Prognostic value of programmed death.1, programmed death-ligand 1, programmed death-ligand 2 expression, and CD8(+) T cell density in primary tumors and metastatic lymph nodes from patients with stage T1.4N+M0 gastric adenocarcinoma

Background: Anti-programmed death-1/programmed death-ligand 1(PD-1/PD-L1) immunotherapy has been proved to be effective on gastric cancer in ongoing clinical trials. However, the value of PD-L1 in predicting responses of patients with gastric cancer to anti-PD-1/PD-L1 immunotherapy is controversial. Some studies suggested that intra-and inter-tumoral heterogeneity of PD-L1 expression might explain the controversy.This study aimed to analyze the expression of PD-L1, PD-L2, and PD-1 as well as CD8(+) T-cell density in primary tumors and lymph nodes from patients with stage T1-4 N+M0 gastric adenocarcinoma to explore the heterogeneity of PD-1 signaling pathway molecules.Methods: In primary tumors and metastatic as well as non-metastatic lymph nodes from patients with stage T1-4 N+M0 gastric adenocarcinoma, we detected PD-L1 and PD-L2 expression with immunohistochemistry. CD8(+)T-cell density in primary tumors and PD-1 expression on CD8(+)T cells were detected with immunofluorescence. Univariate analysis was used to determine the prognostic values of them. Cox proportional hazard regression model was used to identify independent risk factors that affect patients' overall survival and disease-free survival.Results: Among 119 eligible patients who had undergone surgical resection, the positive rate of PD-L1 was higher in metastatic lymph nodes than in primary tumors(45.4% vs. 38.7%, P = 0.005); the positive rate of PD-1 on CD8(+)T cells was significantly higher in primary tumors and metastatic lymph nodes than in tumor-free lymph nodes(both P < 0.001). The intensity of PD-1 expression on CD8(+) T cells in primary tumors and in metastatic lymph nodes were stronger than that in tumor-free lymph nodes from the same patient. Beside, the positive rate of PD-L2 did not show any differences between primary tumors and metastatic lymph nodes. In multivariate analysis, PD-L1 expression,PD-L2 expression, a low density of CD8(+) T cells in primary tumors, and PD-1 expression on CD8(+) T cells in primary tumors were associated with poor prognosis.Conclusion: The expression of PD-L1 is heterogeneous in primary tumors and in metastatic lymph nodes from patients with stageT1-4 N+M0 gastric adenocarcinoma, which might explain the inconsistent results in assessing the prognostic value of PD-L1 expression in previous studies.

Blind reconstruction of convolutional code based on segmented Walsh-Hadamard transform

Walsh-Hadamard transform （WriT） can solve linear error equations on Field F2, and the method can be used to recover the parameters of convolutional code. However, solving the equations with many unknowns needs enormous computer memory which limits the application of WriT. In order to solve this problem, a method based on segmented WriT is proposed in this paper. The coefficient vector of high dimension is reshaped and two vectors of lower dimension are obtained. Then the WriT is operated and the requirement for computer memory is much reduced. The code rate and the constraint length of convolutional code are detected from the Walsh spectrum. And the check vector is recovered from the peak position. The validity of the method is verified by the simulation result, and the performance is proved to be optimal.

Efficacy and safety of chemotherapy combined with bevacizumab in Chinese patients with metastatic colorectal cancer:A prospective,multicenter,observational,non-interventional phaseⅣtrial

Objective:Bevacizumab has an important and evolving role in improving outcomes in patients with metastatic colorectal cancer(mCRC)worldwide and was approved in China in 2010.However,there are limited real-world data on the efficacy and safety of chemotherapy regimens combined with bevacizumab in Chinese patients with mCRC.This observational,phase IV trial study aimed to obtain more experience on the efficacy and safety of bevacizumab combined with chemotherapy in Chinese mCRC patients.Methods:Between September 2013 and November 2016,patients with histologically confirmed mCRC were enrolled in a prospective,multicenter,observational,non-interventional phase IV trial at 26 centers across China.Eligible patients received different chemotherapeutic regimens combined with bevacizumab.The efficacy and safety data in the intention-to-treat study population were analyzed.Results:A total of 611 patients were included in the efficacy analysis.The median overall survival and median progression-free survival was 18.00 and 10.05 months,respectively.The objective response rate was 21.00%and disease control rate was 89.40%.In subgroup analyses,the survival differences were observed according to metastatic status,duration of treatment and elevation in blood pressure.A total of 613 patients were evaluable for safety assessments.And 569(92.82%)patients reported at least one adverse event(AE),and 151(24.63%)experienced grade 3 or higher AEs.The incidence of bevacizumab-associated AEs of special interest was reported in 31(5.06%)patients with hypertension(n=12),abscesses and fistulae(n=7),bleeding(n=6),proteinuria(n=3),gastrointestinal perforation(n=2)and venous thrombotic events(n=1).Conclusions:This observational phase IV trial broadens our experience and knowledge of bevacizumab in the Chinese population and provides a good indication of its overall efficacy and safety.Bevacizumab in combination with chemotherapy offers clinical benefits to Chinese patients with mCRC and has an acceptable and manageable safety profile.

