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Combined detections of interleukin 27, interferon-γ, and adenosine deaminase in pleural effusion for diagnosis of tuberculous pleurisy 被引量:42
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作者 WU Yan-bin YE Zhi-jian +3 位作者 QIN Sou-ming WU Cong CHEN Yi-qiang SHI Huan-zhong 《Chinese Medical Journal》 SCIE CAS CSCD 2013年第17期3215-3221,共7页
Background Previous studies reported interleukin-27 (IL-27), interferon-y (IFN-γ), or adenosine deaminase (ADA) alone plays a helpful role in diagnosing tuberculous pleural effusion (TPE). The present study a... Background Previous studies reported interleukin-27 (IL-27), interferon-y (IFN-γ), or adenosine deaminase (ADA) alone plays a helpful role in diagnosing tuberculous pleural effusion (TPE). The present study aims at comparing the diagnostic accuracy of pleural IL-27, IFN-γ, and ADA, and investigate the diagnostic accuracy of the combination of IL-27, IFN-γ, or/ and ADA for differentiating TPE from pleural effusions with the other etiologies. Methods The concentrations of IL-27, IFN-γ and ADA were simultaneously determined in pleural fluids and sera from 40 patients with TPE; 26 with malignant pleural effusion, seven with infectious pleural effusion, and eight with transudative pleural effusion by enzyme linked immunosorbent assay and colorimetric method. The corresponding biochemical indexs were also simultaneously determined. Results The concentrations of pleural IL-27 and IFN-γ in the tuberculous group were significantly higher than those in the malignant, infectious, and transudative groups. The concentrations of ADA in TPE were significantly higher than those in MPE or transudative effusions, while much lower than those in infectious effusions. Among these three biomarkers, IL- 27 was the most effective for TPE diagnosis, with the cut off value of 900.8 ng/L. IL-27 had a high sensitivity of 95% and specificity of 97.6% for differential diagnosis of TPE from non-TPEs. Combinations of IL-27, IFN-γ and ADA measurements further increased the sensitivity or specificity up to 100%. Conclusions Compared to non-TPEs, IL-27, IFN-γ and ADA all simultaneously increased in TPE; and among these three rapid detection methods, IL-27 appeared to be the best for distinguishing tuberculous from non-TPEs, especially from MPE. Combinations of the three markers (IL-27, IFN-γ and ADA) yielded the highest sensitivity and specificity. These findings suggest that the applications of a new biomarker, IL-27, alone or with IFN-γ and ADA, may contribute to more efficient diagnosis strategies in the management 展开更多
关键词 adenosine deaminase INTERFERON-Γ interleukin 27 tuberculous pleurisy
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Heat shock protein 27 regulates oxidative stress-induced apoptosis in cardiomyocytes:mechanisms via reactive oxygen species generation and Akt activation 被引量:16
