15 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

    Racial disparities in adequacy of prenatal care during the COVID-19 pandemic in South Carolina, 2018–2021

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    Abstract Background During the COVID-19 pandemic, hospitals’ decision of not admitting pregnant women’s partner or support person, and pregnant women’s fear of contracting COVID-19 in hospitals may disrupt prenatal care. We aimed to examine whether prenatal care utilization in South Carolina varied before and during the COVID-19 pandemic, and whether the variation was different by race. Methods We utilized 2018–2021 statewide birth certificate data using a pre-post design, including all women who delivered a live birth in South Carolina. The Kotelchuck Index - incorporating the timing of prenatal care initiation and the frequency of gestational age-adjusted visits - was employed to categorize prenatal care into inadequate versus adequate care. Self-reported race includes White, Black, and other race groups. Multiple logistic regression models were used to calculate adjusted odds ratio of inadequate prenatal care and prenatal care initiation after first trimester by maternal race before and during the pandemic. Results A total of 118,925 women became pregnant before the pandemic (before March 2020) and 29,237 women during the COVID-19 pandemic (March 2020 – June 2021). Regarding race, 65.2% were White women, 32.0% were Black women and 2.8% were of other races. Lack of adequate prenatal care was more prevalent during the pandemic compared to pre-pandemic (24.1% vs. 21.6%, p < 0.001), so was the percentage of initiating prenatal care after the first trimester (27.2% vs. 25.0%, p < 0.001). The interaction of race and pandemic period on prenatal care adequacy and initiation was significant. The odds of not receiving adequate prenatal care were higher during the pandemic compared to before for Black women (OR 1.26, 95% CI 1.20–1.33) and White women (OR 1.10, 95% CI 1.06–1.15). The odds of initiating prenatal care after the first trimester were higher during the pandemic for Black women (OR 1.18, 95% CI 1.13–1.24) and White women (OR 1.09, 95% CI 1.04–1.13). Conclusions Compared to pre-pandemic, the odds of not receiving adequate prenatal care in South Carolina was increased by 10% for White women and 26% for Black women during the pandemic, highlighting the needs to develop individual tailored interventions to reverse this trend

    T-complex protein 1 subunit zeta-2 (CCT6B) deficiency induces murine teratospermia

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    Background The CCT complex is an important mediator of microtubule assembly and intracellular protein folding. Owing to its high expression in spermatids, CCT knockdown can disrupt spermatogenesis. In the present report, we therefore evaluated the in vivo functionality of the testis-specific CCT complex component CCT6B using a murine knockout model system. Methods A CRISPR/Cas9 approach was used to generate Cct6b−/− mice, after which candidate gene expression in these animals was evaluated via qPCR and Western blotting. Testicular and epididymal phenotypes were assessed through histological and immunofluorescent staining assays, while a computer-assisted sperm analyzer was employed to assess semen quality. Results Cct6b−/− mice were successfully generated, and exhibited no differences in development, fertility, appearance, testis weight, or sperm counts relative to control littermates. In addition, no differences in spermatogenesis were detected when comparingCct6b+/+ and Cct6b−/− testes. However, when progressive motility was analyzed, the ratio of normal sperm was significantly decreased in Cct6b−/− male mice, with nuclear base bending being the primary detected abnormality. In addition, slight decreases in Cct4 and Cct7 expression were detected. Conclusion These data indicated that CCT6B is an important regulator of murine spermatogenesis, with the loss of this protein resulting in CCT complex dysfunction, providing a foundation for further studies

    Breastfeeding Initiation: Impact of Obesity in a Large Canadian Perinatal Cohort Study

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    <div><p>Objective</p><p>To evaluate incidence of breastfeeding initiation according to maternal pre-pregnancy body mass index (BMI) in “Grossesse en Santé”, a large prospective birth cohort in Quebec City.</p><p>Methods</p><p>Breastfeeding initiation in the post-partum period, pre-pregnancy BMI, sociodemographic determinants and obstetrical and neonatal factors were collected from years 2005 to 2010 in 6592 women with single pregnancies. Prenatal non-intention to breastfeed was documented in a subgroup of the cohort (years 2009–2010). Log-binomial regression analyses were performed to assess relative risk (RR) of non-initiation of breastfeeding between maternal BMI categories in models including pre- and post-natal determinants, after exclusion of variables with a mediating effect.</p><p>Results</p><p>Twenty percent (20%) of obese women did not initiate breastfeeding in the post-natal period at hospital compared to 12% for normal weight women. Compared with those having a normal pre-pregnancy BMI, obese women had a higher risk of non-initiation of breastfeeding (RRunadj 1.69, 95% CI 1.44–1.98), even after adjustment for prenatal and sociodemographic factors (RRadj 1.26, 95% CI 1.08–1.46). Furthermore, the risk of non-initiation of breastfeeding in obese women still remained higher after introduction of per- and post-natal factors (RR 1.22, 95% CI 1.04–1.42). The prenatal non-intention to breastfeed was strongly associated with the non-initiation of breastfeeding for all categories of BMI.</p><p>Conclusion</p><p>Maternal obesity is associated with a two-fold rate of non-initiation of breastfeeding. Considering the benefits of breastfeeding and the increasing obesity rate, adapted interventions and specialized support should target both pre- and immediate post-natal periods in this population.</p></div

    Newborn’s characteristics according to maternal pre-pregnancy body mass index.

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    <p>Note: BMI = Body mass index; SD = Standard deviation; SGA = Small of gestational age; APA = appropriate for gestational age; LGA = Large for gestational age</p><p>*Unless stated otherwise</p><p><sup>†</sup><i>p</i> value indicates statistical difference between each BMI category and the reference category for the related characteristic</p><p><sup>a</sup> One value is missing</p><p>Newborn’s characteristics according to maternal pre-pregnancy body mass index.</p
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