[Objectives]This study was conducted to improve the genetic transformation rate of maize. [Methods]The seeds of maize " Zheng 58" as the experimental material were germinated and treated under freezing temperature o...[Objectives]This study was conducted to improve the genetic transformation rate of maize. [Methods]The seeds of maize " Zheng 58" as the experimental material were germinated and treated under freezing temperature of-18 ℃ for 30 and 35 min. The EGFP gene was transformed into the growth points of these seed buds by Agrobacterium tumefaciens EHA105. The transformation effect was determined by fluorescence protein detection on transformed buds. [Results]After a certain period of treatment at-18 ℃ following germination and transformation of maize bud growth points with A. tumefaciens,although the survival rate of maize buds was reduced,the percentage of transformed cells significantly increased. [Conclusions]Low temperature treatment can improve the transformation efficiency of A. tumefaciens to the growth point of maize bud.展开更多
To address the issues of large volume change and low conductivity of silicon(Si)materials,carbon coatings have been widely employed as surface protection agent and conductive medium to encapsulate the Si materials,whi...To address the issues of large volume change and low conductivity of silicon(Si)materials,carbon coatings have been widely employed as surface protection agent and conductive medium to encapsulate the Si materials,which can improve the electrochemical performance of Si-based electrodes.There has been a strong demand to gain a deeper understanding of the impact of efficient carbon coating over the lithiation and delithiation process of Si materials.Here,we report the first observation of the extended two-phase transformation of carbon-coated Si nanoparticles(Si/C)during electrochemical processes.The Si/C nanoparticles were prepared by sintering Si nanoparticles with polyvinylidene chloride precursor.The Si/C electrode underwent a two-phase transition during the first 20 cycles at 0.2 C,but started to engage in solid solution reaction when the ordered compact carbon coating began to crack.Under higher current density conditions,the electrode was also found to be involved in solid solution reaction,which,however,was due to the overwhelming demand of kinetic property rather than the breaking of the carbon coating.In comparison,the Si/C composites prepared with sucrose possessed more disordered and porous carbon structures,and presented solid solution reaction throughout the entire cycling process.展开更多
Wheat-rye T1BL·1RS translocation lines are widely used,especially in China,but their processing quality is generally poor.An interfering expression vector targeting theω-secalin genes was constructed with the 1B...Wheat-rye T1BL·1RS translocation lines are widely used,especially in China,but their processing quality is generally poor.An interfering expression vector targeting theω-secalin genes was constructed with the 1Bx7 seed-specific promoter.Biolistic-mediated genetic transformation of the wheat cultivar KN199 carrying the T1BL·1RS translocation generated 10 transgenic lines.Two representative transgenic lines,8-2 and 13-7,were selected for analysis.Compared with the control,the two transformants showed an up to 4.5-fold decrease in totalω-secalins and various levels of decrease inω-gliadins,γ-gliadins,and low-molecular-weight glutenins.A decrease in high molecular weight(HMW)glutenin 1Bx7 was detected only in 8-2,owing possibly to promoter methylation.Increased levels ofα-gliadins were observed in both transformants,but increased levels of HMW glutenins were observed only in 13-7.Line 13-7 showed increases in gluten index,Zeleny sedimentation value,stabilization time,and maximum resistance.Its bread volume was 849.6 mL,an 11.9%increase over that of the control.Line 8-2 showed decreases in these parameters,but its total cake-making quality score was 88,an 17.3%increase over that of the control.The study demonstrates that the same RNAi construct may produce different effects on wheat processing quality and highlights the influence of the vector promoter in RNA interference.展开更多
This study investigated the seasonal variation in the atmospheric response to oceanic mesoscale eddies in the North Pacific Subtropical Countercurrent(STCC)and its mechanism,based on satellite altimetric and reanalysi...This study investigated the seasonal variation in the atmospheric response to oceanic mesoscale eddies in the North Pacific Subtropical Countercurrent(STCC)and its mechanism,based on satellite altimetric and reanalysis datasets.Although mesoscale eddy in the study area is more active in summer,the sea surface temperature(SST)anomaly associated with mesoscale eddies is more intense and dipolar in winter,which is largely due to the larger background SST gradient.Similarly,the impact of the oceanic eddy on sea surface wind speed and heat flux is strongest in winter,whereas its effect on precipitation rate is more significant in summer.The study revealed that the SST gradient in STCC could impact the atmosphere layer by up to 800 h Pa(900 h Pa)in boreal winter(summer)through the dominant vertical mixing mechanism.Moreover,the intensity of the SST gradient causes such seasonal variation in mesoscale air-sea coupling in the study region.In brief,a stronger(weaker)background SST gradient field in wintertime(summertime)leads to a larger(smaller)eddy-induced SST anomaly,thus differently impacting atmosphere instability and transitional kinetic energy flux over oceanic eddies,leading to seasonal variation in mesoscale air-sea coupling intensity.展开更多
