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某型航空发动机封严片的材料优化和组织演变研究
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作者 赵世炜 贾心怡 +1 位作者 李艳明 孟令琪 《风机技术》 2024年第2期93-96,共4页
封严片在航空发动机的密封和减振中起到关键作用。针对某型航空发动机多次发生因封严片硬度低导致的开裂和变形问题,提出了将封严片材料由固溶态GH600材料更换为冷轧态GH5188材料的优化改进方案。试验结果表明,冷轧态GH5188材料封严片... 封严片在航空发动机的密封和减振中起到关键作用。针对某型航空发动机多次发生因封严片硬度低导致的开裂和变形问题,提出了将封严片材料由固溶态GH600材料更换为冷轧态GH5188材料的优化改进方案。试验结果表明,冷轧态GH5188材料封严片在设计许用上限温度条件下保温100h后,硬度依然可保持在350HV以上的较高水平,且即使经历一定的短时超温后,硬度仍能与改进前封严片的硬度相当。提出的优化改进方案效果明显,可以保证封严片长期工作可靠性,具有良好的工程实用价值。 展开更多
关键词 航空发动机 封严片 GH600 GH5188 组织演变
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Sleep-disordered breathing is associated with depletion of circulating endothelial progenitor cells and elevation in pulmonary arterial pressure in patients with decompensated systolic heart failure 被引量:5
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作者 Han ZHANG liu FENG +4 位作者 Qi-lin WAN Yan HONG yan-ming li Guan-Chang CHENG Xin-Qiang HAN 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2015年第4期424-430,共7页
Background Sleep-disordered breathing (SDB) is known to occur frequently in and may predict worsening progression of patients with congestive heart failure (CHF). SDB is also known to play an important role in the... Background Sleep-disordered breathing (SDB) is known to occur frequently in and may predict worsening progression of patients with congestive heart failure (CHF). SDB is also known to play an important role in the development of idiopathic pulmonary arterial hyper- tension (PAH) via inducing endothelial dysfunction and vascular remodeling, a pathological process that can be significantly influenced by factors such as osteoprotegerin (OPG) and endothelial progenitor cells (EPCs). The objective of this study is to determine if CHF with SDB is associated with changes in OPG, EPCs, and PAIl. Methods EPCs were isolated, cultured, and quantified from CHF patients with SDB (n = 52), or without SDB (n - 68). OPG and N-terminal pro-brain natriuretic peptide (NT-proBNP) from each group was analyzed and cor- related with EPCs and the mean pulmonary artery pressure (mPAP) measured by right heart catheterization. Results A significant decrease in circulating EPCs (29.30 ± 9.01 vs. 45.17 ± 10.51 EPCs/x 200 field; P 〈 0.05) was found in CHF patients with SDB compared to those without SDB. Both OPG (789.83 ±89.38 vs. 551.29 ± 42.12 pg/mL; P 〈 0.05) and NT-proBNP (5946.50 ± 1434.50 vs. 3028.60 ± 811.90 ng/mL; P 〈 0.05) were also significantly elevated in SDB CHF patients who also had significantly elevated mPAP (50.2 ± 9.5 vs. 36.4 ± 4.1 mm Hg; P 〈 0.05). EPC numbers correlated inversely with the episodes of apnea and hypopnea per hour (RDI, r = -0.45, P = 0.037) and blood level of OPG (r =-0.53, P = 0.011). Although NT-proBNP was also increased significantly in patients with SDB, it had no correlation with either EPCs or RD1. Conclusions SDBdue to hypoxemia from decompensated CHF is associated with (1) OPG elevation, (2) EPC depletion, and (3) mPAP elevation. The inverse relationship of circulating OPG with EPCs suggests a likely mechanism for hypoxemia and OPG in the development of pulmonary vascular dysfunction via depleting EPCs, thus worsening prognosis of CHF. 展开更多
关键词 Congestive heart failure Endothelial progenitor cells OSTEOPROTEGERIN Sleep-disordered breathing
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某航空发动机高压涡轮导向叶片高温失效分析 被引量:4
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作者 孙睿毓 李艳明 +2 位作者 李青 黄芒通 周梦志 《风机技术》 2023年第1期87-91,共5页
通过外观检查、断口分析、材质检查、气膜孔检查和热模拟等试验工作,对故障高压涡轮导向叶片裂纹性质及产生机理进行分析。结果表明:故障叶片裂纹性质为疲劳,疲劳起源于气膜孔外壁的尖角区域。热障涂层涂覆后引起前缘气膜孔孔径减小,且... 通过外观检查、断口分析、材质检查、气膜孔检查和热模拟等试验工作,对故障高压涡轮导向叶片裂纹性质及产生机理进行分析。结果表明:故障叶片裂纹性质为疲劳,疲劳起源于气膜孔外壁的尖角区域。热障涂层涂覆后引起前缘气膜孔孔径减小,且使用过程中气膜孔受燃气氧化附着物影响导致孔口堵塞;叶片前缘局部超温导致基体组织转变,降低了基体的抗疲劳性能,促使叶片过早疲劳开裂。本文提出了适当加大气膜孔孔径,完善加工工艺要求,加强孔表面附着物清理等建议,可有效避免类似故障重复发生。 展开更多
关键词 涡轮导向叶片 疲劳裂纹 气膜孔 超温 热障涂层
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焦虑情绪对老年食管癌患者围手术期血清MPO、LXA4水平及血管内皮功能的影响 被引量:4
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作者 郝雁冰 王丽 +3 位作者 容宇 魏东 李彦明 陈万生 《中国现代医学杂志》 CAS 2018年第21期68-73,共6页
