633 research outputs found
Detecting Image Attribution for Text-to-Image Diffusion Models in RGB and Beyond
Modern text-to-image (T2I) diffusion models can generate images with
remarkable realism and creativity. These advancements have sparked research in
fake image detection and attribution, yet prior studies have not fully explored
the practical and scientific dimensions of this task. In addition to
attributing images to 12 state-of-the-art T2I generators, we provide extensive
analyses on what inference stage hyperparameters and image modifications are
discernible. Our experiments reveal that initialization seeds are highly
detectable, along with other subtle variations in the image generation process
to some extent. We further investigate what visual traces are leveraged in
image attribution by perturbing high-frequency details and employing mid-level
representations of image style and structure. Notably, altering high-frequency
information causes only slight reductions in accuracy, and training an
attributor on style representations outperforms training on RGB images. Our
analyses underscore that fake images are detectable and attributable at various
levels of visual granularity than previously explored.Comment: Code available at https://github.com/k8xu/ImageAttributio
Correlation between childhood tuberculosis and abundance of T cell gene transcription and impaired T cell function
Purpose: To investigate the relationship amongst childhood tuberculosis, abundance of T cell gene transcription and impairment of T cell function.
Methods: A total of 329 pediatric patients treated for tuberculosis in Central Hospital of Zibo, Zibo, China from 2017 to 2019 were enrolled in the study. Among them, 167 cases of tuberculosis-hospitalized children were assigned to the TB group. Additionally, 162 well- and adequately-treated patients with a previous history of tuberculosis were selected as the control group. The abundance of continuous gene transcripts in the peripheral blood of the children was analyzed. The RNA profiles were analyzed via microarray, while interferon (IFN) level was measured by enzyme linked immunosorbent assay (ELISA). The T cell proliferation was determined by thymidine assay.
Results: Within 6 months of the commencement of treatment, the differentially expressed transcripts returned the expression in children in the control group. The abundance of Talipes equinovarus, atrial septal defect, robin sequence, and the persistence of the left superior vena cava (TARP) gene transcription in the TB group was lower than in the control group on days 30, 120 and 180 (p < 0.05), while IL1R2 gene transcription abundance in the TB group was higher than in the control group on days 30, 120 ,180 (p < 0.05). The proliferation of T cells and IFNγ in tuberculosis children (TB group) were lower than in healthy controls (p < 0.05). In this study, a total of 129 genes were found to have significant differences in expression, and hence it is speculated that changes in RNA abundance altered the immune pathway.
Conclusion: The reduced abundance of T cell gene transcription and renovated T cell function in children with tuberculosis are related to acquired immunodeficiency. The results of this study provide a theoretical basis for the clinical diagnosis and treatment of tuberculosis in children
MiR-103a targeting Piezo1 is involved in acute myocardial infarction through regulating endothelium function
Background: Acute myocardial infarction (AMI) is commonly known as the heart attack. The molecular events involved in the development of AMI remain unclear. This study was to investigate the expression of miR-103a in patients with high blood pressure (HBP) and AMI patients with and without HBP, as well as its effect on endothelial cell functions.
Methods: MiR-103a expression in plasma and peripheral blood mononuclear cells (PBMCs) was measured by real-time polymerase chain reaction (PCR). The regulatory effect of miR-103a on Piezo1 gene was identified by a luciferase reporter system. The role of miR-103a in endothelial cells was evaluated by the capillary tube formation ability and cell viability of human umbilical vein endothelial cells (HUVECs).
Results: The plasma miR-103a concentration was significantly elevated in patients with HBP alone, AMI alone, and comorbidity of AMI and HBP. The miR-103a expression in PBMCs in patients with AMI and HBP was significantly higher than the one in healthy controls (p < 0.05), however miR-103a expression in PBMCs was not significantly different among patients with HBP alone, patients with AMI alone, and healthy controls. MiR-103a targeted Piezo1 and inhibited Piezo1 protein expression, which subsequently reduced capillary tube formation ability and cell viability of HUVECs.
