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264篇 您的检索式:作者名="Xu MD"
    题名 作者 年代 出处 被引量
1多端直流系统分区协调保护策略显示文摘针对多端直流系统的故障保护问题,首先分析了直流故障特性及多端直流系统保护难点,总结了现有多端直流系统故障保护方法。然后,基于一种典型的多端直流系统拓扑结构,以使用最少数量直流断路器为目标,提出了多端直流系统区域保护划分原则和分区保护策略。该方法将直流故障区域通过直流断路器与非故障区域进行隔离,从而使非故障区域可以继续维持正常运行,而故障区域则通过换流站交流侧断路器和直流侧开关进行保护和隔离。最后,通过MATLAB/Simulink仿真平台建模及仿真分析,验证了多端直流系统分区保护的有效性和经济性。吴婧 姚良忠 王志冰 Md Habibur RAHMAN Lie XU 鲁宗相 2017电力系统自动化2017,41,4:11
2Putrescine, spermidine, and spermine play distinct roles in rice salt tolerance显示文摘Polyamines(PAs) play diverse roles in plant growth and development,as well as responses to environmental stimuli.In this study,the effects of PAs on rice salt tolerance were investigated.Salt stress resulted in the alteration of endogenous PAs levels in rice roots and leaves,where spermidine(Spd) and spermine(Spm) contents were increased,and putrescine(Put) content was decreased.RT-qPCR analysis revealed that PAs biosynthesis-related genes ADC1,ODC,and Arginase were significantly downregulated by salt treatment;however,SAMDC transcription was significantly upregulated.Exogenous Spm enhanced rice salt tolerance remarkably;however,exogenous Put and Spd undermined rice salt tolerance.Transgenic rice plants overexpressing SAMDC display a higher ratio of Spm/(Put+Spd) and enhanced salt tolerance.Salt stress also increased polyamine oxidase activities in rice,resulting in elevated reactive oxygen species(ROS) production.Our findings revealed that accumulation of Put and Spd substantially reduced salt tolerance in rice,likely by facilitating ROS production;whereas,conversion of Put and Spd to Spm contributes to rice salt tolerance.Md Azizul ISlam PANG Jin-huan MENG Fan-wei LI Ya-wen XU Ning YANG Chao LIU Jun 2020Journal of Integrative Agriculture2020,19,3:5
3Protection of large partitioned MTDC Networks Using DC-DC converters and circuit breakers显示文摘This paper proposes a DC fault protection strategy for large multi-terminal HVDC(MTDC)network where MMC based DC-DC converter is configured at strategic locations to allow the large MTDC network to be operated interconnected but partitioned into islanded DC network zones following faults.Each DC network zone is protected using either AC circuit breakers coordinated with DC switches or slow mechanical type DC circuit breakers to minimize the capital cost.In case of a DC fault event,DC-DC converters which have inherent DC fault isolation capability provide‘firewall’between the faulty and healthy zones such that the faulty DC network zone can be quickly isolated from the remaining of the MTDC network to allow the healthy DC network zones to remain operational.The validity of the proposed protection arrangement is confirmed using MATLAB/SIMULINK simulations.Md Habibur Rahman Lie Xu Liangzhong Yao 2016Protection and Control of Modern Power Systems2016,1,1:2
4Angioplasty with Stent for Symptomatic Intracranial Stenosis Trial I (ASSIT-Ⅰ) Study显示文摘Background and Purpose Annual stroke rates might be as high as 10% to 24% in patients with symptomatic intracranial stenosis on best medical therapy. Angioplasty with stent for symptomatic intracranial stenosis trial Ⅰ (ASSIST-Ⅰ) was a prospective and nonrandomized feasibility and safety study to evaluate the APOLLO Stent System for treatment of symptomatic intracranial artery stenosis, and prepare for ASSIST Ⅱ-a prospective, multicenter,and randomized controlled-study. The APOLLO stent delivery system (MicroPort Medical [Shanghai] Limited Co.), specifically