Self-assembly formation of dense carbon nanotube (CNT) filaments is demonstrated with gas discharge breakdown. CNT filament formation is triggered by irradiation of ions generated by gas discharge ...breakdown on a CNT mat placed on a cathode. The ion irradiation causes detachment of CNTs from the CNT mat on the cathode. Those CNTs are collected on a counter electrode and reassembled into filaments from the effect of an electric field. We examined the CNT filament formation characteristics using the combination of a plate-shaped cathode covered with a CNT mat and a wire-shaped anode as the discharge electrodes. CNT filament formation strongly depended on the discharge gas (Ar) pressure. Low Ar gas pressure of 4–6 kPa resulted in dense tree-like CNT filament formation on the anode. Addition of a collection electrode to the anode and cathode resulted in drastic enhancement of CNT filament formation. Dense and long filaments, approximately 10 mm in length, formed on the collection electrode. These results indicate that CNT filament formation by discharge breakdown can be used as a versatile dry spinning method for various kinds of CNTs that are unspinnable by conventional methods.
•Carbon nanotube mat exposed to gas discharge breakdown creates a lot of dust.•Carbon nanotubes in the dust is reassembled in long filaments in an electric field.•Using triode configuration significantly enhances the filament formation.•The filament formation can be used for simple carbon nanotube spinning method.
We previously developed a non-cell-dependent biodegradable scaffold to create in situ tissue-engineered vasculature (iTEV) and tested it in a canine inferior vena cava (IVC) model. As iTEV features ...change dramatically during tissue generation, practical, simple, and accurate methods to evaluate iTEV are needed. The present study examined the usefulness of a novel method to evaluate iTEV growth and remodeling according to a simple formula using angiography: hepatic vein (HV) index = (IVC-HV junction angle) ÷ (π × minimal internal iTEV diameter ÷ 22). HV index strongly correlated with the pressure gradient across iTEV, which tended to improve during the tissue generation period up to 12 months post-implantation. Time-course changes in HV index reflected iTEV tissue development and in-vivo characteristics, such as hemodynamic congestion. In conclusion, HV index is useful to assess iTEV graft function because it represents both the morphometrics and hemodynamics of iTEV with only diagnostic imaging data.
The COVID-19 pandemic has caused Japanese workers psychological distress through crises of health, economics, and social relationships. To assess whether these effects are amplified by the gender ...bias that exists in Japan, we examined male and female worker’s psychological distress and difficulties during the pandemic. An online “COVID-19-related difficulties” questionnaire, based on item response theory, gathered responses from 3464 workers in October and November 2020. The workers’ psychological distress was found concerned to be significantly worse than before the pandemic. Basic stressors related to infection anxiety, economic anxiety, and restrictions on social interactions and outings. Men’s and women’s experiences of difficulties were consistent with traditional gender roles in Japan: men were more likely to face job-related stressors, such as economic insecurity and work-style changes; women were more likely to face non-job-related stressors, such as increased living costs and reduced social interactions. Policymakers and employers should consider the association between gender differences and industry types, and implement measures to strengthen the acceptability of mental health care.
Many individuals who were affected by the Great East Japan earthquake and tsunami and the subsequent Fukushima Daiichi Nuclear Power Plant accident continue to face a challenging recovery. We ...reviewed the long-term mental health consequences of three major nuclear power plant accidents: the Three Mile Island (TMI, 1979), Chernobyl (1986), and Fukushima (2011) nuclear disasters. We examined the relevant prospective cohort studies and before-and-after studies that covered more than two timepoints, searching four databases (PubMed, Ichushi, PsyArticles, and PTSDPub). We identified a total of 35 studies: TMI, n = 11; Chernobyl, n = 6; and Fukushima, n = 18. The smaller numbers of early-phase studies (within 6 months) of the Chernobyl and Fukushima disasters may also indicate the chaotic situation at those timepoints, as large-scale interviews were conducted in the early phase after the TMI disaster. Although the patterns of effects on mental health outcomes were diverse, more than half of the participants in the studies we evaluated were categorized into low or under-threshold symptom groups in all three disasters. Across the three disasters, the radiation exposure level estimated by the proximity and stigma were the common risk factors for mental health outcomes. Our findings will contribute to a comprehensive understanding of the impact of the worst nuclear accidents in history on the affected individuals’ mental health, and our results illustrate the longitudinal consequences of such disasters.
