The gold nanoparticles (AuNPs) were synthesized using the lichen Parmelia sulcata extract (PSE) and characterized. The peaks of ultraviolet spectrophotometer and Fourier transmission infrared confirmed the formation of nanoparticles and the bioactive compounds of the lichen being responsible for reducing and capping of the particles. The face-centered cubic particles were determined by XRD peaks at 111, 200, 220, and 311. The elemental composition and spherical shape of AuNPs were confirmed by energy-dispersive spectroscopy and transmission electron microscopy. The average particle size is 54 nm, and the zeta potential − 18 was ascertained by dynamic light scattering. The potential effect of synthesized nanoparticles and lichen extracts was evaluated for antioxidant bioassays like DPPH and H₂O₂ and tested for mosquitocidal activity against Anopheles stephensi. Results showed that the lichen extract and AuNPs have the capability to scavenge the free radicals with the IC₅₀ values of DPPH being 1020 and 815 μg/ml and the IC₅₀ values of H₂O₂ being 694 and 510 μg/ml, respectively. The mosquitocidal experimental results in this study showed the inhibition of A. stephensi and A. aegypti against the larvae (I–IV instar), pupae, adult, and egg hatching. On comparison, A. stephensi showed effective inhibition than A. aegypti even at low concentration. Based on the obtained results, gold nanoparticles synthesized using PSE showed an excellent mosquitocidal effect against Anopheles stephensi.

Agricultural watersheds are a crucial contributor of terrestrial dissolved organic matter (DOM) for the adjacent aquatic environment. Recently, ecological engineering of the buffer zone such as a rice-paddy field was established to reduce the export of nutrients and contaminants from a small agricultural watershed. However, the potential of the rice-paddy field to reduce the terrestrial signature of DOM is unclear. Therefore, two small agricultural sub-catchments (i.e., sub-1 and sub-2) with different land uses and hill slope angles in the Three Gorges Reservoir (TGR) area of China were studied from 2014 to 2015. The results showed that the terrestrial DOM signals are indicated by optical indices (SUVA₂₅₄, SR, fluorescence index) in the steeper and more forest covered, but rice-paddy field buffered sub-catchment (i.e., sub-2) decreased significantly, as compared to the reference sub-catchment (i.e., sub-1). Regardless of seasonal variations, the rice-paddy field retained a buffering role to reduce the terrestrial property of DOM and the highest capacity was observed during the rice-growth period. However, during storm events, the differences of DOM properties for two sub-catchments were not significant, because the buffer system was weakened. Finally, environmental implications of the role of such a buffer zone in the TGR areas are discussed. These results demonstrate that rice-paddy fields are successful in mitigating the terrestrial property of exported DOM, but the weaker performance during storm events still needs to be considered.

The aim of the present study was to investigate whether curcumin (CUR) can ameliorate cadmium-induced reproductive toxicity and its mechanism. A total of 48 male mice were equally divided into 4 groups: control, CdCl₂ (2 mg/kg, intraperitoneally inject) curcumin (50 mg/kg, intraperitoneally inject), co-treatment with curcumin (50 mg/kg), and CdCl₂ (2 mg/kg) for 10 days. The results demonstrated that CdCl₂ reduces sperm motility, decreases the sperm density and serum testosterone content, and significantly improves the rate of sperm deformity. CdCl₂ increased the level of testicular total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) activity, and glutathione (GSH), and CdCl₂ declined the level of malondialdehyde (MDA). However, the semen quality of the mice in the curcumin intervention group was improved. Moreover, the testosterone content and antioxidant capacity were increased. In the Cd group mice, the expression of testicular Nrf2, as well as the mRNA and protein expressions of the downstream target molecules, glutathione peroxidase (GSH-Px), and γ-glutamylcysteine synthetase (γ-GCS) of Nrf2 declined, while the above genetic expressions elevated significantly in the curcumin intervention group. Our results suggested that curcumin could protect against Cd-induced testicular injury via activating the Nrf2/ARE signaling pathway.

