1.Application of time series and machine learning models in predicting the trend of sickness absenteeism among primary and secondary school students in Shanghai
WANG Zhengzhong, ZHANG Zhe, ZHOU Xinyi, YUAN Linlin, ZHAI Yani, SUN Lijing, LUO Chunyan
Chinese Journal of School Health 2025;46(3):426-430
Objective:
To analyze the temporal variation patterns of sickness absenteeism among primary and secondary school students in Shanghai, so as to explore models suitable for predicting peaks and intensity of absenteeism rates.
Methods:
The seasonal and trend decomposition using loess (STL) method was used to analyze the seasonal and long term trend changes in sickness absenteeism among primary and secondary school students from September 1 in 2010 to June 30 in 2018, in Shanghai. A hierarchical clustering method based on Dynamic Time Warping (DTW) was employed to classify absenteeism symptoms with similar temporal patterns. Based on historical data, the study constructed and evaluated different time series algorithms and machine learning models to optimize the accuracy of predicting the trend of sickness absenteeism.
Results:
During the research period, the average new absenteeism rate due to illness was 16.86 per 10 000 person day for every academic year, and the trend of sickness absenteeism exhibited both seasonality and a long term upward trend, reaching its highest point in the 2017 academic year (22.47 per 10 000 person day). The symptoms of absenteeism were divided into three categories: high incidence in winter and spring (respiratory symptoms, fever and general discomfort, etc.), high incidence in summer (eye symptoms, nosebleeds, etc.) and those without obvious seasonality (skin symptoms, accidental injuries, etc.).The constructed time series models effectively predicted the trend of absenteeism due to illness, although the accuracy of predicting peak intensity was relatively low. Among them, the multi layer perceptron (MLP) model performed the best, with an root mean squared error (RMSE) of 8.96 and an mean absolute error (MAE) of 4.37, reducing 36.51% and 39.02% compared to the baseline model.
Conclusion
Time series models and machine learning algorithms could effectively predict the trend of sickness absenteeism, and corresponding prevention and control measures can be taken for absenteeism caused by different symptoms during peak periods.
2.Analysis of Differences in Secondary Metabolites Between Dendrobium nobile Bionic Wild Cultivated on Epiphytic Stones and Trees Based on Widely Targeted Metabolomics
Yifan SHI ; Changqing ZHOU ; Jiaojiao WANG ; Lin CHEN ; Hongping CHEN ; Fu WANG ; Yuan HU ; Youping LIU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(10):218-224
ObjectiveTo explore the differences in the accumulation of secondary metabolites of Dendrobium nobile cultivated on epiphytic stones and trees, so as to elucidate the scientific connotation of "only those that grow on stones has superior quality", and provide a direction for the cultivation and quality evaluation of D. nobile. MethodsUltra-performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometry(UPLC-QTRAP-MS/MS)-based widely targeted metabolomics was used to detect the metabolites of D. nobile cultivated on epiphytic stones and trees. And the combination of principal component analysis(PCA), hierarchical cluster analysis(HCA), and orthogonal partial least squares-discriminant analysis(OPLS-DA) was performed for multivariate statistical analysis of metabolites. Differential metabolites were screened by variable importance in the projection(VIP) value≥1 and log2fold change(FC)≥1 or ≤-1, and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis was conducted. ResultsA total of 1 267 metabolites were identified in the stems of D. nobile from the two cultivation modes, dominated by flavonoids(292), phenolic acids(284), and alkaloids(189). Through OPLS-DA screening, 473 differential metabolites were obtained. Compared to epiphytic tree-cultivated D. nobile, epiphytic stone-cultivated D. nobile exhibited upregulation of flavonoids, phenolic acids, alkaloids, lignans and coumarins, while quinones and terpenoids were down-regulated. The differential metabolites mainly included flavonoid glycosides and alkaloids, and these differential metabolites significantly contributed to characterizing the two cultivation patterns. KEGG enrichment analysis revealed significant enrichment in pathways of flavone and flavonol biosynthesis, flavonoid biosynthesis, tyrosine metabolism, and phenylalanine metabolism in epiphytic stone-cultivated D. nobile. ConclusionEpiphytic stone cultivation is beneficial for the accumulation of phenolic acids, flavonoids, and alkaloids in D. nobile, indicating that the "only those that grow on stones has superior quality" documented in the materia medica has certain scientific basis, and the findings also provide a reference for quality evaluation and discrimination research between epiphytic stone and tree cultivated D. nobile.
