A detailed analysis of the influence of Rydberg states to the behavior of GPS satellite signals in the D and E atmospheric layers has been carried out. It is demonstrated that these states are the main reason for the ...A detailed analysis of the influence of Rydberg states to the behavior of GPS satellite signals in the D and E atmospheric layers has been carried out. It is demonstrated that these states are the main reason for the GPS signal distortion. It is shown that the behavior of satellite signals is associated with the spectral characteristics of the UHF radiation of the Rydberg states depending on the geomagnetic conditions of ionosphere. The foundations of the quantum theory of distortion and delay of GPS satellite signal propagation through D and E atmospheric layers are analyzed and expounded. The problem reduces to the resonant scattering of photons, moving in the electromagnetic field of the signal, to the Rydberg complexes populated in a two-temperature non-equilibrium plasma. The processes of creation of additional photons because of stimulated emission and resonance scattering of photons are considered. In the present work, the quantum theory of the propagation of a satellite signal in the Earth’s upper atmosphere, firstly earlier proposed by the same authors, is described in detail. The general problems of the theory and possible theoretical and applied consequences are discussed. It is explained that two main processes occurring here, are directly related to the resonant quantum properties of the propagation medium. The first process leads to a direct increase in the power of the received signal, and second—to a shift in the signal carrier frequency??and the time delay??of its propagation. The main reasons of the processes are scattering of the Rydberg electron by the ion core and presence of the neutral medium molecule in the intermediate autoionization states of the composite system populated by the strong non-adiabatic coupling of electron and nuclear motions. The main purposes of our investigation are the physical justification of the formation of parameters ?and??using the quantum dynamics of the electron behavior in the intermediate state of the Rydberg complex A**M and the estimation of the quantities of??and??in the elementary act of elastic (Rayleigh) photon scattering.展开更多
The nearby bright M-dwarf star L 98–59 has three terrestrial-sized planets.One challenge remaining in characterizing atmospheres around such planets is that it is not known a priori whether they possess any atmospher...The nearby bright M-dwarf star L 98–59 has three terrestrial-sized planets.One challenge remaining in characterizing atmospheres around such planets is that it is not known a priori whether they possess any atmospheres.Here we report on study of the atmospheres of L 98–59 c and L 98–59 d using near-infrared spectral data from the G141 grism of Hubble Space Telescope(HST)/Wide Field Camera 3.We can reject the hypothesis of a clear atmosphere dominated by hydrogen and helium at a confidence level of ~3σ for both planets.Thus they could have a primary hydrogen-dominated atmosphere with an opaque cloud layer,or could have lost their primary hydrogen-dominated atmosphere and re-established a secondary thin atmosphere,or have no atmosphere at all.We cannot distinguish between these scenarios for the two planets using the current HST data.Future observations with the James Webb Space Telescope would be capable of confirming the existence of atmospheres around L 98–59 c and d and determining their compositions.展开更多
Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflect...Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflection of the pile.This paper investigated the influence of vertical load on the behaviour of monopiles installed in the sand under combined load using three-dimensional numerical methods.The commercial software PLAXIS was used for simulations in this paper.Monopiles were modelled as a structure incorporating linear elastic material behaviour and soil was modelled using the Hardening-Soil(HS)constitutive model.The monopiles under vertical load,lateral load and combined vertical and lateral loads were respectively studied taking into account the sequence of load application and pile slenderness ratio(L/D;L and D are the length and diameter of the pile).Results suggest that the sequence of load application plays a major role in how vertical load affects the deflection behaviour of the pile.Specifically,when L/D ratios obtained by lengthening the pile while keeping its diameter constant are 3,5 and 8,the relationships between lateral load and the deflection behaviour of the pile under the effect of vertical load demonstrate a similar trend.Furthermore,the cause of increased lateral capacity of the pile under the action of applied vertical load in the common practical application case and in the VPL case was analyzed by studying the variation law of soil stress along the pile embedment.Results confirm that the confining effect of vertical load increases means effective stress of the soil around the pile,thus increasing soil stiffness and pile capacity.展开更多
Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflect...Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflection of the pile.This paper investigated the influence of vertical load on the behaviour of monopiles installed in the sand under combined load using three-dimensional numerical methods.The commercial software PLAXIS was used for simulations in this paper.Monopiles were modelled as a structure incorporating linear elastic material behaviour and soil was modelled using the Hardening-Soil(HS)constitutive model.The monopiles under vertical load,lateral load and combined vertical and lateral loads were respectively studied taking into account the sequence of load application and pile slenderness ratio(L/D;L and D are the length and diameter of the pile).Results suggest that the sequence of load application plays a major role in how vertical load affects the deflection behaviour of the pile.Specifically,when L/D ratios obtained by lengthening the pile while keeping its diameter constant are 3,5 and 8,the relationships between lateral load and the deflection behaviour of the pile under the effect of vertical load demonstrate a similar trend.Furthermore,the cause of increased lateral capacity of the pile under the action of applied vertical load in the common practical application case and in the VPL case was analyzed by studying the variation law of soil stress along the pile embedment.Results confirm that the confining effect of vertical load increases means effective stress of the soil around the pile,thus increasing soil stiffness and pile capacity.展开更多
Effect of perturbations in Coriolis and centrifugal forces on the non-linear stability of the libration point L4 in the restricted three body problem is studied when both the primaries are axis symmetric bodies (triax...Effect of perturbations in Coriolis and centrifugal forces on the non-linear stability of the libration point L4 in the restricted three body problem is studied when both the primaries are axis symmetric bodies (triaxial rigid bodies) and the bigger primary is a source of radiation. Moser’s conditions are utilized in this study by employing the iterative scheme of Henrard for transforming the Hamiltonian to the Birkhoff’s normal form with the help of double D’Alembert’s series. It is found that L4 is stable for all mass ratios in the range of linear stability except for the three mass ratios μc1, μc2 and μc3, which depend upon the perturbations ε1 and ε1 in the Coriolis and centrifugal forces respectively and the parameters A1,A2,A3 and A4 which depend upon the semi-axes a1,b1,c1;a2,b2,c2 of the triaxial rigid bodies and p, the radiation parameter.展开更多
Because the inhibition of Nogo proteins can promote neurite growth and nerve cell differentiation, a cell-scaffold complex seeded with Nogo receptor （NgR）-silenced neural stem cells and Schwann cells may be able to ...Because the inhibition of Nogo proteins can promote neurite growth and nerve cell differentiation, a cell-scaffold complex seeded with Nogo receptor （NgR）-silenced neural stem cells and Schwann cells may be able to improve the microenvironment for spinal cord injury repair. Previous studies have found that mild hypothermia helps to attenuate secondary damage in the spinal cord and exerts a neuroprotective effect. Here, we constructed a cell-scaffold complex consisting of a poly（D,L-lactide-co-glycolic acid） （PLGA） scaffold seeded with NgR-silenced neural stem cells and Schwann cells, and determined the effects of mild hypothermia combined with the cell-scaffold complexes on the spinal cord hemi-transection injury in the T9 segment in rats. Compared with the PLGA group and the NgR-silencing cells ＋ PLGA group, hindlimb motor function and nerve electrophysiological function were dearly improved, pathological changes in the injured spinal cord were attenuated, and the number of surviving cells and nerve fibers were increased in the group treated with the NgR-silenced cell scaffold ＋ mild hypothermia at 34℃ for 6 hours. Furthermore, fewer pathological changes to the injured spinal cord and more surviving cells and nerve fibers were found after mild hypothermia therapy than in injuries not treated with mild hypothermia. These experimental results indicate that mild hypothermia combined with NgR gene-silenced cells in a PLGA scaffold may be an effective therapy for treating spinal cord injury.展开更多
