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A Case of Acute Upper Gastrointestinal Bleeding in Liver Cirrhosis Complicated by Acute Cerebral Infarction and Acute Myelitis
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作者 Xiaohui Liao Tengteng Xu +3 位作者 xianhua zhang Xianliang Mi Changqing Yang Zibai Wei 《Journal of Biosciences and Medicines》 CAS 2023年第5期303-309,共7页
Background: Acute upper gastrointestinal bleeding in liver cirrhosis combined with acute cerebral infarction is uncommon in clinical work, and then combined with acute myelitis is even rarer and more complex, which po... Background: Acute upper gastrointestinal bleeding in liver cirrhosis combined with acute cerebral infarction is uncommon in clinical work, and then combined with acute myelitis is even rarer and more complex, which poses a greater challenge to clinical diagnosis and treatment. This paper reports a case of acute upper gastrointestinal bleeding in liver cirrhosis complicated by acute cerebral infarction and acute myelitis, which be hoped to provide a reference for clinical work. Methods: We retrospectively evaluated the clinical information of a 68-year-old female admitted to the Digestive Medical Department with acute gastrointestinal bleeding and appeared limb movement disorder on the third day. Results: The patient was eventually diagnosed with acute upper gastrointestinal bleeding in liver cirrhosis complicated by acute cerebral infarction and acute myelitis. Conclusions: When patients with liver cirrhosis have abnormal neurological symptoms, in addition to liver cirrhosis-related complications, doctors need to consider cerebrovascular diseases and myelitis. 展开更多
关键词 Liver Cirrhosis Upper Gastrointestinal Bleeding Acute Cerebral Infarction Acute Myelitis
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Chemical looping oxidative propane dehydrogenation controlled by oxygen bulk diffusion over FeVO_(4)oxygen carrier pellets 被引量:1
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作者 Hongbo Song Wei Wang +5 位作者 Jiachen Sun Xianhui Wang xianhua zhang Sai Chen Chunlei Pei Zhi-Jian Zhao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第1期409-420,共12页
The oxygen distribution and evolution within the oxygen carrier exert significant influence on chemical looping processes.This paper describes the influence of oxygen bulk diffusion within FeVO4 oxygen carrier pellets... The oxygen distribution and evolution within the oxygen carrier exert significant influence on chemical looping processes.This paper describes the influence of oxygen bulk diffusion within FeVO4 oxygen carrier pellets on the chemical looping oxidative propane dehydrogenation(CL-ODH).During CL-ODH,the oxygen concentration at the pellet surface initially decreased and then maintained stable before the final decrease.At the stage with the stable surface oxygen concentration,the reaction showed a stable C3H6 formation rate and high C3H6 selectivity.Therefore,based on Fick’s second law,the oxygen distribution and evolution in the oxygen carrier at this stage were further analyzed.It was found that main reactions of selective oxidation and over-oxidation were controlled by the oxygen bulk diffusion.C3H8 conversion rate kept decreasing during this stage due to the decrease of the oxygen flux caused by the decline of oxygen gradient within the oxygen carrier,while C3H6 selectivity increased due to the decrease of overoxidation.In addition,reaction rates could increase with the propane partial pressure due to the increase of the oxygen gradient within the oxygen carrier until the bulk transfer reached its limit at higher propane partial pressure.This study provides fundamental insights for the diffusion-controlled chemical looping reactions. 展开更多