目的探讨老年食管癌患者合并焦虑情绪对围手术期血清髓过氧化物酶(MPO)、血清脂氧素A4(LXA4)水平及血管内皮功能的影响。方法选取2015年10月-2016年10月该院所收治的60例老年食管癌合并焦虑情绪患者作为研究对象,并将其随机分为观察组... 目的探讨老年食管癌患者合并焦虑情绪对围手术期血清髓过氧化物酶(MPO)、血清脂氧素A4(LXA4)水平及血管内皮功能的影响。方法选取2015年10月-2016年10月该院所收治的60例老年食管癌合并焦虑情绪患者作为研究对象,并将其随机分为观察组和对照组,每组各30例。两组均行食管癌根治性手术治疗,观察组在手术治疗基础上加抗焦虑干预治疗。比较和分析两组焦虑情绪、血清MPO、血清LXA4及血管内皮功能变化情况;治疗后6个月预后情况和观察组治疗后不同焦虑自评量表评分(SAS)与血清MPO、LXA4水平及血管内皮功能变化情况。结果两组治疗后SAS比较有差异(P<0.05),观察组SAS低于对照组;两组治疗后血清MPO比较有差异(P<0.05),观察组血清MPO低于对照组;两组治疗后血清LXA4比较有差异(P<0.05),观察组血清LXA4低于对照组;两组治疗后内皮素(ET)比较有差异(P<0.05),观察组低于对照组;两组治疗后一氧化氮(NO)、血管扩张率(FMD)及动脉内径变化率(GTN)比较有差异(P<0.05),观察组高于对照组;观察组治疗后不同SAS评分与血清MPO、LXA4水平及血管内皮功能指标变化情况比较有差异(P<0.05);两组治疗后6个月预后情况比较有差异(P<0.05),观察组预后情况优于对照组(P<0.05)。结论抗焦虑干预治疗能有效消除老年食管癌患者合并焦虑的负性情绪,改善患者围手术期血清MPO、LXA4水平及血管内皮功能,可作为理想的辅助治疗方案在临床应用和推广。 展开更多
关键词 食管癌 焦虑 髓过氧化物酶 脂氧素 血管内皮功能
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Evaluation of Rapid Detection of Nasopharyngeal Colonization with MRSA by Real-Time PCR
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作者 Feng-feng Kang Shu-yan Cao +4 位作者 yan-ming li Jiang-tao li Qing He Yi li Yun-jian Hu 《国际感染病学(电子版)》 CAS 2012年第1期-,共5页
Objective To investigate the clinical application of Real-Time PCR for rapid detection of methicillin-resistant Staphylococcus aureus(MRSA) directly from nasopharyngeal swab specimens.Methods We collected the nasal an... Objective To investigate the clinical application of Real-Time PCR for rapid detection of methicillin-resistant Staphylococcus aureus(MRSA) directly from nasopharyngeal swab specimens.Methods We collected the nasal and throat swab specimens from patients or medical staffs in 3 intensive care units,blood laminar flow ward and respiratory ward in Beijing Hospital,Ministry of Health from December 2010to April 2011.Each sample was tested by RT-PCR and conventional culture-based method for the presence of MRSA.Results The total number of the specimens was 206.Compared with the conventional culture-based method,we demonstrated the diagnostic values for Real-Time PCR were 96.4%sensitivity,96.6%specificity,81.8%positive predictive rate,and 99.4%negative predictive rate.And the limit of detection was 10~2CFU/ml.Conclusions This Real-Time PCR is a simple,rapid,sensitive and specific method.With the high negative predictive value,it can be used for the exclusion of MRSA colonization or infection.However,the application of its low positive predictive value should be further evaluated. 展开更多
关键词 Real-Time PCR MRSA Nasopharyngeal swab
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Mass Spectrometry-based Proteomics in Acute Respiratory Distress Syndrome: A Powerful Modality for Pulmonary Precision Medicine 被引量:7
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作者 Xue-Feng Xu Hua-Ping Dai +2 位作者 yan-ming li Fei Xiao Chen Wang 《Chinese Medical Journal》 SCIE CAS CSCD 2016年第19期2357-2364,共8页
Objective:Acute respiratory distress syndrome (ARDS) is an acute and lethal clinical syndrome that is characterized by hypoxemic respiratory failure and diffuse alveolar inflammatory damage.This review aimed to sea... Objective:Acute respiratory distress syndrome (ARDS) is an acute and lethal clinical syndrome that is characterized by hypoxemic respiratory failure and diffuse alveolar inflammatory damage.This review aimed to search and discuss the mass spectrometry (MS)-based proteomic studies on different subsets of ARDS patients.Data Sources:Original research articles were collected from the PubMed database published in English up to December 2015.Study Selection:The literature search was done using the term "(acute lung injury OR acute respiratory distress syndrome)AND (proteomics OR proteome OR mass spectrum OR differential in-gel electrophoresis OR two-dimensional polyacrylamide gel electrophoresis)".Related original research articles were included and were carefully analyzed.Results:Eight original proteomic researches on ARDS patients were found.The common proteomic modalities were two-dimensional (2D)high-performance liquid chromatography-based electronic spray ion-MS/MS and 2D-polyacrylamide gel electrophoresis/differential in-gel electrophoresis-based matrix-assisted laser desorption ionization-time of flight/MS.They compared the proteome between