Photomechanical bending of 4-aminoazobenzene crystals

Upon photoirradiation at 365 nm, platelike microcrystals of trans-4-aminoazobenzene quickly bend away from the light source, returning to their initial linear shape when irradiation was terminated. However, relative to the observations upon cessation of 365 nm irradiation, the bent crystals recovered their initial shape more rapidly when exposed to visible light (530 nm) irradiation.     

Photoinduced Synthesis of P‐Perfluoroalkylated Phosphines from Triarylphosphines and Their Application in the Copper‐Free Cross‐Coupling of Acid Chlorides and Terminal Alkynes

A practical synthesis yielding P‐perfluoroalkylated phosphines from triarylphosphines and perfluoroalkyl iodides has been developed. The photoinduced reaction involves the substitution of aryl groups on the phosphorus atom with perfluoroalkyl groups to successfully afford P‐perfluoroalkylated phosphines. In addition, the P‐perfluoroalkylated phosphines were found to promote the Cu‐free cross‐coupling reaction of acid chlorides with terminal alkynes.

     

Antisense Oligonucleotide Modified with Disulfide Units Induces Efficient Exon Skipping in mdx Myotubes through Enhanced Membrane Permeability and Nucleus Internalization

We have found that antisense oligonucleotides and siRNA molecules modified with repeat structures of disulfide units can be directly introduced into the cytoplasm and exhibit a suppressive effect on gene expression. In this study, we analyzed the mechanism of cellular uptake of these membrane-permeable oligonucleotides (MPONs). Time-course analysis by confocal microscopy showed that the uptake of MPONs from the plasma membrane to the cytoplasm reached 50 % of the total uptake in about 5 min. In addition, analysis of the plasma membrane proteins to which MPONs bind, identified several proteins, including voltage-dependent anion channel. Next, we analyzed the behavior of MPONs in the cell and found them to be abundant in the nucleus as early as 24 h after addition with the amount increasing further after 48 and 72 h. The amount of MPONs was 2.5-fold higher than that of unmodified oligonucleotides in the nucleus after 72 h. We also designed antisense oligonucleotides and evaluated the effect of MPONs on mRNA exon skipping using DMD model cells; MPONs caused exon skipping with 69 % efficiency after 72 h, which was three times higher than the rate of the control. In summary, the high capacity for intracytoplasmic and nuclear translocation of MPONs is expected to be useful for therapeutic strategies targeting exon skipping.     

Fuel properties of bio-oil/bio-diesel mixture characterized by TG, FTIR and 1H NMR

There has been an increasing interest in alternative fuels made from biomass which is abundant and renewable. Bio-oil and bio-diesel seem to be such promising liquid fuels. Bio-oil produced by fast pyrolysis of biomass is highly viscous, acidic, and has high water content. To overcome these problems as a fuel, a method of emulsifying bio-oil with bio-diesel was performed in the previous paper, and a stable mixture of bio-oil and bio-diesel was successfully prepared. In this paper, several properties of the mixture are discussed by using TG, FTIR and ¹H NMR. The results show us that, compared with crude bio-oil, some properties of bio-oil/bio-diesel mixture such as water content, acid number, viscosity are much improved. The thermal decomposition of the mixture under air/nitrogen is shown using a thermogravimetric analyzer (TGA). Further information about the functional groups is exhibited through Fourier Transform infrared spectrometer (FTIR) and nuclear magnetic spectroscopy (NMR).     

3D Scan matching for mobile robot localization over rough terrain

In order to enable an autonomous mobile robot to travel over rough terrain, it necessitates the capability to detect self‐position accurately even when the odometry errors are increased in traveling. The conventional method can keep high speed and precise localization using iterative closest point algorithms or feature matching techniques. However, effects of steep changes of a mobile robot position are not considered when it travels over rough terrain. In this article, we propose the method for efficient real‐time 6D pose tracking using a rotating 2D laser scanner in traveling over rough terrain. For adaptation to steep changes of the position, weighted point clouds are generated based on the angular and the linear velocity measured by sensors mounted on the robot. And the position and posture of the robot are sequentially optimized by the scan matching in increments of 10 scans. In indoor experiments, we evaluated accuracy of our method when the robot passes on rugged floor. As a result, our method was performed with less than 0.078 m RMS positional error in real time.     

