The prevalence of hepatitis B in Chinese general population from 2018 to 2022: a systematic review and meta-analysis.

BACKGROUND: Within China, Hepatitis B virus (HBV) infection remains widely prevalent and one of the major public health problems. There have been only two previous estimates of its prevalence at the population level in China, with the latest survey conducted in 2006. A meta-analysis estimated the prevalence of HBV within China between 2013 and 2017 as 7%. This review provides an updated estimate of HBV prevalence in China from 2018 to 2022. METHODS: Systematic searches of literature from January 1, 2018 to December 25, 2022 were conducted in four international databases (Medline, Web of Science, Embase, Cochrane Database of Systematic Reviews) and three Chinese databases (CNKI, CBM, and WanFang data). Random-effects meta-analyses were conducted to calculate the pooled HBV prevalence with 95% confidence intervals in the overall population and subgroups. Publication bias, heterogeneity between studies, and study quality were assessed. RESULTS: Twenty-five articles were included in the meta-analysis. The pooled prevalence of HBV infection in the Chinese general population from 2018 to 2022 was 3% (95%CI: 2-4%). The prevalence of HBV infection was similar between males and females (both 3%), while rural areas had a higher prevalence than urban areas (3% vs 2%). The highest prevalence of HBV was reported in the eastern provinces (4, 95%CI: 2-6%). The HBV prevalence of people aged ≥18 years old (6, 95%CI: 4-8%) was higher than people aged < 18 years old (0, 95%CI: 0-1%). CONCLUSION: Compared to the previous meta-analysis prevalence in 2013-2017, the updated meta-analysis estimated prevalence of HBV infection (3%) from 2018 to 2020 showed a decreasing trend, suggesting China had moved into a lower intermediate epidemic area (2-5%). However, the prevalence of HBV in rural areas and eastern regions was still higher than the national average. People aged ≥18 years old showed a higher HBV prevalence. HBV prevention should be prioritized in the highest-prevalence areas and high-risk populations. Due to heterogeneity in data collection methods among studies, there remains a need for systematic surveillance of nationwide HBV prevalence.

Unsupervised cluster analysis reveals distinct subgroups in healthy population with different exercise responses of cardiorespiratory fitness.

Background: Considerable attention has been paid to interindividual differences in the cardiorespiratory fitness (CRF) response to exercise. However, the complex multifactorial nature of CRF response variability poses a significant challenge to our understanding of this issue. We aimed to explore whether unsupervised clustering can take advantage of large amounts of clinical data and identify latent subgroups with different CRF exercise responses within a healthy population. Methods: 252 healthy participants (99 men, 153 women; 36.8 ± 13.4 yr) completed moderate endurance training on 3 days/week for 4 months, with exercise intensity prescribed based on anaerobic threshold (AT). Detailed clinical measures, including resting vital signs, ECG, cardiorespiratory parameters, echocardiography, heart rate variability, spirometry and laboratory data, were obtained before and after the exercise intervention. Baseline phenotypic variables that were significantly correlated with CRF exercise response were identified and subjected to selection steps, leaving 10 minimally redundant variables, including age, BMI, maximal oxygen uptake (VO2max), maximal heart rate, VO2 at AT as a percentage of VO2max, minute ventilation at AT, interventricular septal thickness of end-systole, E velocity, root mean square of heart rate variability, and hematocrit. Agglomerative hierarchical clustering was performed on these variables to detect latent subgroups that may be associated with different CRF exercise responses. Results: Unsupervised clustering revealed two mutually exclusive groups with distinct baseline phenotypes and CRF exercise responses. The two groups differed markedly in baseline characteristics, initial fitness, echocardiographic measurements, laboratory values, and heart rate variability parameters. A significant improvement in CRF following the 16-week endurance training, expressed by the absolute change in VO2max, was observed only in one of the two groups (3.42 ± 0.4 vs 0.58 ± 0.65 ml⋅kg-1∙min-1, P = 0.002). Assuming a minimal clinically important difference of 3.5 ml⋅kg-1∙min-1 in VO2max, the proportion of population response was 56.1% and 13.9% for group 1 and group 2, respectively (P<0.001). Although group 1 exhibited no significant improvement in CRF at group level, a significant decrease in diastolic blood pressure (70.4 ± 7.8 vs 68.7 ± 7.2 mm Hg, P = 0.027) was observed. Conclusions: Unsupervised learning based on dense phenotypic characteristics identified meaningful subgroups within a healthy population with different CRF responses following standardized aerobic training. Our model could serve as a useful tool for clinicians to develop personalized exercise prescriptions and optimize training effects.

Crystalline Silicon White Light Sources Driven by Optical Resonances.

Silicon (Si) is generally considered as a poor photon emitter, and various scenarios have been proposed to improve the photon emission efficiency of Si. Here, we report the observation of a burst of the hot electron luminescence from Si nanoparticles with diameters of 150-250 nm, which is triggered by the exponential increase of the carrier density at high temperatures. We show that the stable white light emission above the threshold can be realized by resonantly exciting either the mirror-image-induced magnetic dipole resonance of a Si nanoparticle placed on a thin silver film or the surface lattice resonance of a regular array of Si nanopillars with femtosecond laser pulses of only a few picojoules, where significant enhancements in two- and three-photon-induced absorption can be achieved. Our findings indicate the possibility of realizing all-Si-based nanolasers with manipulated emission wavelength, which can be easily incorporated into future integrated optical circuits.