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Nitrogen is a significant element that constitutes ambient organic aerosol. Individual N-containing organic molecules are known to have both natural and anthropogenic sources and implicated in a wide-ranging health and environmental effects. Yet, unlike carbon (C), the total quantity of aerosol organic nitrogen (ON) remains largely unquantified, hindering a quantitative understanding of their major sources and impacts. Here, for the first time, aerosol ON is quantified in hundreds of aerosol filter samples collected from sites of varying urban influence in China using our recently developed method that permits simple, and yet sensitive, simultaneous detection of inorganic and organic nitrogen. Annual average ON concentration was in the range of 0.4-1.4 μg N m-3, representing 17-31% of aerosol total nitrogen. Monte Carlo simulations constrained by paired ON and organic carbon (OC) measurements suggest N-containing organic molecules contributed typically 37-50%, with a 95% confidence interval of [12%, 94%], to ambient organic aerosols. Source apportionment analysis reveals that biomass burning and secondary formation are dominant ON sources, accounting for 21-24% and ~30% of ON, respectively. Primary biological aerosol is also a significant source of ON (7-18%), with its contribution more prominent in non-urban atmospheres. The revelation of the large presence of nitrogenous molecules in atmospheric aerosols implies their role in carbon chemistry has likely been under-appreciated in the past. This new compositional insight, we anticipate, would bring forth a breakthrough in our ability to describe and model organic aerosols and to rethink the focus of studying and modeling OA.

Supplementary Table S1. Factors associated with oral cutaneous HPV infection in the univariate and multivariate analyses in rural Anyang, China, 2009-2011

Background: Despite the established link between oral human papillomavirus (HPV) infection and a subset of oropharyngeal squamous cell carcinoma (OSCC), little is known about the epidemiology of oral HPV infection among healthy adults in China.Methods: Oral swab specimens and questionnaires were collected from 5,410 individuals (ages 25–65 years). HPV DNA in oral exfoliated cells was tested by general primer-mediated (SPF1/GP6+) PCR and sequencing. Univariate and multivariate analyses were performed to assess the associations between exposure factors and oral infection.Results: Alpha mucosal HPV types were detected in 0.67% [95% confidence interval (CI), 0.47%–0.93%] of 5,351 β-globin–positive specimens, and cutaneous HPV in 5.46% (95% CI, 4.86%–6.10%). HPV 16 and 3 were the most prevalent types of α mucosal (0.43%; 95% CI, 0.27%–0.64%) and cutaneous HPV (4.17%; 95% CI, 3.65%–4.74%), respectively. The prevalence of α mucosal HPV decreased with increasing age (25–65 years) from 0.93% to 0.36% (Ptrend = 0.033), and was associated with self-reported history of oral disease [adjusted odds ratio (OR), 4.78; 95% CI, 1.07–21.41]. In 1,614 heterosexual couples, cutaneous HPV in one partner was found to increase the other partner's risk of cutaneous HPV infection (adjusted OR, 2.33; 95% CI, 1.22–4.48).Conclusions: Oral HPV infection, particularly with α mucosal types, is rare among healthy adults in China. A younger age and a history of oral disease imply higher risk of α mucosal HPV infection.Impact: This study addresses the paucity of epidemiological data on oral HPV infection among healthy population in China. Cancer Epidemiol Biomarkers Prev; 23(10); 2101–10. ©2014 AACR.

The collision cross-section (CCS) values of ions determined by ion mobility-mass spectrometry (IM-MS) can be used to deduce the shape and size of the ions. For each compound, as well as its isomer or tautomer, a unique arrival time peak was obtained in extracted ion mobility (EIM) spectra, which corresponded to a specific CCS value. However, the generation of solvated ions by electrospray ionization (ESI) increases the number of mobility peaks, which makes the EIM spectra difficult to interpret. In this study, solvent clusters formed by acetonitrile and methanol around 1,8-naphthalic anhydride (1,8-NA) cations ([C

Molecular characterization of sulfur-containing compounds in petroleum is of great significance for not only the oil refining but also geochemical application. One practical approach for the charac...

Atmospheric organosulfates (OSs) derived from biogenic volatile organic compounds (BVOCs) encode chemical interaction strength between anthroposphere and biosphere. We report BVOC-derived OSs in the summer of 2016 and the winter of 2017 at four locations in China (i.e., Hong Kong (HK), Guangzhou (GZ), Shanghai (SH), and Beijing (BJ)). The spatial coverage of three climatic zones from the south to the north in China is accompanied with a wide range of aerosol inorganic sulfate (4.9–13.8 μg/m3). We employed a combined targeted and untargeted approach using high-performance liquid chromatography-Orbitrap mass spectrometry to quantify/semi-quantify ~200 OSs and nitrooxy OSs derived from four types of precursors, namely C2-C3 oxygenated VOCs, isoprene, monoterpenes (MT), and sesquiterpenes (ST). The seasonal averages of the total quantified OSs across the four sites are in the range of 201–545 (summer) and 123–234 ng/m3 (winter), with the isoprene-derived OSs accounting for more than 80% (summer) and 57% (winter). The C2–3 OSs and isoprene-derived OSs share the same seasonality (summer >winter) and the same south-north spatial gradient as those of isoprene emissions. In contrast, the MT- and ST-derived OSs are of either comparable abundance or slightly higher abundance in the winter at the four sites. The spatial contrasts for MT- and ST-derived OSs are not clearly discernable among GZ, SH, and BJ. HK is noted to have invariably lower abundances of all groups of OSs, in line with its aerosol inorganic sulfate being the lowest. These results indicate that BVOC emissions are the driving factor regulating the formation of C2–3 OSs and isoprene-derived OSs. Other factors, such as sulfate abundance, however, play a more important role in the formation of MT- and ST-derived OSs. This in turn suggests that the formation kinetics and/or pathways differ between these two sub-groups of BVOCs-derived OSs.

