Objective:To establish the rat cardiac arrest model in high-altitude hypobaric hypoxia environment, and to explore the effect of the treatment time in the hypobaric oxygen chamber on the reproduction of high-altitude rat cardiac arrest model.Methods:SPF grade healthy male Sprague-Dawley (SD) rats were used as observation subjects. The experiment was conducted in two different altitude areas. The rats from the Plateau Branch of Institute of Cardiopulmonary and Cerebral Resuscitation of Sun Yat-sen University (Xining, Qinghai) were weighed and numbered, and they were placed in a hypobaric oxygen chamber (simulated altitude of 3 000 meters, speed of ascent and descent of 15 m/min, temperature of 20 ℃, cabin pressure of 69.5 kPa, cabin oxygen pressure of 14.5 kPa). After 30 days of feeding, the rats were obtained according to random number table method, and the cardiac arrest model was established by asphyxia method as the 30-day hypobaric hypoxia group. After 60 days of feeding, rats were randomly selected again, and the cardiac arrest model was established as the 60-day hypobaric hypoxia group. Thirty rats were randomly selected from the Institute of Cardiopulmonary Cerebral Resuscitation at Sun Yat-sen University (Guangzhou, Guangdong) by the same method, and the cardiac arrest model was established as the plain control group. The differences in the body weight of rat modeling precursors and the induction time of asphyxia during the modeling process among different groups were compared.Results:Finally, cardiac arrest model was established in 16 rats in the 30-day hypobaric hypoxia group and in 22 rats in the 60-day hypobaric hypoxia group. There was no significant difference in the body weight of rats before modeling among the plain control group, 30-day hypobaric hypoxia group and 60-day hypobaric hypoxia group [g: 429.00 (389.25, 440.75), 440.00 (415.50, 486.25), 440.00 (400.00, 452.50), all P > 0.05]. The asphyxia induction time of rats in the 60-day hypobaric hypoxia group was significantly longer than that in the 30-day hypobaric hypoxia group (s: 294.59±75.39 vs. 234.31±93.86, P < 0.01), even about 1.4 times of the plain control group (s: 294.59±75.39 vs. 208.73±30.88, P < 0.01). There was no significant difference in the asphyxia induction time between the 30-day hypobaric hypoxia group and the plain control group ( P > 0.05). Conclusion:Rats treated in a hypobaric oxygen chamber for 60 days are more suitable for the preparation of high-altitude cardiac arrest model, and are also consistent with the oxygen reserve and hypoxia tolerance of high-altitude rats.

Objective:To explore the relationship between blood glucose levels and blood glucose fluctuations and short-term prognosis in patients with acute cerebral hemorrhage.Methods:A retrospective analysis was conducted on the medical records of patients with acute cerebral hemorrhage admitted to our hospital's Emergency Intensive Care Unit (EICU) from January 2020 to December 2022. Patients were divided into the survival group and death group based on their 28-day survival status. Differences in general information, intravenous blood glucose data, and cerebral hemorrhage-related scoring data between the two groups were compared. Multivariate logistic regression analysis was used to identify independent risk factors, and the predictive significance was verified using the ROC curve.Results:The results of the multivariate logistic regression analysis indicated that intracranial hemorrhage volume of no less than 30 mL, GCS score at admission, systolic blood pressure at admission, and the maximum amplitude of blood glucose fluctuations were correlated with the mortality rate of cerebral hemorrhage cases within 28 days. The relationship between the maximum amplitude of blood glucose fluctuations and death within 28 days was established using the ROC curve, with an area under the curve (AUC) of 0.711 ( P<0.01). Conclusions:The largest amplitude of glucose excursion (LAGE) is an independent risk factor for short-term death and has predictive value for the prognosis in patients with ICH.