Co-delivery of anti-cancer drugs is promising to improve the efficacy of cancer treatment.This study was aiming to investigate the potential of concurrent delivery of resveratrol(RES)and docetaxel(DTX)via polymeric na...Co-delivery of anti-cancer drugs is promising to improve the efficacy of cancer treatment.This study was aiming to investigate the potential of concurrent delivery of resveratrol(RES)and docetaxel(DTX)via polymeric nanocarriers to treat breast cancer.To this end,methoxyl poly(ethylene glycol)-poly(D,L-lactide)copolymer(mPEG-PDLA)was prepared and characterized using FTIR and 1H NMR,and their molecular weights were determined by GPC.Isobologram analysis and combination index calculation were performed to find the optimal ratio between RES and DTX to against human breast adenocarcinoma cell line(MCF-7 cells).Subsequently,RES and DTX were loaded in the mPEG-PDLA micelles simultaneously,and the morphology,particle size distribution,in vitro release,pharmacokinetic profiles,as well as cytotoxicity to the MCF-7 cells were characterized.IC50 of RES and DTX in MCF-7 cells were determined to be 23.0μg/ml and 10.4μg/ml,respectively,while a lower IC50 of 4.8μg/ml of the combination of RES and DTX was obtained.The combination of RES and DTX at a ratio of 1:1(w/w)generated stronger synergistic effect than other ratios in the MCF-7 cells.RES and DTX loaded mPEG-PDLA micelles exhibited prolonged release profiles,and enhanced cytotoxicity in vitro against MCF-7 cells.The AUC(0→t)of DTX and RES in mPEG-PDLA micelles after i.v.administration to rats were 3.0-fold and 1.6-fold higher than that of i.v.injections of the individual drugs.These findings indicated that the co-delivery of RES and DTX using mPEG-PDLA micelles could have better treatment of tumors.展开更多
Nanoparticles of biodegradable methoxy poly(ethylene glycol)-b-polyester amphiphilic diblock copolymers have widely investigated for use as controlled release drug delivery carriers. In this work, blend nanoparticles ...Nanoparticles of biodegradable methoxy poly(ethylene glycol)-b-polyester amphiphilic diblock copolymers have widely investigated for use as controlled release drug delivery carriers. In this work, blend nanoparticles of methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (MPEG-b-PDLL) and methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (MPEG- b-PCL) were prepared by nano-precipitation method without any surfactants. 1H-NMR spectra showed significant difference in integral peak areas, suggesting the nanoparticles with different MPEG-b-PDLL/MPEG-b-PCL blend ratios can be prepared. Transmission electron microscope revealed the blend nanoparticles had nearly spherical in shape with smooth surface. Average size of the blend nanoparticles obtained from light-scattering analysis slightly decreased with increase in blend ratio of MPEG-b-PCL. The MPEG-b-PDLL and MPEG-b-PCL were amorphous and semi-crystalline, respectively. Thermal transition properties of the blend nanoparticles were studied with differential scanning calorimetry (DSC). The DSC results showed that glass transition temperatures of the blend nanoparticles decreased and heats of melting steadily increased, while the melting temperature did not change as the MPEG-b-PCL blend ratio increased. This indicates the miscibility of MPEG-b-PDLL and MPEG-b-PCL in the amorphous phase of the blend nanoparticles. Thermogravimetric analysis showed that the blend nanoparticles clearly exhibited two thermal decomposition steps due to MPEG-b-PDLL decomposition followed with MPEG-b-PCL. The blend nanoparticles had two temperatures of maximum decomposition rate (Td, max) accorded to each blend component. The Td, max of MPEG-b- PDLL phase significantly decreased, while Td, max of MPEG-b-PCL phase did not change as the MPEG-b-PCL blend ratio increased. These results suggested that the desired thermal properties of blend nanoparticles can be tailored by varying the blend ratio.展开更多
A novel cyclodextrin-containing polymer was prepared by graftingβ-cyclodextrin onto the backbone of poly(D,L-lactic acid)(PLA).First,mono(6-(2-aminoethyl)amino-6-deoxy)-β-cyclodextrin(β-CD-6-en)was prepared by sulf...A novel cyclodextrin-containing polymer was prepared by graftingβ-cyclodextrin onto the backbone of poly(D,L-lactic acid)(PLA).First,mono(6-(2-aminoethyl)amino-6-deoxy)-β-cyclodextrin(β-CD-6-en)was prepared by sulfonylation and amination ofβ-cyclodextrin and modified poly(D,L-lactic acid)(MPLA)was prepared by free radical polymerization of maleic anhydride and PLA.Then,grafting ofβ-cyclodextrin derivative to MPLA backbone was carried out by N-acylation reaction of MPLA andβ-CD-6-en in dimethyl formamide.The...展开更多