Soluble microbial products (SMPs) discharged into rivers from sewage treatment plants may increase the health risk for downstream drinking water by acting as a precursor of DBPs. Biotransformation or biodegradation could alter the characteristics of SMPs and affect the subsequent formation of DBPs. This study observed the relative contribution of chemical fractions in SMPs and explored the biodegradation of each fraction and their effect on disinfection by-products (DBPs) formation in surface water. The hydrophilic acid (HPIA) and hydrophobic acid (HPOA) constituted the major portion of the SMPs, which were dominated by fulvic acid and humic acids. The transphilic acid (TPIA) and hydrophobic bases (HPOB) were relatively minor but it contained a relative substantial portion of protein-like materials in SMPs. TPIA and HPOB produced insignificant amounts of DBP corresponding to 13% and 14% in the original samples, but they were collectively responsible for 50% of the DBPs yield. Much larger amounts of hydrophobic fractions were utilized than hydrophilic fractions after biodegradation. The increase in SUVA values indicating aromatic structures, except for HPOA fraction, was observed after biodegradation. The protein-like materials in both the HPOA and HPIA fractions and polycarboxylate-type humic acid in the HPIA fraction decreased but the enrichment of HPOA (MW 100 kDa) and TPIA (MW 1 kDa) was observed after biodegradation. The production of = C-H in HPIA fraction and the appearance of double peak at 1100 cm

Soluble microbial products (SMPs) discharged into surface water may increase the formation of disinfection by-products (DBPs) in downstream drinking water treatment plants. In this study, ultrafiltration (UF) fractionation was used to separate SMPs into homogenous components. An aerobic microbial experiment was conducted to evaluate the bioavailability of individual molecular weight (MW) fractions of SMPs in surface water and the impact on their DBP formation, facilitating the interpretation of SMPs characterization and DBPs reactivity. For SMPs, organics with MW 1 kDa were the primary fraction, containing the most abundant humic substances. The 30 kDa MW 100 kDa fraction was the lowest in SMPs but had the highest SUVA values. After biodegradation, the bioavailability of physical fractions increased with the increasing MW size. However, the SUVA value, except for MW 1 kDa, increased in individual fraction after biodegradation. Low molecular weight SMPs fractions (MW10 kDa) were major precursors for DBP in which trichloromethane (TCM) was the most abundant. The 10 kDaMW 100 kDa fractions were found to be more active in formation of chloral hydrate (CH), and MW 100KDa had relative abundant dichloroacetonitrile (DCAN) formation. After biodegradation, TCM precursors with MW 1 kDa were removed by approximately 20%, whereas the increase of TCM formation was observed in 1 kDa MW 100 kDa fraction. CH formation from 1 kDa MW 10 kDa increased considerably, but those from 10 kDa MW 30 kDa decreased after biodegradation, as a result of the biotransformation of large organic acids to small organic acids. In terms of DBP reactivity, the TCM yield for the MW 1 kDa fraction had no significant change while the 30 kDaMW 100 kDa fraction exhibited the greatest increase (approximately 8 times) in TCM yield.

To study the biosorption behaviors of bacteria on heavy metal chelators, the biosorption kinetics, biosorption thermodynamics and pH influence tests of the Ochrobactrum MT180101 on ionic and chelate copper were investigated. Furthermore, the biosorption mechanisms of the Ochrobactrum MT180101 on ionic copper and chelate copper were explained by means of an excitation emission matrix as well as infrared and X-ray photoelectron spectroscopy. The results indicated the following. 1) The biosorption on chelate copper was needed to destroy the complexation group first through metabolic and secretory activities. 2) The biosorption mechanism of the Ochrobactrum MT180101 on copper involved surface biosorption, extracellular chelation and bienzyme-mediated biotransformation. The results suggested that Ochrobactrum had a superior biosorption efficiency to ionic and chelate copper.

As major precursors of disinfection by-products (DBPs), soluble microbial products (SMPs) generated by sewage discharge can adversely affect drinking water quality. It is essential to understand the adsorption behaviours of SMPs onto sediments and the effect of DBPs formation. In this study, the adsorption ability of sediments was evaluated by adsorption isotherms with respect to temperature and salinity. Adsorption behaviours were investigated using X-ray photoelectron spectroscopy, electron microscopy analysis, and excitation emission matrix fluorescence analysis. Chlorination was also employed to explore the influence of sediment adsorption on drinking water quality. The results indicated that the maximum adsorption potential of sediments to SMPs was 1.60 mg/g, which involved exothermic processes. SMPs adsorption declined with increasing temperature and salinity, and fulvic acid and protein in SMPs were more readily adsorbed on sediments than was humic acid. Correlation analysis results indicated that adsorption behaviours of sediments to SMPs could significantly reduce the generation potential of DBPs (r = 0.882-0.938, p 0.01). In addition, the decrease of C-DBPs was considerably greater than that of N-DBPs. These research findings are of importance to assessments of the fate and transport of SMPs in water-sediment systems, as well as the effect of following DBPs formation in the drinking water supply.

