Objective Evaluation of ochratoxin A (OTA) contamination inGejie Dingchuan Pills. Methods Eighty-six samples from sevenpharmaceutical manufacturers were analyzed for OTA content usingultra-high-performance liquid chromatography-tandem mass spectrometry.Results The method displayed excellent linearity within the range ofconcentrations ${0.1}\sim {10}\mathrm{{ng}}/\mathrm{{mL}}$ .The limits of detection and quantification were ${0.2}\mathrm{{\mu g}}/\mathrm{{kg}}$ and $1\mathrm{{\mu g}}/\mathrm{{kg}}$ ,respectively. Seventy-two samples were detected to be contaminated withOTA, resulting in an 84% positive rate. Furthermore, ten samples failedto meet the required standards, reflecting a failure rate of 12%. Theactual sample test results showed that the OTA detection rate of GejieDingchuan pills was high and the pollution was serious, which suggestedthe urgency of detecting and determining the maximum OTA limit ofproprietary Chinese medicine. Conclusion This study assesses the extentof OTA contamination in Gejie Dingchuan pills, offering a scientificbasis for future investigations of OTA maximum limits in Chineseproprietary medicines.

Objective To analyze the application results offluorescence quantitative reverse transcription-polymerase chainreaction (RT-PCR) in the detection of pathogenic microorganisms. MethodsA retrospective analysis was made of 7502 microbiological test dataexamined in the laboratory of our hospital from January 14th, 2023 toDecember 14th, 2023. Conventional RT-PCR method and fluorescentquantitative RT-PCR method were performed respectively, and the goldstandard was the results of special staining microscopy. The diagnosticefficiency and other indicators of the two test results were analyzed.Results ① The ratio of negative to positive by gold standard was ${490}: {7012}$ , the ratio of negative topositive by conventional RT-PCR was ${479}:{6358}$ , and the ratio of negative to positive by fluorescencequantitative RT-PCR was 488 : 7010. ② The sensitivity, specificity andaccuracy of fluorescence quantitative RT-PCR method were 99.97%, 99.59%and 99.95%, which were higher than that of conventional RT-PCR method,with statisticalsignificance $\left({P<{0.05}}\right)$ . ③ The detection rates of variousmicroorganisms by fluorescence quantitative RT-PCR were 99.91%, 100.00%,100.00%, 99.91%, 100.00%, 100.00%, 99.97%, higher than that byconventional RT-PCR, with statistical significance ( $P <{0.05}$ ). Conclusion Fluorescencequantitative RT-PCR method has high diagnostic efficiency and detectionrate in pathogenic microorganisms, which can provide scientific basisfor doctors’ diagnosis and treatment and can be implemented.

Objective To determine the content of phosphoric ester flame retardants in samples and provide a scientific basis for optimizing the flame retardancy of plastic products. Methods The phosphoric ester flame retardants were extracted from plastic samples with suitable solvent, and the content of phosphoric ester flame retardants was determined by GC-MS. Results The method is fine and can effectively remove impurity interference, can effectively remove the interference of impurities, has a good linearity with a correlation coefficient of more than 0.995; has a good precision with a relative standard deviation of less than 10%; a spiked recovery test was carried out throughout the process, and the recovery rate was 80%~120%. Conclusion This method is accurate and reliable, and can be used for the determination of the content of phosphate ester flame retardants in samples.

Objective To evaluate the uncertainty in the determinationof thiamethoxam content in corn by high-performance liquidchromatography-tandem mass spectrometry. Methods According to GB/T20770-2008 Determination of 486 Pesticides and Related ChemicalsResidues in Grains-Liquid Chromatography-Tandem Mass Spectrometrymethod, by establishing a mathematical model, the sources of uncertaintywere analyzed and the effects of different sources were measured andcalculated. Results Forthe corn samples with a mass fraction of ${0.282}\mathrm{{mg}}/\mathrm{{kg}}$ ofthiamethoxam, the extended uncertainty was ${0.041}\mathrm{{mg}}/\mathrm{{kg}}\left({P={95}\%, k = 2}\right)$ . Conclusion The main source ofuncertainty affecting the test result is the determination of samplesolution.

Objective To compare the different extraction methods of soybean crude fatty acid value with the national standard method GB 5009.229-2016 National Standard forFood Safety-Determination of Acid Value in Food. Methods The room temperature extraction method, organic solvent oscillation method, and ultrasonic assisted method were used to detect the crude fatty acid value of soybeans, and compared with the Soxhlet extraction method required by the national standard method. Results The crude fatty acid value of soybeans measured by 3 kinds of extraction methods is basically consistent with the national standard method, and the extraction speed is significantly faster than the Soxhlet extraction method in the national standard. Among them, the ultrasonic assisted extraction method has the shortest extraction time, only requiring 20 minutes; as the sample size increases, the extraction efficiency of the room temperature extraction method improves more significantly. Conclusion Daily testing of grain and oil enterprises can shorten time, reduce costs, and improve efficiency by selecting suitable extraction methods based on sample batch size.

