27 research outputs found

    A Multi-Agent Evolutionary algorIthm for Connector-Based Assembly Sequence Planning

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    AbstractSome Evolutionary algorithms for connector-based ASP have been researched. But those algorithms have lots of blind searching because individuals have little intelligence in making use of geometry and assembly process information of product assembly body. To improve individuals’ intelligence, A multi-agent evolutionary algorithm for connector-based ASP (MAEA-ASP) is presented which is integrated with the multi-agent systems. learning, competition and crossover -mutation are designed as the behaviors of agent which locate lattice-like structure environment. Experimental results show that MAEA-ASP can find an approximate solution faster compared with other evolutionary algorithms

    Implications of whole-disc DSCOVR EPIC spectral observations for estimating Earth's spectral reflectivity based on low-earth-orbiting and geostationary observations

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    Earth’s reflectivity is among the key parameters of climate research. National Aeronautics and Space Administration (NASA)’s Earth Polychromatic Imaging Camera (EPIC) onboard National Oceanic and Atmospheric Administration (NOAA)’s Deep Space Climate Observatory (DSCOVR) spacecraft provides spectral reflectance of the entire sunlit Earth in the near backscattering direction every 65 to 110 min. Unlike EPIC, sensors onboard the Earth Orbiting Satellites (EOS) sample reflectance over swaths at a specific local solar time (LST) or over a fixed area. Such intrinsic sampling limits result in an apparent Earth’s reflectivity. We generated spectral reflectance over sampling areas using EPIC data. The difference between the EPIC and EOS estimates is an uncertainty in Earth’s reflectivity. We developed an Earth Reflector Type Index (ERTI) to discriminate between major Earth atmosphere components: clouds, cloud-free ocean, bare and vegetated land. Temporal variations in Earth’s reflectivity are mostly determined by clouds. The sampling area of EOS sensors may not be sufficient to represent cloud variability, resulting in biased estimates. Taking EPIC reflectivity as a reference, low-earth-orbiting-measurements at the sensor-specific LST tend to overestimate EPIC values by 0.8% to 8%. Biases in geostationary orbiting approximations due to a limited sampling area are between −0.7% and 12%. Analyses of ERTI-based Earth component reflectivity indicate that the disagreement between EPIC and EOS estimates depends on the sampling area, observation time and vary between −10% and 23%.The NASA/GSFC DSCOVR project is funded by NASA Earth Science Division. W. Song, G. Yan, and X. Mu were also supported by the key program of National Natural Science Foundation of China (NSFC; Grant No. 41331171). This research was conducted and completed during a 13-month research stay of the lead author in the Department of Earth and Environment, Boston University as a joint Ph.D. student, which was supported by the Chinese Scholarship Council (201606040098). DSCOVR EPIC L1B data were obtained from the NASA Langley Research Center Atmospheric Science Data Center. The authors would like to thank the editor who handled this paper and the two anonymous reviewers for providing helpful and constructive comments and suggestions that significantly helped us improve the quality of this paper. (NASA Earth Science Division; 41331171 - key program of National Natural Science Foundation of China (NSFC); 201606040098 - Chinese Scholarship Council)Accepted manuscrip

    Knockdown of ATF3 suppresses the progression of ischemic stroke through inhibiting ferroptosis

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    ObjectiveCurrent therapies towards ischemic stroke (IS) are still not satisfied, and alternative strategies targeting ferroptosis may be another choice. The purpose of this study is to screen potential ferroptosis-related genes involving in IS.MethodsA rat model of IS was established via middle cerebral artery occlusion. Differentially expressed genes (DEGs) were screened from the model rats through transcriptional sequencing. Among the isolated DEGs, the expression of several attractive DEGs relating with ischemic injury was confirmed by qRT-PCR. Then, ATF3 relating with both IS and ferroptosis was selected a candidate gene for functional assays. After knockdown of ATF3 in the model rats, the infarction, histopathology, apoptosis, and ferroptosis in brain tissues were evaluated.ResultsIS model was successfully established in rats, exhibiting the emergence of infarction area, histopathological injury, and enhanced cell apoptosis. Total 699 up-regulated DEGs and 461 down-regulated DEGs were screened from the model rats. qRT-PCR verified the up-regulation of Hspa1b, Tfpi2, Ptx3, and Atf3, and the down-regulation of Smyd1 and Tacr2 in the Model group compared with those in the Sham group. It is noteworthy that knockdown of ATF3 decreased the infarction area, relieved histopathological injury, weakened apoptosis, and inhibited ferroptosis in the model rats.ConclusionSeveral candidate genes in relation with IS were revealed. More importantly, knockdown of ATF3 may relieve IS through inhibiting ferroptosis

    Predictors of futile recanalization in basilar artery occlusion patients undergoing endovascular treatment: a post hoc analysis of the ATTENTION trial

