Effects of brefeldin-A on Golgi morphology in human cultured fibroblasts observed in three-dimensional stereo scanning electron microscopy

Brefeldin A (BFA) has been reported to cause disassembly of the Golgi. We have used three-dimensional (3-D) high-resolution scanning electron microscopy (HRSEM) to investigate these effects in human skin fibroblast cells. The spontaneous reassembly during prolonged exposure to BFA and some effects of forskolin were observed. A BFA concentration of 5μg/ml caused Golgi complexes to become vesicular, resulting in a progressive decrease in the size of the Golgi. Morphologic changes were visible within 2 min of BFA incubation, and by 30 min no identifiable Golgi could be found. Spontaneous reassembly of the Golgi apparatus upon the removal of the BFA or with continued long-term exposure with BFA could not be confirmed. Preliminary experiments with forskolin were not effective in reversing or inhibiting the effects of BFA in human fibroblast cells grown in culture. This inability for spontaneous reassembly and nonreversal by forskolin may reflect a differential effect of BFA in various cell types. HRSEM has proven to be useful for observing 3-D morphologic effects of BFA in Golgi.     

Pit to crack transition in stress corrosion cracking of a steam turbine disc steel

Long term exposure tests have been carried out on a 3 NiCrMoV steam turbine disc steel in the form of cylindrical tensile test specimens self-loaded to 90% of σ_0.2 and exposed to three environmental conditions, viz. deaerated pure water, aerated pure water, and aerated water containing 1.5 ppm of chloride ion. Pitting occurred in all environments but the density and depth of pits in the chloride-containing medium was markedly greater. No cracking was observed in deaerated pure water but cracks initiated in aerated water between 13 and 19 months and in less than 7 months in aerated 1.5 ppm Cl⁻ solution. The probability of a crack initiating from a pit of specific depth in aerated solution could be described well by a Weibull function. Profiling of pits and cracks in the disc steel tested in aerated 1.5 ppm Cl⁻ solution showed that there while there were many cracks with a depth greater than that of the corresponding pit the depth of some cracks was smaller than that of the corresponding pit, suggesting that cracks do not necessarily initiate from the bottom of the pits. The growth rate of short cracks emerging from pits appeared greater than that of long cracks in fracture mechanics specimens.     

Thermodynamic and kinetic consideration on the corrosion of Fe, Ni and Cr beneath a molten KCl-ZnCl2 mixture

Thermogravimetric (TG) experiments have been carried out to study the kinetics of hot corrosion of Fe, Cr and Ni, covered by a molten KCl-ZnCl₂ mixture of a composition close to the eutectic (50 mol% KCl-50 mol% ZnCl₂). Furthermore binary and ternary phase diagrams were calculated in order to describe the corrosion process. The tests were conducted at a temperature of 320 °C in an atmosphere consisting of argon and oxygen. For iron different stages are observed in a TG curve. They can be attributed to the different reaction steps of iron chloride formation (incubation phase), oxide precipitation (linear stage) and scale formation (parabolic or logarithmic stage). Based on these observations a model, described by Spiegel [A. Spiegel, Molten Salt Forum 7 (2003) 253], is confirmed. For Cr and Ni these stages are not observed. At 8 vol% O₂ only slight oxidation of Cr and Ni was observed accompanied by evaporation of the salt deposit. At 16 vol% O₂ the rate of oxidation increases and the experiments yield a curve that is either parabolic or logarithmic for both Ni and Cr. As a result it is shown that the solubility of iron chloride in the KCl-ZnCl₂ melt is higher than the solubility of nickel chloride and chromium (III) chloride in the KCl-ZnCl₂ melt. This enables a higher diffusibility of iron chloride to the upper region of the melt where a higher oxygen partial pressure (p(O₂)) is present leading to a higher oxidation rate of iron.     

大电流监测信号提取的光收发及信号处理

近年来,大电流的监测成了人们十分关心的问题,这是由于大电流有强磁、高压、电流大等一系列的直接监测所不能克服的问题。这就需要把高压大电流的强电信号,经过提取后变成能在实验室中直接观测的弱电信号。为此,如何从高压大电流的信号中提取出随实时信号变化而实时变化的小信号就变成了一个关键问题。详细介绍了监测信号提取的光收发电路原理和后续信号处理电路,分析了各部分的作用,给出了必要的分析结果。     

串行接口LED数码管及键盘管理器件ZLG7289A的原理与应用

介绍了LED数码管及键盘管理器ZLG7289A的原理与应用。该芯片具有SPI串行接口，可同时驱动8位共阴式数码管(或64只独立LED)，还可连接多达64键的键盘矩阵，单块芯片即可完成LED显示、键盘接口等全部功能。文章给出了ZLG7289A的特点、引脚功能、指令说明和经典电路．并以单片机AT89C51为例，给出了其接口电路及相应源程序。     

汽车摩擦片厚度测量装置驱动电路的研究

本文通过对摩擦片厚度在线测量装置系统构成的全面分析，对其驱动电路子系统进行了理论探索和技术研究，完成了相应的电路设计、误差分析及器件选择等工作，并进行了具体的实验验证，证明该驱动电路具有良好的性能，可圆满实现摩擦片厚度在线检测和实时分析的工作任务。     

基于LonWorks和DSPs的智能节点

本文提出了一种基于LonWorks和DSPs的智能节点设计方案，并给出了具体的实现方法。该方案简单、可靠，充分利用了LonWorks强大的网络性、可靠性和DSPs强大的数据处理能力，大大提升了节点的智能化程度。     

Comments on Finley's "Critique of rational-emotive philosophy."

Reply to Finley's (1987; see record 1988-00015-001) critique of rational-emotive philosophy, which claims that Ellis's (1981) response to Sharkey's (1981) criticisms of rational-emotive psychology reveals logical and philosophical confusion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)