Objective:To analyze the differences in determination of fluoride level in drinking water by ion-selective electrode method and high-throughput rapid determination method.Methods:The precision test was carried out by using the two methods to measure two kinds of fluoride standard substances, water samples of external quality control assessment from 2021 to 2023 (two kinds each year) and the fluoride level in three drinking water samples (for 5 times/each sample). Accuracy testing was conducted by measuring the external quality control assessment water samples and the spiked recovery rates drinking water, and water samples were grouped (water fluoride ≤1.00, > 1.00 mg/L) and analyzed according to the "Hygienic Standards for Drinking Water" (GB 5749-85). SPSS 23.0 software was used for statistical analysis of the measurement results.Results:(1) The correlation coefficients ( r) of the working curves of the two methods were both > 0.990, meeting the quality control requirements. (2) In the precision test, when comparing the results of the two methods for detecting two kinds of fluoride standard substances, there was no statistically significant difference ( F = 0.36, 0.15, P = 0.564, 0.707), and the coefficients of variation ( CV) were all < 5%. The CV of the detection results of the external quality control assessment water samples and drinking water samples were < 5%. (3) In the accuracy test, when the fluoride concentration in water was ≤1.00 mg/L, there was no statistically significant difference in the spiked recovery rates between the two methods ( F = 0.49, P = 0.504). When the fluoride concentration in water was > 1.00 mg/L, there was a statistically significant difference in the spiked recovery rates between the two methods ( F = 24.75, P = 0.003). Conclusions:The ion-selective electrode method has the advantages of wide detection range and wide adaptability, while the high-throughput rapid determination method has high accuracy. Testing personnel can weigh and choose the appropriate determination method based on the actual laboratory conditions and sample concentration range.

OBJECTIVES: To design a deep learning model that balances model complexity and performance to enable its integration into wearable ECG monitoring devices for automated diagnosis of atrial fibrillation. METHODS: This study was performed based on data from 84 patients with atrial fibrillation, 25 patients with atrial fibrillation, and 18 subjects without obvious arrhythmia collected from the publicly available datasets LTAFDB, AFDB, and NSRDB, respectively. A lightweight attention network based on depthwise separable convolution and fusion of channel-spatial information, namely DSC-AttNet, was proposed. Depthwise separable convolution was introduced to replace standard convolution and reduce model parameters and computational complexity to realize high efficiency and light weight of the model. The multilayer hybrid attention mechanism was embedded to compute the attentional weights of the channels and spatial information at different scales to improve the feature expression ability of the model. Ten-fold cross-validation was performed on LTAFDB, and external independent testing was conducted on AFDB and NSRDB datasets. RESULTS: DSC-AttNet achieved a ten-fold average accuracy of 97.33% and a precision of 97.30% on the test set, both of which outperformed the other 4 comparison models as well as the 3 classical models. The accuracy of the model on the external test set reached 92.78%, better than those of the 3 classical models. The number of parameters of DSC-AttNet was 1.01M, and the computational volume was 27.19G, both smaller than the 3 classical models. CONCLUSIONS This proposed method has a smaller complexity, achieves better classification performance, and has a better generalization ability for atrial fibrillation classification.
Atrial Fibrillation/diagnosis* ; Humans ; Electrocardiography ; Deep Learning ; Wearable Electronic Devices ; Neural Networks, Computer

Objective:To analyze the differences in determination of fluoride level in drinking water by ion-selective electrode method and high-throughput rapid determination method.Methods:The precision test was carried out by using the two methods to measure two kinds of fluoride standard substances, water samples of external quality control assessment from 2021 to 2023 (two kinds each year) and the fluoride level in three drinking water samples (for 5 times/each sample). Accuracy testing was conducted by measuring the external quality control assessment water samples and the spiked recovery rates drinking water, and water samples were grouped (water fluoride ≤1.00, > 1.00 mg/L) and analyzed according to the "Hygienic Standards for Drinking Water" (GB 5749-85). SPSS 23.0 software was used for statistical analysis of the measurement results.Results:(1) The correlation coefficients ( r) of the working curves of the two methods were both > 0.990, meeting the quality control requirements. (2) In the precision test, when comparing the results of the two methods for detecting two kinds of fluoride standard substances, there was no statistically significant difference ( F = 0.36, 0.15, P = 0.564, 0.707), and the coefficients of variation ( CV) were all < 5%. The CV of the detection results of the external quality control assessment water samples and drinking water samples were < 5%. (3) In the accuracy test, when the fluoride concentration in water was ≤1.00 mg/L, there was no statistically significant difference in the spiked recovery rates between the two methods ( F = 0.49, P = 0.504). When the fluoride concentration in water was > 1.00 mg/L, there was a statistically significant difference in the spiked recovery rates between the two methods ( F = 24.75, P = 0.003). Conclusions:The ion-selective electrode method has the advantages of wide detection range and wide adaptability, while the high-throughput rapid determination method has high accuracy. Testing personnel can weigh and choose the appropriate determination method based on the actual laboratory conditions and sample concentration range.

