Photochemical Transformation of Dissolved Organic Matter in Surface Water Augmented the Formation of Disinfection Byproducts.

Sunlight may lead to changes in disinfection byproducts (DBPs) formation potentials of source water via transforming dissolved organic matter (DOM); however, the underlying mechanisms behind these changes remain unclear. This work systematically investigated the effect of photochemical transformation of DOM from reservoir water (DOMRe) and micropolluted river water (DOMRi) after 36 h of simulated sunlight irradiation (equivalent to one month under natural sunlight) on DBPs formation. Upon irradiation, high molecular weight (MW) and aromatic molecules tended to be mineralized or converted into low-MW and highly oxidized (O/C > 0.5) ones which might react with chlorine to generate high levels of DBPs, resulting in an elevation in the yields (µg DBP/mg C) of almost all the measured DBPs and the quantities of unknown DBPs in both DOM samples after chlorination. Additionally, DOMRi contained more aromatic molecules susceptible to photooxidation than DOMRe. Consequently, irradiated DOMRi exhibited a greater increase in the formation potentials of haloacetonitriles, halonitromethanes, and specific regulated DBPs, with nitrogenous DBPs being responsible for the overall rise in the calculated cytotoxicity following chlorination. This work emphasized the importance of a comprehensive removal of phototransformation products that may serve as DBPs precursors from source waters, especially from micropolluted source waters.

Novel multiplexed alkali enzyme lysis coupled with EDTA pretreatment for RNA virus extraction from wastewater sludge: Optimization, recovery, and detection.

RNA viruses are readily enriched in wastewater sludge owing to adsorption by extracellular polymeric substances (EPS) during wastewater treatment, causing pathogenicity. However, conventional wastewater extraction methods often fail to fully extract these viruses from sludge. In this study, three methods: enzymatic (ENP), alkaline (ALP), and ethylenediaminetetraacetic acid (EDTA) pretreatments were applied to sludges and promote the RNA virus extraction from sludge. Our results show that the total recovery rate of RNA viruses increased by 87.73% after ENP pretreatment, whereas ALP pretreatment inhibited virus extraction. The highest recovery rate of viruses from sludge, reaching 296.80%, was achieved with EDTA pretreatment (EDP) coupled with ENP. Notably, the most significant increase was observed in the abundance of Astroviruses, which increased from 7.60 × 107 to 7.86 × 108 copies/g TSS after EDP + ENP treatment. Our investigations revealed that virus extraction was affected by a class of short-wavelength protein substances, as opposed to tryptophan or tyrosine, which were eluted by proteins with beef paste buffer by substitution after EDP + ENP treatment. The results of this study provide essential insights for sludge-based epidemiology with the required sensitivity for managing the extraction of RNA epidemic viruses to control viral transmission.

Environmental impact and optimization suggestions of pig manure and wastewater treatment systems from a life cycle perspective.

With the rapid development of the pig farming industry in China, a large amount of pig manure is inevitably generated. The management and utilization of pig manure in a sustainable approach require a systematic analysis of the environmental impacts generated from the existing pig manure treatment and disposal routes. In this study, three typical pig manure treatment and disposal routes: pig manure solid-liquid separation, i) wastewater biological treatment, direct land application of manure/sludge; ii) black-film anaerobic digestion of wastewater, mono-composting of manure/sludge and land use; iii) wastewater biological treatment, co-composting of manure/sludge and land use, were comparatively assessed in terms of their environmental impacts using the life cycle assessment. The results show that the added chemicals in wastewater treatment and the consumed electricity in composting the manure/sludge are the two main contributors to all environmental impacts. Thus, using green chemicals, controlling the dosage of added chemicals accurately, and selecting composting types with low energy consumption will significantly reduce the environmental burden of pig manure treatment and disposal routes. For the global warming potential of the evaluated three pig manure treatment and disposal routes, direct emissions of greenhouse gases during the composting process contribute the most, accounting for 77 %, 95 %, and 79 %, respectively. Furthermore, the struvite recovery with anaerobic digestion from pig manure will bring excellent environmental benefits, which will markedly offset the toxicity impacts and carbon emissions derived from pig manure treatment and disposal process. Overall, this work quantitatively evaluates the potential environmental impacts of the existing pig manure treatment and disposal routes, providing insights on optimization for future technical improvement and development.