designed for intracranial artery stenosis, consists of a stent and a balloon and a rapid-exchange delivery catheter. The stent is made of 316L stainless steel, with diameters of 2.0 to 4.0 mm and length of 8 mm or 13 mm. Only two links connect the rings of 1 mm in length, rendering the stent a good flexibility enough to navigate tortuous intracranial vessels. The nominated pressure of the stent is designed at 6 atm to reduce the risk of occlusion to side branches and perforators and rupture and dissection of target vessel. The crimping technique is applied in this system, insuring a compact ability of stent so wonderful that the struts of stent do not lift when the stent negotiates a turn, which lessen the likelihood of vessel wall injury and stent migrating. Materials and methods Thirty-four patients with 35 symptomatic intracranial stenoses of ≥50%, which resulted in transient ischemic attacks (TIAs [23 lesions /22 patients]) and minor stroke (7 lesions/7 patents), and both TIAs and stroke (5 lesions/ 5 patients), and with 1 asymptomatic severe stenosis, were enrolled in ASSIST-Ⅰ from December 10, 2003 to August 12, 2004. Their age was 54.3 years±SD of 9.49, three patients were male, and all had ≥1 risk factors of atherosclerosis. Patients received the evaluation of National Institutes of Health Stroke Scale (NIHSS), modified Rankin scale (mRS )and Barthel idex (BI) before and one-, three-, six-, and 12-month after the procedure. Results Stent success, defined as stent-assisted angioplasty successfully, resulting in ≤20% residual stenosis, was obtained in 35 lesions ( 97.2%, 35/36) and 33 patients ( 97.1%, 33/34). The stenosis rate of pre- and post -procedure was 80.5%± SD of 12.65 and 7.4%±SD 15.74, respectively. The Procedure-related complications were 8.3% for lesion (3/36) and 8.8% for patient (3/34), included 1 acute thrombosis, which obtained complete patency by means of intrathrombus thombolysis at once without sequelae, and 2 ischemic perforator strokes (1 irreversible stroke and 1 reversible). The disable stroke, defined as one that led to mRS score of ≥2, 30 days after the stroke, occurred in one patient ( 2.9%, 1/34; mRS of 2). Procedure success, defined as stent success without disable stroke or death at discharge by means of the endovascular therapy, was achieved in 33 lesions ( 91.7%, 33/36) and in 31 patients ( 91.2%, 31/34). Treatment success, defined as stent success without disable stroke and death at the 30th day, by means of the endovascular and medical therapy, was obtained in 34 lesions ( 94.4%, 34/36) and 32 patients ( 94.1%, 32/34). Clinical Follow-up, median 170 days (ranged from 30 days to 273 days; ≥1 month, n=34; ≥3 months, n=23; ≥6 months, n=13), was performed in 34 patients. There were no ischemic neurological events and death occurred. Cumulated disable stroke occurred in 1 patient ( 2.9%, 1/34). NIHSS was 1.09±SD of 1.694 and 0.47±SD of 1.051, before procedure and at the 30th day (n=34), respectively, and 0.57±SD of 0.992 at 3 months (n=23), 0.15±SD of 0.376 at 6 months (n=13), respectively; mRS was 0.65±SD of 0.812 and 0.47±SD of 0.563, before procedure and at 30 days, respectively, and 0.61±SD of 0.583 at 3 months, 0.38±SD of 0.506 at 6 months, respectively; and BI was 97.54±SD of 5.918 and 99.26±SD of 2.179, before procedure and at 30 days, respectively, and 99.35±SD of 2.288 at 3 months, 100.00±SDWei-Jian Jiang, MD Min Jin, MD Bin Du, MD Yong-Jun Wang, MD Xiao-Tong Xu, MD Qing-He Wang, MD Ning Ma, MD Long-Yi Wang, MO Jian-Ping Dai, MD From the Neurovascular Angioplasty Team, Department of Neurology and Neuroradiology, Beijing Tiantan Hospital, Capital University of Medical Sciences, Beijing, China. Correspondence to Wei-Jian Jiang, MD, Department of Neurology and Neuroradiology, Beijing Tiantan Hospital, Capital University of Medical Sciences, Beijing, 100050, China. 2004介入放射学杂志2004,13,S1:2