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作者 LIU Li ZHANG Xiao-jin +4 位作者 JIANG Su-rong DING Zheng-nian DING Guo-xian HUANG Jun CHENG Yun-lin 《Chinese Medical Journal》 SCIE CAS CSCD 2007年第24期2271-2277,共7页
Background Increased reactive oxygen species (ROS) formation, which in turn promotes cardiomyocytes apoptosis, is associated with the pathogenesis and progression of various cardiac diseases such as ischemia and hea... Background Increased reactive oxygen species (ROS) formation, which in turn promotes cardiomyocytes apoptosis, is associated with the pathogenesis and progression of various cardiac diseases such as ischemia and heart failure. Recent studies have shown that over expression of heat shock protein 27 (Hsp27) confers resistance to cardiac ischemia/reperfusion injury. However, not much is known about the regulation of myocyte survival by Hsp27. Methods The rat cardiac cell line H9c2, with a stable overexpression of Hsp27, was established, with empty vector transfected H9c2 cells as controls. Following the cells challenged by Hydrogen Peroxide (H2O2), lactate dehydrogenase (LDH) release, apoptosis, intracellular ROS, cell morphology, mitochondrial transmembrane potential and the activation of serine/threonine kinase Akt were determined. Results Along with marked suppression of H2O2-induced injury by Hsp27 overexpression in H9c2 cells, ROS generation and the loss of mitochondrial membrane potential were also significantly depressed. Furthermore, augmented Akt activation was observed in Hsp27 overexpressed H9c2 cells following H2O2 exposure. Conclusions Hsp27 inhibits oxidative stress-induced H9c2 damage and inhibition of ROS generation and the augmentation of Akt activation may be involved in the protective signaling. 展开更多
关键词 heat shock protein 27 APOPTOSIS superoxide mitochondrial potential AKT
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韩城梁带村M27出土卣、尊年代辨析——附论扇形钺与特殊的凤鸟纹饰 被引量:15
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作者 陈小三 《文博》 2011年第1期26-31,共6页
韩城粱带村M27中出土的卣和尊具有复古风格,判断复古风格器物的年代不能仅仅依靠器形来判断,应更多关注铜器的细部纹饰。该墓中发现的卣和尊是两周之际对周初器物的仿制。结合该墓发现的其它器物来看,墓主人可能对古物有特殊的喜好。此... 韩城粱带村M27中出土的卣和尊具有复古风格,判断复古风格器物的年代不能仅仅依靠器形来判断,应更多关注铜器的细部纹饰。该墓中发现的卣和尊是两周之际对周初器物的仿制。结合该墓发现的其它器物来看,墓主人可能对古物有特殊的喜好。此外,扇形钺和特殊的凤鸟装饰不能作为寻找芮国始封地域的证据。 展开更多
关键词 梁带村墓地 M27
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Isolation,identification and characterization of an algicidal bacterium from Lake Taihu and preliminary studies on its algicidal compounds 被引量:13
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作者 Chuan Tian Xianglong Liu +3 位作者 Jing Tan Shengqin Lin Daotang Li Hong Yang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第10期1823-1831,共9页
