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1.
嗜酸氧化亚铁硫杆菌冷冻保藏保护剂的正交法优化   总被引:2,自引:0,他引:2  
以甘油、海藻糖、蔗糖和二甲亚砜为考察因素,采用正交实验方法,对嗜酸氧化亚铁硫杆菌冷冻保藏保护剂的优化配比进行研究.直接分析、因素指标分析和方差分析结果表明:在由甘油、海藻糖、蔗糖、二甲亚砜4种保护剂组成的混合保护剂中,对冷冻存活率影响由大至小的顺序为:甘油,海藻糖,蔗糖,二甲亚砜.最佳保护剂组合为100g/L甘油+100g/L海藻糖+180 g/L蔗糖+50 g/L二甲亚砜,该组合能使冷冻存活率达到89%.  相似文献   

2.
以海藻糖、蔗糖、麦芽糖、乳糖、葡萄糖作为冻干血小板的保护剂,研究糖的浓度和种类对血小板冻干保存的影响.结果表明,冻干血小板的保存效果随海藻糖浓度的增加而提高,当海藻糖质量分数增加到20%时,非活化血小板的恢复率达到85.7%;对于质量分数均为20%不同种类的糖保护剂,非活化血小板的恢复率都达到70%以上,海藻糖略优于其他几种糖,但它们之间没有显著性差异.  相似文献   

3.
魔芋花粉保存对于杂交育种克服花期不遇具有重要的意义.以离体收集的魔芋新鲜花粉,通过萌发检测活力,研究了室温4℃、-20℃、-80℃、液氮(-196℃)条件下保存效果.结果表明:适宜魔芋花粉发芽的培养基为5%(w/v)蔗糖、200 mg/L H_3BO_3、400 mg/L CaCl_2和0.7%(w/v)琼脂,0.5%(v/v)甘油可防止花粉管干缩,稀释2000倍的有机硅有利于花粉颗粒在培养基上均匀分布.室温下花粉存活时间为10 h,4℃保存4 d活力变化不大;-20℃保存2d内活力急剧下降;-80℃在5d内下降较快,以后趋于平缓;-196℃保存具有"冷适应"现象,前期下降,后期上升,保存1个月以上仍有较高的活力.91个单株花粉(其中花魔芋26份,白魔芋15份,杂交魔芋42份,西盟魔芋4份,东京魔芋1份,勐海魔芋3份)在4℃、-20℃、-80℃、液氮(-196℃)保存(33.8±0.4) d,花粉平均发芽率为0. 6%、2.5%、11.1%、34.1%.因此,4℃是魔芋新鲜花粉储存1~4 d较好的方法,-80℃和-196℃储存30 d效果较好,珍贵的遗传材料以液氮保存更加安全,-20℃不适宜魔芋花粉储存.本研究为魔芋定向杂交育种实践奠定了基础.  相似文献   

4.
《河南科学》2016,(11):1835-1839
采用青岛产硅胶板GF254,对产海藻糖的菌株筛选过程中的应用薄层层析法定性分析海藻糖的方法进行了研究,确定了最佳展开剂为V(乙醇)∶V(乙醇乙酯)∶V(水)=10∶3∶1,能够较好的把海藻糖、麦芽糖、葡萄糖等小分子糖分开;最佳显色剂为V(浓硫酸)∶V(蒸馏水)=10∶90硫酸溶液,显色后糖的斑点清晰,灵敏度高.用蒽酮-硫酸法对分离的海藻糖进行定量分析,计算菌株产海藻糖的多少,筛选出高产海藻糖的菌株.  相似文献   

5.
目的:寻求一种在液氮条件下冻存猪皮的最佳冷冻保护剂.方法:将新鲜巴马香猪皮肤消毒处理后分为3组,分别用A.20%二甲基亚砜(DMSO)、B.20%二甲基亚砜+6%丙二醇(PG)、C.20%二甲基亚砜+6%丙二醇+0.5 M海藻糖(Trehalose)3种抗冻液作冻存处理后直接投入液氮保存,于15 d、30 d后复温进行活力检测.结果:0.5 mol/L海藻糖与二甲基亚砜、丙二醇联合作为抗冻液所处理的猪皮,复温后其活力明显高于其它两组.结论:海藻糖能有效提高低温储存皮肤的活力,医院在保存皮肤时可以在抗冻液中加入海藻糖以得到较高活力的猪皮用于临床.  相似文献   

