共查询到18条相似文献,搜索用时 78 毫秒
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目的:探讨细胞的增殖状态及细胞周期分布对体外培养的血管平滑肌细胞(VSMC)凋亡的激光诱导率的影响。方法:组织贴块法体外培养VSMC,饥饿法同步法,VSMC在不同的刺激因子作用之后,亚甲基噻唑蓝比色(MTT)法检测细胞增殖状况,流式细胞仪(FCM)检测细胞的周期发布,510.6nm的铜蒸汽激光照射后,TUNEL染色法记数细胞凋亡率。结果:生长活跃,处于增殖期的细胞,在激光的诱导下易发生凋亡;相反,增殖相对不活跃、处于静止期的细胞,凋亡诱导率较低。结论:经不同生长因子刺激后VSMC的增殖状态及细胞的周期分布不同,对激光的凋亡诱导率产生影响。 相似文献
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作者曾报导过相同能量密度连续渡二氧化碳激光和氢激光对鼠脑组织作用的比较研究。他们采用相同的模型,评价了超脉冲二氧化碳激光和铜蒸气激光的作用。所用的脉冲激光的平均能量密度为5000焦耳/厘米^2。超脉冲CO2激光的脉冲宽度为0.1-0.9毫秒,重复频率为每秒1-999个脉冲,输出功率为500瓦。工作波长为510毫微米(70%)与578毫微米(30%)的铜蒸气激光的脉冲宽度为30毫微秒,脉冲间隔200微秒,每个脉冲2毫焦耳,总功率达10瓦。 相似文献
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半导体激光诱导细胞凋亡脱毛及除腋臭的研究 总被引:3,自引:0,他引:3
目的 :通过动物实验观察能否诱导细胞凋亡导致脱毛 ,并探索激光诱导细胞凋亡的机制。同时 ,观察和探讨在脱腋毛的同时 ,大汗腺细胞有无因激光的光热作用或诱导的细胞凋亡受到破坏 ,为治疗腋臭寻找一新的无创伤的治疗方法。方法 :分别用半导体激光以不同剂量对黑毛狗进行脱毛。分别在治疗即刻、治疗后不同时期通过电镜、流式细胞术、TdT介导的RdUTP缺口末端标记法 (Tunel法 )对比治疗效果 ,观察组织变化及其可能存在的凋亡改变 ,并初步探讨诱导细胞凋亡的机制及临床治疗意义。结果 :半导体激光照射后毛囊上皮细胞及大汗腺腺体细胞中出现凋亡细胞 ;低剂量重复治疗凋亡现象增加。结论 :激光照射后 ,毛囊上皮细胞及大汗腺细胞中有细胞凋亡现象。 相似文献
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目的:探讨血管内皮细胞生长因子(vascular endothial growth factor,VEGF)在激光诱导兔视网膜下新生血管形成中的作用,观察其抗体对新生血管的影响。方法:高强度氪激光光凝有色家兔视网膜1、3、7、14d后,制备眼球冰冻切片检查眼底病理变化,用组织原位杂交法观察VEGFmRNA表达时相和部位的变化。VEGF抗体治疗组2只眼于光凝后10min玻璃体内注射5μgVEGF抗体,14d后行眼底荧光造影并与对侧眼对照观察荧光渗漏变化。结果(1)正常对照家兔视网膜中未见VEGFmRNA的表达;(2)激光光凝后1-3d,邻近伤口的视网膜节细胞层和内核层VEGFmRNA表达明显增加;(3)光凝后3d,光凝斑附近的视网膜下有新生血管样结构出现;(4)VEGF抗体治疗组荧光染料渗漏程度明显降低。结论:VEGFmRNA的在激光光凝后的视网膜中表达增多,且与光凝斑周围的新生血管化存在时空对应关系,提示VEGF在视网膜下新生血管形成过程中具有重要的作用。VEGF抗体对新生血管形成具有明显的抑制作用。 相似文献
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低剂量的He-Ne澈光照射可使多向性造血干细胞(CFU-s)和粒系定向干细胞(CFE-e)的增殖能力增加。将激光处理的骨髓细胞从静脉辅注给900拉德^60Co-γ射线照射的受体小鼠,从第三天开始股骨有核细胞数及CFU-1含量明显增多。 相似文献
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用矩阵光学理论计算了由主振荡器和功率放大器组成的种子注入光腔。主振荡器光腔是由曲率半径R1=-250mm,R2=5000mm,相距L=2375mm的球面镜组成的正支非稳腔;功率非稳腔是由曲率半径R3=400mm,R4=5600mm,相距S=3000mm的球面镜构成的负支非稳腔。理论计算表明,该种子注入光腔可输出光束发散角约几十微弧的激光,可满足铜蒸气激光器主振荡器功率放大器(MOPA)的技术要求。 相似文献
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目的:探讨Nd:YAG激光诱导癜痕疙瘩成纤维细胞凋亡的机制。方法:以波长1064nm、功率密度100mW/cm^2的Nd:YAG激光照射培养瘢痕疙瘩成纤维细胞,采用流式细胞仪测定细胞凋亡和Bcl-2,P53和survivin蛋白的表达。结果:在培养增生性瘢痕成纤维细胞有Bcl-2,P53和survivin蛋白低表达,Nd:YAG激光照射后,Bcl-2和survivin表达降低,P53的表达无变化。结论:Nd:YAG激光诱导的瘢痕成纤维细胞凋亡与Bcl-2和survivin表达蛋白有关。 相似文献
