Magnetic molecularly imprinted polymers for extraction of S-phenylmercapturic acid from urine samples followed by high-performance liquid chromatography.

In this study, magnetic molecularly imprinted polymers (MMIPs) were prepared and used as sorbents for extraction of S-phenylmercapturic acid (S-PMA) from urine samples, followed by high-performance liquid chromatography ultraviolet-visible (HPLC-UV/Vis) analysis. The MMIPs were synthesized by the copolymerization reaction of (phenylthio) acetic acid (template molecule), methacrylic acid (functional monomers) and ethylene glycol dimethacrylate (cross-linkers). The morphology, structure property and surface groups of the prepared MMIPs were characterized by scan electron microscopy, transmission electron microscopy, infrared spectroscopy, X-ray diffraction pattern, thermogravimetric analyses, Brunauer-Emmett-Teller and vibrating sample magnetometer. The selectivity of the MMIPs was investigated in the presence of interferents. Various parameters affecting the S-PMA extraction efficiency were investigated, including MMIPs amount, pH, sample volume, desorption solvent, as well as extraction and desorption time. The obtained optimal parameters were as follows: MMIPs amount (20 mg), pH (3.0), sample volume (5 mL), desorption solvent (methanol/acetic acid [9/1, v/v]), extraction time (30 minutes) and desorption time (2 minutes). The method was validated according to the Food and Drug Administration Guidance for Industry on Bioanalytical Method Validation. The calibration curve for the analyte was linear in the concentration range of 0.030-1.0 mg/L (r = 0.9995). The LOD and LOQ of the method were 0.0080 and 0.0267 mg/L, respectively. The enrichment factor of the MMIPs was 5. The relative standard deviations of intra- and inter-day tests were in the range of 3.8-5.1% and 3.9-6.3%, respectively. The recoveries at three different concentrations of 0.10, 0.50 and 0.80 mg/L ranged between 95.2% and 98.6%. In addition, the MMIPs could be reused for at least eight times. The proposed method was successfully applied to the determination of S-PMA in urine samples. In addition, this developed method could be used as a tool in the early screening and clinical diagnosis of benzene intoxication.

Activated carbon/diatomite-based magnetic nanocomposites for magnetic solid-phase extraction of S-phenylmercapturic acid from human urine.

In this study, activated carbon/diatomite-based magnetic nancomposites (denoted as AC/DBMNs) were synthesized and applied as an adsorbent for magnetic solid-phase extraction of S-phenylmercapturic acid (S-PMA) from human urine prior to high-performance liquid chromatography. The surface morphologies and structures of AC/DBMNs were characterized by Fourier transform infrared spectroscopy, transmission and scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area, vibrating sample magnetometer and ζ-potential measurements. The experimental parameters including sample volume, sample pH, adsorbent amount, extraction time, elution solvent and desorption time were investigated in detail. Under the optimum conditions, the method exhibited good linearity (r > 0.9993) within the concentration ranges of 0.03-1.0 mg/L. Moreover, the limits of detection and quantification were 0.01 and 0.03 mg/L, respectively. The enrichment factor was 5, and good recoveries (88.9-97.3%) with relative standard deviations in the range of 5.6-6.8% (n = 6) for inter-day and 6.3-8.1% (n = 6) for intra-day were achieved. The developed method was successfully applied to the analysis of S-PMA in urine samples. In addition, this accurate and sensitive method has great potential to be applied in the early screening and clinical diagnosis of the workers exposed to benzene.

[Assessment of hematopoiesis and cytogenetics changes in interventional radiologists].

Objective: To investigate hematopoiesis and cytogenetics changes in staff of interventional radiology. Methods: A total of 121 intervention radiation workers, 245 common radiation workers and 100 medical personnel (healthy control) without exposure to radiation were enrolled in the study. The peripheral lymphocyte chromosomal aberrations and micronucleus were detected, and the result of white blood cells examination was analyzed. Results: Compared with common radiation group and healthy control group, decreases in white blood cells count, neutrophil ratio, and increase in lymphocyte ratio were observed in intervention radiation group (all P<0.05). Intervention radiation group had higher chromosome aberration rate and micronuclear rate than common radiation group and healthy control group (all P<0.05). Most common chromosome aberrations were dicentric chromosome, acentric ring, fragments and minute chromosome. Abnormal rates in chromosome aberration and micronucleus rates were increased with the rise of length of service, but no statistically significant difference was observed (P>0.05). Conclusion: Long term exposure to ionizing radiation may lead to changes in the human hematopoietic system and cause human chromosome aberration, and the severity of such injuries may be associated with the dose of ionizing radiation.

