Search

Summary: Background: Since 1992, when recombinant hepatitis B vaccine was introduced in China, government health officials have used nationally representative serological surveys to monitor progress in prevention and control of hepatitis B. In 2020, we conducted the fourth seroepidemiological survey, which for the first time included medical evaluation of the clinical status of HBsAg positive subjects over the age of 15 and their medical management. We report survey results in comparison with the three previous surveys. Methods: Consistent with previous national surveys, the 2020 survey used a stratified, three-stage cluster random sampling method to select for evaluation 1-69-year-olds in 120 national disease surveillance points. Blood samples were tested for HBsAg, anti-HBV surface antigen (anti-HBs), and anti-HBV core antigen (anti-HBc) in the National Hepatitis Laboratory of the Institute for Viral Disease Control and Prevention of China CDC. HBsAg positive subjects aged ≥15-year were evaluated for evidence of liver disease, and through face-to-face questionnaire-based survey, we determined the healthcare management cascade of HBV-infected individuals. Findings: HBsAg prevalence in 1–69-year-olds was 5.86%; in children 1–4 years of age, seroprevalence was 0.30%; 75 million people were living with HBV nationwide. Among HBsAg-positive individuals 15 years and older, expert medical examination found that 78.03% were HBsAg carriers with no evidence of liver damage, 19.63% had chronic HBV with liver enzyme abnormalities, 0.84% had evidence of cirrhosis, and 0.15% had evidence of liver cancer. 59.78% of HBsAg + individuals were aware that they were positive before the survey, 30 million were unaware; 38.25% of those who knew they were positive (17 million) had medical indications for antiviral treatment, and 17.33% of these individuals (3 million) were being treated with antivirals. Interpretation: The decline in HBsAg prevalence in the general population, from 9.72% in 1992 to 5.86% in 2020, and in 1–4-year-olds from 9.67% in 1992 to 0.30% in 2020, shows progress that continues on track toward WHO targets for prevention of new infections. Implementation of acceptable strategies to identify infected individuals and offer long-term medical monitoring and management will be important to prevent complications from hepatitis B infection and for meeting WHO cascade-of-care targets. Funding: The study was funded by the Major Science and Technology Special Project of China’s 13th 5-Year Plan (grant no. 2017ZX10105015); Central finance-operation of public health emergency response mechanism of Chinese Center for Disease Control and Prevention (131031001000200001, 102393220020010000017).

【Objective】 Implementation of saving-water irrigation is a strategy affecting not only crop growth but also many other aspects directly or indirectly. How to comprehensively evaluate its consequence is an issue that remains largely elusive. The purpose of this paper is to fill this knowledge gap. 【Method】 A comprehensive evaluation system for water-saving irrigation projects was constructed, with its impacts on technical aspect, socioeconomic aspect, and ecological and environmental aspect taken into account. It considered irrigation precision and intelligence, economical return, and consequence for ecology and carbon; the evaluation system was built based on literature review, content analysis and knowledge management reconstruction. The precision includes effective utilization of irrigation water, irrigation uniformity and implementation of water measurement technologies; the economy includes crop yield increase, investment return, and timely payment for water bills; intelligence includes convenience of operation and management of irrigation project, as well as soil-moisture monitoring network; ecology includes vegetation coverage, soil salinization, surface water and groundwater improvement; carbon includes land and energy saving. We applied the model to three >10 000 mu (1650 acres) irrigation districts with smart irrigation system in Gansu, Ningxia and Qinghai province, respectively. 【Result】 In Qinghai province, the unattended and remote-control photovoltaic water lifting and micro-irrigation district improved photovoltaic water lifting efficiency and irrigation uniformity, thereby increasing comprehensive water efficiency by 32.8%. In Gansu province, implementation of the intelligent scheduling of canals with integrated gates for measurement and control increased the comprehensive water efficiency by 26.6% due to the improved irrigation automation, reliability of measurement, timely payment for water bills, and reduction in energy and labor. In Ningxia, the improvement in flow matching of pumping station units and extended water networking link increased its comprehensive water efficiency by 27.5% due to the enhanced water supply, water saving irrigation guarantee. 【Conclusion】 Constructing modern irrigation districts needs a comprehensive evaluation system to evaluate its impact not only on crops but also on many other aspects such as automatic monitoring of soils and crop traits, intelligent control and precise scheduling of the irrigation projects.

With the advancement of aerodynamic design techniques for turbomachinery, the high-loss flow in the end wall region has emerged as a bottleneck, limiting further improvements in the aerodynamic performance of fans and compressors. In this study, the end wall region of a linear cascade is flexibly parameterized using the advanced extended free-form deformation method and subsequently optimized through adjoint optimization, enabling an integrated design of the entire end wall region. A refined design featuring flexible hub deformation and a smoothly corner region is achieved. The results demonstrated that the finely integrated design significantly reduced the loss coefficient by 16.81% and effectively controlled corner separation. [ABSTRACT FROM AUTHOR]

