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AES-192的相关密钥飞去来器攻击和矩形攻击
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作者 谭林 曾新皓 刘加美 《密码学报(中英文)》 CSCD 北大核心 2024年第5期1018-1028,共11页
相关密钥攻击是对AES十分有效的分析方法之一.在2022年亚密会上,Derbez等利用概率为2−108的10轮相关密钥飞去来器区分器给出了目前最好的AES-192的全轮攻击.本文改进了全轮AES-192的相关密钥飞去来器和矩形攻击.基于Wang等的9轮相关密... 相关密钥攻击是对AES十分有效的分析方法之一.在2022年亚密会上,Derbez等利用概率为2−108的10轮相关密钥飞去来器区分器给出了目前最好的AES-192的全轮攻击.本文改进了全轮AES-192的相关密钥飞去来器和矩形攻击.基于Wang等的9轮相关密钥飞去来器区分器的截断差分,本文利用飞去来器分布表(BDT)技术给出目前概率最高的10轮相关密钥飞去来器区分器,概率为2−105.92.基于该区分器,改进了全轮AES-192的相关密钥飞去来器攻击,时间、数据和存储复杂度分别为2^(121.92)、2^(121.92)和2^(90.92),与之前的结果相比时间复杂度改进了22.08.进一步,给出了全轮AES-192的相关密钥矩形攻击,时间、数据和存储复杂度分别为2^(127.9)、2^(119.5)和2^(131.5),这也是目前在选择明文模式下对全轮AES-192最好的攻击结果. 展开更多
关键词 aeS算法 飞去来器攻击 矩形攻击 相关密钥攻击
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基于AES的车联网通信加密算法
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作者 许小伟 程宇 +2 位作者 钱枫 祝能 邓明星 《计算机与现代化》 2024年第9期45-51,共7页
随着V2X技术发展得越来越快,车辆与其他设备的通信量以及信息重要度都在急速增长,车载信息遭到攻击从而被截取或者发生泄漏的风险也相应地大大增加,因此信息交互安全性成为了一个不可避免的研究课题。本文针对车联网传输数据量大、数据... 随着V2X技术发展得越来越快,车辆与其他设备的通信量以及信息重要度都在急速增长,车载信息遭到攻击从而被截取或者发生泄漏的风险也相应地大大增加,因此信息交互安全性成为了一个不可避免的研究课题。本文针对车联网传输数据量大、数据加解密操作频繁等问题,通过分析经典加密算法,进而改进传统AES加密算法,使用RC4加密算法生成伪随机密钥代替AES加密算法的密钥生成模块,优化加密时间的同时提升安全性能,并开展实验验证了其加密效率以及安全性。 展开更多
关键词 V2X 通信安全 aeS RC4 加密算法 混合加密
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基于AES与ECC混合算法的计算机网络通信数据安全加密方法 被引量:1
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作者 石小兵 《常州工学院学报》 2024年第3期6-10,共5页
为了提高通信数据在计算机网络中的安全性,提出一种基于AES与ECC混合算法的计算机网络通信数据安全加密方法。通过时域分析,得到通信数据在计算机网络边缘的频率分布情况,根据通信数据中冗余信息的密度,离散化处理通信数据内的噪声,提... 为了提高通信数据在计算机网络中的安全性,提出一种基于AES与ECC混合算法的计算机网络通信数据安全加密方法。通过时域分析,得到通信数据在计算机网络边缘的频率分布情况,根据通信数据中冗余信息的密度,离散化处理通信数据内的噪声,提取出通信数据的特征向量。根据通信数据的明文空间进行加密处理,计算出待加密通信数据的密文值,将计算机网络通信数据的加密过程约束成加密函数的计算,设定通信数据安全加密的约束条件,采用AES算法加密通信数据的明文,利用ECC算法加密AES密钥,将AES与ECC结合,生成通信数据的密钥密文,实现通信数据的安全加密。实验结果表明,所提方法能够保证通信数据在计算机网络中的安全,可以将通信数据加密后的受攻击指数控制在0.1以内,提高通信数据的加密效果。 展开更多
关键词 aeS加密算法 ECC加密算法 通信数据 特征向量 计算机网络 安全加密
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基于LSTM-AE的民机空调热交换器性能异常检测方法
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作者 王秋奕 高源 贾宝惠 《中国民航大学学报》 CAS 2024年第3期55-60,共6页
空调热交换器性能异常检测技术是快速判断民机空调系统运行状态并合理安排维修任务的关键,传统的异常检测方法难以有效处理高维时序数据,无法实现系统早期故障预警。为此,本文提出了一种基于长短期记忆网络(LSTM,long-short term memory... 空调热交换器性能异常检测技术是快速判断民机空调系统运行状态并合理安排维修任务的关键,传统的异常检测方法难以有效处理高维时序数据,无法实现系统早期故障预警。为此,本文提出了一种基于长短期记忆网络(LSTM,long-short term memory)与自编码器(AE,autoencoder)模型的无监督异常检测方法,用以识别民机空调系统异常运行状态。首先,基于民机空调系统原始传感器参数构建表征空调热交换器性能的特征监测参数;其次,构建LSTM-AE模型进行数据特征重构并计算重构误差;最后,使用孤立森林(iForest, isolation forest)进行无监督异常监测。将本文构建的无监督异常检测方法与传统方法对比,并建立模型评估指标,验证结果表明,所构建的模型方法可以对民机空调热交换器性能异常状态进行有效检测。 展开更多
关键词 民机空调系统 异常检测 自编码器(ae) 长短期记忆网络 孤立森林(iForest)
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基于混沌序列和AES算法的数据库外层数据传输同步加密方法
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作者 陈琳 《黑龙江工程学院学报》 CAS 2024年第4期38-43,共6页
为保障数据库外层数据的安全传输,提出一种基于混沌序列和AES算法的数据库外层数据传输同步加密方法。该方法结合AES算法的加密安全性和混沌序列的加密速度优势,通过加密代理服务器和应用服务器对数据库外层数据进行处理,利用混沌序列lo... 为保障数据库外层数据的安全传输,提出一种基于混沌序列和AES算法的数据库外层数据传输同步加密方法。该方法结合AES算法的加密安全性和混沌序列的加密速度优势,通过加密代理服务器和应用服务器对数据库外层数据进行处理,利用混沌序列logistic映射参数初始化、混沌序列二进制量化、AES动态加密和尾端处理实现数据库外层数据传输同步加密。实验结果表明,该方法能够成功地对文本和图像数据进行加密和隐藏,同时提高加密效率,并兼顾了数据的安全性和传输效率。 展开更多
关键词 混沌序列 aeS算法 数据库 数据传输 数据加密 外层数据
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基于AES算法的计算机数据库加密系统设计与实现 被引量:1
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作者 戴菲 《电脑编程技巧与维护》 2024年第7期97-99,共3页
随着信息技术的迅猛发展,中等职业(中职)教育面临着教学资源更新和个性化教学需求的双重挑战。知识图谱是一种通过链接和整合广泛信息资源来创建、利用和分享知识的技术,能够在复杂的数据中寻找规律,为用户提供准确的信息推荐服务。研... 随着信息技术的迅猛发展,中等职业(中职)教育面临着教学资源更新和个性化教学需求的双重挑战。知识图谱是一种通过链接和整合广泛信息资源来创建、利用和分享知识的技术,能够在复杂的数据中寻找规律,为用户提供准确的信息推荐服务。研究通过分析数据库加密的常用方式和数据库透明加密(TDE)原理,设计了一套基于知识图谱的中职线上教学资源推荐系统的体系架构。系统采用高级加密标准(AES)算法加密设计保证数据安全,整合数据库提升系统效能,并详细说明了开发过程的实现。通过实验结果及分析,证明了系统的有效性和实用性,为中职教育提供了一种新的线上教学资源推荐解决方案。 展开更多
