Geological samples often contain significant amounts of iron,which,although not typically the target element,can substantially interfere with the analysis of other elements of interest.To mitigate these interferences,...Geological samples often contain significant amounts of iron,which,although not typically the target element,can substantially interfere with the analysis of other elements of interest.To mitigate these interferences,amidoximebased radiation grafted adsorbents have been identified as effective for iron removal.In this study,an amidoximefunctionalized,radiation-grafted adsorbent synthesized from polypropylene waste(PPw-g-AO-10)was employed to remove iron from leached geological samples.The adsorption process was systematically optimized by investigating the effects of pH,contact time,adsorbent dosage,and initial ferric ion concentration.Under optimal conditions-pH1.4,a contact time of 90 min,and an initial ferric ion concentration of 4500 mg/L-the adsorbent exhibited a maximum iron adsorption capacity of 269.02 mg/g.After optimizing the critical adsorption parameters,the adsorbent was applied to the leached geological samples,achieving a 91%removal of the iron content.The adsorbent was regenerated through two consecutive cycles using 0.2 N HNO_(3),achieving a regeneration efficiency of 65%.These findings confirm the efficacy of the synthesized PPw-g-AO-10 as a cost-effective and eco-friendly adsorbent for successfully removing iron from leached geological matrices while maintaining a reasonable degree of reusability.展开更多
Melon fruit flavor is a key quality characteristic that influences consumer preference.Grafting is an effective technique to enhance fruit quality but yields divergent outcomes in terms of fruit flavor.To address this...Melon fruit flavor is a key quality characteristic that influences consumer preference.Grafting is an effective technique to enhance fruit quality but yields divergent outcomes in terms of fruit flavor.To address this problem,we analyzed parallel changes in flavor-related metabolite accumulation and gene expression in two pumpkin rootstock grafted melons during four fruit developmental stages.We identified 26061 expressed genes and 840 metabolites from 21 different compound classes,including carbohydrates,amino acids,and lipids.We also detected 50 aroma volatile compounds in the grafted melons.Results showed that genes and metabolites associated with metabolic pathways(carbohydrate,amino acid,lipid,and phenylpropanoid)play a key role in flavor formation.Compared with‘Sizhuang 12’,‘Tianzhen 1’rootstock improved melon fruit flavor by upregulating sugar-related genes(HK,MPI,MIOX,and STP)and inducing metabolite accumulation(d-ribose-5-phosphate,d-galactose,and trehalose 6-phosphate),whereas decreasing bitterness-related amino acids(l-arginine,l-asparagine,and l-tyrosine)and associated genes(thrC,ACS,and GLUL)expression at ripening stage.Furthermore,‘Tianzhen 1’exhibited higher expression levels of enzyme-coding genes(4CL,CSE,and COMT)responsible for aroma volatile synthesis than‘Sizhuang 12’rootstock.Taken together,our results decipher the basis of the molecular mechanism underlying fruit flavor in grafted melons and provide valuable information for the melons genetic improvement.展开更多
Grafting is widely used in cucumbers to enhance their tolerance to environmental stress.Compatibility is a key factor for successful grafting,however,the physiological mechanisms that affect grafting compatibility are...Grafting is widely used in cucumbers to enhance their tolerance to environmental stress.Compatibility is a key factor for successful grafting,however,the physiological mechanisms that affect grafting compatibility are not clear.This study aimed to investigate the physiological mechanism underlying cucumber/pumpkin grafting compatibility.Two pumpkin cultivars with significant differences in compatibility,Figleaf gourd(compatible rootstock,Cf)and Dongyangshenli(incompatible rootstock,Cmo),were used as rootstocks.Three cucumber cultivars with different growth rates were used as scions,including cucumber‘Shenluchunsi’(strong growth,V1),‘Cuilü’(weak growth,V2),and‘Liangyoulüjian 102’(medium growth,V3).Six grafting combinations(V1/Cf,V2/Cf,V3/Cf,V1/Cmo,V2/Cmo,and V3/Cmo)were used to analyze the effect of scion and rootstock varieties,as well as the chemical composition of the exudate from the stem cutting surface,on the compatibility of grafted plants.Here,we found that rootstock was closely correlated with the compatibility of cucumber/pumpkin grafted plants.The sucrose content in the exudate of the stem,enzyme activity,and the expression of genes related to sucrose biosynthesis in Cmo were significantly higher than those in Cf.Correlation analysis showed that the sucrose content difference between the exudate of rootstock and scion stems was negatively correlated with graft compatibility.Exogenous treatment with a 0.5%sucrose solution on the scions significantly reduced the difference in sucrose content between rootstock and scion and enhanced graft survival rate in the incompatible combination.The stem segment grafting experiment in vitro found that the high difference in sucrose concentration between the rootstock and scion decreased the grafting compatibility of cucumber/pumpkin by reducing the adhesion of the cutting surface.Taken together,the higher sucrose concentration difference between rootstock and scion decreased the adhesion of the cutting surface,resulting in the incompatibility of cucumber/pumpkin grafted plants.展开更多
[Objective] The research aimed to study the effects of reducing the concentrations of Mn2＋, Cu2＋ or Zn2＋ in nutrient solution on the contents of Mn, Cu and Zn of grafted cucumber leaves as well as on the SOD and is...[Objective] The research aimed to study the effects of reducing the concentrations of Mn2＋, Cu2＋ or Zn2＋ in nutrient solution on the contents of Mn, Cu and Zn of grafted cucumber leaves as well as on the SOD and isozymes activities and the rate of electrolytic leakage under cold stress. [Method] Nutrient solution containing low concentrations of Mn2＋, Cu2＋ or Zn2＋ were used for cultivating the grafted cucumber seedlings for the cold treatment. [Result] The results indicated that reducing the concentrations of Mn2＋, Cu2＋ or Zn2＋ in nutrient solution had declined the SOD activities in grafted cucumber leaves and increased the rates of electrolytic leakage. Mn2＋ had shown the maximum influences, followed by Cu2＋, and Zn2＋ had shown the minimum influences. [Conclusion] Cold resistance of cucumber can be improved by changing the contents of Mn2＋, Cu2＋ or Zn2＋ in nutrient solution.展开更多
Aim To determine the effect of silane grafted polypropylene on the property of different filler/polypropylene composites. Methods Polypropylene (PP) composites filled with talc(Ta), baryta sulfate and calcium carbonat...Aim To determine the effect of silane grafted polypropylene on the property of different filler/polypropylene composites. Methods Polypropylene (PP) composites filled with talc(Ta), baryta sulfate and calcium carbonate coupled with silane grafted polypropylene (PP-g-Si) were made, their mechanical properties and thermal properties were investigated, respectively. Results As compared with the non-coupled composites, the mechanical properties of PP/Ta/PP-g-Si composites were improved to some extent, though the values of tensile modulus and the strain at peak were decreased. But for PP/BaSO4 and PP/CaCO3 composites, the values of their mechanical properties varied slightly or even decreased with increasing PP-g-Si content within the experimental component. Meanwhile, PP-g-Si also affected the melting and crystallization behavior of PP in the composites. Conclusion PP-g-Si offers compatibilization in PP/Ta composites, but offers no-compatibilization in PP/BaSO4 and PP/CaCO3 composites within the extent of the present range of PP-g-Si, which shows that PP-g-Si can be used as the macromolecular coupling agent of PP and Ta composite.展开更多
