HPLC-CAD as a supplementary method for the quantification of related structure impurities for the purity assessment of organic CRMs.

In organic purity assessment, chromatography separation with a suitable detector is required. Diode array detection (DAD) has been a widely used technique for high-performance liquid chromatography (HPLC) analyses, but its application is limited to compounds with sufficient UV chromophores. Charged aerosol detector (CAD), as a mass-dependent detector, is advantageous for providing a nearly uniform response for analytes, regardless of their structures. In this study, 11 non-volatile compounds with/without UV chromophores were analyzed by CAD using continuous direct injection mode. The RSDs of CAD responses were within 17%. For saccharides and bisphenols, especially, the RSDs were lower (2.12% and 8.14%, respectively). Since bisphenols exist in UV chromophores, their HPLC-DAD responses were studied and compared with CAD responses, with CAD showing a more uniform response. Besides, the key parameters of HPLC-CAD were optimized and the developed method was verified using a Certified Reference Material (CRM, dulcitol, GBW06144). The area normalization result of dulcitol measured by HPLC-CAD was 99.89% ± 0.02% (n = 6), consistent with the certified value of 99.8% ± 0.2% (k = 2). The result of this work indicated that the HPLC-CAD method could be a good complementary tool to traditional techniques for the purity assessment of organic compounds, especially for compounds lacking UV chromophores.

SI-traceable purity assignment of volatile material ethylbenzene by quantitative nuclear magnetic resonance spectroscopy.

In this study, a quantitative nuclear magnetic resonance (qNMR) method was developed to assign the SI-traceable purity of ethylbenzene, a volatile material, which is a colorless flammable liquid hydrocarbon at room temperature. An ethanol certified reference material having a similar boiling point was used as an internal standard to avoid measurement error arising from the volatilization of ethylbenzene. The reference value of the ethylbenzene study material was obtained by the mass balance method by subtracting all the impurities including water, inorganic impurities, and structurally related impurities (e.g. acetophenone, benzene, isobutylbenzene, sec-butylbenzene, methylcyclohexane), which is regarded as the traditional approach for purity assignment for organic compounds. The results of qNMR showed that the purity of the ethylbenzene study material was 998.6 ± 3.8 mg/g at a 95% confidence interval, which was consistent with the reference value of 998.9 ± 1.3 mg/g.

The exposure levels and health risk assessment of antibiotics in urine and its association with platelet mitochondrial DNA methylation in adults from Tianjin, China: A preliminary study.

There has been extensive research on antibiotics exposure in adults by biomonitoring, but the biological mechanisms and potential risks to human health remain limited. In this study, 102 adults aged 26-44 years in Tianjin were studied and 23 common antibiotics in urine were analyzed by Liquid chromatography-mass spectrometry (LC-MS). All antibiotics were detected in urine, with an overall detection frequency of 40.4% (the detection frequencies of phenothiazines, quinolones, sulfonamides, tetracyclines, and chloramphenicol were 77%, 54%, 24%, 28%, and 49%, respectively.). Ofloxacin and enrofloxacin had the highest detection frequencies (85% and 81%), with median concentrations of 0.26 (IQR: 0.05-1.36) and 0.09 (IQR: 0.03-0.14) ng/mL, respectively. Based on health risk assessment, the predicted estimated daily exposures (EDEs) ranged from 0 µg/kg/day to 13.98 µg/kg/day. The hazard quotient (HQ) values of all the antibiotics except ofloxacin and ciprofloxacin were bellow one, which are considered safe. For all blood samples, the mitochondrial DNA (mtDNA) methylation levels in the MT-ATP6 (ranging between 3.86% and 34.18%) were slightly higher than MT-ATP8 and MT-ND5 (ranging between 0.57% and 9.32%, 1.08% and 19.62%, respectively). Furthermore, mtDNA methylation from MT-ATP6, MT-ATP8 and MT-ND5 were measured by bisulfite-PCR pyrosequencing. The association (P < 0.05) was found between mtDNA methylation level (MT-ATP8 and MT-ND5) and individual antibiotics including chlorpromazine, ciprofloxacin, enrofloxacin, norfloxacin, pefloxacin, sulfaquinoxaline, sulfachloropyridazine, chloramphenicol, and thiamphenicol, indicating that persistent exposure to low-dose multiple antibiotics may affect the mtDNA methylation level and in turn pose health risks.

