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La掺杂改性Co-Beta催化丙烷脱氢
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作者 肖晗 邓维华 +4 位作者 林雨来 梁俊 董佳明 罗永明 何德东 《工业催化》 CAS 2024年第10期43-49,共7页
钴基催化剂在高温反应中易团聚烧结,且对其活性中心认识不足。为此设计了一种新型CoLa双金属催化剂,通过稀土金属La隔离并稳定钴物种,从而提高催化剂的反应活性。通过调控La在材料中的掺杂量,建立不同分散度与催化性能之间的构-效关系,... 钴基催化剂在高温反应中易团聚烧结,且对其活性中心认识不足。为此设计了一种新型CoLa双金属催化剂,通过稀土金属La隔离并稳定钴物种,从而提高催化剂的反应活性。通过调控La在材料中的掺杂量,建立不同分散度与催化性能之间的构-效关系,以深入了解活性中心。采用XRD、XPS、化学吸附、探针分子红外等表征手段对催化剂中Co物种的存在形式、化学环境和尺寸大小等催化相关性质进行分析。结果表明,La的掺杂可以促进Co物种的分散,并增强Co物种与载体之间的相互作用。 展开更多
关键词 催化化学 丙烷脱氢 钴基催化剂 稀土改性 beta沸石 协同作用
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Production of linear alkylbenzene over Ce containing Beta zeolites
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作者 Shiqi Zhang Shengzhi Gan +1 位作者 Baoyu Liu Jinxiang Dong 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期220-227,共8页
Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species dur... Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites,leading to uniform distribution of Ce cluster in the framework of Beta zeolites.Moreover,the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites,improving the utilization of Brønsted acid sites.In addition,Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites,which pave the way for its practical application in the production of alkylbenzene. 展开更多
关键词 beta zeolites CATALYSIS ALKYLATION Long-chain olefins
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Deactivation mechanism of acetone to isobutene conversion over Y/Beta catalyst
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作者 Chang Wang Tingting Yan Weili Dai 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第9期133-142,共10页
The conversion of acetone derived from biomass to isobutene has attracted extensive attentions.In comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a... The conversion of acetone derived from biomass to isobutene has attracted extensive attentions.In comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a higher isobutene selectivity.However,the catalyst stability remains a key problem for the long-running acetone conversion and the reasons for catalyst deactivation are poorly understood up to now.Herein,the deactivation mechanism of Lewis acidic Y/Beta catalyst during the acetone to isobutene conversion was investigated by various characterization techniques,including acetone-temperature-programmed surface reaction,gas chromatography-mass spectrometry,in situ ultraviolet-visible,and ^(13)C cross polarization magic angle spinning nuclear magnetic resonance spectroscopy.A successive aldol condensation and cyclization were observed as the main side-reactions during the acetone conversion at Lewis acidic Y sites.In comparison with the low reaction temperature,a rapid formation and accumulation of the larger cyclic unsaturated aldehydes/ketones and aromatics could be observed,and which could strongly adsorb on the Lewis acidic sites,and thus cause the catalyst deactivation eventually.After a simple calcination,the coke deposits could be easily removed and the catalytic activity could be well restored. 展开更多
关键词 Deactivation mechanism Acetone to isobutene Lewis acid sites Y/beta Spectroscopy
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Molecular Detection of Extended-Spectrum Beta Lactamase and Carbapenemase Genes in Escherichia coli and Salmonella spp. Isolated from Chickens Consumed Outdoors in Ouagadougou, Burkina Faso
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作者 Amana Mètuor Dabiré Stéphanie Lynseh Carine Sita Bénao +4 位作者 Nicolas Ouédraogo Rahimatou Yasmine Wendkouni Tiemtoré Rhaina Olivia Badini Lionel Eliada Benoit Bambara Jacques Simporé 《Journal of Biosciences and Medicines》 2024年第11期221-232,共12页
