Objective: To analyze the epidemiological characteristics and influencing factors of severe fever with thrombocytopenia syndrome (SFTS) in Zhejiang Province from 2019 to 2023, so as to provide the reference for strengthening SFTS prevention and control. Methods: Data on laboratory-confirmed SFTS cases in Zhejiang Province from 2019 to 2023 were collected through the Infectious Disease Reporting Information System of Chinese Disease Prevention and Control Information System. Meteorological data, geographic environment and socioeconomic factors during the same period were collected from the fifth-generation European Centre for Medium-Range Weather Forecasts, Geospatial Data Cloud, and Zhejiang Statistical Yearbook, respectively. Descriptive epidemiological methods were used to analyze the epidemiological characteristics of SFTS from 2019 to 2023, and a Bayesian spatio-temporal model was constructed to analyze the influencing factors of SFTS incidence. Results: A total of 578 SFTS cases were reported in Zhejiang Province from 2019 to 2023, with an annual average incidence of 0.23/105. The peak period was from May to July, accounting for 52.60%. There were 309 males and 269 females, with a male-to-female ratio of 1.15∶1. The cases were mainly aged 50-<80 years, farmers, and in rural areas, accounting for 82.53%, 77.34%, and 75.43%, respectively. Taizhou City and Shaoxing City reported more SFTS cases, while Shaoxing City and Zhoushan City had higher annual average incidences of SFTS. The Bayesian spatio-temporal interaction model showed good goodness of fit. The results showed that mean temperature (RR=1.626, 95%CI: 1.111-2.378) and mean wind speed (RR=1.814, 95%CI: 1.321-2.492) were positively correlated with SFTS risk, while altitude (RR=0.432, 95%CI: 0.230-0.829) and population density (RR=0.443, 95%CI: 0.207-0.964) were negatively correlated with SFTS risk. Conclusions SFTS in Zhejiang Province peaks from May to July. Middle-aged and elderly people and farmers are high-risk populations. Taizhou City, Shaoxing City, and Zhoushan City are high-incidence areas. Mean temperature, mean wind speed, altitude, and population density can all affect the risk of SFTS incidence.

Objective To investigate occupational exposure levels of lead, arsenic and cadmium in the lead smelting plant of Hunan Shui Kou Shan Nonferrous Metals Group Co. Ltd., analyze their effects on health of employees, and compare the applicability of different occupational health risk assessment methods, and to provide a basis for prevention and control of occupational exposure risks in enterprises. Methods According to systematic sampling method, 380 employees with lead, arsenic and cadmium exposure (exposure group) and 100 non-exposure employees (non-exposure group) were selected from 2022 to 2024 for on-site investigation of occupational health [concentration time-weighted average (C_TWA)] and physical examination. The risk was evaluated by qualitative assessment method, the U.S. Environmental Protection Agency (EPA) inhalation risk assessment method, and the Singapore Ministry of Manpower (MOM) semi-quantitative method. The consistency was analyzed by the Kappa test. Results C_TWA values of lead, arsenic, and cadmium in all positions were lower than the occupational exposure limit (OEL). The levels of blood lead, urine arsenic, and urine cadmium, as well as the prevalence of multiple systems in the exposure group were significantly higher than those in the non-exposure group (P<0.05). The proportions of chronic lead, arsenic, and cadmium poisoning were increasing year by year in the exposure group (P<0.05). The qualitative assessment method mainly indicated low and medium risk, while the EPA and MOM methods mainly indicated medium and high risk, with good agreement between the two methods (Kappa=0.676, P<0.05). Conclusion Although the enterprise meets the C_TWA standards, there are still occupational health risks of lead, arsenic, and cadmium. The EPA inhalation risk assessment method is more applicable.