3.A Randomized Controlled Trial of Stone Needle Thermocompression and Massage for Treating Chronic Musculoskeletal Pain in the Shoulder and Back:A Secondary Analysis of Muscle Elasticity as a Mediator
Jingjing QIAN ; Yuanjing LI ; Li LI ; Yawei XI ; Ying WANG ; Cuihua GUO ; Jiayan ZHOU ; Yaxuan SUN ; Shu LIU ; Guangjing YANG ; Na YUAN ; Xiaofang YANG
Journal of Traditional Chinese Medicine 2025;66(9):935-940
ObjectiveTo evaluate the effectiveness of stone needle thermocompression and massage compared to flurbiprofen gel patch in relieving chronic musculoskeletal pain in the shoulder and back, and to explore the potential mediating mechanism through muscle elasticity. MethodsA total of 120 patients with chronic musculoskeletal pain in the shoulder and back were randomly assigned to either stone needle group or flurbiprofen group, with 60 patients in each. The stone needle group received stone needle thermocompression and massage for 30 minutes, three times per week; the flurbiprofen group received flurbiprofen gel patch twice daily. Both groups were treated for 2 weeks. Pain improvement, as the primary outcome, was assessed using the Global Pain Scale (GPS) at baseline, after 2 weeks of treatment, and again 2 weeks post-treatment. To explore potential mechanisms, a mediator analysis was conducted by measuring changes in superficial and deep muscle elasticity using musculoskeletal ultrasound at baseline and after the 2-week treatment period. ResultsThe stone needle group showed significantly greater pain relief than the flurbiprofen group 2 weeks post-treatment. After adjusting for confounders related to pain duration, the between-group mean difference was -8.8 [95% CI (-18.2, -0.7), P<0.05]. Part of the therapeutic effect was mediated by changes in deep muscle elasticity, with a mediation effect size of -1.5 [95% CI (-2.0, -0.9), P = 0.024], accounting for 17.9% of the total effect. ConclusionStone needle thermocompression and massage can effectively relieve chronic musculoskeletal pain in the shoulder and back, partly through a mediating effect of improved deep muscle elasticity.
4.Comorbidity and associated factors of overweight/obesity and dental caries among primary and secondary school students in Guangxi
LUO Yuemei, REN Yiwen, CHEN Li, DONG Yonghui, YUAN Wen, MA Jun, DONG Yanhui, LI Yan, ZHOU Weiwen
Chinese Journal of School Health 2025;46(4):485-488
Objective:
To explore the comorbidity and associated factors of dental caries and overweight/obesity among primary and secondary school students in Guangxi, so as to provide a scientific basis for the development of targeted prevention strategies.
Methods:
A stratified cluster random sampling method was used to survey 178 700 students from the fourth grade of primary school to the third year of high school in Guangxi Zhuang Autonomous Region from September to November 2023, including physical examination, oral screening, and questionnaire survey. Chisquare tests and binary Logistic regression analysis were employed to investigate the related factors of the cooccurrence of dental caries and overweight/obesity among students.
Results:
The comorbidity rate of dental caries and overweight/obesity was 9.55%, with urban areas (9.95%) higher than rural counties (9.24%), boys (10.54%) higher than girls (8.54%), primary school students (11.49%) higher than senior high school students (8.92%) and junior high school students (8.05%), and nonboarding students (11.44%) higher than boarding students (7.94%), and all differences were statistically significant (χ2=26.07, 207.91, 471.54, 629.14,P<0.01). Multivariate Logistic regression analysis showed that consuming cereal for breakfast (OR=0.91, 95%CI=0.88-0.94), drinking milk in the past week (OR=0.89, 95%CI=0.83-0.95), meeting sleep standards (OR=0.95, 95%CI=0.91-0.99), and brushing teeth at least once a day (OR=0.82, 95%CI=0.73-0.93) had a lower risk of the comorbidity of dental caries and overweight/obesity. In contrast, drinking beverages in the past week (OR=1.14, 95%CI=1.09-1.20), consuming fried foods in the past week (OR=1.11, 95%CI=1.06-1.17), eating fruit ≥1 time every day (OR=1.06, 95%CI=1.02-1.11), consuming fruit ≥1 type every day (OR=1.07, 95%CI=1.01-1.12), and having fish, poultry, meat, or eggbased breakfasts (OR=1.03, 95%CI=1.05-1.13) had a higher risk of the comorbidity of dental caries and overweight/obesity (P<0.05).
