63 research outputs found

    Synchronous fluorescence detection of nitrite in meat products based on dual-emitting dye@MOF and its portable hydrogel test kit.

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    peer reviewedA novel ratiometric fluorescent nanoprobe (Rh6G@UIO-66-NH2) was fabricated for efficient nitrite (NO2-) detection in the present study. When NO2- was introduced, it interacted with the amino groups on the surface of Rh6G@UIO-66-NH2, forming diazonium salts that led to the quenching of blue fluorescence. With this strategy, a good linear relationship between NO2- concentration and the fluorescent intensity ratio of the nanoprobe in the range of 1-100 μM was established, with a detection limit of 0.021 μM. This dual-readout nanosensor was applied to analyze the concentration of NO2- in real meat samples, achieving satisfactory recovery rates of 94.72-104.52%, highlighting the practical potential of this method. Furthermore, a portable Gel/Rh6G@UIO-66-NH2 hydrogel test kit was constructed for on-spot dual-mode detection of NO2-. This kit allows for convenient colorimetric analysis and fluorometric detection when used in conjunction with a smartphone. All the photos taken with the portable kit was converted into digital information using ImageJ software. It provides colorimetric and fluorescent visual detection of NO2- over a range of 0.1-1.5 mM, achieving a direct quantitative tool for NO2- identification. This methodology presents a promising strategy for NO2- detection and expands the application prospects for on-spot monitoring of food safety assessment.Beijing Science and Technology Planning ProjectNational Key Research and Development Program of Chin

    The Role of Matrix Metalloproteinase-9 in Atherosclerotic Plaque Instability

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    Matrix metalloproteinase-9 (MMP-9) belongs to the MMP family and has been widely investigated. Excessive MMP-9 expression can enhance extracellular matrix degradation and promote plaque instability. Studies have demonstrated that MMP-9 levels are higher in vulnerable plaques than in stable plaques. Additionally, several human studies have demonstrated that MMP-9 may be a predictor of atherosclerotic plaque instability and a risk factor for future adverse cardiovascular and cerebrovascular events. MMP-9 deficiency or blocking MMP-9 expression can inhibit plaque inflammation and prevent atherosclerotic plaque instability. All of these results suggest that MMP-9 may be a useful predictive biomarker for vulnerable atherosclerotic plaques, as well as a therapeutic target for preventing atherosclerotic plaque instability. In this review, we describe the structure, function, and regulation of MMP-9. We also discuss the role of MMP-9 in predicting and preventing atherosclerotic plaque instability

    Spatiotemporal Dynamics of the Suitability for Ecological Livability of Green Spaces in the Central Yunnan Urban Agglomeration

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    Green spaces are an essential aspect of building an eco-livable city and play an important role in building for eco-livability in the central Yunnan urban agglomeration. However, there are relatively few studies evaluating the eco-livability of green spaces. The establishment of a green-space eco-livability assessment system may help researchers to analyze the eco-livability of urban green spaces more effectively. To address this research gap, we constructed an ecological livability-evaluation index system for green spaces that incorporates three determinants—economic development, social life, and the ecological environment—using the green spaces of the urban agglomeration in central Yunnan as a case study. We used the entropy method to calculate the suitability for ecological livability of the green spaces in each district and county in the central Yunnan urban agglomeration for 2010, 2015 and 2020. We used the spatial autocorrelation analysis function of ArcGIS 10.8 software to explore the spatial clustering characteristics of the suitability for ecological livability of green spaces in the central Yunnan urban agglomeration. The results showed that, from 2010 to 2020, the suitability for ecological livability of green spaces of the 49 districts and counties in the central Yunnan urban agglomeration increased in some districts and decreased in others. The spatial characteristics were high in the central districts and counties and low in the peripheral districts and counties. The spatial characteristics of the suitability of the target layers for economic development and ecological-environment target were consistent with the overall suitability. Through a spatial autocorrelation analysis, we observed that the suitability of green spaces for ecological livability had a positive spatial correlation and demonstrated significant spatial clustering. In this study, we propose recommendations to improve the suitability for ecological livability of green spaces from two dimensions of government policy and urban development, using a combination of the three target layers. The results of the study provide a reference for decision-making in the construction of eco-livable cities in the central Yunnan urban agglomeration

    Effects of layered combined substrates on plant growth and treatment performance and its spatiotemporal variation of vertical-flow constructed wetlands