Block copolymers are a class of soft matter that self-assemble to form ordered morphologies on the scale of nanome- ters, making them ideal materials for various applications. These applications directly depend on the...Block copolymers are a class of soft matter that self-assemble to form ordered morphologies on the scale of nanome- ters, making them ideal materials for various applications. These applications directly depend on the shape and size of the self-assembled morphologies, and hence, a high degree of control over the self-assembly is desired. Grafting block copolymer chains onto a substrate to form copolymer brushes is a versatile method to fabricate functional surfaces. Such surfaces demonstrate a response to their environment, i.e., they change their surface topography in response to different external conditions. Furthermore, such surfaces may possess nanoscale patterns, which are important for some applica- tions; however, such patterns may not form with spun-cast films under the same condition. In this review, we summarize the recent progress of the self-assembly of block copolymers grafted onto a flat substrate. We mainly concentrate on the self-assembled morphologies of end-grafted AB dibloek eopolymers, junction p0int-grafted AB diblock copolymers （i.e., Y-shaped brushes）, and end-grafted ABA triblock copolymers. Special emphasis is placed on theoretical and simulation progress.展开更多
[ Objective] The aim was to provide evidence and countermeasures for study on allelopathy of eggplant and supply a scientific basis for ecological management of allelopathy and establishment of a reasonable, effective...[ Objective] The aim was to provide evidence and countermeasures for study on allelopathy of eggplant and supply a scientific basis for ecological management of allelopathy and establishment of a reasonable, effective intercropping and continuous cropping system. [ Method] Allelopathy of aerial part extracts from grafted eggplants was studied by bioassay. [ Result] The results showed that aerial part extracts of eggplants have autotoxiclty which inhibited seed germination and seedling growth of eggplants. Aerial part extracts of grafted eggplants inhibited seed germination and seedling growth of tomato, pepper and cu cumber at different level. Inhibition intensity of extracts was in order of tomato 〉 pepper 〉 cucumber. The inhibition effect was higher at 0.2 g/ml concentration than 0.1 g/ml concentration. There wasn＇t significance between ownrooted treatments and grafted treatments. [ Conclusion] Eggplant is not suitable for round of inter-cropping with tomato, pepper and cucumber.展开更多
Root–shoot communication has a critical role in plant adaptation to environmental stress.Grafting is widely applied to enhance the abiotic stress tolerance of many horticultural crop species;however,the signal transd...Root–shoot communication has a critical role in plant adaptation to environmental stress.Grafting is widely applied to enhance the abiotic stress tolerance of many horticultural crop species;however,the signal transduction mechanism involved in this tolerance remains unknown.Here,we show that pumpkin-or figleaf gourd rootstock-enhanced cold tolerance of watermelon shoots is accompanied by increases in the accumulation of melatonin,methyl jasmonate(MeJA),and hydrogen peroxide(H_(2)O_(2)).Increased melatonin levels in leaves were associated with both increased melatonin in rootstocks and MeJA-induced melatonin biosynthesis in leaves of plants under cold stress.Exogenous melatonin increased the accumulation of MeJA and H_(2)O_(2) and enhanced cold tolerance,while inhibition of melatonin accumulation attenuated rootstock-induced MeJA and H_(2)O_(2) accumulation and cold tolerance.MeJA application induced H_(2)O_(2) accumulation and cold tolerance,but inhibition of JA biosynthesis abolished rootstock-or melatonin-induced H_(2)O_(2) accumulation and cold tolerance.Additionally,inhibition of H_(2)O_(2) production attenuated MeJA-induced tolerance to cold stress.Taken together,our results suggest that melatonin is involved in grafting-induced cold tolerance by inducing the accumulation of MeJA and H_(2)O_(2).MeJA subsequently increases melatonin accumulation,forming a self-amplifying feedback loop that leads to increased H_(2)O_(2) accumulation and cold tolerance.This study reveals a novel regulatory mechanism of rootstock-induced cold tolerance.展开更多
FLOWERING LOCUS T(FT)can promote early flowering in annual species,but such role has not been well demonstrated in woody species.We produced self and reciprocal grafts involving non-transgenic blueberry(NT)and transge...FLOWERING LOCUS T(FT)can promote early flowering in annual species,but such role has not been well demonstrated in woody species.We produced self and reciprocal grafts involving non-transgenic blueberry(NT)and transgenic blueberry(T)carrying a 35S-driven blueberry FT(VcFT-OX).We demonstrated that the transgenic VcFT-OX rootstock promoted flowering of non-transgenic blueberry scions in the NT(scion):T(rootstock)grafts.We further analyzed RNASeq profiles and six groups of phytohormones in both NT:T and NT:NT plants.We observed content changes of several hormone metabolites,in a descending order,in the transgenic NT:T,non-transgenic NT:T,and non-transgenic NT:NT leaves.By comparing differential expression transcripts(DETs)of these tissues in relative to their control,we found that the non-transgenic NT:T leaves had many DETs shared with the transgenic NT:T leaves,but very few with the transgenic NT:T roots.Interestingly,a number of these shared DETs belong to hormone pathway genes,concurring with the content changes of hormone metabolites in both transgenic and non-transgenic leaves of the NT:T plants.These results suggest that phytohormones induced by VcFT-OX in the transgenic leaves might serve as part of the signals that resulted in early flowering in both transgenic plants and the non-transgenic NT:T scions.展开更多
In this study, biologically inspired silk fibroin grafted polyacrylonitrile(SF-g-PAN) filtration membrane was prepared using ZnCl_2 aqueous solution as solvent, avoiding the use of organic solvents. Phase inversion oc...In this study, biologically inspired silk fibroin grafted polyacrylonitrile(SF-g-PAN) filtration membrane was prepared using ZnCl_2 aqueous solution as solvent, avoiding the use of organic solvents. Phase inversion occurred when Zn^(2+)and Cl-ions gradually diffused into water, creating a well-connected ion channel network and the SF-g-PAN filtration membrane was obtained. The membranes were observed by SEM and 3D ultra-depth microscope. The hydrophilic property, pore size distribution and dye rejection of the membrane were investigated. Results showed that the membrane has no finger hole formation because ZnCl_2 aqueous solution has a lower curing rate parameter compared with organic solvents. SF-gPAN membrane possessed good anti-fouling properties and pH sensitivity. The pore size distribution of the SF-g-PAN membrane was 0.25–1.04 nm. The rejection of direct yellow 27(Mw = 662.6) and amaranth(Mw = 604.5) was 96.51% and 30.63%, with the flux of 72.32 L m^(-2) h^(-1) and 73.83 L m^(-2) h^(-1) respectively at0.1 MPa. The SF-g-PAN membrane has a wide range of applications prospect in fine separation, dye desalination, waste water treatment and biomedical fields.展开更多