Conclusions
Dietary habits and lifestyle behaviors are associated with the comorbidity of dental caries and overweight/obesity among primary and secondary school students in Guangxi. Guiding students to form healthy living habits is helpful to preven dental caries and overweight/obesity.
5.Identification of Alumen and Ammonium alum Based on XRD, FTIR, TG-DTA Combined with Chemometrics
Bin WANG ; Jingwei ZHOU ; Huangsheng ZHANG ; Jian FENG ; Hanxi LI ; Guorong MEI ; Jiaquan JIANG ; Hongping CHEN ; Fu WANG ; Yuan HU ; Youping LIU ; Shilin CHEN ; Lin CHEN
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(13):178-186
ObjectiveTo establish the multi-technique characteristic profiles of Alumen by X-ray diffraction(XRD), Fourier-transform infrared spectroscopy(FTIR) and thermogravimetric-differential thermal analysis(TG-DTA), and to explore the spectral characteristics for rapid identification of Alumen and its potential adulterant, Ammonium alum. MethodsA total of 27 batches of Alumen samples from 8 production regions were collected for preliminary identification based on visual characteristics. The PDF standard cards of XRD were used to differentiate Alumen from A. alum, and the XRD characteristic profiles of Alumen were established, and then the common peaks were screened. Based on hierarchical clustering analysis(HCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA), the characteristic information that could be used for identification of Alumen was selected with variable importance in the projection(VIP) value>1. FTIR characteristic profiles of Alumen were established, and key wavenumbers for identification were screened by HCA and OPLS-DA with VIP value>1. Meanwhile, the thermogravimetric differences between Alumen and A. alum were analyzed by TG-DTA, and the thermogravimetric traits that could be used for identification were screened. ResultsAlumen and A. alum could not be effectively distinguished by traits alone. However, by comparing the PDF standard cards of XRD, 15 batches of Alumen and 12 batches of A. alum could be distinguished. In the XRD profiles, 10 characteristic peaks were confirmed, corresponding to diffraction angles of 14.560°, 24.316°, 12.620°, 32.122°, 17.898°, 34.642°, 27.496°, 46.048°, 40.697° and 21.973°. In the FTIR profiles, 4 wavenumber ranges(399.193-403.050, 1 186.010-1 471.420, 1 801.190-2 620.790, 3 612.020-3 997.710 cm-1) and 12 characteristic wavenumbers(1 428.994, 1 430.922, 1 432.851, 1 434.779, 1 436.708, 1 438.636, 1 440.565, 1 442.493, 1 444.422, 1 446.350, 1 448.279, 1 450.207 cm-1) were identified. In the TG-DTA profiles, there were characteristic decomposition peaks of ammonium ion and mass reduction features near 555.34 ℃ for A. alum. These characteristics could serve as important criteria for distinguishing the authenticity of Alumen. ConclusionXRD, FTIR and TG-DTA can be used to rapidly detect Alumen and A. alum, and combined with the discriminant features selected through chemometrics, the rapid and accurate identification of Alumen and A. alum can be achieved. The research findings provide new approaches for the rapid identification of Alumen.
