7,909 research outputs found
2,4-Dichloro-7-fluoroquinazoline
The molecule of the title compound, C8H3Cl2FN2, is essentially planar, with a maximum deviation of 0.018 (2) Å. In the crystal, π–π stacking is observed between parallel quinazoline moieties of adjacent molecules, the centroid–centroid distance being 3.8476 (14) Å
ProtoEM: A Prototype-Enhanced Matching Framework for Event Relation Extraction
Event Relation Extraction (ERE) aims to extract multiple kinds of relations
among events in texts. However, existing methods singly categorize event
relations as different classes, which are inadequately capturing the intrinsic
semantics of these relations. To comprehensively understand their intrinsic
semantics, in this paper, we obtain prototype representations for each type of
event relation and propose a Prototype-Enhanced Matching (ProtoEM) framework
for the joint extraction of multiple kinds of event relations. Specifically,
ProtoEM extracts event relations in a two-step manner, i.e., prototype
representing and prototype matching. In the first step, to capture the
connotations of different event relations, ProtoEM utilizes examples to
represent the prototypes corresponding to these relations. Subsequently, to
capture the interdependence among event relations, it constructs a dependency
graph for the prototypes corresponding to these relations and utilized a Graph
Neural Network (GNN)-based module for modeling. In the second step, it obtains
the representations of new event pairs and calculates their similarity with
those prototypes obtained in the first step to evaluate which types of event
relations they belong to. Experimental results on the MAVEN-ERE dataset
demonstrate that the proposed ProtoEM framework can effectively represent the
prototypes of event relations and further obtain a significant improvement over
baseline models.Comment: Work in progres
Diagnostic value of two dimensional shear wave elastography combined with texture analysis in early liver fibrosis.
BACKGROUND: Staging diagnosis of liver fibrosis is a prerequisite for timely diagnosis and therapy in patients with chronic hepatitis B. In recent years, ultrasound elastography has become an important method for clinical noninvasive assessment of liver fibrosis stage, but its diagnostic value for early liver fibrosis still needs to be further improved. In this study, the texture analysis was carried out on the basis of two dimensional shear wave elastography (2D-SWE), and the feasibility of 2D-SWE plus texture analysis in the diagnosis of early liver fibrosis was discussed.
AIM: To assess the diagnostic value of 2D-SWE combined with textural analysis in liver fibrosis staging.
METHODS: This study recruited 46 patients with chronic hepatitis B. Patients underwent 2D-SWE and texture analysis; Young\u27s modulus values and textural patterns were obtained, respectively. Textural pattern was analyzed with regard to contrast, correlation, angular second moment (ASM), and homogeneity. Pathological results of biopsy specimens were the gold standard; comparison and assessment of the diagnosis efficiency were conducted for 2D-SWE, texture analysis and their combination.
RESULTS: 2D-SWE displayed diagnosis efficiency in early fibrosis, significant fibrosis, severe fibrosis, and early cirrhosis (AUC \u3e 0.7, P \u3c 0.05) with respective AUC values of 0.823 (0.678-0.921), 0.808 (0.662-0.911), 0.920 (0.798-0.980), and 0.855 (0.716-0.943). Contrast and homogeneity displayed independent diagnosis efficiency in liver fibrosis stage (AUC \u3e 0.7, P \u3c 0.05), whereas correlation and ASM showed limited values. AUC of contrast and homogeneity were respectively 0.906 (0.779-0.973), 0.835 (0.693-0.930), 0.807 (0.660-0.910) and 0.925 (0.805-0.983), 0.789 (0.639-0.897), 0.736 (0.582-0.858), 0.705 (0.549-0.883) and 0.798 (0.650-0.904) in four liver fibrosis stages, which exhibited equivalence to 2D-SWE in diagnostic efficiency (P \u3e 0.05). Combined diagnosis (PRE) displayed diagnostic efficiency (AUC \u3e 0.7, P \u3c 0.01) for all fibrosis stages with respective AUC of 0.952 (0.841-0.994), 0.896 (0.766-0.967), 0.978 (0.881-0.999), 0.947 (0.835-0.992). The combined diagnosis showed higher diagnosis efficiency over 2D-SWE in early liver fibrosis (P \u3c 0.05), whereas no significant differences were observed in other comparisons (P \u3e 0.05).
CONCLUSION: Texture analysis was capable of diagnosing liver fibrosis stage, combined diagnosis had obvious advantages in early liver fibrosis, liver fibrosis stage might be related to the hepatic tissue hardness distribution
Cross-Layer Software-Defined 5G Network
In the past few decades, the world has witnessed a rapid growth in mobile
communication and reaped great benefits from it. Even though the fourth
generation (4G) mobile communication system is just being deployed worldwide,
proliferating mobile demands call for newer wireless communication technologies
with even better performance. Consequently, the fifth generation (5G) system is
already emerging in the research field. However, simply evolving the current
mobile networks can hardly meet such great expectations, because over the years
the infrastructures have generally become ossified, closed, and vertically
constructed. Aiming to establish a new paradigm for 5G mobile networks, in this
article, we propose a cross-layer software-defined 5G network architecture. By
jointly considering both the network layer and the physical layer together, we
establish the two software-defined programmable components, the control plane
and the cloud computing pool, which enable an effective control of the mobile
network from the global perspective and benefit technological innovations.
