Temporal and Spatial Distribution of SARS-CoV-2 Aerosols in a Large-Scale Fangcang Shelter Hospital in Shanghai,China

The coronavirus disease 2019(COVID-19)pandemic caused by frequently mutating severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has had a worldwide impact.However,detailed data on the potential aerosol transmission of SARS-CoV-2 in real-world and controlled laboratory settings remain sparse.During the COVID-19 pandemic in Shanghai,China in 2022,samples were collected in a Fangcang shelter hospital,a large-scale temporary hospital rapidly built by converting the existing National Exhibition and Convention Center(Shanghai)into a health care facility.Aerosol samples at different sites and intervals around patients and in public areas,surface samples,and pharyngeal swab samples from corresponding patients were included.Samples were tested for SARS-CoV-2 using real-time quantitative polymerase chain reaction(RT-qPCR)assays,followed by sequencing if the cycle threshold(Ct)value was<30.The positivity rate for SARS-CoV-2 in aerosol samples was high in contaminated zones(37.5%,104/277),especially around the bed(41.2%,68/165)and near ventilation inlets(45.2%,14/31).The prevalence of SARS-CoV-2 around the bed,public areas,and air inlets of exhaust vents fluctuated and was closely related to the positivity rate among patients at corresponding sampling sites.Some surface samples of different personal protective equipment from medical staff had high positivity rates.Sixty sequences of joined ORF1ab and spike genes obtained from sixty samples represented two main clusters of Omicron SARS-CoV-2.There was consistency in virus sequences from the same patient and their environment,and the detected virus sequences matched those of virus strains in circulation during the collection periods,which indicated a high likelihood of cross-contamination in the Fangcang shelter hospital.In summary,the results provide a quantitative and real landscape of the aerosol transmission of SARS-CoV-2 and a patient-centered view of contamination in large and enclosed spaces and offer a useful guide for taking targeted measures to avoid nosocomial infections during the management of SARS-CoV-2 or other respiratory virus diseases in a Fangcang shelter hospital.

Visualization Techniques viaMLBS for Personnel Management in Major Events

Mobile location-based services(MLBS)refer to services around geographic location data.Mobile terminals use wireless communication networks(or satellite positioning systems)to obtain users’geographic location coordinate information based on spatial databases and integrate with other information to provide users with required location-related services.The development of systems based on MLBS has significance and practical value.In this paper a visualization management information system for personnel in major events based on microservices,namely MEPMIS,is designed and implemented by using MLBS.The system consists of a server and a client app,and it has some functions including map search and query,personnel positioning and scheduling,location management,messaging,and location service.Managers of the events can quickly search and locate the staff on the specific area of the map in real-time,and make broadcasting messages to the staff,and manage the staff.The client app is developed on the Android system,by which staff users can send the positions information to the server timely.The client users can search fuzzily near their peers and list their locations,and also call near peers through sending messages or query the history record of staff locations.In the design of the system,several new proposed techniques,including visual annotation method for overlapping locations,correcting trajectory drift algorithm,microservices-based overall system architecture methodology and other new techniques,which are applied to the implementation of the system.Also,HTML5,JQuery,MLBS APIs(Application Program Interfaces)related programming techniques have been used and combined with loading Ajax asynchronously and Json data encapsulation,map marker optimization techniques,that can improve the positioning accuracy and the performance of the system.The developed system with practical functions can enhance the efficiencies of the organization and management of major events.

Genome-wide analysis of NDR1/HIN1-like genes in pepper(Capsicum annuum L.)and functional characterization of CaNHL4 under biotic and abiotic stresses

Plant NDR1/HIN1-like(NHL)genes play an important role in triggering plant defenses in response to biotic stresses.In this study,we performed a genome-wide identification of the NHL genes in pepper(Capsicum annuum L.)and characterized the functional roles of these CaNHL genes in response to abiotic stresses and infection by different pathogens.Phylogenetic analysis revealed that CaNHLs can be classified into five distinct subgroups,with each group containing generic and specific motifs.Regulatory element analysis showed that the majority of the promoter regions of the identified CaNHLs contain jasmonic acid(JA)-responsive and salicylic acid(SA)-responsive elements,and transcriptomic analysis revealed that CaNHL genes are expressed in all the examined tissues of pepper.The CaNHL1,CaNHL4,CaNHL6,CaNHL10,CaNHL11,and CaNHL12 genes were significantly upregulated under abiotic stress as well as in response to different pathogens,such as TMV,Phytophthora capsici and Pseudomonas syringae.In addition,we found that CaNHL4 localizes to the plasma membrane.CaNHL4-silenced pepper plants display significantly increased susceptibility to TMV,Phytophthora capsici and Pseudomonas syringae,exhibiting reduced expression of JA-related and SA-related genes and reduced ROS production.However,transient overexpression of CaNHL4 in pepper increases the expression of JArelated and SA-related genes,enhances the accumulation of ROS,and inhibits the infection of these three pathogens.Collectively,for the first time,we identified the NHL genes in pepper and demonstrated that CaNHL4 is involved in the production of ROS and that it also regulates the expression of JA-related and SA-related genes in response to different pathogens,suggesting that members of the CaNHL family play an essential role in the disease resistance of pepper.

