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Di-2-ethylhexyl phthalate (DEHP) harms mammalian testis development, yet the specific mechanism of its effect on sperm quality and function is unclear. In this study, male mice were administrated DEHP (200 mg/kg/day) via intragastric (i.g.) injection for 35 days. The sperm quality and function of DEHP-exposed mice were evaluated. DEHP exposure reduced the relative testis weight and serum testosterone levels. In addition, sperm count and motility parameters decreased significantly, which led to reduced sperm fertility characterized by reduced acrosome reaction rate, sperm-egg binding capacity and blastocyte formation. DEHP exposure decreased anti-oxidant indicators and the expressions of Cat, Sod1, Prdx6 and Sirt1 in the testis. DEHP-exposure also resulted in decreased proliferating cell nuclear antigen (PCNA) expression in mice testis, as well as the dose-dependent inhibition of the proliferation of GC-1 and GC-2 cells. These phenotypes may be related to increased cell apoptosis characterized by BAX/BCL2 and P53 up-regulation. DEHP exposure resulted in the down-regulation of SIRT1 and p-AKT in mice testis and decreased levels of GC-1and GC-2 cells. DEHP co-incubation with sperm in vitro resulted in decreased tyrosine phosphorylation and progressive motility, as well as p-AKT expression in capacitated sperm. Differential sperm proteomics identified 495 differentially expressed proteins, including 257 proteins down-regulated in the DEHP-exposure group. Bioinformatics analysis showed that proteins involved in sperm-egg interaction and fertilization processes were significantly down-regulated. Pathway analysis demonstrated that the adhesion pathway was enriched in down-regulated proteins, while the pathway associated with ribosomes was enriched in up-regulated proteins. Conclusively, DEHP exposure impaired male fertility by affecting sperm quality and function, and a pathway mediating the DEHP-induced decline in sperm quality and function was identified. The study provides additional information for understanding the molecular mechanisms of DEHP exposure and its effects on male reproduction.

Chinese medicine residues (CMRs) have always been considered difficult to realize resource treatment because of the possible residual heavy metals (HMs). In this study, CMRs containing HMs (Cu, Cd and Pb) were pyrolized in the tube furnace and the solar pyrolysis equipment. The ratio of HMs entering the pyrolysis products (bio-gas, bio-oil and bio-char) and the stability of HMs in biochar were analyzed. A comparative analysis showed that the less volatile HMs were basically concentrated in the biochar after the pyrolysis treatment, indicating that pyrolysis could enrich the HMs in the biochar. The leaching experiments showed that the leaching rates of Cu, Cd and Pb from biochar were 0-0.41%, 0-3.03% and 0.09-0.86% respectively, while the leaching rates of CMR were as high as 18.85, 10.98 and 2.52%, indicating that the pyrolysis process could improve the fixation effect of HMs in biomass to a greater extent and reduce the leaching toxicity of HMs. Compared with the traditional pyrolysis method, the solar pyrolysis had the same effect on the enrichment and stabilization of heavy metals in CMRs, which means that it is possible to realize the resource treatment of CMR through a renewable green energy (solar energy).

Fluoride is one of the essential trace elements for the human body, but excessive fluoride will cause serious environmental and health problems. This paper summarizes researches on the removal of fluoride from aqueous solutions using newly developed or improved biomass materials and biomass-like organic materials in recent years. These biomass materials are classified into chitosan, microorganisms, lignocellulose plant materials, animal attribute materials, biological carbonized materials and biomass-like organic materials, which are explained and analyzed. By comparing adsorption performance and mechanism of adsorbents for removing fluoride, it is found that carbonizing materials and modifying adsorbents with metal ions are more beneficial to improving adsorption efficiency and the adsorption mechanisms are various. The adsorption capacities are still considerable after regeneration. This paper not only reviews the properties of these materials for fluoride removal, but also focuses on the comparison of materials performance and fluoride removal mechanism. Herein, by discussing the improved adsorption performance and research technology development of biomass materials and biomass-like organic materials, various innovative ideas are provided for adsorbing and removing contaminants.

