Resorption Efficiency of Four Cations in Different Tree Species in a Subtropical Common Garden

High rainfall in subtropical regions can leach cation elements from ecosystems,which may limit plant growth.Plants often develop efficient resorption patterns to recycle elements,but there is relatively little available information on this topic.In February 2012,a common garden was established in a subtropical forest by planting dominant trees from the area.Green and senescent leaves were sampled from 11 tree species.The concentrations of potassium(K),calcium(Ca),sodium(Na)and magnesium(Mg)were determined,and the resorption efficiencies were calculated.The results showed significant K,Na and Mg resorption in most of the investigated tree species,while Ca mainly displayed accumulation.Evergreen coniferous and evergreen broad-leaved trees(such as Cunninghamia lanceolata,Pinus massoniana,Cinnamomum camphora,and Michelia macclurei)exhibited relatively higher resorption efficiencies of K(39.0%-87.5%)and Na(18.3%-50.2%)than deciduous broad-leaved trees.Higher Mg resorption efficiencies(>50%)were detected in Liriodendron chinense,C.lanceolata and P.massoniana than in other trees.Overall,evergreen coniferous and evergreen broad-leaved trees could show higher cation resorption than deciduous broad-leaved trees.K and Mg resorption efficiencies and Ca accumulation decrease with increasing nutrient concentrations in green leaves.Our results emphasize that nutrient resorption patterns largely depend on elements and plant functions,which provides new insights into the nutrient use strategies of subtropical plants and a reference for the selection of suitable tree species in this region.

National survey of the awareness and implementation status of early pulmonary rehabilitation for patients with critical illness in departments of pulmonary and critical care medicine in 2019

To the Editor:The aim of early pulmonary rehabilitation(PR)in the intensive care unit(ICU)is to reduce the incidence of post-ICU syndrome,increase the number of ventilator-free days,reestablish and improve functional capacity,improve health-related life quality,promote mental health,and enhance participation in everyday life.PR in the ICU is highly effective and plays an important role in recovery of patients with reduced exercise endurance,functional capacity,and health-related life quality.Several surveys outside China have assessed the implementation of early rehabilitation in the ICU,[1]but there are few data from China.This study aimed to investigate the awareness and implementation of early PR in secondary-and tertiary-class hospitals with pulmonary and critical care medicine(PCCM)standardized certification.PCCM staff members were recruited to fill out a selfdesigned questionnaire.We defined early PR as PR within 5 days of ICU admission.

The potential of 3D printing in facilitating carbon neutrality

At present,dramatically reduction of fossil fuel usage is regarded as a major initiative to achieve the carbon neutrality goal.Nevertheless,current energy policies are unlikely to achieve the climate goal without sacrificing economic development and people’s livelihood because fossil fuels are currently the dominant energy source.As an environment-friendly manufacturing technology,three-dimensional printing(3DP)is flourishing and is considered beneficial to energy structure adjustment and industrial upgrading.Despite this,its potential to contribute to global carbon neutrality has not attracted enough attention.Herein,we explore the application of 3DP and its potential facilitating carbon neutrality from crucial sectors and applications including manufacturing,construction energy,livestock,and carbon capture and storage(CCS)technologies.The additive manufacturing and decentralized manufacturing characteristics of 3DP allow reducing greenhouse gas(GHG)emissions in manufacturing and construction sectors by optimized and lightweight designs,reduced material and energy consumption,and shortened transport processes.In addition,3DP enables the precise manufacturing of customized complex structures and the expansion of functional materials,which makes 3DP an innovative alternative to the development of novel energy-related devices,cultured meat production technology,and CCS technologies.Despite this,the majority of applications of 3DP are still in an early stage and need further exploration.We call for further research to precisely evaluate the GHG emission reduction potential of 3DP and to make it better involved and deployed to better achieve carbon neutrality.

Comorbidities and high in-hospital mortality of cancer-associated pulmonary embolism:findings from a real-world registry study

To the Editor:Cancer has been recognized as an independent predisposing factor of venous thromboembolism(VTE),including pulmonary embolism(PE)and deep vein thrombosis(DVT).Patients with cancer have a sevenfold increased risk of VTE compared with those without cancer.[1]Evidence from autopsy in cancer patients showed that PE is an important disease complication in patients with cancer.[2]Optimal management of PE patients with cancer has become a major concern that challenges clinicians in daily clinical practice.Understanding the risk factors of all-cause death in PE patients with cancer in the real world may enable optimal management and improve their survival.Therefore,this study was performed to characterize cancerassociated PE and evaluate the clinical predictors of inhospital death based on the data of PE patient population in China.

