A study on the pristine and the doped polyacenic semiconductive materials

A new material supposed to have a mixed structure of polyacenic skeletons has been prepared from phenol-formaldehyde resin through the pyrolytic process. This material is air-stable, showing a wide variation of electrical conductivity with pyrolytic temperature. Moreover, it has been confirmed that the present material can be doped with an electron acceptor (iodine) and an electron donor (sodium) in a successful manner, giving rise to a maximum increase in the conductivity of more than seven and eleven orders of magnitude, respectively. The results of the electron probe X-ray microanalysis (EPMA) with respect to the doped samples have shown a uniform distribution of the dopants inside these materials.     

Immunodeficiency with increased immunoglobulin M associated with growth hormone insufficiency

Growth hormone deficiency associated with hypogammaglobulinemia has been reported only in a few publications. Our patient was a male with recurrent episodes of infections. Serum immunoglobulin (Ig) G was extremely low although IgM concentration was much greater than the normal limit. Growth hormone responses to insulin, 1-Dopa and growth hormone-releasing hormone were low. The mean growth hormone concentration during sleep was less than the normal limit. These results are consistent with hyper-IgM immunodeficiency associated with growth hormone deficiency. The mode of transmission appears to be autosomal dominant. This combination has not been reported previously.     

Electronic structures of polyacenacene and polyphenanthrophen anthrene. Design of one-dimensional graphite

The electronic structures of polyacenacene (PAA) and its geometrical isomer, polyphenanthrophenanthrene (PPhP) have been studied using the tight-binding SCF-CO (self consistent field-crystal orbital) method with respect to a design of one-dimensional (1D) graphite. The geometry of each polymer is optimized from the energetic point of view. It has been found that from the analysis of the electronic structure of its optimized geometry, PAA favours the structure without the carbon-carbon bond alternations, yielding no band gap. In this sense, PAA is a typical 1D-graphite. On the other hand, it is predicted that the magnitude of the band gap of PPhP in its optimized geometry is almost equal to that of trans-polyacetylene.     

Characterization of packing structure of tape cast with non-spherical natural graphite particles

A three-dimensional microstructure of green and pressed tapes cast with graphite particles of non-spherical shape were examined quantitatively on the basis of the distribution of void sizes among the packed particles. The distributions measured over the cross-sections of the tape in three directions were expressed by the theoretical ones deduced for non-spherical particles. Particle shape was characterized by shape indices defined by Fourier analysis of particle outlines measured over the corresponding cross-sections of the green tape. The relationships were totally established between the limiting packing density, characterizing the void size distribution at the same section voidage, and the shape index of particle over the section. As a result, the normalized median void diameter as well as the limiting packing density of the pressed tape was found to increase with the particle shape index, corresponding to wider void size distribution. Therefore, based on developed correlations, the optimization of packing microstructure of the cast tape can be expected to result in high performance battery by using shape-modified graphite particles.     

Shape modification of graphite particles by rotational impact blending

To modify particle shape of graphite materials, a rotational impact-blending machine was utilized and the effect of operational conditions was investigated in relation to the size and shape of particles. It was also examined on the specific surface area and the crystal structure of particle surface.As a result, a particle shape index, defined as a ratio of short to long axis of an approximated ellipse by Fourier analysis, got large, whereas the particle size became small a bit, as the peripheral velocity of a rotor and the treatment time increased. The specific surface area more or less increased after treatments, and R value of Raman spectroscopy also increased with the treatment time as the lattice defects grow on the particle surface by surface milling or impact. Then, it temporarily decreased due to the generation of new surfaces with a few defects by volumetric grinding. Finally, two regression analyses were carried out on the relationship between the operational conditions and the particle properties like the diameter and the shape index so as to get proper particles.     

Quantum annealing with Jarzynski equality

We show a practical application of a well-known nonequilibrium relation, the Jarzynski equality, in quantum computation. Its implementation may open a way to solve combinatorial optimization problems, minimization of a real single-valued function, cost function, with many arguments. It has been disclosed that the ordinary quantum computational algorithm to solve a kind of hard optimization problems, has a bottleneck that its computational time is restricted to be extremely slow without relevant errors. However, by our novel strategy shown in the present study, we might overcome such a difficulty.     