Metal(Al,Ti,Zr)triflate grafted mesoporous SBA‐15(AlTf/S,TiTf/S,ZrTf/S)samples were synthesizedas inexpensive solid acid materials by a simple one‐pot‐two‐step synthesis methodology.These materials were characteri...Metal(Al,Ti,Zr)triflate grafted mesoporous SBA‐15(AlTf/S,TiTf/S,ZrTf/S)samples were synthesizedas inexpensive solid acid materials by a simple one‐pot‐two‐step synthesis methodology.These materials were characterized by X‐ray diffraction,N2‐sorption,thermogravimetric analysis,Fourier transform infrared spectroscopy(FT‐IR),in‐situ pyridine FT‐IR spectroscopy,and elementalanalysis.ZrTf/S was found to be a highly efficient and reusable solid acid catalyst for ring opening ofepoxides with amines and alcohols and producedβ‐amino alcohols andβ‐alkoxy alcohols respectivelyunder ambient reaction conditions.The ZrTf/S catalyst showed the highest activity,whichwas attributed to its high acidity compared with that of the Ti and Al containing samples.展开更多
The aim of this study is to determine the effects of deficit irrigation on nitrogen consumption,yield,and quality in grafted and ungrafted watermelon.The study was conducted in Cukurova region,Eastern Mediterranean,Tu...The aim of this study is to determine the effects of deficit irrigation on nitrogen consumption,yield,and quality in grafted and ungrafted watermelon.The study was conducted in Cukurova region,Eastern Mediterranean,Turkey,between 2006 and 2008,and employed 3 irrigation rates（full irrigation（l_（100）） with no stress,moderate irrigation（Dl_（70））,and low irrigation（Dl_（50））;Dl_（70） and Dl_（50） were considered deficit irrigation） on grafted（CTJ,Crimson Tide＋Jumbo） and the ungrafted（CT,Crimson Tide） watermelon.The amount of irrigation water（IR） applied to the study plots were calculated based on cumulative pan evaporation that occurred during the irrigation intervals.Nitrogen consumption was 16%lower in CTJ plants than in CT plants.On the other hand,consumption of nitrogen was 28%higher in Dl_（50） plants than in Dl_（70） plants while it was 23%higher in Dl_（50） plants than in l_（100） plants.By grafting,the average amount of nitrogen content in seeds,pulps and peels for CTJ was 30,43 and 56%more than those of CT,respectively.The yield and the quality were not significantly affected by the deficit irrigation.In this respect,grafting of watermelon gave higher yield,but,it had a slight effect on fruit quality.The highest yield values of 16.90 and 19.32 kg plant^（-1） in 2008 were obtained with l_（100）and in CTJ plants,respectively.However,Dl_（50） treatment could be taken into account for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited.Additionally,the yield increased by applying CTJ treatment to the watermelon production.展开更多
The NAC transcription factor is a type of plant-specific transcription factor that can regulate plant salt tolerance,but the underlying mechanism is unclear in grafted vegetables.H2O2 and ABA in pumpkin rootstocks can...The NAC transcription factor is a type of plant-specific transcription factor that can regulate plant salt tolerance,but the underlying mechanism is unclear in grafted vegetables.H2O2 and ABA in pumpkin rootstocks can be transported to cucumber scion leaves,promoting stomatal closure to improve salt tolerance of grafted cucumbers.Despite these observations,the regulatory mechanism is unknown.Here,our research revealed that CmoNAC1 is a key transcription factor that regulates H_(2)O_(2) and ABA signaling in pumpkin roots under salt stress.The function of CmoNAC1 was analyzed using root transformation and RNA-seq,and we found that pumpkin CmoNAC1 promoted the production of H_(2)O_(2) and ABA via CmoRBOHD1 and CmoNCED6,respectively,and regulated K^(+)/Na^(+) homeostasis via CmoAKT1;2,CmoHKT1;1,and CmoSOS1 to improve salt tolerance of grafted cucumbers.Root knockout of CmoNAC1 resulted in a significant decrease in H_(2)O_(2)(52.9%and 32.1%)and ABA(21.8%and 42.7%)content and K^(+)/Na^(+) ratio(81.5%and 56.3%)in leaf and roots of grafted cucumber,respectively,while overexpression showed the opposite effect.The root transformation experiment showed that CmoNCED6 could improve salt tolerance of grafted cucumbers by regulating ABA production and K^(+)/Na^(+) homeostasis under salt stress.Finally,we found that CmoNAC1 bound to the promoters of CmoRBOHD1,CmoNCED6,CmoAKT1;2,and CmoHKT1;1 using yeast one-hybrid,luciferase,and electrophoretic mobility shift assays.In conclusion,pumpkin CmoNAC1 not only binds to the promoters of CmoRBOHD1 and CmoNCED6 to regulate the production of H_(2)O_(2) and ABA signals in roots,but also binds to the promoters of CmoAKT1;2 and CmoHKT1;1 to increase the K^(+)/Na^(+) ratio,thus improving salt tolerance of grafted cucumbers.展开更多
The objective of this study was to investigate the potential of methoxy polyethylene glycol（m PEG）grafted chitosan（m PEG-g-CS） to be used as a drug carrier. m PEG-g-CS was successfully synthesized by one-step meth...The objective of this study was to investigate the potential of methoxy polyethylene glycol（m PEG）grafted chitosan（m PEG-g-CS） to be used as a drug carrier. m PEG-g-CS was successfully synthesized by one-step method with formaldehyde. The substitution degree of m PEG on chitosan was calculated by elemental analysis and was found to be（3.23 0.25）%. m PEG-g-CS self-assembled micelles were prepared by ultrasonic method with the controlled size of 178.5–195.1 nm and spherical morphology. Stable dispersion of the micelles was formed with the zeta potential of 2.3–30.2 m V. 5-Fluorouracil（5-FU）, an anticancer chemotherapy drug, was used as a model drug to evaluate the efficiency of the new drug delivery carrier. The loading efficiency of 5-FU was（4.01 0.03）%, and the drug-loaded m PEG-g-CS self-assembled micelle showed a controlled-release effect. In summary, the m PEG-g-CS self-assembled micelle is proved to be a promising carrier with controlled particle size and controlled-release effect. Therefore, it has great potential for the application as 5-FU carriers for effective anti-tumor activity.展开更多
Taking Cucurbita maxima and Cucurbita moschata as root stocks,and‘Jinyou No 3'cucumber as scion,the effects of different root zone temperature conditions optimal temperature(CK)(18-20℃),suboptimal temperature(13...Taking Cucurbita maxima and Cucurbita moschata as root stocks,and‘Jinyou No 3'cucumber as scion,the effects of different root zone temperature conditions optimal temperature(CK)(18-20℃),suboptimal temperature(13-15℃)and low temperature(8-10℃)on the growth and photosynthesis indexes were studied.The results showed that,compared with optimal temperature(CK),suboptimal temperature and low temperature produced a significant inhibition of growth on cucumbers.The plant height,stem diameter,leaf area,number of leaves and dry weight of aboveground part were all reduced,dry weight of underground part and root shoot ratio all increased,while the inhibition was more significant at low temperature.Low and suboptimal temperature conditions also reduced SPAD value,net photosynthetic rate,transpiration rate,intercellular CO_(2) concentration and stomatal conductance of the grafted cucumber.And there were differences between different grafted seedlings,and seedlings with‘black seeds'as stock performed better than those with‘white seeds'as stock at low temperature.展开更多
