灵芝真菌发酵胞外多糖反馈抑制的初步研究

探讨了灵芝胞外多糖自身反馈抑制作用。在摇瓶中考察了灵芝真菌发酵菌丝体生长、胞外多糖(EPS)和胞内多糖(IPS)合成的动态过程。在培养168h时，生物量达到最大值3．18g／L(干重)，培养216h时，胞外多糖达到最高浓度1．24g／L，EPS和生物量的变化趋势大致呈正相关。在摇瓶培养基中添加同源胞外多糖，以浓度梯度实验法考察培养基中的同源胞外多糖浓度对灵芝真菌发酵胞外多糖产量的影响，结果表明：培养基中添加的同源胞外多糖浓度高于0．59g/L时，EPS的产生受到明显抑制，其趋势是随着培养基中同源灵芝胞外多糖浓度的增加，反馈抑制作用逐渐增强，当培养基中添加的同源胞外多糖浓度高于2．34g/L时，菌丝的生长和胞外多糖的产生完全受到抑制。     

天麻醇提物对灰树花胞外多糖单糖组成和生物活性的影响

天麻醇提物参与灰树花液体发酵体系,检测所得胞外多糖的单糖组成变化,研究天麻醇提物对灰树花胞外多糖生物活性的影响。利用高效液相色谱对4种胞外多糖样品进行单糖组成分析,采用小鼠巨噬细胞(RAW264.7)活化模型、人肝癌细胞(HepG 2)模型对灰树花胞外多糖生物活性进行检测。实验结果表明灰树花粗多糖样品主要由葡萄糖、甘露糖及少量的半乳糖等单糖构成;经纯化的胞外精多糖由甘露糖、鼠李糖、葡萄糖、半乳糖、阿拉伯糖、岩藻糖等单糖构成,单糖物质的量比依次为13.8∶3.9∶5∶3.7:1∶1.7,而添加天麻醇提物的胞外精多糖单糖组分物质的量比为12.7∶3.2∶5.6∶3.5∶1∶1.6。通过灰树花胞外多糖对小鼠巨噬细胞活化实验的结果可知,添加天麻醇提物的胞外精多糖对巨噬细胞有明显的活化作用,胞外精多糖、添加天麻醇提物制备的胞外粗多糖对巨噬细胞有一定的活化作用,胞外粗多糖对巨噬细胞无明确的活化作用。通过体外实验检测,4种多糖样品对人肝癌细胞HepG 2无抑制作用。添加天麻醇提物对灰树花胞外多糖单糖组分含量产生明显变化,但并未使灰树花多糖产生新单糖;添加天麻醇提物能提高灰树花胞外多糖对巨噬细胞的活化作用。     

不同环境因子对爪哇伪枝藻分泌胞外多糖的影响

以一种从荒漠土壤中分离的典型丝状蓝藻——爪哇伪枝藻为材料,在实验室条件下研究了温度、盐度、pH和培养时间对爪哇伪枝藻胞外多糖分泌的影响.结果表明:随培养温度升高,伪枝藻胞外多糖分泌量逐渐升高,在35℃时达到最大值;在一定盐度范围内,胞外多糖分泌随盐度的增大而增大;pH在7.5时,胞外多糖产量显著高于酸性和碱性条件下的胞外多糖产量;随着培养时间延长,伪枝藻胞外多糖分泌逐渐增大.     

Lachnum YM328多糖发酵条件优化及抗氧化性

文章在碳源、氮源、金属离子和发酵时间4个单因素试验的基础上,利用正交试验法对Lachnum YM328胞外多糖发酵条件进行了研究,得出最优发酵条件为:ρ(葡萄糖)=20 g/L,ρ(酵母膏)=5 g/L,ρ(硫酸锰)=0.075 g/L,25 ℃下培养10 d;该条件下YM328胞外多糖产量为1.895 mg/mL,相对于优化前提高了36.27%;通过测定其胞外多糖(EPS)对·OH、NO-2的清除作用来研究YM328胞外多糖的抗氧化性;结果表明,YM328胞外多糖对·OH、NO-2均具有明显的清除作用,抗氧化性随着多糖质量浓度的增加呈增强趋势.     