Low‐level viraemia (LLV) occurs in chronic hepatitis B (CHB) patients despite antiviral treatment, which may cause failed histological regression. Our study aimed to investigate the impact of different LLV types on fibrosis regression. The prospective study enrolled CHB patients with paired liver biopsies before and after 260 weeks of entecavir treatment. Fibrosis regression was defined by the Ishak score or P‐I‐R system. Patients were grouped as the SVR (HBV DNA < 20 IU/mL persistently) or LLV (HBV DNA between 20 and 2000 IU/mL), which were further grouped as very low‐level viraemia (VLLV, HBV DNA < 50 IU/mL), occasionally LLV (OLLV, HBV DNA ≥ 50 IU/mL only once) and multiple LLV (MLLV, HBV DNA ≥ 50 IU/mL more than once). Logistic regression models were used to calculate the adjusted odds ratios (aORs) and 95% confidence intervals (CIs). The analysis included 111 CHB patients. In the SVR group (n = 54), 39 (72.2%) patients had fibrosis regression, which was higher than the LLV (56.1%, p = 0.080). The fibrosis regression rates for VLLV (30 patients), OLLV (17 patients) and MLLV (10 patients) were 70.0%, 52.9% and 30.0%, respectively. Compared with SVR, VLLV (aOR = 0.78; 95% CI: 0.28–2.21; p = 0.644) was not associated with fibrosis regression, but patients with non‐VLLV (aOR = 0.27; 95% CI: 0.09–0.85; p = 0.025), especially with MLLV (aOR = 0.19; 95% CI: 0.04–0.97; p = 0.046) is significantly associated with hindered fibrosis regression. Our study suggests that patients with detectable serum HBV DNA levels higher than 50 IU/mL need to be monitored carefully, especially in those with more than once. Trial Registration:ClinicalTrials.gov identifiers NCT01938781 and NCT01938820 [ABSTRACT FROM AUTHOR]

In axial compressors, control of the secondary flow is crucial for enhancing aerodynamic performance. Among various control strategies, vortex generators (VGs) are an effective passive method combining simplicity, cost-effectiveness, and reliability. This study investigates the VG evaluation model to assess VG effectiveness in reducing total pressure loss (ω) and controlling secondary flows. The impact of parameters such as the VG placement, stagger angle α, height, and length on the flow field and underlying flow mechanisms is analyzed, and methods for selecting the design parameters are examined. The findings reveal that positioning VGs near regions with high velocity differentials and away from the suction surface significantly reduces secondary flows. Achieving a balance between reducing total pressure loss ω and controlling secondary flows requires careful selection of the stagger angle α, as well as the height and length of VG. This study presents the design characteristic curve and identifies two key VG operation mechanisms that depend on the stagger angle α. The results of this study advance the development of more efficient VG designs and deepen our understanding of their operational mechanisms. [ABSTRACT FROM AUTHOR]

In this work, a combined design of blade and endwall using the Extended Free Form Deformation technique is proposed and implemented on a transonic compressor rotor (the NASA Rotor 67). The best combined design is explored by numerical investigations and optimization via Kriging surrogate model method. As a result, by only modifying the hub and blade under 15 % span, the peak adiabatic efficiency is increased by 0.4 % and the overall aerodynamic performance for all operating conditions is also improved. An analysis shows that the enlarged dihedral angle between the hub and blade restrains boundary layer intersection and development. Meanwhile, the optimized hub changes the pressure distribution and prevents migration of cross-flow. As a result, the low-energy flow in the corner is accelerated downstream and the separation is limited, leading to an effective improvement in throughflow capability and aerodynamic performance in the corner region. [ABSTRACT FROM AUTHOR]

The adjoint method plays an important role in the aerodynamic design of turbomachinery. However, most optimization objects are only local parts of the fluid domain in turbomachinery, such as blade or end-wall. In this study, a novel parameterization method is adopted in the adjoint optimization framework to merge all design spaces together and then a typical multi-row compressor, Stage 35, is optimized by the in-house adjoint optimizer, TurboSim_un. The adiabatic efficiency of STAGE 35 is improved by 1.7%. Results show that the intersection of shock wave and boundary layer is weakened and the performance in mainstream is significantly improved. [ABSTRACT FROM AUTHOR]

Codonopsis pilosula is a medicinal and edible herb with a rich nutritional value. In Gansu Province, China, its production quality and yield differ during the four seasons. Here, we investigated the differences in the microfloral composition and metabolic functions in the rhizospheric soil and roots of C. pilosula during the four seasons, and we also analyzed their dynamic and synergistic effects on C. pilosula growth and carbohydrate content change. The C. pilosula samples were analyzed for plant physiology, microfloral composition and metabolic functions in the rhizospheric soil and roots using high-throughput sequencing technology. Environmental indices including soil physiochemistry and meteorological conditions were also determined by the coupled chromatography–spectroscopy technique. The results revealed that the C. pilosula growth was affected by temperature, precipitation and light intensity, with the bacterial structures and functions of the soil and root samples showing obvious seasonal changes. Due to the diversity of microbial composition and community metabolic function, and the synergistic effect of microbial and environmental factors, there are significant differences in stress resistance, physiological status and metabolites of C. pilosula in different seasons. Furthermore, the change in seasons was significantly correlated with the quality and yield of C. pilosula. This study provides a scientific basis for soil improvement and the refinement of local Radix C. pilosula cultivation methods. [ABSTRACT FROM AUTHOR]