78 research outputs found

    Query with Assumptions for Probabilistic Relational Databases

    Get PDF
    Users may have prior knowledge about a probabilistic database. They prefer to query over a probabilistic database on their prior knowledge which cannot be written as component clauses of conventional SQL queries. A naive approach is to query over a new database version, which is generated by transforming the original probabilistic database to satisfy users\u27 prior knowledge; however, it is impractical to generate a different probabilistic database version for each prior knowledge. In this paper, we propose the concept of the query with assumptions which allow users to describe their prior knowledge with a newly introduced ASSUMPTION clause of SQL. We also propose an approach to obtain the result of a query based on assumption clauses. The experimental studies show our approach has better performance compared to the naive approach

    Fracture Propagation Behavior of Bedding Shale in the Process of Multistage Cluster Fracturing considering the Intercluster Stress Interference

    Get PDF
    AbstractStaged multicluster fracturing in horizontal wells is the key technology for forming complex fractures in shale reservoirs. The existence of shale bedding plays a conspicuous role for the propagation path of hydraulic fractures, affecting the propagation of the fracture height direction prominently. A 3D finite element model containing three clusters signed as side clusters and middle cluster was established based on the cohesive zone model and the dynamic distribution mechanism of interfracture flow. And the correctness of the model was verified by literature comparison. Some factors including cluster spacing, horizontal stress difference, shale bedding strength, perforation density, injection rate, and viscosity of fracturing fluid which influenced fracture propagation behavior of bedding shale were simulated. The results indicate that the stress interference of the middle cluster by the clusters on both sides will be prominently obvious when the cluster spacing is less than 10 m. Multiclusters will penetrate across the shale bedding when the horizontal stress difference is more than 4 MP, which will conspicuously reduce the activated probability of discontinuities and the complexity of fracture geometry. In correspondence with increase of horizontal stress difference, the interference between clusters also increases prominently, which will conspicuously decrease the propagation of the middle cluster. In order to comprehensively equalize the length of multiclusters, the inhibition of intercluster stress interference on the middle cluster propagation can be counteracted by improving pressure drop in perforation. The high injection rate and viscosity of fracturing fluid will contribute to the shale bedding shear slip increasingly, which is conducive to the formation of complex fractures in areas with well-developed bedding. The study has a certain guiding significance for the operation parameter design of multicluster fracturing in bedded shale

    The relationship between dominant follicle development and clinical outcomes of hormone replacement therapy-frozen embryo transfer: a retrospective clinical study

    Get PDF
    Research questionHormone replacement therapy (HRT) is one of the most used endometrial preparation protocols for frozen embryo transfer (FET) due to the convenience of its administration and stability of pregnancy outcomes. There are several HRT cycles accompanied by the development of dominant follicles. However, the relationship between dominant follicle development and clinical outcomes in HRT-FET cycles remains unclear.DesignWe carried out a retrospective cohort study of 13251 cycles at our reproductive medicine center from 2012 to 2019. Total cycles were divided into two groups according to whether there was dominant follicular development. In addition, we conducted a secondary analysis that used propensity-score matching to reduce confounding variables. A univariate and multivariable logistic regression model was further employed to analyze the effect of dominant follicle development in HRT cycles on clinical pregnancy outcomes.ResultsThere was no significant correlation between dominant follicle development in HRT-FET cycles and the clinical pregnancy rate (adjusted OR = 1.162, 95% CI: 0.737-1.832, P = 0.52). In addition, there was a positive correlation between the basic follicle-stimulating hormone (FSH) level and the development of dominant follicles, while there was a negative correlation between antral follicle count (AFC), menstrual cycle length and the development of dominant follicles in HRT cycles.ConclusionsThe development of dominant follicles in HRT-FET cycles does not affect the clinical pregnancy rate, early miscarriage rate and live birth rate. Therefore, it is not necessary to immediately cancel the FET cycle immediately when dominant follicle development is monitored in the HRT-FET cycle

    Investigations of Hydrocarbon Species on Solid Catalysts by Inelastic Neutron Scattering

    Get PDF
    From Springer Nature via Jisc Publications RouterHistory: accepted 2020-10-01, registration 2020-10-01, pub-electronic 2020-10-26, online 2020-10-26, pub-print 2021-08Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; doi: http://dx.doi.org/10.13039/501100000266; Grant(s): EP/P011632/1Funder: University of ManchesterAbstract: The status of surface species on solid catalysts during heterogeneous catalysis is often mysterious. Investigations of these surface species are crucial to deconvolute the reaction network and design more efficient catalysts. Vibrational spectroscopy is a powerful technique to study the interactions between surface species and the catalysts and infrared (IR) and Raman spectroscopies have been widely applied to study reaction mechanisms in heterogeneous catalysis. However, IR/Raman spectra are difficult to model computationally and important vibrational modes may be IR-, Raman- (or both) inactive due to restrictions by optical selection rules. Inelastic neutron scattering (INS) is another form of vibrational spectroscopy and relies on the scattering of neutrons by the atomic nucleus. A consequence of this is that INS is not subject to any optical selection rules and all vibrations are measurable in principle. INS spectroscopy has been used to investigate surface species on catalysts in a wide range of heterogeneous catalytic reactions. In this mini-review, we focus on applications of INS in two important fields: petrochemical reactions and C1 chemistry. We introduce the basic principles of the INS technique, followed by a discussion of its application in investigating two key catalytic systems: (i) the behaviour of hydrocarbons on metal-oxide and zeolite catalysts and (ii) the formation of hydrocarbonaceous species on methane reforming and Fischer–Tropsch catalysts. The power of INS in studying these important catalytic systems is demonstrated

