[Effects of Polyethylene Microplastics on Soil Nutrients and Enzyme Activities].

The threat of microplastic pollution in soil ecosystems has caused widespread concern. In order to clarify the effect of polyethylene microplastics on soil properties, a 4-month soil incubation experiment was conducted in this study to investigate the effect of different mass fraction (1 %, 2.5 %, and 5 %) and particle sizes (30 mesh and 100 mesh) of polyethylene microplastics on soil chemical properties, nutrient contents, and enzyme activities. The results showed that:① When the particle size was 100 mesh, microplastics at the mass concentrations of the 2.5 % and 5 % treatments significantly reduced soil pH, and the exposure of polyethylene microplastics had no significant effect on soil conductivity. ② Compared to that in CK, the addition of microplastics reduced soil available potassium, available phosphorus, and nitrate nitrogen to varying degrees. The addition of 100 mesh microplastics significantly increased soil organic matter and ammonium nitrogen. ③ When the particle size was 100 mesh, compared to that in CK, treatments of all concentrations significantly increased soil catalase activity and alkaline phosphatase, showing an increasing but not significant trend, and the 5 % concentration treatment significantly decreased soil sucrase activity. ④ Changes in soil properties were influenced by the addition of microplastics of different concentrations and sizes, with higher concentrations and smaller particle sizes having more significant effects. In conclusion, the effects of microplastics on soil properties were not as pronounced as expected, and future research should focus on the mechanisms involved in the different effects.

Circular economy strategies for mitigating metals shortages in electric vehicle batteries under China's carbon-neutral target.

Concerns over supply risks of critical metals used in electric vehicle (EV) batteries are frequently underscored as impediments to the widespread development of EVs. With the progress to achieve carbon neutrality by 2060 for China, projecting the critical metals demand for EV batteries and formulating strategies, especially circular economy strategies, to mitigate the risks of demand-supply imbalance in response to potential obstacles are necessary. However, the development scale of EVs in the transport sector to achieve China's carbon neutrality is unclear, and it remains uncertain to what extent circular economy strategies might contribute to the reduction of primary raw materials extraction. Consequently, we explore the future quantity of EVs in China required to achieve carbon neutrality and quantify the primary supply security levels of critical metals with the effort of battery cascade utilization, technology substitutions, recycling efficiency improvement, and novel business models, by integrating dynamic material flow analysis and national energy technology model. This study reveals that although 18%-30% of lithium and 20%-41% of cobalt, nickel, and manganese can be supplied to EVs through the reuse and recycling of end-of-life batteries, sustainable circular economy strategies alone are insufficient to obviate critical metals shortages for China's EV development. However, the supplementary capacity offered by second-life EV batteries, which refers to the use of batteries after they have reached the end of their first intended life, may prove adequate for China's prospective novel energy storage applications. The cumulative primary demand for lithium, cobalt, and nickel from 2021 to 2060 would reach 5-7 times, 23-114 times, and 4-19 times the corresponding mineral reserves in China. Substantial reduction of metals supply risks apart from lithium can be achieved by the cobalt-free battery technology developments combined with efficient recycling systems, where secondary supply can satisfy the demand as early as 2054.

[Interaction between microplastics and microorganisms in soil environment: a review].

As a widespread pollutant in the environment, research on microplastics have attracted much attention. This review systematically analyzed the interaction between microplastics and soil microorganisms based on existing literatures. Microplastics can change the structure and diversity of soil microbial communities directly or indirectly. The magnitude of these effects depends on the type, dose and shape of microplastics. Meanwhile, soil microorganisms can adapt to the changes caused by microplastics through forming surface biofilm and selecting population. This review also summarized the biodegradation mechanism of microplastics, and explored the factors affecting this process. Microorganisms will firstly colonize the surface of microplastics, and then secrete a variety of extracellular enzymes to function at specific sites, converting polymers into lower polymers or monomers. Finally, the depolymerized small molecules enter the cell for further catabolism. The factors affecting this degradation process are not only the physical and chemical properties of the microplastics, such as molecular weight, density and crystallinity, but also some biological and abiotic factors that affect the growth and metabolism of related microorganisms and the enzymatic activities. Future studies should focus on the connection with the actual environment, and develop new technologies of microplastics biodegradation to solve the problem of microplastic pollution.

[The clinical features of Castleman disease in the head and neck].

Objective:To investigate the clinicopathological features, treatment and prognosis of Castleman disease in the head and neck. Methods:The clinical and pathological data of 18 patients with Castleman disease of the head and neck in Nanjing Drum Tower Hospital from 2007 to 2021 were retrospectively analyzed. There were 14 cases of unicentric type and 4 cases of multicentric type. The clinical characteristics, treatment and prognosis were analyzed. Results:Among the 18 cases of Castleman disease in the head and neck, 1 case was located in the parotid gland, 1 case was behind the ear, 1 case was in the parapharyngeal space, 3 cases were in the neck region Ⅰ, 2 cases were supraclavicular, 2 cases were in the neck region Ⅲ, the rest were located in more than two subregions of the neck. In patients with unicentric type, no tumor recurrence and progression were found in the postoperative re-examination with neck Doppler ultrasound and CT; in the multicentric type, multiple organ dysfunction, such as edema of both lower extremities, hepatosplenomegaly, and cough, were found. Of the 4 patients with multicentric type, only 1 patient received chemotherapy, and the remaining 3 patients refused chemotherapy and only received symptomatic treatment. All patients survived during follow-up, but the disease of multicentric patients progressed significantly, and the number of involved lymph nodes increased, and hepatosplenomegaly were found in some patients. Conclusion:Castleman disease of the head and neck is mostly unicentric type, which is manifested as multiple asymptomatic enlarged lymph nodes in the neck. The surgical resection is effective and the prognosis is good. Multicentric Castleman disease of the head and neck has complex clinical symptoms and involves multiple organs over time, requiring follow-up treatment.

Will China's carbon intensity achieve its policy goals by 2030? Dynamic scenario analysis based on STIRPAT-PLS framework.

China is the largest emitter of greenhouse gases in the world, and the Chinese government proposes to reduce carbon intensity (CI) by 65% in 2030 compared with 2005. However, literature analyzing whether the current emission reduction policies can effectively help CI reach the policy target is rare. China's CI data from 1978 to 2019, divided into phases using the Bai and Perron (BP) breakpoint test, are evaluated in this study. A dynamic scenario simulation analysis using the STIRPAT-PLS framework and Monte Carlo simulation is established. The dynamic trajectory of CI is observed, and its possible value in 2030 is determined. Finally, a dynamic sensitivity analysis is performed to investigate the contribution of different influencing factors. According to research, from 1978 to 2019, CI has three structural breakpoints, 1992, 2002, and 2008, resulting in four specific growth tendencies. Our scenario analysis based on the recent phase shows that under the reference scenario, the CI would drop to 1.912 in 2030, which cannot achieve the Chinese government's policy goals. Under the outlook scenario, CI would fall to 1.638 in 2030, and the policy target can be achieved. Improving energy efficiency and optimizing energy consumption structure would be the most critical factors in reducing CI. As the only barrier, foreign trade should be guided by green trade policies. The study concludes that completing the relevant policies of the Chinese government's 14th Five-Year Report is critical to achieving CI reduction targets.