This study was carried out to assess the prevalence of resistance genes in strains of Escherichia coli and Salmonella spp. isolated from free-range chickens in Ouagadougou, where resistant bacteria can be transmitted ... This study was carried out to assess the prevalence of resistance genes in strains of Escherichia coli and Salmonella spp. isolated from free-range chickens in Ouagadougou, where resistant bacteria can be transmitted to humans via faeces or contaminated meat. A total of 280 strains of Escherichia coli and 129 strains of Salmonella spp. resistant to at least one beta-lactam or carbapenem antibiotic were used in this study. PCR analyses revealed the presence of ESBL (extended spectrum beta lactamase) resistance genes in Escherichia coli isolates, with 3.21% (9/280) possessing the CTX-M (Cefotaximase) gene, 15.35% (43/280) had the SHV (Sulfhydril Variable) gene, and 11.42% (32/280) had carbapenemase resistance genes, more specifically IMP (Imipenemase metallo-beta-lactamase). As regards Salmonella spp. strains, only the presence of the SHV (Sulfhydril Variable) gene was identified in 2.32% (3/129) of isolates belonging to the ESBL family, while 26.35% (34/129) and 13.95% (18/129) of isolates respectively possessed the IMP (Imipenemase metallo-beta-lactamase) and NDM (New Delhi metallo-β-lactamase) genes, both of the carbapenemase type. The significant prevalence of resistance genes in bacterial strains isolated from chickens sold outdoors in Ouagadougou raises major public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections. 展开更多
关键词 BACTERIA Resistance Extended-Spectrum beta Lactamases CARBAPENEMASES OUAGADOUGOU
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Gross Alpha and Beta Activities and Related Lifetime Risks Assessment Due to Ingestion of Drinking Water from Different Sources in the District of Abidjan, Cote d’Ivoire
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作者 Ponaho Claude Kezo Issa Konate Dabo Salif Ignace Agba 《World Journal of Nuclear Science and Technology》 CAS 2024年第1期86-96,共11页
Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the ... Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the objective of this study was to assess the risk of cancer due to the ingestion of alpha and beta emitting radionuclides in the different types of water consumed in the region. A total of 63 water samples with 43 tap water samples, 5 bottled mineral water and 15 sachet water samples was collected and taken to GAEC laboratory for analysis. The low background Gas-less Automatic Alpha/Beta counting system (Canberra iMatic<sup>TM</sup>) was used to determine alpha and beta activity concentrations. Activity concentrations of both gross alpha and gross beta obtained in water sample were respectively lower than the WHO recommended limits of 0.1 Bq/l and 1 Bq/l. Also, the annual effective dose and total equivalent effective dose found in mineral bottled water samples were higher than in other types of water. The assessment of radiological lifetime risk has shown values of cancer risk due to ingestion alpha and beta emitters lower than recommended limit. These results indicate that there is no health hazard associated to consumption of water in the District of Abidjan. 展开更多
关键词 Gross Alpha and beta Activities Drinking Water Effective Dose Radiological Lifetime Risks
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黄芩苷抑制beta淀粉样蛋白诱导的海马COX-2蛋白表达 被引量:11
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作者 李振华 承欧梅 +4 位作者 蒋青松 晏勇 晏宁 马勋泰 韩宇 《中国中西医结合杂志》 CAS CSCD 北大核心 2011年第5期676-679,共4页
目的探讨中药单体黄芩苷对阿尔茨海默病(Alzheimer′s disease,AD)大鼠的脑保护作用及其可能的作用机制。方法将36只健康雄性Wistar大鼠随机分成对照组、AD组、黄芩苷组,每组12只。AD组及黄芩苷组采用双侧海马内注射beta淀粉样蛋白(Aβ1... 目的探讨中药单体黄芩苷对阿尔茨海默病(Alzheimer′s disease,AD)大鼠的脑保护作用及其可能的作用机制。方法将36只健康雄性Wistar大鼠随机分成对照组、AD组、黄芩苷组,每组12只。AD组及黄芩苷组采用双侧海马内注射beta淀粉样蛋白(Aβ1-40),建立AD大鼠模型。对照组采用相同方法行假手术,双侧海马内仅注射等量的0.9%氯化钠溶液。黄芩苷组术前、术后连续腹腔注射黄芩苷[40mg/(kg.d)],每天1次,连续7天。AD组和对照组也经相同时间相同步骤给予相同体积的缓冲液腹腔注射。采用免疫印迹法测定海马环氧合酶-2(COX-2)的表达,T迷宫实验观察大鼠的空间学习记忆能力,HE染色观察神经元组织学改变。结果 T迷宫实验结果显示:AD组[(28.33±7.50)%]和黄芩苷组[(38.33±7.50)%]大鼠自发交替选择率减小,与对照组[(61.67±7.50)%]比较,差异均有统计学意义(P<0.05),两组间比较差异有统计学意义(P<0.05)。HE染色结果显示:与黄芩苷组比较,AD组皮层、海马神经元变性坏死改变更明显。免疫印迹法分析显示:AD组COX-2表达明显增高,黄芩苷组COX-2表达明显降低(P<0.05)。结论黄芩苷能减轻beta淀粉样蛋白所致的脑损伤,可能与抑制COX-2的表达有关。 展开更多
关键词 黄芩苷 阿尔茨海默病 beta淀粉样蛋白 环氧合酶-2
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Fe-Beta zeolite for selective catalytic reduction of NO_x with NH_3:Influence of Fe content 被引量:14
