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淄博市活基尾虾带菌情况调查
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作者 杨洪波 张宇琴 《中国热带医学》 CAS 2002年第3期348-348,共1页
基尾虾味道鲜美,沿海各省和我市居民都有活吃的习惯,为了解基尾虾的带菌情况,保障消费者的食用安全和身体健康,笔者于2001年5~6月份淄博市大的宾馆和饭店进行了活基尾虾随机抽样检测,现将结果报告如下.
关键词 食品卫生 淄博市 活基尾虾
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失活钙基吸收剂环境中自活化机理
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作者 叶江明 梁绍华 +2 位作者 张思文 孙荣岳 毕小龙 《化工进展》 EI CAS CSCD 北大核心 2019年第9期4302-4307,共6页
将经历多次循环后失活的钙基吸收剂置于环境中吸水自活化,通过XRD分析了自活化过程吸收剂物相演变规律,在双固定床反应器系统上分析了吸水率对失活钙基吸收剂循环捕集CO2性能的影响规律,通过SEM和N2吸附分析了自活化提高钙基吸收剂循环... 将经历多次循环后失活的钙基吸收剂置于环境中吸水自活化,通过XRD分析了自活化过程吸收剂物相演变规律,在双固定床反应器系统上分析了吸水率对失活钙基吸收剂循环捕集CO2性能的影响规律,通过SEM和N2吸附分析了自活化提高钙基吸收剂循环碳酸化转化率的机理。结果表明:失活钙基吸收剂首先吸收环境中水分生成Ca(OH)2,当吸水率达到100%后继续吸水生成Ca(OH)2·2H2O,自活化极限为170%;自活化可以提高失活钙基吸收剂循环碳酸化转化率,自活化后钙基吸收剂循环捕集CO2性能与吸水率呈线性比例关系,重复自活化可再次提高吸收剂循环碳酸化转化率;自活化过程中,失活钙基吸收剂颗粒表面重新生成孔隙,比孔容和比表面积增加,有利于吸收剂中CO2的扩散,因此自活化后钙基吸收剂循环捕集CO2性能提高。 展开更多
关键词 钙循环 吸收剂 化机理
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流动化学用于可逆失活自由基聚合的研究进展 被引量:1
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作者 周杨 全钦之 陈茂 《功能高分子学报》 CAS CSCD 北大核心 2022年第3期203-220,共18页
可逆失活自由基聚合(RDRP)是高分子合成领域中应用最广的合成方法之一。RDRP能够实现对分子量、分子量分布、聚合物结构等的精确调控,大大促进了功能高分子的合成与发展。与传统反应瓶和反应釜相比,流动化学反应器具有比表面积大、传质... 可逆失活自由基聚合(RDRP)是高分子合成领域中应用最广的合成方法之一。RDRP能够实现对分子量、分子量分布、聚合物结构等的精确调控,大大促进了功能高分子的合成与发展。与传统反应瓶和反应釜相比,流动化学反应器具有比表面积大、传质/传热高效等优点,不仅能够有效加快聚合反应速率、减少副反应,还能为光控可逆失活自由基聚合(photo-RDRP)提供均匀、充足的光照。此外,随着计算机科学的高速发展,电脑辅助的流动聚合已成为高分子合成领域的前沿技术之一。本文首先对流动化学在热引发和光引发RDRP中的应用进行了概述,然后从定制化合成、高通量合成和自优化合成三个方面对流动RDRP方法的最新研究进展进行了介绍,最后对流动聚合中尚存的问题进行了简单的总结与展望。 展开更多
关键词 可逆失自由聚合 流动化学 定制化合成 高通量合成 自优化合成
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活自由基聚合方法
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《合成树脂及塑料》 CAS 2002年第6期62-62,共1页
关键词 自由聚合方法 发明 自由聚合引发剂 N-烃氧自由 烯健不饱和单体
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循环机活塞支承环压入器
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作者 田树杰 《小氮肥》 2003年第1期21-21,共1页
关键词 循环机 塞支承环 氮肥厂 整体式活基 组装
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汽油机活塞顶部开裂原因分析及改进措施 被引量:5
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作者 祝传亮 王奇峰 +2 位作者 刘小斌 曹国帅 王玉洁 《内燃机与动力装置》 2016年第4期57-60,共4页
本文针对某款汽油机活塞试验后出现顶部开裂的情况,对导致汽油机活塞顶部开裂失效的原因进行了综合分析,最终应用温度场试验的方法,查找到导致失效的根本原因是活塞温度过高。为此,将活塞的冷却方式由原来的飞溅冷却更改为喷油冷却,增... 本文针对某款汽油机活塞试验后出现顶部开裂的情况,对导致汽油机活塞顶部开裂失效的原因进行了综合分析,最终应用温度场试验的方法,查找到导致失效的根本原因是活塞温度过高。为此,将活塞的冷却方式由原来的飞溅冷却更改为喷油冷却,增强了冷却能力,活塞顶面最高温度由原来的337℃降低到256℃,活塞的工作环境得到大幅改善,从而达到了解决活塞顶部开裂的目的。 展开更多
关键词 活基 温度场 有限元分析
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可逆失活自由基聚合制备含氟聚合物的研究进展 被引量:1
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作者 韩善涛 许梦丽 陈茂 《高分子学报》 SCIE CAS CSCD 北大核心 2024年第7期841-855,共15页
含氟聚合物具有许多优异的理化性能,在化工、新能源、生物医药等领域取得重要应用.可逆失活自由基聚合反应(RDRP)是实现聚合物精准合成的重要手段.然而,含氟烯烃单体的RDRP报道相对较少.本综述对侧链含氟聚合物和主链含氟聚合物的可控... 含氟聚合物具有许多优异的理化性能,在化工、新能源、生物医药等领域取得重要应用.可逆失活自由基聚合反应(RDRP)是实现聚合物精准合成的重要手段.然而,含氟烯烃单体的RDRP报道相对较少.本综述对侧链含氟聚合物和主链含氟聚合物的可控合成进展进行介绍,简述了含氟丙烯酸酯、含氟苯乙烯、三氟氯乙烯、四氟乙烯、偏氟乙烯、六氟丙烯、全氟烯基醚等单体的RDRP案例,总结了该领域面临的挑战.鉴于众多前沿领域对定制化合成含氟聚合物提出了迫切需求,发展含氟聚合物的可控合成方法将有助于拓宽含氟聚合物范围,推动开发高性能含氟聚合物材料. 展开更多
关键词 含氟聚合物 含氟烯烃 可控失自由聚合 性聚合
