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333篇 您的检索式:作者名="LENG Yang"
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1Ulinastatin for acute lung injury and acute respiratory distress syndrome: A systematic review and meta-analysis显示文摘AIM: To investigate the efficacy and safety of ulinastatin for patients with acute lung injury(ALI) and those with acute respiratory distress syndrome(ARDS).METHODS: A systematic review of randomized controlled trials(RCTs) of ulinastatin for ALI/ARDS was conducted. Oxygenation index, mortality rate [intensive care unit(ICU) mortality rate, 28-d mortality rate] and length of ICU stay were compared between ulinastatin group and conventional therapy group. Meta-analysis was performed by using Rev Man 5.1.RESULTS: Twenty-nine RCTs with 1726 participants were totally included, the basic conditions of which were similar. No studies discussed adverse effect. Oxygenation index was reported in twenty-six studies(1552 patients). Ulinastatin had a significant effect in improving oxygenation [standard mean difference(SMD) = 1.85, 95%CI: 1.42-2.29, P < 0.00001, I2 = 92%]. ICUmortality and 28-d mortality were respectively reported in eighteen studies(987 patients) and three studies(196 patients). We found that ulinastatin significantly decreased the ICU mortality [I2 = 0%, RR = 0.48, 95%CI: 0.38-0.59, number needed to treat(NNT) = 5.06, P < 0.00001], while the 28-d mortality was not significantly affected(I2 = 0%, RR = 0.78, 95%CI: 0.51-1.19, NNT = 12.66, P = 0.24). The length of ICU stay(six studies, 364 patients) in the ulinastatin group was significantly lower than that in the control group(SMD =-0.97, 95%CI:-1.20--0.75, P < 0.00001, I2 = 86%). CONCLUSION: Ulinastatin seems to be effective for ALI and ARDS though most trials included were of poor quality and no information on safety was provided.Yu-Xin Leng Shu-Guang Yang Ya-Han Song Xi Zhu Gai-Qi Yao 2014World Journal of Critical Care Medicine2014,3,1:61
2Analysis of risk factors for postoperative pancreatic fistula following pancreaticoduodenectomy显示文摘AIM:To explore the morbidity and risk factors of postoperative pancreatic fistula(POPF)following pancreaticoduodenectomy.METHODS:The data from 196 consecutive patients who underwent pancreaticoduodenectomy,performed by different surgeons,in the General Hospital of the People’s Liberation Army between January 1st,2013and December 31st,2013 were retrospectively collected for analysis.The diagnoses of POPF and clinically relevant(CR)-POPF following pancreaticoduodenectomy were judged strictly by the International Study Group on Pancreatic Fistula Definition.Univariate analysis was performed to analyze the following factors:patient age,sex,body mass index(BMI),hypertension,diabetes mellitus,serum CA19-9 level,history of jaundice,serum albumin level,blood loss volume,pancreatic duct diameter,pylorus preserving pancreaticoduodenectomy,pancreatic drainage and pancreaticojejunostomy.Multivariate logistic regression analysis was used to determine the main independent risk factors for POPF.RESULTS:POPF occurred in 126(64.3%)of the patients,and the incidence of CR-POPF was 32.7%(64/196).Patient characteristics of age,sex,BMI,hypertension,diabetes mellitus,serum CA19-9 level,history of jaundice,serum albumin level,blood loss volume,pylorus preserving pancreaticoduodenectomy and pancreaticojejunostomy showed no statistical difference related to the morbidity of POPF or CR-POPF.Pancreatic duct diameter was found to be significantly correlated with POPF rates by univariate analysis and multivariate regression analysis,with a pancreatic duct diameter≤3 mm being an independent risk factor for POPF(OR=0.291;P=0.000)and CR-POPF(OR=0.399;P=0.004).The CR-POPF rate was higher in patients without external pancreatic stenting,which