6.Process Optimization and Health Risk Assessment of Calcined Haematitum Based on QbD Concept
Yue YANG ; Jingwei ZHOU ; Jialiang ZOU ; Guorong MEI ; Yifan SHI ; Lei ZHONG ; Jiaojiao WANG ; Xuelian GAN ; Dewen ZENG ; Xin CHEN ; Lin CHEN ; Hongping CHEN ; Shilin CHEN ; Yuan HU ; Youping LIU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(13):187-196
ObjectiveTo investigate the processing technology of calcined Haematitum based on the concept of quality by design(QbD) and to assess its health risk. MethodsTaking whole iron content, Fe2+ dissolution content and looseness as critical quality attributes(CQAs), and calcination temperature, calcination time, spreading thickness and particle size as critical process parameters(CPPs) determined by the failure mode and effect analysis(FMEA), the processing technology of calcined Haematitum was optimized by orthogonal test combined with analytic hierarchy process-criteria importance through intercriteria correlation(AHP-CRITIC) hybrid weighting method. The contents of heavy metals and harmful elements were determined by inductively coupled plasma mass spectrometry, and the health risk assessment was carried out by daily exposure(EXP), target hazard quotient(THQ) and lifetime cancer risk(LCR), and the theoretical value of the maximum limit was deduced. ResultsThe optimal processing technology for calcined Haematitum was calcination at 650 ℃, calcination time of 1 h, particle size of 0.2-0.5 cm, spreading thickness of 1 cm, and vinegar quenching for 1 time[Haematitum-vinegar(10:3)]. The contents of 5 heavy metals and harmful elements in 13 batches of calcined Haematitum were all decreased with reductions of up to 5-fold. The cumulative THQ of 2 batches of samples was>1, while the cumulative THQ of all batches of Haematitum was>1. The LCR of As in 1 batches of Haematitum was 1×10-6-1×10-4, and the LCR of the rest was<1×10-6, and the LCRs of calcined Haematitum were all<1×10-6, indicating that the carcinogenic risk of calcined Haematitum was low, but special attention should still be paid to Haematitum medicinal materials. Preliminary theoretical values of the maximum limits of Cu, As, Cd, Pb and Hg were formulated as 1 014, 25, 17, 27, 7 mg·kg-1. ConclusionThe optimized processing technology of calcined Haematitum is stable and feasible, and the contents of heavy metals and harmful elements are reduced after processing. Preliminary theoretical values of the maximum limits of Cu, As, Cd, Pb and Hg are formulated to provide a scientific basis for the formulation of standards for the limits of harmful elements in Haematitum.
7.Optimization of Processing Technology of Calcined Pyritum Based on QbD Concept and Its XRD Fingerprint Analysis
Xin CHEN ; Jingwei ZHOU ; Haiying GOU ; Lei ZHONG ; Tianxing HE ; Wenbo FEI ; Jialiang ZOU ; Yue YANG ; Dewen ZENG ; Lin CHEN ; Hongping CHEN ; Shilin CHEN ; Yuan HU ; Youping LIU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(13):197-205
ObjectiveBased on the concept of quality by design(QbD), the processing process of calcined Pyritum was optimized, and its X-ray diffraction(XRD) fingerprint was established. MethodsThe safety, effectiveness and quality controllability of calcined Pyritum were taken as the quality profile(QTPP), the color, hardness, metallic luster, phase composition, the contents of heavy metals and hazardous elements were taken as the critical quality attributes(CQAs), and the calcination temperature, calcination time, paving thickness and particle size were determined as the critical process parameters(CPPs). Differential thermal analysis, X-ray diffraction(XRD) and inductively coupled plasma mass spectrometry(ICP-MS) were used to analyze the correlation between the calcination temperature and CQAs of calcined Pyritum. Then, based on the criteria importance through intercriteria correlation(CRITIC)-entropy weight method, the optimal processing process of calcined Pyritum was optimized by orthogonal test. Powder XRD was used to analyze the phase of calcined Pyritum samples processed according to the best process, and the mean and median maps of calcined Pyritum were established by the superposition of geometric topological figures, and similarity evaluation and cluster analysis were carried out. ResultsThe results of single factor experiments showed that the physical phase of Pyritum changed from FeS2 to Fe7S8 during the process of temperature increase, the color gradually deepened from dark yellow, and the contents of heavy metals and harmful elements decreased. The optimized processing process of calcined Pyritum was as follows:calcination temperature at 750 ℃, calcination time of 2.5 h, paving thickness of 3 cm, particle size of 0.8-1.2 cm, vinegar quenching 1 time[Pyritum-vinegar(10∶3)]. After calcination, the internal structure of Pyritum was honeycomb-shaped, which was conducive to the dissolution of active ingredients. XRD fingerprints of 13 batches of calcined Pyritum characterized by 10 common peaks were established. The similarities of the relative peak intensities of the XRD fingerprints of the analyzed samples were>0.96, and it could effectively distinguish the raw products and unqualified products. ConclusionTemperature is the main factor affecting the quality of calcined Pyritum. After processing, the dissolution of the effective components in Pyritum increases, and the contents of heavy metals and harmful substances decrease, reflecting the function of processing to increase efficiency and reduce toxicity. The optimized processing process is stable and feasible, and the established XRD fingerprint can be used as one of the quality control standards of calcined Pyritum.