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Human AKR1A1 involves in metabolic activation of carcinogenic aristolochic acidⅠ
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作者 GAO Zhenna YOU Xinyue +6 位作者 LIU Weiying WU Jiaying XI Jing CAO Yiyi ZHANG Xiaohong ZHANG Xinyu LUAN Yang 《中国药理学与毒理学杂志》 CAS 北大核心 2024年第9期641-651,共11页
OBJECTIVE To investigate whether aldo-keto reductases(AKRs)can act as a nitrore⁃ductase(NR)and bioactivate aristolochic acidⅠ(AA-Ⅰ)to produce AA-Ⅰ-DNA adducts.METHODS①Human-induced hepatocytes(hiHeps)and human bla... OBJECTIVE To investigate whether aldo-keto reductases(AKRs)can act as a nitrore⁃ductase(NR)and bioactivate aristolochic acidⅠ(AA-Ⅰ)to produce AA-Ⅰ-DNA adducts.METHODS①Human-induced hepatocytes(hiHeps)and human bladder RT4 cells were used as tool cells and treated with AA-Ⅰ0,0.5,1.0 and 2μmol·L^(-1)for 24 h.Cell viability was detected using the CCK-8 method,and the half maximal inhibition concentration(IC_(50))was calculated using the CCK-8 method and the level of DNA adduct production was calculated.②hiHeps and RT4 cells were treated with AKR inhibitor luteotin(0,5,10 and 25μmol·L^(-1))+AA-Ⅰ0.2 and 1.0μmol·L^(-1)for 24 h,respectively,and the levels of DNA adducts were detected by a liquid chromatography-tandem mass spectrometer(LC-MS/MS).③hiHeps cells were incubated with 80 nmol·L^(-1)small interfering RNAs(si-AKRs)for 48 h and treated with AA-Ⅰ1.0μmol·L^(-1)for 24 h.Real-time qualitative PCR(RT-qPCR)method was used to detect the mRNA expression of AKRs gene and LC-MS/MS technology was used to investigate the effect of specific AKR gene knockdown on DNA adduct levels.④500 nmol·L^(-1)human AKR recombinant proteins AKR1A1 and AA-Ⅰwere incubated in vitro under anaerobic conditions and the formation of AA-Ⅰ-DNA adducts was detected.RESULTS①The IC_(50)of AA-Ⅰto hiHeps and RT4 cells was 1.9 and 0.42μmol·L^(-1),respec⁃tively.The level of DNA adduct production of the two cell lines was significantly different(P<0.01).②Luteolin≥5μmol·L^(-1)significantly inhibited the production of AA-Ⅰ-DNA adducts in both cells(P<0.05),and there was a concentration-dependent effect in hiHeps cells(P<0.01,R=0.84).③In the AKR family,the knockdown of AKR1A1 gene up to 80%inhibited the generation of AA-Ⅰ-DNA adducts by 30%-40%.④The AA-Ⅰ-DNA adducts were detected in the incubation of recombinant protein AKR1A1 and AA-Ⅰunder anaerobic conditions in vitro,approximately 1 adduct per 107 nucleotides.CONCLU⁃SION AKR1A1 is involved in AA-Ⅰbioactivation,providing a reference for elucidation of the carcino⁃genic mechanism of AA-Ⅰ. 展开更多
关键词 metabolic activation nitro-reduction aldo-keto reductase superfamily aristolochic acidⅠ
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Mechanism study on the influence of surface properties on the synthesis of dimethyl carbonate from CO_(2)and methanol over ceria catalysts
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作者 Lei Dong Shengjie Zhu +4 位作者 Yangyang Yuan Xiaomin Zhang Xiaowei Zhao Yanping Chen Lei Xu 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第10期138-152,共15页
