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51.
Strohalm M Strohalm J Kaftan F Krásný L Volný M Novák P Ulbrich K Havlíček V 《Analytical chemistry》2011,83(13):5458-5462
Traditional tissue-sectioning techniques for histological samples utilize various embedding media to stabilize the tissue on a sectioning target and to provide a smooth cutting surface. Due to the ion suppression effect in MALDI ionization and number of background peaks in the low-mass region, these media are not suitable for mass spectrometry imaging (MSI) experiments. To overcome this, droplets of water are often used to mount the tissue on a sectioning target, but the ice block formed around the tissue does not provide a good support for sectioning of fragile samples. In this work, we propose a novel embedding media, compatible with MALDI ionization and MSI experiments, based on poly[N-(2-hydroxypropyl)methacrylamide] (pHPMA). Using a reversible addition-fragmentation chain transfer polymerization technique, well-defined pHPMA polymer with narrow mass distribution was prepared. Benefits of the resulted pHPMA-based embedding media were tested on different tissue samples. 相似文献
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A method is described for detecting yeast cells with plasma membrane damage, based on cell staining with bromocresol purple (BCP) which has a convenient fluorescence after entering the cells at pH below 5·2. The method was used to determine the activity of Saccharomyces cerevisiae pore-forming killer toxin K1 in commonly used lethal units. The BCP test is rapid and as precise as the plating test. 相似文献
54.
Partial differential equations describing the transport of mass and electricity in the pores of the negative electrode of a lead-acid battery were derived. The theory is based on exact transport equations and on the assumption that the electrode potential is governed by the Nernst equation. Volume changes in both phases are taken into account. Numerical solutions depend on the product of electrode thickness times current density and on the initial porosity. Differences between the negative and positive plates are discussed. 相似文献
55.
Summary Using determination of the critical molar ratio of functional groups necessary for gel formation with amino groups in excess, network formation was investigated in the reaction of diglycidyl ether of Bisphenol A (DGEBA) and nitrogen-containing epoxy resins — diglycidylaniline and N,N,N,N-tetraglycidyl-4,4-diaminodiphenylmethane with aromatic or aliphatic amines. It was found that in the case of nitrogen-containing epoxides the crosslinking is accompanied by pronounced cyclization, unlike in systems with DGEBA. Gelation depends on the relative reactivity of the primary and secondary hydrogen atom of the amino group. In the case of nitrogen-containing polyepoxides, the dependence of reactivities of adjacent glycidyl groups is also operative. 相似文献
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Gerda H. Schoutens Ruud P. Guit Gerard J. Zieleman Karel Ch. A. M. Luyben Nico W. F. Kossen 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1986,36(7):335-343
For the continuous production of isopropanol-butanol mixtures by immobilised Clostridium spp. (the IBE process) two reactor types were studied: a fluidised bed reactor with liquid recycling (FBR) and an external loop gas lift reactor (GLR). A large scale design (50–65 m3) was made for both reactors. A regime analysis, by evaluating the time constants for e.g. mixing and conversion, identified the ruling regime. Via the scale down approach two representative model reactors were developed: a 10 dm3 FBR reactor (H/D=25, D=0.08 m) and a 15 dm3 external loop GLR (H/D = 12.5, Dr=Dd=0.08 m). For both reactors the hydrodynamical behaviour and the total reactor performance were studied and are described in parts II and III of this study. 相似文献
58.
Apparatus for measurement of crystal growth rate in a fluidized bed has been modified. The improvement consists of a new way of introducing and removing seeds, which substantially speeds up the measurement and, due to better stability of the temperature regime, leads to improved reliability of results. Growth rates of CuSO4 · 5H2O in aqueous solutions, measured in the original and improved apparatus, are compared and they demonstrate the advantages of the new version of the equipment. 相似文献
59.
Summary Analysis of reported data on the swelling and deformation of polymer networks shows that the volume-dependent term in the deformational free energy cannot be neglected. The analysis is based on a comparison between the equilibrium modulof networks prepared at various dilutions and of the same degree of swelling and on a comparison between concentration dependences of the interaction parameter for a linear and a crosslinked polymer. 相似文献
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