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三明治纳米结构的合理构筑实现Fe-N基催化剂酸性环境下高效电催化氧还原
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作者 刘凌云 卢婷静 +3 位作者 施想 王志波 李川 訾振发 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2023年第4期469-476,I0025-I0029,I0035,I0036,共15页
开发具有高活性和高稳定性的非贵金属酸性环境下氧还原反应的催化剂对规模化发展高效质子交换膜燃料电池具有重要意义,但也非常具有挑战性。本文提出了一种快捷的湿化学吸附、热解和后蚀刻策略,有效地将Fe团簇镶嵌在两个氮掺杂碳(NC)层... 开发具有高活性和高稳定性的非贵金属酸性环境下氧还原反应的催化剂对规模化发展高效质子交换膜燃料电池具有重要意义,但也非常具有挑战性。本文提出了一种快捷的湿化学吸附、热解和后蚀刻策略,有效地将Fe团簇镶嵌在两个氮掺杂碳(NC)层之间形成具有三明治夹心的NC/Fe/NC壳层,显著提升了Fe-N基催化剂酸性环境下的氧还原反应性能.所合成的中空夹层NC/Fe/NC催化剂可以在酸性介质中表现出优异的氧还原反应活性,具有0.92V的良好起始电位和高达5.1mA/cm^(2)的扩散极限电流密度.此外,三明治结构的NC/Fe/NC催化剂在酸性环境下具有很强的甲醇耐受性和出色电化学稳定性,是极具潜力的高效质子交换膜燃料电池氧还原催化剂.同步辐射表征结合X射线光电子能谱分析表明,NC/Fe/NC催化剂的NC/Fe/NC三明治壳层中存在大量的Fe-N化学键和强的界面电子耦合作用,其对催化剂电化学活性和耐腐蚀性的提升有很大帮助,是NC/Fe/NC催化剂酸性环境下高氧还原性能的根本来源. 展开更多
关键词 三明治纳米结构 Fe-N基催化剂 酸性环境下氧还原电催化 长期耐受性 电催化
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A viral vector expressing hypoxia-inducible factor 1 alpha inhibits hippocampal neuronal apoptosis 被引量:4
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作者 Xiqing Chai Weina Kong +3 位作者 lingyun liu Wenguo Yu Zhenqing Zhang Yimin Sun 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第11期1145-1153,共9页
Hypoxia-inducible factor 1 (HIF-1) attenuates amyloid-beta protein neurotoxicity and decreases apoptosis induced by oxidative stress or hypoxia in cortical neurons. In this study, we construct-ed a recombinant adeno... Hypoxia-inducible factor 1 (HIF-1) attenuates amyloid-beta protein neurotoxicity and decreases apoptosis induced by oxidative stress or hypoxia in cortical neurons. In this study, we construct-ed a recombinant adeno-associated virus (rAAV) vector expressing the human HIF-1αgene (rAAV-HIF-1α), and tested the assumption that rAAV-HIF-1αrepresses hippocampal neuronal apoptosis induced by amyloid-beta protein. Our results conifrmed that rAAV-HIF-1αsigniifcant-ly reduces apoptosis induced by amyloid-beta protein in primary cultured hippocampal neurons. Direct intracerebral rAAV-HIF-1αadministration also induced robust and prolonged HIF-1αproduction in rat hippocampus. Single rAAV-HIF-1αadministration resulted in decreased apoptosis of hippocampal neurons in an Alzheimer's disease rat model established by intrace-rebroventricular injection of aggregated amyloid-beta protein (25-35). Our in vitro and in vivo ifndings demonstrate that HIF-1 has potential for attenuating hippocampal neuronal apoptosis induced by amyloid-beta protein, and provides experimental support for treatment of neurode-generative diseases using gene therapy. 展开更多
关键词 nerve regeneration Alzheimer's disease adeno-associated virus hypoxia-inducible fac-tor 1~ apoptosis gene therapy calcium concentration TRANSDUCTION intracerebroventricular injec-tion NSFC grant neural regeneration
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Analysis on Sequence and Elements of Cucumisin Promoter
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作者 Siming HOU lingyun liu Xiaohong YANG 《Agricultural Biotechnology》 CAS 2017年第2期19-21,44,共4页
Abstract Leaves of melon were collected and extracted by the CTAB method for total DNA which was used for PCR amplification, obtaining the gene sequence of cucumisin promoter. The sequence results were processed and a... Abstract Leaves of melon were collected and extracted by the CTAB method for total DNA which was used for PCR amplification, obtaining the gene sequence of cucumisin promoter. The sequence results were processed and analyzed with DNAman, DNAstar and other softwares, and bioinformatic element analysis was performed with PlantCARE and PLACE. The analysis results showed that the cucumisin promoter shared 100%, 99% and 99% homology with AY055805, LN713264 and LN681897, respectively. The promoter sequence contains a variety of c/s-acting elements common in fruit promoters of higher plants such as TATA-Box and CAAT-Box, and light-responsive elements, some of which involved in ABA and VP1 responsiveness and salicylic acid responsiveness. This study provides a scien- tific basis for further research on genetic engineering of fruits. 展开更多
关键词 Fruit promoter Sequence analysis Melon gene Bioinformatics analysis Cis-acting elements
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Circular RNA circCCNB1 inhibits the migration and invasion of nasopharyngeal carcinoma through binding and stabilizing TJP1 mRNA 被引量:5