Objective To established an analytical method for indirectdetermination of xylo-oligosaccharides in high gelatinization-bakedfoods by high performance liquid chromatography with refractive indexdetector. Methods After degreased with petroleum ether, the samples wereextracted with 20% ethanol solution, and macromolecular sugars such asdextrin and starch were precipitated with 68% ethanol solution. Thesugars in the extraction solution were hydrolyzed into monosaccharidesby diluted sulfuric acid, the solution before and after hydrolysis wasseparated by amide column, detected by refractive index detector, andquantified by external standard method. The product between thedifference of xylose before and after hydrolysis and the averageconversion coefficient of xylo-oligosaccharides and xylose was thexylo-oligosaccharides. Results When the xylose was ${0.25}\sim {5.00}\mathrm{{mg}}/\mathrm{{mL}}$ ,there was a good linear relationship between peak area and concentration $\left({r ={0.9998}}\right)$ . Therecovery rates ranged from 92.0% to 95.8%, the relative standarddeviations (RSDs) were ${1.8}\%\sim {4.0}\%$ in highgelatinization-baked foods. The limit of detection and limit ofquantization of xylo-oligosaccharides were ${0.03}\mathrm{\;g}/{100}\mathrm{\;g},{0.1}\mathrm{\;g}/{100}\mathrm{\;g}$ respectively. Conclusion The extraction method of low concentrationethanol solution is feasible and specific. The method avoided the impactof high gelatinization on the low extraction efficiency and measurementresults. It can determine xylo-oligosaccharides in highgelatinization-baked foods accurately and quickly.

Taking Jiangnan University as the practice subject, the paper studies the interdependence of the preparation, procurement, use and disposal stages in the full life cycle management system of large scientifiic research instruments and equipment.Taking this as the cornerstone, in view of the main problems existing in the equipment management. The improving measures are proposed including promoting information construction, making good budget demonstration, improving the performance appraisal, widening the channel of disposal, strengthening the team construction. The present study aimed at by means of actively exploring the fine full life cycle management of large scientifiic research instruments and equipment, improving management level of instruments and equipment in colleges and universities in the new era to better service for teaching and scientific research.

Objective To systematically evaluate the applicationpotential of ${35}\mathrm{{kV}}$ modified polypropylene in the field of wire and cable. Methods Themechanical properties, thermal properties and electrical insulationproperties of the material were investigated by differential scanningcalorimetry (DSC), tensile test and electrical property evaluation.Results The modified polypropylene showed excellent mechanical strengthand thermal stability, and the performance of electrical insulation alsomet the high standards of industrial applications. Conclusion Thesystematic test of this study not only provides a scientific basis forfurther modification and optimization of polypropylene materials, butalso lays a solid foundation for its future market promotion, andprovides important theoretical and practical value for promoting thetechnological progress of wire and cable materials and realizing thedevelopment of environmentally friendly materials.

Objective To explore the clinical application value of combined detection of echocardiography, dynamic electrocardiogram, and plate exercise test in the diagnosis of coronary heart disease. Methods 70 suspected coronary heart disease patients were selected and subjected to plate exercise test, dynamic electrocardiogram, echocardiography, and coronary angiography. Analyze the diagnostic performance of each method through ROC curve, and calculate sensitivity, specificity, and AUC values. Results The individual detection AUC values of the three methods were 0.796 (plate exercise test), 0.737 (dynamic electrocardiogram), and 0.773 (echocardiogram), respectively, and the combined detection AUC was 0.826. Conclusion Combined detection can significantly improve the diagnostic accuracy of coronary heart disease, with higher sensitivity and specificity than single detection. It is recommended to widely apply it in clinical practice.

Objective To evaluate the uncertainty of determination oftotal cadmium (Cd), lead (Pb) and chromium (Cr) in soil by microwavedigestion and inductively coupled plasma mass spectrometry (ICP-MS).Methods To ensure the accuracy and reliability of the detection results,the uncertainty of total cadmium (Cd), lead (Pb) and chromium (Cr) insoil was determined by microwave digestion and inductively coupledplasma mass spectrometry (ICP-MS) and according to JJF1059.1-2012Evalution and Expression of Uncertainty in Measurement the syntheticuncertainty was calculated and the extended uncertainty was obtained.Results The main sources of uncertainty were the standard curvepreparation the repeatability measurement of samples and the standardcurve fitting the contribution rates to the uncertainty of $\mathrm{{Cd}},\mathrm{{Pb}}$ and Cr were50.4%~60.3%, 18.7%~26.1% and 12.1%~20.4%. The influence of sampleweighing and resolution volume for the uncertainty was small and thecontribution rate was between 1.5%~2%, which could be ignored.Conclusion The effective measures to control uncertainty were putforward, which ensured the reliability of the experimental data andprovided the reference for the accurate representation of the heavymetal content in soil