Objective:To analyze the registration status of clinical trials related to contraceptives based on the data of World Health Organization International Clinical Trials Registry Platform (ICTRP), so as to understand the situation of contraceptives development, and provide reference for improving the quality of clinical trials.Methods:All records in the database of ICTRP before January 1, 2025 was researched to screen out contraceptives clinical trials, and the registration time, registration platform, regional distribution, trial design and research content were analyzed.Results:A total of 206 clinical trials related to contraceptives were included. The projects were mainly carried out in the United States, Germany, and India. About 95.63% (197/206) of the study subjects were women of reproductive age. The　main　type　of　study　was　intervention [89.32% (184/206)], among which random trials accounted for 53.26% (98/184), and parallel group trials were the most common [82.65% (81/98)]. Over 64.56% (133/206) of the trials were indicated with open-label. Most of the clinical trials were in phase Ⅲ [47.57% (98/206)] and phase Ⅳ [16.50% (34/206)]. The interventions in female studies were mainly in three aspects: oral contraceptive [42.64% (84/197)], intrauterine delivery [15.23% (30/197)], and vaginal delivery [15.23% (30/197)], and the primary outcome included pregnancy rate [54.82% (108/197)], adverse drug reactions [13.20% (26/197)], ovulation inhibition [8.63% (17/197)], and vaginal infection [4.06% (8/197)].Conclusion:The　clinical　trials　of contraceptives were unevenly distributed, the research types were mainly randomized interventional trials, the included participants were mainly women of reproductive age, the intervention measures were mostly oral contraceptive, intrauterine delivery and vaginal delivery.

To address the limitations of the existing automatic electrocardiogram(ECG)diagnosis models in learning long-term dependencies,an automatic 12-lead long-term ECG signal diagnosis model which combines bidirectional selective state space model(bidirectional mamba,BiMamba)with residual multi-scale receptive field block(RMSF)is proposed:(1)designing a multi-scale receptive field module with residual connections to realize more extensive feature extraction and fusion;(2)introducing BiMamba block to enhance the model's temporal modeling capability by employing both forward and backward temporal processing;(3)using the classifier to process features from BiMamba for accomplishing multi-label ECG classification.Five major diagnostic categories from the PTB-XL dataset are extracted and subjected to 5-fold cross-validation experiments.The experimental results from the comparative study show that BiMamba-RMSF achieves an average accuracy of 89.42%,an average AUC of 0.9356,and an average F1 score of 72.85%,outperforming the other 4 automatic ECG diagnosis models.Additionally,ablation study further validates the effectiveness of BiMamba block.It is demonstrated that the proposed model has a high precision in the multi-label classification for 12-lead long-term ECG signals.

Objective:To analyze the registration status of clinical trials related to contraceptives based on the data of World Health Organization International Clinical Trials Registry Platform (ICTRP), so as to understand the situation of contraceptives development, and provide reference for improving the quality of clinical trials.Methods:All records in the database of ICTRP before January 1, 2025 was researched to screen out contraceptives clinical trials, and the registration time, registration platform, regional distribution, trial design and research content were analyzed.Results:A total of 206 clinical trials related to contraceptives were included. The projects were mainly carried out in the United States, Germany, and India. About 95.63% (197/206) of the study subjects were women of reproductive age. The　main　type　of　study　was　intervention [89.32% (184/206)], among which random trials accounted for 53.26% (98/184), and parallel group trials were the most common [82.65% (81/98)]. Over 64.56% (133/206) of the trials were indicated with open-label. Most of the clinical trials were in phase Ⅲ [47.57% (98/206)] and phase Ⅳ [16.50% (34/206)]. The interventions in female studies were mainly in three aspects: oral contraceptive [42.64% (84/197)], intrauterine delivery [15.23% (30/197)], and vaginal delivery [15.23% (30/197)], and the primary outcome included pregnancy rate [54.82% (108/197)], adverse drug reactions [13.20% (26/197)], ovulation inhibition [8.63% (17/197)], and vaginal infection [4.06% (8/197)].Conclusion:The　clinical　trials　of contraceptives were unevenly distributed, the research types were mainly randomized interventional trials, the included participants were mainly women of reproductive age, the intervention measures were mostly oral contraceptive, intrauterine delivery and vaginal delivery.

