Cytochemical characteristics of the golgi apparatus

Lectinocytochemistry provides a useful tool for localizing subcompartments of the complex reticular apparatus of Golgi. The technique is based on interactions of lectins with glycoconjugates present in the limiting membranes and luminal spaces of Golgi elements. Application of a series of lectins of different sugar specificities permits a differentiation between Golgi subcompartments containing glycoconjugates with different oligosaccharide side chains. These may be (a) different glycoconjugates or (b) glycoconjugates at different stages during synthesis or repair of their glycans. The lectinocytochemical studies with mannose-, glucose-, N-acetyl-glucosamine-, N-acetylgalactosamine-, galactose-, fucose-, and sialic acid-recognizing lectins revealed predominating patterns that labeled distinct, i.e., cis, medial, trans, and transmost, regions of the Golgi apparatus. A further refinement could be achieved by differential lectin-inhibition that enables a dissection of lectin binding reactions on the basis of their binding affinities. High-affinity binding reactions showed that subcompartments are not necessarily confined to one single Golgi subregion and may change their position from one to another subregion. Some of the patterns observed may be interpreted in relation to certain steps during synthesis and modifications of glycans.     

Graphit als Werkstoff im Apparatebau. Graphite for the Construction of Chemical Equipment

The growing interest in the use of graphite as a material for chemical equipment is occasioned by the highly corrosion resistant properties of this low-cost material. Economic and safety specifications require a thorough knowledge of the material's properties and performance and also of the effect of these factors on a particular unit. It is to be considered for instance that the material's compressive strength is 3 to 5 times higher than its tensile strength. Another important characteristic is its static strength: the smaller the stressed volume, the higher the breaking strength. This comparatively good performance is of advantage in cases of high voltage gradients as encountered as edge stresses at the openings of tube plates and nozzles. In such cases the breaking strength may reach twice the value of the rupturing strength. A third characteristic to be mentioned is the high dependence of strength on the parameters of production; the strength decreases, for technological reasons, with increasing size. The following design principles are based on the specific properties and performance of the material:

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Anharmonic frequency analysis: the complement to Fourier analysis

Fourier analysis of a finite time series allocates amplitudes and phases to a given set of frequencies which are integer multiples of a basic frequency determined by the length of the time series. Anharmonic frequency analysis (Afa)collects the spectral components between those frequencies and the results are the average amplitude and phase for each band defined by two consecutive frequencies. A repetition of the transform involved for a later reference time determines the effective frequency within each band by the time change of the phase. This process is by far superior to Fourier analysis especially if unknown discrete frequencies are present in the time series and those frequencies are not harmonics of one common basic frequency. The principles of this method, some of its properties and a few results are presented.     

无铅无乙基硫脲氯醚橡胶硫化体系的开发

由于健康和环境方面的原因,在欧洲,氯醚橡胶是不允许使用含铅和乙基硫脲的硫化体系的。因此,研发无铅无乙基硫脲的硫化体系迫在眉睫。通过使用特殊的商业化的材料,可使氯醚混炼胶的物理机械性能、耐热老化性、耐燃油性能、贮存稳定性及成本均达到或超过含铅硫化体系的氯醚混炼胶。新研发的无铅无乙基硫脲硫化体系氯醚胶的贮存期至少可以达到7周。同时,这些无铅无乙基硫脲硫化体系氯醚胶的材料成本与含铅硫化体系的相当。     

Beitr?ge zur Erforschung der Nicotinbildung in der Tabakpflanze

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Vorarbeiten zur Erforschung des Nicotinaufbaues in der Tabakpflanze

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