Ultrasound therapy for a week promotes regeneration and reduces pro-inflammatory macrophages in a rat sciatic nerve autograft model.

Peripheral nerve injury causes long-term motor dysfunction. Ultrasound (US) therapy is expected to accelerate peripheral nerve regeneration. However, its optimal usage and effects on macrophage phenotypes during peripheral nerve regeneration remain unknown. In this study, we investigated the optimal duration of US therapy and its effects on macrophage phenotype. Twenty-seven rats with autologous sciatic nerve grafting were divided into three groups: two received US therapy (1 MHz frequency, intensity of 140 mW/cm2, 20% duty cycle, 5 min/day) for one (US1) or 4 weeks (US4), and one group received sham stimulation. Immunohistochemistry was performed 3 and 7 days after injury in another set of 12 rats. Eight weeks after the injury, the compound muscle action potential amplitude of the gastrocnemius in the US1 and US4 groups was significantly higher than that in the sham group. The toe-spreading test showed functional recovery, whereas the gait pattern during treadmill walking did not recover. There were no significant differences in motor function, histomorphometry, or muscle weight between groups. Immunohistochemistry showed that US therapy decreased the number of pro-inflammatory macrophages seven days after injury. Therefore, US therapy for both one or 4 weeks can similarly promote reinnervation and reduce proinflammatory macrophages in autograft model rats.

Differences in physical activity and mental function according to the employment status of elderly Japanese.

OBJECTIVES: In recent years, the employment statuses of the elderly have become more diverse, and it is important to investigate the differences in health status according to employment statuses. This study aimed to examine the differences in physical activity and mental function among elderly Japanese according to their employment status and to examine the differences between men and women. METHODS: This cross-sectional study used an online questionnaire. The participants were persons aged ≥60 years. Data on their sociodemographic indicators, employment status, physical activity, and mental function were collected. They were classified into six groups according to their employment status: being employed, completely retired, re-hired at the same workplace, re-hired at a different workplace, early retirement, and working at a job without a mandatory retirement age. Differences in the surveyed items according to employment status were compared using the Kruskal-Wallis test. RESULTS: The total number of participants in the analysis with complete responses was 1552 (1207 men and 345 women; mean age 67.8 ± 5.9 years). The results revealed that among men, those who were re-hired at different workplaces had higher walking physical activity, and retirees and early retirees had longer sedentary time and lower sense of self-usefulness. There was no clear difference among women according to their employment status. CONCLUSIONS: The results suggest that physical activity and mental function among older adults may differ according to their employment status, especially for men. Employment among the elderly may play an important role in maintaining their physical activity and mental function.

Explanation of hand, foot, and mouth disease cases in Japan using Google Trends before and during the COVID-19: infodemiology study.

BACKGROUND: Coronavirus Disease 2019 (COVID-19) pandemic affects common diseases, but its impact on hand, foot, and mouth disease (HFMD) is unclear. Google Trends data is beneficial for approximate real-time statistics and because of ease in access, is expected to be used for infection explanation from an information-seeking behavior perspective. We aimed to explain HFMD cases before and during COVID-19 using Google Trends. METHODS: HFMD cases were obtained from the National Institute of Infectious Diseases, and Google search data from 2009 to 2021 in Japan were downloaded from Google Trends. Pearson correlation coefficients were calculated between HFMD cases and the search topic "HFMD" from 2009 to 2021. Japanese tweets containing "HFMD" were retrieved to select search terms for further analysis. Search terms with counts larger than 1000 and belonging to ranges of infection sources, susceptible sites, susceptible populations, symptoms, treatment, preventive measures, and identified diseases were retained. Cross-correlation analyses were conducted to detect lag changes between HFMD cases and search terms before and during the COVID-19 pandemic. Multiple linear regressions with backward elimination processing were used to identify the most significant terms for HFMD explanation. RESULTS: HFMD cases and Google search volume peaked around July in most years, excluding 2020 and 2021. The search topic "HFMD" presented strong correlations with HFMD cases, except in 2020 when the COVID-19 outbreak occurred. In addition, the differences in lags for 73 (72.3%) search terms were negative, which might indicate increasing public awareness of HFMD infections during the COVID-19 pandemic. The results of multiple linear regression demonstrated that significant search terms contained the same meanings but expanded informative search content during the COVID-19 pandemic. CONCLUSIONS: The significant terms for the explanation of HFMD cases before and during COVID-19 were different. Awareness of HFMD infections in Japan may have improved during the COVID-19 pandemic. Continuous monitoring is important to promote public health and prevent resurgence. The public interest reflected in information-seeking behavior can be helpful for public health surveillance.

