T3-sequencing: targeted characterization of the N- and C-termini of undigested proteins by mass spectrometry

A novel extension of the "top-down" approach is introduced for the selective characterization of protein termini that does not involve proteolytic digestion steps. N- and C-terminal peptides were generated from intact proteins in the mass spectrometer and further analyzed by MS/MS-an approach referred to as T(3)-sequencing. N-terminal and C-terminal fragment ion series were obtained by the pseudo-MS/MS technique in-source decay (ISD) on a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS). These ions provided near-terminal sequence tags from the undigested protein in the ISD spectrum acquired in reflector mode and allowed to screen for the proper processing state of the terminus with respect to a reference sequence. In the second step of T(3)-sequencing, the precursor ions, which have been generated by ISD and which included the N- or C-terminal sequence, were selected in the timed ion gate of a MALDI-TOF/TOF mass spectrometer for MS/MS analysis. These spectra allowed identification of the protein, the proper definition of both termini, and allowed confirmation of suspected terminal modifications. T(3)-Sequencing appears to be an alternative to classical Edman sequencing, which is fast and even permits the analysis of N-terminally blocked proteins and their C-terminus.     

Eigenschaften hochtemperaturhydrolytisch hergestellter Kieselsäuren und Metalloxide für Katalysatoren

Catalytic properties of silicic acids and metal oxides prepared hydrolytically at high temperatures . The physical and chemical properties of silicic acids and metal oxides (Al₂O₃ and TiO₂ P25) prepared hydrolytically at high temperatures are described, insofar as they might be of interest to catalyst producers. A highly topical literature survey reveals areas of interest in the fields of research and practical applications. The experimental section deals with the preparation of catalyst supports made of highly dispersed silica gel products. Their characteristics are tabulated.     

The place of psychology in an ideal university: The report of the University Commission to advise on the future of psychology at Harvard.

Reproduces the 1947 report of the Harvard Commission in the context of a contemporary discussion of the place of psychology in the university. The Commission, composed of 12 eminent scientists, reviewed the status of psychology since the close of World War II and made recommendations for its future development in the "ideal" university. 5 of the original Commission members (D. Bronk, L. Carmichael, J. Dollard, E. R. Hilgard, and J. C. Whitehorn) present retrospective comments on their earlier report as seen "Twenty-Five Years Later." The reprint report and commentary are 1 of 3 sections of a Special Issue on "The Place of Psychology in the University" (see M. H. Appley, 44:10). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Twenty-five year later: Retrospective comments by members of the original Harvard Commission.

This article offers a collection of retrospective comments by members of the original Harvard Commission. Each member provides his own comment and discusses his experiences in life and work. Comments are provided by: Detlev W. Bronk, Leonard Carmichael, John Dollard, Ernest R. Hilgard and John C. Whitehorn. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuere Untersuchungen zur Aluminiumbestimmung mit Chromazurol S

Die photometrische Bestimmung von Aluminium im Stahl mit Chromazurol S unter Zusatz von Polyvinylalkohol als Schutzkolloid wurde untersucht. Der Aluminium-Komplex wird bei pH 6 gebildet, die Extinktion bei 620 nm gemessen. Störende Elemente werden durch eine Natronlaugefällung in Gegenwart von Zinkchlorid und Borsäure entfernt. Die Nachweisgrenze des Verfahrens liegt bei 0,0008% Al. Die Standardabweichung bei der Bestimmung von 0,0032% Al beträgt 0,00028% Al. Der Extinktionskoeffizient liegt bei 73 400 l/Mol · cm.     

Growth of Boric Acid Crystallites on the Surface of Boron-Doped Silicon Carbide Samples

White crystallites were visually observed on fractured or polished surfaces of SiC samples (grain sizes below ∼500 nm) during exposure to air at room temperature for several days. Characterization of the crystallites by scanning electron microscopy, secondary ion mass spectroscopy, and X-ray diffraction identified B(OH)₃ crystals with a strong (002) texture. The rate of boric acid formation was determined by a gravimetric experiment. The rate of weight gain increased significantly after an incubation period of 1 week. Nucleation is initially the rate-limiting process. Subsequently small B(OH)₃ crystals form on the surface, whose growth rate is determined by grain boundary diffusion of boron to the SiC surface. An estimated grain boundary diffusion coefficient of boron in SiC was many orders of magnitude higher than extrapolated literature values.     

Kinetic Process of Reoxidation of Base Metal Technology BaTiO3-Based Multilayer Capacitors

Base metal technology, mainly using Ni electrodes in multilayer ceramic capacitors (MLCCs), is now well established. This technology requires a so-called reoxidation treatment after sintering the MLCCs in a reducing atmosphere to guarantee a sufficient electrical reliability. Large numbers of electrodes, and production of physically larger components for high-voltage components, are two technological trends that make the control of the reoxidation process rather difficult. The reoxidation process has been studied to determine oxygen diffusion pathways into commercial MLCCs, using ¹⁸O tracer diffusion and finite element calculations. In MLCCs oxygen diffusion mainly occurs along the Ni electrodes. Furthermore, the reoxidation process is mostly controlled by the thermodynamic potential of the Ni/NiO equilibrium in the interior of the capacitor, but it is the short circuit diffusion along the interface of the electrode that controls the kinetics of the oxygen transport into the interior of the capacitor device.     

Hydroxyl Defect Effect on Reoxidation of Sc‐Doped (Ba,Ca)(Ti,Zr)O3 Fired in Reducing Atmospheres

The behavior of grain and grain‐boundary conductivity of acceptor (Sc)‐doped (Ba,Ca)(Ti,Zr)O₃ ceramics sintered in moist reducing atmosphere and subsequently reoxidized in dry and moist atmosphere was investigated by means of impedance spectroscopy (IS). In moist firing atmosphere, water vapor was found to react with oxygen vacancies, forming positively charged hydroxyl defects on regular oxygen sites in the crystal lattice. Proton hopping is considered to raise the ionic conductivity significantly. Therefore, hydroxyl defects in turn influence the grain conduction. Hydroxyl defects are also considered to be responsible for alternations of the dielectric maximum at the Curie point.