It is necessary to study the mechanism of resistance to heavy metals in microbiological processes. In this study, Ochrobactrum MT180101 was used as the microbial source of an membrane bioreactor to investigate its degradation efficiency for electroplating wastewater and the copper-resistant mechanism. Meanwhile, excitation emission matrix-parallel factor, scanning electron microscope, atomic force microscope, fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and proteome analyses were applied to explain the comprehensive mechanism of the Ochrobactrum MT180101 resisting heavy metal toxicity. The results indicated that the Ochrobactrum MT180101 resisted heavy metal toxicity with the following pathways: i) binding metal cations on cell wall surfaces, ii) generating microbial products such as protein to chelate and stabilize the metal cations, iii) bio-transporting heavy metals from the intramembrane to the outer membrane by means of intracellular transport, and iv) reducing heavy metals through enzyme-mediated biotransformation. The results ensure that Ochrobactrum MT180101 was a copper-resistant bacterium that can be used in the pretreatment or deep treatment of electroplating wastewater.

The urban organic aerosol (OA) may pose a serious threat to human health and ecological environment. In order to understand the molecular characteristics of organic compounds in aerosols, atmospheric PM2.5 samples were collected in Beijing and the extracts were analyzed by liquid chromatography-Orbitrap mass spectrometry combined with negative-ion electrospray ionization, positive-ion electrospray ionization, and positive-ion atmospheric pressure photoionization sources. The combination of multiple ionization sources realized the comprehensive molecular characterization of organic compounds in OA, and 1976 (+APPI), 3038 (−ESI), and 4376 (+ESI) molecular formulas were identified in this study. Significant differences in the species, abundance, and number of subgroups (CHO, CHN, CHON, CHONS, CHOS, and CH compounds) were clarified. Chemical fingerprinting of organics in the PM2.5 extract were investigated by high-throughput non-target compound analytical methods. Structure induction of organic compounds was realized through fragmentation prediction of MS/MS spectra with Sirius software. Furthermore, a total of 50 nitroaromatic formulas, 285 organosulfates (OS) formulas, 57 nitrooxy-OS formulas, 228 CHO- formulas with carboxyl groups, and 36 monoketone formulas were determined based on diagnostic fragmentation filtering. Our results provide important insights into the molecular composition and structural characteristics of OA, and establish foundation for exploring the interaction between composition and physicochemical properties.

The kinetics of ferrate(VI) decomposition in natural water were assessed in the absence and presence of natural organic matter (NOM) (pH = 7.50, [Fe(VI)] = 54 µM, DOC = 0.00–10.00 and 1.00–8.57 mg/L for a simulated natural water and six real natural waters, respectively). Without NOM, Fe(VI) decomposition in simulated natural water exhibited a biphasic kinetics pattern, i.e. a 2nd-order reaction with respect to Fe(VI) concentration followed by a 1st-order reaction. However, an additional instant Fe(VI) loss was observed at the onset in the presence of NOM for both simulated and real natural waters, thereby rendering Fe(VI) decay with NOM a unique three-stage kinetics pattern. The initial instant Fe(VI) loss was caused due to the homogenous Fe(VI) self-decay and the rapid reactions between Fe(VI) and NOM. The latter accounted for a major fraction of the initial Fe(VI) loss and was in direct proportion with the initial DOC (DOC0) (Δ[Fe(VI)]0DOC = αNOM DOC0; αNOM = 1.45 µM Fe(VI)·L/mg DOC for the simulated natural water, and 0.66–1.35 µM Fe(VI)·L/mg DOC for the six natural waters). Fe(VI) decomposition experiments with different Suwannee River NOM isolates revealed that hydrophobic NOM fractions (i.e. fulvic acid (FA) and humic acid (HA)) caused a more significant initial Fe(VI) loss than the hydrophilic group (HPI), suggesting that Fe(VI) preferentially reacted with hydrophobic NOM molecules rather than hydrophilic compounds. Furthermore, an approach developed for the estimation of αNOM revealed a linear correlation between αNOM and specific UV absorbance (SUVA) (αNOM = 0.27SUVA + 0.18, R2 = 0.71). This study provides essential information regarding Fe(VI) decomposition for the determination of Fe(VI) dose and exposure for effective water treatment.