关键词 aeS算法 计算机数据库 加密系统设计 体系架构
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Enhanced Expression of Aquaporin-9 in Rat Brain Edema Induced by Bacterial Lipopolysaccharides 被引量:2
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作者 王怀立 金润铭 +1 位作者 田培超 禚志红 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2009年第2期150-155,共6页
To investigate the role of AQP9 in brain edema, the expression of AQP9 in an infectious rat brain edema model induced by the injection of lipopolysaccharide (LPS) was examined. Immuno- histochemistry and reverse tra... To investigate the role of AQP9 in brain edema, the expression of AQP9 in an infectious rat brain edema model induced by the injection of lipopolysaccharide (LPS) was examined. Immuno- histochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated that the expressions of AQP9 mRNA and protein at all observed intervals were significantly increased in LPS-treated animals in comparison with the control animals. Time-course analysis showed that the first signs of blood-brain barrier disruption and the increase of brain water content in LPS-treated animals were evident 6 h after LPS injection, with maximum value appearing at 12 h, which coincided with the expression profiles of AQP9 mRNA and protein in LPS-treated animals. The further correlation analysis revealed strong positive correlations among the brain water content, the disruption of the blood-brain barrier and the enhanced expressions of AQP9 mRNA and protein in LPS-treated animals. These results suggested that the regulation of AQP9 expression may play im- portant roles in water movement and in brain metabolic homeostasis associated with the pathophysi- ology of brain edema induced by LPS injection. 展开更多
关键词 AQUAPORINS AQUAPORIN-9 lipopolysaccharides infectious brain edema water channels
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Galacto-oligosaccharides improve barrier function and relieve colonic inflammation via modulating mucosa-associated microbiota composition in lipopolysaccharides-challenged piglets 被引量:5
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作者 Ren Gao Shiyi Tian +1 位作者 Jing Wang Weiyun Zhu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2022年第1期240-255,共16页
Background:Galacto-oligosaccharides(GOS)have been shown to modulate the intestinal microbiota of suckling piglets to exert beneficial effects on intestinal function.However,the modulation of intestinal microbiota and ... Background:Galacto-oligosaccharides(GOS)have been shown to modulate the intestinal microbiota of suckling piglets to exert beneficial effects on intestinal function.However,the modulation of intestinal microbiota and intestinal function by GOS in intestinal inflammation injury models has rarely been reported.In this study,we investigated the effects of GOS on the colonic mucosal microbiota composition,barrier function and inflammatory response of lipopolysaccharides(LPS)-challenged suckling piglets.Methods:A total of 18 newborn suckling piglets were divided into three groups,the CON group,the LPS-CON group and the LPS-GOS group.Piglets in the LPS-GOS group were orally fed with 1 g/kg body weight of GOS solution every day.On the d 14,piglets in the LPS-CON and LPS-GOS group were challenged intraperitoneally with LPS solution.All piglets were slaughtered 2 h after intraperitoneal injection and sampled.Results:We found that the colonic mucosa of LPS-challenged piglets was significantly injured and shedding,while the colonic mucosa of the LPS-GOS group piglets maintained its