金针菇液体深层发酵多糖的提取与测定

金针菇液体深层发酵醪中,母液和菌丝体内分别含有胞外多糖、胞内多糖,在母液中加入一定体积９５ ％ 乙醇,得到胞外粗多糖;菌丝体烘干后,粉碎过筛,水浴提取胞内粗多糖。采用蒽酮比色法测定粗多糖中纯多糖的含量。     

富硒金针菇发酵液中胞外多糖的提取与分析

通过对富硒金针菇发酵液中胞外多糖的提取与分析,结果表明,加低浓度的硒可提高金针菇发酵液中粗胞外多糖的提取量和纯胞外多糖含量。     

拟康氏木霉产胞外多糖的分离纯化及组成初步研究

以拟康氏木霉（Trichoderma pseudokoningii SDTP1）产胞外多糖粗品为材料,经木瓜蛋白酶-Sevag法除蛋白、凝胶柱层析分离纯化,得到一种水溶性的拟康氏木霉产胞外多糖纯品（TPP-0）,并研究了其单糖组成.采用紫外光谱和红外光谱法对拟康氏木霉产胞外多糖进行了定性分析.结果表明,拟康氏木霉产胞外多糖具有多糖特征性的紫外和红外吸收峰 高效凝胶渗透色谱法测定结果表明,拟康氏木霉产胞外多糖的峰值分子量为1.8×104 采用气相色谱法测定拟康氏木霉产胞外多糖中单糖的种类和构成比例,结果表明,拟康氏木霉产胞外多糖主要由鼠李糖、葡萄糖、半乳糖等3种单糖组成,含有葡萄糖醛酸,并计算出3种单糖的摩尔组成比例.     

海洋浮游硅藻胞外多糖研究进展

海洋浮游硅藻胞外多糖是其在生长过程中向外界环境所分泌的胞外产物中的一种,在海洋生态系统和海洋生物制药业中发挥着重要作用.本文对海洋浮游硅藻胞外多糖生物量的影响因素,胞外多糖的提取、分离和纯化方法,胞外多糖的成分分析与结构修饰及其药理学活性研究等进行了综述,并展望其在海洋生物制药方面的应用前景.     

天然水生物膜胞外多糖和胞外蛋白吸附镉的特性

研究了长春市南湖天然水环境中生物膜优势菌种胞外多糖和胞外蛋白对镉的吸附特征及其影响因素.结果表明,胞外多糖和胞外蛋白对镉的吸附过程符合Langmuir和Freundlich热力学等温方程,胞外多糖和胞外蛋白对镉的动力学吸附特征符合Langmuir-Hinshelwood方程的一级反应模式.而铅的存在会影响对镉的吸附.     

新型深海中温菌Wangia profunda（SM-A87）胞外多糖对对硝基苯胺的吸附研究

采用深海中温菌Wangia profunda（SM-A87）的胞外多糖对对硝基苯胺进行吸附试验。分别用热分析仪、FTIR和Zeta电位仪对胞外多糖进行表征分析,并研究了吸附时间、胞外多糖用量、pH和温度等方面对其吸附规律的影响。结果表明：胞外多糖可有效去除水中的对硝基苯胺。20℃时,0．1g／L的SM-A87胞外多糖吸附处理50mL初始浓度为15mg／L的对硝基苯胺水样120min后,对硝基苯胺的最大吸附率可达91％;Langmuir、Freundlich、Redlich-Peterson等温方程和准二级动力学方程均能较好地描述SM—A87胞外多糖吸附对硝基苯胺的热力学及动力学过程,由Langmuir方程得到SM—A87胞外多糖对对硝基苯胺的最大吸附量为769．2mg／g（30℃）。     

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.     

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.     

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.     

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.     

A computer generator for randomly layered structures

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

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.