机械化处理对镍包石墨包覆效果的影响

采用机械法对天然石墨进行预处理,对比了机械处理前后的天然石墨进行水热氢还原工艺包覆金属镍的包覆效果,表征了镍包天然石墨的表面形貌,物理性能;并采用火焰喷涂法制备了镍包天然石墨涂层,对比分析了涂层的显微形貌和硬度。研究表明,机械化处理后的天然石墨制备的镍包石墨中镍包覆层更完整和均匀,获得的涂层硬度值更高且分布更均匀。

Counting Method of Mangrove Pests Based on Infrared Thermography

In the field of plant protection,certain methods for assessing the current pest situation and implementing appropriate protection countermeasures can effectively protect plants while saving manpower and material resources.However,current pest monitoring methods are primarily based on the stage of"seeing,hand checking,disc shooting and net catching",and the level of automation is low.Manual methods are time-consuming,prone to error,and difficult to review.We designed a method based on infrared thermography principle for counting Ricania guttata(Walker),a pest which is harmful to mangrove plants.This method,which is based on thermal infrared images and binarized image segmentation,realizes image processing of surface temperature,effectively distinguishes pests and sticky board,automatically counts the number of pests,and expands the data source based on image processing.Furthermore,this method contributes to the solution of the problem that counting error of insect close to the color of sticky board is greater in image recognition of visible light,when the pest color is close to the stick board.It can facilitate manual investigation of mangrove pests,simply and efficiently count the number of pests on the stick board,and provide data and technical support for pest condition analysis and control.

钛合金固相渗硼-稀土渗硼机理研究

表面强化处理可以大幅提升钛合金的耐磨性,也有利于钛合金在高温环境中应用。钛合金高温固相渗硼是重要的表面强化方式,添加稀土提高渗硼效率是重要技术手段。为深入研究稀土的渗硼催化机制,本文开展了900~1050℃渗硼试验,重点分析了渗硼剂在试验后的相组成变化。结果表明,稀土可通过与硼源、氧发生化学反应,生成熔点较低的稀土硼酸盐。本文对该硼酸盐发挥的作用进行了解释,论述了稀土在渗硼反应过程中的作用。经过渗硼的钛合金表面形成了TiB/TiB2双相渗层,显微组织分析表明该渗层与基材结合紧密、无孔洞缺陷。本文还对渗硼钛合金的拉伸性能、表面摩擦系数、维氏硬度、高温洛氏硬度、结合力等基础力学性能进行了测试,结果表明,渗硼钛合金具有优良的综合力学性能。

低烧损ZrB2/SiC复合粉末制备及涂层抗烧蚀性能研究

采用喷雾造粒-胶粘包覆的方法制备了一种低烧损核壳结构ZrB2/SiC复合粉末,研究了胶粘包覆过程中不同清漆含量对粉末包覆效果的影响。结果表明清漆含量不足时细粉包覆不完全,细粉出现单独团聚的现象;清漆含量过多时,造成原始球形颗粒的粘连;当清漆含量为4.5%时,获得包覆效果良好的粉末,外层包覆完整均匀。为了研究等离子喷涂过程中核壳结构粉末SiC发生分解烧损程度,对比了分别采用核壳结构和均匀弥散结构ZrB2/SiC复合粉末所制备涂层的微观形貌及涂层中元素分布。结果表明核壳结构粉末喷涂涂层成分均匀性良好,高熔点ZrB2保护内层SiC,可有效减少SiC在等离子焰流中的烧损,实现涂层和粉末成分的一致性。对核壳结构复合粉末制备的涂层进行了20s的氧-乙炔火焰烧蚀试验,涂层质量烧蚀率为1.837×10-3g/s,对涂层抗烧蚀机理进行了初步探讨。

