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1.
不同方法处理的角膜脱细胞基质组织学生物特性的比较   总被引:6,自引:0,他引:6  
目的:比较不同的角膜脱细胞基质方法,旨在选择最适合的脱细胞基质方法,制备成为组织工程角膜支架材料和角膜替代物的脱细胞基质.方法:分别用胰酶-曲拉通法、SDS-戊二醛法、胰酶-冷冻法等方法对角膜进行脱细胞处理,并对脱细胞彻底的基质进行力学特性、透光率的分析.结果:用胰酶-冷冻法获得的兔角膜全层和分层基质脱细胞最彻底,基质的结构未见明显破坏,脱细胞基质在生物力学特性上与正常角膜接近,透光率低于新鲜角膜.结论:用胰酶-冷冻法获得的脱细胞基质与自然角膜接近,可作为组织工程角膜支架材料和角膜替代物.  相似文献   

2.
降温冷冻是实施精液冷冻保存的必需工艺。目前主要有两种方法:利用程序控制的生物冷冻仪自动调节冷冻速度;用人工操作逐步降低悬吊在液氮蒸气中的精液样品与液氮面的高度来实现降温冷冻。前者在国外使用很普遍,国内也有一些医院开始采用这种方法冷冻精液,后者则是传统的精液冷冻方法。这两种方法有何差别,国内尚无祥细报道。本研究对这两种冷冻方法的冷冻效果进行实验比较。程序控制生物冷冻仪为英国Planer公司的Model10型。冷冻程序采用Watson的6步降温速率:Rt、+2℃,-1℃/then;+2℃、+2℃,0℃/ndn,维持5then;+2℃、-…  相似文献   

3.
本文用新鲜角膜,在不同浓度抗冻剂中作不同时间的抗冻处理后,采用快连冷冻法进行了低温保存的实验研究,并得到了比较满意的结果.实验中采用了茜素红和台盼蓝联合染色法鉴别内皮活性.实验结果认为,为得到较高的细胞存活率,角膜抗冻处理应尽量减小抗冻剂对细胞的毒性影响,可采用高浓度、短时间的方式;角膜冷却的关键是提高内皮层的冷却速率,可采用双级冷却法.  相似文献   

4.
人类精子的冷冻保存,精子要经历与冷冻保护剂孵育、降温冷冻、超低温贮存和解冻复温等过程,这过程的化学和物理效应直接作用于精子,精子功能不可避免地受到影响。本研究应用多种方法探讨人类精子的冷冻生物学特性。精子活动率和活力采用Malker精子计算器测定(n=150),精子膜完整性应用低渗膜肿胀试验(n=60),精子体外存活用培养法观察(n=8),精子ATP含量用LKB荧光测定仪检测(n=55),精子穿透宫颈粘液能力采用Kremer试验评估(n=42),精子受精能力借助去透明带地鼠卵穿透试验检测(n=30)。精子冷冻采用程序控制生物冷…  相似文献   

5.
盾构始发采用冷冻法进行土地加固优于高压旋喷桩的加固工艺,但其中对于冷冻法止水帷摹的计算就更加重要,反而保证施工顺利与最终的止水效果。从冷冻法止水帷幕的原理着手,对冷冻法施工止水惟幕的计算进行介绍,并对施工中的运用要点进行提亲。  相似文献   

6.
哺乳动物胚胎冷冻技术研究进展   总被引:4,自引:0,他引:4  
报道了胚胎冷冻技术的发展及现状。根据它的发展分别介绍了慢冻慢解法、常规快速解冻法、玻璃化冷冻、1步细管法冷冻、1步冷冻和半胚冷冻,并且就胚胎冷冻保护剂、冷冻方法、解冷方法、冷冻保护剂的脱除及胚胎发育时期等对胚胎冷冻效果的影响进行了探讨。  相似文献   

7.
以1.5M的PG为冷冻保护液,0.2M的SU为稀释液,采用Direct法冷冻保存牛体外受精囊胚的效果与One step法无显著差异,以1.5M的PG为冷冻保护液,0.2M的TRE为稀释液,囊胚的发育率低于One step法,但生存率和孵化率均没有显著差异。本研究对于提高牛体外受精卵的培养效果和冷冻效果提供了科学的实验数据。  相似文献   

8.
为了摸索小鼠胎儿成纤维细胞冷冻保存的简易方法,采用常规冷冻和玻璃化冷冻2种模式,探讨了不同的冷冻方法、不同的冷冻前平衡时间、不同的冷冻保护液的配比等因素对成纤维细胞冷冻效果的影响。实验结果表明:常规冷冻采用含10%(体积分数)甘油的DMEM液作保护剂,可将0~5℃下平衡时间缩短至45~60 min,细胞活力可达0.87。玻璃化冷冻采用10%(体积分数)NBS+1.8 mol/L乙二醇+0.1 mol/L蔗糖的PBS冷冻小鼠胎儿成纤维细胞效果好于其他组合,细胞活力可达到0.86。玻璃化冷冻法与常规冷冻法的冷冻效果差异不显著。  相似文献   

9.
设计了三电极电化学测试系统,采用恒电流法进行充放电循环,过程全部由程序控制,本文介绍了贮氢材料的充放电实验装置原理图及相应的程序控制框图,并采用此装置研究了Ti-Ni薄膜的电化学性能。  相似文献   

10.
采用有限单元法对隧道电阻率超前探测进行数值模拟,研究冷冻法施工前后,地下水变化导致的电阻率超前探测视电阻率改变。冷冻法未完成时,超前探测视电阻率为低阻异常;冷冻法完成后,超前探测视电阻率为高阻异常。结果表明,电阻率超前探测可以准确监测隧道冷冻法的施工效果。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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