[ Objective ] This study aimed to confirm the roles of cell wall degrading enzymes (CWDEs) produced by Botryodiplodia theobromae Pat. in the infec- tion of mango fruits. [ Method] Change of activities of five types ...[ Objective ] This study aimed to confirm the roles of cell wall degrading enzymes (CWDEs) produced by Botryodiplodia theobromae Pat. in the infec- tion of mango fruits. [ Method] Change of activities of five types of CWDEs produced by B. theobromae Pat. were studied under both in vitro culture and inocula- tion conditions, along with the pathogenicity and the ability of producing CWDEs of four post-harvest fangal pathogens(B, theobromae Pat. , Colletotrichum gloeos- porioides Penz. , Phomopsis mangiferae Ahmad and Dothiorella dominicana Pet. et Cif. ) which cause stem-end rot of mangoes. [ Result] B. theobromae Pat. was a- ble to produce polygalacturonase(PG), pectinmethylgalacturonase(PMG), polygalacturonic acid trans-eliminase (PGTE), pectin methyltrans-eliminase (PMTE) and cellulase ( Cx. ) under both in vitro culture and inoculation conditions, of which activities of PG, Cx and PMG were significantly higher in than that in either PGTE or PMTE. Among three primary CWDEs, the peak of activities of PG and Cx appeared earlier and that of PMG occured later. The pathogenicity of B. theo- bromae Pat. was significantly higher than that of any other three pathogens; it is the same with the abilities of producing pectinase. [ Conclusion] This paper pro- vides theoretical bases for further exploring the mechanism of host-pathogen interaction and decreasing the post-harvest loss of mango fruits.展开更多
[Objectives]The effect of acetosyringone seed soaking on the transformation of maize seed buds was analyzed,so as to improve the genetic transformation efficiency of maize and to provide technical support for transgen...[Objectives]The effect of acetosyringone seed soaking on the transformation of maize seed buds was analyzed,so as to improve the genetic transformation efficiency of maize and to provide technical support for transgenic breeding of maize.[Methods]The seeds of the"Zheng 58"maize inbred line were used as experimental materials.When the seeds were germinated,AS was added to the water at concentrations of 70,140,210,and 280μmol/L,respectively,and the seeds germinated without the addition of AS served as the CK.The Agrobacterium-mediated method was used to transform bud growth points of maize seeds,and green fluorescent protein detection was performed on the young shoots transformed with EGFP(enhanced green fluorescent protein)gene.The effect of soaking seeds with acetosyringone solution on the transformation of maize bud growth points by Agrobacterium was studied according to the detection results.[Results]Soaking seeds in acetosyringone solutions for germination had the effect of inhibiting the germination of maize seeds and inhibiting sprout elongation,and the higher the concentration of acetosyringone,the stronger the inhibition.When the concentration of acetosyringone solution was 280μmol/L,the germination rate of seeds was only 36.2%of the CK,while soaking seeds with 70-140μmol/L acetosyringone solution for germination could not only ensure a higher germination rate of maize seeds,but also significantly increased the transformation efficiency of maize bud growth points.When the seeds were soaked with 70μmol/L acetosyringone solution for germination,the positive rate of transformed maize buds was the highest,reaching 32.1%.[Conclusions]When maize bud growth points were used as the receptor of Agrobacterium transformation,soaking seeds with 70-140μmol/L acetosyringone for germination basically did not affect the germination of seeds,and was beneficial to the activation of Agrobacterium,thereby promoting the transformation.展开更多
[Objectives] This study was conducted to improve the efficiency of genetic transformation using growing points of corn sprouts. [Methods] A mixed liquid of plant hormones 6-BA and KT at a suitable concentration and ra...[Objectives] This study was conducted to improve the efficiency of genetic transformation using growing points of corn sprouts. [Methods] A mixed liquid of plant hormones 6-BA and KT at a suitable concentration and ratio was added dropwise to the growing points of corn sprouts, followed by culture under appropriate conditions. [Results] Corn sprouts could be induced to form multiple plants, thereby improving the transformation efficiency of growing points in corn sprouts. [Conclusions] This study provides a breeding method using growing points of corn sprouts as transformation receptors for direct plantlet formation without tissue culture by the Agrobacterium transgenic technology.展开更多
