Ecological risk assessment of heavy metals in tea plantation soil around Tai Lake region in Suzhou, China.

Tea plant [Camellia sinensis (L.) O. Kuntze] is one of the important foliar cash crops in China, and its root system absorbs heavy metal (HM) elements enriched in the soil and transports them to the over ground part. In order to ensure the safety of the soil ecological environment and tea raw materials in the tea production area, the HM contents of soil and tea plant leaves in Suzhou tea plantations were detected, the relationship between HMs and soil physicochemical properties was analyzed, and the ecological risk of HMs in tea plantation soils was evaluated by using relevant detection techniques and evaluation models. The results showed that the average pH of tea plantation soils around Tai Lake in Suzhou was within the range suitable for the growth of tea plants. The pH, soil organic matter, total nitrogen, available phosphorus and available potassium of tea plantation soil satisfying the requirements of high quality, high efficiency and high yield ('3H') tea plantation accounted for 47.06%, 26.47%, 8.82%, 79.41% and 67.65%, respectively. Site 2 fully met the requirements of '3H' tea plantation. In addition, the contents of cadmium (Cd) and mercury (Hg) were extremely variable, and the average contents exceeded the background value of soil in Jiangsu Province, but the HM contents of tea leaves all met the pollution-free standard, and the HM contents of tea leaves around Tai Lake in Suzhou were generally at a safe level. The composite ecological risk index ranged from 0.05 to 0.60, and 32 of the 34 sample sites (except site 21 and site 23) are the most suitable agricultural land for tea plantations.

How does government regulation shape residents' green consumption behavior? A multi-agent simulation considering environmental values and social interaction.

Green consumption is an inevitable choice to alleviate environmental pressure and promote sustainable development. Residents' green consumption behavior decisions are influenced by a combination of external government regulation and internal consumer psychological factors. This study incorporated regret theory and environmental values into a multi-agent model to simulate residents' green consumption behavior under various government regulation scenarios. The results show that in the absence of government regulation, residents have little motivation to actively choose green consumption. In terms of a single policy, government subsidy is more conducive to promoting green consumption behavior than government penalty, and the evolutionary trend of group decision making becomes more stable with increased policy intensity. However, neither of the two single regulatory policies can fully promote residents' environmentally conscious consumption decisions. Therefore, a combination of "carrots" (government subsidy) and "sticks" (government penalty) is required to motivate a significant increase in the number of residents who choose green consumption behavior. In addition, the intensity of social interaction between residents is found to influence the stability of behavioral evolution, with higher intensity (i.e., more neighbors) resulting in greater fluctuations in group behavior but driving more residents toward green consumption. These findings can provide a theoretical reference for policy formulation of green consumption behavior.

How does government regulation promote green product diffusion in complex network? An evolutionary analysis considering supply side and demand side.

China has launched a series of regulation policies that promote the diffusion of green products to drive the green development of resources and environment. This study proposes an evolutionary game model of green product diffusion by providing a joint "supply side - demand side" regulatory framework. It simulates the effects of government regulation on green product diffusion in complex network, the related numerical simulation analysis is carried out through a case of electric vehicles diffusion. The study confirms that (1) On the supply side, green subsidies, environmental taxes, and carbon trading market can successfully increase green product diffusion to 0.84, 0.7, and 0.65. On the demand side, green consumption vouchers, as well as publicity and education can increase green product diffusion to 0.7 and 0.67. (2) Among the order-based regulatory instruments, high environmental taxes and poor participation in carbon trading market can inhibit the spread of green products, while low green consumption vouchers fail to stimulate the purchase of green products. It is crucial to enhance emotion-based regulatory instruments like publicity and education. (3) Neither order-based nor emotion-based regulation can achieve complete diffusion of green products. This study provides new insights of green product diffusion under government regulation and its implementation effects.

3D printed miniature atomic emission detector coupling with gas chromatography: A sensitive and cost-effective strategy for the determination of volatile methylsiloxanes in municipal sewage.

