In order to understand the mechanism of the difference of Cd absorption and Cd enrichment in different ryegrass varieties, pot experiment was conducted to study on the response of two varieties of ryegrass (Bond and Abbott) to Cd stress as well as the differences of Cd uptake and expression of MT family genes and NRAMP2. Results showed that root dry weights of two varieties and shoot dry weights of Abbott increased first and then decreased with the increase of Cd level in soil. When exposed to 75 mg kg⁻¹ Cd, shoot dry weight and plant dry weight of Abbott both reached maximum values (10.92 and 12.03 g pot⁻¹), which increased by 11.09 and 10.67% compared with the control, respectively. Shoot dry weight and plant dry weight of Bond decreased with the increase of Cd level in soil. When the Cd level in soil was 75 mg kg⁻¹, shoot Cd concentrations of the two varieties were 111.19 mg kg⁻¹ (Bond) and 133.69 mg kg⁻¹ (Abbott), respectively, both of which exceeded the critical value of Cd hyperaccumulator (100 mg kg⁻¹). The expression of MT gene family and NRAMP2 in the leaf of Bond variety significantly increased at the Cd level of 75 mg kg⁻¹ and reached maximum value (except MT2C) at Cd level of 150 mg kg⁻¹. The expression of MT gene family in the stem of Bond variety showed a double-peak pattern, while the expression of NRAMP2 was a single-peak pattern. The expression of MT gene family and NRAMP2 in Abbott variety was consistent with single-peak pattern. The expression of MT gene family and NRAMP2 in leaf both significantly increased at Cd level of 150 mg kg⁻¹, while that in stem and root significantly increased at Cd level of 75 mg kg⁻¹. For both varieties of ryegrass, the expression amount of MT family genes and Nramp2 in leaf was higher than that in root and stem, indicating the Cd tolerance of ryegrass can be improved by increasing the expression levels of MT family genes and Nramp2 in stem and root. There was significant genotypic difference in the expression of MT gene family and NRAMP2 between the two varieties of ryegrass, and the expression of MT gene family and NRAMP2 in leaves and stems of Bond variety was higher than that in Abbott variety, while the expression of MT gene family and NRAMP2 in roots of Abbott variety was higher than that in Bond variety. The two gene families investigated in this study may be closely related to Cd uptake, but not related to Cd transport from root to leaf and Cd enrichment in shoot.

The present study aimed to determine the level of iron and calcium in the seminal plasma of men with different fertility potentials and to examine its relationship with oxidative stress. Seventy-nine sub-fertile patients with asthenoteratozoospermia (AT), n 27; teratoleucozoospermia (TL), n 20; teratozoospermia (Terato), n 32; and 29 healthy donors were included. The ability of spermatozoa to produce reactive oxygen species (ROS) was evaluated by using nitroblue tetrazolium (NBT) staining. The lipid peroxidation end product, malondialdehyde (MDA), and the trace element levels (iron and calcium) were measured spectrophotometrically. Iron and calcium concentrations in seminal plasma of the patient groups were significantly more elevated than the normal group. Nevertheless, both calcium and iron showed strong negative correlations with the total sperm motility and normal sperm morphology, but only iron was positively and significantly associated with multiple anomalies index and seminal leucocyte concentration. On the other hand, the rates of MDA and ROS production in semen were significantly higher in the three abnormal groups than in controls. These two oxidative stress biomarkers were significantly associated with the percentage of atypical forms in semen. However, only semen ROS level was significantly associated with the decreased sperm motility and the sperm leucocytes concentration. Meanwhile, there are positive correlations between seminal iron and calcium content and the studied oxidative stress biomarkers. Oxidative stress and trace element excess are implicated in low sperm quality. Iron and calcium might be the mediators of the effects of oxidative damage and induces lipid peroxidation.