Conclusions: MiR-103a might be a potential biomarker of myocardium infarction and could be used as an index for the diagnosis of AMI. It may be involved in the development of HBP and onset of AMI through regulating the Piezo1 expression.
Carbon dots modified mesoporous organosilica as an adsorbent for the removal of 2,4-dichlorophenol and heavy metal ions
Periodic mesoporous organosilica embedded with carbon dots are adopted as the adsorbent for removal of the toxic organic pollutant 2,4-dichlorophenol and inorganic metal ions Hg(II), Cu(II), and Pb(II). The composite possesses an ordered 2D hexagonal mesostructure with a space group of p6mm, high specific surface area ([similar]468.46 m2 g−1), and uniform pore size ([similar]5.50 nm). The surface is covered by about 1–2 layers of carbon dot nanoparticles. The maximum adsorption capacity for 2,4-dichlorophenol is 99.70 mg g−1, and the distribution coefficient of metal ions between adsorbent and solution phases is in the range of 2.60–7.41, following the order of Hg(II) > Cu(II) > Pb(II). The Cu(II) and Pb(II) adsorption stays nearly fixed while Hg(II) adsorption is depressed by [similar]45% in a mixed solution of metal ions. The Cu(II) and Hg(II) adsorption shows unapparent variation but Pb(II) adsorption is improved by [similar]55% in a mixed solution of metal ion and 2,4-dichlorophenol. In contrast, all metal ions lead to the depression of 2,4-dichlorophenol adsorption by 37% (Pb(II)), 45% (Cu(II)), and 48% (Hg(II)). Finally, the n–π electron donor–acceptor interaction between O- and N-containing groups in mesoporous organosilica and the benzene ring in 2,4-dichlorophenol is revealed to be responsible for the enhanced adsorption of 2,4-dichlorophenol, while the electrostatic force and complex formation between metal ions and amide groups co-contribute to the improvement of metal ions adsorption
Integrated Biomass Gasification with Catalytic Partial Oxidation for Selective Tar Conversion
Biomass gasification is a flexible and efficient way of utilizing widely available domestic renewable resources. Syngas from biomass has the potential for biofuels production, which will enhance energy security and environmental benefits. Additionally, with the successful development of low Btu fuel engines (e.g. GE Jenbacher engines), syngas from biomass can be efficiently used for power/heat co-generation. However, biomass gasification has not been widely commercialized because of a number of technical/economic issues related to gasifier design and syngas cleanup. Biomass gasification, due to its scale limitation, cannot afford to use pure oxygen as the gasification agent that used in coal gasification. Because, it uses air instead of oxygen, the biomass gasification temperature is much lower than well-understood coal gasification. The low temperature leads to a lot of tar formation and the tar can gum up the downstream equipment. Thus, the biomass gasification tar removal is a critical technology challenge for all types of biomass gasifiers. This USDA/DOE funded program (award number: DE-FG36-O8GO18085) aims to develop an advanced catalytic tar conversion system that can economically and efficiently convert tar into useful light gases (such as syngas) for downstream fuel synthesis or power generation. This program has been executed by GE Global Research in Irvine, CA, in collaboration with Professor Lanny Schmidt's group at the University of Minnesota (UoMn). Biomass gasification produces a raw syngas stream containing H2, CO, CO2, H2O, CH4 and other hydrocarbons, tars, char, and ash. Tars are defined as organic compounds that are condensable at room temperature and are assumed to be largely aromatic. Downstream units in biomass gasification such as gas engine, turbine or fuel synthesis reactors require stringent control in syngas quality, especially tar content to avoid plugging (gum) of downstream equipment. Tar- and ash-free syngas streams are a critical requirement for commercial deployment of biomass-based power/heat co-generation and biofuels production. There are several commonly used syngas clean-up technologies: (1) Syngas cooling and water scrubbing has been commercially proven but efficiency is low and it is only effective at small scales. This route is accompanied with troublesome wastewater treatment. (2) The tar filtration method requires frequent filter replacement and solid residue treatment, leading to high operation and capital costs. (3) Thermal destruction typically operates at temperatures higher than 1000oC. It has slow kinetics and potential soot formation issues. The system is expensive and materials are not reliable at high temperatures. (4) In-bed cracking catalysts