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    BackgroundFew studies have focused on factors associated with futile recanalization in patients with an acute basilar artery occlusion (BAO) that was treated with modern endovascular therapy (EVT). The aim of this study was to explore the factors associated with futile recanalization in patients with an acute BAO presented within 12 h.MethodsThis is a post-hoc analysis of the ATTENTION trial (The Trial of Endovascular Treatment of Acute Basilar-Artery Occlusion, ClinicalTrials.gov, number NCT 04751708). Demographics, clinical characteristics, acute stroke workflow interval times, and imaging characteristics were compared between the futile recanalization and favorable recanalization groups. The favorable outcome was defined as a modified Rankin scale (mRS) score of 0–3 at 90 days, successful reperfusion was defined as thrombolysis in cerebral infarction (TICI) 2b and 3 on the final angiogram, and futile recanalization was defined as failure to achieve a favorable outcome despite successful reperfusion. A multivariate analysis was performed to identify the predictors of futile recanalization.ResultsIn total, 185 patients were included in the final analysis: 89 (48.1%) patients had futile recanalization and 96 (51.9%) patients had favorable recanalization. In the multivariable logistic regression analysis, older age (OR 1.04, 95% CI 1.01 to 1.08, p = 0.01) and diabetes mellitus (OR 3.35, 95% CI 1.40 to 8.01, p = 0.007) were independent predictors of futile recanalization.ConclusionFutile recanalization occurred in nearly half of patients with acute BAO following endovascular treatment. Old age and diabetes mellitus were identified as independent predictors of futile recanalization after endovascular therapy for acute BAO

    Methylprednisolone as Adjunct to Endovascular Thrombectomy for Large-Vessel Occlusion Stroke

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    Importance It is uncertain whether intravenous methylprednisolone improves outcomes for patients with acute ischemic stroke due to large-vessel occlusion (LVO) undergoing endovascular thrombectomy. Objective To assess the efficacy and adverse events of adjunctive intravenous low-dose methylprednisolone to endovascular thrombectomy for acute ischemic stroke secondary to LVO. Design, Setting, and Participants This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 82 hospitals in China, enrolling 1680 patients with stroke and proximal intracranial LVO presenting within 24 hours of time last known to be well. Recruitment took place between February 9, 2022, and June 30, 2023, with a final follow-up on September 30, 2023.InterventionsEligible patients were randomly assigned to intravenous methylprednisolone (n = 839) at 2 mg/kg/d or placebo (n = 841) for 3 days adjunctive to endovascular thrombectomy. Main Outcomes and Measures The primary efficacy outcome was disability level at 90 days as measured by the overall distribution of the modified Rankin Scale scores (range, 0 [no symptoms] to 6 [death]). The primary safety outcomes included mortality at 90 days and the incidence of symptomatic intracranial hemorrhage within 48 hours. Results Among 1680 patients randomized (median age, 69 years; 727 female [43.3%]), 1673 (99.6%) completed the trial. The median 90-day modified Rankin Scale score was 3 (IQR, 1-5) in the methylprednisolone group vs 3 (IQR, 1-6) in the placebo group (adjusted generalized odds ratio for a lower level of disability, 1.10 [95% CI, 0.96-1.25]; P = .17). In the methylprednisolone group, there was a lower mortality rate (23.2% vs 28.5%; adjusted risk ratio, 0.84 [95% CI, 0.71-0.98]; P = .03) and a lower rate of symptomatic intracranial hemorrhage (8.6% vs 11.7%; adjusted risk ratio, 0.74 [95% CI, 0.55-0.99]; P = .04) compared with placebo. Conclusions and Relevance Among patients with acute ischemic stroke due to LVO undergoing endovascular thrombectomy, adjunctive methylprednisolone added to endovascular thrombectomy did not significantly improve the degree of overall disability.Trial RegistrationChiCTR.org.cn Identifier: ChiCTR210005172

    Logging identification and prediction of lithofacies of lacustrine shale system in Shichang Sub-Sag, Nanpu Depression

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    The study of the lithofacies of shale formation is the basic work for shale oil exploration.Due to the limited distribution of the continental lacustrine basin and the fast variations of lithofacies, it is difficult to accurately identify and predict the lithofacies.With high precision and good continuity in vertical direction, the logging curve can be used to accurately identify and predict the lithofacies.Based on the experimental data of whole-rock X-ray diffraction(XRD), thin-section identification and geochemical analysis data, the lithofacies can be divided according to the division scheme named three classes & ternary plots.Fitting logging data with TOC value and mineral content, the lithofacies can be comprehensively identified.Finally, the cycle superposition model of lithofacies is established under the high-resolution sequence frame to study the distribution of lithofacies.The results show that the area is a set of oil-bearing lacustrine source rocks with â…  and â…¡1 kerogen, which can be divided into 18 types of lithofacies, among which organic-rich argillaceous lamellar shale and organic-rich mixed lamellar shale are the dominant lithofacies.The evaluation indexes of the lithofacies can be calculated and predicted through the logging curve.There is a coupling relationship between the lithofacies and the sequence so that the lithofacies are predictable under the isochronous stratigraphic framework.The lithofacies of shale formation of the Es34 sub-member are under this framework, forming two organic-rich layers located in the middle of MSC1 and MSC2 middle cycles and four sedimentary tectonic development zones corresponding to the SQ5-SQ8 ascending semi-cycling

