杂交瘤细胞流加培养中葡萄糖浓度的控制

通过WuT3杂交瘤细胞的流加培养,当葡萄糖浓度分别控制在0.2、0.5、1.0和1.5g/L时,葡萄糖的平均比消耗速率分别为1.14×10-11、1.47×10-11、1.78×10-11和2.24×10-11g/(cell.h),乳酸的平均比生成速率分别为6.0×10-12、8.3×10-12、11.6×10-12和16.6×10-12g/(cell.h).葡萄糖转化成乳酸的比例分别52%、57%、64%和74%.结果表明,在WuT3细胞的流加培养中,当葡萄糖浓度在0.2～1.5g/L时,葡萄糖浓度越低,葡萄糖的比消耗速率和乳酸的比生成速率越低,葡萄糖转化成乳酸的比例越低,从而提高了葡萄糖的有效利用率,减少副产物的生成.     

杂交瘤细胞的无血清低蛋白培养

实现了杂交瘤细胞的体外无血清低蛋白培养。考察了血清浓度、基础培养基和接种密度对细胞生长的影响。在含5%血清培养基、1%血清培养基和无血清低蛋白培养基中适应生长的细胞,μ分别为0.68、0.45、0.44d-1,qGlc分别为13.4×10-9、13.1×10-9、19.2×10-9mmol/(cell·分别为39.4×10-9、44.1×10-9、37.7×10-9mg/(cell·d),YMAb/Xv分别为52.6×10-9、d),qMAb57.8×10-9、54.4×10-9mg/cell,YLac/Glc分别为2.0、1.95、2.0mmol/mmol。无血清培养中葡萄糖代谢途径不变,参与细胞维持代谢的葡萄糖比例增大。血清浓度降低,延迟期变长,最大活细胞密度下降。基础培养基影响细胞的最大活细胞密度,不影响生长速率。无血清培养基中细胞的接种密度选择在0.2×106～0.3×106cells/mL。     

谷氨酰胺限制对rCHO细胞生长和代谢的影响

考察了rCHO细胞(Ch inese ham ster ovary,中国仓鼠卵巢细胞)在批培养和谷氨酰胺限制流加培养过程中的生长、代谢特性。实验发现随着谷氨酰胺浓度的下降,谷氨酰胺的比消耗速率以及氨和丙氨酸的比生成速率显著下降。与批培养相比,在谷氨酰胺限制流加培养过程中,培养时间延长,活细胞密度增加,达到2.4×106cells/mL;谷氨酰胺的代谢途径发生改变,代谢副产物生成明显减少,YAmm/G ln由1.04 mm o l/mm o l略微下降到0.92 mm o l/mm o l,YA la/G ln由0.35 mm o l/mm o l下降到0.08 mm o l/mm o l,YX/G ln由0.383×109cells/mm o l增加至0.504×109cells/mm o l,YAmm/X由2.59×1-0 9mm o l/cell下降到1.85×1-0 9mm o l/cell,表明谷氨酰胺代谢的能量利用率显著提高,也证明其参与细胞合成代谢的分率增加。     

底物限制对杂交瘤细胞生长、代谢和单抗生成的影响

考察了葡萄糖或谷氨酰胺限制的批培养中杂交瘤细胞的生长、代谢和单抗生成。葡萄糖或谷氨酰胺限制时最大活细胞密度基本相同,为(1.0±0.1)×106cells/mL。葡萄糖限制时,乳酸生成减少,YLac/Glc降低,YCell/Glc增加,提示葡萄糖更多地参与三羧酸循环。谷氨酰胺限制时,氨和丙氨酸生成减少,YAmm/Gln增加,YAla/Gln减小,提示谷氨酰胺的能量利用率提高。谷氨酰胺缺失时异亮氨酸、亮氨酸、胱氨酸、缬氨酸、色氨酸、组氨酸等替代谷氨酰胺,维持细胞生长和单抗合成,产物是甘氨酸和天冬氨酸。单抗生成与细胞生长关联,并且细胞停止生长后单抗仍生成。细胞死亡阶段的qMAb约是生长阶段的一半。葡萄糖和谷氨酰胺共限制下细胞对单抗的生产能力比葡萄糖和谷氨酰胺单独限制时小。     