structure.Moreover,GOS significantly reduced the concentration of malondialdehyde(MDA)and the activity of reactive oxygen species(ROS)in the LPS-challenged suckling piglets,and significantly increased the activity of total antioxidant capacity(T-AOC).GOS significantly increased the relative abundance of norank_f_Muribaculaceae and Romboutsia,and significantly decreased the relative abundance of Alloprevotella,Campylobacter and Helicobacter in the colonic mucosa of LPS-challenged suckling piglets.In addition,GOS increased the concentrations of acetate,butyrate and total short chain fatty acids(SCFAs)in the colonic digesta of LPS-challenged suckling piglets.GOS significantly reduced the concentrations of interleukin 1β(IL-1β),interleukin 6(IL-6),tumor necrosis factor-α(TNF-α)and cluster of differentiation 14(CD14),and the relative mRNA expression of Toll-like receptor 4(TLR4)and myeloid differentiation primary response 88(MyD88)in the LPS-challenged suckling piglets.In addition,GOS significantly reduced the relative mRNA expression of mucin2(MUC2),and significantly increased the protein expression of Claudin-1 and zonula occluden-1(ZO-1)in LPS-challenged suckling piglets.Conclusions:These results suggested that GOS can modulate the colonic mucosa-associated microbiota composition and improve the intestinal function of LPS-challenged suckling piglets. 展开更多
关键词 Barrier function GALACTO-OLIGOSACCHARIDES Intestinal microbiota lipopolysaccharides Suckling piglets
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Intragingival injection of Porphyromonas gingivalis-derived lipopolysaccharide induces a transient increase in gingival tumour necrosis factor-a, but not interleukin-6,in anaesthetised rats 被引量:1
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作者 Hiroko Taguchi Yuri Aono +3 位作者 Takayuki Kawato Masatake Asano Noriyoshi Shimizu Tadashi Saigusa 《International Journal of Oral Science》 SCIE CAS CSCD 2015年第3期155-160,共6页
This study used in vivo microdialysis to examine the effects of intragingival application of lipopolysaccharide(LPS) derived from Porphyromonas gingivalis(Pg-LPS) on gingival tumour necrosis factor(TNF)-a and in... This study used in vivo microdialysis to examine the effects of intragingival application of lipopolysaccharide(LPS) derived from Porphyromonas gingivalis(Pg-LPS) on gingival tumour necrosis factor(TNF)-a and interleukin(IL)-6 levels in rats. A microdialysis probe with an injection needle attached to the surface of the dialysis membrane was implanted into the gingiva of the upper incisor. For comparison, the effects of LPS derived from Escherichia coli(Ec-LPS) on IL-6 and TNF-a levels were also analysed. Pg-LPS(1 mg/1 m L) or Ec-LPS(1 or 6 mg/1 m L) was applied by microsyringe, with gingival dialysates collected every hour. Enzyme-linked immunosorbent assay(ELISA) revealed that gingival dialysates contained approximately 389 pg?m L21 of IL-6 basally; basal TNF-a levels were lower than the detection limit of the ELISA. Pg-LPS failed to alter IL-6 levels but markedly increased TNF-a levels, which remained elevated for 2 h after treatment. Neither IL-6 nor TNF-a were affected by Ec-LPS. Reverse transcriptase-polymerase chain reaction(RT-PCR) analysis revealed that the gingiva expresses Toll-like receptor(TLR) 2 and TLR4 m RNA. Immunohistochemical examination showed that TLR2 and TLR4 are expressed by gingival epithelial cells. The present study provides in vivo evidence that locally applied Pg-LPS, but not Ec-LPS, into the gingiva transiently increases gingival TNF-a without affecting IL-6. The present results suggest that TLR2 but not TLR4 expressed on gingival epithelial cells may mediate the Pg-LPS-induced increase in gingival TNF-a in rats. 展开更多