关键词 Chemical looping DIFFUSION Reaction kinetics Oxygen carriers OXIDATION
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Comparative DNA-methylome and transcriptome analysis reveals heterosis-and polyploidy-associated epigenetic changes in rice
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作者 Xiaolan Rao Jun Ren +12 位作者 Wei Wang Rongrong Chen Qian Xie Yanqing Xu Dongmei Li Zhaojian Song Yuchi He Detian Cai Pingfang Yang Shiyou Lyu Li Li Wei Liu xianhua zhang 《The Crop Journal》 SCIE CSCD 2023年第2期427-437,共11页
Heterosis and polyploidy have an overwhelming influence on plant evolution.Recently,polyploid rice hybrids have been used to breed new rice varieties because they combine the advantages of both heterosis and polyploid... Heterosis and polyploidy have an overwhelming influence on plant evolution.Recently,polyploid rice hybrids have been used to breed new rice varieties because they combine the advantages of both heterosis and polyploidy.In this study,we generated six rice lines:autotetraploid rice hybrids and their autotetraploid parents,diploid donors,and hybrids of the diploid donors.To investigate the molecular mechanism controlling the effects of both hybridization and polyploidization,we performed bisulfite and RNA sequencing on young panicles at the pollen meiosis stage to compare the DNA metabolomes and transcriptomes among the six rice lines.The hybrids lines were hypermethylated compared to their corresponding parents and the autotetraploid lines showed globally increased DNA methylation of their transposable elements compared to the diploid donors.The alteration in DNA methylation level corresponded to the differential gene expressions among the rice genotypes,suggesting that methylation changes induced by polyploidization and hybridization may affect gene expression.Groups of gene candidates were identified that may be associated with heterosis and polyploidy.Our results provide DNA information that can be used to investigate epigenetic modification during heterosis and polyploidy in rice. 展开更多
关键词 Oryza sativa Neotetraploid rice HETEROSIS Whole genome duplication Epigenetic changes
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La掺杂TiO_2负载Pt催化剂制备及其室温氧化低浓度甲醛(英文) 被引量:11
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作者 彭洪根 应家伟 +6 位作者 张景岩 张先华 彭程 饶成 刘文明 张宁 王翔 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第1期39-47,共9页
甲醛是室内装修污染的重要组分,已严重危害到人们身体健康,在室温条件下消除甲醛引起了人们的广泛兴趣.目前室温清除甲醛主要有物理吸附法、光催化法、等离子体技术及催化氧化技术.物理吸附法主要采用活性炭等作为吸附剂,其初期吸附效... 甲醛是室内装修污染的重要组分,已严重危害到人们身体健康,在室温条件下消除甲醛引起了人们的广泛兴趣.目前室温清除甲醛主要有物理吸附法、光催化法、等离子体技术及催化氧化技术.物理吸附法主要采用活性炭等作为吸附剂,其初期吸附效果较好,但当吸附饱和之后会重新释放甲醛造成二次污染;光催化法和等离子体技术需要特殊装置,不适合室内室温环境脱除甲醛;而催化氧化技术则可直接将甲醛转化为无毒无害的水和CO2,因而备受关注.Pt/TiO_2被认为是目前消除甲醛最有效的催化剂.为进一步降低贵金属Pt的用量及增强其稳定性(Pt被氧化后其活性会降低),本文首次采用稀土La掺杂锐钛矿型TiO_2,负载少量Pt后用于室内低浓度(0.5 ppm)甲醛的催化氧化.活性测试结果表明,纯TiO_2催化剂上甲醛转化率在5%以下,有可能是物理吸附或可见光催化所致.负载0.5%Pt后,Pt/TiO_2和Pt/La-TiO_2甲醛转化率均高于80%,尤其是La掺杂活性高达96%以上,且在连续反应8 h甚至延长至40 h后其活性均未见下降趋势.电镜结果表明,La掺杂Pt/La-TiO_2催化剂中Pt粒径从未掺杂的2.2 nm降至1.7 nm;CO程序升温脱附测试表明,Pt/La-TiO_2/Pt的分散度达66%,而未掺杂样品仅为51%;X射线光电子能谱测试表明,Pt/La-TiO_2的表面氧物种高于Pt/TiO_2催化剂,说明La掺杂增强了Pt和载体间的相互作用.为探讨Pt/La-TiO_2商业化应用前景,将粉体Pt/La-TiO_2涂覆在堇青石蜂窝陶瓷上制备成整体催化剂.该整体催化剂在容积为2 m3的密室测试中5 min内即可将浓度为0.5 ppm的甲醛将至0.02 ppm以下.该催化剂在存放3个月后活性略有下降,但在10 min内仍可将甲醛浓度降至0.08ppm,达到室内甲醛排放标准.综上,本文成功制备了La掺杂Pt/La-TiO_2用于室内低浓度甲醛催化氧化,该催化剂表现出优异的催化性能.通过多种表征手段表明,La修饰后贵金属Pt纳米粒子尺寸减小、分散度提高及Pt与载体间相互作用增强是其活性优异的主要原因.以Pt/La-TiO_2粉体制备的整体催化剂同样表现出了高的催化性能,具有工业应用前景. 展开更多