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The effects of different polar solvents on the performance of solvent vapor annealing treated polymer solar cell (PSC) with a structure of ITO/ZnO/PTB7: PC71BM/MoO3/Ag was systematically investigated by applying different polar solvents, including methanol, ethanol, dimethylsulfoxide, acetone and isopropanol. By analyzing the variation of PSC performance and the morphology of active layer, we found that both the solubility parameters (Δ) and viscosity of solvent were playing an important role in controlling the morphology of PTB7: PC71BM blend. Especially, the PSC treated by methanol with high Δ and low viscosity exhibited a remarkable enhancement of power conversion efficiency from 6.55% to 8.13%. The performance improvement was mainly due to the formation of the nanoscale crystallization of PTB7: PC71BM blend and the moderated aggregation of PC71BM, resulting in efficient charge separation, balanced charge transport and suppressed charge recombination. 相似文献
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Room-temperature continuous-wave operation of GaN-based laser diodes grown by raised-pressure metalorganic chemical vapor deposition 总被引:1,自引:0,他引:1
Katsunori Yanashima Shigeki Hashimoto Tomonori Hino Kenji Funato Toshimasa Kobayashi Kaori Naganuma Tsuyoshi Tojyo Takeharu Asano Tsunenori Asatsuma Takao Miyajima Masao Ikeda 《Journal of Electronic Materials》1999,28(3):287-289
We report our new raised-pressure metalorganic chemical vapor deposition (RP-MOCVD) technique and the room-temperature continuous-wave
(cw) operation of GaN-based laser diodes grown using this technique. We have found that both the defect density as measured
by etch-pit density and optical pumping threshold-powder density decreases as the growth pressure is increased beyond 1 atm.
We fabricated GaN-based laser diodes and achieved lasing under cw conditions at 20°C. The threshold current density was 3.5
kA/cm2 and the operation voltage at threshold was 16.8 V. 相似文献
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H. Q. Hou M. Hagerott Crawford B. E. Hammons R. J. Hickman 《Journal of Electronic Materials》1997,26(10):1140-1144
We present a study on the growth of visible (∼700 nm) vertical-cavity surface-emitting lasers (VCSELs) by metalorganic vapor
phase epitaxy. The structure was based on AlGaAs for both the quantum well active region and the distributed Bragg reflectors.
Photoluminescence intensity from AlGaAs quantum wells was optimized vs the substrate misorientations from the (100) surface.
The doping efficiency for n-type by Si and p-type by C was studied as a function of the substrate misorientation and the growth temperature. High-quality VCSEL materials
were grown on (311)A substrates. The structure was processed by selective oxidation, and high-performance VCSELs emitting
at ∼700 nm were achieved in a continuous-wave mode at room temperature. 相似文献