336 research outputs found

    NAQPMS-PDAF v2.0: A Novel Hybrid Nonlinear Data Assimilation System for Improved Simulation of PM2.5 Chemical Components

    Get PDF
    PM2.5, a complex mixture with diverse chemical components, exerts significant impacts on the environment, human health, and climate change. However, precisely describing spatiotemporal variations of PM2.5 chemical components remains a difficulty. In our earlier work, we developed an aerosol extinction coefficient data assimilation (DA) system (NAQPMS-PDAF v1.0) that is suboptimal for chemical components. This paper introduces a novel hybrid nonlinear chemical DA system (NAQPMS-PDAF v2.0) to accurately interpret key chemical components (SO42-, NO3-, NH4+, OC, and EC). NAQPMS-PDAF v2.0 improves upon v1.0 by effectively handing and balancing stability and nonlinearity in chemical DA, which is achieved by incorporating the non-Gaussian-distribution ensemble perturbation and hybrid Localized Kalman-Nonlinear Ensemble Transform Filter with an adaptive forgetting factor for the first time. The dependence tests demonstrate that NAQPMS-PDAF v2.0 provides excellent DA results with a minimal ensemble size of 10, surpassing previous reports and v1.0. A one-month DA experiment shows that the analysis field generated by NAQPMS-PDAF v2.0 is in good agreement with observations, especially reducing the underestimation of NH4+ and NO3- and the overestimation of SO42-, OC, and EC. In particular, the CORR values for NO3-, OC, and EC are above 0.96, and R2 values are above 0.93. NAQPMS-PDAF v2.0 also demonstrates superior spatiotemporal interpretation, with most DA sites showing improvements of over 50 %–200 % in CORR and over 50 %–90 % in RMSE for the five chemical components. Compared to the poor performance in global reanalysis dataset (CORR: 0.42–0.55, RMSE: 4.51–12.27 µg/m3) and NAQPMS-PDAF v1.0 (CORR: 0.35–0.98, RMSE: 2.46–15.50 µg/m3), NAQPMS-PDAF v2.0 has the highest CORR of 0.86–0.99 and the lowest RMSE of 0.14–3.18 µg/m3. The uncertainties in ensemble DA are also examined, further highlighting the potential of NAQPMS-PDAF v2.0 for advancing aerosol chemical component studies

    SigRec: Automatic Recovery of Function Signatures in Smart Contracts

    Get PDF
    Millions of smart contracts have been deployed onto Ethereum for providing various services, whose functions can be invoked. For this purpose, the caller needs to know the function signature of a callee, which includes its function id and parameter types. Such signatures are critical to many applications focusing on smart contracts, e.g., reverse engineering, fuzzing, attack detection, and profiling. Unfortunately, it is challenging to recover the function signatures from contract bytecode, since neither debug information nor type information is present in the bytecode. To address this issue, prior approaches rely on source code, or a collection of known signatures from incomplete databases or incomplete heuristic rules, which, however, are far from adequate and cannot cope with the rapid growth of new contracts. In this paper, we propose a novel solution that leverages how functions are handled by Ethereum virtual machine (EVM) to automatically recover function signatures. In particular, we exploit how smart contracts determine the functions to be invoked to locate and extract function ids, and propose a new approach named type-aware symbolic execution (TASE) that utilizes the semantics of EVM operations on parameters to identify the number and the types of parameters. Moreover, we develop SigRec , a new tool for recovering function signatures from contract bytecode without the need of source code and function signature databases. The extensive experimental results show that SigRec outperforms all existing tools, achieving an unprecedented 98.7 percent accuracy within 0.074 seconds. We further demonstrate that the recovered function signatures are useful in attack detection, fuzzing and reverse engineering of EVM bytecode

    Distinct roles of NMB and GRP in itch transmission

    Get PDF
    A key question in our understanding of itch coding mechanisms is whether itch is relayed by dedicated molecular and neuronal pathways. Previous studies suggested that gastrin-releasing peptide (GRP) is an itch-specific neurotransmitter. Neuromedin B (NMB) is a mammalian member of the bombesin family of peptides closely related to GRP, but its role in itch is unclear. Here, we show that itch deficits in mice lacking NMB or GRP are non-redundant and Nmb/Grp double KO (DKO) mice displayed additive deficits. Furthermore, both Nmb/Grp and Nmbr/Grpr DKO mice responded normally to a wide array of noxious stimuli. Ablation of NMBR neurons partially attenuated peripherally induced itch without compromising nociceptive processing. Importantly, electrophysiological studies suggested that GRPR neurons receive glutamatergic input from NMBR neurons. Thus, we propose that NMB and GRP may transmit discrete itch information and NMBR neurons are an integral part of neural circuits for itch in the spinal cord

    Prediction by a multiparametric magnetic resonance imaging-based radiomics signature model of disease-free survival in patients with rectal cancer treated by surgery

