3,339 research outputs found

    Progressive brain metastases in an EGFR mutated adenocarcinoma of the lung: Response to gefitinib after progression on erlotinib

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    AbstractWe report a case of a 59-year-old woman with brain metastases from an EGFR mutated adenocarcinoma of the lung. She was initially treated with erlotinib and two times whole brain radiation therapy. After a second relapse within the CNS the therapy was switched to gefitinib and a partial remission of the brain metastases could be achieved. Our case demonstrates that patients can respond to a switch of the EGFR TKI also within the CNS despite heavy pre-treatment. The article reviews the literature regarding the efficacy of tyrosine kinase inhibitors in brain metastases from lung cancers

    Models and implications for industry compensation in the restructuring of public transport in South Africa

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    Paper presented at the 33rd Annual Southern African Transport Conference 7-10 July 2014 "Leading Transport into the Future", CSIR International Convention Centre, Pretoria, South Africa.The concept of compensating existing public transport operators for the detrimental impact of the roll-out of large-scale, publicly funded IPTNs on their businesses is valid. However, the general approach to compensation adopted by South Africa to date is not financially viable and has serious implications for future developments. Different compensation models that look to align operators’ success, financial and otherwise, with that of the new system they are incorporated into, must be considered and adopted going forward to ensure the sustainability of the country’s public transport transformation programme.This paper was transferred from the original CD ROM created for this conference. The material was published using Adobe Acrobat 10.1.0 Technology. The original CD ROM was produced by CE Projects cc. Postal Address: PO Box 560 Irene 0062 South Africa. Tel.: +27 12 667 2074 Fax: +27 12 667 2766 E-mail: [email protected]

    Fritz Haber: The Damned Scientist

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    In the gallery of famous people tracing their origins to Wroc{\l}aw, few are as controversial, as complex, or as tragic as Fritz Haber, ever more distant in the flux of time, yet still stirring emotions. He developed a method for the direct synthesis of ammonia from its elements and later pioneered chemical warfare on the battlefields of the First World War.Comment: 17 pages; Dedicated to the Fritz Haber Institute,Berlin, on the occasion of its 100th anniversary; German version of this article published in Angew. Chem. 2011, 123, 10226 - 10240; DOI: 10.1002/ange.20110542

    Quantum Arnol'd Diffusion in a Simple Nonlinear System

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    We study the fingerprint of the Arnol'd diffusion in a quantum system of two coupled nonlinear oscillators with a two-frequency external force. In the classical description, this peculiar diffusion is due to the onset of a weak chaos in a narrow stochastic layer near the separatrix of the coupling resonance. We have found that global dependence of the quantum diffusion coefficient on model parameters mimics, to some extent, the classical data. However, the quantum diffusion happens to be slower that the classical one. Another result is the dynamical localization that leads to a saturation of the diffusion after some characteristic time. We show that this effect has the same nature as for the studied earlier dynamical localization in the presence of global chaos. The quantum Arnol'd diffusion represents a new type of quantum dynamics and can be observed, for example, in 2D semiconductor structures (quantum billiards) perturbed by time-periodic external fields.Comment: RevTex, 11 pages including 12 ps-figure

    The twelve principles of CO2 Chemistry

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    This paper introduces a set of 12 Principles, based on the acronym CO2 CHEMISTRY, which are intended to form a set of criteria for assessing the viability of different processes or reactions for using CO2 as a feedstock for making organic chemicals. The principles aim to highlight the synergy of Carbon Dioxide Utilisation (CDU) with the components of green and sustainable chemistry as well as briefly pointing out the connection to the energy sector

    Manifestation of the Arnol'd Diffusion in Quantum Systems

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    We study an analog of the classical Arnol'd diffusion in a quantum system of two coupled non-linear oscillators one of which is governed by an external periodic force with two frequencies. In the classical model this very weak diffusion happens in a narrow stochastic layer along the coupling resonance, and leads to an increase of total energy of the system. We show that the quantum dynamics of wave packets mimics, up to some extent, global properties of the classical Arnol'd diffusion. This specific diffusion represents a new type of quantum dynamics, and may be observed, for example, in 2D semiconductor structures (quantum billiards) perturbed by time-periodic external fields.Comment: RevTex, 4 pages including 7 ps-figures, corrected forma

    Statistical Analysis of Composite Spectra

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    We consider nearest neighbor spacing distributions of composite ensembles of levels. These are obtained by combining independently unfolded sequences of levels containing only few levels each. Two problems arise in the spectral analysis of such data. One problem lies in fitting the nearest neighbor spacing distribution to the histogram of level spacings obtained from the data. We show that the method of Bayesian inference is superior to this procedure. The second problem occurs when one unfolds such short sequences. We show that the unfolding procedure generically leads to an overestimate of the chaoticity parameter. This trend is absent in the presence of long-range level correlations. Thus, composite ensembles of levels from a system with long-range spectral stiffness yield reliable information about the chaotic behavior of the system.Comment: 26 pages, 3 figures; v3: changed conclusions, appendix adde

    Susceptibility of clinical isolates of frequently encountered bacterial species to tigecycline one year after the introduction of this new class of antibiotics: results of the second multicentre surveillance trial in Germany (G-TEST II, 2007)

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    Tigecycline, a broad-spectrum antibiotic for parenteral use, was introduced in Germany in May 2006. In the G-TEST-II trial, the susceptibility of isolates, recovered in 2007 from hospitalised patients in 15 centres, was assessed against tigecycline and comparators. Susceptibility tests were performed by the microdilution procedure. This study reports on the susceptibility of the isolates of 16 bacterial species and compares the results with those of a trial (G-TEST I) conducted prior to the introduction of tigecycline. Between 2005 and 2007, tigecycline retained activity against Gram-positive and Gram-negative organisms. By contrast, the rate of vancomycin-resistant strains among Enterococcus faecium isolates almost doubled. Moreover, an increase in resistance to broad-spectrum beta-lactams and fluoroquinolones was observed for members of the family Enterobacteriaceae. Against a background of a steadily rising number of pathogens that are resistant to various antibiotic classes, tigecycline represents an important treatment option

    Authentication of processed meat products by peptidomic analysis using rapid ambient mass spectrometry

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    We present the application of a novel ambient LESA-MS method for the authentication of processed meat products. A set of 25 species and protein-specific heat stable peptide markers has been detected in processed samples manufactured from beef, pork, horse, chicken and turkey meat. We demonstrate that several peptides derived from myofibrillar and sarcoplasmic proteins are sufficiently resistant to processing to serve as specific markers of processed products. The LESA-MS technique required minimal sample preparation without fractionation and enabled the unambiguous and simultaneous identification of skeletal muscle proteins and peptides as well as other components of animal origin, including the milk protein such as casein alpha-S1, in whole meat product digests. We have identified, for the first time, six fast type II and five slow/cardiac type I MHC peptide markers in various processed meat products. The study demonstrates that complex mixtures of processed proteins/peptides can be examined effectively using this approach
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