In an effort to identify a bio-agent capable of controlling cyanobacterial blooms, we isolated a bacterial strain, A27, which exhibited strong algicidal activity against the dominant bloom-forming species of Microcyst... In an effort to identify a bio-agent capable of controlling cyanobacterial blooms, we isolated a bacterial strain, A27, which exhibited strong algicidal activity against the dominant bloom-forming species of Microcystis aeruginosa in Lake Taihu. Based on 16S rRNA gene sequence analysis, this strain belongs to the genus Exiguobacterium. This is the first report of an algicidal bacterial strain belonging to the genus Exiguobacterium. Strain A27 exhibited algicidal activity against a broad range of cyanobacteria, but elicited little or no algicidal activity against the two green algal strains tested. The algicidal activity of strain A27 was shown to be dependent on the density of the bacteria and to have a threshold density of 1.5×106 CFU/mL. Our data also showed that the algicidal activity of strain A27 depended on different growth stages ofMicrocystis aeruginosa (exponential ≈ lag phase 〉 early stationary) rather than that of the bacterium itself. Our results also suggested the algicidal activity of strain A27 occurred via the production of extracellular algicidal compounds. Investigation of the algicidal compounds revealed that there were at least two different algicidal compounds produced by strain A27. These results indicated that strain A27 has great potential for use in the control of outbreaks of cyanobacterial blooms in Lake Taihu. 展开更多
关键词 algicidal bacteria freshwater cyanobacteriat bloom Microcystis aeruginosa Exiguobacterium sp. A27
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固体核磁共振技术在水泥及其水化产物研究中的应用 被引量:11
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作者 肖建敏 范海宏 《材料科学与工程学报》 CAS CSCD 北大核心 2016年第1期166-172,共7页
固体核磁共振作为一种十分理想的强大的分析手段,已在水泥及水泥水化产物研究领域得到了广泛的应用。本文在介绍核磁共振基本原理以及固体核磁共振技术的基础上,重点介绍了^(27)Al和^(29)Si核磁共振在水泥熟料矿物分析、水泥及其他水泥... 固体核磁共振作为一种十分理想的强大的分析手段,已在水泥及水泥水化产物研究领域得到了广泛的应用。本文在介绍核磁共振基本原理以及固体核磁共振技术的基础上,重点介绍了^(27)Al和^(29)Si核磁共振在水泥熟料矿物分析、水泥及其他水泥掺合料的水化产物分析、水化过程研究中的应用情况,评价了目前固体核磁共振技术在水泥领域存在的问题,并展望了其在无机非金属材料领域的发展趋势。 展开更多
关键词 固体核磁共振 27 Al和29Si核磁共振 水泥 水化产物
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结核性胸腔积液患者胸水中白细胞介素-27、γ-干扰素、腺苷脱氨酶水平及临床意义 被引量:10
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作者 唐添祥 龙明伟 +3 位作者 李俊华 阿衣石布 赵嘉 韩朋飞 《实用医院临床杂志》 2019年第6期141-144,共4页
目的探讨结核性胸腔积液患者胸水中白细胞介素 27(IL 27)、γ 干扰素(IFN γ)、腺苷脱氨酶(ADA)水平及临床意义。方法我院胸腔积液患者170例,其中结核性胸腔积液92例,恶性胸腔积液78例。在治疗前抽取胸水,检测IL 27、IFN γ、ADA水平,... 目的探讨结核性胸腔积液患者胸水中白细胞介素 27(IL 27)、γ 干扰素(IFN γ)、腺苷脱氨酶(ADA)水平及临床意义。方法我院胸腔积液患者170例,其中结核性胸腔积液92例,恶性胸腔积液78例。在治疗前抽取胸水,检测IL 27、IFN γ、ADA水平,并绘制受试者工作特性曲线(ROC曲线)分析诊断结核性胸腔积液的价值,采用Pearson相关性分析IL 27与IFN γ、ADA的相关性。结果结核性胸腔积液组胸水中IL 27、IFN γ、ADA水平均高于恶性胸腔积液组(P<0.05);IL 27、IFN γ、ADA诊断结核性胸腔积液的AUC值分别为0.898、0.899、0.881;IL 27的cut off值为413.815 ng/L,敏感度、特异度为75.00%、96.20%;IFN γ的cut off值为144.255 ng/L,敏感度、特异度为80.40%、96.20%;ADA的cut off值为32.11 U/L,敏感度、特异度为69.60%、98.70%;IL 27水平与IFN γ、ADA水平呈正相关(P<0.05)。结论IL 27、IFN γ、ADA均可作为结核性胸腔积液鉴别诊断的可靠指标,且IL 27诊断效能更高。 展开更多
