16,306 research outputs found

    Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft: a theoretical study

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    Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few spacecraft. This workis motivated by the prospect of possibly having two or three soft X-ray imagers in spacein the coming years, and that many phenomena which occur at the magnetopause boundary, such as reconnection events and pressure pulse responses, do not lend themselvesas well to superposed epoch analysis. If the reconstruction is successful — which we demonstrate in this paper that it can be — this collection of imagers can be used to reconstructthe magnetosheath and magnetopause from a single image from each spacecraft, allowing for high time resolution reconstructions. In this paper we explore the reconstruction using, two, three, and four spacecraft. We show that the location of the subsolar pointof the magnetopause can be determined with just two satellites, and that volume emissions of soft X-rays, and the shape of the boundary, can be reconstructed using three or more satellites

    Large electronegativity differences between adjacent atomic sites activate and stabilize ZnIn2S4 for efficient photocatalytic overall water splitting

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    Photocatalytic overall water splitting into hydrogen and oxygen is desirable for long-term renewable, sustainable and clean fuel production on earth. Metal sulfides are considered as ideal hydrogen-evolved photocatalysts, but their component homogeneity and typical sulfur instability cause an inert oxygen production, which remains a huge obstacle to overall water-splitting. Here, a distortion-evoked cation-site oxygen doping of ZnIn2S4 (D-O-ZIS) creates significant electronegativity differences between adjacent atomic sites, with S1 sites being electron-rich and S2 sites being electron-deficient in the local structure of S1-S2-O sites. The strong charge redistribution character activates stable oxygen reactions at S2 sites and avoids the common issue of sulfur instability in metal sulfide photocatalysis, while S1 sites favor the adsorption/desorption of hydrogen. Consequently, an overall water-splitting reaction has been realized in D-O-ZIS with a remarkable solar-to-hydrogen conversion efficiency of 0.57%, accompanying a ~ 91% retention rate after 120 h photocatalytic test. In this work, we inspire an universal design from electronegativity differences perspective to activate and stabilize metal sulfide photocatalysts for efficient overall water-splitting

    Identified charged-hadron production in pp++Al, 3^3He++Au, and Cu++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV and in U++U collisions at sNN=193\sqrt{s_{_{NN}}}=193 GeV

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    International audienceThe PHENIX experiment has performed a systematic study of identified charged-hadron (π±\pi^\pm, K±K^\pm, pp, pˉ\bar{p}) production at midrapidity in pp++Al, 3^3He++Au, Cu++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV and U++U collisions at sNN=193\sqrt{s_{_{NN}}}=193 GeV. Identified charged-hadron invariant transverse-momentum (pTp_T) and transverse-mass (mTm_T) spectra are presented and interpreted in terms of radially expanding thermalized systems. The particle ratios of K/πK/\pi and p/πp/\pi have been measured in different centrality ranges of large (Cu++Au, U++U) and small (pp++Al, 3^3He++Au) collision systems. The values of K/πK/\pi ratios measured in all considered collision systems were found to be consistent with those measured in pp++pp collisions. However the values of p/πp/\pi ratios measured in large collision systems reach the values of 0.6\approx0.6, which is 2\approx2 times larger than in pp++pp collisions. These results can be qualitatively understood in terms of the baryon enhancement expected from hadronization by recombination. Identified charged-hadron nuclear-modification factors (RABR_{AB}) are also presented. Enhancement of proton RABR_{AB} values over meson RABR_{AB} values was observed in central 3^3He++Au, Cu++Au, and U++U collisions. The proton RABR_{AB} values measured in pp++Al collision system were found to be consistent with RABR_{AB} values of ϕ\phi, π±\pi^\pm, K±K^\pm, and π0\pi^0 mesons, which may indicate that the size of the system produced in pp++Al collisions is too small for recombination to cause a noticeable increase in proton production

    The 5-Hydroxymethylcytosine Landscape of Prostate Cancer.

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    UNLABELLED: Analysis of DNA methylation is a valuable tool to understand disease progression and is increasingly being used to create diagnostic and prognostic clinical biomarkers. While conversion of cytosine to 5-methylcytosine (5mC) commonly results in transcriptional repression, further conversion to 5-hydroxymethylcytosine (5hmC) is associated with transcriptional activation. Here we perform the first study integrating whole-genome 5hmC with DNA, 5mC, and transcriptome sequencing in clinical samples of benign, localized, and advanced prostate cancer. 5hmC is shown to mark activation of cancer drivers and downstream targets. Furthermore, 5hmC sequencing revealed profoundly altered cell states throughout the disease course, characterized by increased proliferation, oncogenic signaling, dedifferentiation, and lineage plasticity to neuroendocrine and gastrointestinal lineages. Finally, 5hmC sequencing of cell-free DNA from patients with metastatic disease proved useful as a prognostic biomarker able to identify an aggressive subtype of prostate cancer using the genes TOP2A and EZH2, previously only detectable by transcriptomic analysis of solid tumor biopsies. Overall, these findings reveal that 5hmC marks epigenomic activation in prostate cancer and identify hallmarks of prostate cancer progression with potential as biomarkers of aggressive disease. SIGNIFICANCE: In prostate cancer, 5-hydroxymethylcytosine delineates oncogene activation and stage-specific cell states and can be analyzed in liquid biopsies to detect cancer phenotypes. See related article by Wu and Attard, p. 3880

    Causal association between snoring and stroke: a Mendelian randomization study in a Chinese populationResearch in context

