集胞藻6803在封闭式光生物反应器中的混合营养培养

采用摇瓶和封闭式光生物反应器进行了蓝藻基因工程常用宿主系统集胞藻Syne-chocystis 6803的混合营养培养研究,在摇瓶中对集胞藻6803利用有机碳源特性进行研究的结果表明,光照是集胞藻6803利用葡萄糖的必需条件,混合营养培养是集胞藻6803的最佳培养方式,以葡萄糖为基质在2.5L封闭式光生物反应器中经过58.5h的混合营养培养,集胞藻6803的藻细胞密度和平均生长速度分别达到2.50g/L和1.01g/L/d,分别是光自养培养同期的9倍和11倍,这表明封闭式光生物反应器混合营养培养方式在促进集胞藻6803生长上有显著作用。     

乙肝表面抗原S2S基因在蓝藻Synechococcus sp.PCC7942中的表达研究

用PCR法将乙肝表面抗原基因S2S片段从乙肝病毒中扩增得到,将其插入到蓝藻热休克表达载体pEUTMT1中,构建成表达重组质粒pES2ST1.将蓝藻Synechococcus sp.PCC7942的总染色体与质粒pES2ST1同时进行EcoRI和SacI双酶切,再连接构建成为系列含有蓝藻染色体DNA同源片段的供体表达质粒.经转化筛选得到蓝藻Synechococcus sp.PCC7942转化藻株.PCR和Southern 杂交证明目的基因已经整合到宿主的染色体中.转化藻通过热诱导后,Northern-blot结果呈阳性,用化学发光检测技术可以检测到微量目的蛋白的表达,检测含量约为0.78～0.64ng/ml,目的蛋白约为可溶性蛋白的1.1×10-6～1.5×10-6.     

An LC-MS-based chemical and analytical method for targeted metabolite quantification in the model cyanobacterium Synechococcus sp. PCC 7002

Herein, we detail the development of a method for the chemical isolation and tandem LC-MS/MS quantification of a targeted subset of internal metabolites from cyanobacteria. We illustrate the selection of target compounds; requirements for and optimization of mass spectral detection channels, screening, and optimization of chromatography; and development of a sampling protocol that seeks to achieve complete, representative, and stable metabolite extraction on the seconds time scale. Several key factors influencing the separation by reversed-phase ion pairing chromatography, specifically the hydrophobicity of the sample matrix and sensitivity to mobile phase acidity, are identified and resolved. We illustrate this methodology with an example from the autofermentative metabolism in the model cyanobacterium Synechococcus sp. PCC 7002, for which intracellular levels of 25 metabolites were monitored over 48 h, including intermediates in central carbon metabolism together with those involved in the cellular energy charge and redox poise. Upon removal of alternative reductant sinks (nitrate), anoxia induces autofermentation of carbohydrates with a parallel rise in the intracellular pyridine nucleotide redox poise that is specific to NAD(H) and alongside a gradual decline in the adenylate energy charge. This LC-MS/MS-based method provides for accurate time-resolved quantification of multiple metabolites in parallel, thus enabling experimental verification of the active metabolic pathways.     

氮源和初始NaHCO3浓度对转Tα1基因聚球藻7942生长与表达的影响

研究了氮源和初始NaHCO3浓度对转基因聚球藻7942生长与胸腺素α1表达的影响。结果表明：最适的氮源为NaNO3，NaNO3浓度低于1g／L时，增加NaNO3浓度能提高藻细胞的生长和表达，但1～2．5g／LiNaNO3对转基因聚球藻7942生长与表达没有明显的影响。最适的初始NaHCO3浓度为8．0g／L。生长在8．0g／L初始NaHCO3浓度培养基中藻细胞密度和胸腺素α1最大表达能力分别为BG-11培养基中的1．94倍和2．01倍。     

Modeling the Responses of Thickness-Shear Mode Resonators under Various Loading Conditions

We develop a general model that describes the electrical responses of thickness-shear mode resonators subject to a variety of surface conditions. The model incorporates a physically diverse set of single-component loadings, including rigid solids, viscoelastic media, and fluids (Newtonian or Maxwellian). The model allows any number of these components to be combined in any configuration. Such multiple loadings are representative of a variety of physical situations encountered in electrochemical and other liquid-phase applications, as well as gas-phase applications. In the general case, the response of the composite load is not a linear combination of the individual component responses. We discuss application of the model in a qualitative diagnostic fashion to gain insight into the nature of the interfacial structure, and in a quantitative fashion to extract appropriate physical parameters such as liquid viscosity and density and polymer shear moduli.     

