基因替换及多基因共表达强化大肠杆菌辅酶Q10的合成能力

为了强化大肠杆菌合成辅酶Q10（CoQ10）的能力,对大肠杆菌进行了相关的基因操作。通过敲除大肠杆菌染色体上的聚八异戊二烯焦磷酸合成酶基因ispB,并导入来自Gluconobactersuboxydans的聚十异戊二烯焦磷酸合成酶基因ddsA,使大肠杆菌具有CoQ10合成能力的同时降低了内源性辅酶Q8（CoQ8）的合成。采用双质粒共表达系统,对CoQ生物合成途径中多个功能基因进行了强化表达,构建得到的重组大肠杆菌CoQ的合成能力、CoQ10合成的专一性都有明显改善,其中ubiCA和ddsA基因的协同表达效果最为明显,CoQ的合成能力比对照提高了65%,而CoQ10的合成量也提高了1.1倍。     

链霉菌辅酶Q9生物合成基因sdsA的鉴定

聚异戊二烯焦磷酸合成酶基因在4个不同种的链霉菌(Streptomyces coelicolor A3(2), Streptomyces maritimus, Streptomyces mycarofaciens ATCC 21454和Streptomyces sp.Tü4128)中分别被克隆.测序结果显示:4个聚异戊二烯焦磷酸合成酶基因均编码336个氨基酸的肽链,4条肽链之间的序列有97%的同源性.将4个不同的聚异戊二烯焦磷酸合成酶基因分别导入大肠杆菌中进行异源表达,有辅酶Q9产生.将4个基因分别导入八聚异戊二烯焦磷酸合成酶(IspB)缺陷的大肠杆菌KO229(ΔispB)中证明它们有替代ispB基因的功能,并且在大肠杆菌中合成辅酶Q9.     

一种合成2,2,—二甲基—4—戊烯酸的方法

报道一种合成２,２－二甲基－戊烯酸的新方法,由异丁醛与烯丙醇缩合得到２,２－二甲基－４－戊烯醛,后者氧化银选择氧化生成２,２－二甲基－４－戊烯酸。此法氧化产率（９６％）高于分子氧氧化法（６１％）和歧化法（４１％）。反应中析出的金属银能定量回收,循环使用。     

NaCl诱导表达的盐藻果糖-1,6-二磷酸醛缩酶基因克隆及原核表达

通过RACE技术克隆到盐藻（Dunaliella salina Teod.)果糖－1，6－二磷酸醛缩酶（DsALDP)的全长cDNA,对其序列分析及在GeneBank中进行同源搜索，发现DsALDP基因属于果糖－1，6－二磷酸醛酶基因家族，其与植物叶绿体果糖－1，6－二磷酸酯缩酶（AldP)基因的一致性为73％－66％。Northern杂交结果及醛缩酶活性分析均表明它角为在盐诱导下特异表达。将DsALDP cDNA构建到pET32a载体上，转入E.coli BL21进行表达分析。IPTG诱导后可以检测到－62ku基因产物大量表达。经不同浓度NaCl处理，表达DsALDP基因产物的细菌耐盐性明显高于对照组。     

ChsA启动子驱动的IPT基因植物表达载体的构建

为研究异戊烯腺苷类细胞分裂素与花衰老进程的相关性,本研究通过PCR方法从矮牵牛中克隆到花瓣特异性表达的矮牵牛查尔酮合成酶基因A(ChsA)的启动子PchsA,并以其取代植物表达载体pBI121中的组成型启动子CaMV35S,然后将IPT基因插入到PchsA启动子下游,测序结果显示花瓣特异性启动子驱动的IPT植物表达载体构建成功.     

ACPDA作为引发剂合成成嵌段共聚物的研究

以4，4‘－偶氮二[4－氰基戊酰（对－二甲基氨基）苯胺]（ACPDA）为引发剂，先热分解引发甲基丙烯酸甲酯聚合，得到含有4，4－二甲胺基端基的预聚物，它与BPO组成氧化还原体系引发丙烯酰胺聚合后，得到聚甲基丙烯酸甲酯－丙烯酰胺嵌段共聚物，研究了反应组成及反应条件对嵌段共聚合反应的影响，结果表明在嵌段共聚物中，丙烯酰胺聚合物的含量随反应组成及反应条件而异，其含量可达50％以上。     

大肠杆菌aroG基因在枯草杆菌中的分泌表达

为了对大肠杆菌中由ａｒｏＧ基因编码的３－脱氧－Ｄ－阿拉伯庚酮糖酸－７－磷酸合成酶（ＤＡＨＰ合成酶）进行结构与功能的深入研究,尝试了ａｒｏＧ基因在枯草杆菌中的表达。表达载体以ｐＵＢ１１０为骨架,采用了枯草杆菌热激蛋白ｇｒｏＥＳＬ基因的启动子,碱性蛋白酶ｓｕｂｔｉｌｉｓｉｎ基因的信号肽和Ｎ－乙酰胞壁酸－Ｌ－丙氨酸酰胺酶ｃｗｌＨＢ基因的转录终止子,将ａｒｏＧ基因在枯草杆菌ＷＢ６００宿主菌中进行了分泌表达     

高产S-腺苷蛋氨酸合成酶基因工程菌的构建

应用PCR技术,以大肠杆菌BL21（DE3）染色体DNA为模板,扩增得到S-腺苷蛋氨酸（SAM）合成酶基因。将所得基因连接至表达载体pET-22b（+）,利用T7强启动子进行转录,然后转化进E. coli BL21（DE3）表达菌株,构建出了具有高效表达SAM合成酶基因的基因工程菌。重组菌所表达的酶活为115U/g（以细胞干重计）。     

多能硫杆菌1,5-二磷酸核酮糖羧化酶/加氧酶基因的启动子克隆和表达

将３．４ｋｂ的多能硫杆菌１，５－二磷酸核酮糖羧化酶／加氧酶基因（ｒｂｃＬ－ｒｂｃＳ）片段亚克隆到启动子探测质粒载体ｐＫＬ６的ＨｉｎｄⅢ位点，该基因片段能够启动ｐＫＬ６的ｌａｃ基因的表达，说明３．４ｋｂ的ｒｂｃＬ－ｒｂｃＳ基因带有自己的启动子．     

去B链羧端三肽人胰岛素原的基因构建和表达

用改进的寡苷酸诱导 突变法将人胰岛素原基因（ＢＣＡ）删除编码Ｂ链羧端三肽的碱基片段，得到去Ｂ链羧端三肽胰岛素原的基因（Ｂ＾－３ＣＡ）。为了便于表达产物的蛋白质后加工，又用ＰＣＲ的方法在Ｂ链Ｎ端起始Ｍｅｔ与Ｐｈｅ密码子之间增加了编码Ｌｙｓ的３个碱基，得到改造后基因ＬＢ＾－３ＣＡ，将ＬＢ＾－３ＣＡ克隆到表达质粒ｐＢＶ２２０上，在大肠杆菌系统中热诱导表达，表达率为１２％。表达产物经蛋白质后加工，得到的去     

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.