Objective:To explore the potential application of two-dimensional speckle tracking echocardiography (2D-STE) in terms of quantification and evaluating left and right atrial function in normal fetuses, and to investigate the relevant factors affecting left and right atrial function in normal fetuses as well as differences between both atrial function.Methods:A total of 100 single fetuses underwent fetal echocardiography in the Department of Diagnostic Ultrasound & Echocardiography, Sir Run Run Shaw Hospital, Zhejiang University College of Medicine from January 2019 to October 2022 were retrospectively enrolled. The standard basal or apical four-chamber view clips were obtained, and the left and right atrial function were quantitatively analyzed using TomTec-ARENA off-line cardiac analysis software for quantitative assessment of both atrial strain measurements including left atrial reservoir phase longitudinal strain (LASr), left atrial ductal phase longitudinal strain (LAScd), left atrial systolic phase longitudinal strain (LASct), right atrial reservoir phase longitudinal strain (RASr), right atrial ductal phase longitudinal strain (RAScd), right atrial systolic phase longitudinal strain (RASct), and the ratio of systolic longitudinal strain to conduit longitudinal strain in left and right atrial systolic display groups were calculated which was denoted as Sct/Scd.Routine fetal obstetric ultrasound measurements and fetal echocardiographic parameters in the two groups were obtained including fetal heart rate (FHR), left atrial end-systolic length (LAESL), left atrial end-systolic diameter (LAESD), left atrial end-systolic area (LAESA), left ventricular end-diastolic transverse diameter (LVEDD), right atrial end-systolic length (RAESL), right atrial end-systolic diameter (RAESD), right atrial end-systolic area (RAESA), right ventricular end-diastolic transverse diameter (RVEDD), peak blood flow velocity of mitral valve and tricuspid valve in early and late diastolic period (E, A), peak ratio of E and A: E/A (MV), E/A (TV), and the difference between the left and right atrial strain indices and the routine fetal obstetric ultrasound and fetal echocardiographic parameters, as well as the correlation between the above parameters and gestational age were analyzed. The repeatability tests were performed using the intra-class correlation coefficientt (ICC).Results:Significant differences were found in LASr and RASr, LAScd and RAScd, LASct and LAScd, Sct/Scd between the left atrium and right atrium, E/A (MV) and E/A (TV), LAESD and RAESD, LAESL and RAESL (all P<0.05), there was significant difference in FHR between the left atrial contraction display group and the no atrial contraction display group ( P=0.011), no significant difference in other parameters (all P>0.05). Correlation analysis showed that, LASr, LASct, RASr, and RASct showed moderate negative correlation with gestational age ( rs=-0.570, -0.601, -0.469, -0.568; all P<0.001). While LAScd, RAScd, E/A (MV), E/A (TV) were moderately positively related with gestational age ( rs=0.310, 0.350, 0.330, 0.343; all P<0.05). LAESL, LAESD, LAESA, RAESL, RAESD, RAESA, LVEDD and RVEDD were significantly positively related with gestational age ( rs=0.662, 0.768, 0.792, 0.728, 0.828, 0.822, 0.838, 0.802, all P<0.001). The inter-examiner ICC of fetal LASr and RASr were 0.89 and 0.84 (both P<0.05) and the intra-examiner ICC of fetal RASr and LASr both were 0.80 (both P<0.05), with good consistency. Conclusions:2D-STE is highly feasible and reproducible in assessing fetal atrial function. The corresponding variation values of fetal atria at different gestational weeks were obtained in this study, which provides a new reference index for us to further study normal fetal atria as well as comparative analysis of fetal cardiac function under prenatal pathological conditions.

ObjectiveTo explore the function of DANCR during the differentiation of human embryonic stem cells （hESC） toward definitive endoderm （DE）. MethodsThe in vitro DE differentiation system was established and its efficiency was verified. The correlation between the expression level of DANCR and DE differentiation process was detected. Using lentivirus system， we stably knocked down DANCR in hESC. The shDANCR hESC line was applied to DE differentiation， using qPCR and Western blot to detect the expression of DE marker genes SOX17 and FOXA2， and that of primitive streak marker genes Brachyury （T）， EOMES， MIXL1 and GSC. Dual luciferase reporter assay and qPCR were used to confirm the interaction between DANCR and the WNT pathway during DE differentiation. ResultsThe in vitro differentiation system mimicked DE differentiation efficiently. And the expression of DANCR was gradually downregulated during differentiation. DANCR was efficiently knocked down in the shDANCR hESC line （P < 0.001）. Compared with those in the control group， the expression levels of primitive markers Brachyury （T）， EOMES， MIXL1 and GSC， as well as DE markers SOX17 and FOXA2， were significantly decreased in shDANCR groups （P < 0.05）. Furthermore， the transcriptional activity of the WNT pathway in shDANCR groups was lower than that in the control group （P < 0.05）. And RNA levels of downstream genes of the WNT pathway， FZD5， FZD8， SFRP1， FRZB and ANKRD6， were significantly decreased in shDANCR groups （P < 0.05）. However， differences in protein levels of the TGFβ pathway effectors SMAD2/3 and p-SMAD2 were statistically insignificant in shDANCR and control groups （P > 0.05）. Forced activation of β-CATENIN rescued DANCR knock down-induced deficiency in DE differentiation. ConclusionsThe expression of DANCR decreases during DE differentiation. DANCR may promote DE differentiation through modulating the activity of the WNT pathway.