Morphological defense is assumed to be an effective anti-grazer strategy in phytoplankton. Scenedesmus obliquus, a globally widespread freshwater chlorophyte, can form colonies in response to the infochemicals of herbivorous zooplankton and survive in coexistence with grazers. However, the inducible defense response is often disturbed by abiotic or biotic factors, especially under the increasing global warming and environmental pollution. In this study, two nonlethal environmental factors, namely, elevated temperature and environmentally relevant Zn2+ concentrations, decreased colony formation of S. obliquus induced by Daphnia grazing infochemicals. Elevated temperature (30 °C) reduced the inducible colony size and shortened the maintenance time of defensive colonies. Decreased colony size was detected with increased Zn2+ concentration. Colony formation was inhibited even at low Zn2+ concentration (0.131 μmol L−1), which neither retarded growth nor affected photosynthesis. Warming promoted the inhibition effect of Zn2+ on inducible colony formation of S. obliquus. Warming also enhanced Zn2+ toxicity, which caused the growth rate of S. obliquus to be hindered by high Zn2+ concentrations at elevated temperature. Specially, S. obliquus which formed inducible colonies under the condition of Daphnia infochemicals had higher tolerance to Zn2+ toxicity and thus likely exerted protective effects against heavy metals. The results indicated the combined effects of global warming and heavy-metal pollution result in more severe impact on the inducible defense of S. obliquus.

Thallium (Tl) commonly occurs in shallow groundwater affected by acid mine drainage (AMD); however, our knowledge of the occurrence of Tl in shallow groundwater is limited. This study observes that the shallow groundwater in an AMD-impacted area in Southern China contains an elevated Tl concentration (22 μg/L) under the oxidizing conditions and a low Tl concentration (1 μg/L) in the reducing environment. The groundwater Tl concentration is positively correlated with oxidation-reduction potential (Eh) and negatively correlated with Cl content. The modelling results of the Tl species demonstrate that Tl

It has not been well understood that the influences of pH and accompanying anions on the toxicity of selenate (Se(VI)). The influences of pH and major anions on Se(VI) toxicity to wheat root elongation were determined and modeled based on the biotic ligand model (BLM) and free ion activity model (FIAM) concepts. Results showed that EC50[Se(VI)]T values increased from 162 to 251 μM as the pH values increased from 4.5 to 8.0, indicating that the pH increases alleviated the Se(VI) toxicity. The EC50{SeO42−} values increased from 133 to 203 μM while the EC50{HSeO4−} values sharply decreased from 210 to 0.102 nM with the pH increasing from 4.5 to 8.0. The effect of pH on Se(VI) toxicity could be explained by the changes of Se(VI) species in different pH solutions as SeO42− and HSeO4−were differently toxic to wheat root elongation. The toxicity of Se(VI) decreased with the increasing activities of H2PO4− and SO42− but not for NO3− and Cl− activities, indicating that only H2PO4− and SO42− had competitive effects with Se(VI) on the binding sites. An extended BLM was developed to consider effects of pH, phosphate and sulphate, and stability constants of SeO42−, HSeO4−, H2PO4− and SO42− to the binding sites were obtained: log K S e O 4 B L = 3.45, log K H S e O 4 B L = 5.98, log K H 2 P O 4 B L = 2.05, log K S O 4 B L = 1.85. Results implied that BLM performed much better than FIAM in the wheat root elongation prediction when coupling with toxic species SeO42− and HSeO4−, and the competitions of H2PO4− and SO42− for the binding sites while developing the Se(VI)-BLM.

Background Bisphenol A (BPA) is a well-known endocrine disruptor that affects male fertility. However, the main biological events through which BPA affects spermatogenesis remain to be identified. Methods Adult male mice were treated by feeding with drinking water containing BPA (0.2 μg/ml, 20 μg/ml, 200 μg/ml, respectively) for two months. Testes were collected for protein extraction or for immunohistochemical analysis. Epididymal spermatozoa were collected for sperm quality evaluation and male fertility assay by in vitro fertility (IVF). Serums were collected for detection of testosterone levels. Proteins associated with germ cell proliferation, meiosis, blood-testis barrier, and steroidogenesis production were examined in BPA-treated and control mice testes. CCK8 assay was used to detect the effect of BPA on the proliferation of GC-1 and GC-2 cells. Results The BPA-treated mice were characterized by decreased sperm quality, serum testosterone levels and, sub-fertile phenotype characterizing with low pregnancy rates and reduced fertilization efficiency. In lower BPA (0.2 μg/ml) treatment, PCNA and PLZF were down-expressed that indicated impaired germ cell proliferation. SYCP3 was down-expressed in BPA-treated mice, but expressions of other proteins associated with meiosis and blood-testis barrier were not significantly altered. CYP11A1 and HSD3B1 were down-expressed in BPA-treated mice that demonstrated reduced steroidogenesis activity. BPA has a concentration-dependent inhibition effect on the proliferation of GC-1 and GC-2 cells. Conclusively, low doses BPA exposure reduced mice sperm quality mainly by impairing germ cell proliferation, leading to reduced male fertility. The study would provide relevant information for investigation on molecular mechanisms and protective strategy on male production.