<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of this research is to develop an immersive virtual fitness center as an intervention to promote physica...<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of this research is to develop an immersive virtual fitness center as an intervention to promote physical activity and examine its impacts on users’ exercise plans and exercise behaviors. The virtual reality (VR)-based intervention includes three main features: enabling the users to control their avatar, personalizing the avatar to look the same as the user, and visualizing the positive consequences of exercising. We conducted an experiment to randomly assign participants to two treatment groups: experiencing either the self or another person losing weight because of exercising in the virtual environment. The findings demonstrated that the self-avatar group exercised more in the voluntary section than the other-avatar group. However, participants in the self-avatar condition perceived a lower level of sense of presence compared to participants in the other-avatar condition. Compared to people in the control condition who watched and followed the exercise from a workout video, those who exercised in the virtual fitness center, regardless of whether the avatar was based on the self’s image or another person’s image, planned to spend more time on exercising in the following week. Theoretical and practical implications for using VR technology to promote health-related behavioral change, and why personalization decreases perceived sense of presence in the virtual environment are discussed.</span> </div>展开更多
The morphology of polymeric nanoparticles prepared by polymerization-induced self-assembly(PISA)is depended on the degree of polymerization of the solvophilic and solvophobic blocks.Herein,a series of poly(N,N-dimethy...The morphology of polymeric nanoparticles prepared by polymerization-induced self-assembly(PISA)is depended on the degree of polymerization of the solvophilic and solvophobic blocks.Herein,a series of poly(N,N-dimethylaminoethyl methacrylate)-b-poly(benzyl methacrylate)(PDMA-b-PBzMA)diblock copolymer spherical nanoparticles were synthesized via reversible addition-frag-mentation chain transfer(RAFT)mediated PISA.These diblock copolymer nanoparticles are with nearly the same hydrodynamic size and solvophobic chain length,but with different solvophilic chain length.We used these nanoparticles to stabilize the oil-in-water Pickering emulsion.We find that the stability of Pickering emulsion increases with the length of solvophilic chain of the nanoparticles.Moreover,the droplet size of the Pickering emulsion can be tailored by varying the oil/water ratio and concentration of nanoparticles.展开更多
基金Supported by Natural Science Foundation of Hebei Province(C2017301071)Financial Project of Hebei Province(2017039339)
文摘[Objectives]This study was conducted to improve the genetic transformation rate of maize. [Methods]The seeds of maize " Zheng 58" as the experimental material were germinated and treated under freezing temperature of-18 ℃ for 30 and 35 min. The EGFP gene was transformed into the growth points of these seed buds by Agrobacterium tumefaciens EHA105. The transformation effect was determined by fluorescence protein detection on transformed buds. [Results]After a certain period of treatment at-18 ℃ following germination and transformation of maize bud growth points with A. tumefaciens,although the survival rate of maize buds was reduced,the percentage of transformed cells significantly increased. [Conclusions]Low temperature treatment can improve the transformation efficiency of A. tumefaciens to the growth point of maize bud.
基金This study is funded by the Assistant Secretary for Energy Efficiency,Vehicle Technologies Office of the U.S.Department of Energy,under the Si Consortium Program.Electron microscopy experiments are conducted at the National Centre for Electron Microscopy and the Molecular Foundry located at Lawrence Berkeley National Laboratory is supported by the Director,Office of Science,Office of Basic Energy Sciences,the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘To address the issues of large volume change and low conductivity of silicon(Si)materials,carbon coatings have been widely employed as surface protection agent and conductive medium to encapsulate the Si materials,which can improve the electrochemical performance of Si-based electrodes.There has been a strong demand to gain a deeper understanding of the impact of efficient carbon coating over the lithiation and delithiation process of Si materials.Here,we report the first observation of the extended two-phase transformation of carbon-coated Si nanoparticles(Si/C)during electrochemical processes.The Si/C nanoparticles were prepared by sintering Si nanoparticles with polyvinylidene chloride precursor.The Si/C electrode underwent a two-phase transition during the first 20 cycles at 0.2 C,but started to engage in solid solution reaction when the ordered compact carbon coating began to crack.Under higher current density conditions,the electrode was also found to be involved in solid solution reaction,which,however,was due to the overwhelming demand of kinetic property rather than the breaking of the carbon coating.In comparison,the Si/C composites prepared with sucrose possessed more disordered and porous carbon structures,and presented solid solution reaction throughout the entire cycling process.