Effects of dissolved organic matter removal and molecular transformation in different water treatment processes on formation of disinfection byproducts.

Alterations in molecular composition of dissolved organic matter (DOM) during water treatments can influence the composition and toxicity of disinfection by-products (DBPs) in subsequent chlorination disinfection process. In this study, the impacts of DOM composition after various water treatment techniques (coagulation, adsorption, nanofiltration, biological aerated filter (BAF), and their integrated processes) on the generation mechanisms of DBPs were comprehensively explored by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in combination with GC-MS and LC-MS analysis. The results indicated that coagulation preferentially removed unsaturated (low H/C) and oxidized (high O/C) compounds, whereas adsorption was prone to remove the reduced (low O/C) component that was more reactive with chlorine, leading to lower yields (µg DBP/mg DOC) of trihalomethanes (THMs) and haloacetic acids (HAAs) during subsequent chlorination. The coagulation-adsorption technique exhibited a relatively high removal of both known and unknown DBPs, demonstrating that coagulation and adsorption were complementary for DOM removal at the molecular level. Nanofiltration selectively removed molecules with relatively high O/C, however, those with very low O/C that were more reactive with chlorine could pass through the nanofiltration membrane, resulting in the highest yields of THMs and HAAs. Although BAF was inefficient in removing DBPs precursors, it could convert molecules with low degree of oxidation and unsaturation into highly oxidized and unsaturated ones, thereby significantly enhancing the removal of DBPs precursors in the subsequent coagulation-adsorption process. These findings are instrumental in developing and selecting more effective techniques to minimize the formation of DBPs in water treatment.

Prevalence of smoking among nurses and its association with blood pressure: A cross-sectional study in 11 cities of China.

AIM: Smoking is harmful to human health. However, the relationship between smoking and blood pressure (BP) has not been consistent. This study aimed to analyse nurses' smoking behaviours and their relationship with BP. METHODS: This cross-sectional study recruited 128 009 nurses in 11 cities in China. They were surveyed with questionnaires including BP measurements. The main contents of the questionnaire included smoking status and other factors that might be associated with hypertension. Multiple linear regression analyses and binary logistic regression analyses were used to analyse the data. RESULTS: The results showed there was a significant difference in the smoking rate among nurses with different characteristics (P < 0.05). For both male and female nurses, smoking was associated with increased diastolic BP and mean arterial pressure, but only with increased systolic BP of male nurses. The prevalence of hypertension among male and female nurses was not related to smoking. CONCLUSION: Despite a relatively low overall smoking rate, rates among some groups are high. Different cities, hospitals, and departments can combine local data and conditions to formulate targeted tobacco control measures to improve nurses' physical and mental health.

Molecular transformation of dissolved organic matter and the formation of disinfection byproducts in full-scale surface water treatment processes.

