Diazadimethano[8]circulene: Synthesis, structure, properties, and isolation of stable radical cation

Hetero[8]circulenes have emerged as novel heteroatom-doped polycyclic aromatic hydrocarbons whose properties depend on the constituent aromatic units. Herein we report a C-doped variant, diazadimethano[8]circulene 3, in which two diphenylcyclopentadiene units are installed into the core of [8]circulene that may prevent effective conjugation. The structure of 3 has been revealed to have two longer C–C bonds in the central eight-membered ring, while the absorption and emission profiles are quite similar to those of tetraaza[8]circulene. Stable radical cation 3⁺ was easily obtained by facile oxidation of 3. X-ray diffraction analysis of 3⁺ showed a slipped dimer arrangement with negligible intermolecular interaction. Interestingly, the lowest-energy absorption of 3⁺ reaches around 2500 nm, while that of 3 is 447 nm

Effectiveness of the Vertical Gas Ventilation Pipes for Promoting Waste Stabilization in Post-Closure Phase

To make inside of the municipal solid waste (MSW) landfill aerobic as much as possible is thought to be preferable for promoting waste stabilization, reducing pollutant's load in leachate, minimizing greenhouse gas emission and shortening post-closure-care period. In Japan, installation of semi-aerobic landfill structure has widely spread in order to promote waste stabilization in MSW landfill from 1980s. In semi-aerobic landfill structure, outlet of main leachate collection pipe is opened to atmosphere. Heat generated by aerobic degradation of waste causes natural convection and natural aeration arises from the outlet of leachate collection pipe to the gas vents. It is so-called stack effect. This air flow is thought to be effective for purifying leachate flowing through drainage layer and leachate collection pipes. And it is also thought to be contributing to expanding aerobic region in waste layer in landfill. Recently, measures attempting the promotion of waste stabilization are taken at several landfills at where stabilization of waste delays, in which many vertical gas vents are newly installed and close structure to semi-aerobic landfill is created. However, in many cases, these gas vents are not connected to leachate collection pipes. Many vertical gas vents are just installed without scientific proof regarding whether they can contribute for waste stabilization. In this study, how such installation of gas vents is effective for waste stabilization and aerobization of waste layer was discussed by numerical analysis. In numerical analysis, heat transfer, gas movement by pressure, gas diffusion, biological degradation of organic matter, and heat generation by biodegradation were taken into account. Simulations were carried out by using the general purpose simulator of finite element method. Three types of landfill structure were assumed. As the results, the following information were obtained. In dig-down type landfill, installation of gas vents has no effect for changing air flow. On the other hand, in pile-up type landfill, installation of vertical gas vents can accelerate air invasion and significantly promote waste stabilization, if it has high permeable horizontal layer

Facile synthesis of fluorescent hetero[8]circulene analogues with tunable solubilities and optical properties

Hetero[8]circulenes are an interesting class of polycyclic heteroaromatic molecules having rigid and planar structures, which are promising in light of their potential applications for OLEDs, OFETs and so forth. Although their synthetic methods have been developed in some specific cases, a facile synthetic protocol of novel hetero[8]circulenes with tunable properties is highly desirable. We herein report the unexpected formation of methoxy-substituted quasi-aza[8]circulene and its conversion into unprecedented triazaoxa[8]circulene. The structures and optical properties were comparatively studied. Remarkably, triazaoxa[8]circulene is highly soluble in THF, acetone and DMSO mainly because of effective hydrogen-bonding of the NH moieties to these solvents. Their highly soluble nature in various solvents enabled us to study the solvent effects of these molecules. In particular, triazaoxa[8]circulene displays a high fluorescence quantum yield of 0.72 in DMSO. Furthermore, enantiomeric separation of highly distorted quasi-aza[8]circulene was successfully achieved by chiral HPLC. Thus, these novel hetero[8]circulene derivatives are practically useful fluorescent nanographene-like molecules with intriguing optical properties

イホウ シュウシュウ ショウコ ハイジョ ホウソク カクセイザイ トリシマリホウ イハン シヨウ ジケン ニオケル ムザイ ジレイ カラ

研究ノー

Adenine-and-Uridine-rich element RNA-binding factor 1 (AUF1) as an additional marker in human gliomas