Objective: To analyze physical fitness of students aged 6-22 years old from seven ethnic groups in Yunnan Province, and to provide reference for physical fitness intervention measures. Methods: The nationality, gender, grade, body shape, vital capacity, exercise quality of students were derived from the 2019 Yunnan Student Physical Health Survey Database. Comprehensive physical fitness score was calculated according to the National Student Physical Fitness Standards(revised in 2014). t test, ANOVA, and χ 2 test were used to analyze physical fitness score and level among students with different ethnic groups, gender, and school stages. Results: The average comprehensive score of physical fitness among students from 7 ethnic groups in Yunnan Province was (70.02±9.69）, with the pass rate being 88.91%. The proportion of excellent was 0.93%, good was 17.90%, pass 70.09 %, and failed was 11.09%. Physical fitness score was highest in BMI (94.99 points), followed by 50 meter running (74.13 points), sitting forward bend (72.63 points), endurance running (70.43 points), standing long jump (67.77 points), sit ups ( 65.71 points) , 1 minute skipping rope (65.25 points), vital capacity (62.97 points), pull up (29.04 points). Physical fitness score and pass rate and evaluation level varied significantly by ethnicity and school stage( F =293.53，452.85， χ 2/ χ 2 trend =466.65， 412.57 ； 1 553.22 ，1 045.36， P <0.01). Conclusion The excellent rate of physical fitness among students in Yunnan Province is relatively low. Physical fitness promotion requires specific guidance and training based on ethnicity and school stage.

Objective:To explore the effect of three-dimensional(3D) design and printing in the reoperation of asymmetric deformity after orthognathic surgery.Methods:Patients of facial asymmetry after orthognathic surgery were included in the Department of Stomatology, Shenzhen University General Hospital and Department of Oral & Maxillofacial Surgery, Shenzhen Stomatology Hospital Affiliated to Shenzhen University from January 2016 to August 2020. Surgical plans and guide plates (positioning guide plate, bone cutting guide plate, reset guide plate) were made by 3D design and printing. During the operations, guide plates were used to guide osteotomy. The facial shape satisfaction of clinicians/patients/third-party were recorded and analyzed at preoperation and 6-12 months postoperation. These patients’ CT scan data was imported to the digital surgery software. Then the distance of chin-midpoint to mid-sagittal plane and the difference of bilateral protuberant point of mandible body to mid-sagittal plane were measured at preoperation and 6-12 months postoperation to determine whether the asymmetry were corrected and postoperative distance were the same as the preoperative design. Data analysis was conducted using SPSS 17.0 statistical software, and measurement data were expressed as Mean±SD. The preoperative and postoperative satisfaction of patients/clinicians/third-party, digital data of preoperation/postoperation and digital data of design-operations/postoperation were analyzed by paired t-test. Analysis of variance and dunnett- t test were used to compare the satisfaction of the surgeon, the third party and patients before and after operation. Results:There were 16 cases of facial asymmetry after orthognathic surgery, including 3 males and 13 females, aged from 18 to 35 years. In 9 cases, genioplasty were used to correct chin deviation. In the other 4 cases, unilateral buccal cortical bone resection were used to correct mandibular body deviation. In the last 3 cases, genioplasty and unilateral buccal cortical bone resection were both applied. All 16 patients successfully received the operation according to the preoperative digital designed plate. Postoperative follow-up ranged 6 months to 1 year. In the 12 cases of genioplasty, the distance of chin-midpoint to mid-sagittal plane reduced from(4.99±0.83) mm preoperatively to (1.63±0.80) mm postoperatively and the difference significant ( t=9.09, P<0.001). There was no significant difference between the distance of preoperative design [(1.50±0.43) mm] and the postoperative one ( t=-0.83, P=0.423). In the 7 cases of unilateral buccal cortical bone resection, the difference of bilateral protuberant point of mandible body to mid-sagitta plane reduced from (7.26±1.20) mm preoperatively to (2.44±0.56) mm postoperatively and the difference was statistically significant ( t=10.26, P<0.001). There was no significant difference was observed between the distance of preoperative design [(2.39±0.16) mm] and the postoperative one ( t=-0.29, P=0.779). The preoperative satisfaction of patients, clinicians and third-party were 65.94±8.21, 79.69±5.91, 79.38±7.50. The postoperative satisfaction of patients, clinicians and third-party were 90.00±5.48, 90.63±2.50, 90.00±4.08. The postoperative satisfaction of patients, chief surgeon and third party was higher than that preoperative satisfaction and the difference was statistically significant( t=-9.15, P<0.001; t=-7.50, P<0.001; t=-6.04, P<0.001). The difference of preoperation satisfaction was statistically significant( F=18.66, P<0.001). The difference of satisfaction of the clinicians and the patients was statistically significant ( P<0.001). The difference of satisfaction of the third-party and the patients was statistically significant ( P<0.001). The difference of postoperation satisfaction was not statistically significant( F=0.12, P=0.889). Conclusions:3D design and printing can 3D analyze comprehensively, simulate surgery accurately, visualize proposed result and guide 3D printing digital guiding plate to perform surgery accurately. In addition, it can improve postoperative satisfaction. So 3D design and printing had obvious advantages in the secondary surgery of asymmetric deformity correction after orthognathic surgery.