Molecular Dynamics Study of Dynamic Responses of Glassy Silica under Shock Impact

In this study, molecular dynamics (MD) simulations are performed to form glassy silica from meltedb-cristobalite using cooling rates of 2, 20 and 200 K/ps. The resulting glassy silica samples are then shocked at particle velocities ranging from 0.3 to 11 km/s in the MD simulations. The effect of the cooling rate on the shock wave velocity is observed for particle velocities below 2 km/s. Moreover, the simulated pressure and density of the shocked glassy silica increase as the cooling rate increases. As compared with the experimental data, the MD simulation can approximately identify the initiation of densification and predict the shock wave velocity within the reasonable accuracy. The simulated pressure and density of the shocked silica match the experimental and EOS analysis data well when the shock pressure is below 500 GPa. However, the proposed MD simulations under-estimate the density when the glass is shocked at pressures above 500 GPa, which indicates that a better interatomic potential model is required for modeling silica under ultrahigh pressures.     

水平任意向地震输入下双塔楼连体结构的动力分析

双塔结构在塔间设置连接可以组成减震控制体系，本文建立了体系的设计模型和运动方程，并在频域内对体系进行随机地震响应分析，同时比较了水平任意向地震输入时，无连接，有连接情况下的双塔结构的随机动力响应。表明有连接时结构的扭转变形不可忽略，最后就连接装置各参数对扭转反应效果的影响进行了分析。     

《不同隧道断面结构处的地表振动分析》

地铁列车的振动对隧道周围土体强度和变形有较大的影响。本文以北京地铁5号线的隧道尺寸和土质特性为研究背景,用有限元软件对圆形隧道和矩形隧道在相同列车振动荷载作用下的动力响应进行计算,给出了隧道周围土体的变形情况和地表位移。并将这两种断面的有限元计算结果进行比较和分析,为以后的工程设计提供依据。     

Isolation and characterization of phenanthrene-degrading strains Sphingomonas sp. ZP1 and Tistrella sp. ZP5

Two bacteria strains Sphingomonas sp. strain ZP1 and Tistrella sp. strain ZP5 were identified as phenanthrene-degrading ones, based on Gram staining, oxydase reaction, biochemical tests, FAME analysis, G+C content and 16S rDNA gene sequence analysis. We isolated these two bacteria strains Sphingomonas sp. ZP1 and Tistrella sp. ZP5 from soil samples contaminated with polycyclic aromatic hydrocarbon (PAH)-containing waste from oil refinery field in Shanghai, China. Strain Sphingomonas sp. ZP1 was able to degrade naphthalene, phenanthrene, toluene, methanol and ethanol, salicylic acid and Tween 80. Moreover, it can remove nearly all the phenanthrene at 0.025% concentration in 8 days. Strain Tistrella sp. ZP5 cannot degrade phenanthrene individually but it can increase the speed of phenanthrene degradation together with ZP1. The growth conditions of strain Sphingomonas sp. ZP1 were optimized. The result also indicated that the degradation rate of phenanthrene ranged from 250 to 1000 ppm with strain ZP1 remained nearly the same, i.e., a high concentration of phenanthrene did not inhibit both the growth of microbial strains and the phenanthrene-degradation ability. Besides, the effect of non-ionic surfactants such as Brij 30, Triton X-100 and Tween 80 on the phenanthrene degradation was determined. Such two strains may be useful for bioremediation applications.     