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作者 夏岩 詹望成 +2 位作者 郭耘 郭杨龙 卢冠忠 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第12期2069-2078,共10页
Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the me... Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the metal salt solution during ion exchange influenced the ion exchange capacity of Fe, and resulted in different activities of the Fe-Beta catalyst. Fe-Beta catalysts with the Fe contents of (2.6, 6.3 and 9) wt% were synthesized using different amounts of 0.02 mol/L Fe salt solution. These catalysts were studied by various characterization techniques and their NH3-SCR activities were evaluated. The Fe-Beta catalyst with the Fe content of 6.3 wt% exhibited the highest activity, with a temperature range of 202-616℃ where the NOx conversion was 〉 80%. The Fe content in Beta zeolite did not influence the structure of Beta zeolite and valence state of Fe. Compared with the Fe-Beta catalysts with low Fe content (2.6 wt%), Fe-Beta catalysts with 6.3 wt% Fe content possessed more isolated Fe3. active sites which led to its higher NH3-SCR activity. A high capacity for NH3 and NO adsorption, and a high activity for NO oxidation also contributed to the high NH3-SCR activity of the Fe-Beta catalyst with 6.3 wt%. However, when the Fe content was further increased to 9.0 wt%, the amount of FexOy nanoparticles increased while the amount of isolated Fe3+ active sites was unchanged, which promoted NH3 oxidation and decreased the NH3-SCR activity at high temperature. 展开更多
关键词 beta zeoliteSelective catalytic reduction Fe contentFe species Ion exchange
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高空速条件Zn改性Co/H-beta催化剂上C_3H_8催化还原NO_x 被引量:7
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作者 张燕婷 潘华 +1 位作者 李伟 施耀 《高校化学工程学报》 EI CAS CSCD 北大核心 2009年第2期236-239,共4页
采用浸渍法制备了双组分Co-Zn/H-beta催化剂,考察了其在富氧(4%)和高空速(20000h-1)条件下丙烷选择性催化还原NOx的性能。结果表明,双组分Co-Zn/H-beta催化剂催化活性高于单组分Co/H-beta和Zn/H-beta的催化活性。在20000h-1的高空速条件... 采用浸渍法制备了双组分Co-Zn/H-beta催化剂,考察了其在富氧(4%)和高空速(20000h-1)条件下丙烷选择性催化还原NOx的性能。结果表明,双组分Co-Zn/H-beta催化剂催化活性高于单组分Co/H-beta和Zn/H-beta的催化活性。在20000h-1的高空速条件下,Co-Zn/H-beta催化剂在723K时NOx转化率达到最高值95%。Co-Zn/H-beta催化剂中Zn的作用是抑制丙烷的燃烧反应,Co的作用是促进NO的氧化反应。高空速范围内(10000~100000h-1),空速对Co-Zn/H-beta催化剂活性的影响不大,在Co-Zn/H-beta催化剂上丙烷能有效地消除NOx。 展开更多
关键词 co-Zn/H-beta催化剂 选择性催化还原 氮氧化物 丙烷 高空速
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经颅磁声电刺激对健康与帕金森病大鼠神经回路中beta振荡的影响 被引量:1
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作者 张帅 由胜男 +2 位作者 杜文静 王磊 徐桂芝 《中国组织工程研究》 CAS 北大核心 2024年第16期2519-2526,共8页
背景:经颅磁声电刺激是一种基于磁声耦合电效应的无创、高精度脑神经聚焦刺激方法,可调节神经节律振荡活动,从而影响大脑的运动、认知等功能。目的:探究经颅磁声电刺激对健康与帕金森病大鼠神经回路中beta振荡的影响。方法:①动物实验:... 背景:经颅磁声电刺激是一种基于磁声耦合电效应的无创、高精度脑神经聚焦刺激方法,可调节神经节律振荡活动,从而影响大脑的运动、认知等功能。目的:探究经颅磁声电刺激对健康与帕金森病大鼠神经回路中beta振荡的影响。方法:①动物实验:采用随机数字表法将24只Wistar大鼠随机分为4组,每组6只:正常对照组不进行任何干预;正常刺激组大脑前额叶皮质接受经颅磁声电刺激(空间峰值脉冲平均强度为13.33 W/cm^(2),基波频率为0.4 MHz,基波周期数为1000,脉冲重复频率为200 Hz);模型对照组、模型刺激组通过腹腔注射1-甲基-4-苯基-1,2,3,6-四氢吡啶建立帕金森病模型,造模成功后,模型对照组大脑前额叶皮质接受经颅磁声电假刺激,模型刺激组大脑前额叶皮质接受经颅磁声电刺激,每天刺激时长2.0 min,刺激结束停留8-10 min后,采集大鼠执行T迷宫过程中局部场电位信号并同时记录行为学正确率,对比分析各组局部场电位信号能量的时频分布情况和行为差异,当大鼠正确率连续3 d高于80%后停止刺激实验和T迷宫实验。②建模仿真实验:构建经颅磁声电刺激下皮质-基底神经节回路模型,分别改变超声发射周期(5,10,20 ms)、超声发射占空比(30%,50%,90%)和感应电流密度(20,50,100μA/cm^(2)),比较不同刺激参数下健康与帕金森病大鼠beta振荡的功率谱密度值。结果与结论:①动物实验:正常对照组大鼠的空间学习能力强于模型对照组(P<0.001),正常刺激组大鼠的空间学习能力强于正常对照组(P<0.05),模型刺激组大鼠的空间学习能力强于模型对照组(P<0.01);正常对照组beta振荡能量分布较为集中,正常刺激组较正常对照组beta振荡信号能量有所降低,模型对照组与模型刺激组beta振荡能量广泛分布且能量值显著高于正常对照组、正常刺激组,并且模型刺激组beta振荡信号能量明显低于模型对照组;②建模仿真实验:不加刺激时,健康大鼠beta频段功率谱密度峰值(30 dB)显著低于帕金森病大鼠(55 dB);施加经颅磁声电刺激后,两组大鼠beta频段功率谱密度值普遍降低;beta频段功率谱密度峰值与超声发射周期呈正相关、与感应电流密度呈负相关,当超声发射占空比为50%时功率谱密度峰值最低;③结果表明:经颅磁声电刺激可抑制健康与帕金森病大鼠的beta振荡,进而改善大鼠的运动功能与决策认知功能。 展开更多
关键词 经颅磁声电刺激 皮质-基底神经节回路 beta振荡 帕金森病 局部场电位 T迷宫 神经调控
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Synthesis of zeolite Beta containing ultra-small CoO particles for ethylbenzene oxidation 被引量:4
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作者 章冠群 王冬娥 +5 位作者 冯培 石松 王从新 郑安达 吕广 田志坚 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第7期1207-1215,共9页