文摘A detailed analysis of the influence of Rydberg states to the behavior of GPS satellite signals in the D and E atmospheric layers has been carried out. It is demonstrated that these states are the main reason for the GPS signal distortion. It is shown that the behavior of satellite signals is associated with the spectral characteristics of the UHF radiation of the Rydberg states depending on the geomagnetic conditions of ionosphere. The foundations of the quantum theory of distortion and delay of GPS satellite signal propagation through D and E atmospheric layers are analyzed and expounded. The problem reduces to the resonant scattering of photons, moving in the electromagnetic field of the signal, to the Rydberg complexes populated in a two-temperature non-equilibrium plasma. The processes of creation of additional photons because of stimulated emission and resonance scattering of photons are considered. In the present work, the quantum theory of the propagation of a satellite signal in the Earth’s upper atmosphere, firstly earlier proposed by the same authors, is described in detail. The general problems of the theory and possible theoretical and applied consequences are discussed. It is explained that two main processes occurring here, are directly related to the resonant quantum properties of the propagation medium. The first process leads to a direct increase in the power of the received signal, and second—to a shift in the signal carrier frequency??and the time delay??of its propagation. The main reasons of the processes are scattering of the Rydberg electron by the ion core and presence of the neutral medium molecule in the intermediate autoionization states of the composite system populated by the strong non-adiabatic coupling of electron and nuclear motions. The main purposes of our investigation are the physical justification of the formation of parameters ?and??using the quantum dynamics of the electron behavior in the intermediate state of the Rydberg complex A**M and the estimation of the quantities of??and??in the elementary act of elastic (Rayleigh) photon scattering.
基金the financial support from the National Key R&D Program of China(2020YFC2201400)National Natural Science Foundation of China(NSFC,Grant Nos.12073092,12103097,and 12103098)+5 种基金the science research grants from the China Manned Space Project(No.CMS-CSST-2021-B09,B12)Guangzhou Basic and Applied Basic Research Program(202102080371)the Strategic Priority Program on Space Science,the Chinese Academy of Sciences(Grant No.XDA15020601)China Postdoctoral Science Foundation(No.2020M672936)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University,Hainan Provincial Natural Science Foundation of China under Grant No.122RC546the National Natural Science Foundation of China under grant Nos.12063001。
文摘The nearby bright M-dwarf star L 98–59 has three terrestrial-sized planets.One challenge remaining in characterizing atmospheres around such planets is that it is not known a priori whether they possess any atmospheres.Here we report on study of the atmospheres of L 98–59 c and L 98–59 d using near-infrared spectral data from the G141 grism of Hubble Space Telescope(HST)/Wide Field Camera 3.We can reject the hypothesis of a clear atmosphere dominated by hydrogen and helium at a confidence level of ~3σ for both planets.Thus they could have a primary hydrogen-dominated atmosphere with an opaque cloud layer,or could have lost their primary hydrogen-dominated atmosphere and re-established a secondary thin atmosphere,or have no atmosphere at all.We cannot distinguish between these scenarios for the two planets using the current HST data.Future observations with the James Webb Space Telescope would be capable of confirming the existence of atmospheres around L 98–59 c and d and determining their compositions.
文摘Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflection of the pile.This paper investigated the influence of vertical load on the behaviour of monopiles installed in the sand under combined load using three-dimensional numerical methods.The commercial software PLAXIS was used for simulations in this paper.Monopiles were modelled as a structure incorporating linear elastic material behaviour and soil was modelled using the Hardening-Soil(HS)constitutive model.The monopiles under vertical load,lateral load and combined vertical and lateral loads were respectively studied taking into account the sequence of load application and pile slenderness ratio(L/D;L and D are the length and diameter of the pile).Results suggest that the sequence of load application plays a major role in how vertical load affects the deflection behaviour of the pile.Specifically,when L/D ratios obtained by lengthening the pile while keeping its diameter constant are 3,5 and 8,the relationships between lateral load and the deflection behaviour of the pile under the effect of vertical load demonstrate a similar trend.Furthermore,the cause of increased lateral capacity of the pile under the action of applied vertical load in the common practical application case and in the VPL case was analyzed by studying the variation law of soil stress along the pile embedment.Results confirm that the confining effect of vertical load increases means effective stress of the soil around the pile,thus increasing soil stiffness and pile capacity.
