Spinal cord injury（SCI） affects thousands of people every year in the USA, and most patients are left with some permanent paralysis. Therapeutic options are limited and only modestly affect outcome. To address this ...Spinal cord injury（SCI） affects thousands of people every year in the USA, and most patients are left with some permanent paralysis. Therapeutic options are limited and only modestly affect outcome. To address this issue, we used magnetic resonance imaging-guided focused ultrasound（MRg FUS） as a non-invasive approach to increase permeability in the blood-spinal cord barrier（BSCB）. We hypothesize that localized, controlled sonoporation of the BSCB by MRg FUS will aid delivery of therapeutics to the injury. Here, we report our preliminary findings for the ability of MRg FUS to increase BSCB permeability in the thoracic spinal cord of a normal rat model. First, an excised portion of normal rat spinal column was used to characterize the acoustic field and to estimate the insertion losses that could be expected in an MRg FUS blood spinal cord barrier opening. Then, in normal rats, MRg FUS was applied in combination with intravenously administered microbubbles to the spinal cord region. Permeability of the BSCB was indicated as signal enhancement by contrast administered prior to T1-weighted magnetic resonance imaging and verified by Evans blue dye. Neurological testing using the Basso, Beattie, and Breshnahan scale and the ladder walk was normal in 8 of 10 rats tested. Two rats showed minor impairment indicating need for further refinement of parameters. No gross tissue damage was evident by histology. In this study, we have opened successfully the blood spinal cord barrier in the thoracic region of the normal rat spine using magnetic resonance-guided focused ultrasound combined with microbubbles.展开更多
Existing conventional megajoule plasma focus machines with 2–3 MA are producing fusion neutron yields of several times 10^(11) in deuterium operation,the fusion yields predominantly being the beam-gas target.Increasi...Existing conventional megajoule plasma focus machines with 2–3 MA are producing fusion neutron yields of several times 10^(11) in deuterium operation,the fusion yields predominantly being the beam-gas target.Increasing the current to 10 MA and using 50%–50%D-T mixture will scale the neutron yield towards 10^(16) D-T fusion neutrons.In this work,we derive the Lawson criterion for plasma focus devices with a beam-target fusion neutron mechanism,so that we may glimpse what future technological advancements are needed for a break-even Q=1 plasma focus.We perform numerical experiments with a present-day feasible 0.9 MV,8.1 MJ,11 MA machine operating in 100 Torr in 50%–50%D-T mixture.The Lee Code simulation gives a detailed description of the plasma focus dynamics through each phase,and provides plasma and yield parameters which show that out of 1.1×10^(19) fast beam ions produced in the plasma focus pinch,only 1.24×10^(14) ions take part in beam-target fusion reactions within the pinch,producing the same number of D-T neutrons.The remnant beam ions,numbering at least 10^(19),exit the focus pinch at 1.9 MeV,which is far above the 115 keV ion energy necessary for an optimum beam-target cross-section.We propose to regain the lost fusion rates by using a high-pressure D-T-filled drift-tube to attenuate the energy of the remnant beam ions until they reach the energy for the optimum fusion cross-section.Such a fusion enhancement tube would further harvest beam-target fusion reactions by increasing the interaction path length(1 m)at increased interaction density(6 atm).A gain factor of 300 is conservatively estimated,with a final yield of 3.7×10^(16) D-T neutrons carrying kinetic energy of 83.6 kJ,demonstrating Q=0.01.展开更多