AIM:To analyze the association between mobile phone addiction and high myopia among college students.METHODS:We conducted a cross-sectional questionnaire survey in December 2022 on all students of a university in Shaanxi Province, and the questionnaire included socio-demographic characteristics, mobile phone addiction, high myopia, and lifestyle. Binary Logistic regression model was used to analyze the association between mobile phone addiction and high myopia among college students.RESULTS:A total of 19 952 college students were included. The prevalence of high myopia was 7.31%. The rate of mobile phone addiction was 25.68%, and the mobile phone addiction score was 37.59±13.38. The incidence of high myopia among college students with mobile phone addiction was higher than non-mobile phone addiction(P<0.001). After adjusting for socio-demographic characteristics and lifestyle, the risk of high myopia among college students with mobile phone addiction was 1.274 times(95%CI:1.131-1.434)higher than non-mobile phone addiction. For each point increase of total mobile phone addiction score, withdrawal symptoms score, salience score, social comfort score, and mood changes score, the risk of high myopia among college students increased by 0.9%(95%CI:1.005-1.013), 2.0%(95%CI:1.010-1.030), 2.6%(95%CI:1.010-1.043), 4.8%(95%CI:1.030-1.066), and 3.3%(95%CI:1.014-1.052), respectively.CONCLUSION:Mobile phone addiction is significantly associated with the increased risk of high myopia among college students, and early intervention of mobile phone use may reduce the risk of high myopia among college students.

ObjectiveTo investigate the effect and mechanism of Yishen Tongluo prescription in protecting mice from oxidative stress injury in diabetic kidney disease （DKD） via the nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1）/NAD（P）H quinone oxidoreductase 1 （NQO1） signaling pathway. MethodsSpecific pathogen-free （SPF） male C57BL/6 mice were assigned into a control group （n=10） and a modeling group （n=50）. The DKD model was established by intraperitoneal injection of streptozotocin. The mice in the modeling group were randomized into a model group， a semaglutide （40 μg·kg^-1） group， and high-， medium-， and low-dose （18.2， 9.1， 4.55 g·kg^-1， respectively） Yishen Tongluo prescription groups， with 10 mice in each group. The treatment lasted for 12 weeks. Blood glucose and 24-h urine protein levels were measured， and the kidney index （KI） was calculated. Serum levels of creatinine （SCr）， blood urea nitrogen （BUN）， alanine aminotransferase （ALT）， and aspartate aminotransferase （AST） were assessed. The pathological changes in the renal tissue were evaluated by hematoxylin-eosin， periodic acid-Schiff， periodic acid-silver methenamine， and Masson’s trichrome staining. Enzyme-linked immunosorbent assay kits were used to measure the levels of β2-microglobulin （β2-MG）， neutrophil gelatinase-associated lipocalin （NGAL）， kidney injury molecule-1 （KIM-1）， liver fatty acid-binding protein （L-FABP）， nitric oxide synthase （NOS）， glutathione （GSH）， total antioxidant capacity （T-AOC）， and 8-hydroxy-2'-deoxyguanosine （8-OHdG）. Immunohistochemical staining was performed to examine the expression of Kelch-like ECH-associated protein 1 （Keap1） and malondialdehyde （MDA）. Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR） and Western blot were employed to determine the mRNA and protein levels， respectively， of factors in the Nrf2/HO-1/NQO1 signaling pathway. ResultsCompared with the control group， the DKD model group showed rises in blood glucose， 24-h urine protein， KI， SCr， BUN， and ALT levels， along with glomerular hypertrophy， renal tubular dilation， thickened basement membrane， mesangial expansion， and collagen deposition. Additionally， the model group showed elevated levels of β2-MG， NGAL， KIM-1， L-FABP， NOS， and 8-OHdG， lowered levels of GSH and T-AOC， up-regulated expression of MDA and Keap1， and down-regulated expression of Nrf2， HO-1， NQO1， and glutamate-cysteine ligase catalytic subunit （GCLC） （P<0.05）. Compared with the model group， the semaglutide group and the medium- and high-dose Yishen Tongluo prescription groups showed reductions in blood glucose， 24-h urine protein， KI， SCr， BUN， and ALT levels， along with alleviated pathological injuries in the renal tissue. In addition， the three groups showed lowered levels of β2-MG， NGAL， KIM-1， L-FABP， NOS， and 8-OHdG， elevated levels of GSH and T-AOC， down-regulated expression of MDA and Keap1， and up-regulated expression of Nrf2， HO-1， NQO1， and GCLC （P<0.05）. ConclusionYishen Tongluo prescription exerts renoprotective effects in the mouse model of DKD by modulating the Nrf2/HO-1/NQO1 signaling pathway， mitigating oxidative stress， and reducing renal tubular injuries.

