318 research outputs found
Understanding Business Process Evolution in Digital Ventures
Business processes are at each company\u27s core and must be adapted permanently to react to changing markets, substantial growth, or legal regulations. Especially digital ventures have the potential to evolve fast, and consequently, their business processes need to change at the same speed. Two streams of literature have looked into this. Traditional business process management sees business processes, once implemented, as relatively stable. In contrast, digital entrepreneurship literature highlights the inherent flexibility of digital ventures. Based on a multiple case study of five digital ventures, we analyze how entrepreneurs deal with this tension when business processes evolve. Building on entrepreneurial bricolage, we propose two types of resource recombination that we find, namely, usage of existing private resources and re-configuring of resources already being used within the venture. These insights contribute to extending our understanding of the evolution of business processes
On the Potential of Business Process Management for Digital Entrepreneurship: Findings from a Literature Review
Digital ventures face significant organizational challenges when scaling, including increasing sales and employee numbers, that withdraw resources from working on their market offerings. While digital entrepreneurship literature stresses the importance of creating processes that balance structure and flexibility to deal with these challenges, business process management (BPM) literature focuses on improving pre-designed business processes. We reconcile these perspectives in a structured literature review to explore how BPM can support digital venturing. We identify synergies and tensions between BPM and digital entrepreneurship and propose three avenues for future research. These include exploring ambidextrous BPM in digital ventures, treating digital venturing as a business process, and developing capabilities for balancing flexibility and structure. We contribute to information systems research by critically reviewing the literature on BPM and digital entrepreneurship and providing potential areas for future investigation
Highly oriented surface-growth and covalent dye labeling of mesoporous metal-organic frameworks
Mesoporous amino-functionalized metal-organic framework thin films with the UiO-68 topology were grown in a highly oriented fashion on two different self-assembled monolayers on gold. The oriented MOF films were covalently modified with the fluorescent dye Rhodamine B inside the pore system, as demonstrated with size-selective fluorescence quenching studies. Our study suggests that mesoporous metal-organic frameworks are promising hosts for the covalent attachment of numerous functional moieties in a molecularly designed crystalline environment. © The Royal Society of Chemistry 2012
Formed Metal Products and Methods of Making the Same
Provided herein are methods of forming a metal product, including applying a water soluble formability film to the metal blank and/or applying a network polymer preprime (e.g., a hybrid organic-inorganic preprime, or a heat-resistant hybrid preprime) to the metal blank, forming the metal blank into a formed metal product, and optionally removing the formability film. A removable formability film and/or a preprime can improve the formability of an aluminum alloy and replace lubricants that used for forming processes by reducing the coefficient of friction of the metal product surface. Further, employing a water soluble polymer film eliminates lubricant removal for downstream processing. The formability film and/or preprime can include chemical additives that provide additional surface properties. The methods of processing the aluminum alloy products described herein provide a more efficient method for producing aluminum alloy products, as required by end users (e.g., original equipment manufacturers (OEMs))
Influence of various types of damage on the fracture strength of ceramic femoral heads
Ceramic-on-ceramic articulations are a frequently used bearing for total hip replacements. This success mainly is due to their excellent tribological properties. Ceramics can withstand high pressure loads due to its brittleness but only low bending stresses. A ceramic ball head fracture is the result of subcritical crack growth. This kind of fracture in vivo can abet by damage or contamination of the stem cone. The main goal of this work is to provide a risk assessment of different possible damage mechanisms and contaminations that may result in lower fracture strength of a ceramic ball head. To simulate potential causes, different types and dimensions of metal wire, foils, hair, and lubricants were inserted between the ceramic ball head and the metal cone of the stem. The test results clearly show that fracture strength is negatively infl uenced by most of the inhomogeneities between the cone and the head because they increase the peak stresses acting on a part of the ceramic ball head. The results of this article clearly confi rm the demand for an undamaged taper fi t “ free of contamination ” between the ceramic head and the metal cone during implantation
MOF nanoparticles coated by lipid bilayers and their uptake by cancer cells
Supramolecular templating techniques have been widely used to direct the formation of porous materials with the goal of introducing permanent mesoporosity. While surfactant-directed self-assembly has been exploited for inorganic materials such as titania, silica, organosilica, and zeolites, it has rarely been applied to metal-organic frameworks (MOFs) and coordination polymers. Here we introduce a new family of gemini surfactant-directed zinc imidazolates, referred to as mesostructured imidazolate frameworks (MIFs), and present a detailed study on the influence of different gemini-type surfactants on the formation mechanism and structures of the resulting zinc imidazolates. The proposed formation mechanism for MIF-type materials involves co-assembly and crystallization processes that yield lamellar mesostructured imidazolate frameworks. Understanding and controlling such processes also has implications for the syntheses of microporous zinc imidazolate framework (ZIF) materials, whose formation can be suppressed in surfactant-rich solutions, whereas formation of MIF materials is favored in the presence of surfactants and triggered by the addition of halogenides. Solid-state 2D 13C1H HETCOR NMR measurements on prototypic CTAB-directed MIF-1 establish that the head group moieties of the surfactant molecules interact strongly with the zinc-imidazolate-bromide sheets. Additionally, the NMR analyses suggest that MIF-1 has a significant fraction of surfactant molecules that are interdigitated between the zinc-imidazolate-bromide sheets with an antiparallel stacking arrangement, consistent with the high thermal and chemical stability of the MIF hybrid materials
The effect of lamotrigine and other antiepileptic drugs on respiratory rhythm generation in the pre-Bötzinger complex.