Blind reconstruction of linear scrambler

An algorithm based on eigenanalysis technique and Walsh-Hadamard transform （WriT） is proposed. The algorithm contains two steps. Firstly, the received sequence is divided into temporal windows, and a covariance matrix is computed. The linear feedback shift register （LFSR） sequence is reconstructed from the first eigenvector of this matrix. Secondly, equations according to the recovered LFSR sequence are constructed, and the Walsh spectrum corresponding to the equations is computed. The feedback polynomial of LFSR is estimated from the Walsh spectrum. The validity of the algorithm is verified by the simulation result. Finally, case studies are presented to illustrate the performance of the blind reconstruction method.

5-氟尿嘧啶和卡培他滨对中国患者的心脏毒性:一项前瞻性研究

背景与目的已有许多研究报道5-氟尿嘧啶(5-Fluorouracil,5-FU)和卡培他滨相关的心脏毒性,严重程度从无症状心电图(electrocardiography,ECG)异常到严重心肌梗塞而不同。目前为止,对中国恶性肿瘤患者的这种心脏毒性尚无研究。本研究旨在前瞻性地对多个中心招募的癌症患者进行5-FU和卡培他滨相关心脏毒性的发生率和临床表现进行评估。方法在完成研究的527例患者中,196例接受基于5-FU的化疗,331例接受基于卡培他滨的化疗并以其为一线或辅助治疗。在治疗期间和长达28 d的随访期间对所发生的不良反应进行记录。疗效测量指标包括心电图、心肌酶、心肌肌钙蛋白、脑钠肽和超声心动图。使用单因素分析和logistic回归方法进行亚组分析和鉴定与两种药物的心脏毒性相关的显著性独立变量。结果 527例患者中有161例(30.6%)出现心脏毒性。卡培他滨组的心脏毒性发生率为33.8%(112/331),显著高于5-FU组25%(49/196)的发生率(P=0.0042)。110/527患者(20.9%)发生心律失常,105/527(19.9%)发生缺血性改变,而只有20/527患者(3.8%)出现心力衰竭,6/527患者(1.1%)出现心肌梗塞。既往的心脏病、高血压、卡培他滨为基础的化疗和治疗时间被确定为与心脏毒性相关的显著风险因素。优势比分别为15.7(心脏病史vs.无病史)、1.86(卡培他滨vs. 5-FU)、1.06(5–8个化疗周期vs. 1–4个化疗周期)和1.58(高血压vs.无高血压)。结论氟嘧啶类药物在中国人群中引起的心脏毒性可能在临床实践中被低估。建议密切监测患者,尤其是对心脏毒性高风险的患者。可能的风险因素包括治疗持续时间、基于卡培他滨的化疗、既往心脏病史和高血压史。

Development of high-strength magnesium alloys with excellent ignition-proof performance based on the oxidation and ignition mechanisms: A review

High reactivity and ease of ignition are the major obstacles for the application of Mg alloys in aerospace.Thus,the ignition mechanisms of Mg alloys should be investigated systematically,which can guide the ignition-proof alloy design.This article concludes the factors influencing the ignition resistance of Mg alloys from oxide film and substrate microstructure,and also the mechanisms of alloying elements improving the ignition resistance.The low strength is another reason restricting the development of Mg alloys.Therefore,at the last section,Mg alloys with the combination of high strength and good ignition-proof performance are summarized,including Mg-Al-Ca based alloys,SEN(Mg-Al-Zn-Ca-Y)alloys as well as Mg-Y and Mg-Gd based alloys.Besides,the shortages and the future focus of theses alloys are also reviewed.The aim of this article is to promote the understanding of oxidation and ignition mechanisms of Mg alloys and to provide reference for the development of Mg alloys with high strength and excellent ignition-proof performance at the same time.

