Creation, storage, and on-demand release of optical quantum states with a negative Wigner function

Highly nonclassical quantum states of light, characterized by Wigner functions with negative values, have been created so far only in a heralded fashion. In this case, the desired output emerges rarely and randomly from a quantum-state generator. An important example is the heralded production of high-purity single-photon states, typically based on some nonlinear optical interaction. In contrast, on-demand single-photon sources were also reported, exploiting the quantized level structure of matter systems. These sources, however, lead to highly impure output states, composed mostly of vacuum. While such impure states may still exhibit certain single-photon-like features such as anti-bunching, they are not enough nonclassical for advanced quantum information processing. On the other hand, the intrinsic randomness of pure, heralded states can be circumvented by first storing and then releasing them on demand. Here we propose such a controlled release, and we experimentally demonstrate it for heralded single photons. We employ two optical cavities, where the photons are both created and stored inside one cavity, and finally released through a dynamical tuning of the other cavity. We demonstrate storage times of up to 300 ns, while keeping the single-photon purity around 50% after storage. This is the first demonstration of a negative Wigner function at the output of an on-demand photon source or a quantum memory. In principle, our storage system is compatible with all kinds of nonclassical states, including those known to be essential for many advanced quantum information protocols.Comment: 14 pages, 5 figure

One-Step Detection of the 2009 Pandemic Influenza A(H1N1) Virus by the RT-SmartAmp Assay and Its Clinical Validation

<div><h3>Background</h3><p>In 2009, a pandemic (pdm) influenza A(H1N1) virus infection quickly circulated globally resulting in about 18,000 deaths around the world. In Japan, infected patients accounted for 16% of the total population. The possibility of human-to-human transmission of highly pathogenic novel influenza viruses is becoming a fear for human health and society.</p> <h3>Methodology</h3><p>To address the clinical need for rapid diagnosis, we have developed a new method, the “RT-SmartAmp assay”, to rapidly detect the 2009 pandemic influenza A(H1N1) virus from patient swab samples. The RT-SmartAmp assay comprises both reverse transcriptase (RT) and isothermal DNA amplification reactions in one step, where RNA extraction and PCR reaction are not required. We used an exciton-controlled hybridization-sensitive fluorescent primer to specifically detect the HA segment of the 2009 pdm influenza A(H1N1) virus within 40 minutes without cross-reacting with the seasonal A(H1N1), A(H3N2), or B-type (Victoria) viruses.</p> <h3>Results and Conclusions</h3><p>We evaluated the RT-SmartAmp method in clinical research carried out in Japan during a pandemic period of October 2009 to January 2010. A total of 255 swab samples were collected from outpatients with influenza-like illness at three hospitals and eleven clinics located in the Tokyo and Chiba areas in Japan. The 2009 pdm influenza A(H1N1) virus was detected by the RT-SmartAmp assay, and the detection results were subsequently compared with data of current influenza diagnostic tests (lateral flow immuno-chromatographic tests) and viral genome sequence analysis. In conclusion, by the RT-SmartAmp assay we could detect the 2009 pdm influenza A(H1N1) virus in patients' swab samples even in early stages after the initial onset of influenza symptoms. Thus, the RT-SmartAmp assay is considered to provide a simple and practical tool to rapidly detect the 2009 pdm influenza A(H1N1) virus.</p> </div

Social Acceptance of Mobile Health among Young Adults in Japan: An Extension of the UTAUT Model

The unprecedented development of information and communication technologies has opened up immense possibilities in the field of health care. Mobile health (mHealth) is gaining increasing attention as an important technology for solving health-related problems. Although a high rate of smartphone usage among young people in Japan has been identified, smartphone usage for health management is not high. As Japanese youth are important potential users of mHealth, it is necessary to explore theories that influence the behavioral intention of Japanese youth to adopt mHealth. This study conducted a questionnaire survey in a Japanese university and collected 233 valuable responses. This study was adapted and extended from the unified theory of acceptance and use of technology (UTAUT) model to measure eight constructs: health consciousness, social influence, facilitation conditions, perceived risk, trust, performance expectancy, effort expectancy, and behavioral intention. Structural equation modeling was used for hypothesis testing. We found that trust, performance expectancy, and effort expectancy directly influenced the behavioral intention to use mHealth. Health consciousness and social influence indirectly influence behavioral intention through trust and performance expectancy. Facilitation conditions indirectly influenced behavioral intention through effort expectancy. This study makes a vital theoretical contribution to policymakers and product developers for the further diffusion of mHealth among young people in Japan