Well-defined polypropylene grafted silica nanoparticles(PP-g-SiO_(2))were prepared through the reaction of maleic anhydride grafted polypropylene(PP-g-MAH)with amino-functionalized silica(SiO_(2)-NH_(2))by the'gra...Well-defined polypropylene grafted silica nanoparticles(PP-g-SiO_(2))were prepared through the reaction of maleic anhydride grafted polypropylene(PP-g-MAH)with amino-functionalized silica(SiO_(2)-NH_(2))by the'grafting-to'method.The grafting density of PP-g-SiO_(2) is found to be controlled by the concentration of silane coupling agent 3-[2-(2-aminoethylamino)ethyl amino]propyl trimethoxy silane(TAMS).The maximum grafting density of grafted PP-g-MAH chains with molecular weight of 9100 g/mol could reach 0.34 chains/nm~2,when the critical concentration of TAMS was 0.0194 mol/L.The critical concentration of TAMS can be explained by the maximum amounts of primary amino groups,which can totally react with PP-g-MAH on the surface of SiO_(2)-NH_(2),when the silane monolayer is formed.The synthesized PP-g-SiO_(2)with different molecular weights was mixed with PP by solution mixing to form a series of nanocomposites.The crystallization temperature(T_(c))of nanocomposites increased significantly with the particle loading.The PP-g-SiO_(2) with high molecular weight of grafted chains exhibits a high nucleation ability at 1 wt%nanoparticle loading in PP/PP-g-SiO_(2)nanocomposites.In summary,we provide an effective method to synthesize the well-defined PP-g-SiO_(2)with controlled grafting density,which shows excellent nucleation ability.展开更多
This paper presented an interesting nanoparticle-based drug delivery system with morphology transition behavior depending on the content of exposed PEG chain on the particle surface, which is adjustable by addition of...This paper presented an interesting nanoparticle-based drug delivery system with morphology transition behavior depending on the content of exposed PEG chain on the particle surface, which is adjustable by addition of different amount of cyclodextrin(α-CD). The effect of α-CD inclusion to the self-assembly behavior of methoxy polyethylene glycol(mPEG) grafted chitosan(CS) was studied. The results showed that the mPEG grafted chitosan(mPEG-g-CS) forms self-assembled nanoparticles with either micelle or hollow sphere morphology depending on the ratio of α-CD to mPEG, as characterized by atomic force microscopy(AFM), transmission electron microscopy(TEM), and X-ray diffraction(XRD). Their sizes and zeta potential increased from 257.6 nmto 768.2 nm and from +4.5 mV to +11.6 mV, respectively, with the increasing amount of α-CD. The correlation between zeta potential and particle size of α-CD/mPEG-g-CS nanoparticles indicated varied PEG density on surface of nanoparticles. Based on the above experimental observations, a likely mechanism for the morphological transition of the rod-coil graft copolymer mPEG-g-CS was proposed.展开更多
Contolling the formation of the conductive network in the polymer nanocomposites(PNCs)is very meaningful to enhance their electrical property.In this work,we investigated the effect of grafted nanoparticles(NPs)on the...Contolling the formation of the conductive network in the polymer nanocomposites(PNCs)is very meaningful to enhance their electrical property.In this work,we investigated the effect of grafted nanoparticles(NPs)on the conductive probability of PNCs in the quiescent state as well as under the shear field via a coarse grained molecular dynamics simulation.It is found that the smallest percolation threshold is realized at the moderate grafting density,the moderate length of grafted chains or the moderate interaction between grafted chains and free chains.Corresponding to it,the dispersion state of NPs varies from the contact aggregation to the uniform dispersion.By analyzing the connection mode among NPs,the probabilty of NPs which connect three other ones reaches the maximum value at their moderate dispersion state which is responsible for the optimal conductive probability.In addition,the main cluster size is characterized to better understand the conductive network which is consistent with the percolation threshold.It is interesting to find that the percolation threshold is smaller under the shear field than under the quiescent state.The shear field induces more NPs which connect three other ones.This benefits the formation of the new conductive network.Meanwhile,the anisotropy of the conductive probability is reduced with increasing the grafting density.In summary,this work provides a clear picture on how the conductive network of grafted NPs evolves under the shear field.展开更多
[Objectives]This study was conducted to explore how to improve the waterlogging tolerance of red-seed watermelon through grafting,to provide a theoretical basis for its cultivation in rainy season.[Methods]The effects...[Objectives]This study was conducted to explore how to improve the waterlogging tolerance of red-seed watermelon through grafting,to provide a theoretical basis for its cultivation in rainy season.[Methods]The effects of flooding stress on the growth and root physiological and biochemical characteristics of grafted and own-rooted red-seed watermelon seedlings were studied using Luffa as rootstocks and"Zhongxin 1"red-seed watermelon as scions.[Results]After flooding stress,the biomass and root activity of grafted seedlings of red-seed watermelon were significantly higher than those of own-rooted seedlings.With the prolongation of flooding stress time,the soluble sugar and proline content showed a trend of first increasing and then decreasing,and the grafted seedlings had a larger increase and a smaller decrease,and were always significantly higher than own-rooted seedlings in the same period.The content of malondialdehyde in the root system of grafted seedlings increased first and then decreased,while it continued to increase in own-rooted seedlings,and the increase in own-rooted seedlings was significantly greater than that in grafted seedlings during the same period.[Conclusions]Grafting on Luffa rootstocks could improve waterlogging tolerance of red-seed watermelon.展开更多
By means of initiation of the high temperature and shearing stress of an extruder,we synthesized the graft copolymer of starch with acrylate monomers based on the simple dry method.The eff...By means of initiation of the high temperature and shearing stress of an extruder,we synthesized the graft copolymer of starch with acrylate monomers based on the simple dry method.The effects of reaction conditions on graft copolymerization were discussed. Grafted starch used as a compatibilizer for the blend system of starch and polyethylene was further investigated. The results indicate that grafted starch as a compatibilizer can improve the mechanical properties and rheologic properties of the blend of starch and polyethylene.展开更多
文摘Geological samples often contain significant amounts of iron,which,although not typically the target element,can substantially interfere with the analysis of other elements of interest.To mitigate these interferences,amidoximebased radiation grafted adsorbents have been identified as effective for iron removal.In this study,an amidoximefunctionalized,radiation-grafted adsorbent synthesized from polypropylene waste(PPw-g-AO-10)was employed to remove iron from leached geological samples.The adsorption process was systematically optimized by investigating the effects of pH,contact time,adsorbent dosage,and initial ferric ion concentration.Under optimal conditions-pH1.4,a contact time of 90 min,and an initial ferric ion concentration of 4500 mg/L-the adsorbent exhibited a maximum iron adsorption capacity of 269.02 mg/g.After optimizing the critical adsorption parameters,the adsorbent was applied to the leached geological samples,achieving a 91%removal of the iron content.The adsorbent was regenerated through two consecutive cycles using 0.2 N HNO_(3),achieving a regeneration efficiency of 65%.These findings confirm the efficacy of the synthesized PPw-g-AO-10 as a cost-effective and eco-friendly adsorbent for successfully removing iron from leached geological matrices while maintaining a reasonable degree of reusability.