The direct synthesis of dimethyl carbonate(DMC)from CO_(2)and methanol has attracted much attention as an environmentally benign and alternative route for conventional routes.Herein,a series of cerium oxide catalysts ... The direct synthesis of dimethyl carbonate(DMC)from CO_(2)and methanol has attracted much attention as an environmentally benign and alternative route for conventional routes.Herein,a series of cerium oxide catalysts with various textural features and surface properties were prepared by the one-pot synthesis method for the direct DMC synthesis from CO_(2)and methanol,and the structure-performance relationship was investigated in detail.Characterization results revealed that both of surface acid-base properties and the oxygen vacancies contents decreased with the rising crystallinity at increasingly higher calcination temperature accompanied by an unexpectedly volcano-shaped trend of DMC yield observed on the catalysts.In situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)studies indicated that the adsorption rate of methanol is slower than that of CO_(2)and the methanol activation state largely influences the formation of key intermediate.Although the enhanced surface acidity-basicity and oxygen vacancies brought by low-temperature calcination could facilitate the activation of CO_(2),the presence of excess strongly basic sites on low-crystallinity sample was detrimental to DMC synthesis due to the preferred formation of unreactive mono/polydentate carbonates as well as the further impediment of methanol activation.Moreover,with the use of 2-cyanopyridine as a dehydration reagent,the DMC synthesis was found to be both influenced by the promotion from the rapid in situ removal of water and the inhibition from the competitive adsorption of hydration products on the same active sites. 展开更多
关键词 CeO_(2) Dimethyl carbonate Surface property Methanol activation 2-Cyanopyridine
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TPOL triggers apoptosis with mitochondrial injury through activating a ROS-dependent p53/p21/p27/Rb/Bax/Cyto C/caspase-mediated signaling
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作者 CHENG Zongwei ZENG Boning XING Feiyue 《中国病理生理杂志》 CAS CSCD 北大核心 2024年第8期1488-1496,共9页
AIM:To explore the influence of ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate(TPOL)on cell apoptosis and its potential mechanism.METHODS:HEK293T cells sensitive to TPOL were treated with different concentrations of T... AIM:To explore the influence of ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate(TPOL)on cell apoptosis and its potential mechanism.METHODS:HEK293T cells sensitive to TPOL were treated with different concentrations of TPOL with or without exposure to light radiation,before treatment with various inhibitors,N-acetyl-Lcysteine(NAC),pifithrin-αand Z-DVED-FMK.Cell viability was measured by CCK-8 assay.Annexin V/propidium iodide staining was used to count the number of apoptotic cells.DCFH-DA staining was used to detect reactive oxygen species(ROS)levels,and JC-1 staining was used to assess mitochondrial membrane potential by flow cytometry.The expression of apoptosis-related proteins and cell