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Guttman量表谱及其发展 被引量:1
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作者 罗洪刚 罗杰 赵守盈 《黔南民族师范学院学报》 2012年第4期47-52,共6页
Guttman量表谱是社会学家Louis Guttman于1944年提出的一种绝然模型。它是Rasch等概然模型的理论基础,是项目反应理论的理论基石。本文简要回顾了Guttman量表谱的基本假设及其发展。Guttman量表谱的基本假设包括:Guttman量表谱的基本模... Guttman量表谱是社会学家Louis Guttman于1944年提出的一种绝然模型。它是Rasch等概然模型的理论基础,是项目反应理论的理论基石。本文简要回顾了Guttman量表谱的基本假设及其发展。Guttman量表谱的基本假设包括:Guttman量表谱的基本模型、数据结构、被试和项目表征、单维性及其检验方法等。并以简单的数据为例介绍了数据分析的原理,为相关研究提供参考。 展开更多
关键词 心理与教育测验 guttman量表谱 RASCH模型
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色谱指纹图谱在制南星饮片质量标准研究的应用 被引量:9
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作者 赫炎 张启伟 +2 位作者 张永欣 孙洁 王祝举 《中国中药杂志》 CAS CSCD 北大核心 2004年第9期874-876,共3页
目的 :通过虎掌南星饮片研究 ,探讨指纹图谱在中药质量标准建立的定量应用。方法 :HPLC指纹图谱检测和化学计量分析 (windowpreprocessing ,principalcomponentanalysis)。结果 :建立虎掌南星饮片指纹图谱的定量表述及定量范围 ;并以此... 目的 :通过虎掌南星饮片研究 ,探讨指纹图谱在中药质量标准建立的定量应用。方法 :HPLC指纹图谱检测和化学计量分析 (windowpreprocessing ,principalcomponentanalysis)。结果 :建立虎掌南星饮片指纹图谱的定量表述及定量范围 ;并以此表征饮片产地和批之间物质基础变异。结论 :用windowpreprocessing ,principalcomponentanalysis分析和标识饮片HPLC指纹图谱 ,并以此作为饮片质量控制指标是可行的。 展开更多
关键词 饮片质 指纹图 HPLC指纹图 analysis) 中药质标准 标准研究 结论
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脑小血管病认知障碍患者脑电功率谱变化与中性粒细胞/淋巴细胞比值相关性及临床价值研究
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作者 郭晓敏 魏爱芹 +2 位作者 刘宗伟 袁维帅 朱娜 《陕西医学杂志》 CAS 2024年第3期361-367,共7页
目的:探索脑小血管病认知障碍(CSVCI)患者脑电功率谱变化与中性粒细胞/淋巴细胞比值(NLR)的相关性,并分析其临床价值。方法:收集脑小血管病(CSVD)患者61例,依据蒙特利尔认知评估量表(MoCA)评分,将其分为伴有认知障碍组(CSVCI组,29例)及... 目的:探索脑小血管病认知障碍(CSVCI)患者脑电功率谱变化与中性粒细胞/淋巴细胞比值(NLR)的相关性,并分析其临床价值。方法:收集脑小血管病(CSVD)患者61例,依据蒙特利尔认知评估量表(MoCA)评分,将其分为伴有认知障碍组(CSVCI组,29例)及无认知功能障碍组(CSVD组,32例),同期招募体检健康者20例为对照组(HC组)。对三组进行脑电图检查,比较全脑定量脑电图功率谱密度(PSD),并分析其与NLR的相关性。结果:CSVCI组年龄高于HC组,受教育年限低于CSVD组和HC组(均P<0.05)。CSVCI组和CSVD组高血压占比高于HC组(均P<0.05)。CSVCI组脑室旁及总脑白质Fazekas评分高于CSVD组和HC组,且CSVD组高于HC组(均P<0.05)。CSVCI组和CSVD组深部脑白质Fazekas评分高于HC组(均P<0.05)。CSVCI组δ、θ频段PSD值高于CSVD组,α频段PSD值低于CSVD组和HC组,CSVD组δ频段PSD值低于HC组(均P<0.05)。多因素Logistic回归表明α频段全脑PSD减低及受教育年限低为CSVCI发生的独立危险因素(均P<0.05)。CSVD患者α频段PSD值与MoCA评分呈正相关,δ频段PSD值与MoCA评分呈负相关,且脑室旁Fazekas评分、深部脑白质Fazekas评分及总脑白质Fazekas评分与MoCA评分呈负相关(均P<0.05)。NLR与θ频段全脑PSD呈正相关(P<0.05)。结论:CSVCI患者脑电快波活动减低而慢波活动增加。α频段全脑PSD值独立于Fazekas评分外影响CSVD患者认知障碍的发生,可能成为评估认知障碍严重程度、预测认知障碍发生的早期客观指标。NLR可能为导致脑电慢化的机制,有可能成为早期预测脑电慢化、认知障碍的客观指标。 展开更多
关键词 脑小血管病认知障碍 中性粒细胞/淋巴细胞比值 蒙特利尔认知评估 脑电图 功率密度 相关性
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认知功能障碍康复评估方法的研究进展
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作者 周季桦 高林 +1 位作者 赵晓庆 邰先桃 《中医康复》 2025年第1期76-80,共5页
认知功能障碍是多种慢性疾病常见的并发症之一,如脑卒中、痴呆、脑性瘫痪、糖尿病等均可导致,其发病率上升带来严重社会问题,早期识别与干预对康复至关重要。本文主要从神经心理学、神经影像学、神经电生理学三方面评估认知功能障碍,发... 认知功能障碍是多种慢性疾病常见的并发症之一,如脑卒中、痴呆、脑性瘫痪、糖尿病等均可导致,其发病率上升带来严重社会问题,早期识别与干预对康复至关重要。本文主要从神经心理学、神经影像学、神经电生理学三方面评估认知功能障碍,发现神经心理学评估以量表为主,如Gesell量表评估儿童智力发育:简易精神状态检查量表(MMSE)应用广泛,但对轻度认知损害不敏感;蒙特利尔认知评估量表(MoCA)特异性高、应用广;日常生活能力评估包括基本和工具性生活能力。神经影像学评估包括结构性磁共振成像(sMRI)、磁共振弥散张量成像(DTI)、功能性近红外光谱(fNIRS),可提供大脑结构和功能信息,辅助诊断和鉴别认知障碍。神经电生理学评估通过定量脑电图(QEEG)、事件相关电位(ERP)等反映大脑皮层活动,评估脑功能变化,且比前两者更直观地提供脑功能的状态和脑细胞损害程度。尽管各方法有局限,但数字化技术发展为认知障碍评估带来新可能,有望提高诊疗效率和准确性,推动脑健康数字诊疗一体化。 展开更多
关键词 认知功能障碍 康复 评估方法 蒙特利尔认知评估 结构性磁共振成像 功能性近红外光 脑电图
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精神分裂症急性发作患者心肌酶谱变化及其临床价值 被引量:3
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作者 吴艳春 方洁 《临床心身疾病杂志》 CAS 2016年第5期7-8,55,共3页
