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ObjectiveTo establish a non-targeted screening method for emerging contaminants in drinking water based on high-resolution mass spectrometry and apply it to actual water samples.MethodsA total of 9 drinking water samples collected from 3 reservoirs in Shanghai were purified and concentrated by HLB solid phase extraction column， then separated and analyzed by liquid chromatography high-resolution mass spectrometer and gas chromatography high⁃resolution mass spectrometer. The acquired data were analyzed by Thermo Tracefinder， Excel and other software combined with mzCloud and NIST databases. The methodology was verified with representative compound standards. Pesticide and perfluorinated compounds were taken as examples to analyze their pollution status.ResultsA non-targeted analysis strategy based on liquid chromatography and gas chromatography tandem high-resolution mass spectrometry was established. The pollution level of 20 kinds of pesticides and 4 kinds of perfluorinated compounds identified in 9 drinking water samples were higher in the Huangpu River than in the Yangtze River estuary.ConclusionThe established non-targeted screening method by high-resolution mass spectrometry can detect potential emerging contaminants in drinking water without relying on the standards， which provides a powerful technical means for water quality monitoring and risk assessment.

Per- and polyfluoroalkyl substances （PFASs） are a new type of persistent organic pollutants with global attention. They have shown multiple toxic effects due to their persistent accumulation in human body through exposure to environmental media such as drinking water， food， atmosphere， and soil. However， the bone toxicity of PFASs has not attracted enough attention. It is believed that the exposure and accumulation of PFASs in human have a significant impact on the bone health， especially hindering the healthy bone development in infants and adolescents， and aggravating the occurrence of bone loss and fracture in the elder populations. This paper will review the research progress of the effects of PFASs exposure on bone health indicators such as bone mineral density， and discuss the mechanisms of PFAS in bone toxicity. This review will provide references for revealing the effects of PFASs exposure on bone health and their toxic mechanisms.

It is a challenge to perform target screening of metabolites on a large scale in metabolomics study using gas chromatography with mass spectrometry (GC-MS). Some metabolites can hardly be detected and identified in biosamples due to their low MS response or poor specificity. Moreover, synthesis and degradation of derivatized metabolites in samples made it difficult to achieve fine method stability. Our method screens 475 metabolites in a single run using GC-MS/MS in MRM mode, and both internal standard and quality control-based normalization strategies were used to correct the peak intensity. A total of 91 and 161 metabolites were detected in plasma and urine, respectively. The method was validated to have fine linearity range and intra-day and inter-day stability. The method was applied to a pilot study, and this study investigated the metabolic perturbation in rats after fluorochloridone (FLC) administration. 18 metabolites exhibited statistical significance in rat urine, and they were confirmed to be associated with FLC treatment, where the upregulation of glucose, lactose, and galactose is potentially linked to oxidative stress reaction. This study has proved its value in large-scale detection of metabolites in biosamples using GC-MS/MS with high sensitivity, specificity, and stability. We hope that our study can promote the GC-MS-based metabolomics studies., Author(s): Liming Xue [sup.1] [sup.2], Jiale Xu [sup.1] [sup.2], Chao Feng [sup.1] [sup.2], Dasheng Lu [sup.1] [sup.2], Zhijun Zhou [sup.3] Author Affiliations: (1) grid.430328.e, Shanghai Municipal Center for Disease Control [...]

ObjectiveTo establish a method for determination of 12 polar pesticide residues in vegetables and fruits by supercritical fluid chromatography­Q­Orbitrap （SFC­Q­Orbitrap）.MethodsThe samples were extracted with 1% acidified methanol，and the extract was purified by dispersed solid phase extraction， separated by ultra silica column （150 mm× 2.1 mm， 3 μm） and obelisc r column （150 mm× 2.1 mm， 5 μm）， determined by SFC­Q­Orbitrap， scanned by segmented mixed product ions， and quantified by isotope internal standard calibration curve.ResultsThe calibration curves for 12 pesticides exhibited good linearity in the range of 20.0­500 μg/L， with the correlation coefficients（R2） above 0.997. The average recoveries at 0.05 and 0.20 mg/kg spiked levels were in the range of 80.2%­120% and the relative standard deviations （RSD，n＝6） were in the range of 2.14%­14.6%. The limits of detection and the limits of quantification were 0.010 1­0.016 2 mg/kg and 0.050 mg/kg.ConclusionThe method has the advantages of simple operation， accurate quantification and high efficiency. It can meet the requirements determination of high polar pesticide residues in vegetables and fruits.