Association between mitochondrial DNA methylation and internal exposure to polycyclic aromatic hydrocarbons (PAHs), nitrated-PAHs (NPAHs) and oxygenated-PAHs (OPAHs) in young adults from Tianjin, China.

Polycyclic aromatic hydrocarbons (PAHs), nitrated-PAHs (NPAHs) and oxygenated-PAHs (OPAHs) are environmental pollutants with adverse effects on human health. The correlation between the concentrations of PAHs, NPAHs and OPAHs in human plasma and the methylation level of mitochondrial DNA (mtDNA) was investigated using data from 110 plasma samples collected in Tianjin, China. The median concentrations of PAHs, NPAHs and OPAHs were 16.0 (IQR: 14.4-20.7) ng/mL, 82.2 (IQR: 63.1-97.6) ng/mL and 49.6 (IQR: 28.6-53.8) ng/mL, and the mean proportions were 13.4%, 56.5% and 30.1%, respectively. Bisulfite-PCR pyrosequencing was used to measure the methylation level of MT-CO1 and tRNA-Leu. The methylation levels of two mitochondrial genes (MT-CO1, tRNA-Leu) including four CpG sites (MT-CO1-P1, MT-CO1-P2, tRNA-Leu-P1 and tRNA-Leu-P2) were 0.67% ± 1.38%, 13.54% ± 2.59%, 7.23% ± 5.35% and 1.64% ± 2.94%, respectively. To the best of our knowledge, this is the first time that significant correlations were found between PAHs and their derivatives exposure and mtDNA methylation levels.

Calculation and Experimental Validation of a Novel Approach Using Solubility Parameters as Indicators for the Extraction of Additives in Plastics.

Accurately quantifying chemical additives with adverse health effects in plastic products is critical for environmental safety and risk assessment. In this work, a novel approach using solubility parameters (δ) as indicators for the extraction of additives in plastics was developed. The mechanism was evaluated by using 10 organic solvents with different solubility parameters to extract brominated flame-retardant-decabrominated diphenyl ether (BDE-209) in polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). Certified reference materials (CRMs) or CRM candidate materials were applied as matrix materials. The extracted BDE-209 and solubility parameters of solvents could fit into a curve of a quadratic function. The value of abscissa corresponding to the vertex of the function was close to the solubility parameter of plastic calculated by the group contribution method (Δδ < 0.37). Toluene, n-hexane, and acetone were the solvents with high extraction efficiency for PE, PP, and PET, confirming the feasibility of the developed approach. The results of ethyl acetate and acetone indicated the high weight of functional groups affecting the dissolution behavior. The developed approach was further verified by analyzing penta-/octa-BDE and phthalate esters in PET and polyvinyl chloride (PVC) and finally applied to analyze 15 plastic products made of PP, PE, PET, polystyrene, and PVC. The detected tetrabromodiphenyl ether (BDE-47), BDE-209, decabromodiphenyl ethane, and di(2-ethylhexyl) terephthalate all matched the approach and verified its practicability for field sample analysis.

Fine particle-bound PAHs derivatives at mountain background site (Mount Tai) of the North China: Concentration, source diagnosis and health risk assessment.

