检索结果-南通市图书馆

Virologica Sinica 2022年第3期37卷 358-369页

作者： Yujing Huang Xin Guo Jing Zhang Jianming Li Mingyi Xu Qing Wang Zhongyang Liu yanping ma Ying Qi Qiang Ruan Virology Laboratory Shengjing Hospital of China Medical UniversityShenyang110004China Department of Pediatrics Shengjing Hospital of China Medical UniversityShenyang110004China Department of Obstetrics and Gynecology Shengjing Hospital of China Medical UniversityShenyang110004China Department of Pediatrics The Fourth Affiliated HospitalChina Medical UniversityShenyang110033China

Human cytomegalovirus(HCMV)is a ubiquitous pathogen belongs to betaherpesvirus subfamily.RNA2.7 is a highly conserved long non-coding RNA accounting for more than 20%of total viral transcripts.In our study,functions of HCMV RNA2.7 were investigated by comparison of host cellular transcriptomes between cells infected with HCMV clinical strain and RNA2.7 deleted mutant.It was demonstrated that RNA polymeraseⅡ(PolⅡ)-dependent host gene transcriptions were significantly activated when RNA2.7 was removed during infection.A145 nt-in-length motif within RNA2.7 was identified to inhibit the phosphorylation of PolⅡSerine-2(PolⅡS2)by reducing the interaction between PolⅡand phosphorylated cyclin-dependent kinase 9(pCDK9).Due to the loss of PolⅡS2 phosphorylation,cellular DNA pre-replication complex(pre-RC)factors,including Cdt1 and Cdc6,were significantly decreased,which prevented more cells from entering into S phase and facilitated viral DNA replication.Our results provide new insights of HCMV RNA2.7 functions in regulation of host cellular transcription.

关键词： Human cytomegalovirus(HCMV) RNA2.7 RNA polymeraseⅡ(PolⅡ) Cyclin-dependent kinase 9(CDK9) Phosphorylation

Dissipative particle dynamics thermostat: a novel thermostat for molecular dynamics simulation of liquid crystals with Gay–Berne potential

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2015年第4期58卷 694-707页

作者： Yuting Ouyang Liang Hao yanping ma Hongxia Guo Beijing National Laboratory for Molecular Sciences (BNLMS) State Key Laboratory for Polymer Physics and ChemistryInstitute of Chemistry Chinese Academy of Sciences

The Gay–Berne(GB) model has been proved to be highly successful in the simulation of liquid crystal phases via both molecular dynamics(MD) and nonequilibrium molecular dynamics(NEMD). However, the conventional thermostats used in the simulations of GB systems, such as Nosé–Hoover and Langevin thermostats, have serious shortcomings especially in NEMD simulations. Recently, dissipative particle dynamics(DPD) has established itself as a useful thermostat for soft matter simulations, whereas the application of DPD thermostat in(NE)MD simulations is limited to the spherically isotropic potential models, such as the Lennard–Jones model. Considering the virtues of the DPD thermostat, that is, local, momentum conserved, and Galilean invariant, we extend the DPD thermostat to the non-spherical GB model. It is interesting to find that the translational DPD and rotational DPD thermostats can be used in the GB system independently and both can achieve the thermostatting effects. Also, we compared the performance of the DPD thermostat with other commonly used thermostats in NEMD simulations by investigating the streaming velocity profiles and the dynamics of phase separation in a typical but simple binary GB mixture under shear field. It is revealed that the known virtues of DPD thermostats, such as Galilean invariant, shear velocity profile-unbiased, and unscreened hydrodynamic interactions, are still intact when applying to GB systems. Finally, the appropriate parameters for the DPD thermostat in the GB system are identified for future investigations.

