12 research outputs found

    A High Performance XML Querying Architecture

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    Data exchange on the Internet plays an essential role in electronic business (e-business). A recent trend in e-business is to create distributed databases to facilitate data exchange. In most cases, the distributed databases are developed by integrating existing systems, which may be in different database models, and on different hardware and/or software platforms. Heterogeneity may cause many difficulties. A solution to the difficulties is XML (the Extensible Markup Language). XML is becoming the dominant language for exchanging data on the Internet. To develop XML systems for practical applications, developers have to addresses the performance issues. In this paper, we describe a new XML querying architecture that can be used to build high performance systems. Experiments indicate that the architecture performs better than Oracle XML DB, which is one of the most commonly used commercial DBMSs for XML

    Fast On-orbit Pulse Phase Estimation of X-ray Crab Pulsar for XNAV Flight Experiments

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    The recent flight experiments with Neutron Star Interior Composition Explorer (\textit{NICER}) and \textit{Insight}-Hard X-ray Modulation Telescope (\textit{Insight}-HXMT) have demonstrated the feasibility of X-ray pulsar-based navigation (XNAV) in the space. However, the current pulse phase estimation and navigation methods employed in the above flight experiments are computationally too expensive for handling the Crab pulsar data. To solve this problem, this paper proposes a fast algorithm of on-orbit estimating the pulse phase of Crab pulsar called X-ray pulsar navigaTion usIng on-orbiT pulsAr timiNg (XTITAN). The pulse phase propagation model for Crab pulsar data from \textit{Insight}-HXMT and \textit{NICER} are derived. When an exposure on the Crab pulsar is divided into several sub-exposures, we derive an on-orbit timing method to estimate the hyperparameters of the pulse phase propagation model. Moreover, XTITAN is improved by iteratively estimating the pulse phase and the position and velocity of satellite. When applied to the Crab pulsar data from \textit{NICER}, XTITAN is 58 times faster than the grid search method employed by \textit{NICER} experiment. When applied to the Crab pulsar data from \textit{Insight}-HXMT, XTITAN is 180 times faster than the Significance Enhancement of Pulse-profile with Orbit-dynamics (SEPO) which was employed in the flight experiments with \textit{Insight}-HXMT. Thus, XTITAN is computationally much efficient and has the potential to be employed for onboard computation

    Resveratrol Relieved Acute Liver Damage in Ducks (Anas platyrhynchos) Induced by AFB1 via Modulation of Apoptosis and Nrf2 Signaling Pathways

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    The presence of aflatoxin B1 (AFB1) in feed is a serious threat to livestock and poultry health and to human food safety. Resveratrol (Res) is a polyphenolic compound with antioxidant, anti-apoptotic and other biological activities; however, it is not clear whether it can improve AFB1 induced hepatotoxicity. Therefore, this study was conducted to investigate the effects of dietary Res on liver injury induced by AFB1 and its mechanisms. A total of 270 one-day-old male specific pathogen free (SPF) ducks, with no significant difference in weight, were randomly assigned to three groups: the control group, the AFB1 group and the AFB1 + Res group, which were fed a basic diet, a basic diet and a basic diet containing 500 mg/kg Res, respectively. On the 70th day, the ducks in theAFB1 group and the AFB1+ 500 mg/kg Res group were given 60 μg/kg AFB1 via gavage. When comparing the AFB1 group and the AFB1 + Res group and also with the control group, AFB1 significantly increased liver damage, cytochrome P450 (CYP450) and AFB1-DNA adduct content, increased oxidative stress levels and induced liver apoptosis, which was improved by Res supplementation. In sum, the addition of Res to feed can increase the activity of the II-phase enzyme, activate the nuclear factor E2-related factor 2 (Nrf2) signal pathway, and protect ducks’ livers from the toxicity, oxidative stress and inflammatory reaction induced by AFB1

    Alleviation of Oral Exposure to Aflatoxin B1-Induced Renal Dysfunction, Oxidative Stress, and Cell Apoptosis in Mice Kidney by Curcumin

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    Aflatoxin B1 is a contaminant widely found in food and livestock feed, posing a major threat to human and animal health. Recently, much attention from the pharmaceutical and food industries has been focused on curcumin due to its strong antioxidant capacity. However, the therapeutic impacts and potential mechanisms of curcumin on kidney damage caused by AFB1 are still incomplete. In this study, AFB1 triggered renal injury in mice, as reflected by pathological changes and renal dysfunction. AFB1 induced renal oxidative stress and interfered with the Keap1–Nrf2 pathway and its downstream genes (CAT, SOD1, NQO1, GSS, GCLC, and GCLM), as manifested by elevated oxidative stress metabolites and reduced antioxidant enzymes activities. Additionally, AFB1 was found to increase apoptotic cells percentage in the kidney via the TUNEL assay, along with increased expression of Cyt-c, Bax, cleaved-Caspase-3, Caspase-9, and decreased expression of Bcl-2 at the transcriptional and protein levels; in contrast, for mice given curcumin, there was a significant reversal in kidney coefficient, biochemical parameters, pathological changes, and the expression of genes and proteins involved in oxidative stress and apoptosis. These results indicate that curcumin could antagonize oxidative stress and apoptosis to attenuate AFB1-induced kidney damage

    A novel biodegradable polymer-coated sirolimus-eluting stent: 1-year results of the HELIOS registry

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    Abstract. Background:. The HELIOS stent is a sirolimus-eluting stent with a biodegradable polymer and titanium oxide film as the tie-layer. The study aimed to evaluate the safety and efficacy of HELIOS stent in a real-world setting. Methods:. The HELIOS registry is a prospective, multicenter, cohort study conducted at 38 centers across China between November 2018 and December 2019. A total of 3060 consecutive patients were enrolled after application of minimal inclusion and exclusion criteria. The primary endpoint was target lesion failure (TLF), defined as a composite of cardiac death, non-fatal target vessel myocardial infarction (MI), and clinically indicated target lesion revascularization (TLR) at 1-year follow-up. Kaplanā€“Meier methods were used to estimate the cumulative incidence of clinical events and construct survival curves. Results:. A total of 2998 (98.0%) patients completed the 1-year follow-up. The 1-year incidence of TLF was 3.10% (94/2998, 95% closed interval: 2.54ā€“3.78%). The rates of cardiac death, non-fatal target vessel MI and clinically indicated TLR were 2.33% (70/2998), 0.20% (6/2998), and 0.70% (21/2998), respectively. The rate of stent thrombosis was 0.33% (10/2998). Age ā‰„60 years, diabetes mellitus, family history of coronary artery disease, acute myocardial infarction at admission, and device success were independent predictors of TLF at 1 year. Conclusion:. The 1-year incidence rates of TLF and stent thrombosis were 3.10% and 0.33%, respectively, in patients treated with HELIOS stents. Our results provide clinical evidence for interventional cardiologists and policymakers to evaluate HELIOS stent. Clinical trial registration:. ClinicalTrials.gov, NCT0391643
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