New applications of pHluorin—measuring intracellular pH of prototrophic yeasts and determining changes in the buffering capacity of strains with affected potassium homeostasis

pHluorin is a pH‐sensitive variant of green fluorescent protein for measuring intracellular pH (pH_in) in living cells. We constructed a new pHluorin plasmid with the dominant selection marker KanMX. This plasmid allows pH measurements in cells without auxotrophic mutations and/or grown in chemically indefinite media. We observed differing values of pH_in for three prototrophic wild‐types. The new construct was also used to determine the pH_in in strains differing in the activity of the plasma membrane Pma1 H⁺‐ATPase and the influence of glucose on pH_in. We describe in detail pHluorin measurements performed in a microplate reader, which require much less hands‐on time and much lower cell culture volumes compared to standard cuvettes measurements. We also utilized pHluorin in a new method of measuring the buffering capacity of yeast cell cytosol in vivo, shown to be ca. 52 mM /pH for wild‐type yeast and moderately decreased in mutants with affected potassium transport. Copyright © 2010 John Wiley & Sons, Ltd.     

我国汽车工业铝材的开发应用趋势与对策

作者在掌握了大量现场资料和文献资料的基地上，全面系统地论述了国外汽车工业用铝材的发展现状与趋势、汽车用铝合金及主要零部件的铝化程度、未来汽车及汽车用铝合金的新开发、我国汽车用铝材的开发与应用状况等问题。指出汽车材料铝化是现代汽车轻量化的主要途径。为加速我国汽车工业用材的国产化和铝化提出了建议。     

A vibrating tube flow densitometer for measurements with corrosive solutions at temperatures up to 723 K and pressures up to 40 MPa

A new version of a vibrating tube flow densitometer has been designed permitting measurements of density differences between two fluids in the temperature range from 298 to 723 K and at pressures up to 40 MPa. The instrument is equipped with a Pt/Rh20 vibrating tube (1.6-mm o.d.) and a Pt/Rh10 transporting tube (1.2-mm o.d.) permitting measurements with highly corrosive liquids. The period of oscillation of the tube is about 7.5 ms, with a typical stability better than 10⁻⁴% over about a 1-h period over the entire temperature interval. The calibration constantK at room temperature is about 530 kg·m⁻³·ms⁻², with a temperature coefficient of approximately −0.13kg·m⁻³·ms⁻²·K⁻¹, and is practically pressure independent. It can be determined by calibration with a reproducibility generally better than 0.1%. The instrument was tested with NaCl(aq) solutions in the temperature range from 373 to 690 K for density differences between sample and reference liquid ranging from 200 to 2 kg·m⁻³; the corresponding errors are believed to be below 0.3 and 5%, respectively. A highly automated temperature control maintains the temperature of the tube stable to within ±0.02 K.     

A novel methodology in transforming bulk properties of refining streams into molecular information

Stricter and ever increasing environmental legislations and demand for higher quality products are the driving forces for the refiner in an attempt to characterise the refining streams on the molecular basis. The objective of this work is to develop a new methodology to interrelate the bulk properties and molecular information of the refining streams in order for refiners to look at the contribution of each molecular group on the properties of the refining streams.The molecular information of a particular refining stream is presented in the form of MTHS (molecular type homologous series) matrix representation [Peng, B., 1999. Molecular modelling of petroleum processes. Ph.D. Thesis, UMIST]. To enhance the accuracy and usability of the method, structural contribution of each isomer on various properties such as octane number, and reid vapour pressure, etc. are considered. Structural lumping rules are then applied to obtain the physical properties of each homologous series. Databases are set up for the properties and molecular information of typical refining streams. Automatic selection of sample matrices through linear combination is used to predict new composition matrices. The methodology is illustrated for refining streams with gasoline range hydrocarbons. The properties predicted based on the new methodology proves to be within 5-6% error range.     

小浪底水库拦沙运用期大洪水对温孟滩移民安置区河段影响的试验研究

小浪底水库移民安置区温孟滩河段河道整治模型试验研究结果表明，在水库拦沙运用期冲刷严重的初始河道地形条件下遭遇大洪水后，河势变化不大，河道整治工程对大洪水是基本适应的，但存在个别工程入流过死，局部冲深大和送溜不力等情况。由于前期河床已冲刷下切，河槽泄洪能力大大增加，洪峰期（Ｑ＝１００００ｍ３／ｓ）基本未出现明显漫滩。本文对局部冲刷的基本规律也作了探讨。     

采空区地表移动盆地对埋地管道的影响分析

分析了采空区地表移动盆地的形成原因和对埋地管道的影响,根据相关公式,对水平矿层地表移动盆地的最大沉降量、移动盆地主断面轴线长度等边界特征值进行了计算.同时,参照有关石油行业标准,对一定长度下管道允许的最大沉降量进行计算,并列举了具体算例.通过移动盆地的最大沉降量与管道允许的最大沉降量的比较,初步判定管道的安全性.     

Use of99m Tc as an energy standard for electron spectroscopy: promise and limitations

An electrostatic spectrometer was used to study the dependence of the position of theM ₅ line of conversion electrons from the 2.17-keV transition in⁹⁹Tc on the source thickness, in samples of different chemical compounds of Tc: metallic technetium, technetium dioxide, and pertechnate. Recommendations are given concerning the use of a source in the form of a film of metallic technetium (less than 10⁻⁷ g/cm² thick) on a platinum substrate for calibrating electron spectrometers in the energy range of a few kiloelectron volts. A procedure is described for preparing films of metallic technetium. Translated from Izmeritel'naya Tekhnika, No. 8, pp. 66–68, August, 1997.     

Ethanol stimulates the formation of free oxygen radicals in the brain of newborn rats

The possibility of free radicals effects in ethanol-induced teratogenesis was investigated by determining the production of reactive oxygen species (ROS) in the neonatal rat brain. Ethanol 33% was administered daily, by i.p. injection from day 8 of pregnancy to day 6-8 p.n. The presence of the lipid peroxidation process (indicating ROS formation) was determined by using a qualitative and quantitative analysis of malondialdehyde (MDA). An important increase of MDA was found suggesting the involvement of ROS in the pathogenetic mechanism of alcohol embryo- and fetopathy.