was found to be an independent risk factor for CR-POPF(OR=0.394;P=0.012).Among the entire patient series,there were three postoperative deaths,giving a total mortality rate of 1.5%(3/196),and the mortality associated with pancreatic fistula was 2.4%(3/126).CONCLUSION:A pancreatic duct diameter≤3 mm is an independent risk factor for POPF.External stent drainage of pancreatic secretion may reduce CR-POPF mortality and POPF severity.Qi-Yu Liu Wen-Zhi Zhang Hong-Tian Xia Jian-Jun Leng Tao Wan Bin Liang Tao Yang Jia-Hong Dong 2014World Journal of Gastroenterology2014,20,46:32
3Total glucosides of paeony attenuates animal psoriasis induced inflammatory response through inhibiting STAT1 and STAT3 phosphorylation显示文摘OBJECTIVE Psoriasis is an immune system meditated disease,especially T cells.It disturbed many people around the world and hard to therapy.Paeonia lactiflora Pall has been used as a medicine in china for thousands of years.Recent studies has found that the main component of Paeonia lactiflora Pall can alleviates the immune response in many diseases.In this study,we researched the effects and possible mechanisms of total glucosides of paeony(TGP)on animal psoriasis in order to study the therapeutic effects and mechanisms of TGP in 5%propranolol creaminduced psoriasis in guinea pigs and Imiquimod(IMQ)cream-induced psoriasis in mice.METHODS The effect of TGP was evaluated using a psoriasis-like model of guinea pigs and mice.Ear thickness was accessed,and pathology injury was observed by HE staining.The levels of serum IL-1β,IL-6,IL-12,IL-17,IL-23,TNF-α,and IFN-γ,skin IL-17A,IL-22 and orphan nuclear receptor(RORγt)mRNA expression,proliferating cell nuclear antigen(PCNA),total or phosphorylated signal transducers and activators of transcription(STAT1 and STAT3)were determined by ELISA,real time PCR,immu⁃nohistochemical staining,and Western blotting,respectively.RESULTS Compared with model group,TGP treatment decreased the ear thickness,improved pathology of psoriasis,alleviated IMQ-induced keratinocyte proliferation,reduced the inflammatory cytokine,and downregulated IL-17A,IL-22,and RORγt mRNA in mice.Further study indicated that TGP inhibited STAT1 and STAT3 phosphorylation in lesion skins of psoriasis-like mice.CONCLUSION TGP alleviates the symptoms of psoriasis-like guinea pigs and mice,and the possible mechanism may relate to inhibit T helper 17(TH17)cell differentiation and keratinocytes proliferation by inhibiting STAT1 and STAT3 phosphorylation.LI Bin-bin HE Shu-cheng LIU Rui HUANG Liang-liang LIU Ge WANG Rui-xuan YANG Zhuo-yue LIU Xin-yi LENG Ye LIU Dan YE Cheng-yu LI Yun-man CHEN Yong-jian IN Hong FANG Wei-rong 2019中国药理学与毒理学杂志2019,33,9:21
4Water regime-nitrogen fertilizer incorporation interaction:Field study on methane and nitrous oxide emissions from a rice agroecosystem in Harbin, China显示文摘Water regime and nitrogen(N) fertilizer are two important factors impacting greenhouse gases(GHG) emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we conducted a two-year field experiment to study the impacts of water regime and N fertilizer on rice yields and GHG emissions in Harbin, China, a cold region located in high latitudes. Our results showed that intermittent irrigation significantly decreased methane(CH_4) emission compared with continuous flooding, however,the decrement was far lower than the global average level. The N_2O emissions were very small when flooded but peaked at the beginning of the disappearance of floodwater. The N fertilizer treatments increased CH_4 emissions at low level(75 kg N/ha). But both CH_4 and N_2O emissions were uninfluenced at the levels of 150 kg N/ha and 225 kg N/ha. Rice yields increased under intermittent irrigation and were highest at the level of 150 kg N/ha. From our results, we recommended that the intermittent irrigation and 150 kg N/ha as the ideal water regime-nitrogen fertilizer incorporation for this area to achieve low GHG emissions without impacting rice yields.Wenjun Dong Jia Guo Lijun Xu Zhifeng Song Jun Zhang Ao Tang Xijuan Zhang Chunxu Leng Youhong Liu Lianmin Wang Lizhi Wang Yang Yu Zhongliang Yang Yilei Yu Ying Meng Yongcai Lai 2018Journal of Environmental Sciences2018,30,2:12