关键词 低浓度甲醛 室温氧化 稀土 镧掺杂 二氧化钛 整体催化剂
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基于FeWOx/SiO2载氧体的甲烷化学链部分氧化反应 被引量:4
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作者 刘蕊 裴春雷 +5 位作者 张先华 陈赛 李洪芳 曾亮 慕仁涛 巩金龙 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第7期1140-1151,共12页
甲烷具有价格低廉且储量丰富的优点,因此将甲烷转化为合成气(一种H2:CO为2的混合物),从而进一步合成有价值的化学品和液体燃料引起了人们的极大关注.化学链甲烷部分氧化(CLPOM)技术能避免甲烷与空气直接接触而引起爆炸的危险,可以降低... 甲烷具有价格低廉且储量丰富的优点,因此将甲烷转化为合成气(一种H2:CO为2的混合物),从而进一步合成有价值的化学品和液体燃料引起了人们的极大关注.化学链甲烷部分氧化(CLPOM)技术能避免甲烷与空气直接接触而引起爆炸的危险,可以降低后续对合成气与氮气分离操作所带来的费用,因此日益受到关注.CLOPM过程主要分为两步:第一步,CH4被载氧体所携带的氧部分氧化,载氧体被还原;第二步,利用氧化剂(例如空气)将被还原的载氧体再氧化恢复.因此,载氧体在CLOPM过程中起到至关重要的作用.载氧体的选择主要存在两个问题:(1)甲烷被活化所产生含碳产物的能力与晶格氧的给氧能力不匹配所带来的严重碳沉积;(2)金属离子间扩散速率不匹配而造成载氧体在氧化还原过程中结构的不可逆变化.基于上述两个问题,本文设计了FeWOx/SiO2载氧体用于CLPOM.与未改性的WO3/SiO2载氧体相比,甲烷的转化率和合成气的收率都有显著提高.FeWOx/SiO2在900℃、1 atm反应条件下表现出62%的甲烷转化率、93%的CO气相选择性、94%的H2选择性和2.4的H2/CO比值,同时在50个循环中表现出优异的催化活性和稳定性.本工作利用CH4脉冲反应研究了FeWOx/SiO2的甲烷表面反应过程;采用CH4-TPR和H2-TPR相结合探究了甲烷活化速率与晶格氧扩散速率之间的关系;通过XPS和XRD对FeWOx/SiO2在氧化还原过程中的结构稳定性进行了探讨.综合上述实验结果,对FeWOx/SiO2应用于CLPOM的反应机理进行了阐述.H2-TPR结果表明,在FeWOx/SiO2中,相较于Fe2O3/SiO2,Fe-O的活性受到抑制,使其更倾向于与甲烷发生部分氧化反应;相较于WO3/SiO2,W-O的活性得到明显提升,因此更多的晶格氧可以参与到部分氧化反应中来氧化积碳,从而使合成气收率大幅度提升.从CH4-TPR结果可以看出,对于FeWOx/SiO2,CO与H2的生成温度最接近,意味着晶格氧的传输速率较快并且能够与甲烷活化产生含碳中间物种的速率相匹配,将其及时氧化生成CO,避免由于积碳造成的催化剂失活.结合XPS和XRD结果可以得出,在甲烷还原过程中,FeWOx经历一步还原形成Fe-W合金,由于其间存在强相互作用,因而抑制了还原过程中催化剂相分离现象的发生.同时,根据铁钨离子在空气条件下扩散速率的公式计算可以得出,其相近的离子氧化速率也保证了在氧化过程中催化剂结构的稳定性.本工作为进一步构建用于甲烷化学链部分氧化制合成气的复合金属氧化物载氧体提供了研究思路. 展开更多
关键词 Fe-W合金 甲烷活化 晶格氧扩散 相分离 离子氧化速率
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Dry reforming of methane on active and coke resistant Ni/Y_2Zr_2O_7 catalysts treated by dielectric barrier discharge plasma 被引量:3
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作者 Xiuzhong Fang Jie Lian +7 位作者 Kaiwen Nie xianhua zhang Yanfeng Dai Xianglan Xu Xiang Wang Wenming Liu Changqing Li Wufeng Zhou 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第5期825-831,共7页
In this study, Ni/YZrOcatalysts prepared with impregnation method and treated by dielectric barrier discharge plasma(DBD) in different atmospheres have been investigated for methane dry reforming. It is revealed by H-... In this study, Ni/YZrOcatalysts prepared with impregnation method and treated by dielectric barrier discharge plasma(DBD) in different atmospheres have been investigated for methane dry reforming. It is revealed by H-TPR that plasma treatment can enhance the interaction between Ni O/Ni particles and the YZrOpyrochlore support. Therefore, catalysts with smaller Ni O and Ni grains sizes, higher metallic Ni active surface areas can be achieved, as evidenced by XRD, TEM and Hadsorption-desorption measurements. As a consequence, the plasma-treated catalysts show significantly improved activity, stability and coke resistance, as testified by the TEM and TGA-DSC results. Plasma treatment in H/Ar gas mixture is found to be the best condition to prepare Ni/YZrO, which can be used to obtain a catalyst with the highest activity, stability and most potent coke resistance. It is believed that the smaller Ni grain size and higher metallic Ni active surface area induced by plasma treatment are the inherent reasons accounting for the promoted reaction performance of the Ni/YZrOpyrochlore catalysts. 展开更多