OBJECTIVE: Lamotrigine and other sodium-channel blocking agents are among the most commonly used antiepileptic drugs (AEDs). Because other sodium channel blockers, such as riluzole, can severely alter respiratory rhythm generation during hypoxia, we wanted to investigate if AEDs can have similar effects. This is especially important in the context of sudden unexpected death in epilepsy (SUDEP), the major cause of death in patients suffering from therapy-resistant epilepsy. Although the mechanism of action is not entirely understood, respiratory dysfunction after generalized tonic-clonic seizures seems to play a major role. METHODS: We used transverse brainstem slice preparations from neonatal and juvenile mice containing the pre-Bötzinger complex (PreBötC) and measured population as well as intracellular activity of the rhythm-generating network under normoxia and hypoxia in the presence or absence of AEDs. RESULTS: We found a substantial inhibition of the gasping response induced by the application of sodium channel blockers (lamotrigine and carbamazepine). In contrast, levetiracetam, an AED-modulating synaptic function, had a much smaller effect. The inhibition of gasping by lamotrigine was accompanied by a significant reduction of the persistent sodium current (INap) in PreBötC neurons. Surprisingly, the suppression of persistent sodium currents by lamotrigine did not affect the voltage-dependent bursting activity in PreBötC pacemaker neurons, but led to a hypoxia-dependent shift of the action potential rheobase in all measured PreBötC neurons. SIGNIFICANCE: Our results contribute to the understanding of the effects of AEDs on the vital respiratory functions of the central nervous system. Moreover, our study adds further insight into sodium-dependent changes occurring during hypoxia and the contribution of cellular properties to the respiratory rhythm generation in the pre-Bötzinger complex. It raises the question of whether sodium channel blocking AEDs could, in conditions of extreme hypoxia, contribute to SUDEP, an important issue that warrants further studies
Cloning, sequencing, and overexpression of gene 16 of salmonella bacteriophage P22
Umlauf B, Dreiseikelmann B. Cloning, sequencing, and overexpression of gene 16 of salmonella bacteriophage P22. Virology. 1992;188(2):495-501.It has been suggested that gene product 16 of bacteriophage P22 forms a pore for DNA transfer and/or that it functions as a pilot protein guiding the DNA across the membrane. We have cloned gene 16 and determined the nucleotide sequence. Within the sequenced region there is an open reading frame that could encode a protein of 609 amino acids having a molecular weight of 64,366. The hydropathic plot of this protein does not reveal putative membrane-spanning regions as expected for a protein forming a membrane pore. Overproduction of gene product 16 in Escherichia coli was successful only in a mutant in which the La protease was inactivated. Gene 16 mutants of phage P22 were not able to infect recBCD mutants of Salmonella typhimurium nor was protein 16, synthesized in E. colifrom a plasmid, able to substitute for the pilot protein of phage T4. It seems that gene product 16 is not a pilot protein in the meaning of binding to the ends of linear DNA, thus protecting it from degradation by nucleases
Optical properties of the Martian aerosols as derived from Imager for Mars Pathfinder midday sky brightness data
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