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9篇 您的检索式:作者名="Meichen Yang"
    题名 作者 年代 出处 被引量
1Persistence of Cry1Ac Protein from Transgenic Bt Cotton Cultivation and Residue Returning in Fields and Its Effect on Functional Diversity of Soil Microbial Communities显示文摘The persistence of Cry1 Ac protein in the soil and its effect on soil microbial communities are a core issue in assessing the ecological risk of transgenic Bacillus thuringiensis(Bt) cotton. In this study a field experiment was conducted on the cultivation of transgenic Bt cotton(Jin 26 and BtJ i 668) with the immediate returning of residues to the fields, in order to quantify the Cry1 Ac protein content in the fields and investigate its effects on the functional diversity of soil microbial communities. Cry1 Ac protein in the residue-soil mixture was gradually degraded in the transgenic Bt cotton fields. After transgenic Bt cotton straw was returned to the fields for 30 d, 63.73%and 58.33% of the initial amounts of Cry1 Ac protein were degraded in the Jin 26 and BtJ i 668 fields, respectively. Before the crops were sown in the following year(180 d after returning the straw), no Cry1 Ac protein was detected in the fields. After returning the cotton straw to the fields for 30 d, the Shannon-Wiener and McIntosh indices of soil microbial communities in the transgenic Bt cotton fields were significantly higher than those in the non-transgenic cotton fields. Meanwhile, the utilization of carbon sources including amino acids, amines, and carbohydrates by the soil microbial communities significantly increased. Both the McIntosh index and the utilization of carbohydrates increased until 180 d. Principal component analysis revealed that amino acids, amides, and carbohydrates were the main carbon sources distinguishing the two principal component factors. These findings indicated that Cry1 Ac protein did not accumulate in the fields after transgenic Bt cotton was planted for one year and the residues were immediately returned to the fields; however, the original functional diversity of soil microbial communities was affected continuously.ZHANG Meijun FENG Meichen XIAO Lujie SONG Xiaoyan Guangwei DING YANG Wude 2019Pedosphere2019,29,1:2
2AoATG5 plays pleiotropic roles in vegetative growth,cell nucleus development,conidiation,and virulence in the nematode-trapping fungus Arthrobotrys oligospora显示文摘Autophagy is an evolutionarily conserved process in eukaryotes,which is regulated by autophagy-related genes(ATGs).Arthrobotrys oligospora is a representative species of nematode-trapping(NT)fungi that can produce special traps for nematode predation.To elucidate the biological roles of autophagy in NT fungi,we characterized an orthologous Atg protein,AoAtg5,in A.oligospora.We found that AoATG5 deletion causes a significant reduction in vegetative growth and conidiation,and that the transcript levels of several sporulation-related genes were significantly downregulated during sporulation stage.In addition,the cell nuclei were significantly reduced in theΔAoATG5 mutant,and the transcripts of several genes involved in DNA bio-synthesis,repair,and ligation were significantly upregulated.InΔAoATG5 mutants,the autophagic process was significantly impaired,and trap formation and nematocidal activity were significantly decreased.Comparative transcriptome analysis results showed that AoAtg5 is involved in the regulation of multiple cellular processes,such as autophagy,nitrogen metabolism,DNA biosynthesis and repair,and vesicular transport.In summary,our results suggest that AoAtg5 is essential for autophagy and significantly contributes to vegetative growth,cell nucleus development,sporulation,trap formation,and pathogenicity in A.oligospora,thus providing a basis for future studies focusing on related mechanisms of autophagy in NT fungi.Duanxu Zhou Yingmei Zhu Na Bai Le Yang Meihua Xie Jiangliu Yang Meichen Zhu Ke-Qin Zhang Jinkui Yang 2022Science China(Life Sciences)2022,65,2:2
