeled consensus oligonucleotide as a competitor. The progression of the binding reaction under various incubation times was monitored, and it was found that the dsOligo and rhNF-κB complex formation reached equilibrium (ca. 90% of the dsOligo was bound to rhNF-κB) after 5 min. Furthermore, without any purification process, even crude NF-κB in nuclear extracts from HeLa cells was specifically detected within 120 s by the μEMSA.     

Dynamic responses of a solid wall in contact with a bubbly liquid excited by thermal shock loading

Several MW-class spallation neutron sources are being developed in the world. Specifically, intensive and high energy protons are injected into heavy liquid metals (mercury, lead or lead-bismuth eutectic) to induce the spallation reaction that produces neutrons. At the moment when the proton beams are injected, thermal shock occurs in the liquid metal, causing pressure waves to propagate in the liquid metal, collide against the container and damage it.It is proposed that microbubbles are injected into the liquid metal to mitigate the impulsive pressure waves by means of absorption and attenuation effects. These effects are dependent on the relationship between bubble size and the rate of pressure increase. In the present experiment, a very rapid rise in pressure in the order of MPa/μs, equivalent to the rise in pressure due to proton beam injection, was simulated by the electric discharge method in a water loop test to investigate the impulsive pressure mitigation effect of injected microbubbles. The solid wall response was measured using an accelerometer, and the dynamic responses of microbubbles were observed using an ultra-high-speed camera filming at 5 × 10⁵ frame/s. The sound velocity in bubbly water was estimated using a differential image technique. It was confirmed from the experimental results that microbubbles are effective in reducing impulsive pressure waves and to suppressing the impact vibration of the solid wall in contact with the liquid.     

Polymer waveguide module for visible wavelength division multiplexing plastic optical fiber communication

We report a polymer waveguide module that provides bidirectional communication over a single plastic optical fiber (POF) with dual visible wavelength LEDs. The module is constructed using light-induced self-written waveguides, which enables a three-dimensional optical circuit for visible wavelength division multiplexing to be fabricated by an extremely simple process. We demonstrated 250 Mbits/s communication using a pair of these modules that each contained one green (lambda = 495 nm) and one red (lambda = 650 nm) LEDs by measuring the bit error rates. The results indicate that the system could transmit over more than 20 m of POF in full duplex mode.     

Annulative coupling of vinylboronic esters: aryne-triggered 1,2-metallate rearrangement

A stereoselective annulative coupling of a vinylboronic ester ate-complex with arynes producing cyclic borinic esters has been developed. An annulation reaction that proceeded through the formation of two C–C bonds and a C–B bond was realized by exploiting a 1,2-metallate rearrangement of boronate triggered by the addition of a vinyl group to the strained triple bond of an aryne. The generated aryl anion would then cyclize to a boron atom to complete the annulation cascade. The annulated borinic ester could be converted to boronic acids and their derivatives by oxidation, halogenation, and cross-coupling. Particularly, halogenation and Suzuki–Miyaura coupling proceeded in a site-selective fashion and produced highly substituted alkylboronic acid derivatives.

A stereoselective annulative coupling of a vinylboronic ester ate-complex with arynes producing cyclic borinic esters has been developed.     

Tensile behaviors of pre-twisted composite strands

In this paper, we address the tensile behaviors of pre-twisted composite strands, which consists of a pre-twisted single core filament surrounded by n-helical side filaments. Based on the extensible rod with zero bending and small twisting moduli for the core filament and inextensible rod for the side filaments, we develop the analytical method of the tensile behaviors of pre-twisted composite strands. Using a numerical continuation scheme, we elucidate the effects of microscopic factors such as initial helical angle, pre-twist of core filament, ratio of elastic modulus of core to that of side filament, and the number of the side filaments on the macroscopic tensile behavior of the strand as a whole structure. As a result, we show that the behavior is not trivial, even though the filament is a linear elastic due to the interplay of both geometrical constraint and finite deformation of the strand.     

A Convenient Biphasic System (Alumina-Dichloromethane) for the Efficient Aromatic Monochlorination of Alkyl Phenyl Ethers with Sodium Chlorite in the Catalytic Presence of Manganese(III) Salt

A combination of sodium chlorite, (salen)manganese(III) catalyst, and chromatographic neutral alumina in dichloromethane can be successfully utilized for the aromatic monochlorination of a variety of alkyl phenyl ethers in excellent to quantitative yields under mild and anhydrous conditions.     

Copper-catalyzed asymmetric propargylic amination of propargylic acetates with amines using BICMAP

The copper-catalyzed asymmetric propargylic amination of propargylic acetates 1 with amines 2 using BICMAP as a chiral ligand gave the desired products 3 in good yields and with moderate to high enantioselectivities (up to 90% ee).