不同认知难度影响因素下数据信息搜索的视觉生理反应规律

目的 数字化产线数据监控界面中的数据图表呈现方式对监测员认知绩效的影响十分关键.以数据形式、任务种类及颜色和呈现方式为变量,依次展开行为反应与眼动追踪实验.方法 以产线生产制造过程中的损失工时数据为实验材料设计实验,通过记录行为反应数据中的反应时间和正确率,以及眼动追踪数据中的凝视时间和瞳孔直径大小指标,分析并讨论在不同影响因素下具有认知难度差异的数据图表认读实验中,反应时间与正确率、凝视时间与瞳孔直径大小间的反应变化一致性规律.结果 数据形式、任务种类对行为反应指标,以及呈现方式、颜色对视觉反应指标均具有显著性影响.结论 随着数据图表不同影响因素下的认知难度差异变化,行为反应体现为正确率与反应时间呈一定程度负相关;视觉反应指标体现为凝视时间与瞳孔直径变化的一致性,并且瞳孔直径变化对颜色因素具有更高敏感度.该结论能在数据图表认知绩效的评价与设计优化中起到一定参考作用.     

Physiological cost of work under hot dry climates in Indian industries An analysis

The possibility of using pulse rate during work as a measure of the energy coat of that work, in lieu of the more cumbersome gas analysis techniques, has been examined in actual industrial environments for varied work and thermal loads. Three sets of data from some hot dry industries situated in different parts of India were analysed : (a) extreme levels ; (b) moderate levelB ; and (c) comparatively low levels of work and heat loads. Pulse rate (PR) measurements, in conjunction with body surface area (BSA) and corrected effective temperature (CET) were found to be significantly correlated with energy expenditure (EE) at both high and moderate levels (τ = 0-889 and 0-902, respectively); the predictive ability of the corresponding regression coefficients was also high (SE of estimate—± 10%).

PR was also found to bear a linear relationship with work load at various levels of heat stress. Further, it was evident that at all levels (a), (b) and (c), the effect of work effort on observed pulse rate was more significant than that of heat exposure during work in hot environments.

From the observed relationships between PR, CET and BSA, on the one hand, and EE, on the other, it could be suggested that it is possible to predict the physiological cost of work from easily measurable parameters on the shop floor.     

任意激励作用下变厚度Reissner板的动力响应

本文提出了一个分析中厚度矩形板动力响应的一般方法。文中借助Laplace 变换和传递矩阵法,并引进节线的相关矩阵,较简便地求得了响应在象空间中的一般解,然后再利用拉氏逆变换的数值解求出板的瞬时位移场和内力场。列举的实例和以往的结果作了比较。     

Decolorization of adsorbed textile dyes by developed consortium of Pseudomonas sp. SUK1 and Aspergillus ochraceus NCIM-1146 under solid state fermentation

The objective of this study was to develop consortium using Pseudomonas sp. SUK1 and Aspergillus ochraceus NCIM-1146 to decolorize adsorbed dyes from textile effluent wastewater under solid state fermentation. Among various agricultural wastes rice bran showed dye adsorption up to 90, 62 and 80% from textile dye reactive navy blue HE2R (RNB HE2R) solution, mixture of textile dyes and textile industry wastewater, respectively. Pseudomonas sp. SUK1 and A. ochraceus NCIM-1146 showed 62 and 38% decolorization of RNB HE2R adsorbed on rice bran in 24h under solid state fermentation. However, the consortium of Pseudomonas sp. SUK1 and A. ochraceus NCIM-1146 (consortium-PA) showed 80% decolorization in 24h. The consortium-PA showed effective ADMI removal ratio of adsorbed dyes from textile industry wastewater (77%), mixture of textile dyes (82%) and chemical precipitate of textile dye effluent (CPTDE) (86%). Secretion of extracellular enzymes such as laccase, azoreductase, tyrosinase and NADH-DCIP reductase and their significant induction in the presence of adsorbed dye suggests their role in the decolorization of RNB HE2R. GCMS and HPLC analysis of product suggests the different fates of biodegradation of RNB HE2R when used Pseudomonas sp. SUK1, A. ochraceus NCIM-1146 and consortium PA.     