cycle-regulated molecules was measured by Western blot.RESULTS:TPOL enhanced the apoptosis of HEK293T cells in a dose-dependent manner(P<0.05),with a decrease in Bcl-2 and increases in Bax and cytochrome C(Cyto C),followed by up-regulation of activated caspase-9 and caspase-3,and the cleavage of PARP(P<0.05).The TPOL-enhanced cleavage of caspase-3 and PARP was rescued by Z-DVED-FMK(P<0.01).TPOL also led to a rapid increase in ROS,a reduction in mitochondrial membrane potential,and the release of Cyto C(P<0.01),all of which could be reversed by the ROS scavenger NAC.Moreover,the TPOL-caused alterations in p21,p27,Rb,and CDK2 were also recovered by the p53 inhibitor pifithrin-α(P<0.05).The TPOL-induced changes in Bax,Bcl-2,cleaved caspase-9,activated caspase-3,and cleaved PARP were subsequently rescued by pretreatment with pifithrin-α(P<0.05).CONCLUSION:TPOL can induce cellular apoptosis with ROS-mediated mitochondrial membrane damage through the activation of a ROS-dependent p53/p21/p27/Rb/Bax/Cyto C/caspase-mediated signal axis. 展开更多
关键词 ethyl(2 4 6-trimethylbenzoyl)phenylphosphinate reactive oxygen species MITOCHONDRIA APOPTOSIS
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Vermiform Ni@CNT derived from one-pot calcination of Ni-MOF precursor for improving hydrogen storage of MgH_(2)
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作者 Zi-yin DAI Bing ZHANG +10 位作者 Hideo KIMURA Li-rong XIAO Rong-han LIU Cui NI Chuan-xin HOU Xue-qin SUN Yu-ping ZHANG Xiao-yang YANG Rong-hai YU Wei DU Xiu-bo XIE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第8期2629-2644,共16页
The Ni-coated carbon nanotubes(Ni@CNT)composite was synthesized by the facile“filtration+calcination”of Ni-based metal−organic framework(MOF)precursor and the obtained composite was used as a catalyst for MgH_(2).Mg... The Ni-coated carbon nanotubes(Ni@CNT)composite was synthesized by the facile“filtration+calcination”of Ni-based metal−organic framework(MOF)precursor and the obtained composite was used as a catalyst for MgH_(2).MgH_(2)was mixed evenly with different amounts of Ni@CNT(2.5,5.0 and 7.5,wt.%)through ball milling.The MgH_(2)−5wt.%Ni@CNT can absorb 5.2 wt.%H_(2)at 423 K in 200 s and release about 3.75 wt.%H_(2)at 573 K in 1000 s.And its dehydrogenation and rehydrogenation activation energies are reduced to 87.63 and 45.28 kJ/mol(H_(2)).The in-situ generated Mg_(2)Ni/Mg_(2)NiH4 exhibits a good catalytic effect due to the provided more diffusion channels that can be used as“hydrogen pump”.And the presence of carbon nanotubes improves the properties of MgH_(2)to some extent. 展开更多
关键词 Mg-based hydrogen storage material activation energy Ni-loaded carbon nanotubes catalyst mechanism
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Integrative analysis of bone-formation associated genes and immune cell infiltration in osteoporosis, and the prediction of active ingredients in targeted traditional Chinese medicine
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作者 WANG Kai DONG Ping GUO Hongzhang 《Digital Chinese Medicine》 CAS CSCD 2024年第2期160-170,共11页