Ten nitrated polycyclic aromatic hydrocarbons (nPAHs) and 4 oxygenated polycyclic aromatic hydrocarbons (oPAHs) in fine particulate matter (PM2.5) samples from Mount Tai were analyzed during summer (June to August), 2015. During the observation campaign, the mean concentration of total nPAHs and oPAHs was 31.62 pg/m3 and 0.15 ng/m3, respectively. Two of the monitored compounds, namely 9-nitro-anthracene (9N-ANT) (6.86 pg/m3) and 9-fluorenone (9FO) (0.05 ng/m3) were the predominant compounds of nPAHs and oPAHs, respectively. The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization (PMF) method and the potential source contribution function (PSCF) methods. The results revealed that biomass/coal burning, gasoline vehicle emission, diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs, which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea. The incremental life cancer risk (ILCR) values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people (infant, children and adult), and the values of ILCR were 7.02 × 10-10, 3.49 × 10-9 and 1.41 × 10-8 for infant, children and adults, respectively. All these values were lower than the standard of EPA (Environmental Protection Agency) (<10-6), indicating acceptable health risk of nPAHs and oPAHs.

Determination of bisphenol analogues in food-contact plastics using diode array detector, charged aerosol detector and evaporative light-scattering detector.

Freshness protection packages and preservative films are widely used food-contact plastic made of polyethylene. Diode array detector (DAD), charged aerosol detector (CAD) and evaporative light-scattering detector (ELSD) were evaluated for determination of 6 bisphenols (bisphenol A, bisphenol S, bisphenol F, bisphenol B, bisphenol AF and tetrabromobisphenol A.) in polyethylene. DAD presented better parameters including limit of quantification (LOQs) ranging from 0.05 to 0.5 µg/g with relative standard deviations (RSDs, n = 5) lower than 1% at two concentration levels. CAD and ELSD are universal detectors with relative consistent response parameters for different analogues which have potential application by using single calibrant for quantification of multiple analytes. Matrix effects were barely observed on three detectors. Samples of freshness protection packages and preservative films were further analyzed and preliminary profiles of bisphenols in products from Beijing market was obtained. Bisphenol S have become most abundant analogue instead of bisphenol A in investigated products.

Development and evaluation of microwave-assisted and ultrasound-assisted methods based on a quick, easy, cheap, effective, rugged, and safe sample preparation approach for the determination of bisphenol analogues in serum and sediments.

Microwave- and ultrasound-assisted methods based on a quick, easy, cheap, effective, rugged, and safe sample preparation approach followed by high-performance liquid chromatography with tandem mass spectrometry were developed for the simultaneous determination of eight bisphenol analogues in serum and sediment. The developed methods provided satisfactory extraction efficiency for the energy provided by microwaves and ultrasound. Compositions of commercial sorbents (primary secondary amine, MgSO4 , octadecyl-modified silica, and graphitized carbon black) were evaluated. The ultrasound-assisted method was suited for serum using primary secondary amine, MgSO4 , and octadecyl-modified silica as sorbents and a mixture of hexane and ethyl acetate as extraction solvent. The microwave-assisted method worked better for sediment with tetrahydrofuran and methanol as solvents and primary secondary amine, MgSO4 , octadecyl-modified silica, and graphitized carbon black as sorbents. Other experimental parameters, such as extraction temperature and time, were also optimized. The inter- and intraday relative standard deviations ranged from 2.7 to 5.5%. The limits of detection were between 0.1 and 1.0 ng/mL for serum and between 0.1 and 0.5 ng/g dry weight for sediment. The proposed methods were successfully applied to seven sediment and 20 human serum samples. The results showed that the developed methods were practical for the analysis and biomonitoring of bisphenols in sera and sediment.

Occurrence of synthetic phenolic antioxidants and major metabolites in municipal sewage sludge in China.

