Search

Water bodies contaminated with the norovirus (NoV) are important vectors for its transmission. Therefore, enhanced monitoring of NoV in aqueous environments plays an active role in preventing diseases. Here, we reverse transcribed viral RNA into cDNA, and then used the constructed RPA-CRISPR/Cas13a-based platform for sensitive and quantitative monitoring of NoV GII.4 in aqueous environments. The use of glycerol as a phase separator and the direct release of nucleic acids from the virus by NaOH significantly enhanced the stability of the assay and reduced its economic cost. This assay is sensitive, specific, and stable. Based on the qualitative detection method, we established a relatively accurate quantitative detection method using the plasmid as a standard. Four water samples, totaling 64 samples, were analyzed using this method and compared with the qPCR method. The results of the two methods showed 100 % concordance with no significant difference in viral load. The entire process of our established method—from viral nucleic acid extraction to the output of the results—was completed in 30 min, much less than the time required for qPCR method. This suggests that the assay can be used as an alternative to qPCR for monitoring the change of NoV GII.4 concentration in water bodies, and shows high potential for application in the immediate detection of viruses in aqueous environments and resource-limited areas.

Hierarchical heterostructures have emerged as promising candidates for the efficient photocatalytic degradation of antibiotics owing to their matched energy levels and tunable absorption bands. Herein, we report the facile synthesis of a heterojunction photocatalyst composed of basic bismuth nitrate (BiON) and BiOCl0.9I0.1 using a simple room-temperature hydrolysis method. Our results demonstrate that the BiON/BiOCl0.9I0.1 composite exhibits superior photodegradation performance compared to pure-phase materials owing to the catalytic enhancement at the heterointerface and the effective separation of the photogenerated carriers. Moreover, the unique three-dimensional microsphere morphology of the synthesized composite enhances its specific surface area and light absorption, further enhancing its photocatalytic activity. In the tetracycline (TC) photodegradation reaction as a model reaction, the catalyst could degrade 88% of TC in just 25 min. Overall, this work provides a promising strategy for the facile and low-cost synthesis of heterogeneous photocatalytic degradation materials.

Abstract Seasonally frozen soils are exposed to freeze‒thaw cycles every year, leading to mechanical property deterioration. To reasonably describe the deterioration of soil under different conditions, machine learning (ML) technology is used to establish a prediction model for soil static strength. Six key influencing factors (moisture content, compaction degree, confining pressure, freezing temperature, number of freeze‒thaw cycles and thawing duration) are included in the modelling database. The accuracy of three typical ML algorithms (support vector machine (SVM), random forest (RF) and artificial neural network (ANN)) is compared. The results show that the ANN outperforms the SVM and RF. Principal component analysis (PCA) is combined with the ANN, and the PCA–ANN algorithm is proposed, which further improves the prediction accuracy. The deterioration of soil static strength is systematically researched using the PCA–ANN algorithm. The results show that the soil static strength decreased considerably after the first several freeze‒thaw cycles before the strength plateau occurred, and the strength reduction increased significantly with increasing moisture content and compaction degree. The PCA–ANN model can generate a reasonable prediction for the static strength or other soil properties of seasonally frozen soil, which will provide a scientific reference for practical engineering.

Noroviruses (NoVs) are major foodborne pathogens that cause acute gastroenteritis. Oysters are significant carriers of this pathogen, and disease transmission from the consumption of NoVs-infected oysters occurs worldwide. The review discusses the mechanism of NoVs bioaccumulation in oysters, particularly the binding of histo-blood group antigen-like (HBGA-like) molecules to NoVs in oysters. The review explores the factors that influence NoVs bioaccumulation in oysters, including temperature, precipitation and water contamination. The review also discusses the detection methods of NoVs in live oysters and analyzes the inactivation effects of high hydrostatic pressure, irradiation treatment and plasma treatment on NoVs. These non-thermal processing treatments can remove NoVs efficiently while retaining the original flavor of oysters. However, further research is needed to reduce the cost of these technologies to achieve large-scale commercial applications. The review aims to provide novel insights to reduce the bioaccumulation of NoVs in oysters and serve as a reference for the development of new, rapid and effective methods for detecting and inactivating NoVs in live oysters.