5Morphological analysis on adhesion and invasion involved in endometriosis with tissue culture显示文摘背景子宫内膜增生(他们) 是主要在繁殖 age.However 的女人发现的良性的妇科的疾病,它的致病仍然糟糕被理解。我们的实验被设计为子宫内膜和腹膜的 coculture 建立一个马厩和可靠文化环境,在 laparoscopy 期间与 endometriois 从 6 个女人被取样以便从病人观察子宫内膜的粘附 / 侵略能力与或没有能分泌的阶段和腹膜的 EM.Methods Endometria。六作为控制与卵巢的 teratoma 或简单卵巢的包囊被拿。我们进四的 cocultured 子宫内膜和腹膜组织(从与从他们的腹膜有教养的他们的子宫内膜,从与从控制的腹膜有教养的控制的子宫内膜,从与从非他们的腹膜有教养的他们的子宫内膜和从与从他们的腹膜有教养的控制的子宫内膜)在煤气液体的表面文化和在里面中等的文化观察粘附/侵略进程。标本为组织学在 1 个小时 6 个小时 12 个小时 24 个小时, 2 天, 3 天, 4 天, 5 天, 6 天和 7 天被收集, cytokeratin 上的 immunofluorescence 和 immunohistochemical 分析 8 ( CK8 )并且 CD10.Results 煤气液体的表面文化比为织物形态学和子宫内膜的幸存的维护的在里面中等的文化优异。CK8 immunoflurescence 没有或没有他们在在病人之间的粘附过程表明显著差别。 CD10 免疫化学从他们病人表明了子宫内膜的 stromal 房间的经常的侵略进多达 3 天文化的腹膜,当从非他们病人的 endometriotic 房间没入侵煤气液体的表面进 peritoneum.Conclusions 时,文化是为观察到在从有他们的病人的他们损害 formation.Endometrium 的早事件在 coculture 期间显示出增加的侵略能力的一个合适的模型,它可能帮助解释子宫内膜增生的病原学。SHI Jing-hua YANG Yan-jun DONG Zhe LANG Jing-he LENG Jin-hua 2011Chinese Medical Journal2011,,1:11
6DBPM signal processing with field programmable gate arrays显示文摘DBPM system performance is determined by the design and implementation of beam position signal processing algorithm.In order to develop the system,a beam position signal processing algorithm is implemented on FPGA.The hardware is a PMC board ICS-1554A-002(GE Corp.)with FPGA chip XC5VSX95T.This paper adopts quadrature frequency mixing to down convert high frequency signal to base.Different from conventional method,the mixing is implemented by CORDIC algorithm.The algorithm theory and implementation details are discussed in this paper.As the board contains no front end gain controller,this paper introduces a published patent-pending technique that has been adopted to realize the function in digital logic.The whole design is implemented with VHDL language. An on-line evaluation has been carried on SSRF(Shanghai Synchrotron Radiation Facility)storage ring.Results indicate that the system turn-by-turn data can measure the real beam movement accurately,and system resolution is 1.1μm.LAI Longwei LENG Yongbin YI Xing YAN Yingbing ZHANG Ning YANG Guisen WANG Baopeng XIONG Yun 2011Nuclear Science and Techniques2011,22,3:10
7Endovascular treatment with or without intravenous alteplase for acute ischaemic stroke due to basilar artery occlusion显示文摘Background and purpose It remains controversial if endovascular treatment(EVT)can improve the outcome of patients with acute basilar artery occlusion(BAO).This study aims to compare the functional outcomes between EVT with and without intravenous thrombolysis(IVT)first in patients who had acute ischaemic stroke(AIS)due to BAO.Methods Patients who had AIS with BAO who underwent EVT within 24 hours of onset were enrolled in this multicentre cohort study,and the efficacy and safety were compared between IVT+EVT and direct EVT.The primary outcome was 90-day functional independence.All outcomes were assessed with adjusted OR(aOR)from the multivariable logistic regression.In addition,a meta-analysis was performed on all recently published pivotal studies on functional independence after EVT in patients with BAO.Results Of 310 enrolled patients with BAO,241(78%)were treated with direct EVT and 69(22%)with IVT+EVT.Direct EVT was associated with a worse functional outcome(aOR,0.46(95%CI 0.24 to 0.85),p=0.01).IVT+EVT was associated with a lower percentage