氧化钆改性铈酸镧热障涂层材料设计及涂层抗热震性能研究

La_(2)Ce_(2)O_(7)(LC)由于具有比YSZ更低的热导率、更高的热膨胀系数和良好的高温相稳定性,是一种极具前景的热障涂层陶瓷材料。但该材料热膨胀系数在200~400℃温度区间存在异常下降现象,从而引起涂层过早失效的问题。目前,通过掺杂Gd_(2)O_(3)可有效解决LC低温段热膨胀系数下降的问题,但是,Gd_(2)O_(3)改性La_(2)Ce_(2)O_(7)热障涂层最优掺杂浓度及涂层性能还未见报道。本文采用化学共沉淀法制备了三种不同浓度Gd_(2)O_(3)改性La_(2)Ce_(2)O_(7)材料((La_(x)Gd_(1-x))2Ce_(2)O_(7)(x=0,0.1,0.2,0.3)),研究了掺杂浓度对其热物理性能及相稳定性的影响,采用等离子喷涂工艺制备了(La_(0.8)Gd_(0.2))2Ce_(2)O_(7)(LGC)涂层,研究了涂层的抗热震性能和涂层的失效机理。研究结果表明:(La_(0.8)Gd_(0.2))2Ce_(2)O_(7)(LGC)材料具有较低的热导率,室温到1400℃无相变,并且经1400℃长时间热处理无相变;其制备的双陶瓷结构LGC/YSZ热障涂层1100℃热震次数可达到109次,较未改性LC/YSZ热障涂层提升了大约60%;两种涂层的失效模式相似,均为陶瓷顶层烧结引起的片状剥落失效。

不同喷涂工艺对Cr3+掺杂Al2O3陶瓷涂层相结构及发光性能影响研究

通过火焰喷涂工艺和等离子喷涂工艺制备了Cr^3+掺杂Al2O3陶瓷涂层。采用扫描电镜、X射线衍射、荧光光谱仪等方法表征了涂层的微观形貌、孔隙率、相结构及发光性能等。对比两种不同工艺制备的Cr^3+掺杂Al2O3陶瓷涂层性能结果表明:等离子喷涂制备的涂层形貌、颗粒熔化状态、厚度均一性均优于火焰喷涂涂层,但火焰喷涂工艺涂层的发光性能远优于等离子工艺涂层,其原因是火焰喷涂制备的涂层中Al2O3粒子的熔融状态更差,保留了更多的α-Al2O3相,未熔粒子部分将以喷涂原粉中稳定的α-Al2O3结构存在涂层中进而影响其光学性能。

Materials design by generalized stability

1.Introduction,Understanding and predicting microstructure and its relationship with the mechanical properties of metallic materials require detailed knowledge of phase transformations(PTs)and plastic deformations(PDs).These two processes,as central topics in material science,can be fundamentally described to a large extent by a framework of thermodynamic and kinetics(thermo-kinetics).The situation of PTs arises when the microstructure is losing phase stability,whereas the issue of PDs corresponds to the break of mechanical stability,all of which can be uniformly defined as the so-called loss of thermodynamic stability(TS).In this context,the higher TS will lead to the higher driving force G essentially required for the PT and/or PD forming and/or changing the microstructure.In the case of PTs,extensive examples showing the high TS can be found,such as martensite transformations(MTs)upon continuous cooling or strain[1,2],coherent precipitation[3,4],so-called Schwarz crystal[5],etc.

中国养老保险制度改革:财务可持续性与公平性

目前,我国养老保险制度正由现收现付制向社会统筹与个人账户相结合的部分积累制转轨。本文从财务可持续性与公平性两方面分析了我国养老保险制度改革的动因及存在的问题,指出我国现阶段养老保险制度改革的各项措施主要是为了维持整个制度的财务可持续性,而缺乏公平性的考虑,这种现象产生的主要原因是政府未解决好制度的转轨成本。

制度改革前后我国基本养老保险的行业差距研究

在我国,行业收入差距已经引起了广泛关注,但是行业养老金差距却一直未引起足够重视。本文通过测算养老金数量、替代率和内含报酬率三种指标,研究了制度改革前后我国基本养老保险的行业差距。主要结论包括:(1)从养老金数量来看,我国养老保险制度改革提高了每个行业的基本养老金待遇,且高收入行业的改善程度更大。(2)从替代率的角度来看,制度改革后各行业总的养老金替代率提高了,且行业之间的差距也缩小了。社会统筹部分的基础养老金替代率尤为明显。(3)从内含报酬率的角度来看,由于制度改革前绝对平均的基础养老金,导致了高收入行业参加基本养老保险面临着'隐性征税'问题。制度改革后,不仅所有行业都存在正的内含报酬率,并且都比改革前要高。在此基础上,本文指出完善我国基本养老保险制度改革还需要重视养老保险缴费基数以及提前退休等问题。

