57 research outputs found

    A Transmissive X-ray Polarimeter Design For Hard X-ray Focusing Telescopes

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    The X-ray Timing and Polarization (XTP) is a mission concept for a future space borne X-ray observatory and is currently selected for early phase study. We present a new design of X-ray polarimeter based on the time projection gas chamber. The polarimeter, placed above the focal plane, has an additional rear window that allows hard X-rays to penetrate (a transmission of nearly 80% at 6 keV) through it and reach the detector on the focal plane. Such a design is to compensate the low detection efficiency of gas detectors, at a low cost of sensitivity, and can maximize the science return of multilayer hard X-ray telescopes without the risk of moving focal plane instruments. The sensitivity in terms of minimum detectable polarization, based on current instrument configuration, is expected to be 3% for a 1mCrab source given an observing time of 10^5 s. We present preliminary test results, including photoelectron tracks and modulation curves, using a test chamber and polarized X-ray sources in the lab

    Composite Hydrogels with the Simultaneous Release of VEGF and MCP-1 for Enhancing Angiogenesis for Bone Tissue Engineering Applications

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    Rapid new microvascular network induction was critical for bone regeneration, which required the spatiotemporal delivery of growth factors and transplantation of endothelial cells. In this study, the linear poly(d,l-lactic-co-glycolic acid)-b-methoxy poly(ethylene glycol) (PLGA-mPEG) block copolymer microspheres were prepared for simultaneously delivering vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1). Then, vascular endothelial cells (VECs) with growth factor loaded microspheres were composited into a star-shaped PLGA-mPEG block copolymer solution. After this, composite hydrogel (microspheres ratio: 5 wt%) was formed by increasing the temperature to 37 °C. The release profiles of VEGF and MCP-1 from composite hydrogels in 30 days were investigated to confirm the different simultaneous delivery systems. The VECs exhibited a good proliferation in the composite hydrogels, which proved that the composite hydrogels had a good cytocompatibility. Furthermore, in vivo animal experiments showed that the vessel density and the mean vessel diameters increased over weeks after the composite hydrogels were implanted into the necrosis site of the rabbit femoral head. The above results suggested that the VECs-laden hydrogel composited with the dual-growth factor simultaneous release system has the potential to enhance angiogenesis in bone tissue engineering

    Transcriptomic analysis reveals transcription factors involved in vascular bundle development and tissue maturation in ginger rhizomes (Zingiber officinale Roscoe)

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    Ginger (Zingiber officinale Roscoe) is an important vegetable with medicinal value. Rhizome development determines ginger yield and quality. However, little information is available about the molecular features underlying rhizome expansion and maturation. In this study, we investigated anatomy characteristics, lignin accumulation and transcriptome profiles during rhizome development. In young rhizomes, the vascular bundle (VB) was generated with only vessels in it, whereas in matured rhizomes, three to five layers of fibre bundle in the xylem were formed, resulting in VB enlargement. It indicates VB development favouring rhizome swelling. With rhizome matured, the lignin content was remarkably elevated, thus facilitating tissue lignification. To explore the regulators for rhizome development, nine libraries including ginger young rhizomes (GYR), growing rhizomes (GGR), and matured rhizomes (GMR) were established for RNA-Seq, a total of 1264 transcription factors (TFs) were identified. Among them, 35, 116, and 14 differentially expressed TFs were obtained between GYR and GGR, GYR and GMR, and GGR and GMR, respectively. These TFs were further divided into three categories. Among them, three ZobHLHs (homologs of Arabidopsis LHW and AtbHLH096) as well as one DIVARICATA homolog in ginger might play crucial roles in controlling VB development. Four ZoWRKYs and two ZoNACs might be potential regulators associated with rhizome maturation. Three ZoAP2/ERFs and one ZoARF might participate in rhizome development via hormone signalling. This result provides a molecular basis for rhizome expansion and maturation in ginger

    Multilevel Determinants of Racial/Ethnic Disparities in Severe Maternal Morbidity and Mortality in the Context of the COVID-19 Pandemic in the USA: Protocol for a Concurrent Triangulation, Mixed-Methods Study

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    Introduction The COVID-19 pandemic has affected communities of colour the hardest. Non-Hispanic black and Hispanic pregnant women appear to have disproportionate SARS-CoV-2 infection and death rates. Methods and analysis We will use the socioecological framework and employ a concurrent triangulation, mixed-methods study design to achieve three specific aims: (1) examine the impacts of the COVID-19 pandemic on racial/ethnic disparities in severe maternal morbidity and mortality (SMMM); (2) explore how social contexts (eg, racial/ethnic residential segregation) have contributed to the widening of racial/ethnic disparities in SMMM during the pandemic and identify distinct mediating pathways through maternity care and mental health; and (3) determine the role of social contextual factors on racial/ethnic disparities in pregnancy-related morbidities using machine learning algorithms. We will leverage an existing South Carolina COVID-19 Cohort by creating a pregnancy cohort that links COVID-19 testing data, electronic health records (EHRs), vital records data, healthcare utilisation data and billing data for all births in South Carolina (SC) between 2018 and 2021 (\u3e200 000 births). We will also conduct similar analyses using EHR data from the National COVID-19 Cohort Collaborative including \u3e270 000 women who had a childbirth between 2018 and 2021 in the USA. We will use a convergent parallel design which includes a quantitative analysis of data from the 2018–2021 SC Pregnancy Risk Assessment and Monitoring System (unweighted n\u3e2000) and in-depth interviews of 40 postpartum women and 10 maternal care providers to identify distinct mediating pathways. Ethics and dissemination The study was approved by institutional review boards at the University of SC (Pro00115169) and the SC Department of Health and Environmental Control (DHEC IRB.21-030). Informed consent will be provided by the participants in the in-depth interviews. Study findings will be disseminated with key stakeholders including patients, presented at academic conferences and published in peer-reviewed journals