基金supported by High-Tech Ship Scientific Research Project in 2018(Research on Key Technologies of Polar Small Cruise Ship Design and Construction,Ministry of Industry and Information Technology Packing Letter[2018]No.473Emergency Evacuation Chute System Development,Ministry of Industry and Information Technology Packing Letter[2017]No.614).
文摘Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflection of the pile.This paper investigated the influence of vertical load on the behaviour of monopiles installed in the sand under combined load using three-dimensional numerical methods.The commercial software PLAXIS was used for simulations in this paper.Monopiles were modelled as a structure incorporating linear elastic material behaviour and soil was modelled using the Hardening-Soil(HS)constitutive model.The monopiles under vertical load,lateral load and combined vertical and lateral loads were respectively studied taking into account the sequence of load application and pile slenderness ratio(L/D;L and D are the length and diameter of the pile).Results suggest that the sequence of load application plays a major role in how vertical load affects the deflection behaviour of the pile.Specifically,when L/D ratios obtained by lengthening the pile while keeping its diameter constant are 3,5 and 8,the relationships between lateral load and the deflection behaviour of the pile under the effect of vertical load demonstrate a similar trend.Furthermore,the cause of increased lateral capacity of the pile under the action of applied vertical load in the common practical application case and in the VPL case was analyzed by studying the variation law of soil stress along the pile embedment.Results confirm that the confining effect of vertical load increases means effective stress of the soil around the pile,thus increasing soil stiffness and pile capacity.
文摘Effect of perturbations in Coriolis and centrifugal forces on the non-linear stability of the libration point L4 in the restricted three body problem is studied when both the primaries are axis symmetric bodies (triaxial rigid bodies) and the bigger primary is a source of radiation. Moser’s conditions are utilized in this study by employing the iterative scheme of Henrard for transforming the Hamiltonian to the Birkhoff’s normal form with the help of double D’Alembert’s series. It is found that L4 is stable for all mass ratios in the range of linear stability except for the three mass ratios μc1, μc2 and μc3, which depend upon the perturbations ε1 and ε1 in the Coriolis and centrifugal forces respectively and the parameters A1,A2,A3 and A4 which depend upon the semi-axes a1,b1,c1;a2,b2,c2 of the triaxial rigid bodies and p, the radiation parameter.
基金supported by a grant from the Application Basis and Front Technology Projects of Tianjin(Science and Technology Foundation of Tianjin),No.12JCYBJC18000
文摘Because the inhibition of Nogo proteins can promote neurite growth and nerve cell differentiation, a cell-scaffold complex seeded with Nogo receptor （NgR）-silenced neural stem cells and Schwann cells may be able to improve the microenvironment for spinal cord injury repair. Previous studies have found that mild hypothermia helps to attenuate secondary damage in the spinal cord and exerts a neuroprotective effect. Here, we constructed a cell-scaffold complex consisting of a poly（D,L-lactide-co-glycolic acid） （PLGA） scaffold seeded with NgR-silenced neural stem cells and Schwann cells, and determined the effects of mild hypothermia combined with the cell-scaffold complexes on the spinal cord hemi-transection injury in the T9 segment in rats. Compared with the PLGA group and the NgR-silencing cells ＋ PLGA group, hindlimb motor function and nerve electrophysiological function were dearly improved, pathological changes in the injured spinal cord were attenuated, and the number of surviving cells and nerve fibers were increased in the group treated with the NgR-silenced cell scaffold ＋ mild hypothermia at 34℃ for 6 hours. Furthermore, fewer pathological changes to the injured spinal cord and more surviving cells and nerve fibers were found after mild hypothermia therapy than in injuries not treated with mild hypothermia. These experimental results indicate that mild hypothermia combined with NgR gene-silenced cells in a PLGA scaffold may be an effective therapy for treating spinal cord injury.