ObjectiveTo prepare a vegetable matrix reference material with pesticide residues and organize a proficiency testing to assess the performance of domestic laboratories on the quantification of pesticide residues.MethodsThrough simulated field planting, chili sprayed with carbofuran and dimethomorph was used as raw materials to prepare chili matrix reference material with pesticide residues. After preparation, the related evaluation and proficiency testing were carried out. Assigned values were obtained from consensus values by robust analysis and the result were assessed using Z-scores.ResultsThe reference material was assessed to be sufficiently homogeneous and stable (all P >0.05). A total of 155 laboratories, from 30 regions in China participated the proficiency testing, while 142 (91.6%), 5 (3.2%) and 8 (5.2%) laboratories had acceptable performance (|z|≤2.0), warning signal (2.0

Introduction: Bleeding after heart valve surgery is a serious clinical challenge. Hypocalcemia has been associated with the extent of bleeding in patients with spontaneous intracerebral hemorrhage. However, the association between blood calcium levels and bleeding extent in heart valve replacement patients has not been clearly established. This study aimed at determining the association between blood calcium levels and perioperative hemorrhage after heart valve replacement therapy. Methods: Based on preoperative blood calcium levels, patients were grouped into the hypocalcemia group and normocalcemia group. Postoperative bleeding, blood product use, and complications were monitored during hospitalization. The association between blood calcium levels and major bleeding was determined by multivariable logistic regression models. Results: In the first 12 h after surgery, bleeding in hypocalcemia group was significantly larger than that of the normocalcemia group (338 ± 234 mL vs 232 ± 96 mL; p =.024). The outcome was the same when the overall chest tube output was considered (950 ± 447 mL vs 738 ± 220 mL; p =.038). The incidence of major bleeding was 65.91% in the hypocalcemia group and 18.97% in the normocalcemia group (p =.001). Postoperative complications in the two groups were similar. After adjusting for multiple covariates, the adjusted odds ratios (OR) for participants in hypocalcemia group was 10.01 (95% CI 3.35–34.82), compared with that in normocalcemia group (p <.001). Conclusion: In patients undergoing heart valve surgery, preoperative blood concentrations of calcium are associated with postoperative blood loss. Hypocalcemia before operation may increase the risk of postoperative bleeding. When patients with valvular heart disease present with hypocalcemia before surgery, prompt intervention may lead to better control of postoperative bleeding. [ABSTRACT FROM AUTHOR]

Bacillus cereus is a food-borne pathogen that can produce cereulide in the growth period, which causes food poisoning symptoms. Due to its resistance to heat, extreme pH, and proteolytic enzymes, cereulide poses a serious threat to food safety. Temperature, pH, and aw can influence cereulide production, but there is still a lack of research with multi-environmental impacts. In this study, the effects of temperature (15~45 °C), pH (5~8), and aw (0.945~0.996) on the emetic reference strain B. cereus F4810/72 growth, cereulide production, relevant ces genes (cesA, cesB, cesP), and transcription regulators genes (codY and abrB) expression at transcription level were studied. B. cereus survived for 4~53 h or grew to 6.85~8.15 log10 CFU/mL in environmental combinations. Cereulide accumulation was higher in mid-temperature, acidic, or high aw environments. Increased temperature resulted in a lower cereulide concentration at pH 8 or aw of 0.970. The lowest cereulide concentration was found at pH 6.5 with an increased aw from 0.970 to 0.996. Water activity had a strong effect on transcriptional regulator genes as well as the cesB gene, and temperature was the main effect factor of cesP gene expression. Moreover, environmental factors also impact cereulide synthesis at transcriptional levels thereby altering the cereulide concentrations. The interaction of environmental factors may result in the survival of B. cereus without growth for a period. Gene expression is affected by environmental factors, and temperature and pH may be the main factors influencing the correlation between B. cereus growth and cereulide formation. This study contributed to an initial understanding of the intrinsic link between the impact of environmental factors and cereulide formation and provided valuable information for clarifying the mechanism of cereulide synthesis in combined environmental conditions. [ABSTRACT FROM AUTHOR]

Chronic intermittent hypoxia (CIH) mimicking obstructive sleep apnea elicits divergent outcomes in the cardiovascular systems. The effect of renal denervation (RDN) on the heart during CIH remains unclear. We aimed to explore the effect of RDN on cardiac remodelling in rats exposed to CIH and to discuss the underlying mechanisms. Adult Sprague Dawley rats were divided into four groups: control, control+RDN, CIH (CIH exposure for 6 weeks, nadir of 5%–7% to peak of 21% O2, 20 cycles/h, 8 h/day) and CIH+ RDN group. Echocardiography, cardiac fibrosis, left ventricle (LV) expressions of nuclear factor‐E2‐related factor 2 (Nrf2)/heme oxygenase‐1 (HO‐1) pathway and inflammatory factors were tested at the end of the study. Cardiac structural remodelling and dysfunction were induced by CIH and attenuated by RDN. Myocardial fibrosis was more severe in the CIH group than in the control group and improved in the CIH + RDN group. Sympathetic activity reflected by tyrosine hydroxylase (TH) expression and noradrenaline were significantly elevated after CIH but blunted by RDN. CIH downregulated LV protein expressions of Nrf2 and HO‐1, which was activated by RDN. The downstream of Nrf2/HO‐1, such as NQO1 and SOD expression, elevated following RDN. RDN also decreased the mRNA expression of IL‐1β and IL‐6. Notably, control+RDN did not affect cardiac remodelling and Nrf2/HO‐1 compared with the control. Taken together, we found that RDN exerted cardio‐protective effects in a rat model of CIH involving Nrf2/HO‐1 pathway and inflammation. [ABSTRACT FROM AUTHOR]