Biogeochemistry of sedimentary organic matter in the Yongjiang River estuary in the southern part of Hangzhou Bay,China,since the Late Pleistocene

A sediment core(YJK19-02)collected from the southern outlet of Hangzhou Bay near the Yongjiang River estuary in East China was analyzed for grain size,lignin,bulk elemental composition,stable carbon isotope,and rare earth elements(REEs)to determine the sources and diagenesis of sedimentary organic matter(OM)of the estuary and adjacent areas since the Late Pleistocene.δ^(13)C values(-24.80‰–-23.60‰),total organic carbon/total nitrogen(TOC/TN)molar ratios(8.00–12.14),and light rare earth element/heavy rare earth element ratios(LREE/HREE=8.34–8.91)revealed the predominance of terrestrial sources of OM,mainly from the Changjiang(Yangtze)River.The lignin parameters of syringyl/vanillyl(S/V=0.20–0.73)and cinnamyl/vanillyl(C/V=0.03–0.19)ratios indicate the predominance of nonwoody angiosperms,and the vanillic acid/vanillin ratios[(Ad/Al)_(V)=0.32–1.57]indicate medium to high degrees of lignin degradation.An increasing trend ofΛ(total lignin in mg/100-mg OC)values from ca.14500 a BP to ca.11000 a BP reflected the increase in temperature during the Late Pleistocene.However,a time lag effect of temperature on vegetation abundance was also revealed.The relatively higher and stableΛvalues correspond to the higher temperature during the mid-Holocene from ca.8500 a BP to ca.4500 a BP.Λvalues decreased from ca.4000 a BP to the present,corresponding to historical temperature fluctuations during this time.Our results show that the vegetation abundance in the Yongjiang River Basin since the Late Pleistocene was related to the temperature fluctuation duo to climate change.

Trends of carbon and nutrient accumulation through time in the Andong salt marsh,Hangzhou Bay,China

Salt marshes are important carbon and nutrient sinks that are threatened by climate changes and human activities.In this study,the accumulation rates of sedimentary total organic carbon(TOC),total nitrogen(TN),and total phosphorus(TP)from two cores in the Andong salt marsh,Hangzhou Bay,were investigated to determine whether TOC,TN,and TP show increasing or decreasing trends toward the present.The TOC accumulation rates at the relatively lower marsh were lower during 1990-1996(1.63-2.37 g/(cm^(2)·a))than 1997-2014(1.15-4.30 g/(cm^(2)·a)).The TN accumulation rates increased from 1990(0.14 g/(cm^(2)·a))toward 2012(0.40 g/(cm^(2)·a)),then decreased toward 2014(0.16 g/(cm^(2)·a)).The TP accumulation rates were lower during 1990-1999(0.10-0.21 mg/(cm^(2)·a)),and decreased from 2000(0.32 mg/(cm^(2)·a))toward 2014(0.15 mg/(cm^(2)·a)).The TOC accumulation rates along the relatively upper marsh during 1982-1992(1.18-3.25 g/(cm^(2)·a))were lower than during 1998-2010(2.30-4.20 g/(cm^(2)·a)),and then decreased toward 2015(2.15 g/(cm^(2)·a)).TN increased from 1982(0.18 g/(cm^(2)·a))to 2005(0.41 g/(cm^(2)·a)),then decreased toward 2015(0.22 g/(cm^(2)·a)).TP accumulation rates fluctuated within a narrow range during 1982-1997(0.21-0.41 mg/(cm^(2)·a)),increased from 1998(0.50 mg/(cm^(2)·a))to 2004(0.87 mg/(cm^(2)·a)),then decreased to 2015(0.38 mg/(cm^(2)·a)).Thus,increases in accumulation rates of TOC,TN,and TP from the 1980s to 1990s indicates that the marsh likely served as carbon and nutrient sinks,then the rates decreased during 2000-2015 due probably to the reduced sediment inputs from rivers and intensified sea level rise.

Long-Term Trend Analysis of Major Human Helminth Infections — Guangdong Province, China, 1988–2021

Introduction:Although helminth infections threaten millions of people worldwide,the spatiotemporal characteristics remain unclear across China.This study systematically describes the spatiotemporal changes of major human helminth infections and their epidemiological characteristics from 1988 to 2021 in Guangdong Province,China.Methods:The survey data in Guangdong Province were primarily obtained from 3 national surveys implemented during 1988–1992,2001–2004,and 2014–2016,respectively,and from the China Information System for Disease Control and Prevention during 2019–2021.A modified Kato-Katz technique was used to detect parasite eggs in collected fecal samples.Results:The overall standardized infection rates(SIRs)of any soil-transmitted helminths(STH)and Clonorchis sinensis decreased from 65.27%during 1988–1992 to 4.23%during 2019–2021.In particular,the SIRs of STH had even more of a decrease,from 64.41%during 1988–1992 to 0.31%during 2019–2021.The SIRs of Clonorchis sinensis in the 4 surveys were 2.40%,12.17%,5.20%,and 3.93%,respectively.This study observed different permutations of gender,age,occupation,and education level on the SIRs of helminths.Conclusions:The infection rate of STH has substantially decreased.However,the infection rate of Clonorchis sinensis has had fewer changes,and it has become the dominant helminth.