8.Phase Change and Quantity-quality Transfer Analysis of Medicinal Materials, Decoction Pieces and Standard Decoction of Haliotidis Concha (Haliotis discus hannai)
Zhihan YANG ; Jingwei ZHOU ; Weichao WANG ; Yu HUANG ; Chuang LUO ; Lian YANG ; Chenyu ZHONG ; Hongping CHEN ; Fu WANG ; Yuan HU ; Youping LIU ; Shilin CHEN ; Lin CHEN
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(13):206-214
ObjectiveTo explore the quantity-quality transfer process of medicinal materials, decoction pieces and standard decoction of Haliotidis Concha(Haliotis discus hannai) by analyzing the physical phase and compositional changes, so as to provide references for the effective control of its quality. MethodsA total of 20 batches of Haliotidis Concha(H. discus hannai) from different habitats were collected and prepared into corresponding calcined products and standard decoction, and the content of CaCO3 of the three samples were determined and the extract yield and transfer rate of CaCO3 were calculated. The changes in elemental composition and their relative contents were investigated by X-ray fluorescence spectrometry(XRF), X-ray diffraction(XRD) was used to study the changes in the phase compositions of the three samples and to establish their respective XRD specific chromatogram. Fourier transform infrared spectrometry(FTIR) was used to study the changes in the chemical composition and content changes of the three samples and to establish their respective FTIR specific chromatogram, while combining hierarchical cluster analysis(HCA), principal component analysis(PCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA) to find the common and differential characteristics, in order to explore the quantity-quality transfer relationship in the preparation process of standard decoction of Haliotidis Concha(H. discus hannai). ResultsThe CaCO3 contents of the 20 batches of medicinal materials, decoction pieces and standard decoction of Haliotidis Concha(H. discus hannai) were 93.87%-98.95%, 96.02%-99.97% and 38.29%-51.96%, respectively, and the extract yield of standard decoction was 1.71%-2.37%, and the CaCO3 transfer rate of decoction pieces-standard decoction was 0.68%-1.27%. XRF results showed that the elemental species and their relative contents contained in Haliotidis Concha and its calcined products had a high degree of similarity, and although there was no obvious difference in the elemental species contained in decoction pieces and standard decoction, the difference in the relative contents was obvious, which was mainly reflected in the decrease of the relative content of element Ca and the increase of the relative content of element Na. XRD results showed that Haliotidis Concha mainly contained CaCO3 of aragonite and calcite, while calcined Haliotidis Concha only contained CaCO3 of calcite, and standard decoction mainly contained CaCO3 of calcite and Na2CO3 of natrite. FTIR results showed that there were internal vibrations of O-H, C-H, C=O, HCO3- and CO32- groups in Haliotidis Concha, while O-H, HCO3- and CO32- groups existed in the calcined products and standard decoction. ConclusionThe changes of Haliotidis Concha and calcined Haliotidis Concha are mainly the increase of CaCO3 content, the transformation of CaCO3 aragonite crystal form to calcite crystal form and the absence of organic components after calcination, and the changes of calcined products and standard decoction are mainly the decrease of CaCO3 content and the increase of Na2CO3 relative content. The method established in the study is applicable to the quality control of the shellfish medicines-decoction pieces- standard decoction, which provides a new idea for the study of quality control of dispensing granules of shellfish medicines.