JAL1杂交瘤细胞的批量培养研究

研究了不同葡萄糖、谷氨酰胺浓度下JAL1细胞的生长、糖耗、乳酸及氨的生成、单抗合成等代谢过程及该株细胞的基本代谢规律，同时对该株细胞生长和单抗生产的动力学方面进行了研究，在细胞培养箱中，采用方瓶批量培养杂交瘤细胞，培养条件为pH7.0-7.5，温度37℃，5％CO2。实验表明，在不同浓度葡萄糖、谷氨酰胺的培养液中，细胞的活性细胞密度、总细胞密度、细胞活性上均有不同，相应地，对细胞的最大比生长速率、葡萄糖最大比消耗速率、乳酸最大比生成速率以及单抗最大比合成速率也有不同程度的影响。实验结果还表明，该株细胞的单抗分泌是属于负生长耦联型的。     

杂交瘤细胞流加培养中葡萄糖浓度的控制

通过 Wu T3杂交瘤细胞的流加培养 ,当葡萄糖浓度分别控制在 0 .2、0 .5、1 .0和 1 .5g/L时 ,葡萄糖的平均比消耗速率为 1 .1 4× 1 0 -11、1 .47× 1 0 -11、1 .78× 1 0 -11和 2 .2 4× 1 0 -11g/( cell· h) ,乳酸的平均比生成速率为 6.0× 1 0 -12 、8.3× 1 0 -12 、1 1 .6× 1 0 -12 和 1 6.6× 1 0 -12 g/( cell· h)。葡萄糖转化成乳酸的比例为 52 %、57%、64%和 74%。结果表明 ,在 Wu T3细胞的流加培养中 ,当葡萄糖浓度在 0 .2～ 1 .5g/L时 ,葡萄糖浓度越低 ,葡萄糖的比消耗速率和乳酸的比生成速率越低 ,葡萄糖转化成乳酸的比例越低 ,从而提高了葡萄糖的有效利用率 ,减少副产物的生成。     

谷氨酰胺对杂交瘤细胞生长代谢的影响

研究了不同浓度的谷氨酰胺对分泌抗小细胞肺癌单克隆抗体的2F7杂交瘤细胞生长、葡萄糖消耗、乳酸及氨的生成等代谢过程的影响。在细胞培养箱中,用含不同浓度谷氨酰胺的培养液培养2F7杂交瘤细胞,培养条件为pH 7.2～7.4,温度37℃,5%CO_2、95%空气。实验表明,适宜于2F7杂交瘤细胞生长的谷氨酰胺浓度为2.5 mmol/L,谷氨酰胺浓度与细胞的葡萄糖消耗呈反比,与乳酸生成浓度呈反比,与氨的生成浓度呈正比。     

葡萄糖限制的流加培养中杂交瘤细胞生长、代谢和单抗生成

研究了葡萄糖限制的流加培养和批培养中杂交瘤细胞的生长、代谢和单抗生成。与批培养相比，流加培养的培养周期长，细胞密度、单抗浓度高。随着葡萄糖浓度的下降，葡萄糖比消耗速率和乳酸比生成速率也下降，葡萄糖转化成乳酸的比例从60％～70％下降到0，葡萄糖更多地参与三羧酸循环，提高了葡萄糖的有效利用率和ATP的生成效率。     

柠檬酸对 CHO 细胞生长和代谢的影响

研究了重组中国仓鼠卵巢细胞(CHO)批培养过程中柠檬酸对细胞生长和代谢的影响。结果表明:柠檬酸明显抑制了细胞的生长。与对照组相比,添加12 mm o l/L柠檬酸的处理组细胞的葡萄糖比消耗速率(QG lc)降低了37.5%,渗透压提高了10.0%,乳酸生成量与葡萄糖消耗量的比值增加了27.0%,氨生成量与谷氨酰胺消耗量的比值也增加了。在谷氨酰胺代谢过程中,更多的谷氨酰胺经谷草转氨酶途径生成α-酮戊二酸,参与能量代谢。柠檬酸促使细胞更多地被捕获在G 1期,阻碍细胞的DNA合成,抑制细胞增殖,并促进蛋白的表达。     

葡萄糖和谷氨酰胺浓度对杂交瘤细胞生长代谢的影响

在生物反应器的批培养过程中考察了葡萄糖及谷氨酰胺浓度对杂交瘤细胞生长及代谢的影响。当葡萄糖浓度降至1～4mmol／L，谷氨酰胺浓度降至0．4～2mmol／L时，细胞生长并未受到明显影响，但细胞代谢途径发生转换，乳酸及氨的生成显著减少。葡萄糖和谷氨酰胺浓度的比例对杂交瘤细胞的生长及代谢也有影响，葡萄糖相对较多时，其细胞得率小，乳酸得率大；而当谷氨酰胺相对较多时，其细胞得率小，氨得率大。实验结果表明谷氨酰胺与葡萄糖的能量代谢在某种程度上可进行相互补充。     

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.     

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.     

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。     

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.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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