关键词 胸腔积液 结核 恶性 白细胞介素 27 γ 干扰素 腺苷脱氨酶
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慢性自发性荨麻疹患者外周血Treg细胞比例和白细胞介素17A、27水平及意义 被引量:9
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作者 王亚婷 石春蕊 +3 位作者 武奕 师蓓 熊潇 周兰霞 《中华皮肤科杂志》 CAS CSCD 北大核心 2017年第12期916-919,共4页
目的 探讨外周血中CD4+CD25+CD127low调节性T(Treg)细胞、白细胞介素17A(IL?17A)和IL?27在慢性自发性荨麻疹发病机制中的作用。方法 收集37例慢性自发性荨麻疹患者和40例健康对照外周血标本。采用流式细胞仪检测外周血中CD4+C... 目的 探讨外周血中CD4+CD25+CD127low调节性T(Treg)细胞、白细胞介素17A(IL?17A)和IL?27在慢性自发性荨麻疹发病机制中的作用。方法 收集37例慢性自发性荨麻疹患者和40例健康对照外周血标本。采用流式细胞仪检测外周血中CD4+CD25+CD127low Treg细胞比例,酶联免疫吸附试验(ELISA)检测血清中IL?17A和IL?27水平。结果 慢性自发性荨麻疹患者外周血中CD4+CD25+CD127low Treg细胞比例(5.99% ± 2.72%)明显低于健康对照组(9.07% ± 3.44 %,t = 4.325,P 〈 0.01),IL?27水平[(20.54 ± 7.65)ng/L]亦低于健康对照组[(26.63 ± 9.72) ng/L,t = 3.039,P = 0.003],IL?17A表达水平与健康对照组差异无统计学意义(P = 0.529)。慢性自发性荨麻疹患者IL?17A表达水平与CD4+CD25+CD127low Treg细胞比例呈负相关(r = -0.359,P = 0.029),IL?17A、IL?27、CD4+CD25+CD127 low Treg细胞比例与UAS评分均无显著相关性(r值分别为-0.076、-0.083、-0.053,均P 〉 0.05)。结论 慢性自发性荨麻疹患者外周血中可能存在Th17/Treg细胞失衡,且IL?27可能参与慢性自发性荨麻疹的发病过程。 展开更多
关键词 荨麻疹 白细胞介素 17 T淋巴细胞 调节性 白细胞介素 27
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煤炭国际标准化发展现状与展望 被引量:8
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作者 罗陨飞 姜英 《煤质技术》 2006年第2期1-3,共3页
介绍了煤炭国际标准化组织机构,分析了煤炭国际标准化工作的现状,讨论了未来煤炭国际标准化工作的发展趋势。
关键词 煤炭 国际标准化 现状与展望 ISO/TC 27
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微RNA-27a介导3T3-L1脂肪细胞胰岛素抵抗的作用机制 被引量:9
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作者 谢军 韩造木 尹琬凌 《安徽医药》 CAS 2019年第12期2378-2381,共4页
目的研究微RNA 27a(miR 27a)介导3T3 L1脂肪细胞胰岛素抵抗的作用机制。方法将3T3 L1细胞诱导分化为脂肪细胞,采用肿瘤坏死因子 α(TNF α)法建立3T3 L1脂肪细胞的胰岛素抵抗模型,检测miR 27a对3T3 L1细胞葡萄糖摄取的影响,蛋白质印迹法... 目的研究微RNA 27a(miR 27a)介导3T3 L1脂肪细胞胰岛素抵抗的作用机制。方法将3T3 L1细胞诱导分化为脂肪细胞,采用肿瘤坏死因子 α(TNF α)法建立3T3 L1脂肪细胞的胰岛素抵抗模型,检测miR 27a对3T3 L1细胞葡萄糖摄取的影响,蛋白质印迹法(Western Blot)检测miR 27a对胰岛素信号通路的影响。实时荧光定量多聚核苷酸链式反应(qPCR)及双荧光素酶报告基因检测法检测miR 27a的作用靶点。结果miR 27a介导了3T3 L1脂肪细胞的胰岛素抵抗[正常对照组,模型组,miR 27a mimics+模型组,miR 27a inhibitor+模型组四组的吸光度值分别为(2.03±0.20),(1.28±0.27),(1.43±0.20),(1.97±0.18),P<0.01],蛋白质印迹法显示miR 27a抑制了胰岛素信号通路中胰岛素受体底物1(IRS1)及Akt蛋白的磷酸化。qPCR显示miR 27a抑制了过氧化物酶体增殖物激活受体γ(PPARγ)的表达[对照组和mir 27a组的相对值分别为(1.00±0.08)和(0.59±0.14),P=0.0048],双荧光素酶报告基因检测验证了PPARγ为miR 27a的作用靶点[PPARγWT+miR NC,PPARγWT+miR 27a,PPARγMut+miR NC,PPARγMut+miR 27a四组的相对荧光值分别为(5.37±0.80)、(3.17±0.57)、(4.94±0.63)、(4.68±0.74),P<0.01]。结论miR 27a通过抑制胰岛素信号通路及靶向PPARγ介导3T3 L1细胞胰岛素抵抗。 展开更多
关键词 代谢综合征X 胰岛素抵抗 微RNAs microRNA 27a 外泌体 抵抗素 过氧化物酶体增殖物激活受体 脂细胞 3T3 L1脂肪细胞
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The Herpes Simplex Virus Type 1 Multiple Function Protein ICP27 被引量:6
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作者 Lei ZHAO Wen-bo ZHU Qiong DING Gui-qing PENG Chun-fu ZHENG 《Virologica Sinica》 SCIE CAS CSCD 2008年第6期399-405,共7页