Zeolite Beta containing ultra-small CoO particles was synthesized from a one-step hydrothermal process. The synthesis route involves the pre-mixture of hydrofluoric acid with tetraethylammo- nium hydroxide (in a mola... Zeolite Beta containing ultra-small CoO particles was synthesized from a one-step hydrothermal process. The synthesis route involves the pre-mixture of hydrofluoric acid with tetraethylammo- nium hydroxide (in a molar ratio of 1.3-1.5:1) before the addition of a silicon and cobalt source.Investigations by scanning electron microscopy, X-ray diffraction, UV-Vi s spectroscopy, X-ray pho-toelectron spectroscopy, H 2 -temperature-programmed reduct i on and transmi ssi on el ectron mi -croscopy confirm the presence of ultra-small CoO particles in the zeolite Beta structure. The ul-tra-small CoO particles in zeolite Beta present high stability against both oxidation and reduction atmospheres at high temperatures. The catalytic performance of the CoO-containing zeolite Beta catalysts was compared with other Co-containing zeolites by evaluating ethylbenzene oxidation reactivity. The CoO-containing zeolite Beta exhibits high ethylbenzene conversion and high selectiv-ity to acetophenone and 1-phenylethanol. The high activity of this catalyst system can be attributed to the high dispersion of the ultra-small CoO particles in the Beta structure. 展开更多
关键词 beta zeolite cobalt monoxide Ultra-small coO particle Ethylbenzene oxidation
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基于Beta分布的目标搜索概率自适应更新策略及其应用
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作者 高瑞周 孔金涛 +1 位作者 汤陈 彭秀辉 《电光与控制》 CSCD 北大核心 2024年第11期102-108,共7页
针对不确定先验信息条件下的目标搜索问题,考虑传感器探测概率和虚警概率,设计了基于Beta分布的目标搜索概率自适应更新策略。首先,通过Beta分布建立了不确定先验环境的概率地图,并提出自适应目标搜索概率更新策略,使得无人机能够根据... 针对不确定先验信息条件下的目标搜索问题,考虑传感器探测概率和虚警概率,设计了基于Beta分布的目标搜索概率自适应更新策略。首先,通过Beta分布建立了不确定先验环境的概率地图,并提出自适应目标搜索概率更新策略,使得无人机能够根据概率信息图动态更新检测次数;其次,在概率更新策略中引入了拒绝概率修正因子,根据地图概率差动态调整概率变化量,避免了搜索任务中可能存在的误检漏检问题;最后,通过数值仿真实验,验证了提出的目标搜索自适应更新策略可在不影响搜索效率的前提下,有效减小无人机的错误检测概率。 展开更多
关键词 协同搜索 动态变化环境 beta分布 自适应概率更新
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Quantitative analysis of transforming growth factor beta 1 mRNA in patients with alcoholic liver disease 被引量:21
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作者 Wei-Xing Chen You-Ming Li Chao-Hui Yu Wei-Min Cai Min Zheng Feng-Chen,Department of Gastroenterology, The First Affiliated Hospital,Medical College of Zhejiang University,Hangzhou 310003,Zhejiang Province,China 《World Journal of Gastroenterology》 SCIE CAS CSCD 2002年第2期379-381,共3页
AIM: To investigate the expression of the transforming growth factor beta 1(TGF-beta 1) mRNA in different stages of alcoholic liver disease (ALD) and its clinical value. METHODS: One hundred and seven male alcoholics ... AIM: To investigate the expression of the transforming growth factor beta 1(TGF-beta 1) mRNA in different stages of alcoholic liver disease (ALD) and its clinical value. METHODS: One hundred and seven male alcoholics were grouped by clinical findings into four groups: alcohol abusers without liver impairment (n =22), alcoholic steatosis (n =30); alcoholic hepatitis (n=31); and alcoholic cirrhosis(n=24). Using peripheral blood mononuclear cells (PBMC) as samples the gene expression of TGF-beta 1 was examined quantitatively by reverse transcription polymerase chain reaction (RT-PCR) and dot blot. There are 34 healthy subjects served as control. RESULTS: The expression of TGF-beta 1 from all ALD patients was significantly greater than that in controls (1.320 +/- 1.162 vs 0.808 +/- 0.276, P【0.001). The differences of the expressions were significant between the patients from each groups (alcoholic steatosis, alcoholic hepatitis and alcoholic cirrhosis) and the controls (1.168 +/- 0.852, 1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.808 +/- 0.276, P【0.050). No significant differences of TGF -beta 1 mRNA expression were observed between alcohol abusers without liver impairment and controls. The expressions in patients with alcoholic hepatitis and alcoholic cirrhosis were significantly greater than that in alcohol abusers respectively (1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.841 +/- 0.706, P【0.050). No significant differences of TGF-beta 1 mRNA expression were observed between alcoholic fatty liver men and alcohol abusers. CONCLUSION: TGF-beta 1 expression level can be a risk factor for alcoholic liver disease and might be related to the inflammatory activity and fibrosis of the liver in patients. 展开更多