关键词：分子动力学模拟耗散粒子动力学恒温器温控器液晶相同性恋非平衡分子动力学水动力相互作用

Fusing Carbocycles of Inequivalent Ring Size to a Bis(imino)pyridine-Iron Ethylene Polymerization Catalyst: Distinctive Effects on Activity, PE Molecular Weight, and Dispersity

在线全文

学校读者我要写书评

暂无评论

Research 2019年第1期2019卷 442-456页

作者： Zheng Wang Gregory A.Solan yanping ma Qingbin Liu Tongling Liang Wen-Hua Sun Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science Institute of ChemistryChinese Academy of SciencesBeijing 100190China CAS Research/Education Center for Excellence in Molecular Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Chemistry University of LeicesterUniversity RoadLeicester LE17RHUK College of Chemistry and material Science Hebei Normal UniversityShijiazhuang 050024China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

The 4,6-bis(arylimino)-1,2,3,7,8,9,10-heptahydrocyclohepta[b]quinoline-iron(II)chlorides(aryl=2,6-Me_(2)C_(6)H_(3) Fe1;2,6-Et_(2)C_(6)H_(3) Fe_(2);2,6-i-Pr_(2)C_(6)H_(3) Fe_(3);2,4,6-Me3C_(6)H_(2) Fe4;and 2,6-Et_(2)-4-Me_(2)C_(6)H_(2) Fe_(5))have been prepared in good yield by a straightforward one-pot reaction of 2,3,7,8,9,10-hexahydro-1H-cyclohepta[b]quinoline-4,6-dione,FeCl_(2)·4H_(2)O,and the appropriate aniline in acetic acid.All ferrous complexes have been characterized by elemental analysis and FT-IR spectroscopy.In addition,the structure of Fe_(3) has been determined by single crystal X-ray diffraction,which showed the iron center to adopt a distorted square pyramidal geometry with the saturated sections of the fused six-and sevenmembered carbocycles to be cis-configured.In combination with either maO or MmaO,Fe1–Fe5 exhibited exceptionally high activities for ethylene polymerization(up to 15:86×10^(6) g(PE)mol^(−1)(Fe)h^(−1) at 40℃(MmaO)and 9:60×10^(6) g(PE)mol^(−1)(Fe)h^(−1) at 60℃(maO))and produced highly linear polyethylene(HLPE,Tm≥128℃)with a wide range in molecular weights;in general,the MmaO-promoted polymerizations were more active.Irrespective of the cocatalyst employed,the 2,6-Me_(2)-substituted Fe1 and Fe4 proved the most active while the more sterically hindered 2,6-i-Pr_(2) Fe_(3) the least but afforded the highest molecular weight polyethylene(Mw:65.6–72.6 kg mol^(-1)).Multinuclear NMR spectroscopic analysis of the polymer formed using Fe4/MmaO at 40℃ showed a preference for fully saturated chain ends with a broad bimodal distribution a feature of the GPC trace(Mw/Mn=13:4).By contrast,using Fe4/maO at 60℃ a vinyl-terminated polymer of lower molecular weight(Mw=14:2 kg mol^(−1))was identified that exhibited a unimodal distribution(Mw/Mn=3:8).Moreover,the amount of aluminoxane cocatalyst employed,temperature,and run time were also found to be influential on the modality of the polymer.

关键词： saturated polymerization straight

Fast approximate matching of binary codes with distinctive bits

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2015年第5期9卷 741-750页

作者： Chenggang Clarence YAN Hongtao XIE Bing ZHANG yanping ma Qiong DAI Yizhi LIU Institute of Information Engineering Chinese Academy of Sciences National Engineering Laboratory for Information Security Technologies Beijing 100093 China Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China Department of Automation Tsinghua University Beijing 100083 China School of Physics Beijing Institute of Technology Beijing 100081 China School of Information Science and Engineering Ocean University of China Qingdao 266100 China School of Computer Science and Engineering Hunan University of Science and Technology Xiangtan 411201 China

Although the distance between binary codes can be computed fast in Hamming space, linear search is not practical for large scale datasets. Therefore attention has been paid to the efficiency of performing approximate nearest neighbor search, in which hierarchical clustering trees （HCT） are widely used. However, HCT select cluster centers randomly and build indexes with the entire binary code, this degrades search performance. In this paper, we first propose a new clustering algorithm, which chooses cluster centers on the basis of relative distances and uses a more homogeneous partition of the dataset than HCT has to build the hierarchical clustering trees. Then, we present an algorithm to compress binary codes by extracting distinctive bits according to the standard deviation of each bit. Consequently, a new index is proposed using compressed binary codes based on hierarchical decomposition of binary spaces. Experiments conducted on reference datasets and a dataset of one billion binary codes demonstrate the effectiveness and efficiency of our method.