of patients who needed≥3 passes of stent retriever(10.14%vs 20.75%).The meta-analysis regression revealed a potential positive correlation between bridging with IVT first and functional independence(r=0.14(95%CI 0.05 to 0.24),p<0.01).Conclusions This study showed that compared with direct EVT,EVT with IVT first was associated with better functional outcomes in patients with BAO treated within 24 hours of onset.The meta-analysis demonstrated similar favourable efficacy of IVT first followed by EVT in patients with BAO.Ximing Nie David Wang Yuehua Pu Yufei Wei Qixuan Lu Hongyi Yan Xin Liu Lina Zheng Jingyi Liu Xinxuan Yang Yarong Ding Dacheng Liu Wanying Duan Zhe Zhang Zhonghua Yang Miao Wen Weibin Gu Xinyi Hou Xinyi Leng Yuesong Pan Zhongrong Miao Liping Liu 2022Stroke & Vascular Neurology2022,7,3:10
8LSD1 coordinates with the SIN3A/HDAC complex and maintains sensitivity to chemotherapy in breast cancer显示文摘Yang Yang Wei Huang Rongfang Qiu Ruiqiong Liu Yi Zeng Jie Gao Yu Zheng Yongqiang Hou Shuang Wang Wenqian Yu Shuai Leng Dandan Feng Yan Wang 2018Journal of Molecular Cell Biology2018,10,4:10
9The status of exploitation techniques of natural gas hydrate显示文摘Natural gas hydrate(NGH)has been widely considered as an alternative form of energy with huge potential,due to its tremendous reserves,cleanness and high energy density.Several countries involving Japan,Canada,India and China have launched national projects on the exploration and exploitation of gas hydrate resources.At the beginning of this century,an early trial production of hydrate resources was carried out in Mallik permafrost region,Canada.Japan has conducted the first field test from marine hydrates in 2013,followed by another trial in 2017.China also made its first trial production from marine hydrate sediments in 2017.Yet the low production efficiency,ice/hydrate regeneration,and sand problems are still commonly encountered;the worldwide progress is far before commercialization.Up to now,many gas production techniques have been proposed,and a few of them have been adopted in the field production tests.Nevertheless,hardly any method appears really promising;each of them shows limitations at certain conditions.Therefore,further efforts should be made on the economic efficiency as well as sustainability and environmental impacts.In this paper,the investigations on NGH exploitation techniques are comprehensively reviewed,involving depressurization,thermal stimulation,chemical inhibitor injection,CO2–CH4 exchange,their combinations,and some novel techniques.The behavior of each method and its further potential in the field test are discussed.The advantages and limitations of laboratory studies are also analyzed.The work could give some guidance in the future formulation of exploitation scheme and evaluation of gas production behavior from hydrate reservoirs.Lei Yang Yulong Liu Hanquan Zhang Bo Xiao Xianwei Guo Rupeng Wei Lei Xu Lingjie Sun Bin Yu Shudong Leng Yanghui Li 2019Chinese Journal of Chemical Engineering2019,27,9:9
10Micro/nano-structured TiO2 surface with dual-functional antibacterial effects for biomedical applications显示文摘Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.Xiang Ge Chengzu Ren Yonghui Ding Guang Chen Xiong Lu Kefeng Wang Fuzeng Ren Meng Yang Zhuochen Wang Junlan Li Xinxin An Bao Qian Yang Leng 2019Bioactive Materials2019,4,1:8
