Effect of particle gradation on pore structure and seepage law of solution in weathered crust elution-deposited rare earth ores

Both CT and Avizo software were used to explore the effect of particle gradation on the evolution characteristics of pore structure and seepage paths in weathered crust elution-deposited rare earth ores during leaching.The results showed that the pore areas in four kinds of ore samples before leaching were mainly concentrated in 10^(4)–10^(7)μm^(2),whose pore quantities accounted for 96.89%,94.94%,90.48%,and 89.45%,respectively,while the corresponding pore volume only accounted for 30.74%,14.55%,7.58%,and 2.84%of the total pore volume.With the decrease of fractal dimension,the average pore throat length increased,but pore throat quantities,the average pore throat radius and coordination number decreased.Compared with that before leaching,the change degree of pore structure during leaching increased with the fractal dimension decreasing.For example,the reduction rate of the average coordination number of ore samples was 14.36%,21.30%,28.00%,and 32.90%,respectively.Seepage simulation results indicated that seepage paths were uniformly distributed before leaching while the streamline density and seepage velocity increased with the fractal dimension decreasing.Besides,the phenomenon of the streamline interruption gradually reduced during leaching while preferential seepage got more obvious with the decrease of the fractal dimension.

新时期健康中国建设中的医防协同:理论机制与政策演变

我国医防协同的实践由来已久,医防协同已成为我国新时期健康中国建设中全方位、全周期保障人民健康的重要途径。尽管我国的医防协同工作已经取得进展,但其相对割裂的现状并未发生根本性扭转。以此为背景,结合自2018年以来对不同地区、不同部门的现场调研以及现有研究,本文介绍了新时期我国医防协同的定义、政策演进过程及内涵,并设计了医防协同的理论机制模型,揭示了医疗服务体系与公共卫生体系整合的组织基础、服务供给内容及协同机制设计,为国内和国际整合型医疗卫生服务体系改革及治理提供理论基础、改革路径和中国经验。

Trends of SARS-CoV-2 Infection in Rural Area in Sentinel Community-Based Surveillance——China,December 2022 to January 2023

Introduction:In late 2022,a rapid transmission of Omicron variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)occurred throughout China.The purpose of this study was to provide the latest data and evaluate trends of SARS-CoV-2 infection in rural China among the community population.Methods:Data on SARS-CoV-2 infection among approximately 90,000 participants in rural China were collected by the National Sentinel Community-Based Surveillance(NSCS)system.Participants were tested for SARS-CoV-2 infection(defined as positive for SARS-CoV-2 nucleic acid or antigen)twice weekly from December 16,2022 to January 12,2023.The daily average of newly positive rate and its estimated daily percentage change were calculated to describe the national and regional trends of SARS-CoV-2 infection in rural China.Results:In rural China,the daily average new positive rate of SARS-CoV-2 infection peaked at 4.79%between December 20–22,2022 and then decreased to 0.57%between January 10–12,2023,with an average decrease of 29.95%per round.The peak of new SARS-CoV-2 infection was slightly earlier and lower in North China(5.28%between December 20–22,2022)than in South China(5.63%between December 23–26,2022),and then converged from December 30,2022 to January 2,2023.The peak of 6.09%occurred between December 20–22,2022 in eastern China,while the peak of 5.99%occurred later,between December 27–29,2022,in central China.Conclusions:Overall,the epidemic wave in rural China peaked between December 20–22,2022,and passed quickly following the optimization of prevention and control measures.Currently,SARSCoV-2 infection in community populations in rural China is sporadic.

Trends of SARS-CoV-2 Infection in Sentinel Community-Based Surveillance After the Optimization of Prevention and Control Measures—China,December 2022-January 2023

Introduction:On December 7,2022,China implemented the“Ten New Measures”to optimize its prevention and control measures for coronavirus disease 2019(COVID-19).To provide the latest data after the optimization,we evaluated trends of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection among the community population in China.Methods:We utilized data from the National Sentinel Community-Based Surveillance(NSCS)system in China to assess trends of SARS-CoV-2 infection.NSCS is a national community-based surveillance cohort with 0.42 million participants from all 31 provincial-level administrative divisions(PLADs)and Xinjiang Production and Construction Corps(XPCC).Participants were tested for infection twice a week(a total of eight rounds)from December 16,2022 to January 12,2023.SARS-CoV-2 infection was defined as testing positive for SARS-CoV-2 nucleic acid or antigen.We calculated the daily average of newly positive rates of SARS-CoV-2 infection.Results:In this national cohort,the daily average newly positive rate of SARS-CoV-2 infection decreased from 4.13% in Round 1(December 16-19,2022)to 0.69% in Round 8(January 10-12,2023).The epidemic peak occurred in Round 2(December 20-22,2022).Similar trends were observed in urban areas(decreasing from 4.65% to 0.73%),rural areas(decreasing from 2.83% to 0.57%),the eastern region(decreasing from 4.18% to 0.67%),the central region(decreasing from 5.43% to 0.61%),and the western region(decreasing from 3.01%to 0.77%).Conclusions:NSCS data showed that the peak of SARS-CoV-2 infection in China had passed.SARSCoV-2 infection in community populations in China is currently at a low epidemic level.

