Anisotropic micro-cloths fabricated from DNA-stabilized carbon nanotubes: one-stop manufacturing with electrode needles

Among a variety of solution-based approaches to fabricate anisotropic films of aligned carbon nanotubes (CNTs), we focus on the dielectrophoretic assembly method using AC electric fields in DNA-stabilized CNT suspensions. We demonstrate that a one-stop manufacturing system using electrode needles can draw anisotropic DNA-CNT hybrid films of 10-100 $\mu$m in size (i.e., free-standing DNA-CNT micro-cloths) from the remaining suspension into the atmosphere while maintaining structural order. It has been found that a maximal degree of polarization (ca. 40 \%) can be achieved by micro-cloths fabricated from a variety of DNA-CNT mixtures. Our results suggest that the one-stop method can impart biocompatibility to the downsized CNT films and that the DNA-stabilized CNT micro-cloths directly connected to an electrode could be useful for biofuel cells in terms of electron transfer and/or enzymatic activity.Comment: For supplementary movies, see http://www.nanoscalereslett.com/content/10/1/107/additiona

Radiation Yield and Radicals Produced in Irradiated Poly (Butylene Succinate)

The main chemical effects of ionizing irradiation on polymers are crosslinking and chain scission. Both processes occur simultaneously and their yields determine the final results of processing. The radiation yield of crosslinking could be determined by several methods depending on the characteristics of the material and properties of the gel. Radiation parameters of gelation, such as gelation dose and ratio of scission yield to crosslinking yield, as well as their values were estimated. In this study, those parameters depend on the amount of Trimethallyl isocyanurate (TMAIC) in Poly(butylene succinate) (PBS), molecular weight of PBS, and irradiation condition. In the absence of TMAIC, higher molecular weight of PBS required less energy to start gelation process compare to lower molecular weight of PBS. While in the presence of TMAIC all of the PBS samples require similar energy to start gelation process. The existence of macroradicals were observed by Electron Spin Resonance measurements. The result showed that the spectra consisted of signals derived from radicals on carbon nearby carbonyl, and signals derived from radicals on carbon reside between two similar carbon on polymer, both of radicals lead to crosslinking

Nonparametric Bayesian Dereverberation of Power Spectrograms Based on Infinite-Order Autoregressive Processes

This paper describes a monaural audio dereverberation method that operates in the power spectrogram domain. The method is robust to different kinds of source signals such as speech or music. Moreover, it requires little manual intervention, including the complexity of room acoustics. The method is based on a non-conjugate Bayesian model of the power spectrogram. It extends the idea of multi-channel linear prediction to the power spectrogram domain, and formulates a model of reverberation as a non-negative, infinite-order autoregressive process. To this end, the power spectrogram is interpreted as a histogram count data, which allows a nonparametric Bayesian model to be used as the prior for the autoregressive process, allowing the effective number of active components to grow, without bound, with the complexity of data. In order to determine the marginal posterior distribution, a convergent algorithm, inspired by the variational Bayes method, is formulated. It employs the minorization-maximization technique to arrive at an iterative, convergent algorithm that approximates the marginal posterior distribution. Both objective and subjective evaluations show advantage over other methods based on the power spectrum. We also apply the method to a music information retrieval task and demonstrate its effectiveness

感染予防からみた緑茶の特性に関する研究

We investigated the infection-preventive characteristics of Japanese green tea (middle grade) in reference to itscatechin (CAT) concentration. Colorimetric analysis showed that CAT was extracted most effectively at 80℃. When green tea extract (GTE) was prepared from the same green tea leaves (5g/80ml water) repeatedly six times at 80℃ for 1 min, almost the 2/3 of total CAT content was extracted during the first three extractions in which the second extraction gave the highest CAT concentration. Therefore, GTE prepared under this condition (5g/80ml water at 80℃ for 1 min) was referred to as standard GTE (SGTE) in this study. Bacteriological studies using Staphylococcus aureus, Escherichiac oli and Pseudomonas aeruginosa showed that the maximum inhibitory and bactericidal dilutions of the second SGET were ranged in 8-and4-fold dilutions, corresponding to 0.33mg/ml and 0.68mg/ml CAT concentrations, respectively, against either bacterial species and the differences between these two values were within 2-fold dilutions, indicating that SGTE shows the bactericidal activity. However, SGTE required as long as 4 to 5 h for bactericidal time in sharp contrast to iodine with that of as short as 1 min. When SGTE with CAT concentration ranging 1.2 mg/ml to 2.7mg/ml was incubated with influenza A/Aichi virus at 37℃ for at least 30min, SGTE also completely inhibited viral hemagglutination (HA) activity essential for the viral attachment to cell surface. The CAT-deficient SGTE, prepared by the treatment with FeCl_3, could not show both bactericidal and HA inhibitory activities, confirming that CAT in GTE is mainly responsible for these activities. In summary, GTE might be taken as a beneficial herbal medicine to promote the infection-safety conditions in the patients. However, on the application of GTE, its advantage/disadvantage and presence of sufficient CAT concentration should betightly recognized.緑茶（煎茶）の抗菌性とインフルエンザウイルス赤血球凝集（HA）活性阻害の特性を検証した．酒石酸鉄比色法による検討から，低温域（50℃と65℃）より高温域（80℃と91℃）でより多くカテキン（CAT）は抽出され，就中80℃が最大CAT量を示した．5g茶葉/80ml水，80℃，1分（標準緑茶液:SGTE）で６回抽出したところ，２回目で最高CAT量（2.7mg/ml）を示し，３回目までにほぼその2/3が抽出された．黄色ブドウ球菌，大腸菌と緑膿菌に対するSGTEの最大発育阻止と最大殺菌希釈度の差は，どの菌に対しても２倍以下であり，緑茶は，広範囲性かつ殺菌的作用を示すことが確認された．但し，ヨード液の１分に比べ，殺菌時間は４～５時間と極めて長いことが注目された．種々CAT量を有するSGTEを，種々時間37℃でインフルエンザウイルスと接触させたところ，CAT量1.2mg/ml～2.7mg/mlの範囲で，30分接触で完全にHA活性を阻害した．さらに，塩化第二鉄処理によるCAT除去SGTEには，抗菌作用も抗HA作用もないことから，種々ある緑茶成分のうち，CATが主な有効成分であることが示された．これらから，緑茶を感染予防として活用する際には，遅効性であること，また十分量なCAT含有（少なくとも1mg/ml）ことの認識は重要であると思われた