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    Layered combined bio-ceramic, zeolite, and anthracite were used as substrates in vertical-flow constructed wetlands (VFCWs) for enhancing contaminant removal from synthetic municipal wastewater. Plant growth and propagation and the removal of organic matter, nitrogen, and phosphorus as well as its spatiotemporal variation were evaluated systematically. The results demonstrated that three different substrates were adequate for the establishment of Canna indica L., especially for zeolite. All small-scale VFCW units were simultaneous efficient in removing CODCr (73.9-78.7%), NH4+-N (83.8-89.9%), TN (88.3-91.5%), SRP (93.8-98.6%), and TP (87.1-90.9%) with a little significant difference on treatment performance. Different pollution removal processes followed a different trend because of their different removal mechanisms driven by the synergy of substrate, plant, and microorganism. Purification space moved down due to the adsorption capacity consumption of upper layer substrate over time. It was concluded that VFCWs filled with layered combined bio-ceramic, zeolite, and anthracite had great potential for treating municipal wastewater.</p

    Prognostic value of serum macrophage migration inhibitory factor levels in pulmonary tuberculosis

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    Abstract Background Macrophage migration inhibitory factor (MIF) makes chemokine-like functions and plays critical roles in various inflammatory diseases. This study was designed to explore the significance of MIF serum levels in predicting the prognosis of pulmonary tuberculosis (PTB) following anti-TB treatment. Methods Patients diagnosed with culture-confirmed PTB without treatment were included and the serum was collected. Levels of MIF in serum were quantified with immunoassay, and the levels of established biomarkers were also determined, including C-reactive protein (CRP) and Interleukin 6 (IL-6). The outcome was estimated with all-cause mortality, with the mortality in 12 months as the primary outcome and the mortality in 3, 6, 9 months as other outcomes. The prognostic value of MIF and other factors in PTB were tested. Results Two hundred eighty-seven PTB patients were included. The median MIF levels in patients with advanced disease, disseminated and drug-resistant TB were significantly higher than that observed in mild -to- moderate disease, non-disseminated and drug-sensitive TB. MIF levels in patients with the outcome of death were higher than those survived [28.0 ng/ml (Inter-quartile range [IQR]: 24.2–33.1) vs. 22.3 ng/ml (IQR: 18.7–26.5); P < 0.001]. Multivariate model analysis was performed for comparing the highest quartiles to the lowest quartile of MIF levels. MIF levels were related to the mortality, with an elevated mortality risk of 236% [Odds ratio (OR) = 3.36; 95% Confidence interval (CI): 1.21–15.14; P = 0.012]. The model was re-analysis after combing MIF with currently established risk indicators. The obtained Area Under the Receiver Operating Characteristic Curve (±standard error) was elevated from 0.81 (±0.035) to 0.84 (±0.031), with a significant difference before and after adding the MIF (difference, 0.03[0.004]; P = 0.03). Conclusion Serum level of MIF was a better biomarker than CRP or IL-6 for predicting death in HIV-negative PTB patients, and increased MIF serum levels were related to higher mortality

    The Influence of Confined Space Size on the Temperature Distribution Characteristics of Internal Window Plume from Well-Ventilated Compartment Fires

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    In this research, the influence of confined space size on the temperature distribution characteristics of internal window plumes from well-ventilated compartment fires was studied. Theoretical analysis was firstly used to establish a mathematical model for the smoke after ejecting from the window in the space. The study considered fire heat release rate and vertical height as dependent variables. Numerical simulations and experimental methods were carried out to study the temperature variations. A critical distance L2 was obtained. Results show that when the space D between the vertical retaining wall and the building façade is greater than L2, the variation of D has little influence on radial temperature. Once D is less than L2, the radial temperature distribution inside the confined space will tend to be consistent, and the temperature in the confined space sharply increases as D decreases. In addition, a dimensionless model was derived to quantify the relationship between temperature rise and vertical height. The experimental and numerical simulation results were processed, which are in good agreement with the model. The study can provide a framework for managing building safety

    Study on the Influence of the Slope Composition of the V-shaped Tunnel on the Smoke Exhaust Efficiency of the Point Exhaust System

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    The influences of the slope composition on both sides of the variable slope point and the opening numbers of the exhaust vent on the smoke diffusion and the smoke and heat exhaust efficiency in V-shaped tunnel were investigated by the numerical method. The results showed that for the asymmetric V-shaped tunnel, increasing the number of exhaust vents on the large slope side can improve the smoke and heat exhaust efficiency, but control the smoke in a smaller rang is relatively difficult. The corresponding smoke exhaust vent opening strategy should be drawn up in accordance with the composition of the slope of the V-shaped tunnel and the goal of the smoke control system in practice
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