目的探讨精神分裂症急性发作期患者心肌酶谱的变化及其临床价值。方法将88例精神分裂症急性发作期患者设为研究组,80名健康志愿者设为对照组。研究组均予以抗精神病药物常规治疗及护理,观察4周。研究组于治疗前后采用简明精神病量表... 目的探讨精神分裂症急性发作期患者心肌酶谱的变化及其临床价值。方法将88例精神分裂症急性发作期患者设为研究组,80名健康志愿者设为对照组。研究组均予以抗精神病药物常规治疗及护理,观察4周。研究组于治疗前后采用简明精神病量表评定精神症状,同时监测血清心肌酶谱的变化;对照组于人组时检测血清心肌酶谱水平。结果研究组治疗前血清心肌酶谱各项指标均显著高于对照组(P〈0.01);治疗2周末起心肌酶谱各项指标及简明精神病量表总分、各因子分均较治疗前显著下降(P〈0.01),治疗第4周末简明精神病量表总分减分率达49.8%。结论精神分裂症急性发作患者心肌酶谱的变化与其症状严重程度密切相关,监测其心肌酶谱的变化对病情程度的评估具有重要价值。 展开更多
关键词 精神分裂症 急性发作 心肌酶 激越 兴奋 精神症状 简明精神病
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窄谱强脉冲光治疗一期单侧唇裂术后瘢痕的疗效评价 被引量:1
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作者 唐晓娟 刘小静 +1 位作者 孙永恒 张景霞 《国际口腔医学杂志》 CAS CSCD 2023年第4期433-437,共5页
目的观察窄谱强脉冲光(DPL)治疗一期单侧唇裂术后瘢痕的疗效及安全性。方法选取2019年9月至2022年6月进行手术治疗的56例一期单侧唇裂患儿,按照随机数字表法分为A组和B组,各28例。2组患者均于拆线后第2天开始使用硅凝胶药物涂抹瘢痕至术... 目的观察窄谱强脉冲光(DPL)治疗一期单侧唇裂术后瘢痕的疗效及安全性。方法选取2019年9月至2022年6月进行手术治疗的56例一期单侧唇裂患儿,按照随机数字表法分为A组和B组,各28例。2组患者均于拆线后第2天开始使用硅凝胶药物涂抹瘢痕至术后6个月;B组除涂抹药物外,在术后4、6、8周给予3次DPL治疗。分别于DPL治疗前、末次DPL治疗后、术后4个月、术后6个月时采用温哥华瘢痕量表(VSS)对瘢痕进行评估。末次随访时采用满意度调查表对家属满意度进行评价。记录治疗期间及末次治疗后1个月内的治疗相关不良事件,并进行统计学分析。结果两组患者在DPL治疗前VSS评分差异无统计学意义(P>0.05);在末次DPL治疗后,B组VSS评分低于A组,差异有统计学意义(P<0.05);术后4个月和6个月时,B组VSS评分低于A组,差异有统计学意义(P<0.05)。末次随访时,A组15例(占53.6%)对疗效表示非常满意,10例(占35.7%)表示满意,3例(占10.7%)表示一般;B组24例(85.7%)对疗效表示非常满意,4例(14.3%)表示满意。B组2例出现治疗后一过性色素沉着。结论窄谱强脉冲光可以有效治疗一期单侧唇裂术后瘢痕,患儿家属满意度高,不良反应少。 展开更多
关键词 强脉冲光 一期单侧唇裂 瘢痕 温哥华瘢痕评分 满意度
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小儿重度感染性脑损伤与心肌酶谱相关性分析 被引量:1
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作者 苏雅拉其木格 刘建平 《中国现代手术学杂志》 2012年第1期22-24,共3页
目的探讨小儿感染引起重度脑损伤后心肌酶谱改变与格拉斯哥昏迷(GCS)评分及预后的关系,指导临床治疗和护理。方法对30例符合重度脑损伤诊断标准的患儿,于入院当天抽血化验心肌酶谱,包括天冬氨酸转氨酶(aspartate aminotransferase,AST)... 目的探讨小儿感染引起重度脑损伤后心肌酶谱改变与格拉斯哥昏迷(GCS)评分及预后的关系,指导临床治疗和护理。方法对30例符合重度脑损伤诊断标准的患儿,于入院当天抽血化验心肌酶谱,包括天冬氨酸转氨酶(aspartate aminotransferase,AST)、乳酸脱氢酶(lactatedehydrogenase,LDH)、α-羟丁酸脱氢酶(α-hydroxybutyrate dehydrogenase,α-HBDH)、肌酸磷酸激酶(creatine phosphokinase,CPK)、心肌型肌酸激酶同功酶(MB isoenzyme of creatine kinase,CKMB)。结果患儿GCS评分3~5分组的19例患者的心肌酶浓度明显高于11例GCS评分6~8分患者(P<0.05)。治愈组11例,留有后遗症组14例,死亡组5例,三组间心肌酶浓度差异显著,死亡组的浓度最高,治愈组的浓度最低(P<0.05)。结论小儿重度感染性脑损伤GCS评分越低,心肌酶谱值越高,预后越差。 展开更多
关键词 颅脑损伤 格拉斯哥昏迷 心肌酶 儿童
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口腔肿瘤患者心理压力与体内相关因素变化的初探 被引量:6
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作者 李博 李黎 +6 位作者 黄一冰 郭黛墨 潘唯一 段泽西 邹晓莉 朱彩蓉 谢蟪旭 《口腔颌面外科杂志》 CAS 2013年第5期369-373,共5页
目的:认识口腔肿瘤患者精神因素变化规律,探索其相关物质基础。方法 :我院2011-12—2012-08间确诊的口腔恶性肿瘤患者40例,良性肿瘤患者35例,应用流行病学调查中心抑郁量表(CES-D)和压力知觉量表(PSS)测评每位受试者抑郁以及心理压力状... 目的:认识口腔肿瘤患者精神因素变化规律,探索其相关物质基础。方法 :我院2011-12—2012-08间确诊的口腔恶性肿瘤患者40例,良性肿瘤患者35例,应用流行病学调查中心抑郁量表(CES-D)和压力知觉量表(PSS)测评每位受试者抑郁以及心理压力状态。于入院次日上午9:00抽取受试者的全血,切取新鲜术后肿瘤组织,分离提取血清,匀浆肿瘤组织,采用高效液相色谱-质谱(HPLC-MS/MS)分析血清中儿茶酚胺以及糖皮质激素含量。结果:口腔恶性肿瘤组CES-D总分得分比口腔良性肿瘤组高,抑郁程度更重,差异有统计学意义(P<0.05)。口腔恶性肿瘤组PSS总分得分与口腔良性肿瘤组之间差异没有统计学意义(P>0.05)。血清中肾上腺素、去甲肾上腺素、氢化可的松及可的松的检测结果,口腔恶性肿瘤组与口腔良性肿瘤组差异有统计学意义(P<0.001);对肿瘤组织的物质分析提示,恶性肿瘤组织中肾上腺素和去甲肾上腺素含量均高于良性肿瘤组织,差异没有统计学意义。结论:口腔肿瘤患者存在明显的精神心理因素变化,同时伴有机体内相关物质变化,影响着恶性肿瘤的发生发展,对进一步研究恶性肿瘤疾病进程的相关机制及探索干预方法有一定价值。 展开更多
关键词 流行病学调查中心抑郁 压力知觉 口腔肿瘤 高效液相色
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The Influence of Surfactants on Chlorophyll Binding Status and Excitation Energy Transfer in Photosystem Ⅰ of Wheat
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作者 郁飞 唐崇钦 +5 位作者 辛越勇 彭德川 李良璧 匡廷云 李济云 李振声 《Acta Botanica Sinica》 CSCD 2001年第7期686-692,共7页