The herpes simplex virus type 1 (HSV-1) infected-cell protein 27 (ICP27) is an essential, highly conserved protein involved in various steps of HSV-1 gene regulation as well as in the shut-off of host gene express... The herpes simplex virus type 1 (HSV-1) infected-cell protein 27 (ICP27) is an essential, highly conserved protein involved in various steps of HSV-1 gene regulation as well as in the shut-off of host gene expression during infection. It functions primarily at the post-transcriptional level in inhibiting precursor mRNA splicing and in promoting nuclear export of viral transcripts. Recently, many novel functions performed by the HSV- 1 ICP27 protein were shown, including leptomycin B resistance, inhibition of the type I interferon signaling, regulation of the viral mRNA translation and determining the composition of HSV-1 virions 展开更多
关键词 Herpes simplex virus type 1 (HSV-1) Infected-cell protein 27 (ICP27 Nuclear export LeptomycinB (LMB) Interferon (IFN)
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Overexpression of HSP27 and HSP70 is associated with decreased survival among patients with esophageal adenocarcinoma 被引量:8
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作者 Henna K S?derstr?m Juha T Kauppi +4 位作者 Niku Oksala Timo Paavonen Leena Krogerus Jari R?s?nen Tuomo Rantanen 《World Journal of Clinical Cases》 SCIE 2019年第3期260-269,共10页
BACKGROUND Overexpression of heat shock proteins(HSPs) is associated with several malignancies and contributes to the development, progression, and metastasis of cancer, in addition to the inhibition of cellular death... BACKGROUND Overexpression of heat shock proteins(HSPs) is associated with several malignancies and contributes to the development, progression, and metastasis of cancer, in addition to the inhibition of cellular death. In recent years, there has been active research into using HSP inhibitors in several malignancies. Due to the poor prognosis of esophageal adenocarcinoma(EAC), it would be valuable to find new biomarkers for the development of cancer treatments.AIM To evaluate the expressions of HSP27 and HSP70 and their effect on survival in EAC.METHODS Immunohistochemical analyses and evaluations of HSP27 and HSP70 expression were performed on all available samples from 93 patients diagnosed with EACbetween 1990 and 2007 at two university hospitals. Fifteen cases with Barrett's metaplasia and 5 control cases from the same patient population were included in the analysis. HSP expression was quantitatively assessed and classified as high or low. Kaplan-Meier analyses and Cox regression models adjusting for age and sex as well as tumor site, stage, and grade were used to evaluate the effect on survival.RESULTS Tumor stage and surgical treatment were the main prognostic factors. High HSP27 expression in cancer cases was a strong negative predictive factor, with a mean survival of 23 mo compared to the 49 mo in cases with a low expression(P= 0.018). The results were similar for HSP70, with a poorer survival of 17 mo in