The determination of volatile methylsiloxanes (VMSs) in municipal sewage has attracted great attention. Gas chromatography-mass spectrometry (GC-MS) is the most mature detection technique for VMSs, however, its instrumentation and operation cost are unfavorable in low- and middle-income countries. Herein, a novel and cost-effective strategy by using a 3D printed miniature microplasma optical emission detector (µAED) as an alternative to MS detector, was developed to detect VMSs in municipal sewage by GC after preconcentration by a laboratory-built automatic purge and trap (P&T) system. Two types of µAEDs have been fabricated and their analytical performances were compared. The one using two tungsten rods as electrodes shows better performance and was thus selected as the detecting system for real sample analysis. Under the optimized conditions, the P&T-GC-µAED system provided limits of detection of 3.6 ng L-1 to 15.5 ng L-1 of Si for tested VMSs. Relative standard deviations were better than 3.0% and good recoveries ranging from 82.4% to 102.8% were obtained for all analytes. The applicability of this system was demonstrated via the measurement of VMSs in the influents and effluents from 10 wastewater treatment plants (WWTPs) in Chengdu, China.

Decision-making dynamic evolution among groups regarding express packaging waste recycling under different reference dependence and information policy.

The reveal of express packaging waste recycling behavior evolution trend is crucial to waste management. Current models are mostly based on the classic expected utility theory, without considering groups are susceptible to internal and external factors. To address this drawback, we construct an evolutionary game model of express packaging waste recycling behavior by considering information policy and reference dependence factors to explore groups' decision-making with different initial adoption rates. A system dynamics simulation model based on survey data is then built, and simulation experiments are also designed to reveal the impacts of key factors on the evolution path of recycling behavior. The results show that, without information policy, groups cyclically oscillate around the initial state. The stable trend depends on the information intensity, and the information effect is marginal diminishing. Groups with a lower initial adoption rate will evolve to an ideal stable strategy only when information intensity exceeds the threshold of ten. Reference points can change behavior strategies and are characterized by significant loss aversion. The benefits and costs affect groups' adoption or rejection behaviors. These findings can provide new ideas for related research and offer a reference for the government to formulate efficient waste management policies.

Screening value for gastrointestinal lesions of magnetic-controlled capsule endoscopy in asymptomatic individuals.

BACKGROUND AND AIM: Most patients with gastric tumors and precancerous lesions are asymptomatic, which often results in delayed diagnosis and treatment. Compared with conventional gastroscopy and capsule endoscopy, magnetic-controlled capsule endoscopy is a non-invasive, effective, and cost-efficient diagnostic modality for gastric examination. We retrospectively investigated magnetic-controlled capsule endoscopy as a screening tool for gastrointestinal lesions (particularly gastric tumors and precancerous lesions) in asymptomatic individuals. METHODS: In this retrospective study, 1757 patients who voluntarily underwent magnetic-controlled capsule endoscopy between January and December 2019 at nine medical centers across Shaanxi province based on strict inclusion and exclusion criteria were enrolled. The primary outcomes were gastric tumor and precancerous lesion detection rates and procedural safety. RESULTS: The upper and lower gastrointestinal lesion detection rates were 98.35% (1728/1757) and 21.61% (78/361), respectively; 2.28% of patients were diagnosed with gastric tumors including gastric cancer (4/1757) and submucosal tumors (36/1757). Three types of precancerous lesions were found in 591 patients (33.64%), including chronic atrophic gastritis (23.16%), gastric polyp (10.98%), and gastric ulcer (2.96%). For patients aged over 40 years, the detection rate of precancerous lesions was higher (14.36% vs 42.58%, P < 0.001). No patient was diagnosed with small intestinal cancer. No adverse events occurred. CONCLUSIONS: Magnetic-controlled capsule endoscopy could be used as a promising novel screening modality for diagnosis of gastrointestinal lesions in asymptomatic individuals, specifically gastric tumors and precancerous lesions, with the advantages of safety, non-invasiveness, effectiveness, and cost-efficiency.

Co-evolutionary simulation study of multiple stakeholders in the take-out waste recycling industry chain.

