7 research outputs found

    One-domain-one-input: adaptive random testing by orthogonal recursive bisection with restriction

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    One goal of software testing may be the identification or generation of a series of test cases that can detect a fault with as few test executions as possible. Motivated by insights from research into failure-causing regions of input domains, the even-spreading (even distribution) of tests across the input domain has been identified as a useful heuristic to more quickly find failures. This finding has encouraged a shift in focus from traditional random testing (RT) to its enhancement, adaptive random testing (ART), which retains the randomness of test input selection, but also attempts to maintain a more evenly distributed spread of test inputs across the input domain. Given that there are different ways to achieve the even distribution, several different ART methods and approaches have been proposed. This paper presents a new ART method, called ART-ORB, which explores the advantages of repeated geometric bisection of the input domain, combined with restriction regions, to evenly spread test inputs. Experimental results show a better performance in terms of fewer test executions than RT to find failures. Compared with other ART methods, ART-ORB has comparable performance (in terms of required test executions), but incurs lower test input selection overheads, especially in higher dimensional input space. It is recommended that ART-ORB be used in testing situations involving expensive test input execution

    A Fast Alternating Minimization Algorithm for Nonlocal Vectorial Total Variational Multichannel Image Denoising

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    The variational models with nonlocal regularization offer superior image restoration quality over traditional method. But the processing speed remains a bottleneck due to the calculation quantity brought by the recent iterative algorithms. In this paper, a fast algorithm is proposed to restore the multichannel image in the presence of additive Gaussian noise by minimizing an energy function consisting of an l2-norm fidelity term and a nonlocal vectorial total variational regularization term. This algorithm is based on the variable splitting and penalty techniques in optimization. Following our previous work on the proof of the existence and the uniqueness of the solution of the model, we establish and prove the convergence properties of this algorithm, which are the finite convergence for some variables and the q-linear convergence for the rest. Experiments show that this model has a fabulous texture-preserving property in restoring color images. Both the theoretical derivation of the computation complexity analysis and the experimental results show that the proposed algorithm performs favorably in comparison to the widely used fixed point algorithm

    A facile strategy to form three-dimensional network structure for mechanically robust superhydrophobic nanocoatings with enhanced transmittance

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    The mechanically robust nanocoatings with high transmittance and superhydrophobic self-cleaning are widely desired in daily-life and industry. However, to the state-of-art, it is still a great challenge to develop a simple and cost-effective approach to construct a multifunctional nanocoating due to structural confliction and technical limitation. In this work, we successfully fabricated such a multifunctional nanocoating through dip-coating a mixed suspension composed of acid-catalyzed silica sol (ACSS) as binder and hydrophobic silica nanoparticles (HSNs) as building block onto the glass substrate without any post-treatments. The introduction of ACSS highly crosslinked the HSNs and formed three-dimensional network structure, which enhanced the adhesion between HSNs and substrate, and thus significantly improved mechanical robustness of the nanocoatings. Moreover, it also retained enough porosity and surface roughness, thus achieving high transmittance and superhydrophobicity. The optimized nanocoating deposited on the glass slide had high transmittance of 96.17% and superhydrophobic self-cleaning property. It also showed highly mechanical robustness (3H pencil scratching test), enhanced adhesion (class of 4B for tape adhesion test), weatherable, and acidic (pH 5.0)/alkaline (pH 10.0) and thermal (250 degrees C) stability. The multifunctional nanocoating with the comprehensive performance has great potentials in practical applications. (C) 2019 Elsevier Inc. All rights reserved

    Ultrafine nano-TiO2 loaded on dendritic porous silica nanoparticles for robust transparent antifogging self-cleaning nanocoatings

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    Multifunctional nanocoatings with mechanical robustness, high transparence, antifogging and self-cleaning have attracted significant attention because of their wide applications in glass-related fields. However, it is still very difficult to construct this kind of multifunctional nanocoatings due to the requirement of their comprehensive structure parameters. In this work, we successfully fabricated robust transparent antifogging self-cleaning nanocoatings by employing dendritic porous silica nanoparticles (DPSNs) evenly loaded with 2-3 nm of small TiO2 nanoparticles (NPs) as a building block. A series of DPSNs@X% TiO2 nanocomposites with tunable weight ratios (X%) of TiO2/DPSNs from 10% to 60% were firstly prepared by controlling the growth of TiO2 on the heterogeneous interface of center-radial large pores of DPSNs, followed by calcination. Noteworthily, DPSNs@10% TiO2 exhibited highest photocatalytic and antibacterial performance mainly due to uniform distribution of TiO2 NPs, their small sizes of 2-3 nm and center-radial pore. Therefore, DPSNs@10% TiO2 was chosen as an optimized building block and combined with acid-catalyzed silica sol (ACSS) to develop an excellent suspension for multifunctional nanocoatings. The obtained glass slide with the optimal nanocoating showed photocatalytic selfcleaning behavior, high transparence, hydrophilic (WCA = 6.2 degrees) antifogging, and high mechanical robustness, which can withstand 4B tape adhesion test and 3H pencil scratching test. This work provides an important exploration for developing multifunctional nanocoatings

    JMJD2D stabilises and cooperates with HBx protein to promote HBV transcription and replication

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    Background & Aims: HBV infection is a global health burden. Covalently closed circular DNA (cccDNA) transcriptional regulation is a major cause of poor cure rates of chronic hepatitis B (CHB) infection. Herein, we evaluated whether targeting host factors to achieve functional silencing of cccDNA may represent a novel strategy for the treatment of HBV infection. Methods: To evaluate the effects of Jumonji C domain-containing (JMJD2) protein subfamily JMJD2A-2D proteins on HBV replication, we used lentivirus-based RNA interference to suppress the expression of isoforms JMJD2A-2D in HBV-infected cells. JMJD2D-knockout mice were generated to obtain an HBV-injected model for in vivo experiments. Co-immunoprecipitation and ubiquitylation assays were used to detect JMJD2D-HBx interactions and HBx stability modulated by JMJD2D. Chromatin immunoprecipitation assays were performed to investigate JMJD2D-cccDNA and HBx-cccDNA interactions. Results: Among the JMJD2 family members, JMJD2D was significantly upregulated in mouse livers and human hepatoma cells. Downregulation of JMJD2D inhibited cccDNA transcription and HBV replication. Molecularly, JMJD2D sustained HBx stability by suppressing the TRIM14-mediated ubiquitin-proteasome degradation pathway and acted as a key co-activator of HBx to augment HBV replication. The JMJD2D-targeting inhibitor, 5C-8-HQ, suppressed cccDNA transcription and HBV replication. Conclusion: Our study clarified the mechanism by which JMJD2D regulates HBV transcription and replication and identified JMJD2D as a potential diagnostic biomarker and promising drug target against CHB, and HBV-associated hepatocarcinoma. Impact and implications: HBV cccDNA is central to persistent infection and is a major obstacle to healing CHB. In this study, using cellular and animal HBV models, JMJD2D was found to stabilise and cooperate with HBx to augment HBV transcription and replication. This study reveals a potential novel translational target for intervention in the treatment of chronic hepatitis B infection
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