Objective To evaluate the role of treadmill exercise‐stress echocardiography in the assessment of left ventricular ( LV ) function in patients with slow coronary flow ( SCF ) ,and discuss the possible mechanism of SCF . Methods Forty‐six patients with diagnosis of SCF were enrolled as SCF group . Forty age and sex matched adults were included as control group . All subjects had underwent clinical evaluation and exercise stress echocardiography . LV diastolic and systolic functions were assessed by conventional echocardiography , tissue Doppler imaging and two‐dimensional speckle tracking echocardiography at rest and during exercise . Results ①LV function in patients with SCF at rest :LV peak systolic longitudinal strain ( LS) was lower in patients with SCF than that in controls ( P ＜0 .05) . T here was no difference of LV ejection fraction ( LVEF) between the two group( P＞0 .05) . Early diastolic mitral annulus velocity ( M itral e′) and the ratio between the early mitral inflow velocity and Mitral e′( M itral E/e′) were significantly decreased in SCF group( all P＜0 .01 ) . ②LV function during exercise :LVEF ,LS and M itral e′were significant increased in two groups ( all P ＜0 .05 ) than those at rest ,but there was no significant difference of LVEF ,LS ,M itral e′ and M itral E/e′ between the two groups ( all P ＞ 0 .05 ) . Compared with control group ,ΔLS and ΔM itral e′were significantly higher in SCF group ( all P＜0 .05 ) . Conclusions LV systolic and diastolic function in patients with SCF are impaired at rest . LV systolic and diastolic function recover in patients with SCF during exercise .

Objective:To investigate college students' acceptance of flipped classroom and its influencing factors, so as to provide basis and suggestions for the promotion of flipped classroom in colleges and universities.Methods:A structured quantitative questionnaire was used to investigate the learning status of 876 students in Chongqing Medical University and their cognition and acceptance of flipped classroom. The influencing factors were analyzed by multiple linear regression.Results:According to the questionnaire, 77.9% of the students did not know about flipped classroom, 32.3% of them had high acceptance to it and 62.0% of them accepted it moderately. The stronger the learning ability and motivation, the higher levels of understanding and acceptance of the flipped classroom.Conclusion:Undergraduates have a certain degree of acceptance to flipped classroom. In daily education, attention should be paid to stimulating students' learning motivation, cultivating their learning ability in various aspects, widely spreading teaching concept of flipped classroom, and actively trying the teaching mode of flipped classroom.

Objective:To observe the effect of noninvasive positive pressure ventilation (NIPPV) and high-flow nasal cannula oxygen therapy (HFNC) on the prognosis of patients with coronavirus disease 2019 (COVID-19) accompanied with acute respiratory distress syndrome (ARDS).Methods:A retrospective study was conducted in Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology when authors worked as medical team members for treating COVID-19. COVID-19 patients with pulse oxygen saturation/fraction of inspiration oxygen (SpO 2/FiO 2, S/F) ratio < 235, managed by medical teams [using S/F ratio instead of oxygenation index (PaO 2/FiO 2) to diagnose ARDS] from February to April 2020 were included. The patients were divided into NIPPV group and HFNC group according to their oxygen therapy modes. Clinical data of patients were collected, including general characteristics, respiratory rate (RR), fraction of FiO 2, SpO 2, heart rate (HR), mean arterial pressure (MAP), S/F ratio in the first 72 hours, lymphocyte count (LYM), percentage of lymphocyte (LYM%) and white blood cell count (WBC) at admission and discharge or death, the duration of dyspnea before NIPPV and HFNC, and the length from onset to admission. The differences of intubation rate, all-cause mortality, S/F ratio and RR were analyzed, and single factor analysis and generalized estimation equation (GEE) were used to analyze the risk factors affecting S/F ratio. Results:Among the 41 patients, the proportion of males was high (68.3%, 28 cases), the median age was 68 (58-74) years old, 28 cases had complications (68.3%), and 34 cases had multiple organ dysfunction syndrome (MODS, 82.9%). Compared with HFNC group, the proportion of complications in NIPPV group was higher [87.5% (21/24) vs. 41.2% (7/17), P < 0.05], and the value of LYM% was lower [5.3% (3.4%-7.8%) vs. 10.0% (3.9%-19.7%), P < 0.05], the need of blood purification was also significantly lower [0% (0/24) vs. 29.4% (5/17), P < 0.05]. The S/F ratio of NIPPV group gradually increased after 2 hours treatment and RR gradually decreased with over time, S/F ratio decreased and RR increased in HFNC group compared with baseline, but there was no significant difference in S/F ratio between the two groups at each time point. RR in NIPPV group was significantly higher than that in HFNC group after 2 hours treatment [time/min: 30 (27-33) vs. 24 (21-27), P < 0.05]. There was no significant difference in rate need intubation and hospital mortality between NIPPV group and HFNC group [66.7% (16/24) vs. 70.6% (12/17), 58.3% (14/24) vs. 52.9% (9/17), both P > 0.05]. Analysis of the factors affecting the S/Fratio in the course of oxygen therapy showed that the oxygen therapy mode and the course of illness at admission were the factors affecting the S/F ratio of patients [ β values were -15.827, 1.202, 95% confidence interval (95% CI) were -29.102 to -2.552 and 0.247-2.156, P values were 0.019 and 0.014, respectively]. Conclusion:Compared with HFNC, NIPPV doesn't significantly reduce the intubation rate and mortality of patients with COVID-19 accompanied with ARDS, but it significantly increases the S/F ratio of those patients.

BACKGROUND: This study aimed to analyse the epidemiological characteristics of bacillary dysentery (BD) caused by Shigella in Chongqing, China, and to establish incidence prediction models based on the correlation between meteorological factors and BD, thus providing a scientific basis for the prevention and control of BD. METHODS: In this study, descriptive methods were employed to investigate the epidemiological distribution of BD. The Boruta algorithm was used to estimate the correlation between meteorological factors and BD incidence. The genetic algorithm (GA) combined with support vector regression (SVR) was used to establish the prediction models for BD incidence. RESULTS: In total, 68,855 cases of BD were included. The incidence declined from 36.312/100,000 to 23.613/100,000, with an obvious seasonal peak from May to October. Males were more predisposed to the infection than females (the ratio was 1.118:1). Children < 5 years old comprised the highest incidence (295.892/100,000) among all age categories, and pre-education children comprised the highest proportion (34,658 cases, 50.335%) among all occupational categories. Eight important meteorological factors, including the highest temperature, average temperature, average air pressure, precipitation and sunshine, were correlated with the monthly incidence of BD. The obtained mean absolute percent error (MAPE), mean squared error (MSE) and squared correlation coefficient (R) of GA_SVR_MONTH values were 0.087, 0.101 and 0.922, respectively. CONCLUSION From 2009 to 2016, BD incidence in Chongqing was still high, especially in the main urban areas and among the male and pre-education children populations. Eight meteorological factors, including temperature, air pressure, precipitation and sunshine, were the most important correlative feature sets of BD incidence. Moreover, BD incidence prediction models based on meteorological factors had better prediction accuracies. The findings in this study could provide a panorama of BD in Chongqing and offer a useful approach for predicting the incidence of infectious disease. Furthermore, this information could be used to improve current interventions and public health planning.