Synthetic phenolic antioxidants (SPAs) are one group of widely used additive chemicals, which have not yet had focused attention except for a few compounds such as 2,6-di-tert-butyl-4-methylphenol (BHT). In this study, the occurrence and composition profiles of 12 frequently used SPAs and three BHT metabolites were investigated in fifty-six sludge samples collected from individual wastewater treatment plants in China. Eleven SPAs were positively found in the sludge samples, in which, to our knowledge, eight SPA compounds were identified for the first time in the environment. BHT, 4-tert-octylphenol (4-tOP), and 2,4,6-tri-tert-bultylphenol (AO 246) were the most dominant SPAs in the sludge at mean concentrations of 4.14 µg/g, 374 ng/g, and 98.1 ng/g d.w. (dry weight). Meanwhile, three BHT metabolites, including 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHT-CHO), 2,6-di-tert-butyl-1,4-benzoquinone (BHT-Q), and 2,6-di-tert-butyl-4-hydroxy-4-methyl-2,5-cyclohexadienone (BHT-quinol), were also found in most of the samples (>98.2%) with mean concentrations of 141, 562, and 225 ng/g d.w., respectively. The activated sludge system (anaerobic, anoxic, and oxic tanks) of a wastewater treatment plant was further investigated for the removal efficiencies of the SPAs. High removal efficiencies (80.1-89.2%) were found for the six detected SPAs in the aqueous phase, while generation of large proportions of the three BHT metabolites was also observed.

Radiation dose and mortality risk to children undergoing therapeutic interventional cardiology.

BACKGROUND: Children undergoing interventional cardiology procedures deserve special concern due to the greater radiation sensitivity of their tissues and more remaining years of life during which a radiation-induced cancer may develop. PURPOSE: To determine the patient radiation dose for pediatric therapeutic interventional cardiology and to estimate the patient effective dose and lifetime mortality risk to children associated with five common procedures. MATERIAL AND METHODS: Ninety children with congenital heart defects undergoing interventional therapy were enrolled in this study. Data regarding fluoroscopy and radiography time, dose-area product (DAP) and peak skin dose (PSD) for each case were measured. Patients were divided into five groups. The patient effective dose (E) was calculated using a multiplicative model of ICRP 60. The overall lifetime mortality risk was evaluated using appropriate risk coefficients. RESULTS: The mean, median, standard deviation, and range of time, PSD, DAP, and E were presented for the five study groups. When these metrics were considered, there were wide variations for different cases within the same group and statistically significant differences between the five groups. The PSD correlated significantly with DAP (Pearson r = 0.70; P < 0.01), but the correlation in individual cases was poor. For all cases, the range of E was found to be between 0.44 and 66.7 mSv. The corresponding risk of lifetime mortality was 1.16 per thousand. CONCLUSION: The current study provides overall data on the time, PSD, E, and lifetime mortality risk for pediatric therapeutic interventional cardiology. Radio frequency ablation showed the highest radiation risk.

Identification and composition of emerging quaternary ammonium compounds in municipal sewage sludge in China.

Quaternary ammonium compounds (QACs) have raised considerable attention due to their wide commercial applications and recent discovery of unknown persistent analogues in aqueous environment. In this work, the occurrence and distribution of alkyltrimethylammonium (ATMAC), benzylakyldimethylethylammonium (BAC) and dialkyldimethylammonium (DADMAC) homologues were investigated in fifty-two municipal sewage sludge samples. ATMAC C10-18, BAC C8-18 and paired DADMAC C8:8-C18:18 as well as emerging homologues such as ATMAC-20, 22 and mixed DADMAC-16:18 and 14:16 were present. Furthermore, paired DADMAC-20:20 and mixed DADMAC-14:18, 18:20 were identified for the first time by nontarget qualitative strategies. A triple quadruple mass spectrometer quantification method was also initially verified with the aid of laboratory synthesized standards for the analysis of the mixed DADMACs with no certificated commercial standards currently available. The total concentrations of ATMACs, BACs and DADMACs were in the range of 0.38-293, 0.09-191 and 0.64-344 µg/g dry weight, respectively, and particularly, mixed DADMACs constituted 39 ± 7% of total DADMAC concentrations. The concentrations and profiles of individual homologues further suggested different QAC applications and fate in China. Significant correlations were also found among the concentrations of various QAC homologues as well as wastewater treatment plant (WWTP) characteristics (total organic carbon contents and daily treatment volumes).

Emerging N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and 6PPD quinone in paired human plasma and urine from Tianjin, China: Preliminary assessment with demographic factors.