    Non-invasive brain stimulation associated mirror therapy for upper-limb rehabilitation after stroke: Systematic review and meta-analysis of randomized clinical trials

    Get PDF
    BackgroundNon-invasive brain stimulation (NIBS) techniques and mirror therapy (MT) are promising rehabilitation measures for stroke. While the combination of MT and NIBS has been employed for post-stroke upper limb motor functional rehabilitation, its effectiveness has not been examined.ObjectiveThis study aimed to evaluate the effectiveness of combined MT and NIBS in the recovery of upper limb motor function in stroke patients.MethodsThe search was carried out in PubMed, EMBASE, Cochrane Library, Web of Science, Science Direct, CNKI, WANFANG and VIP until December 2021. Randomized clinical trials (RCTs) comparing MT or NIBS alone with the combination of NIBS and MT in improving upper extremity motor recovery after stroke were selected. A meta-analysis was performed to calculate the mean differences (MD) or the standard mean differences (SMD) and 95% confidence intervals (CI) with random-effect models. Subgroup analyses were also conducted according to the types of control group, the types of NIBS, stimulation timing and phase poststroke.ResultsA total of 12 articles, including 17 studies with 628 patients, were reviewed in the meta-analysis. In comparison with MT or NIBS alone, the combined group significantly improved body structure and function (MD = 5.97; 95% CI: 5.01–6.93; P < 0.05), activity levels (SMD = 0.82; 95% CI 0.61–1.02; P < 0.05). For cortical excitability, the motor evoked potential cortical latency (SMD = −1.05; 95% CI:−1.57–−0.52; P < 0.05) and the central motor conduction time (SMD=-1.31 95% CI:−2.02-−0.61; P < 0.05) of the combined group were significantly shortened. A non-significant homogeneous summary effect size was found for MEP amplitude (SMD = 0.47; 95%CI = −0.29 to 1.23; P = 0.23). Subgroup analysis showed that there is an interaction between the stimulation sequence and the combined treatment effect.ConclusionIn this meta-analysis of randomized clinical trials, in comparison to the control groups, MT combined with NIBS promoted the recovery of upper extremity motor function after stroke, which was reflected in the analysis of body structure and function, activity levels, and cortical excitability.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD42022304455

    Rescue of HLH with T and B Lymphocyte Involvement Due to Epstein-Barr Virus by PD-1 Inhibitor/Ruxolitinib and Rituximab Combination Regimens: A Case Report

    Get PDF
    Hemophagocytic lymphohistiocytosis (HLH) is a fatal clinical syndrome. The most common cause of secondary HLH is Epstein-Barr virus (EBV) infection. EBV-HLH is a common clinical disease with high mortality, easy relapse, and poor prognosis. Therefore, treating EBV-HLH with T and B lymphocyte involvement is challenging, and selecting an appropriate treatment regimen is critical. Moreover, research on how to evaluate the recurrence index after remission is scarce. In this study, we reported a case of EBV-HLH successfully treated with programmed cell death protein-1 (PD-1) inhibitor in combination with rituximab. The regimen had a good curative effect, and we successfully detected the trend of early recurrence. Our findings indicated that PD-1 inhibitor in combination with rituximab may help to treat EBV-HLH and maintain EBV-infected T and B whole-line lymphocytes

    Effects of Gualou Guizhi Decoction Aqueous Extract on Axonal Regeneration in Organotypic Cortical Slice Culture after Oxygen-Glucose Deprivation

    Get PDF
    Gualou Guizhi decoction (GLGZD) is effective for the clinical treatment of limb spasms caused by ischemic stroke, but its underlying mechanism is unclear. Propidium iodide (PI) fluorescence staining, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), immunohistochemistry, western blot, and real-time qPCR were used to observe the axonal regeneration and neuroprotective effects of GLGZD aqueous extract on organotypic cortical slices exposed to oxygen-glucose deprivation (OGD) and further elucidate the potential mechanisms. Compared with the OGD group, the GLGZD aqueous extract decreased the red PI fluorescence intensity; inhibited neuronal apoptosis; improved the growth of slice axons; upregulated the protein expression of tau and growth-associated protein-43; and decreased protein and mRNA expression of neurite outgrowth inhibitor protein-A (Nogo-A), Nogo receptor 1 (NgR1), ras homolog gene family A (RhoA), rho-associated coiled-coil-containing protein kinase (ROCK), and phosphorylation of collapsin response mediator protein 2 (CRMP2). Our study found that GLGZD had a strong neuroprotective effect on brain slices after OGD injury. GLGZD plays a vital role in promoting axonal remodeling and functional remodeling, which may be related to regulation of the expression of Nogo-A and its receptor NgR1, near the injured axons, inhibition of the Rho-ROCK pathway, and reduction of CRMP2 phosphorylation
    corecore