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Analysis of Ozone Decomposition Rate for Evaluating Surface Partial Discharge Activities in Large-Scale Industrial Motors
Get PDFThis paper analyzes ozone decomposition coefficients and estimates the half-life time concerning insulation degradation diagnostics for large-scale industrial motors by monitoring ozone concentration. Partial discharges (PDs) that lead to the deterioration of insulation materials are significant on the surface of the semiconducting layer in the stator slots, and they appear at the coil ends. Simultaneously, the ozone generated by external PDs diffused into the motor frame. The amount of ozone generated per unit time represents the activity of the external PDs. The ozone generation and decomposition rates are equal at a steady state; therefore, the ozone generation rate is obtained from the ozone decomposition rate. However, the ozone decomposition coefficient due to collisions with water vapor has not yet been determined. The ozone decomposition rate due to collisions with the chamber vessels must be determined individually. Ozone decomposition rates are investigated based on the background described above. This study presents the ozone decomposition rates due to collisions with water vapor and the chamber vessel, analyzed from data in literature. The humidity effect coefficient obtained is approximately 2.75× 10-23 s-1cm3/ particle. The wall effect depends on the configuration and material of the chamber vessel. The halflife time is estimated using the analyzed coefficients and correlates well with the measured data.IEEE Transactions on Dielectrics and Electrical Insulation, doi: 10.1109/TDEI.2025.3564585.journal articl
Impact of COVID-19 vaccination by implementation timing and coverage rate in relation to misinformation prevalence in Japan
Get PDFCOVID-19 vaccines have saved many lives during the pandemic. However, the implementation strategy of vaccination in some countries may not have been ideal. In this study, we investigated the impact of vaccination on COVID-19 mortality in counterfactual scenarios for different vaccine implementation timings and coverage in Japan. To do so, we developed a mathematical model to predict the number of COVID-19 deaths using weekly data on COVID-19 cases, vaccination coverage, vaccine effectiveness, and the proportion of SARS-CoV-2 variants. We also reanalyzed survey data from our previous study about the prevalence of misinformation beliefs and attitudes toward COVID-19 vaccination, in order to build counterfactual scenarios in which we had managed misinformation better or worse. In Japan, the COVID-19 death toll was 14,994 in 2021 before the emergence of the Omicron variant in December. Counterfactual scenario simulations using the mathematical model revealed that 30,117 deaths were averted by vaccination in 2021, considering the direct and indirect effects of vaccines. If we had failed to manage the influence of misinformation, vaccination coverage would have dropped from 83.4 % to 76.6 %. And there would have been 1020 more deaths. The death toll could have decreased by 431 in a scenario for better misinformation management, assuming vaccination coverage of 88.0 %. Three-month delayed vaccination implementation would have increased the death toll by 22,216, whereas three-month early implementation would have averted 7003 deaths. Therefore, implementation timing had a stronger effect than vaccination coverage. This study highlights the importance of assessing vaccination strategies from the perspective of misinformation management and timing to start vaccination rollout.Vaccine, 59, art. no. 127273; 2025journal articl
Development of a new ambulatory oxygen delivery method combining continuous oxygen flow and demand oxygen delivery system: A prospective, single-blind, randomized crossover trial
No full textBackground and objective: Although demand oxygen delivery system (DODS) prolongs ambulatory oxygen supply, the efficacy of preventing hypoxemia is likely to be lower than continuous oxygen flow (CF). We developed a new oxygen delivery method combining CF and DODS (CF + DODS). This study aimed in comparing the efficacy between conventional oxygen delivery methods and a new method during walking in patients with COPD. Methods: We conducted three-treatment crossover study. Stable COPD patients performed three 6-min walk tests (6MWT) with different oxygen delivery methods in random order with CF, DODS, and CF + DODS. Results: Twenty-six COPD patients were included in the study. The linear mixed model on SpO2 revealed significant main effects of oxygen conditions (P < 0.001) and exercise time (P < 0.001), however no significant interaction (P = 0.537). In the post-hoc analysis, SpO2 in DODS was significantly lower than in CF and CF + DODS throughout the 6MWT. CF and CF + DODS showed no significant differences in SpO2 at any exercise timepoint. There were no significant differences among each oxygen delivery method in walking distance and dyspnea before and after 6MWT. DODS utilized significantly less oxygen than CF and CF + DODS, and CF + DODS consumed significantly less oxygen than CF during 6MWT. Conclusion: CF + DODS enables a longer duration of oxygen supply, while preventing hypoxemia to the same degree as CF. These findings suggest that CF + DODS promotes outdoor activities in daily living while preventing hypoxemia in patients with COPD. Trial registration: This study was registered in the UMIN Clinical Trials Registry (UMIN00005299).Respiratory Medicine, 243, art. no. 108140; 2025journal articl