基金supported by the National Natural Science Foundation of China(31972435)to Jintao Cheng,and Agriculture Research System of MOF and MORA(CARS-25)Natural Science Foundation of Hubei Province(2019CFA017)Ningbo Scientific and Technological Project(2021Z006)to Zhilong Bie.
文摘Melon fruit flavor is a key quality characteristic that influences consumer preference.Grafting is an effective technique to enhance fruit quality but yields divergent outcomes in terms of fruit flavor.To address this problem,we analyzed parallel changes in flavor-related metabolite accumulation and gene expression in two pumpkin rootstock grafted melons during four fruit developmental stages.We identified 26061 expressed genes and 840 metabolites from 21 different compound classes,including carbohydrates,amino acids,and lipids.We also detected 50 aroma volatile compounds in the grafted melons.Results showed that genes and metabolites associated with metabolic pathways(carbohydrate,amino acid,lipid,and phenylpropanoid)play a key role in flavor formation.Compared with‘Sizhuang 12’,‘Tianzhen 1’rootstock improved melon fruit flavor by upregulating sugar-related genes(HK,MPI,MIOX,and STP)and inducing metabolite accumulation(d-ribose-5-phosphate,d-galactose,and trehalose 6-phosphate),whereas decreasing bitterness-related amino acids(l-arginine,l-asparagine,and l-tyrosine)and associated genes(thrC,ACS,and GLUL)expression at ripening stage.Furthermore,‘Tianzhen 1’exhibited higher expression levels of enzyme-coding genes(4CL,CSE,and COMT)responsible for aroma volatile synthesis than‘Sizhuang 12’rootstock.Taken together,our results decipher the basis of the molecular mechanism underlying fruit flavor in grafted melons and provide valuable information for the melons genetic improvement.
基金supported by grants from the Gansu Provincial Science and Technology Plan Project(Grant No.22CX8NA030)the National Natural Science Foundation of China(Grant No.32272793)the China Agriculture Research System(Grant No.CARS-23).
文摘Grafting is widely used in cucumbers to enhance their tolerance to environmental stress.Compatibility is a key factor for successful grafting,however,the physiological mechanisms that affect grafting compatibility are not clear.This study aimed to investigate the physiological mechanism underlying cucumber/pumpkin grafting compatibility.Two pumpkin cultivars with significant differences in compatibility,Figleaf gourd(compatible rootstock,Cf)and Dongyangshenli(incompatible rootstock,Cmo),were used as rootstocks.Three cucumber cultivars with different growth rates were used as scions,including cucumber‘Shenluchunsi’(strong growth,V1),‘Cuilü’(weak growth,V2),and‘Liangyoulüjian 102’(medium growth,V3).Six grafting combinations(V1/Cf,V2/Cf,V3/Cf,V1/Cmo,V2/Cmo,and V3/Cmo)were used to analyze the effect of scion and rootstock varieties,as well as the chemical composition of the exudate from the stem cutting surface,on the compatibility of grafted plants.Here,we found that rootstock was closely correlated with the compatibility of cucumber/pumpkin grafted plants.The sucrose content in the exudate of the stem,enzyme activity,and the expression of genes related to sucrose biosynthesis in Cmo were significantly higher than those in Cf.Correlation analysis showed that the sucrose content difference between the exudate of rootstock and scion stems was negatively correlated with graft compatibility.Exogenous treatment with a 0.5%sucrose solution on the scions significantly reduced the difference in sucrose content between rootstock and scion and enhanced graft survival rate in the incompatible combination.The stem segment grafting experiment in vitro found that the high difference in sucrose concentration between the rootstock and scion decreased the grafting compatibility of cucumber/pumpkin by reducing the adhesion of the cutting surface.Taken together,the higher sucrose concentration difference between rootstock and scion decreased the adhesion of the cutting surface,resulting in the incompatibility of cucumber/pumpkin grafted plants.
基金Supported by Shandong Provincial Outstanding Young Scientist Research Award Fund(BS2009NY016)National Natural Science Foundation(30571271)~~
文摘[Objective] The research aimed to study the effects of reducing the concentrations of Mn2＋, Cu2＋ or Zn2＋ in nutrient solution on the contents of Mn, Cu and Zn of grafted cucumber leaves as well as on the SOD and isozymes activities and the rate of electrolytic leakage under cold stress. [Method] Nutrient solution containing low concentrations of Mn2＋, Cu2＋ or Zn2＋ were used for cultivating the grafted cucumber seedlings for the cold treatment. [Result] The results indicated that reducing the concentrations of Mn2＋, Cu2＋ or Zn2＋ in nutrient solution had declined the SOD activities in grafted cucumber leaves and increased the rates of electrolytic leakage. Mn2＋ had shown the maximum influences, followed by Cu2＋, and Zn2＋ had shown the minimum influences. [Conclusion] Cold resistance of cucumber can be improved by changing the contents of Mn2＋, Cu2＋ or Zn2＋ in nutrient solution.
文摘Aim To determine the effect of silane grafted polypropylene on the property of different filler/polypropylene composites. Methods Polypropylene (PP) composites filled with talc(Ta), baryta sulfate and calcium carbonate coupled with silane grafted polypropylene (PP-g-Si) were made, their mechanical properties and thermal properties were investigated, respectively. Results As compared with the non-coupled composites, the mechanical properties of PP/Ta/PP-g-Si composites were improved to some extent, though the values of tensile modulus and the strain at peak were decreased. But for PP/BaSO4 and PP/CaCO3 composites, the values of their mechanical properties varied slightly or even decreased with increasing PP-g-Si content within the experimental component. Meanwhile, PP-g-Si also affected the melting and crystallization behavior of PP in the composites. Conclusion PP-g-Si offers compatibilization in PP/Ta composites, but offers no-compatibilization in PP/BaSO4 and PP/CaCO3 composites within the extent of the present range of PP-g-Si, which shows that PP-g-Si can be used as the macromolecular coupling agent of PP and Ta composite.