关键词 Humans Liver Diseases Alcoholic MALE RNA Messenger Transforming Growth Factor beta
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Spatial and temporal analysis of beta diversity in the Barro Colorado Island forest dynamics plot, Panama 被引量:4
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作者 Pierre Legendre Richard Condit 《Forest Ecosystems》 SCIE CSCD 2019年第1期76-86,共11页
Background: Ecologists are interested in assessing the spatial and temporal variation in ecological surveys repeated over time. This paper compares the 1985 and 2015 surveys of the Barro Colorado Forest Dynamics plot(... Background: Ecologists are interested in assessing the spatial and temporal variation in ecological surveys repeated over time. This paper compares the 1985 and 2015 surveys of the Barro Colorado Forest Dynamics plot(BCI), Panama,divided into 1250(20 m × 20 m) quadrats.Methods, spatial analysis: Total beta diversity was measured as the total variance of the Hellinger-transformed community data throughout the BCI plot. Total beta was partitioned into contributions of individual sites(LCBD indices), which were tested for significance and mapped.Results, spatial analysis: LCBD indices indicated the sites with exceptional community composition. In 1985,they were mostly found in the swamp habitat. In the 2015 survey, none of the swamp quadrats had significant LCBDs.What happened to the tree community in the interval?Methods, temporal analysis: The dissimilarity in community composition in each quadrat was measured between time 1(1985) and time 2(2015). Temporal Beta Indices(TBI) were computed from abundance and presence-absence data and tested for significance. TBI indices can be decomposed into B = species(or abundances-per-species) losses and C = species(or abundances-per-species) gains. B-C plots were produced; they display visually the relative importance of the loss and gain components, through time, across the sites.Results, temporal analysis: In BCI, quadrats with significant TBI indices were found in the swamp area, which is shrinking in importance due to changes to the local climate. A published habitat classification divided the BCI forest plot into six habitat zones. Graphs of the B and C components were produced for each habitat group. Group 4(the swamp) was dominated by species(and abundances-per-species) gains whereas the five other habitat groups were dominated by losses, some groups more than others.Conclusions: We identified the species that had changed the most in abundances in the swamp between T1 and T2.This analysis supported the hypothesis that the swamp is drying out and is invaded by species from the surrounding area. Analysis of the B and C components of temporal beta diversity bring us to the heart of the mechanisms of community change through time: losses(B) and gains(C) of species, losses and gains of individuals of various species. TBI analysis is especially interesting in species-rich communities where we cannot examine the changes in every species individually. 展开更多
关键词 beta DIVERSITY B-C PLOTS BCI forest dynamics PLOT Space-time analysis Temporal beta DIVERSITY
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Enzyme-digested Colla Corii Asini(E’jiao) prevents hydrogen peroxide-induced cell death and accelerates amyloid beta clearance in neuronal-like PC12 cells 被引量:8
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作者 Li Xiao Feng Liao +4 位作者 Ryoji Ide Tetsuro Horie Yumei Fan Chikako Saiki Nobuhiko Miwa 《Neural Regeneration Research》 SCIE CAS CSCD 2020年第12期2270-2277,共8页