Objective: To investigate the mechanism of Yishen Tongluo Formula in ameliorating renal pyroptosis in diabetic nephropathy mice by regulating the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway. Methods: Sixty C57BL/6 male mice were randomly divided into control (10 mice) and intervention groups (50 mice) using random number table method. The diabetes nephropathy model was established by intraperitoneally injecting streptozotocin(50 mg/kg). After modeling, the intervention group was further divided into model, semaglutide (40 μg/kg), and high-, medium-, and low-dose Yishen Tongluo Formula groups (15.6, 7.8, and 3.9 g/kg, respectively) using random number table method. The high-, medium-, and low-dose Yishen Tongluo Formula groups were administered corresponding doses of medication by gavage, the semaglutide group received a subcutaneous injection of semaglutide injection, and the control group and model groups were administered distilled water by gavage for 12 consecutive weeks. Random blood glucose levels of mice in each group were monitored, and the 24-h urinary protein content was measured using biochemical method every 4 weeks; after treatment, the serum creatinine and urea nitrogen levels were measured using biochemical method. The weight of the kidneys was measured, and the renal index was calculated. Hematoxylin and eosin, periodic acid-Schiff, periodic Schiff-methenamine, and Masson staining were used to observe the pathological changes in renal tissue. An enzyme-linked immunosorbent assay was used to detect urinary β2-microglobulin (β2-MG), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) levels. Western blotting and real-time fluorescence PCR were used to detect the relative protein and mRNA expression levels of nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3), Caspase-1, gasdermin D (GSDMD), interleukin-1β (IL-1β), and interleukin-18 (IL-18) in renal tissue. Immunohistochemistry was used to detect the proportion of protein staining area of the TLR4, MyD88, and NF-κB in renal tissue. Results: Compared with the control group, the random blood glucose, 24-h urinary protein, serum creatinine, urea nitrogen, and renal index of the model group increased, and the urine β2-MG, NGAL, and KIM-1 levels increased. The relative protein and mRNA expression levels of NLRP3, Caspase-1, GSDMD, IL-1β, and IL-18 in renal tissue increased, and the proportion of TLR4, MyD88, and NF-κB protein positive staining areas increased (P<0.05). Pathological changes such as glomerular hypertrophy were observed in the renal tissue of the model group. Compared with the model group, the Yishen Tongluo Formula high-dose group showed a decrease in random blood glucose after 12 weeks of treatment (P<0.05). The Yishen Tongluo Formula high- and medium-dose groups showed a decrease in 24-h urinary protein, creatinine, urea nitrogen, and renal index, as well as decreased β2-MG, NGAL, and KIM-1 levels. NLRP3, Caspase-1, GSDMD, IL-1 β, and IL-18 relative protein and mRNA expression levels were also reduced, and the proportion of TLR4, MyD88, and NF-κB protein positive staining areas was reduced (P<0.05). Pathological damage to renal tissue was ameliorated. Conclusion Yishen Tongluo Formula may exert protective renal effects by inhibiting renal pyroptosis and alleviating tubular interstitial injury in diabetic nephropathy mice by regulating the TLR4/MyD88/NF-κB signaling pathway.