11Characterization and fine mapping of an early senescence mutant (es-t) in Oryza sativa L.显示文摘An es-t (early senescence-temporary) mutant, produced by ethylene methylsulfonate treatment of strain Nipponbare, was identified in rice. The leaves of es-t appeared yellow at the seedling stage, and had decreased chlorophyll content. Rust spots were found during growth in es-t, especially at the leaf margin and tip. The plants showed a typical early-senescence phenotype at the milky stage. The leaf surface of es-t appeared smoother than wild-type leaves under a scanning electron microscope, because the leaves lack siliceous protuberances around the stoma. Chloroplasts grow abnormally and are filled with many starch grains in es-t. Paraffin section analysis showed that the development of the sclerenchyma cells and vascular bundles were also abnormal in es-t. Genetic analysis indicated that es-t was controlled by a recessive gene, which was finely mapped to a 42-kb interval on chromosome 5. These results will facilitate the positional cloning and functional studies of the gene.YANG YaoLong RAO YuChun LIU HuiJuan FANG YunXia DONG GuoJun HUANG LiChao LENG YuJia GUO LonBiao ZHANG GuangHeng HU Jiang GAO ZhenYu QIAN Qian ZENG DaLi 2011Chinese Science Bulletin2011,56,23:8
12Allele-defined genome reveals biallelic differentiation during cassava evolution显示文摘Dear Editor,Generation of heterozygous genomes by hybridization between or within species can help maintain plant diversity and serve as a potential source of new species(Baek et al.,2018).Moreover,genomic heterozygosity is associated with genomic coadaptation,developmental stability,and heterosis.Accurate definition of alleles in haplotypes is necessary to precisely characterize allelic variation controlling agriculturally important traits(Shi et al.,2019).Currently,most released genomes have mosaic assembly of haplotypes due to random selection or collapse of alleles during genome assembly(Shi et al.,2019),which masked allelic variation and functional differentiation of divergent alleles in heterozygous species.Wei Hu Changmian Ji Haitao shi Zhe Liang Zehong Ding Jianqiu Ye Wenjun Ou Gang Zhou Weiwei Tie Yan Yan Jinghao Yang Xiaoying Yang Yunxie Wei Zhiqiang Jin Jianghui Xie Ming Peng Wenquan Wang Anping Guo Biyu Xu Jianchun Guo Songbi Chen Liming Ma Mingcheng Wang Yang Zhou Xiaolong Li Ruoxi Li Siyi Guo Xinhui Xiao Zhongqing Wan Feifei An Jie Zhang Qingyun Leng Yin Li Ray Ming Kaimian Li 2021Molecular Plant2021,14,6:8
13LncRNAs-directed PTEN enzymatic switch governs epithelial–mesenchymal transition显示文摘Despite the structural conservation of PTEN with dual-specificity phosphatases,there have been no reports regarding the regulatory mechanisms that underlie this potential dual-phosphatase activity.Here,we report that K27-linked polyubiquitination of PTEN at lysines 66 and 80 switches its phosphoinositide/protein tyrosine phosphatase activity to protein serine/threonine phosphatase activity.Mechanistically,high glucose,TGF-β,CTGF,SHH,and IL-6 induce the expression of a long non-coding RNA,GAEA(Glucose Aroused for EMT Activation),which associates with an RNA-binding E3 ligase,MEX3C,and enhances its enzymatic activity,leading to the K27-linked polyubiquitination of PTEN.The MEX3C-catalyzed PTEN^K27-polyUb activates its protein serine/threonine phosphatase activity and inhibits its phosphatidylinositol/protein tyrosine phosphatase activity.With this altered enzymatic activity,PTEN^K27-polyUb dephosphorylates the phosphoserine/threonine residues of TWIST1,SNAI1,and YAP1,leading to accumulation of these master regulators of EMT.Animals with genetic inhibition of PTEN^K27-polyUb,by a single nucleotide mutation generated using CRISPR/Cas9(Pten^K80R/K80R),exhibit inhibition of EMT markers during mammary gland morphogenesis in pregnancy/lactation and during cutaneous wound healing processes.Our findings illustrate an unexpected paradigm in which the lncRNA-dependent switch in PTEN protein serine/threonine phosphatase activity is important for physiological homeostasis and disease development.Qingsong Hu Chunlai Li Shouyu Wang Yajuan Li Bo Wen Yanyan Zhang Ke Liang Jun Yao Youqiong Ye Heidi Hsiao Tina K.Nguyen Peter K.Park Sergey D.Egranov David H.Hawke Jeffrey R.Marks Leng Han Mien-Chie Hung Bing Zhang Chunru Lin Liuqing Yang 2019Cell Research2019,29,4:8