To address the limitations of the existing automatic electrocardiogram(ECG)diagnosis models in learning long-term dependencies,an automatic 12-lead long-term ECG signal diagnosis model which combines bidirectional selective state space model(bidirectional mamba,BiMamba)with residual multi-scale receptive field block(RMSF)is proposed:(1)designing a multi-scale receptive field module with residual connections to realize more extensive feature extraction and fusion;(2)introducing BiMamba block to enhance the model's temporal modeling capability by employing both forward and backward temporal processing;(3)using the classifier to process features from BiMamba for accomplishing multi-label ECG classification.Five major diagnostic categories from the PTB-XL dataset are extracted and subjected to 5-fold cross-validation experiments.The experimental results from the comparative study show that BiMamba-RMSF achieves an average accuracy of 89.42%,an average AUC of 0.9356,and an average F1 score of 72.85%,outperforming the other 4 automatic ECG diagnosis models.Additionally,ablation study further validates the effectiveness of BiMamba block.It is demonstrated that the proposed model has a high precision in the multi-label classification for 12-lead long-term ECG signals.

Objective:To investigate the prevalence of adult skeletal fluorosis caused by drinking tea-type endemic fluorosis in Yushu Tibetan Autonomous Prefecture (hereinafter referred to as Yushu Prefecture), Qinghai Province, and provide scientific basis for prevention and control of the disease.Methods:In August 2021, one village was selected as a survey site in six counties (cities) in Yushu Prefecture, including Nangqian, Chindu, Yushu, Zadoi, Qumarlêb, and Zhiduo. Drinking water samples and 10 brick tea samples were collected from each village to determine the fluoride content in water and brick tea; at least 100 permanent residents aged ≥ 25, who had a habit of drinking brick tea and had lived in the local area for more than 5 years, were selected for X-ray imaging to examine the prevalence of adult skeletal fluorosis.Results:A total of 75 samples of residential drinking water were collected, with a fluoride content of (0.21 ± 0.05) mg/L, ranging from 0.11 to 0.34 mg/L; 60 samples of brick tea, with a fluoride content of (626.70 ± 157.27) mg/kg, ranging from 324.00 to 2 102.00 mg/kg. A total of 1 136 adults were examined, and 318 cases of skeletal fluorosis were diagnosed, with a detection rate of 27.99%. Among them, the detection rates of mild, moderate, and severe skeletal fluorosis were 20.95% (238/1 136), 6.07% (69/1 136), and 0.97% (11/1 136), respectively, with mild symptoms being the main. The detection rates of skeletal fluorosis in males and females were 29.09% (121/416) and 27.36% (197/720), respectively, with no statistically significant difference between the gender (χ 2 = 0.39, P = 0.533). Comparison of the skeletal fluorosis in different gender, the differences were statistically significant (χ 2 = 22.31, P < 0.001). The detection rates of skeletal fluorosis in the age groups of 25 - 35, 36 - 45, 46 - 55, 56 - 65, 66 - 75, and ≥76 years old were 6.86% (7/102), 22.37% (51/228), 24.02% (92/383), 37.44% (73/195), 43.48% (70/161), and 37.31% (25/67), respectively. The differences between the groups were statistically significant (χ 2 = 59.84, P < 0.001). Moreover, there was a statistically significant difference in the composition of skeletal fluorosis among different age groups ( H = 37.66, P < 0.001). The Spearman correlation analysis results showed that the severity of adult skeletal fluorosis was positively correlated with age ( r = 0.34, P < 0.001). Conclusions:There is a certain degree of prevalence of adult skeletal fluorosis in Yushu Prefecture. And as age increases, the condition of skeletal fluorosis becomes more severe.