关键词 Porphyromonas gingivalis lipopolysaccharidE GINGIVA tumour necrosis factor-a MICRODIALYSIS
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ICP-AES法测定电炉渣中二氧化硅
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作者 刘晓丽 张洪双 +2 位作者 王雨欣 姜涛 陈斌 《中国标准化》 2024年第7期225-228,共4页
本文研究了采用酸溶的方式消解样品,ICP-AES光谱法测定电炉渣中二氧化硅的分析方法。采用浓盐酸和浓硝酸溶解电炉尾料样品,加入氢氟酸消解二氧化硅和硼酸络合氟离子,采用ICP-AES法测定电炉尾料样品中的二氧化硅含量。二氧化硅的相对标... 本文研究了采用酸溶的方式消解样品,ICP-AES光谱法测定电炉渣中二氧化硅的分析方法。采用浓盐酸和浓硝酸溶解电炉尾料样品,加入氢氟酸消解二氧化硅和硼酸络合氟离子,采用ICP-AES法测定电炉尾料样品中的二氧化硅含量。二氧化硅的相对标准偏差RSD为0.35%~0.58%,加标回收率为95.6%~102.3%。方法加标回收率好,满足分析方法要求。 展开更多
关键词 ICP-aeS 二氧化硅 电炉渣 酸溶消解 分析方法
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The effect of lipopolysaccharides on the expression of CD14 and TLR4 in rat Kupffer cells 被引量:1
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作者 Jun-Ming Feng Jing-Quan Shi You-Sheng Liu the Research Institute of Pathology Southwestern Hospital, Third Military Medical University, Chongqing 400038, China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2003年第2期581-585,共5页
OBJECTIVE: To assess the effect of lipopolysaccharides (LPS) on the expression of CD14 and TLR4 in rat Kupffer cells (KCs). METHODS: In rat KCs induced by LPS, the changes of CD14 and TLR4 expression were measured by ... OBJECTIVE: To assess the effect of lipopolysaccharides (LPS) on the expression of CD14 and TLR4 in rat Kupffer cells (KCs). METHODS: In rat KCs induced by LPS, the changes of CD14 and TLR4 expression were measured by RT-PCR and immunohistochemistry, and the expressions of TNF-αmRNA, IL-6mRNA or the concentrations of TNF-α, IL-6 were estimated by in situ hybridization, radioimmunoassay, and others. RESULTS: The expressions of CD14 and TLR4 in KCs induced by LPS were markedly increased in a dose-dependent manner (10 mg/L-1μg/L) or in a time-dependent manner (0.5 h-24 h), with the peaked expression of CD14 at 3-6 hours. The expressions of CD14 and TLR4 in KCs stimulated by the active mediators from KCs which had been exposed to LPS for 1 hour were obviously increased. CONCLUSIONS: There is a close relationship between LPS or the active mediators from KCs induced by LPS and the expressions of CD14, TLR4. It is implied that the increase of TLR4, CD14 expression may be induced by LPS within 1--3 hours, and further increase of TLR4, CD14 expression may be correlated with the cytokines produced bv KCs. 展开更多
关键词 lipopolysaccharides Toll-like receptor TNF INTERLEUKIN MEDIATOR CYTOKINES Kupffer cell
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基于PMC-AE指数模型的中国“双碳”政策量化评价
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作者 薛洁 王梦晗 《科技和产业》 2024年第24期1-13,共13页
通过文本挖掘的方式构建中国“双碳”政策评价指标体系,选取PMC指数模型结合自编码(AE)技术进行指标权重量化与多参数融合,利用9个一级指标和39个二级指标,实现了对中国双碳“1+N”政策体系中10项代表性政策的定量评价。结果表明,“双... 通过文本挖掘的方式构建中国“双碳”政策评价指标体系,选取PMC指数模型结合自编码(AE)技术进行指标权重量化与多参数融合,利用9个一级指标和39个二级指标,实现了对中国双碳“1+N”政策体系中10项代表性政策的定量评价。结果表明,“双碳”政策可分为三个等级,这些政策呈现出自上而下的特点,得分差异的主要原因包括政策性质、政策时效、激励保障和政策客体等方面。基于这些发现,提出了关于“双碳”政策调整和优化的可行性建议。 展开更多
关键词 “双碳”政策 文本挖掘 量化评价 PMC-ae指数模型
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Protective Effect of Emodin against Lipopolysaccharides-induced Corneal Injury in Rats 被引量:1
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作者 Guo-ling Chen Zhi-yu Liu +3 位作者 Jing Wang Xue Gao Lu-wan Wei Yan-Li Liu 《Chinese Medical Sciences Journal》 CAS CSCD 2009年第4期236-240,共5页