As an aging-associated degenerative disease,Alzheimer’s disease is characterized by the deposition of amyloid beta(Aβ),oxidative stress,inflammation,dysfunction and loss of cholinergic neurons.Colla Corii Asini(CCA)... As an aging-associated degenerative disease,Alzheimer’s disease is characterized by the deposition of amyloid beta(Aβ),oxidative stress,inflammation,dysfunction and loss of cholinergic neurons.Colla Corii Asini(CCA)is a traditional Chinese medicine which has been used for feebleness-related diseases and anti-aging.CCA might delay aging-induced degenerative changes in neurons.In the present study,we evaluated antioxidant activity,cytoprotective effects,and Aβremovability of enzyme-digested Colla Corii Asini(CCAD).Oxygen radical absorbance capacity(ORAC)activity assay showed that,as compared to gelatins from the skin of porcine,bovine and cold water fish,CCA exhibited the highest ORAC activity.The ORAC activity of CCA and CCAD was increased gradually by the length of time in storage.Ultrastructure analysis by scanning electron microscopy showed that among CCA manufactured in 2008,2013,2017 and gelatin from cold water fish skin,CCA manufactured in 2008 presented the smoothest surface structure.We further tested the protective effects of CCAD(manufactured in 2008)and enzyme-digested gelatin from cold water fish skin(FGD)on hydrogen peroxide(H2O2)-induced cell death in nerve growth factor-differentiated neuronal-like PC12 cells.Presto blue assay showed that both FGD and CCAD at 0.5 mg/m L increased cell viability in H2O2-treated neuronal-like PC12 cells.The protection of CCAD was significantly superior to that of FGD.Acetylcholinesterase(Ach E)assay showed that both FGD and CCAD inhibited Ach E activity in nerve growth factor-differentiated neuronal-like PC12 cells to 89.1%and 74.5%of that in non-treated cells,respectively.The data suggest that CCAD might be able to increase the neurotransmitter acetylcholine.Although CCAD inhibited Ach E activity in neuronal-like PC12 cells,CCAD prevented H2O2-induced abnormal deterioration of Ach E.ELISA and neprilysin activity assay results indicated that CCAD reduced amyloid beta accumulation and increased neprilysin activity in Aβ1–42-treated neuronal-like PC12 cells,suggesting that CCAD can enhance Aβclearance.Our results suggest that CCA might be useful for preventing and treating Alzheimer’s disease. 展开更多
关键词 acetylcholinesterase activity Alzheimer’s disease amyloid beta clearance antioxidant colla corii Asini collagen NEUROPROTECTION PC12 cells
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Relationship Between Polymorphism of Cystathionine beta Synthase Gene and Congenital Heart Disease in Chinese Nuclear Families 被引量:7
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作者 XIAO-MING SONG XIAO-YING ZHENG +2 位作者 WEN-LI ZHU LEI HUANG YONG LI 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2006年第6期452-456,共5页
Objective To study the relationship between polymorphism of cystathionine beta synthase (CBS) gene and development of congenital heart disease (CHD). Methods One hundred and twenty-seven CHD case-parent triads wer... Objective To study the relationship between polymorphism of cystathionine beta synthase (CBS) gene and development of congenital heart disease (CHD). Methods One hundred and twenty-seven CHD case-parent triads were recruited from Liaoning Province as patient group, and 129 healthy subjects without family history of birth defect were simultaneously recruited as control group together with their biological parents. For all subjects the polymorphism of CBS gene G919A locus was examined by PCR-ARMS method, Results The frequencies of three genotypes (w/w, w/m, and m/m) in control group were 27.2%, 58,4%, and 14.4%, respectively, with no significant difference in gender. A significant difference in the allele frequency was found between CHD patients and controls, the wild allele frequency was 67,9% in patients and 55.7% in controls CHD parents' genotype distribution was significantly different from that in controls. Further comparison of each type of CHD showed that genotype frequencies in several CHD subtypes were significantly different from those in their corresponding controls. The results of TDT analysis showed that no allele transmission disequilibrium existed in CHD nuclear families. Conclusions CBS gene G919A mutation is associated with the development of CHD, and the mutated allele may decrease the risk of CHD. 展开更多
