Objective:To evaluate the systolic function of 24 segments in dichorionic diamniotic (DCDA) twin pregnancy by fetal heart qualification (fetal HQ) analysis, and to compare the difference with singleton pregnancies.Methods:Thirty-one cases of DCDA twin pregnancy (observation group) and 100 cases of singleton pregnancy (control group) matched in gestational age were enrolled. They underwent perinatal health care in the Third Affiliated Hospital of Zhengzhou University from February 2022 to February 2023.Fetal HQ was applied to track endocardial motion trajectories and automatically calculate the global strain (GS), fractional area change (FAC) and fractional shortening (FS) of 24 segments of left and right ventricles in order to compare the difference between DCDA fetuses and singleton fetuses. One case of twins with growth discordance were selected to demonstrate the utility of this technique.Results:①There were no statistically significant differences in GS, FAC and 24-segments FS of left and right ventricles between the two fetuses in the observation group (all P>0.05). ②The LV-FS of segments 1-10 were higher in the observation group than the control group, and the differences were statistically significant (all P<0.05). However, there were no statistically significant differences in GS and FAC of left and right ventricles, LV-FS of segments 11-24 and RV-FS of segments 1-24 between the observation group and the control group (all P>0.05). The intraclass correlation coefficient(ICC) was greater than 0.75, indicating good repeatability. ③Two fetuses with discordant growth in dichorionic diamniotic twins had abnormal FS in some segments of the left and right ventricles. Conclusions:Fetal HQ technology could easily and reliably evaluate fetal heart function in DCDA pregnancy with good repeatability. The changes of fetal cardiac function in twin pregnancy did not always follow the same pattern as in singleton pregnancy. The related data of singleton pregnancy should not be blindly used in the clinical management and scientific research of twin pregnancy.

{L-End}Objective To establish the norm of Core Occupational Stress Scale (COSS) for electronic manufacturing industry workers in China. {L-End}Methods A total of 3 049 workers from five electronic manufacturing enterprises in four prefecture-level cities concentrated distribution of the electronics manufacturing industry in China were selected as research subjects using a stratified sampling method. COSS was used to investigate occupational stress levels, and the mean norm, percentile norm and threshold norms were established. {L-End}Results The average score of COSS for the electronic manufacturing industry workers in China was (43.5±7.4) points, and the average scores of social support, organization and reward, demand and effort, and autonomy dimensions were (9.5±3.1), (15.1±3.9), (13.1±3.0), and (5.7±2.0) points, respectively. A total score of 0.0-<47.0 points was determined as no occupational stress, 47.0-<51.0 points as mild occupational stress, 51.0-≤54.0 points as moderate occupational stress, and >54.0 points as severe occupational stress. {L-End}Conclusion The norm of COSS for workers in China's electronics manufacturing industry has been established, which can provide a reference for the evaluation and intervention of their occupational stress levels.

The combination of healthcare and artificial intelligence is an important direction of medical development. The authors summarized the application of artificial intelligence in such fields as diagnosis, treatment, prevention, scientific research, teaching among others. The analysis covers the problems and challenges facing the development of artificial intelligence, and looks forward to the application prospect of artificial intelligence.

With the development of big data, the Internet and information technology, artificial intelligence is gradually being applied to the field of hospital management. The authors used advanced artificial intelligence technology to conduct structured collection and monitor the hospital′s current medical quality data, identifying key points and key events affecting medical quality and safety from the link, and providing medical personnel′s behavior with pre-warning, process monitoring and post-evaluation to improve hospital medical quality management.

OBJECTIVE: To explore the effects of sub-acute inhalation of 1-bromopropane( 1-BP) on the ultrastructure of cerebral cortex,hippocampus,cerebellum,and brainstem in male rats. METHODS: Specific pathogen free healthy male Wistar rats were randomly divided into control group and exposure group with 6 rats in each group. The rats of exposure group received 1-BP vapor at a concentration of 5 000 mg/m3. The rats in the control group were given fresh air in a dynamic inhalation chamber system for 4 weeks(6 hours/day,5 days/week). After the end of the exposure,the cerebral cortex,hippocampus,cerebellum and brainstem of rats were collected and the ultrastructural changes were observed under transmission electron microscope( TEM). RESULTS: After 3 weeks of exposure to 1-BP,the rats in the exposure group began to have unresponsiveness and decreased muscle strength in hind limbs. The body weight of exposure group was lower than that of control group from the 1 st to the 4 th week( P < 0. 05). TEM results showed destroyed structure of the myelin sheath in the region of cerebral cortex, hippocampus, cerebellum and brainstem, and irregular nucleus, vacuolar degeneration,increased lysosome of endoplasmic reticulum,mitochondrion swelling of neuron cells,karyopyknosis of astrocytes and vacuolation in the neurite of astrocytes located in the blood brain barrier( BBB). CONCLUSION: 1-BP sub-acute inhalation exposure could damage the myelin,neuron,astrocyte and BBB in male rats. The demyelination of nerve fiber and decreased permeability of BBB was particularly noticeable.