Dissolved organic matters (DOM) have important effects on the performance of surface water treatment processes and may convert into disinfection by-products (DBPs) during disinfection. In this work, the transformation of DOM and the chlorinated DBPs (Cl-DBPs) formation in two different full-scale surface water treatment processes (process 1: prechlorination-coagulation-precipitation-filtration; process 2: coagulation-precipitation-post-disinfection-filtration) were comparatively investigated at molecular scale. The results showed that coagulation preferentially removed unsaturated (H/C < 1.0 and DBE > 17) and oxidized (O/C > 0.5) compounds containing more carboxyl groups. Therefore, prechlorination produced more Cl-DBPs with H/C < 1.0 and O/C > 0.5 than post-disinfection. However, the algal in the influent produced many reduced molecules (O/C < 0.5) without prechlorination, and these compounds were more reactive with disinfectants. Sand filtration was ineffective in DOM removal, while microorganisms in the filter produced high molecular weight (MW) substances that were involved in the Cl-DBPs formation, causing the generation of higher MW Cl-DBPs under post-disinfection. Furthermore, the CHO molecules with high O atom number and the CHON molecules containing one N atom were the main Cl-DBPs precursors in both surface water treatment processes. In consideration of the putative Cl-DBPs precursors and their reaction pathways, the precursors with higher unsaturation degree and aromaticity were prone to produce Cl-DBPs through addition reactions, while that with higher saturation degree tended to form Cl-DBPs through substitution reactions. These findings are useful to optimize the treatment processes to ensure the safety of water quality.

Effect of frequency and pattern of night shift on hypertension risk in female nurses: a cross-sectional study.

OBJECTIVES: Understanding the effect of night shift on hypertension risk in nurses is important to improve the health of nurses and ensure patient safety. This study aimed to evaluate the effect of the frequency and pattern of night shift on hypertension risk and the interaction of them in female nurses. METHODS: This cross-sectional study constituted 84 697 female nurses in 13 cities in China. The main contents of the survey included SBP, DBP, the frequency and pattern of night shift, and some other factors that might be associated with hypertension. Logistic regression analyses were used to calculate ORs and 95% CIs to estimate the effect of the frequency and pattern of night shift on hypertension risk and the interaction of them in relation to hypertension risk. RESULTS: Having more than 5 to 10 or more than 10 night shifts per month were significantly more likely to be hypertensive (OR 1.19, 95% CI 1.10-1.28; OR 1.32, 95% CI 1.13-1.54), whereas having less than or equal to 5 night shifts per month was not (OR 1.05, 95% CI 0.95-1.16). The patterns of night shift were all associated with a higher probability of hypertension and participants engaging in rapidly rotating night shift had a lower OR (1.14) than those having slowly rotating night shift (1.23) and permanent night shift (1.46). No significant interaction was observed between the frequency and the pattern of night shift (Pinteraction = 0.281). CONCLUSION: The frequency and pattern of night shift were associated with hypertension risk in female nurses and no significant interaction was observed between them.

Effects of chemical modification on physicochemical properties and adsorption behavior of sludge-based activated carbon.

This study aimed to explore the adsorption performance of sludge-based activated carbon (SBC) towards dissolved organic matters (DOMs) removal from sewage, and investigated the modification effect of different types of chemicals on the structure of synthesized SBC. Waste activated sludge (WAS) was used as a carbon source, and HCl, HNO3, and NaOH were used as different types of chemicals to modify the SBC. With the aid of chemical activation, the modified SBC showed higher adsorption performances on DOMs removal with maximum adsorption of 29.05 mg/g and second-order constant (k) of 0.1367 (L/mol/sec) due to the surface elution of ash and minerals by chemicals. The surface elemental composition of MSBC suggested that the content of C-C and C-O functional groups on the surface of modified sludge-based activated carbon (MSBC) played an important role on the adsorption capacities of MSBC towards DOMs removal in sewage. Additionally, the residual molecular weight of DOMs in sewage was investigated using a 3-dimension fluorescence excitation-emission matrix (3D-EEM) and high-performance size exclusion chromatography (HP-SEC). Results showed that the chemical modification significantly improved the adsorption capacity of MSBC on humic acids (HA) and aromatic proteins (APN), and both of NaOH-MSBC and HCl-MSBC were effective for a wide range of different AMW DOMs removal from sewage, while the HNO3-MSBC exhibited poorly on AMW organics of 2,617 Da and 409 Da due to the reducing content of macropore. In brief, this study provides reference values for the impact of the chemicals of the activation stage before the SBCs application.