Thermo-kinetic connectivity by integrating thermo-kinetic correlation and generalized stability

Designing structured materials with optimized mechanical properties generally focuses on engineering microstructures,which are closely determined by the processing routes,such as phase transformations(PTs)and plastic deformations(PDs).Both PTs and PDs follow inherent trade-off relation between thermodynamic driving force ΔG and kinetic energy barrier Q,i.e.,so-called thermo-kinetic correlation.By analyzing nucleation and growth and proposing a conception of negative driving force integrating strain energy,interface energy and any kind of energy that equivalently inhibits the PT itself,ΔG^(S),unified expressions for the thermo-kinetic correlation and generalized stability(GS)were derived for three kinds of PTs,i.e.,diffusive PTs with simultaneously decreasedΔG and increased Q,diffusive PTs with simultaneously increasedΔG and decreased Q,and displacive PTs with simultaneously increased ΔG and decreased Q.This leads to so-called thermo-kinetic connectivity by integrating the thermo-kinetic correlation and the GS,where,by application in typical PTs,it was clearly shown,a criterion of high ΔG-high GS can be predicted by modulating chemical driving force,negative driving force and kinetic energy barrier for diffusion or nucleation.Following thermo-kinetic connectivity,analogous procedure for dislocation evolution upon PDs was performed,and materials design in terms of the highΔG-high GS criterion was discussed and prospected.

Bimodular effects of D614G mutation on the spike glycoprotein of SARS-CoV-2 enhance protein processing,membrane fusion,and viral infectivity

Dear Editor,By the end of June 2020,the pandemic of coronavirus diseases 2019(COVID-19)had resulted in more than 10 million individuals,all over the world,being infected with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).1 The high contagiousness of SARS-CoV-2 virus was largely attributed to the relatively unique sequence composition in its spike(S)glycoprotein,which is in charge of the host entry by interacting with its cellular receptor angiotensin-converting enzyme 2(ACE2).2,3 The S glycoprotein can be processed into an N terminal S1 fragment that is responsible for receptor binding,and a C terminal S2 fragment that functions to promote membrane fusion.4 SARS-CoV-2 is a type of single-stranded positive-sense ribonucleic acid(RNA)virus,and an increasing number of mutations were identified across the SARS-CoV-2 genome,including the region encoding S glycoprotein.Nevertheless,the functional implications of these mutations remain largely unknown,we here reported the mutation analysis of S gene and a functional exploration of the dominant D614G mutation.

Discovery of potential anti-SARS-CoV-2 drugs based on large-scale screening in vitro and effect evaluation in vivo

The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARSCoV-2)is a global crisis.Clinical candidates with high efficacy,ready availability,and that do not develop resistance are in urgent need.Despite that screening to repurpose clinically approved drugs has provided a variety of hits shown to be effective against SARS-CoV-2 infection in cell culture,there are few confirmed antiviral candidates in vivo.In this study,94 compounds showing high antiviral activity against SARS-CoV-2 in Vero E6 cells were identified from 2,580 FDA-approved small-molecule drugs.Among them,24 compounds with low cytotoxicity were selected,and of these,17 compounds also effectively suppressed SARS-CoV-2 infection in He La cells transduced with human ACE2.Six compounds disturb multiple processes of the SARSCoV-2 life cycle.Their prophylactic efficacies were determined in vivo using Syrian hamsters challenged with SARS-CoV-2infection.Seven compounds reduced weight loss and promoted weight regain of hamsters infected not only with the original strain but also the D614G variant.Except for cisatracurium,six compounds reduced hamster pulmonary viral load,and IL-6 and TNF-αm RNAwhen assayed at 4 d postinfection.In particular,sertraline,salinomycin,and gilteritinib showed similar protective effects as remdesivir in vivo and did not induce antiviral drug resistance after 10 serial passages of SARS-CoV-2 in vitro,suggesting promising application for COVID-19 treatment.

卫生费用与健康产出:中国在追赶OECD国家吗?

本文考察了1978-2013年中国在人均卫生总费用、人均预期寿命、婴儿死亡率与五岁以下儿童死亡率方面是否追赶OECD国家。通过构建中国与OECD国家在以上指标的差距变量,运用第二代面板单位根和DF-GLS单位根检验方法,本文发现:中国与OECD国家在人均卫生总费用方面不存在追赶,但在健康产出方面明显缩小了差距,尤其体现在婴儿死亡率指标上。因此,综合考虑医疗卫生的投入和产出,中国医疗卫生体制改革所取得的成绩不容忽视。