Elucidating the mechanisms of insecticide resistance in malaria vector populations from four endemic countries in Sub-Saharan Africa
Get PDF長崎大学学位論文 [学位記番号]共博（Global Health）甲第13号 [学位授与年月日]令和7年3月24日(2025-03-24)thesi
Mode of antiviral action of the galactose-specific lectin, AJLec, on the Junin virus propagation
No full textJunin virus (JUNV), a member of Arenaviridae, is the causative agent of Argentine hemorrhagic fever (AHF). Available AHF treatments are limited; therefore, development of effective and safe treatments is required. Thus, in this study, novel lectins were examined for anti-JUNV activity. To evaluate JUNV propagation, a recombinant Junin virus vaccine strain (r3Candid #1/ZsGreen) containing the ZsGreen gene as a marker in the viral genome was used. The anti-JUNV effects of four types of marine organism-derived lectins collected in Japan, including the Nagasaki Prefecture, were examined. AJLec, which was extracted from the Sea Anemone Anthopleura japonica, reduced the number of infected cells and viral production. Infection and infection-surrogate assays revealed that incubation of AJLec with viruses and cells before infection, and maintaining it during infection, was required to exhibit full antiviral activity. Moreover, the anti-JUNV activity of AJLec was suppressed by the addition of lactose; hence, the anti-JUNV activity of AJLec was a result of its galactose recognition. This indicates the importance of galactose on the surface of the Junin virion and the cell membrane for entry into cells. Overall, these results provide new insights into the anti-JUNV activity of AJLec. Particularly, the potential of lectins as new antiviral agents that inhibit pathogenic arenavirus replication and propagation is promising.Antiviral Research, 240, art. no. 106189; 2025journal articl
Understanding public trust in information about interim nuclear waste storage: The roles of acceptance, gender, and proximity
Get PDFFollowing the accident at the Fukushima Daiichi Nuclear Power Station in March 2011, the Japanese government implemented extensive decontamination and waste management measures, including the establishment of an interim storage facility in Okuma and Futaba. This study aims to analyze residents’ trust in the information provided by the public authorities regarding this facility and to identify factors influencing that trust. A survey was conducted among 1,558 former residents of Tomioka, Okuma, and Futaba who were 18 years or older and held resident cards for one of these towns in both March 2011 and 2024. The questionnaire collected data on demographic variables; intention to return; thoughts on the storage facility; trust in public information; concerns about radiation-related genetic risks and negative perceptions due to the nuclear accident; and mental health status, assessed using the mental component of the SF-8 health survey. The results showed that 57.7% of respondents trusted the information provided by the public authorities regarding the storage facility. Factors significantly associated with trust included their acceptance of the facility, lack of concerns about radiation-related genetic risks, lack of concerns about negative images resulting from the nuclear accident, and good mental health status. A logistic regression analysis indicated that acceptance of the facility and good mental health significantly increased the likelihood of trusting information provided by the public authorities, while concerns about genetic risks and negative images significantly decreased it. These findings underscore the vital importance of recognizing and addressing residents’ concerns about health risks and negative perceptions related to nuclear waste management. By supporting the mental well-being of the community and fostering transparent communication, authorities can build trust and improve the acceptance of waste management facilities. Actively engaging with residents and responding to their worries facilitates the identification of adequate and acceptable recovery efforts after a nuclear accident.PLoS One, 20(5), art. no. e0323896; 2025journal articl
Associations between pathological features and radioactive iodine-refractory recurrent papillary thyroid carcinoma: with mutation analysis using recurrent samples
Get PDFBackground: Although papillary thyroid carcinomas (PTC) are usually indolent in nature and clinically controllable, two-thirds of metastatic diseases become radioactive iodine-refractory (RAI-R). This study aimed to determine the role of pathological features, BRAFV600E, TERT promoter (TERT-p), and their combinations on Vietnamese patients with RAI-R recurrent PTC. Methods: This cross-sectional study included 174 cases of locoregional recurrent PTC, including 135 and 39 RAI-R and RAI-avid (RAI-A) cases, respectively. Logistic regression analyses were used to evaluate the associations between pathological features, mutations, and RAI-R with tissues from recurrent lesions. Results: Loss of polarity/loss of cell cohesiveness (LOP/LCC) component was exclusively observed in recurrent cancers in the RAI-R group. RAI-R was associated with BRAFV600E mutation, TERT-p mutation, BRAFV600E/TERT-p single mutant (Smut), BRAFV600E/TERT-p double mutant (Dmut), tall cell component, and mitosis ≥ 2/2 mm2 in the unadjusted logistic regression analysis. Multivariable logistic regression analysis revealed that BRAFV600E mutation and Dmut were independent predictors of RAI-R. The presence of Dmut (odds ratio [OR] = 6.64) was more significantly associated with RAI-R compared with that of Smut (OR = 2.75). There was a marginal association between tall cell > 5%, mitosis count ≥ 2/2 mm2 and RAI-R. The combination of BRAFV600E/tall cell components was the strongest predictor of RAI-R. Conclusions: RAI-R PTC cases were independently associated with BRAFV600E, Dmut. The association between Dmut and RAI-R PTC was stronger than that between Smut and RAI-R PTC. Future studies should focus on elucidating the role of mitotic count and LOP/LCC in RAI-R PTC.BMC Endocrine Disorders, 25(1), art. no. 134; 2025journal articl