cases with high HSP70 expression, in contrast to 40 mo(P = 0.006) in cases with a low expression. A Cox regression survival analysis was performed, adjusting for possible confounding factors, and higher HSP27 and HSP70 expressions remained an independent negative prognostic factor. The HSPs' correlation with survival was not affected by cancer treatments. When the analysis was adjusted for all factors, the odds ratios for HSP27 and HSP70 were 3.3(CI: 1.6–6.6, P =0.001) and 2.2(CI: 1.2–3.9, P = 0.02), respectively.CONCLUSION HSP27 and HSP70 overexpression is associated with poor survival in EAC, whic 展开更多
关键词 Esophageal adenocarcinoma HEAT shock proteins HEAT shock PROTEIN 27 HEAT shock PROTEIN 70 OVEREXPRESSION SURVIVAL
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探讨人类白细胞抗原B27对强直性脊柱炎的诊断价值 被引量:8
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作者 王国英 黄海平 周海燕 《中国卫生检验杂志》 CAS 2015年第1期65-66,共2页
目的探讨人类白细胞抗原B 27(HLA-B 27)检测对诊断强直性脊柱炎(AS)的临床意义。方法用流式细胞仪检测651例AS患者、1 085例非AS患者(包括腰腿背痛患者、风湿性关节炎患者、类风湿性关节炎患者)及200例健康体检者3组人群的HLA-B 27抗原... 目的探讨人类白细胞抗原B 27(HLA-B 27)检测对诊断强直性脊柱炎(AS)的临床意义。方法用流式细胞仪检测651例AS患者、1 085例非AS患者(包括腰腿背痛患者、风湿性关节炎患者、类风湿性关节炎患者)及200例健康体检者3组人群的HLA-B 27抗原。结果 AS患者组HLA-B 27阳性率为92.6%,非AS患者组HLA-B 27阳性率为9.6%,健康体检组HLA-B 27阳性率为4.5%,AS患者组HLA-B 27阳性率明显高于非AS患者组和健康体检组,AS患者组与非AS患者组、健康体检组差异有统计学意义(χ2=1 303.01,P<0.01)。男性HLA-B 27阳性率为47.4%,女性HLA-B 27阳性率为14.6%,男性HLA-B 27阳性率明显高于女性(χ2=193.17,P<0.01)。不同年龄组HLA-B 27阳性率差异有统计学意义,<30岁年龄组的阳性率明显高于其他年龄组。结论 HLA-B 27抗原在AS发病过程中起了重要作用,具有很强的相关性,故检测HLA-B 27可为AS的诊断和鉴别诊断提供重要依据。 展开更多
关键词 人类白细胞抗原B 27 强直性脊柱炎 流式细胞分析
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Effect of rare earths on phase transformation in as-cast ZA27 alloy dur-ing compressive creep 被引量:8
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作者 WEIXiaowei SHENBaoluo 《Rare Metals》 SCIE EI CAS CSCD 2003年第4期259-264,共6页
The effect of the mixed rare earths of Ce on the phase transformation in ascast ZA 27 alloy during compressive was investigated under 37 MPa and at 160 deg C by X-raydiffraction technique and SEM. The results showed t... The effect of the mixed rare earths of Ce on the phase transformation in ascast ZA 27 alloy during compressive was investigated under 37 MPa and at 160 deg C by X-raydiffraction technique and SEM. The results showed that the as cast microstructure of ZA 27-RE alloyconsisted of a dendritic Al-rich alpha' surrounded by Zn-rich beta' phase, interdendritic epsilonphase and Zn-rich eta phase together with a complex Z phase which was a complex constitute compound,(RE,Cu)Al_5Zn_(16), dispersed in crystal interfaces or branch crystal interfaces and stable duringcompressive creep test at 160 deg C. The phase transformations of ZA 27-RE alloy, decomposition ofbeta' phase arid four transformation, were delayed by the addition of rare earths, also the lamellarstructure and the spheroidized structure in ZA 27-RE alloy were finer than in ZA 27 alloy duringcompressive creep test at 160 deg C at the same creep time, and the compressive creep resistance ofZA 27-RE alloy was higher than that of ZA 27 alloy. 展开更多