// Chaoting Zhang 1, * , Fangfang Liu 1, * , Yaqi Pan 1 , Qiuju Deng 1 , Xiang Li 1 , Zhonghu He 1 , Mengfei Liu 1 , Tao Ning 1 , Chuanhai Guo 1 , Yongmei Liang 1 , Ruiping Xu 2 , Lixin Zhang 2 , Hong Cai 1 and Yang Ke 1 1 Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Laboratory of Genetics, Peking University Cancer Hospital & Institute, Beijing 100142, China 2 Anyang Cancer Hospital, Anyang 455000, China * These authors have contributed equally to this work Correspondence to: Hong Cai, email: drhcai@gmail.com Yang Ke, email: keyang@bjmu.edu.cn Keywords: oral HPV, natural history, China Received: January 04, 2017 Accepted: February 20, 2017 Published: March 17, 2017 ABSTRACT The natural history of oral human papillomavirus (HPV) infection which is linked with the increased incidence of oropharyngeal squamous cell cancer (OPSCC) has been incompletely studied. Oral swab specimens and questionnaire data were obtained bi-annually for up to 6 visits from 4314 healthy adults aged 25-69 in rural Anyang, China. HPV infection status was evaluated with PCR-based sequencing. Participants with at least two consecutive valid HPV results within the study period were included in the incidence and clearance analysis. Among 3289 participants included in this analysis (median follow-up time 18.3 months), incidence rates of mucosal HPV, oncogenic mucosal HPV and cutaneous HPV were 0.53 (95% CI: 0.39-0.73), 0.30 (95% CI: 0.20-0.46), and 4.17 (95% CI: 3.70-4.70) per 1,000 person-months respectively. Most newly acquired infections were cleared within one year. Recent practice of oral sex increased the risk of incident infection with mucosal HPV (Adjusted HR, 5.03; 95% CI, 1.16-21.73) and oncogenic mucosal HPV (Adjusted HR, 10.13; 95% CI, 2.14-48.06). Newly acquired oral mucosal HPV infections are rare and most are cleared within one year in rural Chinese. This study expands understanding of the natural history of oral HPV in countries with a lower incidence of HPV-OPSCC.

In this study, we analyzed the effects of sludge aging pre-treatment on the stabilization mechanisms of heavy metals during sludge pyrolysis. First, the form of copper (Cu) and chromium (Cr) was conducted using the sequential extraction procedure proposed by the European Community Bureau of Reference (BCR). The stabilization mechanisms for the sludge pyrolysis of Cu and Cr were then analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Results indicate the following: 1) with aging pre-treatment, the improvement in adsorption performance and the formation of newly crystallized materials, like polyhydroxy copper phosphate and chromium phosphate minerals, occur concurrently with the stabilization of heavy metals during pyrolysis; 2) after four weeks of aging, active functional groups like amino and carboxyl groups were significantly sharpened, and caused sustained complexation of the heavy metals. Results suggested that the aging pre-treatment aided the stabilization of heavy metals during sludge pyrolysis. Notably, the aging effect can decrease the potential ecological risk of heavy metals.

We aimed to investigate heart rate recovery (HRR) in patients with transient ischemic attack (TIA) and the relationship between HRR and health-related quality of life (HRQOL). All available patients were enrolled during the enrollment period. A total of 120 patients with TIA and 120 healthy controls were included in this study. A treadmill stress test was performed to calculate the HRR. The HRR were calculated as follows: HRR 1, 2, 3, and 5 minutes = heart rate at peak during exercise − heart rate at 1, 2, 3, and 5 minutes at rest. All patients enrolled were asked to fill in the Short Form 36 Health Survey to calculate HRQOL. We found that the maximum heart rate of TIA patients was significantly higher than that of healthy controls (166 ± 11 vs. 162 ± 14 beats/min, P = .015). Similarly, maximum systolic blood pressure (SBP) and diastolic blood pressure (DBP) were higher in TIA group compared with healthy control group (SBP: 172 ± 15 vs. 165 ± 14 mm Hg, P

Nitroaromatic compounds (NACs) have received much attention as a kind of toxic and important light-absorbing components in atmospheric PM2.5. In order to clarify the chemical composition, concentration levels and sources of NACs in the atmosphere, PM2.5 samples were collected from April 2016 to April 2017 in Beijing. Selective and non-targeted analytical method based on liquid chromatography-Orbitrap MS (LC-Orbitrap MS) was used to characterize atmospheric NACs for the first time. A total of 190 NACs were quantified and semi-quantified with authentic standards or surrogates, of which 165 NACs were identified tentatively. Nitro-polyaromatic compounds (NPCs) were identified and semi-quantified for the first time, including nitronaphthol, nitroacenaphthenol, nitrofluorenol, nitroaceanthrylenol, nitropyrenol and their methyl derivatives, etc. The seasonal average concentrations of total NACs were from 10.8 in summer to 100 ng/m3 in winter, which was higher than in many other areas. Nitrophenols (NP) and nitrocatechols (NC) were the most abundant NACs species, and the proportion to total NACs were 31% and 32%, respectively. The seasonal average concentration of NPCs ranged from 1.5 in summer to 9.6 ng/m3 in winter with an annual average contribution of 12%, which cannot be ignored. In winter, the contribution of NACs to organic matter (OM) and PM2.5 were up to 2.88‰ and 1.59‰, respectively. Four major sources were assigned, coal combustion and secondary formation had the highest contribution of 35%, followed by biomass combustion (32%), dust (18%), and transportation (6%).