Photocrosslinked silicone acrylates are used in a variety of applications, such as printing inks, adhesives, or adhesive release liners. Their production requires the use of a photoinitiator. Even if the photoinitiator represents a minor mass in the photocurable formulation (2–10%), it is used in excess and residual amounts may therefore remain in the polymerized products and possibly migrate into the environment during the use of the products and/or at their end-of-life stage. Little is known on the possible degradation of silicone acrylate which may increase the potential release. The present study investigated the release of Darocur 1173, the most commonly used photoinitiator, from silicone matrix and the effect of accelerated photoageing on the extent of the phenomenon. Leaching tests in water were conducted on thin-coated plastic film (release liners) made of a mixture of polypropylene and polyethylene. Results showed that 44% of the Darocur 1173 photoinitiator initially used in silicone formulation was released from silicone matrix in the leaching test. Accelerated photoageing obtained by UV irradiation of the films for up to 200 h was found to favor photoinitiator degradation but also induced a strong and fast oxidation of silicone-coated liners as compared to that of uncoated ones. Graphical abstract

Crocin (C₄₄H₆₄O₂₄) is an isolated bioactive molecule of saffron extract. It has different pharmacological effects such as antioxidant and anti-inflammatory activities. In the present study, radioprotective property of crocin was investigated in the rat liver. Thirty-two rats were equally divided into four groups: (1) control (normal saline), (2) crocin (200 mg/kg), (3) γ-rays (6Gy), and (4) crocin plus γ-rays-treated groups. The liver histopathology, serum transaminases (ALT and AST), alkaline phosphatase (ALP), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and hepatic lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) have been assessed. The histopathological result of hepatic tissue in group 3 showed hydropic degeneration and this progressed to focal or spotty necrosis through the lobule. Moreover, some sinusoids are distended with blood or with leukocytic infiltrations. Other cases in group 3 showed periportal leukocytic infiltrations and necrosis extended out from the portal tract to involve hepatic lobules with fibrinous necrosis in portal vessels, while the examination of hepatic tissues of group 4 showed reduced deformities, irregular arrangement, congested hepatic vessels, and necrosis in hepatocytes. The results also showed significant decreased level of liver function activities, inflammatory markers, lipid peroxidation, and increased levels of liver antioxidants enzymes in group 4. Crocin showed moderate protective effect against γ-rays-induced liver toxicity. The antioxidant effect of crocin may be a major reason for its positive impact on liver parameters. Graphical abstract .

Plastic pollution in aquatic environments is one of the most fatal environmental issues in the world. Although the distribution of plastic debris in the sea and at coasts has been addressed, the transportation of plastics through a river system is unclear but important. The distribution of plastic debris in the Selenga River system is responsible for the environmental pollution of Lake Baikal. Twelve sampling sites along the river shore of the Selenga River system have been surveyed considering the industrial activity and population density. The number of plastics significantly correlates with the population density. The higher the number of plastics is, the smaller is the average size. The size fractions of foam and film plastics show a significant relationship, suggesting that the plastic debris fragmented on-site on the river shores. The most abundant plastic debris is polystyrene foam (PSF), which is usually used for construction and packaging. Plastic debris occurs due to insufficient plastic waste management. Its distribution is affected by seasonal changes of the water level and flow rate of tributaries. Furthermore, the fragmentation of plastic debris is related to temperature changes associated with freeze and thaw cycles, solar radiation, and mechanical abrasion. Smaller microplastics with microscopic sizes were detected in PSF debris. Based on micro-Fourier transform infrared spectroscopy, these microplastics are polystyrene and polyethylene. This study proves that invisible and visible microplastics are transported together.

The increased exposure to cadmium (Cd) through environmental pollutants, food and cigarette smoke is a concern worldwide. The association of Cd with impaired learning disabilities led us to hypothesise that cadmium levels in brain tissue could be dose-dependently related to the extent of memory impairment and oxidative stress. In this study, we proposed to study whether cadmium exposure to dams could alter the brain Cd levels, memory parameters, antioxidant enzymes in brain and their gene expression in the F1-F2 generation mice and whether quercetin could modulate this effect. Animals were administered Cd alone and in combination with quercetin for 7 days during their gestation period. Their newborn pups (F1 and F2 mice) were reared until adulthood and were tested for memory using Morris water maze and step-down latency test. The brain tissue of F1 mice was collected. Cd levels were estimated using the atomic absorption spectrophotometer. G-S-transferase (GST) and catalase (CAT) activity were measured and fold increase in their respective gene expression was observed using the RT-PCR method. Cd levels were significantly increased in the brain tissue of animals exposed to Cd but cotreatment with quercetin showed decreased levels in both generations. Memory impairment was observed in animals of F1 generation exposed to Cd and cotreatment with quercetin (100 mg/kg) reversed this effect. Cd exposure significantly enhanced both activity and expression of GST and CAT in the brain tissue of F1 generation mice and quercetin attenuated this effect. In F2 generation, results were variable. GST activity and expression increased with Cd and decreased with quercetin cotreatment. However, CAT activity showed no significant change despite a decrease in gene expression. Quercetin cotreatment enhanced activity as well gene expression in F2 generation. Our study insinuates that Cd levels could act as a predictor of memory impairment and altered enzyme activity and gene expression in brain tissue. Quercetin helped to reduce Cd levels in brain tissue of F1 and F2 generation and modulated the antioxidant system of the cell by affecting expression of antioxidant enzymes at the transcription level.