With increasing concerns about N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and 6PPD-quinone (6PPD-Q), relevant environmental investigations and toxicological research have sprung up in recent years. However, limited information could be found for human body burden assessment. This work collected and analyzed 200 samples consisting of paired urine and plasma samples from participants (50 male and 50 female) in Tianjin, China. Low detection frequencies (DF, <15 %) were found except for urinary 6PPD-Q (86 %), which suggested the poor residue tendency of 6PPD and 6PPD-Q in blood. The low DFs also lead to no substantial association between two chemicals. Data analysis based on urinary 6PPD-Q showed a significant difference between males and females (p < 0.05). No significant correlation was found for other demographic factors (Body Mass Index (BMI), age, drinking, and smoking). The mean values of daily excretion (ng/kg bw/day) calculated using urinary 6PPD-Q for females and males were 7.381 ng/kg bw/day (female) and 3.360 ng/kg bw/day (male), and apparently female suffered higher daily exposure. Further analysis with daily excretion and ALT (alanine aminotransferase)/TSH (thyroid stimulating hormone)/ blood cell analysis indicators found a potential correlation with 6PPD-Q daily excretion and liver/immune functions. Considering this preliminary assessment, systematic research targeting the potential organs at relevant concentrations is required.

The association between internal polycyclic aromatic hydrocarbons exposure and risk of Obesity-A systematic review with meta-analysis.

Exposure to polycyclic aromatic hydrocarbons (PAHs) is emerging as a risk factor for obesity, but with conflicting findings. The aim of this systematic review is to investigate and summarize the current evidence towards the associations between PAHs exposure and risk of obesity. We conducted a systematic search of online databases, including PubMed, Embase, Cochrane Library, and Web of Science up to April 28, 2022. Eight cross-sectional studies with data from 68,454 participants were included. The present study illustrated that there was a significant positive association between naphthalene (NAP), phenanthrene (PHEN), and total OH-PAH metabolites and risk of obesity, the pooled OR (95% CI) was estimated at 1.43 (1.07, 1.90), 1.54 (1.18, 2.02), and 2.29 (1.32, 3.99), respectively. However, there was no significant association between fluorene (FLUO) and1-hydroxypyrene (1-OHP) metabolite and risk of obesity. Subgroup analyses showed that associations between PAHs exposure and risk of obesity were more apparent in children, female, smokers and developing regions.

Phthalates and phthalate metabolites in urine from Tianjin and implications for platelet mitochondrial DNA methylation.

Background: Phthalates (PAEs) are important synthetic substances in plastics, attracting much attention due to their potential effects on the cardiovascular system. Methods: In this study, urine and blood samples from 39 individuals were collected in Tianjin, China. Phthalates and phthalate metabolites (mPAEs) were analyzed using gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-mass spectrometry (HPLC-MS), respectively. The polymerase chain reaction (PCR) products from bisulfite-treated mitochondrial DNA (mtDNA) samples were analyzed using pyrosequencing technology. Results: The detection frequencies for 9 PAEs varied from 2.56 to 92.31%, and those for 10 mPAEs varied from 30.77 to 100%. The estimated daily intakes (EDIs) and cumulative risk of PAEs were calculated based on the experimental statistics of urinary PAEs and mPAEs. For PAEs, the HIRfD (hazard index corresponding to reference doses) values of 10.26% of participants and the HITDI (hazard index corresponding to tolerable daily intake) values of 30.77% of participants were estimated to exceed 1, suggesting a relatively high exposure risk. The mtDNA methylation levels in the MT-ATP8 and MT-ND5 were observed to be lower than in the MT-ATP6. Mono-ethyl phthalate (MEP) and MT-ATP8 were positively correlated with triglyceride levels (p < 0.05). Based on the association of PAEs, mtDNA methylation, and triglycerides, the mediating role of mtDNA methylation between PAEs and cardiovascular diseases (CVDs) was analyzed in this study, but no mediated effect was observed. Conclusion: The effects of PAE exposure on cardiovascular diseases (CVDs) should be investigated further.