Surgical implication of aortic dissection on long-term outcome in Marfan patients

We herein review our 17-year surgical experience for the treatment of ascending aortic aneurysm in patients with Marfan syndrome to clarify the risks of increased mortality and reoperation. The subjects consisted of 15 patients who had all undergone surgery for the aortic root and ascending aorta at Niigata University Hospital between July 1978 and January 1995. Aortic valve replacement and ascending aortic wrapping were performed in 5 patients, Bentall or Cabrol operation in 6, and combined aortic arch reconstruction and Cabrol operation in 2, as the initial surgery. Patients who had an aortic dissection (Stanford type A) at initial surgery were assigned to group I (n = 7), while those with an aortic root aneurysm were assigned to group II (n = 8). In group I, 3 patients required a second operation for the remaining aortic arch aneurysm, and 1 died due to a late rupture of the distal aneurysm. In group II, no patient needed a reoperation; however, 1 died due to an intracranial hemorrhage and another due to composite valve graft failure and distal dissection. The results thus indicate that aortic dissection seems to affect long-term outcome, and therefore the combined repair of the aortic root and transverse arch is recommended in Marfan patients with aortic dissection involving the transverse aortic arch.     

Dichromatism causes color variations in leaves and spices

Although the color phase (hue) of plants plays fundamental roles in quality of foods and horticultural species, principles of variations in hues of plant materials are neither fully understood nor extensively examined by researchers. This may be partly because plant colors are determined by complex physicochemical factors non‐understandable to most biologists. For example, hue of soluble pigment has been demonstrated to change at different thickness of a layer or pigment concentrations in exceptional substances such as pumpkin seed oil. Such strange effect (dichromatism) of layer thickness on pigment hue was previously explained by application of Beer–Lambert law on absorbance spectra (Naturwissenschaften 2007;94:935–939). In this report, we demonstrate dichromatism in plant leaves and red spices. Dichromatism of these materials can be quite simply observed by extraction and dilution of pigments with dimethylformamide, a scarcely evaporating organic solvent. Hue of pigment solutions gradually changed with dilution from green to yellow‐green for leaves, and from red to yellow for spices. These changes were also explained by changes in absorbance spectra with dilution, nevertheless spectra of absorption coefficient were stable. Dichromatism in leaves caused uniform negative correlation between lightness and hue in any plant species examined. Such correlation was successfully explained by calculation with a normalized RGB color matching function. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 605–611, 2015     

Direct observation of X-ray induced atomic motion using scanning tunneling microscope combined with synchrotron radiation

X-ray induced atomic motion on a Ge(111)-c(2 x 8) clean surface at room temperature was directly observed with atomic resolution using a synchrotron radiation (SR)-based scanning tunneling microscope (STM) system under ultra high vacuum condition. The atomic motion was visualized as a tracking image by developing a method to merge the STM images before and after X-ray irradiation. Using the tracking image, the atomic mobility was found to be strongly affected by defects on the surface, but was not dependent on the incident X-ray energy, although it was clearly dependent on the photon density. The atomic motion can be attributed to surface diffusion, which might not be due to core-excitation accompanied with electronic transition, but a thermal effect by X-ray irradiation. The crystal surface structure was possible to break even at a lower photon density than the conventionally known barrier. These results can alert X-ray studies in the near future about sample damage during measurements, while suggesting the possibility of new applications. Also the obtained results show a new availability of the in-situ SR-STM system.     

Controlling the Fluorescence of Benzofuran‐Modified Uracil Residues in Oligonucleotides by Triple‐Helix Formation

We developed fluorescent turn‐on probes containing a fluorescent nucleoside, 5‐(benzofuran‐2‐yl)deoxyuridine (dU^BF) or 5‐(3‐methylbenzofuran‐2‐yl)deoxyuridine (dU^MBF), for the detection of single‐stranded DNA or RNA by utilizing DNA triplex formation. Fluorescence measurements revealed that the probe containing dU^MBF achieved superior fluorescence enhancement than that containing dU^BF. NMR and fluorescence analyses indicated that the fluorescence intensity increased upon triplex formation partly as a consequence of a conformational change at the bond between the 3‐methylbenzofuran and uracil rings. In addition, it is suggested that the microenvironment around the 3‐methylbenzofuran ring contributed to the fluorescence enhancement. Further, we developed a method for detecting RNA by rolling circular amplification in combination with triplex‐induced fluorescence enhancement of the oligonucleotide probe containing dU^MBF.