Benefiting from the induced image charge on film surface,the nanoparticle aggregating on metal exhibits interesting optical properties.In this work,a linear metal nanoparticle trimer on metal film system has been inve...Benefiting from the induced image charge on film surface,the nanoparticle aggregating on metal exhibits interesting optical properties.In this work,a linear metal nanoparticle trimer on metal film system has been investigated to explore the novel optical phenomenon.Both the electric field and surface charge distributions demonstrate the light is focused on film greatly by the nanoparticles at two sides,which could be strongly modulated by the wavelength of incident light.And the influence of nanoparticle in middle on this light focusing ability has also been studied here,which is explained by the plasmon hybridization theory.Our finding about light focusing in nanoparticle aggregating on metal film not only enlarges the novel phenomenon of surface plasmon but also has great application prospect in the field of surface-enhanced spectra,surface catalysis,solar cells,water splitting,etc.展开更多
Background:Enhanced depth-of-focus intraocular lenses(EDOF IOL)have filled the gap between monofocal and multifocal intraocular implants with optical qualities of monofocal lenses and usually minor dysphotopsias typic...Background:Enhanced depth-of-focus intraocular lenses(EDOF IOL)have filled the gap between monofocal and multifocal intraocular implants with optical qualities of monofocal lenses and usually minor dysphotopsias typical for multifocal lenses.The purpose of this study was to evaluate visual outcomes after bilateral implantation of a new EDOF IOL in patients with requirements for perfect near and intermediate vision.Methods:The study included 15 patients(29 eyes as one was amblyopic)with bilateral implantation of LUXSMART EDOF IOL(Bausch&Lomb)with a targeted myopia(between-0.25 and-0.50D)in both eyes.Monocular corrected and uncorrected visual acuity for far,intermediate and near as well as refractive outcomes were evaluated at 1,3,6 and 12 months after the surgery.Additionally,binocular visual acuity,contrast sensitivity and defocus curve were measured at the final follow-up visit.At 12 months’visit patients completed a questionnaire evaluating patient satisfaction,spectacle independence and presence of dysphotopsias.Results:Binocular uncorrected visual acuities at 12 month’s visit were 0.13±0.16,0.06±0.08,0.07±0.09 and 0.15±0.09 logMAR for far distance,80 cm,66 cm and 40 cm respectively.Corrected binocular visual acuities at 12 months were 0.00±0.00,0.05±0.07,0.05±0.06,0.13±0.16 respectively for distance,80 cm,66 cm and 40 cm.Automated refraction spherical equivalent at 12 months’visit stood at-0.70±0.48D,which was 0.46D less than calculated biometric target,however spherical equivalent of subjective refraction at 12 months equaled–0.49±0.46D,which was closer to preoperative biometric target.Defocus curve had gentle shape without peaks typical for monofocal IOLs.Binocular contrast sensitivity results were superior to average results for that age group and equaled 1.78±0.16 logMAR without correction and 1.81±0.13 logMAR with correction.Spectacle independence for near and intermediate distances was achieved in all patients and for far distance in 73.3%of patients.Burdensome dysphotopsias were not reported in any case.Conclusions:EDOF IOLs targeted bilaterally at low myopia can provide excellent near and intermediate visual acuity and independence of any optical correction in majority of cases.This approach can be used in selected patients who are focused on stationary activities.展开更多
目的:探讨应用超声造影技术评价高强度聚焦超声(HIFU)治疗原发性肝细胞癌(HCC)的有效性.方法:HIFU治疗HCC患者32例,分别采取部分覆盖肿瘤治疗23例及完全覆盖肿瘤治疗9例,于治疗前和治疗后1-4d行超声造影检查,通过对比观察HIFU治疗前后...目的:探讨应用超声造影技术评价高强度聚焦超声(HIFU)治疗原发性肝细胞癌(HCC)的有效性.方法:HIFU治疗HCC患者32例,分别采取部分覆盖肿瘤治疗23例及完全覆盖肿瘤治疗9例,于治疗前和治疗后1-4d行超声造影检查,通过对比观察HIFU治疗前后肿瘤内血流灌注变化来判断肿瘤是否凝固性坏死.结果:HIFU治疗前超声造影显示肿瘤内血流灌注丰富;HIFU治疗后,超声造影显示治疗区无血流灌注,提示治疗区域发生凝固性坏死.以最终诊断为金标准,超声造影对肿瘤灭活诊断的准确性高于常规彩超(90.6% vs 46.9%,P<0.05).结论:超声造影能准确判断HIFU对肿瘤消融范围及程度,为HCC患者HIFU治疗后的早期疗效评价提供依据.展开更多