AUF1 is one of Adenine-and-Uridine-rich elements binding protein which regulates the mRNA stability of many genes related to growth regulation, cytokines, and cell cycle-regulatory genes. There was no report about the expression of AUF1 in gliomas. Sections of formalin-fixed, paraffin-embedded tissues from 71 gliomas were stained immunohistochemically using a polyclonal antibody against the adenine-and-uridine-rich element RNA-Binding factor 1 (AUF1) oncoprotein. Positive staining, which is known to correlate with gene amplification, was not associated with patients\u27 sex, age, Karnofsky performance status scores (KPS), tumor size, Bcl-2 expression, or longer overall survival. However, positive staining was negatively correlated with the MIB-1 labeling index, while it was positively correlated with the lower grade group of WHO classification. Expression of the AUF1 oncoprotein appears to be an important additional indicator in human gliomas

The OVAL experiment: A new experiment to measure vacuum magnetic birefringence using high repetition pulsed magnets

A new experiment to measure vacuum magnetic birefringence (VMB), the OVAL experiment, is reported. We developed an original pulsed magnet that has a high repetition rate and applies the strongest magnetic field among VMB experiments. The vibration isolation design and feedback system enable the direct combination of the magnet with a Fabry-P\'erot cavity. To ensure the searching potential, a calibration measurement with dilute nitrogen gas and a prototype search for vacuum magnetic birefringence are performed. Based on the results, a strategy to observe vacuum magnetic birefringence is reported.Comment: 9 pages, 11 figure

Effectiveness of the Vertical Gas Ventilation Pipes for Promoting Waste Stabilization in Post-Closure Phase

To make inside of the municipal solid waste (MSW) landfill aerobic as much as possible is thought to be preferable for promoting waste stabilization, reducing pollutant's load in leachate, minimizing greenhouse gas emission and shortening post-closure-care period. In Japan, installation of semi-aerobic landfill structure has widely spread in order to promote waste stabilization in MSW landfill from 1980s. In semi-aerobic landfill structure, outlet of main leachate collection pipe is opened to atmosphere. Heat generated by aerobic degradation of waste causes natural convection and natural aeration arises from the outlet of leachate collection pipe to the gas vents. It is so-called stack effect. This air flow is thought to be effective for purifying leachate flowing through drainage layer and leachate collection pipes. And it is also thought to be contributing to expanding aerobic region in waste layer in landfill. Recently, measures attempting the promotion of waste stabilization are taken at several landfills at where stabilization of waste delays, in which many vertical gas vents are newly installed and close structure to semi-aerobic landfill is created. However, in many cases, these gas vents are not connected to leachate collection pipes. Many vertical gas vents are just installed without scientific proof regarding whether they can contribute for waste stabilization. In this study, how such installation of gas vents is effective for waste stabilization and aerobization of waste layer was discussed by numerical analysis. In numerical analysis, heat transfer, gas movement by pressure, gas diffusion, biological degradation of organic matter, and heat generation by biodegradation were taken into account. Simulations were carried out by using the general purpose simulator of finite element method. Three types of landfill structure were assumed. As the results, the following information were obtained. In dig-down type landfill, installation of gas vents has no effect for changing air flow. On the other hand, in pile-up type landfill, installation of vertical gas vents can accelerate air invasion and significantly promote waste stabilization, if it has high permeable horizontal layer

Motion Control of a Ship Hull Cleaning Robot

As the fuel cost will rise continuously, the reduction of fuel consumption and CO2 emissions are required more severely in the transportation industry. To achieve more efficient ship transportation, the prevention of marine biofouling is inevitable. Anti-fouling paint is effective to prevent biofouling to the ship hulls like barnacles, however, even the painted hull acquires slime-like biofouling caused by marine alga on its surface easily. In general, the cleaning of the ship hull is carried out during inspection in dockyard once a year or by divers, which are high costs and high risk task. Frequent cleaning during the ship berthing is desirable to keep good fuel efficiency, and if possible, ships can keep good fuel efficiency that contributes the reduction of costs and CO2 production. As a solution for this issue, we have been introducing underwater robots for ship hull cleaning. In this paper, the motion control system of the robot is described.The 2022 International Conference on Artificial Life and Robotics (ICAROB 2022), January 20-23, 2022, on line, Oita, Japa

Report on the 5th Tomato‐harvesting Robot Competition

Tomato is one of the important fruit vegetables and most tomatoes are produced in the greenhouses, or large-scale farms, where the high temperature and humidity, and long harvest age force the farmer heavy works. To develop the tomato harvesting robot, many research issues exist such as manipulator design, end-effector design, collaborative behavior, artificial intelligence, motor control, image processing, target recognition and so on. With an aim to promote the automation of tomato harvesting, we have organized the tomato harvesting robot competition since 2014. In this paper, we report on the results of 5th tomato harvesting robot competition in 2018.The 2020 International Conference on Artificial Life and Robotics (ICAROB 2020), January 13-16, 2020, B-Con Plaza, Beppu, Oit