Surfactants are widely used in the purification and research of structure and function of the protein complexes in photosynthetic membrane. To elucidate the mechanism of interaction between surfactants and photosystem... Surfactants are widely used in the purification and research of structure and function of the protein complexes in photosynthetic membrane. To elucidate the mechanism of interaction between surfactants and photosystem Ⅰ (PSⅠ), effects of two typical surfactants, Triton X_100 and sodium dodecyl sulfate (SDS) on PSⅠ, were studied at different concentrations. The results were: SDS led to the reduction of apparent absorption intensity and blue shift of absorption peaks; while Triton X_100 led to the decrease of apparent absorption intensity in red region and blue shift of the peak, but to the increase of apparent absorption intensity in blue region. The fourth derivative spectra show that the longwavelength (669 nm and 683 nm) absorbing chlorophyll a was affected greatly and their relative changes of absorbance were axially symmetrical. The presence of surfactant could make the long wavelength fluorescence emission decrease greatly and a new fluorescence peak appeared around 680 nm, it was obvious that the surfactant interceded the transfer of excitation energy from antenna pigments to reaction center. The surfactants might affect the microenvironment of proteins, even the structure of PSⅠ protein subunits and hence changed the binding status of pigments with protein subunits, or the pigments might be released from the subunits. All of these might affect the absorption and the transfer of excitation energy. 展开更多
关键词 SURFACTANT Photosystem CHLOROPHYLL absorption spectra fluorescence spectra
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Determination of Dehydroepiandrosterone Sulfate with High Performance Liquid Chromatography
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作者 池华 刘玉玲 谷士杰 《Journal of Chinese Pharmaceutical Sciences》 CAS 1992年第1期75-78,共4页
本文报道了用高效液相色谱-示差检测法(HPLC-RI)测定去氢表雄酮硫酸酯钠盐(DHA-S)及其制剂含量的方法。采用反相 ODS C_(18)色谱柱,乙腈-水(含0.8%磷酸和10μmol/L 四丁基氢氧化铵)作流动相,研究了色谱条件、回收率、检测限量及线性范围。
关键词 Dehydroepiandrosterone sulfate HPLC
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Electrophoresis Analysis on the Protein Expression in Heteromorphic Leaves of Populus euphratica Oliv. 被引量:1
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作者 岳宁 郑彩霞 Cai-xia 《Agricultural Science & Technology》 CAS 2010年第5期41-45,共5页
[Objective] This study was to elucidate the cellular and molecular mechanism of the development of heteromorphic leaves of Populus euphratica Oliv. [Method] By employing SDS-PAGE and 2-demensional electrophoresis (2-D... [Objective] This study was to elucidate the cellular and molecular mechanism of the development of heteromorphic leaves of Populus euphratica Oliv. [Method] By employing SDS-PAGE and 2-demensional electrophoresis (2-DE) techniques,proteins in various heteromorphic leaves from the same adult tree of P. euphratica were isolated and separated to the electrophoresis technique suitable for the separation and analysis of proteins in leaves of P. euphratica tree. [Results] There were significant differences in the expressions of proteins in various heteromorphic leaves of P. euphratica tree. SDS-PAGE pattern showed that bands of proteins with molecular weight of 57.2,13.2,30.2,23.9 and 33.3 kDa were remarkably different. 2-D electrophoresis pattern presented that proteins in leaves of P. euphratica tree mainly belong to acidic proteins distributed at pH value of 5.0-6.5 and with molecular weight of 20-40 kDa; totally 73 different protein spots were observed,of which 51 were up expressed and other 22 were down expressed in the serrated ovate leaves. [Conclusion] Based on these results,we speculate that regulated gene expression in leaves of P. euphratica tree results in the generation of different shapes of leaves,in order to adapt to the surroundings better. 展开更多
