Objective To establish a method for simultaneous determination of four high-molecular-weight thiol derivatives (TDs) in workplace air by gas chromatography. Methods The four kinds of vapor-phase macromolecular TDs (1-pentanethiol, 1-hexanethiol, 1-benzyl mercaptan, and n-octanethiol) in the workplace air were collected using the GDH-1 air sampling tubes, desorbed with anhydrous ethanol, separated on a DB-FFAP capillary column, and determined by flame ionization detector. Results The quantitation range of the four TDs was 0.30-207.37 mg/L, with the correlation coefficients greater than 0.999 00. The minimum detection mass concentrations and minimum quantitation mass concentrations were 0.18-0.32 and 0.60-1.05 mg/m³, respectively (both calculated based on the 1.5 L sample and 3.0 mL desorption solvent). The mean desorption efficiencies ranged from 87.07% to 103.59%. The within-run and between-run relative standard deviations were 1.92%-8.22% and 1.89%-8.45%, respectively. The samples can be stored at room temperature or 4 ℃ for three days and up to 7 days at -18 ℃. Conclusion This method is suitable for the simultaneous determination of four vapor-phase TDs in workplace air.

Objective:To seek the optimal melanin-removal method for hematoxylin and eosin (HE) staining, immunohistochemistry and molecular detection.Methods:Thirty-eight paraffin tissue samples of malignant melanoma diagnosed at the Fujian Cancer Hospital, Fuzhou, China between January 2018 and March 2022 were collected and used to make a tissue microarray. Melanin in these cases was removed using warm hydrogen peroxide, double oxidation depigmentation, modified potassium permanganate-oxalic acid or trichloroisocyanuric acid, followed by HE staining. The cases were divided into two cohorts: one was subject to the one of the above four methods to remove melanin first, followed by immunohistochemistry (SOX-10, Ki-67, HMB45 and Melan A), while the other was subject to immunohistochemical staining first and then a melanin removal. Following that, seventeen melanin-rich paraffin tissue samples were collected and depigmented using the methods described above. DNA extraction was then done, followed by assessments of DNA content and quality. Moreover, the completeness of melanin removal, the effect on HE and immunohistochemical staining, and the quality of DNA were compared between the depigmented methods.Results:Regarding the effectiveness of melanin removal, the modified potassium permanganate-oxalic acid and the warm hydrogen peroxide methods were the most effective, and both showed residual melanin in only 5.26% (2/38) of the cases. The trichloroisocyanuric acid method showed residual melanin in 10.53% (4/38) of the cases. The worst was the double oxidation depigmentation method, which showed pigment residue in 15.79% (6/38) of the cases. For HE staining, the percentage of good staining with the warm hydrogen peroxide method was 92.11%, higher than the other three methods. For immunohistochemical staining, the mean staining scores of immunohistochemistry first followed by melanin removal with modified potassium permanganate-oxalic acid, double oxidation and trichloroisocyanuric acid were 20.84, 26.63 and 35.02, respectively. These immunohistochemical staining scores were higher than those of melanin removal first followed by immunohistochemistry (8.70, 15.41 and 21.22, respectively). The mean staining score of melanin removal by warm hydrogen peroxide method followed by immunohistochemistry was 33.57, superior to that of immunohistochemistry followed by the melanin removal (19.96). Moreover, the staining scores of HMB45, MelanA and Ki-67 with immunohistochemical staining followed by trichloroisocyanuric acid method were 36.45, 33.79, and 36.24, respectively, while the staining score of SOX10 with melanin removal by warm hydrogen peroxide followed by immunohistochemistry was 34.39. The DNA was significantly degraded by modified potassium permanganate-oxalic acid, double oxidation depigmentation and trichloroisocyanuric acid, whereas the mean concentration of DNA extracted after melanin removal by hydrogen peroxide method was 59.59 μg/L, substantially higher than that of DNA extracted without melanin removal (30.3 μg/L, P=0.001). The A260/ A280 of DNA extracted after melanin removal by hydrogen peroxide was between 1.8 and 2.0 in all cases, and the A260/ A230 was above 2.0 in sixteen cases, suggesting high purity of DNA. However, the DNA extracted without removing the melanin showed poor purity, with A260/ A280 below 1.8 in eight cases and A260/ A230 below 2.0 in sixteen cases. Conclusions:Warm hydrogen peroxide showed the least melanin residue, superior HE staining and a minimal effect on DNA purity/quality compared to the other three methods. It thus appears most suitable for PCR, NGS and other molecular detection. Melanin removal with trichloroisocyanuric acid after immunohistochemical staining has the least melanin residual, and thus could be the most convenient and efficient. However, it is noted that the efficacy of the same depigmentation method varies with different antibodies. Therefore, the optimal depigmentation method should be selected based on the specific markers of interest.