耐高温微系统气密封装技术及高温可靠性研究

针对武器装备、航空航天等领域高温封装需求,提出一种耐高温微系统气密封装技术.选用氮化铝直接电镀陶瓷基板(direct plated ceramic substrate, DPC)作为封装散热基板,可伐(Kovar)合金作为封装盖板,金锡合金(Au80Sn20)作为焊接材料实现气密封装,并通过有限元模拟优化了最小焊接应力下的焊环厚度.根据设计方案制备了集成热敏电阻和微型加速度计的微系统器件.测试结果表明,微系统封装样品焊接质量良好,界面无孔隙和裂纹.将封装后的微系统在200℃下老化1000 h,测试其老化前后的气密性和芯片电性能.结果表明,老化后微系统仍具有较高气密性,封装漏率达到10-9Pa·m3/s量级,热敏电阻及微型加速度计电信号正常.实验证明该耐高温微系统气密封装技术可满足高温应用可靠性需求,有望应用于航空航天及军工领域.

Effectiveness of COVID-19 Vaccination Against SARS-CoV-2 Omicron Variant Infection and Symptoms—China,December 2022–February 2023

Summary What is already known about this topic?A considerable percentage of the population has received both primary and booster vaccinations,which could potentially provide protection against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron infections and related symptoms.What is added by this report?The self-reported infection rate,as determined from an online survey,reached its peak(15.5%)between December 19 and 21,2022,with an estimated 82.4%of individuals in China being infected as of February 7,2023.During the epidemic,the effectiveness of booster vaccinations against SARS-CoV-2 Omicron infection was found to be 49.0%within three months of vaccination and 37.9%between 3 and 6 months following vaccination.Furthermore,the vaccine effectiveness of the booster vaccination in relation to symptom prevention varied from 48.7%to 83.2%within three months and from 25.9%to 69.0%between 3 and 6 months post-booster vaccination.

When and How to Adjust Non-Pharmacological Interventions Concurrent with Booster Vaccinations Against COVID-19—Guangdong,China,2022

Introduction:With the large-scale roll-out of the coronavirus disease 2019(COVID-19)booster vaccination effort(a vaccine dose given 6 months after completing primary vaccination)in China,we explore when and how China could lift non-pharmacological interventions(NPIs)against COVID-19 in 2022.Methods:Using a modified susceptible-infectiousrecovered(SIR)mathematical model,we projected the COVID-19 epidemic situation and required medical resources in Guangdong Province,China.Results:If the number of people entering from overseas recovers to 20%of the number in 2019,the epidemic in 2022 could be controlled at a low level by a containment(215 local cases)or suppression strategy(1,397 local cases).A mitigation strategy would lead to 21,722 local cases.A coexistence strategy would lead to a large epidemic with 6,850,083 local cases that would overwhelm Guangdong’s medical system.With 50%or 100%recovery of the 2019 level of travelers from overseas,the epidemic could also be controlled with containment or suppression,but enormous resources,including more hotel rooms for border quarantine,will be required.However,coexistence would lead to an uncontrollable epidemic with 12,922,032 local cases.Discussion:With booster vaccinations,the number of travelers from overseas could increase slightly in 2022,but a suppression strategy would need to be maintained to ensure a controllable epidemic.

Ambient Temperature and Years of Life Lost:A National Study in China

Although numerous studies have investigated premature deaths attributable to temperature,effects of temperature on years of life lost(YLL)remain unclear.We estimated the relationship between temperatures and YLL,and quantified the YLL per death caused by temperature in China.We collected daily meteorological and mortality data,and calculated the daily YLL values for 364 locations(2013–2017 in Yunnan,Guangdong,Hunan,Zhejiang,and Jilin provinces,and 2006–2011 in other locations)in China.A time-series design with a distributed lag nonlinear model was first employed to estimate the location-specific associations between temperature and YLL rates(YLL/100,000 population),and a multivariate meta-analysis model was used to pool location-specific associations.Then,YLL per death caused by temperatures was calculated.The temperature and YLL rates consistently showed U-shaped associations.A mean of 1.02(95%confidence interval:0.67,1.37)YLL per death was attributable to temperature.Cold temperature caused 0.98 YLL per death with most from moderate cold(0.84).The mean YLL per death was higher in those with cardiovascular diseases(1.14),males(1.15),younger age categories(1.31 in people aged 65–74 years),and in central China(1.34)than in those with respiratory diseases(0.47),females(0.87),older people(0.85 in people R75 years old),and northern China(0.64)or southern China(1.19).The mortality burden was modified by annual temperature and temperature variability,relative humidity,latitude,longitude,altitude,education attainment,and central heating use.Temperatures caused substantial YLL per death in China,which was modified by demographic and regional characteristics.