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Effects of acetylcysteine on micro-inflammation and pulmonary ventilation in chronic obstructive pulmonary disease exacerbation
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作者 Li-Yuan Huang Bin Huang +1 位作者 zheng lv Xiao-Dan Lu 《World Journal of Clinical Cases》 SCIE 2024年第18期3482-3490,共9页
BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is a serious complication of chronic obstructive pulmonary disease,often characterized by increased morbidity and mortality.In traditional ... BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is a serious complication of chronic obstructive pulmonary disease,often characterized by increased morbidity and mortality.In traditional Chinese medicine,AECOPD is linked to phlegm-heat and blood-stasis,presenting symptoms like thick sputum,fever,and chest pain.It has been shown that acetylcysteine inhalation in conjunction with conventional therapy significantly reduced inflammatory markers and improved lung function parameters in patients with AECOPD,suggesting that acetylcysteine may be an important adjunctive therapy for patients with phlegm-heat-blood stasis type AECOPD.AIM To investigate the effect of acetylcysteine on microinflammation and lung ventilation in patients with phlegm-heat and blood-stasis-type AECOPD.METHODS One hundred patients with phlegm-heat and blood-stasis-type AECOPD were randomly assigned to two groups.The treatment group received acetylcysteine inhalation(10%solution,5 mL,twice daily)along with conventional therapy,whereas the control group received only conventional therapy.The treatment duration was 14 d.Inflammatory markers(C-reactive protein,interleukin-6,and tumor necrosis factor-alpha)in the serum and sputum as well as lung function parameters(forced expiratory volume in one second,forced vital capacity,and peak expiratory flow)were assessed pre-and post-treatment.Acetylcysteine inhalation led to significant reductions in inflammatory markers and improvements in lung function parameters compared to those in the control group(P<0.05).This suggests that acetylcysteine could serve as an effective adjunct therapy for patients with phlegm-heat and blood-stasis-type AECOPD.RESULTS Acetylcysteine inhalation significantly reduced inflammatory markers in the serum and sputum and improved lung ventilation function parameters in patients with phlegm-heat and blood-stasis type AECOPD compared with the control group.These differences were statistically significant(P<0.05).The study concluded that acetylcysteine inhalation had a positive effect on microinflammation and lung ventilation function in patients with this type of AECOPD,suggesting its potential as an adjuvant therapy for such cases.CONCLUSION Acetylcysteine inhalation demonstrated significant improvements in reducing inflammatory markers in the serum and sputum,as well as enhancing lung ventilation function parameters in patients with phlegm-heat and bloodstasis type AECOPD.These findings suggest that acetylcysteine could serve as a valuable adjuvant therapy for individuals with this specific type of AECOPD,offering benefits for managing microinflammation and optimizing lung function. 展开更多
关键词 Acute exacerbation Chronic obstructive pulmonary disease Traditional Chinese medicine ACETYLCYSTEINE Phlegm-heat and blood-stasis Lung ventilation function
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A direct probabilistic approach to solve state equations for nonlinear systems under random excitation 被引量:1
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作者 zheng lv Zhiping Qiu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第5期941-958,共18页