Stereoscopy in Dental Education: An Investigation.

The aim of this study was to investigate whether stereoscopy can play a meaningful role in dental education. The study used an anaglyph technique in which two images were presented separately to the left and right eyes (using red/cyan filters), which, combined in the brain, give enhanced depth perception. A positional judgment task was performed to assess whether the use of stereoscopy would enhance depth perception among dental students at Osaka University in Japan. Subsequently, the optimum angle was evaluated to obtain maximum ability to discriminate among complex anatomical structures. Finally, students completed a questionnaire on a range of matters concerning their experience with stereoscopic images including their views on using stereoscopy in their future careers. The results showed that the students who used stereoscopy were better able than students who did not to appreciate spatial relationships between structures when judging relative positions. The maximum ability to discriminate among complex anatomical structures was between 2 and 6 degrees. The students' overall experience with the technique was positive, and although most did not have a clear vision for stereoscopy in their own practice, they did recognize its merits for education. These results suggest that using stereoscopic images in dental education can be quite valuable as stereoscopy greatly helped these students' understanding of the spatial relationships in complex anatomical structures.

Bonding effectiveness of self-adhesive and conventional-type adhesive resin cements to CAD/CAM resin blocks. Part 1: Effects of sandblasting and silanization.

The present study assessed the effect of sandblasting and silanization on resin cement bond strengths to CAD/CAM resin blocks. Twenty four blocks (KATANA AVENCIA BLOCK) were divided into two resin cement groups (PANAVIA V5 [PV5] and PANAVIA SA CEMENT HANDMIX [PSA]), and further divided into four subgroups representing different surface treatment methods: no treatment (Ctl), silanization (Si), sandblasting (Sb), and Sb+Si. After resin application, microtensile bond strengths (µTBSs) were measured immediately, 1, 3 and 6 months after water storage. In addition, surfaces resulting from each of the treatment methods were analyzed by scanning electron microscopy (SEM). Three-way analysis of variance revealed a statistically significant effect for the parameters 'surface treatment' (p<0.001, F=370), 'resin cement' (p<0.001, F=103, PSA

Bonding effectiveness of self-adhesive and conventional-type adhesive resin cements to CAD/CAM resin blocks. Part 2: Effect of ultrasonic and acid cleaning.

The present study assessed the effect of ultrasonic and acid cleaning on resin cement bonding to CAD/CAM resin blocks. One of two resin cements, PANAVIA V5 (PV5) or PANAVIA SA CEMENT HANDMIX (PSA), were bonded to one of 24 CAD/CAM blocks (KATANA AVENCIA BLOCK). Each cement group was divided into four subgroups: no cleaning (Ctl), ultrasonic cleaning (Uc), acid cleaning (Ac) and Uc+Ac. Micro-tensile bond strengths (µTBSs) were measured immediately and 1, 3, and 6 months after water storage. Block surfaces after each treatment were analyzed by scanning electron microscopy. Analysis of variance revealed a statistically significant effect for the parameters 'surface treatment' (p<0.001, F=40), 'resin cement' (p<0.001, F=696) and 'water aging' (p<0.001, F=71). The PV5 group exhibited higher µTBS values than the PSA group. Although cleaning after sandblasting was effective in removing residual alumina particles, it did not affect the long-term bonding durability with non-contaminated CAD/CAM resin blocks.

Nondestructive observation of teeth post core-space using optical coherence tomography: comparison with microcomputed tomography and live images.

No previous reports have observed inside the root canal using both optical coherence tomography (OCT) and x-ray microcomputed tomography (µCT) for the same sample. The purpose of this study was to clarify both OCT and µCT image properties from observations of the same root canal after resin core build-up treatment. As OCT allows real-time observation of samples, gap formation may be able to be shown in real time. A dual-cure, one-step, self-etch adhesive system bonding agent, and dual-cure resin composite core material were used in root canals in accordance with instructions from the manufacturer. The resulting OCT images were superior for identifying gap formation at the interface, while µCT images were better to grasp the tooth form. Continuous tomographic images from real-time OCT observation allowed successful construction of a video of the resin core build-up procedure. After 10 to 12 s of light curing, a gap with a clear new signal occurred at the root-core material interface, proceeding from the coronal side (6 mm from the cemento-enamel junction) to the apical side of the root.