Influencing factors and prediction of neutralizing antibodies in post-exposure rabies vaccine recipients.

To assess the factors that influencing the persistence of virus neutralizing antibody (VNA), and to establish prediction models to provide the appropriate timing for booster administration, a cohort of post-exposure rabies vaccine recipients was investigated. The VNA determined records from 2019 to 2023 and interrelated factors were analyzed, including gender, age, rabies immunoglobulin (RIG) administration, vaccine products, vaccination schedule, and vaccination intervals etc. The geometric mean of VNA titre within 1 month after primary vaccination with 2-1-1 schedule was statistically higher than that with 5-dose course (P = 0.031). The interaction between exposure and vaccination schedule was observed on primary vaccination, which showed that a decrease of 19.74 % (95 % CI: 5.99%-64.95 %, P = 0.008) of VNA titre among vaccinee with 5-dose and exposure III. Individuals with RIG administration produced lower VNA titres than those without RIG administration (P = 0.001). Vaccine products (Chengda, P = 0.015; human diploid cell, P = 0.026) and re-exposed time (P = 0.000) exhibited independent effects following booster vaccination. Based on the prediction model, the 99 % individual prediction intervals (IPI) of VNA titres were established at 3, 6, 12 and 18 months for the 12 characteristic populations respectively. The cases of VNA below 0.5 IU/ml first appeared at 6 months in group D of primary vaccinations and at 10 years in group F of boosters. We conclude that for primary vaccination 2-1-1 schedule is more efficient than 5-dose; the use of residual rabies immunoglobulin for distal intramuscular injection isn't recommended. The 99 % IPI of VNA titres could provide the appropriate timing for booster vaccination.

'Asian water towers' are not a sustainable solution to the downstream water crisis.

Quantifying climate change- and socioeconomic development-induced changes in the 'water tower' function is a major challenge in high-mountain Asia (HMA), especially when considering the affected downstream areas. This study applies historical monsoon-influenced rainfall patterns and the water stress index to quantify the climate change- and socioeconomic growth-induced changes in the 'Asian water tower' function through the middle of the 21st century by nonparametric empirical quantile mapping and empirical orthogonal function analysis. Water pressures are predicted to intensify in 25.84 ± 7.87 % of 'water tower' downstream watersheds. Enhancements in the 'Asian water tower' function are vulnerable to help stop the deterioration of downstream water pressure while increasing the water sufficiency probability by 7.97 ± 15.52 %. Water withdrawals are projected to explain 55.90 ± 21.77 % of water security in the 'water tower' function-affected watersheds in 2050; thus, this study calls for more effective policies and the development of technologies to reduce the water crisis in downstream HMA.

Characterization of welding fume and airborne heavy metals in electronic manufacturing workshops in Hangzhou, China: implication for occupational population exposure.

Occupational exposure to contaminants created by electronic manufacturing process is not well characterized. The aim of this study was to carry out risk assessments of exposure to welding fume and airborne heavy metals (HMs) in electronic manufacturing workshops. Seventy-six air samples were collected from five sites in Hangzhou, China. In welding workshops, the most abundant contaminant found was welding fume, followed by Fe, Mn, Zn, Cu, Pb, Cd, and Cr. The concentration of Mn was positively correlated with Fe (r = 0.906). When compared with non-welding workshops, the Fe content in the air of welding workshops increased significantly (P < 0.05), while the Cu content decreased significantly (P < 0.05). Singapore semi-quantitative health risk assessment model and the United States Environmental Protection Agency (US EPA) inhalation risk assessment model were applied to assess the occupational exposure. In welding workshops, the levels of 8-h time weighted average (8 h-TWA) calculated for welding fume (range 0.288 ~ 6.281 mg/m3), Mn (range Nd ~ 0.829 mg/m3), and Fe (range 0.027 ~ 2.234 mg/m3) partly exceeded the permissible limits. While, in non-welding workshops, the average of 8 h-TWA for Cu (0.411 mg/m3) was higher than the limit. The risk rates (RR) assessed for Pb (2.4 vs 1.7), Mn (2.0 vs 1.4), and Fe (1.4 vs 1.0) were higher in welding workshops than that in non-welding workshops, but Cu (1.0 vs 2.2) were lower. The mean excess lifetime cancer risks (ELCR) in welding (5.59E - 06 per 1000 people) and non-welding (1.88E - 06 per 1000 people) workshops were acceptable. The mean non-cancer risk (HQ) estimated for Mn was greater than 10 in both welding (HQ = 164) and non-welding (HQ = 11.1) workshops. These results indicate that there was a risk of occupational exposure implication in the electronic manufacturing workshops. Reducing contaminant exposure through engineering controls and management strategies, such as efficient ventilation and reducing exposure hours, is thus suggested.