Development of a solubility parameter calculation-based method as a complementary tool to traditional techniques for indoor dust microplastic determination and risk assessment.

Herein, a method based on solubility parameter calculation was first used to analyze microplastics in indoor dust. The limit of quantification (LOQ) reached 0.2 mg/g, and the result of reference material SRM 2585 (n = 3) was 14.8 mg/g ± 1.8 %, suggesting satisfying sensitivity and precision. Recoveries of spiking experiments were > 80 % with no obvious matrix interferences observed, except ethylene propylene diene monomer (EPDM) MPs. Further, 69 indoor dust samples were analyzed to verify the method and to assess exposure scenarios for graduate students in Tianjin, China. EPDM was identified in an indoor environment for the first time as the second most widely detected type after PET in this work. The mass-based result is complementary to the outcomes from thermogravimetric analysis-gas chromatography-mass spectrometry and laser direct infrared imaging. Significant correlations were found between total organic carbon (TOC), microplastics, and BDE-209 concentrations, indicating microplastics important contaminant vectors in indoor dust. Dormitory stays and PET contributed the most to health risks among the three exposure scenarios and detected four polymers, respectively. This work provides an approach with the potential for the standardized determination of microplastics in complex environmental matrices and reveals exposure characteristics of indoor dust microplastics.

The Levels of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Plasma and Their Effect on Mitochondrial DNA Methylation in the Oilfield Workers.

This study focuses on the components and levels of polycyclic aromatic hydrocarbons (PAHs) and their derivatives (MPAHs and OPAHs) in plasma samples from 19 oil workers, pre- and post-workshift, and their exposure-response relationship with mitochondrial DNA (mtDNA) methylation. PAH, MPAH, OPAH, and platelet mtDNA methylation levels were determined using a gas chromatograph mass spectrometer (GC-MS) and a pyrosequencing protocol, respectively. The total plasma concentrations of PAHs in mean value were, respectively, 31.4 ng/mL and 48.6 ng/mL in pre- and post-workshift, and Phe was the most abundant (13.3 ng/mL in pre-workshift and 22.1 ng/mL in post-workshift, mean value). The mean values of total concentrations of MPAHs and OPAHs in the pre-workshift were 2.7 ng/mL and 7.2 ng/mL, while in the post-workshift, they were 4.5 ng/mL and 8.7 ng/mL, respectively. The differences in the mean MT-COX1, MT-COX2, and MT-COX3 methylation levels between pre- and post-workshift were 2.36%, 5.34%, and 0.56%. Significant (p < 0.05) exposure-response relationships were found between PAHs and mtDNA methylation in the plasma of workers; exposure to Anthracene (Ant) could induce the up-regulation of the methylation of MT-COX1 (ß = 0.831, SD = 0.105, p < 0.05), and exposure to Fluorene (Flo) and Phenanthrene (Phe) could induce the up-regulation of methylation of MT-COX3 (ß = 0.115, SD = 0.042, p < 0.05 and ß = 0.036, SD = 0.015, p < 0.05, respectively). The results indicated that exposure to PAHs was an independent factor influencing mtDNA methylation.

Distribution and preliminary exposure assessment of bisphenol AF (BPAF) in various environmental matrices around a manufacturing plant in China.

Increasing attention has been paid to bisphenol A and bisphenol (BP) analogues due to high production volumes, wide usage and potential adverse effects. Bisphenol AF (BPAF) is considered a new bisphenol analogue which is used as raw material in plastic industry, but little is known about its occurrence in the environment and the potential associated risk. In this work, BPAF levels and environmental distribution were reported in samples collected around a manufacturing plant and a preliminary exposure risk assessment to local residents was conducted. BPAF was detected in most of the samples, with levels in river ranging between

Concentrations and composition profiles of benzotriazole UV stabilizers in municipal sewage sludge in China.