14On the heterogeneous microstructure development in the welded joint of 12MnNiVR pressure vessel steel subjected to high heat input electrogas welding显示文摘Microstructure features of 12 MnNiVR pressure vessel steel welded joint deposited by the high heat input electrogas welding have been systematically investigated. It is revealed that the welded joint is featured by a heterogeneous juxtaposition. The coarse grained heat-affected zone(CGHAZ) primarily consists of lath bainites and minor granular bainites. The fine grained heat-affected zone(FGHAZ) is dominated by polygonal ferrites, pearlites, and fine cementite particles. Moreover, electron backscatter diffraction results further demonstrate that the CGHAZ is populated by coarse prior austenite grains(PAGs) with high frequency(61.3%) of low angle grain boundaries(LAGBs). On the other hand, the FGHAZ is filled with fine PAGs with a lower frequency(19.6%) of LAGBs. Such microstructural differences may likely contribute to differed mechanical properties for samples tested at designed positions.Yang Shen Ju Leng Cong Wang 2019Journal of Materials Science & Technology2019,35,8:8
15Molecular hydrogen isotope analysis of living and fossil plants—Metasequoia as an example显示文摘Molecular hydrogen isotope analysis preformed on modern and fossil plants has made a significant impact on diverse research fields in biology and geology. Using living and fossil Metasequoia as an example, we review the technology of online GC-IRMS that made the molecular analysis of hydrogen isotope possible and discuss critical issues concerning with the studies of molecular dD and its applications. The apparent hydrogen fractionation factors between lipid molecules and source water (ewater–lipid) vary across plant taxonomy and differ among biomolecules and are affected by multiple environmental factors in which precipitation dD values exercise the first order of control. Eco-physiological factors and environmental parameters are also known to influence dD in plants. Molecular hydrogen isotope analysis of chemically stable lipid molecules, such as n-alkanes, finds a wide range of applications in detecting source sediments, reconstruction of paleoclimatic parameters, inference of air-mass trajectory, as well as in petroleum industry and environmental studies.Hong Yang Qin Leng 2009Progress in Natural Science:Materials International2009,19,8:7
16A Scenario-Based Evaluation of COVID-19-Related Essential Clinical Resource Demands in China显示文摘The coronavirus disease 2019(COVID-19)pandemic is a global crisis,and medical systems in many countries are overwhelmed with supply shortages and increasing demands to treat patients due to the surge in cases and severe illnesses.This study aimed to assess COVID-19-related essential clinical resource demands in China,based on different scenarios involving COVID-19 spreads and interventions.We used a susceptible–exposed–infectious–hospitalized/isolated–removed(SEIHR)transmission dynamics model to estimate the number of COVID-19 infections and hospitalizations with corresponding essential healthcare resources needed.We found that,under strict non-pharmaceutical interventions(NPIs)or mass vaccination of the population,China would be able to contain community transmission and local outbreaks rapidly.However,under scenarios involving a low intensity of implemented NPIs and a small proportion of the population vaccinated,the use of a peacetime–wartime transition model would be needed for medical source stockpiles and preparations to ensure a normal functioning healthcare system.The implementation of COVID-19 vaccines and NPIs in different periods can influence the transmission