Objective To investigate the effect of emodin on lipopolysaccharides (LPS)-induced corneal injury in rats. Methods Three parallel incisions on the central surface of corneal epithelium were made and LPS was applied... Objective To investigate the effect of emodin on lipopolysaccharides (LPS)-induced corneal injury in rats. Methods Three parallel incisions on the central surface of corneal epithelium were made and LPS was applied on them to induce corneal injury in Wistar rats. All rats were randomly divided into emodin group (n=40) and keratitis group (n=40). Rats in the emodin group received subconjunctival injection of emodin and rats in the keratitis group received its vehicle 30 minutes before LPS exposure. At different time points-1 3, 6, 12, and 24 hours after LPS exposure, the symptoms of all rats were observed and the severity of their ocular inflammation was examined with a slit lamp microscope, then 8 rats in each group were killed through cervical dislocation and their eyes were enucleated and prepared to observe pathological changes of corneal tissue under a light microscope. The activation of nuclear factor-loB (NF-κB) under different condi- tions was determined by Western blot. Immunocytochemistry staining with an antibody against intercellular adhesion molecule-1 (ICAM-1) was performed to identify positive cells in corneal tissues. Results The model of acute keratitis was successfully established in Wistar rats. LPS could induce a typical corneal inflammatory response, such as hyperemia, corneal edema and opacity, which were observed in model rats. Compared with keratitis group, both ocular behaviors and damages of the corneal structure were improved in emodin group. Furthermore, the activation of NF-κB and the expression of ICAM-1 induced by LPS were markedly inhibited in emodin group. Conclusion Emodin can inhibit the activation of NF-κB and the expression of ICAM-I induced by LPS in corneas, protect against acute corneal injury, and improve symptoms in rats. 展开更多
关键词 corneal injury EMODIN lipopolysaccharides nuclear factor-κB
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The roles of serine protease, intracellular and extracellular phenoloxidase in activation of prophenoloxidase system, and characterization of phenoloxidase from shrimp haemocytes induced by lipopolysaccharide or dopamine 被引量:1
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作者 谢鹏 潘鲁青 +1 位作者 徐武杰 岳峰 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第5期1018-1027,共10页
We investigated the effects of lipopolysaccharide (LPS) and dopamine (DA) on the activation of the prophenoloxidase (proPO) system of Litopenaeus vannamei. LPS and DA were shown with a negative dose-dependent ef... We investigated the effects of lipopolysaccharide (LPS) and dopamine (DA) on the activation of the prophenoloxidase (proPO) system of Litopenaeus vannamei. LPS and DA were shown with a negative dose-dependent effect on hyalne cells (HC), semi-granular cells (SGC), large granular cells (LGC), and total haemocyte count (THC). When haemocytes were treated with LPS or DA, serine proteinase activity and intracellular phenoloxidase (PO) activity were significantly reduced, but extracellular PO activity increased significantly. These findings indicated that the reduction in haemocyte counts was mainly because of the degranulation and activation of the proPO system from semi-granule and large granule cells. The PKC inhibitor, chelerythrine, and the TPK inhibitor, genistein, had an inhibitory effect on extracellular PO activity, while serine proteinase and intracellular PO activity increased. This suggests that the LPS and DA induce the activation of proPO in haemocytes via PKC and TPK-related signaling pathways, but serine proteinase may be activated only by PKC, as the genistein effects were not statistically significant. Electrophoresis analysis revealed that POs induced by LPS or DA have the same molecular mass and high diphenolase activity. Two PO bands at 526 kDa and 272 kDa were observed in PAGE, while in the haemocyte lysate supematant (HLS), only a 272-kDa band was observed. This band was resolved after SDS-PAGE under non-reducing and reducing conditions into two groups of POs, 166 kDa and 126 kDa, and 78.1 kDa and 73.6 kDa, respectively, suggesting that PO in L. vannamei is an oligomer, which may have different compositions intra- and extracellularly. 展开更多