TDS is modeled for an aquifer near an unlined landfill in Canada. Canadian Drinking Water Guidelines and other indices are used to evaluate TDS concentrations in 27 monitoring wells surrounding the landfill. This study aims to predict TDS concentrations using three different modeling approaches: dual-step multiple linear regression (MLR), hybrid principal component regression (PCR), and backpropagation neural networks (BPNN). An analysis of the bias and precision of each models follows, using performance evaluation metrics and statistical indices. TDS is one of the most important parameters in assessing suitability of water for irrigation, and for overall groundwater quality assessment. Good agreement was observed between the MLR1 model and field data, although multicollinearity issues exist. Percentage errors of hybrid PCR were comparable to the dual-step MLR method. Percentage error for hybrid PCR was found to be inversely proportional to TDS concentrations, which was not observed for dual-step MLR. Larger errors were obtained from the BPNN models, and higher percentage errors were observed in monitoring wells with lower TDS concentrations. All models in this study adequately describe the data in testing stage (R² > 0.86). Generally, the dual-step MLR and hybrid PCR models fared better (R²ₐᵥg = 0.981 and 0.974, respectively), while BPNN models performed worse (R²ₐᵥg = 0.904). For this dataset, both regression and machine learning models are more suited to predict mid-range data compared to extreme values. Advanced regression methods (hybrid PCR and dual-step MLR) are more advantageous compared to BPNN.

Emission utilization permission is an interesting but complex issue regarding the environmental effect of pollution. This paper proposes a mathematical programming–based approach to emission utilization permission taking environmental efficiency into consideration. We use this approach for an environmental efficiency analysis and emission utilization permission (extra emission permission) of selected economic sectors in Iran, namely, agriculture, oil, industry, transportation, and domestic, commercial, and public. We use a gradually decreasing scheme for the process of emission utilization permission to investigate the condition of each sector during the process. The result reveals a vital need of improvement for two sectors, namely, oil sector and transportation sector, at the end of emission utilization permission process that is very tight in terms of emission permission.

Stereocaulon sorediiferum is expected to be a Cu-hyperaccumulator lichen and has fluorescent substances. To clarify the relationship between the fluorescence (FL) of the lichen and its Cu concentration, we collected S. sorediiferum samples at Cu-contaminated and uncontaminated sites in Japan, determined the concentration of Cu, K, Mg, Al, Ca, Mn, Fe, Zn, chlorophyll a,b, and total carotenoids in them, analyzed lichen secondary metabolites and fluorescent substances extracted from them, and measured the FL of them and their extracts. We found that the FL intensity of S. sorediiferum samples is significantly negatively correlated with their Cu concentration. The application of its FL for Cu monitoring may allow a new nondestructive quantitative method for assessing Cu contamination. The spectroscopic and chromatographic analysis shows that the fluorescent substances negatively correlated with Cu concentration are not major lichen secondary metabolites (lobaric acid and atranorin) and remain after immersion in acetone. The correlation analysis and the comparison with the causal relationship between Cu concentration and the chlorophyll a/b ratio suggest that the reason for the decrease in FL intensity with increasing Cu concentration is a structural change of the fluorescent substances by accumulated Cu. These findings lead to a better understanding of the relationship between the FL of S. sorediiferum and its Cu concentration and provide new insights into fluorescent lichen substances.

This study investigates the impact of the human capital index, globalization, and financial development on carbon dioxide of grouping OECD countries using pool mean group estimation technique from 1990 to 2015. This study also applies the second-generation cross-sectional augmented Dickey-Fuller and cross-sectional Im, Pesaran, Shin panel (CIPS) unit root, and the latest (Westerlund 2008) cointegration tests for further investigations. The result shows that both the human development index and financial development stimulate environmental improvement by using PMG long-run panel estimation approach. Furthermore, the pairwise Dumitrescu-Hurlin panel causality results prove the two-way causal association between financial development and carbon emissions. The unidirectional causality running from globalization and human development index towards carbon emission is also supported. Based on the aforementioned results, we provide a set of recommendations for policy implication. Graphical abstract