关键词 congenital heart disease Gene polymorphism Cystathionine beta synthase Case-control family study
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The complexities underlying age-related macular degeneration: could amyloid beta play an important role? 被引量:6
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作者 Savannah A. Lynn Eloise Keeling +4 位作者 Rosie Munday Gagandeep Gabha Helen Griffiths Andrew J.Lotery J.Arjuna Ratnayaka 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第4期538-548,共11页
e-related macular degeneration (AMD) causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests fr... e-related macular degeneration (AMD) causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer's-linked amyloid beta (Aβ) group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer's disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for latestage AMD. 展开更多
关键词 amyloid beta (Aβ) retinal neurons RETINA mouse models age related macular degeneration(AMD)
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Diabetes recurrence after metabolic surgeries correlates with re-impaired insulin sensitivity rather than beta-cell function 被引量:5
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作者 Teng Liu Ming-Wei Zhong +10 位作者 Yi Liu Dong Sun Meng Wei Xin Huang Yu-Gang Cheng Qun-Zheng Wu Dong Wu Xiao-Qian Zhang Ke-Xin Wang San-Yuan Hu Shao-Zhuang Liu 《World Journal of Gastroenterology》 SCIE CAS 2017年第19期3468-3479,共12页
AIM To investigate factors causing diabetes recurrence after sleeve gastrectomy(SG)and duodenal-jejunal bypass(DJB).METHODS SG and DJB were performed on rats with diabetes induced by high-fat diet(HFD)and streptozotoc... AIM To investigate factors causing diabetes recurrence after sleeve gastrectomy(SG)and duodenal-jejunal bypass(DJB).METHODS SG and DJB were performed on rats with diabetes induced by high-fat diet(HFD)and streptozotocin(STZ).HFD was used to induce diabetes recurrence at 4 wk postoperatively.Body weight,oral glucose tolerance test,homeostatic model assessment of insulin resistance(HOMA-IR),insulin signaling[IR,insulin receptor substrate(IRS 1,IRS2,phosphatidylinositol3-kinase and AKT in liver and skeletal muscle],oral glucose stimulated insulin secretion,beta-cell morphology(mass,apoptosis and insulin secretion),glucagon-like peptide(GLP)-1,PYY and ghrelin were compared among SG rats with common low-fat diet(SG-LFD),SG with HFD(SG-HFD),DJB rats with LFD(DJB-LFD),DJB with HFD(DJB-HFD)and shamoperation with LFD(Sham)at targeted postoperative times.RESULTS SG and DJB resulted in significant improvement in glucose tolerance,lower HOMA-IR,up-regulated hepatic and muscular insulin signaling,higher levels of oral glucose-stimulated insulin secretion,bigger betacell mass,higher immunofluorescence intensity of insulin,fewer transferase-mediated d UTP-biotin 3’nick end-labeling(TUNEL)-positive beta cells and higher postprandial GLP-1 and PYY levels than in the Sham group.The improvement in glucose tolerance was reversed at 12 wk postoperatively.Compared with the SG-LFD and DJB-LFD groups,the SG-HFD and DJB-HFD groups showed higher HOMA-IR,down-regulated hepatic and muscular insulin signaling,and more TUNEL-positive beta cells.No significant difference was detected between HFD and LFD groups for body weight,glucose-stimulated insulin secretion,betacell mass,immunofluorescence intensity of insulin,and postprandial GLP-1 and PYY levels.Fasting serum ghrelin decreased in SG groups,and there was no difference between HFD-SG and LFD-SG groups.CONCLUSION HFD reverses the improvement in glucose homeostasis after SG and DJB.Diabetes recurrence may correlate with re-impaired insulin sensitivity,but not with alterations of beta-cell function and body weight. 展开更多
关键词 Apoptosis Diabetes recurrence Duodenaljejunal bypass Pancreatic beta cell Sleeve gastrectomy
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Thrombophilia Caused by Beta2-Glycoprotein I Deficiency: In Vitro Study of a Rare Mutation in APOH Gene 被引量:5