To increase the degree of immobilization of heavy metals subjected to sludge pyrolysis, we investigated the effects of pretreating sludge with Ochrobactrum supplementation on the immobilization of chromium (Cr) and copper (Cu) during sludge pyrolysis. The sequential extraction procedure was used to test the metallic forms of Cr and Cu. The immobilization of Cr and Cu was characterized with X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, etc. Results show that: 1) the addition of Ochrobactrum (1-8%) can accelerate the mineralization process in blank sludge and can accelerate the conversion of the oxidizable forms of Cr and Cu into the residual forms subjected to pyrolysis; 2) pretreatment with Ochrobactrum supplementation can inhibit the volatilization of Cr and Cu during sludge pyrolysis, particularly in the case of a high concentration of Cu. Notably, the pretreatment with Ochrobactrum can reduce 20.38-85.09% of the potential ecological risk of Cr and Cu. The pretreatment with Ochrobactrum contributes to the immobilization of Cr and Cu subjected to sludge pyrolysis and thus can prevent pollution of the environment. The results of this study can be used for harmless disposal of municipal sludge.

The exchange bias effect with anisotropy perpendicular to the device plane is promising for exploring the next generation of spintronics devices. However, the effective modulating of exchange bias remains challenging because the understanding of the mechanism on tuning the exchange bias anisotropy is lacking and worth investigation. In this study, epitaxial La0.7Sr0.3MnO3/NiO (LSMO/NiO) bilayers were deposited on the (001)-orientated SrTiO3 and MgO substrates by pulse laser deposition to further explore the mechanism behind the anisotropy of EB effect at the LSMO/NiO interface. The results demonstrate the exchange bias transition from in-plane to out-of-plane by changing the substrate from SrTiO3 to MgO. According to the strain analyses, the substrate strain-induced spin reorientation transition of NiO plays an important role on the exchange coupling at the LSMO/NiO interface, leading to the EB effect transition. The significance of the interaction between strain and spin at the heterointerface is revealed, which provides a possible way for the regulation of interfacial magnetism.

Pharmaceutically active compounds in wastewater released from human consumption have received considerable attention because of their possible risks for aquatic environments. In this study, the occurrence and removal of 10 pharmaceuticals in three municipal wastewater treatment plants in southern China were investigated and the environmental risks they posed were assessed. Nifedipine, atenolol, metoprolol, valsartan and pravastatin were detected in the influent wastewater. The highest average concentration in the influents was observed for metoprolol (164.6 ng/L), followed by valsartan (120.3 ng/L) in August, while median concentrations were higher in November than in August. The total average daily mass loadings of the pharmaceuticals in the three plants were 289.52 mg/d/person, 430.46 mg/d/person and 368.67 mg/d/person, respectively. Elimination in the treatment plants studied was incomplete, with metoprolol levels increasing during biological treatment. Biological treatment was the most effective step for PhACs removal in all of the plants studied. Moreover, the removal of PhACs was observed with higher efficiencies in August than in November. The WWTP equipped with an Unitank process exhibited similar removals of most PhACs as other WWTPs equipped with an anoxic/oxic (A/O) process or various anaerobic-anoxic-oxic (A2/O) process. The environmental risk assessment concluded that all of the single PhAC in the effluents displayed a low risk (RQ

Soluble microbial products (SMPs), as a major part of the effluent organic matter discharged into surface water, may affect the formation of disinfection by-products (DBP) in downstream drinking water treatment plants. In this study, excitation emission matrix fluorescence with parallel factor analysis (EEM-PARAFAC), infrared spectroscopy (IR), high performance size-exclusion chromatography (HPSEC) and 16SrRNA high-throughput sequencing were used to investigate the aerobic and anoxic bioavailability of SMPs in surface water and evaluate their influences on DBP formation upon chlorination in a subsequent drinking water plant. In this study, SMPs were utilized by enriched microbial communities such as Bacteroidetes and Proteobacteria, but the accumulation of SUVA was pronounced during the two oxygen conditions. Biodegraded SMPs had higher humic substructures and lower protein-like components. Due to the presence of SMPs, microbial community compositions were influenced during biodegradation. Moreover, DO was the main factor in biodegradation of SMPs, thus affecting a series of processes, such as microbial compositions, properties of SMPs, DBP formation and reactivity. DBP formation potential decreased after anoxic and aerobic incubations. However, SMPs after aerobic degradation had higher DBP reactivity meanwhile the opposite was found for anoxic incubation. Based on the analysis of IR and HPSEC, it was found that some new substrates or intermediates with MW (220 KDa,1 KDa) during microbial incubation may contribute to the formation of trihalomethane (THMs), chloral hydrate (CH), dichloroacetonitrile (DCAN) and trichloronitromethane (TCNM) in each DBP sampling episode.

In the Pearl River Delta area, the upstream municipal wastewater is commonly discharged into rivers which are a pivotal source of downstream drinking water. Solar irradiation transforms some of the dissolved organic matter discharged from the wastewater, also affecting the formation of disinfection by-products in subsequent drinking water treatment plants. The effect of simulated solar radiation on soluble microbial products extracted from activated sludge was documented in laboratory experiments. Irradiation was found to degrade macromolecules in the effluent, yielding smaller, more reactive intermediate species which reacted with chlorine or chloramine to form higher levels of noxious disinfection by-products. The soluble microbial products were found to be more active in formation of disinfection by-products regard than naturally-occurring organic matter. The results show that solar irradiation induced the formation of more trihalomethane (THMs), chloral hydrate (CH) and trichloronitromethane (TCNM), causing greater health risks for downstream drinking water.