关键词 Populus euphratica Oilv. Heteromorphic leaves SDS-PAGE 2-demensional electrophoresis
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In situ studies of energy-related electrochemical reactions using Raman and X-ray absorption spectroscopy 被引量:6
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作者 Heng‐Quan Chen Lie Zou +4 位作者 Di‐Ye Wei Ling‐Ling Zheng Yuan‐Fei Wu Hua Zhang Jian‐Feng Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第1期33-46,共14页
Electrochemical energy conversion technologies involving processes such as water splitting and O_(2)/CO_(2) reduction,provide promising solutions for addressing global energy scarcity and minimizing adverse environmen... Electrochemical energy conversion technologies involving processes such as water splitting and O_(2)/CO_(2) reduction,provide promising solutions for addressing global energy scarcity and minimizing adverse environmental impact.However,due to a lack of an in-depth understanding of the reaction mechanisms and the nature of the active sites,further advancement of these techniques has been limited by the development of efficient and robust catalysts.Therefore,in situ characterization of these electrocatalytic processes under working conditions is essential.In this review,recent applications of in situ Raman spectroscopy and X-ray absorption spectroscopy for various nano-and single-atom catalysts in energy-related reactions are summarized.Notable cases are highlighted,including the capture of oxygen-containing intermediate species formed during the reduction of oxygen and oxidation of hydrogen,and the detection of catalyst structural transformations occurring with the change in potential during the evolution of oxygen and reduction of CO_(2).Finally,the challenges and outlook for advancing in situ spectroscopic technologies to gain a deeper fundamental understanding of these energy-related electrocatalytic processes are discussed. 展开更多
关键词 Raman spectroscopy X-ray absorption spectroscopy In situ characterization ELECTROCATALYSIS Energy conversion and storage
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Clinical implication of 14-3-3 epsilon expression in gastric cancer 被引量:6
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作者 Mariana Ferreira Leal Danielle Queiroz Calcagno +4 位作者 Smia Demachki Paulo Pimentel Assumpo Roger Chammas Rommel Rodríguez Burbano Marília de Arruda Cardoso Smith 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第13期1531-1537,共7页