Intervertebral disc degeneration (IVDD) is a multifactorial pathological process associated with low back pain in which nucleus pulposus cell senescence is disrupted. Increasing evidence reveals that IVDD can be modulated by microRNAs (miRNAs or miRs). In the current study, we set out to elucidate the role of miR-199a-5p in nucleus pulposus cell apoptosis and IVDD progression. After sample collection, we found highly expressed miR-199a-5p in nucleus pulposus tissues of both patients diagnosed with IVDD and in IVDD rat models. Next, normal and degenerated nucleus pulposus cells were isolated and transfected with miR-199a-5p mimic, miR-199a-5p inhibitor, overexpressed sirtuin 1 (oe-SIRT1), and oe-p21, followed by detection of nucleus pulposus cell apoptosis and proliferation. In addition, the binding of miR-199a-5p and SIRT1, the interaction between p21 and SIRT1, and the regulation of p21 acetylation by SIRT1 were analyzed. We found that miR-199a-5p overexpression promoted nucleus pulposus cell apoptosis and IVDD. Overexpression of SIRT1 countered the effect of miR-199a-5p overexpression, while overexpression of p21 reversed the effect of miR-199a-5p silencing. Also, miR-199a-5p inhibited SIRT1, promoted p21 acetylation, and upregulated p21 expression, thus accelerating nucleus pulposus cell apoptosis and IVDD. Overall, miR-199a-5p promotes nucleus pulposus cell apoptosis and IVDD by suppressing SIRT1-dependent deacetylation of p21.

A real flight trajectory varying from 5–60 km altitude was adopted for analyzing the effects of the angle of attack (AOA) on the IR signatures of rocket exhaust plumes. Three representative under-expanded states based on nozzle pressure ratio (NPR), including moderately under-expanded (NPR = 1.27), highly under-expanded (NPR = 12.5), and over-highly under-expanded (NPR = 120) states, were discussed. The results show that the appearance of the AOA shortens the plume scale size and afterburning region, but the peak temperature cannot significantly change. As an increase in the AOA, the high-temperature region and Mach cells are compressed to a small domain. The spectral radiant intensity is reduced and the decreasing rate is gradual for a large AOA. The peak radiance in the $2.7~\mu \text{m}$ band decreases, but that in the $4.3~\mu \text{m}$ band increases. The peak radiance curve shifted toward the increasing NPR as the AOA increases, and then the curve decreases monotonically from an initial “arched” shape. In addition, a group of band pairs can be observed by two intersecting in-band profiles as a function of altitude. The characteristic altitude of band pairs became more concentrated and moved toward low altitude with the increase in AOA.

Norovirus (NoV) is the main pathogen that causes acute gastroenteritis and brings a heavy socio-economic burden worldwide. In this study, five polysaccharide fractions, labeled pSFP-1-5, were isolated and purified from Sargassum fusiforme (S. fusiforme). In vitro experiments demonstrated that pSFP-5 significantly prevented the binding of type A, B and H histo-blood group antigens (HBGAs) to NoV GII.4 virus-like particles (NoV GII.4 VLPs). In addition, in vivo experiments revealed that pSFP-5 was effective in reducing the accumulation of NoV in oysters, indicating that pSFP-5 could reduce the risk of NoV infection from oyster consumption. The results of transmission electron microscopy showed that the appearance of NoV GII.4 VLPs changed after pSFP-5 treatment, indicating that pSFP-5 may achieve antiviral ability by altering the morphological structure of the viral particles so that they could not bind to HBGAs. The results of the present study indicate that pSFP-5 may be an effective anti-NoV substance and can be used as a potential anti-NoV drug component. [ABSTRACT FROM AUTHOR]

Hierarchical heterostructures have emerged as promising candidates for the efficient photocatalytic degradation of antibiotics owing to their matched energy levels and tunable absorption bands. Herein, we report the facile synthesis of a heterojunction photocatalyst composed of basic bismuth nitrate (BiON) and BiOCl0.9I0.1 using a simple room-temperature hydrolysis method. Our results demonstrate that the BiON/BiOCl0.9I0.1 composite exhibits superior photodegradation performance compared to pure-phase materials owing to the catalytic enhancement at the heterointerface and the effective separation of the photogenerated carriers. Moreover, the unique three-dimensional microsphere morphology of the synthesized composite enhances its specific surface area and light absorption, further enhancing its photocatalytic activity. In the tetracycline (TC) photodegradation reaction as a model reaction, the catalyst could degrade 88% of TC in just 25 min. Overall, this work provides a promising strategy for the facile and low-cost synthesis of heterogeneous photocatalytic degradation materials. [ABSTRACT FROM AUTHOR]