Comparison of the inhibitory effects of tooth brushing and povidone-iodine mouthwash on salivary bacterial counts in patients undergoing surgery for malignant solid tumors other than head and neck cancers
Get PDFNagasaki University (長崎大学)博士(歯学)Background/purpose: Infectious complications after invasive surgeries may originate from oral sources through either hematogenous infection or direct exposure to salivary bacteria. Perioperative oral management aims to remove oral foci of infection. However, the type of oral care that can reduce the salivary bacterial load remains unclear. This study aimed to identify factors influencing salivary bacterial counts during the perioperative period in patients with malignant tumors and to evaluate the effectiveness of tooth brushing and povidone-iodine mouthwash in reducing oral bacterial counts. Materials and methods: Patients aged ≥18 years who underwent surgery under general anesthesia for malignant solid tumors other than head and neck cancer were included. Participants were randomly assigned to the brushing or povidone-iodine mouthwash groups. Factors such as sex, age, primary disease, preoperative blood-test results, oral functional metrics, and salivary bacterial counts were analyzed. Saliva samples were collected before and on the day after surgery, both before and after oral-care interventions. The total bacterial and streptococcal counts were determined using real-time polymerase chain reaction (PCR), and delayed real-time PCR was used to determine the viable bacterial count. Results: Postoperatively, the salivary bacterial counts increased slightly. Significant factors affecting postoperative bacterial counts included high preoperative counts and postoperative fasting status. Brushing increased salivary bacterial counts, whereas the povidone-iodine mouthwash decreased them. Conclusion: Poor preoperative oral hygiene and postoperative fasting were significantly associated with increased salivary bacterial counts. The povidone-iodine mouthwash reduced postoperative bacterial counts, indicating its effectiveness as a perioperative oral-care method.長崎大学学位論文 学位記番号:博(医歯薬)甲第1657号 学位授与年月日:令和7年3月19日Author: Moeko Nakamatsu, Sakiko Soutome, Yuichi Nakamura, Akira Imakiire, Masahiro UmedaCitation: Journal of Dental Sciences, 20(2), pp.854-861; 2025Nagasaki University (長崎大学), 博士(歯学) (2025-03-19)doctoral thesi
Molecular and phenotypic characterization of Streptococcus pneumoniae isolates in a Japanese tertiary care hospital
Get PDFNagasaki University (長崎大学)博士(医学)This study aimed to investigate the bacterial characteristics of pneumococcal isolates obtained from a tertiary care hospital in Japan. We analyzed the antimicrobial susceptibility, possession of macrolide resistance genes, pneumococcal serogroup/serotype, and sequence type (ST) of pneumococcal isolates from patients aged 15 years or older between 2011 and 2020 at Nagasaki University Hospital. Of the 73 isolates analyzed, 86.3% showed resistance to macrolides, and 28.8%, 46.6%, and 11.0% harbored mefA, ermB, and both, respectively. Of the isolates possessing ermB, 97.6% showed high levels of macrolide resistance [minimal inhibitory concentration (MIC) range, > 16 µg/mL]. Solithromycin (MIC range, 0.03–0.25 µg/mL), regardless of the presence of macrolide resistance genes, and lascufloxacin (MIC range, 0.06–0.5 µg/mL) showed potent in vitro activity against pneumococci. Serotype 19A was the most prevalent (six isolates), followed by serotypes 10A, 15A, and 15B/C (five isolates each). Four serotypes (11A, 19A, 22F, and 23B) and five STs (36, 99, 433, 558, and 3111) were significantly correlated with the presence of macrolide resistance genes. All four isolates with serotype 11A/ST99 and three isolates with serotype 19A/ST3111 harbored both mefA and ermB. No macrolide resistance genes were detected in either of the two isolates with serotype 22F/ST433, while all ten isolates with serogroup 15 (serotypes 15A and 15B/C, five isolates each) possessed ermB alone. Our study revealed the bacterial characteristics of the pneumococcal isolates obtained from our hospital. In vitro activity of solithromycin and lascufloxacin against these isolates was confirmed.長崎大学学位論文 学位記番号:博(医歯薬)甲第1660号 学位授与年月日:令和7年3月19日Author: Takumi Nakao, Kosuke Kosai, Norihiko Akamatsu, Kenji Ota, Fujiko Mitsumoto-Kaseida, Hiroo Hasegawa, Koichi Izumikawa, Hiroshi Mukae and Katsunori YanagiharaCitation: Frontiers in Cellular and Infection Microbiology, 14, art. no. 1391879 ; 2024Nagasaki University (長崎大学), 博士(医学) (2025-03-19)doctoral thesi
Comparison of risks of cancer, infection, and MACEs associated with JAK inhibitor and TNF inhibitor treatment: a multicentre cohort study
Get PDFNagasaki University (長崎大学)博士(医学)長崎大学学位論文 学位記番号:共博(医歯薬)甲第48号 学位授与年月日:令和7年3月19日Nagasaki University (長崎大学), 博士(医学) (2025-03-19)thesi