基金supported by the National Natural Science Foundation of China(Grant Nos.20990234,20925414,and 91227121)the Program for Changjiang Scholars and Innovative Research Team in University,China(Grant No.IRT1257)+1 种基金the Programme of Introducing Talents of Discipline to Universities,Chinaby the Tianhe No.1,China
文摘Block copolymers are a class of soft matter that self-assemble to form ordered morphologies on the scale of nanome- ters, making them ideal materials for various applications. These applications directly depend on the shape and size of the self-assembled morphologies, and hence, a high degree of control over the self-assembly is desired. Grafting block copolymer chains onto a substrate to form copolymer brushes is a versatile method to fabricate functional surfaces. Such surfaces demonstrate a response to their environment, i.e., they change their surface topography in response to different external conditions. Furthermore, such surfaces may possess nanoscale patterns, which are important for some applica- tions; however, such patterns may not form with spun-cast films under the same condition. In this review, we summarize the recent progress of the self-assembly of block copolymers grafted onto a flat substrate. We mainly concentrate on the self-assembled morphologies of end-grafted AB dibloek eopolymers, junction p0int-grafted AB diblock copolymers （i.e., Y-shaped brushes）, and end-grafted ABA triblock copolymers. Special emphasis is placed on theoretical and simulation progress.
基金Supported by National Natural Science Foundation of China(30370971)863 Program of China(2004AA247010)And theResearch Project of Liaoning Education Department(2004D206)~~
文摘[ Objective] The aim was to provide evidence and countermeasures for study on allelopathy of eggplant and supply a scientific basis for ecological management of allelopathy and establishment of a reasonable, effective intercropping and continuous cropping system. [ Method] Allelopathy of aerial part extracts from grafted eggplants was studied by bioassay. [ Result] The results showed that aerial part extracts of eggplants have autotoxiclty which inhibited seed germination and seedling growth of eggplants. Aerial part extracts of grafted eggplants inhibited seed germination and seedling growth of tomato, pepper and cu cumber at different level. Inhibition intensity of extracts was in order of tomato 〉 pepper 〉 cucumber. The inhibition effect was higher at 0.2 g/ml concentration than 0.1 g/ml concentration. There wasn＇t significance between ownrooted treatments and grafted treatments. [ Conclusion] Eggplant is not suitable for round of inter-cropping with tomato, pepper and cucumber.
基金the National Key Research and Development Program of China(2018YFD1000800)the National Natural Science Foundation of China(31801884,31972479)+1 种基金the Earmarked Fund for Modern Agroindustry Technology Research System of China(CARS-25)the Tang Scholar of Northwest A&F University.
文摘Root–shoot communication has a critical role in plant adaptation to environmental stress.Grafting is widely applied to enhance the abiotic stress tolerance of many horticultural crop species;however,the signal transduction mechanism involved in this tolerance remains unknown.Here,we show that pumpkin-or figleaf gourd rootstock-enhanced cold tolerance of watermelon shoots is accompanied by increases in the accumulation of melatonin,methyl jasmonate(MeJA),and hydrogen peroxide(H_(2)O_(2)).Increased melatonin levels in leaves were associated with both increased melatonin in rootstocks and MeJA-induced melatonin biosynthesis in leaves of plants under cold stress.Exogenous melatonin increased the accumulation of MeJA and H_(2)O_(2) and enhanced cold tolerance,while inhibition of melatonin accumulation attenuated rootstock-induced MeJA and H_(2)O_(2) accumulation and cold tolerance.MeJA application induced H_(2)O_(2) accumulation and cold tolerance,but inhibition of JA biosynthesis abolished rootstock-or melatonin-induced H_(2)O_(2) accumulation and cold tolerance.Additionally,inhibition of H_(2)O_(2) production attenuated MeJA-induced tolerance to cold stress.Taken together,our results suggest that melatonin is involved in grafting-induced cold tolerance by inducing the accumulation of MeJA and H_(2)O_(2).MeJA subsequently increases melatonin accumulation,forming a self-amplifying feedback loop that leads to increased H_(2)O_(2) accumulation and cold tolerance.This study reveals a novel regulatory mechanism of rootstock-induced cold tolerance.
文摘FLOWERING LOCUS T(FT)can promote early flowering in annual species,but such role has not been well demonstrated in woody species.We produced self and reciprocal grafts involving non-transgenic blueberry(NT)and transgenic blueberry(T)carrying a 35S-driven blueberry FT(VcFT-OX).We demonstrated that the transgenic VcFT-OX rootstock promoted flowering of non-transgenic blueberry scions in the NT(scion):T(rootstock)grafts.We further analyzed RNASeq profiles and six groups of phytohormones in both NT:T and NT:NT plants.We observed content changes of several hormone metabolites,in a descending order,in the transgenic NT:T,non-transgenic NT:T,and non-transgenic NT:NT leaves.By comparing differential expression transcripts(DETs)of these tissues in relative to their control,we found that the non-transgenic NT:T leaves had many DETs shared with the transgenic NT:T leaves,but very few with the transgenic NT:T roots.Interestingly,a number of these shared DETs belong to hormone pathway genes,concurring with the content changes of hormone metabolites in both transgenic and non-transgenic leaves of the NT:T plants.These results suggest that phytohormones induced by VcFT-OX in the transgenic leaves might serve as part of the signals that resulted in early flowering in both transgenic plants and the non-transgenic NT:T scions.
基金supported by the National Natural Science Foundation of China (Nos. 51678409, 145 708407, 21476172)Tianjin Science Technology Research Funds of China (Nos. 16JCZDJC37500, 15JCZDJC38300)+1 种基金Program for Innovative Research Team in University of Tianjin (No. TD13-5042)Science Foundation for the Youth Teachers of Peking Union Medical College (No. 2014ZLGC0754)
文摘In this study, biologically inspired silk fibroin grafted polyacrylonitrile(SF-g-PAN) filtration membrane was prepared using ZnCl_2 aqueous solution as solvent, avoiding the use of organic solvents. Phase inversion occurred when Zn^(2+)and Cl-ions gradually diffused into water, creating a well-connected ion channel network and the SF-g-PAN filtration membrane was obtained. The membranes were observed by SEM and 3D ultra-depth microscope. The hydrophilic property, pore size distribution and dye rejection of the membrane were investigated. Results showed that the membrane has no finger hole formation because ZnCl_2 aqueous solution has a lower curing rate parameter compared with organic solvents. SF-gPAN membrane possessed good anti-fouling properties and pH sensitivity. The pore size distribution of the SF-g-PAN membrane was 0.25–1.04 nm. The rejection of direct yellow 27(Mw = 662.6) and amaranth(Mw = 604.5) was 96.51% and 30.63%, with the flux of 72.32 L m^(-2) h^(-1) and 73.83 L m^(-2) h^(-1) respectively at0.1 MPa. The SF-g-PAN membrane has a wide range of applications prospect in fine separation, dye desalination, waste water treatment and biomedical fields.