Relationship between the physicochemical properties of sludge-based carbons and the adsorption capacity of dissolved organic matter in advanced wastewater treatment: Effects of chemical conditioning.

Pyrolysis carbonisation is a promising technology to convert organic waste into valuable carbon-based materials. However, sludge is generally highly compressible and difficult to dewater because of its high concentrations of biopolymers; the bound water of sludge is trapped in a network composed of biopolymers. Therefore, chemical conditioning is an indispensable step for improving sludge dewaterability performance. In the present work, the effects of different chemical conditioning agents (polymeric aluminium chloride (PACl), iron(III) chloride (FeCl3), KMnO4-Fe(II) and Fenton's reagent) on the physicochemical properties of sludge-based carbons (SBCs) were systematically studied and the SBCs were further used in advanced wastewater treatment. The adsorption mechanisms of dissolved organic matters (DOMs) by different SBCs were also investigated. The results showed that conditioning with KMnO4-Fe(II) and Fenton's reagent improved the specific surface area of the SBCs, whereas inorganic salt flocculation conditioning reduced the porosity of the SBCs. In addition, we found that the Fenton-SBC and Mn/Fe-SBC performed better than the other investigated SBCs in the removal of organic compounds from secondary effluent and that the pseudo-second-order kinetic model could better describe the process of DOMs adsorption by all of the investigated SBCs. Moreover, three-dimensional fluorescence excitation-emission matrix spectroscopy in combination with an analysis of the physical and chemical fractionation of DOMs showed that all of the SBCs performed well in the adsorption of aromatic substances, hydrophobic acids and hydrophobic neutrals, whereas the Mn/Fe-SBC and Fenton-SBC performed better than the other SBCs in the removal of weakly hydrophobic acids.

The early examination of combined serum and imaging data under flexible fiberoptic bronchoscopy as a novel predictor for refractory Mycoplasma pneumoniae pneumonia diagnosis.

The treatment role of flexible bronchoscopy (FOB) for pediatric refractory Mycoplasma pneumoniae pneumonia (RMPP) has been well documented. Besides, the application indication of FOB is also studied in patients with general MPP (GMPP), especially in those with large pulmonary lesions. This study was designed to examine the diagnostic value of bronchoscopic features for RMPP.The FOB and bronchoalveolar lavage (BAL) were adopted for pediatric patients who showed clinical and radiograph indications. On the basis of the final diagnosis on discharge, patients were divided into general and refractory MPP groups. The clinical, laboratory, and bronchoscopic imaging features were retrospectively investigated between these 2 groups.From June 2012 to May 2014, a total of 62 RMPP and 101 GMPP patients were treated with therapeutic bronchoscopy. The comparison analysis showed that the CRP, HBDH, LDH were significantly different between RMPP and GMPP groups (all P < .001). In the bronchoscopic imaging, the mucus plug was significantly more commonly seen in the RMPP group (P < .001). Receiver operating characteristic (ROC) analysis revealed that the combined serum, clinical, and FOB imaging data possessed greater specificity and sensitivity than serum and clinical data alone.Our data suggest that the combined serum, clinical, and bronchoscopic imaging data might serve as a promising predictor for early RMPP diagnosis for pediatric patients with large pulmonary lesions.

Reduction of α-dystroglycan expression is correlated with poor prognosis in glioma.