Objective To explore the differential expression and mechanisms of bone formation-related genes in osteoporosis(OP)leveraging bioinformatics and machine learning methodologies;and to predict the active ingredients of ... Objective To explore the differential expression and mechanisms of bone formation-related genes in osteoporosis(OP)leveraging bioinformatics and machine learning methodologies;and to predict the active ingredients of targeted traditional Chinese medicine(TCM)herbs.Methods The Gene Expression Omnibus(GEO)and GeneCards databases were employed to conduct a comprehensive screening of genes and disease-associated loci pertinent to the pathogenesis of OP.The R package was utilized as the analytical tool for the identification of differentially expressed genes.Least absolute shrinkage and selection operator(LASSO)logis-tic regression analysis and support vector machine-recursive feature elimination(SVM-RFE)algorithm were employed in defining the genetic signature specific to OP.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses for the selected pivotal genes were conducted.The cell-type identification by estimating rela-tive subsets of RNA transcripts(CIBERSORT)algorithm was leveraged to examine the infiltra-tion patterns of immune cells;with Spearman’s rank correlation analysis utilized to assess the relationship between the expression levels of the genes and the presence of immune cells.Coremine Medical Database was used to screen out potential TCM herbs for the treatment of OP.Comparative Toxicogenomics Database(CTD)was employed for forecasting the TCM ac-tive ingredients targeting the key genes.AutoDock Vina 1.2.2 and GROMACS 2020 softwares were employed to conclude analysis results;facilitating the exploration of binding affinity and conformational dynamics between the TCM active ingredients and their biological targets.Results Ten genes were identified by intersecting the results from the GEO and GeneCards databases.Through the application of LASSO regression and SVM-RFE algorithm;four piv-otal genes were selected:coat protein(CP);kallikrein 3(KLK3);polymeraseγ(POLG);and transient receptor potential vanilloid 4(TRPV4).GO and KEGG pathway enrichment analy-ses revealed that these trait genes were predominantly engaged in the regulation of defense response activation;maintenance of cellular metal ion balance;and the production of chemokine ligand 5.These genes were notably associated with signaling pathways such as ferroptosis;porphyrin metabolism;and base excision repair.Immune infiltration analysis showed that key genes were highly correlated with immune cells.Macrophage M0;M1;M2;and resting dendritic cell were significantly different between groups;and there were signifi-cant differences between different groups(P<0.05).The interaction counts of resveratrol;curcumin;and quercetin with KLK3 were 7;3;and 2;respectively.It shows that the interac-tions of resveratrol;curcumin;and quercetin with KLK3 were substantial.Molecular docking and molecular dynamics simulations further confirmed the robust binding affinity of these bioactive compounds to the target genes.Conclusion Pivotal genes including CP;KLK3;POLG;and TRPV4;exhibited commendable significant prognostic value;and played a crucial role in the diagnostic assessment of OP.Resveratrol;curcumin;and quercetin;natural compounds found in TCM;showed promise in their potential to effectively modulate the bone-forming gene KLK3.This study provides a sci-entific basis for the interpretation of the pathogenesis of OP and the development of clinical drugs. 展开更多