In vivo evaluation of laser-induced choroidal neovascularization in rats simultaneously using optical coherence tomography and photoacoustic microscopy

Determination of the precise location and the degree of the Choroidal neovascularization(CNV)lesion is essential for diagnosation Neovascular age-related macular degeneration(AMD)and evaluation the efficacy of treatment.Noninvasive imaging techniques with specific contrast for CNV evaluation are demanded.In this paper,two noninvasive imaging techniques,namely Optical coherence tomography(OCT)and Photoacoustic microscopy(PAM),are combined to provide specific detection of CNV for their complimentary contrast mechanisms.In vivo time-serial evaluation of Laser-induced CNV in rats is present at days 1,3,5,7,14,21 after laser photocoagulation is applied to the rat fundus.Both OCT and PAM show that the CNV increases to its maximum at day 7 and decreases at day 14.Quantification of CNV area and CNV thickness is given.The dual-modal information of CNV is consistent with the histologic evaluation by hematoxylin and eosin(H&E)staining.

Preliminary outcome of rituximab-containing salvage regimens on relapsed or refractory B-cell non-Hodgkin’s lymphoma: single institution experience

Objective： The prognosis of relapsed or refractory B-cell lymphoma is poor, with a short-term survival after conventional second-line chemotherapy, Rituximab, a chimeric anti-CD20 antigen, in combination with CHOP or CHOP-like chemotherapy may improve both disease free survival （DFS） and overall survival （OS） of naive patients, but its role in the second-line therapy for relapsed non-Hodgkin＇s Lymphoma （NHL） remains to be defined, This study aimed to evaluate the efficacy of rituximab-containing salvage regimens for relapsed or refractory NHL, and observe the toxicities. Methods： The clinical data of 54 patients, who were with relapsed or refractory NHL and treated in the Cancer Center of Sun Yat-sen University, were analyzed retrospectively, Of the 54 patients, 29 were man, 25 were women, with a median age of 52.5 years old （range 18 to 75）; 50 patients （92.6%） scored 0-1 for the ECOG performance status; for second-line international prognostic index （slPI）, 21 （38.9%） scored 0-1,30 （55.6%） scored 2 to 3, and 3 （5.6%） scored 4-5; 40 cases were diffuse large B-cell lymphoma （DLBCL）, accounting for 74.1% of all subtypes, Rituximab was administered intravenously at a dose of 375 mg/m^2 at the day before each chemotherapy cycle, The second or third-line salvage regimens included EPOCH, CHOP, DHAP, DICE, IVAC, IMVP-16 and FND, Results： Of the 54 patients, 49 received retuximab-containing salvage regimens, The objective response rate of the 45 evaluable cases was 68,8%, with a complete remission （CR） rate of 37.7%; 3 patients achieved CR after radiotherapy following rituximab-based regimens and 3 achieved CR after autologous hematopoietic stem cell transplantation, The most frequent adverse events were leucopenia, nausea and alopecia. The addition of rituximab to chemotherapy only elevated the occurrence of mild infusion-related reactions, such as chills, fever and pruritus. The median follow-up time was 18 months （range 2-86 months）; 5 patients were lost, 24 were dead （23 died of lymphoma, and 1 died of severe hepatitis）, the other patients remained alive. The median survival time was 32 months （range 2-86 months, 95% confidential interval 16-48 months）. The 1-, 2- and 3-year OS rates were 70.6%, 53,6% and 41,5%, respectively, The median TTP was 6 months （range 0-52 months）, The median PFS was 10 months （range 0-47 months, 95% CI 0-26 months）, The 1- and 2-year PFS were 49,3% and 41,3%. Conclusion： Rituximab-containing salvage regimens are effective and well tolerated therapy for patients with relapsed or refractory B-cell NHL, even those were extensively treated.