Objectives Hysterectomy is one of the most common surgical procedures performed on women in developed countries; however, little is known about the epidemiology of hysterectomy in low-income to middle-income regions. This study seeks to evaluate the prevalence of hysterectomy and its risk factors in rural China. Methods Questionnaires were collected from 3328 female adults aged 25–69 years in rural Anyang, China, in 2009–2011. Hysterectomy status was ascertained by the gynaecologist at the time of cytological test. Univariate and multivariate regression analyses were performed to assess the risk factors for hysterectomy. Results The overall prevalence of hysterectomy was 3.31% (110/3328). Women above the age of 40 years had a higher prevalence of prior hysterectomy, compared with those aged 25–39 years (5.01% vs 0.33%). Obesity was marginally related with a higher risk of hysterectomy (adjusted OR=1.59; 95% CI 0.99 to 2.56; body mass index (BMI) ≥28.0 vs 18.5 ≤ BMI

Background: Despite the established link between oral human papillomavirus (HPV) infection and a subset of oropharyngeal squamous cell carcinoma (OSCC), little is known about the epidemiology of oral HPV infection among healthy adults in China. Methods: Oral swab specimens and questionnaires were collected from 5,410 individuals (ages 25–65 years). HPV DNA in oral exfoliated cells was tested by general primer-mediated (SPF1/GP6+) PCR and sequencing. Univariate and multivariate analyses were performed to assess the associations between exposure factors and oral infection. Results: Alpha mucosal HPV types were detected in 0.67% [95% confidence interval (CI), 0.47%–0.93%] of 5,351 β-globin–positive specimens, and cutaneous HPV in 5.46% (95% CI, 4.86%–6.10%). HPV 16 and 3 were the most prevalent types of α mucosal (0.43%; 95% CI, 0.27%–0.64%) and cutaneous HPV (4.17%; 95% CI, 3.65%–4.74%), respectively. The prevalence of α mucosal HPV decreased with increasing age (25–65 years) from 0.93% to 0.36% (Ptrend = 0.033), and was associated with self-reported history of oral disease [adjusted odds ratio (OR), 4.78; 95% CI, 1.07–21.41]. In 1,614 heterosexual couples, cutaneous HPV in one partner was found to increase the other partner's risk of cutaneous HPV infection (adjusted OR, 2.33; 95% CI, 1.22–4.48). Conclusions: Oral HPV infection, particularly with α mucosal types, is rare among healthy adults in China. A younger age and a history of oral disease imply higher risk of α mucosal HPV infection. Impact: This study addresses the paucity of epidemiological data on oral HPV infection among healthy population in China. Cancer Epidemiol Biomarkers Prev; 23(10); 2101–10. ©2014 AACR.

Aromatic fractions derived from aerosol samples were characterized by gas chromatography and mass spectrometry (GC-MS), high temperature simulated distillation (SIMDIS), and positive-ion atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), respectively. It was found that about 27 wt % compounds in aromatic fractions could not be eluted from a GC column and some large molecule PAHs were neglected in GC-MS analysis. APPI FT-ICR MS was proven to be a powerful approach for characterizing the molecular composition of aromatics, especially for the large molecular species. An aromatic sample from Beijing urban aerosol was successfully characterized by APPI FT-ICR MS. Results showed that most abundant aromatic compounds in PM2.5 (particles with aerodynamic diameter ≤ 2.5 μm) were highly condensed hydrocarbons with 4-8 aromatic rings and their homologues with very short alkyl chains. Furthermore, heteroatom-containing hydrocarbons were found as the significant components of the aromatic fractions: O1, O2, N1, and S1 class species with 10-28 DBEs (double bond equivalents) and 14-38 carbon numbers were identified by APPI FT-ICR MS. The heteroatom PAHs had similar DBEs and carbon number distribution as regular PAHs.

The synergistic effects of sequential ultraviolet (UV) radiation and chlorination on tailing during disinfection of Escherichia coli in secondary effluent were investigated. To accomplish this, the effects of UV and chlorination, pH, dose of chlorine and dose of UV on kinetic curves of E. coli were evaluated. Total suspended solids (TSS) were found to be responsible for tailing during disinfection, and their concentrations were linearly correlated with the overall inactivation rate. Specifically, inactivation decreased by 10 times as suspended solids increased from 6 to 85 mg/L. The synergistic effects of sequential UV radiation and chlorination were identified. Sequential UV radiation and chlorination substantially increased the inactivation rate by 1.08–1.25 times in the first-order region and increased the log-inactivation value by 2–2.5 times in the tailing region with respect to chlorination. Reducing pH and/or increasing chlorine and UV dose magnified the enhancements of the first-order ina...

The fluid catalytic cracking (FCC) performances of three typical coker gas oil (CGO) in China were investigated in a fixed fluidized-bed reactor. Effects of the blending ratio of CGO to vacuum gas oil (VGO), comparative FCC performances of different CGOs, and effects of operating conditions on CGO catalytic cracking performance were discussed. Based on these, the competitive adsorption effects on CGO catalytic cracking were analyzed. The results show that the conversion decreases with the increasing blending ratio of CGO to VGO due to lower reactivity of coker gas oils. The catalyst to oil ratio (CTO) has a larger influence on CGO catalytic cracking performance than the reaction temperature and weight hourly space velocity (WHSV) has. A competitive reaction area and a free reaction area can be distinguished based on the relation of CTO and CGO catalytic cracking performance.