5Percutaneous microwave and radiofrequency ablation for hepatocellular carcinoma: a retro- spective comparative study 显示文摘Lu MD Xu HX Xie XY 2005J Gastroenterol2005,40,11:1
6Cyanuric acid and melamine on Au(111) : structure and energetics of hydrogen-bonded networks 显示文摘XU W DONG MD GERSEN H 2007Small2007,3,5:1
7Phospholipase A2 in the central nervous system : implications for neurodegenerative diseases 显示文摘Sun GY Xu J Jensen MD 2004J Lipid Res2004,45,2:1
8Imaging of peripheral cholangiocar-cinoma with low - mechanical index contrast - enhanced sonography and SonoVue: initialexperience显示文摘Xu HX Lu MD Liu GJ 2006J RasoundMed2006,25,1:1
9Strong nanocom?posites with Ca, PO 4' and F release for caries inhibition显示文摘Xu HH Weir MD Sun L 2010J Dent Res2010,89,1:1
10Circulating CUDR, LSINCT-5 and PTENP1 long noncoding RNAs in sera distinguish patients with gas- tric cancer from healthy controls显示文摘Dong L Qi P Xu MD 2015Int J Cancer2015,137,5:1
11Percutaneous microwave and radiofrequeney ablation for hepatocelullar carcinoma a retro- spective comparative study 显示文摘Lu MD Xu HX Xie XY 2005J Gastroenterol2005,40,11:1
12Decreased expression of the long non-coding RNA FENDRR is associated with poor prognosis in gastric cancer and FENDRR regulates gastric cancer cell metastasis by affecting fibronectin I expression显示文摘Xu TP Huang MD Xia R 2014J Hematol Oncol2014,7,1:1
13Submucosal tunneling en- doscopic resection: a new technique for treating upper GI submucosal tumors originating from the muscularis propria layer ( with videos) 显示文摘Xu MD Cai MY Zhou PH 2012Gastrointest Endosc2012,75,1:1
14chavacterization of small focal liver lesions using real - time contrast - enhanced ultrasound: diagnostic performanace analysis in 200 patients显示文摘Xu HX Lu MD Liu GJ 2006J Ultrasound Med2006,25,3:1
15Vascular adhesion protein-1 plays an important role in postischemic inflammation and neuropathology in diabetic,estrogen-treated ovariectomized female rats subjected to transient forebrain ischemia显示文摘Xu HL Salter-Cid L Linnik MD Wang EY Paisansathan C Pelligrino DA 2006J Pharmacol Exp Ther2006,317,1:1
16Antibacterial and physical properties of calcium-phosphate and calcium?fluoride nanocomposites with chlorhexidine显示文摘Cheng L Weir MD Xu HH 2012Dent Mater2012,28,5:1
17An injectable calcium phosphate-alginate hydrogel-umbilical cord mesenchymal stem cell paste for bone tissue engineering显示文摘Zhao L Weir MD Xu HH 0,,25:1
18Human umbilical cord stem cel encapsulation in calcium phosphate scaffolds for bone engineering显示文摘Zhao L Weir MD Xu HH 0,,14:1
19Submucosal tunneling en- doscopic resection for submucosal tumors of the esopha- gogastric junction originating from the muscularis propria layer : a feasibility study ( with videos ) 显示文摘Wang XY Xu MD Yao LQ 2014Surg Endosc2014,28,6:1
20Characterization of focal liver lesions using contrast-enhanced sunography with a low mechanical index mode and a sulfur hexafluoride-filled microbubble contrast agent显示文摘Xu HX Liu GJ Lu MD 2006J Clin Ultrasound2006,34,:1
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