Objective To analyze differential metabolites (DMs) in the urine of workers with occupational nickel exposure using non-targeted metabolomics, and to screen differential metabolic pathways. Methods A total of 30 nickel exposed workers were selected as the exposure group, and 30 administrative staff from the same factory were selected as the control group using the judgment sampling method. Urine samples of the individuals from the two groups were collected. The ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry and non-targeted metabolomics were used to detect and identify metabolites. The differential metabolic profiles were compared between workers of the two groups, and key differential metabolic pathways and potential biomarkers were screened. The association of DMs and urinary nickel level were evaluated by Spearman correlation coefficients. The sensitivity and specificity of biomarkers were assessed by receiver operating characteristic (ROC) curve analysis. Results A total of 418 metabolites were identified in the urine of worker in the exposure and control groups. The result of principal component analysis and orthogonal partial least squares analysis showed that there were 128 DMs in the urine of workers in the exposure group compared with the control group. These DMs were mainly enriched in glutathione metabolism, carnitine synthesis, and amino acid and nucleotide metabolism pathways, including glycine and serine metabolism. The result of correlation analysis and ROC curve analysis revealed that 4-methylcatechol, 4-vinylphenol sulfate, 2-hydroxyphenylacetone sulfate, 2-dodecylbenzenesulfonic acid, and decylbenzenesulfonic acid could be the potential biomarkers for nickel exposure (all area under the ROC curve >0.800). Conclusion There were significant differences in the urinary metabolic profiles of workers with occupational nickel exposure. The five DMs including 4-methylcatechol, 4-vinylphenol sulfate, 2-hydroxyphenylacetone sulfate, 2-dodecylbenzenesulfonic acid, and decylbenzenesulfonic acid. These DMs could be potential biomarkers of occupational nickel exposure.

Biotoxins, which include bacterial, fungal, marine, plant, and animal toxins, are widespread in living and occupational environments, posing potential threats to human health. Rapid detection of biotoxins in blood is crucial for preventing health hazards and enabling timely disease diagnosis and treatment. Biosensors and immunoassay technologies have critical advantages in the rapid detection of biotoxins in blood. Common biosensors, such as surface plasmon resonance biosensors and fluorescent biosensors, enhance sensitivity and reduce detection limits through signal amplification. Common immunoassay methods, such as colloidal gold immunochromatography, fluorescence immunochromatography, and chemiluminescence immunoassay, improve detection efficacy and sensitivity through specific antibody-antigen binding and nanotechnology. However, current rapid detection technologies of bitoxins in blood face challenges such as matrix interference and insufficient specificity, and they fall short in high-throughput detection of multiple toxins simultaneously. Future developments should focus on improving sample pretreatment, innovating signal amplification methods, enhancing specificity on recognition of elements, and designing portable detection devices and high-throughput platforms for simultaneous toxin analysis. These advancements aim to improve the sensitivity and reliability of detection methods, providing more accurate and convenient solutions for biotoxin detection in blood.

Objective: To investigate the specificity of endogenous metabolic profile in plasma of patients with occupational acute methyl acetate poisoning using non-targeted metabolomics. Methods: A total of six patients with occupational acute methyl acetate poisoning were selected as the poisoning group, while 10 healthy workers without occupational exposure history of chemical hazards in the same industry were selected as the control group using the judgment sampling method. Metabolites in patient plasma of the two groups were detected using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and non-targeted metabolomics analysis was performed. Principal component analysis and partial least squares discriminant analysis were used to identify differential metabolites and analyze their metabolic pathways. Results: There were significant differences in metabolite profiles in patient plasma between poisoning group and control group. A total of 195 differentially expressed metabolites were screened in plasma of patients in poisoning group, including 119 upregulated and 76 downregulated metabolites. Lipid substances (lipids and lipid-like molecules) accounted for the highest proportion (21.5%). The differential metabolites of poisoning group were related to folate biosynthesis, amino acid metabolism, pyrimidine metabolism, sphingolipid biosynthesis and other metabolic pathways in plasma compared with the control group (all P<0.05). Conclusion: Occupational acute methyl acetate poisoning affects metabolism of the body. The folic acid biosynthesis, amino acid and lipid metabolism and other pathways may be involved in the occurrence and development of poisoning.

