Visible-to-telecom quantum frequency conversion of light from a single quantum emitter

Quantum frequency conversion (QFC), a nonlinear optical process in which the frequency of a quantum light field is altered while conserving its non-classical correlations, was first demonstrated 20 years ago. Meanwhile, it is considered an essential tool for the implementation of quantum repeaters since it allows for interfacing quantum memories with telecom-wavelength photons as quantum information carriers. Here we demonstrate efficient (>30%) QFC of visible single photons (711 nm) emitted by a quantum dot (QD) to a telecom wavelength (1,313 nm). Analysis of the first and second-order coherence before and after wavelength conversion clearly proves that important properties, such as the coherence time and photon antibunching, are fully conserved during the frequency translation process. Our findings underline the great potential of single photon sources on demand in combination with QFC as a promising technique for quantum repeater schemes.Comment: 11 pages, 4 figure

Radiation synergizes with antitumor activity of CD13-targeted tissue factor in a HT1080 xenograft model of human soft tissue sarcoma

Background: Truncated tissue factor (tTF) retargeted by NGR-peptides to aminopeptidase N (CD13) in tumor vasculature is effective in experimental tumor therapy. tTF-NGR induces tumor growth inhibition in a variety of human tumor xenografts of different histology. To improve on the therapeutic efficacy we have combined tTF-NGR with radiotherapy. Methods: Serum-stimulated human umbilical vein endothelial cells (HUVEC) and human HT1080 sarcoma cells were irradiated in vitro, and upregulated early-apoptotic phosphatidylserine (PS) on the cell surface was measured by standard flow cytometry. Increase of cellular procoagulant function in relation to irradiation and PS cell surface concentration was measured in a tTF-NGR-dependent Factor X activation assay. In vivo experiments with CD-1 athymic mice bearing human HT1080 sarcoma xenotransplants were performed to test the systemic therapeutic effects of tTF-NGR on tumor growth alone or in combination with regional tumor ionizing radiotherapy. Results: As shown by flow cytometry with HUVEC and HT1080 sarcoma cells in vitro, irradiation with 4 and 6 Gy in the process of apoptosis induced upregulation of PS presence on the outer surface of both cell types. Proapoptotic HUVEC and HT1080 cells both showed significantly higher procoagulant efficacy on the basis of equimolar concentrations of tTF-NGR as measured by FX activation. This effect can be reverted by masking of PS with Annexin V. HT1080 human sarcoma xenografted tumors showed shrinkage induced by combined regional radiotherapy and systemic tTF-NGR as compared to growth inhibition achieved by either of the treatment modalities alone. Conclusions: Irradiation renders tumor and tumor vascular cells procoagulant by PS upregulation on their outer surface and radiotherapy can significantly improve the therapeutic antitumor efficacy of tTF-NGR in the xenograft model used. This synergistic effect will influence design of future clinical combination studies

Nature-based social prescribing programmes: opportunities, challenges, and facilitators for implementation.

Background Evidence on the health benefits of spending time in nature has highlighted the importance of provision of blue and green spaces where people live. The potential for health benefits offered by nature exposure, however, extends beyond health promotion to health treatment. Social prescribing links people with health or social care needs to community-based, non-clinical health and social care interventions to improve health and wellbeing. Nature-based social prescribing (NBSP) is a variant that uses the health-promoting benefits of activities carried out in natural environments, such as gardening and walking. Much current NBSP practice has been developed in the UK, and there is increasing global interest in its implementation. This requires interventions to be adapted for different contexts, considering the needs of populations and the structure of healthcare systems. Methods This paper presents results from an expert group participatory workshop involving 29 practitioners, researchers, and policymakers from the UK and Germany’s health and environmental sectors. Using the UK and Germany, two countries with different healthcare systems and in different developmental stages of NBSP practice, as case studies, we analysed opportunities, challenges, and facilitators for the development and implementation of NBSP. Results We identified five overarching themes for developing, implementing, and evaluating NBSPCapacity Building; Accessibility and Acceptability; Networks and Collaborations; Standardised Implementation and Evaluation; and Sustainability. We also discuss key strengths, weaknesses, opportunities, and threats for each overarching theme to understand how they could be developed to support NBSP implementation. Conclusions NBSP could offer significant public health benefits using available blue and green spaces. We offer guidance on how NBSP implementation, from wider policy support to the design and evaluation of individual programmes, could be adapted to different contexts. This research could help inform the development and evaluation of NBSP programmes to support planetary health from local and global scales

European private law

Lawyers around the world roughly agree on the meaning of private law. Whatever their national origins, they will point to contract and tort and identify their roots in the national private law order. Understanding European private law requires clarification of each of the three composite elements which includes Europe is not a state but a quasi-state with a multilevel governance structure, the law is not only private but also has a strong regulatory (public) dimension and law cannot be equated with codified law but has a multifaceted character-ranging from private regulation within a public regulatory frame to contract governance and self-regulation. Constitutionalization of private law through the increasing use of fundamental rights and human rights ranks high on the political, judicial, and academic agendas. The Draft Common Frame of Reference (DCFR) is designed to operate in a framework based on conventional actors: individual private parties, judges, and the legislator