125 research outputs found

    Distributional Impacts of Retail Vaccine Availability

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    We examine the potential for exploiting retailer location choice in targeting health interventions. Using geospatial data, we quantify proximity to vaccines created by a U.S. federal program distributing COVID-19 vaccines to commercial retail pharmacies. We assess the distributional impacts of a proposal to provide vaccines at Dollar General, a low-priced general merchandise retailer. Adding Dollar General to the federal program would substantially decrease the distance to vaccine sites for low-income, rural, and minority U.S. households, groups for which COVID-19 vaccine take-up has been disproportionately slow

    Different patterns of NF-κB and Notch1 signaling contribute to tumor-induced lymphangiogenesis of esophageal squamous cell carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Lymph node involvement and tumor-induced lymphangiogenesis appear as the earliest features of esophageal squamous cell carcinoma (ESCC), although the molecular regulatory mechanisms involved have remained unclear. Our aim was to investigate the contribution of NF-κB and Notch1 signaling to lymph node involvement and tumor-induced lymphangiogenesis in ESCC.</p> <p>Material and methods</p> <p>NF-κB and Notch1 expression in 60 tissue samples of ESCC were assessed by immunohistochemical staining. The correlations of NF-κB and Notch1 with lymph node involvement, lymphatic vessel density (LVD), podoplanin, and vascular endothelial growth factor-C (VEGF-C) were further evaluated to determine the association of NF-κB and Notch1 expression with tumor-induced lymphangiogenesis.</p> <p>Results</p> <p>Chi-square tests revealed that NF-κB and Notch1 expression in ESCC tissues were significant associated with lymph node metastasis, LVD, podoplanin, and VEGF-C expression. Strong expression of NF-κB, but weak expression of Notch1, was observed in tumor tissues with lymph nodes involvement (<it>P </it>< 0.05 for both). The mean histoscores of LVD, podoplanin, and VEGF-C staining were higher in high-NF-κB-expressing tissue than in low-expressing tissue (<it>P </it>< 0.05 for each). In contrast, the mean histoscores of LVD and VEGF-C staining were lower in high-Notch1-expressing tissue than in low-expressing tissue (<it>P </it>< 0.05 for both). A multiple factors analysis of LVD and VEGF-C further demonstrated that LVD and VEGF-C status were significantly correlated with NF-κB and Notch1 expression in tumors. NF-κB and Notch1 expression were also significantly inversely correlated (<it>P </it>< 0.05).</p> <p>Conclusion</p> <p>These results suggest that different patterns of NF-κB and Notch1 signaling contribute to lymph nodes metastasis and tumor-induced lymphangiogenesis of ESCC, and reveal that up-regulation of NF-κB is associated with down-regulation of Notch1 in tumor tissue.</p

    Expanding Limit of Minimum Sampling Time Using Auxiliary Vectors for PMSM Drives with Single DC-Link Current Sensor

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    Phase current reconstruction (PCR) strategy can improve the fault tolerance of permanent magnet synchronous motor (PMSM) drives. The PCR precision is largely affected by the unmeasurable zones and time-sharing sampling errors. The upper limit (Tlimit) of PCR allowable range can reflect the requirement of different PCR methods for the minimum sampling time (Tmin). With a longer Tlimit, there is sufficient time for sampling, even if Tlimit is halved due to the symmetrical waveform. Therefore, the extension of Tlimit is the key to eliminate the unmeasurable zones and time-sharing sampling errors. In this paper, a method to increase Tlimit is proposed, which introduces the suitable auxiliary vectors (AVs) in different regions to extend the duration time of the sampling vectors. With the help of a longer Tlimit (12.5%Ts), its possible to eliminate all the unmeasurable zones and time-sharing sampling errors, relieve the pressure on the hardware of current loop, improve the sampling accuracy, and facilitate the reliable operation of the drive. Besides, the switching action times of IGBTs can be reduced by about one-third in the high modulation area. The proposed method is finally proved to accurately reconstruct the phase currents by the experimental results on the PMSM prototype

    What makes efficient circularly polarised luminescence in the condensed phase: aggregation-induced circular dichroism and light emission

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    In this contribution, we conceptually present a new avenue to construction of molecular functional materials with high performance of circularly polarised luminescence (CPL) in the condensed phase. A molecule (1) containing luminogenic silole and chiral sugar moieties was synthesized and thoroughly characterized. In a solution of 1, no circular dichroism (CD) and fluorescence emission are observed, but upon molecular aggregation, both the CD and fluorescence are simultaneously turned on, showing aggregation-induced CD (AICD) and emission (AIE) effects. The AICD effect is supported by the fact that the molecules readily assemble into right-handed helical nanoribbons and superhelical ropes when aggregated. The AIE effect boosts the fluorescence quantum efficiency (ΦF) by 136 fold (ΦF, ∼0.6% in the solution versus ∼81.3% in the solid state), which surmounts the serious limitations of aggregation-caused quenching effect encountered by conventional luminescent materials. Time-resolved fluorescence study and theoretical calculation from first principles conclude that restriction of the low-frequency intramolecular motions is responsible for the AIE effect. The helical assemblies of 1 prefer to emit right-handed circularly polarised light and display large CPL dissymmetry factors (gem), whose absolute values are in the range of 0.08–0.32 and are two orders of magnitude higher than those of commonly reported organic materials. We demonstrate for the first time the use of a Teflon-based microfluidic technique for fabrication of the fluorescent pattern. This shows the highest gem of −0.32 possibly due to the enhanced assembling order in the confined microchannel environment. The CPL performance was preserved after more than half year storage under ambient conditions, revealing the excellent spectral stability. Computational simulation was performed to interpret how the molecules in the aggregates interact with each other at the molecular level. Our designed molecule represents the desired molecular functional material for generating efficient CPL in the solid state, and the current study shows the best results among the reported organic conjugated molecular systems in terms of emission efficiency, dissymmetry factor, and spectral stability

