7,062 research outputs found

    Resistance is futile: overcoming resistance to targeted therapies in lung adenocarcinoma.

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    The advent of genomics has led to the identification of specific "driver" mutations in oncogenic kinases, and the development of targeted small molecule inhibitors to block their tumor-driving functions. These specific inhibitors have been a clinical success, and often significantly prolong the lives of individuals with cancer. Inevitably, however, the treated tumors recur as resistance to these targeted therapies develops. Here, we review the major mechanisms by which a cancer cell can evade targeted therapy, focusing on mechanisms of resistance to kinase inhibitors in lung cancer. We discuss the promising concept of rational upfront polytherapy in lung cancer, which involves concurrently targeting multiple proteins in critical signaling pathways in a cancer cell to prevent or delay resistance

    General Approach to the Quantum Kicked Particle in a Magnetic Field: Quantum-Antiresonance Transition

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    The quantum kicked particle in a magnetic field is studied in a weak-chaos regime under realistic conditions, i.e., for {\em general} values of the conserved coordinate xcx_{{\rm c}} of the cyclotron orbit center. The system exhibits spectral structures [``Hofstadter butterflies'' (HBs)] and quantum diffusion depending sensitively on xcx_{{\rm c}}. Most significant changes take place when xcx_{{\rm c}} approaches the value at which quantum antiresonance (exactly periodic recurrences) can occur: the HB essentially ``doubles'' and the quantum-diffusion coefficient D(xc)D(x_{{\rm c}}) is strongly reduced. An explanation of these phenomena, including an approximate formula for D(xc)D(x_{{\rm c}}) in a class of wave packets, is given on the basis of an effective Hamiltonian which is derived as a power expansion in a small parameter. The global quantum diffusion of a two-dimensional wave packet for all xcx_{{\rm c}} is briefly considered.Comment: Revised Version, publishe

    Use of magnetic sails for advanced exploration missions

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    The magnetic sail, or magsail, is a field effect device which interacts with the ambient solar wind or interstellar medium over a considerable volume of space to generate drag and lift forces. Two theories describing the method of thrust generation are analyzed and data results are presented. The techniques for maintaining superconductor temperatures in interplanetary space are analyzed and low risk options presented. Comparisons are presented showing mission performance differences between currently proposed spacecraft using chemical and electric propulsion systems, and a Magsail propelled spacecraft capable of generating an average thrust of 250 Newtons at a radius of one A.U. The magsail also provides unique capabilities for interstellar missions, in that at relativistic speeds the magnetic field would ionize and deflect the interstellar medium producing a large drag force. This would make it an ideal brake for decelerating a spacecraft from relativistic speeds and then maneuvering within the target star system

    Experimental Realization of Quantum-Resonance Ratchets

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    Quantum-resonance ratchets associated with the periodically kicked particle are experimentally realized for the first time. This is achieved by using a Bose-Einstein condensate exposed to a pulsed standing light wave and prepared in an initial state differing from the usual plane wave. Both the standing-wave potential and the initial state have a point symmetry around some center and the ratchet arises from the non-coincidence of the two centers. The dependence of the directed quantum transport on the quasimomentum is studied. A detailed theoretical analysis is used to explain the experimental results.Comment: Accepted for publication in Physical Review Letters (November 2007

    Innovative Stormwater Treatment Technologies: Best Management Practices Manual

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    Urban stormwater carries a number of pathogens, nutrients, heavy metals, sediment, and other contaminants as surface runoff flows over land. The increase in impervious or paved surfaces associated with development in urban areas reduces the natural infiltration of precipitation into the ground. With impervious cover, precipitation collects and carries contaminants before draining into nearby surface waters. Stormwater runoff from paved surfaces in developed areas can degrade downstream waters with both contaminants and increased volumes of water. This publication aims to make information on innovative stormwater treatment technologies more available to New Hampshire’s urban planners, developers, and communities. Traditional runoff management techniques such as detention basins and infiltration swales may be preferable, but are not always practical for treating urban stormwater. Lack of space for natural solutions is often a problem in existing developed areas, making innovative treatment technologies an attractive alternative. Mostly designed for subsurface installation, urban “retrofits” use less space than conventional methods to treat stormwater. This manual provides information on the innovative stormwater “retrofit” technologies currently available for use in developed areas in New Hampshire

    URBAN COMFORT IN BUCHAREST.SOCIAL-ECONOMIC PARAMETERS

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    The undergoing concerns for local and regional development focus also on the territorial analyses. The local socio-economic analysis is naturally followed by the strategic planning of development during which the local public authorities initiate and organize, locally, the economic development of the respective territorial unit. This article is intended to analyze a concrete case, that of the Capital City of Romania, the Municipality of Bucharest. One of Romania’s objectives is to sensitize and educate the civil society, the private organizations and the public authorities towards understanding and observing the urban landscape. In the spirit of the aspects mentioned above, the authors have presented a case study, at the end of this article, in which the reconsideration of the urban architectural framework matches perfectly with the wish of introducing elements of spatial dynamics and of balance. In this spirit, the over-crowded City of Bucharest, which has a density of 9009 inhabitants/sq.km, will potentially be turned into an oasis of social comfort that will positively influence the urban organism.local economic development, urban comfort, Bucharest

    Pressures and Preferences Affecting Willingness to Apply Beef Manure on Crops in the Colorado High Plains

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    Little is known about producers' willingness to use manure. Past studies have focused on substitutability for fertilizers. We surveyed crop producers in a cattle-dense region of the Colorado Plains about whether and why they apply manure, focusing on how pressures (like owning cattle) or preferences (pro and con) affect their adoption. Using logistic regression, findings show that pressure and preference (PS/PF) significantly affect adoption. A producer with high PS/PF was 10 times more likely to use manure than one with low PS/PF. Policy and decision makers can use such findings to inform education and policy aimed at increasing the land application of manure.cattle, economic benefits, economic costs, management, manure application, Crop Production/Industries,

    Environment and environmental effects of pollution. Model of eco-dashboard – A tool for analysis of environmental management performances

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    This article presents some conceptual approaches to environment and pollution phenomenon, describing the main factors of pollution and their evolution in Romania. There are described the main centers of pollution from the Slatina area. There is presented a definition of eco-dashboard, the main flight specific businesses within the non-ferrous metallurgical industry of Romania and a model for analysis of environmental management performance of this specific field.steel industry; pollution; eco-dashboard; indicators of environment; performance.
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