基金the Liaoning Province Pan Deng Xue Zhe Grant(M.Yang)Liaoning Provincial Education officer’s Excellent Talents Supporting Plan(D.Cun)National Natural Science Foundation of China(No.81302720 and 81573380)for financial support。
文摘Co-delivery of anti-cancer drugs is promising to improve the efficacy of cancer treatment.This study was aiming to investigate the potential of concurrent delivery of resveratrol(RES)and docetaxel(DTX)via polymeric nanocarriers to treat breast cancer.To this end,methoxyl poly(ethylene glycol)-poly(D,L-lactide)copolymer(mPEG-PDLA)was prepared and characterized using FTIR and 1H NMR,and their molecular weights were determined by GPC.Isobologram analysis and combination index calculation were performed to find the optimal ratio between RES and DTX to against human breast adenocarcinoma cell line(MCF-7 cells).Subsequently,RES and DTX were loaded in the mPEG-PDLA micelles simultaneously,and the morphology,particle size distribution,in vitro release,pharmacokinetic profiles,as well as cytotoxicity to the MCF-7 cells were characterized.IC50 of RES and DTX in MCF-7 cells were determined to be 23.0μg/ml and 10.4μg/ml,respectively,while a lower IC50 of 4.8μg/ml of the combination of RES and DTX was obtained.The combination of RES and DTX at a ratio of 1:1(w/w)generated stronger synergistic effect than other ratios in the MCF-7 cells.RES and DTX loaded mPEG-PDLA micelles exhibited prolonged release profiles,and enhanced cytotoxicity in vitro against MCF-7 cells.The AUC(0→t)of DTX and RES in mPEG-PDLA micelles after i.v.administration to rats were 3.0-fold and 1.6-fold higher than that of i.v.injections of the individual drugs.These findings indicated that the co-delivery of RES and DTX using mPEG-PDLA micelles could have better treatment of tumors.
文摘Nanoparticles of biodegradable methoxy poly(ethylene glycol)-b-polyester amphiphilic diblock copolymers have widely investigated for use as controlled release drug delivery carriers. In this work, blend nanoparticles of methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (MPEG-b-PDLL) and methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (MPEG- b-PCL) were prepared by nano-precipitation method without any surfactants. 1H-NMR spectra showed significant difference in integral peak areas, suggesting the nanoparticles with different MPEG-b-PDLL/MPEG-b-PCL blend ratios can be prepared. Transmission electron microscope revealed the blend nanoparticles had nearly spherical in shape with smooth surface. Average size of the blend nanoparticles obtained from light-scattering analysis slightly decreased with increase in blend ratio of MPEG-b-PCL. The MPEG-b-PDLL and MPEG-b-PCL were amorphous and semi-crystalline, respectively. Thermal transition properties of the blend nanoparticles were studied with differential scanning calorimetry (DSC). The DSC results showed that glass transition temperatures of the blend nanoparticles decreased and heats of melting steadily increased, while the melting temperature did not change as the MPEG-b-PCL blend ratio increased. This indicates the miscibility of MPEG-b-PDLL and MPEG-b-PCL in the amorphous phase of the blend nanoparticles. Thermogravimetric analysis showed that the blend nanoparticles clearly exhibited two thermal decomposition steps due to MPEG-b-PDLL decomposition followed with MPEG-b-PCL. The blend nanoparticles had two temperatures of maximum decomposition rate (Td, max) accorded to each blend component. The Td, max of MPEG-b- PDLL phase significantly decreased, while Td, max of MPEG-b-PCL phase did not change as the MPEG-b-PCL blend ratio increased. These results suggested that the desired thermal properties of blend nanoparticles can be tailored by varying the blend ratio.
基金Funded by the Natural Science Foundation of China(No.50603032)Education Commission of Chongqing(No.KJ090617)the Science and Technology Plan Project of Jiulongpo District,Chongqing,China(No.2008Q95)
文摘A novel cyclodextrin-containing polymer was prepared by graftingβ-cyclodextrin onto the backbone of poly(D,L-lactic acid)(PLA).First,mono(6-(2-aminoethyl)amino-6-deoxy)-β-cyclodextrin(β-CD-6-en)was prepared by sulfonylation and amination ofβ-cyclodextrin and modified poly(D,L-lactic acid)(MPLA)was prepared by free radical polymerization of maleic anhydride and PLA.Then,grafting ofβ-cyclodextrin derivative to MPLA backbone was carried out by N-acylation reaction of MPLA andβ-CD-6-en in dimethyl formamide.The...