Nitrate removal efficiency of bacterial consortium (Pseudomonas sp. KW1 and Bacillus sp. YW4) in synthetic nitrate-rich water

The efficiency of bacterial isolates to reduce nitrate from synthetic nitrate-rich water was tested using a batch scale process. Two efficient nitrate reducing bacterial species were isolated from water samples collected from Kodaikanal and Yercaud lakes. Bacterial analysis of the samples revealed the presence of nitrate reducing bacteria belonging to the genera Pseudomonas, Bacillus, Micrococcus and Alcaligenes. Among the isolates, the consortium of Pseudomonas sp. KW1 and Bacillus sp. YW4 was found to be efficient in nitrate reduction. Influences of various carbon sources, incubation temperature and pH on nitrate reduction from synthetic wastewater were also studied. The results showed a rapid and efficient process of nitrate removal (99.4%) from synthetic wastewater supplemented with starch (1%), inoculated by bacterial consortium (Pseudomonas sp. KW1 and Bacillus sp. YW4) at incubation temperature of 30 degrees C at pH 7. This observation has led to the conclusion that the bacterial consortium was responsible for nitrate removal from synthetic nitrate-rich wastewater.     

地震作用下斜交简支梁桥桥面旋转反应的参数分析

地震引起的斜交简支梁桥桥面面内旋转不仅增大了梁体的纵、横向位移,而且增加了梁体与边界碰撞的几率。为研究地震作用下斜交简支梁桥桥面的旋转反应,利用OpenSees地震仿真模拟平台,建立考虑梁体与桥台间纵向碰撞、梁体与挡块间横向碰撞效应的斜交简支梁桥简化动力计算模型,分析梁体与桥台间纵向碰撞刚度、伸缩缝间隙、梁体与挡块间碰撞刚度、初始间隙、挡块力学特性等对斜交简支梁桥桥面旋转的影响。结果表明：纵向碰撞刚度、伸缩缝间隙、梁体与挡块间初始间隙对斜交简支梁桥桥面转角的影响较大,而横向碰撞刚度对桥面转角的影响相对较小;梁两端锐角区设置纵向垫块对减小桥面转角和纵向位移有较好的效果;设置弹塑性挡块能有效控制桥面的震致转动,减轻挡块的横向受力。     

基于加速度二次协方差矩阵参数变化比法的环境振动下结构损伤识别

在白噪声环境激励下,结构加速度响应的自相关/互相关函数构成一个新的二次协方差（CoC）矩阵,组成这一协方差矩阵的元素经证明是结构模态参数（频率、振型、阻尼）的函数;与提取模态参数的一般损伤识别方法相比,二次协方差矩阵包含结构振动的更多和更高阶模态信息。本文利用结构损伤前和损伤后的二次协方差（CoC）矩阵参数的变化比,对只基于振动输出的、环境振动下的结构进行损伤识别。对一个七层框架结构模型进行了数值模拟,首先对不同噪声程度、不同损伤位置和程度的损伤结构进行损伤定位,再结合模型修正法,对结构损伤程度进行识别,展示了该方法的有效性。     

Novel biodegradation pathways of cyclohexane by Rhodococcus sp. EC1

The metabolism of cyclohexanes by Rodococcus sp. EC1 was investigated using a sequential tracking method of degradation intermediate. Evidence for the formation of cyclohexanol, cyclohexaone, 2-cyclohexen-1-one, and phenol was presented. EC1 metabolized cyclohexane to phenol by aromatization of 2-cyclohexen-1-one, and furthermore gamma-butyrolactone as an intermediate of 2-cyclohexen-1-one was formed. Aromatization by EC1 was confirmed using tetrahydrofuran. Tetrahydrofuran was metabolized through aromatization reaction, involving furan and 2,3-dihydrofuran as key intermediates. EC1 can degrade cyclohexane and tetrahydrofuran in aromatization via desaturation.