328 research outputs found

    Reactive Black 5 Removal by Electrochemical Oxidation Using Titanium Dioxide Nanoparticle Electrodes

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    Reactive Black 5 (RB5) is a commonly employed azo dye that is widely utilized in textile dyeing procedures due to its intense black color and simple application. Wastewater containing this dye may be released into the environment, consequently causing harm to the environment and the organisms therein. Hence, there is a need to treat wastewater containing pollutants such as RB5. Electrocatalysis is an effective method to degrade organic pollutants. Titanium dioxide (TiO2) nanoparticles are examples of electrocatalysts and have demonstrated superior efficacy in the degradation of a variety of organic compounds compared to other investigated electrocatalysts. However, there is a lack of comprehensive knowledge regarding the electrocatalytic degradation efficiency, and reaction kinetics of RB5 degradation using TiO2 nanoparticles. This work aimed to investigate the potential of TiO2 nanoparticle electrodes for electrocatalytic degradation of RB5 dye in wastewater. Electrolysis experiments and analytical measurements were conducted to determine optimal conditions of parameters such as voltage, electrolyte composition, and concentration, as well as pH. Different RB5 concentrations were used to determine the suitable environment for degradation. Optimization revealed that the ideal voltage for RB5 removal was 6 V. Sodium chloride (NaCl), and sodium sulfate (Na2SO4) were used as electrolytes, with NaCl outperforming Na2SO4 in RB5 removal efficiency. The ideal NaCl concentration and pH for RB5 removal were found to be 0.05 M and 7, respectively. The range of system adaptation which yielded the highest removal efficiency was found to be 100 mg/L of RB5. Under these optimized conditions, the apparent rate constant decreased over time, indicating effective degradation.&nbsp

    Strong Gravitational Lensing of Gravitational Waves with TianQin

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    When gravitational waves pass by a massive object on its way to the Earth, strong gravitational lensing effect will happen. Thus the GW signal will be amplified, deflected, and delayed in time. Through analysing the lensed GW waveform, physical properties of the lens can be inferred. On the other hand, neglecting lensing effects in the analysis of GW data may induce systematic errors in the estimating of source parameters. As a space-borne GW detector, TianQin will be launched in the 2030s. It is expected to detect dozens of MBHBs merger as far as z = 15, and thus will have high probability to detect at least one lensed event during the mission lifetime. In this article, we discuss the capability of TianQin to detect lensed MBHBs signals. Three lens models are considered in this work: the point mass model, the SIS model, and the NFW model. The sensitive frequency band for space-borne GW detectors is around milli-hertz, and the corresponding GW wavelength could be comparable to the lens gravitational length scale, which requires us to account for wave diffraction effects. In calculating lensed waveforms, we adopt the approximation of geometric optics at high frequencies to accelerate computation, while precisely evaluate the diffraction integral at low frequencies. Through a Fisher analysis, we analyse the accuracy to estimate the lens parameters. We find that the accuracy can reach to the level of 10^-3 for the mass of point mass and SIS lens, and to the level of 10^-5 for the density of NFW lens. We also assess the impact on the accurate of estimating the source parameters, and find that the improvement of the accuracy is dominated by the increasing of SNR.Comment: 12 pages, 8 figure

    Identification of critical residues of influenza neuraminidase in viral particle release

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    BACKGROUND: Influenza neuraminidase (NA) is essential for virus release from its host cells and it is one of the targets for structure-based antiviral drug design. RESULTS: In this report, we established a pseudoviral particle release assay to study NA function, which is based on lentiviral particles pseudotyped with influenza glycoproteins HA and NA as a surrogate system. Through an extensive molecular analysis, we sought to characterize important residues governing NA function. We identified five residues of NA, 234, 241, 257, 286 and 345, four of which (except 345) map away from the active site of NA when projected onto the three-dimensional structure of avian influenza H5N1 NA, and substitutions of these residues adversely affected the NA-mediated viral particle release, suggesting that these residues are critical for NA enzymatic activity. CONCLUSION: Through extensive chimeric and mutational analyses, we have identified several residues, which map away from the active site and are critical for NA function. These findings provide new insights into NA-mediated pseudoviral particle release and may have important implications in drug design and therapeutics against influenza infection

    Study on Spinnability of PP/PU Blends and Preparation of PP/PU Bi-component Melt Blown Nonwovens

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    Melt blown polymer blends offers a good way to combine two polymers in the same fiber generating nonwovens with new and novel properties. In this study, polypropylene (PP) and polyurethane (PU) were blended to prepare PP/PU bicomponent melt blown nonwovens. The spinnability of PP/PU composites was investigated and PP/PU bi-component nonwovens with compositions of 95/5, 90/10, 80/20 and 70/30 were prepared by using the melt blowing technique. The melt blown fibers exhibited a ‘sea-island’ structure with PP as the continuous phase and PU as the dispersed phase. When the content of PU in the blend was above 40 %, PP/PU melt blown nonwovens could not be produced due to fiber breaking. For PP/PU (90/10) nonwovens, it was found that the average fiber diameter decreased with increasing die to collector (DCD) and elevated hot air pressure

    Understanding the action mechanisms of metformin in the gastrointestinal tract

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    Metformin is the initial medication recommended for the treatment of type 2 diabetes mellitus (T2DM). In addition to diabetes treatment, the function of metformin also can be anti-aging, antiviral, and anti-inflammatory. Nevertheless, further exploration is required to fully understand its mode of operation. Historically, the liver has been acknowledged as the main location where metformin reduces glucose levels, however, there is increasing evidence suggesting that the gastrointestinal tract also plays a significant role in its action. In the gastrointestinal tract, metformin effects glucose uptake and absorption, increases glucagon-like peptide-1 (GLP-1) secretion, alters the composition and structure of the gut microbiota, and modulates the immune response. However, the side effects of it cannot be ignored such as gastrointestinal distress in patients. This review outlines the impact of metformin on the digestive system and explores potential explanations for variations in metformin effectiveness and adverse effects like gastrointestinal discomfort

    Strategies for Exploring Functions from Dynamic Combinatorial Libraries

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    Dynamic combinatorial chemistry (DCC) is a powerful approach for creating complex chemical systems, giving access to the studies of complexity and exploration of functionality in synthetic systems. However, compared with more advanced living systems, the man‐made chemical systems are still less functional, due to their limited complexity and insufficient kinetic control. Here we start by introducing strategies to enrich the complexity of dynamic combinatorial libraries (DCLs) for exploiting unexpected functions by increasing the species of building blocks and/or templates used. Then, we discuss how dynamic isomerization of photo‐switchable molecules help DCLs increase and alter the systemic complexity in‐situ. Multi‐phase DCLs will also be reviewed to thrive complexity and functionality across the interfaces. Finally, there will be a summary and outlook about remote kinetic control in DCLs that are realized by applying exogenous physical transduction signals of stress, light, heat and ultrasound.</p
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