关键词 OSTEOPOROSIS Bone formation Differentially expressed genes Biological information Traditional Chinese medicine(TCM) Active ingredients Molecular mechanism
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室温非均相可逆失活自由基聚合 被引量:2
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作者 林冬妮 张力 谭剑波 《高分子学报》 SCIE CAS CSCD 北大核心 2023年第6期761-777,共17页
非均相可逆失活自由基聚合(RDRP)是高效可控制备结构与功能明确聚合物纳米材料的重要方法.在室温下进行非均相RDRP从聚合技术层面上是一个很小的调整,但这为功能聚合物的可控合成、新非均相RDRP方法的发展及非均相RDRP的机理研究带来了... 非均相可逆失活自由基聚合(RDRP)是高效可控制备结构与功能明确聚合物纳米材料的重要方法.在室温下进行非均相RDRP从聚合技术层面上是一个很小的调整,但这为功能聚合物的可控合成、新非均相RDRP方法的发展及非均相RDRP的机理研究带来了巨大的机遇.在本文中,我们将综述室温非均相RDRP的最新研究进展,这些研究进展难以通过传统的热引发非均相RDRP实现,包括聚合速率调控、耐氧非均相RDRP体系、新非均相RDRP方法的发展、聚合物纳米材料的形貌调控和功能聚合物纳米材料的合成,最后指出了室温非均相RDRP领域目前存在的关键问题和重要挑战. 展开更多
关键词 可逆失自由聚合 非均相聚合 室温 聚合物纳米材料
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酶促聚合:绿色的高分子材料合成技术
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作者 李若雨 陈英翾 +3 位作者 韩浩博 温凯 安泽胜 李全顺 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2023年第5期1017-1029,共13页
以酶促聚合为代表的绿色高分子合成途径,以其反应条件温和、产物多分散性低、无金属催化剂残留、高度立体和区位选择性等优势,成为医用高分子材料合成领域中的研究热点。目前,氧化还原酶、水解酶、转移酶均成功应用于聚合反应,其中脂肪... 以酶促聚合为代表的绿色高分子合成途径,以其反应条件温和、产物多分散性低、无金属催化剂残留、高度立体和区位选择性等优势,成为医用高分子材料合成领域中的研究热点。目前,氧化还原酶、水解酶、转移酶均成功应用于聚合反应,其中脂肪酶催化的缩聚反应及开环聚合反应研究最为广泛,同时,以可逆加成-断裂链转移聚合和原子转移自由基聚合为代表的酶促可逆失活自由基聚合得到了快速发展。针对酶促聚合中单体及合成产物结构与性能单一、应用范围有限等缺陷,基于酶促聚合与原子转移自由基聚合、开环易位聚合等反应的偶联,制备了多种不同结构与性能的聚合物材料,推动了上述材料在药物与基因递送领域中的应用。本文综述了脂肪酶催化聚合、酶促可逆失活自由基聚合、酶促化学偶联催化等方面的研究进展,并探讨了目前研究的局限性和未来研究方向。 展开更多
关键词 酶促聚合 脂肪酶 酶促化学聚合 可逆失自由聚合 生物医用高分子
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三氟氯乙烯与甲基异丙烯基醚的光诱导共聚反应
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作者 易敬霖 陈茂 《化学学报》 SCIE CAS CSCD 北大核心 2024年第2期126-131,共6页
氟聚合物综合性能优异,在诸多领域发挥了重要作用.三氟氯乙烯(chlorotrifluoroethylene,CTFE)与乙烯基醚共聚物被用于高性能涂料,但其较低的玻璃化转变温度对应用场景带来了局限.在本工作中,发展了CTFE与甲基异丙烯基醚(methyl isoprope... 氟聚合物综合性能优异,在诸多领域发挥了重要作用.三氟氯乙烯(chlorotrifluoroethylene,CTFE)与乙烯基醚共聚物被用于高性能涂料,但其较低的玻璃化转变温度对应用场景带来了局限.在本工作中,发展了CTFE与甲基异丙烯基醚(methyl isopropenyl ether,MIE)的光照自由基共聚反应,在室温常压条件下合成了全新化学结构的氟烯烃与烯基醚共聚物.聚合反应过程符合一级动力学与交替共聚特征,通过控制链转移剂用量与MIE转化率可合成不同分子量的共聚物,表明该聚合反应具备一定的可控性,但共聚物分子量分布较宽、链末端保真度有限.在此基础上,本工作首次揭示了CTFE-MIE共聚物比CTFE-乙烯基乙醚共聚物的玻璃化转变温度提高了近50℃,有助于进一步开发高性能氟聚合物材料. 展开更多
关键词 氟聚合物 共聚物 光照聚合 可逆失自由聚合 三氟氯乙烯
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Cloning and Sequencing of a Lectin Protein Gene from the Roots of Sophora flavescens 被引量:9
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作者 马志刚 鄢波 +2 位作者 黄兴奇 王铃仙 曾仲奎 《Acta Botanica Sinica》 CSCD 2001年第8期821-825,共5页