关键词： binary codes approximate nearest neighbor search hierarchical clustering index

Human Cytomegalovirus Influences Host circRNA Transcriptions during Productive Infection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Virologica Sinica 2021年第2期36卷 241-253页

作者： Jingui Deng Yujing Huang Qing Wang Jianming Li yanping ma Ying Qi Zhongyang Liu Yibo Li Qiang Ruan Virology Laboratory The Affiliated Shengjing HospitalChina Medical UniversityShenyang 110004China Department of Laboratory Central Hospital Affiliated to Shenyang Medical CollegeShenyang 110024China Department of Gynecology and Obstetrics The Affiliated Shengjing HospitalChina Medical UniversityShenyang 110004China Department of Obstetrics Central Hospital Affiliated to Shenyang Medical CollegeShenyang 110024China

Human cytomegalovirus(HCMV)is a double-strand DNA virus widely infected in human.Circular RNAs(circ RNAs)are non-coding RNAs with most functions of which keep unknown,and the effects of HCMV productive infection on host circ RNA transcriptions remain unclear.In this study,we profiled 283 host circ RNAs that significantly altered by HCMV productive infection in human embryonic lung fibroblasts(HELF)by RNA deep sequencing and bioinformatics analysis.Among these,circ SP100,circ maP3 K1,circ PLEKHM1,and circ TRIO were validated for their transcriptions and sequences.Furthermore,characteristics of circ SP100 were investigated by RT-q PCR and northern blot.It was implied that circ SP100 was produced from the sense strand of the SP100 gene containing six exons.Kinetics of circ SP100 and SP100 m RNA were significantly different after infection:circ SP100 levels increased gradually along with infection,whereas SP100 m RNA levels increased in the beginning and dropped at 24 h post-infection(hpi).Meanwhile,a total number of 257 proteins,including 10 HCMV encoding proteins,were identified potentially binding to cytoplasmic circ SP100 by RNA antisense purification(RAP)and mass spectrometry.Enrichment analysis showed these proteins were mainly involved in the spliceosome,protein processing,ribosome,and phagosome pathways,suggesting multiple functions of circ SP100 during HCMV infection.

关键词： Human cytomegalovirus(HCMV) Productive infection Circular RNA(circRNA) circ SP100 Transcription

在线全文

学校读者我要写书评

暂无评论

套细胞淋巴瘤发病机制的研究进展

肿瘤研究与临床 2024年第1期36卷 73-76页

作者：李燕玲秦小琪马艳萍山西医科大学第二临床医学院太原030001 山西医科大学第二医院血液内科太原030001

套细胞淋巴瘤(MCL)是一种罕见的B细胞淋巴瘤,其发病率在逐年升高。MCL兼具惰性淋巴瘤和侵袭性淋巴瘤的共同特点,病情进展迅速且预后不佳。最新研究认为,MCL的发病机制是一个连续统一体,细胞周期失调、SOX11过表达、表观遗传畸变等多种... 详细信息

套细胞淋巴瘤(MCL)是一种罕见的B细胞淋巴瘤,其发病率在逐年升高。MCL兼具惰性淋巴瘤和侵袭性淋巴瘤的共同特点,病情进展迅速且预后不佳。最新研究认为,MCL的发病机制是一个连续统一体,细胞周期失调、SOX11过表达、表观遗传畸变等多种因素在疾病的不同阶段发挥作用。文章主要从分子遗传学角度讨论MCL的发病机制和不同亚型的新发现,进一步分析MCL的临床多样性。同时,通过对MCL发病机制的认识,旨在为MCL未来的治疗提供潜在的治疗靶点。

