The characteristic of easy sintering of aluminum nanoparticle(ANP)limits its application in solid propellants.Coating ANP with fluoropolymer could effectively improve its combustion performance.To find out how the coa...The characteristic of easy sintering of aluminum nanoparticle(ANP)limits its application in solid propellants.Coating ANP with fluoropolymer could effectively improve its combustion performance.To find out how the coating layer inhibits sintering and promotes complete combustion of particles from an atomic view,a comparative study has been done for bare ANP and PTFE coated ANP by using reactive molecular dynamics simulations.The sintering process is quantified by shrinkage ratio and gyration radius.Our results show that,at the same heating rate and combustion temperatures,bare ANPs are sintered together after the temperature exceeds the melting point of aluminum but the decomposition of PTFE coating layer pushes particles away and increases reaction surface area by producing small Al-F clusters.The sintering of ANPs which are heated in PTFE is alleviated compared with particles heated in oxygen,but particles still sinter together due to the lack of intimate contact between PTFE and alumina surface.The effect of temperature on the combustion of PTFE coated ANPs is also studied from 1000 to3500 K.The number density analysis shows the particles will not be sintered at any temperature.Aluminum fluoride prefers diffusing to the external space and the remained particles are mainly composed of Al,C and O.Fast ignition simulations are performed by adopting micro canonical ensemble.With the expansion of aluminum core and the melting of alumina shell,bare ANPs are sintered into a liquid particle directly.For PTFE coated ANPs,the volatilization of gaseous aluminum fluoride products continually endows particles opposite momentum.展开更多
AIM:To compare the clinical outcomes of wavefront guided femtosecond LASIK(WFG LASIK)and conventional femtosecond LASIK(NWFG LASIK)in eyes with myopia and myopia astigmatism.METHODS:This was a retrospective,nonrandomi...AIM:To compare the clinical outcomes of wavefront guided femtosecond LASIK(WFG LASIK)and conventional femtosecond LASIK(NWFG LASIK)in eyes with myopia and myopia astigmatism.METHODS:This was a retrospective,nonrandomized,comparative investigation enrolling 236 eyes of 122 patients(18-50 y)with low&moderate and high myopia.The WFG group including 97 eyes(50 patients)undergone WFG LASIK and the NWFG group including 139 eyes(72 patients)undergone conventional LASIK.Mean efficacy index,high order aberrations(HOAs),pupil size and the quality of visual questionnaire were evaluated 6 mo postoperatively.RESULTS:There is no difference between WFG group(-0.054±0.049 in logMAR)and NWFG group(-0.040±0.056)in uncorrected distance visual acuity(UDVA)postoperatively.The myopia astigmatism is higher in WFG group than that in NWFG group(P<0.05).However,the mean efficacy index(MEI)in the WFG group(1.09±0.106)is better than that in the NWFG group(1.036±0.124;P<0.001).Increased HOAs were observed in NWFG group(0.30±0.196)than that in WFG group(0.146±0.188;P<0.001).The pupil size is larger in WFG group(5.15±0.76 mm)than that in NWFG group(4.32±0.52 mm).The patients are satisfied with the clinical surgery,yet WFG group showed better visual quality using the questionnaire survey.Meanwhile,high myopia would result in worse MEI,HOAs and visual quality than low&moderate myopia.CONCLUSION:WFG and NWFG FS-LASIK are both effective and safe procedures to correct low&moderate and high myopia,but WFG FS-LASIK gives a better postoperative MEI,aberrometric control and predictable outcome.Meanwhile,WFG FS-LASIK is better than NWFG FS-LASIK in correction of myopia astigmatism.Low&moderate myopia allow better clinical outcomes than high myopia using any surgical method.展开更多
AIM： To investigate the effect of gold nanoparticles on retinal angiogenesis in vitro and in vivo, and to reveal the possible mechanism.METHODS： Seed growth method was used to synthesize gold nanoparticles（GNPs）. ...AIM： To investigate the effect of gold nanoparticles on retinal angiogenesis in vitro and in vivo, and to reveal the possible mechanism.METHODS： Seed growth method was used to synthesize gold nanoparticles（GNPs）. The size, zeta potential, absorption spectrum and morphology of GNPs were identified using Malvern Nano-ZS, multimode reader（Bio Tek synergy2） and transmission electron microscope. Cell viability was analyzed using cell counting kit-8 method and cell growth was assessed with EdU kit. Transwell chamber was used to investigate cell migration. Tube formation method was used to assess the angiogenic property in vitro. Oxygen induced retinopathy（OIR） model was used to investigate the effect of GNPs on retinal angiogenesis. Confocal microscope and Western blot were used to study the possible mechanism of GNPs inhibited angiogenesis.RESULTS： The GNPs synthesized were uniform and well dispersed. GNPs of 10 μg/mL and 20 μg/mL were able to inhibit human umbilical vein endothelial cells proliferation（50% and 72% separately, P〈0.001）, migration（54% and 83% separately, P〈0.001） and tube formation（52% and 90% separately, P〈0.001）. Further data showed that GNPs were able to improve the retinopathy in an OIR model. The possible mechanism might be that GNPs were able to induce autophagy significantly（P〈0.05）.CONCLUSION： The present study suggests that GNPs are able to inhibit retinal neovascularization in vitro and in vivo. GNPs might be a potential nanomedicine for the treatment of retinal angiogenesis.展开更多
基金supported by the fellowship of China Postdoctoral Science Foundation(Grant No.2021TQ0267)。
文摘The characteristic of easy sintering of aluminum nanoparticle(ANP)limits its application in solid propellants.Coating ANP with fluoropolymer could effectively improve its combustion performance.To find out how the coating layer inhibits sintering and promotes complete combustion of particles from an atomic view,a comparative study has been done for bare ANP and PTFE coated ANP by using reactive molecular dynamics simulations.The sintering process is quantified by shrinkage ratio and gyration radius.Our results show that,at the same heating rate and combustion temperatures,bare ANPs are sintered together after the temperature exceeds the melting point of aluminum but the decomposition of PTFE coating layer pushes particles away and increases reaction surface area by producing small Al-F clusters.The sintering of ANPs which are heated in PTFE is alleviated compared with particles heated in oxygen,but particles still sinter together due to the lack of intimate contact between PTFE and alumina surface.The effect of temperature on the combustion of PTFE coated ANPs is also studied from 1000 to3500 K.The number density analysis shows the particles will not be sintered at any temperature.Aluminum fluoride prefers diffusing to the external space and the remained particles are mainly composed of Al,C and O.Fast ignition simulations are performed by adopting micro canonical ensemble.With the expansion of aluminum core and the melting of alumina shell,bare ANPs are sintered into a liquid particle directly.For PTFE coated ANPs,the volatilization of gaseous aluminum fluoride products continually endows particles opposite momentum.