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    Summary: Background: Previous observational studies established a positive relationship between snoring and stroke. We aimed to investigate the causal effect of snoring on stroke. Methods: Based on 82,339 unrelated individuals with qualified genotyping data of Asian descent from the China Kadoorie Biobank (CKB), we conducted a Mendelian randomization (MR) analysis of snoring and stroke. Genetic variants identified in the genome-wide association analysis (GWAS) of snoring in CKB and UK Biobank (UKB) were selected for constructing genetic risk scores (GRS). A two-stage method was applied to estimate the associations of the genetically predicted snoring with stroke and its subtypes. Besides, MR analysis among the non-obese group (body mass index, BMI <24.0 kg/m2), as well as multivariable MR (MVMR), were performed to control for potential pleiotropy from BMI. In addition, the inverse-variance weighted (IVW) method was applied to estimate the causal association with genetic variants identified in CKB GWAS. Findings: Positive associations were found between snoring and total stroke, hemorrhagic stroke (HS), and ischemic stroke (IS). With GRS of CKB, the corresponding HRs (95% CIs) were 1.56 (1.15, 2.12), 1.50 (0.84, 2.69), 2.02 (1.36, 3.01), and the corresponding HRs (95% CIs) using GRS of UKB were 1.78 (1.30, 2.43), 1.94 (1.07, 3.52), and 1.74 (1.16, 2.61). The associations remained stable in the MR among the non-obese group, MVMR analysis, and MR analysis using the IVW method. Interpretation: This study suggests that, among Chinese adults, genetically predicted snoring could increase the risk of total stroke, IS, and HS, and the causal effect was independent of BMI. Funding: National Natural Science Foundation of China, Kadoorie Charitable Foundation Hong Kong, UK Wellcome Trust, National Key R&D Program of China, Chinese Ministry of Science and Technology

    Healthcare-Seeking Delays in Acute Ischemic Stroke Patients: The Influence of Gender, Immigrant Status, and Educational Background

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    Youli Jiang, Yao Xiong, Yue Chi, Fu Lin, Qingshi Zhao, Yanfeng Li Department of Neurology, People’s Hospital of Longhua, Shenzhen, 518109, People’s Republic of ChinaCorrespondence: Qingshi Zhao; Yanfeng Li, Email [email protected]; [email protected]: Timely medical attention is crucial for patients with Acute Ischemic Stroke (AIS), as delays can significantly impact therapeutic outcomes. These delays are influenced by a combination of socio-cultural, educational, and clinical factors.Patients and Methods: An in-depth analysis was conducted to assess the prevalence and median duration of healthcare-seeking delays in AIS patients. The study specifically investigated the independent impacts of sociocultural and clinical determinants on these delays, with a focus on immigrant status, gender disparities, and educational levels. Multivariate regression analysis was employed to identify these independent effects while controlling for potential confounding factors.Results: Among 1419 AIS patients, 82.52% (n = 1171) experienced delays exceeding 2 hours from symptom onset of symptoms to hospital arrival. The median delay was 12.3 hours. Immigrant populations encountering longer delays compared to native groups. Younger males (< 45 years) and elderly females were more prone to delay in healthcare-seeking. Identified independent risk factors for delay included male gender (OR = 1.65 [95% CI:1.14− 2.48]), self-acknowledged diabetes (OR = 2.50 [95% CI:1.21– 5.17]), small vessel (OR = 2.07 [95% CI:1.27– 3.36]), and wake stroke (OR = 7.04 [95% CI:3.69– 13.44]). Educational background (high school and above), GCS score with 3– 8 points (OR = 0.52 [95% CI:0.09– 0.69]), understanding stroke-related knowledge (OR = 0.26 [95% CI:0.09– 0.44]), conscious disturbance (OR = 0.25 [95% CI:0.10– 0.62]) and limb weakness (OR=0.21[95% CI:0.21– 0.49]) are protective factors for timely treatment.Conclusion: Immigrant populations experienced longer delays from symptom onset to hospital arrival. The crucial roles of education and knowledge about stroke underscore the need for enhanced health literacy campaigns and public awareness, with a targeted focus on younger males and elderly females.Keywords: healthcare-seeking behavior, immigrant population, educational disparity, pre-hospital delay, AI

    Identified charged-hadron production in pp++Al, 3^3He++Au, and Cu++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV and in U++U collisions at sNN=193\sqrt{s_{_{NN}}}=193 GeV

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    International audienceThe PHENIX experiment has performed a systematic study of identified charged-hadron (π±\pi^\pm, K±K^\pm, pp, pˉ\bar{p}) production at midrapidity in pp++Al, 3^3He++Au, Cu++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV and U++U collisions at sNN=193\sqrt{s_{_{NN}}}=193 GeV. Identified charged-hadron invariant transverse-momentum (pTp_T) and transverse-mass (mTm_T) spectra are presented and interpreted in terms of radially expanding thermalized systems. The particle ratios of K/πK/\pi and p/πp/\pi have been measured in different centrality ranges of large (Cu++Au, U++U) and small (pp++Al, 3^3He++Au) collision systems. The values of K/πK/\pi ratios measured in all considered collision systems were found to be consistent with those measured in pp++pp collisions. However the values of p/πp/\pi ratios measured in large collision systems reach the values of 0.6\approx0.6, which is 2\approx2 times larger than in pp++pp collisions. These results can be qualitatively understood in terms of the baryon enhancement expected from hadronization by recombination. Identified charged-hadron nuclear-modification factors (RABR_{AB}) are also presented. Enhancement of proton RABR_{AB} values over meson RABR_{AB} values was observed in central 3^3He++Au, Cu++Au, and U++U collisions. The proton RABR_{AB} values measured in pp++Al collision system were found to be consistent with RABR_{AB} values of ϕ\phi, π±\pi^\pm, K±K^\pm, and π0\pi^0 mesons, which may indicate that the size of the system produced in pp++Al collisions is too small for recombination to cause a noticeable increase in proton production
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