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Due to their prevalence in urban contaminated water, the driving factors of organophosphate esters (OPEs) need to be well examined, and their related ecological impacts should include that of their transformation products (TPs). Additionally, a robust framework needs to be developed to integrate multiple variables related to ecological impacts for improving the ecological health assessment. Therefore, OPEs and TPs in urban stormwater and wastewater in Hong Kong were analyzed to fill these gaps. The results revealed that the total concentrations of OPEs in stormwater were positively correlated with the area of transportation land. Individual TP concentrations and the mass ratios of individual TPs/OPEs were somewhat higher in sewage effluents than that in stormwater. OPEs generally showed relatively higher risk quotients than TPs; however, the total risk quotients increased by approximately 38% when TPs were factored in. Moreover, the molecular docking results suggested that the investigated TPs might cause similar endocrine disruption in marine organisms as their parent OPEs. This study employed the Toxicological-Priority-Index scheme to successfully integrate the ecological risks and endocrine-disrupting effects to refine the ecological health assessment of the exposure to OPEs and their TPs, which can better inform the authority on the prioritization for regulating these contaminants of emerging concern in urban built environments.

Increasing chemical pollution of aquatic environments is a growing concern with global relevance. A large number of organic chemicals are termed as “micropollutants” due to their low concentrations, and long-term exposure to micropollutants may pose considerable risks to aquatic organisms and human health. In recent decades, numerous treatment methods and technologies have been proposed to remove micropollutants in water, and typically several micropollutants were chosen as target pollutants to evaluate removal efficiencies. However, it is often unclear whether their toxicity and occurrence levels and frequencies enable them to contribute significantly to the overall chemical pollution in global aquatic environments. This review intends to answer an important lingering question: Which micropollutants or class of micropollutants deserve more attention globally and should be removed with higher priority? Different risk-based prioritization approaches were used to address this question. The risk quotient (RQ) method was found to be a feasible approach to prioritize micropollutants in a large scale due to its relatively simple assessment procedure and extensive use. A total of 83 prioritization case studies using the RQ method in the past decade were compiled, and 473 compounds that were selected by screening 3466 compounds of three broad classes (pharmaceuticals and personal care products (PPCPs), pesticides, and industrial chemicals) were found to have risks (RQ > 0.01). To determine the micropollutants of global importance, we propose an overall risk surrogate, that is, the weighted average risk quotient (WARQ). The WARQ integrates the risk intensity and frequency of micropollutants in global aquatic environments to achieve a more comprehensive priority determination. Through metadata analysis, we recommend a ranked list of 53 micropollutants, including 36 PPCPs (e.g., sulfamethoxazole and ibuprofen), seven pesticides (e.g., heptachlor and diazinon), and 10 industrial chemicals (e.g., perfluorooctanesulfonic acid and 4-nonylphenol) for risk management and remediation efforts. One caveat is that the ranked list of global importance does not consider transformation products of micropollutants (including disinfection byproducts) and new forms of pollutants (including antibiotic resistance genes and microplastics), and this list of global importance may not be directly applicable to a specific region or country. Also, it needs mentioning that there might be no best answer toward this question, and hopefully this review can act as a small step toward a better answer.

Antibiotic resistant bacteria (ARB) with antibiotic resistance genes (ARGs) can reduce or eliminate the effectiveness of antibiotics and thus threaten human health. The United Nations Environment Programme considers antibiotic resistance the first of six emerging issues of concern. Advanced oxidation processes (AOPs) that combine ultraviolet (UV) irradiation and chemical oxidation (primarily chlorine, hydrogen peroxide, and persulfate) have attracted increasing interest as advanced water and wastewater treatment technologies. These integrated technologies have been reported to significantly elevate the efficiencies of ARB inactivation and ARG degradation compared with direct UV irradiation or chemical oxidation alone due to the generation of multiple reactive species. In this study, the performance and underlying mechanisms of UV/chlorine, UV/hydrogen peroxide, and UV/persulfate processes for controlling ARB and ARGs were reviewed based on recent studies. Factors affecting the process-specific efficiency in controlling ARB and ARGs were discussed, including biotic factors, oxidant dose, UV fluence, pH, and water matrix properties. In addition, the cost-effectiveness of the UV-based AOPs was evaluated using the concept of electrical energy per order. The UV/chlorine process exhibited a higher efficiency with lower energy consumption than other UV-based AOPs in the wastewater matrix, indicating its potential for ARB inactivation and ARG degradation in wastewater treatment. Further studies are required to address the trade-off between toxic byproduct formation and the energy efficiency of the UV/chlorine process in real wastewater to facilitate its optimization and application in the control of ARB and ARGs.

