Objective To reduce the toxicity and side effects of arsenic trioxide(ATO)and provide a new approach for the treatment of primary liver cancer,a folic acid-modified calcium arsenite liposomal“target-controlled”drug ...Objective To reduce the toxicity and side effects of arsenic trioxide(ATO)and provide a new approach for the treatment of primary liver cancer,a folic acid-modified calcium arsenite liposomal“target-controlled”drug delivery system(FA-LP-CaAs)was fabricated using the reverse microemulsion method.Methods A Malvern particle size analyzer and a transmission electron microscope were employed to determine the particle size,distribution,zeta potential and morphology of FA-LP-CaAs.Further,inductively coupled plasma emission spectrometry was employed to determine the drug loading capacity,entrapment efficiency,and in vitro release behavior of FA-LP-CaAs.To determine its toxicity in human hepatoma cells(HepG2)and human normal hepatocytes(LO2)and its effect on HepG2 cell cycle and apoptosis,the MTT method was used.Laser confocal and flow cytometry were also employed to determine the uptake of FA-LP-CaAs by cells.After establishing a mouse liver cancer model,the in vivo distribution of the drug included in the formulation was investigated using in vivo fluorescence.To evaluate the liver cancer targeting and anti-tumor effects of FALP-CaAs in vivo,the distribution of ATO in tissues and changes in tumor volume and body weight after liposomal administration were investigated using hematoxylin-eosin(HE)-stained tumor sections.Results The particle size,zeta potential and PDI of FA-LP-CaAs were(122.67±2.18)nm,(12.81±0.75)mV and 0.22±0.01,respectively,while its drug loading capacity was 18.49%±1.14%.In vitro experimental results revealed that FA-LP-CaAs had a strong killing effect on HepG2 cells.Further,the cell uptake capacity of this formulation was found to improve.Based on in vivo assessments,FA-LP-CaAs could significantly increase the distribution of ATO in tumor sites and inhibit tumor growth.Conclusions Herein,an FA-LP-CaAs formulation was successfully fabricated.This liposomal drug delivery system had a round appearance,uniform particle size,good polydispersity coefficient,evident“core-shell”structure,high drug loading capacity and pH response,tumor targeted drug delivery and sustained drug release.These findings support further research and the application of ATO as an anti-liver cancer prodrug and provide a new method for the treatment of liver cancer.展开更多
We study the effect of structure asymmetry on the energy spectrum and the far-infrared spectrum （FIR） of a lateral coupled quantum dot. The calculated spectrum shows that the parity break of coupled quantum dot resu...We study the effect of structure asymmetry on the energy spectrum and the far-infrared spectrum （FIR） of a lateral coupled quantum dot. The calculated spectrum shows that the parity break of coupled quantum dot results in more coherent superpositions in the low-lying states and exhibits unique anti-crossing in the two-electron FIR spectrum modulated by a magnetic field. We also find that the Coulomb correlation effect can make the FIR spectrum of coupled quantum dot without strict parity deviate greatly from Kohn theorem, which is just contrary to the symmetric case. Our results therefore suggest that FIR spectrum may be used to determine the symmetry of coupled quantum dot and to evaluate the degree of Coulomb interaction.展开更多
The mechanical properties of the TWIP steel subjected to impact loading at various strain rates were analyzed by the split Hopkinson pressure bar. Meanwhile the microstructure of the TWIP steel fore-and-aft dynamic de...The mechanical properties of the TWIP steel subjected to impact loading at various strain rates were analyzed by the split Hopkinson pressure bar. Meanwhile the microstructure of the TWIP steel fore-and-aft dynamic deformation was oberseved and analyzed by optical microscope （OM）, X-ray diffraction （XRD）, and transmission electron microscope （TEM）. The results show that when the TWIP steel was deformed under dynamic condition, the stress, microhardness and work hardening rate increase with the increase of strain and strain rate; there is decline of work hardening rate for adiabatic temperature rising softening. There are many pin-like deformation twins in the microstructure of the TWIP steel subjected to impact loading, and the grain size after deformation is bigger than that before; the interaction of twins with dislocation and twins with twins, especially emergence of multiple deformation twins are the main strengthening mechanisms of the TWIP steel. The nucleation mechanism of deformation twins will be ＂rebound mechanism＂;the incomplete deformation twins can be observed when the strain rate is low; when strain rate increases, deformation twins unite together;and deformation twins become denser because the nucleation rate increases with increasing the strain rate.展开更多