Take-out waste causes severe environmental pollution and wastes resources; thus, recycling of take-out waste is an urgent problem that must be addressed. From the co-evolutionary viewpoint, we used evolutionary game theory to build a tripartite game model involving government, consumers and enterprises, and then made simulation analysis using Vensim® software, exploring the evolutionary equilibrium and the main driving factors. The simulation results showed that (1) no matter what government's, consumers' or enterprises' initial strategy is, through imitation and evolution, the three will eventually arrive at the state in which government chooses regulation, the consumer chooses a green approach, and an enterprise chooses to participate in the recycling industry chain. (2) The consumer (government) plays a role of promoter (guide) in the evolutionary process in the take-out waste recycling industry chain. (3) The higher the regulatory costs or penalties for enterprises not participating in the recycling industry chain, and the larger the subsidy to consumers for choosing a green approach and to enterprises for participating in the recycling chain, the sooner the government will stabilize a no-regulation strategy. (4) The higher the cost of enterprise participation in the recycling chain, the later the government will arrive at the stabilization strategy. (5) The higher the penalty to an enterprise, the earlier the enterprise will evolve to the stabilization strategy; the higher the subsidy to consumers (enterprises), the earlier consumers (enterprises) will evolve into the stabilization strategy, and the higher the cost of enterprise participation, the later the enterprise will evolve into a stable strategy. This study is expected to provide a reference for governments to formulate effective waste management policies.

A review of studies on urban energy performance evaluation.

Energy is a foundation for a city to create economic wealth, satisfy people's desires, and achieve benefits. However, the increasing mismatch between energy supply and demand and the worsening of environmental pollution have highlighted the importance of improving urban energy performance, so the number of studies related to urban energy performance evaluation is increasing. Based on describing the authors, numbers, regional sources, and themes of these studies, this paper reviews and analyzes the conceptions, evaluation indicators, influencing factors, evaluation methods, and evaluation systems related to urban energy performance. Most countries have expressed concern about this topic. Researchers in China, Belgium, and the USA have had the most achievements and collaborations. The concept of urban energy performance further extends to a comprehensive performance. It is measured based on an input-output process. In addition to the original evaluation indicators, new desirable outputs and undesirable outputs are included. Industrial structure, energy price, population density, home car ownership, climate factors, Gini coefficient, health expenditure level, and unemployment rate are regarded as influencing factors. Therefore, a new framework of evaluation indicators and influencing factors is constructed. Stochastic frontier analysis (SFA) and data envelopment analysis (DEA) are commonly used to evaluate. With changes in conceptions, evaluation indicators, and influencing factors, the evaluation method should rather focus on measuring multiple input-output variables, determining the evaluation results and the impacts of factors at the same analysis stage, and highlighting policy orientations. As an important management tool, the evaluation system would continue to be studied and developed.

Assessment of the degradation rates and effectiveness of different coated Mg-Zn-Ca alloy scaffolds for in vivo repair of critical-size bone defects.

Surgical repair of bone defects remains challenging, and the search for alternative procedures is ongoing. Devices made of Mg for bone repair have received much attention owing to their good biocompatibility and mechanical properties. We developed a new type of scaffold made of a Mg-Zn-Ca alloy with a shape that mimics cortical bone and can be filled with morselized bone. We evaluated its durability and efficacy in a rabbit ulna-defect model. Three types of scaffold-surface coating were evaluated: group A, no coating; group B, a 10-µm microarc oxidation coating; group C, a hydrothermal duplex composite coating; and group D, an empty-defect control. X-ray and micro-computed tomography(micro-CT) images were acquired over 12 weeks to assess ulnar repair. A mechanical stress test indicated that bone repair within each group improved significantly over time (P < 0.01). The degradation behavior of the different scaffolds was assessed by micro-CT and quantified according to the amount of hydrogen gas generated; these measurements indicated that the group C scaffold better resisted corrosion than did the other scaffold types (P < 0.05). Calcein fluorescence and histology revealed that greater mineral densities and better bone responses were achieved for groups B and C than for group A, with group C providing the best response. In conclusion, our Mg-Zn-Ca-alloy scaffold effectively aided bone repair. The group C scaffold exhibited the best corrosion resistance and osteogenesis properties, making it a candidate scaffold for repair of bone defects.