A lectin protein(SFL) with molecular weight about 32 kD which markedly agglutinated rabbit and human red blood cells was purified from the roots of Sophora flavescens Ait. This protein, and apparently inhibited the gr... A lectin protein(SFL) with molecular weight about 32 kD which markedly agglutinated rabbit and human red blood cells was purified from the roots of Sophora flavescens Ait. This protein, and apparently inhibited the growth of Fusarium vasinfectum Atk., Gibberella saubinetii (Mont.) Sacc., and Piricularia oryzae Cav. A set of degenerate PCR primer was synthesized according to the N-terminal sequence of the purified protein. The full-length cDNA coding the lectin was cloned by RT-PCR and 5'-RACE and sequenced (GenBank AF285121). The deduced amino acid sequence indicates that a preprotein with 284 amino acid residues is firstly translated and then processed to a mature protein with 254 amino acids. A N-Glycosylation site is the Asn 182 residue. 展开更多
关键词 Sophora flavescens LECTIN inhibitory activity CLONING
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Cloning and Expression of Curcin, a Ribosome-Inactivating Protein from the Seeds of Jatropha curcas 被引量:7
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作者 林娟 陈钰 +3 位作者 徐莺 颜钫 唐琳 陈放 《Acta Botanica Sinica》 CSCD 2003年第7期858-863,共6页
Curcin, a ribosome-inactivating protein with a molecular weight of about 28.2 kD, which strongly inhibits the protein synthesis in rabbit reticulocyte lysate system with an IC50 value of about (0.19 +/- 0.01) nmol/L, ... Curcin, a ribosome-inactivating protein with a molecular weight of about 28.2 kD, which strongly inhibits the protein synthesis in rabbit reticulocyte lysate system with an IC50 value of about (0.19 +/- 0.01) nmol/L, was purified from the seeds of Jatropha curcas L. The protein has the activity of rRNA N-glycosidase. Degenerate primers were designed based on the N-terminal partial sequence from purified curcin. The full-length curcin cDNA by RT-PCR and 5'-RACE was cloned. The deduced amino acids sequence indicates that a preprotein with 20 amino acid residues is first translated and then processed to a mature protein with 251 amino acids. The deduced amino acids sequence shares homology of 33% and 57% to those of type I ribosome-inactivating proteins (RIPs) and A chain of type II RIPs, respectively. The sequence encoding mature curcin was integrated into the pQE-30 vector for expression in Escherichia coli strain M15 (pREP4). The purified recombinant curcin was able to inhibit protein synthesis in rabbit reticulocyte lysate system. 展开更多
关键词 Jatropha curcas CURCIN RNA N-glycosidase CLONING in Escherichia coli expression
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Extraction Storage and Qualitative Analysis of Free Radicals Scavenging Substances from Sweet Potato Leaves 被引量:9
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作者 王友升 董银卯 +1 位作者 宋彦 黑维俭 《Agricultural Science & Technology》 CAS 2008年第2期1-5,9,共6页