A 2-year field experiment was carried out with aim to assess the phytoremediation potential of Miscanthus × giganteus cultivated on the flotation tailings and to evaluate the effects of mineral NPK fertilizer on metal accumulation and plant physiological parameters and growth. Flotation tailings of the mine Rudnik (Serbia) are burdened with Pb, Cu and Zn and cause heavy metal pollution and deterioration of the surrounding ecosystems. In the second year of growth, plants retained the major portion of metals within their roots, with bioconcentration factor > 1 for Cu and Zn and < 1 for Pb. Their translocation factors were far below 1, showing that M. × giganteus acts as excluder of Cu, Zn and especially Pb. Higher amounts of Pb and Zn in leaves reduced the photosynthetic rate and total antioxidative capacity, but increased lipid peroxidation level. Changes at physiological level resulted in pronounced leaf senescence, reduced plant growth rate and annual biomass yield. Fertilization enhanced metal uptake by plant roots, but had no effect on their translocation to leaves. It improved chlorophyll a content, potential efficiency of Photosystem II photochemistry and biomass yield. Overall results indicate that M. × giganteus can be cultivated on the abandoned flotation tailings and that fertilization had positive effects on its physiology and growth.

Moss and lichen bag technique (Dicranum sp., Hypnum sp., Polytrichum sp., Hypogymnia physodes) and activity of soil enzymes (urease, acid and alkaline phosphatase, fluorescein diacetate, ß-glucosidase) were used as bioindicators of air and soil pollution in Dubník former mining area (East Slovakia). Ten open mining pits and 8 heaps of waste material were chosen for the research purposes. Contamination factor (Cf), degree of contamination (Cd), and pollution load index (PLI) were used to evaluate the level of soil pollution and relative accumulation factor (RAF) expressed the level of air pollution by risk elements (As, Cd, Cu, Fe, Mn, Ni, Sb, Pb, Zn). Based the degree of contamination results, the study area was polluted by individual elements in the following order: Fe>Cd>As>Pb>Sb>Zn>Cu>Ni>Mn. The highest values of Mn and Ni and lower values of urease were determined in open mining pits comparing heaps of waste material. The results of PLI index confirmed extreme pollution at all sampling sites. Considering the average RAF values showed the decrease of accumulation abilities of evaluated taxa in the following order: Dicranum sp.>Hypnum sp.>Hypogymnia physodes>Polytrichum sp.

Based on the idea of a “Community of Human Destiny,” the Chinese government proposed the “Belt and Road” initiative, and clearly proposed to promote green development and strengthen ecological environmental protection. However, a considerable number of countries are resource-rich economies with serious market misallocations. Using the stochastic frontier analysis (SFA) combined with the directional distance function (DDF) framework, this paper measures the green total factor productivity (GTFP) and its items (i.e., technical change and efficiency change) of 33 countries along the Belt and Road in 1995–2012, and then the impact of market misallocations on GTFP is analyzed. The following conclusions are drawn: (1) The main driving force for GTFP promotion in Asian countries came from technical change, while in European countries, it came from efficiency change. (2) Market misallocations had significantly hindered the GTFP of these economies. Countries with greater market misallocations have smaller GTFP. (3) Results based on counterfactual measures showed that GTFP could be increased by up to 4.04% and the average can be increased by 1.24% after eliminating market misallocations.

Neural network models have been used to predict chlorophyll-a concentration dynamics. However, as model generalization ability decreases, (i) the performance of the models gradually decreases over time; (ii) the accuracy and performance of the models need to be improved. In this study, Transfer learning (TL) is employed to optimize neural network models (including feedforward neural networks (FNN), recurrent neural networks (RNN) and long short-term memory (LTSM)) and overcome these problems. Models using TL are able to reduce the influence of mutable data distribution and enhance generalization ability. Thus, it can improve the accuracy of prediction and maintain high performance in long-term applications. Also, TL is compared with parameter norm penalties (PNP) and dropout—two other methods used to improve model generalization ability. In general, TL has a better prediction effect than PNP and dropout. All the models, including FNN with different architectures, RNN and LSTM, as well as models optimized by PNP, dropout, and TL, are applied to an estuary reservoir in eastern China to predict chlorophyll-a dynamics at 5-min intervals. According to the results of this study, (i) models with TL produce the best prediction results; (ii) the original models and the models with PNP and dropout lose their ability to predict within 3 months, while TL models retain a high prediction accuracy.