6.
目的:寻求一种在液氮条件下冻存猪皮的最佳冷冻保护剂.方法:将新鲜巴马香猪皮肤消毒处理后分为3组,分别用A.20%二甲基亚砜(DMSO)、B.20%二甲基亚砜+6%丙二醇(PG)、C.20%二甲基亚砜+6%丙二醇+0.5 M海藻糖(Trehalose)3种抗冻液作冻存处理后直接投入液氮保存,于15 d、30 d后复温进行活力检测.结果:0.5 mol/L海藻糖与二甲基亚砜、丙二醇联合作为抗冻液所处理的猪皮,复温后其活力明显高于其它两组.结论:海藻糖能有效提高低温储存皮肤的活力,医院在保存皮肤时可以在抗冻液中加入海藻糖以得到较高活力的猪皮用于临床.  相似文献   

7.
为满足大量松材线虫虫株长期保存的需要,对其低温冷冻保存技术进行了研究。试验比较了不同种类及浓度冷冻保护剂对松材线虫在低温冷冻保存时的保护效果,以及冷冻线虫繁殖力与致病力的变化。结果表明:使用15%甘油和4%DMSO作为冷冻保护剂,经-80℃保存1 d后,松材线虫存活率分别为(39.4±6.6)%和(37.5±21.8)%,且冻存10 d、1个月后均没有显著性下降。与未冷冻的线虫相比,冷冻线虫的繁殖力与致病力均未发生改变。  相似文献   

8.
桑椹期鼠胚在1.0—2.5M 的二甲亚砜(DMSO)溶液中经三步程序快速冷冻到-196℃;试样在-4—-8℃诱异结晶,在-20℃的酒精浴槽保持10分钟,在—100℃液氮上垂悬10分钟,然后,立即放入液氮(—196℃)。在-20℃—-75℃之间降温速度为~17℃/分。快速解冻(360℃/分)在所有的 DMSO 浓度中培养48小时后发育到完整囊胚的比例高于慢速解冻(25℃/分)。在1.5—2.0M-DMSO 浓度中快速冷冻的胚胎获得最高的成活率(分别为36和53%)。经三步冷冻和快速解冻的胚胎用多种除去 DMSO 成分的方法进行试验。获得培养到完整囊胚的最好结果是在室温下在磷酸缓冲液(PBS) 2.0M-DMSO 0.5M 蔗糖溶液停留(2分钟),然后,在 PBS 0.5M 蔗糖溶液(2分钟)(82%)以及在30℃下分阶段稀释在 PBS 溶液中的胚胎(70%)。当胚胎快速冷冻并快速解冻后在培养液中培养到囊胚期的26个胚胎移植给2支受体得到11个仔鼠(42%)。  相似文献   

9.
研究不同贮藏方法对桂花花粉活力的影响,探索桂花花粉保存的适宜条件。以4个品种群中的9种桂花品种为试验材料,对其进行常温、低温、低温冷冻和超低温冷冻贮藏,并对不同贮藏时间内的花粉活力进行检测。结果表明:桂花花粉在10%的蔗糖、0.01%硼酸和1%的琼脂糖组成的固体培养基上,25℃恒温培养24 h后花粉基本充分萌发,可用于萌发率的统计;光照和黑暗对花粉萌发无显著影响。不同贮藏条件下花粉保存效果差异显著,室温条件(15~20℃)下,大多数品种花粉寿命为15~20 d;低温贮藏(4℃)花粉活力可延长至50 d,低温冷冻(-20℃)和超低温冷冻(-70℃)贮藏100 d后大多数桂花品种的花粉萌发率差异不显著。在低温冷冻和超低温冷冻条件下桂花花粉活力下降较慢,可用于花粉较长时间的保存。  相似文献   

10.
海藻糖是一种有效的冻干保护剂,实验采用电渗透的方法强化海藻糖载入红细胞,在不同电压、脉宽、频率和细胞外海藻糖浓度的条件下对红细胞进行电渗透.实验结果表明,当电压300 V、脉宽1 ms、频率4 次/min、细胞外海藻糖浓度800 mmol/L时,细胞内海藻糖浓度达到(63.68±2.14)mmol/L.电渗透后红细胞形态正常,细胞膜的渗透脆性略有降低,电渗透致溶血率为17%,ATP酶活性与新鲜红细胞无显著差异.  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
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   

14.
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   

15.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

16.
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   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
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