The organic matter in International Humic Substances Society Natural Organic Matter (IHSS NOM) water exposed to ultraviolet (UV) irradiation and chlor(am)ine sequentially under practically relevant conditions was characterized based on fluorescence spectra. IHSS NOM water exposed to UV irradiation or chlor(am)ine alone was also evaluated. Both chlor(am)ine alone and UV/chlor(am)ine exposure showed similar chlor(am)ine demand and fluorescence spectra. UV irradiation and UV/chlorine exposure diminished the fluorescence intensity of IHSS NOM water, while UV/chloramine exposure resulted in increased fluorescence intensity. When compared with the results obtained following chlor(am)ination alone, IHSS NOM water showed decreased chlorine decay and increased chloramine decay after UV irradiation/chlor(am)ination. Additionally, IHSS NOM water exposed to UV/chloramine and chloramine showed less disinfection by-product (DBP) formation than water subjected to UV/chlorine and chlorine. Overall, these findings indicate that UV irradiation degrades NOM molecules to low-molecular-weight fractions, facilitating the subsequent reaction with chlor-(am)ine. However, chlorine and chloramine play different roles in the reaction. Chlorine degradation and substitution dominates the process of UV/chlorine exposure, while chloramine substitution is the major reaction during UV/chloramine exposure.

A pilot-scale study was carried out to evaluate the in situ anaerobic digestion of nutrient-deficient activated sludge (AS) from southern China. A single and two-stage system were compared and the performance of ultrasound pretreatment and co-digestion with kitchen garbage was evaluated by comparing volatile solids removal and biogas production. The results showed that two-stage systems performed better than single-stage systems at high feeding concentration and short retention time. Ultrasonic pretreatment significantly enhanced sludge solubilization though cell lysis and subsequently increased biogas yields. Mixture with kitchen garbage resulted in substantial volatile solids reductions in both single and two-stage systems of up to 47% as well as significant increases in biogas yields. Processes including digestion, dewatering, drying and incineration of this type of sludge were proposed, and mass balance calculation showed that these processes were feasible and had the potential to provide environmental and economic benefits for wastewater treatment plants in southern China.

Sodium hypochlorite (NaOCl) is a common cleaning agent for treating ultrafiltration (UF) membranes. Although it efficiently removes fouling, NaOCl accelerates membrane degradation and reduces membrane integrity. In this paper, new and polluted polyvinylchloride hollow fiber membranes were treated with NaOCl solutions. The effects on the membrane were evaluated by using transmembrane pressure, bovine serum albumin permeability, particle-size distribution of the effluent (PSDE), attenuated total reflectance-Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The membrane pore size increased after exposure to solutions with a NaOCl mass fraction of 1%. The PSDE was successfully used to test membrane integrity. When the NaOCl mass fraction was

Contrast experiments of fluid catalytic cracking (FCC) were conducted in a technical pilot scale riser FCC apparatus. The results showed that the use of a low-temperature regenerated catalyst and high ratio of catalyst to oil (CTO) improved the initial contact between the catalyst and feedstock. Thermal cracking was inhibited and catalytic cracking was promoted in the FCC riser, which were favorable for increasing the conversion and generation of desirable products. A modified FCC process was proposed and numerical simulation were used in the selection of the equipment structure for mixing cold and hot regenerated-catalyst streams to achieve optimal contact between the catalyst and the feedstock. A commercial unit was revamped based on the experimental results to test the modified FCC process. Results from industrial practice showed that product distributions under optimal conditions of low-temperature contact and high ratio of catalyst to oil in the modified FCC process were superior to those from routin...

ZnO and Er-doped ZnO with different molar ratios of Er/Zn were prepared using the homogeneous precipitation method. The photocatalysts prepared were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction (XRD), UV-vis spectroscopy, and photoluminescence spectroscopy. The results showed that the Er-doped ZnO displayed characteristic wurtzite-type peaks in the XRD spectra. The Er-doped ZnO absorbed much more light than ZnO in the ultraviolet region. And the doping of Er into ZnO enhanced the intensity of the fluorescence emission. The degradation of methylene blue (MB) solution demonstrated that the photocatalytic activity of ZnO was significantly improved with Er doping.

Self-rated health (SRH) has been shown to be a good predictor of mortality. Data on SRH and its associated factors in the Chinese general population are limited. This study aims to assess the epidemiology of SRH in rural Anyang, China. SRH (categorized as “healthy”, “fair” or “unhealthy”) was measured in a population-based study of 2,814 adults (including 697 couples) aged 25 to 69 who were recruited from rural Anyang in 2014. Of 2,814 subjects, 63.1% rated their health as “healthy”, whereas 28.1% and 8.8% rated their health as “fair” and “unhealthy”. Compared to males, females had a higher likelihood of reporting a better SRH. Health ratings declined with increasing age, unmarried status, lower education levels. Poor SRH was positively correlated with medical history as well as high levels of fasting plasma glucose and total cholesterol, but not with unhealthy lifestyle indicators including smoking, drinking, and obesity. High household income was predictive of better SRH in men but not in women. Among couples, a positive spousal SRH concordance was observed, although the strength of this concordance was low. These findings will be useful for formulation of appropriate strategies for improving risk perception and promoting general health in economically developing regions.

