小鼠胚胎一步冷冻法

本文描述了冷冻小鼠胚胎直接投入液氮的简单一步法。这项研究的主要目的是评价小鼠胚胎在下列不同浓度的甘油和蔗糖混合液中预脱水后冷冻胚胎解冻后的活力。同时研究了脱水前甘油的预处理及胚胎阶段的不同效果。当蔗糖浓度保持恒定(0.25M),甘油浓度变化范围为1.0～4.0M时,以甘油浓度2.0M冷冻胚胎解冻后活力最高(67％)。采用甘油预处理并不优于不预处理。当甘油浓度保持恒定(2.0M)。蔗糖浓度变化范围为0—1.0M时,发现在0.5M蔗糖中冷冻胚胎解冻后活力最佳(81％)。桑椹胚存活率优于囊胚(86％),VS72％)。与鲜胚移植54％的出生率相比较。胚胎冷冻最佳处理(2.0M甘油+0.5M蔗糖)解冻后移植出生率为41％。这项技术可实际应用于家畜胚胎的冷冻与解冻。     

小鼠胚胎冷冻方法的研究

本试验共用小鼠胚胎7858枚,对冷冻-解冻小鼠胚胎过程中的一些环节进行了对比试验,结果表明,冷冻过程中诱发结晶温度最好为-7℃左右,致冷时间以15—20秒为宜。致冷时间过长或过短都会引起解冻后胚胎成活率的下降。将胚胎缓慢冷冻至—0——40℃再投入液氮可获得较理想成功率。而—25℃以前投入液氮的胚胎其解冻后体外发育能力明显不如—30℃以后投入者。将胚胎冷冻管投入液氮的方式,对解冻后胚胎的形态和体外发育能力均有显著影响。将胚胎冷冻管插入液氮深部的效果显著优于漂浮于液氮表面者。添加甘油的方法对解冻后胚胎的体外发育能力无显著影响,三步添加甘油和一步添加甘油的胚胎,在解冻后培养的发育率和膨胀率方面均无显著差异。脱除甘油的方法明显影响解冻后胚胎的体外发育能力,在1/3M蔗糖液中分步脱除甘油的方法。明显优于在0.5M蔗糖液中一步脱除法。缓慢冷却至—36℃投入液氮的胚胎,在30～35℃水浴中解冻后体外培养成活率最高,而在0℃,10℃和20℃解冻的胚胎成活率明显降低。     

牛体外受精卵的冷冻保存研究

将胚胎分别以PBS 20?S 10%乙二醇和PBS 20?S 10%甘油为冷冻保护液,或者在PBS 20?S 10%乙二醇中添加或不加蔗糖为保护液,用常规冷冻方法进行冷冻处理.胚胎保存1～18天后将其解冻,并在发育用培养液TCM199 10%OCS(发情母牛血清) 丙酮酸钠中培养48小时.结果表明解冻胚的形态正常率和培养后的发育率在乙二醇处理组和甘油处理组中分别为81.2%(13/19)、56.2%(9/16)和84.6%(11/13)、46.2%(6/13),两组之间无量著差异.在添加蔗糖和不加蔗糖的处理组中,胚胎解冻后的形态正常率和培养后的发育率分别为75.0%(15/20)、55.0%(11/20)和83.3%(15/18)、61.1%(11/18),两组之间也无明曼差异.试验结果证明,用乙二醇为防冻剂对牛体外受精胚胎进行冷冻保存,其效果相当于或略优于甘油,在乙二醇处理组中,添加蔗糖与否并不影响其冷冻效果.     

快速冷冻和解冻鼠胚的存活力

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%)。     

小鼠胚胎快速冷冻方法的研究

3770枚小鼠胚胎随机分为以下12个试验组:三个不同浓度甘油(2.1、2.8和3.5M)分别与四个浓度蔗糖(0.25、O.5、0.75和1.00)配合成12种不同高渗快速冷冻液。通过对比筛选试验,对昆明小鼠的紧缩致密期早囊胚快速冻存试验.确定3.5M甘油和0.25M蔗糖混合成的快速冷冻液为最佳组合,用其处理的胚胎,经快速冷冻、解冻后。胚胎体外培养发育率最高,达84.3％,其中膨胀期和孵化期胚胎为78.3％,明显高于其它11种组合(P<0.01)。     