The issue of recycling waste solar cells is critical with regard to the expanded use of these cells, which increases waste production. Technology establishment for this recycling process is essential with respect to the valuable and hazardous metals present therein. In the present study, the leaching potentials of Acidithiobacillus thiooxidans, Acidithiobacillus ferrooxidans, Penicillium chrysogenum, and Penicillium simplicissimum were assessed for the recovery of metals from spent solar cells, with a focus on retrieval of the valuable metal Te. Batch experiments were performed to explore and compare the metal removal efficiencies of the aforementioned microorganisms using spent media. P. chrysogenum spent medium was found to be most effective, recovering 100% of B, Mg, Si, V, Ni, Zn, and Sr along with 93% of Te at 30 °C, 150 rpm and 1% (w/v) pulp density. Further optimization of the process parameters increased the leaching efficiency, and 100% of Te was recovered at the optimum conditions of 20 °C, 200 rpm shaking speed and 1% (w/v) pulp density. In addition, the recovery of aluminum increased from 31 to 89% upon process optimization. Thus, the process has considerable potential for metal recovery and is environmentally beneficial.

Gaseous fuel as a combustion enhancer with a pilot fuel offers significant benefits in improving engine efficiency. Hydrogen and hydroxy are the two most common gaseous fuels that have been widely investigated in the CI engine but which one performs best is still inconvenient. In this study, hydrogen and hydroxy were injected with BD40 (v/v) separately in a common diesel engine to compare the performance and emission characteristics of these fuels. Engine performance parameters include brake thermal efficiency (BTE) and brake-specific energy consumption (BSEC), and exhaust emissions include hydrocarbon (HC), CO, CO₂, NOx, and smoke opacity. The induction of both hydroxy and hydrogen with BD40 has a positive effect on engine performance and emissions except NOx when compared to neat diesel fuel and BD40. The BTE of hydroxy-rich BD40 increased by 7.2% while BSEC reduced by 7.6% as compared to BD40 with hydrogen. The CO, HC, and smoke opacity of hydroxy-operated engine was found to be better than hydrogen-inducted engine. The NOx emission increased with the induction of both gaseous fuels and hydroxy-enriched BD40 produced 12.5% more emission than hydrogen-operated BD40 engine. Thus, more concisely, hydroxy-operated biodiesel engine performed better than hydrogen engine in terms of BTE, BSEC, CO, HC, and smoke opacity.

Agricultural farmers in developing countries are at high risk of pesticide exposure and adverse effects because of unsafe practices and inappropriate legislation. Biological monitoring is considered a useful tool for pesticide exposure assessment; however, its use is limited in developing countries due to a lack of techniques and resources such as laboratory analysis, trained staff and budgets. This study examines whether the World Health Organization predicted exposure assessment model (WHO-PEAM) is a suitable alternative tool for assessing insecticide exposure among agricultural farmers. WHO-PEAM was used to predict daily doses (PDD) of chlorpyrifos for a group of Vietnamese rice farmers using a set of exposure parameters obtained from a questionnaire survey of participant famers during a field study. These results were compared to absorbed daily doses (ADD) of chlorpyrifos for the farmers measured using a biological monitoring program, in which 24-h urine samples were collected and analysed for the chlorpyrifos metabolite, 3,5,6-trichloro-2-pyridinol (TCP) using LC/MS. Validation of the model results was tested using the Wilcoxon signed-rank test (WSR) and two-way mixed-model intraclass correlation coefficient (ICC). The mean of total ADD was 20 μg/kg/day while that of total PDD was 22 μg/kg/day. The WSR test revealed no statistically significant difference in the average values of ADDT and PDDT. ICC indicated substantial agreement for both single and average measures between ADDT and PDDT (ICC, 0.62 and 0.77, respectively). The results demonstrate that a refined WHO-PEAM model can be readily used as a field method, without biological monitoring, to evaluate chlorpyrifos exposure among agricultural farmers in Vietnam and similar developing countries.