Red sandalwood(Pterocarpus santalinus)is the most precious species of Pterocarpus,and the long maturity period of its heartwood is an important factor limiting its development.The 1-year-old plants of P.macarocarpus w...Red sandalwood(Pterocarpus santalinus)is the most precious species of Pterocarpus,and the long maturity period of its heartwood is an important factor limiting its development.The 1-year-old plants of P.macarocarpus were chosen as the rootstocks to graft red sandalwood with single-bud scions of 1-year-old shoots in spring.The 5-month survival rate reached over 80%,and the grafted plants grew well.Moreover,the grafting significantly promoted the formation and development of the heartwood of red sandlawood.At 18^(th)month after grafting,compared with the seedling plants,the diameter of heartwood was increased by 82.8%and 29.6%,respectively,and the ratio of heartwood increased by 64.8%and 29.6%,respectively.The propagation technology had outstanding practical value and scientific significance,which has not been reported at home and abroad.展开更多
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 t...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.展开更多
The codon usage bias and the base compositions in the available 49 complete fish rhabdovirus genome sequences were investigated. The high correlation between GC12% and GC3% suggested that mutational pressure rather th...The codon usage bias and the base compositions in the available 49 complete fish rhabdovirus genome sequences were investigated. The high correlation between GC12% and GC3% suggested that mutational pressure rather than natural selection was the main factor determining the codon usage and base component in fish rhabdovirns, most of the spots lying below the expected curve ( ENC vs GC3% ) also suggested that codon usage bias in these 49 genomes was influenced by mutational pressure in codon usage pattern. Through PCA analysis based on RSCU, all ORFs in the 49 fish rhabdoviurs genomes were clustered into two parts, and this result showed that hosts played a role in codon usage pattern of fish rhabdovirns genomes. Further, comparison between SVCV, INHV, VHSV and their hosts suggested the effect of natural host on the codon usage pattern took part in the evolution process of fish rhabdovirns. This study represents the most comprehensive analysis to date for fish rhabdovirus eodon usage patterns.展开更多
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)...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.展开更多
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 ho...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.展开更多
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 ...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.展开更多
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 o...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.展开更多
The information of affiliation 1 and 3 was incorrect.The information of affiliations should read as given below.Author information 1 Virology Lab,Shengjing Hospital of China Medical University,Shenyang 110004,China 2 ...The information of affiliation 1 and 3 was incorrect.The information of affiliations should read as given below.Author information 1 Virology Lab,Shengjing Hospital of China Medical University,Shenyang 110004,China 2 Department of Laboratory,Central Hospital Affiliated to Shenyang Medical College,Shenyang 110024,China.展开更多
The Gay-Berne (GB) model has been proved to be highly successful in the simulation of liquid crystal phases via both molec- ular dynamics (MD) and nonequilibrium molecular dynamics (NEMD). However, the conventio...The Gay-Berne (GB) model has been proved to be highly successful in the simulation of liquid crystal phases via both molec- ular dynamics (MD) and nonequilibrium molecular dynamics (NEMD). However, the conventional thermostats used in the simulations of GB systems, such as Nose-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 appro- priate parameters for the DPD thermostat in the GB system are identified for future investigations.展开更多
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...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.展开更多
基金Supported by the National Natural Science Foundation of China(31270674)the Platform Project for Key Research Platform Project for Innovative School of Zhaoqing University(CQ201607)
文摘Red sandalwood(Pterocarpus santalinus)is the most precious species of Pterocarpus,and the long maturity period of its heartwood is an important factor limiting its development.The 1-year-old plants of P.macarocarpus were chosen as the rootstocks to graft red sandalwood with single-bud scions of 1-year-old shoots in spring.The 5-month survival rate reached over 80%,and the grafted plants grew well.Moreover,the grafting significantly promoted the formation and development of the heartwood of red sandlawood.At 18^(th)month after grafting,compared with the seedling plants,the diameter of heartwood was increased by 82.8%and 29.6%,respectively,and the ratio of heartwood increased by 64.8%and 29.6%,respectively.The propagation technology had outstanding practical value and scientific significance,which has not been reported at home and abroad.
基金Supported by National Natural Science Foundation(31270674)Important Innovation Research Project of Zhaoqing University(CQ201607)Science and Technology Project of Liyang Tianmu Lake Longtan Eco-Technology Valley Co.,Ltd
文摘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.
基金Supported by National Natural Science Foundation of China(No.31402347)Guangdong Special Marine Fishery Science and Technology Project(A201701C04)+3 种基金"Molecular epidemiological study of Cy HV-3 in Guangdong Province",2016 Guangdong Special Funds for Fish DiseasesGuangzhou Science and Technology Plan Projects(201707010216)Guangdong Science and Technology Plan Projects(2017A020224019)Guangdong Science and Technology Plan Projects(2016A020210029)
文摘The codon usage bias and the base compositions in the available 49 complete fish rhabdovirus genome sequences were investigated. The high correlation between GC12% and GC3% suggested that mutational pressure rather than natural selection was the main factor determining the codon usage and base component in fish rhabdovirns, most of the spots lying below the expected curve ( ENC vs GC3% ) also suggested that codon usage bias in these 49 genomes was influenced by mutational pressure in codon usage pattern. Through PCA analysis based on RSCU, all ORFs in the 49 fish rhabdoviurs genomes were clustered into two parts, and this result showed that hosts played a role in codon usage pattern of fish rhabdovirns genomes. Further, comparison between SVCV, INHV, VHSV and their hosts suggested the effect of natural host on the codon usage pattern took part in the evolution process of fish rhabdovirns. This study represents the most comprehensive analysis to date for fish rhabdovirus eodon usage patterns.
基金supported by the National Natural Science Foundation of China (81371788 and 81171580)the Specialized Research Fund for the Doctoral Program of Higher Education (20112104110012)the Outstanding Scientific Fund of Shengjing Hospital
文摘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.
基金supported by the National Natural Science Foundation of China (81672028 and 81371788)。
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China(82071664)。
文摘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.
文摘The information of affiliation 1 and 3 was incorrect.The information of affiliations should read as given below.Author information 1 Virology Lab,Shengjing Hospital of China Medical University,Shenyang 110004,China 2 Department of Laboratory,Central Hospital Affiliated to Shenyang Medical College,Shenyang 110024,China.
基金support of the National Natural Science Foundation of China(20674093)
文摘The Gay-Berne (GB) model has been proved to be highly successful in the simulation of liquid crystal phases via both molec- ular dynamics (MD) and nonequilibrium molecular dynamics (NEMD). However, the conventional thermostats used in the simulations of GB systems, such as Nose-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 appro- priate parameters for the DPD thermostat in the GB system are identified for future investigations.
基金This work was supported by the National Natural Science Foundation of China(No.21871275).GAS thanks the Chinese Academy of Sciences for a Visiting Fellowship.
文摘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.