基金The financial support by Key Research and Development Plan of Hebei Province(20326348D)Hebei Modern Agricultural Science and Technology Innovation Project(2019-4-08-1)are gratefully acknowledged.
文摘Wheat-rye T1BL·1RS translocation lines are widely used,especially in China,but their processing quality is generally poor.An interfering expression vector targeting theω-secalin genes was constructed with the 1Bx7 seed-specific promoter.Biolistic-mediated genetic transformation of the wheat cultivar KN199 carrying the T1BL·1RS translocation generated 10 transgenic lines.Two representative transgenic lines,8-2 and 13-7,were selected for analysis.Compared with the control,the two transformants showed an up to 4.5-fold decrease in totalω-secalins and various levels of decrease inω-gliadins,γ-gliadins,and low-molecular-weight glutenins.A decrease in high molecular weight(HMW)glutenin 1Bx7 was detected only in 8-2,owing possibly to promoter methylation.Increased levels ofα-gliadins were observed in both transformants,but increased levels of HMW glutenins were observed only in 13-7.Line 13-7 showed increases in gluten index,Zeleny sedimentation value,stabilization time,and maximum resistance.Its bread volume was 849.6 mL,an 11.9%increase over that of the control.Line 8-2 showed decreases in these parameters,but its total cake-making quality score was 88,an 17.3%increase over that of the control.The study demonstrates that the same RNAi construct may produce different effects on wheat processing quality and highlights the influence of the vector promoter in RNA interference.
基金The Shandong Provincial Natural Science Foundation under contract No.ZR2021YQ28the Provincial College Student Innovation Training Project under contract No.S202110446040。
文摘This study investigated the seasonal variation in the atmospheric response to oceanic mesoscale eddies in the North Pacific Subtropical Countercurrent(STCC)and its mechanism,based on satellite altimetric and reanalysis datasets.Although mesoscale eddy in the study area is more active in summer,the sea surface temperature(SST)anomaly associated with mesoscale eddies is more intense and dipolar in winter,which is largely due to the larger background SST gradient.Similarly,the impact of the oceanic eddy on sea surface wind speed and heat flux is strongest in winter,whereas its effect on precipitation rate is more significant in summer.The study revealed that the SST gradient in STCC could impact the atmosphere layer by up to 800 h Pa(900 h Pa)in boreal winter(summer)through the dominant vertical mixing mechanism.Moreover,the intensity of the SST gradient causes such seasonal variation in mesoscale air-sea coupling in the study region.In brief,a stronger(weaker)background SST gradient field in wintertime(summertime)leads to a larger(smaller)eddy-induced SST anomaly,thus differently impacting atmosphere instability and transitional kinetic energy flux over oceanic eddies,leading to seasonal variation in mesoscale air-sea coupling intensity.
基金Supported by the Special Fund for Agro-scientific Research(3-44-2)the Special Fund for Basic Research of Central Universities in the Public Interest,China(N0.2009hzs1J011,NO.2011hzs1J027,NO.2011hzs1J004)
文摘[ Objective ] This study aimed to confirm the roles of cell wall degrading enzymes (CWDEs) produced by Botryodiplodia theobromae Pat. in the infec- tion of mango fruits. [ Method] Change of activities of five types of CWDEs produced by B. theobromae Pat. were studied under both in vitro culture and inocula- tion conditions, along with the pathogenicity and the ability of producing CWDEs of four post-harvest fangal pathogens(B, theobromae Pat. , Colletotrichum gloeos- porioides Penz. , Phomopsis mangiferae Ahmad and Dothiorella dominicana Pet. et Cif. ) which cause stem-end rot of mangoes. [ Result] B. theobromae Pat. was a- ble to produce polygalacturonase(PG), pectinmethylgalacturonase(PMG), polygalacturonic acid trans-eliminase (PGTE), pectin methyltrans-eliminase (PMTE) and cellulase ( Cx. ) under both in vitro culture and inoculation conditions, of which activities of PG, Cx and PMG were significantly higher in than that in either PGTE or PMTE. Among three primary CWDEs, the peak of activities of PG and Cx appeared earlier and that of PMG occured later. The pathogenicity of B. theo- bromae Pat. was significantly higher than that of any other three pathogens; it is the same with the abilities of producing pectinase. [ Conclusion] This paper pro- vides theoretical bases for further exploring the mechanism of host-pathogen interaction and decreasing the post-harvest loss of mango fruits.