Chinese Society of Clinical Oncology(CSCO):Clinical guidelines for the diagnosis and treatment of pancreatic cancer

Pancreatic cancer is one of the leading causes of cancer-related mortality in both developed and developing coun-tries.The incidence of pancreatic cancer in China accounts for about a quater of the global incidence,and the epidemiological characteristics and therapeutic strategies differ due to social,economic,cultural,environmental,and public health factors.Non-domestic guidelines do not reflect the clinicopathologic characteristics and treat-ment patterns of Chinese patients.Thus,in 2018,the Chinese Society of Clinical Oncology(CSCO)organized a panel of senior experts from all sub-specialties within the field of pancreatic oncology to compile the Chinese guidelines for the diagnosis and treatment of pancreatic cancer.The guidelines were made based on both the Western and Eastern clinical evidence and updated every one or two years.The experts made consensus judg-ments and classified evidence-based recommendations into various grades according to the regional differences,the accessibility of diagnostic and treatment resources,and health economic indexes in China.Here we present the latest version of the guidelines,which covers the diagnosis,treatment,and follow-up of pancreatic cancer.The guidelines might standardize the diagnosis and treatment of pancreatic cancer in China and will encourage oncologists to design and conduct more clinical trials about pancreatic cancer.

The measurement of responsivity of infrared photodetectors using a cavity blackbody

For the measurement of responsivity of an infrared photodetector,the most-used radiation source is a blackbody.In such a measurement system,distance between the blackbody,the photodetector and the aperture diameter are two parameters that contribute most measurement errors.In this work,we describe the configuration of our responsivity measurement system in great detail and present a method to calibrate the distance and aperture diameter.The core of this calibration method is to transfer direct measurements of these two parameters into an extraction procedure by fitting the experiment data to the calculated results.The calibration method is proved experimentally with a commercially extended InGaAs detector at a wide range of blackbody temperature,aperture diameter and distance.Then proof procedures are further extended into a detector fabricated in our laboratory and consistent results were obtained.

Expression of NSE and AFI in Fatal Lamb’s Lungs before and after Relieving Ureteral Obstruction

Aims: to evaluate the Expression of NSE and AFI before and after relieving ureteral obstruction in fatal lamb’s lungs with unilateral hydronephrosis. Study Design and Subjects: Forty-five pregnant lambs were randomly divided into 3 groups. Eighteen lambs were in the hydronephrotic model group. The second group included 9 lambs in which ureteral obstruction was relieved 3 weeks after the initial operation. Eighteen lambs were in the control group which was just performed open hysterotomies. Outcome measures: The amniotic fluid index (AFI) and the expression of neuronspecific enolase (NSE) in the lungs were tested. Results: In the hydronephrotic model group, the AFI was less and the expression of NSE was greater than the control group. The AFI and expression of NSE were similar to the control group after relieving the ureteral obstruction. Conclusions: The AFI and expression of NSE return to normal after after relieving the ureteral obstruction, which meant that relieving ureteral obstruction is perhaps beneficial to lung development.

糖尿病患者视网膜血管直径的影响因素

目的:了解2型糖尿病患者视网膜血管直径及其影响因素。方法:横断面研究。将2012年7月至2013年5月辽宁省抚顺市将军街道15个社区所有已确诊为2型糖尿病的居民1913例纳入研究。采用计算机辅助软件定量测量视网膜中央动脉直径(CRAE)、视网膜中央静脉直径(CRVE),并计算视网膜动静脉比值(AVR)。不同特征的组间CRAE、CRVE和AVR差异比较采用Student-t检验或者方差分析。采用广义线性回归分别探讨CRAE、CRVE和AVR的影响因素。采用LOWESS下的广义估计方程探讨糖尿病视网膜病变(DR)严重程度与CRAE、CRVE和AVR之间可能存在的非线性关系。结果:身体质量指数(BMI)较大、高血压、高密度脂蛋白较低、糖化血红蛋白较低患者的CRAE较低,差异有统计学意义(均P<0.05);年龄较大、女性、糖尿病病程较长、不吸烟、糖化血红蛋白<7%患者的CRVE较低,差异有统计学意义(均P<0.05);年龄较大、女性、不吸烟、BMI较小、无高血压、高密度脂蛋白较高、甘油三酯较低、糖化血红蛋白<7%患者的AVR较高,差异有统计学意义(均P<0.05)。多因素回归显示男性、高血压、高糖化血红蛋白、较低的高密度脂蛋白和高BMI是较小的CRAE的影响因素(均P<0.05);年龄较大、吸烟、糖尿病病程增加、较高的高密度脂蛋白是较大的CRVE的影响因素(均P<0.05);年龄较小、吸烟、高血压是较小的AVR的影响因素(均P<0.05)。随着DR严重程度增加,CRAE、CRVE、AVR的改变并不呈线性关系,CRAE和CRVE存在先逐渐增加再逐渐减小的趋势;AVR存在先减小再增加的趋势。结论:DR患者的CRAE、CRVE显著降低,AVR显著升高,这种关系在中度非增生型DR和增生性DR患者中更明显。