    Hydrogel of HEMA, NVP, and Morpholine-Derivative Copolymer for Sulfate Ion Adsorption: Behaviors and Mechanisms

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    SO42−-containing compounds are widely present in wastewater generated from various industries and mining industries, such as slag leachate, pulp and paper wastewater, modified starch wastewater, etc. When the concentration of SO42− is too high, it will not only be corrosive to metal equipment but also accumulate in the environmental media. Based on this, a novel cationic hydrogel HNM was synthesized in this study by introducing morpholine groups into the conventional hydrogel HEMA–NVP system for the adsorption of SO42− in aqueous solutions. Characterizations by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that morpholine groups had been introduced into the as-synthesizedhydrogels. The scanning electron microscope (SEM) characterization results show that the introduction of morpholine groups changed the surface of the hydrogel from micron-scale wrinkles to nanoscale gaps, increasing the contact area with the solution. The results of static water contact angle (WCA), equilibrium water content (EWC), and SO42− adsorption capacity show that the introduction of morpholine groups not only further improved the equilibrium water content and hydrophilicity of the hydrogel but also greatly improved the SO42− adsorption capacity of the hydrogel, with the maximum SO42− adsorption amount of 21.59 mg/g, which was much higher than that of the hydrogel without morpholine groups of 5.15 mg/g. Further studies found that the adsorption of SO42− on the hydrogel HNM was pH-dependent, and acidic conditions were favorable for the adsorption. Therefore, the introduction of morpholine groups greatly enhanced the ability of conventional HEMA–NVP hydrogels to remove SO42− from aqueous solutions

    Hydrogel of HEMA, NVP, and Morpholine-Derivative Copolymer for Sulfate Ion Adsorption: Behaviors and Mechanisms

    No full text
    SO42−-containing compounds are widely present in wastewater generated from various industries and mining industries, such as slag leachate, pulp and paper wastewater, modified starch wastewater, etc. When the concentration of SO42− is too high, it will not only be corrosive to metal equipment but also accumulate in the environmental media. Based on this, a novel cationic hydrogel HNM was synthesized in this study by introducing morpholine groups into the conventional hydrogel HEMA–NVP system for the adsorption of SO42− in aqueous solutions. Characterizations by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that morpholine groups had been introduced into the as-synthesizedhydrogels. The scanning electron microscope (SEM) characterization results show that the introduction of morpholine groups changed the surface of the hydrogel from micron-scale wrinkles to nanoscale gaps, increasing the contact area with the solution. The results of static water contact angle (WCA), equilibrium water content (EWC), and SO42− adsorption capacity show that the introduction of morpholine groups not only further improved the equilibrium water content and hydrophilicity of the hydrogel but also greatly improved the SO42− adsorption capacity of the hydrogel, with the maximum SO42− adsorption amount of 21.59 mg/g, which was much higher than that of the hydrogel without morpholine groups of 5.15 mg/g. Further studies found that the adsorption of SO42− on the hydrogel HNM was pH-dependent, and acidic conditions were favorable for the adsorption. Therefore, the introduction of morpholine groups greatly enhanced the ability of conventional HEMA–NVP hydrogels to remove SO42− from aqueous solutions

    Paeoniflorin Inhibits Hepatocyte Growth Factor- (HGF-) Induced Migration and Invasion and Actin Rearrangement via Suppression of c-Met-Mediated RhoA/ROCK Signaling in Glioblastoma

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    Paeoniflorin (PF), as one of the important valid natural compounds of the total glucosides of peony, has displayed a potential effect in cancer prevention and treatment. Aggressive migration and invasion, as an important process, can contribute to tumor progression through infiltrating the surround normal tissue. Actin cytoskeleton rearrangement plays a key role in cells migration and invasion, involving multiple signal pathways. HGF/c-Met signal, as an important couple of oncoprotein, has been demonstrated to regulate actin cytoskeleton rearrangement. In our study, we aim to explore whether paeoniflorin can inhibit migration and invasion and actin cytoskeleton rearrangement via regulation of HGF/c-Met/RhoA/ROCK signal. Various approaches were applied to demonstrate the mechanism of paeoniflorin-mediated anticancer effect, including cell wound healing assay, invasion assay, immunofluorescence staining and transfection, and western blotting. We observed that paeoniflorin inhibited HGF-induced migration and invasion and actin cytoskeleton rearrangement in glioblastoma cells. Furthermore, the inhibition of HGF-induced migration and invasion and actin cytoskeleton rearrangement involved c-Met-mediated RhoA/ROCK signaling in glioblastoma. Thus, our study proved that paeoniflorin could inhibit migration and invasion and actin cytoskeleton rearrangement through inhibition of HGF/c-Met/RhoA/ROCK signaling in glioblastoma, suggesting that paeoniflorin might be a candidate compound to treat glioblastoma
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