基金Natural Science Foundation of Hebei Province(C2017301071)"Science and Technology Innovation Project"of Hebei Academy of Agriculture and Forestry Sciences(F18C10002).
文摘[Objectives]The effect of acetosyringone seed soaking on the transformation of maize seed buds was analyzed,so as to improve the genetic transformation efficiency of maize and to provide technical support for transgenic breeding of maize.[Methods]The seeds of the"Zheng 58"maize inbred line were used as experimental materials.When the seeds were germinated,AS was added to the water at concentrations of 70,140,210,and 280μmol/L,respectively,and the seeds germinated without the addition of AS served as the CK.The Agrobacterium-mediated method was used to transform bud growth points of maize seeds,and green fluorescent protein detection was performed on the young shoots transformed with EGFP(enhanced green fluorescent protein)gene.The effect of soaking seeds with acetosyringone solution on the transformation of maize bud growth points by Agrobacterium was studied according to the detection results.[Results]Soaking seeds in acetosyringone solutions for germination had the effect of inhibiting the germination of maize seeds and inhibiting sprout elongation,and the higher the concentration of acetosyringone,the stronger the inhibition.When the concentration of acetosyringone solution was 280μmol/L,the germination rate of seeds was only 36.2%of the CK,while soaking seeds with 70-140μmol/L acetosyringone solution for germination could not only ensure a higher germination rate of maize seeds,but also significantly increased the transformation efficiency of maize bud growth points.When the seeds were soaked with 70μmol/L acetosyringone solution for germination,the positive rate of transformed maize buds was the highest,reaching 32.1%.[Conclusions]When maize bud growth points were used as the receptor of Agrobacterium transformation,soaking seeds with 70-140μmol/L acetosyringone for germination basically did not affect the germination of seeds,and was beneficial to the activation of Agrobacterium,thereby promoting the transformation.
基金Supported by Natural Science Foundation of Hebei Province(C2017301071)Financial Project of Hebei Province(2017039339)
文摘[Objectives] This study was conducted to improve the efficiency of genetic transformation using growing points of corn sprouts. [Methods] A mixed liquid of plant hormones 6-BA and KT at a suitable concentration and ratio was added dropwise to the growing points of corn sprouts, followed by culture under appropriate conditions. [Results] Corn sprouts could be induced to form multiple plants, thereby improving the transformation efficiency of growing points in corn sprouts. [Conclusions] This study provides a breeding method using growing points of corn sprouts as transformation receptors for direct plantlet formation without tissue culture by the Agrobacterium transgenic technology.
文摘<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of this research is to develop an immersive virtual fitness center as an intervention to promote physical activity and examine its impacts on users’ exercise plans and exercise behaviors. The virtual reality (VR)-based intervention includes three main features: enabling the users to control their avatar, personalizing the avatar to look the same as the user, and visualizing the positive consequences of exercising. We conducted an experiment to randomly assign participants to two treatment groups: experiencing either the self or another person losing weight because of exercising in the virtual environment. The findings demonstrated that the self-avatar group exercised more in the voluntary section than the other-avatar group. However, participants in the self-avatar condition perceived a lower level of sense of presence compared to participants in the other-avatar condition. Compared to people in the control condition who watched and followed the exercise from a workout video, those who exercised in the virtual fitness center, regardless of whether the avatar was based on the self’s image or another person’s image, planned to spend more time on exercising in the following week. Theoretical and practical implications for using VR technology to promote health-related behavioral change, and why personalization decreases perceived sense of presence in the virtual environment are discussed.</span> </div>
基金This work was supported by the National Natural Science Foundation of China(Nos.21871162 and 22071131)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University(No.KF2009).
文摘The morphology of polymeric nanoparticles prepared by polymerization-induced self-assembly(PISA)is depended on the degree of polymerization of the solvophilic and solvophobic blocks.Herein,a series of poly(N,N-dimethylaminoethyl methacrylate)-b-poly(benzyl methacrylate)(PDMA-b-PBzMA)diblock copolymer spherical nanoparticles were synthesized via reversible addition-frag-mentation chain transfer(RAFT)mediated PISA.These diblock copolymer nanoparticles are with nearly the same hydrodynamic size and solvophobic chain length,but with different solvophilic chain length.We used these nanoparticles to stabilize the oil-in-water Pickering emulsion.We find that the stability of Pickering emulsion increases with the length of solvophilic chain of the nanoparticles.Moreover,the droplet size of the Pickering emulsion can be tailored by varying the oil/water ratio and concentration of nanoparticles.