Chronic cellular inflammation and airway wall remodeling with subepithelial fibrosis and airway smooth muscle thickening are features of chronic asthma. We determined the role of nitric oxide in the pathogenesis of allergen-induced airway cell proliferation and inflammation by studying the effects of a relatively selective prodrug inhibitor of nitric-oxide synthase type 2 (NOS2), L-N6-(1-iminoethyl)-lysine-5-tetrazole amide (SC-51). Brown-Norway rats were sensitized to ovalbumin and were exposed to ovalbumin aerosol every 3rd day on six occasions and were treated orally with either vehicle or SC-51 (10 mg. kg(-1); 12 doses). We measured inflammatory cell accumulation in the airways and proliferation of cells by incorporation of bromodeoxyuridine. There was an increase in the total number of airway smooth muscle cells expressing bromodeoxyuridine from 1.3% of airway smooth muscle cells in saline exposed to 5.4% after allergen-exposure (P < 0.001) and airway epithelial cells from 3.3 cells/mm basement membrane to 9.6 after allergen-exposure (P < 0.001). SC-51 had no effect on airway smooth muscle or epithelial cell proliferation. SC-51 attenuated the allergen-induced increase in major basic protein (MBP+) eosinophil (P < 0.05) and CD4+ T-cell (P < 0.05) accumulation. We conclude that nitric oxide derived during allergic inflammation is involved in the expression of eosinophilic inflammation and not in epithelial or airway smooth muscle cell DNA synthesis induced by chronic allergen exposure.

Abstract: Some fundamental issues on statistical inferences relating to varying-coefficient regression models are addressed and studied. An exact testing procedure is proposed for checking the goodness of fit of a varying-coefficient model fited by the locally weighted regression technique versus an ordinary linear regression model. Also, an appropriate statistic for testing variation of model parameters over the locations where the observations are collected is constructed and a formal testing approach which is essential to exploring spatial non-stationarity in geography science is suggested.

Calreticulin is a widely expressed calcium binding protein that can bind to an amino acid sequence motif, KXGFFKR, which is present in the cytoplasmic domain of all integrin α-subunits. Closely related sequences, KXFFKR and KXFFRR, are encoded in the DNA-binding domain of all members of the steroid/thyroid/retinoid receptor superfamily and it has recently been demonstrated that calreticulin inhibits their activity bothin vitroandin vivo.Here we present novel evidence that calreticulin can interfere directly with the retinoic acid (RARs) and retinoid X (RXRs) receptor pathways. Calreticulin exhibits the ability to inhibit DNA-binding activity of both heterodimeric RAR/RXR and homodimeric RXR complexesin vitro.Inhibition of RXR binding to DNA is achieved with a concentration of calreticulin that is approximately fourfold lower than that required for inhibition of RAR/RXR binding to a cognate binding site. Coprecipitation experiments suggest a direct protein:protein interaction between calreticulin and retinoid receptors. Stable overexpression of calreticulin in P19 embryonal carcinoma cells significantly decreases the rapid activation of the endogenous RA-responsive RARβ gene, abrogates the ability of endogenous RAR/RXR complexes to bind to DNA, and inhibits the emergence of the RA-induced differentiated phenotype. These data demonstrate that calreticulin can interfere with the two distinct retinoid signaling pathways through a mechanism likely involving direct protein:protein interactions and that disruption of the retinoid signal alters biological processesin vivo.