65 research outputs found

    Proton-Boron Fusion Yield Increased by Orders of Magnitude with Foam Targets

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    A novel intense beam-driven scheme for high yield of the tri-alpha reaction 11B(p,{\alpha})2{\alpha} was investigated. We used a foam target made of cellulose triacetate (TAC, C_9H_{16}O_8) doped with boron. It was then heated volumetrically by soft X-ray radiation from a laser heated hohlraum and turned into a homogenous, and long living plasma. We employed a picosecond laser pulse to generate a high-intensity energetic proton beam via the well-known Target Normal Sheath Acceleration (TNSA) mechanism. We observed up to 10^{10}/sr {\alpha} particles per laser shot. This constitutes presently the highest yield value normalized to the laser energy on target. The measured fusion yield per proton exceeds the classical expectation of beam-target reactions by up to four orders of magnitude under high proton intensities. This enhancement is attributed to the strong electric fields and nonequilibrium thermonuclear fusion reactions as a result of the new method. Our approach shows opportunities to pursue ignition of aneutronic fusion

    Molecular subtypes predict the preferential site of distant metastasis in advanced breast cancer: a nationwide retrospective study

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    ObjectiveThis study aimed to explore possible associations between molecular subtypes and site of distant metastasis in advanced breast cancer (ABC).Methods3577 ABC patients were selected from 21 hospitals of seven geographic regions in China from 2012-2014. A questionnaire was designed to collect medical information regarding demographic characteristics, risk factors, molecular subtype, recurrence/metastasis information, and disease-free survival (DFS). The cancers were classified into Luminal A, Luminal B, HER2-enriched and Triple Negative subtypes. Chi-square test and multivariate Cox proportional hazard models were performed to explore the associations between molecular subtypes and distant metastasis sites.ResultsA total of 2393 cases with molecular subtypes information were finally examined. Patients with Luminal A (51.1%) and Luminal B (44.7%) were most prone to bone metastasis, whereas liver metastasis was more frequently observed in HER2-enriched ABC patients (29.1%).The cumulative recurrence and metastasis rates of ABC patients at 36 months of DFS were the most significant within molecular types, of which Triple Negative was the highest (82.7%), while that of Luminal A was the lowest (58.4%). In the adjusted Cox regression analysis, Luminal B, HER2-enriched and Triple Negative subtypes increased the risk of visceral metastasis by 23%, 46% and 87% respectively. In addition, Triple Negative patients had a higher probability of brain metastasis (HR 3.07, 95% CI: 1.04-9.07).ConclusionMolecular subtypes can predict the preferential sites of distant metastasis, emphasizing that these associations were of great help in choices for surveillance, developing appropriate screening and cancer management strategies for follow-up and personalized therapy in ABC patients

    Corporate Entrepreneurship Activities through Strategic Alliances: A Resource-Based Approach toward Competitive Advantage

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    Corporate entrepreneurship (CE) activities may significantly benefit from interfirm strategic alliances, although such benefits have not been sufficiently examined in the literature. In this paper, a resource-based framework is presented to examine how strategic alliances offer entrepreneurial firms needed resources that may not otherwise be available. We argue that CE activities are likely to lead to resource gaps. We compare various options to fill resource gaps, and identify the pros and cons of the alliance approach. We then discuss the resource conditions that provide competitive advantage for a firm, if alliances are properly used to help implement CE. Finally, we examine how different types of alliance (e.g. joint ventures, R&D alliances, and learning alliances) facilitate various CE activities, including innovation, corporate venturing, and strategic renewal. Copyright Blackwell Publishing Ltd 2006.

    A risk perception model of alliance structuring

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    The literature on the strategic alliance structuring process does not provide an adequate view of the role of decision-makers in that process, especially about how alliance partners form their structural preferences. Given the critical role of structure in alliance management, the decision-making process regarding the choice of an appropriate alliance structure deserves particular research attention. We propose a model of strategic alliance structuring that has managerial risk perception as its core. Our model consists of the following parts: the antecedents of risk perception, relational risk and performance risk, risk perception and structural preference, and the resolution of preferences. We suggest that the structural preferences of partners are based on their perceptions of relational risk and performance risk, and the overall objective is to minimize the total risk. We also develop a number of propositions as elaboration of the model to facilitate empirical research and the effective management of the structuring process.Alliances Risk perception model Relational risk Performance risk Alliance structuring
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