Disulfide‐Unit Conjugation Enables Ultrafast Cytosolic Internalization of Antisense DNA and siRNA

Development of intracellular delivery methods for antisense DNA and siRNA is important. Previously reported methods using liposomes or receptor‐ligands take several hours or more to deliver oligonucleotides to the cytoplasm due to their retention in endosomes. Oligonucleotides modified with low molecular weight disulfide units at a terminus reach the cytoplasm 10 minutes after administration to cultured cells. This rapid cytoplasmic internalization of disulfide‐modified oligonucleotides suggests the existence of an uptake pathway other than endocytosis. Mechanistic analysis revealed that the modified oligonucleotides are efficiently internalized into the cytoplasm through disulfide exchange reactions with the thiol groups on the cellular surface. This approach solves several critical problems with the currently available methods for enhancing cellular uptake of oligonucleotides and may be an effective approach in the medicinal application of antisense DNA and siRNA.     

Hydrogen Effects for Propylene Polymerization with Ultra Low TiCl3 Loading MgCl2-Supported Catalyst

Hydrogen effects for propylene polymerization were investigated with ultra low TiCl₃ loading MgCl₂-supported catalysts in which the electric states of Ti species can be almost uniform. Hydrogen did not affect the catalyst activity, while the efficiency of hydrogen as a chain transfer agent was found to depend on the Ti content of the catalyst and the stereospecificity of the polymerization sites: Hydrogen was effective for isospecific sites independent of Ti contents, but inert for aspecific sites only at the extremely low Ti content. These results were explained within the island model, where isospecific sites may be located in the islands with other Ti species in their surroundings acting, as a steric hindrance for isospecific polymerization and as hydrogen dissociation sites after deactivation. Most of the aspecific sites should be isolated only at the extremely low Ti content. These isolated sites have no other Ti species in their surroundings, i.e. no hydrogen dissociation sites, and are inert to hydrogen.     

Copper-catalyzed enantioselective conjugate addition of diethylzinc using axially chiral aminoethyloxy-phosphine ligands

New axially chiral P,O,N-type ligands bearing both a diphenylphosphino group and 2-(dialkylamino)ethyloxy (or 2-pyridylmethyloxy) groups were designed and prepared along with P,O,O-type ligands by employing an easily available chiral component, (R)-2-hydroxy-2′-diphenylphosphinyl-1,1′-binaphthyl. Among the ligands the simplest P,O,N-type one bearing a 2-(dimethylamino)ethyloxy group was found to be the most efficient in copper-catalyzed enantioselective conjugate addition of diethylzinc to a cyclic enone, 2-cyclohexen-1-one, providing high enantioselectivity up to 99% ee.     

Stability of degenerate abelian varieties

We compactify canonically the moduli scheme of abelian schemes over Z[+_N,1/N] by introducing the noncommutative level structures. Any degenerate abelian scheme on the boundary of the compactification is a singular one among our models - projectively stable quasi-abelian schemes. We prove that a degenerate abelian scheme has Kempf-stable Hilbert points if and only if it is a projectively stable quasi-abelian scheme.     

Effects of Hydrogen for Different Stereospecific Active Sites on Ultra Low TiCl3 Loading Supported Catalyst

The relationship between the stereospecificity of active sites and hydrogen effects on propylene polymerization was investigated for MgCl₂‐supported TiCl₃ catalysts at ultra‐low Ti contents. Hydrogen had no effect on the catalyst activities for isospecific sites and for aspecific sites. The efficiency of hydrogen as a chain‐transfer agent was found to depend on the stereospecificity of the active sites. Hydrogen was effective for isospecific sites but was not effective for aspecific sites. From the viewpoint of hydrogen dissociation, isospecific sites should have hydrogen dissociation sites in their surroundings. Therefore, isospecific sites may be in the island to be affected by hydrogen and isolated sites may be aspecific or have low isospecificity.

     

Propylene Polymerization Performance of Isolated and Aggregated Ti Species Studied Using a Well‐Designed TiCl3/MgCl2 Ziegler‐Natta Model Catalyst

In propylene polymerization with MgCl₂‐supported Ziegler‐Natta catalysts, it is known that the reduction of TiCl₄ with alkylaluminum generates Ti³⁺ active species, and at the same time, leads to the growth of TiCl_x aggregates. In this study, the aggregation states of the Ti species were controlled by altering the Ti content in a TiCl₃/MgCl₂ model catalyst prepared from a TiCl₃ · 3C₅H₅N complex. It is discovered that all the Ti species become isolated mononuclear with a highly aspecific feature below 0.1 wt.‐% of the Ti content, and that the isolated aspecific Ti species are more efficiently converted into highly isospecific ones by the addition of donors than active sites in aggregated Ti species.

     

Evoked magnetoencephalographic responses to omission of a tone in a musical scale

The musical scale is a basis for melodies and can be a simple melody by itself. The present study investigated magnetoencephalographic (MEG) responses to omissions of one tone out of the C major scale. The tone preceding the omitted "target" tone was either prolonged or repeated. In another series, the tone after the target tone was repeated. In "normal" oddball experiments, the complete C major scale was presented more frequently than an incomplete scale lacking one tone, and in "reverse" oddball experiments, the roles were exchanged. In the normal oddball experiments, omission of any tone produced a response significantly different in amplitude from the standard response in the group of non-musicians, although the responses differed depending on the types of omission. The leading tone (B in the C major scale) was shown to elicit a large response when omitted and also when its presence was emphasized. The Reverse oddball experiments showed that repeated presentation of an incomplete scale lacking one tone temporarily reduced the influence of the complete scale but could not even temporarily replace it working as "standard." In addition, an auxiliary study was done to see possible influence of rhythmic variations.     

Modeling Study on Effects of Liquid Propylene in Horizontally Stirred Gas-Phase Reactors for Polypropylene

Modeling study was carried out for JPP-HORIZONE, which has horizontally stirred gas reactors in which the heat of polymerization is removed by vaporization of liquid propylene (LPP). The effects of LPP were estimated by the model which has a couple of continuous stirred bed reactors different in propylene form, gas of liquid, combined with a less stereospecific catalyst as a probe. LPP affects isotacticity further than catalyst efficiency in the developed model. Observed isotacticity was lower than that estimated by the model without LPP, which can be explained only by the presence of LPP.     

Frequency Stabilization of 421.671 nm Second-Harmonic Generation for Studies of 88 Sr+ Ions Confined in an RF Trap

The frequency of a SHG of a high power laser diode has been stabilized to the 5s²S_1/2#x2212;5p²P_1/2 transition of ⁸⁸Sr^#x002B; at 421.671 nm using the differential detection of the absorption signal of a hollow-cathode lamp. The frequency fluctuation never exceeded 10 MHz. The fluorescence signal of ⁸⁸Sr^#x002B; ions was detected.