In this paper, a direct probabilistic approach(DPA) is presented to formulate and solve moment equations for nonlinear systems excited by environmental loads that can be either a stationary or nonstationary random p... In this paper, a direct probabilistic approach(DPA) is presented to formulate and solve moment equations for nonlinear systems excited by environmental loads that can be either a stationary or nonstationary random process.The proposed method has the advantage of obtaining the response's moments directly from the initial conditions and statistical characteristics of the corresponding external excitations. First, the response's moment equations are directly derived based on a DPA, which is completely independent of the It?/filtering approach since no specific assumptions regarding the correlation structure of excitation are made.By solving them under Gaussian closure, the response's moments can be obtained. Subsequently, a multiscale algorithm for the numerical solution of moment equations is exploited to improve computational efficiency and avoid much wall-clock time. Finally, a comparison of the results with Monte Carlo(MC) simulation gives good agreement.Furthermore, the advantage of the multiscale algorithm in terms of efficiency is also demonstrated by an engineering example. 展开更多
关键词 Direct probabilistic approach Nonlinear dynamic system Nonstationary random process Response’s moments Multiscale algorithm
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Utilizing Dynamic Data to Quickly Evaluate Advantageous Channels and Applications
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作者 Jianguo Liu Rui Zhang +2 位作者 zheng lv Meinan Wang Guohao Zhang 《World Journal of Engineering and Technology》 2023年第3期417-423,共7页
In response to the high cost and difficulty of high-speed development and testing data in offshore oil fields, this paper proposes to use the most easily available production performance data as the basis and use the ... In response to the high cost and difficulty of high-speed development and testing data in offshore oil fields, this paper proposes to use the most easily available production performance data as the basis and use the grey correlation method to calculate the correlation coefficient between oil and water wells to characterize the degree of development of advantageous channels. The consistency between the calculated results of this method and the tracer test results is over 80%. Based on the fitting results, the correlation coefficient exceeds 0.74 to determine the existence of an advantageous channel. According to the research results of grey correlation method, Bohai K oilfield has completed the combined profile control and flooding measures, and the daily oil production has increased by 20 m3</sup>/d. This method is simple, fast, and can achieve quantitative evaluation, which saves time and investment compared to offshore testing. It has strong application and reference value for the development of other offshore water injection oilfields. 展开更多
关键词 Offshore Oil Fields Production Performance Correlation Coefficient Advantageous Channel Quantitative Assessment
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An Effective Thin Reservoir Identification Method for Fine Oilfield Development
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作者 zheng lv Xin Wang +1 位作者 Chunyuan Shi Junting Zhang 《Engineering(科研)》 CAS 2023年第5期342-351,共10页
Thin reservoirs prediction method such as spectral inversion has drawn considerable attention in recent years. In order to avoid extracting wavelets within the whole field area purposeless and to make the filtered dat... Thin reservoirs prediction method such as spectral inversion has drawn considerable attention in recent years. In order to avoid extracting wavelets within the whole field area purposeless and to make the filtered data has preferable fidelity as well as signal-to-noise ratio, an effective structural constrained thin reservoir description method which combines spectral inversion and wide-band Ricker wavelet filtering technology has been proposed in this paper. The method given here is more credible and is suitable for the prediction of middle-deep thin reservoirs. We take LD-A structure within Bohai Bay Basin as an example to show the implement of our method. Several sets of thin sand layers which are hardly to recognize originally have been finally identified. Also, with the application of this method, a high-production thin reservoir of LD-B structure has been identified accurately, which provides credible information for subsequent fine oil exploration and development. 展开更多
