924 research outputs found

    NLH: A Blind Pixel-level Non-local Method for Real-world Image Denoising

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    Non-local self similarity (NSS) is a powerful prior of natural images for image denoising. Most of existing denoising methods employ similar patches, which is a patch-level NSS prior. In this paper, we take one step forward by introducing a pixel-level NSS prior, i.e., searching similar pixels across a non-local region. This is motivated by the fact that finding closely similar pixels is more feasible than similar patches in natural images, which can be used to enhance image denoising performance. With the introduced pixel-level NSS prior, we propose an accurate noise level estimation method, and then develop a blind image denoising method based on the lifting Haar transform and Wiener filtering techniques. Experiments on benchmark datasets demonstrate that, the proposed method achieves much better performance than previous non-deep methods, and is still competitive with existing state-of-the-art deep learning based methods on real-world image denoising. The code is publicly available at https://github.com/njusthyk1972/NLH.Comment: 14 pages, 9 figures, 10 tables, accept by IEEE TI

    STAR: A Structure and Texture Aware Retinex Model

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    © 2020 IEEE. Retinex theory is developed mainly to decompose an image into the illumination and reflectance components by analyzing local image derivatives. In this theory, larger derivatives are attributed to the changes in reflectance, while smaller derivatives are emerged in the smooth illumination. In this paper, we utilize exponentiated local derivatives (with an exponent γ ) of an observed image to generate its structure map and texture map. The structure map is produced by been amplified with γ \u3e 1, while the texture map is generated by been shrank with γ \u3c 1. To this end, we design exponential filters for the local derivatives, and present their capability on extracting accurate structure and texture maps, influenced by the choices of exponents γ. The extracted structure and texture maps are employed to regularize the illumination and reflectance components in Retinex decomposition. A novel Structure and Texture Aware Retinex (STAR) model is further proposed for illumination and reflectance decomposition of a single image. We solve the STAR model by an alternating optimization algorithm. Each sub-problem is transformed into a vectorized least squares regression, with closed-form solutions. Comprehensive experiments on commonly tested datasets demonstrate that, the proposed STAR model produce better quantitative and qualitative performance than previous competing methods, on illumination and reflectance decomposition, low-light image enhancement, and color correction. The code is publicly available at https://github.com/csjunxu/STAR

    The prevalence of autism spectrum disorders in China: A comprehensive meta-analysis

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    There are conflicting prevalence estimates of autism spectrum disorders (ASDs) in mainland China (China thereafter). This study is a comprehensive meta-analysis of the pooled prevalence of ASDs in the general population in China. Study investigators independently conducted a systematic literature search of the following databases: PubMed, EMBASE, PsycINFO, China National Knowledge Infrastructure, Chinese biomedical literature service system, and Wan Fang. Studies reporting prevalence of ASDs and autism in Chinese population were identified and analysed using the Comprehensive Meta-Analysis program with the random effects model. Forty-four studies were included in the meta-analysis comprising 2,337,321 subjects of whom 46.66 % were females. The mean age of subjects ranged from 1.6 to 8 years. Based on diagnostic criteria the pooled prevalence of ASDs was 39.23 per 10,000 (95% CI: 28.44-50.03 per 10,000, I2=89.2%); specifically, the prevalence of autism was 10.18 per 10,000 (95% CI: 8.46-11.89 per 10,000, I2=92.5%). Subgroup analyses revealed significant difference in the prevalence of ASDs between genders (72.77 per 10,000 in males vs. 16.45 per 10,000 in females). In conclusion, the prevalence of ASDs and autism in China was found generally lower than those reported in other countries. Further studies are needed to clarify the variation in prevalence

    The multitasking Fasciola gigantica Cathepsin B interferes with various functions of goat peripheral blood mononuclear cells in vitro