关键词：淋巴瘤,套细胞细胞周期蛋白类 SOX11蛋白表观遗传学

Human cytomegalovirus miR-US5-1 inhibits viral replication by targeting Geminin mRNA

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2017年第5期32卷 431-439页

作者： Shujuan Jiang Yujing Huang Ying Qi Rong He Zhongyang Liu yanping ma Xin Guo Yaozhong Shao Zhengrong Sun Qiang Ruan Virus Laboratory the Affiliated Shengjing Hospital China Medical University Shenyang 110122 China Clinical Genetics the Affiliated Shengjing Hospital China Medical University Shenyang 110122 China

Viruses commonly create favorable cellular conditions for their survival through multiple mechanisms. Micro RNAs(mi RNAs), which function as post-transcriptional regulators, are utilized by human cytomegalovirus(HCMV) in its infection and pathogenesis. In the present study, the DNA replication inhibitor Geminin(GMNN) was identified to be a direct target of hcmv-mi R-US5-1. Overexpression of hcmv-mi R-US5-1 could block the accumulation of GMNN during HCMV infection, and the decrease of GMNN expression caused by hcmv-mi R-US5-1 or GMNN specific si RNA reduced HCMV DNA copies in U373 cells. Meanwhile, ectopic expression of hcmv-mi R-US5-1 and consequent lower expression of GMNN influenced host cell cycle and proliferation. These results imply that hcmv-mi R-US5-1 may affect viral replication and host cellular environment by regulating expression kinetics of GMNN during HCMV infection.

关键词： Human cytomegalovirus(HCMV) hcmv-mi R-US5-1 Geminin(GMNN) DNA replication cell cycle

贮藏温度对核桃果实冷藏期青皮不同部位褐变、活性氧代谢和种仁品质的影响

在线全文

学校读者我要写书评

暂无评论

食品与发酵工业 2024年第11期50卷 261-269页

作者：钟紫璇高梦璐马文睿闫金姣马艳萍刘朝斌西北农林科技大学林学院陕西杨凌712100

核桃果实采后青皮极易发生褐变,目前有关不同温度贮藏核桃果实青皮不同部位的褐变差异及其原因未见报道。该文研究不同温度(0、2、5、8℃)贮藏对‘清香’核桃果实青皮不同部位外观、褐变指数、活性氧代谢及其种仁品质相关指标的影响。... 详细信息

核桃果实采后青皮极易发生褐变,目前有关不同温度贮藏核桃果实青皮不同部位的褐变差异及其原因未见报道。该文研究不同温度(0、2、5、8℃)贮藏对‘清香’核桃果实青皮不同部位外观、褐变指数、活性氧代谢及其种仁品质相关指标的影响。结果表明,贮藏期间核桃果实青皮的褐变程度随贮藏温度的升高而增加,0、2℃核桃果实青皮内部的褐变指数高于外部,5、8℃果实青皮内部的褐变指数低于外部;4种温度下果实青皮外部的过氧化物酶(peroxidase,POD)活性、多酚氧化酶(polyphenol oxidase,PPO)活性、总酚含量和过氧化氢(H2O2)含量均高于内部,超氧阴离子(·O2-)产生率和丙二醛(malondialdehyde,MDA)含量均低于内部;萼端褐变指数、·O2-产生率、可溶性总糖和游离脯氨酸含量高于梗端;0℃则更好地保持了果实的品质,延缓了种仁酸败,贮藏60 d时种仁的可溶性蛋白质和粗脂肪含量显著高于2℃果实。综合各项指标认为,核桃果实在0、2℃贮藏期为60 d,5、8℃贮藏期不足30 d;青皮的褐变可能是因其活性氧和MDA过量积累加重了膜脂过氧化作用所致。

