410 research outputs found

    Feasibility of GNSS-R Altimetry Using CyGNSS 8-Satellite Constellation Mission Data

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    Ponencia expuesta en Scientific Assembly of the International Association of Geodesy (2021) celebrado en Beijing del 28 de junio al 2 de juli

    Simultaneous compression of the passively mode-locked pulsewidth and pulse train

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    Simultaneous compression of the passively mode-locked pulse width and pulse train have been achieved by using a plano-convex unstable resonator hybrided by a nonlinear Sagnac ring interferometer. The greater than 30 mJ single pulse energy of a lone oscillator and less than or equal to 10 ps pulsewidth have been obtained. Using this system, the LAGEOS and ETALON satellites' laser ranging have been performed successfully

    Roles of sulfate-reducing bacteria in sustaining the diversity and stability of marine bacterial community

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    Microbes play central roles in ocean food webs and global biogeochemical processes. Yet, the information available regarding the highly diverse bacterial communities in these systems is not comprehensive. Here we investigated the diversity, assembly process, and species coexistence frequency of bacterial communities in seawater and sediment across ∼600 km of the eastern Chinese marginal seas using 16S rRNA gene amplicon sequencing. Our analyses showed that compared with seawater, bacterial communities in sediment possessed higher diversity and experienced tight phylogenetic distribution. Neutral model analysis showed that the relative contribution of stochastic processes to the assembly process of bacterial communities in sediment was lower than that in seawater. Functional prediction results showed that sulfate-reducing bacteria (SRB) were enriched in the core bacterial sub-communities. The bacterial diversities of both sediment and seawater were positively associated with the relative abundance of SRB. Co-occurrence analysis showed that bacteria in seawater exhibited a more complex interaction network and closer co-occurrence relationships than those in sediment. The SRB of seawater were centrally located in the network and played an essential role in sustaining the complex network. In addition, further analysis indicated that the SRB of seawater helped maintain the high stability of the bacterial network. Overall, this study provided further comprehensive information regarding the characteristics of bacterial communities in the ocean, and provides new insights into keystone taxa and their roles in sustaining microbial diversity and stability in ocean

    A Renal Function Based Trade-Off Analysis of Non-vitamin K Antagonist Oral Anticoagulants in Nonvalvular Atrial Fibrillation

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    Background: Non-vitamin K antagonist oral anticoagulants (NOACs) depend on some degree of renal excretion, and no head-to-head comparisons based on renal function is available. This study mainly investigated the trade-off property of NOACs in nonvalvular atrial fibrillation (NVAF) with varying degrees of renal function.Methods: A comprehensive search of Medline, Embase, Cochrane Library, and Clinical Trials.gov Website was performed for eligible randomized controlled trials (RCTs) that reported the efficacy and safety outcomes according to renal function of NOACs. Primary efficacy outcome was any Stroke or systemic embolism (S/SE). Major bleeding was considered as a primary safety outcome. Risk ratios (RRs) with their confidence intervals (CIs), the surface under the cumulative ranking curve (SUCRA), and trade-off analysis were conducted by renal function.Results: Finally, 5 phase III Clinical Trials (72961 NVAF patients) comparing NOACs with warfarin in NVAF patients were included. In terms of normal renal function, dabigatran-150 mg was ranked first for efficacy (SUCRA: 90.3), and edoxaban-30 mg was ranked first for safety (SUCRA: 93.3). Dabigatran-110 mg/150 mg, and apixaban-5 mg were regarded as the most effective and reasonably safe interventions in the trade-off analysis. Regarding mild renal impairment, edoxaban-60 mg was ranked first for efficacy (SUCRA: 97.8), and edoxaban-30 mg was ranked first for safety (SUCRA: 99.5). Edoxaban-60 mg and dabigatran-150 mg were accounted as the most effective and reasonably safe interventions. With regards to moderate renal impairment, dabigatran-150 mg was ranked first for efficacy (SUCRA: 95.1), and edoxaban-15 mg was ranked first for safety (SUCRA: 98.2). Apixaban-2.5 mg and Edoxaban-30 mg was considered as the reasonably effective and the safest interventions.Conclusions: Dabigatran-150 mg seems the most effective therapy in patients with normal renal function and moderate renal impairment, and edoxaban-60 mg in patients with mild renal impairment. Low dose edoxaban (15 and 30 mg) seems the safest intervention. Apixaban-2.5 mg and edoxaban-30 mg might be the best trade-off property in moderate renal insufficiency.HIGHLIGHTS Dabigatran-150 mg seems the most effective therapy for normal renal function and moderate renal impairment patients, edoxaban-60 mg for mild renal impairment patients.Low-dose edoxaban can be considered as a good choice in NVAF patients at high risk of bleeding.Apixaban-2.5 mg and edoxaban-30 mg might be the balanced option in NVAF patients with moderate renal insufficiency.STUDY REGISTRATION: PROSPERO Identifier, CRD42017054235

