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Innovation and entrepreneurship as the core development mode is the only way to continue my country's economic development. Therefore, research on the synergistic impact of innovation on China's economic development is of great significance. With the continuous development of sharing economy, Internet finance, and other fields, the digital economy is reshaping the entire social ecology and becoming an important part of the national economy. Aiming at China's digital economy, this article takes the Shanghai Composite Index and three listed stocks in the stock market as examples, collects the closing data of the Shanghai Composite Index and the stock market prices of three listed companies as sample data, uses the BP neural network prediction model and the optimized particle swarm optimization-neural networks (PSO-BP) neural network model predicts the future trends of the Shanghai Composite Index and the three stocks, respectively. Compared with other models, PSO-BP requires fewer parameters and draws more accurate conclusions. It is a model that is very suitable for digital economic forecasting. The experimental results show that the prediction effect of the PSO-BP neural network is higher than that of the BP neural network prediction model obtained by the two prediction models in the prediction process of the Shanghai Composite Index; the error rate of the BP neural network prediction model in the three listed stocks 6.37%, 3.01%, 9.85%; PSO-BP neural network prediction model predicts the future trend of the three listed stocks with error rates of 3.21%, 0.37%, and 0.89%. After comparing and analyzing the results of the forecast error value, it is concluded that the PSO-BP neural network forecast model has a more accurate forecast of stock prices and smaller errors, and the forecast of future trends is also consistent with actual trends. [ABSTRACT FROM AUTHOR]

To evaluate the relationship between exposure to air pollutants and respiratory emergency room visits, a generalized additive model (GAM) was used to analyze the exposure-effect relationship between air pollutants and respiratory emergency room visits. The results showed that NO, SO, and PM have positive relationships with respiratory disease. Concentration increases of 10 μg/m in NO, SO, and PM corresponded to 3.90% (95%CI 3.56-4.25), 0.81% (95%CI −0.09-1.72), and 0.64% (95%CI 0.55-0.74) increases in respiratory emergency room visits. In addition, there is a strong synergic effect of PM and NO on respiratory diseases. The threshold values of the national standard grade II limits used in Beijing should be adjusted. An appropriate standard could effectively promote a significant decline in respiratory room visits and would eventually be beneficial to air quality management in residential areas. [ABSTRACT FROM AUTHOR]

This mediation analysis aimed to investigate the associations among areal bone mineral density, mobility-related brain atrophy, and specific gait patterns. A total of 595 participants from the Taizhou Imaging Study, who underwent both gait and bone mineral density measurements, were included in this cross-sectional analysis. We used a wearable gait tracking device to collect quantitative gait parameters and then summarized them into independent gait domains with factor analysis. Bone mineral density was measured in the lumbar spine, femoral neck, and total hip using dual-energy X-ray absorptiometry. Magnetic resonance images were obtained on a 3.0-Tesla scanner, and the volumes of brain regions related to mobility were computed using FreeSurfer. Lower bone mineral density was found to be associated with higher gait variability, especially at the site of the lumbar spine (β = 0.174, FDR = 0.001). Besides, higher gait variability was correlated with mobility-related brain atrophy, like the primary motor cortex (β = 0.147, FDR = 0.006), sensorimotor cortex (β = 0.153, FDR = 0.006), and entorhinal cortex (β = 0.106, FDR = 0.043). Bidirectional mediation analysis revealed that regional brain atrophy contributed to higher gait variability through the low lumbar spine bone mineral density (for the primary motor cortex, P = 0.018; for the sensorimotor cortex, P = 0.010) and the low lumbar spine bone mineral density contributed to higher gait variability through the primary motor and sensorimotor cortices (P = 0.026 and 0.010, respectively). [ABSTRACT FROM AUTHOR]

In radio-frequency (RF) transceiver system, the receiver is used to convert RF signal to low/medium frequency for signal processing and information gathering. In the paper, a novel high-gain, low-noise CMOS mixer is designed and analyzed. In the design, gain-boosting and PMOS dynamic switching current are employed to achieve better effects of noise cancellation and trans-conductance enhancement. In order to improve the mixer's performance, the designed structure is mainly based on the double-balanced Gilbert lattice mixer combined with the parallel LC resonant and optimum biasing networks. The mixer shows high conversion gain (CG), low noise figure (NF), and low power consumption performances based on made possible by 90-nm CMOS technology. Operated at 77 GHz, the input third-order intercept point (IIP3) is −6.14 dBm, and the maximum conversion gain is 18.4 dB. At an IF frequency of 200 MHz, a bilateral band noise figure of 9.2 dB is recorded, while 6.96 mW is consumed with 1.2-V and 2-dBm LO power. [ABSTRACT FROM AUTHOR]

A broadband circularly polarized (CP) printed monopole antenna which fed by coplanar waveguide (CPW) is proposed in the paper. The structure of the novel antenna includes a quarter circular disc radiating monopole, a coupled circular patch, and a bent L-shaped microstrip stub line. The L-shaped microstrip stub line is used to widen the impedance bandwidth and generate a horizontal component of the electromagnetic wave. The adoption of the asymmetric ground coplanar waveguide structure with the single-feed technology and the coupled circular patch, simultaneously achieve wide impedance bandwidth and wide axial ratio (AR) bandwidth. The structure parameters and the surface current of the designed antenna are analysed. The simulation and the measurement are conducted, showing good characterizations of the designed antenna. The 10-dB impedance bandwidth is 7.57 GHz, the fractional bandwidth from 6.05 to 13.62 GHz is 76.9%, the 3-dB axial ratio bandwidth is 3.01 GHz, and the fractional bandwidth from 6.05 to 9.06 GHz is 39.8%. The antenna can generate right/left hand circularly polarized waves in the direction of ± z axis. The designed antenna has wide applications in the fields of Internet of Things (IoT), broadband dual-CP communication systems and polarization diversity systems, wireless personal area network and other advanced communication systems. [ABSTRACT FROM AUTHOR]

Asymptomatic brain abnormalities are common incidental findings on brain MRI in the elderly population and can be regarded as imaging markers of early stroke and dementia. We initiated the Taizhou Imaging Study (TIS) to examine the prevalence and correlates of incidental findings using brain MRI among an elderly population residing in a rural area of China. A total of 562 individuals, at the age of 55 to 65 years, participated in the TIS study with a response rate of 90%. The prevalence of lacunes, white matter hyperintensity (WMH), cerebral microbleeds (CMB), perivascular space, and intracranial arterial stenosis was 26.69%, 10.68%, 18.51%, 27.76%, and 12.81%, respectively. Age and hypertension were the major correlates of these incidental findings. Per each year increase in age, the risks of WMH and CMB increased by 15% and 14%. Compared to individuals with normal blood pressure, individuals with hypertension had an increased risk of all incidental findings, with the adjusted odds ratios of 2.28 to 5.45. Correlations of age, gender and body mass index with brain gray matter fraction were also observed. The high prevalence of these findings indicates a need of preventative strategy to help prevent future stroke and dementia in this population. [ABSTRACT FROM AUTHOR]