关键词 Structure Constrained Thin Reservoir Spectral Inversion Wide-Band Ricker Wavelet Exploration and Development
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Establishment of Unstable Flow Model and Well Testing Analysis for Viscoelastic Polymer Flooding
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作者 zheng lv Meinan Wang 《World Journal of Engineering and Technology》 2023年第2期273-280,共8页
At present, the polymer solution is usually assumed to be Newtonian fluid or pseudoplastic fluid, and its elasticity is not considered on the study of polymer flooding well testing model. A large number of experiments... At present, the polymer solution is usually assumed to be Newtonian fluid or pseudoplastic fluid, and its elasticity is not considered on the study of polymer flooding well testing model. A large number of experiments have shown that polymer solutions have viscoelasticity, and disregarding the elasticity will cause certain errors in the analysis of polymer solution seepage law. Based on the percolation theory, this paper describes the polymer flooding mechanism from the two aspects of viscous effect and elastic effect, the mathematical model of oil water two-phase three components unsteady flow in viscoelastic polymer flooding was established, and solved by finite difference method, and the well-test curve was drawn to analyze the rule of well test curve in polymer flooding. The results show that, the degree of upward warping in the radial flow section of the pressure recovery curve when considering polymer elasticity is greater than the curve which not considering polymer elasticity. The relaxation time, power-law index, polymer injection concentration mainly affect the radial flow stage of the well testing curve. The relaxation time, power-law index, polymer injection concentration and other polymer flooding parameters mainly affect the radial flow stage of the well testing curve. The larger the polymer flooding parameters, the greater the degree of upwarping of the radial flow derivative curve. This model has important reference significance for well-testing research in polymer flooding oilfields. 展开更多
关键词 Polymer Flooding VISCOELASTICITY Well Testing Mathematical Model Seepage Law
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Diagnostic Method and Adaptability Analysis of Multiple Water Breakthroughs in Horizontal Well in Combined Well Pattern
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作者 zheng lv Meinan Wang +2 位作者 Guohao Zhang Rui Zhang Jianguo Liu 《Journal of Geoscience and Environment Protection》 2023年第5期150-158,共9页
The combined well pattern has been widely used in reservoir development, with a common pattern being a horizontal well in the center for oil production and multiple vertical wells around for water injection. For this ... The combined well pattern has been widely used in reservoir development, with a common pattern being a horizontal well in the center for oil production and multiple vertical wells around for water injection. For this type of well pattern, determining the horizontal well is affected by which injection wells, especially when the injecting water breaks through, accurately determining the direction of water inflow will provide an important basis for targeted water well measures. Based on the production performance data of horizontal wells, the semi logarithmic relationship curves of water-oil ratio, derivative water-oil ratio, and cumulative production were used for the first time to determine the breakthrough problem of water injection in the surrounding water injection wells of horizontal wells based on their response characteristics. The adaptability of this method under different influencing factors was analyzed. Introducing the parameter of cumulative production not only preserves the variation trend of the derivative of water-oil ratio with time, but also facilitates the processing of actual production data. 展开更多