Trends of SARS-CoV-2 Infection Among Couriers in Risky Business After the Optimization of Prevention and Control Measures——China,December 2022 to January 2023

Introduction:On December 7,2022,China implemented“Ten New Measures”to optimize prevention and control measures for coronavirus disease 2019(COVID-19).The purpose of this study was to evaluate the national and regional trends of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection among couriers in China from December 2022 to January 2023.Methods:Data from the National Sentinel Community-based Surveillance in China was utilized,including participants from 31 provincial-level administrative divisions and Xinjiang Production and Construction Corps.Participants were tested for SARS-CoV-2 infection twice a week from December 16,2022 to January 12,2023.Infection was defined as a positive result for SARS-CoV-2 nucleic acid or antigen.The daily average newly positive rate of SARSCoV-2 infection and the estimated daily percentage change(EDPC)were calculated.Results:In this cohort,8 rounds of data were collected.The daily average newly positive rate of SARS-CoV-2 infection decreased from 4.99%in Round 1 to 0.41%in Round 8,with an EDPC of−33.0%.Similar trends of the positive rate were also observed in the eastern(EDPC:−27.7%),central(EDPC:−38.0%)and western regions(EDPC:−25.5%).Couriers and community population showed a similar temporal trend,with the peak daily average newly positive rate of couriers being higher than that of community population.After Round 2,the daily average newly positive rate of couriers decreased sharply,becoming lower than that of community population in the same period.Conclusions:The peak of SARS-CoV-2 infection among couriers in China has passed.As couriers are a key population for SARS-CoV-2 infection,they should be monitored continuously.

The impact of probiotics on gut health via alternation of immune status of monogastric animals

The intestinal immune system is affected by various factors during its development,such as maternal antibodies,host genes,intestinal microbial composition and activity,and various stresses(such as weaning stress).Intestinal microbes may have an important impact on the development of the host immune system.Appropriate interventions such as probiotics may have a positive effect on intestinal immunity by regulating the composition and activity of intestinal microbes.Moreover,probiotics participate in the regulation of host health in many ways;for instance,by improving digestion and the absorption of nutrients,immune response,increasing the content of intestinal-beneficial microorgan-isms,and inhibiting intestinal-pathogenic bacteria,and they participate in regulating intestinal diseases in various ways.Probiotics are widely used as additives in livestock and the poultry industry and bring health benefits to hosts by improving intestinal microbes and growth performance,which provides more choices for promoting strong and efficient productivity.

Potential role of Lactobacillus plantarum in colitis induced by dextran sulfate sodium through altering gut microbiota and host metabolism in murine model

Inflammatory bowel disease(IBD) is a chronic lifelong disease characterized by inflammation of the gastrointestinal tract.Although more and more treatment options serve IBD, there is still no cure. It is important to find an effective treatment for IBD.This study aims to investigate whether Lactobacillus plantarum(L. plantarum) could alleviate colitis induced by dextran sulfate sodium(DSS). Following the DSS challenge, L. plantarum on DSS-mediated inflammatory colon lesions in mice, and L.plantarum therapy heightened the relative abundance of the colon-resident Actinobacteria. Analysis of serum metabolomics also indicated that the content of MG(18:4(6 Z, 9 Z, 12 Z, 15 Z)/0:0/0:0) was increased in response to L. plantarum therapy, and this was also the case for indolepyruvate and 1-hydroxyibuprofen. However, 13-oxooctadecadienoic acid(13-oxo ODE) and indolylacryloylglycine content fell following the DSS challenge. Based on these results, the study elucidates the mitigatory effects of L. plantarum in colitis, which depend on its regulation of the colonic microbial community and its modification of serum metabolites. The results revealed that L. plantarum mitigated inflammatory colon lesions, reprogrammed the microbial community and altered the level of serum metabolites in a murine model challenged with DSS. The study may present a potential therapeutic strategy for colitis.

Dietary polyphenols in lipid metabolism: A role of gut microbiome

Polyphenols are a class of non-essential phytonutrients,which are abundant in fruits and vegetables.Dietary polyphenols or foods rich in polyphenols are widely recommended for metabolic health.Indeed,polyphenols(i.e.,catechins,resveratrol,and curcumin)are increasingly recognized as a regulator of lipid metabolism in host.The mechanisms,at least in part,may be highly associated with gut microbiome.This review mainly discussed the beneficial effects of dietary polyphenols on lipid metabolism.The potential mechanisms of gut microbiome are focused on the effect of dietary polyphenols on gut microbiota compositions and how gut microbiota affect polyphenol metabolism.Together,dietary polyphenols may be a useful nutritional strategy for manipulation of lipid metabolism or obesity care.

Helmholtz Solving and Performance Optimization in Global/Regional Assimilation and Prediction System

Despite efficient parallelism in the solution of physical parameterization in the Global/Regional Assimilation and Prediction System(GRAPES),the Helmholtz equation in the dynamic core,with the increase of resolution,can hardly achieve sufficient parallelism in the solving process due to a large amount of communication and irregular access.In this paper,optimizing the Helmholtz equation solution for better performance and higher efficiency has been an urgent task.An optimization scheme for the parallel solution of the Helmholtz equation is proposed in this paper.Specifically,the geometrical multigrid optimization strategy is designed by taking advantage of the data anisotropy of grid points near the pole and the isotropy of those near memory equator in the Helmholtz equation,and the Incomplete LU(ILU)decomposition preconditioner is adopted to speed up the convergence of the improved Generalized Conjugate Residual(GCR),which effectively reduces the number of iterations and the computation time.The overall solving performance of the Helmholtz equation is improved by thread-level parallelism,vectorization,and reuse of data in the cache.The experimental results show that the proposed optimization scheme can effectively eliminate the bottleneck of the Helmholtz equation as regards the solving speed.Considering the test results on a 10-node two-way server,the solution of the Helmholtz equation,compared with the original serial version,is accelerated by 100,with one-third of iterations reduced.