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Eff ects of continuous renal replacement therapy on infl ammation-related anemia, iron metabolism and prognosis in sepsis patients with acute kidney injury

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World Journal of Emergency Medicine 2023年第3期14卷 186-192页

作者： Meng-meng An chen-xi liu Ping Gong Intensive Care Unit the Affi liated Dalian Friendship Hospital of Dalian Medical UniversityDalian 116100China Department of Emergency Medicine the First Affi liated Hospital of Dalian Medical UniversityDalian 116011China Department of Emergency Medicine Shenzhen People's Hospital(the Second Clinical Medical College of Jinan Universitythe First Affi liated Hospital of Southern University of Science and Technology)Shenzhen 518020China

BACKGROUND:This study aims to evaluate the eff ect of continuous renal replacement therapy(CRRT)on inflammation-related anemia,iron metabolism,and the prognosis in sepsis patients with acute kidney injury(AKI).METHODS:Sepsis patients with AKI were prospectively enrolled and randomized into the CRRT and control *** clinical and laboratory data on days 1,3 and 7 after intensive care unit(ICU)admission were *** serum interleukin(IL)-6,hepcidin,erythropoietin,ferritin,and soluble transferrin receptor(sTfR)were determined by enzyme-linked immunosorbent *** Sequential Organ Failure Assessment(SOFA)score and 28-day mortality were *** were analyzed using Pearson’s Chi-square test or Fisher’s exact test(categorical variables),and Mann-Whitney U-test or t-test(continuous variables).RESULTS:The hemoglobin and serum erythropoietin levels did not signifi cantly diff er between the CRRT and control groups though gradually decreased within the first week of ICU *** days 3 and 7,the serum IL-6,hepcidin,ferritin,and red blood cell distribution width significantly decreased in the CRRT group compared to the control group(all P<0.05).On day 7,the serum iron was significantly elevated in the CRRT group compared to the control group(P<0.05).However,the serum sTfR did not signifi cantly diff er between the groups over *** addition,the SOFA scores were signifi cantly lower in the CRRT group compared to the control group on day *** 28-day mortality did not signifi cantly diff er between the control and CRRT groups(38.0%vs.28.2%,P=0.332).CONCLUSION:CRRT might have beneficial effects on the improvement in inflammationrelated iron metabolism and disease severity during the fi rst week of ICU admission but not anemia and 28-day mortality in sepsis patients with AKI.

关键词： Sepsis Continuous renal replacement therapy Acute kidney injury Anemia Iron metabolism

Effects of tantalum on austenitic transformation kinetics of RAFM steel

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Journal of Iron and Steel Research International 2017年第7期24卷 705-710页

作者： Jian-guo chen Yong-chang liu chen-xi liu Bi-yu Yan Hui-jun Li State Key Laboratory of Hydraulic Engineering Simulation and Safety School of Materials Science & EngineeringTianjin University

The RAFM（reduced activation ferritic/martensitic）steels containing different tantalum contents（0wt.%,0.027wt.%,0.073wt.%）were designed and *** scanning calorimetry and optical microscopy were employed to explore the influence of tantalum content on the austenitic transformation of RAFM *** austenitic transformation kinetics was described by aphase-transformation *** model,involving site saturation nucleation,diffusion-controlled growth and impingement correction,was established based on the classical Johnson-Mehl-Avrami-Kolmogorov *** phase-transformation kinetics parameters,including D_0（pre-exponential factor for diffusion）and Q_d（activation energy for diffusion）,were calculated by fitting the experimental data and the kinetic *** results indicated that the average grain size is decreased with the increase of *** values of A_（c1） and A_（c3）（onset and finish temperature of austenitic transformation,respectively）are increased by increasing the tantalum *** increase of tantalum caused the decrease of D_***,Q_d is increased with the increase of *** addition,as a carbides forming element,tantalum would reduce the carbon diffusion coefficient and slow down the austenitic transformation rate.

关键词： RAFM steel Tantalum content Grain growth Austenitic transformation kinetics Activation energy

Regioselective Oxidation Approaches to Concise Synthesis of （±）-Canabisin D

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Chinese Journal of Chemistry 2015年第7期33卷 717-722页

作者： Wenling Li Qian liu Hao liu PeUan chen xi Yang Yingying liu School of Chemical and Biological Engineering Lanzhou Jiaotong University Lanzhou Gansu 730070 China

The regioselective effects of tert-butyl or bromine as the position-protecting group of feruloytyamide on the oxidative coupling reactions for the synthesis of natural （±）-canabisin D were investigated in detail. The coupling yield of 8-8-coupled aryldihydronaphthalene product of 5-Br-feruloytyamide was higher than that of tert-butyl substituted precursor under FeCl3·6H2O-acetone-water oxidative condition.