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作者 Mengyao Zhao Yian Wang +17 位作者 Fenghua Tan lingyun liu Xiangchan Hou Chunmei Fan Le Tang Yongzhen Mo Yumin Wang Qijia Yan Zhaojian Gong Zheng Li Qianjin Liao Can Guo He Huang Xi Zeng Guiyuan Li Zhaoyang Zeng Wei Xiong Fuyan Wang 《Science China(Life Sciences)》 SCIE CAS CSCD 2022年第11期2233-2247,共15页
Nasopharyngeal carcinoma(NPC)is a malignant tumor that usually occurs in people from Southeast Asia and Southern China.NPC is prone to migration and invasion,leading to poor prognosis.A large number of circular RNAs(c... Nasopharyngeal carcinoma(NPC)is a malignant tumor that usually occurs in people from Southeast Asia and Southern China.NPC is prone to migration and invasion,leading to poor prognosis.A large number of circular RNAs(circ RNAs)exacerbate the process of metastasis in NPC;however,their underlying mechanisms remain unclear.We found that the circular RNA circ CCNB1,encoded by the oncogene CCNB1,was downregulated in NPC biopsies and cell lines.In vitro assays show that circ CCNB1 inhibits NPC cell migration and invasion.Moreover,circ CCNB1 induces a protein,nuclear factor 90(NF90),to bind and prolong the half-life of tight junction protein 1(TJP1)m RNA.Upregulation of TJP1 enhances tight junctions between cancer cells and inhibits NPC cell migration and invasion.This study reveals a novel biological function of circ CCNB1 in the migration and invasion of NPC by enhancing the tight junctions of cancer cells by binding to NF90 proteins and TJP1 m RNA,and may provide a potential therapeutic target for NPC. 展开更多
关键词 nasopharyngeal carcinoma circCCNB1 NF90 TJP1 migration and invasion
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染色质调节元件与不同启动子的相互作用对基因表达调控的影响 被引量:3
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作者 王斌 郭庆 +5 位作者 刘凌云 李美荃 戴利利 陈奇娜 刘雪莉 翟书华 《生物工程学报》 CAS CSCD 北大核心 2021年第9期3310-3322,共13页
为探究DNA序列元件对不同启动子调节转基因稳定表达的影响,利用遍在染色质开放元件(Ubiquitous chromatin opening elements,UCOE)和基质黏附序列(Scaffold/matrix-attachment regions,MAR)分别与含增强子的oct4基因启动子、含CpG岛的s... 为探究DNA序列元件对不同启动子调节转基因稳定表达的影响,利用遍在染色质开放元件(Ubiquitous chromatin opening elements,UCOE)和基质黏附序列(Scaffold/matrix-attachment regions,MAR)分别与含增强子的oct4基因启动子、含CpG岛的sox2基因启动子和不含调控元件的nanog基因启动子以及同时包含增强子和CpG岛的CMV启动子组合构建pOCT4-MAR、pOCT4-UCOE、pSOX2-MAR、pSOX2-UCOE、pNANOG-MAR、pNANOG-UCOE、pCMV-UCOE、pCMV-MAR等质粒,分析这些质粒稳定转染后的表达量和嵌合表达差异。结果发现,UCOE与含增强子元件的oct4启动子组合能较稳定高效表达,而MAR与含CpG岛的sox2启动子组合能较稳定高效表达。利用排除位置效应原因的嵌合表达对染色质高级结构调控基因表达的稳定性分析表明:(1)通常情况下UCOE比MAR调节的表达载体的表达更高效和更稳定;UCOE连接含CpG岛的启动子形成开放染色质调节的高表达更稳定;(2)MAR与启动子上TATA盒或增强子可能通过染色质环产生高表达,但相对不稳定。结论:染色质调节元件UCOE和MAR与启动子调控元件之间能通过染色质开放状态或染色质环调控基因稳定表达。 展开更多
关键词 染色质调节序列 启动子调控元件 开放染色质 染色质环
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Simultaneous determination of free methamphetamine,pethidine,ketamine and tramadol in urine by dispersive liquid–liquid microextraction combined with GC–MS 被引量:3
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作者 Fangmin Xu lingyun liu 《Forensic Sciences Research》 CSCD 2019年第2期188-194,共7页
A simple and rapid dispersive liquid–liquid microextraction(DLLME)technique coupled with gas chromatography–ion trap mass spectrometry(GC–MS)was developed for the extraction and analysis of methamphetamine(MA),peth... A simple and rapid dispersive liquid–liquid microextraction(DLLME)technique coupled with gas chromatography–ion trap mass spectrometry(GC–MS)was developed for the extraction and analysis of methamphetamine(MA),pethidine(PD),ketamine(KT)and tramadol(TD)from human urine.In this study,different parameters affecting the extraction process such as the type and volume of extraction solvent,type and volume of disperser solvent,extraction time and pH value and salt effect were studied and optimized.Under optimized conditions,the enrichment factor ranged from 185 to 226 and the average recovery ranged from 80.45%to 95.55%.The linear range was 10.0–1000.0 mg/L,the limit of detection and quantitation were in the range 0.43–1.96 mg/L and 1.44–6.53 mg/L,respectively.The relative standard deviations were in the range 1.98%–3.90%(n=7).The obtained results show that DLLME combined with GC–MS is a fast and simple method for the determination of MA,PD,KT and TD in human urine. 展开更多