Association between serum copper/zinc ratio and lung cancer: A systematic review with meta-analysis.

BACKGROUND: Numerous studies have investigated the relationship between serum copper/zinc ratio and lung cancer. However, the results are inconsistent. Therefore, we evaluated the association between copper/zinc ratio and lung cancer. MATERIALS AND METHODS: Observational studies reporting serum copper/zinc ratio in lung cancer patients and controls were identified from PubMed, Web of Science, EMBASE, CNKI and Wanfang databases online before December 2021. Summary standard mean difference (SMD) and the corresponding 95 % confidence interval (95 % CI) were applied to compare the serum serum copper/zinc ratio between lung cancer patients and controls using a random-effects model. RESULTS: Thirty-nine articles including 3598 lung cancer patients, 1402 benign lung diseases, and 3314 healthy controls were included in this study. The pooled results showed that the lung cancer patients had significantly higher serum copper/zinc ratio than healthy controls [SMD (95 % CI): 1.62 (1.31, 1.93)] and patients with benign lung diseases [SMD (95 % CI): 0.60 (0.36, 0.84)]. The results were robust according to sensitivity analysis. Meanwhile, consistent results were obtained both in European populations and Asian populations. Moreover, serum copper/zinc ratio was significant higher in patients with advanced stage of lung cancer than that in patients with early stage of lung cancer. CONCLUSION: The results showed that elevated serum copper/zinc ratio might be associated with increased risk of lung cancer.

Analytical techniques for monitoring of toluene and xylene exposure biomarkers hippuric acid and methylhippuric acid in human urine samples.

Quantification of hippuric acid and methylhippuric acid in human urine matrices provides information on the toluene and xylene exposure conditions. High performance liquid chromatography coupled with UV detection is the preferable technique for hippuric acid and methylhippuric acid detection in human urine. This study was conducted to present analytical techniques developed for monitoring of hippuric acid and methylhippuric acid in human urine matrices during 2016-2021.

Review of Detection and Quantification of Rabies Virus Antibodies.

Rabies is an almost invariably fatal disease. According to the World Health Organization (WHO), rabies virus neutralizing antibody (RVNA) titers of ≥0.5 IU/mL are considered adequate for rabies protection. Therefore, detection and quantification of RABV antibodies are important. Many methods have been developed for detecting RABV antibodies. In the present study, we reviewed several methods of detecting RABV antibodies in human and animal samples and evaluated and compared their performance. Of 34 methods, 5 demonstrated unsatisfactory sensitivity or specificity. The others exhibited sensitivity and specificity of ≥75%. The correlation coefficient for five of eight methods was >0.8. The Bland-Altman mean bias of five of five methods was <±2.0. The kappa values of 25 of 28 methods were higher than 0.4, demonstrating at least moderate agreement. Analysis of the performance of these methods emphasized that any new technology should be considered carefully and objectively before being used as an appropriate and applicable alternative.

Facile Preparation of Activated Carbon from Peanut Shell for Determination of Bisphenol A in Human Urine by High-Performance Liquid Chromatography.

Herein, a facile and low-cost method for the preparation of activated carbon from peanut shell was developed for the first time for the fast extraction and determination of Bisphenol A in human urine. Bisphenol A was separated by EC-C18 column (250 mm×4.6 mm, 4 µm) and was detected by VWD, with retention time for qualitative analysis and peak area for quantitation. The parameters, pH values of the urine, adsorbent dose, adsorption time and so on, were optimized to achieve the excellent extraction performance. The detection limit of Bisphenol A in human urine was 1.0 ng · mL-1 (S/N = 3), and the standard curve was linear in the range of 5.0 ng · mL-1˜200.0 ng · mL-1 (r = 0.9993). The average recovery of Bisphenol A was 78.5˜96.2% at three spiked levels in the range of 5.00 ng · mL-1˜200.00 ng·mL-1. The method was proved simple, practical and highly sensitive, which could satisfy the request for the determination of Bisphenol A in human urine.