A Comparative Analysis of Social Entrepreneurship and Entrepreneurship: An Examination of International Co-Authorship Networks

This study aimed to identify the boundaries between social entrepreneurship and entrepreneurship research through conducting a comparative analysis of international co-authorship networks. Analyzing 29,510 papers published in the Web of Science database from 1999 to 2021, this study utilized bibliometric analysis to examine international co-authorship networks, the strength of international co-authorship, and the top collaborative and collaborating countries. The results found that based on quantitative analysis, social entrepreneurship research focuses more on local challenges and less on international collaboration as compared to entrepreneurship research. Moreover, the findings reveal the involvement of developed countries in the international co-authorship for social entrepreneurship research field. This study sheds light on the characteristics of social entrepreneurship research, which focuses on local and regional challenges. Contrastingly, entrepreneurship research focuses on the globalized field while sharing information and technology. These insights could benefit researchers, practitioners, and educators in prioritizing globalization in entrepreneurship and localization in social entrepreneurship

A novel multi-collimator using BP-1 glass and an application for X-ray CCDs

Charge-coupled devices (CCDs) are widely used in X-ray astronomy as a focal plane detector for X-rays up to 10 keV. For future X-ray space missions, thick CCDs are being developed to improve the detection efficiency of high energy X-rays beyond 10 keV. We propose a new method to produce a novel multi-collimator using a barium phosphate glass, BP-1, which was originally developed as a solid state track detector. The BP-1 collimator allows the realization of small through-holes, several hundred nano-meters in radius. We performed the first experiment of this project in which a xenon beam of 80MeV=u was used to irradiate the 1.3 mm-thick-BP-1 glass. After an etching process, we obtained the first prototype BP-1 collimator. There were a large number of tapered pinholes which are randomly distributed and with extremely high aspect ratio. Taking X-ray photographs demonstrated that the first prototype has a capability of fine collimation for X-rays up to 20 keV.r 2006 Elsevier B.V. All rights reserved

Palladium-Catalyzed Cyanothiolation of Internal Alkynes Using Organic Disulfides and <i>tert</i>-Butyl Isocyanide

Despite the availability of selective synthetic approaches to multifunctionalized substituted olefins, the cyanothiolation of internal alkynes has been much less explored. Herein, we show that nonactivated internal alkynes can be successfully cyanothiolated with diaryl disulfides and <i>tert</i>-butyl isocyanide in the presence of a Pd catalyst (e.g., Pd­(PPh₃)₄) with the release of isobutene and arenethiol to afford β-thiolated alkenyl cyanides in yields of 34–89%

Palladium-Catalyzed Cyanothiolation of Internal Alkynes Using Organic Disulfides and <i>tert</i>-Butyl Isocyanide

Despite the availability of selective synthetic approaches to multifunctionalized substituted olefins, the cyanothiolation of internal alkynes has been much less explored. Herein, we show that nonactivated internal alkynes can be successfully cyanothiolated with diaryl disulfides and <i>tert</i>-butyl isocyanide in the presence of a Pd catalyst (e.g., Pd­(PPh₃)₄) with the release of isobutene and arenethiol to afford β-thiolated alkenyl cyanides in yields of 34–89%

Palladium-Catalyzed Cyanothiolation of Internal Alkynes Using Organic Disulfides and <i>tert</i>-Butyl Isocyanide

Despite the availability of selective synthetic approaches to multifunctionalized substituted olefins, the cyanothiolation of internal alkynes has been much less explored. Herein, we show that nonactivated internal alkynes can be successfully cyanothiolated with diaryl disulfides and <i>tert</i>-butyl isocyanide in the presence of a Pd catalyst (e.g., Pd­(PPh₃)₄) with the release of isobutene and arenethiol to afford β-thiolated alkenyl cyanides in yields of 34–89%