    Interplanetary scintillation observation and space weather modelling

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    Interplanetary scintillation (IPS) refers to random fluctuations in radio intensity of distant small-diameter celestial object, over time periods of the order of 1 s. The scattering and scintillation of emergent radio waves are ascribed to turbulent density irregularities transported by the ubiquitous solar wind streams. The spatial correlation length of density irregularities and the Fresnel radius of radio diffraction are two key parameters in determining the scintillation pattern. Such a scintillation pattern can be measured and correlated between multi-station radio telescopes on the Earth. Using the “phase-changing screen” scenario based on the Born approximation, the bulk-flow speed and turbulent spectrum of the solar wind streams can be extracted from the single-station power spectra fitting and the multi-station cross-correlation analysis. Moreover, a numerical computer-assisted tomography (CAT) model, iteratively fit to a large number of IPS measurements over one Carrington rotation, can be used to reconstruct the global velocity and density structures in the inner heliosphere for the purpose of space weather modelling and prediction. In this review, we interpret the underlying physics governing the IPS phenomenon caused by the solar wind turbulence, describe the power spectrum and cross correlation of IPS signals, highlight the space weather application of IPS-CAT models, and emphasize the significant benefits from international cooperation within the Worldwide IPS Stations (WIPSS) network

    The applicability and efficacy of Micro-Video Psychological Training Camp in groups with mild to moderate symptoms of depression and anxiety: A prospective and randomized controlled trial protocol

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    BackgroundMental health is a global issue requiring global attention. Depression and anxiety are two of the most common mental disorders (CMDs) and are characterized by high incidence and high comorbidity. In recent years, the prolonged COVID-19 pandemic and exacerbated social instability have posed significant challenges to the mental resilience and mental health outcomes of the global population. Now more than ever, with an increase in mental health needs, it has become even more crucial to find an effective solution to provide universal mental healthcare. Psychotherapy is of vital importance for those coping with symptoms of depression and anxiety and is used to enhance mental resilience. However, such therapy can be difficult to access in reality. In this context, the Micro-Video Psychological Training Camp (MVPTC) platform will be developed.ObjectivesAs an online self-help platform for psychological intervention, the MVPTC platform was developed for those who suffer from mild to moderate symptoms of depression and/or anxiety and is tasked with the goal of reducing depressive and anxious symptoms while improving mental resilience. Thus, this study will be carried out to verify its efficacy and applicability.MethodsIn this parallel-group, randomized controlled trial, a total of 200 mild to moderately depressed and/or anxious adults seeking self-help will be randomly recruited and assigned to either the micro-video psychological intervention group or the wait list control group. Online measurements by self-assessment will be taken at baseline, post-intervention, 1-month, and 3-month follow-up.ResultsThe primary results will involve symptoms of depression and anxiety. The secondary results will involve mental resilience. An analysis will be conducted based on the intention-to-treat principle.DiscussionThis trial will examine whether the MVPTC platform for the relief of symptoms and the enhancement of resilience in a population screened for depression and anxiety symptoms proves effective and applicable. Large-scale resilience enhancement may benefit public mental health in terms of preventive interventions, managing depressive and anxiety symptoms, and promoting mental health. With the MVPTC-based method being applied, a brief, efficient, and structured intervention model can potentially be established, having the potential to provide necessary and accessible mental support for an extensive target group.Clinical trial registrationhttp://www.chictr.org.cn/, identifier ChiCTR2100043725

    Solar Ring Mission: Building a Panorama of the Sun and Inner-heliosphere

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    Solar Ring (SOR) is a proposed space science mission to monitor and study the Sun and inner heliosphere from a full 360{\deg} perspective in the ecliptic plane. It will deploy three 120{\deg}-separated spacecraft on the 1-AU orbit. The first spacecraft, S1, locates 30{\deg} upstream of the Earth, the second, S2, 90{\deg} downstream, and the third, S3, completes the configuration. This design with necessary science instruments, e.g., the Doppler-velocity and vector magnetic field imager, wide-angle coronagraph, and in-situ instruments, will allow us to establish many unprecedented capabilities: (1) provide simultaneous Doppler-velocity observations of the whole solar surface to understand the deep interior, (2) provide vector magnetograms of the whole photosphere - the inner boundary of the solar atmosphere and heliosphere, (3) provide the information of the whole lifetime evolution of solar featured structures, and (4) provide the whole view of solar transients and space weather in the inner heliosphere. With these capabilities, Solar Ring mission aims to address outstanding questions about the origin of solar cycle, the origin of solar eruptions and the origin of extreme space weather events. The successful accomplishment of the mission will construct a panorama of the Sun and inner-heliosphere, and therefore advance our understanding of the star and the space environment that holds our life.Comment: 41 pages, 6 figures, 1 table, to be published in Advances in Space Researc
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