OBJECTIVE: To evaluate the diagnostic ability of toxicity pathology in patho-toxicological testing institutions in China. METHODS: The institutions participated in the 2018 Interlaboratory Comparison Activity of Toxicity Pathology Testing(hereinafter referred to as reference unit) were selected as the research subjects. The heart, spleen, skin, soft tissue, liver and mammary gland of SD rats of different groups in the 2-year carcinogenesis test were selected. The femur, knee joint and nose of Beagle dogs in the 4-week toxicity test and a total of 10 pathological tissues were selected as the comparison samples. The pathological diagnosis was carried out by the pathological diagnostic personnel of the reference unit, and the diagnostic results were reported. The expert appointed by the Toxicology and Pathology Committee of Chinese Toxicology Association compared the diagnostic results with the appointed value. RESULTS: A total of 167 pathological diagnostic personnel from 75 reference units in 24 provinces and municipalities participated in the comparison activity. The reference units were mainly distributed in East China, South China and North China, accounting for 77.3%(58/75). Totally 75 reference units fed back 750 effective diagnostic results. The qualified rates of diagnosis on heart, spleen, skin, soft tissue and breast samples were higher than 60.0%. The qualified rates of diagnosis on femur and knee joint, and nose samples were low(30.7% and 6.7%, respectively). There were 1(1.3%), 46(61.4%) and 28(37.3%) reference units rated as unqualified, qualified and excellent, respectively. CONCLUSION: Most of the testing institutions in China have a high level of patho-toxicological diagnostic ability, that can provide reliable diagnostic results for toxicology safety evaluation tests.

OBJECTIVE: To investigate the chronic toxicity and carcinogenicity of kresoxim-methyl in rats. METHODS: Specific pathogen free SD rats were randomly divided into control group and low-, medium-and high-dose groups according to the body weight of rats, 120 rats in each group with half male and half female rats. The chronic toxicity and carcinogenesis was induced in rats for 104 weeks by oral feeding. The dose of kresoxim-methyl in feed of male and female rats was 0, 75, 300 and 1 200 mg/kg. During the process of experiment, the body weight of rats was weighed. The blood biochemistry, organ coefficient and histopathology were examined at the end of the exposure, and the tumor incidence was calculated. RESULTS: There was no significant difference in mortality of the female or male rats in the four groups(P>0.05). At the 32 nd, 48 th and 56 th week after exposure, the body mass of female rats in the high dose group was lower than that in control group(P<0.05); at the 8 th, 16 th, 24 th and 32 nd week, the body mass of male rats in the high dose group was lower than that in the control group(P<0.05). The organ coefficients of heart and adrenal gland of female rats in the high dose group were higher than those in the control group and the low dose group(P<0.05). The organ coefficient of liver of male rats in the high dose group was lower than that in the control group(P<0.05). The alkaline phosphatase of male rats in the three dose groups was lower than that in the control group(P<0.05). The blood glucose of male rats in the high dose group was higher than that in the control group(P<0.05). The aspartate aminotransferase of male rats in the high dose group was lower than that in the control group(P<0.05). There was no significant difference among the three indexes in female rats(P>0.05). The tumor incidence of the control group and the low, medium and high dose groups were 68.3%, 75.0%, 75.0% and 78.8%, respectively, with no significant difference(P>0.05). The tumor incidence of the female rats was higher than that of the male rats(87.0% vs 61.5%,P<0.01).The tumor multiplicity of the above four groups were 38.3%, 35.8%, 35.0%, 39.8%, respectively, with no significant difference(P>0.05). The tumor multiplicity in female rats was higher than that in male rats(56.9% vs 17.6%,P<0.01). CONCLUSION: The no observed adverse effect level of kresoxim-methyl to female and male SD rats was 24.726 and 20.002 mg/(kg·d), respectively. No carcinogenicity of kresoxim-methyl to SD rats was observed.

OBJECTIVE: To observe the pathological changes of rat silicosis model at different time points. METHODS: The specific pathogen free SD rats were randomly divided into control group and 7, 15, 21, 30, 45, 60, 75 and 90 day model groups based on their body weight, with 5 rats in each group. Non-exposed endotracheal intubation was performed. Silicosis rat model was established by intratracheal instillation of 250 g/L silica suspension in each rat, and 0.9% sodium chloride solution was perfused into the trachea of rats in the control group. The rats in the control group were sacrificed on the 90 th day after exposure, and the model rats in the other 8 groups were sacrificed on the 7 th, 15 th, 21 st, 30 th, 45 th, 60 th, 75 th and 90 th days after the end of exposure. The gross appearance of the lung tissue of rats was observed. The rat lung tissues were stained with hematoxylin-eosin and Masson staining to observe the pathological changes, and Ashcroft score was evaluated. RESULTS: The gross observation showed that the lungs of rats in the model groups had varying degree of gray changes, hardened texture, and spots and nodules on the surface of the lobes. These changes were aggravated with the increase of time after dust exposure. The results of histopathological examination of the lungs showed that the rats developed acute alveolar inflammation, and a large number of macrophages and neutrophils were seen in the lung tissues in the 7 th and 15 th day model groups. Cellular nodules appeared in the lung tissue, and fibrosis appeared in the center of the nodule in the rats of 21 st, 30 th, and the 45 th day model groups; the silicosis nodules appeared in the lung tissues of rats in the 60 th, 75 th, and 90 th day model groups, and the small nodules gradually merged into larger ones. Simultaneously, with the increase of time after dust exposure, the lung tissue of rats gradually showed severe pulmonary fibrosis. The lung organ coefficient and Aschcroft score of rats increased with the increase of time after dust exposure(P<0.01). CONCLUSION: The rat lung changes after dust exposure. Acute alveolar inflammation occurs on the 7 th to 15 th day after dust exposure; cellular nodules develop on the 21 st to 45 th day after dust exposure; silicosis nodules develop on the 60 th to 90 th day after dust exposure. The severity of lung fibrosis after dust exposure showed a time-effect relationship in rats.