关键词：核桃果实贮藏温度褐变不同部位活性氧代谢

不同厚度聚乙烯包装对花椒嫩芽冷藏品质和抗氧化酶活力的影响

在线全文

学校读者我要写书评

暂无评论

食品与发酵工业 2024年第8期50卷 219-225页

作者：裴子欣汪煜纯王继路李建国尤雨洁马艳萍西北农林科技大学林学院陕西杨凌712100

为筛选能够延长花椒嫩芽冷藏期的适宜包装,该文以“大红袍”花椒嫩芽为材料,采用厚度0.02、0.03、0.05 mm的聚乙烯(polyethylene,PE,PE20、PE30、PE50)袋包装后于4℃冷藏,研究其冷藏期间感官品质、脱落率、失重率、含水率、可溶性蛋白质... 详细信息

为筛选能够延长花椒嫩芽冷藏期的适宜包装,该文以“大红袍”花椒嫩芽为材料,采用厚度0.02、0.03、0.05 mm的聚乙烯(polyethylene,PE,PE20、PE30、PE50)袋包装后于4℃冷藏,研究其冷藏期间感官品质、脱落率、失重率、含水率、可溶性蛋白质、H_(2)O_(2)和总酚含量、超氧阴离子自由基(·O_(2)^(-))生成率和抗氧化酶活力的变化。结果表明,PE20和PE50包装花椒嫩芽冷藏24 d时叶片脱落率分别为8.79%和15.08%,PE30包装则避免了花椒嫩芽冷藏期间的脱落现象,显著维持了其感官品质和含水率,抑制了可溶性蛋白质和总酚含量的下降以及多酚氧化酶活力的上升,提升了超氧化物歧化酶、过氧化氢酶和过氧化物酶的活力,减少了·O_(2)^(-)和H_(2)O_(2)的积累,从而延缓了花椒嫩芽的衰老进程。综上,PE30包装能够有效提升花椒嫩芽4℃冷藏期间的品质。

关键词：花椒嫩芽冷藏聚乙烯袋品质抗氧化酶活性

Effect of Soil p H on the Growth,Photosynthesis and Mineral Element Content in Own-Rooted Saplings and Grafted Saplings of Blueberry

在线全文

学校读者我要写书评

暂无评论

Asian Agricultural Research 2017年第11期9卷 75-81页

作者： Chengxiang XU yanping ma Feng GUO College of Life Sciences Zhaoqing University Liyang Tianmu Lake Longtan Eco-Technology Valley Co. Ltd.

The adaptation of blueberry to higher soil p H is poor. To explore the effect and probable mechanism of the adaptation of grafted blueberry( Vaccinium spp.) saplings to the soil environment with higher p H value. We took three types of saplings,( i) own-rooted Wufanshu( V. bracteatum),an economical shrub belonging to the same genus and family with blueberry,also known as oriental blueberry,( ii) own-rooted‘Sharpblue',a southern highbush blueberry( V. corymbosum) cultivar,and( iii) grafted-bluebedrry as experimental materials,which were grown in quartz sand medium for 90 d,irrigated with nutrient solution of three levels of p H values,respectively,i. e. p H 4. 6,p H 5. 8 and p H7. 0. Results showed that root development,shoot growth and dry biomass accumulation of grafted blueberry were significantly better than those of own-rooted blueberry grown in higher p H medium; compared with own-rooted blueberry saplings,leaf chlorophyll content,chlorophyll a/b ratio,chlorophyll fluorescence chemical efficiency and photosynthetic efficiency of grafted blueberry saplings grown in higher p H medium were all significantly improved. Results also showed that mineral element content of leaves,especially Mg and Fe elemental content of grafted blueberry was significantly higher than that of own-rooted blueberry saplings grown in higher p H media. Grafting-propagation of blueberry saplings taking Wufanshu as rootstock significantly enhanced the adaptation of blueberry to soil environment with higher p H value.

关键词： Blueberry Wufanshu Grafting p H stress Adaptation