非极性表面活性剂对小鼠早期胚胎冷冻保护作用的初步研究

许多研究者报道了某些非极性表面活性剂在防止蛋白质低温冷冻变性方面有着明显的效果．本研究就某些非极性表面活性剂对胚胎的防冻作用作了初步探索．方法是分别将不同浓度的两种表面活性剂Ｐｏｌｙｓｔｅｎ２０（Ｐ２０）和ＳＹ－ｇｌｙｓｔｅｒＭＬ－７５０（ＭＬ７５０）添加于改进的磷酸缓冲液（ＰＢ１）和本研究采用的防冻液（ＦＳ：ＰＢ１＋３ｍｏｌ乙烯二醇＋０．２５ｍｏｌ乳糖）中，处理小鼠早期胚２０ｍｉｎ后培养并观察对胚胎发育的影响，以确定它们对胚胎的临界安全浓度（ＣＳＣ）．在ＰＢ１中，两种表面活性剂的ＣＳＣ值均为０．５％，而在ＦＳ中，则为０．０５％．然后将两种表面活性剂Ｐ２０和ＭＬ７５０分别以０．０５％和０．０３％两种浓度添加于ＦＳ中，以ＦＳ作为对照组．在室温下平衡处理小鼠桑椹胚和早期囊胚５ｍｉｎ后连同防冻液一起装入塑料冷冻细管中．在液氮蒸气（－１７０℃）中预冷冻１ｍｉｎ后即投入液氮内保存．在３８℃水浴中快速解冻并去除防冻剂后在Ｗｈｉｔｔｅｎ培养液中培养２４ｈ．分别观察和统计冷冻－解冻胚的形态正常率和发育率．结果表明：处理组与对照组在冷冻－解冻胚形态正常率方面无显著差异（Ｐ＞０．０５），而添加０．０３％Ｐ＿２Ｏ或ＭＬ７５０的两     

奶牛胚胎简易快速冷冻及其移植试验研究

将7日龄的黑白花奶牛胚胎,采用简易冷冻仪,以液氮作冷冻源的快速冷冻、解冻法对胚胎进行冷冻.甘油作冷冻保护剂,以1℃/min的速度由室温降至-7℃,在-7℃下绣发结晶,并在-7℃下维持5分钟;又以0.3℃/min降到-10℃,最后以0.5℃/min速度降至-30℃,平衡10分钟后,胚胎直接投入液氮罐申保存。需移植时,直接在37℃温水中解冻。本试验解冻了25枚胚胎,取1,2级胚胎15枚,除去甘油后,将15枚胚胎用凯氏枪输卵器分别移植给15头同期受体的的母牛,现已产下3头牛犊.结果表明,采用简易冷冻仪、以液氮作冷冻源的快速冷冻、解冻的胚胎可以成活,且有利在生产实践中推广应用。     

小鼠胚胎一步冷冻法的探讨

超排处理81只昆明小白鼠、把出现阴道栓的42只小鼠进行冲卵,得到301枚胚胎。选用205枚晚期桑椹胚进行一步法冷冻至-196℃,经37℃水浴中解冻后,回收胚胎202枚,回收率为98.5％。将解冻后形态正常的175枚胚胎,经过处理,放置在37℃的CO_2培养箱中进行培养。同时,又用64枚新鲜胚胎(晚期桑椹胚)、一并放入培养箱中进行培养。经过24小时的培养,取出镜检,经过冷冻一解冻后培养的胚胎,发育的有54枚,新鲜胚胎发育的有35枚,48小时后再次镜检结果。发育到囊胚的解冻胚胎仅有10枚,占5.7％。新鲜胚胎发育到囊胚的为9.4％。通过本试验证明:小鼠的晚期桑椹胚,经过一步法冷冻至-196℃。再经解冻后进行培养。是能够获得进一步发育的。     

小鼠受精卵(胚)的快速冷冻法

<正> 在进行哺乳动物受精卵(胚)冷冻保存时,为了使冷冻装置简易化和缩短冷冻时间,进行了小鼠受精卵(胚)的快速冷冻实验。以甘油和蔗糖作为冷冻保护剂,将受精卵(胚)从室温直接移入液氮中,用超低温做瞬间冷冻。并对添加剂甘油和蔗糖的浓度与解冻后存活率的关系等方面进行了探讨。     

冷冻保存小鼠胚胎简易方法的研究

小鼠胚胎在冷冻保护剂二甲亚砜(DMSO)存在下,冷冻到-196℃,解冻以后可以存活。在无胚胎冷冻机的条件下,我们用简易冷冻装置,将不同胚龄的鼠胚放入其中,经缓慢降温后保存于液氮内。冷冻胚胎快速解冻后,胚胎回收率达67—79%。选择解冻后正常胚胎进行体外培养,48—72小时后能进一步发育为其存活标准,冷冻后胚胎存活率为66.07%。此方法简便易行便于推广。     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

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.