关键词 Plasma treatment Y2Zr2O7 pyrochlore support Supported Ni catalysts Methane dry reforming Coke resistance
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Conversion of syngas to methanol and DME on highly selective Pd/ZnAl_(2)O_(4) catalyst
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作者 Liang Liu Zenan Lin +8 位作者 Shanya Lin Yeyun Chen Lina zhang Shaopeng Chen xianhua zhang Jingdong Lin Zhaoxia zhang Shaolong Wan Yong Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第7期564-572,共9页
Supported Pd catalysts with varied Pd loadings(x=0.5 wt%, 2.0 wt%, 5.0 wt%, 7.5 wt%, 15.0 wt%) were prepared by the incipient wetness impregnation method using a ZnAl_(2)O_(4) spinel support.We found that ZnAl_(2)O_(4... Supported Pd catalysts with varied Pd loadings(x=0.5 wt%, 2.0 wt%, 5.0 wt%, 7.5 wt%, 15.0 wt%) were prepared by the incipient wetness impregnation method using a ZnAl_(2)O_(4) spinel support.We found that ZnAl_(2)O_(4) supported Pd catalysts with low Pd loadings(e.g., 0.5 wt%) are very selective in syngas conversion to methanol and dimethyl-ether(DME).XRD and TEM characterization shows that,after reduction at350℃,PdZnβ phase with Pd:Zn molar ratio of 1:1 is favored to form predominantly on the spinel support at relatively low Pd loadings,i.e.less than 5.0 wt%, while Pd-rich PdZnα alloy phase exists at Pd loadings above 5.0 wt%.A higher reduction temperature such as 500℃ can facilitate the transformation from PdZnα to PdZnβ phase in those catalysts with high Pd loading.We further found that catalysts with predominant PdZnβ phase are selective in the methanol and DME production from syngas,while the presence of PdZnα phase leads to the notable formation of alkanes byproducts,resulting in reduced methanol and DME selectivity.DME formation from dehydration of methanol depends on the acidity of catalysts,which was found to increase with Pd loading,probably due to the formation of isolated Al_(2)O_(3) as a result of Zn migrating from ZnAl_(2)O_(4) spinel phase to form the PdZn phases with Pd. 展开更多
关键词 Pd/ZnAl_(2)O_(4) SYNGAS METHANOL Dimethyl ether
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Prokaryotic Expression and Antigenic Analysis of Wbkc Gene from Brucella abortus
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作者 Xiangyang LI Xueli WANG +4 位作者 Kai LIU Xiaowei HUO Yinghong WU xianhua zhang Jiabao zhang 《Agricultural Biotechnology》 CAS 2014年第2期51-53,共3页
[ Objective ] This study aimed to clone and express formyltransferase (Wbkc) gene from Brucella abortus in E. coli, purify the expressed protein and analyze its immunogenicity. [Method] A gene encoding 27 -35 ku for... [ Objective ] This study aimed to clone and express formyltransferase (Wbkc) gene from Brucella abortus in E. coli, purify the expressed protein and analyze its immunogenicity. [Method] A gene encoding 27 -35 ku formyltransferase (Wbkc) was amplified from the genomic DNA of BruceUa abortus by PCR. The amplified fragments were digested with BamH I and Sal I, and inserted into pET28a vector. The constructed recombinant plasmid pET 28a-Wbkc was trans- formed into E. coli BL21 and was induced to express the fusion protein. Subsequently, the protein was purified by histidine-binding resin column chromatography, and the immunogenicity was detected by Western blot assay. The recombinant plasmid was identified by colony PCR, double digestion and sequencing analysis. [ Result] Wbkc was successfully cloned and expressed in E. coli. A specific protein band of 29 ku was detected by SDS-PAGE. Western blot showed specific im- munoreactivity of the purified fusion protein. [ Conclusion] This study provided a solid foundation for further investigating diagnostic proteins for brucellosis and developing Brucella gene-deletion vaccines. 展开更多