关键词： oxidative coupling biomimetic synthesis regioselectivity liganamides canabisin D

Microstructural evolution and constitutive models of 9CrMoCoB heatresistant steel during high-temperature deformation

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Journal of Iron and Steel Research International 2019年第11期26卷 1228-1239页

作者： Chao-hang Jia chen-xi liu Yong-chang liu Chong Li Hui-jun Li Key Lab of Hydraulic Engineering Simulation and Safety School of Materials Science and EngineeringTianjin UniversityTianjin 300354China

In order to research the hot deformation behavior of 9CrMoCoB heat-resistant steel,hot compression tests were performed over a wide range of temperatures from 850 to 1150℃ and strain rates from 0.01 to 10.00 s^-*** flow stress appears to increase with the decrease in deformation temperature and the increase in strain *** relationship between microstructural evolution and deformation parameters was studied,indicating that both low strain rate and high deformation temperature appear to promote the dynamic recrystallization,while excessively high temperature with low strain rate would result in the high non-uniformity of grain *** experimental stress-strain data was applied to calculate the material constants involved in the Arrhenius-type constitutive model and the modified Zerilli-Armstrong(MZA)model,and feasibility of these two models was *** results show that the MZA model is more accurate to predict the high-temperature flow behavior of the experimental steel than the Arrhenius-type constitutive equation.

关键词： 9CrMoCoB steel-Hot deformation behavior Dynamic recrystallization Arrhenius-type constitutive model Modified Zerilli-Armstrong model

Coarsening behavior of MX carbonitrides in type 347H heat-resistant austenitic steel during thermal aging

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International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 283-293页

作者： Ying-hui Zhou chen-xi liu Yong-chang liu Qian-ying Guo Hui-jun Li State Key Lab of Hydraulic Engineering Simulation and Safety School of Materials Science and Engineering Tianjin University

In this work, the growth kinetics of MX （M - metal, X - C/N） nanoprecipitates in type 347H austenitic steel was systematically studied. To investigate the coarsening behavior and the growth mechanism of MX carbonitrides during long-term aging, experiments were performed at 700, 800, 850, and 900℃ for different periods （1, 24, 70, and 100 h）. The precipitation behavior of carbonitrides in specimens subjected to various aging conditions was explored using carbon replicas and transmission electron microscopy （TEM） observations. The corresponding sizes ofMX carbonitrides were measured. The results demonstrates that MX carbonitrides precipitate in type 347H austenitic steel as Nb（C,N）. The coarsening rate constant is time-independent; however, an increase in aging temperature results in an increase in coarsening rate of Nb（C,N）. The coarsening process was analyzed according to the calculated diffusion activation energy of Nb（C,N）. When the aging temperature was 800-900℃, the mean activation energy was 294 kJ·mol -1, and the coarsening behavior was controlled primarily by the diffusion of Nb atoms.

关键词： austenitic steel heat resistance carbonitrides coarsening nanoparticles diffusion thermal aging

Microstructure and Mechanical Properties of RAFM-316L Dissimilar Joints by Friction Stir Welding with Different Butt Joining Modes

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Acta Metallurgica Sinica(English Letters) 2020年第1期33卷 135-146页

作者： Bin He Lei Cui Dong-Po Wang Hui-Jun Li chen-xi liu Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin 300354China

Dissimilar welded joints of reduced activation ferritic/martensitic(RAFM)steel and 316 L austenitic stainless steel were prepared by friction stir welding with different butt joining modes and welding *** weld quality of the joint was improved by placing the 316 L steel on the advancing side and the RAFM steel on the retreating side,and using a relatively high rotational speed of 400 *** microstructure of the stir zone on the 316 L steel side consisted of single-phase austenite,and the microstructure of the stir zone on the RAFM steel side mainly consisted of lath martensite and equiaxed ferrite.A mechanical mixture of the two steels and diffusion of Cr and Ni could be detected near the bonding *** of Ni from the 316 L steel to the RAFM steel resulted in the formation of a dual-phase structure consisting of austenite and *** as-welded joints showed good strength and ductility at room temperature and 550°C,which were nearly equal to those of the 316 L base *** heat-affected zone on the RAFM side had the lowest impact toughness throughout the weld with a value of 13.2 J at-40°C,~52%that of the RAFM base material.