Objective To establish a rapid qualitative analysis method for volatile organic components in chemicals. Methods Headspace gas chromatography-mass spectrometry was used to qualitatively determine 19 volatile organic components, including benzene, 1,2-dichloroethane, and n-hexane, in chemicals. Different sample amounts, heating temperatures, heating times, and sample volumes were analyzed to assess their effects on detection results and optimize sampling conditions. Results Based on the set chromatography, the optimal sampling process of this method was as follows： 5.0 g sample in a 20.0 mL headspace bottle, incubated at 40 ℃ for 30 minutes in a constant-temperature drying incubator, and a 1.00 mL headspace gas injection. The within-run and between-run relative standard deviations of all components ranged from 0.00% to 21.05% and 0.00% to 33.33%, respectively. The samples stored in sealed glass containers were stable at room temperature for at least 60 days. Conclusion This method offers simplicity, good reproducibility, and stability, making it suitable for rapid qualitative analysis of volatile organic components in chemicals.

Objective To establish a high performance liquid chromatography (HPLC) method for simultaneous determination of six aniline compounds (ADs) in workplace air. Methods GDH-1 air sampling tube was used to collect six co-existing ADs such as aniline, o-toluidine, N-methylaniline, m-methylaniline, p-methylaniline and N,N-dimethylaniline in the vapor and aerosol of workplace air. The samples were desorbed and eluted using a methanol solution containing 1.00% ammonia water, followed by separation on a C₁₈ chromatographic column and detection using a diode array detector. Results The quantification range of the method was 0.19 -253.50 mg/L, with the correlation coefficient of 0.999 9 for all six ADs. The minimum detection range was 0.02-0.06 mg/m³, and the minimum quantitation range was 0.04-0.19 mg/m³ [both calculated for a 15.0 L sample with a desorption (elution) solution volume of 3.00 mL]. The average desorption and elution efficiencies were 92.15%-104.41% (silica gel) and 94.29%-104.29% (filter membrane). The intra-assay relative standard deviation (RSD) ranged from 0.90%-9.72% (silica gel) and 0.57%-6.96% (filter membrane). The inter-assay RSD ranged from 2.03%-9.78% (silica gel) and 2.50%-8.62% (filter membrane). The samples were stable at room temperature for seven days. Conclusion This method can be used for the simultaneous determination of six ADs in workplace air.

{L-End}Objective To establish a method for the simultaneous determination of dimethyltin (DMT), trimethyltin (TMT), diethyltin (DET), and triethyltin (TET) in human whole blood using high performance liquid chromatography-inductively coupled plasma-mass spectrometry (ICP-MS). {L-End}Methods The 1.0 mL of blood was added with 4.0 mL 65% aqueous solution (containing 6% acetic acid), extracted and separated by C₄ column (150 mm×3 mm×3 μm) using a mobile phase of methanol and 4% acetic acid aqueous solution (containing 0.25 mmol/L tropolone) at a volume ratio of 35∶65, and detected by ICP-MS. {L-End}Results The linear range of DMT, TMT, DET, and TET was 30.60-550.80, 29.00-522.00, 46.10-829.80, and 34.05-612.90 μg/L, respectively. All correlation coefficients were 0.999. The detection limit of DMT, TMT, DET and TET was 21.40, 20.30, 32.27 and 23.80 μg/L, respectively. The recovery rate was 81.9%-104.9%. The within-run and between-run relative standard deviation was 1.6%-6.9% and 0.1%-10.0%, respectively. The samples can be stored at -20 ℃ and 4 ℃ for at least three days. {L-End}Conclusion This method can be used for trace analysis of DMT, TMT, DET, and TET in whole blood.