Objective To evaluate the predictive ability and clinical application value of artificial intelligence (AI) systems in the benign and malignant differentiation and pathological type of pulmonary nodules, and to summarize clinical application experience. Methods A retrospective analysis was conducted on the clinical data of patients with pulmonary nodules admitted to the Department of Thoracic Surgery, Second Hospital of Lanzhou University, from February 2016 to February 2025. Firstly, pulmonary nodules were divided into benign and non-benign groups, and the discriminative abilities of AI systems and clinicians were compared. Subsequently, lung nodules reported as precursor glandular lesions (PGL), microinvasive adenocarcinoma (MIA), and invasive adenocarcinoma (IAC) in postoperative pathological results were analyzed, comparing the efficacy of AI systems and clinicians in predicting the pathological type of pulmonary nodules. Results In the analysis of benign/non-benign pulmonary nodules, clinical data from a total of 638 patients with pulmonary nodules were included, of which there were 257 males (10 patients and 1 patient of double and triple primary lesions, respectively) and 381 females (18 patients and 1 patient of double and triple primary lesions, respectively), with a median age of 55.0 (47.0, 61.0) years. Different lesions in the same patient were analyzed as independent samples. Univariate analysis of the two groups of variables showed that, except for nodule location, the differences in the remaining variables were statistically significant (P<0.05). Multivariate logistic regression analysis showed that age, nodule type (subsolid pulmonary nodule), average density, spicule sign, and vascular convergence sign were independent influencing factors for non-benign pulmonary nodules, among which age, nodule type (subsolid pulmonary nodule), spicule sign, and vascular convergence sign were positively correlated with non-benign pulmonary nodules, while average density was negatively correlated with the occurrence of non-benign pulmonary nodules. The area under the receiver operating characteristic curve (AUC) of the malignancy risk value given by the AI system in predicting non-benign pulmonary nodules was 0.811, slightly lower than the 0.898 predicted by clinicians. In the PGL/MIA/IAC analysis, clinical data from a total of 411 patients with pulmonary nodules were included, of which there were 149 males (8 patients of double primary lesions) and 262 females (17 patients of double primary lesions), with a median age of 56.0 (50.0, 61.0) years. Different lesions in the same patient were analyzed as independent samples. Univariate analysis results showed that, except for gender, nodule location, and vascular convergence sign, the differences in the remaining variables among the three groups of PGL, MIA, and IAC patients were statistically significant (P<0.05). Multinomial multivariate logistic regression analysis showed that the differences between the parameters in the PGL group and the MIA group were not statistically significant (P>0.05), and the maximum diameter and average density of the nodules were statistically different between the PGL and IAC groups (P<0.05), and were positively correlated with the occurrence of IAC as independent risk factors. The average AUC value, accuracy, recall rate, and F1 score of the AI system in predicting lung nodule pathological type were 0.807, 74.3%, 73.2%, and 68.5%, respectively, all better than the clinical physicians’ prediction of lung nodule pathological type indicators (0.782, 70.9%, 66.2%, and 63.7% respectively). The AUC value of the AI system in predicting IAC was 0.853, and the sensitivity, specificity, and optimal cutoff value were 0.643, 0.943, and 50.0%, respectively. Conclusion This AI system has demonstrated high clinical value in predicting the benign and malignant nature and pathological type of lung nodules, especially in predicting lung nodule pathological type, its ability has surpassed that of clinical physicians. With the optimization of algorithms and the adequate integration of multimodal data, it can better assist clinical physicians in formulating individualized diagnostic and treatment plans for patients with lung nodules.

ObjectiveTo analyze the protective effect of different types of influenza vaccines (InfV) against influenza A among the individuals aged between 3‒17 years old, and to provide a scientific basis for the prevention and control of influenza in the future. MethodsA retrospective cohort study was conducted to collect data on the incidence and InfV vaccination of the individuals aged between 3‒17 years during the influenza epidemic season from 2022 to 2023. Vaccine effectiveness (VE) was calculated, and a log-binomial regression model was used to calculate the corrected VE. ResultsThe incidence rate of influenza in InfV vaccinated and un-vaccinated groups was 7.32% (1 937/ 26 446) and 9.65% (4 421/45 837), respectively. After adjusting for age and gender factors, the unadjusted VE (95%CI) was 54.57% (52.24%‒56.78%). The unadjusted VE (95%CI) was 53.66% (50.36%‒56.74%) for males and 55.60% (52.24%‒58.72%) for females, respectively. The unadjusted VE (95%CI) for the age group of 3‒ years, 6‒ years, 9‒ years, 12‒ years, and 15‒17 years were 64.08% (60.89%‒67.01%), 57.40% (53.71%‒60.80%), 57.77% (52.49%‒62.47%), 24.36% (9.49%‒36.79%), and 24.09% (-17.59%‒51.00%), respectively. The unadjusted VE (95%CI) for quadrivalent split-virion inactivated influenza vaccine, trivalent split-virion inactivated influenza vaccine, trivalent subunit influenza vaccine, and trivalent live attenuated influenza vaccine were 53.84% (51.32%‒56.24%), 62.17% (56.28%‒67.26%), 79.83% (69.94%‒86.46%), and 31.59% (19.07%‒42.18%), respectively. ConclusionThe InfV used during the 2022‒2023 influenza season had a good protective effect against influenza A among the individuals aged between 3‒17 years old, especially in those aged between 3‒11 years old.