关键词 lipopolysaccharide (LPS) dopamine (DA) Litopenaeus vannamei phenoloxidase (PO) signaling pathway
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电感耦合等离子体原子发射光谱(ICP-AES)法测定真空精炼镁合金物料中铁、铜、镍 被引量:2
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作者 孙洪飞 王立鹏 +5 位作者 李蕊 唐飞龙 杨柒梅 伍秋云 田阳 吴鉴 《中国无机分析化学》 CAS 北大核心 2024年第4期464-472,共9页
真空精炼是目前镁金属提纯的重要工艺,工艺原料及真空精炼提纯镁金属过程残留物中Fe、Cu、Ni含量的准确测定对工艺参数的优化及调整具有重要的指导作用。传统测定方法中以邻二氮杂菲分光光度法、新亚铜灵分光光度法、丁二酮肟分光光度... 真空精炼是目前镁金属提纯的重要工艺,工艺原料及真空精炼提纯镁金属过程残留物中Fe、Cu、Ni含量的准确测定对工艺参数的优化及调整具有重要的指导作用。传统测定方法中以邻二氮杂菲分光光度法、新亚铜灵分光光度法、丁二酮肟分光光度法测定三种元素含量,结果准确,但操作繁琐,周期较长,难以满足工业生产中高效、快速测定的需要,且方法中所需的有机萃取剂对环境污染较大。选择电感耦合等离子体发射光谱(ICP-AES)法测定真空蒸馏精炼镁合金物料中Fe、Cu、Ni,系统探究溶解酸、溶解温度、溶解时间对物料溶解和测定的影响,选择盐酸(1+1)和过氧化氢溶解体系,200℃加热条件下反应20 min为最佳消解镁合金原料条件;选择王水溶解体系,200℃加热条件下反应25 min为真空精炼残留物最佳溶解条件。并探讨ICP-AES测定过程中各元素的检出限和测定下限以及共存元素的干扰情况,建立了ICP-AES法测定真空精炼提纯镁合金物料的方法。测定结果的相对标准偏差(RSD,n=11)为Fe 5.9%~11.5%、Cu 2.6%~11.8%、Ni 3.4%~11.5%,各元素加标回收率为Fe 96.4%~102%、Cu 101%~108%、Ni 103%~105%;按照建立的方法测定镁合金原料、真空精炼残留物中的铁、铜、镍,并与国家标准方法测定结果进行对比,结果相一致。实现了ICP-AES法快速、准确测定真空蒸馏精炼镁合金物料中铁、铜、镍含量,对及时、高效、准确评估真空精炼提纯镁工艺及产品具有重要意义。 展开更多
关键词 电感耦合等离子体发射光谱法(ICP-aeS) 真空精炼 残留物
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基于单通道AE盲源分离的结构损伤定位
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作者 何鹏举 王博成 +1 位作者 刘欣 刘应礼 《振动.测试与诊断》 EI CSCD 北大核心 2024年第5期1002-1009,1043,共9页
声发射(acoustic emission,简称AE)能够实现复杂板状结构损伤定位,但多数AE检测定位方法仅针对单AE源的情况,而实际中复杂板状结构产生损伤时会伴随多个AE卷积混合信号。为了解决工程中多AE源定位的问题,提出一种单通道AE盲分离-模态提... 声发射(acoustic emission,简称AE)能够实现复杂板状结构损伤定位,但多数AE检测定位方法仅针对单AE源的情况,而实际中复杂板状结构产生损伤时会伴随多个AE卷积混合信号。为了解决工程中多AE源定位的问题,提出一种单通道AE盲分离-模态提取定位方法。首先,对采集的AE信号进行信号降噪,使用单通道盲源分离算法分离出无回波成分的AE信号,将多源定位转为多个单源定位问题;其次,通过提取单频模态,求取声波传播速度,估计到达时间差来进行疲劳裂纹损伤定位;最后,经过计算机仿真实验和钢箱梁桥断铅半实物仿真实验,验证了方法的准确性和有效性,并通过载荷破坏AE检测实验验证了方法的实用性。结果表明,所提方法能够应用于复杂板状结构多AE源定位问题,为实际工程应用提供了可靠的依据及参考价值。 展开更多
关键词 板状结构体 声发射 多源定位 ae盲分离-模态提取
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Difference between periportal and pericentral Kupffer cells in uptaking lipopolysaccharides in rats
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作者 CHEN Xian Ming 1, LIU Jin_Chun 2, XU Rei Ling 1, MA Xue Hui 1, ZHAO Yuan Chang 1 and HAN De Wu 1 1Institute of Hepatology, Shanxi Medical University, Taiyuan 030001, Shanxi Province, China 2First Teaching Hospital of Shanxi Medical Un 《World Journal of Gastroenterology》 SCIE CAS CSCD 1997年第3期40-40,共1页
AIM To reveal the difference of Kupffer cells in the periportal and pericentral regions in the liver to uptake lipopolysaccharides (LPS) injected by the portal vein. METHODS Male Wistar rats were divided into two g... AIM To reveal the difference of Kupffer cells in the periportal and pericentral regions in the liver to uptake lipopolysaccharides (LPS) injected by the portal vein. METHODS Male Wistar rats were divided into two groups: normal control group ( n =6) and GdCl 3 treated group ( n =8). Sixteen hours before the experiment, rats of GdCl 3 treated group were injected GdCl 3 by the tail vein to eliminate the Kupffer cell function in the periportal region selectively. LPS at a dose of 20μg/100g body weight was injected to rats of both groups by the portal vein. Zero, 2, 5, 10, 30, 60 minutes after LPS injection, liver samples were obtained and distribution of LPS