关键词 microstructure change compressive creep rare earths ZA 27 alloy
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27t轴重条件下轨道结构劣化规律和适应性分析 被引量:8
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作者 潘振 马战国 +3 位作者 郄录朝 张欢 尤瑞林 李闯 《铁道建筑》 北大核心 2020年第1期89-94,共6页
针对既有轨道结构在27 t轴重条件下的劣化问题,在北同蒲(大同—蒲州)线、大秦(大同—秦皇岛)线选择有代表性区段建立跟踪观测试验段,在试验段内铺设了强化型扣件进行长期跟踪观测,并结合仿真计算和现场测试,研究27 t轴重条件下轨道结构... 针对既有轨道结构在27 t轴重条件下的劣化问题,在北同蒲(大同—蒲州)线、大秦(大同—秦皇岛)线选择有代表性区段建立跟踪观测试验段,在试验段内铺设了强化型扣件进行长期跟踪观测,并结合仿真计算和现场测试,研究27 t轴重条件下轨道结构的劣化规律和适应性。研究结果表明:目前使用的U78CrV在线热处理钢轨、Ⅲ型混凝土轨枕及配套的弹条Ⅱ型扣件、道床基本适应27 t轴重车辆运营需求,但建议小半径曲线区段更换为加强型扣件或Ⅳ型混凝土轨枕,以提高线路稳定性和承载能力。 展开更多
关键词 重载铁路 轨道结构 27 t轴重 现场测试 劣化规律 适应性
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不同轴重货物列车编组方案的计算分析 被引量:7
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作者 郭刚 常崇义 +1 位作者 王俊彪 马大炜 《铁道机车车辆》 2014年第5期12-16,共5页
通过列车纵向动力学仿真软件,建立27t轴重通用货物与23t和21t轴重车辆混编的纵向动力学模型。通过仿真分析得到27t轴重及以下通用货物列车以各种轴重混编、空重混编在一定的线路条件下进行紧急制动时的纵向力分布规律,对列车的编组方式... 通过列车纵向动力学仿真软件,建立27t轴重通用货物与23t和21t轴重车辆混编的纵向动力学模型。通过仿真分析得到27t轴重及以下通用货物列车以各种轴重混编、空重混编在一定的线路条件下进行紧急制动时的纵向力分布规律,对列车的编组方式进行对比分析,提出不同轴重货物列车合理的编组方式。 展开更多
关键词 27 t轴重通用货物列车 纵向动力学 合理编组 紧急制动
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曲线几何参数对不同类型货车转向架轮轨动力作用的影响分析 被引量:3
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作者 杨春雷 黄运华 丁军君 《振动工程学报》 EI CSCD 北大核心 2023年第1期159-169,共11页
27 t轴重的侧架交叉支撑转向架和副构架径向转向架是中国最近研制的两种重载货车转向架。为研究比较两转向架的曲线性能,分析曲线几何参数、轨道谱激励对不同类型转向架轮轨动力的影响特性,综合考虑转向架结构形式、技术参数和重载曲线... 27 t轴重的侧架交叉支撑转向架和副构架径向转向架是中国最近研制的两种重载货车转向架。为研究比较两转向架的曲线性能,分析曲线几何参数、轨道谱激励对不同类型转向架轮轨动力的影响特性,综合考虑转向架结构形式、技术参数和重载曲线轨道相关要求,建立重载货车⁃轨道耦合动力学模型和曲线参数化模型。结果表明,副构架径向转向架曲线性能在小半径曲线(≤800 m)线路上具有相对优势,曲线半径越小,优势越明显,但增大曲线半径和施加线路谱激励均会弱化其优势;两种转向架对外轨超高和缓和曲线长度变化的动力响应趋势基本一致,都在欠超高(0~15 mm)范围内轮轨综合响应较小;缓和曲线长度对两者均存在拐点,且拐点近乎相同,如当速度为80 km/h,曲线半径为800 m时,计算拐点都是约50 m,与TB 10627—2017《重载铁路设计规范》标准中规定的缓和曲线长度最小取值一致。 展开更多
关键词 轮轨动力学 转向架 曲线几何参数 27 t轴重 曲线性能
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Processes of the deposition and vicissitude of Mu Us Desert,China since 150 ka B.P. 被引量:6
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作者 李保生 靳鹤龄 +6 位作者 吕海燕 祝一志 董光荣 孙东怀 张甲坤 高全洲 闫满存 《Science China Earth Sciences》 SCIE EI CAS 1998年第3期248-254,共7页
Milanggouwan stratigraphical section" named lately takes down 27 cycles of alternately evolutionary histories of desert depositions in the Mu Us area with the fluviolacustrine facies and palaeosols since 150 ka B... Milanggouwan stratigraphical section" named lately takes down 27 cycles of alternately evolutionary histories of desert depositions in the Mu Us area with the fluviolacustrine facies and palaeosols since 150 ka B.P. Studies show that the sedimentary form was induced by the growth and decline and confrontation each other between the winter monsoon and the summer monsoon of East Asia in the past 150 ka. 展开更多