AIM:To evaluate for the first time the protein and mRNA expression of 14-3-3εin gastric carcinogenesis.METHODS:14-3-3εprotein expression was determined by western blotting,and mRNA expression was examined by real-ti... AIM:To evaluate for the first time the protein and mRNA expression of 14-3-3εin gastric carcinogenesis.METHODS:14-3-3εprotein expression was determined by western blotting,and mRNA expression was examined by real-time quantitative RT-PCR in gastric tumors and their matched non-neoplastic gastric tissue samples.RESULTS:Authors observed a significant reduction of 14-3-3εprotein expression in gastric cancer(GC)samples compared to their matched non-neoplastic tissue.Reduced levels of 14-3-3εwere also associated with diffuse-type GC and early-onset of this pathology.Our data suggest that reduced 14-3-3εmay have a role in gastric carcinogenesis process.CONCLUSION:Our results reveal that the reduced 14-3-3εexpression in GC and investigation of 14-3-3ε interaction partners may help to elucidate the carcino-genesis process. 展开更多
关键词 Gastric cancer 14-3-3 epsilon YWHAE GENEEXPRESSION Protein expression
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Decreased blood riboflavin levels are correlated with defective expression of RFT2 gene in gastric cancer 被引量:6
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作者 Maynur Eli De-Sheng Li +6 位作者 Wei-Wei Zhang Bing Kong Chen-Song Du Maimaitiaili Wumar Batur Mamtimin Ilyar Sheyhidin Ayshamgul Hasim 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第24期3112-3118,共7页
AIM:To investigate the relationship between blood riboflavin levels and riboflavin transporter 2(RFT2) gene expression in gastric carcinoma(GC) development.METHODS:High-performance liquid chromatography was used to de... AIM:To investigate the relationship between blood riboflavin levels and riboflavin transporter 2(RFT2) gene expression in gastric carcinoma(GC) development.METHODS:High-performance liquid chromatography was used to detect blood riboflavin levels in patients with GC.Real-time fluorogenic quantitative polymerase chain reaction and immunohistochemistry were used to analyze the expression of RFT2 mRNA and protein in samples from 60 GC patients consisting of both tumor and normal tissue.RESULTS:A significant decrease in the RFT2 mRNA levels was detected in GC samples compared with those in the normal mucous membrane(0.398 ± 0.149 vs 1.479 ± 0.587;P = 0.040).Tumors exhibited low RFT2 protein expression(75%,16.7%,8.3% and 0% for no RFT2 staining,weak staining,medium staining and strong staining,respectively),which was significantly lower than that in the normal mucous membrane(10%,16.7%,26.7% and 46.7% for no RFT2 staining,weak staining,medium staining and strong staining,respectively;P < 0.05).Tumors with low RFT2 expression were significantly associated with tumor stage and histological grade.Moreover,a significantly decrease in Uyghur patients was observed compared with Han patients.However,other parameters-gender,tumor location and lymph node metastasis-showed no significant relationship with RFT2 expression.Blood riboflavin levels were reverse correlated with development of GC(1.2000 ± 0.97 569 ng/mL in high tumor stage patients vs 2.5980 ± 1.31 129 ng/mL in low tumor stage patients;P < 0.05).A positive correlation of plasma riboflavin levels with defective expression of RFT2 protein was found in GC patients(2 = 2.619;P = 0.019).CONCLUSION:Defective expression of RFT2 is associated with the development of GC and this may represent a mechanism underlying the decreased plasma riboflavin levels in GC. 展开更多
关键词 Gastric carcinoma Riboflavin transporter 2gene RIBOFLAVIN Prognosis High-performance liquid chro-matography
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Estimation of the Land Surface Emissivity in the Hinterland of Taklimakan Desert 被引量:4