    The Prognostic Impact of the Metastatic Lymph Nodes Ratio in Colorectal Cancer

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    Background: This study was designed to validate the prognostic significance of the ratio of positive to examined lymph nodes (LNR) in patients with colorectal cancer.Methods: 218,314 patients from the SEER database and 1,811 patients from the three independent multicenter were included in this study. The patients were divided into 5 groups on a basis of previous published LNR: LNR0, patients with no metastatic lymph nodes; LNR1, patients with the LNR between 0.1 and 0.17; LNR2, patients with the LNR between 0.18 and 0.41; LNR3, patients with the LNR between 0.42 and 0.69; LNR4, patients with the LNR >0.7. The 5-year OS and CSS rate were estimated using Kaplan-Meier method and the survival difference was tested using log-rank test. Multivariate Cox analysis was used to further assess the influence of the LNR on patients' outcome.Results: The 5-year OS rate of patients within LNR0 to LNR4 group was 71.2, 55.8, 39.3, 22.6, and 14.6%, respectively (p < 0.001) in the SEER database. While the 5-year OS rate of those with LNR0 to LNR4 was 75.2, 66.1, 48.0, 34.0, and 17.7%, respectively (p < 0.001) in the international multicenter cohort. In the multivariate analysis, LNR was demonstrated to be a strong prognostic factor in patients with < 12 and ≥12 metastatic lymph nodes. Furthermore, the LNR had a similar impact on the patients' prognosis in colon cancer and rectal cancer.Conclusion: The LNR allowed better prognostic stratification than the positive node (pN) in patients with colorectal cancer and the cut-off values were well validated

    Non-vitamin K Antagonist Oral Anticoagulants and Cognitive Impairment in Atrial Fibrillation: Insights From the Meta-Analysis of Over 90,000 Patients of Randomized Controlled Trials and Real-World Studies

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    Background: The relationship between the use of non-vitamin K antagonist oral anticoagulants (NOACs) and the impairment of cognition in atrial fibrillation (AF) remains unknown.Methods: A comprehensive database search of Medline, Embase, Cochrane Library databases, and ClinicalTrials.gov Website was performed for randomized controlled trials (RCTs) reporting cognitive impairment events and observational nationwide database studies reporting adjusted hazard ratio (HR) in AF patients with NOACs. The primacy outcome was a composite of any cognitive impairment. Summary of HRs and 95% confidence intervals (95%CI) were calculated using the fixed- and random-effects models. Subgroup analyses were undertaken according to the individual NOACs, study types, and duration of follow-up.Results: Finally, eight studies including 97,595 patients (77,643 patients in 6 RCTs and 19,952 patients in 2 observational database studies) met the inclusion criteria, among which 55,337 (56.7%) patients were receiving NOACs and 42,258 (43.3%) patients were receiving vitamin K Antagonists (VKAs) or acetylsalicylic acid. The results showed a borderline significant association between the use of NOACs and the lower risk of cognitive impairment when compared with VKAs/ acetylsalicylic acid (HR: 0.80, 95%CI: 0.63–0.98 for fixed-effects model; HR: 0.77; 95%CI: 0.53–1.01 for random-effects model), with no significant heterogeneity between the studies (I2 = 39.4%, P = 0.12). The results were consistent across the key subgroups (Pinteraction > 0.05 for each).Conclusions: The results indicated that the use of NOACs might lower the tendency on the risk of cognitive impairment in comparison to VKAs/acetylsalicylic acid, and further RCTs and real-world studies are required on an urgent basis to obtain a robust result

    Diffusion-coefficient power laws and defect-driven glassy dynamics in swap acceleration

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    Particle swaps can drastically accelerate dynamics in glass. The mechanism is expected to be vital for a fundamental understanding of glassy dynamics. To extract defining features, we propose a partial swappability with a fraction {\phi_s} of swap-initiating particles, which can only swap locally with each other or with regular particles. We focus on the swap-dominating regime. At all temperatures studied, particle diffusion coefficients scale with {\phi_s} in unexpected power laws with temperature-dependent exponents, consistent with the kinetic picture of glass transition. At small {\phi_s}, swap-initiators, becoming defect particles, induce remarkably typical glassy dynamics of regular particles. This supports defect models of glass.Comment: 11 pages, 18 figure

    Functional and Structural Insights into a Novel Promiscuous Ketoreductase of the Lugdunomycin Biosynthetic Pathway