in Kupffer cells was observed by the immunofluorescent method using a monoclonal antibody specific to LPS with a confocal laser scanning microscope. RESULTS In normal control group, positive reactions to LPS were found in Kupffer cells in the periportal region with the peak at 2 minutes after LPS injection. Kupffer cells in the pericentral region showed the peak at 5 minutes after LPS injection, but its fluorescent intensity to LPS at the peak time in the cytoplasm was significantly lower than that of Kupffer cells in the pericentral region at the peak point. In GdCl 3 treated group, Kupffer cells in the pericentral region showed the peak at 2 minutes after LPS injection, and its fluorescent intensity to LPS showed no significant difference from that of the normal control rats at the peak point. No significant changes of fluorescent intensities to LPS were found in Kupffer cells in the periportal region at various time points after LPS injection in GdCl 3 treated rats. CONCLUSION Kupffer cells in the periportal and pericentral regions showed difference to uptake LPS in the portal vein. 展开更多
关键词 liver/metabolism \ KUPFFER CELLS lipopolysaccharides/metabolism \ portal vein \ ENDOTOXINS \ ESCHERICHIA coli
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AE81镁合金轧制变形显微组织演变的研究
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作者 武红飞 胡文鑫 +4 位作者 马少博 杨正华 王玮 刘峰 何伟 《热加工工艺》 北大核心 2024年第11期129-133,共5页
通过重力铸造法制备了AE81稀土镁合金,并对固溶处理后的合金在300℃和350℃进行压下量分别为15%、20%、25%和30%的轧制变形。结果表明:稀土元素Ce的加入导致铸态组织中Mg_(17)Al_(12)相不连续分布,镁基体上分布的Al4Ce相以块状形貌、中... 通过重力铸造法制备了AE81稀土镁合金,并对固溶处理后的合金在300℃和350℃进行压下量分别为15%、20%、25%和30%的轧制变形。结果表明:稀土元素Ce的加入导致铸态组织中Mg_(17)Al_(12)相不连续分布,镁基体上分布的Al4Ce相以块状形貌、中空管状形貌和针状形貌存在。轧制变形后,AE81合金所产生的变形组织的体积分数随着压下量的增大而增大,当压下量增大到25%时出现了明显的动态再结晶现象,再结晶晶粒的平均尺寸主要分布在200~400nm之间,且动态再结晶区域主要分布在Al_(4)Ce相周围。同时,Mg_(17)Al_(12)析出相的体积分数随着轧制温度和压下量的增大而增大,Mg_(17)Al_(12)相在基体上的分布得到改善。 展开更多
关键词 ae81镁合金 轧制 显微组织
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Hemorrhagic transformation in patients with large-artery atherosclerotic stroke is associated with the gut microbiota and lipopolysaccharide 被引量:1
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作者 Qin Huang Minping Wei +3 位作者 Xianjing Feng Yunfang Luo Yunhai Liu Jian Xia 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1532-1540,共9页
Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases mortality.Disruption of the gut microbiota is an importa... Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases mortality.Disruption of the gut microbiota is an important feature of stroke,and some specific bacteria and bacterial metabolites may contribute to hemorrhagic transformation pathogenesis.We aimed to investigate the relationship between the gut microbiota and hemorrhagic transformation in largearte ry atheroscle rotic stro ke.An observational retrospective study was conducted.From May 2020 to September 2021,blood and fecal samples were obtained upon admission from 32 patients with first-ever acute ischemic stroke and not undergoing intravenous thrombolysis or endovascular thrombectomy,as well as 16 healthy controls.Patients with stro ke who developed hemorrhagic transfo rmation(n=15)were compared to those who did not develop hemorrhagic transformation(n=17)and with healthy controls.The gut microbiota was assessed through 16S ribosomal ribonucleic acid sequencing.We also examined key components of the lipopolysaccharide pathway:lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.We observed that bacterial diversity was decreased in both the hemorrhagic transformation and non-hemorrhagic transfo rmation group compared with the healthy controls.The patients with ischemic stro ke who