A Review on Particle Reinforced Mg Matrix Composites Fabricated by Powder Metallurgy

This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder metallurgy.The article discusses different strategies,such as micro-sized,nano-sized particles,and multi-particle hybridization,which has been employed to enhance the performance of the composites.In addition,a range of preparation techniques that optimize the dispersion of the reinforcing particles are summarized.The paper also highlights how the different configurations between the reinforcements and matrix alloy impact the composites’performance.Finally,the article outlines the prospects of particles reinforced Mg matrix composites fabricated via powder metallurgy and recommends modification methods that could be explored to further develop these materials for various applications.

Prediction of the short-term efficacy of anti-VEGF therapy for neovascular age-related macular degeneration using optical coherence tomography angiography

Background To evaluate whether the specific choroidal neovascularization(CNV)characteristics measured using optical coherence tomography angiography(OCTA)can predict the 6-month prognosis of neovascular age-related macular degeneration(nAMD)after anti-vascular endothelial growth factor(anti-VEGF)therapy.Methods Patients with type 1,type 2,or mixed-type neovascularization(NV)were prospectively included.Participants underwent an initial loading phase of three consecutive monthly intravitreal injections of Conbercept(0.5 mg)and were switched to a pro re nata(PRN)treatment strategy.OCTA images were evaluated for eyes that underwent follow-up assessments for more than 6 months.CNV lesions were manually segmented,and the CNV area,vessel area,greatest vascular caliber(GVC),and greatest linear dimension(GLD)were compared between responders and non-responders.Two masked graders independently measured the above-mentioned parameters using OCTA,and consistency was assessed using the intraclass correlation coefficient(ICC)values.Multiple logistic regression analysis was performed to evaluate the effect of a 3-month change in the CNV area,GLD,and GVC on the 6-month response to anti-VEGF agents.Results Among the 60 eyes of 60 patients with nAMD,39 were responders and 21 were non-responders.The proportion of CNV types was significantly different between responders and non-responders(P=0.009).Patients with type 2 or mixed NV seemed more likely to respond to the treatment(28.2%vs.0.0%,and 30.8%vs.23.8%,respectively).The change in GVC showed a significant difference between responders(−4.98±17.17μm)and non-responders(11.01±14.10μm)after three monthly intravitreal anti-VEGF injections.Multiple logistic regression analysis showed that only the change in GVC remained significant after controlling for baseline GVC,injection number,and CNV type(adjusted OR=1.083;P=0.008).Conclusions Type 2 and mixed-type NV were significantly associated with a better response to anti-VEGF therapy.Changes in GVC after 3 months of treatment were significantly associated with a response to anti-VEGF therapy at 6 months.

The real-world study of the clinical characteristics,diagnosis,and treatment of advanced pancreatic cancer in China

Objective:Real-world diagnostic and treatment data for pancreatic cancer in China are lacking.As such,the present study investigated the clinical characteristics,diagnosis,and treatment of advanced pancreatic cancer(including locally advanced and metastatic disease)in the Hospital-based Advanced Pancreatic Cancer Cohort in China of the China Pancreas Data Center database.Methods:A total of 5349 Chinese patients with advanced pancreatic cancer were identified from a database.The entire course of real-world pancreatic cancer management was analyzed.Results:The proportion of patients with advanced pancreatic cancer was higher among males than females(62.4%vs 37.6%,respectively).Patients typically had a history of hypertension(30.8%),diabetes(21.6%),and cholangitis(20.2%).Abdominal pain(51.6%),abdominal distension(27.1%),jaundice(20.1%),and weight loss(16.3%)were the main symptoms observed in patients with advanced pancreatic cancer in this cohort.Serum carbohydrate antigen(CA)19-9 is one of the most common tumor markers.In the present study,2562 patients underwent first-line therapy.The median progression-free survival(PFS)for patients undergoing first-line therapy was 4.1 months.The major options for first-line therapy included gemcitabine(GEM)plus S-1(GS/X)(23.4%),nab-paclitaxel plus GEM(AG)(18.1%),oxaliplatin,irinotecan,and leucovorin-modulated fluorouracil(FOLFIRINOX;11.9%),nab-paclitaxel plus S-1(AS)(8.9%),and GEM combined with oxaliplatin/cisplatin(GEMOX/GP)(7.6%).The AS and GS/X regimens were associated with the highest PFS rates.Conclusion:This is the first study to report multicenter,real-world data regarding advanced pancreatic cancer in China.Results revealed that real-world treatment options differed from guideline recommendations,and PFS was shorter than that in previously reported data.Improving intelligent follow-up systems and standardizing diagnosis and treatment of pancreatic cancer is recommended.