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    Angucyclines are a structurally diverse class of actinobacterial natural products defined by their varied polycyclic ring systems, which display a wide range of biological activities. We recently discovered lugdunomycin (1), a highly rearranged polyketide antibiotic derived from the angucycline backbone that is synthesized via several yet unexplained enzymatic reactions. Here, we show via in vivo, in vitro, and structural analysis that the promiscuous reductase LugOII catalyzes both a C6 and an unprecedented C1 ketoreduction. This then sets the stage for the subsequent C-ring cleavage that is key to the rearranged scaffolds of 1. The 1.1 Å structures of LugOII in complex with either ligand 8-O-Methylrabelomycin (4) or 8-O-Methyltetrangomycin (5) and of apoenzyme were resolved, which revealed a canonical Rossman fold and a remarkable conformational change during substrate capture and release. Mutational analysis uncovered key residues for substrate access, position, and catalysis as well as specific determinants that control its dual functionality. The insights obtained in this work hold promise for the discovery and engineering of other promiscuous reductases that may be harnessed for the generation of novel biocatalysts for chemoenzymatic applications.</p

    HypertenGene: extracting key hypertension genes from biomedical literature with position and automatically-generated template features

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    <p>Abstract</p> <p>Background</p> <p>The genetic factors leading to hypertension have been extensively studied, and large numbers of research papers have been published on the subject. One of hypertension researchers' primary research tasks is to locate key hypertension-related genes in abstracts. However, gathering such information with existing tools is not easy: (1) Searching for articles often returns far too many hits to browse through. (2) The search results do not highlight the hypertension-related genes discovered in the abstract. (3) Even though some text mining services mark up gene names in the abstract, the key genes investigated in a paper are still not distinguished from other genes. To facilitate the information gathering process for hypertension researchers, one solution would be to extract the key hypertension-related genes in each abstract. Three major tasks are involved in the construction of this system: (1) gene and hypertension named entity recognition, (2) section categorization, and (3) gene-hypertension relation extraction.</p> <p>Results</p> <p>We first compare the retrieval performance achieved by individually adding template features and position features to the baseline system. Then, the combination of both is examined. We found that using position features can almost double the original AUC score (0.8140vs.0.4936) of the baseline system. However, adding template features only results in marginal improvement (0.0197). Including both improves AUC to 0.8184, indicating that these two sets of features are complementary, and do not have overlapping effects. We then examine the performance in a different domain--diabetes, and the result shows a satisfactory AUC of 0.83.</p> <p>Conclusion</p> <p>Our approach successfully exploits template features to recognize true hypertension-related gene mentions and position features to distinguish key genes from other related genes. Templates are automatically generated and checked by biologists to minimize labor costs. Our approach integrates the advantages of machine learning models and pattern matching. To the best of our knowledge, this the first systematic study of extracting hypertension-related genes and the first attempt to create a hypertension-gene relation corpus based on the GAD database. Furthermore, our paper proposes and tests novel features for extracting key hypertension genes, such as relative position, section, and template features, which could also be applied to key-gene extraction for other diseases.</p

    Global publication trends and research trends of necroptosis application in tumor: A bibliometric analysis

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    Introduction: Necroptosis is an alternative, caspase-independent programmed cell death that appears when apoptosis is inhibited. A gowing number of studies have reflected the link between necroptosis and tumors. However, only some systematical bibliometric analyses were focused on this field. In this study, we aimed to identify and visualize the cooperation between countries, institutions, authors, and journals through a bibliometric analysis to help understand the hotspot trends and emerging topics regarding necroptosis and cancer research.Methods: The articles and reviews on necroptosis and cancer were obtained from the Web of Science Core Collection on 16 September 2022. Countries, institutions, authors, references, and keywords in this field were visually analyzed by CtieSpace 5.8.R3, VOSviewer 1.6.18, and R package “bibliometrix.”Results: From 2006 to 2022, 2,216 qualified original articles and reviews on necroptosis in tumors were published in 685 academic journals by 13,009 authors in 789 institutions from 75 countries/regions. Publications focusing on necroptosis and cancer have increased violently in the past 16 years, while the citation number peaked around 2008–2011. Most publications were from China, while the United States maintained the dominant position as a “knowledge bridge” in necroptosis and cancer research; meanwhile, Ghent University and the Chinese Academy of Sciences were the most productive institutions. Moreover, only a tiny portion of the articles were multiple-country publications. Peter Vandenabeele had the most significant publications, while Alexei Degterev was most often co-cited. Peter Vandenabeele also gets the highest h-index and g-index in this research field. Cell Death and Disease was the journal with the most publications on necroptosis and cancer, which was confirmed to be the top core source by Bradford’s Law. At the same time, Cell was the leading co-cited journal, and the focus area of these papers was molecular, biology, and immunology. High-frequency keywords mainly contained those that are molecularly related (MLKL, NF-kB, TNF, RIPK3, RIPK1), pathological process related (necroptosis, apoptosis, cell-death, necrosis, autophagy), and mechanism related (activation, expression, mechanisms, and inhibition).Conclusion: This study comprehensively overviews necroptosis and cancer research using bibliometric and visual methods. Research related to necroptosis and cancer is flourishing. Cooperation and communication between countries and institutions must be further strengthened. The information in our paper would provide valuable references for scholars focusing on necroptosis and cancer
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