The environmental contamination and fate of benzotriazole UV stabilizers (BZTs) have received increasing attention due to their large production volume and wide usage in various consumer and industrial products. In the present work, 60 municipal sewage sludge samples from wastewater treatment plants (WWTPs) in 33 cities in China were collected to investigate the occurrence and distribution of 9 frequently used BZTs. The most dominant analogue was 2-[3,5-bis(1-methyl-1-phenylethyl)-2-hydroxyphenyl]benzotriazole (UV-234) at a median concentration of 116 ng/g (dry weight) and accounted on average for 27.2% of total BZTs. The abundance was successively followed by 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole (UV-329, average 24.3%), 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole (UV-326, average 22.2%), 2-(3,5-di-tert-amyl-2-hydroxyphenyl)benzotriazole (UV-328, average 17.7%), and 2-(2-hydroxy-5-methylphenyl)benzotriazole (UV-P, average 6.6%), with median concentrations of 66.8, 67.8, 57.3, and 20.6 ng/g, respectively. 5-Chloro-2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-327) and 2-(3-sec-butyl-5-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-350) had low detection frequency, while 2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-320) and 2-(5-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-PS) were not detectable in any sample. To our knowledge, this is the first study reporting the occurrence of UV-234, UV-329, and UV-350 in sewage sludge in China. Significant correlations were found among the BZT concentrations and also with a WWTP characteristic (daily treatment volume). Furthermore, results from degradation prediction and multimedia fate simulation based on a quantitative structure-property relationship (QSPR) model at screening level also implied that the commercial BZT chemicals and their plausible transformation products might be persistent in the environment.

The efficacy and safety of 125I brachytherapy combined with pre-operative transarterial chemoembolization in patients with locally advanced head and neck cancer.

Objective: To evaluate the safety and effectiveness of Iodine-125 ( 125I) brachytherapy combined with pre-operative transarterial chemoembolization in patients with locally advanced head and neck cancer. Methods: In this study, a total of thirty-seven individuals suffering from locally advanced head and neck cancer were involved. The patients were subjected to transarterial chemoembolization as well as implantation of 125I seeds under the guidance of CT and ultrasonography. Follow-up was conducted for 36 months to study the following parameters: the local control rate, survival rate, and clinical complications. Results: In total, thirty-six patients at the end of three months showed an objective response rate of 69.8% and disease control rate of 93.0%, respectively. The 1, 2, and 3-year cumulative overall survival rate was 89.2%, 73.0%, and 45.9%, respectively. The adverse events of the treatment included infection (n=1, Grade III), radiation brachial plexus injury (n=1, Grade III), leukopenia (n=1, Grade III), cerebrovascular embolism (n=1, Grade IV). Conclusion: The combination of 125I brachytherapy and pre-operative transarterial chemoembolization was safe and effective in patients with locally advanced head and neck cancer.

Identification of two-dimensional copper signatures in human blood for bladder cancer with machine learning.

Currently, almost all available cancer biomarkers are based on concentrations of compounds, often suffering from low sensitivity, poor specificity, and false positive or negative results. The stable isotopic composition of elements provides a different dimension from the concentration and has been widely used as a tracer in geochemistry. In health research, stable isotopic analysis has also shown potential as a new diagnostic/prognostic tool, which is still in the nascent stage. Here we discovered that bladder cancer (BCa) could induce a significant variation in the ratio of natural copper isotopes (65Cu/63Cu) in the blood of patients relative to benign and healthy controls. Such inherent copper isotopic signatures permitted new insights into molecular mechanisms of copper imbalance underlying the carcinogenic process. More importantly, to enhance the diagnostic capability, a machine learning model was developed to classify BCa and non-BCa subjects based on two-dimensional copper signatures (copper isotopic composition and concentration in plasma and red blood cells) with a high sensitivity, high true negative rate, and low false positive rate. Our results demonstrated the promise of blood copper signatures combined with machine learning as a versatile tool for cancer research and potential clinical application.