developed hemorrhagic transfo rmation exhibited altered gut micro biota composition,in particular an increase in the relative abundance and dive rsity of members belonging to the Enterobacteriaceae family.Plasma lipopolysaccharide and lipopolysaccharide-binding protein levels were higher in the hemorrhagic transformation group compared with the non-hemorrhagic transfo rmation group.lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14 concentrations were associated with increased abundance of Enterobacte riaceae.Next,the role of the gut microbiota in hemorrhagic transformation was evaluated using an experimental stroke rat model.In this model,transplantation of the gut microbiota from hemorrhagic transformation rats into the recipient rats triggered higher plasma levels of lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.Ta ken togethe r,our findings demonstrate a noticeable change in the gut microbiota and lipopolysaccharide-related inflammatory response in stroke patients with hemorrhagic transformation.This suggests that maintaining a balanced gut microbiota may be an important factor in preventing hemorrhagic transfo rmation after stro ke. 展开更多
关键词 gut microbiota hemorrhagic transformation INFLAMMATION lipopolysaccharidE STROKE
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Effects of Tension Force on Proliferation and Differentiation of Human Periodontal Ligament Cells Induced by Lipopolysaccharides
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作者 Yanqi Yang Linkun Zhang +2 位作者 Chongshan Liao Jiajing Lu Chengfei Zhang 《Journal of Biosciences and Medicines》 2014年第3期13-19,共7页
Human periodontal ligament cells (hPDLCs), with the potential for multi-directional differentiation and reproduction, are the target cells of orthodontic tooth movement. The aim of this study was to examine the effect... Human periodontal ligament cells (hPDLCs), with the potential for multi-directional differentiation and reproduction, are the target cells of orthodontic tooth movement. The aim of this study was to examine the effect of mechanical tension force and lipopolysaccharides (LPS) on hPDLCs and whether they induce proliferative and differentiated characters in vitro. Tension force was applied to hPDLCs stimulated with and without LPS for 24 hrs. Real-time polymerase chain reaction (qPCR) was carried out to analyze the mRNA expression of Cyclin 2 (CCND2), WNT1 inducible signaling pathway protein 1 (WISP1), runt-related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP). Analysis of variance (ANOVA) was used for statistical analysis. Significant differences were indicated by P < 0.05. The results showed that tension force promoted the mRNA expression of both the proliferation-related genes (CCND2 and WISP1) and differentiation-related genes (RUNX2 and ALP), and that both were enhanced by the simulation of LPS. In addition, the relative expression ratios CCND2/RUNX2 and CCND2/ALP both increased significantly after the application of tension, and this effect was further enhanced by LPS. All results indicated that with the assessed level of mechanical force loading, tension could promote both the proliferation and differentiation of hPDLCs, which could be enhanced by LPS, and that proliferation is promoted to a greater extent than differentiation. These findings may be valuable for understanding the importance of the application of suitable mechanical force in periodontal remodeling, especially in the process of orthodontic tooth movement with inflammation. 展开更多
关键词 Human PERIODONTAL LIGAMENT Cells Tension FORCE lipopolysaccharides PROLIFERATION DIFFERENTIATION
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