Using anticancer drugs as examples, we examined the possibility of reusing residual drugs. The use of residual drugs is not widespread owing to concerns regarding bacterial contamination. We combined ...anticancer drugs and bacteria to investigate their effects on bacterial growth. The anticancer drugs carboplatin, paclitaxel, etoposide, irinotecan, methotrexate, and 5-fluorouracil (5-FU) were mixed with Staphylococcus aureus, Enterococcus faecalis, Serratia marcescens, and Escherichia coli. After a certain period, the bacteria were counted. Irinotecan showed no antibacterial activity, whereas 5-FU exhibited high antibacterial activity against the tested bacteria. The 5-FU also showed a minimum inhibitory concentration value in the range of 8–80 μg/mL, depending on the bacterial species. 5-FU dose-dependently inhibited S. aureus growth at more than 0.8 µg/mL. Because protein synthesis systems are reportedly antibiotic targets, we used a cell-free protein synthesis system to confirm the mechanism of the antibacterial activity of the anticancer agent. 5-FU and methotrexate had direct inhibitory effects on protein synthesis. It has been suggested that even if residual drugs are contaminated with bacteria, there will be no microbial growth, or the microbes will be killed by the drug. With careful monitoring, 5-FU can potentially be used for antimicrobial purposes.
Routine therapeutic drug monitoring is a promising approach for the rational use of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and anaplastic lymphoma kinase (ALK) ...inhibitors. The purpose of this study was to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of 5 EGFR-TKIs (afatinib, dacomitinib, erlotinib, gefitinib, and osimertinib) and 3 ALK inhibitors (alectinib, ceritinib, and crizotinib).
A 100-mL aliquot of serum was diluted with 100 μL of 1% aqueous ammonia containing internal standards and then purified using the supported liquid extraction method. LC-MS/MS was conducted in positive ionization mode, and the method was validated according to published guidelines.
Calibration curves were linear across concentration ranges examined. The intra- and interassay accuracies were 90.7%-110.7% and 94.7%-107.6%, respectively. All intra- and interassay imprecision values were ≤10.1%. The EGFR-TKIs and ALK inhibitors examined in this study, except osimertinib, which could be stored on ice for at least 5 hours, were stable at room temperature for 3 hours. For the internal standard-normalized matrix factors, the mean recovery and percent coefficient of variation values ranged between 54%-112% and 1.7%-11.7%, respectively. This method successfully determined serum concentrations of afatinib, alectinib, erlotinib, gefitinib, and osimertinib in clinical samples. Serum levels of kinase inhibitors consistently reflected those reported in previous studies.
An LC-MS/MS method suitable for the simultaneous determination of 5 EGFR-TKIs and 3 ALK inhibitors in serum was developed and validated. The newly developed method enabled the determination of 5 of 8 target drugs examined in clinical samples. However, a large number of clinical samples need to be analyzed to verify the usefulness of the method.
When a voltage applied between a pair of metal electrodes is increased in gas atmosphere, gas discharge breakdown occurs at a certain voltage (a breakdown voltage). This voltage depends on gas ...species. In other words, gas sensing possible by measuring their breakdown voltages. However, voltage for gas discharge breakdown using conventional metal electrode is generally high under atmospheric pressure. Thus, reduction of the discharge voltage is desirable for the application mentioned above. This study aims at considering possibility to develop gas sensing method by detecting gas discharge breakdown occurring at a relatively low voltage. Electrodes on which carbon nanotubes (CNTs) were attached were used for this purpose. CNTs possess fibrous shapes with nano-sized tip radii. This shape generates very high electric field on the tip. The high field enables reduction of the breakdown voltage. Our results showed that the electrode with CNTs gave dependence of gas discharge breakdown voltages on gas species with relatively lower applied voltages. The breakdown voltage linearly changed with respect to composition ratios of gas mixtures. It is considered that these characteristics originate in field emission electrons from the CNTs.
Following the Paris Agreement in 2015, the worldwide focus on global warming countermeasures has intensified. The Japanese government has declared its aim at achieving carbon neutrality by 2050. The ...concept of zero-energy buildings (ZEBs) is based on measures to reduce energy consumption in buildings, the prospects of which are gradually increasing. This study investigated the annual primary energy consumption; as well as evaluated, renewed, and renovated buildings that had a solar power generation system, and utilized solar and geothermal heat. It further examines the prospects of hydrogen production from on-site surplus electricity and the use of hydrogen fuel cells. A considerable difference was observed between the actual energy consumption (213 MJ/m2), and the energy consumption estimated using an energy simulation program (386 MJ/m2). Considerable savings of energy were achieved when evaluated based on the actual annual primary energy consumption of a building. The building attained a near net zero-energy consumption considering the power generated from the photovoltaic system. The study showed potential energy savings in the building by producing hydrogen, using surplus electricity from on-site power generation, and introducing hydrogen fuel cells. It is projected that a building’s energy consumption will be lowered by employing the electricity generated by the hydrogen fuel cell for standby power, water heating, and regenerating heat from the desiccant system.
From the perspective of oligopoly theory, this paper clarifies the effectiveness of ambient charges as a policy measure for reducing industrial non-point source pollution. Ganguli and Raju argue that ...ambient charges have perverse effects in the context of Bertrand competition. By contrast, this paper examines the effects of ambient charges in the context of Cournot competition, clarifying that they are an effective policy measure. The result presented here is consistent with previous results in the field of experimental economics.
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