9.Identification of Alumen and Ammonium alum Based on XRD, FTIR, TG-DTA Combined with Chemometrics
Bin WANG ; Jingwei ZHOU ; Huangsheng ZHANG ; Jian FENG ; Hanxi LI ; Guorong MEI ; Jiaquan JIANG ; Hongping CHEN ; Fu WANG ; Yuan HU ; Youping LIU ; Shilin CHEN ; Lin CHEN
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(13):178-186
ObjectiveTo establish the multi-technique characteristic profiles of Alumen by X-ray diffraction(XRD), Fourier-transform infrared spectroscopy(FTIR) and thermogravimetric-differential thermal analysis(TG-DTA), and to explore the spectral characteristics for rapid identification of Alumen and its potential adulterant, Ammonium alum. MethodsA total of 27 batches of Alumen samples from 8 production regions were collected for preliminary identification based on visual characteristics. The PDF standard cards of XRD were used to differentiate Alumen from A. alum, and the XRD characteristic profiles of Alumen were established, and then the common peaks were screened. Based on hierarchical clustering analysis(HCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA), the characteristic information that could be used for identification of Alumen was selected with variable importance in the projection(VIP) value>1. FTIR characteristic profiles of Alumen were established, and key wavenumbers for identification were screened by HCA and OPLS-DA with VIP value>1. Meanwhile, the thermogravimetric differences between Alumen and A. alum were analyzed by TG-DTA, and the thermogravimetric traits that could be used for identification were screened. ResultsAlumen and A. alum could not be effectively distinguished by traits alone. However, by comparing the PDF standard cards of XRD, 15 batches of Alumen and 12 batches of A. alum could be distinguished. In the XRD profiles, 10 characteristic peaks were confirmed, corresponding to diffraction angles of 14.560°, 24.316°, 12.620°, 32.122°, 17.898°, 34.642°, 27.496°, 46.048°, 40.697° and 21.973°. In the FTIR profiles, 4 wavenumber ranges(399.193-403.050, 1 186.010-1 471.420, 1 801.190-2 620.790, 3 612.020-3 997.710 cm-1) and 12 characteristic wavenumbers(1 428.994, 1 430.922, 1 432.851, 1 434.779, 1 436.708, 1 438.636, 1 440.565, 1 442.493, 1 444.422, 1 446.350, 1 448.279, 1 450.207 cm-1) were identified. In the TG-DTA profiles, there were characteristic decomposition peaks of ammonium ion and mass reduction features near 555.34 ℃ for A. alum. These characteristics could serve as important criteria for distinguishing the authenticity of Alumen. ConclusionXRD, FTIR and TG-DTA can be used to rapidly detect Alumen and A. alum, and combined with the discriminant features selected through chemometrics, the rapid and accurate identification of Alumen and A. alum can be achieved. The research findings provide new approaches for the rapid identification of Alumen.
10.Process Optimization and Health Risk Assessment of Calcined Haematitum Based on QbD Concept
Yue YANG ; Jingwei ZHOU ; Jialiang ZOU ; Guorong MEI ; Yifan SHI ; Lei ZHONG ; Jiaojiao WANG ; Xuelian GAN ; Dewen ZENG ; Xin CHEN ; Lin CHEN ; Hongping CHEN ; Shilin CHEN ; Yuan HU ; Youping LIU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(13):187-196
ObjectiveTo investigate the processing technology of calcined Haematitum based on the concept of quality by design(QbD) and to assess its health risk. MethodsTaking whole iron content, Fe2+ dissolution content and looseness as critical quality attributes(CQAs), and calcination temperature, calcination time, spreading thickness and particle size as critical process parameters(CPPs) determined by the failure mode and effect analysis(FMEA), the processing technology of calcined Haematitum was optimized by orthogonal test combined with analytic hierarchy process-criteria importance through intercriteria correlation(AHP-CRITIC) hybrid weighting method. The contents of heavy metals and harmful elements were determined by inductively coupled plasma mass spectrometry, and the health risk assessment was carried out by daily exposure(EXP), target hazard quotient(THQ) and lifetime cancer risk(LCR), and the theoretical value of the maximum limit was deduced. ResultsThe optimal processing technology for calcined Haematitum was calcination at 650 ℃, calcination time of 1 h, particle size of 0.2-0.5 cm, spreading thickness of 1 cm, and vinegar quenching for 1 time[Haematitum-vinegar(10:3)]. The contents of 5 heavy metals and harmful elements in 13 batches of calcined Haematitum were all decreased with reductions of up to 5-fold. The cumulative THQ of 2 batches of samples was>1, while the cumulative THQ of all batches of Haematitum was>1. The LCR of As in 1 batches of Haematitum was 1×10-6-1×10-4, and the LCR of the rest was<1×10-6, and the LCRs of calcined Haematitum were all<1×10-6, indicating that the carcinogenic risk of calcined Haematitum was low, but special attention should still be paid to Haematitum medicinal materials. Preliminary theoretical values of the maximum limits of Cu, As, Cd, Pb and Hg were formulated as 1 014, 25, 17, 27, 7 mg·kg-1. ConclusionThe optimized processing technology of calcined Haematitum is stable and feasible, and the contents of heavy metals and harmful elements are reduced after processing. Preliminary theoretical values of the maximum limits of Cu, As, Cd, Pb and Hg are formulated to provide a scientific basis for the formulation of standards for the limits of harmful elements in Haematitum.


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