基金funding support from the National Natural Science Foundation of China (No. 81873014)。
文摘Objective To reduce the toxicity and side effects of arsenic trioxide(ATO)and provide a new approach for the treatment of primary liver cancer,a folic acid-modified calcium arsenite liposomal“target-controlled”drug delivery system(FA-LP-CaAs)was fabricated using the reverse microemulsion method.Methods A Malvern particle size analyzer and a transmission electron microscope were employed to determine the particle size,distribution,zeta potential and morphology of FA-LP-CaAs.Further,inductively coupled plasma emission spectrometry was employed to determine the drug loading capacity,entrapment efficiency,and in vitro release behavior of FA-LP-CaAs.To determine its toxicity in human hepatoma cells(HepG2)and human normal hepatocytes(LO2)and its effect on HepG2 cell cycle and apoptosis,the MTT method was used.Laser confocal and flow cytometry were also employed to determine the uptake of FA-LP-CaAs by cells.After establishing a mouse liver cancer model,the in vivo distribution of the drug included in the formulation was investigated using in vivo fluorescence.To evaluate the liver cancer targeting and anti-tumor effects of FALP-CaAs in vivo,the distribution of ATO in tissues and changes in tumor volume and body weight after liposomal administration were investigated using hematoxylin-eosin(HE)-stained tumor sections.Results The particle size,zeta potential and PDI of FA-LP-CaAs were(122.67±2.18)nm,(12.81±0.75)mV and 0.22±0.01,respectively,while its drug loading capacity was 18.49%±1.14%.In vitro experimental results revealed that FA-LP-CaAs had a strong killing effect on HepG2 cells.Further,the cell uptake capacity of this formulation was found to improve.Based on in vivo assessments,FA-LP-CaAs could significantly increase the distribution of ATO in tumor sites and inhibit tumor growth.Conclusions Herein,an FA-LP-CaAs formulation was successfully fabricated.This liposomal drug delivery system had a round appearance,uniform particle size,good polydispersity coefficient,evident“core-shell”structure,high drug loading capacity and pH response,tumor targeted drug delivery and sustained drug release.These findings support further research and the application of ATO as an anti-liver cancer prodrug and provide a new method for the treatment of liver cancer.
基金supported by the National Natural Science Foundation of China (Grant No.11074025)the National Basic Research Program of China (Grant No.2011CB922200)a grant from the China Academy of Engineering Physics
文摘We study the effect of structure asymmetry on the energy spectrum and the far-infrared spectrum （FIR） of a lateral coupled quantum dot. The calculated spectrum shows that the parity break of coupled quantum dot results in more coherent superpositions in the low-lying states and exhibits unique anti-crossing in the two-electron FIR spectrum modulated by a magnetic field. We also find that the Coulomb correlation effect can make the FIR spectrum of coupled quantum dot without strict parity deviate greatly from Kohn theorem, which is just contrary to the symmetric case. Our results therefore suggest that FIR spectrum may be used to determine the symmetry of coupled quantum dot and to evaluate the degree of Coulomb interaction.
基金Item Sponsored by Scientific Research Plan of Shanxi Province of China(20090321072)
文摘The mechanical properties of the TWIP steel subjected to impact loading at various strain rates were analyzed by the split Hopkinson pressure bar. Meanwhile the microstructure of the TWIP steel fore-and-aft dynamic deformation was oberseved and analyzed by optical microscope （OM）, X-ray diffraction （XRD）, and transmission electron microscope （TEM）. The results show that when the TWIP steel was deformed under dynamic condition, the stress, microhardness and work hardening rate increase with the increase of strain and strain rate; there is decline of work hardening rate for adiabatic temperature rising softening. There are many pin-like deformation twins in the microstructure of the TWIP steel subjected to impact loading, and the grain size after deformation is bigger than that before; the interaction of twins with dislocation and twins with twins, especially emergence of multiple deformation twins are the main strengthening mechanisms of the TWIP steel. The nucleation mechanism of deformation twins will be ＂rebound mechanism＂;the incomplete deformation twins can be observed when the strain rate is low; when strain rate increases, deformation twins unite together;and deformation twins become denser because the nucleation rate increases with increasing the strain rate.
