The Viscoelastic Properties of Wood Used for Musical Instruments II

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。In order to make clear the relation between the acoustic properties and the fine structures of wood, the present paper deals with the dynamic mechanical and dielectric properties in relation to the angle of micellar orientation and the degree of crystallinity estimated by X-ray measurements of wood using for the musical instruments (Sitka spruce) and other few wood species (Hinoki, Sugi and Hoonoki). The dynamic elastic modulus, loss modulus, dielectric constant and loss factor for Sitka spruce were large in magnitude for its specific gravity compared with the other species. The mean angle of micellar orientation and the half width in the distribution function of spiral angle for Sitka spruce were the smallest among the coniferous wood species used. The crystallinity indexes calculated from transmission method for Sitka spruce and Hinoki were smaller than those for Sugi and Hoonoki. From these results, it may be concluded that the principal cause which the dynamic elastic and loss modulus for Sitka spruce are large in magnitude for its density is due to its small angle of micellar orientation and/or its uniformity in the gross structures

<Note>Some Physical Properties of Wood and Cellulose Irradiated with Gamma Rays

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。The effect of gamma irradiation from cobalt-60 on specific gravity, degree of crystallinity, thermal softening temperature, tensile strength and torsional creep behavior of wood and cellulose were investigated and the following results were obtained. 1) A dosage up to about 10^8 rad had little effect on the specific gravity of wood and cellulose. 2) The degree of crystallinity of wood and cellulose remained almost unchanged up to 3×10^7 rad, but started to decrease rapidly at about 1×10^8 rad. 3) The softening temperature of cellulose shifted gradually to a lower temperature region up to about 3×10^7 rad and abruptly in the range exceeding 3×10^7 rad. 4) Strength of wood decreased with increasing irradiation dosage, depending remarkably on loading modes. 5) The value of creep compliance of wood at time 0.1 min did not change up to 1×10^7 rad, but increased markedly in the range exceeding about 3×10^7 rad

Quantum error correction beyond qubits

Quantum computation and communication rely on the ability to manipulate quantum states robustly and with high fidelity. Thus, some form of error correction is needed to protect fragile quantum superposition states from corruption by so-called decoherence noise. Indeed, the discovery of quantum error correction (QEC) turned the field of quantum information from an academic curiosity into a developing technology. Here we present a continuous-variable experimental implementation of a QEC code, based upon entanglement among 9 optical beams. In principle, this 9-wavepacket adaptation of Shor's original 9-qubit scheme allows for full quantum error correction against an arbitrary single-beam (single-party) error.Comment: realization of a Gaussian error correction protocol suitable for non-Gaussian error correctio

Formation of oxidative photoproduct of tri-acetyl-modified 6-thioguanosine by UVA irradiation

Thio-substituted nucleobases such as 6-thioguanine are known to be photosensitive to UVA light and capable of generating singlet molecular oxygen (1O2*). 2’,3 ’,5 ’- Tri-O-acetyl-6-thioguanosine (ta6TGuo) was prepared and its photochemistry was investigated. ta6TGuo in the aerated acetonitrile solution under UVA irradiation generates 1O2* that can also oxidize ta6TGuo itself and finally convert into tri-acetylated guanosine sulfonate (taGuoSO3). The decay rate constant of ta6TGuo was found to be in good agreement with the formation rate constant of taGuoSO3, revealing that the first step in the reaction of ta6TGuo with 1O2* would be the rate-determining step in forming taGuoSO3 as the final product. Thiolated nucleosides such as 6-thioguanosine could be used as a photosensitive agent for light-induced therapies. The key feature in the UVA irradiation of the thionucleosideis to produce 1O2*, but the resultant oxidative products would also contribute to the effect on therapies

Trial of Brain Redox Imaging and Estimation of Radiation-Induced Redox Change in Mouse Brain

The in vivo T1-weighted contrasting abilities and signal decay behaviors of several nitroxyl contrast agents, which have been used as redox responsive contrast agents in several magnetic resonance-based imaging modalities, in mouse brain were compared. In addition, daily variations of redox behavior in mouse brain after irradiation of X-ray or carbon-ion beams (C-beam) were tried to estimate based on the in vivo reduction rate of amphiphilic nitroxyl contrast agents.Injection solutions of five types of five-membered-ring nitroxyl contrast agents, i.e. 3-carboxy-2,2,5,5-tetramethylpyrrolidine-N-oxyl (CxP), 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (CmP), 3-methoxy-carbonyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (MCP), acetoxymethyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl-3-carboxylate (CxP-AM), and 4-(N-methylpiperidine)-2,2,5,5-tetramethylpyrroline-N-oxyl (23c), and a six-membered-ring nitroxyl contrast agent, i.e. 4-hydroxyl-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL), were prepared. The nitroxyl contrast agent was i.v. injected to a mouse through tail vein. Then, the distributions and pharmacokinetics of nitroxyl contrast agents were compared based on the time course of T1-weighted MRI. The MRI experiments using CMP or TEMPOL were repeated for mice irradiated by X-ray or C-beam to their head on several deferent timings, i.e. 1, 2, 4, 8 day(s) after irradiation. C-beam was irradiated at Heavy-Ion Medical Accelerator in Chiba (HIMAC, National Institute of Radiological Sciences/ National Institutes for Quantum and Radiological Science and Technology).The blood-brain-barrier (BBB)-impermeable CxP could not be distributed in the brain. The slightly lipophilic CmP showed slight distribution only in the ventricle, but not in the medulla and cortex. The amphiphilic MCP and TEMPOL had good initial uniform distribution in the brain and showed typical 2-phase signal decay profiles. A brain-seeking nitroxyl probe, CxP-AM, showed an accumulating phase, and then its accumulation was maintained in the medulla and ventricle regions, but not in the cortex. The lipophilic 23c was well distributed in the cortex and medulla, but slightly in the ventricle, and showed relatively rapid linear signal decay.Decay rates of MCP in mouse brain after irradiation of 8 Gy X-ray, 8 Gy C-beam or 16 Gy C-beams did not show marked clear changes, however relatively little decreasing were observed at day 1 and day 2 after irradiation. Decay rates of TEMPOL was increased 1 after irradiation then gradually recovered to the control level. MCP and TEMPOL showed opposite responses but the timing of redox change may be 1 or 2 days after irradiation.Nitroxyl contrast agents equipped with a suitable lipophilic substitution group could be BBB-permeable functional contrast agents. MR redox imaging, which can estimate not only the redox characteristics but also the detailed distribution of the contrast agents, is a good candidate for a theranostic tool. Irradiation of ionized radiation to head could cause alternation of redox status in the brain. Detail of redox mechanisms were still in progress.第7回国際放射線神経生物学会大