Bismuth oxychloride ultrathin nanoplates (BiOCl-UTNs) are highly active, but their preparation are limited to closed-vessel hydrothermal and solvothermal techniques at high temperatures (110–180 °C). Here we report a straightforward poly (sodium 4-styrenesulfonate) (PSS)-mediated route for the largescale synthesis of BiOCl-UTNs at room-temperature. In an open vessel, 6.15 g of BiOCl-UTNs with 3–5 nm thickness, and planar dimensions of 30–50 nm were produced. The strong electrostatic interaction between PSS and [Bi2O2]2+ layers inhibited the growth rate of BiOCl nanoplates along <001> direction, and Na+ ions governed the electrolyte sedimentation to produce BiOCl-UTNs. The resulting BiOCl-UTNs exhibited high photocatalytic activity for the degradation of antibiotics and organic dyes because of their large specific surface area, increased light absorption ability, and fast separation and transfer efficiency of the photoexcited charge carriers. [ABSTRACT FROM AUTHOR]

Indoor formaldehyde (HCHO) removal is very important to reduce public health risk. Herein, we report a facile method for preparing N-doped nanoporous carbon through direct carbonization of metal–organic frameworks (ZIF-8) to remove harmful formaldehyde. The prepared N-doped nanoporous carbon exhibited uniform morphology and large specific surface area. Moreover, the type of N-functional groups on the N-doped nanoporous carbon had a dominant effect on its HCHO adsorption activity. As a result, HCHO adsorption capacity of the optimized N-doped nanoporous carbon was approximately five times higher than that of the commercially activated carbon. The detailed HCHO adsorption process, including physical adsorption and chemical adsorption, was also confirmed through in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). In addition, it should be noted that the N-doped nanoporous carbon exhibited high stability for HCHO adsorption, even after six adsorption cycles, indicating its good recyclability for long-term application. This study is expected to pave a way for expanding the environmental applications of the N-doped nanoporous carbon. [ABSTRACT FROM AUTHOR]

We report the preparation of MnMoO4 nanosheet array on nickel foam (MnMoO4 NSA/NF) as an excellent 3D hydrogen evolution reaction (HER) electrocatalyst with good catalytic performance applied under basic, acidic and neutral conditions. In 0.5 M H2SO4, this MnMoO4 NSA/NF electrode needs an overpotential of 89 mV to drive current densities of 10 mA cm−2, to achieve the same current density, it demands overpotentials of 105 mV in 1.0 M KOH, 161 mV in 1.0 M PBS (pH = 7), respectively. After continuous CV scanning for 1000 cycles under different pH conditions, it also demonstrates an excellent stability with ignorable activity decrease. Such preeminent HER performance may be derived from the synergistic effect between manganese (Mn) and molybdenum (Mo) atoms, exposure of more active sites on the nanosheets and effective electron transport along the nanosheets. This MnMoO4 NSA/NF electrocatalyst provides us a highly efficient material for water splitting devices for industrial hydrogen production. [ABSTRACT FROM AUTHOR]

Uniform Au nanoparticle (NP)/poly (acrylamide-co-acrylic acid) [P(AAm-co-AA)] hydrogel microbeads were successfully prepared using droplet microfluidics technology. The microbeads exhibited a good stimuli-responsive behavior to pH value. Particularly in the pH value ranging from pH 2–pH 9, the composite microbead sizes gradually increased along with the increase of pH value. The homogeneous Au NPs, which were encapsulated in the P(AAm-co-AA) hydrogel microbeads, could transform the volume changes of hydrogel into optical signals by a tested single microbead with a microspectrometre system. The glucose was translated into gluconic acid by glucose oxidase. Thus, the Au NP/P(AAm-co-AA) hydrogel microbeads were used for detecting glucose based on pH effects on the composite microbeads. For this, the single Au NP/P(AAm-co-AA) hydrogel microbead could act as a good pH- or glucose-visualizing sensor. [ABSTRACT FROM AUTHOR]