To investigate the expression of polyadenosine diphospho-ribose polymerase 1 (PARP-1) and p16/ retinoblastoma (Rb) protein in hydroquinone (HQ)-induced TK6 cells and their regulatory mechanisms. Methods According to the 2×2 factorial design model, TK6 cells were divided into PBS-TK6 group and HQ-TK6 group based on HQ exposure, and then sub-divided into non-DOX intervention subgroup and DOX intervention subgroup based on DOX intervention, a total of four groups. The PBS-TK6 group was treated with phosphate buffer saline, and the HQ-TK6 group was treated with HQ at a final concentration of 20.0 μmol/L. The non-DOX intervention subgroup was added with 0.05% dimethyl sulfoxide; and the DOX intervention subgroup was added with PARP-1 agonist DOX at a final concentration of 0.5 μmol/L. The distribution of cell cycle was detected by flow cytometry. The protein expression of p16/Rb, cyclin D1 (cyclinD1), multifunctional protein E2 transcription factor 1 (E2F1), Rb, and p-Rb were detected by Western blot, and the level of p16 ribosylation was detected by immunofluorescence and immunoprecipitation. Results Compared with the PBS-TK6 group, the cell cycle distribution percentage in G0/G1 phase and the relative expression levels of p16 proteins were decreased in the cells of the HQ-TK6 group (all P<0.05). The cell cycle distribution percentage in S phase and the relative expression levels of cyclinD1 and p-Rb proteins were up-regulated (all P<0.05). Compared with the non-DOX intervention group, the cell cycle distribution percentage in G0/G1 and G2/M phases and the relative expression level of p16 protein increased in the DOX intervention group (all P<0.05). The percentage of cells in S phase and the relative expression levels of cyclinD1 and p-Rb proteins were down-regulated (all P< 0.05). The results of interaction effect analysis showed that compared with the non-DOX PBS-TK6 cells, the relative expression levels of Rb and E2F1 protein in the DOX PBS-TK6 cells intervention group were down-regulated (all P<0.05). The relative expression level of Rb protein in non-DOX HQ-TK6 cell group was down-regulated (P<0.05), and the relative expression of E2F1 protein was up-regulated (P<0.05). Compared with DOX PBS-TK6 cell group, the relative expression level of Rb protein in DOX HQ-TK6 cell group was down-regulated and that of E2F1 protein was up-regulated (all P<0.05). Compared with the non-DOX HQ-TK6 cell group, the relative expression level of Rb protein in the DOX HQ-TK6 cell group was up-regulated and that of E2F1 protein was down-regulated (all P<0.05). Conclusion PARP-1 participates in cell cycle regulation by regulating the p16/Rb signaling pathway in TK6 cells.

Objective To explore the diagnostic value of MR elastography and diffusion?weighted imaging in patients with liver fibrosis in the context of chronic hepatitis B. Methods Twenty?four patients with chronic hepatitis B, whose course of liver disease was more than 6 months and hepatitis B surface antigen was positive, were prospectively enrolled in the First Affiliated Hospital of Soochow University from July to December 2017. All of the patients underwent abdominal transient elastography (TE), routine MRI, magnetic resonance elastography (MRE) and DWI examination, TE and MRI were performed within one week. TE liver stiffness was measured, the MRE liver stiffness and ADC value were measured on MR imagings. All patients were divided into three groups: mild and non fibrosis (F0 to 1), significant fibrosis(F2 to 3) and cirrhosis (F4), according to the recommended standard of FibroTouch. Correlation between TE liver stiffness, MRE liver stiffness and ADC values were identified by using Spearman correlation test. The difference of the MRE liver stiffness and ADC value among the three groups was tested using independent sample t test. The overall predictive ability of MRE and DWI in assessment of liver fibrosis and cirrhosis was analyzed by constructing ROC curve. Results TE and MRI were successfully performed in all subjects, and the image quality was good. The MRE liver stiffness in mild and non fibrosis, significant fibrosis and cirrhosis was (2.32±0.31),(3.43±1.05),(4.77±0.68) kPa with statistically significant difference(F=61.690, P<0.01). The ADC values in three groups were (1.31 ± 0.14)×10-3, (1.23 ± 0.15)×10-3,(1.22±0.12)×10-3mm2/s without significant difference(F=1.074,P=0.360). The TE liver stiffness in three groups was (5.61±1.05),(9.56±0.57),(17.25±3.55)kPa, respectively, there was significant correlation between the MRE liver stiffness and the TE liver stiffness(t=0.858, P<0.01), but no significant correlation between the TE liver stiffness and the ADC value was found (r=-0.326,P=0.120). The area under ROC of MRE liver stiffness in diagnosing liver fibrosis grade (≥F2 and F4) was 0.96 and 1.00 respectively, while the AUC of ADC value was less than 0.70, which were 0.67 and 0.62 respectively. Conclusion MRE is a non?invasive promising tool for assessing liver fibrosis with chronic hepatitis B, while DWI has limited role.