Rare earth elements (REEs), known as “industrial vitamins”, are widely used in medical treatment, industry, agriculture, etc. However, with the increasing demand for REEs, excess REEs, such as gadolinium (Gd), are considered micropollutants in the environment. In this paper, the distributions of dissolved REEs were analyzed in three small streams, in order to determine the extent and occurrence of Gd anomalies. The shale-normalized REE patterns in the three streams were less smooth with heavy REEs higher than light REEs, for a weak reaction of the heavy REE complexes. A negative Ce (cerium) anomaly and positive samarium (Sm) and europium (Eu) anomalies were observed in the three streams and the negative Ce anomaly was affected by the pH of the alkaline rivers. However, a positive Gd anomaly was found in only a typical urban small stream, Jinzhong. With a population of approximately 60,000, Jinzhong runs by a hospital and through wastewater treatment plants (WWTPs). The concentrations of Gd in Jinzhong ranged from 1.54 to 86.65 ng/L with high anthropogenic Gd proportions (63.64%–98.07%). Anthropogenic Gd showed significant seasonal variations and distinct spatial disparities from upstream to downstream, and it was associated with certain ions such as Cl−. Anthropogenic Gd could be attributed to gadopentetic acid (Gd-DTPA), which is used in magnetic resonance imaging (MRI) in hospitals. This type of Gd was shown to be correlated with municipal wastewater. Due to the high stability and low particulate reactivity in water, anthropogenic Gd has great potential to serve as a tracer to prove the presence of medical wastewater.

Trace element pollution derived from human activities in aquatic systems has raised widespread concerns due to its toxicity, persistence, and bioaccumulation. In this article, we presented a systematic investigation of the anthropogenic overprints on trace elements geochemistry in three streams of the human-impacted (agriculture, urban area, and abandoned mining), located at Lake Aha, Guiyang, Southwest China. Concentrations reported in the study demonstrated that the abandoned mining stream showed the highest trace elements (608.16 μg/L), followed by the urban stream (566.11 μg/L) and agricultural stream (457.51 μg/L). Nonmetric multidimensional scaling (NMDS), used to display sampling dates and trace elements, showed discernible temporal variation in trace element concentrations. Trace element concentrations in months (May, September, and October) with less rainfall were higher than in June, July, and August indicated by NMDS. Principal component analysis (PCA) had shown that As, Ba, Mo, and Zn were mainly impacted by the urbanized streams, and Fe and Sr influenced by the mine. Risk assessment of human beings to trace elements demonstrated that As may pose a detrimental health risk. The research found that trace elements were potential tracers for the presence of human activities and environmental changes.

Background With the popularization of higher education, the problems of academic adaptability and learning burnout among college students have become increasingly prominent. The purpose of this study was to investigate the relationship between academic adaptability, learning burnout, self-esteem and self-efficacy of college students and their underlying mechanisms. Methods The study was conducted on 2110 college students using the College Student Learning Adjustment Scale, the Learning Burnout Undergraduates Scale, the Self-Esteem Scale, and the Self-Efficacy Scale to establish a mediating model of adjustment. SPSS 26.0 was used for descriptive statistics and Pearson correlation analysis. Model 4 and Model 14 in the process plug-in prepared by Hayes (2017) were used for mediating effects analysis and moderating mediator analysis respectively, and the significance of the mediating effects was tested using the bias-corrected percentile Bootstrap method. Results (1) academic adaptability significantly and positively predicted self-esteem; (2) self-esteem significantly and negatively predicted learning burnout; (3) academic adaptability significantly and negatively predicted learning burnout; (4) self-esteem partially mediated the effect of academic adaptability on learning burnout; and (5) self-efficacy moderated the latter half of the mediation process of academic adaptability-self-esteem-learning burnout. Conclusion These findings are useful for college educators and related researchers to better understand the mechanisms underlying the relationship between academic adaptability and learning burnout, thus providing practical and effective operational suggestions on the prevention and intervention of learning burnout in college students.

As an emerging contaminant, rare earth elements (REEs) are becoming an environmental concern, especially in Chinese cities. This study investigated the distribution of REEs in river water and tap water samples in Guiyang, Southwest China. In all water samples, the concentrations of total dissolved REE (∑REE) ranged from 15.1 to 53.3 ng·L–1, with the heavy rare earth elements enriched than the light rare earth elements. Most of the water samples showed significant positive Gd anomalies, with the highest abnormal value calculated to be 29.23. The main reason for the positive Gd anomalies was found to be the release of medical wastewaters containing Gadopentetic acids (Gd-DTPA). Overall, anthropogenic Gd could contributed >60% of total Gd in river waters and tap waters. Because Gd-DTPA is commonly used in large Chinese hospitals, the results of this study implied that anthropogenic Gd release could be common in Chinese cities.