Objective:To explore the effect of three-dimensional(3D) design and printing in the reoperation of asymmetric deformity after orthognathic surgery.Methods:Patients of facial asymmetry after orthognathic surgery were included in the Department of Stomatology, Shenzhen University General Hospital and Department of Oral & Maxillofacial Surgery, Shenzhen Stomatology Hospital Affiliated to Shenzhen University from January 2016 to August 2020. Surgical plans and guide plates (positioning guide plate, bone cutting guide plate, reset guide plate) were made by 3D design and printing. During the operations, guide plates were used to guide osteotomy. The facial shape satisfaction of clinicians/patients/third-party were recorded and analyzed at preoperation and 6-12 months postoperation. These patients’ CT scan data was imported to the digital surgery software. Then the distance of chin-midpoint to mid-sagittal plane and the difference of bilateral protuberant point of mandible body to mid-sagittal plane were measured at preoperation and 6-12 months postoperation to determine whether the asymmetry were corrected and postoperative distance were the same as the preoperative design. Data analysis was conducted using SPSS 17.0 statistical software, and measurement data were expressed as Mean±SD. The preoperative and postoperative satisfaction of patients/clinicians/third-party, digital data of preoperation/postoperation and digital data of design-operations/postoperation were analyzed by paired t-test. Analysis of variance and dunnett- t test were used to compare the satisfaction of the surgeon, the third party and patients before and after operation. Results:There were 16 cases of facial asymmetry after orthognathic surgery, including 3 males and 13 females, aged from 18 to 35 years. In 9 cases, genioplasty were used to correct chin deviation. In the other 4 cases, unilateral buccal cortical bone resection were used to correct mandibular body deviation. In the last 3 cases, genioplasty and unilateral buccal cortical bone resection were both applied. All 16 patients successfully received the operation according to the preoperative digital designed plate. Postoperative follow-up ranged 6 months to 1 year. In the 12 cases of genioplasty, the distance of chin-midpoint to mid-sagittal plane reduced from(4.99±0.83) mm preoperatively to (1.63±0.80) mm postoperatively and the difference significant ( t=9.09, P<0.001). There was no significant difference between the distance of preoperative design [(1.50±0.43) mm] and the postoperative one ( t=-0.83, P=0.423). In the 7 cases of unilateral buccal cortical bone resection, the difference of bilateral protuberant point of mandible body to mid-sagitta plane reduced from (7.26±1.20) mm preoperatively to (2.44±0.56) mm postoperatively and the difference was statistically significant ( t=10.26, P<0.001). There was no significant difference was observed between the distance of preoperative design [(2.39±0.16) mm] and the postoperative one ( t=-0.29, P=0.779). The preoperative satisfaction of patients, clinicians and third-party were 65.94±8.21, 79.69±5.91, 79.38±7.50. The postoperative satisfaction of patients, clinicians and third-party were 90.00±5.48, 90.63±2.50, 90.00±4.08. The postoperative satisfaction of patients, chief surgeon and third party was higher than that preoperative satisfaction and the difference was statistically significant( t=-9.15, P<0.001; t=-7.50, P<0.001; t=-6.04, P<0.001). The difference of preoperation satisfaction was statistically significant( F=18.66, P<0.001). The difference of satisfaction of the clinicians and the patients was statistically significant ( P<0.001). The difference of satisfaction of the third-party and the patients was statistically significant ( P<0.001). The difference of postoperation satisfaction was not statistically significant( F=0.12, P=0.889). Conclusions:3D design and printing can 3D analyze comprehensively, simulate surgery accurately, visualize proposed result and guide 3D printing digital guiding plate to perform surgery accurately. In addition, it can improve postoperative satisfaction. So 3D design and printing had obvious advantages in the secondary surgery of asymmetric deformity correction after orthognathic surgery.

