A Convenient General Access to α-Sulfenylated Acetophenones and Alkanones

Friedel-Crafts acylation of arenes with methylthio- (1) or phenylthio-acetyl chloride (2) provides ready access to α-methylthio- or α-phenylthio-substituted acetophenones. The acyl chlorides 1 and 2 reacted also with organoaluminum reagents to give α-sulfenylated alkanones.     

Design of sugar–oligonucleotide conjugates installed gold nanoparticle for effective delivery to hepatic parenchymal cells

A novel oligonucleotide delivery system that is based on oligonucleotide–nanoparticle conjugates has been described. Installed oligonucleotides were modified with the carbohydrate at the 3′ terminus, accordingly, constructed nanoparticles display clustered carbohydrates on their outer layer for the targeted delivery of oligonucleotides. The method for the construction of ligand-functionalized nanoparticle was simple and reproducible. The stability of the nanoparticles displaying clustered carbohydrates greatly increased in serum compared to nanoparticles without carbohydrates. In order to investigate the targetability of oligonucleotide–nanoparticle conjugates into primary hepatic parenchymal cells, freshly isolated rat hepatocytes were incubated with nanoparticles and the amount of internalized gold nanoparticles was evaluated by an inductively coupled plasma mass spectroscopy analysis. Nanoparticles displaying clustered carbohydrates internalized more efficiently than nanoparticles without carbohydrate modifications. In particular, the cellular uptakes of oligonucleotide-conjugated gold nanoparticle increased 1.7 ～2.0-fold by galactose modification. Competition assay revealed that clustered galactose enhanced the internalization of the nanoparticle into primary hepatic parenchymal cells by a receptor-mediated process.

Effects produced by metal-coated near-field probes on the performance of silicon waveguides and resonators

We study the effects of metal-coated fiber near-field probes on the performance of nanophotonic devices. Employing a heterodyne near-field scanning optical microscope and analyzing transmission characteristics, we find that a metal-coated probe can typically introduce a 3 dB intensity loss and a 0.2 rad phase shift during characterization of a straight waveguide made in a silicon-on-insulator system. In resonant nanophotonic structures such as a 5 mum radius microring resonator, we demonstrate that the probe induces a 1 nm shift in resonant wavelength and decreases the resonator quality factor, Q, from 1100 to 480.     

Observation of B0-->pi0pi0

We report the observation of the decay B0-->pi(0)pi(0), using a 253 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) collider. The measured branching fraction is B(B0-->pi(0)pi(0))=(2.3(+0.4+0.2)(-0.5-0.3))x10(-6), with a significance of 5.8 standard deviations including systematic uncertainties. We also make a measurement of the direct CP violating asymmetry in this mode.     

Measurement of the neutron beam polarization of BL05/NOP beamline at J-PARC

We measured the neutron beam polarization of the BL05/NOP (Neutron Optics and Physics) beamline at J-PARC with an accuracy of less than 10⁻³ using polarized ³He gas as a neutron spin analyzer. Precise polarimetry of the neutron beam is necessary to understand the beamline optics as well as for the asymmetry measurements of the neutron beta decay, which are planned in this beamline.     

Maximum number of connectable laser diode optical switch (LDSW) systems

The maximum number of connectable laser diode optical switches (LDSWs) was studied through the baseband signal-to-noise ratio calculation. For an NRZ 100 Mbits^–1 PCM-IM signal, 60 stages of LDSWs can be connected with a 6-nm optical bandpass filter inserted after the last stage at an input signal level of –30 dB m and an internal gain of 16 dB. A PCM-IM signal of 10 Gbits^–1 can be transmitted through 130 stages of LDSWs at an internal gain of 8 dB and an input signal level of –20 dB m.     

Reactions of a Silylyne Complex with Aldehydes: Formation of W−Si−O−C Four-Membered Metallacycles and Their Metathesis-Like Fragmentation

A tungsten silylyne complex having a W≡Si triple bond reacted with two molecules of aldehydes at room temperature to give W−Si−O−C four-membered metallacycles by [2+2] cycloaddition and subsequent formyl hydrogen transfer from one aldehyde molecule to another. Upon heating to 70 °C, the four-membered metallacycles underwent metathesis-like fragmentation cleanly to afford carbyne complexes and “silanoic esters,” in a manner similar to that of metallacyclobutadiene, an intermediate of alkyne metathesis reactions, and dimerization of the latter products gave 1,3-cyclodisiloxanes. The “silanoic ester” was also trapped by pivalaldehyde to give a [2+2] cycloaddition product in high yield.