of COVID-19 and subsequently affect the demand for clinical diagnosis and treatment.An increased proportion of asymptomatic infections in simulations will not reduce the demand for medical resources;however,attention must be paid to the increasing difficulty in containing COVID-19 transmission due to asymptomatic cases.This study provides evidence for emergency preparations and the adjustment of prevention and control strategies during the COVID-19 pandemic.It also provides guidance for essential healthcare investment and resource allocation.Ting Zhang Qing Wang Zhiwei Leng Yuan Yang Jin Yang Fangyuan Chen Mengmeng Jia Xingxing Zhang Weiran Qi Yunshao Xu Siya Chen Peixi Dai Libing Ma Luzhao Feng Weizhong Yang 2021Engineering2021,7,7:7
17World’s first spaceflight on-orbit demonstration of a flexible solar array system based on shape memory polymer composites显示文摘With a 10%reversible compressive strain in more than 10 deformation cycles,the shape memory polymer composites(SMPCs)could be used for deployable structure and releasing mechanism.In this paper,without traditional electro-explosive devices or motors/controllers,the deployable SMPC flexible solar array system(SMPC-FSAS)is studied,developed,ground-based tested,and finally on-orbit validated.The epoxy-based SMPC is used for the rolling-out variable-stiffness beams as a structural frame as well as an actuator for the flexible blanket solar array.The releasing mechanism is primarily made of the cyanate-based SMPC,which has a high locking stiffness to withstand 50 g gravitational acceleration and a large unlocking displacement of 10 mm.The systematical mechanical and thermal qualification tests of the SMPC-FSAS flight hardware were performed,including sinusoidal sweeping vibration,shocking,acceleration,thermal equilibrium,thermal vacuum cycling,and thermal cycling test.The locking function of the SMPC releasing mechanisms was in normal when launching aboard the SJ20 Geostationary Satellite on 27 Dec.,2019.The SMPC-FSAS flight hardware successfully unlocked and deployed on 5 Jan.,2020 on geostationary orbit.The triggering signal of limit switches returned to ground at the 139 s upon heating,which indicated the successful unlocking function of SMPC releasing mechanisms.A pair of epoxy-based SMPC rolled variable-stiffness tubes,which clapped the flexible blanket solar array,slowly deployed and finally approached an approximate 100%shape recovery ratio within 60 s upon heating.The study and on-orbit successful validation of the SMPC-FSAS flight hardware could accelerate the related study and associated productions to be used for the next-generation releasing mechanisms as well as space deployable structures,such as new releasing mechanisms with low-shocking,testability and reusability,and ultra-large space deployable solar arrays.LAN Xin LIU LiWu ZHANG FengHua LIU ZhengXian WANG LinLin LI QiFeng PENG Fan HAO SiDa DAI WenXu WAN Xue TANG Yong WANG Mian HAO YanYan YANG Yang YANG Cheng LIU YanJu LENG JinSong 2020Science China(Technological Sciences)2020,63,8:7
18Ecological provinces of spring phytoplankton in the Yellow Sea:species composition显示文摘Phytoplanktonic ecological provinces of the Yellow Sea(31.20°–39.23°N, 121.00°–125.16°E) is derived in terms of species composition and hydrological factors(temperature and salinity). 