基金supported by the CAS President’s International Fellowship Initiative (2016PT028)the National Natural Science Foundation of China (21273225 and 21403219)~~
文摘Metal(Al,Ti,Zr)triflate grafted mesoporous SBA‐15(AlTf/S,TiTf/S,ZrTf/S)samples were synthesizedas inexpensive solid acid materials by a simple one‐pot‐two‐step synthesis methodology.These materials were characterized by X‐ray diffraction,N2‐sorption,thermogravimetric analysis,Fourier transform infrared spectroscopy(FT‐IR),in‐situ pyridine FT‐IR spectroscopy,and elementalanalysis.ZrTf/S was found to be a highly efficient and reusable solid acid catalyst for ring opening ofepoxides with amines and alcohols and producedβ‐amino alcohols andβ‐alkoxy alcohols respectivelyunder ambient reaction conditions.The ZrTf/S catalyst showed the highest activity,whichwas attributed to its high acidity compared with that of the Ti and Al containing samples.
基金the University of cukurova,Turkey,for providing funding through the Scientific Research Projects of Qukurova University(ZF2006D16 and ZF2008BAP1)
文摘The aim of this study is to determine the effects of deficit irrigation on nitrogen consumption,yield,and quality in grafted and ungrafted watermelon.The study was conducted in Cukurova region,Eastern Mediterranean,Turkey,between 2006 and 2008,and employed 3 irrigation rates（full irrigation（l_（100）） with no stress,moderate irrigation（Dl_（70））,and low irrigation（Dl_（50））;Dl_（70） and Dl_（50） were considered deficit irrigation） on grafted（CTJ,Crimson Tide＋Jumbo） and the ungrafted（CT,Crimson Tide） watermelon.The amount of irrigation water（IR） applied to the study plots were calculated based on cumulative pan evaporation that occurred during the irrigation intervals.Nitrogen consumption was 16%lower in CTJ plants than in CT plants.On the other hand,consumption of nitrogen was 28%higher in Dl_（50） plants than in Dl_（70） plants while it was 23%higher in Dl_（50） plants than in l_（100） plants.By grafting,the average amount of nitrogen content in seeds,pulps and peels for CTJ was 30,43 and 56%more than those of CT,respectively.The yield and the quality were not significantly affected by the deficit irrigation.In this respect,grafting of watermelon gave higher yield,but,it had a slight effect on fruit quality.The highest yield values of 16.90 and 19.32 kg plant^（-1） in 2008 were obtained with l_（100）and in CTJ plants,respectively.However,Dl_（50） treatment could be taken into account for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited.Additionally,the yield increased by applying CTJ treatment to the watermelon production.
基金supported by grants from the National Natural Science Foundation of China(31772357,32072653)the Natural Science Foundation of Hubei Province(2019CFA017)+1 种基金the Fundamental Research Funds for the Central Universities(2662023YLPY008)the Ningbo Scientific and Technological Project(2021Z006).
文摘The NAC transcription factor is a type of plant-specific transcription factor that can regulate plant salt tolerance,but the underlying mechanism is unclear in grafted vegetables.H2O2 and ABA in pumpkin rootstocks can be transported to cucumber scion leaves,promoting stomatal closure to improve salt tolerance of grafted cucumbers.Despite these observations,the regulatory mechanism is unknown.Here,our research revealed that CmoNAC1 is a key transcription factor that regulates H_(2)O_(2) and ABA signaling in pumpkin roots under salt stress.The function of CmoNAC1 was analyzed using root transformation and RNA-seq,and we found that pumpkin CmoNAC1 promoted the production of H_(2)O_(2) and ABA via CmoRBOHD1 and CmoNCED6,respectively,and regulated K^(+)/Na^(+) homeostasis via CmoAKT1;2,CmoHKT1;1,and CmoSOS1 to improve salt tolerance of grafted cucumbers.Root knockout of CmoNAC1 resulted in a significant decrease in H_(2)O_(2)(52.9%and 32.1%)and ABA(21.8%and 42.7%)content and K^(+)/Na^(+) ratio(81.5%and 56.3%)in leaf and roots of grafted cucumber,respectively,while overexpression showed the opposite effect.The root transformation experiment showed that CmoNCED6 could improve salt tolerance of grafted cucumbers by regulating ABA production and K^(+)/Na^(+) homeostasis under salt stress.Finally,we found that CmoNAC1 bound to the promoters of CmoRBOHD1,CmoNCED6,CmoAKT1;2,and CmoHKT1;1 using yeast one-hybrid,luciferase,and electrophoretic mobility shift assays.In conclusion,pumpkin CmoNAC1 not only binds to the promoters of CmoRBOHD1 and CmoNCED6 to regulate the production of H_(2)O_(2) and ABA signals in roots,but also binds to the promoters of CmoAKT1;2 and CmoHKT1;1 to increase the K^(+)/Na^(+) ratio,thus improving salt tolerance of grafted cucumbers.
基金support from the Fundamental Research Funds for the Central Universities(No.WY1213013ECUST)supported by Science and Technology Commission of Shanghai Municipality(STCSM,contract Nos.11DZ2260600 and 10DZ2220500)
文摘The objective of this study was to investigate the potential of methoxy polyethylene glycol（m PEG）grafted chitosan（m PEG-g-CS） to be used as a drug carrier. m PEG-g-CS was successfully synthesized by one-step method with formaldehyde. The substitution degree of m PEG on chitosan was calculated by elemental analysis and was found to be（3.23 0.25）%. m PEG-g-CS self-assembled micelles were prepared by ultrasonic method with the controlled size of 178.5–195.1 nm and spherical morphology. Stable dispersion of the micelles was formed with the zeta potential of 2.3–30.2 m V. 5-Fluorouracil（5-FU）, an anticancer chemotherapy drug, was used as a model drug to evaluate the efficiency of the new drug delivery carrier. The loading efficiency of 5-FU was（4.01 0.03）%, and the drug-loaded m PEG-g-CS self-assembled micelle showed a controlled-release effect. In summary, the m PEG-g-CS self-assembled micelle is proved to be a promising carrier with controlled particle size and controlled-release effect. Therefore, it has great potential for the application as 5-FU carriers for effective anti-tumor activity.