[ Objective ] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [ Method ] The extraction and storage conditions for free radicals scavenging sub... [ Objective ] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [ Method ] The extraction and storage conditions for free radicals scavenging substances from sweet potato leaves were optimized by orthogonal test and the bioactive components in extracts were investigated by correlation analysis. [ Result] Sweet potato leaves contain the bioactive substances scavenging DPPH free radical and hydroxyl free radical. Extracting solvent species is the most important factor that influencing extraction yield. The optimal extraction and storage conditions are as following: water as solvent, pH 8.0 of extracting liquid, storage at 25 ℃. There is a good positive linear relationship between the content of total phenols in sweet potato leaves and corresponding scavenging rates against both the DPPH free radical and hydroxyl free radical. For the content of total flavones in sweet potato leaves, just a correlation with scavenging rate against hydroxyl free radical shown in test. [ Conclusion] The phenols in ex- tracts could effectively scavenge both the DPPH free radical and hydroxyl free radical, whereas the flavones in extracts can only function on the hydroxyl free radical. 展开更多
关键词 Sweet potato leaves Free radicals scavenging Total phenol Total flavones
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Cloning and Differential Gene Expression of Two Catalases in Suaeda salsa in Response to Salt Stress 被引量:6
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作者 马长乐 王萍萍 +2 位作者 曹子谊 赵彦修 张慧 《Acta Botanica Sinica》 CSCD 2003年第1期93-97,共5页
Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ... Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ( L.) Pall aerial tissue. Sscat1 (1.7 kb) contains a full open reading frame of 492 amino acids and Sscat2 (1.1 kb) is a partial clone. BLAST analysis indicates that the two clones share 71.9% identity in nucleotide sequence and 75% identity in deduced amino acid sequence within the last 287 amino acid residues of Sscat1. Southern blotting analysis showed that Sscat1 is multicopy in S. salsa genome, while Sscat2 is a single copy gene. Northern blotting analysis showed a rapid increase in the steady-level of both genes in roots after 48 It salt treatment, but only Sscat1 was induced in salinity treated leaves. Time-course analysis carried out in leaves confirmed that Sscat1 was induced by salt stress, in contrast to Sscat2. These implied that the expression of Sscat1 and Sscat2 genes are differentially regulated in S. salsa. The activity of total catalase is dramatically increased in response to salt stress. 展开更多
关键词 CATALASE salt stress Suaeda salsa reactive oxygen species
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等温壁面条件壁面反应对微小通道内H_2/空气预混火焰的影响 被引量:2
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作者 冯耀勋 杨浩林 赵黛青 《中国电机工程学报》 EI CSCD 北大核心 2013年第23期84-91,5,共8页
为了考察等温壁面条件下壁面反应对微通道内氢气/空气预混火焰的影响,该文建立了考虑火焰中活性自由基与壁面相互作用的二维数值模拟程序。计算程序中气相燃烧采用氢气详细化学反应动力学机理,壁面反应采用改进的氢气壁面反应机理,改进... 为了考察等温壁面条件下壁面反应对微通道内氢气/空气预混火焰的影响,该文建立了考虑火焰中活性自由基与壁面相互作用的二维数值模拟程序。计算程序中气相燃烧采用氢气详细化学反应动力学机理,壁面反应采用改进的氢气壁面反应机理,改进的壁面反应机理包括5个吸附反应和7个解附反应。计算结果表明:等温壁面时,壁面反应会大量消耗壁面附近的H、O及OH等活性自由基,导致贴近壁面处燃烧反应减弱,靠近壁面处放热量减少甚至消失,进而使火焰总的热量释放率减少,火焰温度及传播速度降低,火焰拉伸减弱。随着壁面温度的升高,壁面反应作用越显著。考虑壁面反应时,壁面H自由基的覆盖度最大,对壁面反应影响最大。 展开更多
关键词 微尺度燃烧 化学熄火 壁面反应 自由 等温壁面
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