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    Cathepsin B, a lysosomal cysteine protease, is thought to be involved in the pathogenesis of Fasciola gigantica infection, but its exact role remains unclear. In the present study, a recombinant F. gigantica cathepsin B (rFgCatB) protein was expressed in the methylotrophic yeast Pichia pastoris. Western blot analysis confirmed the reactivity of the purified rFgCatB protein to serum from F. gigantica-infected goats. The effects of serial concentrations (10, 20, 40, 80, and 160 μg/ml) of rFgCatB on various functions of goat peripheral blood mononuclear cells (PBMCs) were examined. We demonstrated that rFgCatB protein can specifically bind to the surface of PBMCs. In addition, rFgCatB increased the expression of cytokines (IL-2, IL-4, IL-10, IL-17, TGF-β, and IFN-γ), and increased nitric oxide production and cell apoptosis, but reduced cell viability. These data show that rFgCatB can influence cellular and immunological functions of goat PBMCs. Further characterization of the posttranslational modification and assessment of rFgCatB in immunogenicity studies is warranted

    3-Hydr­oxy-N′-(2-hydroxy­benzyl­idene)benzohydrazide

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    The title compound, C14H12N2O3, was synthesized by the condensation of salicylaldehyde with 3-hydroxy­benzo­hydrazide. The dihedral angle between the two benzene rings is 12.4 (2)°. The 2-hydr­oxy group forms an intra­molecular O—H⋯N hydrogen bond with the imide N atom. Mol­ecules are linked through inter­molecular O—H⋯O and N—H⋯O hydrogen bonds into a two-dimensional polymeric structure parallel to the ab plane

    Bostrycin inhibits proliferation of human lung carcinoma A549 cells via downregulation of the PI3K/Akt pathway

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    <p>Abstract</p> <p>Background</p> <p>Bostrycin is a novel compound isolated from marine fungi that inhibits proliferation of many cancer cells. However, the inhibitory effect of bostrycin on lung cancers has not been reported. This study is to investigate the inhibitory effects and mechanism of bostrycin on human lung cancer cells in vitro.</p> <p>Methods</p> <p>We used MTT assay, flow cytometry, microarray, real time PCR, and Western blotting to detect the effect of bostrycin on A549 human pulmonary adenocarcinoma cells.</p> <p>Results</p> <p>We showed a significant inhibition of cell proliferation and induction of apoptosis in bostrycin-treated lung adenocarcinoma cells. Bostrycin treatment caused cell cycle arrest in the G0/G1 phase. We also found the upregulation of microRNA-638 and microRNA-923 in bostrycin-treated cells. further, we found the downregulation of p110α and p-Akt/PKB proteins and increased activity of p27 protein after bostrycin treatment in A549 cells.</p> <p>Conclusions</p> <p>Our study indicated that bostrycin had a significant inhibitory effect on proliferation of A549 cells. It is possible that upregulation of microRNA-638 and microRNA-923 and downregulaton of the PI3K/AKT pathway proteins played a role in induction of cell cycle arrest and apoptosis in bostrycin-treated cells.</p

    Dimension Increase via Hierarchical Hydrogen Bonding from Simple Pincer-like Mononuclear complexes

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    A tetradentate symmetric ligand bearing both coordination and hydrogen bonding sites, N1,N3-bis(1-(1H-benzimidazol-2-yl)-ethylidene)propane-1,3-diamine (H2bbepd) was utilized to synthesize a series of transition metal complexes, namely [Co(H2bbepd)(H2O)2]·2ClO4 (1), [Cu(H2bbepd)(OTs-)]·OTs- (2),[Cu(bbepd)(CH3OH)] (3), [Cd(H2bbepd)(NO3)2]·CH3OH (4), [Cd(H2bbepd)(CH3OH)Cl]·Cl (5), and [Cd(bbepd)(CH3OH)2] (6). These complexes show similar discrete pincer-like coordination units, possessing different arrangements of hydrogen bonding donor and acceptor sites. With or without the aid of uncoordinated anions and solvent molecules, such mononuclear units have been effectively involved in the construction of hierarchical hydrogen bonding assemblies (successively via level I and level II), leading to discrete binuclear ring (complex 2), one-dimensional chain or ribbon (complexes 3, 4 and 6) and two-dimensional layer (complexes 1 and 5) aggregates

    Antibacterial Activity and Mode of Action of Mentha arvensis Ethanol Extract against Multidrug-Resistant Acinetobacter baumannii