3Wood waste biochar promoted anaerobic digestion of food waste:focusing on the characteristics of biochar and microbial community analysis显示文摘Anaerobic digestion(AD)has been considered as a promising technique for food waste(FW)recycling.However,the accumulation of volatile fatty acids(VFAs)restricts the stability of anaerobic reactors.The present study investigated the use of biochar produced at different conditions(750℃-30 min,750℃-60 min,750℃-120 min,550℃-60 min,650℃-60 min,850℃-60 min,950℃-60 min)for enhancing the AD of FW.Batch experiments showed that all the biochar increased the methane production rates and biochar obtained at 750℃-60 min resulted in the highest enhance-ment by 21.5%.It was further showed surface oxygen-containing functional groups and graphitization degree of biochar were the critical factors for improving methane production.Microbial analysis showed that biochar addi-tion formed different microbial communities,and Methanosaeta,Romboutsia,and norank_f_Anaerolineaceae were enriched,which might be correlated with direct interspecies electron transfer(DIET).This research showed biochar could enhance the AD of FW and also revealed the main characteristics of biochar relating with the enhancement of AD.Chao Zhang Rui Yang Meichen Sun Shicheng Zhang Mingjing He Daniel C.W.Tsang Gang Luo 2022Biochar2022,4,1:2
4Sealing reliability modeling of aviation seal based on interval uncertainty method and multidimensional response surface显示文摘Many variables affect the sealing performance, and their distribution characteristics are difficult to obtain with probabilistic methods owing to the high cost involved. Numerous problems in engineering are similar due to the appearance of small-sample parameters. In this study, the sealing reliability of an aviation seal was defined as the research object, and an interval uncertainty method and multidimensional response surface were proposed to calculate the sealing reliability.Based on this, we first analyzed the failure mechanism of the aviation seal and established a leakage rate model. Then, based on the non-probabilistic interval model, an interval uncertainty method was proposed to construct the analytical model. With reference to the limit state equation from the structural reliability theory, the multidimensional response surface was used for fast calculation.Then, we chose the single-cylinder gas steering gear used in aircraft as the case study, its sealing reliability in working and non-working statuses were calculated, and the results were verified with the actual maintenance records. By analyzing the sensitivity of some variables, we can improve the sealing reliability of the aviation seal by improving the surface roughness only if the cost allows.Finally, we consider that the method proposed in this study realizes the application of smallsample uncertainty analysis in reliability analysis, and could provide a feasible way to solve the similar problems in engineering with multidimensional and small-sample parameters.Baopeng LIAO Bo SUN Yu LI Meichen YAN Yi REN Qiang FENG Dezhen YANG Kun ZHOU 2019Chinese Journal of Aeronautics2019,32,9:1
5Coculture engineering for efficient production of vanillyl alcohol in Escherichia coli显示文摘Vanillyl alcohol is a precursor of vanillin,which is one of the most widely used flavor compounds.Currently,vanillyl alcohol biosynthesis still encounters the problem of low efficiency.In this study,coculture engineering was adopted to improve production efficiency of vanillyl alcohol in E.coli.First,two pathways were compared for biosynthesis of the immediate precursor 3,4-dihydroxybenzyl alcohol in monocultures,and the 3-dehydroshikimate-derived pathway showed higher efficiency than the 4-hydroxybenzoate-derived pathway.To enhance the efficiency of the last methylation step,two strategies were used,and strengthening S-adenosylmethionine(SAM)regeneration showed positive effect while strengthening SAM biosynthesis showed negative effect.Then,the optimized pathway was assembled in a single cell.However,the biosynthetic efficiency was still low,and was not significantly improved by modular optimization of pathway genes.Thus,coculturing engineering strategy was adopted.At the optimal inoculation ratio,the titer reached 328.9 mg/L.Further,gene aroE was knocked out to reduce cell growth and improve 3,4-DHBA biosynthesis of the upstream strain.As a result,the titer was improved to 559.4 mg/L in shake flasks and to 3.89 g/L in fed-batch fermentation.These are the highest reported titers of vanillyl alcohol so far.This work provides an effective strategy for sustainable production of vanillyl alcohol.Meichen Yang Hao Meng Xianglai Li Jia Wang Xiaolin Shen Xinxiao Sun Qipeng Yuan 2022aBIOTECH2022,3,4:1
6Expression, purification and antibody preparation using different constructs of PCV2 capsid protein显示文摘Fuwang Chen Xin Yang Daxing Pang Zhiyuan Peng Meichen Dong Xiaoyun Liu Hongsheng Ouyang Linzhu Ren 2014International Journal of Biological Macromolecules2014,,:1