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作者 LIU Yong-qiang Ali MAMTIMIN +4 位作者 HUO Wen YANG Xing-hua LIU Xin-chun MENG Xian-yong HE Qing 《Journal of Mountain Science》 SCIE CSCD 2014年第6期1543-1551,共9页
An accurate accounting of land surface emissivity(ε) is important both for the retrieval of surface temperatures and the calculation of the longwave surface energy budgets.Since ε is one of the important parameteriz... An accurate accounting of land surface emissivity(ε) is important both for the retrieval of surface temperatures and the calculation of the longwave surface energy budgets.Since ε is one of the important parameterizations in land surface models(LSMs),accurate accounting also improves the accuracy of surface temperatures and sensible heat fluxes simulated by LSMs.In order to obtain an accurate emissivity,this paper focuses on estimating ε from data collected in the hinterland of Taklimakan Desert by two different methods.In the first method,ε was derived from the surface broadband emissivity in the 8–14 μm thermal infrared atmospheric window,which was determined from spectral radiances observed by field measurements using a portable Fourier transform infrared spectrometer,the mean ε being 0.9051.The second method compared the observed and calculated heat fluxes under nearneutral atmospheric stability and estimated ε indirectly by minimizing the root-mean-square difference between them.The result of the second method found a mean value of 0.9042,which is consistent with the result by the first method.Although the two methods recover ε from different field experiments and data,the difference of meanvalues is 0.0009.The first method is superior to the indirect method,and is also more convenient. 展开更多
关键词 Taklimakan Desert Land surface emissivity Thermal infrared spectra Surface temperature Heat flux
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Effect of the surface properties of an activated coke on its desulphurization performance 被引量:10
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作者 ZHANG Xiang-lan ZHANG Yan DING Fang-sheng HUANG Qi-jiang LI Yuan 《Mining Science and Technology》 EI CAS 2009年第6期769-774,共6页
Commercial coke was modified by H2O2 and/or NH3.H2O to obtain an activated coke containing additional oxygen functional groups and/or nitrogen functional groups. The aim of the modification was to enhance the SO2 adso... Commercial coke was modified by H2O2 and/or NH3.H2O to obtain an activated coke containing additional oxygen functional groups and/or nitrogen functional groups. The aim of the modification was to enhance the SO2 adsorption capacity of the activated coke. Several techniques, including total nitrogen content measurements, SO2 adsorption, XPS and FTIR analysis, were used to characterize the coke samples. The XPS and FTIR spectra suggest the existence of -CONH2 groups in the H2O2 plus ammonia modified coke. The SO2 adsorption capacity of an activated coke increases slightly with an increase in H2O2 concentration during the modification process. The desulphurization performance of a modified coke is considerably enhanced by increasing the treatment temperature during ammonia modification. The amount of nitrogen in a coke modified by H2O2 plus NH3.H2O is the highest, and the SO2 adsorption capacity of the coke is also the highest (89.9 mg/gC). The NH3.H2O (only) modified sample has lower nitrogen content and lower desulphurization capacity (79.9 mg/gC). H2O modification gives the lowest SO2 adsorption capacity (28.9 mg/gC). The H2O2 pre-treatment is beneficial for the introduction of nitrogen onto the surface of a sample during the following ammonia treatment process. 展开更多