173 samples were collected from 40 stations from April 28 to May 18, 2014, and a total of 185 phytoplanktonic algal species belonging to 81 genera of 7phyla were identified by Uterm?hl method. Phytoplankton abundance in surface waters is concentrated in the west coast of Korean Peninsula and Korea Bay, and communities in those areas are mainly composed of diatoms and cyanobacteria with dominant species of Cylindrotheca closterium, Synechocystis pevalekii, Chroomonas acuta,Paralia sulcata, Thalassiosira pacifica and Karenia mikimotoi, etc. The first ten dominant species of the investigation area are analyzed by multidimensional scaling(MDS) and cluster analysis, then the Yellow Sea is divided into five provinces from Province I(P-I) to Province V(P-V). P-I includes the coastal areas near southern Liaodong Peninsula, with phytoplankton abundance of 35 420×10~3–36 163×10~3 cells/L and an average of 35 791×10~3 cells/L, and 99.84% of biomass is contributed by cyanobacteria. P-II is from Shandong Peninsula to Subei coastal area. Phytoplankton abundance is in a range of 2×10~3–48×10~3 cells/L with an average of 24×10~3cells/L, and 63.69% of biomass is contributed by diatoms. P-III represents the Changjiang(Yangtze River) Diluted Water. Phytoplankton abundance is 10×10~3–37×10~3 cells/L with an average of 24×10~3 cells/L, and 73.14% of biomass is contributed by diatoms. P-IV represents the area affected by the Yellow Sea Warm Current.Phytoplankton abundance ranges from 6×10~3 to 82×10~3 cells/L with an average of 28×10~3 cells/L, and 64.17% of biomass is contributed by diatoms. P-V represents the cold water mass of northern Yellow Sea. Phytoplankton abundance is in a range of 41×10~3–8 912×10~3 cells/L with an average of 1 763×10~3 cells/L, and 89.96% of biomass is contributed by diatoms. Overall, structures of phytoplankton community in spring are quite heterogeneous in different provinces. Canonical correspondence analysis(CCA) result illustrates the relationship between dominant species and environmental factors, and demonstrates that the main environmental factors that affect phytoplankton distribution are nitrate, temperature and salinity.ZHANG Shan LENG Xiaoyun FENG Yuanyuan DING Changlin YANG Yang WANG Jing WANG Houjie SUN Jun 2016Acta Oceanologica Sinica2016,35,8:7
19Mechanism and kinetics study on removal of Iron from phosphoric acid by cation exchange resin显示文摘Iron element is one of the main impurities in wet-process phosphoric acid and it has a significant impact on the subsequent phosphorus chemical products. This paper studied the feasibility of using Sinco-430 cation exchange resin for iron removal from phosphoric acid. The specific surface area and the total exchange capacity of resin were 8.91 m2·g-1 and 5.18 mmol·g-1, respectively. The sorption mechanism was determined by FTIR and XPS and the results indicated that iron was combined with-SO3 H in resin. The removal process was studied as a function of temperature, H3 PO4 content and mass ratio between resin and solution. The unit mass of resin to remove iron was 0.058 g·g-1 resin when the operating parameters were T = 50 ℃, H3 PO4 content = 27.61 wt%and S/L = 0.1, respectively. Kinetics study demonstrated that pseudo-second-order reaction model fits this study best and the calculated activation energy of overall reaction is 29.10 kJ·mol-1. The overall reaction process was mainly controlled by pore diffusion.Xinke Leng Yanjun Zhong Dehua Xu Xinlong Wang Lin Yang 2019Chinese Journal of Chemical Engineering2019,27,5:7
20Development of the bunch-by-bunch beam position acquisition system based on BEEcube显示文摘In this paper, we report the development of a bunch-by-bunch beam position acquisition system.Through a wideband synthesizer of PLL, the system realizes synchronous clock of bunch signal. Based on the highperformance FPGA hardware DAQ environment, fourchannel raw data of beam signal can be achieved. Test results in the SSRF storage ring show that the system can obtain beam position of single bunch with the resolution of10 lm and multi-bunch instability can be observed.Yong Yang Yong-Bin Leng Ying-Bing Yan Wei-Min Zhou Ren-Xian Yuan Zhi-Chu Chen 2016Nuclear Science and Techniques2016,27,2:6
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