关键词 Combined Well Pattern Multiple Water Breakthroughs in Horizontal Derivative of Water-Oil Ratio
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局部氧自由基的性质促进电催化乙醇选择性生成CO_(2)
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作者 周双龙 赵亮 +4 位作者 吕征 代钰 张琦 赖建平 王磊 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第9期154-163,共10页
碱性燃料电池可以避免卡诺循环效应的限制,因而被认为是最具有发展潜力的能源转换器件之一.与其它燃料相比,乙醇来源丰富,储存和运输成本较低,更适合作为燃料电池的能量来源.但在乙醇氧化反应(EOR)过程中,通常发生2个或6个电子转移的不... 碱性燃料电池可以避免卡诺循环效应的限制,因而被认为是最具有发展潜力的能源转换器件之一.与其它燃料相比,乙醇来源丰富,储存和运输成本较低,更适合作为燃料电池的能量来源.但在乙醇氧化反应(EOR)过程中,通常发生2个或6个电子转移的不完全氧化反应,而不是转移12个电子的完全氧化过程.除催化剂对C-C键裂解能力较低外,中间体对催化剂的毒化也是造成乙醇不能被完全氧化的原因.大量研究表明,增强催化剂对OH*和O*的吸附可以有效促进C-C键的裂解并提高催化剂的抗毒化性能.然而,不同氧物种对C-C键裂解的作用尚不明确.本文将人工氧化酶应用在EOR中,并在此基础上探究了不同氧自由基在乙醇氧化过程中的作用.本文发现一种可以催化氧气原位生成活性氧物种(ROS)的人工氧化酶,并利用该特点,将人工氧化酶应用于EOR中,同时探究了不同ROS在乙醇完全氧化中的作用.当没有ROS时,催化剂的质量活性为7.6 A mg_(Pt)^(-1),二氧化碳的法拉第效率仅为12.4%;而在ROS的作用下,催化剂的质量活性可以达到18.2 A mg_(Pt)^(-1),二氧化碳的法拉第效率达到98.7%.这说明ROS的存在有助于提升催化剂活性和二氧化碳选择性.与PtSn IM/C相比,商业Pt/C只能生成少量的羟基自由基,没有检测到单线态氧和超氧阴离子,表明Sn元素的引入可以优化Pt的电子结构,并改善催化剂的表面配位方式,提高催化剂的氧化酶活性.利用原位红外测试技术研究了反应过程中生成的中间体和催化剂整体性能,结果表明,在ROS作用下催化剂表面没有生成有毒的*CO中间体,说明ROS显著提升了催化剂的抗毒化性能.另外,经过8次电解液的更新,二氧化碳的选择性没有发生明显衰减,表明ROS可以增强催化剂的耐久性.CO剥离实验结果表明,在ROS的作用下,催化剂对CO的氧化电位降低了46mV,进一步证明ROS可以有效避免催化剂被中间产物毒化.为进一步研究反应的机理,对体系中生成的ROS进行了电子顺磁共振测试.结果表明,PtSn IM/C可以催化氧气原位生成大量的·OH,·O_(2)~-和~1O_(2).通过向体系中加入不同的自由基捕获剂探究不同氧物种对EOR活性和C-C键裂解的影响.结果表明,单线态氧可以显著提升催化剂活性和C-C键的裂解能力.理论计算结果表明,*CH_(3)CO的C-C键断裂产生*CH_(3)和*CO是Cl途径的决速步骤.当单线态氧存在于PtSn IM/C表面上时,C-C键的离解能为-0.51 eV,低于羟基自由基的1.07 eV和超氧阴离子的-0.47 eV.综上所述,乙醇燃料电池是未来最具有潜力的能源转换器件之一.本研究为乙醇燃料电池阳极催化剂的设计提供了一种新思路.本研究还为探究氧自由基在乙醇氧化反应中的作用和用于多元醇完全氧化反应的催化剂的制备提供参考. 展开更多
关键词 乙醇 高性能 离解能 自由基
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Restoration and protection of brachial plexus injury: hot topics in the last decade 被引量:1
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作者 Kaizhi Zhang zheng lv +2 位作者 Jun Liu He Zhu Rui Li 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第18期1723-1728,共6页
Brachial plexus injury is frequently induced by injuries, accidents or birth trauma. Upper limb function may be partially or totally lost after injury, or left permanently disabled. With the de- velopment of various m... Brachial plexus injury is frequently induced by injuries, accidents or birth trauma. Upper limb function may be partially or totally lost after injury, or left permanently disabled. With the de- velopment of various medical technologies, different types of interventions are used, but their effectiveness is wide ranging. Many repair methods have phasic characteristics, i.e., repairs are done in different phases. This study explored research progress and hot topic methods for pro- tection after brachial plexus injury, by analyzing 1,797 articles concerning the repair of brachial plexus injuries, published between 2004 and 2013 and indexed by the Science Citation Index database. Results revealed that there are many methods used to repair brachial plexus injury, and their effects are varied. Intervention methods include nerve transfer surgery, electrical stimula- tion, cell transplantation, neurotrophic factor therapy and drug treatment. Therapeutic methods in this field change according to the hot topic of research. 展开更多
关键词 nerve regeneration brachial plexus injury repair NEUROPROTECTION nerve transfer celltransplantation ELECTROACUPUNCTURE neurotrophic factor DRUGS BIBLIOMETRICS neural regeneration
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Classification Study on Relative Permeability Curves