全球尺度上氮添加影响植物生物量分配但不影响不同器官间的异速生长关系

生物量在不同器官间的分配是植物对环境变化响应的一个关键生态生理学过程。然而,在全球尺度上有关不同陆地生态系统植物生物量分配对氮沉降响应的认识还比较欠缺。本文通过整合分析333篇己发表文章的5474个观测值,基于“最优分配假说”和“异速分配假说”,评估了全球尺度上氮添加对植物生物量及其在不同器官间分配的影响。结果表明:(1)氮添加显著增加了整株植物或不同器官的生物量,降低了根冠比和根质量分数,但对叶质量分数和茎质量分数无显著影响;(2)氮添加对不同器官质量分数的影响受实验条件、植物功能性状、纬度、氮添加率等因子单独或交互作用的调控;(3)氮添加对生物量在不同器官间的异速分配率无显著影响,表明氮添加导致的根冠比和根质量分数减少是在异速分配模式下由整株植物生物量增加而致。虽然氮添加改变了地上和地下部分的质量分数,但不同器官生物量间异速分配模式的稳定性表明“异速分配假说”能更好地描述植物生物量分配对氮添加的响应规律。该研究结果将有助于深入认识氮沉降环境下植物生物量的分配规律,同时表明将生物量分配纳入有关氮沉降对陆地生态系统影响的预测模型中的重要性。

白蚁活动对中亚热带次生林和人工林的危害差异

中亚热带地区是中国南方重要的木材生产基地,大量的地带性常绿阔叶林被转换成以杉木(Cunninghamia lanceolata)为代表的人工林。白蚁是森林中最主要的社会性昆虫之一,其取食行为既对森林类型转换后林中的树木产生危害,也对林间枯枝落叶的分解具有十分重要的意义,但对二者缺乏统一的认识。本文以中亚热带典型的米槠(Castanopsis carlesii)次生林、米槠人工林和杉木人工林为研究对象,调查了不同林分白蚁的活动特点及其范围。结果表明,米槠次生林与杉木、米槠人工林中均普遍存在白蚁取食现象,但白蚁对次生林的取食高度和面积均远低于人工林。白蚁对生物多样性较高的米槠次生林树干韧皮部的取食面积仅分别为米槠人工林的1.65%和杉木人工林的0.59‰,取食高度的11.1%和1.2%。同时,白蚁对杉木韧皮部的取食显著大于米槠,对杉木的取食面积和高度分别是米槠的27.7倍和9.2倍。每隔0.5 m为一个统计区间,白蚁对杉木树干2 m以下韧皮部取食面积比例由低往高为4:3:2:1,对米槠1 m以下高度部位的取食面积比为99:1。此外,白蚁对次生林地表覆盖的凋落枝和凋落叶的平均取食面积分别为51.7%和46.1%,而人工林对应均值分别为17.5%和29.4%,均表现为次生林高于人工林。这些结果表明白蚁对生物多样性较高的次生林危害小于杉木人工林,且在人工林中可见危害主要体现在白蚁对韧皮部的取食,在次生林主要体现在白蚁对凋落物残体的分解作用,这为区域森林经营管理提供理论支撑。

Increased microbial sequestration of soil organic carbon under nitrogen deposition over China’s terrestrial ecosystems

Background:China’s terrestrial ecosystems have been receiving increasing amounts of reactive nitrogen(N)over recent decades.External N inputs profoundly change microbially mediated soil carbon(C)dynamics,but how elevated N affects the soil organic C that is derived from microbial residues is not fully understood.Here,we evaluated the changes in soil microbial necromass C under N addition at 11 forest,grassland,and cropland sites over China’s terrestrial ecosystems through a meta-analysis based on available data from published articles.Results:Microbial necromass C accounted for an average of 49.5%of the total soil organic C across the studied sites,with higher values observed in croplands(53.0%)and lower values in forests(38.6%).Microbial necromass C was significantly increased by 9.5%after N addition,regardless of N forms,with greater stimulation observed for fungal(+11.2%)than bacterial(+4.5%)necromass C.This increase in microbial necromass C under elevated N was greater under longer experimental periods but showed little variation among different N application rates.The stimulation of soil microbial necromass C under elevated N was proportional to the change in soil organic C.Conclusions:The stimulation of microbial residues after biomass turnover is an important pathway for the observed increase in soil organic C under N deposition across China’s terrestrial ecosystems.

3D Printing Challenges in Enabling Rapid Response to Public Health Emergencies

The coronavirus disease 2019(COVID-19)epidemic has become a global public health emergency over last months.As of September 14th,over 28,000,000 confirmed cases and 917,000 deaths have been reported from all over the world.1 Its large-scale outbreak and pandemic cause an extreme shortage of personal protective equipment(PPE)andmedical supplies such as face masks,testing kits,nasopharyngeal swabs,and medical ventilators in the early stage,which consequently leads to the collapse of local medical systems.2 It turns out that measures like lockdown and travel bans are themost effective strategies in response to an epidemic at an early stage with insufficient knowledge.3 However,those physical isolation measures will inevitably result in work stoppages and have a great impact on industrial production.The supply of raw materials and components,and the production and transportation of final products are greatly restricted under a global supply chain.4 This further aggravates the shortage of anti-epidemic supplies and so the vicious cycle begins.