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作者 Xiao-ping ZHANG Wei ZENG +7 位作者 Hui LIU Liang TANG Qing-yun WANG Zhi-peng CHENG Ying-ying WU Bei HU Wei SHI Yu HU 《Current Medical Science》 SCIE CAS 2018年第2期379-385,共7页
This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophil... This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophilia. The plasma level of β2GPI was measured by ELISA and Western blotting, and anti-β2GPI antibody by ELISA. Lupus anticoagulant (LA) was assayed using the dilute Russell viper venom time. Deficiency of the major natural anticoagulants including protein C (PC), protein S (PS), antithrombin (AT) and thrombomodulin (TM) was excluded from the proband. A mutation analysis was performed by amplification and sequencing of the APOH gene. Wild type and mutant (c.112A〉G) APOH expression plasmids were constructed and transfected into HEK293T cells. The results showed that the thrornbin generation capacity of the proband was higher than that of the other family members. Missense mutation p.Lys38Glu in APOH gene and LA coexisted in the proband. The mutation led to β2GPI deficiency and thrombosis by impairing the protein production and inhibiting the platelet aggregation. It was concluded that the recurrent thrombosis of the proband is associated with the coexistence ofp.Lys38Glu mutation in APOH gene and LA in plasma. 展开更多
关键词 beta2-glycoprotein I lupus anticoagulant MUTATION apolipoprotein H THROMBOPHILIA
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G-protein beta 3 subunit polymorphisms and essential hypertension: a case-control association study in northern Han Chinese 被引量:4
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作者 Mei LI Bei ZHANG Chuang LI Jie-Lin LIU Li-Juan WANG Ya LIU Zuo-Guang WANG Shao-Jun WEN 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2015年第2期127-134,共8页
Objective To explore the association between the three polymorphisms [ C825T, C1429T and G(-350)A] of the gene encoding the G protein beta 3 subunit (GNB3) and hypertension by performing a case-control study in th... Objective To explore the association between the three polymorphisms [ C825T, C1429T and G(-350)A] of the gene encoding the G protein beta 3 subunit (GNB3) and hypertension by performing a case-control study in the northern Han Chinese population. Methods We recnaited 731 hypertensive patients and 673 control subjects (the calculated power value was 〉 0.8). Genotyping was performed to identify C825T, C1429T and G(-350)A polymorphisms using the TaqMan assay. Comparisons of allelic and genotypic frequencies between cases and controls were made by using the chi-square test. Logistic regression analyses were performed to investigate the relationships between the three polymorphisms of GNB3 gene under different genetic models (additive, dominant and recessive models). Results The genotype dis- tribution and allele frequencies of C825T, C1429T and G(-350)A polymorphisms did not differ significantly between hypertensive patients and control subjects, either when the full sample was assessed, or when the sample was stratified by gender. No significant association was observed between C825T, C 1429T and G(-350)A polymorphisms and the risk of essential hypertension in any genetic model. Linkage dis- equilibrium was only detected between C825T and C 1429T polymorphisms. Haplotype analyses observed that none of the three estimated haplotypes significantly increased the risk of hypertension. Conclusions Our study suggested that the GNB3 gene polymorphisms [C825T, C 1429T and G(-350)A] were not significantly associated with essential hypertension in northern Han Chinese population. 展开更多
关键词 G protein beta 3 subunit gene HAPLOTYPE Hypertension POLYMORPHISM
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Ba空间中的Beta算子加Jacobi权的同时逼近
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作者 康正华 吴嘎日迪 《内蒙古师范大学学报(自然科学汉文版)》 CAS 2009年第1期17-21,25,共6页
利用加权K-泛函与加权Ditzian-Totik光滑模的等价性,给出了Beta算子及其导数在Ba空间中加Jacobi权逼近的正、逆结果和逼近阶的特征刻画.
关键词 BA空间 beta算子 加权逼近 特征刻画
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