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Polypropylene microplastics (PP-MPs), an emerging pollutant, adversely affect the ability of aquatic plants to restore water bodies, thereby compromising the functionality and integrity of wetland ecosystems. This study examines the effects of microplastic stress on the nitrogen and phosphorus removal capacities of Acorus calamus and Iris tectorum, as well as on functional microorganisms within the aquatic system. The findings indicate that under PP-MP stress, the nitrogen and phosphorus absorption capabilities of both plants were diminished. Additionally, there was a significant reduction in the metabolic enzyme activities related to nitrogen and phosphorus in the plants, alongside a notable decrease in leaf nitrogen content. PP-MPs hinder the nutrient uptake of plants, affecting their growth and indirectly reducing their ability to utilize nitrogen and phosphorus. Specifically, in the 10 mg L -1 treatment group, A. calamus and I. tectorum showed reductions in leaf nitrogen content by 23.1% and 31.0%, respectively, and by 14.8% and 27.7% in the 200 mg L -1 treatment group. Furthermore, I. tectorum had higher leaf nitrogen levels than A. calamus. Using fluorescent tagging, the distribution of PP-MPs was traced in the roots, stems, and leaves of the plants, revealing significant growth impairment in both species. This included a considerable decline in photosynthetic pigment synthesis, enhanced oxidative stress responses, and increased lipid peroxidation in cell membranes. PP-MP exposure also significantly reduced the abundance of functional microorganisms involved in denitrification and phosphorus removal at the genus level in aquatic systems. Ecological function predictions revealed a notable decrease in nitrogen cycling functions such as nitrogen respiration and nitrite denitrification among water microorganisms in both treatment groups, with a higher ecological risk potential in the A. calamus treatment group. This study provides new insights into the potential stress mechanisms of PP-MPs on aquatic plants involved in water body remediation and their impacts on wetland ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The objective of this study is to unravel the modification mechanism of a coupling agent on the water sensitivity of phosphogypsum asphalt mortar. The adhesion process of phosphogypsum asphalt mastic modified with three kinds of coupling agents (KH-550, KH-570, and CS-101) and raw phosphogypsum to the aggregate minerals was simulated based on the molecular dynamics software, Materials Studio 2020, and the water film layer was considered along the simulation. When the three coupling agents were added, the interfacial adhesion work gradually increased with the increase of modified phosphogypsum dosage, and the trends of each model were relatively similar. With the increase of simulation time, the mean square displacement of water molecules of the three interfacial models showed different trends, and the increasing trend rank was unmodified phosphogypsum > KH-550 > KH-570 > CS-101. The diffusion coefficient of the water molecular layer of asphalt mastic modified with CS-101 coupling agent in phosphogypsum shows a significant decrease with the increase of CS-101-modified phosphogypsum (more than 5% mass ratio to asphalt). Compared to raw phosphogypsum asphalt mortar, the addition of coupling agents can significantly limit the diffusion of water molecules and effectively improve the interfacial adhesion work, in which CS-101 coupling agent has the best effect, followed by KH-570 and KH-550.

In the context of the global pandemic of COVID-19, the use and disposal of medical masks have created a series of ethical and environmental issues. The purpose of this paper is to study and evaluate the high temperature properties and thermal storage stability of discarded-mask (DM)-modified asphalt from a multi-scale perspective using molecular dynamics (MD) simulation and experimental methods. A series of tests was conducted to evaluate the physical, rheological, thermal storage stability and microscopic properties of the samples. These tests include softening point, rotational viscosity, dynamic shear rheology (DSR), Fourier transform infrared (FT-IR) spectroscopy and molecular dynamics simulation. The results showed that the DM modifier could improve the softening point, rotational viscosity and rutting factor of the asphalt. After thermal storage, the DM-modified asphalt produced segregation. The difference in the softening point between the top and bottom of the sample increased from 2.2 °C to 17.1 °C when the DM modifier admixture was increased from 1% to 4%. FT-IR test results showed that the main component of the DM modifier was polypropylene, and the DM-modified asphalt was mainly a physical co-blending process. MD simulation results show that the DM modifier can increase the cohesive energy density (CED) and reduce the fractional free volume (FFV) of asphalt and reduce the binding energy between base asphalt and DM modifier. Multi-scale characterization reveals that DM modifiers can improve the high temperature performance and reduce the thermal storage stability of asphalt. It is noteworthy that both macroscopic tests and microscopic simulations show that 1% is an acceptable dosage level.

University students' physical health test is an important part of university physical education. The data obtained by the physical health test play an extremely important role in the field of students' physical health research. This paper clarifies the current situation of data collection of the physical health test for college students by sorting out the development status and trend of the physical health test system in China. To further ensure the accuracy and validity of the physical health test data, this article puts forward the corresponding optimization measures for the data collection link of the existing physical health testing system given the problems existing in the implementation of university students' physical health tests. Optimization measures are as follows: (1) add a test data collection type for test video collection; (2) optimize the authentication process to increase face recognition; and (3) enhance posttest test data management by stamping time., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Xiaohui Zhai et al.)