关键词 MU Us DESERT Milanggouwan stratigraphical section 150 KA 27 PERIODS of DESERT depositions.
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棉花独脚金内酯D27基因表达与功能分析
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作者 周强 郭栋财 +3 位作者 蔡永生 陈全家 曲延英 郑凯 《核农学报》 CAS CSCD 北大核心 2024年第7期1234-1248,共15页
为探究D27基因在棉花纤维及植株发育过程中的生物学功能,本研究通过生物信息学方法鉴定得到棉属中18个D27基因成员,分析其理化性质、结构及进化关系,利用实时荧光定量PCR(qRT-PCR)技术探究了海岛棉纤维中6个GbD27基因的表达特异性,通过... 为探究D27基因在棉花纤维及植株发育过程中的生物学功能,本研究通过生物信息学方法鉴定得到棉属中18个D27基因成员,分析其理化性质、结构及进化关系,利用实时荧光定量PCR(qRT-PCR)技术探究了海岛棉纤维中6个GbD27基因的表达特异性,通过同源重组的方法获得了6个陆地棉GhD27基因,构建GhD27基因的病毒诱导的基因沉默(VIGS)载体并转化至棉花,使用qRT-PCR技术检测其沉默效率及独脚金内酯(SLs)处理下的表达模式,并借助酶联免疫吸附(ELISA)技术测定了沉默植株的内源独脚金内酯含量。结果显示,棉花D27基因家族的开放阅读框(ORF)长度为726~816 bp,编码的D27蛋白含241~271个氨基酸;D27蛋白主要由α-螺旋与无规卷曲构成;进化分析结果显示D27基因高度同源。海岛棉材料新海21的GbD27基因在0~35 d的棉纤维中均存在表达,可能对棉纤维发育存在重要调节作用。陆地棉材料新农大棉4号的GhD27基因在叶片和根部均得到有效沉默,表明已获得GhD27基因沉默植株。在陆地棉GhD27基因的沉默植株中,GhD27基因对独脚金内酯处理均有不同程度的响应,内源性独脚金内酯含量与GhD27基因的表达水平有一定关联。本研究为进一步了解棉花D27基因的分子生物学功能奠定了基础。 展开更多
关键词 棉花 D27 基因克隆 表达分析 独脚金内酯
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多籽五层龙中1个新的木栓烷型三萜
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作者 牛琦 许浩楠 +5 位作者 王浩鑫 陈林 谢红茜 丁祖霄 左爱学 江志勇 《中草药》 CAS CSCD 北大核心 2024年第6期1884-1889,共6页
目的对多籽五层龙Salacia polysperma枝叶进行化学成分研究。方法采用正反相硅胶柱色谱、MCI、Sephadex LH-20柱色谱以及半制备高效液相色谱等分离手段进行分离纯化,根据1D和2D NMR、MS、IR等波谱数据和理化性质对化合物进行结构鉴定。... 目的对多籽五层龙Salacia polysperma枝叶进行化学成分研究。方法采用正反相硅胶柱色谱、MCI、Sephadex LH-20柱色谱以及半制备高效液相色谱等分离手段进行分离纯化,根据1D和2D NMR、MS、IR等波谱数据和理化性质对化合物进行结构鉴定。采用分光光度法测定化合物对α-葡萄糖苷酶的抑制作用。结果从多籽五层龙枝叶90%乙醇提取物的石油醚萃取部分中分离鉴定了7个化合物,分别为3α,27,28-三羟基木栓烷(1)、kokoonol(2)、28-hydroxyfriedelan3-one-29-oic acid(3)、maytenfolone(4)、黑蔓醇酯乙(5)、α-香树脂素(6)、赤桐甾醇(7)。化合物3表现出较好的α-葡萄糖苷酶抑制活性,半数抑制浓度(median inhibition concentration,IC50)值为15.1μmol/L。化合物1、2、4也具有一定的α-葡萄糖苷酶抑制作用,IC50值分别为57.8、39.4、27.6μmol/L,其余化合物在100μmol/L的较高浓度下未显示出对α-葡萄糖苷酶的抑制作用。结论化合物1为1个新的木栓烷型三萜,命名为多籽五层龙醇(polysperol);所有化合物均为首次从该植物中分离得到。化合物3具有较好的α-葡萄糖苷酶抑制活性。 展开更多
关键词 多籽五层龙 27 28-三羟基木栓烷 Α-葡萄糖苷酶 28-hydroxyfriedelan-3-one-29-oic acid 多籽五层龙醇
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基于单原子铁纳米催化剂的纳米催化疗法对 口腔鳞癌细胞Cal27的作用
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作者 谢玉婷 熊屏 《上海口腔医学》 CAS 2024年第2期117-122,共6页
目的:制备单原子铁纳米催化剂(single-atom Fe nanocatalysts,SAF NCs),探讨其体外治疗口腔鳞癌的疗效,为口腔鳞癌治疗提供新策略。方法:用隔离与热解结合方法制备SAF NCs,利用透射电镜和球差电镜观察微观形态,X射线衍射图和元素分布能... 目的:制备单原子铁纳米催化剂(single-atom Fe nanocatalysts,SAF NCs),探讨其体外治疗口腔鳞癌的疗效,为口腔鳞癌治疗提供新策略。方法:用隔离与热解结合方法制备SAF NCs,利用透射电镜和球差电镜观察微观形态,X射线衍射图和元素分布能谱分析其结构和成分,溶液层面采用TMB显色实验和电子自旋共振试验检测催化性能,最后通过CCK-8和流式细胞技术、共聚焦显微镜观察体外处理口腔鳞癌Cal27细胞后的活性变化。采用GraphPad Prism 9软件包对数据进行统计学分析。结果:成功合成和表征SAF NCs,在溶液层面显示出优异的催化特性。细胞实验中,SAF NCs显示出良好的生物相容性,在模拟肿瘤微环境特性的条件下,进行体外催化治疗,Cal27细胞活性低至32.08%。结论:初步实验证明,SAF NCs具有良好的生物催化性能,在体外可有效抑制口腔鳞癌细胞增殖,为口腔鳞癌治疗提供了新策略。 展开更多
关键词 口腔鳞癌 纳米催化 单原子纳米催化剂 Cal 27
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