Data on simultaneous analysis of human papillomavirus (HPV) DNA and serology and the correlations within a single general population are limited. Among 1603 men and 2187 women enrolled from rural China, serum antibodies against bacterially derived GST-L1 fusion proteins of HPV were assessed with multiplexed serology and HPV DNA was evaluated with PCR-based sequencing. Few subjects were dually positive to HPV DNA and serum antibodies for any HPV (6.6% of men and 3.1% of women). The proportion of men ever having been infected with any HPV (DNA and/or antibody positive) was higher than that of women (71.0% vs. 65.2%, P

Ozone (O3) and ozone/hydrogen peroxide (O3/H2O2) can be used in water treatment facilities to remove many organic micropollutants with taste, odor, and color implications. The effects of O3 and O3/H2O2 on the formation of disinfection byproducts (DBPs) in subsequent chlorination and chloramination processes, however, are not well determined. In this study, we compared the yields of a series of regulated and emerging DBPs during sequenced O3-Cl2, O3/H2O2-Cl2, O3-NH2Cl, and O3/H2O2-NH2Cl oxidation of 11 samples, each with different hydrophobicity, bromide concentration, soluble microbial products, and humic substances. For most water, pretreatment with O3 and O3/H2O2 increased the formation of chloral hydrate (CH), trichloronitromethane (TCNM) and haloketones (HKs) but lowered the yields of haloacetonitriles (HANs) during chlorination processes. Compared with O3 alone, O3/H2O2 in combination generated more CH and HKs during chlorination, and their extents of formation appeared to depend on the O3 doses. In terms of chloramination, both O3 and O3/H2O2 reduced THM, HAA, and HAN formation significantly without increasing CH, TCNM, or HKs. These results suggest that O3 or O3/H2O2 pretreatments may provide some benefits for the chloramination process in controlling regulated and emerging DBPs in waters without high bromide content.

The formation of trichloronitromethane (TCNM) and dichloroacetonitrile (DCAN) was investigated during chlorination and chloramination of 31 organic nitrogen (org-N) compounds, including amino acids, amines, dipeptides, purines, pyrimidones and pyrroles. Tryptophan and alanine generated the greatest amount of TCNM during chlorination process and asparagine and tyrosine yielded the highest amount of TCNM during chloramination process. Tryptophan, tyrosine, asparagine, and alanine produced more DCAN than other org-N compounds regardless of chlorination or chloramination. TCNM and DCAN formation was higher by chlorination than by chloramination. NH 2 Cl:org-N molar ratios, reaction time, and pH affected N-DBPs formation in varying degrees. TCNM and DCAN yields were usually high during chloramination of tyrosine, asparagine, and methylpyrrole under the following reaction conditions: NH 2 Cl:org-N molar ratios greater than 10, reaction time for 1 d, and at pH 7.2. NH 2 Cl as a major nitrogen origin in TCNM and DCAN was confirmed via labeled 15 N-monochloramine during chloramination of tyrosine, asparagine and methylpyrrole. In contrast, the majority of nitrogen in TCNM originated from glycine, and that in DCAN originated from pyrrole. Based on the intermediates identified by gas chromatography/mass spectrometry (GC/MS), a pathway scheme was proposed for TCNM and DCAN formation.

The influences of the boiling point and fractional composition of coker gas oil (CGO) on the fluid catalytic cracking performance were investigated. Nitrogen compounds and condensed aromatics in CGO were identified by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) and gas chromatography-mass spectrometry (GC-MS), respectively, and their effects were studied systematically. The result shows that the catalytic cracking performance of CGO does not correspond to the boiling point of narrow fractions but rather to the basic nitrogen compounds and condensed aromatics that have high molecular weight and/or high condensation tendencies adversely. On the basis of these results, a divisional fluid catalytic cracking (DFCC) process was proposed where a separate reaction zone was added to reduce the contents and effects of the adverse compounds in CGO during catalytic cracking. The simulation experiments of the DFCC process show that improved conversion and enhance...

The coking phenomenon of coker gas oil (CGO) feedstock during fluid catalytic cracking (FCC) using a commercial equilibrium catalyst was investigated. Different types of coke formed via coker gas oil (CGO) catalytic cracking were also analyzed. The coke formed was composed of adsorption coke (Cad), dehydrogenation condensation coke (Cdh), and hydrogen transfer coke (Cht). Cad, derived from nitrogen compounds, adsorbed on the acid sites of the catalyst and accounted for 37 wt % of the total coking content under conventional reaction conditions. Cdh was formed by the dehydrogenation condensation of polycyclic aromatic hydrocarbons and accounted for about 43 wt % of the total coking content. The coking content of Cht was greatly determined by the degree of the secondary reaction. Coke selectivity can be decreased and Cht yield can be controlled by simultaneously increasing the reaction temperature and shortening the reaction time.