Ultrafiltration attenuates cardiopulmonary bypass–induced acute lung injury in a canine model of single-lung transplantation

ObjectiveThe purpose of this study was to investigate the effects of cardiopulmonary bypass and ultrafiltration on graft function in a canine single-lung transplantation model.MethodsFifteen left single-lung transplantations were done in weight-mismatched canine pairs. The animals were divided into 3 groups: group 1, in which transplantation was done without cardiopulmonary bypass; group 2, in which transplantation was done with cardiopulmonary bypass and in which the cardiopulmonary bypass flow was decreased slowly with controlled pulmonary artery pressure; and group 3, in which transplantation was done with cardiopulmonary bypass and ultrafiltration. Hemodynamic parameters and lung function were monitored for 6 hours after reperfusion. The grafts were harvested for histologic studies, myeloperoxidase assay, and real-time quantitive reverse transcription–polymerase chain reaction of mRNA encoding interleukin 6.ResultsThe hemodynamic parameters were similar among the 3 groups. In group 1 Pao2 and alveolar to arterial gradient for O2 levels were excellent throughout the 6-hour observation period, but in group 2 they progressively deteriorated. However, ultrafiltration significantly (P = .02) improved the Pao2 level in group 3. On histology, interstitial edema and polynuclear cell infiltration were most marked in group 2 and significantly worse than in groups 1 and 3. Myeloperoxidase assay and real-time quantitative reverse transcription–polymerase chain reaction showed increased myeloperoxidase activity and interleukin 6 gene expression in group 2 grafts compared with group 1 grafts. Myeloperoxidase activity and interleukin 6 gene expression were suppressed with ultrafiltration.ConclusionsCardiopulmonary bypass had negative effects on the graft, but ultrafiltration attenuated acute lung dysfunction by reducing the inflammatory response

Effects of the Prophylactic Use of Amiodarone Infusion to Prevent Postoperative Atrial Fibrillation after Cardiac Surgery

Postoperative atrial fibrillation（AF）is associated with significant morbidity after cardiac surgery. We examined the effects of a prophylactic postoperative amiodarone infusion to prevent postoperative AF. A prospective randomized study was performed in patients with a high risk of postoperative AF between March 2016 and March 2019. High risk of AF was defined as combined valve surgery, aortic valve replacement（age＞70）, or off-pump coronary bypass grafting（age＞65）. Forty-two patients were enrolled and randomly assigned to receive prophylactic amiodarone infusion（amiodarone group, n＝20）or saline infusion（control group, n＝22）. In the amiodarone group, amiodarone was infused intravenously for 48hr postoperatively（initially 125mg/10min, then 288mg/6hr, then maintenance of 1,040mg/42hr）. There were no significant differences between the two groups in age, sex, body height, body weight, surgical procedure, and perioperative use of beta blockers. The occurrence of sustained AF for＞1hr was significantly lower in the amiodarone group（30.0％）than in the control group（63.6％, p＝0.04）. The total duration of AF over one week was also significantly shorter in the amiodarone group（296.8±676.9min）than in the control group（921.4±1641.6min, p＝0.04）, as was the postoperative hospital stay（17.3±6.1 vs. 24.5±11.3 days, respectively, p＝0.01）. There were no major side effects with amiodarone infusion except for one case of bradycardia. These results show the prophylactic use of intravenous amiodarone infusion for the first 48hr of the postoperative period is a safe and effective treatment to prevent postoperative AF after cardiac surgery and to shorten the hospital stay

Isolation and identification of the antimicrobial substance included in tempeh using Rhizopus stolonifer NBRC 30816 for fermentation

In this study, we focus on the antimicrobial properties of tempeh, a soybean fermented food, against oral bacteria. Tempeh showed antimicrobial activity against dental caries pathogenic bacterium Streptococcus mutans at a final concentration of 1 mg/mL. An antimicrobial substance contained in tempeh was present in the 100 kDa or greater fraction generated by ultrafiltration, but it was found not to be proteinaceous by native-PAGE, SDS-PAGE and protein degradation tests. Next, when the fraction was purified with an ODS column, the 80% and 100% methanol eluates showed antimicrobial activity against S. mutans. The 100% methanol eluate was further subjected to a 2nd column purification, and isolation of the target was confirmed by HPLC. When the isolated material was analyzed by ESI-MS, the m/z was 279.234. Further analysis by Raman spectroscopy revealed a peak similar to linoleic acid. This substance also possessed antimicrobial properties equivalent to linoleic acid