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Effect of vaccine booster dose on coronavirus disease 2019 prevention by age group: Analysis of data collected at polymerase chain reaction centers in Hiroshima Prefecture, Japan
No full textFor three years, the world has faced the coronavirus disease (COVID-19) pandemic, and vaccination against severe acute respiratory syndrome coronavirus 2 remains the best defense. In Japan, vaccination with a booster dose started in early December, with healthcare workers receiving priority, followed by elderlies aged > 65 years. We aimed to assess the effectiveness of vaccine boosters in preventing infection in various age groups of Japanese people in Hiroshima. A pre-administered questionnaire, the J-SPEED-style COVID-19 polymerase chain reaction (PCR) center version, was used to collect data from PCR centers in Hiroshima Prefecture between February 1, 2022 and March 17, 2022. The highest infection rate was observed in those aged between 10 and 19 years (6.0%), whereas the lowest infection rate was observed in those aged 45–64 years and > 65 years (3.3%). For all age groups, three doses of the vaccine provided lower infection rates than two doses. Elderlies aged > 65 years with booster doses (odds ratio [OR] = 0.499, 95% confidence interval [CI] = 0.400–0.622) were less infected compared to the same groups who received two doses, followed by those aged 45–64 years (OR = 0.663, 95% CI = 0.558–0.788) and 20–44 years (OR = 0.758, 95% CI = 0.655–0.877). In general, those aged > 65 years who received three doses (OR = 0.499, 95%CI = 0.400–0.622) were less likely to be infected with COVID-19 than those aged < 65 years (OR = 0.674, 95%CI = 0.604–0752). We analyzed the association between vaccination status and infection status; therefore, we recommend future research using data on the exact vaccination date and infection status
Gradient magnetic-oscillation topography depicts high-frequency oscillations on the brain surface related to the epileptic focus in intractable epilepsy with lesions
No full textThis study aimed to evaluate high-frequency oscillations (HFOs), a potential biomarker of epileptic activity, using magnetoencephalography (MEG). We developed a new spatial filter, termed “gradient magnetic-oscillation topography” (GMOT), to visualize color-coded topographies on the brain surface using a spectrogram calculated at each sensor level. We enrolled 15 patients with lesions and intractable neocortical epilepsy who underwent focal resection surgery and preoperative MEG. We compared GMOT findings with those of the equivalent current dipole (ECD) and resected area based on intracranial video-electroencephalography (IVEEG) or intraoperative electrocorticography (ECoG) with respect to seizure outcomes. We also calculated the proportion of the power of each sensor relative to the entire head at each frequency band. GMOT successfully visualized the high-power gradient magnetic field at the fast ripple band (FR band, 201–330 Hz) and detected the highest power at the FR band around the lesion in 13 of the 15 patients. The resected area included both clustered ECDs and the highest power in the FR band on GMOT in 9 of the 15 patients. The resected area had a statistically higher proportion of power as the frequency band increased in the HFO group (p < 0.01). We visualized high power in the FR band of the brain surface. The areas of highest power in the FR band were correlated with epileptic focus based on IVEEG and intraoperative ECoG
Binocular vision measurement system for geometric error of 3D printers at high temperature
No full textThe accuracy of material extrusion-based 3D printers is greatly affected by the high temperature in the chamber due to the thermal-induced deformation of components. However, most existing measurement equipment cannot be applied to high-temperature environments, which hinders the corresponding error measurement. To address this issue, a geometric error detection system and identification algorithm based on binocular vision are proposed. Firstly, a corner detection algorithm and a ray-intersection binocular model are used to identify the three-dimensional displacement of the target. Secondly, an error separation and identification algorithm is proposed to identify 21 position-dependent geometric errors. Error measurement experiments are conducted on a 3D printer at room temperature and high temperature, respectively. The experimental results at room temperature are verified using a double-ball bar. Finally, an error compensation experiment is conducted to verify the effectiveness of error identification, which also shows the contribution of error motions of linear axes on the printing accuracy.The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China (No. 52075337) and the State Key Laboratory of Mechanical System and Vibration (No. MSVZD202113)