This is the first study to investigate the reduction mechanism of Tl (III) to Tl(I) in the presence of plants, especially rice. Smaller plant density could effectively reduce the content of organic acids in the hydroponic system to keep the stability of Tl(III). As the plant density was reduced from 40 seedlings to 10 seedlings in 100 mL Tl(III) solution, the content of oxalate was declined to one-third of the original, and the ratio of Tl(III)/total Tl was increased from 39.6% to 81.0% in the first 2 h treatment. Then the differences in antioxidant capacity of rice exposed to the two Tl species were studied. The contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion (O2˙-) of rice roots exposed to Tl(III) were all higher than those to Tl(I). Meanwhile, the catalase (CAT) activity was significantly depressed and peroxidase (POD) was increased by Tl(III), whereas superoxide dismutase (SOD) showed a rise in both Tl(I) and Tl(III) with no significant difference between them. The expression of metallothionein gene OsMT1a to Tl(I) was upregulated to 255.5 times of Tl(III) though OsMT2c was downregulated to 0.39 times of Tl(III). Overall, the different responses in metallothionein gene expression and antioxidative enzyme activation might result in more ROS accumulation to rice roots by Tl(III) treatment than those by Tl(I).

Morphological defense is assumed to be an effective anti-grazer strategy in phytoplankton. Scenedesmus obliquus, a globally widespread freshwater chlorophyte, can form colonies in response to the infochemicals of herbivorous zooplankton and survive in coexistence with grazers. However, the inducible defense response is often disturbed by abiotic or biotic factors, especially under the increasing global warming and environmental pollution. In this study, two nonlethal environmental factors, namely, elevated temperature and environmentally relevant Zn

This study aimed to investigate the influence of temperature on the ability of the mixotrophic flagellate Ochromonas to eliminate a toxic Microcystis population and degrade microcystins. We exposed Microcystis to cultures with or without Ochromonas YZ1 at 20, 25, and 30 °C for 10 days. Results showed that increased temperature promoted the growth of Ochromonas YZ1 and Microcystis, with the latter achieving high abundance without grazing. With increased temperature, Ochromonas YZ1 clearance rate increased, and Microcystis populations were earlier eliminated. Importantly, Ochromonas YZ1 degraded both intracellular and extracellular microcystins by grazing effects. The reduction ratios of Microcystis abundances and microcystins were both approximately 100% after 6 days at high temperature. In addition, more microcystins were released outside at 20 °C than at the higher temperatures. Overall, this study showed that high temperature favors elimination of toxin-producing Microcystis and degradation of microcystins by mixotrophic Ochromonas.

The extensive application of herbicides has led to a serious threat of herbicide contamination to aquatic ecosystem. Herbicide exposure affects aquatic communities not only by exerting toxicity on single species but also by changing interspecific interactions. This study investigated the antigrazer defenses of the common green alga Scenedesmus obliquus against different herbicides [glyphosate, 2,4-dichlorophenoxyacetic acid (2,4-D), and atrazine] at various concentrations (0–2.0 mg L−1). In the presence of grazer (Daphnia)-derived cues, S. obliquus populations without herbicides formed high proportions of multicelled (e.g., four- and eight-celled) colonies. This result confirms that S. obliquus exhibits a morphological defense against grazing risk. At the low concentration range of 0.002–0.02 mg L−1, the three herbicides exerted no influence on the growth and photosynthetic efficiency of S. obliquus, and multicelled colonies showed constant proportions. At the high concentration range of 0.20–2.0 mg L−1, atrazine significantly inhibited the algal growth and photosynthesis whereas glyphosate or 2,4-D did not. Nonetheless, these levels of glyphosate or 2,4-D remarkably decreased the proportion of multicelled colonies, with reduced numbers of cells per particle in Daphnia filtrate-treated population. No eight-celled colony was formed after treatment with atrazine at 0.20–2.0 mg L−1 despite the addition of Daphnia filtrate. These results suggest that herbicide exposure impairs antigrazer colonial morphs in phytoplankton although it is not sufficient to hamper algal growth. This phenomenon can increase the risk of predation by herbivores, thereby disrupting the inducible phytoplankton community. Furthermore, the predator-prey interactions between herbivores and phytoplankton can be potentially changed more seriously than previously considered.