Objective:To investigate the clinical characteristics of patients with acute aortic dissection (AAD) through a retrospective and observational study, and to construct an early warning model of AAD that could be used in the emergency room.Methods:The data of 11 583 patients in the Emergency Chest Pain Center from January to December 2019 were retrospectively collected from the Chest Pain Database of Zhongshan Hospital Affiliated to Fudan University. Inclusion criteria: patients with chest pain who attended the Emergency Chest Pain Center between January and December 2019. Exclusion criteria were 1) younger than 18 years, 2) no chest/back pain, 3) patients with incomplete clinical information, and 4) patients with a previous definite diagnosis of aortic dissection who had or had not undergone surgery. The clinical data of 9668 patients with acute chest/back pain were finally collected, excluding 53 patients with previous definite diagnosis of AAD and/or without surgical aortic dissection. A total of 9 615 patients were enrolled as the modeling cohort for early diagnosis of AAD. The patients were divided into the AAD group and non-AAD group according to whether AAD was diagnosed. Risk factors were screened by univariate and multivariate logistic regression, the best fitting model was selected for inclusion in the study, and the early warning model was constructed and visualized based on the nomogram function in R software. The model performance was evaluated by accuracy, specificity, sensitivity, positive likelihood ratio and negative likelihood ratio. The model was validated by a validation cohort of 4808 patients who met the inclusion/exclusion criteria from January 2020 to June 2020 in the Emergency Chest Pain Center of the hospital. The effect of early diagnosis and early warning model was evaluated by calibration curve.Results:After multivariate analysis, the risk factors for AAD were male sex ( OR=0.241, P<0.001), cutting/tear-like pain ( OR=38.309, P<0.001), hypertension ( OR=1.943, P=0.007), high-risk medical history ( OR=12.773, P<0.001), high-risk signs ( OR=7.383, P=0.007), and the first D-dimer value ( OR=1.165, P<0.001), Protective factors include diabetes( OR=0.329, P=0.027) and coronary heart disease ( OR=0.121, P<0.001). The area under the ROC curve (AUC) of the early diagnosis and warning model constructed by combining the risk factors was 0.939(95 CI:0.909-0.969). Preliminary validation results showed that the AUC of the early diagnosis and warning model was 0.910(95 CI:0.870-0.949). Conclusions:Sex, cutting/tear-like pain, hypertension, high-risk medical history, high-risk signs, and first D-dimer value are independent risk factors for early diagnosis of AAD. The model constructed by these risk factors has a good effect on the early diagnosis and warning of AAD, which is helpful for the early clinical identification of AAD patients.

Objective:To investigate the effect of venous blood carbon dioxide binding capacity (CO 2-CP) on the short-term prognosis of patients with acute ischemic stroke (AIS) after thrombolytic therapy. Methods:A total of 86 AIS inpatients who received thrombolytic therapy in the emergency department of Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University from April 2019 to May 2021 were analyzed retrospectively. According to the venous blood CO 2-CP levels at admission, the patients were divided into two groups: low CO 2-CP group (CO 2-CP < 23 mmol/L, n = 52) and high CO 2-CP group (CO 2-CP ≥ 23 mmol/L, n = 34). The CO 2-CP levels and changes between the two groups before and after thrombolytic therapy were compared. The National Institutes of Health Stroke scale (NIHSS) score was used to evaluate the improvement rate of patients after thrombolytic therapy [NIHSS score at admission-NIHSS score at discharge)/NIHSS score at admission ×100%] and in-hospital death was also recorded. The correlation between CO 2-CP levels and prognosis of patients with AIS during emergency visit was analyzed, the receiver operator characteristic curve (ROC curve) was drawn and the area under the ROC curve (AUC) was calculated to evaluate the predictive value of CO 2-CP in the prognosis of AIS patients. Results:The CO 2-CP levels of low CO 2-CP group and high CO 2-CP group after thrombolytic therapy were significantly higher than those before treatment (mmol/L: 23.08±2.34 vs. 20.46±1.51, 25.24±2.16 vs. 23.94±1.07, both P < 0.05). The differences of CO 2-CP before and after treatment in low CO 2-CP group were significantly higher than those in high CO 2-CP group (mmol/L: 2.62±0.83 vs. 1.30±1.09, P < 0.05). The improvement rate of CO 2-CP levels in the high CO 2-CP group (NIHSS improvement rate > 45%) was significantly higher than that in the low CO 2-CP group [85.29% (29/34) vs. 23.08% (12/52)], while the mortality in the low CO 2-CP group was significantly higher than that in the high CO 2-CP group [11.54% (6/52) vs. 0% (0/34), P < 0.05]. The AUC of CO 2-CP for the prognosis of patients with AIS thrombolysis was 0.820, the 95% confidence interval (95% CI) was 0.727-0.924, P = 0.000 1. Conclusion:AIS patients with CO 2-CP levels less than 23 mmol/L have a poor short-term prognosis, which has certain predictive and clinical reference value for choosing thrombolytic time in emergency stroke patients.