关键词 activated coke surface property desulphurization property
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Effects of Sintering Atmosphere on the Microstructure and Surface Properties of Symmetric TiO2 Membranes 被引量:3
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作者 周守勇 仲兆祥 +2 位作者 范益群 徐南平 贺跃辉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第5期739-745,共7页
The effects of sintering atmosphere on the properties of symmetric TiO2 membranes are studied with regard to sintering behavior, porosity, mean pore size, surface comPosition. and surface charge properties. The exerim... The effects of sintering atmosphere on the properties of symmetric TiO2 membranes are studied with regard to sintering behavior, porosity, mean pore size, surface comPosition. and surface charge properties. The exerimental results show that the symmetric TiO2 membranes display better sintering activity in the air than in argon, and the mean pore diameters and porosities of the membrane sintered in argon are higher than those of the membrane sintered in the air at the same temperature. The surface compositions of the symmetric TiO2 membrane sintered in the air and in argon at different temperatures, as studied by X-ray photoelectron spectroscopy, are discussed in terms of their chemical composition, with particular emphasis on the valence state of the titanium ions. The correlation between the valence state of the titanium ions at the surface and the surface charge properties is examined.It is found that the presence of Ti^3+, introduced at the surface of the symmetric TiO2 membranes by sintering in a lower partial pressure of oxygen, is related to a significant decrease in the isoelectric point. TiO2 with Ti^4+ at the interface has an isoelectric point of 5.1, but the non-stoichiometric TiO2-x with Ti^3+ at the interface has a lower isoelectric point of 3.6. 展开更多
关键词 TiO2 membrane sintering atmosphere sintering behavior SURFACE MICROSTRUCTURE
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Application of wavelet packet decomposition and its energy spectrum on the coal-rock interface identification 被引量:3
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作者 任芳 杨兆建 +1 位作者 熊诗波 梁义维 《Journal of Coal Science & Engineering(China)》 2003年第1期109-112,共4页
The theory and method of wavelet packet decomposition and its energy spectrum dealing with the coal rock Interface Identification are presented in the paper. The characteristic frequency band of the coal rock signal c... The theory and method of wavelet packet decomposition and its energy spectrum dealing with the coal rock Interface Identification are presented in the paper. The characteristic frequency band of the coal rock signal could be identified by wavelet packet decomposition and its energy spectrum conveniently, at the same time, quantification analysis were performed. The result demonstrates that this method is more advantageous and of practical value than traditional Fourier analysis method. 展开更多
关键词 coal rock interface identification (CII) wavelet packet energy spectrum