关键词 Forensic science forensic toxicology dispersive liquid–liquid microextraction gas chromatography mass spectrometry urine drug abuse sample pretreatment
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MeNA, Controlled by Reversible Methylation of Nicotinate, Is an NAD Precursor that Undergoes Long-Distance Transport in Arabidopsis 被引量:2
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作者 Ranran Wu Fengxia Zhang +3 位作者 lingyun liu Wei Li Eran Pichersky Guodong Wang 《Molecular Plant》 SCIE CAS CSCD 2018年第10期1264-1277,共14页
Nicotinamide adenine dinucleotide (NAD) biosynthesis, including synthesis from aspartate via the de novo pathway and from nicotinate (NA) via the Preiss-Handler pathway, is conserved in land plants. Diverse spe-ci... Nicotinamide adenine dinucleotide (NAD) biosynthesis, including synthesis from aspartate via the de novo pathway and from nicotinate (NA) via the Preiss-Handler pathway, is conserved in land plants. Diverse spe-cies of NA conjugates, which are mainly involved in NA detoxification, were also found in all tested land plants. Among these conjugates, MeNA (NA methyl ester) has been widely detected in angiosperm plants, although its physiological function and the underlying mechanism for its production in planta remain largely unknown. Here, we show that MeNA is an NAD precursor undergoing more efficient long-distance trans-port between organs than NA and nicotinamide in Arabidopsis. We found that Arabidopsis has one meth- yltransferase (designated AtNaMT1) capable of catalyzing carboxyl methylation of NA to yield MeNA and one methyl esterase (MES2) predominantly hydrolyzing MeNA back to NA. We further uncovered that the transfer of [^14C]MeNA from the root to leaf was significantly increased in both MES2 knockdown and NaMTl-overexpressing lines, suggesting that both NaMT1 and MES2 fine-tune the long-distance transport of MeNA, which is ultimately utilized for NAD production. Abiotic stress (salt, abscisic acid, and mannitol) treatments, which are known to exacerbate NAD degradation, induce the expression of NaMT1 but sup-press MES2 expression, suggesting that MeNA may play a role in stress adaption. Collectively, our study indicates that reversible methylation of NA controls the biosynthesis of MeNA in Arabidopsis, which pre-sumably functions as a detoxification form of free NA for efficient long-distance transport and eventually NAD production especially under abiotic stress, providing new insights into the relationship between NAD biosynthesis and NA conjugation in plants. 展开更多
关键词 NICOTINATE METHYLTRANSFERASE ESTERASE long-distance transport NAD
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Determination of five endosulfan pesticides in the fish pond water by dispersive liquid–liquid microextraction combined with GC–MS
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作者 Fangmin Xu lingyun liu +1 位作者 Wanli Wei Ruolun Xu 《Forensic Sciences Research》 2017年第1期40-45,共6页
A simple and rapid dispersive liquid-liquid microextraction(DLLME)technique coupled with gas chromatography-ion trap mass spectrometry(GC-MS)was developed for the extraction and analysis of five endosulfan pesticides ... A simple and rapid dispersive liquid-liquid microextraction(DLLME)technique coupled with gas chromatography-ion trap mass spectrometry(GC-MS)was developed for the extraction and analysis of five endosulfan pesticides from the fish pond water.In this work,different parameters affecting the extraction process such as the type and volume of extraction solvent,type and volume of disperser solvent,and extraction time were studied and optimized.Under optimized conditions,the enrichment factor ranged from 189 to 269 and the relative recovery ranged from 88.5%to 94.9%.The linear range was 2.0-80.0 mg/L;the limits of detection and quantitation were in the range 0.04-1.06 mg/L and 0.12-3.53 mg/L,respectively.The relative standard deviations were in the range 0.94%-2.08%(n D 5).The obtained results show that DLLME combined with GC-MS is a fast and simple method for the determination of endosulfan pesticides in fish pond water. 展开更多
关键词 Forensic science forensic toxicology gas chromatography–mass spectrometry liquid–liquid microextraction analytic sample preparation methods ENDOSULFAN PESTICIDES fish pond water
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