Objective:To compare the predictive value of the HEART, TIMI and GRACE scores for major adversecardiovascular events (MACEs) at 7 and 28 days in patients with actue non-ST-segment elevation myocardial infarction (NSTEMI).Methods:More than 12 000 patients with chest pain from the Emergency Department of Zhongshan Hospital Affiliated to Fudan University from October 2017 to October 2018 were studied, including 566 patients with cardiogenic chest pain, 105 patients with ST-segment elevation myocardial infarction (STEMI) excluded and 15 patients lost to follow-up. Finally, 109 patients with NSTEMI and 337 non-myocardial patients with cardiogenic chest pain were enrolled. NSTEMI patients were divided into subgroups according to whether MACEs occurred. LSD t-test, Mann-Whitney U test or χ2 test were used to analyze and compare the differences between the two subgroups about the baseline data, clinical data, HEART, TIMI and GRACE scores at the time of visit. Multivariate logistic regression analysis was used to explore the independent factors of MACEs at 7 and 28 days. And the predictive values of different scores for 7-day MACEs and 28-day MACEs were compared in NSTEMI patients through the receiver operating characteristic (ROC) curve. Results:Compared NSTEMI patients with non-myocardial patients with cardiogenic chest pain, we found a statistically significant differences in sex, past history of coronary heart disease,≥3 risk factors for atherosclerosis, electrocardiogram, high-sensitivity troponin T (hs-cTnT), creatinine value, past history of myocardial infarction, HEART score, TIMI score and GRACE score. In further subgroup analysis of NSTEMI patients who were divided according to whether MACEs occurred, we found previous history of stroke and increased hs-cTnT were statistically different in 7 days after the onset of the disease. The multivariate analysis showed that the previous history of stroke and increased hs-cTnT were independent factors for the occurrence of MACEs at 7 days after the onset of NSTEMI; The previous history of stroke and increased hs-cTnT, electrocardiogram ST segment depression and TIMI score were statistically different at 28 days after the onset of NSTEMI. The multivariate analysis showed that the previous history of stroke and TIMI score were independent factors for the occurrence of MACEs at 28 days after the onset of NSTEMI patients. ROC curve indicated that the predictive value of TIMI score (AUC=0.715, 95% CI: 0.482-0.948) was better than HEART (AUC=0.659, 95% CI: 0.414-0.904) and GRACE scores (AUC=0.587, 95% CI: 0.341-0.833)in predicting MACEs in NSTEMI patients. Conclusions:HEART score, TIMI score and GRACE score can be used to evaluate NSTEMI patients. There is an independent predictive value on TIMI score for the occurrence of 28-day MACEs in NSTEMI patients.

Objective:To compare the caries experience and the kinds of dental treatment between children with autism spectrum disorders (ASD) and children without systemic disease who were all treated under general anesthesia.Methods:Totally 103 children with ASD who received dental treatments under general anesthesia in 13 professional dental hospitals around China from April to November 2016 were included in the present study. A group of 97 children without systemic disease, according to the age, gender and application propensity score matching method, were chosen as controls, who received dental treatments under general anesthesia between January 2015 to November 2018 in the same hospitals as the children with ASD. Decay missing filling tooth (DMFT/dmft, DMFT for permanent teeth and dmft for primary teeth) indices of two groups of children and the contents of the dental treatments under general anesthesia were analyzed.Results:No significant difference of DMFT/dmft index ［ M( Q25, Q75)］ was found between children with ASD group ［0 (0, 3)/11(8, 14)］ and control group ［0 (0, 3)/9(7, 13)］ ( P>0.05). The average number of dental treatments under general anesthesia and the average number of endodontic treatment in children with ASD were 13 (11, 15) and 3 (2, 6) teeth respectively, while those in the control group were 12 (9, 14) and 2 (1, 4) teeth respectively, the differences were statistically significant ( P<0.01, P<0.05). Conclusions:No significant difference was found between children with ASD and the normal controls who receive dental treatments under general anesthesia in DMFT/dmft index, but the treatment needs of children with ASD is relatively higher, and their tooth decay is relatively severer.