关键词： Friction stir welding Dissimilar joint RAFM steel 316L steel Microstructures Mechanical properties

Analysis of cracks origin behaviors during sulfide stress corrosion (SSC) in HSLA steel at different temperatures by electrochemical noise

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Journal of Iron and Steel Research International 2022年第11期29卷 1836-1845页

作者： xiao-hua Li chen-xi liu Biao He Chuan-tao Lv Zhi-ming Gao Yong-chang liu School of Mechanical Engineering Tianjin University of Technology and EducationTianjin 300222China State Key Lab of Hydraulic Engineering Simulation and Safety School of Materials Science and EngineeringTianjin UniversityTianjin 300350China Tianjin Pipe Corporation Tianjin 300301China

The sulfide stress corrosion(SSC)behaviors of the high strength low alloy steel at the different temperatures were investigated by the microstructural observation and electrochemical noise(EN)*** the corrosion temperature increasing from 20 to 40℃,SSC ruptured time is *** increase in corrosion temperature results in the decrease of the saturation solubility of H_(2)S in the solution and thus increases pH value of *** increase in corrosion temperature decreases the size of the holes and cracks in the corrosion product film on the surface of the sample,which is due to the formation of the dense FeS corrosion product *** current kurtosis results indicate that the time for the first occurrence of crack initiation is postponed by the increase in the corrosion *** standard deviation of current noise signals,current kurtosis,power spectral density and energy distribution plot results shows a great consistency,which suggests that EN analysis method can reflect SSC behaviors in real time.

关键词： Sulfide stress cracking High strength low alloy(HSLA)steel Electrochemical noise Corrosion temperature Hydrogen sulfide corrosion products

High-temperature creep rupture behavior of dissimilar welded joints of RAFM steel and 316L steel by friction stir welding

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Journal of Iron and Steel Research International 2024年第10期31卷 2438-2447页

作者： xin Ji Bin He Wei Guan chen-xi liu Hui-jun Li Lei Cui Yong-chang liu Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin300354China State Key Lab of Hydraulic Engineering Simulation and Safety School of Materials Science and EngineeringTianjin UniversityTianjin300350China

Creep rupture of the reduced activation ferritic/martensitic(RAFM)steel and 316L steel dissimilar joint by friction stir welding was *** creep rupture time of the dissimilar joint was 1941 h at 600℃/100 MPa and 120 h at 650℃/100 *** creep fracture occurred in heat affect zone(HAZ)of RAFM steel side where coarse Laves phase was *** formation and coarsening of the Laves phase particles in HAZ of RAFM steel side were the main reasons that caused the creep fracture of the dissimilar *** Laves phase particles nucleated adjacent to the large M_(23)C_(6) particles at the grain boundaries where W element segregated and grew fast during creep *** large Laves phase would deteriorate the pinning effect of M_(23)C_(6) carbides and weaken the solid solution strengthening ***,the size of the Laves phase in HAZ of RAFM steel side was bigger than that in stir zone of RAFM steel *** reasons explain the creep fracture in HAZ of RAFM steel side of dissimilar joint.

关键词： Creep behavior Dissimilar joint Friction stir welding Laves phase M23C6 carbide

Effect of microstructure variation on the corrosion behavior of high-strength low-alloy steel in 3.5wt% NaCl solution

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International Journal of Minerals,Metallurgy and Materials 2015年第6期22卷 604-612页

作者： Yu-bing Guo Chong Li Yong-chang liu Li-ming Yu Zong-qing Ma chen-xi liu Hui-jun Li State Key Laboratory of Hydraulic Engineering Simulation and Safety School of Materials Science and EngineeringTianjin University

The effect of microstructure variation on the corrosion behavior of high-strength low-alloy（HSLA） steel was investigated. The protective property of the corrosion product layer was also explored. Experimental results reveal that the type of microstructure has significant effect on the corrosion resistance of HSLA steel. The measurement results of weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy indicate that the steel with acicular ferrite microstructure exhibits the lowest corrosion rate. Martensite exhibits a reduced corrosion resistance compared with polygonal ferrite. It is found that the surface of the acicular ferrite specimen uniformly covered by corrosion products is seemingly denser and more compact than those of the other two microstructures, and can provide some amount of protection to the steel; thus, the charge transfer resistance and modulus values of the acicular ferrite specimen are the largest. However, corrosion products on martensite and polygonal ferrite are generally loose, porous, and defective, and can provide minor protectiveness; thus, the charge transfer resistance values for polygonal ferrite and martensite are lower.

关键词： high-strength low-alloy steel microstructure corrosion sodium chloride solutions