基金supported by the University of Utah RadiologyNeuroscience Initiative Pilot grantthe Department of Neurosurgery pilot fund
文摘Spinal cord injury（SCI） affects thousands of people every year in the USA, and most patients are left with some permanent paralysis. Therapeutic options are limited and only modestly affect outcome. To address this issue, we used magnetic resonance imaging-guided focused ultrasound（MRg FUS） as a non-invasive approach to increase permeability in the blood-spinal cord barrier（BSCB）. We hypothesize that localized, controlled sonoporation of the BSCB by MRg FUS will aid delivery of therapeutics to the injury. Here, we report our preliminary findings for the ability of MRg FUS to increase BSCB permeability in the thoracic spinal cord of a normal rat model. First, an excised portion of normal rat spinal column was used to characterize the acoustic field and to estimate the insertion losses that could be expected in an MRg FUS blood spinal cord barrier opening. Then, in normal rats, MRg FUS was applied in combination with intravenously administered microbubbles to the spinal cord region. Permeability of the BSCB was indicated as signal enhancement by contrast administered prior to T1-weighted magnetic resonance imaging and verified by Evans blue dye. Neurological testing using the Basso, Beattie, and Breshnahan scale and the ladder walk was normal in 8 of 10 rats tested. Two rats showed minor impairment indicating need for further refinement of parameters. No gross tissue damage was evident by histology. In this study, we have opened successfully the blood spinal cord barrier in the thoracic region of the normal rat spine using magnetic resonance-guided focused ultrasound combined with microbubbles.
文摘Existing conventional megajoule plasma focus machines with 2–3 MA are producing fusion neutron yields of several times 10^(11) in deuterium operation,the fusion yields predominantly being the beam-gas target.Increasing the current to 10 MA and using 50%–50%D-T mixture will scale the neutron yield towards 10^(16) D-T fusion neutrons.In this work,we derive the Lawson criterion for plasma focus devices with a beam-target fusion neutron mechanism,so that we may glimpse what future technological advancements are needed for a break-even Q=1 plasma focus.We perform numerical experiments with a present-day feasible 0.9 MV,8.1 MJ,11 MA machine operating in 100 Torr in 50%–50%D-T mixture.The Lee Code simulation gives a detailed description of the plasma focus dynamics through each phase,and provides plasma and yield parameters which show that out of 1.1×10^(19) fast beam ions produced in the plasma focus pinch,only 1.24×10^(14) ions take part in beam-target fusion reactions within the pinch,producing the same number of D-T neutrons.The remnant beam ions,numbering at least 10^(19),exit the focus pinch at 1.9 MeV,which is far above the 115 keV ion energy necessary for an optimum beam-target cross-section.We propose to regain the lost fusion rates by using a high-pressure D-T-filled drift-tube to attenuate the energy of the remnant beam ions until they reach the energy for the optimum fusion cross-section.Such a fusion enhancement tube would further harvest beam-target fusion reactions by increasing the interaction path length(1 m)at increased interaction density(6 atm).A gain factor of 300 is conservatively estimated,with a final yield of 3.7×10^(16) D-T neutrons carrying kinetic energy of 83.6 kJ,demonstrating Q=0.01.
基金the National Key Research and Development Program(Grant No.2019YFC1906100)the National Natural Science Foundation of China(Grant Nos.11974067 and 12074054)+1 种基金the Natural Science Foundation Project of CQ CSTC(cstc2019jcyj-msxmX0145,cstc2019jcyj-bshX0042,and cstc2019jcyj-msxmX0828)the Sharing Fund of Chongqing University’s Large-scale Equipment.