Dystroglycan (DG), a multifunctional protein dimer of non-covalently linked α and ß subunits, is best known as an adhesion and transduction molecule linking the cytoskeleton and intracellular signaling pathways to extracellular matrix proteins. Loss of DG binding, possibly by degradation or disturbed glycosylation, has been reported in a variety of cancers. DG is abundant at astroglial endfeet forming the blood-brain barrier (BBB) and glia limitans; so, we examined if loss of expression is associated with glioma. Expression levels of α-DG and ß-DG were assessed by immunohistochemistry in a series of 78 glioma specimens to determine the relationship with tumor grade and possible prognostic significance. α-DG immunostaining was undetectable in 44 of 49 high-grade specimens (89.8%) compared to 15 of 29 low-grade specimens (51.72%) (P<0.05). Moreover, loss of α-DG expression was an independent predictor of shorter disease-free survival (DFS) (hazards ratio (HR) = 0.142, 95% confidence interval (CI) 0.033-0.611, P=0.0088). Reduced expression of both α-DG and ß-DG was also a powerful negative prognostic factor for DFS (HR=2.556, 95% CI 1.403-4.654, P=0.0022) and overall survival (OS) (HR=2.193, 95% CI 1.031-4.666, P=0.0414). Lack of α-DG immunoreactivity is more frequent in high-grade glioma and is an independent predictor of poor clinical outcome. Similarly, lack of both α-DG and ß-DG immunoreactivity is a strong independent predictor of clinical outcome.

Effects of selective hypothermia on blood-brain barrier integrity and tight junction protein expression levels after intracerebral hemorrhage in rats.

Hypothermia has neuroprotective effects on global cerebral ischemic injuries. However, its efficacy after intracerebral hemorrhage (ICH) is inconclusive. In this study, bacterial collagenase was used to induce ICH stroke in male Wistar rats. We assessed the effects of normothermia and 4 h of local hypothermia (~33.2°C) initiated 1, 6, or 12 h after collagenase infusion on hemorrhage volume and neurological outcomes. Following early cooling initiated after 1 h, blood-brain barrier (BBB) disruption and brain water content were tested. Furthermore, the expression levels of tight junction (TJ) proteins (claudin 5 and occludin) and the proinflammatory cytokines interleukin 1ß (IL-1ß) and tumor necrosis factor α (TNF-α) were determined using Western blotting, real-time quantitative PCR, and immunohistochemical staining at 1 and 3 d after ICH. Early local hypothermia tends to reduce hemorrhagic volume and neurological deficits, but the difference is not statistically significant compared with other groups. However, early hypothermia significantly reduces BBB disruption, edema formation, the expression levels of IL-1ß and TNF-α, and the loss of TJ proteins. Together, these data suggest that local hypothermia is an effective treatment for edema formation and BBB disruption via the upregulation of TJ proteins and the suppression of TNF-α and IL-1ß.

Molybdenum nitride based hybrid cathode for rechargeable lithium-O2 batteries.

Molybdenum nitride/nitrogen-doped graphene nanosheets (MoN/NGS) are synthesized and used as an alternative O(2) electrode for Li-O(2) batteries. In comparison with electrocatalysts proposed previously, this hybrid cathode exhibits a high discharge potential (around 3.1 V) and a considerable specific capacity (1490 mA h g(-1), based on carbon + electrocatalyst).

Mesoporous coaxial titanium nitride-vanadium nitride fibers of core-shell structures for high-performance supercapacitors.

In this study, titanium nitride-vanadium nitride fibers of core-shell structures were prepared by the coaxial electrospinning, and subsequently annealed in the ammonia for supercapacitor applications. These core-shell (TiN-VN) fibers incorporated mesoporous structure into high electronic conducting transition nitride hybrids, which combined higher specific capacitance of VN and better rate capability of TiN. These hybrids exhibited higher specific capacitance (2 mV s(-1), 247.5 F g(-1)) and better rate capability (50 mV s(-1), 160.8 F g(-1)), which promise a good candidate for high-performance supercapacitors. It was also revealed by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) characterization that the minor capacitance fade originated from the surface oxidation of VN and TiN.

A biocompatible titanium nitride nanorods derived nanostructured electrode for biosensing and bioelectrochemical energy conversion.