Objective:To learn about the detection quality and external quality control assessment of fluoride and arsenic in laboratories at all levels in Qinghai Province.Methods:The Z-score method was used to analyze and evaluate the evaluation results of 1 provincial, 8 municipal and 43 county level laboratories of disease prevention and control institutions participating in the external quality control assessment of water fluoride and brick tea fluoride in Qinghai Province in 2021, as well as 1 provincial, 1 municipal and 2 county level laboratories of disease prevention and control institutions participating in the external quality control assessment of water arsenic and urine arsenic. The feedback rate and qualification rate of external quality control of each assessment laboratory were calculated.Results:In 2021, the feedback rate of external quality control of water fluoride, brick tea fluoride, water arsenic and urine arsenic in provincial and municipal level laboratories of Qinghai Province were 100.00%; except that the qualified rate of water fluoride was 7/9, the qualified rate of external quality control of other projects was 100.00%. The feedback rate of external quality control of water fluoride, brick tea fluoride, water arsenic and urine arsenic in county level laboratories was 100.00%; except that the qualified rate of water fluoride was 86.05% (37/43), the qualified rate of external quality control of other projects was 100.00%. In the specific assessment results of the laboratory, the assessment results of water fluoride sample FS20210101 from 1 provincial, 1 municipal and 2 county level laboratories, and FS20210102 from 1 county level laboratory were suspicious; the assessment results of water fluoride sample FS20210101 from 3 county level laboratories were not satisfactory; the assessment results of fluoride and arsenic sample in other laboratories were satisfactory.Conclusions:The qualified rate of external quality control of fluoride and arsenic in laboratories at all levels in Qinghai Province is relatively high, but some county level laboratories are still dissatisfied with the assessment results of water fluoride. Therefore, it is necessary to strengthen the detection level of water fluoride in laboratories.

Objective:To observe the changes of serum C-terminal peptide of type Ⅰ collagen (CTX-1) and N-terminal lengthening peptide of type Ⅰ collagen (P1NP) in adult patients with skeletal fluorosis in the tea-drinking-borne endemic fluorosis area in Qinghai Province, and to find sensitive indicators for diagnosis of skeletal fluorosis.Methods:From April to August 2019, a case-control study was carried out in tea-drinking-borne endemic fluorosis area in Zhiduo County, Yushu Tibetan Autonomous Prefecture, and Gangcha County, Haibei Tibetan Autonomous Prefecture of Qinghai Province. According to the Diagnostic Standard for Endemic Skeletal Fluorosis (WS/T 192-2008), the clinical diagnosis and X-ray examination of skeletal fluorosis were carried out for permanent residents ≥25 years old and living for more than 10 years in the area, combined with face-to-face inquiry and investigation of past disease history, lifestyle and clinical manifestations. The patients with skeletal fluorosis and healthy people were selected as skeletal fluorosis group and control group, respectively. Randomized urine samples and fasting venous blood from the two groups were collected. The content of fluoride in urine was determined by ion selective electrode method, and the contents of CTX-1 and P1NP in serum were determined by enzyme-linked immunosorbent assay (ELISA).Results:A total of 127 people in the disease area were investigated, including 63 cases in skeletal fluorosis group and 64 cases in control group. There was no statistically significant difference in age and sex ratio between the two groups ( t = 0.42, χ 2 = 0.07, P > 0.05). The X-ray examination results showed that the patients with skeletal fluorosis were mainly mild, accounting for 71.43% (45/63); X-ray changes were mainly ossification of interosseous membrane and tendon. The urinary fluoride in control group and skeletal fluorosis group was 1.62 (1.12, 1.95) and 3.22 (2.38, 4.89) mg/L, respectively, with statistically significant difference between the two groups ( Z = 7.07, P < 0.001). The difference of serum CTX-1 and P1NP contents between the two groups was statistically significant ( Z = 2.00, 4.89, P < 0.05). Conclusions:The levels of serum CTX-1 and P1NP in patients with skeletal fluorosis are higher than those in healthy people. Serum CTX-1 and P1NP may be used as sensitive indicators for diagnosis of skeletal fluorosis.