基金National Natural Science Foundation of China(No.81800624,No.81700839,No.82171081)the“Chen Guang”Project the Shanghai Municipal Education Commission and the Shanghai Education Development Foundation(No.18CG40)+1 种基金234 Mountain Climbing Plan of Changhai Hospital(No.2020YXK048,No.2020YXK058)“Sailing Project”Naval Medical University。
文摘AIM:To compare the clinical outcomes of wavefront guided femtosecond LASIK(WFG LASIK)and conventional femtosecond LASIK(NWFG LASIK)in eyes with myopia and myopia astigmatism.METHODS:This was a retrospective,nonrandomized,comparative investigation enrolling 236 eyes of 122 patients(18-50 y)with low&moderate and high myopia.The WFG group including 97 eyes(50 patients)undergone WFG LASIK and the NWFG group including 139 eyes(72 patients)undergone conventional LASIK.Mean efficacy index,high order aberrations(HOAs),pupil size and the quality of visual questionnaire were evaluated 6 mo postoperatively.RESULTS:There is no difference between WFG group(-0.054±0.049 in logMAR)and NWFG group(-0.040±0.056)in uncorrected distance visual acuity(UDVA)postoperatively.The myopia astigmatism is higher in WFG group than that in NWFG group(P<0.05).However,the mean efficacy index(MEI)in the WFG group(1.09±0.106)is better than that in the NWFG group(1.036±0.124;P<0.001).Increased HOAs were observed in NWFG group(0.30±0.196)than that in WFG group(0.146±0.188;P<0.001).The pupil size is larger in WFG group(5.15±0.76 mm)than that in NWFG group(4.32±0.52 mm).The patients are satisfied with the clinical surgery,yet WFG group showed better visual quality using the questionnaire survey.Meanwhile,high myopia would result in worse MEI,HOAs and visual quality than low&moderate myopia.CONCLUSION:WFG and NWFG FS-LASIK are both effective and safe procedures to correct low&moderate and high myopia,but WFG FS-LASIK gives a better postoperative MEI,aberrometric control and predictable outcome.Meanwhile,WFG FS-LASIK is better than NWFG FS-LASIK in correction of myopia astigmatism.Low&moderate myopia allow better clinical outcomes than high myopia using any surgical method.
基金Supported by the National Natural Science Foundation of China (No.81401063)Shanghai Municipal Planning Commission of Science and Research Fund (No.201740054)+5 种基金Natural Science Foundation of Beijing (No.7153175)the Capital Health Research and Development of Special (No.2018-4-5111)Beijing Nova Program (No. Z16111000490000)Research Foundation for Youth of Second Military Medical University (No.2017QN13)Research Foundation for Youth of Changhai Hospital (No.CH201712 No.CH201820)
文摘AIM： To investigate the effect of gold nanoparticles on retinal angiogenesis in vitro and in vivo, and to reveal the possible mechanism.METHODS： Seed growth method was used to synthesize gold nanoparticles（GNPs）. The size, zeta potential, absorption spectrum and morphology of GNPs were identified using Malvern Nano-ZS, multimode reader（Bio Tek synergy2） and transmission electron microscope. Cell viability was analyzed using cell counting kit-8 method and cell growth was assessed with EdU kit. Transwell chamber was used to investigate cell migration. Tube formation method was used to assess the angiogenic property in vitro. Oxygen induced retinopathy（OIR） model was used to investigate the effect of GNPs on retinal angiogenesis. Confocal microscope and Western blot were used to study the possible mechanism of GNPs inhibited angiogenesis.RESULTS： The GNPs synthesized were uniform and well dispersed. GNPs of 10 μg/mL and 20 μg/mL were able to inhibit human umbilical vein endothelial cells proliferation（50% and 72% separately, P〈0.001）, migration（54% and 83% separately, P〈0.001） and tube formation（52% and 90% separately, P〈0.001）. Further data showed that GNPs were able to improve the retinopathy in an OIR model. The possible mechanism might be that GNPs were able to induce autophagy significantly（P〈0.05）.CONCLUSION： The present study suggests that GNPs are able to inhibit retinal neovascularization in vitro and in vivo. GNPs might be a potential nanomedicine for the treatment of retinal angiogenesis.