In this study, a facile method is proposed to fabricate biocompatible TiN nanorod arrays through solvent-thermal synthesis and subsequent nitridation in ammonia atmosphere. The TiN nanorod arrays are potential excellent nanostructured electrodes owing to their good electronic conductivity and large surface area. These nanostructured electrodes not only deliver superior electrocatalytic activity (the limit of detection, LOD is 0.5 µM) and highly selective sensing towards H(2)O(2), but also exhibit excellent biocompatibility with horseradish peroxidase (HRP) in a highly sensitive enzymatic biosensor for H(2)O(2) (the LOD can reach to 0.05 µM). Furthermore, a novel biocatalytic cathode based Li air fuel cell (bio-Li-air fuel cell) is explored based on the combination of TiN nanorod arrays and laccase (LAC) for electrochemical energy conversion. These results demonstrate that TiN nanorod arrays can be served as excellent nanostructured electrodes for multifunctional bioelectrochemical applications.

[Expression of nuclear factor-kappaB and its inhibitor in alveolar macrophages of patients with neonatal hyaline membrane disease].

OBJECTIVE: Inflammatory reaction and injury in immature lungs are associated with activation of nuclear factor-kappa B (NF-kappaB) to trigger proinflammatory cytokine release, but the mechanism thereof is not fully understood. The present study was conducted to understand possible relationship between expression of NF-kappaB and its inhibitor and severity and outcome of neonates with hyaline membrane disease (HMD). METHODS: Serial samples of bronchoalveolar lavage fluid (BALF) were obtained during mechanical ventilation from 31 preterm infants with HMD. These infants were divided into two groups: survivors group [n = 22, birth weight (1500 +/- 320) g and gestational age (31.2 +/- 1.8) weeks] and nonsurvivors group [birth weight (1340 +/- 280) g, gestational age (30.8 +/- 2.1) weeks]. Nineteen preterm infants [birth weight (1470 +/- 280) g, gestational age (30.6 +/- 1.9) weeks] without respiratory disorders were enrolled as control subjects. Alveolar macrophages (AM) were isolated by differential adherence. AM was cultured and treated with lipopolysaccharide (LPS) for 1 hr. Then, nuclear extracts of AM were analyzed by electrophoretic mobility shift assay (EMSA) for NF-kappaB expression. NF-kappaB inhibitor (IkappaB-alpha protein) in cytoplasmic extracts was detected by using Western blotting and IL-1beta and IL-8 in BALF by enzyme-linked immunosorbent assay (ELISA). RESULTS: NF-kappaB complexes were observed by EMSA, they were characterized by competition with cold oligonucleotide and p65-specific antibodies. The addition of an excess of cold oligonucleotide, corresponding to the NF-kappaB binding site, turned off the signal of the band, showing that the band was specific. An excess of an irrelevant oligonucleotide (corresponding to the SP-1) did not show any effect. The addition of an anti-p65 antibody caused the supershift of the two upper bands. After EMSA, the NF-kappaB complexes were quantified by using a ImageQuant software. NF-kappaB expression in AM at 24 hrs was higher in all the patients with HMD as compared with control subjects (survives/control, 34.1 vs 11.4 RDU, P < 0.01; nonsurvivors/control, 55.2 vs 11.4 RDU, P < 0.01). The NF-kappaB expression in AM at 72 hrs was higher than that in control subjects but not for nonsurvivors (survivors/control, 47.8 vs 25.6 RDU, P < 0.01; nonsurvivors/control, 21.8 vs 25.6, P > 0.05). The NF-kappaB expression in AM from nonsurvivors was depressed at 72 hrs as compared to 24 hrs (21.8 vs 55.2, P < 0.01), whereas the NF-kappaB expression in AM from survivors was still higher at 72 hrs than that at 24 hrs (47.8 vs 34.1, t = 4.43, P < 0.01). CONCLUSION: Altered NF-kappaB activation in AM of BALF of neonates with HMD was observed, and it may be mediated by decreased IkappaB synthesis, increased IkappaB degradation, or both. In HMD nonsurvivors NF-kappaB translocation was hampered upon LPS activation.