Trajectories of internationalization: knowledge and national business styles in the making of two Dutch publishing multinationals, 1950-1990

The internationalization of business is the subject of an extensive theoretical literature as well as a growing number of historical studies. Historians have paid relatively little attention to the development of multinationals in the service sector, and studies about international publishing are especially scarce. This article discusses the early internationalization of two Dutch publishing firms, Kluwer (nowWolters Kluwer) and Elsevier (now Reed Elsevier) and confronts these case histories with the evolutionary theory of internationalization. The Dutch cases underline the important role of experience, knowledge and learning as well as of the national context in which companies develop. They also show that these factors allow for very different trajectories of internationalization within the same branch of business and the same country

Chromatofocusing nonporous reversed-phase high-performance liquid chromatography/electrospray ionization time-of-flight mass spectrometry of proteins from human breast cancer whole cell lysates: a novel two-dimensional liquid chromatography/mass spectrometry method

A novel two-dimensional two-column liquid chromatography/mass spectrometry (LC/MS) technique is described in this work, where chromatofocusing (CF) has been coupled to nonporous reversed-phase (NPS-RP) HPLC to separate proteins from human breast epithelial whole cell lysates. The liquid fractions from NPS-RP-HPLC are readily amenable to direct on-line analysis using electrospray ionization orthogonal acceleration time-of-flight mass spectrometry (ESI-TOFMS). A key advantage of this technique is that proteins can be ‘peeled off’ in the liquid phase from the CF column according to their isoelectric points ( pI ) in the first chromatographic separation dimension. The NPS-RP-HPLC column further separates these pI -focused fractions based upon protein hydrophobicity as the second chromatographic dimension. The third dimension involves on-line molecular weight determination using ESI-TOFMS. As a result, this method has the potential to be fully automated. In addition, a 2-D protein map of pI versus molecular weight is generated, which is analogous to a 2-D gel image. Thus, this technique may provide a means to study differential expression of proteins from whole cell lysates. Copyright © 2001 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35081/1/227_ftp.pd

Modellierung und Stabilisierung passiv modensynchronisierter Faserlaser

In der vorliegenden Arbeit wird eine Modellierung von Ultrakurzimpuls-Faserlasern vorgenommen. Die Modellierung basiert auf einer numerischen Berechnung der Impulsausbreitung in den Fasern des Laserresonators, leitet aber darüber hinaus Laserratengleichungen ab. Diese ermöglichen eine Beurteilung der Stabilität von Impulszuständen und einen Vergleich mit konkurrierenden Laserregimen. Auf der experimentellen Seite wurden zwei Versionen des sog. Figure-Eight-Lasers realisiert und charakterisiert. Diese Laser wurden mit Hilfe einer polarisationserhaltenden Gestaltung des sättigbaren Absorbers stabilisiert. Dabei blieb der wichtige Parameter des Phasenoffsets justierbar. An den beiden Lasern wurden die Aussagen der Modellierung hinsichtlich der genauen Impulsform überprüft. Es wurde eine gute Übereinstimmung gefunden. Des weiteren wurden mit Hilfe der Modellierung theoretisch die Dispersionskompensation im Figure-Eight-Laser und die Gestaltung des Resonators mit normaler Gesamtdispersion untersucht

A two-step procedure for purification of papain from extract of papaya latex

A method is presented for purifying papain from extracts of papaya latex. The procedure involves precipitation of the extract of papaya latex with sodium chloride followed by affinity chromatography of the redissolved precipitate. Precipitation of the protein from the latex extract is necessary to separate the papain from material which interferes with the binding of papain to the affinity column. During affinity chromatography, the affinity column is overloaded to insure absence in the final product of impurities which are capable of binding to the affinity column.The papain prepared by this procedure yielded an amino acid analysis and an N-terminal amino acid analysis expected for a sample of pure papain. No Met was detected on amino acid analysis nor was the presence of N-terminal residues other than He detected. On polyacrylamide disc gel electrophoresis at pH 4.3, papain prepared by the method described in this work was indistinguishable from crystalline papain which was prepared by the method of Kimmel and Smith, and further purified by affinity chromatography. Both disc gel patterns consisted of a single band and a trailing shadow which was less than 5% of the main band. In routine spectrophotometric assays, the specific activity toward N,[alpha]-benzoyl--arginine ethyl ester of papain prepared by the procedure described in this work was indistinguishable from crystalline papain prepared by the method of Kimmel and Smith, and further purified by affinity chromatography. Values of 24 sec-1' and 15 m were obtained from the turnover number and Km for the papain-catalyzed hydrolysis of N,[alpha]-benzoyl--arginine ethyl ester at 25 [deg]C, pH 6.00, [Gamma]/2 0.30 using a pH stat.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22283/1/0000723.pd

Low-energy electron microscopy of graphene outside UHV: electron-induced removal of PMMA residues used for graphene transfer

Two-dimensional materials, such as graphene, are usually prepared by chemical vapor deposition (CVD) on selected substrates, and their transfer is completed with a supporting layer, mostly polymethyl methacrylate (PMMA). Indeed, the PMMA has to be removed precisely to obtain the predicted superior properties of graphene after the transfer process. We demonstrate a new and effective technique to achieve a polymer-free CVD graphene - by utilizing low-energy electron irradiation in a scanning low-energy electron microscope (SLEEM). The influence of electron-landing energy on cleaning efficiency and graphene quality was observed by SLEEM, Raman spectroscopy (the presence of disorder D peak) and XPS (the deconvolution of the C 1s peak). After removing the absorbed molecules and polymer residues from the graphene surface with slow electrons, the individual graphene layers can also be distinguished outside ultra-high vacuum conditions in both the reflected and transmitted modes of a scanning low-energy (transmission) electron microscope

Purification and Characterization of a Sperm Motility Inhibiting Factor from Caprine Epididymal Plasma

Several studies have been reported on the occurrence of sperm motility inhibiting factors in the male reproductive fluids of different mammalian species, but these proteins have not been adequately purified and characterized. A novel sperm motility inhibiting factor (MIF-II) has been purified from caprine epididymal plasma (EP) by Hydroxylapatite gel adsorption chromatography, DEAE-Cellulose ion-exchange chromatography and chromatofocusing. The MIF-II has been purified to apparent homogeneity and the molecular weight estimated by Sephacryl S-300 gel filtration is 160 kDa. MIF-II is a dimeric protein, made up of two subunits each having a molecular mass of 80 kDa as shown by SDS-PAGE. The isoelectric point of MIF-II is 5.1 as determined by chromatofocusing and isoelectric focusing. It is a heat labile protein and maximal active at the pH 6.9 to 7.5. The sperm motility inhibiting protein factor at 2 µg/ml (12.5 nM) level showed maximal motility-inhibiting activity. The observation that the epididymal plasma factor lowered the intracellular cAMP level of spermatozoa in a concentration-dependent manner suggests that it may block the motility of caprine cauda spermatozoa by interfering the cAMP dependent motility function. The results revealed that the purified protein factor has the potential of sperm motility inhibition and may serve as a vaginal contraceptive. The antibody raised against the MIF-II has the potential for enhancement of forward motility of cauda-spermatozoa. This antibody may thus be useful for solving some of the problems of male infertility due to low sperm motility