OBJECTIVE: To observe the effect of electroacupuncture (EA) pretreatment of "biaoben acupoint combination" on cardiomyocyte mitochondrial fission in the rats with myocardial ischemia-reperfusion injury (MIRI) and explore its mechanism. METHODS: Fifty male SD rats were randomly divided into a sham-operation group, a model group, an EA pretreatment group, an EA pretreatment + Compound C group and an EA pretreatment+ML385 group, 10 rats in each group. In the EA pretreatment, the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, EA was delivered at bilateral "Neiguan" (PC6), "Zusanli" (ST36) and "Guanyuan" (CV4) for 20 min, with continuous wave and 2 Hz of frequency, 1 mA of current, once daily for consecutive 7 days. On day 8, in the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, 30 min before model preparation, the intraperitoneal injection with Compound C (0.3 mg/kg) and ML385 (30 mg/kg) was administered respectively. Except in the sham-operation group, the ligation of the left anterior descending coronary artery was performed to prepare MIRI rat model in the rest groups. In the sham-operation group, the thread was not ligated. After modeling, the content of reactive oxygen species (ROS) in the ischemic area was measured by flow cytometry, superoxide dismutase (SOD) was detected using xanthine oxidase method, and malondialdelyde (MDA) was detected using thiobarbituric acid (TBA) chromatometry. The morphology of myocardial tissue in the ischemic area was observed with HE staining, and the mitochondria ultrastructure of cardiomyocytes observed under transmission electron microscopy. Using immunofluorescence analysis, the positive expression of mitochondrial fission factor (MFF), mitochondrial fission 1 protein antibody (Fis1) and dynamin-related protein 1 (Drp1) was detected; and with immunohistochemical method used, the protein expression of adenosine monophosphate-activated protein kinase (AMPK), nuclear factor E2-associated factor2 (Nrf2) and Drp1 in the ischemic area was detected. RESULTS: Compared with the sham-operation group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 increased in the model group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 decreased (P<0.01), and the protein expression of Drp1 elevated (P<0.01). Compared with the model group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01), and the protein expression of Drp1 declined (P<0.01); and in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the positive expression of MFF, Fis1 and Drp1, and the protein expression of Drp1 were all reduced (P<0.01). When compared with the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01, P<0.05), and the protein expression of Drp1 decreased (P<0.05). In comparison with the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the cardiac muscle fiber rupture, cell swelling and mitochondrial disorders were obviously alleviated in the EA pretreatment group. The morphological changes were similar among the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group. CONCLUSION Electroacupuncture pretreatment of "biaoben acupoint combination" attenuates myocardial injury in MIRI rats, probably through promoting the phosphorylation of AMPK and Nrf2, inhibiting the excessive mitochondrial fission induced by Drp1, and reducing mitochondrial dysfunction caused by mitochondrial fragmentation and vacuolation.