Targeted mutagenesis in chicken using CRISPR/Cas9 system

The CRISPR/Cas9 system is a simple and powerful tool for genome editing in various organisms including livestock animals. However, the system has not been applied to poultry because of the difficulty in accessing their zygotes. Here we report the implementation of CRISPR/Cas9-mediated gene targeting in chickens. Two egg white genes, ovalbumin and ovomucoid, were efficiently (> 90%) mutagenized in cultured chicken primordial germ cells (PGCs) by transfection of circular plasmids encoding Cas9, a single guide RNA, and a gene encoding drug resistance, followed by transient antibiotic selection. We transplanted CRISPR-induced mutant-ovomucoid PGCs into recipient chicken embryos and established three germline chimeric roosters (G0). All of the roosters had donor-derived mutant-ovomucoid spermatozoa, and the two with a high transmission rate of donor-derived gametes produced heterozygous mutant ovomucoid chickens as about half of their donor-derived offspring in the next generation (G1). Furthermore, we generated ovomucoid homozygous mutant offspring (G2) by crossing the G1 mutant chickens. Taken together, these results demonstrate that the CRISPR/Cas9 system is a simple and effective gene-targeting method in chickens.ArticleSCIENTIFIC REPORTS.6:23980(2016)journal articl

Radiation Yield and Radicals Produced in Irradiated Poly (Butylene Succinate)

The main chemical effects of ionizing irradiation on polymers are crosslinking and chain scission. Both processes occur simultaneously and their yields determine the final results of processing. The radiation yield of crosslinking could be determined by several methods depending on the characteristics of the material and properties of the gel. Radiation parameters of gelation, such as gelation dose and ratio of scission yield to crosslinking yield, as well as their values were estimated. In this study, those parameters depend on the amount of Trimethallyl isocyanurate (TMAIC) in Poly(butylene succinate) (PBS), molecular weight of PBS, and irradiation condition. In the absence of TMAIC, higher molecular weight of PBS required less energy to start gelation process compare to lower molecular weight of PBS. While in the presence of TMAIC all of the PBS samples require similar energy to start gelation process. The existence of macroradicals were observed by Electron Spin Resonance measurements. The result showed that the spectra consisted of signals derived from radicals on carbon nearby carbonyl, and signals derived from radicals on carbon reside between two similar carbon on polymer, both of radicals lead to crosslinking

Suzaku Detection of Diffuse Hard X-Ray Emission outside Vela X

Vela X is a large, 3x2 degrees, radio-emitting pulsar wind nebula (PWN) powered by the Vela pulsar in the Vela supernova remnant. Using four Suzaku/XIS observations pointed just outside Vela X, we find hard X-ray emission extending throughout the fields of view. The hard X-ray spectra are well represented by a power-law. The photon index is measured to be constant at Gamma~2.4, similar to that of the southern outer part of Vela X. The power-law flux decreases with increasing distance from the pulsar. These properties lead us to propose that the hard X-ray emission is associated with the Vela PWN. The larger X-ray extension found in this work strongly suggests that distinct populations relativistic electrons form the X-ray PWN and Vela X, as was recently inferred from multiwavelength spectral modeling of Vela X.Comment: 18 pages, 7 figures, accepted for publication in PASJ (Suzaku Special Issue

A robot uses its own microphone to synchronize its steps to musical beats while scatting and singing

Abstract—Musical beat tracking is one of the effective technologies for human-robot interaction such as musical ses-sions. Since such interaction should be performed in various environments in a natural way, musical beat tracking for a robot should cope with noise sources such as environmental noise, its own motor noises, and self voices, by using its own microphone. This paper addresses a musical beat tracking robot which can step, scat and sing according to musical beats by using its own microphone. To realize such a robot, we propose a robust beat tracking method by introducing two key techniques, that is, spectro-temporal pattern matching and echo cancellation. The former realizes robust tempo estimation with a shorter window length, thus, it can quickly adapt to tempo changes. The latter is effective to cancel self noises such as stepping, scatting, and singing. We implemented the proposed beat tracking method for Honda ASIMO. Experimental results showed ten times faster adaptation to tempo changes and high robustness in beat tracking for stepping, scatting and singing noises. We also demonstrated the robot times its steps while scatting or singing to musical beats. I