国际跨文化管理研究综述——基于Web of Science十年的数据分析

本文综述了Web of Science所收录的管理学期刊中关于跨文化管理的高水平学术论文,对时间跨度为十年的相关文献进行了系统的数据分析工作。从研究机构、文献影响力、关键词分析、跨文化管理领域代表学者、期刊、发表国家以及案例研究等方面,考察了国外的跨文化管理研究现状,并基于相关统计结果,探讨了2003年至2013年国际跨文化管理研究的热点问题。

高度近视患者黄斑病变分型与视网膜劈裂的关系

目的:观察高度近视患者黄斑病变国际分型特征及其与视网膜劈裂之间的关系。方法:回顾性系列病例研究。收集2015年10月至2017年12月于上海交通大学附属第一人民医院眼科门诊就诊的116例(174眼)高度近视患者的病史资料和眼科检查信息,所有患者均接受眼底照相及高清OCT扫描检查,对图像进行分析评价。计量资料采用独立样本t检验或单因素方差分析。计数资料的比较采用Fisher's精确概率法。结果:116例(174眼)高度近视患者根据眼底彩照图像特征可分为5型:C0无近视退行性病变型(10眼)、C1豹纹状眼底病变型(74眼)、C2弥漫视网膜脉络膜萎缩型(36眼)、C3片状视网膜脉络膜萎缩型(25眼)、C4黄斑萎缩型(29眼)。其中70眼(40%)合并视网膜劈裂,均发生在C1、C2、C3、C4型中,其中C2型的发生率(58%)最高。结论:基于眼底彩照的国际分型结合OCT显示弥漫视网膜脉络膜萎缩型高度近视黄斑病变发生视网膜劈裂的可能性大。

基于电子化信息平台的新生血管性年龄相关性黄斑变性真实世界研究进展

年龄相关性黄斑变性(AMD)是目前全球致盲的主要病因之一。抗血管内皮生长因子(Anti-VEGF)疗法已成为新生血管性AMD的一线治疗方案。考虑到抗VEGF药物的费用昂贵,患者需要长期甚至终身接受反复抗VEGF注射治疗,了解真实世界中抗VEGF的治疗情况,对于指导临床实践、改善患者诊疗路径乃至卫生决策都十分重要。近年来基于电子化信息平台的新生血管性AMD数据分析研究向我们展现了不同国家和地区新生血管性AMD的流行病学、真实世界抗VEGF的治疗情况以及医疗支出等,笔者就此作一综述。

The texture and its optimization in magnesium alloy

The crystallographic orientations are generally non-random in wrought Mg alloy,which will lead to their macroscopic physical properties to be anisotropic.Understanding the texture evolution in processing of Mg alloy billets and its effect on mechanical properties is therefore an important project for all scientists and engineers in material area.This paper is concerned with the description of texture,with the mechanisms of texture evolution and with the interrelationships between texture and mechanical properties in Mg alloy.It is a full review of understanding of the basic mechanism on texture evolution,of texture altering by alloying or processing,and of the mechanism of texture weakening.Moreover,it provides theories necessary and available techniques to develop high-performance Mg wrought with optimized texture in the field.

High strength and ductility Mg-8Gd-3Y-0.5Zr alloy with bimodal structure and nano-precipitates

To resolve the strength-ductility trade-off problem for high-strength Mg alloys,we prepared a high performance Mg-8Gd-3Y-0.5 Zr(wt%)alloy with yield strength of 371 MPa,ultimate tensile strength of 419MPa and elongation of 15.8%.The processing route involves extrusion,pre-deformation and aging,which leads to a bimodal structure and nano-precipitates.Back-stress originated from the deformationincompatibility in the bimodal-structure alloy can improve ductility.In addition,dislocation density in coarse grains increased during the pre-deformation strain of 2%,and the dislocations in coarse grains can promote the formation of chain-like nano-precipitates during aging treatment.The chain-like nanoprecipitates can act as barriers for dislocations slip and the existing mobile dislocations enable good ductility.