7Evolution of Quasicrystals and Long-Period Stacking Ordered Structures During Severe Plastic Deformation and Mixing of Dissimilar Mg Alloys Upon Friction Stir Welding显示文摘Microstructural evolution during severe plastic deformation and mixing of Mg95.8Zn3.6Gd0.6 and Mg97Cu1Y2(at%)alloys upon friction stir welding was studied.A laminated onion-ring structure composed of alternative distribution of layers with signifi cantly refi ned microstructures from diff erent alloys was formed in the stirred zone.Coarse quasicrystals were broken up and dispersed with most of them being transformed into cubic W-phase particles,and thick 18R long-period stacking ordered plates were fractured and transformed into fi ne 14H-LPSO lamellae in the stirred zone(SZ)experiencing complex material flow under high strain rate.Fine W-phase particles and 14H-LPSO lamellae formed during dissimilar friction stir welding(FSW)usually have no specifi c orientation relationship with surrounding Mg matrix.Chemical measurements demonstrated occurrence of interdiff usion between dissimilar layers in the SZ.Phase transformation was observed for some particles of quasicrystals and long-period stacking ordered(LPSO)in regions slightly outside the SZ.An ultimate tensile strength of~415 MPa and an elongation to failure of~27.8%,both exceeding those of base materials,were obtained in the SZ,due to microstructural refi nement and formation of a laminated structure.Meichen Liang Hao Zhang Lifeng Zhang Peng Xue Dingrui Ni Weizhen Wang Zongyi Ma Hengqiang Ye Zhiqing Yang 2021Acta Metallurgica Sinica(English Letters)2021,34,1:0
8Dose-Response Meta-Analysis on Risk of Diabetes in Relation to Red and Processed Meat Consumption—Asian Populations,2006−2021显示文摘Summary What is already known about this topic?Red and processed meat consumption has been positively related to an increased risk of diabetes in Western populations.However,the results remain inconclusive within Asian populations.What is added by this report?This dose-response meta-analysis of prospective cohort studies conducted in East Asian populations reveals a positive relation between the consumption of processed meat and increased risk of diabetes.Furthermore,a Ushaped association was identified between the consumption of unprocessed red meat and the risk of diabetes.What are the implications for public health practice?This research presents substantive evidence advocating for the reduction of processed and unprocessed red meat consumption as a viable strategy for mitigating the risk of diabetes in East Asian populations.Hancheng Yu Jijuan Zhang Jinchi Xie Xianli Li Youjing Wang Yijia Yang Fengshuang Zhou Meichen Liu Zhe Zhang Zhilei Shan Gang Liu An Pan 2023China CDC weekly2023,5,45:0
9Effects of grain size on landscape patterns in mineral resource zones:a case study of Wu’an,China显示文摘A mineral resource zone,rich in resources and energy,is intensively developed and disturbed by human activities,which causes an obvious change of landscapes.Taking Wu’an of Hebei Province,China,as a case study,this paper extracts landscape information of mineral resource zones through overlapping mineral resources distribution map and landscape pattern map.And then,various landscape indices are selected for analyzing the effects of grain size(30,60,90,120,150,180,210,240,270 and 300 m)on landscape patterns.Due to different kinds of landscape information transmitted by indices,the changing trends vary with the increase of grain sizes.Accordingly the landscape indices are classified into three types of effects:disturbance,continuity and sustainability,and each type of effect has its own optimal range for grain sizes.Then the optimal range of grain size on landscape patterns in mineral resource zones is gained through a comparison of the effects in various grain sizes of landscape indices.The best first domain of scale covers 30-90 m,with a suitable grain size of 30-60 m before intensive mining and a suitable grain size of 60-90 m after intensive mining.Besides,the suitable grain sizes for reflecting disturbance,continuity and sustainability before intensive mining are 30-60,30-60 and 30-90 m,respectively,however,the sizes are changed to 60-90,60-90 and 30-90 m,respectively,after intensive mining.The results are helpful for rational land use and optimal landscape allocation.Jianjun Zhang Yongheng Rao Yang Xu Meichen Fu 2014International Journal of Coal Science & Technology2014,1,2:0
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