Polyvinyl Chloride Microplastics Affect Methane Production from the Anaerobic Digestion of Waste Activated Sludge through Leaching Toxic Bisphenol-A.

The retention of polyvinyl chloride (PVC) microplastics in sewage sludge during wastewater treatment raises concerns. However, the effects of PVC microplastics on methane production from anaerobic digestion of waste activated sludge (WAS) have never been documented. In this work, the effects of PVC microplastics (1 mm, 10-60 particles/g TS) on anaerobic methane production from WAS were investigated. The presence of 10 particles/g TS of PVC microplastics significantly ( P = 0.041) increased methane production by 5.9 ± 0.1%, but higher levels of PVC microplastics (i.e., 20, 40, and 60 particles/g TS) inhibited methane production to 90.6 ± 0.3%, 80.5 ± 0.1%, and 75.8 ± 0.2% of the control, respectively. Model-based analysis indicated that PVC microplastics at >20 particles/g TS decreased both methane potential (B0) and hydrolysis coefficient (k) of WAS. The mechanistic studies showed that bisphenol A (BPA) leaching from PVC microplastics was the primary reason for the decreased methane production, causing significant ( P = 0.037, 0.01, 0.004) inhibitory effects on the hydrolysis-acidification process. The long-term effects of PVC microplastics revealed that the microbial community was shifted in the direction against hydrolysis-acidification and methanation. In conclusion, PVC microplastic caused negative effects on WAS anaerobic digestion through leaching the toxic BPA.

Association between cadmium exposure and urolithiasis risk: A systematic review and meta-analysis.

BACKGROUND: We performed a meta-analysis to determine whether a consistent relationship exists between cadmium exposure and urolithiasis in humans. Accordingly, we summarized and reviewed previously published quantitative studies. METHODS: Eligible studies with reference lists published before June 1, 2017 were obtained from searching several databases. Random effects models were used to summary the overall estimate of the multivariate adjusted odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Six observational studies involving 88,045 participants were identified and stratified into the following categories according to cadmium assessment results: occupational (n = 4) and dietary (n = 2). The findings of the meta-analysis suggested that the risk of urolithiasis increases significantly by 1.32 times at higher cadmium exposure (OR = 1.32; 95% CI = 1.08-1.62; for highest vs lowest category urinary cadmium values). The summary OR in occupational exposure (OR = 1.56; 95% CI = 1.13-2.14) increased at the same condition. Meanwhile, no association was observed between cadmium exposure and urolithiasis risk in dietary exposure (OR = 1.13; 95% CI = 0.87-1.47). A significant association remained consistent, as indicated by subgroup analyses and sensitivity analyses. CONCLUSIONS: The meta-analysis indicated that increased risk of urolithiasis is associated with high cadmium exposure, and this association is higher in occupational exposure than in dietary exposure. Nevertheless, well-designed observational studies with different ethnic populations are still needed.

Strategy of extraction methods and reconstruction algorithms in computed tomography of diffraction enhanced imaging.

Computed tomography of diffraction enhanced imaging (DEI-CT) is a novel x-ray phase-contrast computed tomography which is applied to inspect weakly absorbing low-Z samples. Refraction-angle images which are extracted from a series of raw DEI images measured in different positions of the rocking curve of the analyser can be regarded as projections of DEI-CT. Based on them, the distribution of refractive index decrement in the sample can be reconstructed according to the principles of CT. How to combine extraction methods and reconstruction algorithms to obtain the most accurate reconstructed results is investigated in detail in this paper. Two kinds of comparison, the comparison of different extraction methods and the comparison between "two-step" algorithms and the Hilbert filtered backprojection (HFBP) algorithm, draw the conclusion that the HFBP algorithm based on the maximum refraction-angle (MRA) method may be the best combination at present. Though all current extraction methods including the MRA method are approximate methods and cannot calculate very large refraction-angle values, the HFBP algorithm based on the MRA method is able to provide quite acceptable estimations of the distribution of refractive index decrement of the sample. The conclusion is proved by the experimental results at the Beijing Synchrotron Radiation Facility.

Association between butchers and cancer mortality and incidence: A systematic review and meta-analysis.

BACKGROUND: In this study, we evaluated whether increased risks of mortality and cancer incidence exist among butchers worldwide. To achieve this goal, we conducted a systematic review and meta-analysis to investigate the correlations of the risks of cancer death and incidence with male and female butchers. METHODS: We obtained data by performing a comprehensive literature search in several databases for eligible studies published before March 2017. Multivariable-adjusted standardized mortality ratios (SMRs) and odds ratio (OR), as well as associated 95% confidence intervals (CIs) and those by subgroups, were extracted and pooled. RESULTS: A total of 17 observational studies comprising 397,726 participants were included in the meta-analysis. The butcher occupation was not associated with all-cancer mortality risk, with pooled overall SMRs of 1.07 (95% CI 0.96-1.20). However, the pooled ORs revealed that butchers hold an elevated risk of total cancer incidence (OR, 1.51; 95% CI, 1.33-1.73). No proof of publication bias was obtained, and the findings were consistent in the subgroup analyses. CONCLUSION: Our results suggest that working as butchers did not significantly influence all-cancer mortality risk but significantly contributed to elevated all-cancer incidence risk. Nevertheless, well-designed observational studies on this topic are necessary to confirm and update our findings.

α7 Nicotinic Acetylcholine Receptor is a Novel Mediator of Sinomenine Anti-Inflammation Effect in Macrophages Stimulated by Lipopolysaccharide.

Sinomenine (SIN), an alkaloid derived from the plant Sinomenium acutum, has anti-inflammatory and analgesic effects and has been used for rheumatoid arthritis treatment in China. This study aims to verify the hypothesis that SIN acts on α7 nicotinic acetylcholine receptor (α7nAChR) to inhibit the activation of macrophages stimulated by lipopolysaccharide. The prototypical α7nAChR antagonist α-bungarotoxin and mecamylamine attenuated the effect of SIN on tumor necrosis factor-α and interleukin-6 in RAW264.7 murine macrophage-like cells and primary peritoneal macrophages of mouse induced by lipopolysaccharide. With the knockdown of α7nAChR expression in RAW264.7 cells by small interfering RNA, the inhibitory effect of SIN on tumor necrosis factor-α and interleukin-6 was reversed. Sinomenine decreased p65 expression in nuclear and increased IκBα expression in cytoplasm, and these effects were reversed by the α7nAChR small interfering RNA as well. These results indicate that the anti-inflammatory effects of SIN on macrophages in vitro depend on α7nAChR.

Full-field hard x-ray microscopy below 30 nm: a challenging nanofabrication achievement.

The fabrication of devices to focus hard x-rays is one of the most difficult-and important-challenges in nanotechnology. Here we show that Fresnel zone plates combining 30 nm external zones and a high aspect ratio finally bring hard x-ray microscopy beyond the 30 nm Rayleigh spatial resolution level and measurable spatial frequencies down to 20-23 nm feature size. After presenting the overall nanofabrication process and the characterization test results, we discuss the potential research impact of these resolution levels.