    Disclosure Patterns of Opioid Use Disorders in Perinatal Care During the Opioid Epidemic on X from 2019 to 2021: Thematic Analysis

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    BACKGROUND: In 2021, the United States experienced a 14% rise in fatal drug overdoses totaling 106,699 deaths, driven by harmful opioid use, particularly among individuals in the perinatal period who face increased risks associated with opioid use disorders (OUDs). Increased concerns about the impacts of escalating harmful opioid use among pregnant and postpartum persons are rising. Most of the current limited perinatal OUD studies were conducted using traditional methods, such as interviews and randomized controlled trials to understand OUD treatment, risk factors, and associated adverse effects. However, little is known about how social media data, such as X, formerly known as Twitter, can be leveraged to explore and identify broad perinatal OUD trends, disclosure and communication patterns, and public health surveillance about OUD in the perinatal period. OBJECTIVE: The objective is 3-fold: first, we aim to identify key themes and trends in perinatal OUD discussions on platform X. Second, we explore user engagement patterns, including replying and retweeting behaviors. Third, we investigate computational methods that could potentially streamline and scale the labor-intensive manual annotation effort. METHODS: We extracted 6 million raw perinatal-themed tweets posted by global X users during the opioid epidemic from May 2019 to October 2021. After data cleaning and sampling, we used 500 tweets related to OUD in the perinatal period by US X users for a thematic analysis using NVivo (Lumivero) software. RESULTS: Seven major themes emerged from our thematic analysis: (1) political views related to harmful opioid and other substance use, (2) perceptions of others\u27 substance use, (3) lived experiences of opioid and other substance use, (4) news reports or papers related to opioid and other substance use, (5) health care initiatives, (6) adverse effects on children\u27s health due to parental substance use, and (7) topics related to nonopioid substance use. Among these 7 themes, our user engagement analysis revealed that themes 4 and 5 received the highest average retweet counts, and theme 3 received the highest average tweet reply count. We further found that different computational methods excel in analyzing different themes. CONCLUSIONS: Social media platforms such as X can serve as a valuable tool for analyzing real-time discourse and exploring public perceptions, opinions, and behaviors related to maternal substance use, particularly, harmful opioid use in the perinatal period. More health promotion strategies can be carried out on social media platforms to provide educational support for the OUD perinatal population

    Research on Value and Approaches of Tourism Aesthetic Construction

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    Association between direct government subsidies and service scope of primary care facilities: a cross-sectional study in China

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    Abstract Background Comprehensive primary care practices, through preconception, preventive, curative, and rehabilitative care, have been a global priority in the promotion of health. However, the scope of primary care services has still been in decline in China. Studies on the factors for primary care service scope have centred on human resources and infrastructure; the role of direct government subsidies (DGS) on services scope of primary care facilities were left unanswered. This study aimed to explore the association between the DGS and services scope of primary care facilities in China. Methods A multi-stage, clustered cross-sectional survey using self-administrated questionnaire was conducted among primary care facilities of 36 districts/counties in China. A total of 770 primary care facilities were surveyed with 757 (98.3%) valid respondents. Of the 757 primary care facilities, 469 (62.0%) provided us detailed information of financial revenue and DGS from 2009 to 2016. Therefore, 469 primary care facilities from 31 counties/districts were included in this study. Sasabuchi-Lind-Mehlum tests and multivariate regression models were used to examine the inverted U-shaped relationship between the DGS and service scope. Results Of 469 PCFs, 332 (70.8%) were township health centres. Proportion of annul DGS to FR arose from 26.5% in 2009 to 50.5% in 2016. At the low proportion of DGS to financial revenue, an increase in DGS was associated with an increased service scope of primary care facilities, whereas the proportion of DGS to financial revenue over 42.5% might cause narrowed service scope (P = 0.023, 95% CI 11.59–51.74%); for the basic medical care dimension, the cut point is 42.6%. However, association between DGS and service scope of public health by primary care facilities is statistically insignificant. Conclusion While the DGS successfully achieved equalization of basic preventive and public health services, the disproportionate proportion of DGS to financial revenue is associated with narrowed service scope, which might cause underutilization of primary care and distorted incentive structure of primary care. Future improvements of DGS should focus on the incentive of broader basic medical services provision, such as clarifying service scope of primary care facilities and strategic procurement with a performance-based subsidies system to determine resource allocation. </jats:sec

    A Preliminary Investigation of Chinese Tourists in Berlin

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    A coding unit classification based AVC-to-HEVC transcoding with background modeling for surveillance videos

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    To save the storage and transmission cost, it is applicable now to develop fast and efficient methods to transcode the perennial surveillance videos to HEVC ones, since HEVC has doubled the compression ratio. Considering the longtime static background characteristic of surveillance videos, this paper presents a coding unit (CU) classification based AVC-to-HEVC transcoding method with background modeling. In our method, the background frame modeled from originally decoded frames is firstly transcoded into HEVC stream as long-term reference to enhance the prediction efficiency. Afterwards, a CU classification algorithm which employs decoded motion vectors and the modeled background frame as input is proposed to divide the decoded data into background, foreground and hybrid CUs. Following this, different transcoding strategies of CU partition termination, prediction unit candidate selection and motion estimation simplification are adopted for different CU categories to reduce the complexity. Experimental results show our method can achieve 45% bit saving and 50% complexity reduction against traditional AVC-to-HEVC transcoding.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000335493500069&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Artificial IntelligenceImaging Science &amp; Photographic TechnologyTelecommunicationsEICPCI-S(ISTP)
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