基金Supported by National Natural Science Foundation of China(31060269)Science and Technology Planning Project of the Inner Mongolia Autonomous Region(20110710)+2 种基金Doctor Station Fund of Ministry of Education(20101515110005)Program of Research and Innovation for Graduate Students in Inner Mongolia(B20151012904Z)Science Research Project of Colleges and Universities in the Inner Mongolia Autonomous Region(NJZY060,NJZC17068)
文摘Taking Cucurbita maxima and Cucurbita moschata as root stocks,and‘Jinyou No 3'cucumber as scion,the effects of different root zone temperature conditions optimal temperature(CK)(18-20℃),suboptimal temperature(13-15℃)and low temperature(8-10℃)on the growth and photosynthesis indexes were studied.The results showed that,compared with optimal temperature(CK),suboptimal temperature and low temperature produced a significant inhibition of growth on cucumbers.The plant height,stem diameter,leaf area,number of leaves and dry weight of aboveground part were all reduced,dry weight of underground part and root shoot ratio all increased,while the inhibition was more significant at low temperature.Low and suboptimal temperature conditions also reduced SPAD value,net photosynthetic rate,transpiration rate,intercellular CO_(2) concentration and stomatal conductance of the grafted cucumber.And there were differences between different grafted seedlings,and seedlings with‘black seeds'as stock performed better than those with‘white seeds'as stock at low temperature.
基金financially supported by the National Natural Science Foundation of China(No.51820105005)the Ministry of Science and Technology of China(No.2017YFE0117800)。
文摘Well-defined polypropylene grafted silica nanoparticles(PP-g-SiO_(2))were prepared through the reaction of maleic anhydride grafted polypropylene(PP-g-MAH)with amino-functionalized silica(SiO_(2)-NH_(2))by the'grafting-to'method.The grafting density of PP-g-SiO_(2) is found to be controlled by the concentration of silane coupling agent 3-[2-(2-aminoethylamino)ethyl amino]propyl trimethoxy silane(TAMS).The maximum grafting density of grafted PP-g-MAH chains with molecular weight of 9100 g/mol could reach 0.34 chains/nm~2,when the critical concentration of TAMS was 0.0194 mol/L.The critical concentration of TAMS can be explained by the maximum amounts of primary amino groups,which can totally react with PP-g-MAH on the surface of SiO_(2)-NH_(2),when the silane monolayer is formed.The synthesized PP-g-SiO_(2)with different molecular weights was mixed with PP by solution mixing to form a series of nanocomposites.The crystallization temperature(T_(c))of nanocomposites increased significantly with the particle loading.The PP-g-SiO_(2) with high molecular weight of grafted chains exhibits a high nucleation ability at 1 wt%nanoparticle loading in PP/PP-g-SiO_(2)nanocomposites.In summary,we provide an effective method to synthesize the well-defined PP-g-SiO_(2)with controlled grafting density,which shows excellent nucleation ability.
基金supported by Science and Technology Commission of Shanghai Municipality (Nos. 17ZR1406600, 10DZ2220500, 11DZ2260600)National Natural Science Foundation of China (No.21577037)
文摘This paper presented an interesting nanoparticle-based drug delivery system with morphology transition behavior depending on the content of exposed PEG chain on the particle surface, which is adjustable by addition of different amount of cyclodextrin(α-CD). The effect of α-CD inclusion to the self-assembly behavior of methoxy polyethylene glycol(mPEG) grafted chitosan(CS) was studied. The results showed that the mPEG grafted chitosan(mPEG-g-CS) forms self-assembled nanoparticles with either micelle or hollow sphere morphology depending on the ratio of α-CD to mPEG, as characterized by atomic force microscopy(AFM), transmission electron microscopy(TEM), and X-ray diffraction(XRD). Their sizes and zeta potential increased from 257.6 nmto 768.2 nm and from +4.5 mV to +11.6 mV, respectively, with the increasing amount of α-CD. The correlation between zeta potential and particle size of α-CD/mPEG-g-CS nanoparticles indicated varied PEG density on surface of nanoparticles. Based on the above experimental observations, a likely mechanism for the morphological transition of the rod-coil graft copolymer mPEG-g-CS was proposed.
基金supported by the National Natural Science Foundation of China(Nos.51973012,21704003,and 51903122)National 973 Basic Research Program of China(No.2015CB654704)+1 种基金the Foundation for Innovative Research Groups of the NSF of China(No.51521062)The authors acknowledge the National Supercomputer Center in Guangzhou,Lvliang,and Shenzhen.
文摘Contolling the formation of the conductive network in the polymer nanocomposites(PNCs)is very meaningful to enhance their electrical property.In this work,we investigated the effect of grafted nanoparticles(NPs)on the conductive probability of PNCs in the quiescent state as well as under the shear field via a coarse grained molecular dynamics simulation.It is found that the smallest percolation threshold is realized at the moderate grafting density,the moderate length of grafted chains or the moderate interaction between grafted chains and free chains.Corresponding to it,the dispersion state of NPs varies from the contact aggregation to the uniform dispersion.By analyzing the connection mode among NPs,the probabilty of NPs which connect three other ones reaches the maximum value at their moderate dispersion state which is responsible for the optimal conductive probability.In addition,the main cluster size is characterized to better understand the conductive network which is consistent with the percolation threshold.It is interesting to find that the percolation threshold is smaller under the shear field than under the quiescent state.The shear field induces more NPs which connect three other ones.This benefits the formation of the new conductive network.Meanwhile,the anisotropy of the conductive probability is reduced with increasing the grafting density.In summary,this work provides a clear picture on how the conductive network of grafted NPs evolves under the shear field.
基金Supported by"Watermelon and Muskmelon Germplasm Innovation and Genetic Improvement"Post of Guangxi Bagui Scholars(2016A11)。
文摘[Objectives]This study was conducted to explore how to improve the waterlogging tolerance of red-seed watermelon through grafting,to provide a theoretical basis for its cultivation in rainy season.[Methods]The effects of flooding stress on the growth and root physiological and biochemical characteristics of grafted and own-rooted red-seed watermelon seedlings were studied using Luffa as rootstocks and"Zhongxin 1"red-seed watermelon as scions.[Results]After flooding stress,the biomass and root activity of grafted seedlings of red-seed watermelon were significantly higher than those of own-rooted seedlings.With the prolongation of flooding stress time,the soluble sugar and proline content showed a trend of first increasing and then decreasing,and the grafted seedlings had a larger increase and a smaller decrease,and were always significantly higher than own-rooted seedlings in the same period.The content of malondialdehyde in the root system of grafted seedlings increased first and then decreased,while it continued to increase in own-rooted seedlings,and the increase in own-rooted seedlings was significantly greater than that in grafted seedlings during the same period.[Conclusions]Grafting on Luffa rootstocks could improve waterlogging tolerance of red-seed watermelon.
文摘By means of initiation of the high temperature and shearing stress of an extruder,we synthesized the graft copolymer of starch with acrylate monomers based on the simple dry method.The effects of reaction conditions on graft copolymerization were discussed. Grafted starch used as a compatibilizer for the blend system of starch and polyethylene was further investigated. The results indicate that grafted starch as a compatibilizer can improve the mechanical properties and rheologic properties of the blend of starch and polyethylene.