ARDS patients and normal controls and analyzed the dynamic changes ofproteome at different ARDS stages or severity.The disturbed proteome in ARDS patients includes plasma acute-phase proteins,inflammatory/immune-associated proteins,and coagulation proteins.Conclusions:Although several previous studies have provided some useful information about the lung proteome in ARDS patients and gained several interesting disease-associated biomarkers,clinical proteomic studies in ARDS patients are still in the initial stage.An increased cooperation is still needed to establish a global and faithful database containing disease-specific proteome from the largest ARDS subsets. 展开更多
关键词 Acute Respiratory Distress Syndrome Biomarkers Mass Spectrometry PROTEOMICS
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Expert consensus on clinical standardized application of high-flow nasal cannula oxygen therapy in adults 被引量:2
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作者 Jian-Qiao Xu Long-Xiang Su +20 位作者 Peng Yan Xing-Shuo Hu Ruo-Xuan Wen Kun Xiao Hong-Jun Gu Jin-Gen Xia Bing Sun Qing-Tao Zhou Yu-Chao Dong Jia-lin liu Pin-Hua Pan Hong Luo Qi li li-Qiang Song Si-Cheng Xu yan-ming li Dao-Xin Wang Dan li Qing-Yuan Zhan li-Xin Xie 《Chinese Medical Journal》 SCIE CAS CSCD 2020年第11期1322-1324,共3页
High-flow nasal cannula oxygen therapy(HFNC)is a novel respiratory support technology and has been extensively applied in clinics in recent years.This therapeutic equipment mainly includes an air-oxygen blender,an act... High-flow nasal cannula oxygen therapy(HFNC)is a novel respiratory support technology and has been extensively applied in clinics in recent years.This therapeutic equipment mainly includes an air-oxygen blender,an active humidifier,a high-flow nasal cannula,and a connecting inspiratory circuit.It provides patients a humidified high-flow gas(8-80 L/min)with relatively stable oxygen concentration(21-100%),temperature(31-37℃)and performs oxygen therapy via a nasal cannula,which is very comfortable. 展开更多
关键词 FLOW connecting high
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Nontuberculous mycobacteria in China:incidence and antimicrobial resistance spectrum from a nationwide survey 被引量:21
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作者 Chun-Fa liu Yi-Meng Song +6 位作者 Wen-Cong He Dong-Xin liu Ping He Jing-Jing Bao Xin-Yang Wang yan-ming li Yan-lin Zhao 《Infectious Diseases of Poverty》 SCIE 2021年第2期96-96,共1页
Background:Information on the prevalence and resistance spectrum of nontuberculous mycobacteria(NTM)in China is mainly based on regional or local data.To estimate the proportion of NTM cases in China,a national survey... Background:Information on the prevalence and resistance spectrum of nontuberculous mycobacteria(NTM)in China is mainly based on regional or local data.To estimate the proportion of NTM cases in China,a national survey of NTM pulmonary disease was carried out based on acid-fast positive sputum samples collected in 2013. 展开更多
关键词 Nontuberculous mycobacteria Pulmonary disease PREVALENCE Drug resistance
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Intrinsic feature extraction using discriminant diffusion mapping analysis for automated tool wear evaluation 被引量:1
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作者 Yi-xiang HUANG Xiao liU +1 位作者 Cheng-liang liU yan-ming li 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2018年第11期1352-1361,共10页
We present a method of discriminant diffusion maps analysis(DDMA) for evaluating tool wear during milling processes. As a dimensionality reduction technique, the DDMA method is used to fuse and reduce the original fea... We present a method of discriminant diffusion maps analysis(DDMA) for evaluating tool wear during milling processes. As a dimensionality reduction technique, the DDMA method is used to fuse and reduce the original features extracted from both the time and frequency domains, by preserving the diffusion distances within the intrinsic feature space and coupling the features to a discriminant kernel to refine the information from the high-dimensional feature space. The proposed DDMA method consists of three main