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作者 Pingzhi Gong Bin Liu +2 位作者 Junting Zhang zheng lv Guohao Zhang 《World Journal of Engineering and Technology》 2018年第4期723-737,共15页
The classification method of relative permeability curves is rarely reported, when relative permeability curves are applied;if the multiple relative permeability curves are normalized directly, but not classified, the... The classification method of relative permeability curves is rarely reported, when relative permeability curves are applied;if the multiple relative permeability curves are normalized directly, but not classified, the calculated result maybe cause a large error. For example, the relationship curve between oil displacement efficiency and water cut, which derived from the relative permeability curve in LD oilfield is uncertain in the shape of low water cut stage. If being directly normalized, the result of the interpretation of the water flooded zone is very high. In this study, two problems were solved: 1) The mathematical equation of the relationship between oil displacement efficiency and water cut was deduced, and repaired the lost data of oil displacement efficiency and water cut curve, which solve the problem of uncertain curve shape. After analysis, the reason why the curve is not available is that relative permeability curves are not classified and optimized;2) Two kinds of classification and evaluation methods of relative permeability curve were put forward, the direct evaluation method and the analogy method;it can get the typical relative permeability curve by identifying abnormal curve. 展开更多
关键词 RELATIVE PERMEABILITY CURVE DISPLACEMENT Efficiency CLASSIFICATION CORRECTION
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Polysulfide modified PtCu intermetallic nanocatalyst with enrichment realizes efficient electrooxidation ethanol to CO_(2)
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作者 Shuanglong Zhou zheng lv +7 位作者 Liang Zhao Dan Zhang Zuocao Wang Yu Dai Bin Li Olga Starostenko Jianping Lai Lei Wang 《Nano Research》 SCIE EI CSCD 2024年第4期2320-2327,共8页
The main problem faced by ethanol oxidation reaction(EOR)includes low activity,poor selectivity,and durability.In the study,we found that polysulfide modified on the surface of PtCu intermetallic(IM)/C can simultaneou... The main problem faced by ethanol oxidation reaction(EOR)includes low activity,poor selectivity,and durability.In the study,we found that polysulfide modified on the surface of PtCu intermetallic(IM)/C can simultaneously enrich hydroxyl and ethanol,which could effectively improve the catalytic activity,CO_(2) selectivity,and durability of catalyst.The mass activity and the specific activity of the product in 1 M KOH electrolyte reached 17.83 A·mgPt^(-1) and 24.67 mA·cm^(-2).The CO_(2) selectivity of polysulfide modified product achieved 93.5%,which was 30 folds higher than Pt/C.In addition,the catalyst showed high catalytic stability.The mechanism study demonstrates that the surface modified polysulfide could significantly boost the enrichment effect of ethanol and hydroxyl species,accelerating C–C bond cleavage and CO oxidation. 展开更多
关键词 Pt CO_(2) selectivity enrichment effect ethanol oxidation reaction(EOR) electrocatalyst
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Regulate electric double layer for one-step synthesize and modulate the morphology of(oxy)hydroxides
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作者 Jiaxin Liu Yue Shi +6 位作者 Yanli Gu zheng lv Liang Zhao Yu Yang Tianrong Zhan Jianping Lai Lei Wang 《Nano Research》 SCIE EI CSCD 2024年第5期3675-3683,共9页