Animals ; Electroacupuncture ; Male ; Rats, Sprague-Dawley ; Myocardial Reperfusion Injury/physiopathology* ; Myocytes, Cardiac/cytology* ; Rats ; Acupuncture Points ; Mitochondrial Dynamics ; Humans ; Reactive Oxygen Species/metabolism* ; NF-E2-Related Factor 2/genetics* ; Superoxide Dismutase/metabolism*

Objective:To analyze the drug resistance characteristics and influencing factors in human immunodeficiency virus (HIV)-1 treated patients in Henan Province.Methods:HIV-1 treated patients who had received anti-retroviral therapy (ART) for more than six months and had a viral load >200 copies/mL in the Zhengzhou Sixth People′s Hospital from January to December 2024 were enrolled. Plasma samples were collected. Partial pol region gene sequences and integrase gene sequences of HIV-1 were amplified by reverse transcription nested polymerase chain reaction. The REGA HIV-1 subtype analysis tool was used to determine the subtypes of HIV-1 isolates, and the HIV drug resistance database of Stanford University in the United States was used to analyze the genetic drug resistance mutations and antiviral drug susceptibility. The multivariate logistic regression analysis was used to analyze the factors related to drug resistance. Results:Among 933 HIV-1 treated patients with ART failure, 825 samples were successfully amplified, with the amplification success rate of 88.42%. The overall drug resistance rate was 70.06%(578/825), among which the drug resistance rates of nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI), protease inhibitor (PI), and integrase inhibitor (INSTI) were 55.15%(455/825), 64.36%(531/825), 5.70%(47/825), and 2.31%(19/821), respectively. The most common drug resistance mutations included M184I/V (47.88%(395/825)), K103N/S (38.18%(315/825)), and K70E/G/N/Q/R/S/T/del (16.61%(137/825)). Multivariate analysis showed that the baseline CD4 + T cell count <200 cells/μL (adjusted odds ratio ( OR)=2.239, 95% confidence interval ( CI)1.011 to 4.960), an initial 2NRTI+ NNRTI-based treatment regimen (adjusted OR=44.332, 95% CI 5.191 to 378.593), initial 2NRTI+ PI/r (r means ritonavir)-based regimen (adjusted OR=14.391, 95% CI 1.304 to 158.805) and a change in the ART regimen (adjusted OR=5.941, 95% CI 2.373 to 14.878) were independent risk factors for drug resistance (all P<0.05). Conclusions:The drug resistance rate after virological failure in HIV-1 treated patients in Henan Province is relatively high, which is mainly characterized by NNRTI resistance. The baseline immune status and the choice of the initial treatment regimen are important factors affecting the occurrence of drug resistance. The treatment monitoring and drug resistance monitoring should be strengthened.

Objective To examine the correlation between fetal rectal ampulla diameter and gestational age,and to establish reference value ranges for low-risk fetuses between 18 and 40 weeks of gestation in Yibin region.Methods A total of 1,103 low-risk singleton pregnant women between 18 and 40 weeks of gestation were recruited from five hospitals in Yibin City(the Second People's Hospital,the First People's Hospital,the Fifth People's Hospital,the Maternal and Child Health Hospital of Yibin City,and the Maternal and Child Health Hospital of Cuiping District)for routine level Ⅰ,Ⅱ,and Ⅲ prenatal ultrasound screening from October 2022 to March 2024.Fetal rectal ampulla diameters,including anteroposterior diameter,transverse diameter,and area,were measured using prenatal ultrasound.The normality of these measurements was assessed using the Shapiro-Wilk test.Scatter plots depicting the relationship between fetal rectal ampulla diameter parameters and gestational age were generated using the"Overlap Scatter Plot"function in SPSS.Percentiles were calculated using the"Explore"function in SPSS,with reference value ranges described by P5,P10,P50,P90,and P95.Results The visual-ization rate of the fetal rectal ampulla diameter was 55%at 18～20 weeks of gestation,100%at 21～37 weeks,and 96%at greater than 37 weeks.The fetal rectal ampulla diameter exhibited a significant positive correlation with gestational age(r=0.925～0.949,P<0.01).Conclusions Prenatal ultrasound measurement of fetal rectal ampulla diameter demonstrates a robust correlation with gestational age.The reference intervals for the rectal ampulla diameter of low-risk fetuses between 18 and 40 weeks of gestation,established in this study,may offer valuable theoretical guidance for prenatal diagnosis of fetal rectal and anal abnormalities in Yibin region.