关键词 Brucella abortus Formyltransferase (Wbkc) gene Prokaryotic expression ANTIGENICITY
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调控氧传输以实现甲烷化学链部分氧化表面和体相速率的匹配 被引量:1
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作者 杨婷婷 罗冉 +5 位作者 石向成 张先华 吴仕灿 裴春雷 赵志坚 巩金龙 《Science China Materials》 SCIE EI CAS CSCD 2024年第4期1217-1224,共8页
甲烷化学链部分氧化(CL-POM)是一种有前景的合成气生产技术,具有高选择性和低爆炸风险的优势.然而,开发性能优异、可持续释氧的金属载氧体仍然面临挑战.为此,本研究设计了一种复合载氧体(LaFeO_(3-δ)/Ca_(1-η)Sr_(η)MnO_(3)),通过调... 甲烷化学链部分氧化(CL-POM)是一种有前景的合成气生产技术,具有高选择性和低爆炸风险的优势.然而,开发性能优异、可持续释氧的金属载氧体仍然面临挑战.为此,本研究设计了一种复合载氧体(LaFeO_(3-δ)/Ca_(1-η)Sr_(η)MnO_(3)),通过调控Ca_(1-η)Sr_(η)MnO_(3)的氧扩散来维持LaFeO_(3-δ)(121)缺陷表面的活性结构,从而提升了CL-POM的活性和选择性.理论计算结果表明,甲烷在LaFeO_(3-δ)(121)缺陷表面上的反应活性位点主要是Fe-O_(4)(O_(V))和Fe-O_(3)(O_(V))_(2),它们表现出相近的反应能垒(ΔG_(a)=1.44和1.40 eV).氧扩散系数和表面反应速率常数分别由体相氧迁移能垒和表面反应能垒确定,进而计算得到体相氧扩散和表面反应的速率,用以评估两者的匹配程度.最后,本研究证实了LaFeO_(3-δ)/Ca_(0.75)-Sr_(0.25)MnO_(3)是一种有潜力的CL-POM载氧体,其能够实现体相氧扩散速率与表面氧消耗速率的合理匹配,并有效地抑制不利的相变过程. 展开更多
关键词 反应速率常数 表面反应 载氧体 化学链 氧扩散 部分氧化 活性结构 氧化表面
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Glycolysis regulates gene expression by promoting the crosstalk between H3K4 trimethylation and H3K14 acetylation in Saccharomyces cerevisiae
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作者 Yinsheng Wu Shihao zhang +7 位作者 Xuanyunjing Gong Qi Yu Yuan zhang Mingdan Luo xianhua zhang Jerry L.Workman Xilan Yu Shanshan Li 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2019年第12期561-574,共14页
Cells need to coordinate gene expression with their metabolic states to maintain cell homeostasis and growth.However,how cells transduce nutrient availability to appropriate gene expression response via histone modifi... Cells need to coordinate gene expression with their metabolic states to maintain cell homeostasis and growth.However,how cells transduce nutrient availability to appropriate gene expression response via histone modifications remains largely unknown.Here,we report that glucose specifically induces histone H3K4 trimethylation(H3K4me3),an evolutionarily conserved histone covalent modification associated with active gene transcription,and that glycolytic enzymes and metabolites are required for this in?duction.Although glycolysis supplies S-adenosylmethionine for histone methyltransferase Setl to catalyze H3K4me3,glucose induces H3K4me3 primarily by inhibiting histone demethylase Jhd2-catalyzed H3K4 demethylation.Glycolysis provides acetyl-CoA to stimulate histone acetyltransferase Gcn5 to acetylate H3K14,which then inhibits the binding of Jhd2 to chromatin to increase H3K4me3.By repressing Jhd2-mediated H3K4 demethylation,glycolytic enzymes regulate gene expression and cell survival during chronological aging.Thus,our results elucidate how cells reprogram their gene expression programs in response to glucose availability via histone modifications. 展开更多
关键词 Gene transcription GLYCOLYSIS HISTONE modifications YEAST H3K4me3 H3K14ac
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