steps:(1) signal processing and feature extraction;(2) intrinsic dimensionality estimation;(3) feature fusion implementation through feature space mapping with diffusion distance preservation. DDMA has been applied to current signals measured from the spindle in a machine center during a milling experiment to evaluate the tool wear status. Compared with the popular principle component analysis method, DDMA can better preserve the useful intrinsic information related to tool wear status. Thus, two important aspects are highlighted in this study: the benefits of the significantly lower dimension of the intrinsic features that are sensitive to tool wear, and the convenient availability of current signals in most industrial machine centers. 展开更多
关键词 Tool condition monitoring MANIFOLD learning Dimensionality reduction DIFFUSION MAPPING ANALYSIS INTRINSIC feature extraction
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Potentials of marine natural products against malaria, leishmaniasis, and trypanosomiasis parasites: a review of recent articles
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作者 Justus Amuche Nweze Florence N.Mbaoji +7 位作者 yan-ming li li-Yan Yang Shu-Shi Huang Vincent N.Chigor Emmanuel A.Eze li-Xia Pan Ting Zhang Deng-Feng Yang 《Infectious Diseases of Poverty》 SCIE 2021年第1期95-96,共2页
Background:Malaria and neglected communicable protozoa parasitic diseases,such as leishmaniasis,and trypanosomiasis,are among the otherwise called diseases for neglected communities,which are habitual in underprivileg... Background:Malaria and neglected communicable protozoa parasitic diseases,such as leishmaniasis,and trypanosomiasis,are among the otherwise called diseases for neglected communities,which are habitual in underprivileged populations in developing tropical and subtropical regions of Africa,Asia,and the Americas.Some of the currently available therapeutic drugs have some limitations such as toxicity and questionable efficacy and long treatment period,which have encouraged resistance.These have prompted many researchers to focus on fin ding new drugs that are safe,effective,and affordable from marine environ merits.The aim of this review was to show the diversity,structural scaffolds,in-vitro or in-vivo efficacy,and recent progress made in the discovery/isolation of marine natural products(MNPs)with potent bioactivity against malaria,leishmaniasis,and trypanosomiasis.Main text:We searched PubMed and Google scholar using Boolean Operators(AND,OR,and NOT)and the combination of related terms for articles on marine natural products(MNPs)discovery published only in English language from January 2016 to June 2020.Twenty nine articles reported the isolation,identification and antiparasitic activity of the isolated compounds from marine environment.A total of 125 compounds were reported to have been isolated,out of which 45 were newly isolated compounds.These compounds were all isolated from bacteria,a fungus,sponges,algae,a bryozoan,cnidarians and soft corals.In recent years,great progress is being made on anti-malarial drug discovery from marine organisms with the isolation of these potent compounds.Comparably,some of these promising antikinetoplastid MNPs have potency better or similar to conventional drugs and could be developed as both antileishmanial and antitrypanosomal drugs.However,very few of these MNPs have a pharmaceutical destiny due to lack of the following:sustainable production of the bioactive compounds,stan da rd efficient screening methods,knowledge of the mechanism of action,partnerships between researchers and pharmaceutical industries.Conclusions:It is crystal clear that marine organisms are a rich source of antiparasitic compounds,such as alkaloids,terpenoids,peptides,polyketides,terpene,coumarins,steroids,fatty acid derivatives,and lactones.The current and future technological innovation in natural products drug discovery will bolster the drug armamentarium for malaria and neglected tropical diseases. 展开更多
关键词 Marine natural products Neglected tropical diseases Anti-trypanosoma Anti-leishmania Anti-plasmodia Protozoa parasites
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