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Influence of Alumina Content on Catalytic Performance of PtSn/Al_2O_3/SBA-15 Catalysts for Propane Dehydrogenation 被引量:4
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作者 Zhang Peixin Zhou Yuming +2 位作者 Duan Yongzheng Zhang Yiwei Sheng Xiaoli 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第4期9-16,共8页
The alumina-modified SBA-15 (A12OJSBA-15) zeolite was prepared in a non-aqueous system by using toluene as the solvent, and was used to support the PtSn-based catalyst for propane dehydrogenation. The BET surface ar... The alumina-modified SBA-15 (A12OJSBA-15) zeolite was prepared in a non-aqueous system by using toluene as the solvent, and was used to support the PtSn-based catalyst for propane dehydrogenation. The BET surface area mea- surements, hydrogen chemisorption, FT-IR spectroscopy, NH3-TPD, XPS and TPO techniques were used to characterize the catalysts. Test results showed that the addition of alumina not only could modify the acid function of the support but also the structure of the metallic phase, thus affecting their catalytic properties. Among these catalysts studied, the PtSn/AI203 (5%)/ SBA-15 catalyst exhibited a best catalytic performance in terms of propane conversion and selectivity to propene. The high catalytic performance might be attributed to the relatively good Pt metal dispersion and/or the strong interaction between Pt and Sn species. 展开更多
关键词 SBA- 15 A1203 propane dehydrogenation PROPENE Pt
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Tribological characteristics and self-repairing effect of hydroxy-magnesium silicate on various surface roughness friction pairs 被引量:6
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作者 张博 徐滨士 +1 位作者 许一 张保森 《Journal of Central South University》 SCIE EI CAS 2011年第5期1326-1333,共8页
Tribological characteristics and self-repairing effect of hydroxy-magnesium silicate (HMS) dispersed in lubricant oil on steel-to-steel friction pairs with various surface roughness were analyzed.The friction-reductio... Tribological characteristics and self-repairing effect of hydroxy-magnesium silicate (HMS) dispersed in lubricant oil on steel-to-steel friction pairs with various surface roughness were analyzed.The friction-reduction,anti-wear and self-repairing performance of various surface roughness friction pairs were examined by friction testing machine.An operation comparison was made between SJ10W-40 lubricant with and without HMS.The surface morphology and elementary composition of the grinding cracks were analyzed by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The results show that the lubrication state changes from boundary lubrication into mixed lubrication after operation in lubricant with HMS.The friction-reduction,anti-wear and self-repairing performance of the friction pairs with various surface roughness are distinctly different.There is a repairing film whose material is different from substrate material on the grinding cracks.In addition,Si,Mg,O,Al and other elements are deposited on the repairing film which contains nanocrystals of these elements.And HMS self-repairing material possesses superior performance of friction-reduction,anti-wear and self-repairing effects. 展开更多
关键词 hydroxy-magnesium silicate surface roughness FRICTION WEAR SELF-REPAIRING
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