ObjectiveTo explore the impact of COVID-19-related stress on the social adaptation of college students， and to analyze and compare the mediating effects of patience and social support. MethodsStratified cluster sampling method was applied to enroll 3 219 college students， and they were assessed using the COVID-19-related Stress Questionnaire， Social Adaptation Inventory （SAI）， Patience Questionnaire （PQ） and Social Support Rating Scale （SSRS）， thereafter， the mediating effect was assessed via the SPSS Process macro. ResultsCollege students' COVID-19-related Stress Questionnaire score were positively correlated with the scores of PQ and SSRS （r=0.297， 0.229， P<0.01）， and negative correlated with SAI score （r=-0.430， P<0.01）. PQ and SSRS scores were positively correlated with SAI score （r=0.374， 0.283， P<0.01）. PQ score was positively correlated with SSRS score （r=0.271， P<0.01）. Patience partially mediated the relationship between COVID-19-related stress and social adaptation （β=0.049， 95% CI： 0.039~0.062）. Meanwhile， social support also partially mediated the relationship between COVID-19-related stress and social adaptation （β=0.016， 95% CI： 0.009~0.025）. ConclusionCOVID-19-related stress exerts a negative impact on college students' social adaptation ability， while the impact is mediated by patience and social support， and the mediation effect of patience is more significant.

Objective To analyze the clinical courses and outcomes of COVID-19 cases and the influencing factors in Guangdong province and provide basis for the formulation or adjustment of medical care and epidemic control strategy for COVID-19. Methods We collected demographic data, medical histories, clinical courses and outcomes of 1 350 COVID-19 patients reported in Guangdong as of 4 March 2020 via epidemiological investigation and process tracking. Disease severity and clinical course characteristics of the patients and influencing factors of severe illness were analyzed in our study. Results Among 1 350 cases of COVID-19 cases in Guangdong, 72 (5.3%) and 1049 (77.7%) were mild and ordinary cases, 164 (12.1%) were severe cases, 58 (4.3%) were critical cases and 7 (0.5%) were fatal. The median duration of illness were 23 days ( P 25 - P 75 : 18-31 days) and the median length of hospitalization were 20 days ( P 25 - P 75 : 15-27 days). For severe cases, the median time of showing severe manifestations was on the 12th day after onset ( P 25 - P 75 : 9th to 15th days), and the median time of severe manifestation lasted for 8 days P 25 - P 75 : 4-14 days). Among 1 066 discharged/fetal cases, 36.4% (36/99) and 1.0% (1/99) of the mild cases developed to ordinary cases and severe cases respectively after admission; and 5.2% (50/968) and 0.6% (6/968) of the ordinary cases developed to severe cases, and critical cases respectively after admission. In severe cases, 11.4% developed to critical cases (10/88). The influencing factors for severe illness or worse included male (a HR =1.87, 95% CI : 1.43-2.46), older age (a HR =1.67, 95% CI : 1.51-1.85), seeking medical care on day 2-3 after onset (a HR =1.73, 95% CI : 1.20-2.50) pre-existing diabetes (a HR =1.75, 95% CI : 1.12-2.73) and hypertension (a HR =1.49, 95% CI : 1.06-2.09). Conclusions The course of illness and length of hospitalization of COVID-19 cases were generally long and associated with severity of disease clinical outcomes. The severe cases were mainly occurred in populations at high risk. In the epidemic period, classified management of COVID-19 cases should be promoted according to needs for control and prevention of isolation and treatment for the purpose of rational allocation of medical resources.

Objective:Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province.Methods:The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared.Results:A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M( P25, P75) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant ( P=0.003). Conclusion:COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

Objective:Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province.Methods:The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared.Results:A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M( P25, P75) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant ( P=0.003). Conclusion:COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

Ischemic stroke is prone to recurrence, which is the leading cause of death and disability in stroke. Using predictive model to assess the recurrence risk in patients with ischemic stroke, stratifying risk, and formulating corresponding interventions to reduce the recurrence rate are the core contents of secondary prevention. In this paper, research progress on the prediction of recurrence risks of ischemic stroke recently is summarized from the predicting content or factors, including clinical factors, imaging factors, biological markers and traditional Chinese Medicine syndrome differentiation, and the methods of constructing prediction models about traditional statistical methods and machine learning, in order to provide a reference for clinical work.