Specifically, by the cross-layer design for software-defining, the logically
centralized and programmable control plane abstracts the control functions from
the network layer down to the physical layer, through which we achieve the
fine-grained controlling of mobile network, while the cloud computing pool
provides powerful computing capability to implement the baseband data
processing of multiple heterogeneous networks. We discuss the main challenges
of our architecture, including the fine-grained control strategies, network
virtualization, and programmability. The architecture significantly benefits
the convergence towards heterogeneous networks and it enables much more
controllable, programmable and evolvable mobile networks.Comment: 9 pages, 5 figures, submitted to Mobile Networks & Application
A “Double-Multi” Model for Electromigration of Lithiums and Chlorides in ASR Affected Concrete
Existing reinforced concrete structures experience severe durability degradation when subjected to alkali– silica reaction (ASR) and chloride attack. A special electrochemical rehabilitation treatment, containing lithium compound anolyte, has been developed to drive lithium ions into concrete as well as remove chlorides simultaneously, for mitigating both the ASR-induced cracks and the chloride-induced corrosion. Good performance of introduced lithiums in controlling ASR-induced expansion has already been proved. Unfortunately, the migration mechanism of lithium in concrete under an external electric field is seldom investigated in existing literature. In this study, with help of the “double-multi” model, the efficiency of impregnation of lithium ions and simultaneously the removal of chloride ions through a specific electrochemical treatment are numerically evaluated, which results into the distribution profiles of all typical ionic species. The heterogeneous concrete model examines the aggregate effect, especially on the interaction with lithiums which are supposed to mitigate ASR. The ionic interaction between different species and the electrochemical reaction at electrodes are also considered. Through a relative thorough modelling of multi-phase and multi-species, a systemic parametric analysis based on a series of significant factors during electrochemical treatment (e.g., current density, treatment time, temperature, cathode position and concentration of lithium solution) reveals some important tendencies of ionic electromigration in concrete, which are supposed to guide the field application
Fast Generation of High-Fidelity Mechanical Non-Gaussian States via Additional Amplifier and Photon Subtraction
Non-Gaussian states (NGSs) with higher-order correlation properties have
wide-range applications in quantum information processing. However, the
preparation of such states with high quality still faces practical challenges.
Here, we propose a protocol to rapidly generate two types of mechanical NGSs,
Schr\"{o}dinger cat states and Fock states, in dissipative optomechanical
systems, even when the cooperativity is smaller than one
(). In contrast to the usual scheme of directly applying
non-Gaussian operations on the entangled optical mode, we show that an
additional phase-sensitive amplifier can accelerate the generation and also
precisely control the type of NGSs. Then, a principally deterministic
multi-photon subtraction induced by the Rydberg-blockade effect is adopted to
produce large-sized NGSs. The protocol can be implemented with state-of-the-art
experimental systems with close to unit fidelity. Moreover, it can also be
extended to generate a four-component cat state and provide new possibilities
for future quantum applications of NGSs.Comment: 7 pages, 4 figure
Association between prospective registration and overall reporting and methodological quality of systematic reviews: a meta-epidemiological study
Objective: To investigate the differences in main characteristics, reporting and methodological quality between prospectively registered and non-registered systematic reviews. Methods: PubMed was searched to identify systematic reviews of randomized controlled trials published in 2015 in English. After title and abstract screening, potentially relevant reviews were divided into three groups: registered non-Cochrane reviews, Cochrane reviews, and non-registered reviews. For each group, random number tables were generated in Microsoft Excel, and the first 50 eligible studies from each group were randomly selected. Data of interest from systematic reviews were extracted. Regression analyses were conducted to explore the association between total R-AMSTAR or PRISMA scores and the selected characteristics of systematic reviews. Results: The conducting and reporting of literature search in registered reviews were superior to non-registered reviews. Differences in nine of the 11 R-AMSTAR items were statistically significant between registered and non-registered reviews. The total R-AMSTAR score of registered reviews was higher than non-registered reviews (MD=4.82, 95%CI: 3.70, 5.94). Sensitivity analysis by excluding the registration related item presented similar result (MD=4.34, 95%CI: 3.28, 5.40). Total PRISMA scores of registered reviews were significantly higher than non-registered reviews (all reviews: MD=1.47, 95%CI: 0.64-2.30; non-Cochrane reviews: MD=1.49, 95%CI: 0.56-2.42). However, the difference in the total PRISMA score was no longer statistically significant after excluding the item related to registration (item 5). Regression analyses showed similar results. Conclusions: Prospective registration may at least indirectly improve the overall methodological quality of systematic reviews, although its impact on the overall reporting quality was not significant
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