Study on the retention behavior of hydrogen isotopes and the change of chemical states of boron film exposed to hydrogen plasma in LHD

The behavior of hydrogen retention and the change of chemical states of boron film exposed to hydrogen plasma in LHD were investigated. The sample was prepared in LHD, and atomic concentrations for the boron film after hydrogen plasma exposure were changed from 75% for boron, 15% for carbon and 8% for oxygen to 53%, 18% and 22%, respectively. BC bond was a major chemical state of the boron film after hydrogen plasma exposure, although abundance of BB bond was the highest before the plasma exposure. Total hydrogen retention measured by TDS was evaluated to be 1.7 × 10²⁰ H m^?2, and the retentions of hydrogen as BHB, BH and BCH bonds were, respectively, 4.8 × 10¹⁹, 7.2 × 10¹⁹ and 5.2 × 10¹⁹ H m^?2. It was concluded that the hydrogen retention could be estimated by taking account not only of chemical states of impurities, but also of hydrogen depth profile.     

Characteristic distributions of fatty acids in different lipids from Jack beans (Canavalia gladiata DC.)

Extracted lipids obtained from Jack beans (white and red) were fractionated by TLC into nine subfractions. The major components were TAGs (TAG: 43.8–45.7 wt%) and phospholipids (PL: 46.7–47.0 wt%), while other components were also present in minor proportions (0.3–2.7 wt%). The principal fatty acids (FA) are generally palmitic (18.8–28.8%), stearic (0.7–6.8%), oleic (42.0–51.8%), linoleic (16.2–22.8%), and α‐linolenic (3.0–8.2%) acids, the distribution of which differs according to these lipid classes. There were no significant differences (p>0.05) in the positional distribution of FA in the TAG; unsaturated FA (97.5%) were predominantly concentrated in the sn‐2 position while saturated FA (33.3%) primarily occupied the sn‐1 position or sn‐3 position. However, significant differences (p<0.05) in FA distribution existed when the individual PL were compared between the white and red beans. Based on the FA composition of these lipids, it seems that the two cultivars of Jack beans are very similar to each other with a few exceptions. The results could be useful to both producers and consumers for our daily diet to improve value of the Japanese diet. Practical applications : The lipid composition suggests that these beans could be a good source of nutraceuticals with providing heath benefits. The white and red beans may be well incorporated into our daily Japanese diets to improve nutritional value. The data obtained in this study provide valuable information for manufacturing functional drinks such as Jack bean tea in Japan.     

A thermally-stable self-mending polymer networked by Diels-Alder cycloaddition

A novel self-mending polymer with high thermal stability is developed based on the DA reaction between anthracene and maleimide. A network polymer, PEAA₂M₃ is prepared by the DA reaction of anthryl-telechelic poly(ethylene adipate) and a tris-maleimide. While the forward DA (addition) reaction is favored at room temperature, the reverse DA (dissociation) reaction is induced by mechanical stress. This mechanochemical reversibility allows the autonomous mending of cracks in PEAA₂M₃ at room temperature. It is well known that the thermal dissociation of the DA reaction occurs only at very high temperatures at which organic polymers degrades significantly. Therefore, thermal stability is successfully combined with self-mending ability in PEAA₂M₃.     

Rheological properties of sodium caprate-induced β-lactoglobulin gel and changes in secondary structure during gelation

In this study, we found that transparent gels of β-lactoglobulin (β-LG) were formed by adding different concentrations of sodium caprate to protein solutions at ambient temperature. We investigated changes in the dynamic viscoelasticity of the mixture with time at 25°C and found that more than 12% β-LG induced the formation of a viscoelastic gel with a suitable amount of sodium caprate (for example, 12% β-LG and 3.6% sodium caprate). Furthermore, we analyzed the changes in the secondary structure of proteins during the gelation step by FHR spectroscopy. Dissociation of the β-LG dimer was first observed just after mixing with sodium caprate. Furthermore, in the β-LG protein in which the original contents were predominantly β-sheets, intermolecular β-sheets attributable to aggregation increased with a decrease in the content of intramolecular β-sheets. Sodium caprate-induced gel was heated at 80°C for 30 min after the gel was formed, and a large increase in the intermolecular β-sheet bands was observed by heat treatment. These results suggest that the formation of sodium caprate-induced gels of β-LG was accompanied by less marked changes in the protein conformation than those in heat-induced gels.