    Get PDF
    ObjectiveThe aim of this study was to assess the ability of a multiparametric magnetic resonance imaging (MRI)-based radiomics signature model to predict disease-free survival (DFS) in patients with rectal cancer treated by surgery.Materials and methodsWe evaluated data of 194 patients with rectal cancer who had undergone radical surgery between April 2016 and September 2021. The mean age of all patients was 62.6 ± 9.7 years (range: 37–86 years). The study endpoint was DFS and 1132 radiomic features were extracted from preoperative MRIs, including contrast-enhanced T1- and T2-weighted imaging and apparent diffusion coefficient values. The study patients were randomly allocated to training (n=97) and validation cohorts (n=97) in a ratio of 5:5. A multivariable Cox regression model was used to generate a radiomics signature (rad score). The associations of rad score with DFS were evaluated using Kaplan–Meier analysis. Three models, namely a radiomics nomogram, radiomics signature, and clinical model, were compared using the Akaike information criterion.ResultThe rad score, which was composed of four MRI features, stratified rectal cancer patients into low- and high-risk groups and was associated with DFS in both the training (p = 0.0026) and validation sets (p = 0.036). Moreover, a radiomics nomogram model that combined rad score and independent clinical risk factors performed better (Harrell concordance index [C-index] =0.77) than a purely radiomics signature (C-index=0.73) or clinical model (C-index=0.70).ConclusionAn MRI radiomics model that incorporates a radiomics signature and clinicopathological factors more accurately predicts DFS than does a clinical model in patients with rectal cancer

    New phenolic glycosides from Citrillus lanatus with radical scavenging properties

    Get PDF
    Three new compounds (1 – 3) were isolated from the whole plant of Citrullus lanatus (Cucurbitaceae). The structures of these compounds were characterized by MS, IR, 1D and 2D NMR. The DPPH radical scavenging property of these compounds as well as vitamin C which served as the positive control group was determined. The result showed that Compound 3 exhibited the highest scavenging activity with an EC50 value of 0.34 mM while Compounds 1 and 2 showed scavenging activity of 0.52 and 5.37 mM respectively. The EC50 value for vitamin C is 1.36 mM. The result therefore showed that Compounds 1 and 2 possess better scavenging property than vitamin C and thus may serve as potent antioxidant drugs in oxidative stress managemen

    Radical scavenging activity of novel phenolic glycosides from Citrullus lanatus

    Get PDF
    Three new compounds (1 – 3) were isolated from the whole plant of Citrullus lanatus (Cucurbitaceae). The structures of these compounds were characterized by MS, IR, 1D and 2D NMR. The DPPH radical scavenging property of these compounds as well as vitamin C which served as the positive control group was determined. The result showed that Compound 3 exhibited the highest scavenging activity with an EC50 value of 0.34 mM while Compounds 1 and 2 showed scavenging activity of 0.52 and 5.37 mM respectively. The EC50 value for vitamin C is 1.36 mM. The result therefore showed that Compounds 1 and 2 possess better scavenging property than vitamin C and thus may serve as potent antioxidant drugs in oxidative stress managemen

    Comparison of netupitant/palonosetron with 5-hydroxytryptamine-3 receptor antagonist in preventing of chemotherapy-induced nausea and vomiting in patients undergoing hematopoietic stem cell transplantation

    Get PDF
    BackgroundThe use of 5-hydroxytryptamine-3 receptor antagonists (5HT3RA) has long been considered the standard regimen for preventing chemotherapy-induced nausea and vomiting (CINV) prior to hematopoietic stem cell transplantation (HSCT). However, their therapeutic outcomes have been unsatisfactory. NEPA, an oral formulation combining the neurokinin-1 receptor antagonist netupitant and the 5HT3RA palonosetron, has received regulatory approval for the management of highly and moderately emetogenic chemotherapy. This study aims to compare the efficacy of NEPA with that of 5HT3RA alone in preventing CINV among patients undergoing multiday conditioning chemotherapy prior to HSCT.Patients and methodsWe conducted a retrospective analysis of patients who underwent HSCT between September 2019 and September 2022. Efficacy outcomes were assessed based on the rates of patients achieving complete response (CR: no emesis and no use of rescue medication), complete control (CC: CR without significant nausea), no vomiting, and no significant nausea.ResultsThe NEPA group consisted of 106 patients, while the 5HT3RA group included 107 patients. The NEPA group exhibited significantly higher rates of CR compared to the 5HT3RA group during the overall phase (71.7% vs. 32.7%, P<0.001), acute phase (78.3% vs. 43.0%, P<0.001), and delayed phase (84.9% vs. 58.9%, P<0.001). Similarly, rates of CC, no vomiting, and no significant nausea were significantly better in the NEPA group across all phases (P<0.001).ConclusionNEPA demonstrated superior efficacy compared to 5HT3RA in preventing CINV during all phases of multiday conditioning regimens among patients undergoing HSCT
    • …
    corecore