FeOOH have received considerable attention due to their natural abundance and cost-effectiveness.Despite the significant progress achieved,the one-step synthesis of integrated FeOOH is still a major challenge.Meanwhil... FeOOH have received considerable attention due to their natural abundance and cost-effectiveness.Despite the significant progress achieved,the one-step synthesis of integrated FeOOH is still a major challenge.Meanwhile,the current research on FeOOH catalyst still suffers from the unclear mechanism of controlling morphology.Here,density functional theory(DFT)calculations and X-ray photoelectron spectroscopy(XPS)demonstrated the strong electron-capturing and hydrogen absorption ability of Co in FeOOH,which further promotes the formation and stabilization of FeOOH.We used a one-step electrodeposition method to synthesize Co introduced FeOOH integrated electrocatalyst and propose to introduce ions with different valence states to regulate the morphology of FeOOH by precise modulation of electric double layer(EDL)composition and thickness.The prepared Co-FeOOH-K^(+)has a larger electrochemically active surface area(ECSA)(325 cm^(2))and turnover frequency(TOF)value(0.75 s^(-1)).In the electrochemical experiments of an alkaline anion exchange membrane electrolyzer,Co-FeOOH-K^(+)shows better oxygen evolution performance than commercial RuO_(2) under industrial production conditions and has good industrial application prospects. 展开更多
关键词 integrated(oxy)hydroxides electrodeposition electric double layer(EDL) oxygen evolution reaction(OER) morphology regulation
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SRSF1通过可变剪接调控小鼠减数分裂期间的同源染色体配对和联会 被引量:1
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作者 孙龙杰 陈娟 +12 位作者 叶融 吕征 陈雪雪 谢小梅 李雨衡 王超凡 吕鹏博 阎璐 田爽 姚晓红 陈忱 崔胜 刘佳利 《Science Bulletin》 SCIE EI CAS CSCD 2023年第11期1100-1104,M0003,共6页
同源染色体配对和联会是第一次减数分裂过程中的重要环节.然而,可变剪接(AS)在同源染色体配对和联会中发挥作用的基本机制仍不清楚.本文揭示了SRSF1对于同源染色体配对和联会中的AS和基因表达至关重要.小鼠生精细胞中Srsf1的缺失导致同... 同源染色体配对和联会是第一次减数分裂过程中的重要环节.然而,可变剪接(AS)在同源染色体配对和联会中发挥作用的基本机制仍不清楚.本文揭示了SRSF1对于同源染色体配对和联会中的AS和基因表达至关重要.小鼠生精细胞中Srsf1的缺失导致同源染色体配对和联会异常,引发非阻塞性无精子症(NOA).在同源染色体识别、端粒介导的染色体移动以及联会复合体(SC)组装过程中,SRSF1与TRA2B和U2AF2相互作用,直接结合并通过AS调控Dmc1、Sycp1和Sun1的表达.总之,本研究揭示了在同源染色体配对和联会中SRSF1介导的转录后调控的关键作用,为阐明雄性减数分裂转录后调控的分子网络提供理论依据. 展开更多
关键词 可变剪接 同源染色体 减数分裂 联会复合体 分子网络 转录后调控 基因表达 组装过程
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Venovenous extracorporeal membrane oxygenation for COVID-19 and influenza H1N1 associated acute respiratory distress syndrome:A comparative cohort study in China 被引量:1
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作者 Yonghao Xu Yin Xi +17 位作者 Shuijiang Cai Yuheng Yu Sibei Chen Weijie Guan Weibo Liang Hongkai Wu Weiqun He Xilong Deng Yuanda Xu Rong Zhang Manshu Li Jieyi Pan Zhenting Liang Ya Wang Shaofeng Kong Xiaoqing Liu zheng lv Yimin Li 《Journal of Intensive Medicine》 CSCD 2023年第4期326-334,共9页
Background Venovenous extracorporeal membrane oxygenation(VV-ECMO)has been demonstrated to be effective in treating patients with virus-induced acute respiratory distress syndrome(ARDS).However,whether the management ... Background Venovenous extracorporeal membrane oxygenation(VV-ECMO)has been demonstrated to be effective in treating patients with virus-induced acute respiratory distress syndrome(ARDS).However,whether the management of ECMO is different in treating H1N1 influenza and coronavirus disease 2019(COVID-19)-associated ARDS patients remains unknown.Methods This is a retrospective cohort study.We included 12 VV-ECMO-supported COVID-19 patients admitted to The First Affiliated Hospital of Guangzhou Medical University,Guangzhou Eighth People's Hospital,and Wuhan Union Hospital West Campus between January 23 and March 31,2020.We retrospectively included VV-ECMO-supported patients with COVID-19 and H1N1 influenza-associated ARDS.Clinical characteristics,respiratory mechanics including plateau pressure,driving pressure,mechanical power,ventilatory ratio(VR)and lung compliance,and outcomes were compared.Results Data from 25 patients with COVID-19(n=12)and H1N1(n=13)associated ARDS who had received ECMO support were analyzed.COVID-19 patients were older than H1N1 influenza patients(P=0.004).The partial pressure of arterial carbon dioxide(PaCO_(2))and VR before ECMO