15 research outputs found

    Interactions of Gold Plasmons and Vanadium Dioxide

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    Quarkonium states in a complex-valued potential

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    We calculate quarkonium binding energies using a realistic complex-valued potential for both an isotropic and anisotropic quark-gluon plasma. We determine the disassociation temperatures of the ground and first excited states considering both the real and imaginary parts of the binding energy. We show that the effect of momentum-space anisotropy is smaller on the imaginary part of the binding energy than on the real part of the binding energy. In the case that one assumes an isotropic plasma, we find disassociation temperatures for the J/psi, Upsilon and chi_b of 1.6 T_c, 2.8 T_c, and 1.5 T_c, respectively. We find that a finite oblate momentum-space anisotropy increases the disassociation temperature for all states considered and results in a splitting of the p-wave states associated with the chi_b first excited state of bottomonium.Comment: 23 pages, 9 figures; v4: subtraction of V_infinity corrected to only subtract Re[V_infinity

    Instantaneous band gap collapse in photoexcited monoclinic VO2_2 due to photocarrier doping

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    Using femtosecond time-resolved photoelectron spectroscopy we demonstrate that photoexcitation transforms monoclinic VO2_2 quasi-instantaneously into a metal. Thereby, we exclude an 80 femtosecond structural bottleneck for the photoinduced electronic phase transition of VO2_2. First-principles many-body perturbation theory calculations reveal a high sensitivity of the VO2_2 bandgap to variations of the dynamically screened Coulomb interaction, supporting a fully electronically driven isostructral insulator-to-metal transition. We thus conclude that the ultrafast band structure renormalization is caused by photoexcitation of carriers from localized V 3d valence states, strongly changing the screening \emph{before} significant hot-carrier relaxation or ionic motion has occurred

    Surveillance after treatment for cervical intraepithelial neoplasia: Outcomes, costs, and cost-effectiveness

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    Objective: To estimate outcomes and costs of surveillance strategies after treatment for high-grade cervical intraepithelial neoplasia (CIN). Methods: A hypothetical cohort of women was evaluated after treatment for CIN 2 or 3 using a Markov model incorporating data from a large study of women treated for CIN, systematic reviews of test accuracy, and individual preferences. Surveillance strategies included initial conventional or liquid-based cytology, human papillomavirus testing, or colposcopy 6 months after treatment, followed by annual or triennial cytology. Estimated outcomes included CIN, cervical cancer, cervical cancer deaths, life expectancy, costs, cost per life-year, and cost per quality-adjusted life-year. Results: Conventional cytology at 6 and 12 months, followed by triennial cytology, was least costly. Compared with triennial cytology, annual cytology follow-up reduced expected cervical cancer deaths by 73% to 77% and had an average incremental cost per life-year gained of 69,000to69,000 to 81,000. For colposcopy followed by annual cytology, the incremental cost per life-year gained ranged from 70,000tomorethan70,000 to more than 1 million, depending on risk. Between-strategy differences in mean additional life expectancy per woman were less than 4 days; differences in mean incremental costs per woman were as high as 822.Inthecostutilityanalysis,colposcopyat6monthsfollowedbyannualcytologyhadanincrementalcostperqualityadjustedlifeyearoflessthan822. In the cost-utility analysis, colposcopy at 6 months followed by annual cytology had an incremental cost per quality-adjusted life-year of less than 5,500. Human papillomavirus testing or liquid-based cytology added little to no improvement to life-expectancy with higher costs. Conclusion: Annual conventional cytology surveillance reduced cervical cancers and cancer deaths compared with triennial cytology. For high risk of recurrence, a strategy of colposcopy at 6 months increased life expectancy and quality-adjusted life expectancy. Human papillomavirus testing and liquid-based cytology increased costs, but not effectiveness, compared with traditional approaches

    Criteria to assess potential reverse innovations: opportunities for shared learning between high- and low-income countries

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    Abstract Background Low- and middle-income countries (LMICs) are developing novel approaches to healthcare that may be relevant to high-income countries (HICs). These include products, services, organizational processes, or policies that improve access, cost, or efficiency of healthcare. However, given the challenge of replication, it is difficult to identify innovations that could be successfully adapted to high-income settings. We present a set of criteria for evaluating the potential impact of LMIC innovations in HIC settings. Methods An initial framework was drafted based on a literature review, and revised iteratively by applying it to LMIC examples from the Center for Health Market Innovations (CHMI) program database. The resulting criteria were then reviewed using a modified Delphi process by the Reverse Innovation Working Group, consisting of 31 experts in medicine, engineering, management and political science, as well as representatives from industry and government, all with an expressed interest in reverse innovation. Results The resulting 8 criteria are divided into two steps with a simple scoring system. First, innovations are assessed according to their success within the LMIC context according to metrics of improving accessibility, cost-effectiveness, scalability, and overall effectiveness. Next, they are scored for their potential for spread to HICs, according to their ability to address an HIC healthcare challenge, compatibility with infrastructure and regulatory requirements, degree of novelty, and degree of current collaboration with HICs. We use examples to illustrate where programs which appear initially promising may be unlikely to succeed in a HIC setting due to feasibility concerns. Conclusions This study presents a framework for identifying reverse innovations that may be useful to policymakers and funding agencies interested in identifying novel approaches to addressing cost and access to care in HICs. We solicited expert feedback and consensus on an empirically-derived set of criteria to create a practical tool for funders that can be used directly and tested prospectively using current databases of LMIC programs
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