Objective To investigate the effect of mild hypothermia on the myocardial and microcirculation dysfunction induced by epinephrine during early post-resuscitation in a rat model of cardiac arrest and cardiopulmonary resuscitation (CPR).Methods Transesophageal cardiac pacing was performed in order to elicit cardiac arrest for 5 min in SD male rats.Totally 40 rats were randomly (random number) divided into 4 groups (n=10):normothermic control group (N),normothermic epinephrine group (N+E),hypothermic control group (H),and hypothermic epinephrine group (H+E).Chest compression was then initiated.Epinephrine (0.02 mg/kg) or saline was administrated at 1 min during CPR.Restoration of spontaneous circulation (ROSC) was recorded,and the rates of ROSC were observed.Myocardial and microcirculatory function were observed at 1,2,3,and 4 h during early post-resuscitation.Serum lactate level was assessed at baseline and ROSC 4 h.Results The ROSC rates were 10/10 in the H+E group,9/10 in the N+E group,4/10 in the H group,and 1/10 in the N group,respectively.Ejection fraction (EF)and cardiac output (CO) in the H+E group were significantly higher than that of other groups (P＜0.05).Total vessel density,perfused vessel density,proportion of perfused vessels,and microvascular flow index in the H+E group were also significantly higher than those of other groups during early post-resuscitation.The serum lactate level in the H+E group was significantly lower than that in the N+E and H groups..Conclusions Both epinephrine and mild hypothermia can improve the success rate of resuscitation.However,mild hypothermia can improve the epinephrine induced myocardial and microcirculatory dysfunction during postresuscitation in the rat cardiac arrest.

Objective To investigate the pharmacological hypothermic effect of WIN55, 212-2 on neuronal apoptosis after cardiopulmonary resuscitation. Methods Cardiac Arrest ( CA ) was induced in Sprague-Dawley rats.Five minutes after onset of CA, cardiopulmonary resuscitation ( CPR) was carried out.At 30 minutes post-resuscitation, the animals were randomized into three groups (n=10 in each group): (1) WIN55, 212-2 hypothermia group [W group, WIN55, 212-2, 1 mg/(kg· h)].(2) Normothermia group (NT group, 5%DMSO);(3) WIN55, 212-2 with normothermia group (W+NT group, WIN55, 212-2, 1 mg/(kg· h).Animals in WIN55, 212-2 hypothermia group and WIN55, 212-2 with normothermia group were dealt with continuous intravenous infusion of WIN55, 212-2 [1 mg/(kg· h)] for 4 h, while rats in NT group were infused with equal volume of 5% DMSO instead.The survival time and neurological deficit score ( NDS) were observed.The CA models were established in three groups.After rats were sacrificed, the brains were harvested for detecting histopathological changes and apoptosis of neural cell at 24 h, 48 h and 72 h after ROSC respectively.Five animals of each group were chosen randomly ( random number ) .Results Body temperatures of rats in W group decreased from 37°C to 34°C in 4 hours.Accumulated survival rate in W group was higher than that in the other two groups ( P=0.02) .NDS was significantly improved in W group than that in the other two groups ( P<0.05) .Morphological change in W group was less serious than that in the other two groups.The number of neuron apoptosis in W group was smaller than that in the other two groups.Conclusions WIN55, 212-2 inducing pharmacologically hypothermia during post-resuscitation prolonged survival and improved cerebral function in rat cardiac arrest models.The beneficial effects of WIN55, 212-2 were associated with ameliorating the histopathological damage in brain and alleviating the neuron apoptosis.

Objective Objectives To investigate the gender difference affecting the efficacy of cardiopulmonary resuscitation (CPR) in the mouse cardiac arrest (CA) model.Methods CA was induced in 30 Kunming mice (15 male and 15 female) by trans-oesophageal cardiac pacing for 4 minutes.Epinephrine was then administrated intra-artery,and CPR was performed.The time required for restoration of spontaneous circulation (ROSC) was observed,but if ROSC failed to appear at 10 minutes after CPR,resuscitation was discontinued.Blood pressure and electrocardiograms of resuscitated animals were invasively monitored for an additional 60 minutes.Blood pressure,heart rate,the restoration of spontaneous respiration (ROSR) and survival time were observed and recorded.Results All 15 female mice and 14 of 15 male mice had ROSC.There were no significant differences in the time required for ROSC,ROSR,and survival between the two groups [(50±17)svs.(46±12)s; (2.4±1)minvs.(2.5±1)min; 28 (1,72)h vs.16 (3,72)h,P ＞ 0.05)].Moreover,neither blood pressure nor heart rate showed significant differences one hour after ROSC between the two groups.Conclusions Sex differences did not affect the efficacy of CPR,but the precise mechanism is still unclear,and further investigations are required.

This paper discusses the effectiveness of tutor-postgraduate communication in terms of frequency,approach,activeness and content by analyzing the questionnaire filled by the postgraduate students who graduate in 2013 in Peking University Health Science Center.3 suggestions were put forward to enhance the efficiency and quality of tutor-postgraduate communication,including guideline from tutors,active involvement of graduates and facilitation of Scientific research management.