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    Purpose: To evaluate the antibacterial effect of ethanol extract of Mentha arvensis against multi-drug resistant Acinetobacter baumannii using liquid chromatography–mass spectrometry (LC-ESI-MS).Methods: Disc diffusion and microdilution assays were used to evaluate the antibacterial effect of the extract by measuring the zone of inhibition, minimum inhibitory concentration (MIC) and and minimum bacteriocidal concentration (MBC) of the extract against the test bacteria. Scanning electron microscopy (SEM) was employed to evaluate the morphological changes induced by the extract in cellular membrane of the bacteria. Reactive oxygen species (ROS) generation and protein leakage from the bacterial cells induced by the extract were also evaluated.Results: The extract showed dose-dependent growth inhibitory effects against A. baumannii with MIC and MBC of 23.5 and 72.1 μg/mL, respectively. The extract also induced potent ROS generation and protein leakage in A. baumannii bacterial cells. SEM findings revealed that the extract induced potential cellular damage which increased with increasing extract concentration.Conclusion: The ethanol extract of Mentha arvensis is a potent antibacterial agent against A. baumannii and acts by inducing lethal cellular damage to the bacterium.Keywords: Mentha arvensis, Acinetobacter baumannii, Reactive oxygen species, Antibacterial activity, Cellular membrane damag

    Identification of two novel host proteins interacting with Toxoplasma gondii 14-3-3 protein by yeast two-hybrid system

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    Toxoplasma gondii deploys many effector proteins in order to hijack and manipulate host cell signaling pathways, allowing parasite colonization, subversion of immune responses, and disease progression. T. gondii effector protein 14-3-3 (Tg14-3-3) promotes parasite dissemination inside the body, by enhancing the migratory ability of infected microglia and dendritic cells. Understanding both the mechanism of action and the host targets of Tg14-3-3 effector is important because of their importance to the parasite’s virulence. The aim of the present study was to explore the function of Tg14-3-3 by utilizing the yeast two-hybrid system (Y2HS) to identify novel Tg14-3-3 interactors/substrates in host cells. A human cDNA library was screened using Tg14-3-3 as the bait. Tg14-3-3 (RH strain, Type I) was cloned into the pGBKT7 vector and expressed in the Y2HGold yeast strain. The bait protein expression was validated by Western blotting analysis, auto-activation, and toxicity investigation compared with control (Y2HGold yeast strain transformed with empty pGBKT7 vector). Two positive Tg14-3-3 interactors identified by this screening, hCG1821272 and eIF5B (eukaryotic translation initiation factor 5B), were isolated and characterized. This approach made it possible to gain a better understanding of the function of Tg14-3-3 in regulating host proteins involved in key cellular processes, such as translational initiation and cell migration

    Protective Efficacy Against Acute and Chronic Toxoplasma gondii Infection Induced by Immunization With the DNA Vaccine TgDOC2C

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    Toxoplasma gondii is a ubiquitous intracellular apicomplexan parasite that can cause zoonotic toxoplasmosis. Effective vaccines against T. gondii infection are necessary to prevent and control the spread of toxoplasmosis. The present study analyzed the B-linear epitopes of T. gondii DOC2 (TgDOC2) protein and then cloned the C-terminus of the TgDOC2 gene (TgDOC2C) to construct the pVAX-TgDOC2C eukaryotic vector. After intramuscular injection of pVAX-TgDOC2C, immune responses were monitored. Two weeks after the last immunization, the protective effects of pVAX-TgDOC2C against acute and chronic toxoplasmosis were evaluated by challenges with T. gondii RH tachyzoites (genotype I) and PRU cysts (genotype II). The DNA vaccine elicited strong humoral and cellular immune responses with high levels of IgG antibody, IL-2 and IFN-γ production compared to those of the controls. The percentage of CD4+ and CD8+ T cells in mice immunized with pVAX-TgDOC2C was significantly increased compared to that of mice injected with empty pVAX I or PBS. After acute infection with 103 lethal tachyzoites, mice immunized with pVAX-TgDOC2C survived longer (12.5 days) than mice treated with pVAX I (8 days) and PBS (7.5 days). Mice immunized with pVAX-TgDOC2C had significantly less brain cysts (1600.83 ± 284.61) compared to mice immunized with pVAX I (3016.67 ± 153.84) or PBS (3100 ± 246.98). Together, these results demonstrated that TgDOC2C confers protective immunity against T. gondii infection and may be a promising candidate antigen for further development of an effective multicomponent vaccine for veterinary use against toxoplasmosis in livestock animals
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