show rapid deactivation, with durability to be demonstrated. (5) External catalytic cracking or steam reforming has low thermal efficiency and is faced with problematic catalyst coking. Under this program, catalytic partial oxidation (CPO) is being evaluated for syngas tar clean-up in biomass gasification. The CPO reaction is exothermic, implying that no external heat is needed and the system is of high thermal efficiency. CPO is capable of processing large gas volume, indicating a very compact catalyst bed and a low reactor cost. Instead of traditional physical removal of tar, the CPO concept converts tar into useful light gases (eg. CO, H2, CH4). This eliminates waste treatment and disposal requirements. All those advantages make the CPO catalytic tar conversion system a viable solution for biomass gasification downstream gas clean-up. This program was conducted from October 1 2008 to February 28 2011 and divided into five major tasks. - Task A: Perform conceptual design and conduct preliminary system and economic analysis (Q1 2009 ~ Q2 2009) - Task B: Biomass gasification tests, product characterization, and CPO tar conversion catalyst preparation. This task will be conducted after completing process design and system economics analysis. Major milestones include identification of syngas cleaning requirements for proposed system design, identification and selection of tar compounds and 2 mixtures for use in CPO tests, and preparation of CPO catalysts for validation. (Q3 2009 ~ Q4 2009) - Task C: Test CPO with biomass gasification product gas. Optimize CPO performance with selected tar compounds. Optimize CPO performance with multi-component mixtures. Milestones include optimizing CPO catalysts design, collecting CPO experimental data for next stage kinetic modeling and understanding the effect of relative reactivities on ultimate tar conversion and syngas yields. (Q1 2010 ~ Q3 2010) - Task D: Develop tar CPO kinetic model with CPO kinetic model and modeling results as deliverables. (Q3 2010 ~ Q2 2011) - Task E: Project management and reporting. Milestone: Quarterly reports and presentations, final report, work presented at national technical conferences (Q1 2009 ~ Q2 2011) At the beginning of the program, IP landscaping was conducted to understand the operation of various types of biomass gasifiers, their unique syngas/tar compositions and potential tar mitigation options using the catalytic partial oxidation technology. A process simulation model was developed to quantify the system performance and economics impact of CPO tar removal technology. Biomass gasification product compositions used for performance evaluation tests were identified after literature review and system modeling. A reaction system for tar conversion tests was designed, constructed, with each individual component shaken-down in 2009. In parallel, University of Minnesota built a lab-scale unit and evaluated the tar removal performance using catalytic reforming. Benzene was used as the surrogate compound. The biomass gasification raw syngas composition was provided by GE through system studies. In 2010, GE selected different tar compounds and evaluated the tar removal effectiveness of the CPO catalyst. The catalytic performance was evaluated under different operating conditions, including catalyst geometry, S/C ratio, O/C ratio, GHSV, and N2 dilution. An understanding of how to optimize catalytic tar removal efficiency by varying operating conditions has been developed. GE collaborated with UoMn in examining inorganic impurities effects. Catalysts were pre-impregnated with inorganic impurities commonly present in biomass gasification syngas, including Si, Ca, Mg, Na, K, P and S. UoMn performed catalyst characterization and has acquired fundamental understandings of impurities effect on catalytic tar removal. Based on experimental data and the proposed reaction pathway, GE constructed a model to predict kinetic performance for biomass gasification tar cleanup process. Experimental data (eg. tar conversion, reactor inlet and outlet temperatures, product distribution) at different operating conditions were used to validate the model. A good fit between model predictions and experimental data was found. This model will be a valuable tool in designing the tar removal reactor and identifying appropriate operating conditions. We attended the 2011 DOE Biomass Program Thermochemical Platform Review held in Denver, CO from February 16 to 18 and received very positive comments from the review panel. Further, syngas utility and biomass to power/fuel companies expressed strong interest in our tar removal technology
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