文摘Benefiting from the induced image charge on film surface,the nanoparticle aggregating on metal exhibits interesting optical properties.In this work,a linear metal nanoparticle trimer on metal film system has been investigated to explore the novel optical phenomenon.Both the electric field and surface charge distributions demonstrate the light is focused on film greatly by the nanoparticles at two sides,which could be strongly modulated by the wavelength of incident light.And the influence of nanoparticle in middle on this light focusing ability has also been studied here,which is explained by the plasmon hybridization theory.Our finding about light focusing in nanoparticle aggregating on metal film not only enlarges the novel phenomenon of surface plasmon but also has great application prospect in the field of surface-enhanced spectra,surface catalysis,solar cells,water splitting,etc.
文摘Background:Enhanced depth-of-focus intraocular lenses(EDOF IOL)have filled the gap between monofocal and multifocal intraocular implants with optical qualities of monofocal lenses and usually minor dysphotopsias typical for multifocal lenses.The purpose of this study was to evaluate visual outcomes after bilateral implantation of a new EDOF IOL in patients with requirements for perfect near and intermediate vision.Methods:The study included 15 patients(29 eyes as one was amblyopic)with bilateral implantation of LUXSMART EDOF IOL(Bausch&Lomb)with a targeted myopia(between-0.25 and-0.50D)in both eyes.Monocular corrected and uncorrected visual acuity for far,intermediate and near as well as refractive outcomes were evaluated at 1,3,6 and 12 months after the surgery.Additionally,binocular visual acuity,contrast sensitivity and defocus curve were measured at the final follow-up visit.At 12 months’visit patients completed a questionnaire evaluating patient satisfaction,spectacle independence and presence of dysphotopsias.Results:Binocular uncorrected visual acuities at 12 month’s visit were 0.13±0.16,0.06±0.08,0.07±0.09 and 0.15±0.09 logMAR for far distance,80 cm,66 cm and 40 cm respectively.Corrected binocular visual acuities at 12 months were 0.00±0.00,0.05±0.07,0.05±0.06,0.13±0.16 respectively for distance,80 cm,66 cm and 40 cm.Automated refraction spherical equivalent at 12 months’visit stood at-0.70±0.48D,which was 0.46D less than calculated biometric target,however spherical equivalent of subjective refraction at 12 months equaled–0.49±0.46D,which was closer to preoperative biometric target.Defocus curve had gentle shape without peaks typical for monofocal IOLs.Binocular contrast sensitivity results were superior to average results for that age group and equaled 1.78±0.16 logMAR without correction and 1.81±0.13 logMAR with correction.Spectacle independence for near and intermediate distances was achieved in all patients and for far distance in 73.3%of patients.Burdensome dysphotopsias were not reported in any case.Conclusions:EDOF IOLs targeted bilaterally at low myopia can provide excellent near and intermediate visual acuity and independence of any optical correction in majority of cases.This approach can be used in selected patients who are focused on stationary activities.
文摘目的:探讨应用超声造影技术评价高强度聚焦超声(HIFU)治疗原发性肝细胞癌(HCC)的有效性.方法:HIFU治疗HCC患者32例,分别采取部分覆盖肿瘤治疗23例及完全覆盖肿瘤治疗9例,于治疗前和治疗后1-4d行超声造影检查,通过对比观察HIFU治疗前后肿瘤内血流灌注变化来判断肿瘤是否凝固性坏死.结果:HIFU治疗前超声造影显示肿瘤内血流灌注丰富;HIFU治疗后,超声造影显示治疗区无血流灌注,提示治疗区域发生凝固性坏死.以最终诊断为金标准,超声造影对肿瘤灭活诊断的准确性高于常规彩超(90.6% vs 46.9%,P<0.05).结论:超声造影能准确判断HIFU对肿瘤消融范围及程度,为HCC患者HIFU治疗后的早期疗效评价提供依据.