initiation were significantly higher in COVID-19 patients than in H1N1 influenza patients(P<0.001 and P=0.004,respectively).COVID-19 patients showed increased plateau and driving pressure compared with H1N1 subjects(P=0.013 and P=0.018,respectively).Patients with COVID-19 remained longer on ECMO support than did H1N1 influenza patients(P=0.015).COVID-19 patients who required ECMO support also had fewer intensive care unit and ventilator-free days than H1N1.Conclusions Compared with H1N1 influenza patients,COVID-19 patients were older and presented with increased PaCO_(2) and VR values before ECMO initiation.The differences between ARDS patients with COVID-19 and influenza on VV-ECMO detailed herein could be helpful for obtaining a better understanding of COVID-19 and for better clinical management. 展开更多
关键词 Coronavirus disease 2019 H1N1 influenza Acute respiratory distress syndrome
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Effect of annealing time and phosphorus addition on bake hardening behavior of ultra-low carbon bake hardening steel 被引量:1
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作者 Xi-liang Zhang Hua-feng Hou +5 位作者 Tao Liu Qian Zhou Hong-ji Liu Yu-long Zhang Hao-xuan Cui zheng lv 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2018年第12期1287-1295,共9页
The relationship of the P and C grain boundary segregation and its effect on bake hardening behavior were investigated in ultra-low carbon bake hardening (ULC-BH)steel with and without P addition annealed at 810 ℃ fo... The relationship of the P and C grain boundary segregation and its effect on bake hardening behavior were investigated in ultra-low carbon bake hardening (ULC-BH)steel with and without P addition annealed at 810 ℃ for various time using electron probe micro-analyzer,electroh backscattered diffraction,and three-dimensional atomic probe techniques.Results revealed that P addition and annealing duration considerably affected the bake hardening behavior of experimental steel. The BH value of ULC-BH steel without P addition is lower than that with P addition within a short annealing time,and the difference in the BH value gradually decreases as the annealing duration is prolonged.P segregation is dominant in terms of a high P bulk content in steels with P addition at the expense of C segregation during annealing.By contrast,opposite effects are observed in low carbon bake hardening steel.The high residual solute C content in steel with P addition is due to P segregation at the grain boundary.Site competition is mainly responsible for the lower BH value in ULC-BH steel without P addition than that with P addition.As the annealing time is further extended,C segregation begins at grain boundary despite the delayed P segregation,leading to a gradual decrease in the solute concentration in the matrix of steels with P addition.C and P segregations reach the equilibrium as the annealing time increases to 60 min at 810 ℃ in the two steel samples.Theoretical calculations reveal that the residual solute C concentration in the matrix decreases to zero,and this finding is consistent with the change trend of the bake hardening value.Hence,the C segregation at grain boundary. adversely influences the bake hardening property of ULC-BH steel. 展开更多
关键词 Ultra-low CARBON BAKE HARDENING steel CARBON PHOSPHORUS ADDITION BAKE HARDENING BEHAVIOR Grain boundary segregation
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Polarity-activated super-resolution imaging probe for the formation and morphology of amyloid fibrils 被引量:1
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作者 zheng lv Li Li +6 位作者 Zhongwei Man Zhenzhen Xu Hongtu Cui Rui Zhan Qihua He Lemin zheng Hongbing Fu 《Nano Research》 SCIE EI CAS CSCD 2020年第9期2556-2563,共8页
The formation of amyloid plaques usually occurs in the early-stage of Alzheimer’s disease(AD).Stimulated emission depletion(STED)imaging provided a powerful tool for visualizing amyloid structures on the nanometer sc... The formation of amyloid plaques usually occurs in the early-stage of Alzheimer’s disease(AD).Stimulated emission depletion(STED)imaging provided a powerful tool for visualizing amyloid structures on the nanometer scale.However,many commercial probes adopted in detecting amyloid fibrils are inapplicable to STED imaging,owing to their unmatched absorption and emission wavelengths,small Stokes'shift,easy photo-bleaching,etc.Herein,we demonstrated a polarity-activated STED probe based on an intramolecular charge transfer donor(D)-7c-acceptor(A)compound.The electron-rich carbazole group and the electron-poor pyridinium bromide group,linked by 7i-conjugated thiophen-bridge,ensure strong near infrared(NIR)emission with a Stokes'shift larger than 200 nm.The tiny change in polarity before and after binding with amyloid plaques leads to a transition from weakly emission charge-transfer(CT)state(Φ<0.04)to highly emissive locally-excited(LE)state(Φ=0.57),giving rise to a fluorescence Turn-On probe.Together with large Stokes'shift,good photostability and high depletion efficiency,the super-resolution imaging of the formation and morphology of amyloid fibrils in vitro based on this probe was realized with a lateral spatial resolution better than 33 nm at an extremely low depletion power.Moreover,the ex-vivo super-resolution imaging of(E)-1-butyl-4(2-(5-(9-ethyl-9Hcarbazol-3-yl)thiophen-2-yl)vinyl)pyridinium bromide(CTPB)probe in Aβ plaques in the brain slices of a Tg mouse was demonstrated.This research provides a demonstration of the super resolution imaging probe of amyloid fibrils based on polarity-response mechanism,providing a new approach to the development of future amyloid probes. 展开更多
关键词 polarity-activated amyloid fibrils super-resolution imaging charge transfer near infrared(NIR)emission
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Inverse associations of outdoor activity and vitamin D intake with the risk of Parkinson's disease 被引量:1
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作者 Dan ZHU Gui-you LIU +3 位作者 zheng lv Shi-rong WEN Sheng BI Wei-zhi WANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2014年第10期923-927,共5页
Early studies had suggested that vitamin D intake was inversely associated with neurodegenerative diseases, such as Alzheimer's disease and multiple sclerosis. However, the associations of vitamin D intake and outdoo... Early studies had suggested that vitamin D intake was inversely associated with neurodegenerative diseases, such as Alzheimer's disease and multiple sclerosis. However, the associations of vitamin D intake and outdoor activities with Parkinson's disease(PD) are still unclear, so this study is to evaluate these relationships from a case-control study in elderly Chinese. The study population involved 209 cases with new onsets of PD and 210 controls without neurodegenerative diseases. The data on dietary vitamin D and outdoor activities were collected using a food-frequency questionnaire and self-report questionnaire. Multivariable logistic regressions were used to examine the associations between dietary outdoor activities, vitamin D intake and PD. Adjustment was made for sex, age, smoking, alcohol use, education, and body mass index(BMI). Adjusted odds ratios(ORs) for PD in quartiles for outdoor physical activity were 1(reference), 0.739(0.413, 1.321), 0.501(0.282, 0.891), and 0.437(0.241, 0.795), respectively(P=0.002 for trend). Adjusted ORs for PD in quartiles for total vitamin D intake were 1(reference), 0.647(0.357, 1.170), 0.571(0.318, 1.022), and 0.538(0.301, 0.960), respectively(P=0.011 for trend). Our study suggested that outdoor activity and total vitamin D intake were inversely associated with PD, and outdoor activity seems to be more significantly associated with decreased risk for PD. 展开更多
关键词 Outdoor activity Vitamin D intake Parkinson's disease
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